CN111094431A

CN111094431A - Polypropylene composition with good electromagnetic shielding performance

Info

Publication number: CN111094431A
Application number: CN201780094582.6A
Authority: CN
Inventors: 陈世平; 周信
Original assignee: Bolu Plastic Shanghai Co Ltd
Current assignee: Bolu Plastic Shanghai Co Ltd
Priority date: 2017-09-22
Filing date: 2017-09-22
Publication date: 2020-05-01
Also published as: WO2019056283A1

Abstract

The present invention relates to a polypropylene composition comprising: a)30 to 54 parts by weight of a Propylene Polymer (PP) having an MFR, measured according to ISO1133 at 230 ℃ and under a load of 2.16kg₂2.0g/10min to 80g/10 min; b)11 to 30 parts by weight of an ethylene copolymer (PE) having an MFR, measured according to ISO1133 at 190 ℃ and under a load of 2.16kg₂Is 0.5g/10min to 35g/10 min; c)26 to 50 parts by weight of a carbon fiber masterbatch; d)0.10 to 2.0 parts by weight of a Polar Modified Polypropylene (PMP), wherein the Polar Modified Polypropylene (PMP)) Containing 0.5 to 5.0 wt% of groups derived from polar groups; and articles made from the composition, such as molded or foamed articles, preferably injection molded articles, such as at least a portion of a housing for electrical equipment and/or for automotive applications.

Description

Polypropylene composition with good electromagnetic shielding performance

Technical Field

The invention relates to a polypropylene composition with good electromagnetic shielding performance and a product prepared from the polypropylene composition.

Background

Since the polypropylene composition is one of the main materials commonly used for housings of electrical equipment, such as instrument panel brackets, for example, in electrical and electronic applications, energy applications, and healthcare, particularly automotive applications, there is a need for a polypropylene composition having good electromagnetic interference (EMI) shielding properties.

To provide good electromagnetic interference (EMI) shielding, the polypropylene composition needs to have a low surface resistivity. Currently, carbon black is used, and a sufficiently low surface resistivity cannot be provided by a small amount of carbon black, while addition of an amount of carbon black sufficient to achieve a desired surface resistivity results in deterioration of mechanical properties such as increase in brittleness and decrease in rigidity.

Thus, there is a need for a polypropylene composition that overcomes the contradiction of the objectives.

Disclosure of Invention

Accordingly, the present invention provides a polypropylene composition comprising:

a)30 to 54 parts by weight of a Propylene Polymer (PP) having an MFR, measured according to ISO1133 at 230 ℃ and under a load of 2.16kg₂2.0g/10min to 80g/10 min;

b)11 to 30 parts by weight of an ethylene copolymer (PE) having an MFR, measured according to ISO1133 at 190 ℃ and under a load of 2.16kg₂Is 0.5g/10min to 35g/10 min;

c)26 to 50 parts by weight of a carbon fiber masterbatch;

d)0.10 to 2.0 parts by weight of a Polar Modified Polypropylene (PMP), wherein the Polar Modified Polypropylene (PMP) comprises 0.5 to 5.0 wt% of groups derived from polar groups;

the parts by weight are based on the total parts by weight of component a), component b), component c) and component d).

It was surprisingly found that the combination of the compounds according to the invention allows a significant reduction of the surface resistivity while maintaining or at least not significantly affecting the mechanical properties of the composition. This makes the composition particularly suitable for use in electrical enclosures, such as in automotive applications.

Detailed Description

Propylene Polymers (PP)

The Propylene Polymer (PP) may be a propylene homopolymer, a random propylene copolymer or a heterophasic propylene copolymer.

Preferably, the Propylene Polymer (PP) has an MFR, measured according to ISO1133 at 230 ℃ and under a load of 2.16kg₂From 5.0g/10min to 60g/10min, more preferably from 5.0g/10min to 40g/10min, most preferably from 5.0g/10min to 20g/10 min.

In case the Propylene Polymer (PP) is a random copolymer, the comonomer is preferably selected from C₂And/or C₄To C₂₀α -olefins, more preferably selected from C₂And/or C₄To C₁₀α -olefins, most preferably selected from C₂、C₄、C₆And/or C₈α -olefins.

In case the Propylene Polymer (PP) is a random copolymer, the comonomer content is preferably from 0.5 to 10 wt. -%, preferably from 0.5 to 5.0 wt. -%, based on the total amount of the Propylene Polymer (PP).

The preparation of propylene homopolymers and propylene random copolymers is known in the art.

The Propylene Polymer (PP) is preferably a heterophasic polypropylene (HECO).

In the following, unless explicitly stated to the contrary, the Propylene Polymer (PP) is described as a preferred feature of the heterophasic polypropylene (HECO).

Preferably, the heterophasic polypropylene (HECO) is characterized by an MFR measured according to ISO1133 at 230 ℃ and under a load of 2.16kg₂From 5.0g/10min to 60g/10min, more preferably from 5.0g/10min to 40g/10min, most preferably from 5.0g/10min to 20g/10 min.

Preferably, the heterophasic polypropylene (HECO) is characterized by a total comonomer content of 5.0 to 18 wt%, more preferably 7.0 to 15 wt%, most preferably 10.0 to 15 wt%.

Further preferably, the heterophasic polypropylene (HECO) is characterized by a Xylene Cold Soluble (XCS) content of from 20 wt% to 36 wt%, more preferably from 25 wt% to 34 wt%, most preferably from 28 wt% to 34 wt%, based on the heterophasic polypropylene (HECO).

Preferably, the heterophasic polypropylene (HECO) is characterized by an intrinsic viscosity of the xylene cold soluble (IV) of from 2.0dl/g to 4.0dl/g, preferably of from 2.3dl/g to 3.5dl/g, most preferably of from 2.3dl/g to 2.8 dl/g.

Preferably, the heterophasic polypropylene (HECO) is characterized by a comonomer content of Xylene Cold Soluble (XCS) of 30 to 45 wt%, more preferably 35 to 40 wt%.

Preferably, the heterophasic propylene copolymer (HECO) according to the present invention comprises:

(a) a polypropylene matrix (M); and

(b) an elastomeric copolymer (E) comprising units derived from:

-propylene; and

ethylene and/or C₄To C₂₀α -olefins, more preferably ethylene and/or C₄To C₁₀α -olefins, most preferably ethylene, C₄、C₆And/or C₈α -olefin, for example ethylene and optionally units derived from a conjugated diene.

Preferably, the propylene content in the heterophasic propylene copolymer (HECO) is from 82 to 95 wt. -%, more preferably from 85 to 93 wt. -%, most preferably from 85 to 90 wt. -%, based on the total amount of the heterophasic propylene copolymer (HECO). The remainder being composed of a comonomer other than propylene (preferably C)₂And/or C₄To C₂₀α -olefin) and more preferably ethylene accordingly, the heterophasic propylene copolymer (HECO) comprises from 5.0 to 18 wt% (more preferably from 5.0 to 15 wt%, most preferably from 7.0 to 13 wt%) of comonomers (preferably ethylene and/or C)₄To C₁₂α -olefin, more preferably ethylene).

As described herein, the heterophasic propylene copolymer (HECO) comprises only the polypropylene matrix (M) and the elastomeric copolymer (E) as polymer components.

Throughout the present invention, the Xylene Cold Insoluble (XCI) fraction of the heterophasic propylene copolymer (HECO) represents the matrix (M) and optionally the polyethylene; whereas the Xylene Cold Soluble (XCS) fraction represents the elastomeric fraction of the heterophasic propylene copolymer (HECO), i.e. the elastomeric copolymer (E).

Thus, the matrix (M) content (i.e. Xylene Cold Insoluble (XCI) content) in the heterophasic propylene copolymer (HECO) is preferably between 64 wt% and 88 wt%, more preferably between 66 wt% and 75 wt%, most preferably between 66 wt% and 72 wt%.

On the other hand, the elastomeric copolymer (E) content (i.e. Xylene Cold Soluble (XCS) content) in the heterophasic propylene copolymer (HECO) is preferably from 20 to 36 wt. -%, more preferably from 25 to 34 wt. -%, most preferably from 28 to 34 wt. -%.

The polypropylene matrix (M) is preferably a random propylene copolymer (R) or a propylene homopolymer (H), the latter being particularly preferred.

Thus, the polypropylene matrix (M) has a comonomer content of 1.0 wt% or less, more preferably 0.8 wt% or less, even more preferably 0.5 wt% or less, e.g. 0.2 wt% or less.

As mentioned above, the polypropylene matrix (M) is preferably a propylene homopolymer (H).

The expression "propylene homopolymer" as used in the present invention relates to a polypropylene consisting essentially of propylene units (i.e. a polypropylene consisting of more than 99.7 wt%, even more preferably of at least 99.8 wt% of propylene units). In a preferred embodiment, only propylene units are detectable in the propylene homopolymer.

In case the polypropylene matrix (M) is a random propylene copolymer (R), it is understood that the random propylene copolymer (R) comprises monomers copolymerizable with propylene, e.g. comonomers such as ethylene and/or C₄To C₂₀α -olefins, in particular ethylene and/or C₄To C₁₀α -olefins, e.g. ethylene, C₄、C₆Preferably, the random propylene copolymer (R) according to the invention comprises monomers copolymerizable with propylene, in particular, the random propylene copolymer (R) according to the invention consists of monomers copolymerizable with propylene, selected fromEthylene, 1-butene and 1-hexene. More specifically, the random propylene copolymer (R) of the invention comprises, in addition to propylene, units derived from ethylene and/or 1-butene. In a preferred embodiment, the random propylene copolymer (R) comprises only units derived from ethylene and propylene.

Furthermore, it is to be understood that the comonomer content of the random propylene copolymer (R) is preferably from 0.3 to 1.0 wt. -%, more preferably from 0.3 to 0.8 wt. -%, even more preferably from 0.3 to 0.7 wt. -%. .

The term "random" denotes that the comonomers (R) of the random propylene copolymer (R) and (R) are randomly distributed within the propylene copolymer. The term "random" is understood in accordance with IUPAC (compilation of basic terms in Polymer science; IUPAC recommendation 1996).

As described below, the heterophasic propylene copolymer and its individual components (matrix and elastomeric copolymer) can be prepared by compounding different types of polymers, e.g. carrier polymers of carbon fiber masterbatches. Preferably, however, the heterophasic propylene copolymer and its individual components (matrix and elastomeric copolymer) are prepared in a continuous step process using reactors configured in series and operated under different reaction conditions.

Furthermore, it is understood that the polypropylene matrix (M) of the heterophasic propylene copolymer (HECO) has a moderate melt flow rate MFR₂Measured according to ISO1133 under a load of 2.16kg and a temperature of 230 ℃. As mentioned above, the melt flow rate MFR of the polypropylene matrix (M) measured according to ISO1133 under a load of 2.16kg and at a temperature of 230 ℃₂Equal to the melt flow rate MFR of the Xylene Cold Insoluble (XCI) fraction of the heterophasic propylene copolymer (HECO)₂. Thus, the melt flow rate MFR of the Xylene Cold Insoluble (XCI) fraction of the heterophasic propylene copolymer (HECO)₂Preferably 20.0g/10min to 150.0g/10min, more preferably 25.0g/10min to 110g/10min, even more preferably 30.0g/10min to 100g/10min, even more preferably 35.0g/10min to 90g/10 min.

Preferably, the polypropylene matrix (M) is isotactic. It will therefore be appreciated that the polypropylene matrix (M) has a rather high pentavalent (pentad) concentration, i.e. higher than 80%, more preferably higher than 85%, still more preferably higher than 90%, even more preferably higher than 92%, even still more preferably higher than 93%, for example higher than 95%.

The second component of the heterophasic propylene copolymer (HECO) is the elastomeric copolymer (E).

The elastomeric copolymer (E) comprises a copolymer derived from (i) propylene and (ii) ethylene and/or C₄-C₂₀α -olefins (more preferably ethylene and/or C)₄-C₁₀α -olefins, most preferably ethylene, C₄、C₆And/or C8 α -olefins, for example ethylene), preferably elastomeric copolymers (E) made of a mixture of monomers derived from (i) propylene and (ii) ethylene and/or C₄-C₂₀α -olefins (more preferably ethylene and/or C)₄-C₁₀α -olefins, most preferably ethylene, C₄、C₆And/or C₈α -an olefin, for example ethylene) the elastomeric copolymer (E) may also comprise units derived from a conjugated diene, for example butadiene, or a non-conjugated diene, but preferably the elastomeric copolymer (E) consists only of units derived from (i) propylene and (ii) ethylene and/or C₄To C₁₂α -units of an olefin suitable non-conjugated dienes (if used) include straight and branched chain acyclic dienes such as 1, 4-hexadiene, 1, 5-hexadiene, 1, 6-octadiene, 5-methyl-1, 4-hexadiene, 3, 7-dimethyl-1, 6-octadiene, 3, 7-dimethyl-1, 7-octadiene, and mixed isomers of dihydromyrcene and dihydroocimene, and monocyclic alicyclic dienes such as 1, 4-cyclohexadiene, 1, 5-cyclooctadiene, 1,5-cyclododecadiene (1,5-cyclododecadiene), 4-vinylcyclohexene, 1-allyl-4-isopropylidenecyclohexane, 3-allylcyclopentene, 4-cyclohexene, and 1-isopropenyl-4- (4-butenyl) cyclohexane.

In the present invention, the content of units derived from propylene in the elastomeric copolymer (E) is equal to the content of propylene detected in the Xylene Cold Soluble (XCS) fraction. Thus, the propylene detected in the Xylene Cold Soluble (XCS) fraction is from 50.0 wt% to 75.0 wt%, more preferably from 55.0 wt% to 70.0 wt%, even more preferably from 58.0 wt% to 67.0 wt%. Thus, in a specific embodiment, the elastomeric copolymer (E), i.e. the Xylene Cold Soluble (XCS) fraction, comprises 25.0wt% to 50.0 wt.% (more preferably 30.0 wt.% to 45.0 wt.%, even more preferably 33.0 wt.% to 42.0 wt.%) of a catalyst derived from ethylene and/or at least one other C₄To C₂₀α -units of an olefin preferably the elastomeric copolymer (E) is an ethylene propylene non-conjugated diene monomer polymer (EPDM) or an Ethylene Propylene Rubber (EPR), the latter being particularly preferred, wherein the propylene and/or ethylene content is as described in this paragraph.

Preferably the polypropylene composition (PP) of the present invention comprises α -nucleating agent even more preferably the present invention does not comprise β -nucleating agent according to the present invention nucleating agent is understood to be a nucleating agent different from the inorganic filler (F).

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

(ii) dibenzylidene sorbitol (e.g. 1,3:2,4 dibenzylidene sorbitol) and C₁-C₈Alkyl-substituted dibenzylidene sorbitol derivatives, e.g. methyl dibenzylidene sorbitol, ethyl dibenzylidene sorbitol or dimethyl dibenzylidene sorbitol (e.g. 1,3:2, 4-di (methylbenzylidene) sorbitol)), or substituted nonitol (nonitol) derivatives, e.g. 1,2, 3-triseoxy-4, 6:5, 7-bis-O- [ (4-propylphenyl) methylene]-nonitol; and

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

(iv) vinyl cycloalkane polymers and vinyl alkane polymers; and

(v) mixtures thereof.

Such additives are generally commercially available and are described, for example, in "plastics additives handbook" of Hans Zweifel (5 th edition, 2001).

Most preferably, the α -nucleating agent is part of the heterophasic propylene copolymer (HECO), and thus of the polypropylene composition (PP), thus, the heterophasic propylene copolymer (HECO) preferably has a α -nucleating agent content of at most 5.0 wt%. in a preferred embodiment, the heterophasic propylene copolymer (HECO) contains not more than 3000ppm (more preferably 1 to 2000ppm) of α -nucleating agent, in particular, the α -nucleating agent is selected from dibenzylidene sorbitol (e.g. 1,3:2, 4-dibenzylidene sorbitol), dibenzylidene sorbitol derivatives, preferably, the α -nucleating agent is selected from dimethylbenzylidenesorbitol (e.g. 1,3:2, 4-di (methylbenzylidene) sorbitol) or substituted nonitol derivatives (e.g. 1,2, 3-trideoxy-4, 6:5, 7-bis-O- [ (4-propylphenyl) methylene ] -nonitol), vinyl cycloalkane polymers, vinyl alkane polymers and mixtures thereof.

In a preferred embodiment the heterophasic propylene copolymer (HECO) and thus the polypropylene composition (PP) comprises a vinylcycloalkane (e.g. Vinylcyclohexane (VCH)) polymer and/or a vinylcaraffin polymer as α -nucleating agent preferably in this embodiment the heterophasic propylene copolymer (HECO) comprises a vinylcycloalkane (e.g. Vinylcyclohexane (VCH)) polymer and/or a vinylcaraffin polymer, preferably Vinylcyclohexane (VCH). preferably the vinylcycloalkane is a Vinylcyclohexane (VCH) polymer which is introduced into the heterophasic propylene copolymer (HECO) by the BNT technique and thus into the polypropylene composition (PP) in this preferred embodiment more preferably the amount of vinylcycloalkane (e.g. Vinylcyclohexane (VCH)) polymer and/or the vinylcyclohexane polymer (VCH) in the heterophasic propylene copolymer (HECO) does not exceed 500ppm, more preferably 1 to 200ppm, most preferably 5 to 100ppm, more preferably the amount of Vinylcyclohexane (VCH) polymer and/or Vinylcyclohexane (VCH) polymer in the heterophasic propylene copolymer (HECO) does not exceed 500ppm, more preferably the amount of Vinylcyclohexane (VCH) does not exceed 200ppm, more preferably the amount of Vinylcyclohexane (VCH) polymer does not exceed 1.100 ppm, preferably the polypropylene composition (PP) does not exceed 200ppm, preferably the amount of 100ppm of Vinylcyclohexane (VCH) does not exceed 1.0 to 200ppm, preferably the amount of the maximum of the Vinylcyclohexane (VCH) to 200ppm of the vinylcyclohexane.

For BNT technology, reference is made to International applications WO99/24478, WO99/24479, in particular WO 00/68315. According to this technique, the catalyst system, preferably a Ziegler-Natta procatalyst (procatalyst), can be modified by polymerizing the vinyl compound in the presence of the catalyst system; in particular, the catalyst system comprises a special ziegler-natta procatalyst, an external donor and a cocatalyst; wherein the vinyl compound has the formula:

CH₂＝CH-CHR³R⁴

wherein R is³And R⁴Together forming a 5-or 6-membered saturated, unsaturated or aromatic ring or independently representing an alkyl group containing 1 to 4 carbon atoms, and the modified catalyst is used for the preparation of the heterophasic polypropylene of the invention, i.e. the heterophasic propylene copolymer (HECO) the polymerized vinyl compound is used as α -nucleating agent in the catalyst modification step the weight ratio of vinyl compound to solid catalyst component is preferably at most 5 (5: 1), preferably at most 3 (3: 1), most preferably 0.5 (1: 2) to 2 (2: 1) the most preferred vinyl compound is Vinylcyclohexane (VCH).

The heterophasic propylene copolymer (HECO) according to the present invention is preferably produced in a continuous polymerization process, i.e. in a multistage process known in the art, wherein the respective matrix (propylene homopolymer matrix (M)) is produced in at least one slurry reactor and then the elastomeric copolymer (E) is produced in at least one, i.e. one or two, gas phase reactors.

More precisely, the heterophasic propylene copolymer (HECO) is obtained by producing a propylene homopolymer matrix (M) in at least one reactor system comprising at least one reactor, said propylene homopolymer matrix (M) being transferred to a subsequent reactor system comprising at least one reactor in which an elastomeric propylene copolymer (E) is produced in the presence of the propylene homopolymer matrix (M).

Thus, each 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 loop reactors and gas phase reactors, in particular the process employs at least one loop reactor and at least one gas phase reactor. Several reactors of various types may also be used, for example one loop reactor and two or three gas phase reactors in series, or two loop reactors and one or two gas phase reactors in series.

Preferably, the process for preparing the heterophasic propylene copolymer (HECO) further comprises a prepolymerization with a selected catalyst system comprising a ziegler-natta procatalyst, an external donor and a cocatalyst as described in more detail below.

In a preferred embodiment, the prepolymerization is carried out as a bulk slurry polymerization in liquid propylene, i.e. the liquid phase comprises mainly propylene with dissolved minor amounts of other reactants and optionally inert components.

Generally, the prepolymerization is carried out at a temperature of 0 ℃ to 50 ℃ (preferably 10 ℃ to 45 ℃, more preferably 15 ℃ to 40 ℃).

The pressure in the prepolymerization reactor is 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, it is possible to introduce only a part of the cocatalyst into the prepolymerization stage and the remaining part into the subsequent polymerization stage. Also in this case, it is necessary to introduce enough cocatalyst into the prepolymerization stage to obtain sufficient polymerization in this stage.

Other components may also be added in 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.

Precise control of the prepolymerization conditions and reaction parameters is within the skill of the art.

Slurry reactor refers to any reactor operating in bulk or slurry form, such as a continuous or simple batch stirred tank reactor or a loop reactor, in which the polymer is formed in particulate form. "bulk" refers to polymerization in a reaction medium comprising at least 60.0 wt% monomer. 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 with a gas velocity of at least 0.2 m/s.

A particularly preferred embodiment for the preparation of the heterophasic propylene copolymer (HECO) of the present invention comprises: the polymerization is carried out with a process comprising one loop reactor and one or a combination of two or three gas phase reactors or a combination of two loop reactors and one or two gas phase reactors.

A preferred multistage process is the slurry-gas phase process, such as developed by the northern Europe chemical industry (Borealis) and referred to as the slurry-gas phase process

A method of the technology. In this respect, reference is made to EP0887379A1, WO92/12182, WO2004/000899, WO2004/111095, WO99/24478, WO99/24479 and WO 00/68315. Which are incorporated herein by reference.

Another suitable slurry-gas phase process is Basell

The method is carried out.

Preferably, the heterophasic propylene copolymer (HECO) of the present invention is produced by using a special ziegler-natta procatalyst in combination with a special external donor, as described below, preferably with

Or

A method.

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 comprising a specific ziegler-natta procatalyst (i), an external donor (iii) and a cocatalyst (ii), as detailed below, both slurry reactors using the same polymerization conditions;

-transferring the product of the slurry reactor into at least one first gas phase reactor (e.g. one gas phase reactor or a first and a second gas phase reactor connected in series);

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

-recovering the polymer product for further processing.

With respect to the preferred slurry-gas phase process described above, general information regarding process conditions is provided below.

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, optionally with addition of hydrogen 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; wherein the temperature is preferably 50 ℃ to 130 ℃, more preferably 60 ℃ to 100 ℃; the pressure is from 5 bar to 50 bar, preferably from 8 bar to 35 bar, hydrogen again optionally being added in a manner known per se to control the molecular weight.

In the above reactor zones, the average residence time may vary. In one embodiment, the average residence time in the slurry reactor (e.g., loop reactor) is from 0.5 hours to 5 hours, such as from 0.5 hours to 2 hours; while the average residence time in the gas phase reactor is generally from 1 hour to 8 hours.

If desired, the polymerization can be carried out under supercritical conditions in a slurry reactor, preferably a loop reactor, in a known manner and/or the polymerization can be carried out in a gas phase reactor in a condensed manner.

According to the present invention, the heterophasic polypropylene is preferably obtained by a multistage polymerization process as described above in the presence of a catalyst system comprising as components (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 of alcohols with TiCl₄Carrying out reaction;

b) at the C₁-C₂Reacting the product of step a) with a dialkyl phthalate of formula (I) under conditions such that transesterification between an alcohol and said dialkyl phthalate of formula (I) forms an internal donor:

wherein R is^1'And R^2'Independently is at least C₅An alkyl group;

c) washing the product of step b); or

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

For example, the procatalyst is produced as described in patent applications WO87/07620, WO92/19653, WO92/19658 and EP0491566, EP591224 and EP 586390. The contents of these documents are incorporated herein by reference.

First forming MgCl₂And C₁-C₂Adducts of alcohols (of the formula MgCl)₂nROH), wherein R is methyl or ethyl, and n is 1 to 6. The alcohol is preferably ethanol.

The adduct, which is first melted and then spray-crystallized or emulsion-solidified, is used as catalyst support.

Next, the compound of formula MgCl₂Spray-or emulsion-solidified adducts of nROH (wherein R is methyl or ethyl, preferably ethyl, and n is 1 to 6) with TiCl₄Contacting to form a titanized support, followed by the steps of:

adding to the titanized support to form a first product:

(i) a dialkyl phthalate of the formula (I) in which R^1'And R^2'Independently is at least C₅Alkyl radicals, e.g. at least C₈An 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 C₈An alkyl group;

alternatively, and more preferably,

(iii) a dialkyl phthalate of formula (I) selected from propylhexyl phthalate (PrHP), dioctyl phthalate (DOP), diisodecyl phthalate (DIDP) and tricosyl phthalate (DTDP); 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. transesterification of the methanol or ethanol with the ester groups of the dialkyl phthalate of formula (I) at a temperature above 100 ℃ (preferably from 100 ℃ to 150 ℃, more preferably from 130 ℃ to 150 ℃) to form preferably at least 80 mol% (more preferably 90 mol%, most preferably 95 mol%) of the dialkyl phthalate of formula (II):

wherein R is¹And R²Is methyl or ethyl, preferably ethyl;

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 compound of formula (I) is MgCl₂The adduct of nROH (where R is methyl or ethyl and n is 1 to 6) is melted and the melt is then preferably injected by means of a gas into a cooled solvent or cooled gas, whereby the adduct crystallizes into a morphologically advantageous form, for example as described in WO 87/07620.

This 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.

When the catalyst residue is removed by extraction, an adduct of the titanized support and the internal donor is obtained, the group derived from the ester alcohol in the adduct having been changed.

When sufficient titanium is retained 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 to ensure activity.

Preferably, the procatalyst used according to the invention comprises at most 2.5 wt% titanium, preferably at most 2.2 wt% titanium, more preferably at most 2.0 wt% titanium. The donor content is preferably from 4 to 12% by weight, more preferably from 6 to 10% by weight.

More preferably, the procatalyst used according to the invention is prepared by using ethanol as alcohol and dioctyl phthalate (DOP) as dialkyl phthalate of formula (I) yielding diethyl phthalate (DEP) as internal donor compound.

Even more preferably, the catalyst used in the present invention is a catalyst as described in the examples section; in particular, according to WO92/19658, dioctyl phthalate is used as dialkyl phthalate of the formula (I).

In another embodiment, as described above, the Ziegler-Natta procatalyst may be modified by polymerizing a vinyl compound in the presence of a catalyst system comprising a particular Ziegler-Natta procatalyst, an external donor and a cocatalyst, the vinyl compound having the formula:

CH₂＝CH-CHR³R⁴

wherein R is³And R⁴Together forming a 5 or 6 membered saturated, unsaturated or aromatic ring or independently representing an alkyl group containing 1 to 4 carbon atoms, and the modified catalyst is used for the preparation of the heterophasic polypropylene composition of the present invention the polymerized vinyl compound may be used as α -nucleating agent.

With regard to the modification of the catalyst, reference is made to international applications WO99/24478, WO99/24479, in particular WO00/68315, the contents of which with regard to the reaction conditions for the catalyst modification and the polymerization reaction are incorporated herein by reference.

To prepare the heterophasic polypropylene according to the present invention, the catalyst system used preferably comprises as component (ii) in addition to the specific ziegler-natta procatalyst an organometallic cocatalyst.

Thus, the cocatalyst is preferably selected from trialkylaluminums (e.g. Triethylaluminum (TEA)), dialkylaluminum chlorides and alkylaluminum sesquichlorides.

Component (iii) of the catalyst system used is an external donor represented by formula (IIIa) or (IIIb). Formula (IIIa) is defined as

Si(OCH₃)₂R₂ ⁵(IIIa)

Wherein R is⁵Represents a branched alkyl group having 3 to 12 carbon atoms, preferably a branched alkyl group having 3 to 6 carbon atoms, or a cycloalkyl group having 4 to 12 carbon atoms, preferably a cycloalkyl group having 5 to 8 carbon atoms.

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)

Wherein R is^xAnd R^yWhich may be the same or different, represent a hydrocarbon group having 1 to 12 carbon atoms.

R^xAnd R^yIndependently selected from the group consisting of a straight chain aliphatic hydrocarbon group having 1 to 12 carbon atoms, a branched chain aliphatic hydrocarbon group having 1 to 12 carbon atoms, and a cyclic aliphatic hydrocarbon group having 1 to 12 carbon atoms. 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 betterOptionally, R^xAnd R^yAre all ethyl groups.

More preferably, the external donor of formula (IIIb) is diethylaminotriethoxysilane.

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]In particular dicyclopentyldimethoxysilane [ Si (OCH)₃)₂(cyclopentyl)₂]。

Ethylene copolymer (PE)

Another essential requirement is the presence of ethylene copolymers (PE). The ethylene copolymer (PE) is (chemically) different from the elastomeric copolymer (E) of the heterophasic polypropylene (HECO).

Furthermore, the ethylene copolymer (PE) is characterized by a specific melt flow rate (i.e.the melt flow rate MFR, measured according to ISO1133 under a load of 2.16kg and at a temperature of 190 ℃)₂) Preferably from 0.1g/10min to 45g/10min, more preferably from 0.5g/10min to 35g/10min, even more preferably from 1g/10min to 20g/10 min.

Preferably, the ethylene copolymer (PE) is a copolymer comprising predominantly units derived from ethylene. Thus, it is understood that the ethylene copolymer (PE) comprises at least 50.0 wt% of units derived from ethylene, more preferably at least 55.0 wt% of units derived from ethylene. Thus, it is understood that the ethylene copolymer (PE) comprises from 50.0 wt% to 70.0 wt% (more preferably from 55.0 wt% to 65 wt%) of units derived from ethylene. The comonomer present in the ethylene copolymer (PE) is C₄To C₂₀α -olefins, such as 1-butene, 1-hexene and 1-octene, the latter being particularly preferred in one particular embodiment, the ethylene copolymer (PE) is an ethylene-1-octene polymer, the content of which is given in this paragraph.

Suitable ethylene copolymers (PE) are commercially available, for example elastomeric copolymers of ethylene and octane, "Engage 8200" from dow chemical pacific corporation of hong kong.

Carbon fiber master batch

The carbon fiber masterbatch typically comprises from 25 wt% to 50 wt% carbon fibers, preferably the carbon fiber masterbatch comprises from 25 wt% to 50 wt% carbon fibers and from 50 wt% to 75 wt% polypropylene (typically a propylene homopolymer) as a carrier for the carbon fibers, based on 100% total weight of the masterbatch. Preferably, the masterbatch comprises from 30% to 45% carbon fiber and from 55% to 70% polypropylene (preferably propylene homopolymer) carrier.

The carbon fibres preferably have an average length of from 0.5mm to 30mm, more preferably from 1.0 to 20mm, for example from 2.0mm to 15 mm.

The carbon fibers preferably have an average diameter of 1.0mm to 30 μm, more preferably mm 2.0 to 25 μm, and most preferably 3.0mm to 15 μm.

Preferably, the carbon fibers have an average length of 0.5mm to 30mm and an average diameter of 1.0 μm to 30 μm; more preferably, the carbon fibers have an average length of 1.0mm to 20mm and an average diameter of 2.0 μm to 25 μm; most preferably, the carbon fibers have an average length of 2.0mm to 15mm and an average diameter of 3.0mm to 15 mm.

Preferably, the carbon fibers do not contain any metal coating.

MFR of the masterbatch measured according to ISO1133 at a temperature of 230 ℃ and a load of 2.16kg₂Is 0.5g/10min to 20g/10min, preferably 1g/10min to 10g/10min, more preferably MFR₂Is 1g/10min to 5g/10 min.

Preferably, the propylene homopolymer used as carrier is generally a conventional propylene homopolymer.

Polarity Modified Polypropylene (PMP)

In order to make the Carbon Fibers (CF) more easily and uniformly dispersed, the polypropylene composition comprises a specific coupling agent.

The coupling agent of the present invention is a specific Polar Modified Polypropylene (PMP).

The Polar Modified Polypropylene (PMP) comprises 1 to 5 wt% of groups derived from polar groups. Hereinafter, the polypropylene of the Polar Modified Polypropylene (PMP) will be more specifically defined, which is subsequently modified to the Polar Modified Polypropylene (PMP) as described in detail below.

The polypropylene of the Polar Modified Polypropylene (PMP) is preferably a propylene homopolymer or a random propylene copolymer, for exampleSuch as (i) propylene with (ii) ethylene and/or C₄To C₁₂α -olefin, preferably (i) propylene and (ii) a α -olefin selected from ethylene, 1-butene, 1-hexene and 1-octene.

Preferably, the comonomer content is from 1.0 to 7.5 wt%, more preferably from 4.0 to 7.0 wt%, based on the total amount of the random propylene copolymer.

In one embodiment, the Polar Modified Polypropylene (PMP) is a modified random propylene copolymer, wherein the random propylene copolymer comprises ethylene as the sole comonomer unit.

Furthermore, it is understood that the melting temperature T of the random propylene copolymer of Polar Modified Polypropylene (PMP)_mFrom 125 ℃ to 140 ℃, more preferably from 128 ℃ to 138 ℃, most preferably from 131 ℃ to 136 ℃. The melting temperatures given in this paragraph are the melting temperatures of the unmodified random propylene copolymer.

Additionally or alternatively, the random propylene copolymer of Polar Modified Polypropylene (PMP), i.e. the non-modified random propylene copolymer, has a melt flow rate MFR, measured according to ISO1133 at 190 ℃ and under a load of 2.16kg₂Is 1g/10min to 500g/10min, preferably 20g/10min to 150g/10min, and more preferably 1g/10min to 100g/10 min.

It is understood that the Polar Modified Polypropylene (PMP) comprises groups derived from polar groups. In this case, preference is given to Polar Modified Polypropylene (PMP) comprising groups derived from polar compounds, in particular selected from the group consisting of anhydrides, carboxylic acids, carboxylic acid derivatives, primary and secondary amines, hydroxyl compounds, oxazolines and epoxides, and also ionic compounds.

Specific examples of the polar group are unsaturated cyclic anhydrides and aliphatic diesters and diacid derivatives thereof. In particular, maleic anhydride and a compound selected from the group consisting of: c₁To C₁₀Linear and branched dialkyl maleates, C₁To C₁₀Linear and branched dialkyl fumarates, itaconic anhydride, C₁To C₁₀Linear and branched dialkyl itaconates, maleic acid, fumaric acid, itaconic acid, and mixtures thereofA compound (I) is provided.

With respect to the structure, the Polar Modified Polypropylene (PMP) is preferably selected from graft or block copolymers of the above-mentioned polypropylenes, for example the above-mentioned random propylene copolymers for Polar Modified Polypropylene (PMP).

Preferably, the Polar Modified Polypropylene (PMP), i.e. the coupling agent, is a polypropylene grafted with such polar groups (e.g. the random propylene copolymer for Polar Modified Polypropylene (PMP) described above in this section).

It is particularly preferred to use polypropylene grafted with maleic anhydride, such as the random propylene copolymer for Polar Modified Polypropylene (PMP) described above in this section, as the Polar Modified Polypropylene (PMP), i.e. the coupling agent.

In one embodiment, the Polar Modified Polypropylene (PMP) is a random propylene copolymer as described above grafted with maleic anhydride. Thus, in a particularly preferred embodiment, the Polar Modified Polypropylene (PMP) is a random propylene ethylene copolymer grafted with maleic anhydride, more preferably wherein the ethylene content is from 1.0 wt% to 7.5 wt%, more preferably from 4.0 wt% to 7.0 wt%, based on the total amount of the random propylene ethylene copolymer.

The desired amount of groups derived from polar groups in the Polar Modified Polypropylene (PMP) is preferably from 0.5 to 5.0 wt. -%, more preferably from 0.8 to 3.0 wt. -%, most preferably from 1.0 to 1.8 wt. -%, for example from 1.2 to 1.6 wt. -%, based on the total weight of the Polar Modified Polypropylene (PMP).

Thus, in a particularly preferred embodiment, the Polar Modified Polypropylene (PMP) is a random propylene ethylene copolymer grafted with maleic anhydride, more preferably wherein the ethylene content is from 2.0 wt% to 7.5 wt%, more preferably from 4.0 wt% to 7.0 wt%, based on the total amount of the random propylene ethylene copolymer; and/or the amount of groups derived from maleic anhydride in the polar modified polypropylene (PMP2) is from 0.5 wt% to 3.0 wt%, more preferably from 0.8 wt% to 2.0 wt%, most preferably from 1.0 wt% to 1.8 wt%, for example from 1.2 wt% to 1.6 wt%, based on the total weight of the Polar Modified Polypropylene (PMP).

Preferably, the Polar Modified Polypropylene (PMP) is in accordance with ISO1133 at 19Melt flow Rate MFR determined at 0 ℃ and under a load of 2.16kg₂From 1.00g/10min to 500g/10min, for example from 20g/10min to 150g/10 min.

Polar Modified Polypropylene (PMP) can be produced in a simple manner by reactive extrusion of the polymer with, for example, maleic anhydride in the presence of a free-radical generator, for example an organic peroxide, as described in EP 0572028.

Polar modified polypropylene (PMP2) is known in the art and is commercially available. A suitable example is BYK SCONATPPP 8112 FA.

Polypropylene composition

As mentioned above, the polypropylene composition comprises:

c)26 to 50 parts by weight of a carbon fiber masterbatch;

Preferably, the polypropylene composition comprises:

a)35 to 50 parts by weight of a Propylene Polymer (PP), more preferably 40 to 50 parts by weight of a Propylene Polymer (PP);

b)11 to 30 parts by weight of an ethylene copolymer (PE), more preferably 11 to 25 parts by weight of an ethylene copolymer (PE), most preferably 11 to 20 parts by weight of an ethylene copolymer (PE);

c)30 to 45 parts by weight of a carbon fiber masterbatch, more preferably 33 to 40 parts by weight of a carbon fiber masterbatch;

and/or

d)0.25 to 1.75 parts by weight of Polar Modified Polypropylene (PMP), more preferably 0.5 to 1.5 parts by weight of Polar Modified Polypropylene (PMP), most preferably 0.75 to 1.25 parts by weight of Polar Modified Polypropylene (PMP);

Particularly preferably, component b) is present in an amount of at least 11 wt%, based on the whole polypropylene composition.

Preferably, the sum of components a) to d) is at least 85 wt%, more preferably at least 90 wt%, most preferably at least 95 wt%, for example at least 98 wt%, based on the total amount of the polypropylene composition.

The surface resistivity of the polypropylene composition is preferably 1.0-10⁶Ohm/m²Hereinafter, more preferably 5.0 · 10⁵Ohm/m²Hereinafter, the most preferable range is 1.0.10⁵Ohm/m²The following.

MFR of the Polypropylene composition measured according to ISO11 at a temperature of 230 ℃ and under a load of 2.16kg₂Preferably 1.0g/10min to 30g/10min, more preferably 3.0g/10min to 25g/10min, most preferably 5.0g/10min to 15g/10 min.

Furthermore, the polypropylene composition preferably has a tensile strength of at least 20MPa, more preferably at least 30MPa, most preferably at least 40MPa, measured according to ISO 527-2. Generally, the tensile strength does not exceed 70 MPa.

Preferably the polypropylene composition has a flexural modulus measured according to ISO178 of at least 3500MPa, more preferably at least 4000MPa, most preferably at least 4500 MPa. Typically, the flexural modulus does not exceed 6000 MPa.

The polypropylene composition preferably has a Charpy notched impact strength of at least 2.0kJ/m, measured at 23 ℃ in accordance with ISO 1791 eA²More preferably at least 4.0kJ/m²Most preferably at least 6.0kJ/m². Usually, the Charpy notched impact strength is not higher than 10kJ/m²。

The polypropylene composition may comprise compounds other than compounds a) to d) described herein, wherein the total amount of these compounds other than compounds a) to d) preferably does not exceed 15 wt%, more preferably does not exceed 10 wt%, most preferably does not exceed 5 wt%, e.g. does not exceed 2 wt%.

Preferably, the compounds different from compounds a) to d) are selected from conventional additives different from carbon fibers and carrier polymers, such as antioxidants, slip agents, antiblocking agents, antifogging agents, pigments, antistatic agents, etc. As noted above, carrier polymers are often used to incorporate additives into polymer compositions.

The compounds other than compounds a) to d) may comprise carbon black as pigment. However, in case carbon black is present in the polypropylene composition of the present invention, the carbon black content is typically not more than 5.0 wt%, more preferably not more than 2.5 wt%, most preferably not more than 1.5 wt%, e.g. not more than 1 wt%.

In one variation, the polypropylene composition comprises:

a)30 to 54 parts by weight (preferably 35 to 50 parts by weight, more preferably 40 to 50 parts by weight) of a Propylene Polymer (PP) having an MFR, measured according to ISO1133 at 230 ℃ and under a load of 2.16kg₂2.0g/10min to 80g/10 min;

b)11 to 30 parts by weight (preferably 11 to 25 parts by weight, most preferably 11 to 20 parts by weight) of an ethylene copolymer (PE) having an MFR, measured according to ISO1133 at 190 ℃ under a load of 2.16kg₂Is 0.5g/10min to 35g/10 min;

c)26 to 50 parts by weight (more preferably 33 to 40 parts by weight) of a carbon fiber master batch;

d)0.10 to 2.0 parts by weight (more preferably 0.5 to 1.5 parts by weight, most preferably 0.75 to 1.25 parts by weight) of a Polar Modified Polypropylene (PMP), wherein the Polar Modified Polypropylene (PMP) comprises 0.5 to 5.0 wt% of groups derived from polar groups;

e) the sum of components a) to d) is at least 85 wt%, more preferably at least 90 wt%, most preferably at least 95 wt%, such as at least 98 wt%, based on the total amount of the polypropylene composition;

the parts by weight are based on the total parts by weight of the component a), the component b), the component c) and the component d);

and

f) the polypropylene composition has an MFR, measured according to ISO1133 at a temperature of 230 ℃ and under a load of 2.16kg, of from 1.0g/10min to 30g/10min, more preferably of from 3.0g/10min to 25g/10min, most preferably of from 5.0g/10min to 15g/10 min;

wherein preferably the carbon fibres have an average length of 0.5mm to 30mm and/or an average diameter of 1.0 μm to 30 μm, more preferably the carbon fibres have an average length of 1.0mm to 20mm and/or an average diameter of 2.0 μm to 25 μm, most preferably the carbon fibres have an average length of 2.0mm to 15mm and/or an average diameter of 3.0 μm to 15 μm.

In another variation, the polypropylene composition comprises:

a)35 to 50 parts by weight (more preferably 40 to 50 parts by weight) of a Propylene Polymer (PP) having an MFR, measured according to ISO1133 at 230 ℃ and under a load of 2.16kg₂2.0g/10min to 80g/10 min;

b)11 to 25 parts by weight (most preferably 11 to 20 parts by weight) of an ethylene copolymer (PE) having an MFR, measured according to ISO1133 at 190 ℃ and under a load of 2.16kg₂0.5 to 35g/10 min;

d)0.5 to 1.5 parts by weight (most preferably 0.75 to 1.25 parts by weight) of a Polar Modified Polypropylene (PMP), wherein the Polar Modified Polypropylene (PMP) comprises 0.5 to 5.0 wt% of groups derived from polar groups;

the parts by weight being based on the total parts by weight of the component a), the component b), the component c) and the component d)

e) The sum of components a) to d) is at least 90 wt%, most preferably at least 95 wt%, such as at least 98 wt%, based on the total amount of the polypropylene composition; and

f) the polypropylene composition has an MFR, measured according to ISO1133 at a temperature of 230 ℃ and under a load of 2.16kg, of from 3.0g/10min to 25g/10min, most preferably from 5.0g/10min to 15g/10 min;

In another variation, the polypropylene composition comprises:

b)11 to 25 parts by weight (most preferably 11 to 20 parts by weight) of an ethylene copolymer (PE) having an MFR, measured according to ISO1133 at 190 ℃ and under a load of 2.16kg₂Is 0.5g/10min to 35g/10 min;

wherein the carbon fibers have an average length of 0.5mm to 30mm and/or an average diameter of 1.0 μm to 30 μm, more preferably an average length of 1.0mm to 20mm and/or an average diameter of 2.0 μm to 25 μm, most preferably an average length of 2.0mm to 15mm and/or an average diameter of 3.0 μm to 15 μm.

Article of manufacture

The invention further relates to an article comprising the polypropylene composition according to the invention, preferably the article is a moulded or foamed article, more preferably an injection moulded article.

Molding and foaming processes are well known in the art.

Preferably, the article according to the invention is at least part of a housing for an electrical device and/or for an automotive application (e.g. a device for electrical and electronic applications, energy applications and healthcare, in particular automotive applications, such as an instrument panel holder).

Typically, the surface resistivity of the polypropylene composition is reduced by at least a factor of 10, more preferably by at least a factor of 100, most preferably by at least a factor of 1000, for example by at least a factor of 5000, compared to the same composition comprising the same amount of carbon black instead of carbon fibers.

Experimental part

Defining/measuring method

The following definitions of terms and determination methods apply to the above general description of the invention as well as to the following examples, unless otherwise defined.

Quantification of microstructure by NMR spectroscopy

Quantitative Nuclear Magnetic Resonance (NMR) spectroscopy was used to quantify the isotacticity and regioregularity of polypropylene homopolymers.

To is directed at¹H and¹³c, recording of quantification in solution state using Bruker Advance III400NMR spectrometer operating at 400.15MHz and 100.62MHz respectively¹³C{¹H } NMR spectrum. Use of¹³C optimal 10mm extended temperature probe, all spectra were recorded at 125℃ for all atmospheres using nitrogen.

For a polypropylene homopolymer, about 200mg of the material was dissolved in 1, 2-tetrachloroethane-d₂(TCE-d₂). 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. Selecting this settingMainly the high resolution required for the quantification of tacticity distribution (tactility distribution) (Busico, V., Cipullo, R., prog.Polym.Sci.26(2001) 443; Busico, V., Cipullo, R., Monaco, G., Vacatello, M., Segre, A.L., Macromolecules 30(1997) 6251). Using the NOE and bi-level WALTZ16 decoupling scheme, standard single pulse excitation was used (Zhou, z., Kuemmerle, r., Qiu, x., Redwine, d., Cong, r., Taha, a., Baugh, d.winnnford, b., j.mag.reson.187(2007) 225; Busico, v., Carbonniere, p., Cipullo, r., pellechia, r., Severn, j., Talarico, g., macromol.rapid command.2007, 28,11289). A total of 8192(8k) transient signals were collected for each spectrum.

Quantification using a dedicated computer program¹³C{¹H NMR spectra were processed, integrated and the relevant quantitative properties were determined from the integration.

For polypropylene homopolymer, all chemical shifts are referenced internally by methyl isotactic pentads (mmmm) at 21.85 ppm.

Characteristic signals corresponding to regio-defects (Resconi, L., Cavallo, L., Fait, A., Piemontesi, F., chem.Rev.2000,100, 1253;;; (Wang, W-J., Zhu, S., Macromolecules 33(2000), 1157; Cheng, H.N., Macromolecules 17(1984),1950) or comonomers are observed.

The tacticity distribution was quantified by integrating the methyl regions between 23.6ppm and 19.7ppm, correcting for any sites not related to the target stereosequence (Busico, V., Cipullo, R., prog.Polym.Sci.26(2001) 443; Busico, V., Cipullo, R., Monaco, G., Vacatello, M., Segre, A.L., Macromolecules 30(1997) 6251).

Specifically, the effect of regio-defects and comonomer on the quantification of tacticity distribution is corrected by subtracting the representative regio-defects and comonomer integrals from the specific integrated regions of the stereosequence.

Isotacticity is measured at the pentad level and is reported as the percentage of isotactic pentad (mmmm) sequences relative to all pentad sequences:

[ mmmm ]% ═ 100 (mmmm/sum of all pentavalent bases)

The presence of 2,1 erythro defects was indicated by the presence of two methyl sites at 17.7ppm and 17.2ppm and confirmed by other characteristic sites. No characteristic signals corresponding to other types of area defects were observed (Resconi, l., cavalo, l., Fait, a., pimonetisi, f., chem. rev.2000,100, 1253).

The average integral of the two characteristic methyl sites at 17.7ppm and 17.2ppm was used to quantify the amount of 2,1 erythro regio defects:

P_21e＝(I_e6+I_e8)/2

the amount of 1,2 major insertions of propylene was quantified from the methyl region and corrected for sites not involved in the major insertions contained in this region and major insertion sites excluded from this region:

P₁₂＝I_CH3+P_12e

the total amount of propylene was quantified as the sum of the main inserted propylene and all other current area defects:

P_{general assembly}＝P₁₂+P_21e

The molar percentage of 2, 1-erythro regio defects was quantified relative to all propylene:

[21e]mol％＝100*(P_21e/P_{general assembly})

A characteristic signal corresponding to ethylene incorporation was observed (as described in Cheng, h.n., Macromolecules 1984, 17, 1950), and the comonomer fraction was calculated as the fraction of ethylene in the polymer relative to all monomers in the polymer.

Quantification of comonomer fraction using the method of W-J.Wang and S.Zhu, Macromolecules 2000, 331157 by pairing¹³C{¹H spectrum by integrating multiple signals over the entire spectral region. This method was chosen because of its robustness and ability to calculate area defects when needed. The integration region is adjusted slightly to improve the suitability for the comonomer content encountered over the entire range.

The mole percent comonomer incorporation was calculated from the mole fraction.

The weight percent comonomer incorporation was calculated from the mole fraction.

The density of the polymer composition is determined according to ISO 1183-187. Sample preparation was according to ISO 1872-2: 2007 is done by compression molding.

Xylene Cold Soluble (XCS) was determined according to ISO16152 (first edition; 2005-07-01) at 25 ℃.

The intrinsic viscosity was measured according to DIN ISO1628/1 (in decalin at 135 ℃) at 10 months 1999.

A tensile modulus; tensile strength was measured according to ISO527-2 (crosshead speed 1 mm/min; 23 ℃) using injection-moulded specimens described in ENISO1873-2 (dog-bone shape, thickness 4 mm).

Flexural modulus according to ISO178, three-point bending, 80X 10X 4mm prepared according to EN ISO1873-2³The injection molded samples of (2) were subjected to the measurement.

Charpy notched impact strength according to ISO 1791 eA at 23 ℃ 80X 10X 4mm injection moulded according to EN ISO1873-2³The bar was tested for determination.

Average fiber diameter according to ISO 1888: 2006(E) method B, microscope magnification 1000.

Melt Flow Rate (MFR) is measured according to ISO1133 at a given temperature and load.

DSC analysis, melting temperature (T)_m) And enthalpy of fusion (Hm), crystallization temperature (Tc) and enthalpy of crystallization (Hc): measurements were performed on 5mg to 7mg samples using TAInstrucnt Q200 Differential Scanning Calorimetry (DSC). DSC was run according to ISO 11357/part 3/method C2 in a heating/cooling/heating cycle at a scan rate of 10 ℃/min over a temperature range of-30 ℃ to +225 ℃. The crystallization temperature and the crystallization enthalpy (Hc) are determined from the cooling step, while the melting temperature and the crystallization enthalpy (Hm) are determined from the second heating step.

Surface resistivity: the test was performed using test equipment "HS-699" purchased from Shenzhen Haishen (Hoslen) electronic technology Co., Ltd., Guangdong, China.

Sample for testing: plates with dimensions of 150mm (length) 90mm (width) 3mm (height) were produced by injection moulding.

And (3) testing conditions are as follows: the temperature was 23 ℃ and the relative humidity was 50%.

Production of PP1

Catalyst preparation

First, 0.1 mole of MgCl was added under inert conditions at atmospheric pressure₂X 3EtOH was suspended in 250 ml decane in the reactor. The solution was cooled to a temperature of-15 ℃ and 300ml of cold TiCl were added while maintaining the temperature at the above level₄. The temperature of the suspension was then slowly raised to 20 ℃. At this temperature, 0.02 mol of dioctyl phthalate (DOP) was added to the suspension. After addition of the phthalate, the temperature was raised to 135 ℃ over 90 minutes and the suspension was allowed to stand for 60 minutes. Then, 300ml of TiCl were added₄The temperature was maintained at 135 ℃ for 120 minutes. After this time, the catalyst was filtered from the liquid and washed six times with 300ml of heptane at 80 ℃. Then, the solid catalyst component was filtered and dried.

For example, catalysts and their preparation concepts are generally described in the patent publications WO87/07620, WO92/19653, WO92/19658 and EP0491566, EP591224 and EP 586390.

The catalyst was further modified (VCH modification of the catalyst).

At room temperature, under inert conditions, 35ml of mineral oil (Paraffinum Liquidum PL68) was added to a 125ml stainless steel reactor, followed by 0.82g of Triethylaluminum (TEAL) and 0.33g of dicyclopentyldimethoxysilane (donor D). After 10 minutes, 5.0g of the catalyst prepared above (titanium content 1.4 wt%) was added, and after a further 20 minutes, 5.0g of Vinylcyclohexane (VCH) were added. The temperature was raised to 60 ℃ over 30 minutes and maintained at this temperature for 20 hours. Finally, the temperature was lowered to 20 ℃ and the oil/catalyst mixture was analyzed for the concentration of unreacted VCH and found to be 200ppm by weight.

Bis (cyclopentyl) dimethoxysilane (donor D) was used as external donor.

Table 1: polymerization conditions for PP1

The properties of the product obtained from the individual reactors are naturally not measured on homogeneous material but on reactor samples (field samples). The properties of the final resin are measured on a homogeneous material, MFR, as described below₂Is measured on pellets made therefrom in an extrusion compounding process.

PP1 was mixed with 0.1% by weight of pentaerythritol tetrakis (3- (3',5' -di-tert-butyl-4-hydroxyphenyl) propionate (CAS No. 6683-19-8, trade name Irganox 1010), supplied by BASF AG, 0.1% by weight of tris (2, 4-di-tert-butylphenyl) phosphite (CAS No. 31570-04-4, trade name 10 Irgafos 168), supplied by BASF AG, and 0.05% by weight of calcium stearate (CAS No. 1592-23-0), supplied by Croda Polymer Additives, in a twin-screw extruder.

Table 2: formulations for preparing the inventive and reference compositions

"PE 1" is a commercial product Engage 8200 from Tao chemical Pacific, Inc. (hong Kong), which has a density of 0.870g/cm³Melt flow Rate MFR₂(190 ℃, 2.16kg) of an ethylene-1-octene copolymer at 5.0g/10 min;

"PP-H, GD, 225" propylene homopolymer, used as a carrier for Irgafos 168 and Irganox 1010, Tm: 160 ℃;

"Irgafos 168" tris (2, 4-di-tert-butylphenyl) phosphite, CAS number 31570-04-4, available from BASF;

"Irganox 1010" pentaerythritol-tetrakis (3- (3',5' -di-tert-butyl-4-hydroxyphenyl) -propionate, CAS number 6683-19-8, available from BASF;

a "carbon fiber masterbatch" is a mixture of 40 wt% carbon fiber and 60 wt% polypropylene homopolymer carrier, the MFR of which is₂(ISO1133, 230 ℃, 2.16kg load) is 2g/10min, and the flexural modulus is 18500 MPa;

"TPPP 8112" is a polypropylene (functionalized with maleic anhydride) "TPPP 8112 FA" of BYK Co. Ltd, Germany "MFR of₂(190 ℃; 2.16kg) is more than 80g/10min, the maleic anhydride content is 1.4 wt%;

the composition is prepared by compounding the raw materials in a twin screw extruder.

All feeds were heated and homogeneously mixed in an extruder at a temperature of 180 ℃ to 250 ℃ and the mixture thus formed was extruded from the extruder.

Table 3: the following temperature profile was used in the compounding process

The properties of the composition are as follows.

From the above, it can be seen that the surface resistivity is reduced by four orders of magnitude compared to compositions comprising carbon black, while the compositions have excellent mechanical properties.

Claims

1. A polypropylene composition, said composition comprising:

a)30 to 54 parts by weight of a propylene polymer PP having an MFR, measured according to ISO1133 at 230 ℃ and under a load of 2.16kg₂2.0g/10min to 80g/10 min;

b)11 to 30 parts by weight of an ethylene copolymer PE having an MFR, measured according to ISO1133 at 190 ℃ and under a load of 2.16kg₂Is 0.5g/10min to 35g/10 min;

c)26 to 50 parts by weight of a carbon fiber masterbatch;

d)0.10 to 2.0 parts by weight of a polar modified polypropylene PMP, wherein the polar modified polypropylene PMP comprises 0.5 to 5.0 wt% of groups derived from polar groups;

2. The polypropylene composition according to claim 1, wherein the propylene polymer PP is a heterophasic polypropylene HECO.

3. The polypropylene composition according to claim 2, wherein the heterophasic polypropylene HECO has at least one of the following characteristics i) to v):

i) MFR measured according to ISO1133 at 230 ℃ and under a load of 2.16kg₂5.0g/10min to 60g/10 min;

ii) the total comonomer content is from 5.0 to 18 wt%;

iii) xylene cold soluble XCS content from 20 to 36 wt%;

iv) comonomer content of xylene cold soluble XCS from 30 to 45 wt%; and

v) intrinsic viscosity IV of xylene cold soluble material ranging from 2.0dl/g to 4.0 dl/g.

4. Polypropylene composition according to any one of the preceding claims, wherein the ethylene copolymer PE is an ethylene copolymer having a comonomer content of not more than 50.0 wt%.

5. Polypropylene composition according to any of the preceding claims, wherein the ethylene copolymer PE is C₂/C₄To C₂₀α -olefin copolymer.

6. The polypropylene composition according to any of the preceding claims, wherein the polar modified polypropylene PMP comprises groups derived from polar groups selected from the group consisting of acid anhydrides, carboxylic acids, carboxylic acid derivatives, primary and secondary amines, hydroxyl compounds, oxazolines and epoxides and ionic compounds; preferably, the polar modified polypropylene PMP is a propylene polymer grafted with maleic anhydride.

7. Polypropylene composition according to any one of the preceding claims, wherein the carbon fiber masterbatch comprises from 25 to 45 wt% of carbon fibers, based on the total weight of the carbon fiber masterbatch.

8. Polypropylene composition according to any one of the preceding claims, wherein the carbon fibres are free of any metal coating.

9. Polypropylene composition according to any one of the preceding claims, wherein the carbon fibres have:

i) an average diameter of 1.0 μm to 30 μm;

ii) an average length of 0.5mm to 30 mm; or

iii) i) and ii).

10. Polypropylene composition according to any of the preceding claims, wherein the polypropylene composition has a surface resistivity of 10⁶Ohm/m²The following.

11. An article comprising the polypropylene composition of any of the preceding claims.

12. The article according to claim 11, wherein the article is a molded or foamed article, preferably an injection molded article.

13. The article of any one of the preceding claims 11 or 12, wherein the article is at least a portion of a housing for electrical equipment and/or for use in automotive applications.