Indian Patents
Title of Invention

FIRE-RESISTANT PIPING MATERIAL
Abstract It is an object to provide a fire-resistant piping material that can be fire-protection measures by itself and is excellent in construction workability. A single-layered fire-resistant piping material according to the present invention is constituted of a fire-resistant resin composition containing heat-expandable graphite in an amount of 1 to 10 parts by weight based on 100 parts by weight of a polyvinyl chloride-based resin. A multilayered fire- resistant piping material according to the present invention includes a tubular fire-resistant expandable layer made of a heat-expandable fire-resistant resin composition and a covering layer covering at least one of the outer surface and the inner surface of the fire-resistant expandable layer, and the fire-resistant expandable layer is formed of a fire-resistant resin composition containing heat- expandable graphite in an amount of 1 to 15 parts by weight based on 100 parts by weight of a polyvinyl chloride-based resin, and the covering layer is formed of a polyvinyl chloride-based resin composition not containing heat- expandable fire-resistant materials.
Full Text DESCRIPTION
FIRE-RESISTANT PIPING MATERIAL
Technical Field
[0001]
The present invention particularly relates to a fire-
resistant piping material that is excellent in fire
resistance and is used in a construction passing through a
partition of a building.
Background Art
[0002]
Buildings have fireproof compartments defined depending
on the types and specifications of the buildings. In the
fireproof compartments, according to the specifications,
flooring materials and wall materials for fireproof
construction or semi-fireproof construction prescribed by
the Building Standards Act are used. The flooring materials
and the wall materials for fireproof construction or semi-
fireproof construction prescribed by the Building Standards
Act are those defined by the Minister of Land,
Infrastructure, Transport and Tourism or certified by the
Minister of Land, Infrastructure, Transport and Tourism, and
examples thereof include ferroconcrete; concrete blocks,
brick constructions, and stone constructions that are
reinforced with iron materials; iron materials covered with
steel mortar or concrete on both surfaces thereof;
lightweight foamed concrete; precast concrete plates; and
laminates of plywood and gypsum board, hard wood chip cement
board, or lightweight foamed concrete.
[0003]
Incidentally, buildings are provided with piping (such
as electrical conduits, drain pipes, and ducts). Such
piping passes through the above-mentioned fireproof
compartment in some cases.
When a through-hole through which piping or the like
passes (hereinafter, referred to as "compartment pass-
through portion") is provided to the above-mentioned
fireproof compartment, occurrence of fire may cause a big
fire accident within a short period of time by that the fire
and smoke quickly penetrate from the room where the fire
occurred to the next room having the fireproof compartment
therebetween through the compartment pass-through portion.
Therefore, the Building Standards Act establishes that
only materials that passed a fire-resistant test for
compartment pass-through and certified by the Minister of
Land, Infrastructure, Transport and Tourism or evaluated by
fire defense can be used as the piping material passing
through the compartment pass-through portion in a building.
Therefore, the compartment pass-through portion is
provided with fire-protection measures for caulking a gap
with a noncombustible material such as mortar after
installing the piping passing through the compartment so
that no gap is formed between the compartment pass-through
portion and the piping.
[0004]
When the piping material is a metal, since the piping
material itself is heat resistant and noncombustible, a
sufficient effect is observed only by caulking the gap with
a noncombustible material such as mortar, as described
above. However, the metal piping has a large weight and
therefore has a problem that the workability in transferring
and in construction is inferior.
On the other hand, when the piping material is a
synthetic resin, the piping is light in weight, excellent in
workability, and easy to bond, compared to the metal piping.
The synthetic resin piping has thus various merits, but is
inferior in heat resistance and fire resistance. Therefore,
in fire, the piping material is lost by burning or is
deformed by the heat to generate a gap between the
compartment pass-through portion and the piping material,
which may allow the heat, fire, and smoke occurred at one
side of the fireproof compartment to reach the other side.
[0005]
Accordingly, for example, it is employed fire-
protection measures in which a sheet-like covering material
having fire-resistance and expansibility is wound on the
outer surface of the synthetic resin piping material. As
the fire-resistant resin composition constituting the sheet-
like covering material, proposed are those in which a vinyl
chloride-based resin is blended with heat-expandable
graphite, an inorganic filler, and a plasticizer and also
blended with a specific phosphorus compound (for example,
refer to Patent Document 1) and those in which a base resin,
such as rubber, a thermoplastic elastomer, or a liquid
polymer, is blended with heat-expandable graphite serving as
an inorganic expansion agent and also blended with a resin
serving as a deformation-preventing resin, such as a
polycarbonate resin or a polyphenylene sulfide resin (for
example, refer to Patent Document 2).
[0006]
However, in the fire-protection measures using the
sheet-like covering material, a synthetic resin piping
material is temporarily installed, and then the sheet-like
covering material is wound to the piping material at a
portion previously determined. Subsequently, the piping
material is supported and fixed, and then the opening is
filled back with mortar. Therefore, the measures has a
large number of work units and takes a long time and also
has a problem that the adjustment of the piping position
after the winding of the sheet-like covering material to the
piping material is difficult.
[0007]
Accordingly, the above-mentioned problems can be solved
by directly producing a piping material with a resin
composition having fire-resistance and expansibility, but
since the fire-resistant resin composition in Patent
Document 1 contains large amounts of an inorganic filler and
a plasticizer in a vinyl chloride-based resin, the piping
material formed therewith cannot obtain a high mechanical
strength that is an indispensable requirement in a pipe.
Furthermore, since the fire-resistant resin composition in
Patent Document 2 contains rubber, a thermoplastic
elastomer, or a liquid polymer as the base resin, the piping
material formed therewith cannot obtain a high mechanical
strength that is an indispensable requirement in a pipe, as
in the fire-resistant resin composition of Patent Document
1.
[0008]
[Patent Document 1] Japanese Unexamined Patent
Application Publication No. 2006-348228
[Patent Document 2] Japanese Patent No. 3133683
Disclosure of Invention
[0009]
The present invention has been proposed in the light of
the above-mentioned problems, and it is an object thereof to
provide a fire-resistant piping material that can be fire-
protection measures by itself.
[0010]
In order to solve the above-mentioned problems, a
single-layered fire-resistant piping material of the
invention according to Claim 1 is constituted of a fire-
resistant resin composition containing heat-expandable
graphite in an amount of 1 to 10 parts by weight based on
100 parts by weight of a polyvinyl chloride-based resin.
[0011]
A single-layered fire-resistant piping material of the
invention according to Claim 2 is constituted of a fire-
resistant resin composition containing heat-expandable
graphite having a pH of 1.5 to 4.0 in an amount of 1 to 10
parts by weight based on 100 parts by weight of a polyvinyl
chloride-based resin.
[0012]
In a single-layered fire-resistant piping material of
the invention according to Claim 3, in the invention
according to Claim 2, the fire-resistant resin composition
according to Claim 2 contains an additive for providing heat
stability during molding.
[0013]
In a single-layered fire-resistant piping material of
the invention according to Claim 4, in the invention
according to Claim 3, at least one selected from the group
consisting of lead-based stabilizers, organic tin-based
stabilizers, and higher fatty acid metal salts is contained
as the additive for providing heat stability during molding
at a total additive amount of 0.3 to 5.0 parts by weight
based on 100 parts by weight of the polyvinyl chloride-based
resin.
[0014]
A single-layered fire-resistant piping material of the
invention according to Claim 5, in the invention according
to Claim 4, further includes a basic compound as the
additive for providing heat stability during molding in a
total additive amount of 0.3 to 5.0 parts by weight based on
100 parts by weight of the polyvinyl chloride-based resin.
[0015]
A single-layered fire-resistant piping material of the
invention according to Claim 6 is constituted of a fire-
resistant resin composition containing heat-expandable
graphite having an expansion volume in the range of 100 to
250 mL/g in an amount of 1 to 10 parts by weight based on
100 parts by weight of a polyvinyl chloride-based resin.
[0016]
A single-layered fire-resistant piping material of the
invention according to Claim 7 is constituted of a fire-
resistant resin composition containing heat-expandable

graphite having a 1.3-time expansion temperature of 180 to
240°C in an amount of 1 to 10 parts by weight based on 100
parts by weight of a polyvinyl chloride-based resin.
[0017]
In a single-layered fire-resistant piping material of
the invention according to Claim 8, in the invention
according to any one of Claims 1 to 7, when the piping
material is constructed so as to pass through a flooring
material and is subjected to a fire-resistant test
(complying with ISO 834-1) in which the underside of the
floor is heated under conditions that one end of the piping
material is exposed to a heating side by 300 mm from the
surface on the heating side of the flooring material and
that the other end of the piping material is exposed to a
non-heating side by 800 mm from the surface on the non-
heating side of the flooring material, a pipe inner cross-
sectional area SI at the end of the piping material before
burning on the heating side and a pipe inner cross-sectional
area S2 at a minimum inner diameter of the piping material
after burning satisfy a relationship of (S2/Sl)xl00 [0018]
The invention according to Claim 9 provides a
multilayered fire-resistant piping material including a
tubular fire-resistant expandable layer made of a heat-
expandable fire-resistant resin composition and a covering
layer covering at least one of the outer surface and the
inner surface of the fire-resistant expandable layer. The
fire-resistant expandable layer is formed of a fire-
resistant resin composition containing heat-expandable
graphite in an amount of 1 to 15 parts by weight based on
100 parts by weight of a polyvinyl chloride-based resin, and
the covering layer is formed of a polyvinyl chloride-based
resin composition not containing heat-expandable fire-
resistant materials.
[0019]
The invention according to Claim 10 provides a
multilayered fire-resistant piping material including a
tubular fire-resistant expandable layer made of a heat-
expandable fire-resistant resin composition and a covering
layer covering at least one of the outer surface and the
inner surface of the fire-resistant expandable layer. The
fire-resistant expandable layer is formed of a fire-
resistant resin composition containing heat-expandable
graphite having a pH of 1.5 to 4.0 in an amount of 1 to 15
parts by weight based on 100 parts by weight of a polyvinyl
chloride-based resin, and the covering layer is formed of a
polyvinyl chloride-based resin composition not containing
heat-expandable fire-resistant materials.
[0020]
In a multilayered fire-resistant piping material of the
invention according to Claim 11, in the invention according
to Claim 10, the fire-resistant resin composition according
to Claim 10 contains an additive for providing heat
stability during molding.
[0021]
A multilayered fire-resistant piping material of the
invention according to Claim 12, in the invention according
to Claim 11, includes at least one selected from the group
consisting of lead-based stabilizers, organic tin-based
stabilizers, and higher fatty acid metal salts as the
additive for providing heat stability during molding in a
total additive amount of 0.3 to 5.0 parts by weight based on
100 parts by weight of the polyvinyl chloride-based resin.
[0022]
A multilayered fire-resistant piping material of the
invention according to Claim 13, in the invention according
to Claim 12, further includes a basic compound as the
additive for providing heat stability during molding in a
total additive amount of 0.3 to 5.0 parts by weight based on
100 parts by weight of the polyvinyl chloride-based resin.
[0023]
The invention according to Claim 14 provides a
multilayered fire-resistant piping material including a
tubular fire-resistant expandable layer made of a heat-
expandable fire-resistant resin composition and a covering
layer covering at least one of the outer surface and the
inner surface of the fire-resistant expandable layer. The
fire-resistant expandable layer is constituted of a fire-
resistant resin composition containing heat-expandable
graphite having an expansion volume in the range of 100 to
250 mL/g in an amount of 1 to 15 parts by weight based on
100 parts by weight of a polyvinyl chloride-based resin, and
the covering layer is constituted of a polyvinyl chloride-
based resin composition not containing heat-expandable fire-
resistant materials, and the covering layer is constituted
of a polyvinyl chloride-based resin composition not
containing heat-expandable fire-resistant materials.
[0024]
The invention according to Claim 15 provides a
multilayered fire-resistant piping material including a
tubular fire-resistant expandable layer formed of a heat-
expandable fire-resistant resin composition and a covering
layer covering at least one of the outer surface and the
inner surface of the fire-resistant expandable layer. The
fire-resistant expandable layer is constituted of a fire-
resistant resin composition containing heat-expandable
graphite having a 1.3-time expansion temperature of 180 to
240°C in an amount of 1 to 15 parts by weight based on 100
parts by weight of a polyvinyl chloride-based resin, and the
covering layer is constituted of a polyvinyl chloride-based

resin composition not containing heat-expandable fire-
resistant materials.
[0025]
A multilayered fire-resistant piping material of the
invention according to Claim 16, in the invention according
to any one of Claims 9 to 15, when the piping material is
constructed so as to pass through a flooring material and is
subjected to a fire-resistant test (complying with ISO 834-
1) in which the underside of the floor is heated under
conditions that one end of the piping material is exposed to
a heating side by 300 mm from the surface on the heating
side of the flooring material and that the other end of the
piping material is exposed to a non-heating side by 800 mm
from the surface on the non-heating side of the flooring
material, a pipe inner cross-sectional area SI at the end of
the piping material before burning on the heating side and a
pipe inner cross-sectional area S2 at a minimum inner
diameter of the piping material after burning satisfy a
relationship:
(S2/S1)X100 [0026]
A multilayered fire-resistant piping material of the
invention according to Claim 17, in the invention according
to any one of Claims 9 to 16, the covering layer is provided
on each of the outer surface and the inner surface of the
fire-resistant expandable layer.
[0027]
In the invention according to any of Claims 1 to 8, 1
to 10 parts by weight of heat-expandable graphite is blended
with 100 parts by weight of a polyvinyl chloride-based
resin. This is because that when the amount of the heat-
expandable graphite is smaller than 1 part by weight, a
sufficient heat expansibility cannot be obtained during
burning, which causes insufficient caulking of the inside of
a pipe, ascending of hot air through the inside of the pipe,
and a decrease in fire-resistance performance. On the other
hand, when the amount of the heat-expandable graphite is
larger than 10 parts by weight, the heated composition is
thermally expanded too much to maintain the shape, resulting
in dropping of the residue to decrease the fire-resistance.
Herein, the amount of the heat-expandable graphite is
preferably 1 to 8 parts by weight and further preferably 2
to 7 parts by weight.
[0028]
In the invention according to any of Claims 9 to 17, 1
to 15 parts by weight of heat-expandable graphite is blended
with 100 parts by weight of a polyvinyl chloride-based
resin. This is because that when the amount of the heat-
expandable graphite is smaller than 1 part by weight, a
sufficient heat expansibility cannot be obtained during
burning, which causes insufficient caulking of the inside of
a pipe, ascending of hot air through the inside of the pipe,
and a decrease in fire-resistance performance. On the other
hand, when the amount of the heat-expandable graphite is
larger than 15 parts by weight, the heated composition is
thermally expanded too much to maintain the shape, resulting
in dropping of the residue to decrease the fire-resistance.
Herein, the amount of the heat-expandable graphite is
preferably 1 to 12 parts by weight and further preferably 2
to 10 parts by weight.
[0029]
The heat-expandable graphite used in the present
invention is a crystalline compound maintaining a layer
structure of carbon and is obtained by acid treatment of a
powder such as natural flake graphite, pyrolytic graphite,
or Kish graphite by inserting an inorganic acid between
layers of the graphite using an inorganic acid such as
concentrated sulfuric acid, nitric acid, or selenic acid and
a strong oxidant such as concentrated nitric acid,
perchloric acid, perchlorate, permanganate, dichromate, or
hydrogen peroxide.
[0030]
The heat-expandable graphite having a pH of 1.5 to 4.0
is prepared by adjusting the pH after the acid treatment
described above. The pH adjustment of the heat-expandable
graphite is not particularly limited, but, in the state
after acid treatment by inserting an inorganic acid between
layers of raw material graphite as in above, the pH is
usually 1 or less. Therefore, for example, the acid-treated
graphite is washed with water for removing the remaining
acid on the surface of the graphite, followed by drying.
That is, the pH of the heat-expandable graphite can be
increased by repeating washing with water and drying.
[0031]
In the invention according to any of Claims 2 to 5 and
Claims 10 to 13, heat-expandable graphite that is adjusted
to acidic is used. This is because that the fire-resistance
performance is improved by preventing burning by effectively
carbonizing a polyvinyl chloride resin during burning. This
is based on a property of a polyvinyl chloride-based resin
that repeats a hydrogen chloride elimination reaction in the
presence of an acid to generate a flame-retardant carbide.
However, when the pH of heat-expandable graphite is lower
than 1.5, the too strong acidity may, for example, cause
corrosion of a molding apparatus. On the other hand, when
the pH of h'eat-expandable graphite is higher than 4.0, the
effect of accelerating the carbonization of a polyvinyl
chloride-based resin is low, which may cause insufficient
fire-resistance performance. Accordingly, it is determined
to use heat-expandable graphite having a pH of 1.5 to 4.0.
[0032]
Examples of the polyvinyl chloride-based resin used in
the invention according to any of Claims 1 to 17 include
polyvinyl chloride homopolymers; copolymers of vinyl
chloride monomers and monomers having unsaturated bonds that
are copolymerizable with the vinyl chloride monomers; and
graft copolymers in which vinyl chloride is graft-
copolymerized with (co)polymers other than vinyl chloride.
These may be used alone or in a combination of two or more.
In addition, the polyvinyl chloride-based resin may be
chlorinated, according to need.
[0033]
The monomers having unsaturated bonds that are
copolymerizable with the vinyl chloride monomers are not
particularly limited, and examples thereof include a-olefins
such as ethylene, propylene, and butylene; vinyl esters such
as vinyl acetate and vinyl propionate; vinyl ethers such as
butylvinyl ether and cetylvinyl ether; (meth)acrylic acid
esters such as methyl (meth)acrylate, ethyl (meth)acrylate,
and butyl acrylate; aromatic vinyls such as styrene and a~
methyl styrene; and N-substituted maleimides such as N-
phenyl maleimide and N-cyclohexyl maleimide. These may be
used alone or in a combination of two or more.
[0034]
Any (co)polymer that can graft-(co)polymerize vinyl
chloride can be used for graft-copolymerizing the vinyl
chloride without particular limitation, and examples thereof
include ethylene-vinyl acetate copolymers, ethylene-vinyl
acetate-carbon monoxide copolymers, ethylene-ethyl acrylate
copolymers, ethylene-butyl acrylate-carbon monoxide
copolymers, ethylene-methyl methacrylate copolymers,
ethylene-propylene copolymers, acrylonitrile-butadiene
copolymers, polyurethane, polyethylene chloride, and
polypropylene chloride. These may be used alone or in a
combination of two or more.
[0035]
The average degree of polymerization of the polyvinyl
chloride-based resin is not particularly limited, but is
preferably 400 to 1600 and most preferably 600 to 1400,
since a low average degree of polymerization causes a
decrease in physical properties of a molded article, and a
high average degree causes an increase in melting viscosity
to make molding difficult. In addition, the above-mentioned
"average degree of polymerization" refers to an average
degree of polymerization measured in conformity with JIS K-
6721 "testing method for vinyl chloride resin" using a resin
sample prepared by dissolving a composite vinyl chloride-
based resin in tetrahydrofuran (THF), filtering the solution
for removing insoluble components, and then removing the THF
in the filtrate by drying.
[0036]
The polymerization method of the polyvinyl chloride-
based resin is not particularly limited. Any known
polymerization method may be employed, and examples thereof
include a bulk polymerization method, a solution
polymerization method, an emulsion polymerization method,
and a suspension polymerization method.
[0037]
The chlorination method of the polyvinyl chloride-based
resin is not particularly limited. Any known chlorination
method may be employed, and examples thereof include thermal
chlorination and photochlorination.
[0038]
The polyvinyl chloride-based resin may be cross-linked
or modified within the range that does not impair the fire-
resistance performance as a resin composition. In such a
case, a resin that is cross-linked or modified in advance
may be used, or the cross-linking or modification may be
simultaneously performed when an additive or other component
is blended. Alternatively, the cross-linking or
modification may be performed after blending of the additive
or other component with the resin. The cross-linking of the
resin may be performed by any method without particular
limitation, and a usual cross-linking method of a polyvinyl
chloride-based resin, such as cross-linking using various
types of cross-linking agents or oxides, cross-linking by
electron beam irradiation, or a method using a water cross-
linking agent, may be employed.
[0039]
In the invention according to Claim 4 or 12, the total
additive amount of the group consisting of lead-based
stabilizers, organic tin-based stabilizers, and higher fatty
acid metal salts is 0.3 to 5.0 parts by weight based on 100
parts by weight of the polyvinyl chloride-based resin. This
is because that when the total additive amount of the group
consisting of lead-based stabilizers, organic tin-based
stabilizers, and higher fatty acid metal salts is smaller
than 0.3 parts by weight, the heat stability of the
polyvinyl chloride-based resin is difficult to be ensured
during molding, which may cause easy generation of carbides
during molding. On the other hand, when the total additive
amount of the group consisting of lead-based stabilizers,
organic tin-based stabilizers, and higher fatty acid metal
salts is larger than 5.0 parts by weight, the acceleration
of the carbonization of the polyvinyl chloride-based resin
during burning is inhibited, which may cause insufficient
fire-resistance performance.
[0040]
Examples of the lead-based stabilizers include white
lead, basic lead sulfite, tribasic lead sulfate, dibasic
lead phosphite, dibasic lead phthalate, tribasic lead
maleate, a coprecipitate of silica gel and lead silicate,
dibasic lead stearate, lead stearate, and lead naphthalate.
[0041]
Examples of the organic tin-based stabilizers include
mercaptides such as dibutyltin mercapto, dioctyltin
mercapto, and dimethyltin mercapto; maleates such as
dibutyltin maleate, dibutyltin maleate polymers, dioctyltin
maleate, and dioctyltin maleate polymers; and carboxylates
such as dibutyltin mercapto, dibutyltin laurate, and
dibutyltin laurate polymers.
[0042]
Examples of the higher fatty acid metal salts include
lithium stearate, magnesium stearate, calcium stearate,
calcium laurate, calcium ricinoleate, strontium stearate,
barium stearate, barium laurate, barium ricinoleate, cadmium
stearate, cadmium laurate, cadmium ricinoleate, cadmium
naphthenate, cadmium 2-ethylhexanoate, zinc stearate, zinc
laurate, zinc ricinoleate, zinc 2-ethylhexanoate, lead
stearate, dibasic lead stearate, and lead naphthenate.
[0043]
In the invention according to Claim 5 or 13, the amount
of the basic compound is 0.3 to 5.0 parts by weight based on
100 parts by weight of the polyvinyl chloride-based resin.
This is because that when the additive amount of the basic
compound is smaller than 0.3 parts by weight, the heat
stability of the polyvinyl chloride-based resin is difficult
to be ensured during molding, which may cause easy
generation of carbides during molding. On the other hand,
when the additive amount of the basic compound is larger
than 5.0 parts by weight, the acceleration of carbonization
of the polyvinyl chloride-based resin during burning is
inhibited, which may cause insufficient fire-resistance
performance.
[0044]
The basic compound is not particularly limited, and
examples thereof include calcium carbonate, calcium
silicate, calcium hydroxide, calcium oxide, magnesium
carbonate, magnesium hydroxide, magnesium oxide, barium
carbonate, aluminum hydroxide, zinc oxide, zinc hydroxide,
and iron oxide.
[0045]
In the invention according to Claim 6 or 14, the term
"expansion volume of the heat-expandable graphite" refers to
the volume per gram of heat-expandable graphite after heat
expansion.
[0046]
The expansion volume of heat-expandable graphite is
determined by the following process:
1) One gram of a sample is put in a 500-cc. beaker that
is heated in advance for 20 minutes or more in a heating
furnace and is heated in the heating furnace (furnace
temperature: 1000°C);
2) After 30 seconds, the beaker is taken out from the
heating furnace;
3) The sample in the beaker is cooled to room
temperature;
4) The weight and the volume of the sample after
expansion are measured; and
5) The value of (volume of the sample after expansion)/
(weight of the sample after the expansion) is calculated.
[0047]
The expansion volume of heat-expandable graphite varies
depending on the type and amount of the interlayer compound
of the heat-expandable graphite and on the particle diameter
of the heat-expandable graphite itself, and is a very
important factor for exhibiting fire-resistance.
In the invention according to Claim 6 or 14, the
expansion volume of heat-expandable graphite is 100 to 250
mL/g. This is because that when the expansion volume of
heat-expandable graphite is smaller than 100 mL/g, the
expansion volume is too small to achieve sufficient fire-
resistance, which requires a large amount of heat-expandable
graphite for increasing the fire-resistance and may cause
defects in, for example, physical properties or molding
properties. On the other hand, when the expansion volume of
heat-expandable graphite is larger than 250 mL/g, the heated
composition is thermally expanded too much to maintain the
shape, which may cause dropping of the residue and a
decrease in the fire-resistance. Herein, the expansion
volume of heat-expandable graphite is preferably 120 to 230
mL/g and more preferably 140 to 220 mL/g.
[0048]
In the invention according to Claim 7 or 15, the 1.3-
time expansion temperature of heat-expandable graphite is a
temperature of a heating furnace when a sample of heat-
expandable graphite is heated for 30 minutes in the furnace
in which the temperature is kept constant and the expansion
magnification of the sample is 1.3 times or more at the
temperature.
In addition, expansion magnification is defined by
(volume of sample after heating)/(volume of sample before
heating).
The resin temperature during molding refers to the
highest temperature of the resin during melting.
[0049]
In the invention according to Claim 7 or 15, the 1.3-
time expansion temperature of heat-expandable graphite is
180 to 240°C. This is because that when the 1.3-time
expansion temperature of heat-expandable graphite is lower
than 180°C, the heat-expandable graphite may expand during
molding, which causes a defect in appearance of a pipe and
also may decrease the fire-resistance during burning. On
the other hand, when the 1.3-time expansion temperature of
heat-expandable graphite is higher than 240°C, there is no
risk of starting of expansion of the heat-expandable
graphite during molding, but thermal decomposition (foaming)
of the polyvinyl chloride-based resin progresses during
burning. Therefore, since the heat-expandable graphite
expands after a reduction in plasticity of the polyvinyl
chloride-based resin, the polyvinyl chloride-based resin may
not bear the expansion of the heat-expandable graphite to be
broken to pieces.
[0050]
The fire-resistant test in the invention according to
Claim 8 or 16 is carried out according to an evaluation
method of a performance test for pipe passing through, for
example, a fireproof compartment, based on the revised
Building Standards Act in force on June 1, 2000 (Heisei 12).
The flooring material used was PC (precast concrete) plate
(length: 600 mm, width: 1200 mm, thickness: 100 mm), which
is a flooring material of fireproof construction or semi-
fireproof construction prescribed by the Building Standards
Act.
Examples of the flooring material to be used include,
in addition to the PC plate, the followings:
1) A wood frame member in which a gypsum board
(thickness: 9.5 mm) is bonded to the upper surface of a
structural plywood (thickness: 12 mm) and a reinforced
gypsum board (thickness: 15 mm) is bonded to the lower
surface of the plywood;
2) A wood frame member in which a gypsum board
(thickness: 12.5 mm) is bonded to the upper surface of a
structural plywood (thickness: 12 mm) and two reinforced
gypsum boards (thickness: 12.5 mm) are bonded to the lower
surface of the plywood;
3) A lightweight foamed concrete (ALC) plate having a
thickness of 100 mm or more; and
4) A precast concrete (PC) plate having a thickness of
70 mm or more. In particular, the ALC plate and the PC
plate having a thickness of 100 mm or more are preferred.
The gap between the piping material and the compartment
pass-through portion was caulked with mortar. One end of
the piping material was exposed to a heating side by 300 mm
from the surface on the heating side of the flooring
material, and the other end of the piping material was
exposed to a non-heating side by 800 mm from the surface on
the non-heating side of the flooring material.
The furnace used in the fire-resistant test had a
structure that can heat one surface of a floor material and
can almost uniformly give a temporal change in temperature
based on the following Expression 1 complying with
regulation of ISO 834-1 to all over the entire test surface
of the floor material, when the surface on the heating side
of the floor material was the test surface.
That is, the fire-resistant test furnace was provided
with a thermocouple (hereinafter, referred to as "furnace
thermocouple") for measuring temperature in the furnace at a
position apart from the floor material by 100 to 300 mm such
that one to ten hot junctions were arranged uniformly with
respect to the test surface of the floor material.
Then, according to the regulation of ISO 834-1, the
fire-resistant test furnace was heated so that the temporal
change in temperature (hereinafter, referred to as "heating
temperature") measured by the thermocouple can be expressed
by a numerical value represented by the following Expression
1:
T = 3451ogio (8t+l)+20 a(Expression 1)
In Expression 1, T denotes an average temperature (°C) in
the furnace, and t denotes elapsed time (minute) in the
test, and the temperature was measured within every one
minute period.
[0051]
Regarding the pipe inner cross-sectional area SI at the
end on the heating side of the piping material before
burning, the piping material is measured for inner diameters
at least in two directions before starting of the fire-
resistance test to calculate the average inner diameter, and
then the pipe inner cross-sectional area SI is calculated.
Regarding the pipe inner cross-sectional area S2 at the
minimum inner diameter portion of the piping material after
burning, after starting of the fire-resistance test, when
smoke appears from the gap between the compartment pass-
through portion and the piping material on the non-heating
side, the burning in the fire-resistant test furnace is
terminated, and then the flooring material panel is
immediately removed from the fire-resistant furnace. After
cooling of the pipe, the caulked pipe is observed from the
heating side to determine the projected area S2 thereof.
The S2 may be measured by any method such as the followings:
a method by image analysis of a photograph taken from
the heating side, or
a method by sketching a projected portion on a paper,
cutting out the sketched portion and weighing the cut-out
paper, and determining the S2 by proportional calculation
based on the weight of the paper of which weight per unit
area is already known.
When no smoke was observed for 2 hours, the test is
terminated after 2 hours, and the S2 is measured by the
above-mentioned process.
[0052]
In the invention according to Claim 8 or 16, the value
obtained by the Expression of (S2/Sl)xl00 represents a pipe
inner cross-sectional area proportion (%) after burning. In
the invention according to Claim 8 or 16, the pipe inner
cross-sectional area proportion is 50% or less. This is
because that when the pipe inner cross-sectional area
proportion is larger than 50%, the pass-through portion in a
pipe after burning cannot be effectively caulked, which may
not give a desired fire-resistance performance.
[0053]
In the invention according to any of Claims 1 to 17,
additives, such as a flame retardant, a stabilizer, a
lubricant, a processing aid, an impact modifier, a heat-
resistance-improving agent, an antioxidant, a light
stabilizer, an ultraviolet absorber, a pigment, a
plasticizer, and a thermoplastic elastomer, may be added
within a range that does not impair the physical properties.
[0054]
As the flame retardant, any flame retardant that
increases flame retardancy during burning can be used
without particular limitation, and examples thereof include
hydroxides such as aluminum hydroxide and magnesium
hydroxide; hydrotalcite; antimony oxides such as antimony
dioxide, antimony trioxide, and antimony pentoxide;
molybdenum compounds such as molybdenum trioxide, molybdenum
disulfide, and ammonium molybdate; bromine-based compounds
such as tetrabromobisphenol A, tetrabromethane,
tetrabromethane, tetrabromethane, and tetrabromethane;
phosphorus-based compounds such as triphenyl phosphate and
ammonium polyphosphate; calcium borate; and zinc borate.
From the viewpoint of the effect of preventing burning of
polyvinyl chloride, antimony trioxide is particularly
preferred, because antimony compounds generate halogenated
antimony compounds in the presence of halogenated compounds
under high temperature conditions and prevent a burning
cycle with a very high effect, and the synergetic effect
thereof is significant.
[0055]
By using the flame retardant, the synergetic effect
between the heat-insulating effect by the expansion of heat-
expandable graphite and the flame-retarding effect by the
flame retardant can more efficiently improve the fire-
resistance performance during burning. The additive amount
of the flame retardant is not particularly limited, but is
preferably 1 part by weight or more and 20 parts by weight
or less based on 100 parts by weight of the polyvinyl
chloride-based resin. When the amount of the flame
retardant is less than 1 part by weight, sufficient
synergetic effect may not be obtained. When the amount of
the flame retardant is higher than 20 parts by weight, the
molding properties and the physical properties may be
significantly decreased.
[0056]
The stabilizer is not particularly limited, and
examples thereof include heat stabilizers and heat
stabilization aids. The heat stabilizers are not
particularly limited, and example thereof include organic
tin-based stabilizers such as dibutyltin mercapto,
dioctyltin mercapto, dimethyltin mercapto, dibutyltin
mercapto, dibutyltin maleate, dibutyltin maleate polymers,
dioctyltin maleate, dioctyltin maleate polymers, dibutyltin
laurate, and dibutyltin laurate polymers; lead-based
stabilizers such as lead stearate, dibasic lead phosphate,
and tribasic lead sulfate; calcium-zinc-based stabilizers;
barium-zinc-based stabilizers; and barium-cadmium-based
stabilizers. These may be used alone or in a combination of
two or more.
[0057]
The heat stabilization aids are not particularly
limited, and examples thereof include epoxidized soybean
oil, phosphate esters, polyols, hydrotalcite, and zeolite.
These may be used alone or in a combination of two or more.
[0058]
The lubricant includes an inner lubricant and an outer
lubricant.
The inner lubricant is used for reducing the fluid
viscosity of a melting resin during a molding process to
prevent friction heat generation. The inner lubricant is
not particularly limited, and examples thereof include butyl
stearate, lauryl alcohol, stearyl alcohol, epoxidized
soybean oil, glycerin monostearate, stearic acid, and
bisamides. These may be used alone or in a combination of
two or more.
The outer lubricant is used for accelerating sliding
effect between a melting resin and a metal surface during a
molding process. The outer lubricant is not particularly
limited, and examples thereof include paraffin wax,
polyolefin wax, ester wax, and montanoic acid wax. These
may be used alone or in a combination of two or more.
[0059]
The processing aid is not particularly limited, and
examples thereof include acryl-based processing aids such as
alkyl acrylate-alkyl methacrylate copolymers having a weight
average molecular weight of 100000 to 2000000. The acryl-
based processing aids are not particularly limited, and
examples thereof include n-butyl acrylate-methyl
methacrylate copolymers and 2-ethylhexyl acrylate-methyl
methacrylate-butyl methacrylate copolymers. These may be
used alone or in a combination of two or more.
[0060]
The impact modifier is not particularly limited, and
examples thereof include methyl methacrylate-butadiene-
styrene (MBS) copolymers, polyethylene chloride, and acrylic
rubber.
[0061]
The heat-resistance-improving agent is not particularly
limited, and examples thereof include a-methylstyrene-based
and N-phenylmaleimide-based resins.
[0062]
The antioxidant is not particularly limited, and
examples thereof include phenol-based antioxidants.
[0063]
The light stabilizer is not particularly limited, and
examples thereof include hindered amine light stabilizers.
[0064]
The ultraviolet absorber is not particularly limited,
and examples thereof include salicylic acid ester-based,
benzophenone-based, benzotriazole-based, and cyanoacrylate-
based ultraviolet absorbers.
[0065]
The pigment is not particularly limited, and examples
thereof include organic pigments such as azo-based,
phthalocyanine-based, surene-based, and dye lake-based
pigments; and inorganic pigments such as oxide-based,
molybdenum chromate-based, sulfide/selenide-based, and
ferrocyanide-based pigments.
[0066]
The polyvinyl chloride-based resin may contain a
plasticizer, but since the plasticizer may decrease the
heat-resistance and fire-resistance of a molded article, the
amount thereof is preferably small.
The plasticizer is not particularly limited, and
examples thereof include dibutyl phthalate, di-2-ethylhexyl
phthalate, and di-2-ethylhexyl adipate.
[0067]
The thermoplastic elastomer is not particularly
limited, and examples thereof include acrylnitrile-butadiene
(NBR) copolymers, ethylene-vinyl acetate (EVA) copolymers,
ethylene-vinyl acetate-carbon monoxide (EVACO) copolymers,
vinyl chloride-based thermoplastic elastomers such as vinyl
chloride-vinyl acetate copolymers and vinyl chloride-
vinylidene chloride copolymers, styrene-based thermoplastic
elastomers, olefin-based thermoplastic elastomers, urethane-
based thermoplastic elastomers, polyester-based
thermoplastic elastomers, and polyamide-based thermoplastic
elastomers. These thermoplastic elastomers may be used
alone or in a combination of two or more.
[0068]
The method for mixing the additives with the polyvinyl
chloride-based resin is not particularly limited, and
examples thereof include a method by hot-blending and a
method by cold blending.
[0069]
Examples of the fire-resistant piping material of the
present invention include fire-resistant pipes and fire-
resistant pipe joints. Furthermore, the fire-resistant
piping material of the present invention is molded with an
extruder or an injection molder that is usually used. The
type and the screw shape of the molder are not particularly
limited as long as sufficient kneading can be performed,
considering the tensile strength and the impact, and an
extruder allowing continuous molding is preferred.
[0070]
Since the single-layered fire-resistant piping material
of the invention according to Claim 1 is constituted of a
fire-resistant resin composition containing heat-expandable
graphite in an amount of 1 to 10 parts by weight based on
100 parts by weight of a polyvinyl chloride-based resin, the
molding properties thereof are excellent. For example, the
piping material can be continuously produced with high size
accuracy using an extruder, an injection molder, or the
like.
Furthermore, since the polyvinyl chloride-based resin
is self-extinguishing, the burning rate is effectively
reduced, and thereby the flame propagation velocity during
burning can be suppressed. In addition, since the resin
forms foam in the beginning of burning, an advantage that
the heat-expandable graphite readily expands is also
provided.
Furthermore, since heat-expandable graphite itself
hardly burns and thereby exhibits a heat-insulating effect
by being expanded by heat, the burning rate is further
effectively reduced.
Therefore, the single-layered fire-resistant piping
material of the present invention has excellent fire-
resistance and expansibility in itself and thereby can
prevent flame and smoke from penetrating to the other side
partitioned by the compartment pass-through portion by the
expansion of the piping material itself during burning and
the effect of reducing burning rate.
[0071]
The single-layered fire-resistant piping material of
the invention according to Claim 2 includes a fire-resistant
expandable layer made of a fire-resistant resin composition
containing heat-expandable graphite having a pH of 1.5 to
4.0 in an amount of 1 to 10 parts by weight based on 100
parts by weight of a polyvinyl chloride-based resin, and
thereby has the following excellent effects.
That is, since the single-layered fire-resistant piping
material of the invention contains heat-expandable graphite
having a PH of 1.5 to 4.0, during burning, not only the acid
disposed between layers of the heat-expandable graphite but
also the acid remaining on the surface of the heat-
expandable graphite are discharged. Therefore, the amount
of discharged acid is larger than that of the neutralized
heat-expandable graphite, and an elimination reaction of
hydrogen chloride from the polyvinyl chloride-based resin is
accelerated. Consequently, the polyvinyl chloride-based
resin during burning can be effectively carbonized. As a
result, during burning, the residue formed by the expanded
heat-expandable graphite and the carbide of the polyvinyl
chloride-based resin that strongly entwining with each other
can reliably caulk the end of the pipe on the heating side.
In addition, since the heat-expandable graphite has a
pH in the range of 1.5 to 4.0, there is no risk of damaging
a molding apparatus for molding the piping material.
[0072]
In the invention according to Claim 3, in the invention
according to Claim 2, since the fire-resistant resin
composition in Claim 2 contains an additive for providing
heat stability during molding, the elimination reaction of
hydrogen chloride from the polyvinyl chloride-based resin
during molding is suppressed to prevent the resin from being
deteriorated and carbonized during molding.
[0073]
In the invention according to Claim 4, in the invention
according to Claim 3, the additive for providing heat
stability during molding contains at least one selected from
the group consisting of lead-based stabilizers, organic tin-
based stabilizers, higher fatty acid metal salts, and basic
compounds in a total additive amount of 0.3 to 5.0 parts by
weight based on 100 parts by weight of the polyvinyl
chloride-based resin. Therefore, the deterioration and
carbonization of the resin during molding can be prevented
by suppressing the elimination reaction of hydrogen chloride
from the polyvinyl chloride-based resin during molding by
any of the following actions 1) to 4):
1) capture and neutralization of hydrogen chloride;
2) substitution with chlorine atoms;
3) capture and inactivation of radicals; and
4) isolation of conjugate double bond.
Furthermore, since the lead-based stabilizers, organic
tin-based stabilizers, and higher fatty acid metal salts are
further excellent in heat stability during molding, compared
to other additives that provide heat stability during
molding, the product yield is high, and also the long-
running continuous operation in extrusion molding is
excellent.
In addition, the lead-based stabilizers, the organic
tin-based stabilizers, and the higher fatty acid metal salts
provide high molding stability even if the amount thereof is
small. Therefore, since the additive amounts of these
additives, based on the amount of the polyvinyl chloride-
based resin, may be smaller than those of other additives
that provide heat stability during molding, the tensile
strength and fire-resistance of a pipe are hardly decreased.
[0074]
In the invention according to Claim 5, in the invention
according to Claim 4, a basic compound is further contained
as the additive for providing heat stability during molding
in a total additive amount of 0.3 to 5.0 parts by weight
based on 100 parts by weight of the polyvinyl chloride-based
resin. Therefore, the heat stability during molding and the
tensile strength and fire-resistance of a pipe can be
further reliably ensured.
[0075]
Since the single-layered fire-resistant piping material
of the invention according to Claim 6 is constituted of a
fire-resistant resin composition containing heat-expandable
graphite having an expansion volume in the range of 100 to
250 mL/g in an amount of 1 to 10 parts by weight based on
100 parts by weight of the polyvinyl chloride-based resin,
the heat-expandable graphite effectively expands during
burning, and the piping material is excellent in maintaining
the shape of the residue. Furthermore, the polyvinyl
chloride-based resin repeats de-hydrochloric acid to
accelerate carbonization of the polyvinyl chloride-based
resin. As a result, strong residue is formed, and excellent
effect of reducing the burning rate is obtained by the
synergetic effect with the heat-expandable graphite.
[0076]
Since the single-layered fire-resistant piping material
of the invention according to Claim 7 is constituted of a
fire-resistant resin composition containing heat-expandable
graphite having a 1.3-time expansion temperature of 180 to
240°C in an amount of 1 to 10 parts by weight based on 100
parts by weight of the polyvinyl chloride-based resin,
melting/thermal decomposition (foaming) of the polyvinyl
chloride-based resin do not progress even if the heat-
expandable graphite has reached the 1.3-time expansion
temperature, and the elongation viscosity of the polyvinyl
chloride-based resin is maintained. Therefore, the
polyvinyl chloride-based resin effectively extends according
to the expansion of the heat-expandable graphite to form a
fire-resistant expandable layer. Since the polyvinyl
chloride-based resin is subsequently carbonized, highly
excellent fire-resistance can be provided even if the amount
of the heat-expandable graphite is small.
[0077]
In the single-layered fire-resistant piping material of
the invention according to Claim 8, in the invention
according to any one of Claims 1 to 7, when the piping
material is constructed so as to pass through a flooring
material and.is subjected to a fire-resistant test
(complying with ISO 834-1) in which the underside of the
floor is heated under the conditions that one end of the
piping material is exposed to a heating side by 300 mm from
the surface on the heating side of the flooring material and
that the other end of the piping material is exposed to a
non-heating side by 800 mm from the surface on the non-
heating side of the flooring material, a pipe inner cross-
sectional area SI at the end of the piping material before
burning on the heating side and a pipe inner cross-sectional
area S2 at a minimum inner diameter of the piping material
after burning satisfy a relationship of (S2/Sl)xl00 Therefore, the pipe inner cross-sectional area during
burning becomes 50% or less of the pipe inner cross-
sectional area Si before the burning.
As a result, when the single-layered fire-resistant
piping material of the present invention is installed so as
to pass through the floor, even if the underside of the
floor is heated to 1000°C or more, the residue does not drop
from the underside of the floor so that a state that the
pipe is almost caulked continues for a long period of time.
That is, a reduction in the pipe inner cross-sectional area
during burning can prevent heat from ascending in the pipe
and suppress an increase in temperature of the piping
material on the non-heating side with respect to the floor.
Therefore, the piping material is inhibited from burning
out, and smoke generation on the non-heating side, due to a
gap with a mortar interface generated by softening of the
piping material, can be prevented, resulting in improvements
in flame shielding performance, heat shielding performance,
and smoke shielding performance.
[0078]
Thus, the single-layered fire-resistant piping material
of the invention according to any of Claims 1 to 8 has
excellent fire-resistance and expansibility in itself and
thereby can prevent flame and smoke from penetrating to the
other side partitioned by the compartment pass-through
portion by the expansion of the piping material itself
during burning and the reduction in burning rate.
Therefore, it is not necessary to dispose other fire-
resistant member, which is necessary in the conventional
way, around the piping material.
Furthermore, processes such as marking for confirming
positions are unnecessary in temporary pipe fitting during
construction, and the single-layered fire-resistant piping
material is simply inserted into the compartment pass-
through portion. Consequently, the work is considerably
reduced, and the workability in the construction site is
dramatically improved.
Furthermore, in the single-layered fire-resistant
piping material of the present invention, the pipe outer
diameter is smaller than that of a so-called fire-resistant
double-layered pipe in which fiber-reinforced mortar covers
the outer circumference of the pipe made of a vinyl chloride
resin. Therefore, when a plurality of through-holes is
provided, the distances among the through-holes can be
small, and also when the pipe is installed under the floor,
slope can be easily obtained. Thus, workability is
dramatically improved.
[0079]
The multilayered fire-resistant piping material of the
invention according to any of Claims 9 to 16 includes a
covering layer formed of a polyvinyl chloride-based resin
composition not containing heat-expandable graphite on at
least one of the outer surface and the inner surface of the
fire-resistant expandable layer. Therefore, in addition to
the effects of the invention according to any of Claims 1 to
8, the multilayered fire-resistant piping material is
further excellent in the molding properties and can be
continuously produced with high size accuracy by, for
example, injection molding or extrusion molding.
Furthermore, the fire-resistant expandable layer
contains a polyvinyl chloride-based resin as a main
component and thereby has sufficient mechanical strength and
chemical proof necessary as a piping material.
In addition, since the base resins of both the fire-
resistant expandable layer and the covering layer
constituting the piping material are polyvinyl chloride-
based resins, the affinity between the layers is high.
Therefore, the layers are tightly adhered to each other at
the interface, resulting in providing of excellent water
cutoff performance. Consequently, when the multilayered
fire-resistant piping materials of the present invention are
connected to each other with a pipe joint, the treatment of
the end of the piping material is unnecessary, resulting in
dramatic improvement in construction workability.
When the outer surface of the fire-resistant expandable
layer is covered with a covering layer formed of a polyvinyl
chloride-based resin composition not containing a heat-
expandable fire-resistant material, the outer circumference
surface of the piping material is excellent in adhesion and,
for example, can be easily and reliably connected to another
member such as a pipe joint.
When the inner surface of the fire-resistant expandable
layer is covered with a covering layer formed of polyvinyl
chloride-based resin composition not containing a heat-
expandable fire-resistant material, the inner circumference
surface of the piping material is smooth to allow fluid to
smoothly pass. In addition, since the inner circumference
surface of the piping material is excellent in chemical
proof, the piping material hardly limits the type of fluid,
which allows general purpose application.
[0080]
Since the multilayered fire-resistant piping material
of the invention according to Claim 17, in the invention
according to any one of Claims 9 to 16, includes the
covering layer on each of the outer surface and the inner
surface of the fire-resistant expandable layer, the outer
circumference surface of the piping material is excellent in
adhesion and, for example, can be easily and reliably
connected to another member such as a pipe joint, and also
the inner circumference surface of the piping material is
excellent in chemical proof, and thereby the piping material
hardly limits the type of fluid, which allows general
purpose application.
Brief Description of Drawings
[0081]
[Fig. 1] Fig. 1 is a cross-sectional view of a single-
layered fire-resistant piping material PI according to an
embodiment of the present invention.
[Fig. 2] Fig. 2 is a cross-sectional view of a
multilayered fire-resistant piping material P2 according to
an embodiment of the present invention.
[Fig. 3] Fig. 3 is a cross-sectional view of a
multilayered fire-resistant piping material P3 according to
an embodiment of the present invention.
[Fig. 4] Fig. 4 is a cross-sectional view of a
multilayered fire-resistant piping material P4 according to
an embodiment of the present invention.
[Fig. 5] Fig. 5 is an explanatory drawing simply
showing a structure of a fire-resistant test furnace X used
in a fire-resistant test.
[Fig. 6] Fig. 6 is an explanatory drawing showing a
pipe inner cross-sectional area SI of a piping material P,
before burning, of the invention according to Claim 8 or 16.
[Fig. 7] Fig. 7 is an explanatory drawing showing a
pipe inner cross-sectional area S2 of the piping material P,
after burning, of the invention according to Claim 8 or 16.
[Fig. 8] Fig. 8 is an explanatory drawing showing the
state that a conventional piping material P was thermally
expanded by heating and could not maintain the shape to drop
the residue.
[Fig. 9] Fig. 9 is an explanatory drawing schematically
showing the state of burning of a conventional piping
material P constructed so as to pass through a flooring
material.
[Fig. 10] Fig. 10 is an explanatory drawing
schematically showing the state of burning of a piping
material P according to the present invention constructed so
as to pass through a flooring material.
[Fig. 11] Fig. 11 is an explanatory drawing showing the
state of a piping material P according to the present
invention that holds the shape to maintain the fire
resistance after being thermally expanded by heating.
Best Modes for Carrying Out the Invention
[0082]
A single-layered fire-resistant piping material PI of a
first embodiment according to the present invention is
composed of a fire-resistant resin composition alone, as
shown in Fig. 1.
The present invention will be described in detail with
reference to examples below.
[0083]
In Examples 1 to 16 and Comparative Examples 1 to 5,
the following materials were used:
Vinyl chloride resin (manufactured by Taiyo Vinyl
Corp., trade name: "TH1000");
Heat-expandable graphite (manufactured by Tosoh Corp.,
trade name: "GREP-EG");
Calcium carbonate (manufactured by Shiraishi Calcium
Kaisha, Ltd., trade name: "Whiton SB");
Lead-based stabilizer (manufactured by Sakai Chemical
Industry Co., Ltd., trade name: "SL-1000"); and
Lubricant (manufactured by Mitsui Chemicals, Inc.,
trade name: "Hiwax 4202E").
[0084]
In Examples 17 to 41 and Comparative Examples 6 to 15,
the following materials were used:
Vinyl chloride resin (manufactured by Tokuyama Sekisui
Co., Ltd, trade name: "TS1000R");
Heat-expandable graphite (manufactured by Chuetsu
Graphite Works Co., Ltd., trade name: "SFF");
Lead-based stabilizer: lead stearate (manufactured by
Mizusawa Industrial Chemicals, Ltd., trade name:
"StabinexNC18");
Organic tin-based stabilizer: octyltin mercapto
(manufactured by Sankyo Organic Chemicals Co., Ltd., trade
name: "ONE-100F");
Higher fatty acid metal salt: Ca/Zn-based composite
stabilizer (manufactured by Sakai Chemical Industry Co.,
Ltd., trade name: "NWP-6000");
Basic compound: calcium carbonate (manufactured by
Shiraishi Calcium Kaisha, Ltd., trade name: "Whiton SB"),
magnesium hydroxide (manufactured by Kyowa Chemical Industry
Co., Ltd., trade name: "KISUMA5A");
Hydrotalcite (manufactured by Kyowa Chemical Industry
Co., Ltd., trade name: "DHT-4A");
Epoxidized soybean oil (manufactured by ADEKA Corp.,
trade name: "Adekacizer 0130P"); and
Lubricant (manufactured by Mitsui Chemicals Inc., trade
name: "Hiwax 4202E").
[0085]
The pH of the heat-expandable graphite was confirmed by
the following method:
1) A graphite mixture is prepared by adding 25 mL of
ion-exchange water to 5 g of a heat-expandable graphite
sample;
2) The resulting graphite mixture is stirred with a
glass rod for 30 seconds; and
3) After leaving the solution for 20 minutes, the pH of
the graphite mixture is measured with a pH meter
(manufactured by Horiba, Ltd., trade name: "pH/ION METER F-
23") .
[0086]
The pH of the heat-expandable graphite was adjusted by
the following method:
The heat-expandable graphite was put in a beaker, and
ion exchange water was added thereto, followed by stirring.
The acid remaining on the surface of the heat-expandable
graphite was removed by washing, while the pH of the
graphite mixture was confirmed with the pH meter. Then, the
graphite mixture was filtered, followed by drying in a
thermostatic chamber to give heat-expandable graphite having
a desired pH. When a desired pH was not obtained by washing
once, the washing and drying processes were repeated.
[0087]
In Examples 42 to 57 and Comparative Examples 16 to 18,
the following materials were used:
Vinyl chloride resin (manufactured by Tokuyama Sekisui
Co., Ltd., trade name: "TS1000R");
Heat-expandable graphite (expansion volume: 65 mL/g):
(manufactured by Sanyo Trading Co., Ltd., trade name:
"SYZR1003");
Heat-expandable graphite (expansion volume: 100 mL/g):
(grain size-controlled product);
Heat-expandable graphite (expansion volume: 150 mL/g):
(manufactured by Sanyo Trading Co., Ltd., trade name:
"SYZR1002");
Heat-expandable graphite (expansion volume: 180 mL/g):
(manufactured by Chuetsu Graphite Works Co., Ltd., trade
name: "SFF");
Heat-expandable graphite (expansion volume: 190 mL/g):
(manufactured by Sanyo Trading Co., Ltd., trade name:
"SYZR502");
Heat-expandable graphite (expansion volume: 200 mL/g):
(manufactured by Sanyo Trading Co., Ltd., trade name:
"SYZR802");
Heat-expandable graphite (expansion volume: 250 mL/g):
(grain size-controlled product);
Heat-expandable graphite (expansion volume: 275 mL/g):
(manufactured by Sanyo Trading Co., Ltd., trade name:
"SYZR322");
Calcium carbonate (manufactured by Shiraishi Calcium
Kaisha, Ltd., trade name: "Whiton SB");
Organic tin-based stabilizer (manufactured by Sankyo
Organic Chemicals Co., Ltd., trade name: "ONZ-142F");
Lubricant (manufactured by Mitsui Chemicals Inc., trade
name: "Hiwax 220MP"); and
Stearic acid (manufactured by Kao Corp., trade name:
"S-30").
[0088]
In Examples 58 to 70 and Comparative Examples 19 and
20, the following materials were used:
Vinyl chloride resin (manufactured by Tokuyama Sekisui
Co., Ltd., trade name: "TS1000R");
Heat-expandable graphite (manufactured by Chuetsu
Graphite Works Co., Ltd., trade name: "SFF", expansion
volume: 180 mL/g);
Calcium carbonate (manufactured by Shiraishi Calcium
Kaisha, Ltd.-, trade name: "Whiton SB");
Lead-based stabilizer (manufactured by Sakai Chemical
Industry Co., Ltd., trade name: "SL-1000"); and
Lubricant (manufactured by Mitsui Chemicals Inc., trade
name: "Hiwax 4202E").
[0089]
In Examples 71 to 75 and Comparative Examples 21 and
22, the following materials were used:
Vinyl chloride resin (manufactured by Taiyo Vinyl
Corp., trade name: "TH1000");
Heat-expandable graphite (1.3-time expansion
temperature-controlled product);
Lead-based stabilizer (manufactured by Sakai Chemical
Industry Co., Ltd., trade name: "SL-1000"); and
Lubricant (manufactured by Mitsui Chemicals Inc., trade
name: "Hiwax 4202E").
[0090]
Then, the above-mentioned materials were mixed at
ratios shown in Tables 1 to 14, and each mixture was stirred
and mixed in a Henschel mixer having a capacity of 200
liters (manufactured by Kawada Industries, Inc.) to give a
resin composition. The resulting resin composition was
extrusion molded with a generally used extruder to a test
piping material P to be used for fire-resistance evaluation.
The resin temperature during molding for those that are not
shown in the Tables was 180°C.
As shown in Fig. 1, the test piping material P was
formed so as to have a length of 1200 mm, an outer diameter
of 114 mm, a thickness of 6.6 mm, and a nominal diameter of
100 mm.
Furthermore, test pieces to be used for performance
evaluation and heat expansibility evaluation were produced
from the test piping material P by cutting out a part of the
pipe wall of the test piping material P, press-molding the
cut-out pipe wall with a load of 200 kgf at 190°C for 3
minutes to a press plate having a thickness of 3 mm, and
cutting the press plate into 1-cm square pieces.
[0091]
A multilayered fire-resistant piping material P2 of a
second embodiment according to the present invention is
constituted of a fire-resistant expandable layer 11 and an
inner side covering layer 12 covering the inner
circumference surface of the fire-resistant expandable layer
11, as shown in Fig. 2.
A multilayered fire-resistant piping material P3 of a
third embodiment according to the present invention is
constituted of a fire-resistant expandable layer 11, an
inner side covering layer 12 covering the inner
circumference surface of the fire-resistant expandable layer
11, and an outer side covering layer 13 covering the outer
circumference surface of the fire-resistant expandable layer
11, as shown in Fig. 3.
Furthermore, a multilayered fire-resistant piping
material P4 of a fourth embodiment according to the present
invention is constituted of a fire-resistant expandable
layer 11 and an outer side covering layer 13 covering the
outer circumference surface of the fire-resistant expandable
layer 11, as shown in Fig. 4.
The present invention will be described in detail with
reference to Examples below.
[0092]
In Examples 7 6 to 98 and Comparative Examples 23 to 32,
the following materials were used:
Vinyl chloride resin (manufactured by Taiyo Vinyl
Corp., trade name: "TH1000");
Heat-expandable graphite (manufactured by Tosoh Corp.,
trade name: "GREP-EG", 1.3-time expansion temperature:
210°C);
Lead-based stabilizer (manufactured by Sakai Chemical
Industry Co., Ltd., trade name: "SL-1000");
Lubricant (manufactured by Mitsui Chemicals, Inc.,
trade name: "Hiwax 4202E");
Calcium carbonate (Shiraishi Calcium Kaisha, Ltd.,
trade name: "Whiton SB"); and
Ammonium polyphosphate (Sumitomo Chemical Co., Ltd.,
trade name: "Sumisafe P").
[0093]
Examples 99 to 120 and Comparative Examples 33 to 35
Vinyl chloride resin (manufactured by Taiyo Vinyl
Corp., trade name: "TH1000");
Heat-expandable graphite (1.3-time expansion
temperature-controlled product);
Lead-based stabilizer (manufactured by Sakai Chemical
Industry Co., Ltd., trade name: "SL-1000");
Lubricant (manufactured by Mitsui Chemicals, Inc.,
trade name: "Hiwax 4202E"); and
Calcium carbonate (manufactured by Shiraishi Calcium
Kaisha, Ltd., trade name: "Whiton SB").
[0094]
Then, the resulting resin composition was extrusion
molded with a generally used extruder to a test piping
material P to be used for fire-resistance evaluation. The
resin temperature during molding for those that are not
shown in the Tables was 190°C.
The test piping material P was formed so as to have a
length of 1200 mm, an outer diameter of 114 mm, a thickness
of 6.6 mm, and a nominal diameter of 100 mm. The
thicknesses of the fire-resistant expandable layer 11, the
inner side covering layer 12, and the outer side covering
layer 13 were adjusted to those shown in Tables 15 to 20.
Furthermore, test pieces to be used for performance
evaluation and heat expansibility evaluation were produced
from the test piping material P by cutting out a part of the
pipe wall of the test piping material P, press-molding the
cut-out pipe wall with a load of 200 kgf at 190°C for 3
minutes to a press plate having a thickness of 3 mm, and
cutting the press plate into 1-cm square pieces.
[0095]
Fire-resistance evaluation
A fire-resistance test (an evaluation method of fire-
resistance performance test of the revised Building
Standards Act in force on June 1, 2000 (Heisei 12),
complying with ISO 834-1) was performed using the fire-
resistant test furnace X shown in Fig. 5.
As the floor material Y, a precast concrete plate
(length: 1200 mm, width: 600 mm, thickness: 100 mm) was
used. As the fireproof construction method, the gap between
the test piping material P and the compartment pass-through
portion R was caulked with mortar.
Furthermore, one end of the test piping material P was
exposed to the heating side by 300 mm from the surface on
the heating side of the flooring material Y, and the other
end of the test piping material P was exposed to the non-
heating side by 800 mm from the surface on the non-heating
side of the flooring material Y.
The inner side wall of the heating chamber Z of the
fire-resistant test furnace X was provided with burners V,
V. In addition, in the inside of the heating chamber Z, two
hot junctions of a furnace thermocouple Q were installed at
positions apart from the flooring material Y by 300 mm so as
to be evenly arranged with respect to the test surface of
the flooring material. Furthermore, the fire-resistant test
furnace X was equipped with an apparatus (not shown) for
measuring pressure in the furnace.
The period of time (smoke-generating time) after the
start of heating until the appearance of smoke from the gap
between the compartment pass-through portion R and the test
piping material P was measured. The appearance of smoke was
visually determined. A test piece of which smoke-generating
time was 130 minutes or more was determined as ®
(excellent), a test piece of 120 minutes or more was
determined as O (acceptance) , a test piece of 75 minutes or
more was determined as A; and a test piece of shorter than
75 minutes was determined as x (rejection).
The pipe inner cross-sectional area proportion was
determined as follows:
First, the fire-resistant test furnace X was heated so
that the temporal change in heating temperature could be
expressed by a numerical value represented by the
aforementioned Expression 1.
Then, the burning of the test piping material P was
visually observed through the observation window G, and when
smoke was observed from the gap between the compartment
pass-through portion R and the test piping material P, the
burning of the fire-resistant test furnace X was terminated.
Then, the degree of caulking of the inside of the test
piping material P after burning was calculated as the pipe
inner cross-sectional area proportion after burning by the
following calculation expression using a pipe inner cross-
sectional area SI at the end of the test piping material P,
before burning, on the heating side as shown in Fig. 6 and a
pipe inner cross-sectional area S2 at a minimum inner
diameter of the test piping material P after burning as
shown in Fig. 7.
Pipe inner cross-sectional area proportion after
burning = (S2/Sl)xl00.
Herein, the pipe inner cross-sectional area SI was
determined by measuring inner diameters of a piping material
in two directions (orthogonal to each other) before the
start of the fire-resistance test and calculating the
average inner diameter.
Regarding the pipe inner cross-sectional area S2 at a
minimum inner diameter of the piping material after burning,
when smoke appeared on the non-heating side from the gap
between the compartment pass-through portion and the piping
material after the starting of the fire-resistant test, the
burning of the fire-resistant test furnace was terminated,
and then the flooring material panel was immediately removed
from the fire-resistant furnace. After cooling the pipe,
the caulked pipe was observed from the heating side to
determine the projected area as the S2.
In the measurement of S2, the minimum inner diameter
portion in the pipe was sketched on a pape.r from a
photograph taken from the heating side, the sketched portion
was cut out and measured the weight thereof, and the S2 was
proportionally calculated on the basis of the weight and the
area of the paper that were already known.
Regarding the elongated length L of the residue, when
smoke appeared on the non-heating side from the gap between
the compartment pass-through portion and the piping material
after the start of the fire-resistant test, the burning of
the fire-resistant test furnace was terminated, and then the
flooring material panel was immediately removed from the
fire-resistant furnace. After cooling of the pipe, the
elongated length L orthogonal to the surface on the heating-
side of the flooring material was measured.
When no smoke was observed for 2 hours, the fire-
resistant test was terminated after 2 hours, and the pipe
inner cross-sectional area S2 and the elongated length L of
the residue were measured by the above-mentioned processes.
[0096]
Performance evaluation
The resulting test pieces were subjected to a tensile
test (evaluation temperature: 23°C) regulated in JIS K7113
for determining whether performance required as a pipe is
satisfied.
In order to determine whether practical performance
required as a pipe is satisfied, a test piece having a
tensile strength of 45 MPa or more at 23°C was determined as
® (excellent), a test piece of 30 MPa or more was determined
as O (acceptance), and a test piece of less than 30 MPa was
determined as x (rejection).
[0097]
Molding property evaluation
A sample that could be extrusion molded and had a
satisfactory pipe appearance in appearance visual
observation was determined as O (acceptance), and a sample
that could not be extrusion molded was determined as x
(rejection). A sample that had abnormality in pipe
appearance was determined as A-
[0098]
Apparatus corrosive evaluation
After conducted manufacturing for three hours, the
apparatus was left for three days. Then, the metal hopper
portion of the raw material feeding portion was visually
observed for investigating the degree of corrosion. When no
abnormality was observed, it was determined as O
(acceptance), and when red rust was observed, it was
determined as x (rejection).
[0099]
Extrusion molding stability evaluation
During continuous operation for three hours, the resin
composition discharged from the tip of an extruder was
visually confirmed. A case of no carbonization and no
burning (yellowing), it was determined as ® (excellent), a
case of no carbonization, it was determined as O
(acceptance), and a case of carbonization, it was determined
as x (rejection).
[0100]
Heat expansibility evaluation
The test pieces were subjected to a fire-resistant
test. The test was performed by, first, putting the test
pieces in an electric furnace heated to 500°C, leaving them
for 40 minutes, then taking out the test pieces from the
furnace and cooling them, and then measuring the thicknesses
of the test pieces.
When the thickness (thickness after expansion) of a
test piece after the fire-resistant test was 4 mm or more,
the test piece was accepted, and when the thickness was
smaller than 4 mm, the test piece was rejected.
[0101]
[0104]
Experimental results
As shown in Table 1, since heat-expandable graphite was
not used in Comparative Examples 1 and 3, the smoke-
generating time was short, and thereby the samples were
rejected in the fire-resistance evaluation. In Comparative
Example 2, since the blending ratio of heat-expandable
graphite was too large, the smoke-generating time was short,
and thereby the sample was rejected in the fire-resistance
evaluation.
Furthermore, as shown in Table 3, since heat-expandable
graphite was not used in Comparative Example 4, the smoke-
generating time was short, and thereby the sample was
rejected in the fire-resistance evaluation. In Comparative
Example 5, since the blending ratio of heat-expandable
graphite was too large, the smoke-generating time did not
reach 120 minutes.
Therefore, it was well confirmed that in order to
obtain a single-layered fire-resistant piping material that
satisfies all the fire-resistance evaluation, performance
evaluation, and molding property evaluation requirements,
heat-expandable graphite is required to be contained in the
range of 1 to 10 parts by weight based on 100 parts by
weight of the vinyl chloride resin.
Furthermore, samples in Examples 4 and 5 in Table 2
were further excellent than those in Examples 3 and 6 to 10
in fire-resistance and tensile strength. Therefore, it was
confirmed that when a single-layered fire-resistant piping
material contains heat-expandable graphite and also an
inorganic filler in the ranges of 1 to 10 parts by weight
and 2 to 5 parts by weight, respectively, based on 100 parts
by weight of the vinyl chloride resin, a pipe being further
well-balanced in any of the fire-resistance, tensile
strength, and molding properties can be obtained.
Incidentally, when the amount of the heat-expandable
graphite was larger than 10 parts by weight, the heated
composition was thermally expanded too much to maintain the
shape, resulting in dropping of the residue 2, as shown in
Fig. 8.
[0111]
Experimental results
As shown in Table 4, in Comparative Examples 6 and 7,
since the acidity of heat-expandable graphite was too
strong, corrosion was observed in the apparatus. In
Comparative Examples 8 and 9, the acidity of heat-expandable
graphite was too weak, and therefore the carbonization of
the vinyl chloride resin during burning was hardly
accelerated, resulting in that a smoke-generating time of
120 minutes was not achieved in the fire-resistance
evaluation.
It was confirmed from these results that in order to
exhibit excellent fire resistance without causing corrosion
of apparatus, the pH of heat-expandable graphite is required
to be in the range of 1.5 to 4.0.
As shown in Table 5, in Comparative Examples 10 and 11,
since the blending ratio of heat-expandable graphite was too
small, a smoke-generating time of 120 minutes was not
achieved in the fire-resistance evaluation. On the other
hand, in Comparative Examples 12 and 13, since the blending
ratio of heat-expandable graphite was too large, a smoke-
generating time of 120 minutes was not achieved in the fire-
resistance evaluation.
It was confirmed from these results that in order to
obtain excellent fire resistance while strength necessary as
a pipe is maintained, the heat-expandable graphite is
required to have a pH of 1.5 to 4.0 and is contained in an
amount of 1 to 10 parts by weight based on 100 parts by
weight of the vinyl chloride resin. Furthermore, when the
amount of the heat-expandable graphite was larger than 10
parts by weight, the heated composition was thermally
expanded too much to maintain the shape, resulting in
dropping of the residue 2, as shown in Fig. 8.
As shown in Table 6, in Example 31, since the additive
amount of the stabilizer is too large, the tensile strength
was lower than those in Examples 2 6 to 30.
As shown in Table 7, in Example 34, epoxidized soybean
oil was blended as an additive for providing heat stability
during molding. Epoxidized soybean oil does not have high
ability of providing heat stability during molding, but has
high effect of plasticization. As a result, the sample of
Example 34 was rejected in the extrusion molding stability
and was also slightly reduced in tensile strength and fire
resistance, compared to those in other Examples shown in
Table 7.
It was confirmed from these results that in order to
obtain a pipe that is excellent in tensile strength and fire
resistance and also excellent in molding stability, it is
preferred that at least one selected from the group
consisting of lead-based stabilizers, organic tin-based
stabilizers, and higher fatty acid metal salts be contained
as the additive for providing heat stability during molding
in a total additive amount of 0.3 to 5.0 parts by weight
based on 100 parts by weight of the polyvinyl chloride-based
resin.
As shown in Table 8, in Example 35, since calcium
carbonate serving as a basic compound was not contained, the
extrusion molding stability was slightly lower than those in
other Examples shown in Table 8. On the other hand, in
Example 39, the additive amount of calcium carbonate serving
as a basic compound was too large, and thereby the tensile
strength was slightly lower than those in other Examples
shown in Table 8.
As shown in Table 9, in Example 41, no stabilizer was
blended as the additive for providing heat stability during
molding, and only hydrotalcite was blended. Though
hydrotalcite has an ability of providing heat stability,
sufficient heat stability cannot be achieved by hydrotalcite
alone. Consequently, the sample was rejected in the
extrusion molding stability.
It was confirmed from these results that in order to
obtain a pipe that is excellent in tensile strength and fire
resistance and also excellent in molding stability, it is
further preferred that each of a stabilizer as the additive
for providing heat stability during molding and a basic
compound be contained in an amount of 0.3 to 5.0 parts by
weight based on 100 parts by weight of the vinyl chloride
resin.
[0116]
Experimental results
As shown in Tables 11 and 13, in Comparative Examples
16 and 19, since heat-expandable graphite was not blended at
all, the.piping material burned out. As a result, the
increase in temperature of the piping material was rapid on
the heating- side, and thereby the smoke-generating time was
short.
In Comparative Examples 17 and 20, since the blended
amount of the heat-expandable graphite was too large, the
piping material could not maintain the shape thereof after
expansion, and dropped. As a result, the temperature of the
piping material was rapidly increased on the heating side,
and thereby the smoke-generating time was short.
Furthermore, when the amount of the heat-expandable
graphite was larger than 10 parts by weight, the heated
composition was thermally expanded too much to maintain the
shape, resulted in dropping of the residue, as shown in Fig.
8.
Therefore, it was well confirmed that in order to
obtain a single-layered fire-resistant piping material that
satisfies all the heat expansibility evaluation, performance
evaluation, and fire-resistance evaluation requirements, the
heat-expandable graphite is required to have an expansion
volume of 100 to 250 mL/g and to be contained in the range

of 1 to 10 parts by weight based on 100 parts by weight of
the vinyl chloride resin.
Furthermore, in Examples 42 to 70, not only the tensile
strength necessary as a pipe was achieved, but also the
smoke-generating time was drastically elongated, compared to
those in Comparative Examples. This may be caused by that
in Examples 42 to 70, the pipe inner cross-section was
caulked with the residue to inhibit an increase in
temperature of the pipe.
Furthermore, in Examples 59 and 60, not only the pipe
inner cross-sectional area proportion but also the elongated
length L of the residue H was excellent, compared to those
in Examples 58 and 61. In Examples 63 and 64, not only the
pipe inner cross-sectional area proportion but also the
elongated length L of the residue H was excellent, compared
to those in Examples 62 and 65. In addition, in Examples 67
to 69, not only the pipe inner cross-sectional area
proportion but also the elongated length L of the residue H
was excellent, compared to those in Examples 66 and 70. As
a result, in these Examples, the smoke-generating time was
further improved compared to other Examples.
[0117]
Incidentally, when a synthetic resin piping material
constructed so as to pass through a floor material is heated
from the underside of the floor, first, the portion of the
piping material protruding below the floor is directly
heated to start softening and burning. Then, a difference
in hardness occurs between the portion lying inside the
composition and the burning portion of the floor piping
material, causing sharp softening. Then, the portion of the
piping material protruding below the f.loor falls apart from
the floor and drops (falls away) about 5 to 20 minutes after
the start of the burning. The bottom surface of the
remaining piping material is in nearly the same plane as the
bottom surface of the floor. When the heat is further
applied, the phenomena vary depending on the blending
composition of the piping material.
Specifically, in the piping material composed of the
composition shown in Comparative Example 19, as shown in
Fig. 9, after the portion protruding below the floor
dropped, the resin run down to once caulk the end on the
heating side. However, since no heat-expandable graphite
was blended, fire resistance was not obtained, and the end
of the piping material on the heating side dropped after
all. As a result, hot air flowed in the inside of the pass-
through portion of the piping material, and the potion
inside the floor structure burned out to generate smoke on
the non-heating side.
Since the piping material composed of the composition
shown in Comparative Example 20 contained a large amount of

heat-expandable graphite, the heated composition was
expanded too much to maintain the shape, resulting in
dropping.
[0118]
On the other hand, in the piping materials composed of
compositions shown in Examples 66 to 70, as shown in Fig.
10, after the portion protruding below the floor dropped,
the remaining portion was softened from the lower part by
being heated, and the inner diameter slightly shrank in the
direction in which the pipe contracts. Then, the heat-
expandable graphite started expanding by heating. The
expansion continued in the central direction of the pipe
cross-section till that the pipe inner cross-sectional area
after burning became 50% or less of the pipe inner cross-
sectional area before the burning. The residue after the
expansion was thought that the main component thereof was a
graphite crystal, which gives a very strong, flame-retardant
residue H extending from the underside of the floor to the
heating side and can prevent itself from dropping and
burning. As a result, even though the underside of the
floor was heated to 1000°C or higher, the residue H did not
drop from the underside of the floor, and a state of almost
caulking the pipe continued for a long period of time. In
addition, since the pipe inner cross-sectional area was
reduced during burning and also the residue extended to the
heating side, hot air was prevented from ascending inside
the pipe and an increase in temperature of the piping
material on the non-heating side with respect to the floor
surface could be suppressed. As a result, the piping
material was prevented from burning out, and also smoke
generation on the non-heating side, which is caused.by
softening of the piping material to form a gap with the
mortar interface, was prevented.
[0119]
Therefore, it was confirmed that in order to obtain a
single-layered fire-resistant piping material that satisfies
all the strength as a pipe, stability during molding, and
caulking of the end on the heating side of the pipe during
heating, it is necessary that heat-expandable graphite
having an expansion volume in the range of 100 to 250 mL/g
is contained in an amount of 1 to 10 parts by weight based
on 100 parts by weight of the vinyl chloride resin.
Furthermore, it was confirmed that further preferred
blending ratios are, based on 100 parts by weight of the
vinyl chloride resin, 4 to 7 parts by weight of the heat-
expandable graphite having an expansion volume in the range
of 100 to 250 mL/g, 1 to 5 parts by weight of calcium
carbonate serving as the inorganic filler, and 0.3 to 5
parts by weight of the stabilizer.
[0121]
Experimental results
It was confirmed that in order to provide strength
necessary as a pipe and to exhibit excellent fire
resistance, it is necessary that the heat-expandable
graphite having a 1.3-time expansion temperature T3 of 180
to 240°C is contained in an amount of 1 to 10 parts by
weight based on 100 parts by weight of the vinyl chloride
resin.
When the amount of the heat-expandable graphite was
larger than 10 parts by weight, the heated composition was
thermally expanded too much to maintain the shape, resulting
in dropping of the residue 2, as shown in Fig. 8.
[0127]
Experimental results
As shown in Tables 15 to 19, in Comparative Examples 23
to 28 and 30, the smoke-generating time was short, and the
samples were rejected in the fire-resistance evaluation. In
addition, in Comparative Example 29, the tensile strength
was slightly low. Therefore, in order to obtain a
multilayered fire-resistant piping material that satisfies
both the fire-resistance evaluation and performance
evaluation requirements, it is necessary, as shown in
Examples 76 to 90, that the material include a tubular fire-
resistant expandable layer composed of a heat-expandable
fire-resistant resin composition and a covering layer
covering at least one of the outer surface and the inner
surface of the fire-resistant expandable layer, the fire-
resistant expandable layer is formed of a fire-resistant
resin composition containing heat-expandable graphite in an
amount of 1 to 15 parts by weight based on 100 parts by
weight of the vinyl chloride resin, and the covering layer
is formed of a vinyl chloride resin composition not
containing heat-expandable fire-resistant materials.
When the amount of the heat-expandable graphite was
larger than 15 parts by weight, the heated test piping
material P was thermally expanded too much to maintain the
shape, resulting in dropping of the residue, as shown in
Fig. 8.
[0129]
Experimental results
As shown in Table 20, in Comparative Example 31, the
smoke-generating time was very short, compared to those in
Examples 99 to 101, and the sample was rejected in the fire-
resistance evaluation.
In Examples 102 and 106, the smoke-generating time was
slightly short, and the samples were slightly inferior in
the fire-resistance evaluation, compared to those in
Examples 100, 103, 104, and 105.
Therefore, it was confirmed that in order to satisfy
both the fire-resistance evaluation and performance
evaluation requirements, it is preferable that the fire-
resistant expandable layer 11 is formed of a fire-resistant
resin composition containing heat-expandable graphite having
a 1.3-time expansion temperature in the range of 180 to
240°C in an amount of 5 to 15 parts by weight based on 100
parts by weight of the polyvinyl chloride-based resin.
[0131]
Experimental results
As shown in Table 21, in Example 112, since the
thicknesses of the inner side covering layer 12 and the
outer side covering layer 13 were each extremely thin, 0.1
mm, the tensile strength was slightly inferior, compared to ,
those in other Examples. On the other hand, in Example 113,
since the thicknesses of the inner side covering layer 12
and the outer side covering layer 13 were each extremely
thick, 2.2 mm, the fire resistance was slightly inferior,
compared to those in other Examples.
Therefore, it was confirmed that it is preferable that
the thicknesses of the inner side covering layer 12 and the
outer side covering layer 13 each be in the range of 0.2 to
2.0 mm.
[0133]
Experimental results
As shown in Table 22, in Comparative Example 32, since
the resin temperature during molding was too low, the
tensile strength was slightly inferior. Furthermore, in
Comparative Example 33, since the resin temperature during
molding was too high, the tensile strength was slightly
inferior. Therefore, it is preferable that the resin
temperature during molding of the resin composition be 170
to 210°C.
[0135]
Experimental results
As shown in Table 23, in Comparative Example 23, since
the 1.3-time expansion temperature of the heat-expandable
graphite was lower than the resin temperature during molding
by 10°C, the tensile strength was lower than those in
Examples 117 to 120. Furthermore, in Example 120, since the
1.3-time expansion temperature of the heat-expandable
graphite was higher than 240°C, the smoke-generating time
was slightly short, and the tensile strength was slightly
inferior, compared to those in Examples 117 to 119.
Therefore, it was confirmed that it is preferable that
the resin temperature during molding be lower than the 1.3-
time expansion temperature of heat-expandable graphite by
5°C and be in 170 to 210°C.
[0136]
Conclusion
As described in detail with reference to Examples in
the above, in the single-layered fire-resistant piping
material and the multilayered fire-resistant piping material
according to the present invention, each layer constituted
of a fire-resistant resin composition effectively expands
during burning, and, as shown in Fig. 11, the residue caulks
the gap between the piping material and the compartment
pass-through portion and the inside of the piping material
to prevent flame and smoke from penetrating to the other
side partitioned by the floor material. The piping
materials are thus excellent in fire resistance and also
excellent in molding properties and have mechanical strength
sufficient as pipes.
Furthermore, unlike a piping structure in which only
the compartment pass-through portion is subjected to fire-
resistant treatment with a conventional fire-resistant
expandable sheet-like covering material, the present
invention can impart fire resistance to the entire piping.
In the present fire-resistance evaluation, the fire
resistance was compared by an alternative evaluation
technique in which heating is conducted under a condition
that one end of a piping material protrudes in a fire-
resistant furnace by 300 mm. In the case of a fire under a
condition that the piping material of the present invention
is practically constructed in a building so as to pass
through each slab of every floor or each partition wall of
every floor, the difference in fire resistance may be
further distinguished.
That is, the piping material of the present invention
rapidly and reliably caulks the compartment pass-through
portion during burning, and also the entire pipe can undergo
burning for a long period of time. Even if the piping
material partially dropped during burning, it is suggested
that the opening portion of the piping material is quickly-
caulked to maintain the shape, and thereby flame and smoke
hardly penetrate to the outside of the burning chamber,
resulting in prevention of the fire from spreading.
Furthermore, in the multilayered fire-resistant piping
material having an inner side covering layer, the inner
circumference surface of the piping material is smooth and
thereby can allow fluid to smoothly pass, and also the inner
circumference surface of the piping material is excellent in
chemical proof and thereby hardly limits the type of fluid,
which allows general purpose application.
In addition, in the multilayered fire-resistant piping
material having an outer side covering layer, the outer
circumference surface of the piping material is excellent in
adhesion and, for example, can be easily and reliably
connected to another member such as a pipe joint.
[0137]
Furthermore, the multilayered fire-resistant piping
material of the present invention is not limited to the
above-described Examples. For example, in the Examples, the
piping materials have a nominal diameter of 100 mm, but may
have a nominal diameter different therefrom.
CLAIMS
1. A single-layered fire-resistant piping material,
comprising a fire-resistant resin composition containing
heat-expandable graphite in an amount of 1 to 10 parts by
weight based on 100 parts by weight of a polyvinyl chloride-
based resin.
2. A single-layered fire-resistant piping material,
comprising a fire-resistant resin composition containing
heat-expandable graphite having a pH of 1.5 to 4.0 in an
amount of 1 to 10 parts by weight based on 100 parts by
weight of a polyvinyl chloride-based resin.
3. The single-layered fire-resistant piping material
according to Claim 2, wherein the fire-resistant resin
composition in Claim 2 contains an additive for providing
heat stability during molding.
4. The single-layered fire-resistant piping material
according to Claim 3, wherein at least one selected from the
group consisting of lead-based stabilizers, organic tin-
based stabilizers, and higher fatty acid metal salts is
contained as the additive for providing heat stability
during molding in a total additive amount of 0.3 to 5.0
parts by weight based on 100 parts by weight of the
polyvinyl chloride-based resin.
5. The single-layered fire-resistant piping material
according to Claim 4, wherein a basic compound is further
contained as the additive for providing heat stability
during molding in a total additive amount of 0.3 to 5.0
parts by weight based on 100 parts by weight of the
polyvinyl chloride-based resin.
6. A single-layered fire-resistant piping material,
comprising a fire-resistant resin composition containing
heat-expandable graphite having an expansion volume in the
range of 100 to 250 mL/g in an amount of 1 to 10 parts by
weight based on 100 parts by weight of a polyvinyl chloride-
based resin.
7. A single-layered fire-resistant piping material,
comprising a fire-resistant resin composition containing
heat-expandable graphite having a 1.3-time expansion
temperature of 180 to 240°C in an amount of 1 to 10 parts by
weight based on 100 parts by weight of a polyvinyl chloride-
based resin.
8. The single-layered fire-resistant piping material
according to any one of Claims 1 to 7, wherein
when the piping material is constructed so as to pass
through a flooring material and is subjected to a fire-
resistant test (complying with ISO 834-1) in which the
underside of the floor is heated under conditions that one
end of the piping material is exposed to a heating side by
300 mm from the surface on the heating side of the flooring
material and that the other end of the piping material is
exposed to a non-heating side by 800 mm from the surface on
the non-heating side of the flooring material,
a pipe inner cross-sectional area SI at the end of the
piping material before burning on the heating side and a
«
pipe inner cross-sectional area S2 at a minimum inner
diameter of the piping material after burning satisfy a
relationship:
(S2/Sl)xl00 9. A multilayered fire-resistant piping material,
comprising a tubular fire-resistant expandable layer made of
a heat-expandable fire-resistant resin composition and a
covering layer covering at least one of the outer surface
and the inner surface of the fire-resistant expandable
layer, wherein
the fire-resistant expandable layer is formed of a
fire-resistant resin composition containing heat-expandable
graphite in an amount of 1 to 15 parts by weight based on
100 parts by weight of a polyvinyl chloride-based resin, and
the covering layer is formed of a polyvinyl chloride-based
resin composition not containing heat-expandable fire-
resistant materials.
10. A multilayered fire-resistant piping material,
comprising a tubular fire-resistant expandable layer made of
a heat-expandable fire-resistant resin composition and a
covering layer covering at least one of the outer surface
and the inner surface of the fire-resistant expandable
layer, wherein
the fire-resistant expandable layer is formed of a
fire-resistant resin composition containing heat-expandable
graphite having a pH of 1.5 to 4.0 in an amount of 1 to 15
parts by weight based on 100 parts by weight of a polyvinyl
chloride-based resin; and the covering layer is formed of a
polyvinyl chloride-based resin composition not containing
heat-expandable fire-resistant materials.
11. The multilayered fire-resistant piping material
according to Claim 10, wherein the fire-resistant resin
composition contains an additive for providing heat
stability during molding.
12. The multilayered fire-resistant piping material
according to Claim 11, wherein at least one selected from
the group consisting of lead-based stabilizers, organic tin-
based stabilizers, and higher fatty acid metal salts is
contained as the additive for providing heat stability
during molding in a total additive amount of 0.3 to 5.0
parts by weight based on 100 parts by weight of the
polyvinyl chloride-based resin.
13. The multilayered fire-resistant piping material
according to Claim 12, wherein a basic compound is further
contained as the additive for providing heat stability
during molding in a total additive amount of 0.3 to 5.0
parts by weight based on 100 parts by weight of the
polyvinyl chloride-based resin.
14. A multilayered fire-resistant piping material,
comprising a tubular fire-resistant expandable layer made of
a heat-expandable fire-resistant resin composition and a
covering layer covering at least one of the outer surface
and the inner surface of the fire-resistant expandable
layer, wherein
the fire-resistant expandable layer is constituted of a
fire-resistant resin composition containing heat-expandable
graphite having an expansion volume in the range of 100 to
250 mL/g in an amount of 1 to 15 parts by weight based on
100 parts by weight of a polyvinyl chloride-based resin; and
the covering layer is constituted of a polyvinyl chloride-
based resin composition not containing heat-expandable fire-
resistant materials; and the covering layer is constituted
of a polyvinyl chloride-based resin composition not
containing heat-expandable fire-resistant materials.
15. A multilayered fire-resistant piping material,
comprising a tubular fire-resistant expandable layer made of
a heat-expandable fire-resistant resin composition and a
covering layer covering at least one of the outer surface
and the inner surface of the fire-resistant expandable
layer, wherein
the fire-resistant expandable layer is constituted of a
fire-resistant resin composition containing heat-expandable
graphite having a 1.3-time expansion temperature of 180 to
240°C in an amount of 1 to 15 parts by weight based on 100
parts by weight of a polyvinyl chloride-based resin; and the
covering layer is constituted of a polyvinyl chloride-based
resin composition not containing heat-expandable fire-
resistant materials.
16. The multilayered fire-resistant piping material
according to any one of Claims 9 to 15, wherein
when the piping material is constructed so as to pass
through a flooring material and is subjected to a fire-
resistant test (complying with ISO 834-1) in which the
underside of the floor is heated under conditions that one
end of the piping material is exposed to a heating side by
300 mm from the surface on the heating side of the flooring
material and that the other end of the piping material is
exposed to a non-heating side by 800 mm from the surface on
the non-heating side of the flooring material,
a pipe inner cross-sectional area SI at the end of the
piping material before burning on the heating side and a
pipe inner cross-sectional area S2 at a minimum inner
diameter of the piping material after burning satisfy a
relationship:
(S2/Sl)xl00 17. The multilayered fire-resistant piping material
according to any one of Claims 9 to 16, wherein the covering
layer is provided on each of the outer surface and the inner
surface of the fire-resistant expandable layer.

It is an object to provide a fire-resistant piping
material that can be fire-protection measures by itself and
is excellent in construction workability. A single-layered
fire-resistant piping material according to the present
invention is constituted of a fire-resistant resin
composition containing heat-expandable graphite in an amount
of 1 to 10 parts by weight based on 100 parts by weight of a
polyvinyl chloride-based resin. A multilayered fire-
resistant piping material according to the present invention
includes a tubular fire-resistant expandable layer made of a
heat-expandable fire-resistant resin composition and a
covering layer covering at least one of the outer surface
and the inner surface of the fire-resistant expandable
layer, and the fire-resistant expandable layer is formed of
a fire-resistant resin composition containing heat-
expandable graphite in an amount of 1 to 15 parts by weight
based on 100 parts by weight of a polyvinyl chloride-based
resin, and the covering layer is formed of a polyvinyl
chloride-based resin composition not containing heat-
expandable fire-resistant materials.

Documents:

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Patent Number 272391
Indian Patent Application Number 369/KOLNP/2010
PG Journal Number 14/2016
Publication Date 01-Apr-2016
Grant Date 31-Mar-2016
Date of Filing 29-Jan-2010
Name of Patentee SEKISUI CHEMICAL CO., LTD.
Applicant Address 4-4, NISHITEMMA 2-CHOME, KITA-KUOSAKA-SHI, OSAKA 5308565 JAPAN
Inventors:
# Inventor's Name Inventor's Address
1 KIMURA, HIDEHARU C/O SEKISUI CHEMICAL CO., LTD., 2-2, KAMICHOSHI-CHO, KAMITOBA, MINAMI-KU, KYOTO-SHI, KYOTO 6018105 JAPAN
2 SANNI, TOSHIFUMI C/O SEKISUI CHEMICAL CO., LTD., 4560 KAISEI-CHO, SYUNAN-SHI, YAMAGUCHI 7460006 JAPAN
3 OKABE, MASASHI C/O SEKISUI CHEMICAL CO., LTD., 2-3-17, TORANOMON, MINATO-KU, TOKYO 1050001 JAPAN
4 ICHIHARA, KOJI C/O SEKISUI CHEMICAL CO., LTD., 2-2, KAMICHOSHI-CHO, KAMITOBA, MINAMI-KU, KYOTO-SHI, KYOTO 6018105 JAPAN
PCT International Classification Number C08L 27/06,C08J 5/00
PCT International Application Number PCT/JP2007/066765
PCT International Filing date 2007-08-29
PCT Conventions:
# PCT Application Number Date of Convention Priority Country
1 NA