Title of Invention

THERMOPLASTIC POLYOLEFINS WITH HIGH FLOWABILITY AND EXCELLENT SURFACE QUALITY PRODUCED BY A MULTISTAGE PROCESS

Abstract Reactor grade thermoplastic polyolefins with high flowability and excellent surface quality comprising (A) 40 - 90 wt% of a propylene homo- or copolymer matrix with an MFR in accordance with ISO 1 133 (230°C, 2.16 kg load) of ≥ 200 g/10 min and (B) 2-30 wt% of an elastomeric ethylene-propylene copolymer having an intrinsic viscosity IV (according to ISO 1628 with decalin as solvent) of ≤ 2.8 dl/g and an ethylene content of > 50 to 80 wt% and (C) 8 - 30 wt% of an elastomeric ethylene- propylene copolymer having an intrinsic viscosity IV (according to ISO 1628 with decalin as solvent) of 3.0 - 6.5 dl/g and an propylene content of 50 to 80 wt%, the reactor grade thermoplastic polyolefins being obtainable by a multistage polymerization process with at least 3 polymerization steps in the presence of a catalyst system comprising (i) a Ziegler-Natta procatalyst which contains a trans-esterification product of a lower alcohol and a phthalic ester and (ii) an organometallic cocatalyst and (iii) external donor represented by formula (I) Si(OCH2CH3)3(NR1R2) wherein R1 and R2 can be the same or different a represent a hydrocarbon group having 1 to 12 carbon atoms, as well as the use of these reactor grade thermoplastic polyolefins and molded articles produced from them.
Full Text This invention is in the field of thermoplastic polyolefins and more specifically reactor grade
thermoplastic polyolefins (RTPO).
The invention is further directed to RTPOs having high flowability and excellent surface
quality, when molded into articles of manufacture, especially for automotive applications, a
process for producing them and their use.
Furthermore the invention is related to the use of a special Ziegler-Natta procatalyst, which
contains a trans-esterification product of a lower alcohol and a phthalic ester in combination
with a special external donor for the production of RTPOs with high flowability and excellent
surface quality.
State of the art
Thermoplastic polyolefins (TPOs), which typically comprise polypropylene and an elastomer,
have many desirable properties, e.g. lightweight, durability, low costs, etc., that make them
an attractive material for the construction of many interior and exterior automotive parts.
There are two types of TPOs which essentially differ in their method of preparation. The first,
which is commonly referred to as "compound grade TPO", is made by physically blending
polypropylene with elastomer. The second, which is commonly referred to as "reactor grade
TPO" (RTPO) and is more economical to produce than compound grade TPO, is made by
first polymerizing propylene to polypropylene and then polymerizing elastomer components,
such as ethylene and propylene, in the presence of the polypropylene.
The RTPOs are known to be suitable for injection molding to produce large, shaped articles,
for example for automotive applications, especially bumpers.
Unfortunately the problem of optical irregularity arises during injection molding of such large
articles due to the necessary long flow paths of the resin.
Such surface defects, which are also known as "Tigerstripes" or flow marks, are a common
problem for surface quality respectively appearance in plastic industry. Tigerstripes, as
known in the plastic industry, describe a visible periodic inhomogeneity in surface gloss.
Mostly these are alternating dull (or rough) and glossy (or smooth) areas on the surface of
injection molded or extruded plastic parts, which surface should be glossy (or smooth) all
over.
Many attempts to avoid these surface defects, while keeping a good balance of other
physical properties have been made in the past.
It has however been found, that either the occurrence of flow marks could not be entirely
prevented, or the physical properties of the polymer compositions were unsatisfactory.
Furthermore it is desired that the RTPOs exhibit as high values of melt flow rate (MFR) as
possible in order to improve processability of the RTPOs for injection molding.
For example WO 2004/000899 describes reactor grade thermoplastic polyolefins on the
basis of a polypropylene matrix material including bimodal rubber compositions, whereby the
two rubber parts have differentiated Mw (respectively intrinsic viscosity IV) and the low IV
rubber is ethylene rich.
These RTPOs are produced in a multistage process comprising at least one slurry reactor
and two gas phase reactors. A particularly preferred catalyst system is, according to WO
2004/000899, a high yield Ziegler-Natta catalyst having a catalyst component, a cocatalyst
and optionally an external donor, or a metallocene catalyst, having a bridged structure giving
high stereoregularity and which, as an active complex, is impregnated on a carrier. No further
details regarding the used catalyst and external donor are given.
The RTPOs produced according to WO 2004/000899 show improved surface toughness in
terms of scratch resistance and can be used for producing car interiors and exteriors, like
bumpers, dashboards and the like, where improved scratch resistance properties are
needed.
According to the Examples the RTPOs exhibit an MFR of at most 13.2 g/10 min.
From experience it is known that RTPOs, produced according to WO 2004/000899 show flow
marks.
EP 1 600 480 describes an improved propylene polymer composition on the basis of a
polypropylene matrix material with an MFR in accordance with ISO 1133 (230°C, 2.16kg)
> 80 g/10 min, including bimodal rubber compositions, whereby the two rubber parts have
differentiated Mw (IV) and the low IV rubber is ethylene rich.
The RTPO is mixed with an elastomeric ethylene-1-octene copolymer, having an ethylene
content of at least 80 mol% and having a MFR in accordance with ISO 1133 (190°C, 2.16 kg)
of 3 - 100 g/10 min, and with an inorganic filler. These RTPOs are, according to EP 1 600
480, suitable for automotive applications because they have excellent impact
strength/stiffness balance, high flowability and are not susceptible to the occurrence of flow
marks.
The RTPO is produced in a multistage process using a Ziegler-Natta catalyst or a
metallocene. According to the examples ZN104 (commercially available from
LyondellBaseli), triethylaluminium as cocatalyst and dicyclopentyldimethoxysilane as external
donor are used.
According to the Examples of EP 1 600 480 MFR-values of at most 100 g/10 min for the
propylene matrix and of at most 17.6 g/10 min of the final RTPO can be achieved by using
this combination of catalyst, cocatalyst and external donor.
It is known by the art skilled man that the highest achievable MFR of the matrix of the base
resin used according to EP 1 600 480 hardly exceeds 120 due to the high amounts of fines
produced and high hydrogen response generated for these flowability conditions.
Accordingly, although much development work has been done in the field of RTPOs, there
remains a continuing search for alternative or improved RTPOs with desirable properties,
such as excellent surface quality, good impact strength/stiffness balance and high flowability
e.t.c.
It was therefore an object of the invention to provide a propylene polymer composition, which
can be injection molded into large shaped articles, which articles show no flow marks and
which composition simultaneously shows a good impact strength/stiffness balance and high
flowability.
This object was achieved by using a special Ziegler-Natta procatalyst which contains a trans-
esterification product of a lower alcohol and a phthalic ester in combination with a special
external donor. Surprisingly this special Ziegler-Natta procatalyst in combination with a
special external donor can be used for the production of a great variety of RTPOs with high
flowability and excellent quality, like RTPOs on the basis of a polypropylene matrix including
cross-bimodal rubber compositions, nucleated or non-nucleated RTPOs, with different multi-
stage processes, like Borstar® from Borealis or Spheripol® from LyondellBaseli.
Thus in a first aspect, the present invention is therefore directed to reactor grade
thermoplastic polyolefins with high flowability and excellent surface quality comprising
(A) 40 - 90 wt% of a propylene homo- or copolymer matrix with an MFR in accordance with
ISO 1133 (230°C, 2.16 kg load) of > 200 g/10 min and
(B) 2-30 wt% of an elastomeric ethylene-propylene copolymer having an intrinsic viscosity
IV (ISO 1628, with decalin as solvent) of 50 to 80
wt% and
(C) 8-30 wt% of an elastomeric ethylene-propylene copolymer having an intrinsic viscosity
IV (ISO 1628, with decalin as solvent) of 3.0-6.5 dl/g and a propylene content of 50 to 80
wt%,
the reactor grade thermoplastic polyolefins being obtainable by a multistage polymerization
process with at least 3 polymerization steps in the presence of a catalyst system comprising
(i) a Ziegler-Natta procatalyst which contains a trans-esterification product of a lower
alcohol and a phthalic ester and
(ii) an organometallic cocatalyst and
(iii) an external donor represented by the formula
Si(OCH2CH3)3(NRxRy)
wherein Rx and Ry can be the same or different and represent a hydrocarbon group
having 1 to 12 carbon atoms.
The polymer matrix (A) of the reactor grade thermoplastic polyolefins (RTPOs) according to
the invention must be a polypropylene matrix (A), which is in the following called propylene
matrix (A).
The propylene matrix (A) can be a propylene homopolymer, a propylene copolymer or
mixtures thereof, like a homo/random copolymer. However it is preferred that the propylene
matrix (A) is a propylene homopolymer.
The expression homopolymer used in the instant invention relates to a polypropylene that
consists substantially, i.e. of at least 97 wt%, preferably of at least 98 wt%, more preferably
of at least 99 wt%, still more preferably of at least 99.8 wt% of propylene units. In a preferred
embodiment only propylene units in the propylene homopolymer are detectable.
Where the propylene matrix (A) comprises a propylene copolymer or is a homo/random
propylene copolymer, the propylene copolymer comprises monomers copolymerizable with
propylene, for example comonomers such as ethylene and C4 to C20 alpha-olefins, in
particular ethylene and C4 to C10 alpha-olefins, e.g. 1-butene or 1-hexene. The comonomer
content in the propylene matrix is in such a case preferably relatively low, i.e. up to 4.0 wt%,
more preferably 0.1 to 3.0 wt%, still more preferably 0.2 to 2.0 wt%, yet more preferably 0.3
to 1.0 wt%.
The propylene matrix (A) can be unimodal or multimodal, like bimodal. However it is
preferred that the propylene matrix (A) is unimodal. Concerning the definition of unimodal
and multimodal, like bimodal, it is referred to the definition below.
When the matrix is unimodal with respect to the molecular weight distribution, it may be
prepared in a single stage process e.g. a slurry or gas phase process in a slurry or gas
phase reactor. Preferably, the unimodal matrix is polymerized as a slurry polymerization.
Alternatively, the unimodal matrix may be produced in a multistage process using at each
stage process conditions which result in similar polymer properties.
Where the propylene matrix (A) comprises two or more different propylene polymers these
may be polymers with different monomer make up and/or with different molecular weight
distributions. These components may have identical or differing monomer compositions and
tacticities.
Moreover it is preferred that the polymer matrix (A) has a rather high melt flow rate (MFR),
i.e. a rather low molecular weight. The melt flow rate measured under a load of 2.16 kg at
230°C (ISO 1133) is denoted as MFR (230°C). Accordingly, it is preferred that in the present
invention the propylene matrix (A) has an MFR (230°C) equal to or above 200 g/10 min and
upto 500g/10min.
As a further requirement of the RTPOs the elastomeric copolymers B and C must fulfill some
properties so that the desired results can be achieved.
Accordingly the elastomeric ethylene-propylene copolymer (B) must comprise ethylene in a
content of above 50 to 80 wt%, preferably 55 to 75 wt%.
Furthermore the elastomeric ethylene-propylene copolymer (B) must have an intrinsic
viscosity IV = 2.8 dl/, preferably S 2.6 dl/g and more preferably = 2.4 dl/g.
The elastomeric ethylene-propylene copolymer (C) must comprise propylene in a content of
50 to 80 wt%, preferably 55 to 75 wt%.
Furthermore the elastomeric ethylene-propylene copolymer (C) must have an intrinsic
viscosity IV of 3.0 to 6.5 dl/g, preferably 3.2 to 6.0 dl/g and more preferably 3.5 to 6.0 dl/g.
Like the propylene matrix (A) the elastomeric copolymers (B) and (C) can be unimodal or
multimodal, like bimodal. However it is preferred that the elastomeric copolymers (B) and (C)
are unimodal. Concerning the definition of unimodal and multimodal, like bimodal, it is
referred to the definition below.
Of course also the ratio of propylene matrix (A) and elastomeric copolymers (B) and (C) of
the RTPOs has some influence on the desired properties; a straightforward example is the
adjustment of the impact/stiffness balance.
Thus the RTPOs comprise
(a) 40 to 90 wt%, preferably 45 to 85 wt% and more preferably 50 to 80 wt% of the
propylene matrix (A) based on the total amount of the RTPO,
(b) 2 to 30 wt%, preferably 5 to 25 wt% and more preferably 10 to 20 wt% of the
elastomeric ethylene-propylene copolymer (B) and
(c) 8 to 30 wt%, preferably 10 to 27 wt% and more preferably 15 to 27 wt% of the
elastomeric ethylene-propylene copolymer (C) based on the total amount of the
RTPO.
Moreover it is appreciated that the MFR (230°C) of the RTPO is rather high, i.e. above 20
g/10 min, more preferably above 25 g/10 min and most preferably above 30 g/10 min.
The expressions "multimodal" or "bimodal" or "unimodal" used herein refer to the modality of
the polymer, i.e. the form of its molecular weight distribution curve, which is the graph of the
molecular weight fraction as a function of its molecular weight. As will be explained below,
the polymer components of the present invention are produced in a sequential step process,
using reactors in serial configuration and operating at different reaction conditions. As a
consequence, each fraction prepared in a specific reactor will have its own molecular weight
distribution. When the molecular weight distribution curves from these fractions are
superimposed to obtain the molecular weight distribution of the final polymer, that curve may
show two or more maxima or at least be distinctly broadened when compared with curves for
the individual fractions.
The RTPOs of the present invention are produced by multistage process polymerization
comprising at least 3 polymerization steps, such as bulk polymerization, gas phase
polymerization, slurry polymerization, solution polymerization or combinations thereof.
One skilled in the art is aware of the various possibilities and polymerization reactor systems
to produce RTPOs.
Thus, the polymerization system can comprise one or more conventional stirred slurry
reactors and/or one or more gas phase reactors. Preferably the reactors used are selected
from the group of loop and gas phase reactors and, in particular, the process employs at
least one loop reactor and at least two gas phase reactors. It is also possible to use several
reactors of each type, e.g. one loop and two or three gas phase reactors, or two loops and
two gas phase reactors, in series.
Preferably the process comprises also a prepolymerization with the chosen catalyst system,
as described in detail below, comprising the special Ziegler-Natta procatalyst, the special
external donor and optionally the cocatalyst.
In a preferred embodiment, the prepolymerisation is conducted as bulk slurry polymerisation
in liquid propylene, i.e. the liquid phase mainly comprises propylene, with minor amount of
other reactants and optionally inert components dissolved therein.
The prepolymerisation reaction is typically conducted at a temperature of 0 to 50 °C,
preferably from 10 to 45 °C, and more preferably from 15 to 40 °C.
The pressure in the prepolymerisation reactor is not critical but must be sufficiently high to
maintain the reaction mixture in liquid phase. Thus, the pressure may be from 20 to 100 bar,
for example 30 to 70 bar.
The catalyst components are preferably all introduced to the prepolymerisation step.
However, where the solid catalyst component and the cocatalyst can be fed separately it is
possible that only a part of the cocatalyst is introduced into the prepolymerisation stage and
the remaining part into subsequent polymerisation stages. Also in such cases it is necessary
to introduce so much cocatalyst into the prepolymerisation stage that a sufficient
polymerisation reaction is obtained therein.
It is possible to add other components also to the prepolymerisation stage. Thus, hydrogen
may be added into the prepolymerisation stage to control the molecular weight of the
prepolymer as is known in the art. Further, antistatic additive may be used to prevent the
particles from adhering to each other or the walls of the reactor.
The precise control of the prepolymerization conditions and reaction parameters is within the
skill of the art.
A slurry reactor designates any reactor, such as a continuous or simple batch stirred tank
reactor or loop reactor, operating in bulk or slurry and in which the polymer forms in
particulate form. "Bulk" means a polymerization in reaction medium that comprises at least
60wt-% monomer. According to a preferred embodiment the slurry reactor comprises a bulk
loop reactor.
"Gas phase reactor" means any mechanically mixed or fluid bed reactor. Preferably the gas
phase reactor comprises a mechanically agitated fluid bed reactor with gas velocities of at
least 0.2 m/sec.
The particularly preferred embodiment of the invention comprises carrying out the
polymerization in a process comprising either a combination of one loop and two or three gas
phase reactors or a combination of two loops and two gas phase reactors.
A preferred multistage process is a slurry-gas phase process, such as developed by Borealis
and known as the Borstar® technology. In this respect, reference is made to EP 0 887 379,
WO 2004/000899, WO 2004/111095, WO 99/24478, WO 99/24479 and WO 00/68315
incorporated herein by reference.
A further suitable slurry-gas phase process is the Spheripol® process of LyondellBasell.
Preferably the reactor grade thermoplastic polyolefins with high flowability and excellent
surface quality according to the invention are produced by using the special Ziegler-Natta
procatalysts in combination with a special external donor, as described in detail below, in the
Spheripol® or in the Borstar®PP process, more preferably in the Borstar®PP process.
One preferred multistage process may therefore comprise the steps of.
producing a polypropylene polymer matrix in the presence of the chosen catalyst
system comprising the special Ziegler-Natta procatalyst in combination with the
special external donor and the cocatalyst in at least one slurry reactor
- transferring the slurry reactor product into a first gas phase reactor (GPR)
- producing a first ethylene/propylene-copolymer in the polymer matrix in the presence
of the catalyst system in said first GPR
- transferring the first GPR product into a 2nd GPR
- producing a second ethylene/propylene-copolymer in the polymer matrix in the
presence of catalyst system in said 2nd GPR
- recovering the polymer product for further processing,
said 1st and 2nd ethylene/propylene mixtures having different composition ratios,
respectively having different ethylene content and intrinsic viscosities, so that a bimodal
rubber composition is obtained.
A further preferred multistage process may comprise the steps of:
producing a polypropylene polymer matrix in the presence of the chosen catalyst
system comprising the special Ziegler-Natta procatalyst in combination with the
special external donor and the cocatalyst in at least one slurry reactor
- transferring the slurry reactor product into a first gas phase reactor (GPR),
- wherein the slurry reactor product is further polymerized in the presence of the
catalyst system in said first GPR
- transferring the first GPR product into a 2nd GPR
- producing a ethylene/propylene-copolymer in the polymer matrix in the presence of
catalyst system in said 2nd GPR
- transferring the 2nd GPR product into a 3rd GPR and producing a second
ethylene/propylene-copolymer in the polymer matrix in the presence of catalyst
system in said 3rd GPR, said 1s' and 2nd ethylene/propylene mixtures having different
composition ratios and
- recovering the polymer product for further processing,
yielding a polypropylene polymer matrix containing said 1st and 2nd ethylene/propylene
mixtures having different composition ratios, respectively having different ethylene
content and intrinsic viscosities, so that a bimodal rubber composition is obtained.
In a preferred embodiment the composition ratios of said first and second ethylene/propylene
mixtures are adjusted so that in the first gas phase reactor (respectively second GPR) a
propylene rich EPR rubber is produced in the propylene polymer matrix and in the second
gas phase reactor (respectively third GPR) an ethylene rich EPR rubber is produced in the
propylene polymer matrix.
Furthermore a molar H2/C2 ratio between preferably 0.01 to 0.1, more preferably 0.02 to 0.06
should be adjusted in the 1st GPR (respectively 2nd GPR) and a molar H2/C2 ratio between
preferably 0.15 to 0.6, more preferably 0.20 to 0.4 should be adjusted in the 2nd GPR
(respectively 3rd GPR) to achieve the desired intrinsic viscosities of the two different rubbers.
Nevertheless the GPR polymerisations can also be carried out in reversed order.
With respect to the above-mentioned preferred slurry-gas phase process, the following
general information can be provided with respect to the process conditions:
The slurry reactor is operated at temperature of from 40°C to 110°C, preferably between
50°C and 100°C, in particular between 60°C and 90°C, with a pressure in the range of from
20 to 80 bar, preferably 30 to 60 bar, with the option of adding hydrogen in order to control
the molecular weight in a manner known per se.
The reaction product of the slurry polymerization, which preferably is carried out in a loop
reactor, is then transferred to the subsequent gas phase reactor, wherein the temperature
preferably is within the range of from 50°C to 130°C, more preferably 60°C to 100°C, at a
pressure in the range of from 5 to 50 bar, preferably 8 to 35 bar, again with the option of
adding hydrogen in order to control the molecular weight, with the option of adding hydrogen
in order to control the molecular weight in a manner known per se.
The average residence time can vary in the reactor zones identified above. In one
embodiment, the average residence time in the slurry reactor, for example a loop reactor, is
in the range of from 0.5 to 5 hours, for example 0.5 to 2 hours, while the residence time in
the gas phase reactor generally will be from 1 to 8 hours.
If desired, the polymerization may be effected in a known manner under supercritical
conditions in the slurry, preferably loop reactor, and/or as a condensed mode in the gas
phase reactor.
The polymerization process enables highly feasible means for producing and further tailoring
the propylene polymer composition within the invention. The precise control of the
polymerization conditions and reaction parameters is within the skill of the art.
According to the invention the RTPOs with high flowability and excellent surface quality are
obtained by a multistage polymerization process, as described above, in the presence of a
catalyst system comprising as component (i) a Ziegler-Natta procatalyst which contains a
trans-esterification product of a lower alcohol and a phthalic ester.
The procatalyst used according to the invention is prepared by
a) reacting a spray crystallized or emulsion solidified adduct of MgCl2 and a C1-C2 alcohol
with TiCI4
b) reacting the product of stage a) with a dialkylphthalate of formula (I)

wherein R1' and R2' are independently at least a C5-alkyl
under conditions where a transesterification between said C1-C2 alcohol and said
dialkylphthalate of formula (I) takes place to form the internal donor
c) washing the product of stage b) or
d) optionally reacting the product of step c) with TiCl4.
The procatalyst is produced as defined for example in the patent applications WO 87/07620,
WO 92/19653, WO 92/19658 and EP 0 491 566. The content of these documents is herein
included by reference.
First an adduct of MgCI2 and a C1-C2 alcohol of the formula MgCI2*nROH, wherein R is
methyl or ethyl and n is 1 to 6, is formed. Ethanol is preferably used as alcohol.
The adduct, which is first melted and then spray crystallized or emulsion solidified, is used as
catalyst carrier.
In the next step the spray crystallized or emulsion solidified adduct of the formula
MgCI2*nROH, wherein R is methyl or ethyl, preferably ethyl and n is 1 to 6, is contacted with
TiCl4 to form a titanised carrier, followed by the steps of
• adding to said titanised carrier
a dialkylphthalate of formula (I) with R1' and R2' being independently at least a C5-
alkyl, like at least a C8-alkyl or being the same and being at least a C5-alkyl, like at
least a C8-alkyl
to form a first product
• subjecting said first product to suitable transesterification conditions, i.e. at a
temperature between 100 to 150 °C, such that said methanol or ethanol is
transesterified with said ester groups of said dialkylphthalate of formula (I) to form
preferably at least 80 mol%, more preferably 90 mol%, most preferably 95 mol%, of a
dialkylphthalate of formula (II)

with R1 and R2 being methyl or ethyl, preferably ethyl, being the internal donor and
• recovering said transesterification product as the procatalyst composition.
The adduct of the formula MgCI2*nROH, wherein R is methyl or ethyl and n is 1 to 6, is in a
preferred embodiment melted and then the melt is preferably injected by a gas into a cooled
solvent or a cooled gas, whereby the adduct is crystallized into a morphologically
advantageous form, as for example described in WO 87/07620.
This crystallized adduct is then used as the catalyst carrier and reacted to the procatalyst
useful in the present invention as described in WO 92/19658 and WO 92/19653.
In the next step the crystallized carrier is reacted with TiCl4 to form a titanised carrier.
A dialkylphthalate of formula (I) is then added to this titanised carrier.
The alkoxy group of the phthalic acid ester used comprises at least 5 carbon atoms and may
be different or the same. Preferably the alkoxy group of the phthalic acid ester used
comprises at least 8 carbon atoms. More preferably the alkoxy groups R1 and R2 are the
same.
Still more preferably a dialkylphthalate of formula (I) selected from the group consisting of
propylhexylphthalate (PrHP), dioctylphthalate (DOP), di-iso-decylphthalate (DIDP), and
ditridecylphthalate (DTDP) is used, yet most preferably the dialkylphthalate of formula (1) is a
dioctylphthalate (DOP), like di-iso-octylphthalate or diethylhexylphthalate, in particular
diethylhexylphthalate.
When adding the dialkylphthalate of formula (I) it is very likely that an adduct of all the
components is produced.
This adduct is then transesterified at a temperature above 100°C and advantageously
between 130 to 150 °C.
As the catalyst residue is removed by extracting, an adduct of the titanised carrier and the
internal donor is obtained, in which the group deriving from the ester alcohol has changed.
In case sufficient titanium remains on the carrier, it will act as an active element of the
procatalyst.
Otherwise the titanisation is repeated after the above treatment in order to ensure a sufficient
titanium concentration and thus activity.
Preferably the procatalyst used according to the invention contains 2.5% by weight of
titanium at the most, preferably 2.2% by weight at the most and more preferably 2.0 % by
weight at the most. Its donor content is preferably between 4 to 12% by weight and more
preferably between 6 and 10 % by weight.
More preferably the procatalyst used according to the invention has been produced by using
ethanol as the alcohol and dioctylphthalate (DOP) as dialkylphthalate of formula (I), yielding
diethylphthalate (DEP) as the internal donor compound.
Still more preferably the catalyst used according to the invention is the BC-1 catalyst of
Borealis or the catalyst Polytrack 8502, commercially available from Grace.
In a further embodiment, the Ziegler-Natta procatalyst can be modified by polymerising a
vinyl compound in the presence of the catalyst system, comprising the special Ziegler-Natta
procatalyst, an external donor and a cocatalyst, which vinyl compound has the formula:

wherein R3 and R4 together form a 5- or 6-membered saturated, unsaturated or aromatic ring
or independently represent an alkyl group comprising 1 to 4 carbon atoms, and the modified
catalyst is used for the preparation of the polymer composition. The polymerised vinyl
compound can act as a nucleating agent.
Concerning the modification of catalyst reference is made to the international applications
WO 99/24478, WO 99/24479 and particularly WO 00/68315, incorporated herein by
reference with respect to the reaction conditions concerning the modification of the catalyst
as well as with respect to the polymerization reaction.
For the production of the RTPOs with high flowability and excellent surface quality according
to the invention the catalyst system used preferably comprises in addition to the special
Ziegler-Natta procatalyst an organometallic cocatalyst as component (ii). Accordingly it is
preferred to select the cocatalyst from the group consisting of trialkylaluminium, like
triethylaluminium (TEA), dialkyl aluminium chloride and alkyl aluminium sesquichloride.
Component (iii) of the catalysts system used is an external donor represented by the formula
Si(OCH2CH3)3(NRxRy)
wherein Rx and Ry can be the same or different a represent a hydrocarbon group having 1 to
12 carbon atoms.
Rx and Ry are independently selected from the group consisting of linear aliphatic
hydrocarbon group having 1 to 12 carbon atoms, branched aliphatic hydrocarbon group
having 1 to 12 carbon atoms and cyclic aliphatic hydrocarbon group having 1 to 12 carbon
atoms. It is in particular preferred that Rx and Ry are independently selected from the group
consisting of methyl, ethyl, n-propyl, n-butyl, octyl, decanyl, iso-propyl, iso-butyl, iso-pentyl,
tert.-butyl, tert.-amyl, neopentyl, cyclopentyl, cyclohexyl, methylcyclopentyl and cycloheptyl.
More preferably both Rx and Ry are the same, yet more preferably both Rx and Ry are an
ethyl group.
Most preferably diethylaminotriethoxysilane is used as external donor.
The external donor may be produced according to the methods disclosed in EP 1 538 167.
The content of this document is herein included by reference.
The current invention also provides a multistage process for producing reactor grade
thermoplastic polyolefins using the special catalyst system comprising components (i), (ii)
and (iii).
Preferably the catalyst system used comprises
a) a procatalyst composition comprising titanium, magnesium, chlorine and
diethylphthalate as internal donor, prepared as disclosed above,
b) diethylaminotriethoxysilane as external donor and
c) triethylaluminium as cocatalyst.
A further aspect of the invention is therefore the use of a catalyst system comprising
a) a procatalyst composition comprising titanium, magnesium, chlorine and
diethylphthalate as internal donor, prepared as disclosed above,
b) diethylaminotriethoxysilane as external donor and
c) triethylaluminium as cocatalyst
for producing a reactor grade thermoplastic polyolefin with high flowability and excellent
surface quality in a multistage process including at least 3 polymerization steps.
Advantageously an MFR (230°C) of the RTPO of above 20 g/10 min, more preferably above
25 g/10 min and most preferably above 30 g/10 min can be reached directly with the use of
the above described combination of special Ziegler-Natta procatalyst and external donor
represented by the formula Si(OCH2CH3)3(NRxRy) without any need of degrading by
visbreaking using peroxides.
By using conventional combinations of Ziegler-Natta procatalysts and external donors, as for
example ZN104 or the procatalyst described previously and dicyclopentyldimethoxysilane,
such high MFR-values for the RTPOs can be achieved only by degrading with peroxides.
Due to such a degrading step peroxide residues remain in the end polymer leading to a
decrease of purity and increase in odour causing components.
Furthermore, by using the above described combination of special Ziegler-Natta procatalyst
and external donor represented by the formula Si(OCH2CH3)3(NRxRy). it is possible to
achieve high MFR-values (230°C) of equal to or above 200 g/10 min for the propylene
matrix, with considerably less amounts of fines produced compared to processes using the
combination of conventional ZN104 catalyst and dicyclopentyldimethoxysilane as external
donor.
The RTPOs according to the invention may comprise conventional adjuvants, such as
additives, fillers and reinforcing agents or additional impact modifiers.
The following are optional additives: elastomers, nucleating agents, process and heat
stabilisers, UV stabilizers, slip agents, antistatic agents, pigments and other colouring agents
including carbon black. Depending on the type of additive, these may be added in an amount
of 0.001 to 10 wt % based on the weight of the RTPO.
In a preferred embodiment, the polymer composition includes 1 to 15wt% based on the
weight of the polymer composition, of one or more elastomers. Examples of suitable
elastomers include an ethylene/alpha-olefin random copolymer, an ethylene/alpha-
olefin/non-conjugated polyene random copolymer, a hydrogenated block copolymer and
other elastic polymers or mixtures thereof. Preferred elastomers are elastomeric ethylene-1-
octene copolymers.
In a further preferred embodiment, the polymer composition includes 0.05 to 3 wt% based on
the weight of the polymer composition of one or more alpha-nucleating agents such as
dibenzylidene sorbitol, sodium benzoate, methylen-bis(4,6-di-t-butylphenyl)-phosphate
sodium salt (NA-11), aluminium hydroxyl-bis[2,4,8,10-tetrakis(1,1-dimethylethyl)-6-hydroxy-
12H-dibenzo-[d,g]-dioxa-phoshocin-6-oxidato] (NA-21) and di(alkyl-benzylidene)sorbitol or
mixtures thereof. The alpha-nucleating agent is usually added in small amounts of 0.0001 to
1 wt%, more preferably 0.001 to 0.7 wt%. Since talc can act both as a nucleating agent and
as filler, it can be added in higher amounts. When added as a nucleating agent, talc is
preferably added in an amount of 0.05 to 3 wt%, more preferably 0.1 to 2 wt%, most
preferably less than 1 wt%, based on the weight of the polymer composition. Further details
about these nucleating agents can be found e.g. in WO 99/24479 and WO 99/24501.
Molding resin formulations comprising the RTPO produced according to the invention may
further comprise 5 to 60 wt% of one or more particulate of fibrous reinforcing fillers such as
glass fiber or carbon fiber, graphite, carbon black or the like, or fillers such as clay, talc and
mineral fillers and the like commonly employed in the trade for the manufacture of molded
articles and extruded goods.
It is thus a preferred embodiment of the present invention to add 5 to 25 wt% of an inorganic
filler, more preferably of talc.
In the preferred embodiments, the additives are added to the RTPO, which is collected from
the final reactor of the series of reactors. Preferably, these additives are mixed into the
composition prior to or during the extrusion process in a one-step compounding process.
Alternatively, a master batch may be formulated, wherein the RTPO is first mixed with only
some of the additives.
For mixing, a conventional compounding or blending apparatus, e.g. a Banbury mixer, a 2-
roll rubber mill, Buss-co-kneader or a twin screw extruder may be used. The polymer
materials recovered from the extruder are usually in the form of pellets. These pellets are
then preferably further processed, e.g. by injection molding to generate articles and products
of the inventive RTPOs.
RTPO compositions according to the invention may be pelletized and compounded using any
of the variety of compounding and blending methods well known and commonly used in the
resin compounding art.
The compositions of the current invention are preferably used for the production of molded
articles, preferably injection molded articles. Even more preferred is the use for the
production of automotive parts, like bumpers, spoilers, fenders, body panels, side bump
strips and the like.
The current invention also provides articles comprising the inventive RTPOs with high
flowability and excellent surface quality. Preferably, these articles are produced by injection
molding.
Surprisingly, it was found that the molded articles manufactured with the RTPO resins
prepared according to the invention display excellent surface quality.
The surface quality of injection molded parts, which is determined according to the procedure
described in the experimental section, must be "excellent", i.e. only polymer compositions
which can be injection molded without showing any flow mark, solve the problem which is
underlying the present invention.
Examples:
Methods:
Melt Flow Rate
Unless otherwise specified, the melt flow rate is measured as the MFR in accordance with
ISO 1133 (230X, 2.16 kg load) for polypropylene and is indicated in g/10 min. The MFR is
an indication of the flowability, and hence the processability, of the polymer. The higher the
melt flow rate, the lower the viscosity of the polymer.
Comonomer content was measured with Fourier transform infrared spectroscopy (FTIR)
calibrated with 13C-NMR. When measuring the ethylene content in polypropylene, a thin film
of the sample (thickness about 250 mm) was prepared by hot-pressing. The area of -CH2-
absorption peak (800-650 cm'1) was measured with Perkin Elmer FTIR 1600 spectrometer.
The method was calibrated by ethylene content data measured by 13C-NMR.
Flexural modulus was measured according to ISO 178 by using injection molded test
specimens as described in EN ISO 1873-2 (80 x 10 x 4 mm)
Xylene solubles
The xylene soluble fraction (XS) as defined and described in the present invention was
determined as follows: 2.0 g of the polymer are dissolved in 250 ml p-xylene at 135 °C under
agitation. After 30 minutes, the solution was allowed to cool for 15 minutes at ambient
temperature and then allowed to settle for 30 minutes at 25 ± 0.5 °C. The solution was
filtered with filter paper into two 100 ml flasks. The solution from the first 100 ml vessel was
evaporated in nitrogen flow and the residue dried under vacuum at 90 °C until constant
weight is reached. The xylene soluble fraction (percent) can then be determined as follows:

wherein m0 designates the initial polymer amount (grams), m1 defines the weight of residue
(grams), v0 defines the initial volume of solvent taken (250 millilitres) and v1 defines the
volume of the aliquot taken for determination (analysed sample; 100 millilitres).
The intrinsic viscosity (IV) value increases with the molecular weight of a polymer. The IV
values were measured according to DIN EN ISO 1628-1 in Decalin at 135°C.
The tensile modulus was measured according to ISO 572-3 at 1mm/min and 23°C. Test
specimens as described in EN IS01873-2 (80 x 10 x 4 mm) were used.
Charpy, notches impact strength (NIS), was measured according to ISO 179/1eA at
+23°C, 0°C and at -20°C by using injection molded test specimens as described in EN ISO
1873-2 (80x10x4 mm)
Shrinkage was measured according to an internal standard using 150x80x2 mm injection
molded plaques. Measurements were performed after injection and conditioning at room
temperature for at least 96h in the flow direction and perpendicular to the flow direction.
Following conditions were used for injection molding: injection time: 3s, melt temperature:
240°C, mold temperature: 50°C, hold pressure: from 73 to 23 bars in 10 steps, hold time: 10
s, cooling time: 20s.
The fines were determined by sieving the polymer powder according to ASTM D1921-06.
The screen set consisted of screens having openings of 4,000 mm; 2,800 mm; 2,000 mm;
1,400 mm; 1,000 mm; 0,500 mm; 0,180 mm; 0,106 mm and 0,053 mm.
The powder passing the 0,180 mm screen was considered as fines.
Zinc oxide was used as antistat.
Example 1: Preparation of base resin according to the invention
The base resin was produced in a plant having a prepolymerization reactor, a loop reactor
and two fluid bed gas-reactors connected in series. The catalyst used in the polymerization
was prepared according to WO 92/19653 with DOP as dialkylphthalat of the formula (I) and
ethanol as alcohol, the cocatalyst was Triethylaluminium (TEA) and as an external donor (D)
diethylamino triethoxy silane was used.
After a first pre-polymerisation step the catalyst system was fed to the slurry reactor, where
the polymerisation of the polypropylene homopolymer matrix phase was performed. The
slurry phase loop reactor was then followed by a first gas phase reactor in series, in which a
first elastomeric rubber disperse phase was produced by copolymerisation of propylene with
ethylene comonomer. The polymerisation temperature in the slurry phase loop reactor was
62°C, whereas the temperature in the first gas phase reactor was 80°C. After transfer to a
second gas phase reactor the second ethylene/propylene copolymer was produced. The
operating temperature in the second gas phase reactor was 80°C.
The split between loop, 1st GPR and 2nd GPR was: 70.5%:17.0%:12.5%
Reaction conditions:

Values for CVEPR, IV/XS, MFR and XS of the 2nd Gas phase reactor product are total values
for the final RTPO.
Since the IV of the EPR produced in the 2nd Gas phase reactor (IV/XS(epr 2nd gpr)) can not be
measured directly it has been calculated using the following formula:

Where:
IVtotal is the IV of the fraction soluble in xylene of the final composition
Wtotal = 100% EPR [the sum of polymer splits for the 1st and the 2nd gas phase reactor (17% +
12.5% = 29.5%) represents the total of EPR (100% EPR) produced]
IV(EPR 1st GPR) is the IV of the fraction soluble in xylene produced in the 1st gas phase reactor
w1st GpR is the percentage of EPR produced in the 1st gas phase reactor based on 100%EPR
[(17%polymor split for 1stGPR X 100%EPR lotal)/29.5%sum of polymer splits for 1st and 2nd GPR]
w2ndGPR is the percentage of EPR produced in the 2nd gas phase reactor based on 100%EPR
[(12.5%polymer split for 2ndGPR X 100%EPR total)/29.5%sum of polymer splits for 1st and 2nd GPR]
The IV of the fraction soluble in xylene produced in the 2nd gas phase reactor was therefore
1.68 dl/g
The Cramount of the EPR produced in the 2nd Gas phase reactor (C3/EPR(epr 2nd gpr)) has
been calculated accordingly using the following formula:
C3/EPR (EPR 2nd GPR) = [(C3/EPR total X Wtotal) - (C3/EPR (EPR 1st GPR) X W1st Gpr)] / W2nd GPR
Where:
C3/EPR total is the C3-amount of the EPR of the final composition
wtotal = 100% EPR [the sum of polymer splits for the 1st and the 2nd gas phase reactor (17% +
12.5% = 29.5%) represents the total of EPR (100% EPR) produced]
C3/EPR (epr 1st GPR) is the C3-amount of the EPR produced in the 1st gas phase reactor
W 1st GPR is the percentage of EPR produced in the 1st gas phase reactor based on 100%EPR
[(17%polymer split for 1stGPR X 100%EPR total)/29.5%sum of polymer soils for 1st and 2nd GPR]
w2nd GPR is the percentage of EPR produced in the 2nd gas phase reactor based on 100%EPR
[(12.5%polymer split for 2ndGPR X 1 00%epr total)/29.5%sum of polymer splits for 1st and 2nd GPr]
The C3-amount of the EPR produced in the 2nd gas phase reactor was therefore 33.54wt%
This value complies with datas evaluated by using so-called master curves.
Such master curves were generated by determining the C3-amount of an EPR produced in
the first gas phase reactor of the above described reactor set up using the same catalyst
system as described above but different C2/C2+C3 ratios, leading to corresponding C3-
amounts in the EPR. From these master curves an art skilled person can determine the C3-
amount of the EPR produced in the 2nd gas phase reactor using a special C2/C2+C3 ratio.
Example 2:
In order to show the advantageousness of the catalyst system used according to inventive
Example 1 in comparison to the catalyst system used according to EP 1 600 480 (ZN104
(commercially available from LyondellBasell), triethylaluminium as cocatalyst and
dicyclopentyldimethoxysilane as external donor) regarding fines produced during production
of the polypropylene matrix, several polypropylene matrices with different MFR were
produced in the above described plant set up and the amount of fines produced in the loop
reactor were determined by sieving the polymer powder obtained from the loop reactor.
The powder passing a 0.180 mm screen was considered as fines.

With the combination of ZN104/DCDMS it was not possible to produce a polypropylene
matrix with an MFR of above 100 g/10 min, especially of 250 g/10 min due to the high
amount of fines produced, which block the reactor.
Example 3: Testing of the base resin
The base resin (RTPO) was initially obtained in powder form.
The resin together with 10 wt% Titai15 (talc from Ankerport) and 0.1% NA11 as well as 10
wt% of EG8200 (elastomer Engage®8200 from DuPont Dow Elastomers) were palletized by
feeding the blend to a Prism 24twin-screw extruder (Prism Ltd., Staffordshire, UK). The
polymer was extruded through a strand die, cooled and chopped to form pellets.

Surface quality (Tigerskin)
Plaques of a dimension of 210x189x3mm3, grained with VW grain K50, were produced under
following conditions:
Melt temperature: 240°C
Mold temperature: 30°C
Dynamic pressure: 10 bar hydraulic
The filmgate over the whole width had a thickness of 1,4mm.
With the above mentioned conditions 5 plaques with different injection speed were produced.
The test series were done with following screw advance velocities:
10, 20, 42, 60, 75 mm/sec, where the screw diameter was 50mm and different injection times
of 8, 4, 2, 1.5 and 1 sec.
The produced plaques are judged visually by a tester in terms of tigerskin.
The tigerskin level was assessed by a number between 1 (no flow mark "excellent") and 5 (a
large area of flow marks, "insufficient") according to Figure 3.

Result: With the RTPO of the present invention no flow marks could be seen, independently
of the test conditions; the surface quality was in each case excellent.
WE CLAIM
1. Reactor grade thermoplastic polyolefins with high flowability and excellent surface quality
comprising
(A) 40 - 90 wt% of a propylene homo- or copolymer matrix with an MFR in accordance
with ISO 1133 (230°C, 2.16 kg load) of > 200 g/10 min and
(B) 2-30 wt% of an elastomeric ethylene-propylene copolymer having an intrinsic
viscosity IV (according to ISO 1628 with decalin as solvent) of ethylene content of > 50 to 80 wt% and
(C) 8-30 wt% of an elastomeric ethylene-propylene copolymer having an intrinsic
viscosity IV (according to ISO 1628 with decalin as solvent) of 3.0-6.5 dl/g and a
propylene content of 50 to 80 wt%,
the reactor grade thermoplastic polyolefins being obtainable by a multistage
polymerization process with at least 3 polymerization steps in the presence of a catalyst
system comprising
(i) a Ziegler-Natta procatalyst which contains a trans-esterification product of a lower
alcohol and a phthalic ester and
(ii) an organometallic cocatalyst and
(iii) external donor represented by the formula
Si(OCH2CH3)3(NRxRy)
wherein Rx and Ry can be the same or different a represent a hydrocarbon group
having 1 to 12 carbon atoms.
2. Reactor grade thermoplastic polyolefins according to claim 1, wherein the propylene
matrix (A) is a propylene homopolymer.
3. Reactor grade thermoplastic polyolefins according to claim 1 or 2 characterized in that
they additionally contain
a) 5 to 15 wt% based on the weight of the polymer composition of an inorganic filler or
b) 1 to 15 wt% based on the weight of the polymer composition of an elastomer or
c) 0.05 to 3 wt% based on the weight of the polymer composition an alpha-nucleating
agents
or mixtures therefrom.
4. Reactor grade thermoplastic polyolefins according to any of the preceding claims 1 to 3
characterized in that the MFR (230°C, 2.16 kg load) according to ISO 1133 of the reactor
grade thermoplastic polyolefin is above 20 g/10 min.
5. Use of catalyst system comprising
(i) a Ziegler-Natta procatalyst which contains a trans-esterification product of a lower
alcohol and a phthalic ester and
(ii) an organometallic cocatalyst and
(iii) external donor represented by the formula
Si(OCH2CH3)3(NRxRy)
wherein Rx and Ry can be the same or different a represent a hydrocarbon group
having 1 to 12 carbon atoms
for the production of Reactor grade thermoplastic polyolefins with high flowability and
excellent surface quality comprising
(A) 40 - 90 wt% of a propylene homo- or copolymer matrix with an MFR2 in accordance
with ISO 1133 (230°C, 2.16 kg load) of > 200 g/10 min and
(B) 2-30 wt% of an elastomeric ethylene-propylene copolymer having an intrinsic
viscosity IV (according to ISO 1628 with decalin as solvent) of ethylene content of > 50 to 80 wt% and
(C) 8-30 wt% of an elastomeric ethylene-propylene copolymer having an intrinsic
viscosity IV (according to ISO 1628 with decalin as solvent) of 3.0-6.5 dl/g and an
propylene content of 50 to 80 wt%,
in a multistage polymerization process with at least 3 polymerization steps.
6. Use of a catalyst system according to claim 5, wherein the procatalyst (i) has been
prepared by
a) reacting a spray crystallized or emulsion solidified adduct of MgCI2 and a C1-C2 alcohol
with TiCl4
b) reacting the product of stage a) with a dialkylphthalate of formula (I)
wherein R1' and R2' are independently at least a C5 alkyl
under conditions where a transesterification between said C1 to C2 alcohol and said
dialkylphthalate of formula (I) takes place to form the internal donor
c) washing the product of stage b) or
d) optionally reacting the product of step c) with TiCl4.
7. Use of a catalyst system according to claim 6, characterized in that the dialkylphthalate of
formula (T) is dioctylphthalate and that the C1 to C2 alcohol is ethanol.
8. Use of a catalyst system according to anyone of the preceding claims 5 to 7, wherein the
Ziegler-Natta procatalyst (i) is used in the presence of an organometallic cocatalyst (ii)
select from the group consisting of trialkylaluminium, dialkyl aluminium chloride and alkyl
aluminium sesquichloride.
9. Use of a catalyst system according to claim 8, characterized in that the cocatalyst is
triethylaluminium.
10. Use of a catalyst system according to anyone of the preceding claims 5 to 9, wherein the
Ziegler-Natta procatalyst is used in the presence of diethylaminotriethoxysilane as
external donor.
11. Process for producing reactor grade thermoplastic polyolefins according to anyone of the
preceding claims 1 to 4 characterized in that the process is a multistage process,
comprising either a combination of one loop and two or three gas phase reactors or a
combination of two loops and two gas phase reactors.
12. Process according to claim 11, comprising the steps of:
- producing a polypropylene polymer matrix (A) using a catalyst system according to
anyone of claims 5 to 10, comprising the Ziegler-Natta procatalyst (i), an external
donor (iii) and the cocatalyst (ii) in at least one slurry reactor
- transferring the slurry reactor product into a gas phase reactor
- producing a first ethylene/propylene-copolymer in the polymer matrix in the presence
of the catalyst system in said first gas phase reactor
- transferring the first gas phase reactor product into a 2nd gas phase reactor
- producing a second ethylene/propylene-copolymer in the polymer matrix in the
presence of the catalyst system in said 2nd GPR
- recovering the polymer product for further processing,
said 1st and 2nd ethylene/propylene mixtures having different composition ratios, so that a
bimodal rubber composition is obtained.
13. Process according to claim 11, comprising the steps of:
- producing a polypropylene polymer matrix (A) using a catalyst system according to
anyone of claims 5 to 10, comprising the Ziegler-Natta procatalyst (i), an external
donor (iii) and the cocatalyst (ii)in at least one slurry reactor
- transferring the slurry reactor product into a first gas phase reactor
- wherein the slurry reactor product is further polymerized in the presence of the
catalyst system in said first GPR
- transferring the first GPR product into a 2nd GPR
- producing a ethylene/propylene-copolymer in the polymer matrix in the presence of
the catalyst system in said 2nd GPR
- transferring the 2nd GPR product into a 3rd GPR and producing a second
ethylene/propylene-copolymer in the polymer matrix in the presence of the catalyst
system in said 3rd GPR and
- recovering the polymer product for further processing,
said 1st and 2nd ethylene/propylene mixtures having different ethylene content and
intrinsic viscosities, so that a bimodal rubber composition is obtained.
14. Use of reactor grade thermoplastic polyolefins with high flowability and excellent surface
quality according to any of claims 1 to 4 for the production of injection molded articles for
automotive parts.
15. Molded articles produced by the reactor grade thermoplastic polyolefins according to any
ofclaims 1-4.

Reactor grade thermoplastic polyolefins with high flowability and excellent surface quality comprising (A) 40 - 90
wt% of a propylene homo- or copolymer matrix with an MFR in accordance with ISO 1 133 (230°C, 2.16 kg load) of ≥ 200 g/10
min and (B) 2-30 wt% of an elastomeric ethylene-propylene copolymer having an intrinsic viscosity IV (according to ISO 1628
with decalin as solvent) of ≤ 2.8 dl/g and an ethylene content of > 50 to 80 wt% and (C) 8 - 30 wt% of an elastomeric ethylene-
propylene copolymer having an intrinsic viscosity IV (according to ISO 1628 with decalin as solvent) of 3.0 - 6.5 dl/g and an
propylene content of 50 to 80 wt%, the reactor grade thermoplastic polyolefins being obtainable by a multistage polymerization
process with at least 3 polymerization steps in the presence of a catalyst system comprising (i) a Ziegler-Natta procatalyst which
contains a trans-esterification product of a lower alcohol and a phthalic ester and (ii) an organometallic cocatalyst and (iii) external
donor represented by formula (I) Si(OCH2CH3)3(NR1R2) wherein R1 and R2 can be the same or different a represent a hydrocarbon
group having 1 to 12 carbon atoms, as well as the use of these reactor grade thermoplastic polyolefins and molded articles
produced from them.

Documents:

http://ipindiaonline.gov.in/patentsearch/GrantedSearch/viewdoc.aspx?id=FWXewEZQ54Q5aaHXe6/rSA==&loc=wDBSZCsAt7zoiVrqcFJsRw==


Patent Number 269627
Indian Patent Application Number 4234/KOLNP/2010
PG Journal Number 44/2015
Publication Date 30-Oct-2015
Grant Date 29-Oct-2015
Date of Filing 11-Nov-2010
Name of Patentee BOREALIS AG
Applicant Address WAGRAMERSTRAßE 17-19, A-1220 VIENNA, AUSTRIA
Inventors:
# Inventor's Name Inventor's Address
1 GREIN, CHRISTELLE HARRACHSTRAßE 28, A-4020 LINZ, AUSTRIA
2 BERNREITER, KLAUS ZAUBERTALSTRAßE, A-4010 LINZ, AUSTRIA
PCT International Classification Number C08L 23/12
PCT International Application Number PCT/EP2009/057256
PCT International Filing date 2009-06-12
PCT Conventions:
# PCT Application Number Date of Convention Priority Country
1 08158320.5 2008-06-16 EUROPEAN UNION