Title of Invention

TEMPERATURE CONTROL UNIT FOR ELECTROPHOTOGRAPHIC PHOTOCONDUCTOR SUBSTRATE

Abstract There is provided a temperature control unit for an electrophotographic photoconductor substrate, containing a stretchable membrane member which is detachably disposed in a hollow space of the cylindrical substrate, wherein the membrane member is configured to sequentially stretch until reaching the deepest part of the hollow space of the cylindrical substrate as a result of an introduction of a refrigerant therein to closely contact with an entire inner wall of the cylindrical substrate, and to sequentially shrink to the original shape thereof as a result of a release of the refrigerant therefrom, so that the membrane member is detachably disposed in the hollow space, and wherein the membrane member is configured to make a heat transfer between a surface of the cylindrical substrate and the refrigerant via the membrane member closely contacted with the inner surface of the cylindrical substrate, to control a surface temperature of the cylindrical substrate.
Full Text


DESCRIPTION
TEMPERATURE CONTROL UNIT FOR
ELECTROPHOTOGRAPHIC PHOTOCONDUCTOR SUBSTRATE
Technical Field
The present invention relates to a temperature control
unit for a substrate of an electrophotographic photoconductor.
Background Art
In recent years, an organic photoconductor (OPC) has
replaced an inorganic photoconductor, and has been commonly
used for a copying machine, a facsimile, a laser printer, or a
complex machine combining thereof in view of its excellent
performances and various advantages. The main reasons
therefore are, for example, (a) optical characteristics thereof such
as a wide wavelength region and large quantity of light
absorption, (b) electrical characteristics thereof such as high
sensitivity and stable charging ability, (c) a wide range of
selections for a material to be used, (d) easy production, (e) low
cost, (f) no hazards, and the like.
In addition to the above, the diameter of the
photoconductor has been more and more downsized along with
the downsizing of the image forming devices, and highly resistant
photoconductor has been strongly desired in view of high-speeded

6
operation and maintenance-free for the device. From, this point
of view, the organic photoconductor has disadvantages such that
it is generally soft as the main components of the surface layer
thereof are a low molecular charge transport material and an
inactive polymer, the abrasions are prone to occur due to the
physical loads from the developing system or cleaning system at
the time of repeated use in the process of the electrophotography.
In addition, the increase in the hardness of the rubber of the
cleaning blade and the increased contact pressure are necessary
as the diameters of the toner particles are more and more
downsized for the purpose of achieving the high image quality.
These are other factors to accelerate the wearing of the
photoconductor. Such the wearing of the photoconductor leads
the deterioration of the sensitivity, deterioration of the electric
characteristics such as lowing of the chargability, lowing of the
image density, and the generation of defective images such as
background depositions. Moreover, the scratches from the
partially caused wearing lead images of lined depositions due to
the cleaning failure. Under the current circumstances, the
life-long of the photoconductor is limited as a result of this
wearing or scratches, and the replacement thereof becomes
necessary.
Accordingly, it is necessary to reduce the amount of the
aforementioned wearing in view of the achievement of the highly




durable organic photoconductor, and this is an urgent problem to
be solved in this field.
As the technique which improves the abrasion resistance
of the photoconductive layer, (1) the technique which uses a
curable binder resin in the surface layer (for example, refer to
Patent Literature 1), (2) the technique which uses a
macromolecular charge transporting material (for example, refer
to Patent Literature 2), and (3) the technique in which inorganic
fillers are dispersed in the surface layer (for example, refer to
Patent Literature 3) are proposed. Among these techniques, the
technique (1) using the curable binder resin tends to increase the
residual potential and thus lowers the image density due to the
impurities such as unreacted residual groups, as the
compatibility of the charge transporting material and the
polymerization initiator is poor. Moreover, the technique (2)
using the macromolecular charge transporting material and the
technique (3) dispersing the inorganic fillers are capable of
improving the abrasion resistance at a certain degree, but such
abrasion resistance is not sufficient enough to achieve the degree
required for the organic photoconductor. Furthermore, the
technique (3) dispersing the inorganic fillers increases the
residual potential due to the trap present on the surfaces of the
inorganic fillers, and thus the image density is prone to be
lowered. The techniques (1), (2) and (3) have not sufficiently



achieved the total resistance including the electrical resistance
and physical resistance required for the organic photoconductor.
As an alternative technique for improving the abrasion
resistance of the photoconductor to the above, it has been known
the technique such that a charge transporting layer is formed by
using a coating liquid containing a monomer having a OC double
bond, a charge transporting material having a OC double bond,
and a binder resin (for example, refer to Patent Literature 4).
The abrasion resistance and the electric characteristics are
significantly improved especially by disposing, as a surface layer,
a crosslinked resin layer which is formed by curing at least a tri-
or more functional radical polymerizable monomer having no
charge transporting structure and a radical polymerizable
compound having a charge transporting structure by UV
radiation (for example, refer to Patent Literatures 5, 6, and 7).
In the crosslinked resin layer, three-dimensional crosslinkages
are formed as a result that the coated layer of the tri- or more
functional radical polymerizable monomer having no charge
transporting structure and the radical polymerizable compound
are irradiated with a UV light. However, if a cylindrical
substrate is exposed with the UV light, the cylindrical substrate
will have an extremely high temperature due to such the light
energy and heat of the reaction at the time of crosslinking.
Although the appropriate increase of the temperature smoothly



proceed with the crosslinking reaction, the extreme increase of
the temperature may lead the deterioration of the electric
characteristics, and thus the temperature of the cylindrical
substrate needs to be controlled.
It has been known the technical concept of the broad sense,
such that a substrate for a photoconductor is cooled at the time of
producing an electrophotographic photoconductor by coating
various coating liquids, drying the coated films, and then curing
the films. For example, Patent Literature 8 discloses that the
substrate of hollow tube is cooled by externally blowing a cooled
air at the time of dip-coating and drying the substrate of the
photoconductor in the manufacturing process of the
electrophotographic photoconductor. Patent Literature 9
discloses that the substrate drum is cooled by introducing a gas
or liquid for cooling into the chuck which fix, support and moves
the substrate drum while griping. Patent Literature 10
discloses that the cylindrical substrate is cooled by inserting the
small cylindrical tube having the cooling water supplying tube
and the cooling water releasing tube into the hollow space of the
cylindrical substrate. In these conventional techniques, the
problems such as the depositions from the ultra fine suspended
substances generated in a cooling medium as a result of the direct
contact of the cooling medium with the surface of the substrate
material, time-loss caused by blast drying the wet cooling


medium, the stains on the inner wall of the cylindrical tube as the
marks of fine droplets, depositions of the dirt contained in the
blast, and the like are not taken into consideration. Although it
is presumed to achieve the good heat transfer efficiency as a
result of the direct contact and the uniform cooling, however,
those techniques still remains the aforementioned problems to be
solved. Therefore, it has been desired to solve various problems
due to the direct contact of the cooling medium, as well as
achieving the uniform cooling and high efficiency of the cooling.
For example, if the substrate is placed in the resting state, it may
not cause an extreme defect such as a drip of the liquid, but
uneven drying or curing of the coated film, or partially uneven
cooling may be occur.
Patent Literature 11 discloses that the cooling device is
formed from an elastic material such as a rubber, whose shape is
enlarged and expanded once it is inserted inside a cylindrical
substrate, and the cooling device is inserted in the cylindrical
substrate, and the liquid is poured into the cooling device to
thereby cool the cylindrical substrate. However, the cylindrical
substrate cannot be cooled while being rotated in accordance with
this method. Moreover, the elastic body is not used simply to
introduce a refrigerant, but to press using a pressure control
valve. The chucking part thereof is not connected with the
elastic body, the temperature thereof cannot be controlled if the


UV light is irradiated thereto, and the temperature of the
chucking part becomes high. Moreover, Patent Literature 10
does not disclose any special consideration for the even cooling
and the improvement of the cooling efficiency by uniformly
contacting the elastic material to the inner wall of the cylindrical
substrate in accordance with a simple method.
[Patent Literature 1] Japanese Patent Application
Laid-Open (JP-A) No. 56-48637
[Patent Literature 2] Japanese Patent Application
Laid-Open (JP-A) No. 64-1728
[Patent Literature 3] Japanese Patent Application
Laid-Open (JPA) No. 04-281461
[Patent Literature 4] Japanese Patent (JP-B) No. 3194392
[Patent Literature 5] Japanese Patent Application
Laid-Open (JP-A) No. 2004302450
[Patent Literature 6] Japanese Patent Application
Laid-Open (JP-A) No. 2004302451
[Patent Literature 7] Japanese Patent Application
Laid-Open (JP-A) No. 2004-302452
[Patent Literature 8] Japanese Patent Application
Laid-Open (JPA) No. 2006-255679
[Patent Literature 9] Japanese Patent Application
Laid-Open (JP-A) No. 6377061
[Patent Literature 10] Japanese Patent Application


Laid-Open (JP-A) No. 08-15876
[Patent Literature 11] Japanese Patent (JP-B) No.
3154263
Disclosure of Invention
An object of the present invention is to provide a
temperature control unit for a cylindrical substrate, which is
configured to easily and uniformly control and suppress an
increase in a temperature of the cylindrical substrate as a whole
at the time of ultraviolet radiation.
As a result of the intensive studies and researches
conducted by the present inventors, it was found that the
aforementioned problems could be solved by the following
temperature control unit, and this led the present invention.
The means for solving the aforementioned problems are as
follows-
A temperature control unit for an electrophotographic
photoconductor substrate, in which the electrophotographic
photoconductor substrate contains a coated layer, and an entire
face of the electrophotographic photoconductor substrate is
exposed to energy externally applied from a heating element
while being rotated by a rotation system, characterized in that-
the temperature control unit containing a stretchable
membrane member, said membrane member detachably disposed


in a hollow space of the cylindrical substrate,
wherein the membrane member is configured to
sequentially stretch until reaching the deepest part of the hollow
space of the cylindrical substrate as a result of an introduction of
a refrigerant therein so as to closely contact with an entire inner
wall of the cylindrical substrate, and to sequentially shrink to the
original shape thereof as a result of a release of the refrigerant
therefrom, so that the membrane member is detachably disposed
in the hollow space of the cylindrical substrate, and
wherein the membrane member is configured to make a
heat transfer between a surface of the cylindrical substrate and
the refrigerant introduced in the hollow space of the cylindrical
substrate via the membrane member closely contacted with the
inner surface of the cylindrical substrate, so as to control a
surface temperature of the cylindrical substrate.
The temperature control unit of according to , further
containing a membrane member assisting system for a close
contact configured to assist the membrane member to closely
contact with the entire inner wall of the cylindrical substrate at
the time when the refrigerant is introduced.
The temperature control unit according to any one of or
, further containing:
a refrigerant introducing part, from which the pressurized
refrigerant is introduced into the hollow space of the cylindrical


substrate; and
a refrigerant releasing part, to which the refrigerant
introduced in the inside of the hollow part of the cylindrical
substrate is spontaneously released.
The temperature control unit according to , wherein the
refrigerant introducing part and the refrigerant releasing part
are a double pipe comprising an inner pipe and an outer pipe,
wherein the double pipe is disposed so as to be on the same
axis to a rotation axis of the cylindrical substrate, and is
configured to introduce and release the refrigerant in and from
the hollow space of the cylindrical substrate,
wherein the outer pipe is connected to an entrance part of
the hollow space of the cylindrical substrate, and the inner pipe
is inserted into the hollow space of the cylindrical space in a
manner such that an opening thereof is located at the deepest
part of the hollow space of the cylindrical substrate, so that the
refrigerant flown out from the entrance part or the deepest part
pushes and presses the membrane member towards the inner wall
of the cylindrical substrate to make the membrane member
contact with the inner wall of the cylindrical substrate.
The temperature control unit according to , wherein the
double pipe has a width of an annular channel of 2 mm or more,
where the annular channel is a space between an outer face of the
inner pipe and an inner face of the outer pipe.


The temperature control unit according to any one of to
, wherein the membrane member is at least one side of a bag
structure,
wherein said side has an elasticity, and functions as a
chuck in a manner such that said side stretches as the refrigerant
is introduced into the bag structure, and contacts with the inner
wall of the cylindrical substrate so as to hold the cylindrical
substrate.
The temperature control unit according to , wherein the
bag structure is configured to release the refrigerant and shrink
back to the original shape, once the introduction of the
refrigerant is terminated.
The temperature control unit according to any one of or
, wherein the temperature control unit further contains a
rigid tube disposed in the hollow space of the cylindrical
substrate so as to be on the same axis to a rotation axis of the
cylindrical substrate, and the bag structure is a cylindrical bag
structure comprising a circular through-hole in a center thereof,
wherein the cylindrical bag structure is disposed on the
rigid tube so that an inner circumference of an inner surface of
the membrane member contacts with an outer circumference of a
surface of the rigid tube, and the refrigerant is introduced in
between the outer circumference of the surface of the rigid tube
and the inner circumference of the inner surface of the membrane


member.
The temperature control unit according to any one of to
, wherein the bag structure is a cylindrical elastic body which
is detachably disposed in the hollow space of the cylindrical
substrate.
The temperature control unit according to any one of to
, wherein the bag structure is a chuck configured to hold the
cylindrical substrate from the hollow space of the cylindrical
substrate, and to rotate thereof so as to rotate the cylindrical
substrate while holding thereof.
The temperature control unit according to any one of to
, further containing a refrigerant circulation system
configured to reintroduce the spontaneously released refrigerant
into the refrigerant introducing part via a temperature-constant
bath.
The temperature control unit according to any one of to
, further comprising a pipe for the refrigerant, which is
inserted into the circular through-hole of the cylindrical bag
structure, and is configured to introduce and release the
refrigerant.
The temperature control unit according to any one of to
, wherein a thickness of the cylindrical elastic body at where
closely contacting with the entire inner wall of the cylindrical
substrate is 1.0 time to 2.0 times of a thickness of the top and


bottom ends of the cylindrical elastic body at where contacting
with the inner wall of the cylindrical substrate, and
wherein a part of the cylindrical elastic body where the
thickness thereof changes is shaped in a taper or a curve.
The temperature control unit according to any one of to
, further comprising a couple of metal or resin disk pressing
tools respectively disposed at the top and bottom of the
cylindrical substrate,
wherein the couple of metal or resin disk pressing tools are
configured to perform a positioning of a location where the
cylindrical substrate is held with the cylindrical elastic body.
The temperature control unit according to any one of
to , further containing:
a refrigerant storage tank as the constant-temperature
tank;
a refrigerant supplying pipe connecting between the
refrigerant storage tank and the cylindrical elastic body;
a pump equipped with the refrigerant supplying pipe, and
configured to send the refrigerant from the refrigerant storage
tank into the cylindrical elastic body;
a refrigerant releasing pipe connecting between the
cylindrical elastic body and the refrigerant storage tank, and
configured to release the circulated the refrigerant in the
cylindrical elastic body to the refrigerant storage tank;


a pressure detector configured to monitor a pressure of the
refrigerant; and
a flow rate control system configured to control the flow-
rate of the refrigerant.
In accordance with the temperature control unit for an
electrophotographic photoconductor substrate of the present
invention, the increase in the temperature of the cylindrical
substrate caused, for example, by the heat from the UV lamp is
easily and uniformly suppressed by controlling the temperature
of the cylindrical substrate, and as a result, the high abrasion
resistance and scratch resistance, and stable static
characteristics of the electrophotographic photoconductor can be
maintained.
Brief Description of Drawings
FIG. 1 is a schematic diagram showing a structural
example of the temperature control unit which is suitable for
carrying out the present invention.
FIG. 2 is a schematic diagram showing a structural
example of the temperature control unit which is suitable for
carrying out the present invention.
FIG. 3 is a schematic diagram showing a structural
example of the temperature control unit which is suitable for
carrying out the present invention.


FIG. 4 is a schematic diagram showing a structural
example of the temperature control unit which is suitable for
carrying out the present invention.
FIG. 5 is a schematic diagram showing a structural
example of the temperature control unit which is suitable for
carrying out the present invention.
FIG. 6 is a schematic diagram showing a structural
example of the temperature control unit which is suitable for
carrying out the present invention.
FIG. 7 is a schematic diagram showing a structural
example of the temperature control unit which is suitable for
carrying out the present invention.
FIG. 8A is a schematic diagram showing a structural
example of the temperature control unit which is suitable for
carrying out the present invention (before the refrigerant is
introduced).
FIG. 8B is a schematic diagram showing a structural
example of the temperature control unit which is suitable for
carrying out the present invention (after the refrigerant is
introduced).
FIG. 9 is a schematic diagram showing a structural
example of the temperature control unit which is suitable for
carrying out the present invention.
FIG. 10 is a diagram explaining an example of a schematic


structure of the present invention.
FIG. 11A and FIG. 11B are schematic diagrams showing
examples of the state where the cylindrical substrate is held with
the cylindrical elastic body.
FIG. 12 is a schematic diagram showing an example of the
installment of the cylindrical elastic body.
FIG. 13 is a cross-sectional view of an example of an
electrophotographic photoconductor for use in the present
invention.
FIG. 14A and FIG. 14B are cross-sectional views of
examples of an electrophotographic photoconductor for use in the
present invention.
FIG. 15A and FIG. 15B are cross-sectional views of
examples of an electrophotographic photoconductor for use in the
present invention.
Best Mode for Carrying Out the Invention
Hereinafter, the present invention will be precisely
described with reference to the drawings.
The temperature control unit of the present invention
contains a membrane member which is fixed on, or detachably
attached to an entire inner wall of a cylindrical substrate that
has a coated layer and is exposed to energy externally applied
from a heating element, wherein a refrigerant is introduced into


a inner part of the membrane member and is configured to control
a surface temperature of the cylindrical substrate via the
membrane member, while self-rotating the cylindrical substrate.
In accordance with the present invention, the surface
temperature of the cylindrical photoconductive substrate is
controlled and maintained at 150oC or lower, preferably 130oC or
lower. The surface temperature of the substrate can be easily
determined, for example, by measuring the surface temperature
at the opposite position to the irradiating position of the heating
element (e.g. an irradiation lamp) (a position where is 180
degrees apart from the irradiated position on the cylinder which
is rotated at the rotation frequency of 25 rpm).
The membrane member is easily inserted into a hollow
space of the cylindrical substrate, is elongation-expandable at a
pressure of 500 hPa/cm2 to 10,000 hPa/cm2 or by the weight of
the liquid refrigerant, e.g. water, to be introduced therein, and is
highly stretchable so as to closely contact with the inner wall of
the cylindrical substrate. The membrane member is preferably
elongated in two axial directions, and stretches till reaching the
deepest part of the cylindrical substrate in the longer direction
thereof. The aforementioned degree of the pressure is
sufficiently attained by water pressure of an urban water supply
system. Moreover, the membrane member has enough thermal
conductivity to cool the cylindrical substrate promptly.


The material for the membrane member is preferably the
one having a high stretchability, such as natural rubber,
synthetic rubber, or the like. In addition, other rubber
materials, which excel in water resistance, abrasion resistance,
light fastness, heat resistance, and the like, may be formulated in
the aforementioned material. The forming method of the
membrane member is selected from the conventional forming
methods known in the art. Specific examples thereof include a
sheet forming method, extrusion molding method, and the like.
As shown in FIG. 1, in the case where the heating element
2 such as a UV lamp or the like is disposed nearby the cylindrical
substrate 1 which is rotated by means of a rotation system (which
is not illustrated), the heat generated on the cylindrical substrate
1 by the heating element 2 is removed by introducing the
refrigerant 8 into the inner part of the membrane member 3
which is closely contacted with the inner part of the cylindrical
substrate 1, and the temperature of the cylindrical substrate 1 is
controlled via the membrane member 3 in this manner. The
membrane member 3 is sequentially expanded and elongated as
the refrigerant 8 is introduced therein, and sequentially closely
contacts with the entire inner wall of the cylindrical substrate 1.
In the embodiment shown in FIG. 1, the air in the hollow space of
the cylindrical substrate 1 is removed by means of an air release
valve 9 which is one example of the assisting means for the close


contact of the membrane member 3 so as to assist the membrane
member to sufficiently closely contact with the cylindrical
substrate 1 at the time when the refrigerant 8 is introduced. In
this manner, any insufficient contacts are completely removed.
As has mentioned above, it can be understood from the
aforementioned example of the vacuumed contact that the
membrane member 3 is elongated-expandable at the pressure of
500 hPa/cm2 to 10,000 hPa/cm2, and is highly stretchable so as to
closely contact with the inner wall of the cylindrical substrate 1.
In FIG. 1, the references 3e and 3f respectively denote top and
bottom pressing tools (lid members).
Since the liquid used as the refrigerant and the cylindrical
substrate do not have any contact to each other, the liquid will
not be scattered on a photoconductive layer even in the case
where the photoconductive layer is disposed on the surface of the
cylindrical substrate, and thus any defects on the coated layer
due to the deposition of the liquid can be prevented, and thus
uniform cooling can be easily and accurately achieved.
FIG. 2 shows another embodiment of the temperature
control unit of the present invention. As shown in FIG. 2, in the
present invention, the membrane member 3 is closely contacted
with the inner wall of the cylindrical substrate 1 which is rotated
while receiving thermal energy from the heating element 2, and
the refrigerant 8 is introduced into the membrane member 3 from


one direction (shown with the arrow directing the down side in
FIG. 2) and is released to another direction (shown with the
arrow directing the up side in FIG. 2). In this manner, the
interchange of heat is efficiently performed. In this embodiment,
the membrane member 3 is an elastic body in the shape of the
cylinder (referred as a cylindrical elastic body, hereinafter) which
contacts with the entire inner wall of the cylindrical substrate 1.
Moreover, the air release valve as the assisting means for the
close contact of the membrane member is not used in the unit of
this embodiment. The flows occurred by the
introduction-release of the refrigerant support the close contact
of the membrane member 3. In addition, the flow direction of
the refrigerant can be reversely changed.
Other embodiments of the heat control unit of the present
invention are shown in FIGs. 3 and 4. In these embodiments,
the refrigerant 8 is introduced into the hollow part through a
double pipe comprised of an outer pipe 9a having a relatively
large diameter and inner pipe 9b having a relatively small
diameter and inserted from one end (the bottom end in the
drawings) of the rotated cylindrical elastic body comprised of the
membrane member 3 into the inner part. The refrigerant 8 is
then released from the hollow part, while transferring the heat
via the cylindrical elastic body of the membrane member 3 which
contacts with the entire inner wall of the cylindrical substrate 1.


The double pipe is disposed on the same axis to the rotation axis
of the rotated cylindrical substrate 1. The outer pipe 9a of the
double pipe is connected in a manner such that an opening
thereof becomes an entrance part (the bottom part in the
drawings) of the hollow part of the cylindrical substrate 1, and
the inner pipe 9b of the double pipe is disposed in a manner such
that an opening thereof is positioned at the deepest part of the
hollow space of the cylindrical substrate 1. The refrigerant 8 is
introduced in an annular channel 5 which is a space made
between the outer pipe 9a and the inner pipe 9b. After entering
into the annular channel 5, the refrigerant 8 moves forward until
it reaches the deepest part, while sequentially pressing the
membrane member 3 of the cylindrical elastic body functioned as
the outer pipe 9a towards the inner wall of the substrate 1 so as
to make the membrane member 3 closely contact with the inner
wall of the substrate 1. Thereafter, the refrigerant 8 is flown
into the inner pipe 9b, and then released therefrom (FIG. 3). In
the case where the refrigerant 8 is introduced from the inner pipe
9b as shown in FIG. 4, the refrigerant 8 is flown into the outer
pipe 9a after reaching the deepest end of the inner pipe 9b, and is
then released from the terminal part (the bottom part in FIG. 4)
of the annular channel 5. Note that, the annular channel 5
defines a space in between the outer surface of the inner pipe 9b
and the inner surface of the outer pipe 9a.


The width of the annular channel 5 is preferably 2 mm or
more as shown in FIG. 5. Specifically, the annular channel 5 is a
space in between the outer surface of the inner pipe 9b and the
inner surface of the outer pipe 9a within the double pipe, the
double pipe is disposed inside the membrane member 3 of the
cylindrical elastic body so as to be parallel to the rotation axis
direction of the cylindrical substrate 1 and to have the same axis
as the centric axis of the cylindrical substrate, and the membrane
member 3 of the cylindrical elastic body is disposed so as to
contact with the entire inner surface of the cylindrical substrate
1 of the heat control unit.
By adjusting the width (space) of the annular channel 5
between the outer surface of the inner pipe 9b and the inner
surface of the outer pipe 9a, any loss of the pressure is reduced
and the appropriate circulated flow rate of the refrigerant is
maintained. In the case where the space (5) is smaller than 2
mm, the loss of the pressure is increased, the circulated flow rate
of the refrigerant is reduced, and thus the variations in the
temperature of the cylindrical substrate 1 become significant.
In the temperature control unit of the present invention,
the membrane member is at least an outer face of a bag structure
3a, the outer face of the bag structure 3a is elastic and stretched
as the refrigerant is introduced inside the bag structure 3a, and
the elastic outer face of the bag structure 3a enables to be held


from the inner surface of the cylindrical substrate 1. Moreover,
the bag structure is shrunk to the original shape once the
introduction of the refrigerant is terminated and the refrigerant
is released therefrom.
Namely, the elastic bag structure 3a does not contact with
the cylindrical substrate 1, when no refrigerant is introduced, as
shown in FIG. 6. In this state, the cylindrical substrate 1 is
detachable from the heat control unit.
As shown in FIG. 7, the elastic outer face of the elastic bag
structure 3a presses onto the inner surface of the cylindrical
substrate 1 as a result of the introduction of the refrigerant, and
then the cylindrical substrate 1 is held with the elastic bag
structure 3a. Once the introduction of the refrigerant 8 is
terminated, the elastic bag structure 3a is shrunk to the original
shape, and then the cylindrical substrate 1 is removed from the
temperature control unit.
As shown in FIGs. 8A and 8B, it is preferably that the bag
structure 3a is a cylindrical bag structure having a circular
through-hole 8b in its center, the cylindrical bag structure is
disposed on the rigid structure 6 so that the inner circumference
of the inner surface of the membrane member 3 contacts with the
outer circumference of the surface of the rigid tube structure 6,
and the refrigerant 8 is introduced in the unfixed part 6a (the
space in between the outer circumference of the surface of the


rigid tube 6 and the inner circumference of the inner surface of
the membrane member 3). By fixing the membrane member
around the rigid tube structure 6, the holding ability of the
cylindrical substrate 1 is improved. In addition, the accuracy in
the positioning is increased as the rigid tube structure 6 is
disposed as a central axis. In the embodiment shown in FIG. 8,
the double pipe of inner and outer pipes 9a, 9b is disposed in the
circular through-hole 8b, and it is preferable that the pipe for the
refrigerant (in the drawing, it is the outer pipe 9a, but the inner
pipe 9b may be also set as the pipe for the refrigerant) is disposed
and the refrigerant is introduced into and released from the pipe
for the refrigerant.
The positioning of the location where the cylindrical
substrate 1 is held with the cylindrical elastic body 6 is
performed by using metal or resin disk pressing tools 3e, 3f.
Note that, the top pressing tool 3e is comprised of a flange 3g and
an inner cap 3h.
A thickness of the membrane member 3 of the cylindrical
elastic body which contacts with the entire inner surface of the
cylindrical substrate 1 is preferably 1.0 to 2.0 times of the
thickness of the top and bottom parts of the membrane member 3
of the cylindrical elastic body at where the cylindrical substrate 1
is contacted. It is also preferable that the cross-section of the
thickness changing part 3b of the membrane member 3 of the


cylindrical elastic body is shaped in taper or curve.
Moreover, the bag structure 3a is, though it is not
illustrated in the drawing, is a chuck which holds the cylindrical
substrate 1 from the hollow space, and rotates so as to rotate the
cylindrical substrate 1 while holding the same from the hollow
space thereof.
Furthermore, the temperature control unit of the present
invention includes the embodiment such that the refrigerant is
circulated via a constant temperature water bath which controls
the temperature, and then is re-introduced into the temperature
control unit.
The device shown in FIG. 9 illustrates one example of such
the embodiment. Two cooling tubes 9c, 9d, are respectively
extended from the double pipe 9a, 9b, and are connected to the
constant-temperature water bath 7. As a result of that the
refrigerant 8 returning from the temperature control unit is
passed through the constant temperature water bath 7 and is
re-introducing into the temperature control unit, the refrigerant
having the controlled temperature can be circulated within the
temperature control unit, the abrasion resistance and stable
electric characteristics are attained. Among two cooling tube 9c,
9d, one of them is used as an outward path for introducing the
refrigerant 8, and the other is used as a return path for releasing
the refrigerant from the temperature control unit.


The temperature control unit of the present invention
contains another embodiment such that the temperature control
unit contains a pressure detector which monitors the pressure of
the refrigerant 8, and a flow rate control unit wherein the liquid
circulated inside of the membrane member 3 of the cylindrical
elastic body as the refrigerant 8 is supplied from the refrigerant
storage tank by means of a pump via a refrigerant supply pipe,
and the refrigerant 8 is released into the refrigerant storage tank
after circulating inside of the membrane member 3 of the
cylindrical elastic body.
[Embodiment of temperature control unit]
Hereinafter, one embodiment of the present invention is
explained with reference to the drawings. FIG. 10 is a
cross-sectional plane view showing an example of a schematic
structure of a temperature control unit for an
electrophotographic photoconductor substrate in accordance with
the present invention.
The embodiment of the temperature control unit for a part
of the device such as the electrophotographic photoconductor is
roughly classified into a device support 20, a rotation system 21
rotationally disposed in the centric area of the device support 20,
a holding system 22 connected with the edge of the rotation
system 21, a UV radiation system 23 disposed at the perimeter of
the device support 20, and a refrigerant storage tank 24


connected with the holding system 22 by a pipe arrangement.
The rotation system 21 contains a flange 25, a bearing 26,
a pulley 27 fitted with a bearing case which stores the bearing 26,
a rotation axis 28, and a belt 29 suspended by the pulley 27. The
flange 25 has an opening 25a, and the rotation axis 28 is disposed
and rotationally supported in the opening 25a via the bearing 26.
The pulley 27 is fixed to the rotation axis 28, the pulley 27 is
connected with a driving means (which is not illustrated in the
drawing) via the belt 29, and the driving force of the driving
means is transmitted to the rotation axis 28.
The structure of the holding system 22 is roughly
classified into the rotation axis 28, a refrigerant supplying pipe
30 and a refrigerant releasing pipe 31, a cylindrical elastic body
32, a cylindrical frame 33, and a cylindrical pressing tool 34. In
the centric part of the rotation axis 28, the refrigerant releasing
pipe 31 is passed through, and the end edge of the refrigerant
releasing pipe 31 is connected with a rotational joint 35. The
rotational joint 35 is configured to connect with two systems of
the refrigerant, and the first system is used for supplying, and
the second system is used for releasing. The end edge of the
refrigerant releasing pipe 31 is connected with the second system
for releasing. The refrigerant supplying pipe 30 connected with
the first system for supplying is connected with the bottom
circumferential side of the cylindrical frame 33. The cylindrical


frame 33 has a hole 36 to which the refrigerant supplying pipe 30
is connected at the bottom circumferential side thereof, so that
the refrigerant is supplied to the surface of the cylindrical frame
33. The cylindrical frame 33 has a hole 37 from which the
refrigerant is recycled to the refrigerant releasing pipe 31 at the
upper circumferential side thereof. The hole 37 and the
refrigerant releasing pipe 31 are connected with a pipe 38.
The cylindrical elastic body 32 is disposed on the surface of
the cylindrical frame 33. At the upper and bottom parts of the
cylindrical frame 33, recesses 39 are formed so as to fix the
cylindrical elastic body 32 thereto. In order to fix the edges 40
of the cylindrical elastic body 32 to the recesses 39, the upper
part and bottom part of the cylindrical elastic body is configured
to have a thickness of 1.0 to 2.0 times thicker than the thickness
of the cylindrical elastic body 32 which is attached to the center
part of the cylindrical frame 33. Therefore, the cylindrical
elastic body 32 is easily located to the cylindrical frame 33 at the
time of replacing the cylindrical elastic body 32. In addition, the
cylindrical elastic body 32 is prevented from dislocation caused
by the repeated use by replacing the cylindrical substrate 41
which is a work-piece.
FIG. 11A shows the state where the cylindrical elastic body
32 is attached to the surface of the cylindrical frame 33. FIG.
11B shows the state where the cylindrical elastic body 32 holds


the cylindrical substrate 41 which is a work-piece. The
cylindrical substrate 41 is configured to be held by the
swollenness of the cylindrical elastic body 32.
FIG. 12 shows a structural view in which the area around
the edge 40 of the cylindrical elastic body 32 is enlarged. As
shown in FIG. 12, a tilt 42 is formed between the recess 39 and
the surface of the cylindrical frame 33. The thickness of the
edge of the cylindrical elastic body 32 is formed with the gradient
in the shape of taper or curve, along with the tilt 42. As a result
of that the edge of the cylindrical elastic body 32 is shaped in the
taper or curve, the edge 40 which changes its thickness is
prevented from receiving the excessive stress at the time when
the cylindrical elastic body 32 is stretched. Moreover, the
surface of the tilt 42 is preferably mirror finished so as not to
damage the cylindrical elastic body 32.
The cylindrical elastic body 32 is fixed at the upper and
bottom parts thereof with stainless steel bands 43 for the purpose
of easy replacement. A rubber ring 44 of self-bubble sponge is
placed in between the surface of the cylindrical frame 33 and the
cylindrical elastic body 32. As a result of the rubber ring 44, the
refrigerant 45 filled in the cylindrical elastic body 32 and the
cylindrical frame 33 is prevented from leaking. In the case
where the cylindrical elastic body 32 is fasten by the stainless
steel bands 43, a seamless rubber ring 46 is placed in between the


stainless steel band 43 and the cylindrical elastic body 32 so as to
protect the surface of the cylindrical elastic body 32.
The cylindrical elastic body 32 is stretched by the pressure
of the refrigerant at the time when the refrigerant 45 is supplied
from the refrigerant supplying pipe 30, so that the stretched
cylindrical elastic body 32 is closely attached to the inner surface
of the cylindrical substrate 41 and holds the cylindrical substrate
41. In this manner, the surface of the cylindrical substrate 41 is
uniformly cooled.
The cylindrical substrate 41 is equipped with cylindrical
pressing tools 34 formed of a metal or resin at the top and bottom
parts thereof, so that the cylindrical substrate 41 is easily located
in the up and down directions. Moreover, the cylindrical elastic
body 32 is prevented from being exposed with the UV light during
the heating process of the cylindrical substrate 41 by means of
the UV radiation unit 23. Therefore, the cylindrical elastic body
32 is prevented from the deterioration due to the UV light. The
cylindrical pressing tools 34 are movable up and down, and
enables to cool the cylindrical substrates 41 having different
sizes in the longitudinal direction.
After the termination of the heating of the cylindrical
substrate 41, the supply of the refrigerant 45 from the refrigerant
supplying pipe 30 to the space between the cylindrical elastic
body 32 and the elastic frame 33 is terminated. When the supply


of the refrigerant 45 is terminated, the pressure of the
refrigerant 45 is reduced so that the cylindrical elastic body 32 is
shrunk and closely attached to the surface of the cylindrical
frame 33. At this time, the inner diameter of the cylindrical
elastic body 32 is smaller than the outer diameter of the
cylindrical frame 33 so that the refrigerant 45 is recycled into the
cylindrical frame 33.
Moreover, the air release valve 48 is disposed at the top
part of the refrigerant releasing pipe 31 so as to prevent the
generation of bubbles in the refrigerant 45 at the time when the
refrigerant 45 is supplied into the space between the cylindrical
elastic body 32 and the cylindrical frame 33. The air release
valve 48 is opened for a certain period at the time of supplying
the refrigerant 45.
In the refrigerant storage tank 24 connected to the holding
system 22 via the pipe arrangement, the refrigerant 45 is stored,
and is passed to the rotational joint 35 disposed at the bottom
part of the holding system 22 via a pipe 50 by means of a pump 49.
The refrigerant 45 released from the rotational joint 35 of the
holding system 22 is returned to the refrigerant storage tank 24
via a pipe 51. The pipe 51 is equipped with a pressure censer 52
which monitors the pressure of the refrigerant 45, and a valve 53
which controls the flow rate of the refrigerant 45. In the heating
process of the cylindrical substrate 41 by means of the UV


radiation system 23, once the sensor 52 recognizes the drop in the
pressure, the pressure error signal is transmitted to a control
device which is not illustrated in the drawing, and then the
device is stopped. This is because that the drop in the pressure
of the refrigerant 45 released from the holding system 22 is
considered to be an occurrence of a leak of the refrigerant 45 due
to a breakage of the cylindrical elastic body 32. In this manner,
the pressure state of the refrigerant 45 released from the holding
system 22 can be used for a monitoring of the device. Moreover,
the internal pressure in the space between the cylindrical elastic
body 32 and the cylindrical frame 33 is controlled by operating
the valve 53 which controls the flow rate of the refrigerant 45,
and the holding force of the cylindrical substrate 41 is arbitrarily
adjusted.
As a modified embodiment, the pipe 50 is equipped with a
flow meter 54a and the pipe 51 is equipped with a flow meter 54b
as shown in FIG. 13, the leak of the refrigerant 45 due to the
breakage of the cylindrical elastic body 32 can be detected by
detecting the difference in the flow rates of the pipe 50 and the
pipe 51.
Moreover, the refrigerant storage tank 24 is equipped with
a thermometer 55a, the pipe 51 is equipped with a thermometer
55b, and then the cooling efficiency of the cylindrical substrate 41
by means of the cylindrical elastic body 32 can be detected by


detecting a difference in the temperature of the refrigerant in the
refrigerant storage tank 24 and the temperature of the
refrigerant in the pipe 51. In addition, the detected value of the
temperature deference is continuously recorded in the control
device which is not illustrated in the drawing, and the variation
of the temperature with time can be detected from the beginning
of the production. This variation of the temperature with time
is corresponded to the variation of the light quantity of the UV
lamp or the like used for the UV radiation system 23, the timing
for replacing the UV lamp or the like can be detected as when the
variation of the temperature with time is exceeded at a certain
threshold.
The material used for the cylindrical elastic body 32 is
preferably selected from the material having excellent water
resistance, and abrasion resistance. Specific examples thereof
include ethylene-propylene-diene rubber, and the like.
[Layer structure of an electrophotographic photoconductor]
The electrophotographic photoconductor for use with the
present invention will be described with reference to the
drawings.
FIGs. 14A and 14B are cross-sectional views of the
electrophotographic photoconductor, and said photoconductor has
a single-layered structure wherein, on a conductive substrate 11,
a photoconductive layer 12 having the both charge generating


function and charge transporting function is disposed. FIG. 14A
shows the case where the crosslinked surface layer 13 constitutes
the entire photoconductive layer 12. FIG. 14B shown the case
where the crosslinked surface layer 13 constitutes a surface
portion of the photoconductive layer 12.
FIGs. 15A and 15B are cross-sectional views of the
electrophotographic photoconductor, and said photoconductor has
a laminate-layered structure wherein, on a conductive substrate
11, a charge generating layer 12a having the charge generating
function and a charge transporting layer 12b having the charge
transporting function are disposed. FIG. 15A shows the case
where the crosslinked surface layer 13 constitutes the entire
charge transporting layer 12b. FIG. 15B shown the case where
the crosslinked surface layer 13 constitutes a surface portion of
the charge transporting layer 12b.
[Conductive substrate]
The conductive substrate is suitably selected depending on
the intended purpose without any restrictions, provided that it
has a conductivity and volume resistance of 1010 Qcm or less.
Examples thereof include a film of or cylindrical plastic or paper
to which metal oxide, e.g. aluminum, nickel, chrome, nichrome,
cupper, gold, silver, platinum, etc., is deposited by sputtering, a
tube which is prepared by extruding a plate of aluminum,
aluminum alloy, nickel, stainless steel, or the like, shaping into a


tube in accordance with a method such as a drawing or the like,
and subjected to a surface treatment such as cutting, super
finishing, polishing or the like. Moreover, the nickel endless
belt and stainless steel endless belt disclosed in JP-A No.
52-36016 are also used as the conductive substrate.
Furthermore, those prepared by dispersing conductive
powder in a binder resin and coating the same on the substrate
can be also used as the conductive substrate.
Examples of the conductive powder include carbon black,
acetylene black, metal powder of aluminum, nickel, iron,
nichrome, copper, zinc, silver or the like, and metal oxide powder
of conductive tin oxide, ITO, or the like. Examples of the binder
resin used at the same time include thermoplastic resins,
thermoset resins, or photocuring resins, such as polystyrene,
styrene-acrylonitrile copolymer, styrene-butadiene copolymer,
styrenemaleic anhydride copolymer, polyester, polyvinyl chloride,
vinyl chloride-vinyl acetate copolymer, polyvinyl acetate,
polyvinylidene chloride, polyarylate resin, phenoxy resin,
polycarbonate, cellulose acetate resin, ethyl cellulose resin,
polyvinyl butyral, polyvinyl formal, polyvinyl toluene,
poly-N-vinyl carbazole, acrylic resin, silicone resin, epoxy resin,
melamine resin, urethane resin, phenol resin, alkyd resin, and
the like. Such the conductive layer is disposed, for example, by
dispersing the aforementioned conductive powder and binder


resin in a suitably selected solvent, e.g. tetrahydrofuran,
dichloromethane, methylethylketone, toluene, or the like, and
coating the solution.
Moreover, the one in which a conductive layer formed from
a thermal contraction tube is disposed on an appropriate
cylindrical substrate can also be suitably used as the conductive
substrate. Here, the thermal contraction tube is formed of a
material, such as polyvinyl chloride, polypropylene, polyester,
polystyrene, polyvinylidene chloride, polyethylene, chloride
rubber, Teflon (registered trade mark), or the like, containing the
conductive powder therein.
[Photoconductive layer]
The photoconductive layer will be explained next. The
photoconductive layer may have a single-layered structure or
laminate-layered structure.
In the case where the photoconductive layer has a
laminate-layered structure, the photoconductive layer is
comprised of a charge generating layer having a charge
generating function, and a charge transporting layer having a
charge transporting function. In the case where the
photoconductive layer has a single-layered structure, the
photoconductive layer is a layer which has the charge generating
function and the charge transporting function at the same time.
Hereinafter, the laminate-layered photoconductive layer


and single-layered photoconductive layer will be explained.
[Laminate-layered photoconductive layer]
(Charge generating layer)
The charge generating layer contains a charge generating
compound having a charge generating function, as a main
component, and optionally contains a binder resin in combination,
if necessary. As the charge generating compound, an inorganic
material and an organic material are used.
Examples of the inorganic material include crystalline
selenium, amorphous selenium, selenium-tellurium,
selenium-tellurium-halogen, selenium-arsenic compound,
amorphous silicon, and the like. The preferable example of the
amorphous selenium is the one in which a dangling-bond is
terminated with a hydrogen atom and/or a halogen atom, or the
one doped with a boron atom, a phosphorous atom, or the like.
As the organic material, the known materials in the art
can be used. Examples thereof include phthalocyanine pigments
such as metal phthalocyanine and metal-free phthalocyanine,
azulenium salt pigments, squaric acid methyne pigments, azo
pigments having a carbazole skeleton, azo pigments having a
triarylamine skeleton, azo pigments having a diphenylamine
skeleton, azo pigments having a fluorenone skeleton, azo
pigments having an oxadiazole skeleton, azo pigments having a
bisstilbene skeleton, azo pigments having a distyryl oxadiazole


skeleton, azo pigments having a distyryl carbazole skeleton,
perylene pigments, anthraquinone or polycyclic quinone pigments,
quinone imine pigments, diphenylmethane and triphenylmethane
pigments, benzoquinone and naphthoquinone pigments, cyanine
and azomethine pigments, indigoid pigments, bisbenzimidazole
pigments, and the like. Each of these charge generating
compounds may be used singly or in combination of two or more.
Examples of the optionally used binder resin include
polyamide, polyurethane, epoxy resin, polyketone, polycarbonate,
silicone resin, acrylic resin, polyvinyl butyral, polyvinyl formal,
polyvinyl ketone, polystyrene, poly-N-vinylcarbazole,
polyacrylamide, polyvinylbenzal, and the like. Each of these
binder resins may be used singly or in combination with two or
more. Other than the aforementioned binder resins as the
binder resin of the charge generating layer, a macromolecular
charge transporting compound having a charge generating
function can be used. Examples of such the macromolecular
charge transporting compound include- polycarbonate, polyester,
polyurethane, polyether, polysiloxane, acrylic resin, each of
which has an aryl amine, benzidine, hydrazone, carbazole,
stilbene, or pyrazoline structure therein; and polymeric material
having a polysilane structure.
The specific examples of the aforementioned former
example are charger transporting polymeric materials disclosed


in JP-A Nos. 01-001728, 01009964, 01-013061, 01-019049,
01-241559, 04011627, 04-175337, 04183719, 04-225014,
04-230767, 04320420, 05-232727, 05-310904, 06-234836,
06-234837, 06234838, 06-234839, 06-234840, 06-234841,
06-239049, 06-236050, 06236051, 06-295077, 07-056374,
08-176293, 08-208820, 08-211640, 08-253568, 08-269183,
09-062019, 09043883, 0971642, 09-87376, 09-104746, 09110974,
09-110976, 09-157378, 09-221544, 09-227669, 09235367,
09-241369, 09-268226, 09-272735, 09-302084, 09-302085,
09-328539, and the like.
Moreover, the specific examples of the aforementioned
latter example are polysilylene polymers disclosed in JP-A Nos.
63-285552, 05-19497, 05-70595, 1073944, and the like.
Furthermore, the charge generating layer may further
contain a low molecular charge transporting compound.
The low molecular charge transporting compound which
can be used in the charge generating layer is classified into a hole
transporting material and an electron transporting material.
Examples of the electron transporting material include
electron receiving compounds such as chrolanil, bromanil,
tetracyanoethylene, tetracyanoquinodimethane,
2,4,7-trinitro-9-fluorenone, 2,4,5,7-tetranitro-9-fluorenone,
2,4,5,7-tetranitroxanthone, 2,4,8-trinitrothioxanthone,
2,6,8-trinitro-4H-indeno[l,2-b]thiophen-4-one,


l,3,7'trinitrobenzothiophene-5,5-dioxide, diphenoquinone
derivative, and the like. These are used singly or in combination
of two or more, as the electron transporting material.
As the hole transporting material, the electron donating
compounds listed below can be suitably used. Specifically,
examples of the hole transporting material include oxazole
derivatives, oxadiazole derivatives, imidazole derivatives,
monoaryl amine derivatives, diaryl amine derivatives, triaryl
amine derivatives, stilbene derivatives, α-phenyl stilbene
derivatives, benzidine derivatives, diaryl methane derivatives,
triaryl methane derivatives, 9-styrylanthracene derivatives,
pyrazoline derivatives, divinyl benzene derivatives, hydrazone
derivatives, indene derivatives, butadiene derivatives, pyrene
derivatives, bisstilbene derivatives, enamine derivatives, other
materials known in the art, and the like. These are used singly
or in combination of two or more, as the hole transporting
material.
The forming method of the charge generating layer is
roughly classified into a vacuum thin film forming method, and a
casting method using dispersion solution.
Specific examples of the vacuum thin film forming method
include a vapor deposition method, a glow discharge
decomposition method, an ion-plating method, a sputtering
method, a reactive sputtering method, CVD method, and the like.


In the aforementioned methods, the layer of the aforementioned
inorganic or organic material can be suitably formed.
In the case where the charge generating layer is formed in
accordance with the aforementioned casting method, the
aforementioned inorganic or organic charge generating compound
is dispersed, if necessary together with a binder resin, in a
solvent such as tetrahydrofuran, dioxane, dioxolane, toluene,
dichloromethane, monochlorobenzene, dichloroethane,
cyclohexane, cyclopentanone, anisole, xylene, methylethylketone,
acetone, ethyl acetate, butyl acetate, or the like, by means of a
ball mill, attritor, sand mill, bead mill, or the like, and then the
dispersion is appropriately diluted and coated to thereby form the
electron generating layer. If necessary, a leveling agent, e.g.
dimethyl silicone oil, methylphenyl silicone oil, etc., can be added
thereto. The coating is carried out in accordance with a dip
coating method, spray coating method, bead coating method, ring
coating method, or the like.
The charge generating layer prepared in the manner
mentioned above has a thickness of 0.01 µm to 5 µm, preferably
0.05 µm to 2 µm.
[Charge transporting layer]
The charge transporting layer is a layer having a charge
transporting function, and a crosslinked surface layer having a
charge transporting structure is effectively used as the charge


transporting layer. In the case where the crosslinked surface
layer is the entire charge transporting layer, the crosslinked
surface layer is formed by coating, on the charge generating layer,
a coating solution containing a radical polymerization compound
(a radical polymerizable monomer having no charge transporting
structure and a radical polymerizable monomer having a charge
transporting structure; hereinafter, the radical polymerization
compound denotes the same definition) and filler, optionally
drying the coated layer, and externally imparting an energy so as
to initiate a curing reaction. A thickness of the crosslinked
surface layer has a thickness of 10 µm to 30 µm, preferably 10 µm.
to 25 µm. When the thickness thereof is thinner than 10 µm, a
sufficient charging potential cannot be maintained. When the
thickness thereof is thicker than 30 µm, the crosslinked surface
layer tends to be separated from an under layer due to a volume
contraction at the time of curing.
In the case where the crosslinked surface layer is formed
at a surface portion of the charge transporting layer and the
charge transporting layer is of laminate-layered structure, the
bottom part of the charge transporting layer is formed by coating,
on the charge generating layer, a solution in which a charge
transporting compound having a charge transporting function
and a binder resin are dissolved and/or dispersed in an
appropriate solvent, and drying the coated solution, and then a


top part of the charge transporting layer is formed by coating, on
the thus formed bottom layer, a coating solution containing a
radical polymerizable compound and filler, and crosslinking and
curing he coated layer by the application of external energy.
As the charge transporting compound, the electron
transporting materials, hole transporting materials, and
macromolecular charge transporting materials listed in the
descriptions of the aforementioned charge generating layer can
be used. The use of the macromolecular charge transporting
material is effective as the solubility of the bottom layer is
suppressed at the time of coating the surface layer.
Examples of the binder resin include thermoplastic or
thermoset resins such as polystyrene, styrene-acrylonitril
copolymer, styrene-butadiene copolymer, styrene-maleic
anhydride copolymer, polyester, polyvinyl chloride, vinyl
chloride-vinyl acetate copolymer, polyvinyl acetate,
polyvinylidene chloride, polyacrylate resin, phenoxy resin,
polycarbonate, cellulose acetate resin, ethyl cellulose resin,
polyvinyl butyral, polyvinyl formal, polyvinyl toluene,
poly-N-vinyl carbazole, acrylic resin, silicone resin, epoxy resin,
melamine resin, urethane resin, phenol resin, alkyd resin, and
the like.
The amount of the charge transporting compound is 20
parts by mass to 300 parts by mass, and preferably 40 parts by


mass to 150 parts by mass, with respect to 100 parts by mass of
the binder resin. Note that, in case where the macromolecular
charge transporting material is used, it can be used alone, or in
combination with the binder resin.
As the solvent used for coating of the bottom part of the
charge transporting layer, the one similar to the solvent used for
the charge generating layer can be used, but suitable examples
thereof are the ones dissolves the charge transporting compound
and the binder resin well. Here, a single solvent or mixed
solvent of two or more is used. Moreover, the bottom part of the
charge transporting layer is formed in accordance with a coating
method similar to the coating method of the charge generating
layer.
The bottom part of the charge transporting layer may
optionally contain a plasticizer and a leveling agent.
As the plasticizer used in the bottom part of the charge
transporting layer, the conventional plasticizers for resin such as
dibutyl phthalate, dioctyl phthalate, and the like can be used.
The usage amount thereof is appropriately 0 to 30 parts by mass
with respect to 100 parts by mass of the binder resin.
As the leveling agent used in the bottom part of the charge
transporting layer, silicone oil such as dimethyl silicone oil,
methylphenyl silicone oil and the like, and polymer or oligomer
having a perfluoroalkyl group at a side chain thereof can be used.


The usage amount thereof is appropriately 0 to 1 part by mass
with respect to 100 parts by mass of the binder resin.
A thickness of the bottom part of the charge transporting
layer is appropriately 5 µm to 40 µm, and preferably 10 µm to 30
µm.
In the case where the crosslinked surface layer is the
entire charge transporting layer, as mentioned in the forming
method of the crosslinked surface layer, the crosslinked surface
layer is formed by coating a coating, on the bottom part of the
charge transporting layer, a coating solution containing a radical
polymerizable compound, optionally drying the coated layer, and
externally imparting an energy such as heat or light so as to
initiate a curing reaction. A thickness of the crosslinked surface
layer is 1 µm to 20 µm, and preferably 2 µm to 10 µm. When the
thickness thereof is thinner than 1 µm, the durability is varied
due to the uneven film thickness. When the thickness thereof is
thicker than 20 µm, the reproducibility is declined due to the
diffusion of the charge as the film thickness of the entire charge
transporting layer becomes large.
[Single-layered photoconductive layer]
The photoconductive layer of a single-layered structure is
a layer having both the charge generating function and charge
transporting function at the same time. The crosslinked surface
layer having the charge transporting structure is effectively used


as a single-layered photoconductive layer by adding therein a
charge generating compound having a charge generating function.
As mentioned in the casting method for forming the charge
generating layer, the crosslinked surface layer is formed by
dispersing the charge generating compound in the coating
solution containing the radical polymerizable compound, coating
the coating solution on the substrate, optionally drying the
coated layer, and externally imparting energy so as to initiate a
curing reaction. Note that, a dispersion solution in which the
charge generating compound is dispersed in a solvent can be
added to the coating solution of the crosslinked surface layer. A
thickness of the crosslinked surface layer is 10 pm to 30 pm, and
preferably 10 pm to 25 pm. When the thickness thereof is
thinner than 10 pm, the sufficient charging potential cannot be
maintained. When the thickness thereof is thicker than 30 µm,
the crosslinked surface layer tends to be separated from an under
layer due to a volume contraction at the time of curing.
In the case where the crosslinked surface layer is a top
part of the single-layered photoconductive layer, the bottom part
of the single-layered photoconductive layer is formed by
dissolving and/or dispersing the charge generating compound
having a charge generating function, the charge transporting
compound having a charge transporting function and the binder
resin in an appropriate solvent, coating the thus prepared


solution, and drying the coated layer. If necessary, additives
such as a plasticizer, a leveling agent, or the like can be added
thereto. The dispersing method, the charge generating
compound, the charge transporting compound, the plasticizer,
and the leveling agent are the same as those described in the
descriptions of the charge generating layer and the charge
transporting layer. As the binder resin, the binder resin listed
in the descriptions of the charge generating layer can be mixed
for use other than the binder resin listed in the descriptions of
the charge transporting layer. Moreover, the aforementioned
macromolecular charge transporting compound can be also used,
and the use thereof is effective as the components of the lower
photoconductive layer in the crosslinked surface layer can be
suppressed. A thickness of the bottom part of the
photoconductive layer is appropriately 5 µm to 30 µm, and
preferably 10 µm to 25 µm.
In the case where the crosslinked surface layer is a top
part of the single-layered photoconductive layer, the crosslinked
surface layer is formed by coating, on the aforementioned bottom
part of the photoconductive layer, a coating solution containing
the radical polymerizable compound and the charge generating
compound, optionally drying the coated layer, and curing the
coated layer by externally imparting energy such as heat or light.
The thickness of the crosslinked surface layer is 1 µm to 20 µm,


and preferably 2 µm to 10 µm. When the thickness thereof is
thinner than 1 µm, the durability is varied due to the uneven film
thickness.
The amount of the charge generating compound contained
in the single-layered photoconductive layer is preferably 1% by
mass to 30% by mass with respect to the total mass of the
photoconductive layer. The preferable amounts of the binder
resin and the charge transporting compound contained in the
bottom part of the photoconductive layer are respectively 20% by
mass to 80% by mass and 10% by mass to 70% by mass with
respect to the total amount of the bottom part of the
photoconductive layer.
[Intermediate layer]
In the case where the crosslinked surface layer is a top
part of the photoconductive layer, an intermediate layer can be
disposed in the photoconductor for use in the present invention
for the purpose of preventing the contamination of the
components of the bottom layer in the crosslinked surface layer
and improving the adherence between the crisslinked surface
layer and the layer below. The intermediate layer prevents any
inhibition of the curing reaction and formation of uneven surface
of the crosslinked surface layer, which are cased by the
contamination of the components of the bottom part of the
photoconductive layer in the outermost surface layer containing


the radical polymerizable compound. Moreover, the
intermediate layer also improves the adherence between the
bottom part of the photoconductive layer and the crosslinked
surface layer.
The intermediate layer generally contains a binder resin
as a main component. Examples of the binder resin include
polyamide, alcohol-soluble nylon, water-soluble polyvinyl butyral,
polyvinyl butyral, polyvinyl alcohol, and the like. A formation
method of the intermediate layer is selected from the
aforementioned conventional coating method. A thickness of the
intermediate layer is appropriately 0.05 µm to 2 µm.
[Undercoat layer]
In the photoconductor for use in the present invention, an
undercoat layer may be formed in between the conductive
substrate and the photosensitive layer.
The undercoat layer generally contains a resin as the main
component, however, in consideration that the undercoat layer is
coated with the photosensitive layer using a solvent, it is
preferable to use a resin having high resistance to typically used
organic solvents.
Examples of such resin include- water-soluble resins such
as polyvinyl alcohol, casein and sodium polyacrylateJ alcohol
soluble resins such as nylon copolymer and methoxymethylated
nylon; and curable resins capable of forming a three-dimensional


network structure such as polyurethane, melamine resin, phenol
resin, alkyl-melamine resin and epoxy resin. Moreover, to the
undercoat layer, a fine powder pigment of metal oxide can be
added to prevent occurrence of moire and reduce the residual
potential, etc. Examples of the metal oxide include titanium
oxide, silica, alumina, zirconium oxide, tin oxide, indium oxide,
and the like.
The undercoat layer can be formed by using an appropriate
solvent and the coating method as described in the photosensitive
layer. Moreover, a silane coupling agent, a titanium coupling
agent, a chrome coupling agent, or the like can be added to the
undercoat layer. Besides the above, for the undercoat layer used
in the present invention, it is preferable to use a layer formed by
anodically-oxidizing Al2O3 or a layer formed using an organic
material such as polyparaxylylene (parylene) and an inorganic
material such as SiO2, SnO2, TiO2, ITO and CeO2 by vacuum
thin-layer forming method. Besides the material described
above, conventional undercoat layers can be used. The
thickness of the undercoat layer is appropriately 0 µm to 5 µm.
[Addition of antioxidant in each layer]
The antioxidant may be added in each layer such as the
crosslinked surface layer, charge generating layer, charge
transporting layer, undercoat layer, intermediate layer and the
like, for the purpose of improving whether resistance, especially


for preventing decline of the sensitivity and increase of the
residual potential.
Examples of the antioxidant are as listed below-
(Phenol compound)
Examples of the phenol compound include:
2,6,-di-t-butyl-p-crezole; buthylated hydroxyanisole;
2,6-di-t-butyl-4-ethylphenol;
stearyl-β-(3,5-di-t-butyl-4-hydroxyphenyl)propionate;
2,2'-methylene-bis-(4-methyl-6-tbutylphenol);
2,2'-methylene-bis-(4-ethyl-6tbutylphenol);
4,4'-thiobis-(3-methyl-6-tbutylphenol);
4,4,-butylidenebis-(3methyl-6t-butylphenol);
1,1,3-tris-(2-methyl-4-hydroxy-5-t-butyphenyl)butane;
1,3,5-trimethyl-2,4,6-tris(3,5-di-t-butyl-4-hydroxybenzyl)benzene

tetrakis-[methylene-3-(3',5'-dit-butyl-4'-hydroxyphenyl)propiona
telmethane; bis[3,3'-bis(4'-hydroxy-3'-t-butylphenyl)butylic
acid]glycol ester; tocopherol; and the like.
(Paraphenylene diamine)
Examples of paraphenylenediamine include:
N-phenyl-N'-isopropyl-p-phenylenediamine;
N,N'-di-sec-butyl-p-phenylenediamine;
N-phenyl-N-sec-butyl-p-phenylenediamine;
N,N'-di-isopropyl-p-phenylenediamine;


N,N'-dimethyl-N,N'-di-t-butyl-p-phenylenediamine>" and the like.
(Hydroquinone)
Examples of hydroquinone include:
2,5'ji-t-octylhydroquinone," 2,6-didodecylhydroquinone;
2-dodecylhydroquinone," 2-dodecyl-5-chlorohydroquinone;
2-t-octyl-5-methylhydroquinone;
2-(2-octadecenyl)-5-methylhydroquinone; and the like.
(Organic sulfur compound)
Examples of the organic sulfur compound include^
dilauryl-3,3'-thiodipropionate; distearyl-3,3'-thiodipropionate;
ditetradecyl-3,3'-thiodipropionate; and the like.
(Organic phosphorus compound)
Examples of the organic phosphorus compound include:
triphenyl phosphine; tri(nonylphenyl)phosphine;
tri(dinonylphenyl)phosphine; tricresyl phosphine;
tri(2,4dibutylphenoxy)phosphine; and the like.
These compounds are known as a antioxidant for rubber,
plastic, oil, or the like, and can be obtained as a commercial
product.
The addition amount of the antioxidant is 0.01% by mass
to 10% by mass with respect to the total amount of the layer to be
added.
[Crosslinked surface layer]
The aforementioned radical polymerizable monomer


having no charge transporting structure is a tri- or more
functional radical polymerizable monomer having no charge
transporting structure. The tri or more functional radical
polymerizable monomer denotes a monomer which has no charge
transporting structure such as a hole transporting structure (e.g.
triaryl amine, hydrazone, pyrrazoline and/or carbazol) and an
electron transporting structure (e.g. condensated polycyclic
quinone, diphenoquinone, and an electron attractive aromatic
ring having a cyano group and/or a nitro group), but has three or
more functional radical polymerizable groups. The radical
polymerizable functional group is suitably selected without any
restrictions, provided that it has a C_C double bond, and is
radically polymerizable. Examples of the radical polymerizable
functional group include (1) 1-substitued ethylene functional
group, (2) 1,1-substituted ethylene functional group, and the like.
Examples of (1) 1-substituted ethylene functional group
include the functional group represented by the following
formula-
CH2=CH-X2- Formula (I)
In the above formula, X2 denotes an arylene group (e.g.,
phenylene and naphthylene) which may have a substituent;
alkenylene group which may have a substituent; —CO— group; -
COO- group; -CON(R36)- group (wherein R36 represents a
hydrogen atom; alkyl group (e.g., methyl and ethyl); aralkyl


group (e.g., benzyl, naphthylmethyl and phenethyl); aryl group
(e.g., phenyl and naphthyl)); or -S— group.
Examples of the substituent include a vinyl group, styryl
group, 2-methyl-l,3-butadienyl group, vinylcarbonyl group,
acryloyloxy group, acryloylamino group and vinylthioether group.
Examples of (2) 1,1-substituted ethylene functional group
include a functional group represented by the following formula:
CH2=C(Y4)-X3- Formula (II)
In the above formula, Y4 denotes an alkyl group which may
have a substituent; aralkyl group which may have a substituent;
aryl group (e.g., phenyl and naphthyl) which may have a
substituent; halogen atom; cyano group; nitro group; alkoxy
group (e.g. methoxy and ethoxy); and -COOR37 group ((wherein
R37 represents a hydrogen atom; alkyl group (e.g., methyl and
ethyl) which may have a substituent; aralkyl group (e.g., benzyl
and phenethyl) which may have a substituent; aryl group (e.g.,
phenyl and naphthyl) which may have a substituent; or
-CONR38R39 group (wherein R38 and R39, which may be identical
or different, each denotes a hydrogen atom; alkyl group (e.g.,
methyl and ethyl) which may have a substituent; aralkyl group
(e.g. benzyl, naphthylmethyl and phenethyl) which may have a
substituent; or aryl group (e.g., phenyl and naphthyl) which may
have a substituent)); and X3 denotes any one of the groups
described in relation to X2, single bond, or alkylene group; with


the proviso that at least one of Y4 and X3 is an oxycarbonyl group,
cyano group, alkenylene group or aromatic ring group.
Examples of the substituent include an
α-chloroacrylqyloxy group, methacryloyloxy group,
crcyanoethylene group, crcyanoacryloyloxy group,
α-rcyanophenylene group and methacryloylamino group.
Examples of substituent which further substitutes the
substituent of groups represented by X2, X3 and Y4 include a
halogen atom; nitro group; cyano group; alkyl group (e.g., methyl
and ethyl); alkoxy group (e.g., methoxy and ethoxy); aryloxy
group (e.g., phenoxy); aryl group (phenyl and naphthyl); and
aralkyl group (e.g., benzyl and phenethyl).
Among these radical-polymerizable functional groups, an
acryloyloxy group and a methacryloyloxy group are particularly
preferred. A compound having three or more acryloyloxy groups
can be produced, for example, by esterifying or transesterifying a
compound having three or more hydroxyl groups in the molecule
with an acrylic acid (salt), an acrylic halide or an acrylate. A
compound having three or more methacryloyloxy groups can be
produced in the similar manner. Notably, in the three or more
radical-polymerizable functional groups-containing monomer,
radical-polymerizable functional groups may be identical or
different.
The tri- or more functional radical-polymerizable monomer


having no charge transportable structure is appropriately
selected depending on the intended purpose without any
restrictions. Examples thereof include trimethylolpropane
triacrylate (TMPTA), trimethylolpropane trimethacrylate,
HPA-modified trimethylolpropane triacrylate, EO-modified
trimethylolpropane triacrylate, PO-modified trimethylolpropane
triacrylate, caprolactone-modified trimethylolpropane triacrylate,
HPA-modified trimethylolpropane triacrylate, pentaerythritol
triacrylate, pentaerythritol tetraacrylate (PETTA), glycerol
triacrylate, ECH-modified glycerol triacrylate, EO-modified
glycerol triacrylate, PO-modified glycerol triacrylate,
tris(acryloxyethyl) isocyanulate, dipentaerythritol hexaacrylate
(DPHA), caprolactone-modified dipentaerythritol hexaacrylate,
dipentaerythritol hydroxypentaacrylate, alkyl-modified
dipentaerythritol pentaacrylate, alkyl-modified dipentaerythritol
tetraacrylate, alkyl-modified dipentaerythritol triacrylate,
dimethylol propanetetraacrylate (DTMPTA), pentaerythritol
ethoxyteteraacrylate, EO-modified phosphoric acid triacrylate
and 2,2,5,5-tetrahydroxymethylcyclopentanone tetraacrylate.
These monomers may be used alone or in combination.
The formulated ratio of the tri- or more functional radical
polymerizable monomer having no charge transporting structure
is 20% by mass to 80% by mass, and preferably 30% by mass to
70% by mass with respect to the total amount of the crosslinked


surface layer. In the case where the ratio thereof is less than
20% by mass, the concentration of the three dimentional
crosslikage becomes low in the crosslinked surface layer, and the
significant improvement of abrasion resistance cannot be
attained compared with the case using the conventional
thermoplastic binder resin. In the case where the ratio thereof
is more than 80% by mass, the content of the charge transporting
compound is decreased, and thus the electric characteristics are
degraded. Although it is uneasy to state as the required
abrasion resistance and electric characteristics tend to change
depending on the process to be used, the formulated ratio thereof
is particularly preferably in the range of 30% by mass to 70% by
mass in view of the balance between the abrasion resistance and
electric characteristics.
The aforementioned radical polymerizable compound
having a charge transporting structure denotes a compound
which has a charge transporting structure such as a hole
transporting structure (e.g. triaryl amine, hydrazone, pyrrazoline
and/or carbazol) and an electron transporting structure (e.g.
condensated poly cyclic quinone, diphenoquinone, and an electron
attractive aromatic ring having a cyano group and/or a nitro
group), and also has a radical polymerizable functional group.
Examples of the radical polymerizable functional group are those
listed in the descriptions of the radical polymerizable monomer.


Among them, an acryloyloxy group and a methacryloyloxy group
are particularly preferred.
The radical polymerizable compound having a charge
transporting structure may have two or more functional groups,
but preferably has one functional group in view of the film quality
and electrostatic characteristics. When two or more functional
radical polymerizable compound having a charge transporting
structure is used, the charge transporting structure is fixed in
the crosslinked structure via a plurality of bonds. However, as
the charge transporting structure is extremely bulky, distortion
may caused in the cured resin and the internal stress of the
crosslinked surface layer becomes high. Therefore, cracks or
scratches tend to be formed due to the deposition of carrier, or the
like. These problems may not occur when the thickness of the
crosslinked surface layer is 5 µm or less. In the case where the
thickness is more than 5 µm, the internal stress of the
crosslinked surface layer becomes extremely high and cracks tend
to be caused just after the formation of crosslinkages.
From the view point of the electrostatic characteristics, in
case where the two or more functional charge transporting
compound is used, an intermediate structure (cation radical) at
the time of the charge transportation cannot be stably
maintained as the charge transporting structure is fixed in the
crosslinked structure via a plurality of bonds. The decline of the


sensitivity and increase of residual potential tend to occur due to
the trapped electric charge. These degradation of the electric
characteristics appears in an image as the lowered image density
or thinned printed characters. Therefore, the radical
polymerizable compound having a mono-functional charge
transporting structure is used as the radical polymerizable
compound having a charge transporting structure, and the charge
transporting structure is fixed in between the crosslinked
structure in the fashion of pendant. Therefore, the formation of
cracks or scratches is suppressed and the electrostatic
characteristics are stabilized.
A triarylamine structure is effective as the charge
transporting structure. The number of the functional group
thereof is preferably one. Specifically, the compound having the
structure represented by the following general formula (1) or (2)
is preferably since the electric characteristics such as sensitivity,
residual potential and the like are suitably maintained.


In the above general formulae, R1 denotes a hydrogen atom,
halogen atom, alkyl group which may have a substitute, aralkyl
group which may have a substitute, aryl group which may have a
substitute, cyano group, nitro group, alkoxy group, -COOR7
(wherein R7 denotes a hydrogen atom, alkyl group which may
have a substitute, aralkyl group which may have a substitute, or
aryl group which may have a substitute), halogenated carbonyl
group, or CONR8R9 (wherein each of R8 and R9 denotes a
hydrogen atom, halogen atom, alkyl group which may have a
substitute, aralkyl group which may have a substitute, or aryl
group which may have a substitute, and R8 and R9 are identical or
different to each other); each of Ar1 and Ar2 denotes an arylene
group which may have a substitute, and Ar1 and Ar2 are identical
or different to each other; each of Ar3 and Ar4 denotes an aryl
group which may have a substitute, and Ar3 and Ar4 are identical
or different to each other; X denotes a single bond, alkylene group
which may have a substitute, cycloalkylene group which may
have a substitute, alkylether group which may have a substitute,
oxygen atom, sulfur atom, or vinylene group; Z denotes an
alkylene group which may have a substitute, alkylene ether
group which may have a substitute, or alkyleneoxycarbonyl
group; and each of m and n denotes an integer of 0 to 3.
Hereinafter, the specific examples of the general formulae
(1) and (2) will be described.


In the general formulae (1) and (2), among the substitutes
of R1, examples of the alkyl groups include a methyl group, ethyl
group, propyl group, butyl group, and the like, examples of the
aryl group include a phenyl group, naphthyl group, and the like,
examples of the aralkyl group include a benzyl group, phenethyl
group, naphthylmethyl group, and the like, and examples of the
alkoxyl group include a methoxy group, ethoxy group, propoxy
group, and the like. These may be further substituted with a
halogen atom, nitro group, cyano group, alkyl group such as a
methyl group or ethyl group, alkoxy group such as a methoxy
group or ethoxy group, aryloxy group such as phenoxy group, aryl
group such as a phenyl group or naphthyl group, aralkyl group
such as a benzyl group or phenethyl group, or the like.
Among the aforementioned example of the substitute of R1,
the hydrogen atom and methyl group are particularly preferable.
Each of Ar3 and Ar4 which may be substituted is an aryl
group, and examples of such an aryl group include a condensed
polycyclic hydrocarbon group, non-condensed cyclic hydrocarbon
group, heterocyclic group, and the like.
Examples of the condensed polycyclic hydrocarbon group
include the ones wherein 18 or less numbers of carbon atoms are
forming a ring. Specific examples thereof include a pentanyl
group, indenyl group, naphthyl group, azulenyl group, heptalenyl
group, biphenylenyl group, as-indacenyl group, s-indacenyl group,


fluolenyl group, acenaphthylenyl group, preiadenyl group,
acenaphthenyl group, phenalenyl group, phenantryl group, antryl
group, fluorantenyl group, acephenanthrylenyl group,
aceanthrylenyl group, triphenyleyl group, pyrenyl group,
chrysenyl group, naphthacenyl group, and the like.
Examples of the non-condensed cyclic hydrocarbon group
include monovalent group of monocyclic hydrocarbon group such
as benzene, diphenyl ether, polyethylene diphenyl ether, diphenyl
thioether, and diphenyl sulfone; monovalent group of
non-condensed polycyclic hydrocarbon group such as biphenyl,
polyphenyl, diphenyl alkans, diphenylalkenes, diphenyl alkyne,
triphenyl methane, distytyl benzene, 1,1-diphenylcycloalkanes,
polyphenyl alkans, polyphenyl alkenes; and a monovalent group
of ring aggrenation hydrocarbon such as 9,9-diphenyl fluorenone.
Examples of the heterocyclic group include a monovalent
group of carbozole, dibenzofuran, dibenzothiophene, oxadiazole,
and thiadiazole.
The aryl groups for use as Ar3 and Ar4 may be substituted
with the following groups.
(1) A halogen atom, cyano group, nitro group, or the like.
(2) An alkyl group, preferably C1-C12 linear or branched alkyl
group, more preferably C1-C8 linear or branched alkyl group,
even more preferably C1-C4 linear or branched alkyl group,
which may have a fluorine atom, hydroxyl group, cayano group,


C1-C4 alkoxy group, phenyl group, phenyl group substituted with
a halogen atom, C1-C4 alkyl group, or C1-C4 alkoxy group.
Specific examples of such groups include a methyl group, ethyl
group, n-butyl group, i-propyl group, t-butyl group, s_butyl group,
n-propyl group, trifluolomethyl group, 2-hydroxyethyl group,
2-ethoxyethyl group, 2_cyanoethyl group, 2-methoxyethyl group,
benzyl group, 4-chlorobenzyl group, 4-methylbenzyl group,
4-phenylbenzyl group, and the like.
(3) An alkoxy group (-OR2), where R2 represents the alkyl group
defined in (2). Specific examples thereof includes a methoxy
group, ethoxy group, n-propoxy group, ipropoxy group, t-butoxy
group, n-butoxy group, sbutoxy group, i-butoxy group,
2-hydroxyethoxy group, benzyloxy group, trifluoromethoxy group,
and the like.
(4) An aryloxy group, wherein the aryl group may be a phenyl
group, naphthyl group, or the like, and the aryloxy group may
have a substitute such as a C1-C4 alkoxy group, C1-C4 alkyl
group, or halogen atom. Specific examples of such the aryloxy
group include a phenoxy group, lnaphthyloxy group,
2-naphthyloxy group, 4-methoxyphenoxy group, 4methylphenoxy
group, and the like.
(5) An alkylmercapto group or aryhnercapto group. Specific
example thereof including a methylthio group, ethylthio group,
phenylthio group, p-methyphenylthio group, and the like.



In the formula above, each of R3 and R4 denotes a hydrogen atom,
alkyl group defined in (2), or aryl group. Examples of the aryl
group include a phenyl group, biphenyl group, and naphthyl
group, and these may have a substitute such as a C1-C4 alkoxy
group, C1-C4 alkyl group, or halogen atom. R3 and R4 may form
a ring in combination. Specific examples of the group expressed
by the above formula include an amino group, diethyl amino
group, N-methyl-N-phenyl amino group, N-diphenyl amino group,
N,N-di(tolyl)amino group, dibenzylamino group, piperidino group,
morpholino group, pyrrolidino group, and the like.
(7) An alkylenedioxy group such as a methylenedioxy group, or an
alkylenedithio group such as a methylenedithio.
(8) A substituted or unsubstituted styryl group, substituted or
unsubstituted β-phenylstyryl group, diphenylaminophenyl group,
ditolylaminophenyl group, and the like.
As the arylene group for use in Ar1 and Ar2, divalent
groups delivered from the aryl groups mentioned above for use in
Ar3 and Ar4 can be used.
X denotes a group of a single bond, specifically a
substituted or unsubstituted alkylene group, substituted or


unsubstituted cycloalkylene group, substituted or unsubstituted
alkylene ether group, oxygen atom, sulfur atom, vinylene group,
or the like.
The substituted or unsubstituted alkylene group is C1-C12
linear or branched alkylene group, preferably C1-C8 linear or
branched alkylene group, and more preferably C1-C4 linear or
branched alkylene group, and these alkylene groups may have a
fluorine atom, hydroxyl group, cyano group, C.1-C4 alkoxy group,
phenyl group, or phenyl group which is further substituted with a
halogen atom, C1-C4 alkyl group, or C1-C4 alkoxy group.
Specific examples of such the substituted or unsubstituted
alkylene group include a methylene group, ethylene group,
n-butylene group, i-propylene group, t-butylene group, s-butylene
group, n-propylene group, trifluoromethylene group,
2-hydroxyethylene group, 2-ethoxyethylene group,
2-cyanoethylene group, 2-methoxyethylene group, benzylidene
group, phenylethylene group, 4-chlorophenylethylene group,
4-methylphenylethylene group, 4-biphenylethylene group, and
the like.
The substituted or unsubstituted cycloalkylene group is a
C5-C7 alkylene group, and such the cyclic alkylene group may
further have a fluorine atom, hydroxyl group, C1-C4 alkyl group,
C1-C4 alkoxy group, or the like. Specific examples thereof
include a cyclohexylidene group, cyclohexylene group,


3,3-dimethylcyclohexylidene group, and the like.
The substituted or unsubstituted alkylene ether group is
any of an ethyleneoxy group, propyleneoxy group, ethyleneglycol
group, propyleneglycol group, diethyleneglycol group,
tetraethylene glycol group, or tripropyleneglycol group, and the
alkylene group within the alkylene ether group may have a
substituent such as a hydroxyl group, methyl group, ethyl group,
or the like.
The vinylene group is expressed by the following formulae:

In the above formulae, R5 denotes an alkyl group (the same
as the alkyl group defined in (2)), or aryl group (the same as the
aryl group denotes by Ar3 and Ar4), and a denotes an integer of 1
or 2 and b denotes any integer of 1 to 3.
Z denotes a substituted or unsubstituted alkylene group,
substituted or unsubstituted alkylene ether group, or
alkyleneoxycarbonyl group.
Examples of the substituted or unsubstituted alkylene
group are those listed as the alkylene group of X.
Examples of the substituted or unsubstituted alkylene

ether group are those listed as alkylene ether group of X.
Examples of the alkyleneoxycarbonyl group include a
caprolactone-modified group.
Moreover, especially preferable examples of the radical
polymerizable compound having a monovalent charge
transporting structure are the compounds having a structure
expressed by the following general formula (3):

In the general formula (3), each of o, p and q denotes an
integer of 0 or 1; Ra denotes a hydrogen atom or methyl group;
each of Rb and Rc denotes a C1-C6 alkyl group (does not include a
hydrogen atom) and in case where there are a plurality of Rb or
Rc, they may be different to each other; s denotes any integer of 0
to 3; and Za denotes a group of a single bond, such as a methylene
group, ethylene group, and the groups expressed by the following
formulae "

The compound expressed by the general formula (3) is
preferably a compound having a methyl group and ethyl group as

substituents of Rb and Rc.
The mono-functional radical polymerizable compound
having the charge transporting structures represented by the
general formulae (1), (2), or especially (3) for use in the present
invention is polymerized by releasing the OC double bond in the
both sides, therefore the charge transporting structure is
incorporated into a polymer chain, not located at the terminals of
the resultant polymer. Specifically, the charge transporting
structure is incorporated in a main chain of the crosslinked
polymer chain which is formed by the aforementioned
mono-functional radical polymerizable compound and the tri- or
more functional radical polymerizable monomer. Moreover, the
charge transporting structure is incorporated in a crosslinking
chain present between two main polymer chains, and such the
crosslinking chain is classified into intermolecular a crosslinking
chain which is present between one polymer molecular and
another polymer molecular, and an intramolecular crosslinking
chain which crosslinks between a segment of a main chain folded
within one polymer molecular and another monomer-derived
segment polymerized at a part of the main chain where is distant
from the aforementioned segment. In any of these cases, a
tricrylamine group which is a pendant of the main chain has at
least three aryl groups spirally positioned from a nitrogen atom,
and is bulky. However, it is connected with the main chain via a


carbonyl group, without directly connecting to the main chain,
and therefore is fixed while being fairly free in a
three-dimensional space. Therefore, these triaryl amine
structures are appropriately adjacent to each other in the space
within the polymer, and thus the crosslinked polymer has little
physical strain. In addition, in the case where the crosslinked
surface layer is formed as an outermost layer, an occurrence of a
problem in that the charge transporting passage is disconnected
can be prevented.
The radical polymerizable compound having a charge
transporting structure for use in the present invention plays an
important roll as it imparts the charge transporting function in
the crosslinked surface layer. The amount thereof is 20% by
mass to 80% by mass, and preferably 30% by mass to 70% by mass
with respect to the total amount of the crosslinked surface layer.
In the case where the amount thereof is less than 20% by mass,
the charge transporting function of the crosslinked surface layer
cannot be sufficiently maintained. In the case where the
amount thereof is more than 80% by mass, the content of the tri-
or more functional monomer having no charge transporting
structure is decreased, and thus high abrasion resistance cannot
be achieved due to the decreased density of the crosslink bond.
Although it cannot be stated as the required electric
characteristics and abrasion resistance are changed depending on


the process for use, it is preferably in the range of 30% by mass to
70% by mass in view of the balance between the both
characteristics.
The crosslinked surface layer is formed by curing the
mixture containing at least the tri- or more functional radical
polymerizable monomer having no charge transporting structure
and the radical polymerizable compound having a charge
transporting structure. In order to control the viscosity at the
time of coating, to reduce the stress in the crosslinked surface
layer, to reduce the surface energy or friction coefficient, a mono-
or bi- functional radical polymerizable monomer, and/or an
oligomer can be added thereto. As the aforementioned radical
polymerizable monomer and/or oligomer, those known in the art
can be used.
Examples of monofunctional radical polymerizable
monomer include 2-ethylhexyl acrylate, 2-hydroxyethyl acrylate,
2-hydroxypropyl acrylate, tetrahydrofurfuryl acrylate,
2-ethylhexylcarbitol acrylate, 3-methoxybutyl acrylate, benzyl
acrylate, cyclohexyl acrylate, isoamyl acrylate, isobutyl acrylate,
methoxytriethyleneglycol acrylate, phenoxytetraethyleneglycol
acrylate, cetylacrylate, isostearyl acrylate, stearyl acrylate,
styrene monomer, and the like.
Examples of bifunctional radical polymerizable monomer
include 1,3-butandiol diacrylate, l,4,butandiol diacrylate,


1,4-butandiol dimethacrylate, 1,6-hexanediol diacrylate,
1,6-hexandiol dimetacrylate, die thylene glycol diacrylate,
neopentylglycol diacrylate, EO-modified bisphenol A diacrylate,
EO-modified bisphenol F diacrylate, and the like.
Examples of the functional monomer include:
fluorine-containing monomers such as octafluoropentyl acrylate,
2-perfluorooctylethyl acrylate, 2-perfluorooctylethyl
methacrylate, and 2-perfluoroisonylethyl acrylate, in which
fluorine atoms are substituted; and vinyl monomers, acrylates
and monoacrylates each having a polysiloxane group such as
siloxane units having a repeating number of 20 to 70, disclosed in
Japanese Patent Application Publication (JP-B) Nos. 0560503
and 0645770, e.g. acryloyl polydimethylsiloxianethyl,
methacryloyl polydimethylsiloxane ethyl, acryloyl
polydimethylsiloxane propyl, acryloyl polydimethylsiloxane butyl,
diacryloyl polydimethylsiloxane diethyl and the like.
Examples of the radical polymerizable oligomer include
oligomers of epoxy acrylate, urethane acrylate, polyester acrylate,
and the like. Note that, the large content of the mono- or bi-
functional radical polymerizable monomer and/or the radical
polymerizable oligomer may practically reduce the density of
three-dimensional crosslinks in the crosslinked surface layer, and
this may cause the declined abrasion resistance thereof.
Therefore, the amount of these monomer and oligomer is 50 parts


by mass or less, and preferably 30 parts by mass or less, with
respect to 100 parts by mass of the tri- or more functional radical
polymerizable monomer.
Moreover, the crosslinked surface layer is a layer formed
by applying an optical energy, and curing the mixture containing
at least the tri- or more functional radical polymerizable
monomer having no charge transporting structure and the radical
polymerizable compound having a charge transporting structure.
However, a polymerization initiator may be optionally contained
in the crosslinked surface layer in order to efficiently proceed
with the crosslink reaction.
Specific examples of the polymerization initiator include:
acetophenone or ketal photopolymerization initiators such as
diethoxyacetophenone, 2,2-dimethoxy-1,2-diphenylethane-1-one,
1-hydroxy-cyclohexyl-phenyl-ketone,
4-(2-hydroxyehoxy)phenyl-(2-hydroxy-2-propyl)ketone,
2-benxyl-2-dimethylamino-1-(4-morpholinophenyl)butanone-1,
2-hydroxy-2-methyl-1-phenylpropane-1-one,
2-methyl-2-morpholino(4-methylthiophenyl)propane- 1-one, and
l-phenyl-l,2-propanedione-2-(o-ethoxycarbonyl)oxime; benzoin
ether photopolymerization initiators such as benzoin, benzoin
methyl ether, benzoin ethyl ether, benzoin isobutyl ether, and
benzoin isopropyl ether; benzophenone photopolymerization
initiators such as benzophenone, 4-hydroxybenzophenone,


o-benzoylbenzoic acid methyl ether, 2-benzoyl naphthalene,
4-benzoyl bisphenyl, 4-benzoyl phenyl ether, acrylated
benzophenone, and 1,4-benzyl benzene; thioxanthone
photopolymerization initiators such as 2-isopropylthioxanthone,
2-chlorothioxane, 2,4-dimethylthioxanthone,
2,4-diethylthioxanthone, and 2,4-dichlorothioxanthone; and other
photopolymerization initoators such as ethylanthraquinone,
2,4,6-trimethylbenzoyldiphenylphosphineoxide,
2,4,6-trimethylbenzoylphenylethoxyphosphineoxide,
bis(2,4,6-trimethylbenzoyl)phenylphosphineoxide,
bis(2,4-dimethoxybenzoyl)-2,4,4-trimethylpentylphosphineoxide,
methylphenylglyoxyester, 9,10-phenanthrene, acridine
compounds, triazine compounds, imidazole compounds, and the
like. In addition, photopolymerization accelerator can be used
alone or in combination with the aforementioned
photopolymerization initiator. Specific examples thereof include
triethanol amine, methyldiethanol amine, ethyl
4-dimethylaminobenzoate, isoamyl 4-dimethylaminobenzoate,
2-dimethylaminoethylbenzoate,
4,4'-dimethylaminobenzophenone, and the like.
The aforementioned polymerization initiator can be used
singly, or in combination of two or more. The amount of the
polymerization initiator is 0.5 parts by mass to 40 parts by mass,
and preferably 1 part by mass to 20 parts by mass, with respect to


100 parts by mass of the total of the radical polymerizable
contents.
Furthermore, a coating solution of the crosslinked surface
layer optionally contains additives such as various plasticizers
(for reducing the stress and improving the adherence), leveling
agent, low molecular charge transporting material having no
radical polymerizability, and the like. Specific examples of the
plasticizer include known plasticizers for use in general resins,
such as dibutyl phthalate, and dioctyl phthalate. The added
amount of the plasticizer is 20% by mass or less, and preferably
10% by mass with respect to the total solid contents of the coating
solution of the crosslinked surface layer. Specific examples of
the leveling agent include- silicone oil such as dimethyl silicone
oil, methylphenyl silicone oil, and the like; polymers and
oligomers having a perfluoroalkyl group in side chains thereof.
The added amount of the leveling agent is appropriately 3% by
mass or less with respect to the total solids content of the coating
solution of the crosslinked surface layer.
The crosslinked surface layer is formed by coating the
coating solution containing at least the tri- or more functional
radical polymerizable monomer having no charge transporting
structure and the radical polymerizable compound having a
charge transporting structure, and curing the coated layer. In
the case where the radical polymerizable monomer is a liquid,


other components can be dissolved therein to form the coating
solution of the crosslinked surface layer, but it may be further
diluted with a solvent, if necessary. Specific examples of the
solvent include: alcohols such as methanol, ethanol, propanol,
butanol, and the like; ketones such as acetone,
methylethylketone, methylisobutylketone, cyclohexanone, and
the like; esters such as ethyl acetate, butyl acetate, and the like;
ethers such as tetrahydrofuran, dioxane, propyl ether, and the
like; halogenated solvents such as dichloromethane,
dichloroethane, trichloroethane, and chlorobenzene; aromatic
solvents such as benzene, toluene, xylene, and the like;
cellosolves such as methyl cellosolve, ethyl cellosolve, cellosolve
acetate, and the like. These solvents can be used singly or in
combination of two or more. The dilution ratio by the solvent is
arbitrary adjusted depending on the solubility of the components,
coating method, intended film thickness, and the like. The
coating can be performed by a dip coating method, spray coating
method, bead coating method, ring coating method, or the like.
After coating the aforementioned coating solution of the
crosslinked surface layer, a light energy is externally applied to
the coated layer so as to cure the layer. Examples of the light
energy include: ultraviolet light sources, such as a high-pressure
mercury lamp and metal halide lamp, each having an emission
wavelength in the ultraviolet region; and visible light sources


which emit the light of a wavelength region covering the
absorption wavelengths of the aforementioned radical
polyerizable contents and photopolymerization initiator. The
light intensity of the radiation is preferably in the range of from
300 mW/cm2 to 1,000 mW/cm2. When the light intensity is less
than 300 mW/cm2, the curing reaction requires a long period of
time to complete. When the light intensity is more than 1,000
mW/cm2, the progress of the reaction becomes uneven within the
layer, and thus the texture of the crosslinked surface layer
becomes significantly rough.
In the case where the curing is performed by the light
energy, it is preferably that the oxygen density is reduced so as to
prevent obstruction of crosslink by oxygen.
As the composition for the coating solution of the
crosslinked surface layer, the binder resin can be contained
therein, provided that it does not adversely affect the smoothness,
electric characteristics, or resistance of the surface of the
photoconductor. However, polymer materials such as the binder
resin does not have a good compatibility with polymer generated
as a result of the curing reaction of the radical polymerizable
composition (radical polymerizable monomer and radical
polymerizable compound having a charge transporting structure),
and then a phase separation may occur in the coating solution of
the crosslinked surface layer. As a result, the resulted layer has


a significantly irregular surface. Therefore, it is preferable that
the binder resin is not contained in the coating solution of the
crosslinked surface layer.
In order to maintain the electric characteristics thereof,
the crosslinked surface layer contains bulky- charge transporting
structures therein, and it is necessary to increase the density of
crosslinks so as to increase the physical strength. If the curing
reaction of such the crosslinked surface layer is rapidly
progressed, after being coated, by externally applying extremely
high energy, the curing is proceeded unevenly and thus the
resulted layer ends up having an irregular surface. Therefore, it
is preferably to use an external light energy which is capable of
controlling the reaction speed depending on the light intensity
and the usage amount of the polymerization initiator.
The coating method of the crosslinked surface layer is
explained as follow. In the case where an acrylate monomer
having three acryloyloxy groups and a tryarylamine compound
having one acryloyloxy group are used for the coating solution,
the usage ratio thereof is 7/3 to 3/7. The polymerization
initiator is added thereto at 3% by mass to 20% by mass with
respect to the total amount of the acrylate compound, and a
solvent is added thereto so as to prepare the coating solution. In
the case where tryarylamine donor is used as the charge
transporting material and polycarbonate is used as the binder


resin in the charge transporting layer which is the underlying
layer of the crosslinked surface layer, and the crsslinked surface
layer is formed by spray coating, the aforementioned solvent of
the coating solution is preferably tetrahydrofuran, 2-butanone,
ethyl acetate, or the like, and the usage ratio of such the solvent
is preferably 3 times to 10 times of the total amount of the
acrylate compound.
Sequentially, the coating solution prepared in the manner
mentioned above is coating by spraying on, for example, a
photoconductor wherein an undercoat layer, a charge generating
layer, and the aforementioned charge transporting layer are
laminated on a substrate, e.g. an aluminum cylinder, in this order.
Thereafter, it is dried at a relatively low temperature for a short
period (25°C to 80°C, 1 minute to 10 minutes), and then is cured
by heating or UV irradiation.
A metal halide lamp or the like is used for the UV
irradiation, and the illuminance (365 nm) thereof is preferably in
the range of 300 mW/cm2 to 1,000 mW/cm2. In the case where
the UV light is irradiated at 600 mW/cm2, the entire surface of
the coated layer is uniformly exposed to the UV light for 45 to 360
seconds while rotating the drum of the photoconductor. At this
time, the temperature of the drum is adjusted so as not to exceed
100°C.
After the completion of the curing, it is heated at 100°C to


150°C for 10 minutes to 30 minutes so as to reduce the residual
solvent, to thereby yield the photoconductor.
Examples
Hereinafter, examples and comparative examples of the
present invention will be explained, but it shall not be construed
to limit the scope of the present invention.
The apparatus used in the examples is shown in FIG. 10.
Evaluation method:
A UV lamp was disposed nearby a cylindrical substrate to
which a charge transporting layer had been coated and dried, the
surface temperature of the cylindrical substrate was measured by
means of a thermocouple and data logger, and the variations of
the temperature were evaluated at three points, i.e. an upper
portion, center portion, and bottom portion of the cylindrical
substrate.
Note that, an Al substrate (outer diameter of 100 mm) was
dip-coated in a coating solution of the charge transporting layer
having the following formula, the coated layer was heated and
dried to thereby form a charge transporting layer having a
thickness of 20 urn.



Bisphenol Z polycarbonate 10 parts by mass
(Panlite TS-2050, manufactured by Teijin
Chemicals Ltd.)
Low molecular charge transfering 10 parts by mass
material

Tetrahydrofulane 80 parts by mass
1% tetrahydrofulane solution of silicone 0.2 parts by mas
oil
The conditions in Examples 1-5 and Comparative Example
1 were as follows:
UV lamp: UV lamp manufacture by Fusion UV Systems
Japan K.K. (bulb type: H-bulb)
Distance between the UV lamp and the surface of the
cylindrical substrate: 53 mm
Duration of irradiation by UV lamp: 2 minutes
Rotation frequency of the cylindrical substrate at the time
of UV irradiation: 50 rpm
[Example 1]
External diameter of the cylindrical conductive substrate: 100
mm
Total length of the cylindrical conductive substrate:380 mm

Refrigerant: water
Length of the refrigerant supplying pipe'- 400 mm
Space between the refrigerant supplying pipe and the holding
part of the cylindrical elastic body: 2 mm
Pressure for supplying the refrigerant: 2,000 hPa/cm2
Thickness of a cylindrical elastic body: 1.5 mm
Temperature of the refrigerant: 30oC
Constant-temperature water bath: setting at 30*C (coolability
1,500 W)
Circulation flow rate of the refrigerant: 5 L/min.
[Example 2]
External diameter of the cylindrical conductive substrate: 100
mm
Total length of the cylindrical conductive substrate:380 mm
Refrigerant: water
Length of the refrigerant supplying pipe: 350 mm
Space between the refrigerant supplying pipe and the holding
part of the cylindrical elastic body: 2 mm
Pressure for supplying the refrigerant: 5,000 hPa/cm2
Thickness of a cylindrical elastic body: 1.0 mm
Temperature of the refrigerant: 30oC
Constant-temperature water bath: setting at 30*C (coolability
1,500 W)
Circulation flow rate of the refrigerant: 3 L/min.



[Example 3]
The conditions were set the same as in Example 1,
provided that the following conditions were changed as described.
Length of the refrigerant supplying pipe: 100 mm
Pressure for supplying the refrigerant: 500 hPa/cm2
Thickness of a cylindrical elastic body: 4.0 mm
[Examples 4]
The conditions were set the same as in Example 1,
provided that the following conditions were changed as described.
Space between the refrigerant supplying pipe and the holding
part of the cylindrical elastic body: 1.5 mm
Thickness of a cylindrical elastic body: 3.5 mm
Circulation flow rate of the refrigerant: 1.8 L/min.
[Example 5]
The conditions were set the same as in Example 2,
provided that the following condition was changed as described.
Constant-temperature water bath: none
[Comparative Example l]
The conditions were set the same as in Example 2,
provided that the following conditions were changed as described.
Refrigerant: none
Constant-temperature water bath: none
The results of the temperature control are shown in Table
1.


Note that, the criteria for the evaluation are as follow '
A: Difference in the temperature is 0°C or more but less than 5°C
B: Difference in the temperature is 5°C or more but less than 10°C
C: Difference in the temperature is 10°C or more but less than
30°C
D: Difference in the temperature is 30°C or more
Table 1

[Example 6]
An undercoat layer was formed by a dip coating method on
the A1 substrate (external diameter: 100 mm) so as to have a
layer thickness of 3.5 µm after drying.

Alkyd resin (BECKOSOL 130760-EL, DIC Corporation)
6 parts by mass
Melamine resin (SUPER BECKAMINE G821-60, DIC
Corporation) 4 parts by mass
Titanium oxide (CR-EL, Ishihara Sangyo Kaisha, Ltd.)
40 parts by mass
Methylethylketone 50 parts by mass

Onto the undercoat layer, the following coating solution of
a charge generating layer was dip-coated, and the coated layer
was heated and dried to therehy form a charge generating layer
having a thickness of 0.3 µm.

Y-form titanyl phthanyl phthalocyanine 4 parts by mass
Polyvinyl hutyral (S-LEC BM-S, Sekisui Chemical Co., Ltd.)
2 parts by mass
Methylethylketone 150 parts by mass
Onto the charge generating layer, the following coating
solution of a charge transporting layer was dip-coated, and the
coated layer was heated and dried to thereby form a charge
generating layer having a thickness of 22 µm.

Bisphenol Z polycarbonate (Panlite® TS-2050, Teijin Chemicals
Ltd.) 10 parts by mass
Low molecular charge transporting material represented by the
following formula 10 parts by mass

Tetrahydrofuran 80 parts by mass
1% tetrahydrofuran solution of silicone oil (KF50, Shin-Etsu

Chemical Co., Ltd.) 0.2 parts by mass
On the charge transporting layer, the following coating
solution of a crosslinked surface layer was spray coated, and the
irradiation of UV light and the temperature control were
performed at the same conditions as in Example 1. After the UV
radiation, it was dried at 130°C for 30 minutes so as to obtain the
crosslinked surface layer having a thickness of 9.0 µm, to thereby
yield an electrophotographic photoconductor.

Tri-or more functional radical polymerizable monomer having no
charge transporting structure (KAYARAD TMPTA, Nippon
Kayaku Co., Ltd.) 8 parts by mass
Tri-or more functional radical polymerizable monomer having no
charge transporting structure (KAYARAD DPCA120, Nippon
Kayaku Co., Ltd.) 2 parts by mass
Radical polymerizable compound having the charge transporting
structure represented by the following formula
10 parts by mass
Photopolymerization initiator, i.e.

1-hydroxy-cylohexyl-phenyl-ketone (IRGACURE 184, Ciba Japan
K.K.) 1 part by mass
Tetrahydrofuran 80 parts by mass
[Comparative Example 2]
The electrophotographic photoconductor of Comparative
Example 2 was prepared in the same manner as in Example 6,
provided that the irradiation of UV light and the temperature
control were performed at the same conditions as in Comparative
Example 1.

Note that, in Table 2, the unit for the depth of wear is µm.
The thus obtained electrophotographic photoconductor was
disposed in Imagio MF1350 (Ricoh Company Limited), and
4,000,000 pieces of paper (A4 size, My Paper, NBS Ricoh Co.,
Ltd.) were subjected to the printing test (Initial charge potential:
-800V). Thereafter, the wear characteristics, charge potential in
the device, and the printed image were evaluated. The results of
the wear characteristics (the depth of wear) are shown in Table 2,
the results of the charge potential in the device are shown in
Table 3, and the evaluations of the image are shown in Table 4.

Table 3

Note that, in Table 3, the unit for the charge potential is
-V.
Table 4

Note that, in Table 4, A represents an excellent image,. B
represents an image having a slightly lowered image density, and
C represents an image having a significantly lowered image
density.
As has clearly explained above, the temperature control
unit of the present invention enables to uniformly control the
temperature of the cylindrical substrate, and as a result, an
electrophotographic photoconductor having excellent wear
characteristics, electric characteristics and image quality can be
produced.

Amended Claims
1. A temperature control unit for an electrophotographic
photoconductor substrate, said electrophotographic photoconductor
substrate comprising a coated layer, and an entire face of said
electrophotographic photoconductor substrate being exposed to
energy externally applied from a heating element while being rotated
by a rotation system, characterized in that:
the temperature control unit comprising a stretchable
membrane member, said membrane member detachably disposed in a
hollow space of the cylindrical electrophotographic photoconductor
substrate,
wherein the membrane member is configured to sequentially
stretch until reaching the deepest part of the hollow space of the
cylindrical substrate as a result of an introduction of a refrigerant
therein so as to closely contact with an entire inner wall of the
cylindrical substrate, and to sequentially shrink to the original shape
thereof as a result of a release of the refrigerant therefrom, so that
the membrane member is detachably disposed in the hollow space of
the cylindrical substrate, and
wherein the membrane member is configured to make a heat
transfer between a surface of the cylindrical substrate and the
refrigerant introduced in the hollow space of the cylindrical substrate
via the membrane member closely contacted with the inner surface of


the cylindrical substrate, so as to control a surface temperature of
the cylindrical substrate.
2. The temperature control unit of according to claim 1, further
comprising an assisting system for a close contact of the membrane
member, configured to assist the membrane member to closely
contact with the entire inner wall of the cylindrical substrate at the
time when the refrigerant is introduced.
3. The temperature control unit according to any one of claim 1 or
2, further comprising:
a refrigerant introducing part, from which the pressurized
refrigerant is introduced into the hollow space of the cylindrical
substrate; and
a refrigerant releasing part, to which the refrigerant
introduced in the inside of the hollow part of the cylindrical substrate
is spontaneously released.
4. The temperature control unit according to claim 3, wherein the
refrigerant introducing part and the refrigerant releasing part are a
double pipe comprising an inner pipe and an outer pipe,
wherein the double pipe is disposed so as to be on the same
axis to a rotation axis of the cylindrical substrate, and is configured
to introduce and release the refrigerant in and from the hollow space

of the cylindrical substrate,
wherein the outer pipe is connected to an entrance part of the
hollow space of the cylindrical substrate, and the inner pipe is
inserted into the hollow space of the cylindrical space in a manner
such that an opening thereof is located at the deepest part of the
hollow space of the cylindrical substrate, so that the refrigerant
flown out from the entrance part or the deepest part pushes and
presses the membrane member towards the inner wall of the
cylindrical substrate to make the membrane member contact with the
inner wall of the cylindrical substrate.
5. The temperature control unit according to claim 4, wherein the
double pipe has a width of an annular channel of 2 mm or more,
where the annular channel is a space between an outer face of the
inner pipe and an inner face of the outer pipe.
6. The temperature control unit according to any one of claims 1
to 4, wherein the membrane member is at least outer face of a bag
structure,
wherein the outer face of the bag structure has an elasticity,
and functions as a chuck in a manner such that the outer face of the
bag structure stretches as the refrigerant is introduced into the bag
structure, and contacts with the inner wall of the cylindrical
substrate so as to hold the cylindrical substrate.


7. The temperature control unit according to claim 6, wherein the
bag structure is configured to release the refrigerant and shrink back
to the original shape, once the introduction of the refrigerant is
terminated.
8. The temperature control unit according to any one of claim 6 or
7, wherein the temperature control unit further comprises a rigid
tube disposed in the hollow space of the cylindrical substrate so as to
be on the same axis to a rotation axis of the cylindrical substrate, and
the bag structure is a cylindrical bag structure comprising a circular
through-hole in a center thereof,
wherein the cylindrical bag structure is disposed on the rigid
tube so that an inner circumference of an inner surface of the
membrane member contacts with an outer circumference of a surface
of the rigid tube, and the refrigerant is introduced in between the
outer circumference of the surface of the rigid tube and the inner
circumference of the inner surface of the membrane member.
9. The temperature control unit according to any one of claims 6
to 8, wherein the bag structure is a cylindrical elastic body which is
detachably disposed in the hollow space of the cylindrical substrate.
10. The temperature control unit according to any one of claims 6


to 9, wherein the bag structure is a chuck configured to hold the
cylindrical substrate from the hollow space of the cylindrical
substrate, and to rotate thereof so as to rotate the cylindrical
substrate while holding thereof.
11. The temperature control unit according to any one of claims 3
to 10, further comprising a refrigerant circulation system configured
to reintroduce the spontaneously released refrigerant into the
refrigerant introducing part via a temperature-constant bath.
12. The temperature control unit according to any one of claims 8
to 11, further comprising a pipe for the refrigerant, which is inserted
into the circular through-hole of the cylindrical bag structure, and is
configured to introduce and release the refrigerant.
13. The temperature control unit according to any one of claims 9
to 12, wherein a thickness of the cylindrical elastic body at where
closely contacting with the entire inner wall of the cylindrical
substrate is 1.0 time to 2.0 times of a thickness of the top and bottom
ends of the cylindrical elastic body at where contacting with the inner
wall of the cylindrical substrate, and
wherein a part of the cylindrical elastic body where the
thickness thereof changes is shaped in a taper or a curve.


14. The temperature control unit according to any one of claims 8
to 13, further comprising a couple of metal or resin disk pressing
tools respectively disposed at the top and bottom of the cylindrical
substrate,
wherein the couple of metal or resin disk pressing tools are
configured to perform a positioning of a location where the cylindrical
substrate is held with the cylindrical elastic body.
15. The temperature control unit according to any one of claims 8
to 14, further comprising:
a refrigerant storage tank;
a refrigerant supplying pipe connecting between the
refrigerant storage tank and the cylindrical elastic body)
a pump equipped with the refrigerant supplying pipe, and
configured to send the refrigerant from the refrigerant storage tank
into the cylindrical elastic body;
a refrigerant releasing pipe connecting between the cylindrical
elastic body and the refrigerant storage tank, and configured to
release the circulated the refrigerant in the cylindrical elastic body
to the refrigerant storage tank;
a pressure detector configured to monitor a pressure of the
refrigerant; and
a flow rate control system configured to control the flow rate of
the refrigerant.


There is provided a
temperature control unit for an
electrophotographic photoconductor substrate,
containing a stretchable membrane
member which is detachably disposed
in a hollow space of the cylindrical
substrate, wherein the membrane member
is configured to sequentially stretch until
reaching the deepest part of the hollow
space of the cylindrical substrate as a
result of an introduction of a refrigerant
therein to closely contact with an entire
inner wall of the cylindrical substrate,
and to sequentially shrink to the original
shape thereof as a result of a release
of the refrigerant therefrom, so that the
membrane member is detachably disposed
in the hollow space, and wherein the
membrane member is configured to make
a heat transfer between a surface of the
cylindrical substrate and the refrigerant via
the membrane member closely contacted
with the inner surface of the cylindrical
substrate, to control a surface temperature
of the cylindrical substrate.

Documents:

http://ipindiaonline.gov.in/patentsearch/GrantedSearch/viewdoc.aspx?id=S5U+GkuqY9dOju4y60/UTQ==&loc=wDBSZCsAt7zoiVrqcFJsRw==


Patent Number 271499
Indian Patent Application Number 2331/KOLNP/2010
PG Journal Number 09/2016
Publication Date 26-Feb-2016
Grant Date 24-Feb-2016
Date of Filing 25-Jun-2010
Name of Patentee RICOH COMPANY, LTD.
Applicant Address 3-6, NAKAMAGOME 1-CHOME, OHTA-KU, TOKYO, 1438555 JAPAN
Inventors:
# Inventor's Name Inventor's Address
1 KAWASAKI, YOSHIAKI 3-3-13, YOBIKO, SUSONO-SHI, SHIZUOKA, 4101109 JAPAN
2 SUGINO, AKIHIRO 194-3, ONO, NUMAZU-SHI, SHIZUOKA, 4100307 JAPAN
3 HIROSE, MITSUAKI REOPALACE ESTA 106, 886-1, OZUWA, NUMAZU-SHI, SHIZUOKA, 4100873 JAPAN
4 MURAMATSU, SUSUMU 620-57, ISSHIKI-FUJI-SHI, SHIZUOKA, 4170808 JAPAN
5 KURIBAYASHI, KATSUO C/O TRAY ENGINEERING CO., LTD. OF 405-1, ASHITAKA, NUMAZU-SHI, SHIZUOKA, 4100001 JAPAN
6 WAKABAYASHI, SHOICHI C/O TRAY ENGINEERING CO., LTD. OF 405-1, ASHITAKA, NUMAZU-SHI, SHIZUOKA, 4100001 JAPAN
PCT International Classification Number G03G 5/00,G03G 21/00
PCT International Application Number PCT/JP2008/072466
PCT International Filing date 2008-12-04
PCT Conventions:
# PCT Application Number Date of Convention Priority Country
1 2007-315465 2007-12-06 Japan