CN112996851B

CN112996851B - Fiber reinforced polypropylene composition with high oil resistance

Info

Publication number: CN112996851B
Application number: CN201880099283.6A
Authority: CN
Inventors: 朱江磊; 孙万锋; 陈世平
Original assignee: Borouge Compounding Shanghai Co ltd
Current assignee: Borouge Compounding Shanghai Co ltd
Priority date: 2018-11-20
Filing date: 2018-11-20
Publication date: 2023-05-26
Anticipated expiration: 2038-11-20
Also published as: WO2020102970A1; CN112996851A; JP7252329B2; JP2022506145A

Abstract

The invention relates to a fiber reinforced polypropylene composition (C) comprising a Propylene Polymer (PP) having a xylene solubles content XCS equal to or lower than 5.0wt%, a fiber (F) and an Adhesion Promoter (AP). Furthermore, the invention relates to injection molded articles comprising said fiber reinforced polypropylene composition (C).

Description

Fiber reinforced polypropylene composition with high oil resistance

Technical Field

The invention relates to a fiber reinforced polypropylene composition (C) comprising a Propylene Polymer (PP) having a xylene solubles content XCS equal to or lower than 5.0wt%, a fiber (F) and an Adhesion Promoter (AP). Furthermore, the present invention relates to an article comprising said fiber reinforced polypropylene composition (C).

Background

The excellent mechanical properties, in particular stiffness and strength, of fiber reinforced polypropylene compositions are highly evaluated in the automotive industry. In particular, increasing the fiber content results in increased stiffness and strength.

A widely used method of improving the impact properties of such compositions is to use heterophasic propylene copolymers as base resin. However, the oil resistance of fiber-reinforced compositions comprising multiphase systems is often unsatisfactory due to the presence of amorphous phases.

Accordingly, there is a need in the art for a fiber reinforced polypropylene composition that exhibits good oil resistance while maintaining a high level of mechanical properties.

Disclosure of Invention

Accordingly, an object of the present invention is to provide a fiber reinforced polypropylene composition having good oil resistance as well as high stiffness and high strength.

Accordingly, the present invention provides a fiber reinforced polypropylene composition (C) comprising:

i) Propylene Polymer (PP) having a xylene solubles content XCS equal to or lower than 5.0wt%,

ii) fiber (F), and

iii) An Adhesion Promoter (AP),

wherein the fiber reinforced polypropylene composition satisfies inequality (I)

Wherein w (PP) is the weight fraction of the Propylene Polymer (PP) in wt% based on the total weight of the fiber-reinforced polypropylene composition (C), and w (AP) is the weight fraction of the Adhesion Promoter (AP) in wt% based on the total weight of the fiber-reinforced polypropylene composition (C).

According to one embodiment of the invention, the Propylene Polymer (PP) is single phase.

According to another embodiment of the invention, the fiber reinforced polypropylene composition (C) does not comprise a propylene polymer having a xylene solubles content XCS of more than 5.0 wt-%.

According to another embodiment of the present invention, the fiber reinforced polypropylene composition (C) satisfies the inequality (II):

wherein w (F) is the weight fraction of the fibers (F) in wt% based on the total weight of the fiber reinforced polypropylene composition (C), and w (AP) is the weight fraction of the Adhesion Promoter (AP) in wt% based on the total weight of the fiber reinforced polypropylene composition (C).

According to another embodiment of the invention, the Propylene Polymer (PP) is at least bimodal.

It is particularly preferred that the Propylene Polymer (PP) is a propylene homopolymer (H-PP).

According to one embodiment of the present invention, the Propylene Polymer (PP) comprises:

i) A first propylene polymer (PP 1) having a melt flow rate MFR measured according to ISO 1133 at 230℃and a load of 2.16kg ₂ Is equal to or lower than 20g/10min, and

ii) an optional second propylene polymer (PP 2) having a melt flow rate MFR measured according to ISO 1133 at 230℃and a load of 2.16kg ₂ Is more than 20g/10min.

According to another embodiment of the invention, the fibers (F) are Short Fibers (SF).

Particularly preferably, the fibers (F) are Glass Fibers (GF), more preferably Short Glass Fibers (SGF).

Preferably, the Short Fibers (SF), more preferably the Short Glass Fibers (SGF) have:

i) Average length of 1.0 to 10.0mm, and/or

ii) an average diameter of 8 to 20 μm.

According to one embodiment of the invention, the Adhesion Promoter (AP) is a polar modified polypropylene (PM-PP) which is a propylene homo-or copolymer grafted with maleic anhydride having a melt flow rate MFR of at least 80.0g/10min, measured according to ISO 1133 at 190℃and a load of 2.16 kg.

According to another embodiment of the present invention, the fiber reinforced polypropylene composition (C) comprises, based on the total weight of the fiber reinforced polypropylene composition (C):

i) 50.0 to 80.0wt% of a Propylene Polymer (PP) having a xylene solubles content XCS equal to or lower than 5.0wt%,

ii) from 15.0 to 40.0% by weight of fibers (F),

iii) 3.0 to 10.0wt% of an Adhesion Promoter (AP), and

iv) optionally 0.1-4.0 wt.% of an Additive (AD).

The present invention further provides an article comprising the above fiber reinforced polypropylene composition (C).

Preferably, the article comprises at least 90wt% of the fiber reinforced polypropylene composition (C).

According to one embodiment of the invention, the article is an automotive article, preferably an automotive engine article.

Particularly preferably, the article is an intake manifold of an engine.

Hereinafter, the present invention will be described in more detail.

Detailed Description

Fiber reinforced polypropylene composition (C)

As described above, the present invention provides a fiber reinforced polypropylene composition (C) comprising a Propylene Polymer (PP) having a xylene solubles content XCS of 5.0wt% or less, a fiber (F) and an Adhesion Promoter (AP).

The fiber reinforced polypropylene composition satisfies the inequality (I), preferably the inequality (Ia), more preferably the inequality (Ib):

In addition or as an alternative to the preceding paragraph, the fiber-reinforced polypropylene composition (C) preferably satisfies the inequality (II), more preferably the inequality (IIa), still more preferably the inequality (IIb)

Preferably, the fiber reinforced polypropylene composition (C) comprises, based on the total weight of the fiber reinforced polypropylene composition (C):

i) 50.0 to 80.0wt%, more preferably 53.0 to 75.0wt%, still more preferably 55.0 to 70.0wt%, such as 56.0 to 61.0wt%, of a Propylene Polymer (PP) having a xylene solubles content XCS equal to or lower than 5.0wt%,

ii) 15.0 to 40.0wt%, more preferably 20.0 to 38.0wt%, still more preferably 25.0 to 36.0wt%, such as 30.0 to 35.0wt%, of fiber (F), and

iii) 3.0 to 10.0wt%, more preferably 3.2 to 8.0wt%, still more preferably 3.5 to 6.0wt%, such as 4.0 to 5.0wt% of an Adhesion Promoter (AP).

Furthermore, the fiber reinforced polypropylene composition (C) may contain an Additive (AD).

Accordingly, the fiber reinforced polypropylene composition (C) comprises, based on the total weight of the fiber reinforced polypropylene composition (C):

ii) 15.0 to 40.0 wt.%, more preferably 20.0 to 38.0 wt.%, still more preferably 25.0 to 36.0 wt.%, such as 30.0 to 35.0 wt.% of fibers (F),

iii) 3.0 to 10.0wt%, more preferably 3.2 to 8.0wt%, still more preferably 3.5 to 6.0wt%, such as 4.0 to 5.0wt%, of an Adhesion Promoter (AP), and

iv) optionally 0.1 to 4.0wt%, more preferably 1.0 to 3.0wt%, still more preferably 1.5 to 2.8wt%, such as 2.0 to 2.6wt% of Additive (AD).

As outlined in more detail below, the Propylene Polymer (PP) having a xylene solubles content XCS equal to or below 5.0wt% may be bimodal or not bimodal. The Propylene Polymer (PP) thus preferably comprises a first propylene polymer (PP 1) and optionally a second propylene polymer (PP 2) having a melt flow rate determined according to ISO 1133 at 230℃and a load of 2.16kgRate MFR ₂ Higher than the first propylene polymer (PP 1).

Accordingly, the fiber reinforced polypropylene composition (C) preferably comprises, based on the total weight of the fiber reinforced polypropylene composition (C), more preferably consists of:

i) 50.0 to 80.0wt%, more preferably 51.0 to 70.0wt%, still more preferably 53.0 to 65.0wt%, such as 55.0 to 60.0wt% of the first propylene polymer (PP 1),

ii) optionally, from 0.1 to 15.0wt%, more preferably from 1.0 to 10.0wt%, still more preferably from 1.5 to 5.0wt%, such as from 2.0 to 4.0wt% of a second propylene polymer (PP 2),

iii) 15.0 to 40.0 wt.%, more preferably 20.0 to 38.0 wt.%, still more preferably 25.0 to 36.0 wt.%, such as 30.0 to 35.0 wt.% of fibers (F),

iv) 3.0 to 10.0wt%, more preferably 3.2 to 8.0wt%, still more preferably 3.5 to 6.0wt%, such as 4.0 to 5.0wt%, of an Adhesion Promoter (AP), and

v) optionally 0.1 to 4.0 wt.%, more preferably 1.0 to 3.0 wt.%, still more preferably 1.5 to 2.8 wt.%, such as 2.0 to 2.6 wt.% of Additive (AD).

As mentioned above, it is preferred that the fiber reinforced polypropylene composition (C) does not comprise any amorphous propylene polymer. In other words, it is preferred that the fiber reinforced polypropylene composition (C) does not comprise any propylene polymer having a xylene solubles content XCS of 5.0 wt.% or more, more preferably does not comprise any propylene polymer having a xylene solubles content XCS of 3.0 wt.% or more, more preferably does not comprise any propylene polymer having a xylene solubles content XCS of 2.3 wt.% or more.

More preferably, the xylene solubles content XCS of the fiber reinforced polypropylene composition (C) is equal to or lower than 5.0 wt. -%, more preferably equal to or lower than 3.0 wt. -%, still more preferably equal to or lower than 2.3 wt. -%.

In addition, preferably, the fiber-reinforced polypropylene composition (C) has a melt flow rate MFR measured according to ISO 1133 at 230℃and a load of 2.16kg ₂ From 0.1 to 15.0g/10min, more preferably from 1.0 to 10.0g/10min, still more preferably in the range from 2.0 to 8.0g/10min, such as in the range from 3.0 to 5.0g/10 min.

Furthermore, it is preferred that the fiber reinforced polypropylene composition (C) is characterized by excellent mechanical properties. Accordingly, it is preferable that the tensile modulus of the fiber reinforced polypropylene composition (C) as determined by ISO 527 is at least 3000MPa, more preferably 4000-11000MPa, still more preferably 6000-10000MPa, such as in the range of 7000 to 9000 MPa.

Additionally or alternatively to the preceding paragraph, it is preferred that the fiber reinforced polypropylene composition (C) has a flexural modulus, measured according to ISO 178, of at least 3000MPa, more preferably in the range of 4000 to 11000MPa, still more preferably in the range of 6000 to 10000MPa, for example in the range of 7000 to 9000 MPa.

In addition, it is preferred that the fiber reinforced polypropylene composition (C) has a tensile strength of at least 70MPa, more preferably 75-150MPa, still more preferably 90-140MPa, such as 100-130 MPa, as determined according to ISO 527.

As described above, the fiber reinforced polypropylene composition (C) is characterized by high resistance to oil. Accordingly, it is preferred that the fiber reinforced polypropylene composition (C) maintains a high level of mechanical properties after exposure to oil.

In particular, it is preferable that the fiber reinforced polypropylene composition (C) satisfies the inequality (III),

wherein TS is _R250 The tensile strength retention, TS, of the fiber-reinforced polypropylene composition (C) after immersing it in an oil for 250 hours ₂₅₀ Is a fiber reinforced polypropylene composition (C) having a tensile strength [ MPa ] after immersing in an oil for 250 hours]TS is the tensile Strength [ MPa ] of the fiber-reinforced polypropylene composition (C) before it is immersed in oil]。

Furthermore, the fiber-reinforced polypropylene composition (C) preferably satisfies the Inequality (IV),

wherein TS is _R500 Is to mix the fiberReinforcing the tensile Strength retention, TS, of the Polypropylene composition (C) after immersing in oil for 500 hours ₅₀₀ The tensile strength [ MPa ] of the fiber-reinforced polypropylene composition (C) after immersing it in an oil for 500 hours]TS is the tensile Strength [ MPa ] of the fiber-reinforced polypropylene composition (C) before it is immersed in oil]。

In addition or alternatively to the preceding paragraph, preferably, the fiber-reinforced polypropylene composition (C) satisfies inequality (V),

wherein TS is _R1000 The tensile strength retention, TS, of the fiber-reinforced polypropylene composition (C) after immersing it in an oil for 1000 hours ₁₀₀₀ The tensile strength [ MPa ] of the fiber-reinforced polypropylene composition (C) after immersing it in an oil for 1000 hours]TS is the tensile Strength [ MPa ] of the fiber-reinforced polypropylene composition (C) before it is immersed in oil]。

In addition to tensile strength, the tensile modulus of the fiber reinforced polypropylene composition (C) remains high after exposure to oil.

Accordingly, it is preferable that the fiber reinforced polypropylene composition (C) satisfies the inequality (VI),

Wherein, TM _R250 The retention of Tensile Modulus (TM) after immersing the fiber-reinforced polypropylene composition (C) in oil for 250 hours ₂₅₀ The tensile modulus [ MPa ] of the fiber reinforced polypropylene composition (C) after immersing it in an oil for 250 hours]TM is the tensile modulus [ MPa ] before immersing the fiber reinforced polypropylene composition (C) in oil]。

In addition, the fiber-reinforced polypropylene composition (C) preferably satisfies the inequality (VII),

wherein, TM _R500 Is to increase the fiberTensile modulus retention, TM, of the Strong Polypropylene composition (C) after 500h immersion in oil ₅₀₀ The tensile modulus [ MPa ] of the fiber reinforced polypropylene composition (C) after immersing it in an oil for 500 hours]TM is the tensile modulus [ MPa ] before immersing the fiber reinforced polypropylene composition (C) in oil]。

In addition to or instead of the preceding paragraph, it is preferred that the fiber-reinforced polypropylene composition (C) satisfies the inequality (VIII),

wherein, TM _R1000 The retention of Tensile Modulus (TM) after immersing the fiber-reinforced polypropylene composition (C) in oil for 1000 hours ₁₀₀₀ The tensile modulus [ MPa ] of the fiber reinforced polypropylene composition (C) after immersing it in an oil for 1000 hours]TM is the tensile modulus [ MPa ] before immersing the fiber reinforced polypropylene composition (C) in oil]。

Hereinafter, the Propylene Polymer (PP), the fiber (F) and the Adhesion Promoter (AP) are described in more detail.

Propylene Polymer (PP)

As described above, the fiber reinforced polypropylene composition (C) comprises a Propylene Polymer (PP).

The Propylene Polymer (PP) may be a propylene copolymer or a propylene homopolymer, the latter being preferred.

In case the Propylene Polymer (PP) is a propylene copolymer, the Propylene Polymer (PP) comprises monomers copolymerizable with propylene, e.g. comonomers, such as ethylene and/or C ₄ To C ₈ Alpha-olefins, in particular ethylene and/or C ₄ To C ₆ Alpha-olefins such as ethylene, 1-butene and/or 1-hexene. Preferably, the Propylene Polymer (PP) according to the present invention comprises, in particular consists of, monomers copolymerizable with propylene, said monomers being selected from the group consisting of ethylene, 1-butene and 1-hexene. More specifically, the Propylene Polymer (PP) of the present invention comprises units derived from ethylene and/or 1-butene in addition to propylene. In a preferred embodiment, the Propylene Polymer (PP) comprises only units derived from ethylene and propylene.

The comonomer content of the Propylene Polymer (PP) is in the range of 0.0 to 5.0 wt. -%, still more preferably in the range of 0.0 to 3.0 wt. -%, still more preferably in the range of 0.0 to 1.0 wt. -%.

According to the present invention, the expression "propylene homopolymer" relates to a polypropylene consisting essentially of propylene units, for example a polypropylene consisting of at least 99.0 wt.%, more preferably at least 99.5 wt.%, still more preferably at least 99.8 wt.%, such as at least 99.9 wt.% of propylene units. In another embodiment, only propylene units are detectable, i.e. only propylene has polymerized.

Preferably, the Propylene Polymer (PP), such as propylene homopolymer (H-PP), is isotactic. Thus, it is preferred that the Propylene Polymer (PP), such as propylene homopolymer (H-PP), has a rather high pentad concentration (mmmm%), i.e. greater than 94.1%, more preferably greater than 94.4%, such as in the range of greater than 94.4 to 98.5%, more preferably at least 94.7%, such as in the range of 94.7 to 98.5%.

Preference is given to Propylene Polymers (PP), such as propylene homopolymers (H-PP), which are characterized by a relatively low Xylene Cold Soluble (XCS) content, i.e.xylene cold soluble (XCS) of less than 3.1% by weight. Thus, the Propylene Polymer (PP), such as propylene homopolymer (H-PP), preferably has a Xylene Cold Soluble (XCS) content in the range of 1.0 to 3.0 wt. -%, more preferably in the range of 1.5 to 2.8 wt. -%, still more preferably in the range of 2.0 to 2.6 wt. -%.

The amount of Xylene Cold Solubles (XCS) also shows that the Propylene Polymer (PP), such as propylene homopolymer (H-PP), preferably does not contain any elastomeric polymer component, such as ethylene propylene rubber. In other words, propylene Polymers (PP), such as propylene homopolymers (H-PP), are not heterophasic polypropylenes, i.e. systems consisting of a polypropylene matrix in which an elastomeric phase is dispersed. Such systems are characterized by relatively high xylene cold solubles content.

The amount of Xylene Cold Solubles (XCS) also shows that Propylene Polymers (PP), such as propylene homopolymers (H-PP), preferably do not contain inclusion forming elastomeric (co) polymers as second phase to improve mechanical properties. In contrast, polymers comprising an elastomeric (co) polymer as the intercalated second phase will be referred to as heterophasic and are preferably not part of the present invention. The presence of second phases or so-called inclusions is for example visible by high resolution microscopy such as electron microscopy or atomic force microscopy or by Dynamic Mechanical Thermal Analysis (DMTA). In particular, in DMTA, the presence of a multiphase structure can be identified by the presence of at least two different glass transition temperatures.

Furthermore, the Propylene Polymer (PP), such as propylene homopolymer (H-PP), is preferably a crystalline propylene homopolymer. The term "crystalline" means that Propylene Polymers (PP), such as propylene homopolymers (H-PP), have a rather high melting temperature. Thus, throughout the present invention, propylene Polymers (PP), such as propylene homopolymers (H-PP), are considered crystalline unless otherwise indicated. Thus, the Propylene Polymer (PP), such as a propylene homopolymer (H-PP), has a melting temperature Tm, as measured by Differential Scanning Calorimetry (DSC), of preferably at least 160 ℃, more preferably at least 161 ℃, still more preferably at least 163 ℃, such as in the range 163 ℃ to 167 ℃.

Furthermore, the Propylene Polymer (PP), such as propylene homopolymer (H-PP), preferably has a crystallization temperature Tc, as measured by Differential Scanning Calorimetry (DSC), of 108 ℃ or more, more preferably in the range of 110 to 130 ℃, more preferably in the range of 120 to 130 ℃.

It will be appreciated that Propylene Polymers (PP) are characterized by a rather low melt flow rate. Therefore, it is preferred that the Propylene Polymer (PP) has a melt flow rate MFR measured according to ISO 1133 at 230℃and a load of 2.16kg ₂ Less than 50.0g/10min, more preferably in the range of 0.1 to 40.0g/10min, still more preferably in the range of 1.0 to 30.0g/10min, still more preferably in the range of 3.0 to 20.0g/10min, still more preferably in the range of 5.0 to 15.0g/10min, such as in the range of 6.0 to 10.0g/10 min.

According to a preferred embodiment of the present invention, the Propylene Polymer (PP) is preferably bimodal.

Thus, it is preferred that the Propylene Polymer (PP) comprises at least two propylene polymers. It is particularly preferred that the Propylene Polymer (PP) comprises two propylene polymers, namely a first propylene polymer (PP 1) and a second propylene polymer (PP 2).

Preferably, the first propylene polymer (PP 1) and the second propylene polymer (PP 2) have a melt flow rate MFR measured according to ISO 1133 at 230℃and a load of 2.16kg ₂ Different.

The first propylene polymer (PP 1) and the second propylene polymer (PP 2) may be a propylene copolymer or a propylene homopolymer, respectively.

In case the first propylene polymer (PP 1) and/or the second propylene polymer (PP 2) is a propylene copolymer, the propylene polymer comprises monomers copolymerizable with propylene, e.g. comonomers, such as ethylene and/or C ₄ To C ₈ Alpha-olefins, in particular ethylene and/or C ₄ To C ₆ Alpha-olefins, such as 1-butene and/or 1-hexene. Preferably, the first propylene polymer (PP 1) and/or the second propylene polymer (PP 2) according to the present invention comprises, in particular consists of, monomers copolymerizable with propylene, said monomers being selected from the group consisting of ethylene, 1-butene and 1-hexene. More specifically, the first propylene polymer (PP 1) and/or the second propylene polymer (PP 2) of the present invention comprise units derived from ethylene and/or 1-butene in addition to propylene. In a preferred embodiment, the Propylene Polymer (PP) comprises only units derived from ethylene and propylene.

As summarized in more detail below, the first propylene polymer (PP 1) may comprise a first propylene polymer fraction (PP 1 a) and a second propylene polymer fraction (PP 1 b). Thus, in embodiments where the Propylene Polymer (PP) comprises only the first propylene polymer (PP 1) and the first propylene polymer (PP 1) comprises a first propylene polymer fraction (PP 1 a) and a second propylene polymer fraction (PP 1 b), the Propylene Polymer (PP) is also bimodal.

The comonomer content of the first propylene polymer (PP 1) and/or the second propylene polymer (PP 2) is in the range of 0.0 to 5.0 wt. -%, still more preferably in the range of 0.0 to 3.0 wt. -%, still more preferably in the range of 0.0 to 1.0 wt. -%, respectively.

However, as mentioned above, it is preferred that the Propylene Polymer (PP) is a propylene homopolymer (H-PP). Therefore, it is preferable that all propylene polymers in the Propylene Polymer (PP), i.e., the first propylene polymer (PP 1) and the second propylene polymer (PP 2), are propylene homopolymers. With respect to the expression "propylene homopolymer", reference is made to the definition provided above.

Hereinafter, the first propylene polymer (PP 1) and the second propylene polymer (PP 2) are described in more detail.

First propylene Polymer (PP 1)

The first propylene polymer (PP 1) preferably has a lower melt flow rate MFR, measured according to ISO 1133 at 230℃and a load of 2.16kg ₂ . Therefore, it is preferred that the first propylene polymer (PP 1) has a melt flow rate MFR as determined according to ISO 1133 at 230℃and a load of 2.16kg ₂ Is less than 50.0g/10min, more preferably in the range of 0.1 to 40.0g/10min, still more preferably in the range of 1.0 to 30.0g/10min, still more preferably in the range of 3.0 to 20.0g/10min, more preferably in the range of 5.0 to 15.0g/10min, such as in the range of 6.0 to 10.0g/10 min.

Another feature of the first propylene polymer (PP 1) is the presence of a smaller amount of propylene misinserted within the polymer chain, which indicates that the first propylene polymer (PP 1) is produced in the presence of a Ziegler-Natta (Ziegler-Natta) catalyst, preferably in the presence of a Ziegler-Natta catalyst (ZN-C1) as defined in more detail below. Therefore, the first propylene polymer (PP 1) preferably has the following characteristics: by passing through ¹³ The minor amount of 2,1 erythro region defects, i.e., equal to or less than 0.4 mole%, more preferably equal to or less than 0.2 mole%, such as not more than 0.1 mole%, of 2,1 erythro region defects, as determined by C-NMR spectroscopy. In a particularly preferred embodiment, no 2,1 erythro region defects are detectable.

Preferably, the first propylene polymer (PP 1) is characterized by a rather low Xylene Cold Soluble (XCS) content, i.e. below 4.1 wt. -% Xylene Cold Soluble (XCS). Therefore, the Xylene Cold Soluble (XCS) content of the first propylene polymer (PP 1) is preferably in the range of 1.0 to 4.0 wt. -%, more preferably in the range of 1.0 to 2.0 wt. -%.

The amount of Xylene Cold Solubles (XCS) also shows that the first propylene polymer (PP 1) preferably does not contain any elastomeric polymer component, e.g. ethylene propylene rubber. In other words, the first propylene polymer (PP 1) should not be heterophasic polypropylene, i.e. a system consisting of a polypropylene matrix in which an elastomeric phase is dispersed. Such systems are characterized by relatively high xylene cold solubles content.

The amount of Xylene Cold Solubles (XCS) also shows that the first propylene polymer (PP 1) preferably does not comprise inclusion forming elastomeric (co) polymers as the second phase to improve mechanical properties. In contrast, polymers comprising elastomeric (co) polymers as the intercalated second phase will be referred to as heterophasic and are preferably not part of the present invention. The presence of second phases or so-called inclusions is for example visible by high resolution microscopy such as electron microscopy or atomic force microscopy or by Dynamic Mechanical Thermal Analysis (DMTA). In particular, in DMTA, the presence of a multiphase structure can be identified by the presence of at least two different glass transition temperatures.

Furthermore, the first propylene polymer (PP 1) is preferably a crystalline propylene homopolymer. The term "crystalline" means that the first propylene polymer (PP 1) has a rather high melting temperature. Thus, throughout the present invention, the first propylene polymer (PP 1) is considered crystalline unless otherwise indicated. Accordingly, the melting temperature Tm of the first propylene polymer (PP 1) as measured by Differential Scanning Calorimetry (DSC) is preferably at least 158 ℃, more preferably at least 160 ℃, still more preferably at least 161 ℃, such as in the range of 161 ℃ to 168 ℃.

Further, it is preferable that the crystallization temperature Tc of the first propylene polymer (PP 1) measured by Differential Scanning Calorimetry (DSC) is equal to or greater than 110 ℃, more preferably in the range of 110 to 140 ℃, still more preferably in the range of 120 to 130 ℃.

According to a preferred embodiment of the present invention, the first propylene polymer (PP 1) is bimodal.

Therefore, it is preferred that the first propylene polymer (PP 1) comprises at least two propylene polymer fractions. It is particularly preferred that the first propylene polymer (PP 1) comprises two propylene polymer fractions, namely a first propylene polymer fraction (PP 1 a) and a second propylene polymer fraction (PP 1 b).

Preferably, the first propylene polymer fraction (PP 1 a) and the second propylene polymer fraction (PP 1 b) have different melt flow rates MFR as determined according to ISO 1133 at 230℃and a load of 2.16kg ₂ And/or different comonomer content.

The first propylene polymer fraction (PP 1 a) and the second propylene polymer fraction (PP 1 b) may be propylene copolymers or propylene homopolymers, respectively.

If the first propylene polymer fraction (PP 1 a) and/or the second propylene polymer fraction (PP 1 b) is a propylene copolymer, the propylene polymer comprises a monomer copolymerizable with propylene, e.g. a comonomer, e.g. ethylene and/or C ₄ To C ₈ Alpha-olefins, in particular ethylene and/or C ₄ To C ₆ For example 1-butene and/or 1-hexene. Preferably, the first propylene polymer fraction (PP 1 a) and/or the second propylene polymer fraction (PP 1 b) according to the present invention comprises, in particular consists of, monomers copolymerizable with propylene, which monomers are selected from the group consisting of ethylene, 1-butene and 1-hexene. More specifically, the first propylene polymer fraction (PP 1 a) and/or the second propylene polymer fraction (PP 1 b) of the present invention comprises units derived from ethylene and/or 1-butene in addition to propylene. In a preferred embodiment, the first propylene polymer (PP 1) comprises only units derived from ethylene and propylene.

Preferably, the first propylene polymer (PP 1) is nucleated, more preferably alpha-nucleated. Thus, it is preferred that the first propylene polymer (PP 1) is prepared in the presence of a nucleating agent, preferably an alpha-nucleating agent.

In case the first propylene polymer (PP 1) comprises an alpha nucleating agent, it is preferably free of beta nucleating agents. The alpha nucleating agent is preferably selected from the following:

(i) Salts of monocarboxylic acids and polycarboxylic acids, e.g. sodium benzoate or aluminum tert-butylbenzoate, and

(ii) Dibenzylidene sorbitol (e.g., 1,3:2,4 dibenzylidene sorbitol) and C ₁ -C ₈ Alkyl-substituted dibenzylidene sorbitol derivatives, e.g. methyldibenzylidene sorbitol, ethyldibenzylidene sorbitol or dimethyldibenzylidene mountainSorbitol (e.g., 1,3:2,4 di (methylbenzylidene) sorbitol), or substituted nonanol derivatives, such as 1,2,3, -trideoxy-4, 6:5, 7-bis-O- [ (4-propylphenyl) methylene]-nonanol, 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' -methylenebis (4, 6-di-tert-butylphenyl) phosphate ], and

(iv) Vinyl cycloalkane polymer and vinyl alkane polymer (as discussed in more detail below), and

(v) Mixtures thereof.

Such additives are generally commercially available and are described, for example, in Hans Zweifel, "Plastic Additives Handbook", pages 871 to 873, 5 th edition, 2001.

Preferably, the first propylene polymer (PP 1) comprises at most 5.0wt% of an alpha-nucleating agent. In a preferred embodiment, the propylene homopolymer comprises no more than 500ppm, more preferably from 0.025 to 200ppm, more preferably from 0.1 to 200ppm, still more preferably from 0.3 to 200ppm, most preferably from 0.3 to 100ppm of an alpha nucleating agent, in particular selected from dibenzylidene sorbitol (e.g. 1,3:2,4 dibenzylidene sorbitol), dibenzylidene sorbitol derivatives, preferably dimethylbenzylidene sorbitol (e.g. 1,3:2,4 di (methylbenzylidene) sorbitol) or substituted nonanol derivatives, such as 1,2,3, -trideoxy-4, 6: sodium 5, 7-bis-O- [ (4-propylphenyl) methylene ] -nonanol, 2' -methylenebis (4, 6, -di-t-butylphenyl) phosphate, vinylcycloalkane polymers, vinylalkane polymers, and mixtures thereof.

Preferably, the first propylene polymer (PP 1) is obtained by polymerizing propylene in the presence of a Ziegler-Natta catalyst (Ziegler-Natta catalyst) as defined below. More preferably, the first propylene polymer (PP 1) according to the present invention is obtained by the process defined in detail below by using a Ziegler-Natta catalyst.

The first propylene polymer (PP 1) according to the present invention is preferably prepared in the presence of:

(a) Ziegler-Natta catalysts (ZN-C1) comprising a compound of a transition metal of the IUPAC 4 to 6 groups (TC), a compound of a metal of the 2 groups (MC) and an Internal Donor (ID);

(b) An optional promoter (Co), and

(c) An optional External Donor (ED).

Preferably, the first propylene polymer (PP 1) is produced in a polymerization process comprising at least one reactor, e.g. two reactors (R1) and (R2). Preferably, the first propylene polymer (PP 1) is produced in one polymerization reactor (R1).

The process for preparing the propylene homopolymer and the Ziegler-Natta catalyst are described in further detail below.

The polymerization reactor (R1) may be a Gas Phase Reactor (GPR) or a Slurry Reactor (SR). The Gas Phase Reactor (GPR) according to the invention is preferably a fluidized bed reactor, a fast fluidized bed reactor or a settled bed reactor or any combination thereof.

Preferably, the polymerization reactor (R1) is a Slurry Reactor (SR), which may be any continuous or simply 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 polymerization reactor (R2) and any subsequent reactors, if present, are preferably Gas Phase Reactors (GPRs). Such a Gas Phase Reactor (GPR) may be any mechanically mixed reactor or fluidized bed reactor. Preferably, the Gas Phase Reactor (GPR) comprises a fluidized bed reactor mechanically stirred at a gas velocity of at least 0.2 m/sec. It will thus be appreciated that the gas phase reactor is a fluidized bed type reactor, preferably with a mechanical stirrer.

If any subsequent reactor is present, it is preferred to feed the propylene homopolymer of the first polymerization reactor (R1) directly into the second polymerization reactor (R2), i.e. directly into the (first) gas phase reactor (GPR 1), without a flash step between these stages. Such direct feeds are described in European patent EP 887379A,EP 887380A,EP 887381A and EP 991684A. "direct feed" refers to a process wherein the contents of the first polymerization reactor (R1), i.e. the Loop Reactor (LR), are passed directly to the gas phase reactor of the next stage.

Alternatively, the propylene homopolymer of the first polymerization reactor (R1), more preferably the polymer slurry of the Loop Reactor (LR), may also be introduced into a flash step or passed through a further concentration step before being fed into the second polymerization reactor (R2), i.e. into the Gas Phase Reactor (GPR). Accordingly, the term "indirect feed" refers to feeding the content of the first polymerization reactor (R1), i.e. the content of the Loop Reactor (LR), i.e. the polymer slurry, via the reaction medium separation unit and as reaction medium of the gas from the separation unit to the second polymerization reactor (R2), i.e. the (first) gas phase reactor (GPR 1).

However, it is preferred to prepare the propylene polymer (PP 1) in one reactor, i.e. the polymerization reactor (R1) being a Loop Reactor (LR).

If desired, a prepolymerization reactor is provided before the Slurry Reactor (SR), i.e. before the Loop Reactor (LR).

Ziegler-Natta catalysts are fed to the polymerization reactor (R1). If the process further comprises a prepolymerization step, it is preferred that all Ziegler-Natta catalysts are fed into the prepolymerization reactor. The prepolymerized product comprising the Ziegler-Natta catalyst is then transferred to a polymerization reactor (R1).

Preferred multi-stage processes are "loop-gas phase" processes, such as those developed by Borealis a/S of denmark (known as

Technology) described, for example, in the patent literature, for example in EP 0 887,379, WO 92/12182, WO 2004/000899, WO 2004/111095, WO 99/24478, WO 99/24479 or WO 00/68315.

Particularly good results can be obtained if the temperature in the reactor is carefully chosen.

Therefore, it is preferable that the operating temperature in the polymerization reactor (R1) is in the range of 62 to 90 ℃, more preferably in the range of 65 to 85 ℃, still more preferably in the range of 67 to 83 ℃.

In general, the pressure in the polymerization reactor (R1), preferably in the Loop Reactor (LR), is from 20 to 80bar, preferably from 30 to 70bar, such as from 35 to 65bar.

For controlling molecular weight, i.e. melt flow rate MFR ₂ Preferably, hydrogen is added to each polymerization reactor.

Preferably, the average residence time in the polymerization reactor (R1) is quite long. In general, the average residence time (τ) is defined as the reaction volume (V) _R ) And the volume flow rate in the reactor (Q) _o ) Ratio (i.e. V _R /Q _o ) I.e. τ=v _R /Q _o [tau＝V _R /Q _o ]. In the case of loop reactors, the reaction volume (V _R ) Equal to the reactor volume.

Thus, the average residence time (τ) in the polymerization reactor (R1) is preferably at least 15min, more preferably in the range of 15 to 90min, still more preferably in the range of 20 to 80min, such as in the range of 24 to 60 min.

As mentioned above, the preparation of the propylene homopolymer comprises, in addition to the (main) polymerization of the propylene homopolymer in the polymerization reactor (R1), a prepolymerization in a Prepolymerization Reactor (PR) upstream of the polymerization reactor (R1).

Polypropylene (Pre-PP) is produced in a Prepolymerization Reactor (PR). The prepolymerization is carried out in the presence of a Ziegler-Natta catalyst. According to this embodiment, ziegler-Natta, cocatalyst (Co) and External Donor (ED) are all introduced into the prepolymerization step. However, this should not exclude the option of adding further cocatalysts (Co) and/or External Donors (ED) in a later stage, e.g. during the polymerization, e.g. in the first reactor (R1). In one embodiment, if the prepolymerization is carried out, only Ziegler-Natta catalyst, cocatalyst (Co) and External Donor (ED) are added to the Prepolymerization Reactor (PR).

The prepolymerization is usually carried out at a temperature of from 0 to 60 ℃, preferably from 15 to 50 ℃, more preferably from 20 to 45 ℃.

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 100bar, for example 30 to 70bar.

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, optionally with inert components dissolved therein. Further, according to the present invention, as described above, an ethylene feed is used in the prepolymerization process.

Other components may also be added during the prepolymerization stage. Thus, as known in the art, hydrogen may be added to the Pre-polymerization stage to control the molecular weight of the polypropylene (Pre-PP). In addition, antistatic additives may be used to prevent particles from adhering to each other or to the walls of the reactor.

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

Due to the above-defined process conditions in the prepolymerization, it is preferred to obtain a Mixture (MI) of Ziegler-Natta catalyst and polypropylene (Pre-PP) produced in the Prepolymerization Reactor (PR). Preferably, the Ziegler-Natta catalyst is (finely) dispersed in the polypropylene (Pre-PP). In other words, the Ziegler-Natta catalyst particles introduced into the Pre-Polymerization Reactor (PR) are split into smaller fragments, which are uniformly distributed in the growing polypropylene (Pre-PP). The size of the Ziegler-Natta catalyst particles introduced and the size of the fragments obtained are not critical to the present invention and to the person skilled in the art.

As described above, if the prepolymerization is used, the Mixture (MI) of the Ziegler-Natta catalyst and the polypropylene (Pre-PP) generated in the Prepolymerization Reactor (PR) is transferred to the first reactor (R1) after the prepolymerization. Typically, the total amount of polypropylene (Pre-PP) in the final propylene polymer (PP 1) is very low and typically not more than 5.0wt%, more preferably not more than 4.0wt%, still more preferably 0.5 to 4.0wt%, e.g. in the range of 1.0 to 3.0 wt%.

Propylene and other components such as Ziegler-Natta catalysts are introduced directly into the first polymerization reactor (R1) without the use of prepolymerization.

Thus, the propylene homopolymer is preferably produced under the above conditions by a process comprising the steps of:

(a) Propylene is polymerized in a first polymerization reactor (R1), i.e. in a Loop Reactor (LR), to obtain a first propylene polymer (PP 1).

The pre-polymerization as described above may be done before step (a).

In the above process, ziegler-Natta catalyst (ZN-C1) is used for the preparation of the first propylene polymer (PP 1). The Ziegler-Natta catalyst (ZN-C1) may be any stereotactic Ziegler-Natta catalyst (ZN-C1) for propylene polymerization, preferably capable of catalyzing the polymerization and copolymerization of propylene and optionally comonomers at a pressure of 500 to 10000kPa, in particular 2500 to 8000kPa, and a temperature of 40 to 110 ℃, in particular 60 to 110 ℃.

Preferably, the Ziegler-Natta catalyst (ZN-C1) comprises a high yield Ziegler-Natta type catalyst comprising an internal donor component that can be used at high polymerization temperatures above 80 ℃. Such high yield Ziegler-Natta catalysts (ZN-C1) may comprise succinates, diethers, phthalates, etc. or mixtures thereof as Internal Donors (ID) and are commercially available, for example, from LyondellBasell under the trade name of Avant ZN. Examples of the Avant ZN series are Avant ZN 126 and Avant ZN168.AvantZN 126 is a Ziegler-Natta catalyst with 3.5wt% titanium and a diether compound as internal electron donors, commercially available from LyondellBasell. Avant ZN168 is a Ziegler-Natta catalyst with 2.6wt% titanium and succinate compounds as internal electron donors, commercially available from lyondellbasell. Another example of the Avant ZN series is LyondellBasell catalyst ZN180M.

Further suitable catalysts are described, for example, in WO 2012/007430, EP2610271, EP261027 and EP 2610272.

The Ziegler-Natta catalyst (ZN-C1) is preferably used in combination with an alkylaluminum cocatalyst and optionally an external donor.

As further components in the polymerization process according to the invention, external Donors (ED) are preferably present. Suitable External Donors (ED) include certain silanes, ethers, esters, amines, ketones, heterocyclic compounds and blends of these. Silane is particularly preferably used. Most preferably, silanes of the general formula:

R ^a _p R ^b _q Si(OR ^c ) _(4-p-q) ，

wherein R is ^a ，R ^b And R is ^c Represents a hydrocarbon radical, in particular an alkyl or cycloalkyl radical,

wherein p and q are numbers from 0 to 3, and their sum p+q is equal to or less than 3.R is R ^a ，R ^b And R is ^c May be selected independently of each other and may be the same or different. A specific example of such a silane is (t-butyl) ₂ Si(OCH ₃ ) ₂ (cyclohexyl) (methyl) Si (OCH) ₃ ) ₂ (phenyl) ₂ Si(OCH ₃ ) ₂ And (cyclopentyl) ₂ Si(OCH ₃ ) ₂ Or a silane of the formula:

Si(OCH ₂ CH ₃ ) ₃ (NR ³ R ⁴ )，

wherein R is ³ And R is ⁴ And may be the same or different and represent a hydrocarbon group having 1 to 12 carbon atoms.

R ³ And R is ⁴ Independently selected from the group consisting of a straight chain aliphatic hydrocarbon group having 1 to 12 carbon atoms, a branched aliphatic hydrocarbon group having 1 to 12 carbon atoms, and a cyclic aliphatic hydrocarbon group having 1 to 12 carbon atoms. Particularly preferably, R ³ And R is ⁴ Independently 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 ³ And R is ⁴ Identical, even more preferably R ³ And R is ⁴ All are ethyl groups.

Particularly preferred External Donors (ED) are dicyclopentyl dimethoxy silane donors (D donors) or cyclohexyl methyl dimethoxy silane donors (C-donors).

In addition to Ziegler-Natta catalysts (ZN-C1) and optionally External Donors (ED), cocatalysts may be used. The cocatalyst is preferably a compound of group 13 of the periodic table (IUPAC), for example an organoaluminum, such as an aluminum compound, such as an aluminum alkyl, an aluminum halide or an aluminum alkyl halide compound. Thus, in a particular embodiment, the cocatalyst (Co) is a trialkylaluminum, such as Triethylaluminum (TEAL), dialkylaluminum chloride or alkylaluminum dichloride, or a mixture thereof. In a particular embodiment, the cocatalyst (Co) is Triethylaluminum (TEAL).

Preferably, the ratio [ Co/ED ] between promoter (Co) and External Donor (ED) and/or the ratio [ Co/TM ] between promoter (Co) and Transition Metal (TM) should be carefully chosen.

Thus, the first and second substrates are bonded together,

(a) The molar ratio [ Co/ED ] of promoter (Co) to External Donor (ED) must be in the range of 5 to 45, preferably in the range of 5 to 35, more preferably in the range of 5 to 25;

and optionally

(b) The molar ratio [ Co/TC ] of the cocatalyst (Co) to the Titanium Compound (TC) must be in the range of more than 80 to 500, preferably in the range of 90 to 350, still more preferably in the range of 100 to 300.

In another embodiment, the Ziegler-Natta catalyst (ZN-C1) may be modified by polymerizing a vinyl compound in the presence of a catalyst system comprising a specific Ziegler-Natta procatalyst (component (i)), an external donor (component (iii)) and optionally a cocatalyst (component (iii)), the vinyl compound having the formula:

CH ₂ ＝CH-CHR ⁵ R ⁶

wherein R is ⁵ And R is ⁶ Together forming a 5-or 6-membered saturated, unsaturated or aromatic ring or independently representing an alkyl group comprising 1 to 4 carbon atoms, and the modified catalyst is used for the preparation of the first propylene polymer (PP 1) according to the invention. The polymerized vinyl compound may be used as an alpha-nucleating agent.

For modification of the catalyst, reference is made to International application WO 99/24478, WO 99/24479, in particular WO 00/68315, which is incorporated herein by reference for the reaction conditions associated with modification of the catalyst and for the polymerization reaction.

Second propylene Polymer (PP 2)

Second propyleneThe polymer (PP 2) preferably has a moderate melt flow rate. Therefore, it is preferred that the second propylene polymer (PP 2) has a melt flow rate MFR as determined according to ISO 1133 at 230℃and a load of 2.16kg ₂ In the range of 20.0 to 150.0g/10min, more preferably in the range of 30.0 to 120.0g/10min, still more preferably in the range of 40.0 to 90.0g/10min, such as in the range of 50.0 to 65.0g/10 min.

Preferably the second propylene polymer (PP 2) is characterized by a rather low Xylene Cold Soluble (XCS) content, i.e. below 4.1 wt. -% Xylene Cold Soluble (XCS). Therefore, the Xylene Cold Soluble (XCS) content of the second propylene polymer (PP 2) is preferably in the range of 1.0 to 4.0 wt. -%, more preferably in the range of 1.0 to 3.0 wt. -%, still more preferably in the range of 1.5 to 2.5 wt. -%.

Thus, like the first propylene polymer (PP 1), it is preferred that the second propylene polymer (PP 2) does not contain any elastomeric component. In this regard, reference is made to the definitions provided above.

In addition, the second propylene polymer (PP 2) is preferably a crystalline propylene homopolymer. For the term "crystalline", reference is made to the definition provided above. Accordingly, the melting temperature Tm of the second propylene polymer (PP 2) as measured by Differential Scanning Calorimetry (DSC) is preferably at least 145 ℃, more preferably at least 150 ℃, still more preferably at least 155 ℃, such as in the range of 150 ℃ to 160 ℃.

Furthermore, it is preferable that the crystallization temperature Tc of the second propylene polymer (PP 2) measured by Differential Scanning Calorimetry (DSC) is equal to or greater than 108 ℃, more preferably in the range of 110 to 130 ℃, still more preferably in the temperature range of 115 to 125 ℃.

Preferably, the second propylene polymer (PP 2) is obtained by polymerizing propylene in the presence of a Ziegler-Natta catalyst. More preferably, the second propylene polymer (PP 2) according to the present invention is obtained by a process using a Ziegler-Natta catalyst.

For the preparation of the second propylene polymer (PP 2), the polymerization process and Ziegler-Natta catalyst described above for the first propylene polymer (PP 1) may be used. Thus, reference is made to the above-described process and Ziegler-Natta catalyst for the first propylene polymer (PP 1).

Fiber (F)

The essential component of the fiber reinforced polypropylene composition (C) of the present invention is the fiber (F).

Preferably, the fibers (F) are Short Fibers (SF).

Preferably, the Short Fibers (SF) are selected from glass fibers, metal fibers, mineral fibers, ceramic fibers, carbon fibers and graphite fibers. Glass fibers are particularly preferred. Therefore, it is preferable that the Short Fibers (SF) are Short Glass Fibers (SGF). In particular, short Glass Fibers (SGF) are cut glass fibers, also known as staple fibers or chopped strands.

Like the glass staple fibers (SGF) used in the fiber-reinforced polypropylene composition (C), the average length of the cut fibers or Staple Fibers (SF) is preferably in the range of 1.0 to 10.0mm, more preferably in the range of 2.0 to 8.0mm, still more preferably in the range of 3.0 to 5.0mm, for example in the range of 3.0 to 4.5 mm.

Like the Short Glass Fibers (SGF) used in the fiber reinforced polypropylene composition (C), the average diameter of the cut fibers or Short Fibers (SF) is preferably 8 to 20. Mu.m, more preferably 9 to 16. Mu.m, still more preferably 9 to 14. Mu.m, for example 9 to 13. Mu.m.

Preferably, the Short Fibers (SF), such as Short Glass Fibers (SGF), have an aspect ratio of 125 to 650, preferably 200 to 600, more preferably 300 to 600, still more preferably 400 to 550. Aspect ratio is the relationship between the average length and average diameter of a fiber.

Adhesion Promoter (AP)

According to the invention, the fiber reinforced polypropylene composition (C) further comprises an Adhesion Promoter (AP). The Adhesion Promoter (AP) is designated as a polar modified polypropylene (PM-PP) homopolymer or copolymer.

The polar modified polypropylene (PM-PP) homo-or copolymer comprises a low molecular weight compound with reactive polar groups. Modified polypropylene homopolymers and copolymers, e.g. copolymers of propylene and ethylene or propylene with other alpha-olefins, e.g. C ₄ To C ₁₀ Copolymers of alpha-olefins are most preferred because they are highly compatible with the Propylene Polymer (PP) of the fiber reinforced polypropylene composition (C) of the present invention.

In terms of structure, the polar modified polypropylene (PM-PP) homo-or copolymer is preferably selected from grafted homo-or copolymers.

Preference is given here to polar modified polypropylene (PM-PP) homopolymers or copolymers which contain groups derived from polar compounds, in particular from the group consisting of anhydrides, carboxylic acids, carboxylic acid derivatives, primary and secondary amines, hydroxyl compounds, oxazolines and epoxides and ionic compounds.

Specific examples of the polar compounds are unsaturated cyclic anhydrides and aliphatic diesters thereof, and diacid derivatives. In particular, maleic anhydride and a compound selected from C ₁ To C ₁₀ Dialkyl maleates, C, straight and branched chain ₁ To C ₁₀ Linear and branched dialkyl fumarates, itaconic anhydride, C ₁ To C ₁₀ Linear and branched dialkyl itaconates of (a), acrylic acid, maleic acid, fumaric acid, itaconic acid and mixtures thereof.

It is particularly preferred to use polypropylene homo-or copolymers grafted with maleic anhydride or acrylic acid as polar modified polypropylene (PM-PP) homo-or copolymers, i.e. Adhesion Promoters (AP).

Modified polymers, i.e. adhesion promoters, are commercially available or are produced in a simple manner by extrusion of the polymer in the presence of free radical generators (e.g. organic peroxides), for example with maleic anhydride or acrylic acid, as disclosed in US 4,506,056,US 4,753,997 or EP 1 805 238.

In the fiber reinforced polypropylene composition (C) of the present invention, the preferred amount of the polar modified polypropylene (PM-PP) homopolymer or copolymer, i.e., the Adhesion Promoter (AP), is 1 to 10% by weight. For example, in the range of 2.0wt% to 8wt%, preferably in the range of 3.0wt% to 6wt%, most preferably in the range of 3.0wt% to 6.0 wt%.

The preferred amount of the polar compound-derived groups in the polar modified polypropylene (PM-PP) homopolymer or copolymer, i.e. the Adhesion Promoter (AP), is 0.5 to 10wt%. For example, in the range of 0.5wt% to 8wt%, preferably in the range of 0.5wt% to 6wt%, more preferably in the range of 0.5wt% to 4wt%, most preferably in the range of 0.5wt% to 3.5 wt%.

Melt flow Rate MFR of polar modified Polypropylene (PM-PP) homo-or copolymer (i.e. Adhesion Promoter (AP)) ₂ The preferred value for (190 ℃) is 30 to 200g/10min. Particularly preferred are melt flow rate MFR of polar modified polypropylene (PM-PP) homopolymers or copolymers ₂ (190 ℃) is at least 80g/10min.

In a preferred embodiment of the invention, the Adhesion Promoter (AP) is a maleic anhydride modified polypropylene homo-or copolymer and/or an acrylic acid modified polypropylene homo-or copolymer. Preferably, the Adhesion Promoter (AP) is a maleic anhydride modified polypropylene homopolymer and/or an acrylic acid modified polypropylene homopolymer, preferably a maleic anhydride modified polypropylene homopolymer. For example, suitable polar modified polypropylene (PM-PP) homopolymers or copolymers include, for example, polypropylene homopolymers grafted with maleic anhydride (PP-g-MAH) and polypropylene homopolymers grafted with acrylic acid (PP-g-AA).

Additive (AD)

The fiber reinforced polypropylene composition (C) of the present invention may contain an Additive (AD) in addition to the Propylene Polymer (PP), the Adhesion Promoter (AP) and the fiber (F). Typical additives are acid scavengers, antioxidants, colorants, light stabilizers, plasticizers, slip agents, scratch resistance agents, dispersants, processing aids, lubricants, pigments, and the like.

Such additives are commercially available and are described, for example, in "Plastic Additives Handbook" of the 2009 sixth edition of Hans Zweifel (pages 1141 to 1190).

Furthermore, the term "Additive (AD)" according to the invention also includes carrier materials, in particular polymeric carrier materials.

Polymeric support material

Preferably, the fiber reinforced polypropylene composition (C) of the present invention does not comprise (a) other polymers than Propylene Polymer (PP) and Adhesion Promoter (AP) in an amount exceeding 15 wt.%, preferably not exceeding 10 wt.%, more preferably not exceeding 5 wt.%, based on the weight of the fiber reinforced polypropylene composition (C). Any polymer as carrier material for the Additive (AD) is not calculated as the amount of polymer compound according to the invention, but as the amount of the respective additive.

The polymer carrier material of the Additive (AD) is a carrier polymer to ensure a uniform distribution in the fiber reinforced polypropylene composition (C) of the present invention. The polymeric carrier material is not limited to a particular polymer. The polymeric support material may be an ethylene homopolymer composed of ethylene and an alpha-olefin comonomer such as C ₃ To C ₈ Ethylene copolymers obtained from alpha-olefin comonomers, propylene homopolymers and/or copolymers made from propylene and alpha-olefin comonomers, e.g. ethylene and/or C ₄ To C ₈ Propylene copolymers obtained from alpha-olefin comonomers, most preferably propylene homopolymers. Preferably, the polymeric support material does not comprise monomer units derived from styrene or derivatives thereof.

Article of manufacture

The invention also provides an injection molded article, such as an injection molded automotive article, comprising the fiber reinforced polypropylene composition (C) as defined above. The present invention particularly provides an injection molded article, such as an injection molded automotive article, comprising at least 60wt%, more preferably at least 80wt%, still more preferably at least 90wt%, such as at least 95wt% or at least 99wt% of the fiber reinforced polypropylene composition (C) as defined above. In a particularly preferred embodiment, the present invention provides an injection molded article, for example an injection molded automotive article, consisting of the fiber reinforced polypropylene composition (C) as defined above.

Particularly preferably, the injection molded automotive article is an automotive engine article, such as an intake manifold of an engine.

The present invention will be described in more detail by way of examples provided below.

Examples

1. Measurement method

MFR ₂ (230 ℃) was measured according to ISO 1133 at 230℃and a load of 2.16 kg.

Melt flow Rate MFR of Propylene Polymer (PP) ₂ (230 ℃) is calculated according to formula (IX):

logMFR(PP)＝w(PP1)×logMFR(PP1)+w(PP2)×logMFR(PP2) (IX)

wherein, the liquid crystal display device comprises a liquid crystal display device,

w (PP 1) is the weight fraction of the first propylene polymer (PP 1),

w (PP 2) is the weight fraction of the second propylene polymer (PP 2),

the MFR (PP 1) is the melt flow rate MFR of the first propylene polymer (PP 1) ₂ (230 ℃,2.16kg load), in g/10min,

the MFR (PP 2) is the melt flow rate MFR of the second propylene polymer (PP 2) ₂ (230 ℃,2.16kg load), in g/10min,

the MFR (PP) is the melt flow rate MFR of the Propylene Polymer (PP) ₂ (230 ℃,2.16kg load), in g/10min,

the same applies to bimodal polymer PP1 and to the two fractions PP1a and PP1b of bimodal PP 1.

Quantification of microstructure by NMR Spectroscopy

The comonomer content and comonomer sequence distribution of the polymer was quantified using quantitative Nuclear Magnetic Resonance (NMR) spectroscopy. For the purpose of ¹ H and ¹³ c, recording the solution state at 400.15MHz and 100.62MHz respectively using a Bruker Advance III 400NMR spectrometer ¹³ C{ ¹ H } NMR quantitative spectra. Using ¹³ C optimal 10mm extension temperature probe all spectra were recorded using nitrogen for all atmospheres at 125 ℃. About 200mg of the material was mixed with chromium (III) acetylacetonate (Cr (acac) ₃ ) Together in 3ml of 1, 2-tetrachloroethane-d ₂ (TCE-d ₂ ) A 65mM relaxation agent solution in a solvent was obtained (Singh, g., kothari, a., gupta, v., polymer Testing 28 5 (2009), 475). To ensure homogeneity of the solution, after initial sample preparation in the hot zone, the NMR tube was further heated in a rotary oven for at least 1 hour. After inserting the magnet, the tube was rotated at 10 Hz. This setting is chosen mainly for obtaining high resolution and accurate quantitative requirements for quantitative ethylene content. Standard single pulse excitation without NOE was used with optimal tip angle, 1s cycle delay and dual stage WALTZ16 decoupling protocol (methou, z., kuemmerle, r., qiu, x., redwire, d., cong r., taha, a., baugh, d.winni. ford, b., j.mag.reson.187 (2007) 225; busico, v., carbonniere, p., cipullo, r., pellercchia, r., severn, j., talarico, g., macromol, rapid Com mux.2007, 28, 1128). 6144 (6 k) transients were acquired per spectrum altogether.

Using proprietary computer program pairs ¹³ C{ ¹ The H } NMR quantitative spectrum is processed, integrated and the quantitative nature of the correlation is determined from the integration. Using chemical shifts of the solvent, all chemical shifts are indirectly referenced to the central methylene of the ethylene block (EEE) at 30.00 ppm. Even without this structural unit, reference can be made similarly to this method. Characteristic signals corresponding to ethylene incorporation were observed (Cheng, h.n., macromolecules 17 (1984), 1950).

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

Characteristic signals corresponding to region defects (Resconi, L., cavallo, L., fait, A., piemontesi, F., chem. Rev.2000,100,1253; wang, W-J., zhu, S., macromolecules 33 (2000), 1157; chem, H.N., macromolecules 17 (1984), 1950) or comonomers were observed.

The isotacticity (tacity) distribution was quantified by integration of the methyl region between 23.6 and 19.7ppm by correction of any sites not related to the target stereochemistry (Busico, v., cipullo, r., prog.polym.sci.26 (2001) 443; busico, v., cipullo, r., monaco, g., vacatello, m., segre, a.l., macromoles 30 (1997) 6251).

Specifically, the effect of regio-defects and comonomer on isotacticity distribution quantification is corrected by subtracting representative regio-defects and comonomer integration from specific integrated regions of the stereocomplex sequence.

Isotacticity was determined at the pentad level and reported as a percentage of isotactic pentad (mmmm) sequences relative to all pentad sequences:

[ mmmm ]% = 100× (mmmm/sum of all five-unit groups)

The presence of 2,1 erythro region 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 region defects were observed (reconi, l., cavalo, l., fait, a., piemontesi, f., chem. Rev.2000, 100, 1253).

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

P _21e ＝(I _e6 +I _e8 )/2，

the amount of 1, 2-major-insertion propylene was quantified based on the methyl region, and correction was made for sites included in the region that are not related to major insertion and sites not included in the region:

P ₁₂ ＝I _CH3 +P _12e

the total amount of propylene was quantified as the sum of the predominantly inserted propylene and all other existing regional defects:

P _{Total (S)} ＝P ₁₂ +P _21e

The mole percent of 2,1 erythro regiodefects relative to all propylene was quantified:

[21e]mol％＝100×(P _21e /P _{total (S)} )

For the copolymer, a characteristic signal corresponding to ethylene incorporation was observed (Cheng, h.n., macromolecules 17 (1984), 1950).

Regional defects were also observed (Resconi, L., cavallo, L., fait, A., piemontesi, F., chem. Rev.2000, 100, 1253; wang, WJ., zhu, S., macromolecules 33 (2000), 1157;Cheng,HN,Macromolecules 17 (1984), 1950), the effect of such defects on comonomer content needed to be corrected.

By penetration using the method of Wang et al ¹³ C{ ¹ The integration of multiple signals over the entire spectral region in the H } spectrum, quantifying the comonomer fraction (Wang, W-j., zhu, s., macromolecules 33 (2000), 1157). The reason for choosing this method is its stability (robust nature) and the computing power of the existing region defects if required. Trimming the integration area to increase the exposure to the full rangeSuitability for comonomer content of (c).

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 that are known to be absent. The method reduces overestimation of the ethylene content in such a system and is achieved by reducing the number of sites for determining the absolute ethylene content:

E＝0.5(Sββ+Sβγ+Sβδ+0.5(Sαβ+Sαγ))

By using this set of sites, the corresponding integral equation becomes:

E＝0.5(I _H +I _G +0.5(I _C +I _D ))

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

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

E[mol％]＝100×fE

the weight percent of comonomer incorporated is calculated from the weight fraction:

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

the comonomer sequence distribution at the triplet level was determined using the analysis method of Kakugo et al. (Kakugo, M., naito, Y., mizunum, K., miyatake, T.macromolecules 15 (1982) 1150). The method is chosen for its stability (robust) and fine tuning of the integration region to improve its applicability in a wider range of comonomer contents.

DSC analysis, melting temperature (T _m ) And heat of fusion (H) _f ) Crystallization temperature (T) _c ) And melting enthalpy (H) _m ): 5 to 7mg samples were measured using a TA instruments Q200 Differential Scanning Calorimeter (DSC). DSC was run at a temperature of-30 to +225 ℃ in accordance with ISO 11357/part 3/method C2 at a scan rate of 10 ℃/min during the heating/cooling/heating cycle. Determination of crystallization temperature (T) by a Cooling step _c ) While the melting temperature (T) is determined by the second heating step _m ) And meltingEnthalpy (H) _m ). By assuming H of fully crystalline polypropylene _m The crystallinity was calculated from the enthalpy of fusion at a value of 209J/g (see Brandrep, J., immergout, E.H., eds.Polymer Handbook, third edition, wili, new York, 1989; chapter 3).

Xylene solubles (XCS, wt%): the content of Xylene Cold Solubles (XCS) is determined according to ISO 16152 at 25 ℃; a first plate; 2005-07-01. The fraction remaining insoluble is the Xylene Cold Insoluble (XCI) fraction.

Ash content was measured according to ISO 3451-1 (1997) standard.

Charpy (Charpy) notched impact strength and Charpy unnotched impact strength: determined according to ISO179-1/1 eA and ISO179-1/1eU at 23℃using injection molded specimens (80X 10X 4 mm) as described in ISO 19069-2.

Tensile properties were determined on injection molded dog bone samples (170X 10X 4 mm) prepared according to ISO 527-1A. The tensile modulus was determined according to ISO 527-1A at 1mm/min and 23 ℃. To determine the yield stress and the yield strain, a speed of 50mm/min was used.

The oil resistance was determined as follows: the tensile test pieces were immersed in engine oil "ow-20" purchased from Mobil company at room temperature for 250 hours, 500 hours and 1000 hours, respectively, and then the Tensile Strength (TS) and Tensile Modulus (TM) were determined. The retention is determined as follows:

Elongation at break: a4 mm thick compression molded sample prepared according to EN ISO 1873-2 was used according to ISO 527/2/5A, determined at 50mm/min and 23 ℃.

Flexural modulus: according to ISO 178, use is made of a composition according to ISO 294-1: the flexural modulus was determined in three-point bending of 80X 10X 4mm injection molded samples prepared in 1996.

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

2. Specific example

The following inventive example IE was prepared by mixing on a co-rotating twin screw extruder. In particular, the Propylene Polymer (PP), i.e. the first propylene polymer (PP 1) and optionally the second propylene polymer (PP 2), is pre-mixed with the Additive (AD) and the Adhesion Promoter (AP). The base resin thus obtained was fed into the main feeder of the extruder, and Short Fibers (SF) were added through the side feeder. The material is extruded at a temperature of 210 to 230 ℃. Table 1 summarizes its composition and properties.

Table 1: composition and Properties of examples and comparative examples

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CE is a commercially available fiber-reinforced propylene copolymer compound comprising 53wt% propylene homopolymer, 8.0wt% propylene/ethylene copolymer rubber, 36wt% glass fiber and 1.5wt% adhesion promoter (which is polypropylene functionalized with maleic anhydride).

PP1 is a propylene homopolymer with a melt flow rate MFR ₂ (230 ℃ C., 2.16 kg) was 8.0g/10min and the xylene solubles content XCS was 1.0wt%.

PP2 is a propylene homopolymer with a melt flow rate MFR ₂ (230 ℃) 60g/10min, xylene solubles content XCS 2.0 wt.% and containing 0.8 wt.% ethylene comonomer units.

SF is a commercially available product 249A from Owens Corning (U.S.A.), 10.0 μm in diameter, and 4.5mm in strand length.

The AP is

The adhesion promoter SCONA TPPP 8112GA, manufactured by BYK-Chemie GmbH (Germany), is oneA polypropylene functionalized with maleic anhydride, having a maleic anhydride content of 1.4 wt.% and an MFR (190 ℃) of more than 80g/10min.

AD is a composition comprising 24 parts by weight of a polymer carrier material being a propylene homopolymer, 24 parts by weight of an antioxidant DSTDP from BASF, 8 parts by weight of an antioxidant Irgafos 168 from BASF, 16 parts by weight of an antioxidant Irganox1010 from BASF, 8 parts by weight of an antioxidant Richnox XL-1 from Rich Yu Chemical Co., ltd (Taiwan), and 20 parts by weight of carbon black.

As can be seen from table 1, the retention of tensile modulus and tensile strength of the fiber reinforced polypropylene composition of the present invention is higher than the corresponding values of the comparative composition comprising the polypropylene compound and the rubber.

Claims

1. A fiber reinforced polypropylene composition (C) comprising:

i) Propylene Polymers (PP) with xylene solubles content XCS equal to or lower than 5.0 wt%,

ii) fiber (F), and

iii) An Adhesion Promoter (AP),

wherein the fiber reinforced polypropylene composition satisfies the inequality (Ib):

(Ib),

wherein w (PP) is the weight fraction of the Propylene Polymer (PP) in the total weight of the fiber-reinforced polypropylene composition (C), in wt%, and w (AP) is the weight fraction of the Adhesion Promoter (AP) in the total weight of the fiber-reinforced polypropylene composition (C), in wt%.

2. The fiber reinforced polypropylene composition (C) according to claim 1, wherein the Propylene Polymer (PP) is single phase.

3. Fiber reinforced polypropylene composition (C) according to claim 1 or 2, wherein the fiber reinforced polypropylene composition (C) does not comprise propylene polymers having a xylene solubles content XCS higher than 5.0 wt%.

4. The fiber reinforced polypropylene composition (C) according to claim 1 or 2, wherein the fiber reinforced polypropylene composition (C) satisfies the inequality (II):

(II),

wherein w (F) is the weight fraction of the fibers (F) in the total weight of the fiber reinforced polypropylene composition (C), in wt%, and w (AP) is the weight fraction of the Adhesion Promoter (AP) in the total weight of the fiber reinforced polypropylene composition (C), in wt%.

5. The fiber reinforced polypropylene composition (C) according to claim 1 or 2, wherein the Propylene Polymer (PP) is bimodal.

6. The fiber reinforced polypropylene composition (C) according to claim 1 or 2, wherein the Propylene Polymer (PP) is a propylene homopolymer (H-PP).

7. The fiber reinforced polypropylene composition (C) according to claim 1 or 2, wherein the Propylene Polymer (PP) comprises:

i) A first propylene polymer (PP 1) having a melt flow rate MFR determined according to ISO 1133 ₂ (230 ℃,2.16 kg) equal to or lower than 20 g/10 min, and

ii) a second propylene polymer (PP 2) having a melt flow rate MFR determined according to ISO 1133 ₂ (230 ℃,2.16 kg) is greater than 20 g/10 min.

8. The fiber reinforced polypropylene composition (C) according to claim 1, wherein said fiber (F) is a Short Fiber (SF).

9. The fiber reinforced polypropylene composition (C) according to claim 1, wherein said fiber (F) is a Glass Fiber (GF).

10. The fiber reinforced polypropylene composition (C) according to claim 1, wherein said fibers (F) are Short Glass Fibers (SGF).

11. The fiber reinforced polypropylene composition (C) according to claim 8 or 10, wherein the fiber (F) has:

i) Average length of 1.0 to 10.0 mm, and/or

ii) an average diameter of 8 to 20 [ mu ] m.

12. The fiber reinforced polypropylene composition (C) according to claim 1 or 2, wherein the Adhesion Promoter (AP) is a polar modified polypropylene (PM-PP) which is a maleic anhydride grafted propylene homo-or copolymer having a melt flow rate MFR (190 ℃,2.16 kg) of at least 80.0 g/10 min as determined according to ISO 1133.

13. The fiber reinforced polypropylene composition (C) according to claim 1 or 2, wherein the fiber reinforced polypropylene composition (C) comprises, based on the total weight of the fiber reinforced polypropylene composition (C):

i) 50.0 to 80.0 wt% of Propylene Polymer (PP) having a xylene solubles content XCS equal to or lower than 5.0 wt%,

ii) 15.0 to 40.0. 40.0 wt% of fibers (F),

iii) 3.0 to 10.0 wt% of an Adhesion Promoter (AP), and

iv) optionally 0.1-4.0. 4.0 wt% of Additive (AD).

14. An article comprising the fiber reinforced polypropylene composition (C) according to any one of claims 1 to 13.

15. The article of claim 14 comprising at least 90 wt% of the fiber reinforced polypropylene composition (C).

16. The article of claim 14 or 15, wherein the article is an automotive article.

17. The article of claim 14 or 15, wherein the article is an automotive engine article.

18. The article of claim 14 or 15, wherein the article is an intake manifold of an automotive engine.