Classifications

• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
  • C08L23/00—Compositions of homopolymers or copolymers of unsaturated aliphatic hydrocarbons having only one carbon-to-carbon double bond; Compositions of derivatives of such polymers
  • C08L23/02—Compositions of homopolymers or copolymers of unsaturated aliphatic hydrocarbons having only one carbon-to-carbon double bond; Compositions of derivatives of such polymers not modified by chemical after-treatment
  • C08L23/10—Homopolymers or copolymers of propene
  • C08L23/12—Polypropene
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
  • C08L23/00—Compositions of homopolymers or copolymers of unsaturated aliphatic hydrocarbons having only one carbon-to-carbon double bond; Compositions of derivatives of such polymers
  • C08L23/02—Compositions of homopolymers or copolymers of unsaturated aliphatic hydrocarbons having only one carbon-to-carbon double bond; Compositions of derivatives of such polymers not modified by chemical after-treatment
  • C08L23/10—Homopolymers or copolymers of propene
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08F—MACROMOLECULAR COMPOUNDS OBTAINED BY REACTIONS ONLY INVOLVING CARBON-TO-CARBON UNSATURATED BONDS
  • C08F110/00—Homopolymers of unsaturated aliphatic hydrocarbons having only one carbon-to-carbon double bond
  • C08F110/04—Monomers containing three or four carbon atoms
  • C08F110/06—Propene
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08F—MACROMOLECULAR COMPOUNDS OBTAINED BY REACTIONS ONLY INVOLVING CARBON-TO-CARBON UNSATURATED BONDS
  • C08F210/00—Copolymers of unsaturated aliphatic hydrocarbons having only one carbon-to-carbon double bond
  • C08F210/04—Monomers containing three or four carbon atoms
  • C08F210/06—Propene
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08K—Use of inorganic or non-macromolecular organic substances as compounding ingredients
  • C08K3/00—Use of inorganic substances as compounding ingredients
  • C08K3/01—Use of inorganic substances as compounding ingredients characterized by their specific function
  • C08K3/013—Fillers, pigments or reinforcing additives
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
  • C08L2205/00—Polymer mixtures characterised by other features
  • C08L2205/02—Polymer mixtures characterised by other features containing two or more polymers of the same C08L -group
  • C08L2205/025—Polymer mixtures characterised by other features containing two or more polymers of the same C08L -group containing two or more polymers of the same hierarchy C08L, and differing only in parameters such as density, comonomer content, molecular weight, structure
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
  • C08L2205/00—Polymer mixtures characterised by other features
  • C08L2205/03—Polymer mixtures characterised by other features containing three or more polymers in a blend
  • C08L2205/035—Polymer mixtures characterised by other features containing three or more polymers in a blend containing four or more polymers in a blend
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
  • C08L2207/00—Properties characterising the ingredient of the composition
  • C08L2207/02—Heterophasic composition
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
  • C08L2207/00—Properties characterising the ingredient of the composition
  • C08L2207/06—Properties of polyethylene
  • C08L2207/062—HDPE
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
  • C08L2308/00—Chemical blending or stepwise polymerisation process with the same catalyst

Definitions

• the present invention is directed to a new heterophasic propylene copolymer (HECO), its manufacture and use.
• HECO heterophasic propylene copolymer
• Heterophasic propylene copolymers are well known in the art. Such heterophasic propylene copolymers comprise a matrix being either a propylene homopolymer or a random propylene copolymer in which an elastomeric copolymer is dispersed. Thus the polypropylene matrix contains (finely) dispersed inclusions being not part of the matrix and said inclusions contain the elastomer.
• inclusion indicates that the matrix and the inclusion form different phases within the heterophasic propylene copolymer, said inclusions are for instance visible by high resolution microscopy, like electron microscopy or scanning force microscopy. Down-gauging and light- weighing is a recurring market need, since it allows for energy and material savings.
• biaxial and triaxial impact strength are two-phase systems like heterophasic propylene copolymers (HECO) both strongly depend on the morphology, increasing both types of impact strength is rather challenging. This is due to the fact that they show an optimum at different particle sizes. Especially the impact strength at biaxial stress state (puncture energy) is improved at small finely dispersed particles. This can be achieved via a rubber of low molecular weight. However, such a rubber is detrimental to the impact strength at triaxial stress state (Charpy impact strength). Using a trimodal matrix concept leads to a propylene of excellent stiffness and to heterophasic copolymers showing an outstanding impact-stiffness balance.
• HECO heterophasic propylene copolymers
• the object of the present invention is to obtain a material of high flowability and stiffness and good impact performance.
• the finding of the present invention is to provide a heterophasic propylene copolymer which contains a matrix with a broad molecular weight distribution and a rather high amount of elastomer, preferably with rather low intrinsic viscosity.
• a heterophasic propylene copolymer comprising: (a) a matrix (M) being a polypropylene (PP), wherein said polypropylene (PP) comprises at least three polypropylene fractions (PPl), (PP2) and (PP3), the three polypropylene fractions (PPl), (PP2) and (PP3) differ from each other by the melt flow rate MFR 2 (230 °C) measured according to ISO 1133, and (b) an elastomer (E) dispersed in said matrix (M), wherein the elastomer (E) is included in an amount of 20 wt.-% or more, based on the weight of the heterophasic propylene copolymer (HECO), optionally a low amount of polyethylene (PE) and optionally an inorganic filler (F).
• HECO heterophasic propylene copolymer
• the present invention also relates to a process for the preparation of a heterophasic propylene copolymer (HECO) as defined above, wherein the process comprises the step of blending the elastomer (E) with the matrix (M).
• the present invention also relates to an article comprising the heterophasic propylene copolymer (HECO) as defined above, and to uses of the heterophasic propylene copolymer (HECO) especially in an automotive application. In the following the invention is described in more detail.
• the heterophasic propylene copolymer (HECO)
• a heterophasic propylene copolymer (HECO) according to this invention comprises a polypropylene (PP) as a matrix (M) and dispersed therein an elastomer (E).
• the polypropylene (PP) matrix contains (finely) dispersed inclusions being not part of the matrix (M) and said inclusions contain the elastomer (E) and may optionally further contain low amounts of crystalline polyethylene (PE).
• inclusion indicates that the matrix (M) and the inclusion form different phases within the heterophasic propylene copolymer (HECO), said inclusions are for instance visible by high resolution microscopy, like electron microscopy or scanning force microscopy.
• the heterophasic propylene copolymer (HECO) comprises as polymer components only the polypropylene (PP) and the elastomer (E).
• the heterophasic propylene copolymer (HECO) may contain further additives but in a preferred embodiment no other polymer in an amount exceeding 8.0 wt-%, more preferably exceeding 6.0 wt.-%, based on the total weight of the heterophasic propylene copolymer (HECO).
• One additional polymer which may be present in such low amounts is a polyethylene (PE) being intimately mixed with the elastomer (E), i.e.
• the elastomer (E) and the optional polyethylene (PE) form the inclsuions in the matrix (M).
• the instant heterophasic propylene copolymer (HECO) contains only the polypropylene (PP) (i.e. the matrix (M)) the elastomer (E) and optionally small amounts of polyethylene (PE) as the only polymer components.
• the heterophasic propylene copolymer contains only the polypropylene (PP) (i.e. the matrix (M)) the elastomer (E) and optionally small amounts of polyethylene (PE) as the only polymer components.
• the heterophasic propylene copolymer contains only the polypropylene (PP) (i.e. the matrix (M)) the elastomer (E) and optionally small amounts of polyethylene (PE) as the only polymer components.
• the heterophasic propylene copolymer contains only the polypropylene (PP) (i.e. the matrix (
• melt flow rate (MFR) is measured in g/10 min of the polymer discharged through a defined die under specified temperature and pressure conditions and the measure of viscosity of the polymer which, in turn, for each type of polymer is mainly influenced by its molecular weight but also by its degree of branching.
• MFR 2 (230 °C).
• the heterophasic propylene copolymer has an MFR 2 (230 °C) of equal or more than 50 g/lOmin, more preferably of equal or more than 70.0 g/10 min, still more preferably in the range of 70.0 to 200.0 g/lOmin, , like in the range of 75.0 to 180 g/lOmin.
• heterophasic propylene copolymer HECO
• heterophasic propylene copolymer has a melting temperature of at least 160 °C, more preferably of at least 162°C, still more preferably in the range of 163 to 170 °C.
• the elastomer (E) of the heterophasic propylene copolymer (HECO) constitutes the main part of the xylene cold soluble fraction of the heterophasic propylene copolymer (HECO).
• the xylene cold soluble (XCS) fraction of heterophasic propylene copolymer (HECO) can be equated with the elastomer (E) content of the the heterophasic propylene copolymer (HECO).
• the xylene cold soluble (XCS) fraction of the heterophasic propylene copolymer (HECO) is preferably equal or higher than 20 wt.-%, more preferably in the range of 20 to 50 wt.-%, yet more preferably in the range of 25 to 40 wt.-%, like in the range of 25 to 35 wt- %., based on the heterophasic propylene copolymer (HECO).
• heterophasic propylene copolymer (HECO) of the instant invention is preferably featured by (i) a tensile modulus measured according to ISO 527-2 of at least 1,100 MPa, more preferably of at least 1,200 MPa, still more preferably in the range from 1,100 to 2500 MPa, like in a range of 1,200 to 2,200 MPa,
• the values of puncture energy preferably refer to a heterophasic propylene copolymer (HECO) without filler (F).
• heterophasic propylene copolymer i.e. the matrix (M) and the elastomer (E) will be defined in more detail.
• the matrix (M) is a polypropylene (PP), more preferably a random propylene copolymer (R-PP) or a propylene homopolymer (H-PP), the latter being especially preferred.
• the comonomer content of the polypropylene (PP) is equal or below 1.0 wt.-%, yet more preferably not more than 0.8 wt.-%, still more preferably not more than 0.5 wt.-%.
• the weight percentage is based on the total weight of the polypropylene (PP).
• polypropylene is preferably a propylene homopolymer (H-PP).
• propylene homopolymer as used throughout the instant invention relates to a polypropylene that consists substantially, i.e. of equal or below than 99.5 wt.-%, of propylene units. In a preferred embodiment only propylene units in the propylene homopolymer are detectable.
• the comonomer content is determined by FT infrared spectroscopy, as described below in the example section.
• the random propylene copolymer (R-PP) comprises monomers copolymerizable with propylene, for example comonomers such as ethylene and/or C4 to C 12 ⁇ -olefins, in particular ethylene and/or C4 to Cg a-olefins, e.g. 1-butene and/or 1-hexene.
• the random propylene copolymer (R-PP) according to this invention comprises, especially consists of, monomers copolymerizable with propylene from the group consisting of ethylene, 1 -butene and 1 -hexene.
• the random propylene copolymer (R-PP) of this invention comprises - apart from propylene - units derivable from ethylene and/or 1-butene.
• the random propylene copolymer (R-PP) comprises units derivable from ethylene and propylene only.
• the random propylene copolymer (R-PP) has preferably a comonomer content in the range of more than 0.1 to 2.0 wt.-%, more preferably in the range of more than 0.1 to 1.6 wt.-%, yet more preferably in the range of 0.1 to 1.0 wt.-%.
• the weight percentage is based on the total weight of random propylene copolymer (R-PP).
• random indicates that the comonomers of the propylene copolymer (R-PP), as well as of the first random propylene copolymer (R-PP1), the second random propylene copolymer (R-PP2), and third random propylene copolymer (R-PP3), are randomly distributed within the propylene copolymers.
• random is understood according to IUPAC (Glossary of basic terms in polymer science; IUPAC recommendations 1996).
• HECO heterophasic propylene copolymer
• M matrix
• PP polypropylene
• polypropylene (PP) has a melt flow rate MFR 2 (230 °C) measured according to ISO 1133 in the range of 30.0 to 500.0 g/lOmin, more preferably of 40.0 to 400.0 g/10 min, still more preferably in the range of 50.0 to 300.0 g/lOmin.
• the matrix (M) of the heterophasic propylene copolymer (HECO) is featured by a moderately broad molecular weight distribution. Accordingly it is appreciated that the matrix of the heterophasic propylene copolymer (HECO), i.e. the polypropylene (PP), has a molecular weight distribution (MWD) of equal or more than 3.0, preferably equal or more than 3.5, more preferably in the range of 3.5 to 8.0, still more preferably in the range of 3.5 to 7.0, like 4.0 to 7.0.
• MLD molecular weight distribution
• the polypropylene (PP) can be defined by its molecular weight.
• the polypropylene (PP) has a weight average molecular weight (Mw) measured by gel permeation chromatography (GPC; ISO 16014-4:2003) of equal or less than 175 kg/mol, more preferably of equal or less than 165 kg/mo 1, yet more preferably in the range of 75 to 160 kg/mol, still more preferably in the range of 80 to 150 kg/mol.
• Mw weight average molecular weight measured by gel permeation chromatography
• the xylene cold soluble (XCS) content of the polypropylene (PP) is rather moderate.
• xylene cold soluble (XCS) content is preferably equal or below 4.0 wt.-%, more preferably equal or below 3.5 wt.-%, still more preferably in the range of 0.5 to 3.0 wt.-%, like in the range of 0.5 to 2.8 wt.-%.
• the weight percentage is based on the total weight of the polypropylene (PP).
• the polypropylene (PP) comprises at least three, more preferably comprises three, yet more preferably consists of three, polypropylene fractions (PPl), (PP2), and (PP3), the three polypropylene fractions (PPl), (PP2), and (PP3) differ from each other by the melt flow rate MFR 2 (230 °C) measured according to ISO 1133.
• the first polypropylene fraction (PPl) has a melt flow rate MFR 2 (230 °C) measured according to ISO 1133 of 80 to 500 g/1 Omin, more preferably 150 to 480 g/10 min, yet more preferably 200 to 450 g/1 Omin, still more preferably 250 to 450 g/1 Omin.
• the second polypropylene fraction (PP2) preferably has a melt flow rate MFR 2 (230 °C) measured according to ISO 1133 of 20 to 300 g/1 Omin, more preferably 50 to 250 g/10 min, yet more preferably 70 to 220 g/1 Omin, still more preferably 100 to 200 g/1 Omin.
• the polypropylene fraction (PP3) has preferably a melt flow rate MFR 2 (230 °C) measured according to ISO 1133 of 1 to 15 g/1 Omin, more preferably 2 to 15 g/1 Omin, yet more preferably 2 to 12 g/10 min, still more preferably 3 to 10 g/lOmin.
• the melt flow rate MFR 2 (230 °C) decreases from the first polypropylene fraction (PPl) to the third polypropylene fraction (PP3).
• the ratio between the melt flow rate MFR 2 (230 °C) of the first polypropylene fraction (PPl) and the third polypropylene fraction (PP3) [MFR (PPl) / MFR (PP3)] is preferably at least 10, more preferably at least 20, yet more preferably at least 30, like in the range of 30 to 60 and/or the ratio between the melt flow rate MFR 2 (230 °C) of the second polypropylene fraction (PP2) and the third polypropylene fraction (PP3) [MFR (PP2) / MFR (PP3)] is preferably at least 5, more preferably at least 7, yet more preferably at least 10.
• melt flow rate MFR 2 decreases from the first polypropylene fraction (PPl) to the second polypropylene fraction (PP2) and from the second polypropylene fraction (PP2) to the third polypropylene fraction (PP3).
• the second polypropylene fraction (PP2) preferably has a lower melt flow rate MFR 2 (230 °C) than the first polypropylene fraction (PPl) but a higher melt flow rate MFR 2 (230 °C) than the third polypropylene fraction (PP3).
• the third polypropylene fraction (PP3) preferably has the lowest melt flow rate MFR 2 (230 °C) of the three polypropylenes fractions (PPl), (PP2), and (PP3), more preferably of all polymers present in the polypropylene (PP).
• MFR 2 230 °C
• at least one of the polypropylene fractions (PPl), (PP2), and (PP3) is a propylene homopolymer, even more preferred all polypropylene fractions (PPl), (PP2), and (PP3) are propylene homopolymers.
• the matrix (M), i.e. the polypropylene (PP), of the heterophasic propylene copolymer (HECO) comprises
• a first polypropylene fraction (PPl) being a first propylene homopolymer (H-PP1) or a first random propylene copolymer (R-PP1),
• a second polypropylene fraction being a second propylene homopolymer (H- PP2) or a second random propylene copolymer (R-PP2),
• PP3 polypropylene fraction
• H-PP3 propylene homopolymer
• R-PP3 random propylene copolymer
• At least one of the three fractions PPl, PP2, and PP3 is a propylene homopolymer, preferably at least the first polypropylene fraction (PPl) is a propylene homopolymer, more preferably all three fractions (PPl), (PP2), and (PP3) are propylene homopolymers.
• At least the first polypropylene fraction (PPl) is a propylene homopolymer, a so called first propylene homopolymer (H-PP1). Even more preferred this first polypropylene fraction (PPl) has the highest melt flow rate MFR 2 (230 °C) of the three polypropylenes (PPl), (PP2), and (PP3).
• either the second polypropylene fraction (PP2) or the third polypropylene fraction (PP3) is a propylene homopolymer.
• the polypropylene (PP) comprises, preferably consists of, only one polypropylene fraction being a random propylene copolymer.
• the second polypropylene fraction (PP2) is a propylene homopolymer, so called second propylene homopolymer (H-PP2)
• the third polypropylene fraction (PP3) is a propylene homopolymer, so called third propylene homopolymer (H- PP3). It is especially preferred that all three polypropylene fractions (PPl), (PP2), and (PP3) are propylene homopolymers.
• the polypropylene fractions (PPl), (PP2), and (PP3) can be random propylene copolymers or propylene homopolymers.
• the comonomer content shall be rather low for each of the polypropylene fractions (PPl), (PP2), and (PP3).
• the comonomer content of each of the three polypropylene fractions (PPl), (PP2), and (PP3) is not more than 1.0 wt.-%, yet more preferably not more than 0.8 wt.-%, still more preferably not more than 0.5 wt.-%.
• the comonomer content for each of the random propylene copolymer fractions (R-PPl), (R-PP2), and (R-PP3) is in the range of more than 0.2 to 3.0 wt.-%, more preferably in the range of more than 0.2 to 2.5 wt.-%, yet more preferably in the range of 0.2 to 2.0 wt.-%.
• the weight percentage is based on the weight of the respective random propylene copolymer fraction.
• the (R-PPl), (R-PP2), and (R-PP3) comprise independently from each other monomers copolymerizable with propylene, for example comonomers such as ethylene and/or C4 to C12 ⁇ -olefins, in particular ethylene and/or C4 to Cg a-olefins, e.g. 1-butene and/or 1-hexene.
• comonomers such as ethylene and/or C4 to C12 ⁇ -olefins, in particular ethylene and/or C4 to Cg a-olefins, e.g. 1-butene and/or 1-hexene.
• (R-PPl), (R-PP2), and (R-PP3) comprise independently from each other, especially consists independently from each other of, monomers copolymerizable with propylene from the group consisting of ethylene, 1-butene and 1-hexene.
• (R-PPl), (R-PP2), and (R-PP3) have apart from propylene the same comonomers.
• the (R-PP1), (R-PP2), and (R-PP3) comprise units derivable from ethylene and propylene only.
• the first polypropylene fraction (PPl) is a random propylene copolymer fraction (R-PP1) or a propylene homopolymer fraction (H-PP1), the latter being preferred.
• the xylene cold soluble (XCS) content of the first polypropylene fraction (PPl) is preferably equal or below 4.0 wt.-%, more preferably equal or below 3.5 wt.-%, still more preferably in the range of 0.8 to 4.0 wt.-%, like in the range of 0.8 to 3.0 wt.-%.
• the weight percentage is based on the weight of the first polypropylene fraction (PPl).
• the first polypropylene fraction (PPl) is featured by a rather high melt flow rate MFR 2 (230 °C). Accordingly it is appreciated that the melt flow rate MFR 2 (230 °C) measured according to ISO 1133 is equal or more than 80 g/lOmin, preferably of equal or more than 150 g/lOmin, more preferably in the range of 80 to 500 g/lOmin, still more preferably in the range of 150 to 480 g/lOmin, yet more preferably in the range of 200 to 450 g/lOmin, still more preferably in the range of 250 to 450 g/lOmin.
• the first polypropylene fraction (PPl) is defined by a low molecular weight.
• the first polypropylene fraction (PPl) has a weight average molecular weight (Mw) measured by gel permeation chromatography (GPC; ISO 16014-4:2003) of equal or less than 130 kg/mol, more preferably of equal or less than 110 kg/mol, yet more preferably in the range of 72 to 110 kg/mol, still more preferably in the range of 75 to 100 kg/mol.
• Mw weight average molecular weight measured by gel permeation chromatography
• the second polypropylene fraction (PP2) can be either a random propylene copolymer fraction (second random propylene copolymer fraction (R-PP2)) or a propylene
• the xylene cold soluble (XCS) content of the second polypropylene fraction (PP2) is preferably equal or below 4.0 wt.-%, more preferably equal or below 3.5 wt.-%, still more preferably in the range of 0.8 to 4.0 wt.-%, like in the range of 0.8 to 3.0 wt.-%.
• the weight percentage is based on the weight of the second polypropylene fraction (PP2).
• the second polypropylene fraction (PP2) has a melt flow rate MFR 2 (230 °C) being higher than the third polypropylene fraction (PP3).
• the melt flow rate MFR 2 (230 °C) of the first polypropylene fraction (PP1) can be higher or equally the same, preferably higher, as the melt flow rate MFR 2 (230 °C) of the second polypropylene fraction (PP2).
• the second polypropylene fraction (PP2) has melt flow rate MFR 2 (230 °C) measured according to ISO 1133 in the range of 20 to 300 g/lOmin, preferably in the range of 50 to 250 g/lOmin, more preferably in the range of 70 to below 220 g/lOmin, yet more preferably in the range of 100 to 200 g/lOmin.
• the third polypropylene fraction (PP3) can be either a random propylene copolymer fraction (third random propylene copolymer fraction (R-PP3)) or a propylene homopolymer fraction (a third propylene homopolymer fraction (H-PP3)), the latter being preferred.
• the xylene cold soluble (XCS) content of the third polypropylene fraction (PP3) is preferably equal or below 4.0 wt.-%, more preferably equal or below 3.5 wt.-%, still more preferably in the range of 0.8 to 4.0 wt.-%, like in the range of 0.8 to 3.0 wt.-%.
• the weight percentage is based on the weight of the third polypropylene fraction (PP3).
• the third polypropylene (PP3) has preferably the lowest melt flow rate MFR 2 (230 °C) of the three polypropylene fractions (PP1), (PP2), and (PP3), more preferably the lowest melt flow rate MFR 2 (230 °C) of the polymer fractions present in the polypropylene (PP). Accordingly it is appreciated that the third polypropylene (PP3) has melt flow rate MFR 2 (230 °C) measured according to ISO 1133 in the range of 1.0 to 15.0 g/lOmin, preferably in the range of 2.0 to 15.0 g/lOmin, still more preferably in the range of 2.0 to 12.0 g/lOmin, such as 3 to 10 g/lOmin.
• the values are based on the total weight of the matrix (M), preferably based on the amount of the polypropylene fractions (PPl), (PP2), and (PP3) together.
• the amount of the polypropylene fraction having a melt flow rate MFR 2 (230 °C) measured according to ISO 1133 in the range of 80.0 to 500.0 g/lOmin, preferably of the first polypropylene fraction (PPl), is in the range of 20 to 55 wt.-%, preferably in the range of 25 to 45 wt.-%, more preferably in the range of 30 to 45 wt.-%, still more preferably 35 to 45 wt.-%.
• the values are based on the total weight of the matrix (M), preferably based on the amount of the polypropylene fractions (PPl), (PP2), and (PP3) together.
• the remaining fraction of the three polypropylene fractions (PPl), (PP2), and (PP3), preferably the second polypropylene fraction (PP2) is present in the range of 20 to 55 wt.-%, preferably in the range of 25 to 55 wt.-%, more preferably 30 to 45 wt.-%, still more preferably 35 to 45 wt.-%.
• the values are based on the total amount of the matrix (M), i.e., the polypropylene (PP), preferably based on the amount of the polypropylene fractions (PPl), (PP2), and (PP3) together.
• polypropylene fraction (PP2) polypropylene fraction (PP2), and the third polypropylene fraction (PP3).
• the polypropylene (PP) is produced in a sequential polymerization process, preferably as described in detail below. Accordingly the three polypropylene fractions (PP1), (PP2), and (PP3) are an intimate mixture, which is not obtainable by mechanical blending.
• the polypropylene (PP) is obtained by blending the polypropylene fractions (PP1), (PP2), and (PP3).
• a further essential component of the present invention is the elastomer (E).
• the properties of the elastomer (E) mainly influence the xylene cold soluble (XCS) of the final heterophasic propylene copolymer (HECO).
• the properties defined below for the elastomer (E) are equally applicable for the the xylene cold soluble (XCS) fraction of the heterophasic propylene copolymer (HECO).
• the elastomer can be any elastomer.
• the elastomer (E) is an ethylene copolymer elastomer comprising ethylene monomer units and comonomer units, wherein the comonomer is selected from C3 to C20 a- olefins, preferably propene, 14outene, 14iexene and 1-octene, or C 5 to C20 ⁇ , ⁇ -alkadienes, preferably 1 ,7-octadiene.
• the comonomer is selected from propene, 14outene, 1 -hexene, and 1 - octene, the latter is especially preferred.
• the elastomer (E) has a melt flow rate MFR 2 (190 °C) measured according to ISO 1133 of 10 to 80 g/lOmin. More preferably, the elastomer (E) has a melt flow rate MFR 2 (190 °C) of 15 to 70 g/lOmin, still more preferably of 20 to 60 g/lOmin, yet more preferably 20 to 50 g/lOmin.
• the elastomer (E) has an intrinsic viscosity of 0.7 to 2.5 dl/g, preferably 0.8 to 2.0 dl/g, more preferably 0.8 to 1.5 dl/g.
• the intrinsic viscosity is measured according to DIN ISO 1628/1, October 1999 (in Decalin at 135 °C).
• the elastomer (E) has preferably a density of lower than 940 kg/m 3 , more preferably 920 kg/m 3 or lower, still more preferably in the range of 850 to 920 kg/m 3 , yet more preferably in the range 860 to 910 kg/m 3 .
• the heterophasic propylene copolymer (HECO) may comprise additionally a polyethylene (PE), in particular a polyethylene (PE) as defined below. In such a case it is preferred that a mixture of the elastomer and the polyethlene (PE) shows a density as given in this paragraph.
• the amount of elastomer (E) in the heterophasic propylene copolymer (HECO) is rather high. Accordingly it is preferred that the elastomer (E) is present in the heterophasic propylene copolymer (HECO) in an amount of equal or more than 20.0 wt.-%, more preferably in an amount of equal or more 20.0 to 50.0 wt.-%, yet more preferably in an amount of 25.0 to 40.0 wt.-%, based on the total weight of the heterophasic propylene copolymer (HECO), preferably based on weight of the matrix (M), i.e. the polypropylene (PP), and the elastomer (E) together.
• M matrix
• PP polypropylene
• the weight ratio between the matrix (M) and the elastomer (E) is less than 4.0, more preferably 1.0 to below 4.0, yet more preferably 1.5 to 3.0.
• heterophasic propylene copolymer comprises,
• (b) equal or more than 20 wt.-%, more preferably 20.0 to 50.0 wt.-%, still more preferably 25.0 to 40.0 wt.-%, of the elastomer (E), based on the heterophasic propylene copolymer (HECO), preferably based on the total amount of the polypropylene (PP) and the elastomer (E).
• HECO heterophasic propylene copolymer
• PE Polyethylene
• the heterophasic propylene copolymer (HECO) optionally further comprises a crystalline polyethylene (PE).
• crystalline indicates that the polyethylene (PE) differs from the elastomers (E). Whereas the polyethylene (PE) is crystalline and not soluble in cold xylene, the elastomer (E) is predominantly non-crystalline and thus soluble in cold xylene.
• the polyethylene (PE) a high density polyethylene (HDPE).
• the high density polyethylene (HDPE) used according to the invention is well known in the art and commercially available.
• the high density polyethylene preferably has a melt flow rate MFR 2 (190 °C) of 15 to 45 g/lOmin, preferably 20 to 40 g/lOmin, more preferably of 25 to 35 g/lOmin.
• the high density polyethylene typically has a density of at least 940 kg/m 3 , preferably of at least 945 kg/m 3 , more preferably at least 955 kg/m 3 , still more preferably in the range of 945 to 970 kg/m 3 , yet more preferably in the range of 950 to 965 kg/m 3 .
• the high density polyethylene (HDPE) may be present in an amount of up to 8 wt.-%, preferably up to 5 wt.-%, more preferably in the range of 0 to 8 wt.-%, like in the range of 1 to 8 wt.-%, yet more preferably in the range of 0 to 6 wt.-%, like in the range of 1 to 6 wt.-%, based on the total weight of the heterophasic propylene copolymer (HECO).
• HECO heterophasic propylene copolymer
• Inorganic filler i.e. the high density polyethylene (HDPE)
• heterophasic propylene copolymer may optionally comprise an inorganic filler (F) in amounts of up to 25 wt.-%, preferably in an amount of up to 22 wt.-%, more preferably in the range of 4 to 25 wt.-%, still more preferably 5 to 20 wt.-%, based on the total weight of the heterophasic propylene copolymer (HECO).
• the inorganic filler (F) is a phyllosilicate, mica or wollastonite.
• the inorganic filler (F) is selected from the group consisting of mica, wollastonite, kaolinite, smectite, montmorillonite and talc.
• the most preferred the inorganic filler (F) is talc.
• the mineral filler (F) preferably has a cutoff particle size d95 [mass percent] of equal or below 20 ⁇ , more preferably in the range of 2.5 to 1 ⁇ , like in the range of 2.5 to 8.0 ⁇ .
• the inorganic filler (F) has a surface area measured according to the commonly known BET method with N 2 gas as analysis adsorptive of less than 22 m 2 /g, more preferably of less than 20 m 2 /g, yet more preferably of less than 18 m 2 /g.
• Inorganic fillers (F) fulfilling these requirements are preferably anisotropic mineral fillers (F), like talc, mica and wollastonite.
• the instant heterophasic propylene copolymer may comprise typical additives, like acid scavengers (AS), antioxidants (AO), nucleating agents (NA), hindered amine light stabilizers (HALS), slip agents (SA), and pigments.
• AS acid scavengers
• AO antioxidants
• NA nucleating agents
• HALS hindered amine light stabilizers
• SA slip agents
• pigments pigments.
• the amount of additives excluding the inorganic filler (F) shall not exceed 7 wt.-%, more preferably shall not exceed 5 wt.-%, like not more than 3 wt.-%, within the instant heterophasic propylene copolymer (HECO).
• heterophasic propylene copolymer preferably comprises
• PE polyethylene
• HDPE high density polyethylene
• the heterophasic propylene copolymer (HECO) of the present invention is preferably used for the production of automotive articles, like moulded automotive articles, preferably automotive injection moulded articles. Even more preferred is the use for the production of car interiors and exteriors, like bumpers, side trims, step assists, body panels, spoilers, dashboards, interior trims and the like, especially bumpers.
• the current invention also provides (automotive) articles, like injection molded articles, comprising at least to 60 wt.-%, more preferably at least 70 wt.-%, yet more preferably at least 75 wt.-%, like consisting, of the inventive heterophasic propylene copolymer (HECO).
• HECO heterophasic propylene copolymer
• the present invention is especially directed to automotive articles, especially to car interiors and exteriors, like bumpers, side trims, step assists, body panels, spoilers, dashboards, interior trims and the like, in particular bumpers, comprising at least to 60 wt- %, more preferably at least 70 wt.-%, yet more preferably at least 75 wt.-%, like consisting, of the inventive heterophasic propylene copolymer (HECO).
• HECO heterophasic propylene copolymer
• the present invention also relates to the use of the heterophasic propylene copolymer (HECO) as described above in an automotive application.
• the heterophasic propylene copolymer (HECO) is used in a bumper.
• the present invention will now be described in further detail by the examples provided below. Preparation of the heterophasic propylene copolymer (HECO)
• the heterophasic propylene copolymer (HECO) as defined above can be produced by a process as defined below.
• the heterophasic propylene copolymer (HECO) according to the present invention can be prepared by a process, comprising the step of blending the elastomer (E) with the matrix (M).
• blending refers according to the present invention to the action of providing a blend out of at least two different, pre-existing materials.
• the term “mixing” includes blending but also includes the in-situ formation of a blend by reacting one material in the presence of another material.
• the process according to the present invention may further comprise the step of blending a polypropylene fraction selected from (PP1), (PP2) and (PP3) with a mixture containing the remaining two polypropylene fractions obtaining thereby the polypropylene (PP).
• the process for the preparation of the polypropylene (PP) comprises the step of (a) blending a polypropylene fraction selected from (PP1), (PP2) and (PP3) with a further different polypropylene fraction selected from (PP1), (PP2) and (PP3) and subsequently adding the remaining fraction selected from (PP1), (PP2) and (PP3), or (b) blending the polypropylene fractions (PP1), (PP2), and (PP3) with each other in one step.
• the individual polypropylene fractions (PP1), (PP2) and (PP3) can be produced in a conventional way, for instance in a loop reactor or in a loop/gas phase reactor system.
• the present invention is directed to a sequential polymerization process for producing the polypropylene (PP) according to the instant invention, said polypropylene (PP) comprises a first polypropylene fraction (PP1), a second polypropylene fraction (PP2) and a third polypropylene fraction (PP3).
• Said process may comprise the steps of
• polypropylene fraction (PPl) propylene and optionally at least one ethylene and/or C4 to C12 a-olefin obtaining thereby the second polypropylene fraction (PP2), the first polypropylene fraction (PPl) being mixed with the second polypropylene fraction (PP2),
• step (dl) transferring the mixture of step (cl) into a third reactor (R3),
• step (el) polymerizing in the third reactor (R3) and in the presence of the mixture obtained in step (cl) propylene and optionally at least one ethylene and/or C4 to C12 a-olefin obtaining thereby the third polypropylene fraction (PP3), wherein the first polypropylene fraction (PPl), the second polypropylene fraction (PP2) and the third polypropylene fraction (PP3) are mixed with each other and form the polypropylene (PP);
• polypropylene fraction (PPl) propylene and optionally at least one ethylene and/or C4 to C12 ⁇ -olefin obtaining thereby the third polypropylene fraction (PP3), the first polypropylene fraction (PPl) being mixed with the third polypropylene fraction (PP3),
• step (d2) transferring the mixture of step (c2) into a third reactor (R3),
• step (e2) polymerizing in the third reactor (R3) and in the presence of the mixture obtained in step (c2) propylene and optionally at least one ethylene and/or C4 to C12 a-olefin obtaining thereby the second polypropylene fraction (PP2), wherein the first polypropylene fraction (PPl), the second polypropylene fraction (PP2) and the third polypropylene fraction (PP3) are mixed with each other and form the polypropylene (PP); polymerizing propylene and optionally at least one ethylene and/or C4 to C 12 a-olefin in a first reactor (Rl) obtaining the second polypropylene fraction (PP2), transferring the second polypropylene fraction (PP2) into a second reactor (R2), polymerizing in the second reactor (R2) and in the presence of said second polypropylene fraction (PP2) propylene and optionally at least one ethylene and/or C4 to C 12 a-olefin obtaining thereby the third polypropylene fraction (PP3)
• step (c4) polymerizing in the third reactor (R3) and in the presence of the mixture obtained in step (c4) propylene and optionally at least one ethylene and/or C4 to C 12 a-olefin obtaining thereby the third polypropylene fraction (PP3), wherein the first polypropylene fraction (PPl), the second polypropylene fraction (PP2) and the third polypropylene fraction (PP3) are mixed with each other and form the polypropylene (PP);
• polypropylene fraction (PP3) propylene and optionally at least one ethylene and/or C4 to C12 a-olefin obtaining thereby the first polypropylene fraction (PPl), the third polypropylene fraction (PP3) being mixed with the first polypropylene fraction (PPl),
• step (d5) transferring the mixture of step (c5) into a third reactor (R3),
• step (e5) polymerizing in the third reactor (R3) and in the presence of the mixture obtained in step (c5) propylene and optionally at least one ethylene and/or C4 to C12 a-olefin obtaining thereby the second polypropylene fraction (PP2), wherein the first polypropylene fraction (PPl), the second polypropylene fraction (PP2) and the third polypropylene fraction (PP3) are mixed with each other and form the polypropylene (PP);
• step (d6) transferring the mixture of step (c6) into a third reactor (R3),
• step (e6) polymerizing in the third reactor (R3) and in the presence of the mixture obtained in step (c6) propylene and optionally at least one ethylene and/or C4 to C12 a-olefin obtaining thereby the first polypropylene fraction (PP1), wherein the first polypropylene fraction (PP1), the second polypropylene fraction (PP2) and the third polypropylene fraction (PP3) are mixed with each other and form the polypropylene (PP).
• the monomers are flashed out.
• polypropylene the first polypropylene fraction (PP1), the second polypropylene fraction (PP2), and the third polypropylene fraction (PP3)
• PP1 the first polypropylene fraction
• PP2 the second polypropylene fraction
• PP3 the third polypropylene fraction
• the term "sequential polymerization process” indicates that the polypropylene is produced in at least three reactors connected in series. Accordingly the present process comprises at least a first reactor (Rl), a second reactor (R2), and a third reactor (R3).
• the term “polymerization reactor” shall indicate that the main polymerization takes place. Thus in case the process consists of four polymerization reactors, this definition does not exclude the option that the overall process comprises for instance a pre-polymerization step in a pre-polymerization reactor.
• the term “consist of is only a closing formulation in view of the main
• the first reactor (Rl) is preferably a slurry reactor (SR) and can be any continuous or simple stirred batch tank reactor or loop reactor operating in bulk or slurry.
• Bulk means a polymerization in a reaction medium that comprises of at least 60 % (w/w) monomer.
• the slurry reactor (SR) is preferably a (bulk) loop reactor (LR).
• the second reactor (R2), and the third reactor (R3) are preferably gas phase reactors (GPR).
• GPR gas phase reactors
• Such gas phase reactors (GPR) can be any mechanically mixed or fluid bed reactors.
• the gas phase reactors comprise a mechanically agitated fluid bed reactor with gas velocities of at least 0.2 m/sec.
• the gas phase reactor is a fluidized bed type reactor preferably with a mechanical stirrer.
• the first reactor (Rl) is a slurry reactor (SR), like loop reactor (LR), whereas the second reactor (R2), and the third reactor (R3) are gas phase reactors (GPR).
• SR slurry reactor
• R2 like loop reactor
• R3 gas phase reactors
• at least three, preferably three polymerization reactors namely a slurry reactor (SR), like loop reactor (LR), a first gas phase reactor (GPR-1), and a second gas phase reactor (GPR-2) connected in series are used. If needed prior to the slurry reactor (SR) a pre-polymerization reactor is placed.
• a preferred multistage process is a "loop-gas phase"-process, such as developed by Borealis A/S, Denmark (known as BORSTAR® technology) described e.g. in patent literature, such as in EP 0 887 379, WO 92/12182 WO 2004/000899, WO 2004/111095, WO 99/24478, WO 99/24479 or in WO 00/68315.
• a further suitable slurry-gas phase process is the Spheripol ® process of Basell.
• the conditions for the first reactor (Rl), i.e. the slurry reactor (SR), like a loop reactor (LR), of step (a) may be as follows:
• the temperature is within the range of 50 °C to 110 °C, preferably between 60 °C and 100 °C, more preferably between 68 and 95 °C,
• the pressure is within the range of 20 bar to 80 bar, preferably between 40 bar to 70 bar,
• step (c) the reaction mixture from step (a) is transferred to the second reactor (R2), i.e. gas phase reactor (GPR-1), i.e. to step (c), whereby the conditions in step (c) are preferably as follows:
• the temperature is within the range of 50 °C to 130 °C, preferably between 60 °C and 100 °C
• the pressure is within the range of 5 bar to 50 bar, preferably between 15 bar to 35 bar
• hydrogen can be added for controlling the molar mass in a manner known per se.
• the condition in the third reactor (R3), preferably in the second gas phase reactor (GPR-2), is similar to the second reactor (R2).
• the residence time can vary in the three reactor zones.
• the residence time in bulk reactor, e.g. loop is in the range 0.1 to 2.5 hours, e.g. 0.15 to 1.5 hours and the residence time in gas phase reactor will generally be 0.2 to 6.0 hours, like 0.5 to 4.0 hours.
• the polymerization may be effected in a known manner under supercritical conditions in the first reactor (Rl), i.e. in the slurry reactor (SR), like in the loop reactor (LR), and/or as a condensed mode in the gas phase reactors (GPR).
• Rl first reactor
• SR slurry reactor
• LR loop reactor
• GPR gas phase reactors
• the process comprises also a prepolymerization with the catalyst system, as described in detail below, comprising a Ziegler-Natta procatalyst, an external donor and optionally a cocatalyst.
• the catalyst system as described in detail below, comprising a Ziegler-Natta procatalyst, an external donor and optionally a cocatalyst.
• the prepolymerization is conducted as bulk slurry polymerization in liquid propylene, i.e. the liquid phase mainly comprises propylene, with minor amount of other reactants and optionally inert components dissolved therein.
• the prepolymerization reaction is typically conducted at a temperature of 10 to 60 °C, preferably from 15 to 50 °C, and more preferably from 20 to 45 °C.
• the pressure in the prepolymerization reactor is not critical but must be sufficiently high to maintain the reaction mixture in liquid phase.
• the pressure may be from 20 to 100 bar, for example 30 to 70 bar.
• the catalyst components are preferably all introduced to the prepolymenzation step.
• hydrogen may be added into the prepolymerization stage to control the molecular weight of the prepolymer as is known in the art.
• antistatic additive may be used to prevent the particles from adhering to each other or to the walls of the reactor.
• the polypropylene (PP) preferably is 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
• R 1 and R 2 are independently at least a C 5 alkyl under conditions where a transesterification between said Ci to C 2 alcohol and said dialkylphthalate of formula (I) takes place to form the internal donor
• step d) optionally reacting the product of step c) with additional T1CI4.
• 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.
• Ethanol is preferably used as alcohol.
• the adduct which is first melted and then spray crystallized or emulsion solidified, is used as catalyst carrier.
• MgCl 2 *nROH wherein R is methyl or ethyl, preferably ethyl and n is 1 to 6, is contacting with T1CI4 to form a titanized carrier, followed by the steps of
• dialkylphthalate of formula (I) selected from the group consisting of propylhexylphthalate (PrHP), dioctylphthalate (DOP), di-iso- decylphthalate (DIDP), and ditridecylphthalate (DTDP), yet more preferably the dialkylphthalate of formula (I) is a dioctylphthalate (DOP), like di-iso-octylphthalate or diethylhexylphthalate, in particular diethylhexylphthalate, to form a first product,
• DOP dioctylphthalate
• R 1 and R 2 being methyl or ethyl, preferably ethyl
• dialkylphthalat of formula (II) being the internal donor
• the adduct of the formula MgCl 2 *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 preferably 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.
• the procatalyst used according to the invention contains 2.5 wt.-% of titanium at the most, preferably 2.2% wt.-% at the most and more preferably 2.0 wt.-% at the most.
• Its donor content is preferably between 4 to 12 wt.-% and more preferably between 6 and 10 w -%.
• 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 diethyl phthalate (DEP) as the internal donor compound.
• DOP dioctylphthalate
• DEP diethyl phthalate
• the catalyst used according to the invention is the BCF20P catalyst of Borealis (prepared according to WO 92/19653 as disclosed in WO 99/24479; especially with the use of dioctylphthalate as dialkylphthalate of formula (I) according to WO 92/19658) or the catalyst Polytrack 8502, commercially available from Grace.
• the catalyst system used preferably comprises in addition to the special Ziegler-Natta procatalyst an
• trialkylaluminium like triethylaluminium (TEA), dialkyl aluminium chloride and alkyl aluminium sesquichloride.
• TAA triethylaluminium
• dialkyl aluminium chloride dialkyl aluminium chloride
• alkyl aluminium sesquichloride alkyl aluminium sesquichloride
• Component (iii) of the catalysts system used is an external donor represented by formula (Ilia) or (Illb).
• Formula (Ilia) is defined by
• R 5 represents a branched-alkyl group having 3 to 12 carbon atoms, preferably a branched-alkyl group having 3 to 6 carbon atoms, or a cyclo-alkyl having 4 to 12 carbon atoms, preferably a cyclo-alkyl having 5 to 8 carbon atoms. It is in particular preferred that R 5 is selected from the group consisting of iso-propyl, iso- butyl, iso-pentyl, tert. -butyl, tert.-amyl, neopentyl, cyclopentyl, cyclohexyl,
• R x and R y can be the same or different a represent a hydrocarbon group having 1 to 12 carbon atoms.
• R x and R y 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 R x and R y 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.
• both R x and R y are the same, yet more preferably both R x and R y are an ethyl group.
• the external donor of formula (Illb) is diethylaminotriethoxysilane .
• the external donor is selected from the group consisting of
• diethylaminotriethoxysilane Si(OCH 2 CH 3 ) 3 (N(CH 2 CH 3 ) 2 )]
• dicyclopentyl dimethoxy silane Si(OCH 3 ) 2 (cyclo-pentyl) 2
• diisopropyl dimethoxy silane Si(OCH 3 ) 2 (CH(CH 3 ) 2 ) 2 ] and mixtures thereof.
• 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 (component (i)), an external donor (component (iii) and optionally a cocatalyst (component (iii)), which vinyl compound has the formula:
• R 3 and R 4 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 heterophasic propylene copolymer according to this invention.
• the polymerized vinyl compound can act as an a-nucleating agent.
• the obtained polypropylene (PP) is belended with the elastomer (E) and the optional additives.
• extruders like single screw extruders as well as twin screw extruders are used for blending.
• suitable devices include planet extruders and single screw co-kneaders.
• twin screw extruders including high intensity mixing and kneading sections.
• Suitable melt temperatures for preparing the heterophasic propylene copolymer (HECO) are in the range from 170 to 300 °C, preferably in the range from 200 to 260 °C.
• the heterophasic propylene copolymer (HECO) recovered from the extruder is usually in the form of pellets. These pellets are then preferably further processed, e.g. by injection molding to generate articles, like the articles defined in more detail above.
• w(PPl) is the weight fraction of the first polypropylene fraction (PP1), i.e. the
• w(PP2) is the weight fraction of the second polypropylene fraction (PP2), i.e. of the polymer produced in the second reactor (R2),
• C(PP1) is the comonomer content [in wt.-%] of the first polypropylene fraction
• C(R2) is the comonomer content [in wt.-%] of the product obtained in the second reactor (R2), i.e. the mixture of the first polypropylene fraction (PP1) and the second polypropylene fraction (PP2),
• C(PP2) is the calculated comonomer content [in wt.-%] of the second polypropylene
• w(PPl) is the weight fraction of the first polypropylene fraction (PP1), i.e. the
• w(PP2) is the weight fraction of the second polypropylene fraction (PP2), i.e. of the polymer produced in the second reactor (R2),
• XS(PPl) is the xylene cold soluble (XCS) content [in wt.-%] of the first
• polypropylene fraction (PP1) i.e. of the product of the first reactor (Rl)
• XS(R2) is the xylene cold soluble (XCS) content [in wt.-%] of the product obtained in the second reactor (R2), i.e. the mixture of the first polypropylene fraction (PP1) and the second polypropylene fraction (PP2),
• XS(PP2) is the calculated xylene cold soluble (XCS) content [in wt.-%] of the second polypropylene fraction (PP2).
• w(PPl) is the weight fraction of the first polypropylene fraction (PP1), i.e. the
• w(PP2) is the weight fraction of the second polypropylene fraction (PP2), i.e. of the polymer produced in the second reactor (R2),
• MFR(PPl) is the melt flow rate MFR 2 (230 °C) [in g/lOmin] of the first polypropylene fraction (PP1), i.e. of the product of the first reactor (Rl),
• MFR(R2) is the melt flow rate MFR 2 (230 °C) [in g/lOmin] of the product obtained in the second reactor (R2), i.e. the mixture of the first polypropylene fraction (PP1) and the second polypropylene fraction (PP2),
• MFR(PP2) is the calculated melt flow rate MFR 2 (230 °C) [in g/lOmin] of the second polypropylene fraction (PP2).
• w(R2) is the weight fraction of the second reactor (R2), i.e. the mixture of the first polypropylene fraction (PP1) and the second polypropylene fraction (PP2)
• w(PP3) is the weight fraction of the third polypropylene fraction (PP3), i.e. of the polymer produced in the third reactor (R3)
• C(R2) is the comonomer content [in wt.-%] of the product of the second reactor
• C(R3) is the comonomer content [in wt.-%] of the product obtained in the third reactor (R3), i.e. the mixture of the first polypropylene fraction (PP1), the second polypropylene fraction (PP2), and the third polypropylene fraction (PP3),
• C(PP3) is the calculated comonomer content [in wt.-%] of the third polypropylene fraction (PP3).
• w(R2) is the weight fraction of the second reactor (R2), i.e. the mixture of the first polypropylene fraction (PP1) and the second polypropylene fraction (PP2)
• w(PP3) is the weight fraction of the third polypropylene fraction (PP3), i.e. of the polymer produced in the third reactor (R3)
• XS(R2) is the xylene cold soluble (XCS) content [in wt.-%] of the product of the second reactor (R2), i.e. of the mixture of the first polypropylene fraction (PP1) and second polypropylene fraction (PP2),
• XS(R3) is the xylene cold soluble (XCS) content [in wt.-%] of the product obtained in the third reactor (R3), i.e. the mixture of the first polypropylene fraction (PP1), the second polypropylene fraction (PP2), and the third polypropylene fraction (PP3),
• XS(PP3) is the calculated xylene cold soluble (XCS) content [in wt.-%] of the third polypropylene fraction (PP3).
• w(R2) is the weight fraction of the second reactor (R2), i.e. the mixture of the first polypropylene fraction (PP1) and the second polypropylene fraction (PP2)
• w(PP3) is the weight fraction of the third polypropylene fraction (PP3), i.e. of the polymer produced in the third reactor (R3)
• MFR(R2) is the melt flow rate MFR 2 (230 °C) [in g/1 Omin] of the product of the second reactor (R2), i.e. of the mixture of the first polypropylene fraction (PP1) and second polypropylene fraction (PP2),
• MFR(R3) is the melt flow rate MFR 2 (230 °C) [in g/1 Omin] of the product obtained in the third reactor (R3), i.e. the mixture of the first polypropylene fraction (PP1), the second polypropylene fraction (PP2), and the third polypropylene fraction (PP3),
• MFR(PP3) is the calculated melt flow rate MFR 2 (230 °C) [in g/1 Omin] of the third polypropylene fraction (PP3).
• M n Number average molecular weight (M n ), weight average molecular weight (M w ) and molecular weight distribution (MWD) are determined by Gel Permeation Chromatography (GPC) according to the following method:
• a Waters Alliance GPCV 2000 instrument equipped with refractive index detector and online viscosimeter was used with 3 x TSK-gel columns (GMHXL-HT) from TosoHaas and 1 ,2,4-trichlorobenzene (TCB, stabilized with 200 mg/L 2,6-Di tert butyl-4-methyl- phenol) as solvent at 145 °C and at a constant flow rate of 1 mL/min.
• sample solution 216.5 ⁇ .
• the column set was calibrated using relative calibration with 19 narrow MWD polystyrene (PS) standards in the range of 0.5 kg/mol to 11 500 kg/mol and a set of well characterized broad polypropylene standards. All samples were prepared by dissolving 5 - 10 mg of polymer in 10 mL (at 160 °C) of stabilized TCB (same as mobile phase) and keeping for 3 hours with continuous shaking prior sampling in into the GPC instrument.
• PS polystyrene
• Density is measured according to ISO 1183-1 - method A (2004). Sample preparation is done by compression moulding in accordance with ISO 1872-2:2007.
• MFR 2 (230 °C) is measured according to ISO 1133 (230 °C, 2.16 kg load).
• MFR 2 (190 °C) is measured according to ISO 1133 (190 °C, 2.16 kg load). Quantification of comonomer content by FTIR spectroscopy
• the comonomer content is determined by quantitative Fourier transform infrared spectroscopy (FTIR) after basic assignment calibrated via quantitative 13 C nuclear magnetic resonance (NMR) spectroscopy in a manner well known in the art. Thin films are pressed to a thickness of between 100-500 ⁇ and spectra recorded in transmission mode.
• FTIR quantitative Fourier transform infrared spectroscopy
• NMR quantitative 13 C nuclear magnetic resonance
• the ethylene content of a polypropylene-co-ethylene copolymer is determined using the baseline corrected peak area of the quantitative bands found at 720-722 and 730- 733 cm “1 .
• the butene or hexene content of a polyethylene copolymer is determined using the baseline corrected peak area of the quantitative bands found at 1377- 1379 cm “1 .
• Quantitative results are obtained based upon reference to the film thickness.
• Intrinsic viscosity is measured according to DIN ISO 1628/1, October 1999 (in Decalin at 135 °C).
• melt- and crystallization enthalpy were measured by the DSC method according to ISO 11357-3.
• the tensile modulus is measured at 23 °C according to ISO 527-1 (cross head speed 1 mm/min) using injection moulded specimens according to ISO 527-2(lB), produced according to EN ISO 1873-2 (dog 10 bone shape, 4 mm thickness).
• Charpy notched impact strength is determined according to ISO 179 / leA at 23 °C and at - 20 °C by using injection moulded test specimens as described in EN ISO 1873-2 (80 x 10 x 4 mm).
• Puncture energy is determined in the instrumental falling weight (IFW) test according to ISO 6603-2 using injection moulded plaques of 60x60x2 mm and a test speed of 4.4 m/s. Puncture energy reported results from an integral of the failure energy curve measured at +23°C and -20°C. Shrinkage is determined on centre gated, injection moulded circular disks (diameter 180 mm, thickness 3 mm, having a flow angle of 355° and a cut out of 5°). Two specimens are moulded applying two different holding pressure times (10s and 20s respectively). The melt temperature at the gate is 260°C, and the average flow front velocity in the mould 100 mm/s. Tool temperature: 40 °C, back pressure: 600 bar.
• IFD instrumental falling weight
• Particle size (d50 and cutoff particle size d95 (Sedimentation)) is calculated from the particle size distribution [mass percent] as determined by gravitational liquid sedimentation according to ISO 13317-3 (Sedigraph)
• Table 1 summarizes the polymer design of trimodal polypropylenes which is used in the working example.
• Table 2 Compound recipes for working example and comparative example
• HK060AE is a commercial product of Borealis AG, which is a polypropylene homopolymer having a MFR 2 (230 °C/2.16 kg) of 125 g/lOmin and a density of 905 kg/m 3 .
• Engage 8400 is a commercial product of Dow Elastomers, which is an ethylene- octene copolymer having a MFR 2 (190 °C, 2.16 kg) of 30 g/lOmin and a density of 870 kg/m 3 .
• HDPE is a commercial high density polypropylene (HDPE) "MG9601" of
• Borealis which has a MFR (190 °C/2.16 kg) of 30 g/lOmin and a density of 960 kg/m 3
• Talcum is a commercially talcum "Steamic T1CA” available from from Luzenac with a d50 of 1.8 ⁇ cutoff particle size (dg 5 ) of 6.2 ⁇ and a BET of 8.0 m 2 /g.
• Table 3 Property profiles of polypropylene plastomer blends
• the working example and the comparative example show a similar melt flow rate
• the working example according to the invention - based on a trimodal polypropylene - shows as significantly improved stiffness level, and a slightly improved Charpy impact strength at room temperature. More significant is the improvement of the puncture energy by using a trimodal matrix, the puncture energy of the blend with elastomer is more than tripled compared to that of the commercial reference.

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