CN113166506A

CN113166506A - Composition suitable for bumper

Info

Publication number: CN113166506A
Application number: CN201880099773.6A
Authority: CN
Inventors: 陈世平; 潘甚颐; 周信; 朱胜全; 黄荣才
Original assignee: Bolu Plastic Shanghai Co ltd
Current assignee: Bolu Plastic Shanghai Co ltd
Priority date: 2018-12-05
Filing date: 2018-12-05
Publication date: 2021-07-23
Anticipated expiration: 2038-12-05
Also published as: CN113166506B; WO2020113461A1

Abstract

A composition comprising: a)40 to 70 wt%, preferably 40 to 60 wt% of a first heterophasic polypropylene HECO-PP1, the MFR (ISO1133, 230 ℃/2.16kg) of the first heterophasic polypropylene HECO-PP1 being 90 to 120g/10 min; d)10 to 30 wt%, preferably 12 to 20 wt%, of an elastomeric copolymer derived from ethylene and at least one C₄‑C₁₂An alpha-olefin, the elastomeric copolymer having an MFR (ISO1133, 190 ℃/2.16kg) of from 0.2g/10min to 8g/10 min; and e)10 to 30 wt%, preferably 16 to 22 wt% of an inorganic filler, preferably talc; wherein the MFR (ISO1133, 230 ℃/2.16kg) of the composition is preferably from 30g/10min to 50g/10 min.

Description

Composition suitable for bumper

Technical Field

The present invention relates to specific polypropylene compounds suitable for use in automotive applications, in particular bumpers (bumpers).

Background

PP compounds are widely used in automotive interior and exterior applications, such as door panels, instrument panels and bumpers, because of their excellent properties and ease of processing. Less consumption and CO due to petrochemical requirements₂With less emissions, automotive OEMs need to reduce part weight to achieve the lighter weight goal. One way to achieve the goal of light weight for bumper systems is to reduce the thickness of the bumper, i.e., thin-walled bumpers. Generally, a common bumper on the market has a thickness of 2.8mm, and a thin-walled bumper is required to have a thickness of 2.3mm to 2.5 mm.

For thin-walled bumpers, the stiffness of the PP compound must be improved to compensate for the stiffness loss due to the reduced thickness. Furthermore, the thinner the wall thickness, the faster the cooling rate and melt solidification in the mold tunnel. Therefore, there is a need for higher flow compounds to make thin wall bumpers. The flowability of the compound should be increased high enough to completely and quickly fill the mold. Unfortunately, higher flow properties will result in limited mechanical properties. Thus, for thin-walled bumpers, there is a conflict between the objectives (i.e., higher melt flow to fully solidify, higher stiffness, and higher impact performance).

Based on this finding, the present invention achieves an excellent balance of stiffness, flow and mechanical properties through compositions that can be obtained from specific blends.

Disclosure of Invention

The present invention provides a composition comprising:

a)40 to 70 wt%, preferably 40 to 60 wt% of a first heterophasic polypropylene HECO-PP1, the MFR (ISO1133, 230 ℃/2.16kg) of the first heterophasic polypropylene HECO-PP1 being 90 to 120g/10 min;

d)10 to 30 wt%, preferably 12 to 20 wt%, of an elastomeric copolymer derived from ethylene and at least one C₄-C₁₂An alpha-olefin, the elastomeric copolymer having an MFR (ISO1133, 190 ℃/2.16kg) of from 0.2g/10min to 8g/10 min; and

e)10 to 30 wt%, preferably 16 to 22 wt% of an inorganic filler, preferably talc;

wherein the composition preferably has an MFR (ISO1133, 230 ℃/2.16kg) of from 30g/10min to 50g/10min, preferably from 30g/10min to 45g/10 min.

In particular, the present invention provides such a composition, wherein the MFR (ISO1133, 230 ℃/2.16kg) of said composition is comprised between 30 and 50g/10min, said composition being obtainable by extruding:

a)40 to 60 wt% of a first heterophasic polypropylene HECO-PP1, the first heterophasic polypropylene HECO-PP1 having an MFR (ISO1133, 230 ℃/2.16kg) of 90 to 120g/10 min;

b)0 to 25 wt% of a second heterophasic polypropylene HECO-PP2, the second heterophasic polypropylene HECO-PP2 having an MFR (ISO1133, 230 ℃/2.16kg) of 10 to 30g/10 min;

c)0 to 11 wt% of a propylene homopolymer (Homo-PP) having an MFR (ISO1133, 230 ℃/2.16kg) of from 1g/10min to 100g/10 min;

d) from 12 to 20 wt% of an elastomeric copolymer derived from ethylene and at least one C₄-C₁₂An alpha-olefin, the elastomeric copolymer having an MFR (ISO1133, 190 ℃/2.16kg) of from 0.2g/10min to 8g/10 min;

e)16 to 22 wt% talc;

f)0 to 3 wt% of a carrier polymer;

g)0 to 3 wt% of an additive, optionally selected from an antioxidant, a UV stabilizer, a scratch-resistant agent, a mold release agent and/or an acid scavenger;

h)0 to 5 weight percent color master batch (color master batch);

wherein the sum of components a) to h) is 100 wt.%.

The invention further provides a process for producing a composition having an MFR (ISO1133, 230 ℃/2.16kg) of from 30g/10min to 50g/10min, comprising the steps of:

I) providing a twin screw extruder having a first side feeder, a second side feeder, and a main feeder;

II) providing the starting materials a) to h):

e)16 to 22 wt% talc;

f)0 to 3 wt% of polypropylene homo-and/or copolymer as additive carrier;

h)0 wt% to 5 wt% of a color concentrate;

wherein the sum of components a) to h) is 100 wt.%;

the method further comprises an extrusion step, wherein:

III) premixing component f) in an amount of up to 3% by weight with one or more additives g), using f) in powder form, resulting in a first premix;

IV) feeding the first pre-mixture into a first side feeder of a twin-screw extruder,

v) feeding component a), component b) (if present), component c) (if present) and component d) into the main feeder of the twin-screw extruder;

VI) feeding talc to the other side feeder of the twin-screw extruder;

wherein the mixture is heated and mixed at a temperature of 100 ℃ to 250 ℃.

In another aspect, the present invention relates to an injection molded article comprising, preferably consisting of, the composition of the present invention.

In another aspect, the present invention relates to the use of a composition for the manufacture of a bumper having a thickness of 2.5mm or less, said composition comprising:

wherein the MFR (ISO1133, 230 ℃/2.16kg) of the composition is preferably from 30g/10min to 50g/10 min.

In another aspect, the invention relates to the use of a composition having an MFR (ISO1133, 230 ℃/2.16kg) of from 30g/10min to 50g/10min for the manufacture of bumpers having a thickness of 2.5mm or less, said composition being obtainable by extruding:

e)16 to 22 wt% talc;

f)0 to 3 wt% of a carrier polymer;

g)0 to 3 wt% of an additive, optionally selected from an antioxidant, a UV stabilizer, a scratch-resistant agent, a mold release agent, and/or an acid scavenger;

h)0 wt% to 5 wt% of a color concentrate;

wherein the sum of components a) to h) is 100 wt.%.

By heterophasic polypropylene is meant a polypropylene having more than one phase, i.e. a matrix phase and an elastomeric phase dispersed in the matrix phase. The heterophasic properties of heterophasic polypropylenes are easy to detect, for example using glass transition point analysis according to ISO 6721-7.

Elastomeric copolymers are copolymers of ethylene having elastomeric properties.

Carrier or carrier polymer means a polymeric material used to incorporate additives into the composition. It goes without saying that the carrier polymer may also be more than one polymer present (i.e. foreseen) in the inventive composition. The inorganic filler means a filler having a skeletal structure (skeletal structure) containing no carbon atom. Carbon black is not an inorganic filler.

Bumpers are structures that are attached to or integrated with the front and rear ends of a motor vehicle to absorb shocks in a light collision and/or to optimize aerodynamics.

The composition of the invention has better fluidity, flexural modulus and toughness, allowing the provision of thin-walled bumpers with a thickness of 2.5mm or less, preferably 2.3mm or less.

Component a), i.e. from 40 to 60 wt% of a first heterophasic polypropylene HECO-PP1, the MFR (ISO1133, 230 ℃/2.16kg) of said first heterophasic polypropylene HECO-PP1 being from 90g/10min to 120g/10 min; component a) ensures essentially high flowability and essential mechanical properties.

Optional component b), i.e. 0 to 25 wt% of a second heterophasic polypropylene HECO-PP2, the second heterophasic polypropylene HECO-PP2 having an MFR (ISO1133, 230 ℃/2.16kg) of 10 to 30g/10 min; component b) can regulate the melt flow rate and, in addition, improve the mechanical properties.

Optional component c), i.e. 0 to 11 wt% of a propylene homopolymer (Homo-PP) having an MFR (ISO1133, 230 ℃/2.16kg) of 1g/10min to 100g/10 min; component c) can be added for increasing the stiffness.

Component d), i.e. from 12 to 20% by weight of an elastomeric polymer derived from ethylene and at least one C₄-C₁₂An alpha-olefin, the MFR (ISO1133, 190 ℃/2.16kg) of the elastomeric polymer being from 0.2g/10min to 8g/10 min; component d) improves the impact properties of the final composition.

Component e), i.e. from 16 to 22% by weight of an inorganic filler, preferably talc; component e) can also improve the stiffness.

Preferably, the inorganic filler is selected from glass fibers, carbon fibers, phyllosilicates, mica, wollastonite or mixtures thereof. More preferably, the inorganic filler is selected from mica, wollastonite, kaolinite, montmorillonite (smectite), montmorillonite (montmorillonite) and talc. The most preferred inorganic filler is talc.

Component f), i.e. from 0.5 to 2% by weight of polypropylene homo-and/or copolymer as a carrier for the additives; component f) ensures good dispersion of the additives.

Optional component g), i.e. 0 to 3 wt% of additives, optionally selected from antioxidants, UV stabilizers, scratch retardants, mold release agents and/or acid scavengers; component g) ensures long-term stability.

Optional component h), i.e. 0 to 5 wt% of a colour concentrate; component h) can provide good appearance.

The sum of all components a) to h) (if present) amounts to 100% by weight.

Preferably, the compositions of the invention have a flexural modulus (ISO 178) of at least 1900MPa, preferably 2000MPa, more preferably 2400MPa, measured on injection moulded samples of 80X 10X 4mm prepared according to ISO 294-1: 1996. The flexural modulus can be adjusted by varying the amount of propylene homopolymer and/or the amount of talc and/or the amount of component b), i.e. the second heterophasic polypropylene HECO-PP 2.

Preferably, the composition of the invention is obtained by extrusion using talc, said composition having a BET (ISO 9277) of 15m²G to 25m²(ii) g, more preferably 16m²G to 22m²(ii) g, most preferably 16m²G to 20m²(ii) in terms of/g. Talc has a higher BET helps to increase the hardness of the composition.

Independently, the composition of the invention is preferably obtained by extrusion using talc having a median diameter D₅₀(ISO 13320-1) is 3.7 to 11.0. mu.m, more preferably 8.0 to 11.0. mu.m, most preferably 9.0 to 11.0. mu.m. On the other hand, the talc used for extrusion has a D95(ISO 13320-1) of preferably 6.8 to 36.0. mu.m, more preferably 31.0 to 35.0. mu.m.

In a preferred aspect, component c), i.e. the optional propylene homopolymer Homo-PP, has an MFR (ISO1133, 230 ℃/2.16kg) of from 1g/10min to 100g/10min, preferably from 2g/10min to 50g/10min, more preferably from 3g/10min to 20g/10min, component c) being added for increasing the stiffness, the content of component c) being at least 0.5 wt. -%, more preferably at least 1.0 wt. -%, particularly more preferably from 0.5 wt. -% to 30.0 wt. -%, even more preferably from 1.0 wt. -% to 15.0 wt. -%, most preferably from 1.0 wt. -% to 11 wt. -%, relative to the total weight of the composition.

In addition to these components, the composition of the invention is obtained by a preferred extrusion process contributing to an excellent balance of properties, the preferred extrusion process being characterized by comprising the steps of:

(i) premixing the carrier polymer or any of the polymer components of the invention in an amount of up to 3% by weight (relative to the total weight of the finally produced composition) with one or more additives g) to produce a first premix, wherein the carrier polymer used is preferably present in powder form;

(ii) feeding the first premix into a first side feeder of a twin screw extruder;

(iii) feeding component a), component b) (if present), component c) (if present) and component d) into the main feeder of the twin-screw extruder;

(iv) feeding talc into the other side feeder of the twin screw extruder;

wherein the mixture is heated and mixed at a temperature of 100 ℃ to 250 ℃.

Independently or in addition, the composition of the invention is preferably obtainable by extrusion, wherein the die (die) temperature of the extruder is from 190 ℃ to 230 ℃.

In another aspect, the composition of the invention is preferably obtainable by extrusion, wherein the screw speed is from 500rpm to 640 rpm.

In another preferred aspect, the composition of the invention is preferably obtainable by extrusion from a twin-screw extruder having a die, wherein the barrel temperature profile in the first section of the extrusion direction increases from 100 to 220 ℃ and in the second section (downstream of the first section and upstream of the die), the barrel temperature optionally decreases from the maximum temperature (reached at the end of the first section) to 190 ℃ to 210 ℃.

Preferably, the composition of the invention comprises as component d) an ethylene octene copolymer or an ethylene butene copolymer, the density of component d) being 0.860g/cm³To 0.880g/cm³And/or a melt flow rate (ISO1133, 190 ℃/2.16kg) of from 0.2g/10min to 3.4g/10 min. More preferably, component d) is an ethylene octene copolymer, the density of component d) being 0.860g/cm³To 0.880g/cm³The melt flow rate (ISO1133, 190 ℃/2.16kg) is between 0.2g/10min and 3.4g/10 min.

As mentioned above, the present invention also relates to a process for producing the composition of the invention having an MFR (ISO1133, 230 ℃/2.16kg) of from 30g/10min to 50g/10 min. All preferred aspects and embodiments described in relation to the composition should also apply to the method.

Furthermore, all preferred aspects and embodiments described in relation to the composition should also be applicable to articles, in particular automotive articles, in particular articles/automotive articles having a thickness of less than 2.8mm (preferably less than 2.6mm, more preferably equal to or less than 2.5 mm).

The article of the invention is preferably a bumper. Particularly preferably, the thickness of the bumper is 2.5mm or less.

c)0 to 11 wt% of a propylene homopolymer having an MFR (ISO1133, 230 ℃/2.16kg) of from 1g/10min to 100g/10 min;

e)16 to 22 wt% talc;

f)0 to 3 wt% of a carrier polymer;

h)0 wt% to 5 wt% of a color concentrate;

wherein the sum of components a) to h) is 100 wt.%.

Detailed Description

The heterophasic propylene copolymer comprises polypropylene as matrix and an elastomeric propylene copolymer (EC) dispersed in the matrix. Thus, the polypropylene matrix comprises (finely) dispersed inclusions, which are not part of the matrix, said inclusions comprising the elastomeric propylene copolymer. For example, inclusions are visible under a high resolution microscope (e.g., an electron microscope or a scanning force microscope).

The matrix of the heterophasic propylene copolymer as well as the rubbery phase of the heterophasic propylene copolymer may consist of only a single polymer or may each be a mixture of two or more polymers, preferably consisting of only a single polymer.

The heterophasic propylene copolymer may be produced by melt blending and/or reactor blending. In this regard, "reactor blending" means that the individual components of the polymer are produced in a subsequent stage in the presence of the product of the previous stage. For example, the matrix phase and the dispersed phase of the heterophasic polypropylene are produced in this subsequent stage.

The content of component a), i.e. the first heterophasic polypropylene HECO-PP1, is preferably between 40 wt% and 55 wt%, relative to the total amount of the composition.

Further preferably, the heterophasic polypropylene HECO-PP1 has one or more of the following properties:

-a xylene solubles content XCS [23 ℃, ISO 6427] of 11 to 18 wt%, more preferably 12 to 16 wt%;

-a content of units derived from ethylene [ IR calibrated by NMR ] in the xylene solubles content C2(XCS) of from 20 to 45 wt%, preferably from 30 to 42 wt%;

the intrinsic viscosity of the xylene solubles content IV (XCS) [ decalin 135 ℃, DIN ISO 1628/1] is from 1.8dl/g to 2.6dl/g, preferably from 2.1dl/g to 2.4 dl/g;

total HECO-PP1 (i.e. C2)_{General assembly}) In [ calibration of IR by NMR ] units derived from ethylene]Is 3.0 wt% to 12.0 wt%, preferably 5.0 wt% to 10.0 wt%.

The content of component b), i.e. the second heterophasic polypropylene HECO-PP2, is preferably from 3 to 20 wt%, more preferably from 5 to 15 wt%, relative to the total weight of the composition.

Further preferably, the heterophasic polypropylene HECO-PP2 has one or more of the following properties:

-a xylene solubles content XCS [23 ℃, ISO 6427] of from 10 to 25 wt%, more preferably from 13 to 22 wt%;

-the content of units derived from ethylene [ IR calibrated by NMR ] in the xylene solubles content C2(XCS) is from 20 to 45 wt%, preferably from 30 to 40 wt%;

-intrinsic viscosity of the xylene solubles content IV (XCS) [ decalin 135 ℃, DIN ISO 1628/1] of from 2.2dl/g to 2.9dl/g, preferably from 2.4dl/g to 2.8 dl/g;

total HECO-PP1 (i.e. C2)_{General assembly}) In units derived from ethylene [ IR calibrated by NMR ]]From 5.0 to 12.0 wt.%, preferably from 6.0 to 9.0 wt.%.

HECO-PP1 and HECO-PP2 differ in at least one respect. Preferably, the melt flow rates of HECO-PP1 and HECO-PP2 will differ.

Further preferably, more than one of the following relationships is satisfied:

the MFR (ISO1133, 230 ℃/2.16kg) of HECO-PP1 is higher than the MFR (ISO1133, 230 ℃/2.16kg) of HECO-PP2, preferably at least 2 times the MFR of HECO-PP2, more preferably at least 3 times the MFR of HECO-PP 2;

and/or

The flexural modulus (ISO 178) of HECO-PP1 is higher than that of HECO-PP 2;

and/or

The xylene solubles content XCS of HECO-PP1 is lower than the xylene solubles content XCS of HECO-PP 2;

and/or

The intrinsic viscosity of the xylene solubles content IV (XCS) of HECO-PP1 (decalin 135 ℃, DIN ISO 1628/1) is lower than the intrinsic viscosity of the xylene solubles content IV (XCS) of HECO-PP2 (decalin 135 ℃, DIN ISO 1628/1).

It is further understood that component c), i.e. a propylene homopolymer having an MFR (ISO1133, 230 ℃/2.16kg) of from 1g/10min to 100g/10min, is different from the matrix polymer of HECO-PP1 and further is different from the matrix polymer of HECO-PP2 in at least one respect. Preferably, component c), i.e. a propylene homopolymer having an MFR (ISO1133, 230 ℃/2.16kg) of from 1g/10min to 100g/10min, is different from the matrix polymer of HECO-PP1 and differs from the matrix polymer of HECO-PP2 in that: the melt flow rate is lower, which helps to increase the stiffness of the composition.

The HECO-PP1 can have a propylene homopolymer as the matrix or a random propylene copolymer as the matrix. Independently, the HECO-PP2 can have a propylene homopolymer as the matrix or a random propylene copolymer as the matrix. For HECO-PP1, a homopolymer matrix is preferred. For HECO-PP2, a homopolymer matrix is preferred. More preferably, both matrix components of HECO-PP1 and HECO-PP2 are homopolymers. If a random propylene copolymer is used as matrix, the comonomer content should preferably not exceed 5.0 wt.%.

It will be appreciated that the blending of two different heterophasic polymers, i.e. HECO-PP1 and HECO-PP2 each having a unimodal matrix and a unimodal rubber component, results in a final material having bimodality with respect to the matrix component and bimodality with respect to the rubber component. If a further component c) is added, i.e.a propylene homopolymer according to the present invention, the matrix component may also be trimodal if the propylene homopolymer is unimodal.

Preferably, component c) (i.e.the propylene homopolymer) has a melt flow rate MFR determined according to ISO1133₂(230 ℃, 2.16kg) is not more than 50g/10min, preferably 1g/10min to 30g/10min, more preferably 2g/10min to 15g/10 min.

Component c) (i.e.propylene homopolymer) has a melting temperature T_mPreferably from 150 ℃ to 170 ℃, for example from 155 ℃ to 170 ℃.

The content of component c), i.e. the propylene homopolymer Homo-PP, is preferably from 0.5 to 30.0 wt. -%, more preferably from 1.0 to 15.0 wt. -%, based on the total weight of the composition of the present invention.

As mentioned above, the expression "homopolymer" as used throughout the present invention refers to a polypropylene consisting essentially (i.e. equal to or greater than 99.9 wt%) of propylene units. In a preferred embodiment, only propylene units are detectable in the propylene homopolymer.

Component c), i.e. the propylene homopolymer Homo-PP, is preferably isotactic. It is therefore understood that the propylene homopolymer (Homo-PP) has a pentad concentration that is rather high, i.e. higher than 80%, more preferably higher than 85%, even more preferably higher than 90%, even more preferably higher than 92%, even more preferably higher than 93%, for example higher than 95%.

The amount of color concentrate may be 0.1 wt% to 5 wt%, preferably 0.1 wt% to 2.0 wt%, most preferably 0.1 wt% to 1.0 wt%. Color concentrates allow for the addition of pigments. The most common and preferred pigment is carbon black.

Two particularly preferred embodiments are described below.

In a first particularly preferred embodiment, a composition having an MFR (ISO1133, 230 ℃/2.16kg) of from 30g/10min to 45g/10min is obtainable by extruding:

a)40 to 55 wt% of a first heterophasic polypropylene HECO-PP1, the first heterophasic polypropylene HECO-PP1 having an MFR (ISO1133, 230 ℃/2.16kg) of 90 to 120g/10 min;

b)0 to 15 wt% of a second heterophasic polypropylene HECO-PP2, the second heterophasic polypropylene HECO-PP2 having an MFR (ISO1133, 230 ℃/2.16kg) of 10 to 30g/10 min;

c)0 to 11 wt% of a propylene homopolymer having an MFR (ISO1133, 230 ℃/2.16kg) of from 1g/10min to 20g/10 min;

d)12 to 20 wt% of an elastomeric copolymer derived from ethylene and 1-octene, the elastomeric copolymer having an MFR (ISO1133, 190 ℃/2.16kg) of 0.2 to 8g/10min, a density of 860kg/m³To 875kg/m³；

e)16 to 22 wt% talc;

f)0.5 to 2 wt% of polypropylene homo-and/or copolymer as a carrier for additives;

h)0 wt% to 5 wt% of a color concentrate;

wherein the sum of components a) to h) is 100 wt.%.

In a second particularly preferred embodiment, a composition having an MFR (ISO1133, 230 ℃/2.16kg) of from 30g/10min to 45g/10min is obtainable by extruding:

e)16 to 22 wt% of talc, wherein the talc used for extrusion satisfies:

BET (ISO 9277) of 15m²G to 25m²/g，

And/or

Median diameter D₅₀(ISO 13320-1) from 8.0 μm to 11.0. mu.m,

and/or

D95(ISO 13320-1) is 31.0 to 35.0 μm;

h)0 wt% to 5 wt% of a color concentrate;

wherein the sum of components a) to h) is 100 wt.%.

Both embodiments may be combined with any of the preferred aspects discussed in the summary of the invention as appropriate.

The preparation of HECO-PP1 and HECO-PP2 will be described below.

HECO-PP1

Preferably, the heterophasic polypropylene (HECO-PP1) of the present invention is produced in a multistage (multistage) process known in the art, wherein the matrix is produced in at least one slurry reactor, followed by the elastomeric copolymer in at least one gas phase reactor. Thus, the polymerization system may comprise more than one conventional stirred slurry reactor and/or more than one gas phase reactor. Preferably, the reactor used is selected from the group consisting of a loop reactor and a gas phase reactor, in particular, the process uses at least one loop reactor and at least one gas phase reactor. Multiple reactors of each type may also be used, such as one loop and two or three gas phase reactors in series, or two loops and one or two gas phase reactors. Preferably, the process further comprises a prepolymerization with the selected catalyst system comprising a ziegler-natta procatalyst, an external donor and a cocatalyst, as described below. In a preferred embodiment, the prepolymerization is carried out in liquid propylene in a bulk (bulk) slurry polymerization, i.e. the liquid phase comprises mainly propylene, in which minor amounts of other reactants and optionally inert components are dissolved. The prepolymerization is usually carried out at a temperature of 0 ℃ to 50 ℃, preferably 10 ℃ to 45 ℃, more preferably 15 ℃ to 40 ℃. The pressure requirements in the prepolymerization reactor are not critical but must be high enough to keep the reaction mixture in the liquid phase. Thus, the pressure may be 20 to 100 bar, for example 30 to 70 bar. Preferably, the catalyst components are all introduced into the prepolymerization step. However, in case the solid catalyst component (i) and the cocatalyst (ii) are fed separately, only a part of the cocatalyst may be introduced into the prepolymerization stage and the remaining part into the subsequent polymerization stage. Also in this case, it is necessary to introduce so much cocatalyst into the prepolymerization stage as to obtain therein an adequate polymerization reaction. Other components may also be added during the prepolymerization stage. Thus, as is known in the art, hydrogen may be added to the prepolymerization stage to control the molecular weight of the prepolymer. Further, an antistatic additive may be used to prevent particles from adhering to each other or to the reactor wall. Precise control of the prepolymerization conditions and reaction parameters is within the skill of the art.

Slurry reactor refers to any reactor, such as a continuous or simple batch stirred tank reactor or loop reactor, operating in bulk or slurry, in which the polymer is formed in particulate form. "bulk" means that the polymerization in the reaction medium contains at least 60% by weight of monomers. According to a preferred embodiment, the slurry reactor comprises a bulk loop reactor. "gas phase reactor" refers to any mechanically mixed or fluidized bed reactor. Preferably, the gas phase reactor comprises a mechanically stirred fluidized bed reactor, wherein the gas velocity is at least 0.2 m/s.

A particularly preferred embodiment for preparing the heterophasic polypropylene (HECO-PP1) of the present invention comprises: the polymerization is carried out in a process comprising a combination of one loop and one or two gas phase reactors or a combination of two loops and one or two gas phase reactors. A preferred multistage process is the slurry-gas phase process, such as that developed by Boreal

A method of the technology. Reference is made in this connection to EP0887379A1, WO92/12182, WO2004/000899, WO2004/111095, WO99/24478, WO99/24479 and WO 00/68315. Which are incorporated herein by reference. Other suitable slurry-gas phase processes are Basell

A method.

Preferably, the heterophasic polypropylene (HECO-PP1) of the present invention is prepared by using a special Ziegler-Natta procatalyst in combination with a special external donor, preferably in combination with a special Ziegler-Natta procatalyst as described below

Or at

-PP process.

Thus, a preferred multi-stage process may comprise the steps of:

-producing a polypropylene matrix in a first slurry reactor and optionally a second slurry reactor in the presence of a selected catalyst system, e.g. as described in detail below, said catalyst system comprising a special ziegler-natta procatalyst (i), an external donor (iii) and a cocatalyst (ii), both slurry reactors using the same polymerization conditions;

-transferring the slurry reactor product to at least one first gas phase reactor, such as one gas phase reactor or a first and a second gas phase reactor in series;

-producing an elastomeric copolymer in the presence of a polypropylene matrix and a catalyst system in the at least first gas phase reactor;

-recovering the polymer product for further processing.

With respect to the preferred slurry-gas phase process described above, the following general information regarding the process conditions can be provided.

The temperature is preferably from 40 ℃ to 110 ℃, preferably from 50 ℃ to 100 ℃, in particular from 60 ℃ to 90 ℃, and the pressure is from 20 bar to 80 bar, preferably from 30 bar to 60 bar, hydrogen being optionally added in a manner known per se to control the molecular weight. The reaction product of the slurry polymerization, preferably carried out in a loop reactor, is then transferred to a subsequent gas phase reactor, at a temperature preferably ranging from 50 ℃ to 130 ℃, more preferably from 60 ℃ to 100 ℃, and at a pressure ranging from 5 bar to 50 bar, preferably from 8 bar to 35 bar, also by selective addition of hydrogen in a manner known per se for controlling the molecular weight. The average residence time of the above-identified reactor zones may vary. In one embodiment, the average residence time in a slurry reactor (e.g. a loop reactor) is from 0.5 to 5 hours, e.g. from 0.5 to 2 hours, while the average residence time in a gas phase reactor is typically from 1 to 8 hours. If desired, the polymerization can be carried out in a known manner under supercritical conditions in a slurry reactor, preferably a loop reactor, and/or in a gas phase reactor in a condensed manner.

According to the present invention, as mentioned above, the heterophasic polypropylene is obtained, preferably by a multistage polymerization process, in the presence of a catalyst system comprising as component (i) a ziegler-natta procatalyst comprising a transesterification product of a lower alcohol and a phthalate.

The main catalyst used in the invention is prepared by the following steps:

a) making MgCl₂And C₁-C₂Spray-or emulsion-solidified adducts (adducts) of alcohols with TiCl₄Carrying out reaction;

b) at the C₁-C₂Reacting the product of stage a) with a dialkyl phthalate of formula (I) under conditions such that an alcohol transesterifies said dialkyl phthalate of formula (I) to form an internal donor:

in the formula, R^1’And R^2’Independently is at least C₅An alkyl group;

c) washing the product of stage b); or

d) Optionally reacting the product of step c) with additional TiCl₄And (4) reacting.

For example, the procatalyst is produced as described in patents WO87/07620, WO92/19653, WO92/19658 and EP 0491566. The contents of these documents are incorporated herein by reference.

First, MgCl is formed₂And the chemical formula is MgCl₂C of nROH (in the formula, R is methyl or ethyl, n is 1 to 6)₁-C₂Adducts of alcohols. Preferably, ethanol is used as alcohol. The adduct, which is melted first and then spray-crystallized or emulsion-solidified, is used as catalyst support. In the next step, MgCl is the chemical formula₂Contacting a spray-or emulsion-solidified adduct of nROH (wherein R is methyl or ethyl, preferably ethyl, and n is 1 to 6) with TiCl4 to form a titanized support, followed by the steps of:

adding to the titanized support the following to form a first product:

(i) a dialkyl phthalate of the formula (I) in which R^1’And R^2’Each independently of the other is at least one C₅Alkyl radicals, e.g. at least one C₈-an alkyl group,

or preferably

(ii) A dialkyl phthalate of the formula (I) in which R^1’And R^2’Are identical and are at least C₅Alkyl radicals, e.g. at least C₈-an alkyl group,

or more preferably

(iii) The dialkyl phthalate of formula (I) is selected from the group consisting of propylhexyl phthalate (PrHP), dioctyl phthalate (DOP), diisodecyl phthalate (DIDP) and tridecyl phthalate (DTDP); even more preferably, the dialkyl phthalate of formula (I) is dioctyl phthalate (DOP), for example diisooctyl phthalate or diethylhexyl phthalate, in particular diethylhexyl phthalate;

subjecting the first product to suitable transesterification conditions (i.e. a temperature above 100 ℃, preferably from 100 ℃ to 150 ℃, more preferably from 130 ℃ to 150 ℃) such that the methanol or ethanol transesterifies with the ester groups of the dialkyl phthalate of formula (I) forming preferably at least 80 mol%, more preferably 90 mol%, most preferably 95 mol% of the dialkyl phthalate of formula (II)

In the formula, R¹And R²Is a methyl or ethyl group, preferably an ethyl group,

a dialkyl phthalate of formula (II) as internal donor; and

recovering the transesterification product as the procatalyst composition (component (i)).

In a preferred embodiment, the chemical formula is MgCl₂The adduct of nROH (where R is methyl or ethyl and n is 1 to 6) is melted and the melt is then injected, preferably by means of a gas, into a cooled solvent or cooled gas, whereby the adduct crystallizes into a morphologically advantageous form, as described for example in WO 87/07620. The crystalline adduct is preferably used as a catalyst support and reacted with a procatalyst useful in the present invention as described in WO92/19658 and WO 92/19653. Removing the catalyst residue by extraction to obtain an adduct of the titanized support and the internal donor, in whichThe radical of the self-ester alcohol has changed. If sufficient titanium remains on the support, it will act as the active element of the procatalyst. Otherwise, titanation is repeated after the above treatment to ensure sufficient titanium concentration and activity. Preferably, the procatalyst used according to the invention comprises at most 2.5 wt%, preferably at most 2.2 wt%, more preferably at most 2.0 wt% titanium. The donor content thereof is preferably from 4 to 12% by weight, more preferably from 6 to 10% by weight. More preferably, the procatalyst used in the present invention is produced by using ethanol as alcohol and dioctyl phthalate (DOP) as the dialkyl phthalate of formula (I), yielding diethyl phthalate (DEP) as the internal donor compound.

In yet another preferred embodiment, the ziegler-natta procatalyst can be modified by polymerizing a vinyl compound in the presence of a catalyst system comprising the special ziegler-natta procatalyst, an external donor and a cocatalyst, said vinyl compound having the formula:

CH₂＝CH-CHR³R⁴

in the formula, R³And R⁴Together form a 5-or 6-membered saturated, unsaturated or aromatic ring or independently represent an alkyl group comprising 1 to 4 carbon atoms, which modified catalyst is used for the preparation of the heterophasic polypropylene composition of the present invention. The polymerized vinyl compound may act as an alpha-nucleating agent. This modification is particularly useful for the preparation of heterophasic polypropylene (H-PP 1). With regard to the modification of the catalyst, reference is made to international applications WO99/24478, WO99/24479 and in particular to WO00/68315, the contents of which are incorporated herein by reference with regard to the reaction conditions for the modification of the catalyst and with regard to the polymerization reaction. For the production of the heterophasic polypropylene of the present invention, the catalyst system used preferably comprises, as component (ii), in addition to the specific Ziegler-Natta procatalyst, an organometallic cocatalyst. Thus, it is preferred that the cocatalyst is selected from trialkylaluminums, such as Triethylaluminum (TEA), dialkylaluminum chlorides and alkylaluminum sesquichlorides. The component (iii) used in the catalyst system is an external donor of formula (IIIa) or (IIIb). The formula (IIIa) is defined as

Si(OCH₃)₂R₂ ⁵ (IIIa)

In the formula, R⁵Is represented by C₃-C₁₂Branched alkyl, preferably C₃-C₆Branched alkyl or C₄-C₁₂Cycloalkyl, preferably C₅-C₈A cycloalkyl group.

Particularly preferably, R⁵Selected from the group consisting of isopropyl, isobutyl, isopentyl, tert-butyl, tert-pentyl, neopentyl, cyclopentyl, cyclohexyl, methylcyclopentyl and cycloheptyl.

Formula (IIIb) is defined as

Si(OCH₂CH₃)₃(NR^xR^y) (IIIb)

In the formula, R^xAnd R^yMay be the same or different and represents C₁-C₁₂A hydrocarbyl group.

R^xAnd R^yIndependently selected from: c₁-C₁₂Straight chain aliphatic hydrocarbon group, C₁-C₁₂Branched aliphatic hydrocarbon group and C₁-C₁₂A cyclic aliphatic hydrocarbon group. Particularly preferably, R^xAnd R^yIndependently selected from the group consisting of methyl, ethyl, n-propyl, n-butyl, octyl, decyl, isopropyl, isobutyl, isopentyl, tert-butyl, tert-pentyl, neopentyl, cyclopentyl, cyclohexyl, methylcyclopentyl and cycloheptyl.

More preferably, R^xAnd R^ySame, even more preferably, R^xAnd R^yAre all ethyl groups.

Most preferably, the external donor has formula (IIIa), for example dicyclopentyldimethoxysilane [ Si (OCH)₃)₂(cyclopentyl)₂]Or diisopropyldimethoxysilane [ Si (OCH)₃)₂(CH(CH₃)₂)₂]。

HECO-PP2 preparation

The heterophasic propylene copolymer of the present invention is preferably produced in a sequential polymerization process, i.e. a multistage process as known in the art as described above.

Thus, preferably, the heterophasic propylene copolymer is produced in a sequential polymerization process comprising the steps of:

(a) in a first reactor (R1), propylene and optionally at least one ethylene and/or C₄-C₁₂Polymerizing an alpha-olefin to obtain a first polypropylene fraction of polypropylene (PP-1), preferably said first polypropylene fraction is a first propylene homopolymer;

(b) transferring the first polypropylene fraction to a second reactor (R2);

(c) in a second reactor (R2), propylene and optionally at least one ethylene and/or C are reacted in the presence of the first polypropylene fraction₄-C₁₂Polymerizing an alpha-olefin, thereby obtaining a second polypropylene component, preferably a second propylene homopolymer, said first polypropylene fraction and said second polypropylene component forming a polypropylene (PP-1), such as a propylene homopolymer (PP-1), i.e. a matrix of a heterophasic propylene copolymer (HECO-PP 2);

(d) transferring the polypropylene (PP-1) of step (c) to a third reactor (R3);

(e) in a third reactor (R3), in the presence of the polypropylene (PP-1) obtained in step (C), propylene and ethylene and/or C₄-C₁₂At least one polymerization of alpha-olefins, thereby obtaining a first elastomeric propylene copolymer fraction, said first elastomeric propylene copolymer fraction being dispersed into polypropylene (PP-1);

(f) transferring the polypropylene (PP-1) having dispersed therein the first elastomeric propylene copolymer fraction to a fourth reactor (R4); and

(g) in a fourth reactor (R4), propylene and ethylene and/or C are reacted in the presence of the mixture obtained in step (e)₄-C₁₂Polymerizing at least one of the alpha-olefins, thereby obtaining a second elastomeric propylene copolymer fraction;

the polypropylene (PP-1), the first elastomeric propylene copolymer fraction and the second elastomeric propylene copolymer fraction form a heterophasic propylene copolymer (HECO-PP 2).

Alternatively, the elastomeric propylene copolymer (E-1) may also be produced in one gas phase reactor, i.e.the fourth reactor (R4) is optional.

Of course, in the first reactor (R1), a second polypropylene component may be produced; in the second reactor (R2), a first polypropylene fraction is obtainable. The same is true of the elastomeric propylene copolymer phase. Thus, a second elastomeric propylene copolymer fraction may be produced in the third reactor (R3); whereas in the fourth reactor (R4) a first elastomeric propylene copolymer fraction may be produced.

Preferably, monomer is flashed off between the second reactor (R2) and the third reactor (R3) and optionally between the third reactor (R3) and the fourth reactor (R4).

The term "sequential polymerization process" means that the heterophasic propylene copolymer (HECO-PP2) is produced in at least two (e.g. three or four) reactors in series. Thus, the process of the present disclosure comprises at least a first reactor (R1) and a second reactor (R2), more preferably comprises a first reactor (R1), a second reactor (R2), a third reactor (R3) and a fourth reactor (R4), more preferably comprises a first reactor (R1), a second reactor (R2) and a third reactor (R3). The term "polymerization reactor" shall mean that the main polymerization reaction takes place. Thus, in the case of a process consisting of four or three polymerization reactors, this definition does not exclude the following options: the overall process includes, for example, a prepolymerization step in a prepolymerization reactor. The term "consisting of … …" is only a closed expression in terms of the main polymerization reactor.

The first reactor (R1) is preferably a Slurry Reactor (SR), which may be any continuous or simple stirred batch tank reactor or loop reactor operating in bulk or slurry form. Bulk refers to polymerization in a reaction medium comprising at least 60% (w/w) monomer. According to the invention, the Slurry Reactor (SR) is preferably a (bulk) Loop Reactor (LR). The second reactor (R2), the third reactor (R3) and the fourth reactor (R4) are preferably Gas Phase Reactors (GPR). Such Gas Phase Reactor (GPR) may be any mechanically mixed or fluidized bed reactor. Preferably, the Gas Phase Reactor (GPR) comprises a mechanically stirred fluidized bed reactor with a gas velocity of at least 0.2 m/s. It will therefore be appreciated that the gas phase reactor is a fluidized bed type reactor preferably with a mechanical stirrer.

Thus, in a preferred embodiment, the first reactor (R1) is a Slurry Reactor (SR) (e.g., a Loop Reactor (LR)); while the second reactor (R2), the third reactor (R3) and the fourth reactor (R4) are Gas Phase Reactors (GPR). Thus, for the present process at least 3, preferably 3, polymerization reactors connected in series are used, namely a Slurry Reactor (SR) (e.g.loop reactor (LR)), a first gas phase reactor (GPR-1) and a second gas phase reactor (GPR-2). Optionally, a prepolymerization reactor is placed before the Slurry Reactor (SR).

With regard to the general method set-up, reference is made to the above.

Preferably, in the inventive process for producing the heterophasic propylene copolymer (HECO-PP2) as described above, the conditions of the first reactor (R1) of step (a), i.e. the Slurry Reactor (SR), e.g. the Loop Reactor (LR), may be as follows:

-a temperature of from 50 ℃ to 110 ℃, preferably from 60 ℃ to 100 ℃, more preferably from 68 ℃ to 95 ℃;

-a pressure of 20 to 80 bar, preferably 40 to 70 bar;

hydrogen can be added in a manner known per se to control the molar mass.

Subsequently, the reaction mixture of step (a) is transferred to a second reactor (R2), i.e. a gas phase reactor (GPR-1), i.e. to step (c), wherein the conditions in step (c) are preferably as follows:

-a temperature of 50 ℃ to 130 ℃, preferably 60 ℃ to 100 ℃;

-a pressure of 5 to 50 bar, preferably 15 to 35 bar;

hydrogen can be added in a manner known per se to control the molar mass.

The conditions in the third reactor (R3) and the fourth reactor (R4), preferably in the second gas phase reactor (GPR-2) and the third gas phase reactor (GPR-3), are similar to the second reactor (R2).

The residence time of the three reactor zones may be different.

In one embodiment of the process for producing polypropylene, the residence time in the bulk reactor (e.g. loop reactor) is for example 0.1 to 2.5 hours, for example 0.15 to 1.5 hours, and the residence time in the gas phase reactor is typically 0.2 to 6.0 hours, for example 0.5 to 4.0 hours.

If desired, the polymerization can be carried out in a known manner in the first reactor (R1), i.e.slurry reactor (SR), for example Loop Reactor (LR), under supercritical conditions and/or in Gas Phase Reactor (GPR) in condensed mode.

Preferably, the process further comprises a prepolymerization using a catalyst system as detailed above, the catalyst system comprising a ziegler-natta procatalyst, an external donor and optionally a cocatalyst.

Preferably, the catalyst components are all introduced into the prepolymerization step. However, in case the solid catalyst component (i) and the cocatalyst (ii) may be fed separately, it is possible that only a part of the cocatalyst is introduced into the prepolymerization stage and the remaining part into the subsequent polymerization stage. Also in this case, it is necessary to introduce so much cocatalyst into the prepolymerization stage as to obtain a sufficient polymerization reaction in this prepolymerization stage. Other components may also be added during the prepolymerization stage. Thus, as is known in the art, hydrogen may be added to the prepolymerization stage to control the molecular weight of the prepolymer. In addition, antistatic additives may be used to prevent particles from adhering to each other or to the reactor walls.

According to the present invention, a heterophasic propylene copolymer (HECO-PP2) 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 comprising a transesterification product of a lower alcohol and a phthalate.

For the preparation of the procatalyst, reference is made to the above.

It is understood that the heterophasic propylene copolymer (HECO-PP2) is alpha-nucleated. As mentioned above, in case the α -nucleation is not affected by the vinylcycloalkane polymer or the vinylalkane polymer, the following α -nucleating agents may be present:

(i) mono-and polycarboxylic acid salts, such as sodium benzoate or aluminum tert-butylbenzoate;

(ii) dibenzylidene sorbitols (e.g. 1,3:2,4 dibenzylidene)Sorbitol) and C₁-C₈Alkyl-substituted dibenzylidene sorbitol derivatives, e.g. methyldibenzylidene sorbitol, ethyldibenzylidene sorbitol or dimethyldibenzylidene sorbitol (e.g. 1,3:2, 4-di (methylbenzylidene) sorbitol), or substituted nonanol (nonitol) derivatives, e.g. 1,2, 3-trideoxy-4, 6:5, 7-bis-O- [ (4-propylphenyl) methylene]-nonanol;

(iii) salts of phosphoric acid diesters, for example sodium 2,2 '-methylenebis (4, 6-di-tert-butylphenyl) phosphate or aluminum bis [2,2' -methylene-bis (4, 6-di-tert-butylphenyl) phosphate ] hydroxide; and

(iv) mixtures thereof.

Component d), i.e.from 12 to 20% by weight, derived from ethylene and at least one C, will be described in more detail hereinafter₄-C₁₂An elastomeric copolymer of alpha-olefins (EEC), component d) having an MFR (ISO1133, 190 ℃/2.16kg) of from 0.2g/10min to 8g/10 min. The comonomer present in the elastomeric copolymer (EEC) is C₄-C₁₂Alpha-olefins such as 1-butene, 1-hexene and 1-octene, the latter being more preferred. Thus, in a particular embodiment, the elastomeric copolymer (EEC) is an ethylene-1-butene copolymer or an ethylene-1-octene copolymer in the amounts given in this paragraph.

An important aspect of the present invention is that the amount of elastomeric copolymer (EEC) in the final composition is rather moderate. Thus, preferably, the amount of elastomeric copolymer in the total composition of the present invention is from 10.0 wt% to 25 wt%, preferably from 13.0 wt% to 19.0 wt%, more preferably from 14.0 wt% to 18.0 wt%, based on the total weight of the polypropylene composition of the present invention.

In a preferred embodiment, the elastomeric copolymer (EEC) is known in the art and belongs to the Queo and Engage products known in the art.

Needless to say, the elastomeric copolymer (EEC) is typically present in dispersed form in the matrix by compounding, i.e. in the polypropylene (PP) homopolymer or random copolymer of the heterophasic propylene copolymer (HECO).

Inorganic Filler (component g)

As a further essential component, the compositions of the present invention comprise an inorganic filler.

The content of inorganic filler (F) in the polypropylene composition (PP) is from 10 to 30 wt. -%, more preferably from 15.0 to 25.0 wt. -%, even more preferably from 16 to 22 wt. -%, even more preferably from 17 to 22 wt. -%, based on the total weight of the composition of the present invention.

Preferably, the inorganic filler is mica, wollastonite, kaolinite, montmorillonite, calcium carbonate, montmorillonite, talc, phyllosilicate, or a mixture thereof. Most preferably, the inorganic filler is talc.

Preferably, the median particle diameter d of the inorganic filler₅₀(calculated from the mass percent particle size distribution, as measured by laser diffraction) from 0.2 μm to 20.0 μm, more preferably from 0.3 μm to 15.0 μm, and even more preferably from 3.0 μm to 12.0. mu.m.

Additionally or alternatively, the inorganic filler has a specific surface area BET of 1.0m²G to 50.0m²A ratio of the total of the components is 5.0m²G to 40.0m²G, even more preferably 15.0m²G to 22.0m²A/g, most preferably 15.0m²G to 20.0m²/g。

Propylene homopolymer (component c)

Another optional component of the composition of the present invention is a propylene homopolymer (Homo-PP). Propylene homopolymer (Homo-PP) is added to the composition of the present invention to improve stiffness. It is understood that the polypropylene composition (PP) comprises from 0.5 wt% to 30.0 wt%, preferably from 1.0 wt% to 15.0 wt%, more preferably from 1.0 wt% to 11.0 wt% of propylene homopolymer (Homo-PP), based on the total weight of the total composition of the present invention.

Propylene homopolymers (Homo-PP) are not heterophasic polymers, i.e. systems comprising a crystalline matrix phase in which an elastomeric phase is dispersed. Thus, the propylene homopolymer (Homo-PP) is a single phase, i.e. no multiphase structure can be identified in DMTA, since only one glass transition temperature is present.

Further, the melting temperature of the propylene homopolymer (Homo-PP) is preferably more than 155 ℃ (e.g., more than 155 ℃ to 169 ℃), more preferably at least 158 ℃ (e.g., 158 ℃ to 168 ℃), more preferably 162 ℃ to 168 ℃.

Preferably, another feature of propylene homopolymer (Homo-PP)Characteristically, the amount of propylene misinsertion in the polymer chain is small, indicating that propylene homopolymer (Homo-PP) is produced in the presence of Ziegler-Natta catalysts. Thus, preferably, the propylene homopolymer (Homo-PP) is characterized by a small amount (i.e. equal to or lower than 0.4 mol%, more preferably equal to or lower than 0.2 mol%, for example not more than 0.1 mol%) of 2,1 erythro-type domain defects (by¹³C-NMR spectrum). In a particularly preferred embodiment, 2,1 erythro-type region defects are not detected.

Preferably, the propylene homopolymer (Homo-PP) has a melt flow rate MFR determined according to ISO1133₂(230 ℃) of 2.0g/10min to 30.0g/10min, preferably 2.0g/10min to 20.0g/10 min.

The propylene homopolymer (Homo-PP) may be chemically identical to the matrix (M) of one of the heterophasic propylene copolymers (HECO-PP1 or HECO-PP 2). In another preferred embodiment, the propylene homopolymer (Homo-PP) is chemically different, preferably has a melt flow rate different, from the matrix of the matrix phase of either of the two heterophasic propylene copolymers (HECO-PP1 and HECO-PP2) (i.e. propylene homopolymer (PP-1)).

In a preferred embodiment, the melt flow rate MFR of the propylene homopolymer (Homo-PP)₂(230 ℃) below (preferably at least 5g/10min below, more preferably at least 8g/10min below, even more preferably from 5g/10min to 50g/10min below, even more preferably from 8g/10min to 20g/10min below) the matrix of either of the two heterophasic propylene copolymers (HECO-PP1 and HECO-PP2) (i.e. propylene homopolymers) which contributes to the improved stiffness of the composition.

The preparation of propylene homopolymers is known in the art. Preferably, a Ziegler-Natta catalyst is used.

Experimental part

Measuring method

Charpy notched impact strength: measured at 23 ℃ and 0 ℃ according to ISO 179/1eA by using injection-molded specimens (80X 10X 4mm) as described in EN ISO 1873-2.

Flexural modulus: flexural modulus was measured according to ISO 178 at 3-point bending on 80X 10X 4mm injection-molded specimens prepared according to ISO 294-1: 1996.

Melt Flow Rate (MFR)₂): root of herbaceous plantMelt Flow Rate (MFR) according to ISO1133, measured at 230 ℃ or 190 ℃ under a load of 2.16kg₂)。

Intrinsic viscosity: measured according to DIN ISO 1628/1 (10 months 1999) in decalin at 135 ℃.

Density: measured according to ISO 1183-. Samples were prepared by compression molding according to ISO 1872-2: 2007.

BET: BET is determined according to ISO 9277. Brunauer-Emmett-Teller (BET) applied adsorption evaluation to surface analysis.

NMR spectroscopic measurement:

quantitative Nuclear Magnetic Resonance (NMR) spectroscopy was used to quantify the comonomer content and comonomer sequence distribution of the polymer. To is directed at¹H and¹³c, recording the state of the solution at 400.15MHz and 100.62MHz respectively using a Bruker Advance III 400NMR spectrometer¹³C{¹H } NMR quantitative spectrum. Use of¹³C optimal 10mm extended temperature probe, all spectra were recorded at 125℃ for all atmospheres using nitrogen. About 200mg of material was mixed with chromium (III) acetylacetonate (Cr (acac)₃) Dissolved together in 3mL of 1, 2-tetrachloroethane-d₂(TCE-d₂) To obtain a 65mM relaxant solution in solvent (Singh, g., Kothari, a., Gupta, v., Polymer Testing 285 (2009), 475). To ensure the solution is homogeneous, after initial sample preparation in the heating block, the NMR tube is further heated in a rotary oven for at least 1 hour. After the magnet was inserted, the tube was rotated at 10 Hz. This setting was chosen primarily to achieve high resolution and quantitative requirements for accurate quantification of ethylene content. Using standard single pulse excitation without NOE, an optimal tip angle, 1s cycle delay and a two-stage WALTZ16 decoupling scheme (Zhou, z., Kue mmerle, r., Qiu, x., Redwine, d., Cong, r., Taha, a., Baugh, d.winnoford, b., j.mag.reson.187(2007) 225; Busico, v., Carbonniere, p., Cipullo, r., Pellecchia, r., Severn, j., talaro, g., macro mol. rapid co.2007, 28,1128) were employed. A total of 6144(6k) transient signals were acquired for each spectrum.

Using a proprietary computer program pair¹³C{¹H quantitative NMR spectra were processed, integrated and the relevant quantitative properties were determined from the integration. Chemical shifts using solvents, allThe chemical shifts are all indirectly referenced to the central methylene group of the ethylene block (EEE) of 30.00 ppm. This method can be referred to similarly even without this structural unit. A characteristic signal corresponding to ethylene incorporation was observed (Cheng, h.n., Macromolecules 17(1984), 1950).

Characteristic signals corresponding to 2,1 erythro-type regional defects (described in l.resconi, l.cavalo, a.fat, f.Piemontesi, chem.Rev.2000, 100 (4): 1253; Cheng, H.N., Macromolecules 1984, 17: 1950; W-J.Wang and S.Zhu, Macromolecules 2000, 33: 1157) were observed, and the effect of regional defects on the measured performance required to be corrected. No characteristic signals corresponding to other types of area defects were observed.

The method of Wang et al (Wang, W-J., Zhu, S., Macromolecules 2000, 33: 1157) was used by¹³C{¹H } the comonomer fraction was quantified by integrating multiple signals over the entire spectral region of the spectrum. This method was chosen because of its robustness and ability to address the presence of regional defects as needed. The integration region is adjusted slightly to improve applicability over the entire range of comonomer contents encountered.

For systems where only isolated ethylene in the PPEPP sequence is observed, the method of Wang et al is modified to reduce the effect of non-zero integration of sites known to be absent. This method reduces the overestimation of ethylene content in such systems and is achieved by reducing the number of sites used to determine absolute ethylene content to the formula:

E＝0.5(Sββ+Sβγ+Sβδ+0.5(Sαβ+Sαγ))

by using this set of points, the corresponding integral equation becomes:

E＝0.5(I_H+I_G+0.5(I_C+I_D))

the same symbols as used in Wang et al (Wang, W-j., Zhu, s., Macromolecules 33(2000),1157) were used. The equation for absolute propylene content is not modified.

The mole percentage of incorporated comonomer was calculated from the mole fraction:

E[mol％]＝100*fE

the weight percentage of incorporated comonomer was calculated from the weight fraction:

E[wt％]＝100*(fE*28.06)/((fE*28.06)+((1-fE)*42.08))

the triad-level comonomer sequence distribution was determined using the analytical method of Kakugo et al (Kakugo, m., Naito, y., mizunma, k., Miyatake, t.macromolecules 15(1982) 1150). This method was chosen because it has robust characteristics, fine tuning the integration region to improve its applicability to a wider comonomer content.

Median diameter D₅₀And D₉₅

ISO 13320-1 (laser diffraction method) was used.

Xylene cold soluble (XCS, wt%)

Xylene Cold Soluble (XCS) was determined according to ISO 6427 at 23 ℃.

Examples

Material

The compositions of the examples were prepared using the following starting materials.

Heterophasic polypropylenes are described for example by HECO-PP1 and HECO-PP 2.

Preparation of HECO-PP 1:

as disclosed in EP0887379A1, by being known

The heterophasic propylene copolymer (HECO-1) used in examples 1-3 according to the present invention was prepared using one slurry loop reactor and two gas phase reactors.

The catalysts used in the polymerization process for preparing the heterophasic propylene copolymer (HECO-1) (inventive examples 1 to 3) were produced as follows:

first, 0.1mol of MgCl was added under inert conditions in a reactor at atmospheric pressure₂X 3EtOH was suspended in 250mL decane. The solution was cooled to-15 ℃ and 300mL of cold TiCl was added₄While maintaining the temperature at the above level. The slurry temperature was then slowly raised to 20 ℃. At this temperature, 0.02mol of dioctyl phthalate (DOP) was added to the slurry. After addition of the phthalate, the temperature was raised to 135 ℃ over 90 minutes and the slurry was allowed to standFor 60 minutes. Then, 300mL of TiCl were added₄The temperature was maintained at 135 ℃ for 120 minutes. Thereafter, the catalyst was filtered from the liquid and washed 6 times with 300mL heptane at 80 ℃. Then, the solid catalyst was filtered and dried. For example, catalysts and processes for their preparation are generally described in patents EP491566, EP591224 and EP 586390. Triethylaluminum (TEAL) was used as a cocatalyst, and dicyclopentyldimethoxysilane [ (C)₅H₉)₂Si(OCH₃)₂]As donor. The aluminum to donor ratio is shown in table 1.

Table 1: preparation and characterization of heterophasic propylene copolymer HECO-1

		HECO1
			TEA/Ti	[mol/mol]	220
TEAL/Donor	[mol/mol]	10
			Ring type
Temperature of	[℃]	75
			Residence time	[h]	0.6
H2/C3 ratio	[mol/kmol]	22
			MFR	[g/10min]	160
Shunting (split)	[wt％]	51
			GPR 1
Temperature of	[℃]	80
			Pressure of	[kPa]	2200
H2/C3 ratio	[mol/kmol]	175
			MFR	[g/10min]	160
XCS	[wt％]	2.0
			Flow diversion	[wt％]	33
GPR 2
			Temperature of	[℃]	80
Pressure of	[kPa]	2190
			H2/C2 ratio	[mol/kmol]	250
Ratio C2/C3	[mol/kmol]	550
			C2	[mol％]	11
XCS	[wt％]	15.0
			C2(XCS)	[mol％]	49
MFR	[g/10min]	95
			Flow diversion	[wt％]	16
IV of XCS	[dl/g]	2.3

Preparation of HECO-PP 2:

as disclosed in EP0887379A1, by being known

The heterophasic propylene copolymer (HECO-PP2) used in the examples of the present invention was prepared using one slurry loop reactor and two gas phase reactors.

The catalyst used in the polymerization of HECO-PP2 was produced as follows:

first, 0.1mol of MgCl was added under inert conditions in a reactor at atmospheric pressure₂X 3EtOH was suspended in 250mL decane. The solution was cooled to-15 ℃ and 300mL of cold TiCl was added₄While maintaining the temperature at the above level. The slurry temperature was then slowly raised to 20 ℃. At this temperature, 0.02mol of dioctyl phthalate (DOP) was added to the slurry. After the addition of the phthalate, the temperature was raised to 135 ℃ over 90 minutes and the slurry was allowed to stand for 60 minutes. Then, 300mL of TiCl were added₄The temperature was maintained at 135 ℃ for 120 minutes. This is achieved byThereafter, the catalyst was filtered from the liquid and washed 6 times with 300mL heptane at 80 ℃. Then, the solid catalyst component was filtered and dried. For example, catalysts and their preparation concepts are described in patent publications EP491566, EP591224 or EP 586390. The catalyst was prepolymerized with vinylcyclohexane in such an amount that the poly (vinylcyclohexane) (PVCH) concentration in the final polymer reached 200ppm (cf. EP1183307A 1). Triethylaluminium (TEAL) was used as cocatalyst and dicyclopentyldimethoxysilane (D-donor) was used as donor. The aluminum to donor ratio is shown in table 2.

Table 2: preparation and characterization of HECO-PP2

Ring type		HECO-PP2
			TEAL/Ti	[mol/mol]	177
TEAL/D donors	[mol/mol]	10.3
			Temperature of	[℃]	80
Pressure of	[ Bar ]]	55
			H₂/C₃Ratio of	[mol/kmol]	36
MFR₂(230℃)	[g/10min]	40
			XCS	[wt％]	1.5
Flow diversion	[wt％]	46
			GPR 1
Temperature of	[℃]	95
			Pressure of	[kPa]	24
H₂/C₃Ratio of	[mol/kmol]	230
			MFR₂(230℃)	[g/10min]	40
XCS	[wt％]	1.4
			Flow diversion	[wt％]	36
GPR 2 (Final)
			Temperature of	[℃]	85
Pressure of	[kPa]	19
			H₂/C₂Ratio of	[mol/kmol]	170
C₂/C₃Ratio of	[mol/kmol]	580
			MFR₂(230℃)	[g/10min]	20
XCS	[wt％]	17.5
			C2 of XCS	[wt％]	34
IV of XCS	[dl/g]	2.6
			C2 in total	[wt％]	7.5
Flow diversion	[wt％]	18

Copolymer of ethylene and octene (Enage 8100POE, available from Dow corporation):

-MFR：1g/10min(190℃/2.16kg)

copolymer of ethylene and butene (Enage 7467POE, available from Dow corporation):

-MFR：1g/10min(190℃/2.16kg)

Homo-PP：

-MFR：8g/10min(230℃/2.16kg)

-flexural modulus: 2100MPa

-charpy notched impact strength at-20 ℃: 6KJ/m²

Jetfine 3CA from Imerys co. ltd. (france)

Median diameter D₅₀: measured by laser diffraction method to be 3.9 μm

Median diameter D₉₅: measured by laser diffraction method to be 7.8 μm

-BET：14.5m²/g

HAR T84 of Imerys co. ltd. (france)

Median diameter D₅₀: 10.5 μm as measured by laser diffraction method

Median diameter D₉₅: 34.2 μm as measured by laser diffraction method

-BET：19.5m²/g

Additive: propylene homopolymer powder (as a carrier), antioxidants, mold release agents, acid scavengers, and color concentrates;

irganox 1076 antioxidant: 3- (3 ', 5' -di-tert-butyl-4-hydroxyphenyl) octadecyl propionate available from BASF, T_mIs 50 ℃;

irgafos 168 antioxidant: tris (2, 4-di-tert-butylphenyl) phosphite from BASF, T_mIs 182 ℃;

rikemal AS-105 Release agent: distilled monoglyceride was purchased from riken vitamin co.

Preparation of the composition by compounding:

a twin screw extruder was used. The additive mixture was premixed with the polypropylene powder. The additive mixture comprises an antioxidant, a mold release agent, an acid scavenger, and a color masterbatch. The resulting premix was fed into feeder 3 (which is the side feeder of a twin-screw extruder). HECO-PP, Homo-PP and POE were fed into the main feeder 1 of the twin-screw extruder. Talc was fed by side feeder 2. All feed materials were heated and homogeneously mixed by extrusion at a temperature of 100 ℃ to 250 ℃.

Table 3: SUMMARY

For comparison, the Bolu brand "EF 296 AEC-9502" was used. Table 4 below shows the results as Comparative Example (CE).

Table 4: results of examples 1-3 and CE

It is immediately apparent that examples 1 to 3 have very good stiffness and still acceptable impact strength. Examples 1 to 3 are applicable to an ultra-thin bumper.

Examples 2 and 3 show even a further improved balance between stiffness and impact, facilitating the production of bumpers having a thickness of only 2.3 mm.

The extrusion conditions used are given in table 5 below.

Table 5: extrusion process parameters in an extruder

The bumper was prepared by injection molding.

Claims

1. A composition comprising:

2. The composition of claim 1, wherein the composition further comprises:

b)0 to 25 wt% of a second heterophasic polypropylene HECO-PP2, the second heterophasic polypropylene HECO-PP2 having an MFR (ISO1133, 230 ℃/2.16kg) of 10 to 30g/10 min.

3. The composition of claim 1 or 2, wherein the composition further comprises:

c)0 to 15 wt.%, preferably 0 to 11 wt.% of a propylene homopolymer having an MFR (ISO1133, 230 ℃/2.16kg) of 1 to 100g/10 min.

4. Composition according to any one of claims 1 to 3, wherein the composition has an MFR (ISO1133, 230 ℃/2.16kg) of from 30g/10min to 45g/10min, said composition being obtainable by extrusion of:

e)16 to 22 wt% talc.

5. Composition according to any one of claims 1 to 3, wherein the composition has an MFR (ISO1133, 230 ℃/2.16kg) of from 30g/10min to 45g/10min, said composition being obtainable by extrusion of:

e)16 to 22 wt% talc;

f)0 to 3 wt% of a carrier polymer;

h)0 wt% to 5 wt% of a color concentrate;

wherein the sum of components a) to h) is 100 wt.%.

6. Composition according to any one of claims 1 to 5, wherein the composition has a flexural modulus (ISO 178) of at least 1900MPa, preferably 2400MPa, measured with an injection moulded specimen of 80 x 10 x 4mm prepared according to ISO 294-1: 1996.

7. Composition according to any one of claims 4 to 6, in which component d) is an ethylene octene copolymer.

8. Composition according to any one of claims 4 to 6, in which component d) is an ethylene octene copolymer having a density of 0.860g/cm³To 0.880g/cm³And/or a melt flow rate (ISO1133, 190 ℃/2.16kg) of from 0.2g/10min to 3.4g/10 min.

9. Injection molded article comprising, preferably consisting of, the composition of any one of claims 1 to 11.

10. The injection molded article according to claim 9, wherein the injection molded article is an automotive article, preferably a bumper, more preferably a bumper having a thickness of 2.5mm or less.

11. Use of a composition for the manufacture of a bumper having a thickness of 2.5mm or less, wherein the composition comprises:

(a)40 to 70 wt%, preferably 40 to 60 wt% of a first heterophasic polypropylene HECO-PP1, the MFR (ISO1133, 230 ℃/2.16kg) of the first heterophasic polypropylene HECO-PP1 being 90 to 120g/10 min;

(d)10 to 30 wt%, preferably 12 to 20 wt%, of an elastomeric copolymer derived from ethylene and at least one C₄-C₁₂An alpha-olefin, the elastomeric copolymer having an MFR (ISO1133, 190 ℃/2.16kg) of from 0.2g/10min to 8g/10 min; and

(e)10 to 30 wt%, preferably 16 to 22 wt% of an inorganic filler, preferably talc;