WO2019010672A1

WO2019010672A1 - Glass fiber reinforced composition with low odor

Info

Publication number: WO2019010672A1
Application number: PCT/CN2017/092801
Authority: WO
Inventors: Rock ZHU; Jenny PAN; Ben Chen
Original assignee: Borouge Compounding Shanghai Co., Ltd.
Priority date: 2017-07-13
Filing date: 2017-07-13
Publication date: 2019-01-17
Also published as: CN110914360B; CN110914360A

Abstract

A glass fiber reinforced composition comprising from 50 to 80 wt.%, based on the total weight of the composition, of a propylene homopolymer (H-PP), having a melt flow rate MFR2 (230 ℃, 2.16 kg) measured according to ISO 1133 in the range from 5 to 70 g/10min, from 15 to 35 wt.%, based on the total weight of the composition, of glass fibers (GF), optionally from 3 to 10 wt.%, based on the total weight of the composition, of an elastomeric ethylene copolymer (EC) comprising one or more comonomer units derived from C4 to C8 α-olefins, from 0.8 to 1.5 wt.%, based on the total weight of the composition, of a polar modified polypropylene (PMP) as compatibilizer, from 0.5 to 1.5 wt.%, based on the total weight of the composition, of one or more antioxidants being free of sulphur atom(s), from 0.2 to 0.5 wt.%, based on the total weight of the composition, of a demoulding agent, and 0.5 to 2 wt.%, based on the total weight of the composition, of one or more additives, an automotive article comprising the glass fiber reinforced composition and a process for the preparation of the glass fiber reinforced composition.

Description

Glass fiber reinforced composition with low odor

Polypropylene is a material used in a wide variety of technical fields， and reinforced polypropylenes have in particular gained relevance in fields previously exclusively relying on non-polymeric materials， in particular metals. One particular example of reinforced polypropylenes are glass fiber reinforced polypropylenes. Such materials enable a tailoring of the properties of the composition by selecting the type of polypropylene， the amount of glass fiber and sometimes by selecting the type of coupling agent used. Accordingly， nowadays glass-fiber reinforced polypropylene is a well-established material for applications requiring good mechanical properties such as high stiffness and thermal stability. However one drawback of the commercially available glass fiber reinforced materials is that they typically release volatile organic small molecules such as aldehydes and ketones and sulphur-containing compounds or maleic anhydrides resulting from the degradation of the base resin and/or the several additives such as antioxidants， demoulding agent and compatibilizers that are added to the composition. Thus， these glass fiber reinforced materials typically do not meet the odor requirements set by the automobile industries for interior parts of automotives.

Therefore， there is still a need in the art to provide a glass fiber reinforced composition having a low emission of volatile organic small molecules and thus has low odor.

The finding of the present invention is that a glass fiber reinforced composition having low odor in combination with acceptable mechanical properties of stiffness and impact strength can be obtained with a specific propylene homopolymer in combination with defined components.

Therefore the present invention is directed to a glass fiber reinforced composition comprising

(a) from 50 to 80 wt. -％， based on the total weight of the composition， of a propylene homopolymer (H-PP) having a melt flow rate MFR₂ (230 ℃， 2.16 kg) measured according to ISO 1133 in the range from 5 to 70 g/10 min，

(b) from 15 to 35 wt. -％， based on the total weight of the composition， of glass fibers (GF) ，

(c) optionally from 3 to 10 wt. -％, based on the total weight of the composition, of an elastomeric ethylene copolymer (EC) comprising one or more comonomer units derived from C₄ to C₈ α-olefins,

(d) from 0.8 to 1.5 wt. -％, based on the total weight of the composition, of a polar modified polypropylene (PMP) as compatibilizer,

(e) from 0.5 to 1.5 wt. -％, based on the total weight of the composition, of one or more antioxidant (s) being free of sulphur atom (s) ,

(f) from 0.2 to 0.5 wt. -％, based on the total weight of the composition, of a demoulding agent, and

(g) from 0.5 to 2 wt. -％％, based on the total weight of the composition, of one or more additives.

According to one embodiment of the present invention, the propylene homopolymer (H-PP) has a comonomer content of ≤ 2.0 wt. -％, based on the total weight of the propylene homopolymer, and/or a xylene cold soluble (XCS) content below 2.5 wt. -％, based on the total weight of the propylene homopolymer.

According to another embodiment of the present invention, the propylene homopolymer (H-PP) is a mixture of at least two propylene homopolymers, preferably two propylene homopolymers, more preferably the mixture comprises two propylene homopolymers and one propylene homopolymer (H-PP1) has a melt flow rate MFR₂ (230 ℃, 2.16 kg) measured according to ISO 1133 in the range from 5 to 30 g/10 min and the other propylene homopolymer (H-PP2) has a melt flow rate MFR₂ (230 ℃, 2.16 kg) measured according to ISO 1133 in the range from > 30 to 70 g/10 min.

According to yet another embodiment of the present invention, the mixture of two propylene homopolymers comprises the two propylene homopolymers in a weight ratio from 5: 1 to 1.2: 1, preferably from 3: 1 to 1.5: 1.

According to one embodiment of the present invention, the mixture of at least two propylene homopolymers comprises one propylene homopolymer being alpha-nucleated, preferably the propylene homopolymer (H-PP1) having a melt flow rate MFR₂ (230 ℃, 2.16 kg) measured according to ISO 1133 in the range from 5 to 30 g/10 min is alpha-nucleated.

According to another embodiment of the present invention, the glass fibers (GF) have a fiber average diameter in the range of 5 to 30 μm and/or an average fiber length from 0.1 to 20 mm.

According to yet another embodiment of the present invention, the elastomeric ethylene copolymer (EC) comprises the one or more comonomer units in an amount from 20 to 40 wt.-％, based on the total weight of the elastomeric ethylene copolymer (EC) , and/or has a melt flow rate MFR₂ (190 ℃, 2.16 kg) in the range from 1 to 40 g/10 min.

According to yet another embodiment of the present invention, 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, oxazoline and epoxides, and also ionic compounds.

According to one embodiment of the present invention, the polar modified polypropylene (PMP) is a propylene polymer grafted with maleic anhydride, preferably a propylene polymer grafted with maleic anhydride containing ≤ 100 ppm, based on the total weight of the polar modified polypropylene (PMP) , of free maleic anhydride.

According to another embodiment of the present invention, the one or more antioxidant (s) is/are selected from phenolic antioxidants (AO) , phosphorous-based antioxidants (AO) and mixtures thereof, preferably the phenolic antioxidant is a sterically hindered phenol (SHP) , like 1, 3, 5-tris (3’ , 5’ -di-tert butyl-4’ -hydroxybenzyl) -isocyanurate, or pentaerythrityl-tetrakis (3- (3’ , 5’ -di-tertbutyl-4-hydroxyphenyl) -propionate, and/or the phosphorous-based antioxidant is tris (2, 4-di-t-butylphenyl) phosphite.

According to yet another embodiment of the present invention, the demoulding agent is free of glyceryl monostearate, more preferably free of alkane glyceryl ester.

According to one embodiment of the present invention, the demoulding agent is a silicone rubber.

According to yet another embodiment of the present invention, the inventive composition is totally free of glyceryl monostearate, more preferably free of alkane glyceryl ester.

According to a further aspect, the present invention refers to an automotive article comprising the glass fiber reinforced composition as defined herein. It is preferred that the automotive article is a car interior article.

According to another aspect, the present invention refers to a process for the preparation of the glass fiber reinforced composition as defined herein comprising the steps of adding

(a) from 50 to 80 wt. -％, based on the total weight of the composition, of a propylene homopolymer (H-PP) having a melt flow rate MFR₂ (230 ℃, 2.16 kg) measured according to ISO 1133 in the range from 5 to 70 g/10 min,

(b) from 15 to 35 wt. -％, based on the total weight of the composition, of glass fibers (GF) ,

(g) from 0.5 to 2 wt. -％, based on the total weight of the composition, of one or more additives,

to an extruder and extruding the same obtaining said glass fiber reinforced composition.

In the following the invention is defined in more detail.

The glass fiber reinforced composition

The glass fiber reinforced composition according to this invention comprises a propylene homopolymer (H-PP) , glass fibers (GF) , optionally an elastomeric ethylene copolymer (EC) comprising one or more comonomer units derived from C₄ to C₈ α-olefins, a polar modified polypropylene (PMP) as compatibilizer, one or more antioxidant (s) being free of sulphur atom (s) , a demoulding agent and one or more additives.

Accordingly it is preferred that the glass fibre reinforced composition comprises

(a) from 50 to 80 wt. -％, preferably from 60 to 75 wt. -％, based on the total weight of the composition, of a propylene homopolymer (H-PP) having a melt flow rate MFR₂ (230 ℃, 2.16 kg) measured according to ISO 1133 in the range from 5 to 70 g/10 min,

(b) from 15 to 35 wt. -％, preferably from 20 to 35 wt. -％, based on the total weight of the composition, of glass fibers (GF) ,

(c) optionally from 3 to 10 wt. -％, preferably from 5 to 10 wt. -％, based on the total weight of the composition, of an elastomeric ethylene copolymer (EC) comprising one or more comonomer units derived from C₄ to C₈ α-olefins,

(d) from 0.8 to 1.5 wt. -％, preferably from 0.8 to 1.2 wt. -％, based on the total weight of the composition, of a polar modified polypropylene (PMP) as compatibilizer,

(e) from 0.5 to 1.5 wt. -％, preferably from 1 to 1.5 wt. -％, based on the total weight of the composition, of one or more antioxidant (s) being free of sulphur atom (s) ,

(f) from 0.2 to 0.5 wt. -％, preferably from 0.2 to 0.4 wt. -％, based on the total weight of the composition, of a demoulding agent, and

(g) 0.5 to 2 wt. -％, preferably from 0.8 to 1.2 wt. -％, based on the total weight of the composition, of one or more additives.

In a preferred embodiment, the glass fiber reinforced composition according to this invention does not comprise (a) further polymer (s) different to the polymers present in the fiber reinforced composition, i.e. different to the propylene homopolymer (H-PP) , the optional elastomeric ethylene copolymer (EC) , the polar modified polypropylene (PMP) and the demoulding agent, in an amount exceeding in total 2 wt. -％, preferably exceeding in total 1 wt.-％, based on the total weight of the glass fiber reinforced composition. Typically if an additional polymer is present, such a polymer is a carrier polymer for additives and thus does not contribute to the improved properties of the claimed glass fiber reinforced composition.

Accordingly in one embodiment the glass fiber reinforced composition consists of the propylene homopolymer (H-PP) , the glass fibers, the polar modified polypropylene (PMP) , one or more antioxidant (s) being free of sulphur atom (s) and the demoulding agent, and additional other additives, which might contain in low amounts of polymeric carrier material. In an alternative embodiment, the glass fiber reinforced composition consists of the propylene homopolymer (H-PP) , the glass fibers, the elastomeric ethylene copolymer (EC) , the polar modified polypropylene (PMP) , one or more antioxidant (s) being free of sulphur atom (s) and the demoulding agent, and additional other additives, which might contain in low amounts of polymeric carrier material. However, this polymeric carrier material is not more than 2 wt. -％, preferably not more than 1 wt. -％, based on the total weight of the glass fiber reinforced composition, present in said glass fiber reinforced composition.

The term “additives” covers also additives which are provided as a masterbatch containing the polymeric carrier material as discussed above. However the term “additive” does not cover nucleating agents, e.g. α-nucleating agents. Typical additives (A) are acid scavengers, colorants, pigments such as carbon black, anti-scratch agents, dispersing agents and carriers.

In addition the glass fiber reinforced composition contains preferably a α-nucleating agent. Even more preferred the present invention is free of β-nucleating agents. Accordingly, the nucleating agent is preferably selected from the group consisting of

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

(ii) dibenzylidenesorbitol (e.g. 1, 3 : 2, 4 dibenzylidenesorbitol) and C₁-C₈-alkyl-substituted dibenzylidenesorbitol derivatives, such as methyldibenzylidenesorbitol, ethyldibenzylidenesorbitol or dimethyldibenzylidenesorbitol (e.g. 1, 3 : 2, 4 di(methylbenzylidene) sorbitol) , or substituted nonitol-derivatives, such as 1, 2, 3, -trideoxy-4, 6: 5, 7-bis-O- [ (4-propylphenyl) methylene] -nonitol, and

(iii) salts of diesters of phosphoric acid, e.g. sodium 2, 2'-methylenebis (4, 6, -di-tert-butylphenyl) phosphate or aluminium-hydroxy-bis [2, 2'-methylene-bis (4, 6-di-t-butylphenyl) phosphate] , and

(iv) vinylcycloalkane polymer and vinylalkane polymer, and

(v) mixtures thereof.

Preferably, the glass fiber reinforced composition contains as α-nucleating agent a vinylcycloalkane polymer and/or a vinylalkane polymer. This nucleating agent is preferably included due to the preparation of the propylene homopolymer (H-PP) .

Such additives and nucleating agents are generally commercially available and are described, for example, in "Plastic Additives Handbook" , 5th edition, 2001 of Hans Zweifel.

Preferably the glass fiber reinforced composition has melt flow rate MFR₂ (230 ℃, 2.16 kg) measured according to ISO 1133 in the range of 5 to 70 g/10 min, more preferably in the range of 8 to 50 g/10min, like in the range of 8 to 30 g/10min.

In a preferred embodiment the glass fiber reinforced composition has

(a) a flexural modulus measured according to ISO 178 of at least 6,000 MPa, more preferably of at least 6,200 MPa, yet more preferably in the range of 6,200 to 7,600 MPa, like in the range of 6,500 to 7,400 MPa；

and/or

(b) a notched Charpy strength measured according to ISO 179 (23 ℃) of at least 10 kJ/m², more preferably in the range of 10.0 to 25.0 kJ/m², yet more preferably in the range of 12.0 to 20.0 kJ/m².

In addition, the present invention also relates to a process for the preparation of the glass fiber reinforced composition as described above and in more detail below, comprising the steps of adding

(g) 0.5 to 2 wt. -％, based on the total weight of the composition, of one or more additives,

The glass fiber reinforced composition according to the invention may be compounded and pelletized using any of the variety of compounding and blending machines and methods well known and commonly used in the resin compounding art.

For blending the individual components of the instant composition a conventional compounding or blending apparatus, e.g. a Banbury mixer, a 2-roll rubber mill, Buss-co-kneader or a twin screw extruder may be used. The polymer materials recovered from the extruder/mixer are usually in the form of pellets. These pellets are then preferably further processed, e.g. by injection molding to generate articles and products of the inventive composition.

In the following the individual components of the glass fiber reinforced composition are described in more detail.

The propylene homopolymer

The fiber reinforced composition must comprise a propylene homopolymer (H-PP) . It is appreciated that the propylene homopolymer (H-PP) has a melt flow rate MFR₂ (230 ℃, 2.16 kg) measured according to ISO 1133 in the range from 5 to 70 g/10 min.

In one embodiment, it is specifically preferred that the fiber reinforced composition comprises several polymer components. To achieve better balanced properties and processability, the propylene homopolymer preferably contains a mixture of at least two different propylene homopolymers. One especially contributes to the properties of the final product, and the other contributes to the processability of the composition.

In a preferred embodiment, the propylene homopolymer (H-PP) is thus a mixture of at least two propylene homopolymers.

It is appreciated that the expression “mixture of at least two propylene homopolymers” means that two or more kinds of said propylene homopolymers are present in the instant composition.

Accordingly, it should be noted that the mixture of at least two propylene homopolymers (H-PP) can be a mixture of two kinds of said propylene homopolymers (H-PP) . Alternatively, the mixture of at least two propylene homopolymers (H-PP) can be a mixture of three or more kinds of said propylene homopolymers (H-PP) , like three kinds of said propylene homopolymers (H-PP) .

In one embodiment of the present invention, the mixture of at least two propylene homopolymers (H-PP) comprises two propylene homopolymers.

If the mixture of at least two propylene homopolymers (H-PP) comprises two propylene homopolymers (H-PP) , it is preferred that the mixture comprises the two propylene homopolymers in a weight ratio from 5: 1 to 1.2: 1. For example, the mixture comprises the two propylene homopolymers in a weight ratio from 3: 1 to 1.5: 1 or from 2.5: 1 to 1.8: 1. Most preferably, the mixture comprises the two propylene homopolymers in a weight ratio from 2.5: 1 to 2: 1.

The term “propylene homopolymer” used in the present invention relates to a polypropylene that consists substantially, i.e. of more than 98.0 wt. -％of, preferably of more than 99.0 wt. -％, even more preferably of more than 99.7 wt. -％, still more preferably of at least 99.8 wt. -％, of propylene units. In a preferred embodiment, only propylene units in the propylene homopolymer are detectable.

In one embodiment, the propylene homopolymer (H-PP) , preferably each of the propylene homopolymers (H-PP) in the mixture of at least two propylene homopolymers, has a comonomer content of ≤ 2.0 wt. -％, based on the total weight of the propylene homopolymer (H-PP) . Preferably, the propylene homopolymer (H-PP) , preferably each of the propylene homopolymers in the mixture of at least two propylene homopolymers (H-PP) , has a comonomer content or less than 1.0 wt. -％, more preferably of less than 0.3 wt. -％and most preferably of less than 0.2 wt. -％, based on the total weight of the propylene homopolymer. In a preferred embodiment, no comonomer units are detectable for the propylene homopolymer (H-PP) , preferably each of the propylene homopolymers (H-PP) in the mixture of at least two propylene homopolymers.

Additionally or alternatively, the propylene homopolymer (H-PP) , preferably each of the propylene homopolymers in the mixture of at least two propylene homopolymers (H-PP) , has a xylene cold soluble (XCS) content below 2.5 wt. -％, based on the total weight of the propylene homopolymer. For example, the propylene homopolymer (H-PP) , preferably each of the propylene homopolymers in the mixture of at least two propylene homopolymers (H-PP) , has a xylene cold soluble (XCS) content below 2.2 wt. -％, such as in the range from 0.5 to 2.2 wt. -％, based on the total weight of the propylene homopolymer (H-PP) .

It is preferred that the propylene homopolymer (H-PP) , preferably each of the propylene homopolymers in the mixture of at least two propylene homopolymers (H-PP) , is free of glyceryl monostearate, more preferably free of alkane glyceryl ester.

It is a further requirement of the present invention that the propylene homopolymer (H-PP) , preferably each of the at least two propylene homopolymers in the mixture of at least two propylene homopolymers (H-PP) , has a melt flow rate MFR₂ (230 ℃, 2.16 kg) measured according to ISO 1133 in the range from 5 to 70 g/10 min.

If the propylene homopolymer (H-PP) is a mixture of at least two propylene homopolymers (H-PP) , it is preferred that one propylene homopolymer in the mixture of at least two propylene homopolymers has a relatively low melt flow rate (H-PP1) and another propylene homopolymer in the mixture of at least two propylene homopolymers has a relatively high melt flow rate (H-PP2) .

Good stiffness can be achieved due to the presence of a propylene homopolymer with relatively low melt flow rate (H-PP1) .

Thus, if the mixture of at least two propylene homopolymers (H-PP) comprises two propylene homopolymers, it is preferred that one propylene homopolymer (H-PP1) has a melt flow rate MFR₂ (230 ℃, 2.16 kg) measured according to ISO 1133 in the range from 5 to 30 g/10 min (H-PP1) and the other propylene homopolymer (H-PP2) has a melt flow rate MFR₂ (230 ℃, 2.16 kg) measured according to ISO 1133 in the range from > 30 to 70 g/10 min.

Accordingly it is preferred that the propylene homopolymer (H-PP1) having a rather low melt flow rate has a melt flow rate MFR₂ (230 ℃, 2.16 kg) measured according to ISO 1133 of ≤ 30 g/10 min, such as in the range from 5 to 30 g/10 min, more preferably in the range from 5 to 20 g/10min, still more preferably in the range from 5 to 15 g/10min, like in the range from 7 to 12 g/10min.

It is preferred that the mixture of at least two propylene homopolymers comprises one propylene homopolymer being alpha-nucleated. In one embodiment, the propylene homopolymer (H-PP1) having a rather low melt flow rate is alpha-nucleated. Thus, it is appreciated that the nucleating agent that can be present in the glass fiber reinforced composition is preferably included in the preparation of the propylene homopolymer (H-PP1) having a relatively low melt flow rate.

The nucleating agent that may be present in the propylene homopolymer having a rather low melt flow rate is preferably selected from the group consisting of

(iv) vinylcycloalkane polymer and vinylalkane polymer, and

(v) mixtures thereof.

Preferably the propylene homopolymer (H-PP1) having a relatively low melt flow rate contains as α-nucleating agent a vinylcycloalkane polymer and/or a vinylalkane polymer.

More preferably, the vinylcycloalkane polymer and/or a vinylalkane polymer used as the α-nucleating agent, is formed during the polymerization of propylene homopolymer. As a result, the propylene homopolymer prepared has a better crystal structure, including a smaller size of crystal and more homogeneous dispersion of crystals, resulting in better mechanical properties of stiffness, strength and impact.

In particular, the Ziegler-Natta catalyst used for preparing propylene homopolymer (H-PP1) is modified by polymerizing a vinyl compound in the presence of the catalyst system, wherein the vinyl compound has the formula:

CH₂＝CH-CHR³R⁴

wherein R³ and R⁴ together form a 5-or 6-membered saturated, unsaturated or aromatic ring or independently represent an alkyl group comprising 1 to 4 carbon atoms. The so modified catalyst is used in the preparation of the propylene homopolymer (H-PP1) to accomplish α-nucleation of the polymer (BNT-technology) , the composition (Co) and thus of the total molded article.

One embodiment of a process for the propylene homopolymer (H-PP) , as discussed above, is a loop phase process or a loop-gas phase process, such as developed by Borealis, known as

technology, described for example in EP 0 887 379 A1 and WO 92/12182.

As already mentioned above, it is preferred that one propylene homopolymer in the mixture of at least two propylene homopolymers (H-PP) has a relatively low melt flow rate (H-PP1) and another propylene homopolymer in the mixture of at least two propylene homopolymers (H-PP) has a relatively high melt flow rate (H-PP2) .

It is appreciated that the processability might be advantageously improved by adding a propylene homopolymer (H-PP2) with relatively high melt flow rate.

Thus, if the mixture of at least two propylene homopolymers (H-PP) comprises two propylene homopolymers (H-PP) , it is preferred that the propylene homopolymer (H-PP2) has a melt flow rate MFR₂ (230 ℃, 2.16 kg) measured according to ISO 1133 of > 30 g/10 min, such as in the range from > 30 to 70 g/10 min, more preferably in the range from 45 to 70 g/10min, still more preferably in the range from 50 to 70 g/10min, like in the range from 55 to 70 g/10min.

Accordingly it is preferred that the propylene homopolymer (H-PP2) and the propylene homopolymer (H-PP1) fulfil together the inequation (Ia) , preferably inequation (Ib) , even more preferably inequation (Ic) , yet more preferably inequation (Id)

wherein

MFR (H-PP2) is the melt flow rate MFR₂ (230 ℃) [g/10 min] of the polypropylene (H-PP2) and

MFR (H-PP1) is the melt flow rate MFR₂ (230 ℃) [g/10 min] of the propylene homopolymer (H-PP1) .

Preferably the weight ratio between the propylene homopolymer (H-PP2) and the propylene homopolymer (H-PP1) [ (H-PP2) / (H-PP1) ] is from 5: 1 to 1.2: 1. For example, the weight ratio between the propylene homopolymer (H-PP2) and the propylene homopolymer (H-PP1) [ (H-PP2) / (H-PP1) ] is from 3: 1 to 1.5: 1 or from 2.5: 1 to 1.8: 1. Most preferably, the weight ratio between the propylene homopolymer (H-PP2) and the propylene homopolymer (H-PP1) [ (H-PP2) / (H-PP1) ] is from 2.5: 1 to 2: 1.

Preferably, the propylene homopolymer (H-PP2) having a relatively high melt flow rate has a melting temperature T_m in the range of 150 to 165℃, like in the range of 155 to 160℃.

The glass fibers (GF)

The composition of the present invention must comprise glass fibers (GF) It is appreciated that the glass fibers (GF) impart improved stiffness and strength to the composition of the present invention.

In particular, the glass fibers are cut glass fibers (GF) , also known as short fibers or chopped strands.

Preferably, the glass fibers (GF) have a fiber average diameter in the range of 5 to 30 μm. More preferably, the glass fiber (GF) have a fiber average diameter in the range of 5 to 25 μm and most preferably in the range of 7 to 20 μm.

For example, the glass fibers (GF) have a fiber average diameter in the range of 9 to 17 μm. More preferably, the glass fibers (GF) have a fiber average diameter in the range of 9 to 15 μm and most preferably in the range of 10 to 14 μm.

In one embodiment, the glass fibers (GF) have an average fiber length of from 0.1 to 20 mm and most preferably of 0.5 to 10 mm.

Glass fibers (GF) being suitable for the present invention can be surface treated with a so called sizing agent.

Examples of sizing agents suitable for the glass fibers (GF) include silane sizing agents, titanate sizing agents, aluminum sizing agents, chromium sizing agents, zirconium sizing agents, borane sizing agents, and preferred are silane sizing agents or titanate sizing agents, and more preferably silane sizing. The amount of the sizing agent related to the glass fibers (GF) is within the common knowledge of a skilled person and can be, for example in the range of from 0.1 to 10 parts by weight of the sizing agent with respect to 100 parts by weight of the glass fiber (GF) .

In one embodiment, the glass fibers (GF) comprise a sizing agent. Preferably, the sizing agent is a silane sizing agent.

The surface treatment of the glass fibers (GF) with a sizing agent can be done with known methods, like for example immersing the fibers in a tank in which a sizing agent is placed, being nipped and then drying in a hot-air oven, or with a hot roller or a hot plate.

The optional elastomeric ethylene copolymer (EC)

A further optional component of the present glass fiber reinforced composition is an elastomeric ethylene copolymer (EC) .

The elastomeric ethylene copolymer (EC) may be added to the glass fiber reinforced composition according to the present invention for improving impact strength.

It is appreciated that the elastomeric ethylene copolymer (EC) can be one or more kinds of elastomeric ethylene copolymer (EC) and is preferably added to the glass fiber reinforced composition in combination with the propylene homopolymer (H-PP) .

Accordingly, the elastomeric ethylene copolymer (EC) can be one kind of an elastomeric ethylene copolymer (EC) . Alternatively, the elastomeric ethylene copolymer (EC) is a mixture of two or more kinds of elastomeric ethylene copolymers (EC) . For example, the elastomeric ethylene copolymer (EC) is a mixture of two or three kinds of elastomeric ethylene copolymers (EC) . Preferably, the elastomeric ethylene copolymer (EC) is one kind of elastomeric ethylene copolymer (EC) .

The elastomeric ethylene copolymer (EC) is an ethylene copolymer comprising ethylene monomer units and one or more comonomer units selected from C₄ to C8 a-olefins, preferably 1-butene, 1-hexene and 1-octene. In a more preferred embodiment, the one or more comonomer is selected from 1-butene, 1-hexene, and 1-octene, wherein 1-butene or 1-octene is most preferred as the comonomer. It is appreciated that the elastomeric ethylene copolymer (EC) preferably comprises ethylene monomer units and one comonomer unit selected from C₄ to C8 a-olefins, preferably 1-butene, 1-hexene and 1-octene, most preferably 1-butene.

The elastomeric ethylene copolymer (EC) preferably contains between 55.0 and 90.0 wt. -％ethylene, preferably between 60.0 and 85.0 wt. -％ethylene, and more preferably between 60.0 and 80.0 wt. -％ethylene, based on the total amount of the elastomeric polyolefin copolymer. The remaining part to 100.0 wt. -％constitute the comonomer units.

Accordingly, the elastomeric ethylene copolymer (EC) comprises the one or more comonomer units in an amount from 10 to 45 wt. -％, preferably from 15 to 40 wt. -％and most preferably from 20 to 40 wt. -％, based on the total weight of the elastomeric ethylene copolymer (EC) . The remaining part to 100.0 wt. -％constitute the ethylene units.

In a preferred embodiment, the elastomeric ethylene copolymer (EC) has an overall melt flow rate MFR₂ (190 ℃, 2.16 kg) measured according to ISO 1133 in the range of from 1 to 40 g/10 min. More preferably, the elastomeric ethylene copolymer (EC) has an overall melt flow rate MFR₂ (190 ℃, 2.16 kg) in the range of from 1 to 30 g/10 min, more preferably in the range of from 1 to 20 g/10 min, and most preferably in the range of from 1 to 15 g/10 min. For example, the elastomeric ethylene copolymer (EC) has an overall melt flow rate MFR₂ (190 ℃, 2.16 kg) measured according to ISO 1133 in the range of from 1 to 10 g/10 min.

Additionally or alternatively, the elastomeric ethylene copolymer (EC) has a glass transition temperature in the range of -70 to -30 ℃, more preferably in the range of -70 to -45 ℃.

The elastomeric ethylene copolymer (EC) is known in the art and belongs in a preferred embodiment to the Tafmer^TM of Mitsui and Engage^TM of Dow, series, respectively.

It is appreciated that the amount of the elastomeric ethylene copolymer (EC) in the glass fiber reinforced composition is rather low compared to the propylene homopolymer (H-PP) .

For example, the weight ratio of the propylene homopolymer (H-PP) to the elastomeric ethylene copolymer (EC) [H-PP/EC] is from 30: 1 to 2: 1. Preferably, the weight ratio of the propylene homopolymer (H-PP) to the elastomeric ethylene copolymer (EC) [H-PP /EC] is from 25: 1 to 5: 1.

The polar modified polypropylene (PMP) as compatibilizer

In order to achieve an easier and more uniform dispersion of the glass fibers (GF) in the polymer components which act in the glass fiber reinforced polymer composition as a matrix, the glass fiber reinforced polymer composition comprises a specific compatibilizer.

The compatibilizer according to this invention is a specific polar modified polypropylene (PMP) .

Modified alpha-olefin polymers, in particular propylene homopolymers and copolymers, like copolymers of ethylene and propylene with each other or with other alpha-olefins, are most preferred, as they are highly compatible with the polymer of the present composition.

In terms of structure, the polar modified polypropylene are preferably selected from graft or block copolymers.

In this context, preference is given to polar modified polypropylene containing groups deriving from polar compounds, in particular selected from the group consisting of acid anhydrides, carboxylic acids, carboxylic acid derivatives, primary and secondary amines, hydroxyl compounds, oxazoline and epoxides, and also ionic compounds.

Specific examples of the said polar compounds are unsaturated cyclic anhydrides and their aliphatic diesters, and the diacid derivatives. In particular, one can use maleic anhydride and compounds selected from C₁ to C₁₀ linear and branched dialkyl maleates, C₁ to C₁₀ linear and branched dialkyl fumarates, itaconic anhydride, C₁ to C₁₀ linear and branched itaconic acid dialkyl esters, maleic acid, fumaric acid, itaconic acid and mixtures thereof.

Particular preference is given to maleic anhydride grafted polypropylene as compatibilizer.

The amounts of groups deriving from polar groups, e.g. maleic anhydride, in the modified polymer, like the modified polypropylene, are preferably from 0.1 to 5.0 wt. -％, more preferably from 0.2 to 5.0 wt. -％, and most preferably from 0.3 to 4.0 wt. -％, such as from 0.4 to 3.0 wt. -％, based on the total weight of the polar modified polypropylene.

In one embodiment, the compatibilizer, like the polar modified polypropylene, has a free amount of maleic anhydride in a range of less than 100 ppm, preferably less than 80 ppm, and most preferably less than 60 ppm, based on the total weight of the polar modified polypropylene.

Particular preference is given to a compatibilizer being a polar modified propylene copolymer or, a polar modified propylene homopolymer, the former is especially preferred. In one embodiment, the compatibilizer is a polar modified (block) propylene copolymer containing polar groups as defined above. In one specific embodiment, the compatibilizer is a (block) propylene copolymer grafted with maleic anhydride. Thus, in one specific preferred embodiment the compatibilizer is a (block) propylene ethylene copolymer grafted with maleic anhydride, more preferably wherein the ethylene content based on the total amount of the blockpropylene ethylene copolymer is in the range of 1.0 to 20.0 wt. -％, more preferably in the range of 3.0 to 18.0 wt. -％, especially more preferably in the range of 5.0 to 15.0 wt. -％.

Required amounts of groups deriving from polar groups in the polar modified (block) propylene copolymer or in the modified propylene homopolymer are preferably from 0.1 to 5.0 wt. -％, more preferably from 0.2 to 5.0 wt. -％, and most preferably from 0.3 to 4.0 wt. -％, such as from 0.4 to 3.0 wt. -％, based on the total weight of the polar modified (block) propylene copolymer.

Preferred values of the melt flow rate MFR₂ (190 ℃； 2.1 kg) measured according to ISO 1133 for the compatibilizer are from 1.0 to 500.0 g/10 min, like in the range of 50.0 to 150.0 g/10 min. For example, the melt flow rate MFR₂ (190 ℃； 2.1 kg) measured according to ISO 1133 for the compatibilizer is from 70.0 to 130.0 g/10 min, like in the range of 95.0 to 120.0 g/10 min.

The polar modified polypropylene, i.e. the compatibilizer, can be produced in a simple manner by reactive extrusion of the polymer, for example with maleic anhydride in the presence of free radical generators (like organic peroxides) , as disclosed for instance in EP 0 572 028.

It is thus preferred that the polar modified polypropylene (PMP) is a propylene block copolymer grafted with maleic anhydride.

In order to further reduce the amount of volatile organic small molecules and thus to further reduce the amount of odorous molecules released from the final article, it is preferred that the polar modified polypropylene (PMP) contains a low amount of the small polar compounds resulting in the polar groups of the polar modified polypropylene (PMP) when preparing same.

Accordingly, it is preferred that the polar modified polypropylene (PMP) contains ≤ 100 ppm, based on the total weight of the polar modified polypropylene (PMP) , of free polar compounds.

In one specifically preferred embodiment, the polar modified polypropylene (PMP) is a propylene polymer grafted with maleic anhydride containing ≤ 100 ppm, based on the total weight of the polar modified polypropylene (PMP) , of free maleic anhydride or free maleic acid, especially preferably ≤ 80 ppm of free maleic anhydride or free maleic acid.

The polar modified polypropylene (PMP) is known in the art and commercially available. A suitable example is FH118 of Nengzhiguang Co. Ltd., Ningpo, China.

In one embodiment, the fiber reinforced polymer composition comprises the polar modified polypropylene (PMP) as defined above as the only polar modified polypropylene (PMP) .

The one or more antioxidant (s)

As a further essential component, the glass fiber reinforced composition comprises one or more antioxidant (s) being free of sulphur atom (s) . It is appreciated that the one or more antioxidant (s) being free of sulphur atom (s) especially help to lower the odor released from articles as the amount of volatile gases such as hydrogen sulphide is drastically decreased.

Accordingly, it is appreciated that the one or more antioxidant (s) can be one antioxidant. Alternatively, the one or more antioxidant (s) can be a mixture of two or more antioxidants. For example, the one or more antioxidant (s) is a mixture of two or three or four antioxidants. Preferably, the one or more antioxidant (s) is a mixture of three antioxidants.

For the sake of completeness, it is appreciated that the one or more antioxidant (s) are free of one or more sulphur atom (s) .

In one embodiment, the one or more antioxidant (s) is selected from the group consisting of phenolic antioxidants (AO) , phosphorous-based antioxidants (AO) , alkyl radical scavengers, aromatic amines, hindered amine stabilisers and mixtures thereof.

Preferably, the one or more antioxidants is/are selected from phenolic antioxidants (AO) , phosphorous-based antioxidants (AO) and mixtures thereof, which are free of sulphur atom (s) .

The one or more antioxidant (s) is/are preferably selected from phenolic antioxidants (AO) being a sterically hindered phenol (SHP) . Such antioxidant is an excellent H-donor. The stability of the radical form is governed by the sterical hindrance of the substituent in the 2, 6 position of the phenol.

In the following the sterically hindered phenol (SHP) is defined more precisely. The term “sterically hindered” according to this invention means that the hydroxyl group (HO-) of the sterically hindered phenol (SHP) is surrounded by sterical alkyl residues.

Accordingly the sterically hindered phenol (SHP) preferably comprise the residue of formula (II)

wherein

R₁ being located at the ortho-or meta-position to the hydroxyl-group and R₁ is (CH₃) ₃C-, CH₃-or H, preferably (CH₃) ₃C-, and

A₁ constitutes the remaining part of the sterically hindered phenol (SHP) and is preferably located at the para-position to the hydroxyl-group.

Preferably the sterically hindered phenol (SHP) preferably comprise the residue of formula (IIa)

wherein

R₁ is (CH₃) ₃C-, CH₃-or H, preferably (CH₃) ₃C-, and

A₁ constitutes the remaining part of the sterically hindered phenol (SHP) .

Preferably A₁ is in para-position to the hydroxyl-group.

Additionally the sterically hindered phenol (SHP) shall preferably exceed a specific molecular weight. Accordingly the sterically hindered phenol (SHP) has preferably a molecular weight of more than 500 g/mol. On the other hand the molecular weight should be not too high, i.e. not higher than 1300 g/mol. A preferred range is from 500 to 1300 g/mol, more preferably from 700 to 1300 g/mol.

Further the sterically hindered phenol (SHP) can be additionally defined by the amount of phenolic residues, in particular by the amount of phenolic residues of formula (II) or (IIa) . Accordingly the sterically hindered phenol (SHP) may comprise (s) 1, 2, 3, 4 or more phenolic residues, preferably 3, 4 or more phenolic residues of formula (II) or (IIa) .

Moreover the sterically hindered phenol (SHP) comprises mainly only carbon atoms, hydrogen atoms and minor amounts of O-atoms, mainly caused due to the hydroxyl group (HO-) of the phenolic residues. However the sterically hindered phenol (SHP) may comprise additionally minor amounts of N and/or P atoms. Preferably the sterically hindered phenol (SHP) is constituted by C, H, O andN atoms only, more preferably the sterically hindered phenol (SHP) is constituted by C, H, O and optionally N only.

The sterically hindered phenol (SHP) may have a rather high molecular weight. A high molecular weight is an indicator for several phenolic residues. Thus it is in particular appreciated that the sterically hindered phenol (SHP) has 3 or more, especially 3, phenolic residues, like the phenolic residue of formula (II) or (IIa) .

Considering the above requirements the sterically hindered phenol (SHP) is preferably selected from the group consisting of

2, 6-di-tert-butyl-4-methylphenol (CAS no. 128-37-0； M 220 g/mol) ,

pentaerythrityl-tetrakis (3- (3’ , 5’ -di-tert-butyl-4-hydroxyphenyl) propionate (CAS no. 6683-19-8； M 1178 g/mol) ,

octadecyl 3- (3’ , 5’ -di-tert-butyl-4-hydroxyphenyl) propionate (CAS no. 2082-79-3； M 531 g/mol)

1, 3, 5-trimethyl-2, 4, 6-tris- (3, 5-di-tert-butyl-4-hydroxybenzyl) benzene (CAS no. 1709-70-2； M 775 g/mol) ,

calciumbis (ethyl 3, 5-di-tert-butyl-4-hydroxybenzylphosphonate) (CAS no. 65140-91-2； M 695 g/mol) ,

1, 3, 5-tris (3’ , 5’ -di-tert. butyl-4’ -hydroxybenzyl) -isocyanurate (CAS no. 27676-62-6, M 784 g/mol) ,

1, 3, 5-tris (4-tert. butyl-3-hydroxy-2, 6-dimethylbenzyl) -1, 3, 5-triazine-2, 4, 6- (1H, 3H, 5H) -trione (CAS no. 40601-76-1, M 813 g/mol) ,

bis (3, 3-bis (3’ -tert-butyl-4’ -hydroxyphenyl) butanic acid) glycolester (CAS no. 32509-66-3； M 794 g/mol) ,

2, 2'-methylene-bis- (6- (l-methyl-cyclohexyl) -para-cresol) (CAS no. 77-62-3； M 637 g/mol) ,

3, 3'-bis (3, 5-di-tert-butyl-4-hydroxyphenyl) -N, N'-hexamethylenedipropionamide (CAS no. 23128-74-7； M 637 g/mol) ,

2, 5, 7, 8-tetramethyl-2- (4’ , 8’ , 12’ -trimethyltridecyl) -chroman-6-ol (CAS no. 10191-41-0； M 431 g/mol) ,

2, 2-ethylidenebis (4, 6-di-tert-butylphenol) (CAS no. 35958-30-6； M 439 g/mol) ,

1, 1, 3-tris (2-methyl-4-hydroxy-5'-tert-butylphenyl) butane (CAS no. 1843-03-4； M 545 g/mol) ,

3, 9-bis (1, 1-dimethyl-2- (beta- (3-tert-butyl-4-hydroxy-5-methylphenyl) propionyloxy) ethyl) -2, 4, 8, 10-tetraoxaspiro [5.5] undecane (CAS no. 90498-90-1； M 741 g/mol) ,

1, 6-hexanediyl-bis (3, 5-bis (1, 1dimethylethyl) -4-hydroxybenzene) propanoate) (CAS no. 35074-77-2； M 639 g/mol) ,

2, 6-di-tert-butyl-4-nonylphenol (CAS no. 4306-88-1； M 280 g/mol) ,

4, 4'-butylidenebis (6-tert-butyl-3-methylphenol (CAS no. 85-60-9； M 383 g/mol) ；

2, 2'-methylene bis (6-tert-butyl-4-methylphenol) (CAS no. 119-47-1； M 341 g/mol) ,

triethylenglycol-bis- (3-tert-butyl-4-hydroxy-5-methylphenyl) propionate (CAS no. 36443-68-2； M 587 g/mol) ,

diethyl- (3, 5-di-tert-butyl-4-hydroxybenzyl) phosphate (CAS no. 976-56-7； M 356 g/mol) , 4, 6-bis (octylthiomethyl) -o-cresol (CAS no. 110553-27-0； M 425 g/mol) , and

1, 1, 3-tris [2-methyl-4- [3- (3, 5-di-tert-butyl-4-hydroxyphenyl) propionyloxy] -5-tert-butylphenyl] butane (CAS no. 180002-86-2； M 1326 g/mol) ,

More preferably, the sterically hindered phenol (SHP) is selected from the group consisting of

triethylenglycol-bis- (3-tert-butyl-4-hydroxy-5-methylphenyl) propionate (CAS no. 36443-68-2； M 587 g/mol) , and

benzenepropanoic acid, 3, 5-bis (1, 1-dimehtyl-ethyl) -4-hydroxy-, C7-C9-branched and linear alkyl esters (CAS no. 125643-61-0； M_w 399 g/mol) ,

The most preferred sterically hindered phenol (SHP) is 1, 3, 5-tris (3’ , 5’ -di-tert. butyl-4’ -hydroxybenzyl) -isocyanurate (CAS no. 27676-62-6, M 784 g/mol) and/or pentaerythrityl-tetrakis (3- (3’ , 5’ -di-tert-butyl-4-hydroxyphenyl) propionate (CAS no. 6683-19-8； M 1178 g/mol) .

In one embodiment, the sterically hindered phenol (SHP) is 1, 3, 5-tris (3’ , 5’ -di-tert. butyl-4’ -hydroxybenzyl) -isocyanurate (CAS no. 27676-62-6, M 784 g/mol) or pentaerythrityl-tetrakis (3- (3’ , 5’ -di-tert-butyl-4-hydroxyphenyl) propionate (CAS no. 6683-19-8； M 1178 g/mol) .

Alternatively, the sterically hindered phenol (SHP) is 1, 3, 5-tris (3’ , 5’ -di-tert. butyl-4’ -hydroxybenzyl) -isocyanurate (CAS no. 27676-62-6, M 784 g/mol) and pentaerythrityl- tetrakis (3- (3’ , 5’ -di-tert-butyl-4-hydroxyphenyl) propionate (CAS no. 6683-19-8； M 1178 g/mol) .

Preferably, the sterically hindered phenol (SHP) is 1, 3, 5-tris (3’ , 5’ -di-tert. butyl-4’ -hydroxybenzyl) -isocyanurate (CAS no. 27676-62-6, M 784 g/mol) and pentaerythrityl-tetrakis (3- (3’ , 5’ -di-tert-butyl-4-hydroxyphenyl) propionate (CAS no. 6683-19-8； M 1178 g/mol) .

Additionally or alternatively, the one or more antioxidant (s) is/are preferably selected from phosphorous-based antioxidants (AO) .

The phosphorous-based antioxidant (AO) preferably exceeds a specific molecular weight. Accordingly the phosphorous-based antioxidant (AO) has preferably a molecular weight of more than 400 g/mol. On the other hand, the molecular weight should be not too high, i.e. not higher than 1200 g/mol. A preferred range is from 500 to 1000 g/mol, more preferably from 600 to 800 g/mol.

Suitable phosphorous-based antioxidants (AO) are selected from the group comprising tris (2, 4-di-t-butylphenyl) phosphite (CAS no. 31570-04-4； M 647 g/mol)

tetrakis- (2, 4-di-t-butylphenyl) -4, 4’ -biphenylen-di-phosphonite (CAS no. 119345-01-6； M 991 g/mol)

bis (2, 4-di-t-butylphenyl) -pentaerythrityl-di-phosphite (CAS no. 26741-53-7； M 604 g/mol)

bis (2, 6-di-t-butyl-4-methylphenyl) pentaerythrityl-di-phosphite (CAS no. 80693-00-1； M 633 g/mol)

bis (2, 4-dicumylphenyl) pentaerythritol diphosphite (CAS no. 154862-43-8； M 852 g/mol)

bis (2-methyl-4, 6-bis (1, 1-dimethylethyl) phenyl) phosphorous acid ethylester (CAS no. 145650-60-8； M 514 g/mol)

2, 2’ , 2” -nitrilo triethyl-tris (3, 3’ , 5, 5’ -tetra-t-butyl-1, 1’ -biphenyl-2, 2’ -diyl) phosphite) (CAS no. 80410-33-9； M 1465 g/mol)

6-3- (3-tert-Butyl-4-hydroxy-5-methylphenyl) propoxy) -2, 4, 8, 10-tetra-tert. butyldibenz (d, t) (1.3.2) dioxaphosphepin (CAS no. 203255-81-6； M 660 g/mol)

tetrakis- (2, 4-di-t-butyl-5-methyl-phenyl) -4, 4’ -biphenylen-di-phosphonite (CAS no. 47192-62-9； M 1092 g/mol) .

The most preferred phosphorous-based antioxidant (AO) is tris (2, 4-di-t-butylphenyl) phosphite (CAS no. 31570-04-4； M 647 g/mol) .

As mentioned above, the one or more antioxidant (s) can be a mixture of two or more antioxidants.

For example, the one or more antioxidant (s) being a mixture of two or more antioxidants can be a mixture of one or more phenolic antioxidant (s) (AO) and one or more phosphorous-based antioxidant (s) (AO) . This embodiment is especially advantageous in order to achieve a low odor.

Preferably, the mixture of two or more antioxidants is a mixture of two or more, such as two or three, phenolic antioxidants (AO) and one or more, such as one or two, phosphorous-based antioxidant (s) (AO) . More preferably, the mixture of two or more antioxidants is a mixture of two or more, such as two phenolic antioxidants (AO) and one phosphorous-based antioxidant (AO) .

If the mixture of two or more antioxidants is a mixture of two or more, such as two or three, phenolic antioxidants and one or more, such as one or two, phosphorous-based antioxidant (s) , the weight ratio of the phenolic antioxidants to the phosphorous-based antioxidant (s) is preferably from 10: 1 to 1: 1, more preferably from 7: 1 to 2: 1 and most preferably from 6: 1 to 3: 1.

In one embodiment, the one or more antioxidant (s) is a mixture of 1, 3, 5-tris (3’ , 5’ -di-tert. butyl-4’ -hydroxybenzyl) -isocyanurate； pentaerythrityl-tetrakis (3- (3’ , 5’ -di-tert. butyl-4-hydroxyphenyl) -propionate, and tris (2, 4-di-t-butylphenyl) phosphite.

For example, the 1, 3, 5-tris (3’ , 5’ -di-tert. butyl-4’ -hydroxybenzyl) -isocyanurate； pentaerythrityl-tetrakis (3- (3’ , 5’ -di-tert. butyl-4-hydroxyphenyl) -propionate, and tris (2, 4-di-t-butylphenyl) phosphite are present in the composition in a weight ratio of about 3: 2: 1.

As mentioned above, the one or more antioxidant (s) are free of sulphur atom (s) , i.e. free of sulphur atom (s) containing antioxidants. Accordingly, it is preferred that also the glass fiber reinforced composition is free of sulphur atom (s) containing antioxidants. Accordingly it is preferred that the one or more antioxidant (s) , and also the glass fiber reinforced composition, does not contain di-stearyl-thio-di-propionate, di-lauryl-thio-di-propionate, di-tridecyl-thio-di-propionate, di-myristyl-thio-di-propionate, di-myristyl-thio-di-propionate, di-octadecyl-disulphide, bis [2-methyl-4- (3-n-dodecylthiopropionyloxy) -5-tert-butylphenyl] sulphide and pentaerythritol-tetrakis- (3-laurylthiopropionate) .

The demoulding agent

The demoulding agent is advantageously used in order to improve the processability of the glass fiber reinforced composition. It is to be noted that the demoulding agent may be also referred to as slipping agent.

It is appreciated that the demoulding agent is preferably free of glyceryl monostearate, more preferably free of alkane glyceryl ester. This is advantageous in order to achieve a low odor. Alkane glyceryl ester, such as glyceryl monostearate, could degrade into aldehyde at high temperature in process.

In view of this, the demoulding agent is preferably a silicone rubber. More preferably, the demoulding agent is in the form of a pelletized concentrate containing reaction products of ultra-high molecular weight silicone polymer reactively dispersed in a thermoplastic carrier. For example, the demoulding agent is in the form of a pelletized concentrate containing reaction products of ultra-high molecular weight silicone polymer reactively dispersed in a polyproyplene homopolymer.

In one embodiment, the demoulding agent consists of 50％propylene homopolymer having an MFR₂ (230 ℃, 2.16 kg) measured according to ISO 1133 of 12 g/10 min and 50％ultra high molecular weight, dimethylvinyl-terminated silicone (PDMS) .

An example of the demoulding agent which may be used, and which is commercially available as a pelletized concentrate containing reaction products of ultra-high molecular weight silicone polymer reactively dispersed in a polyproyplene homopolymer is MB50-001 from Dow Corning.

The additives

The instant glass fiber reinforced composition additionally contains typical other additives useful for instance in the automobile sector, like carbon black, other pigments, UV stabilizers, nucleating agents and antistatic agents, in amounts usual in the art. Preferably, the glass fiber reinforced composition comprises carbon black.

The additives may be introduced into the glass fiber reinforced composition by using a carrier polymer in order to ensure a more evenly distribution of the additives in the composition. Such a carrier polymer for additives does not contribute to the improved properties of the claimed glass fiber reinforced composition.

The carrier polymer may be present in the composition in an amount of not more than 2.0 wt.-％, preferably in an amount of not more than 1.5 wt. -％, more preferably in an amount of not more than 1.0 wt. -％, based on the total weight of the composition.

The carrier polymer is not limited to a particular polymer. The carrier polymer may be ethylene homopolymer, ethylene copolymer obtained from ethylene and α-olefin comonomer such as C₃ to C₈ α-olefin comonomer, propylene homopolymer and/or propylene copolymer obtained from propylene and α-olefin comonomer such as ethylene and/or C₄ to C₈ α-olefin comonomer. Preferably, the carrier polymer is propylene homopolymer and/or propylene copolymer, such as propylene homopolymer.

The process and articles

In addition, the present invention also relates to a process for the preparation of a glass fiber reinforced composition, comprising the steps of adding

With regard to the components provided in steps a) , b) , c) , d) , e) , f) and g) and preferred embodiments, it is referred to the definitions set out above when defining the present glass fiber reinforced composition and its single components.

In view of the above, it is appreciated that the glass fiber reinforced composition is preferably obtained by the process set out herein, namely a process for the preparation of a glass fiber reinforced composition, comprising the steps of adding

The glass fiber reinforced composition according to the invention may be pelletized and compounded using any of the variety of compounding and blending methods well known and commonly used in the resin compounding art.

The composition of the present glass fiber reinforced composition can be used for the production of molded articles, preferably injection molded articles as well as foamed articles. Even more preferred is the use for the production of automotive articles, especially of car interior articles and exterior articles, like instrumental carriers, front end module, shrouds, structural carriers, bumpers, side trims, step assists, body panels, spoilers, dashboards, interior trims and the like.

The present invention thus refers in another aspect to an automotive article comprising the glass fiber reinforced composition as defined herein.

The present invention will now be described in further detail by the examples provided below.

EXAMPLES

1. Definitions/Measuring Methods

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

Density was measured according to ISO 1183-187. Sample preparation is done by compression molding in accordance with ISO 1872-2: 2007

Melting temperature Tm was measured according to ISO 11357-3.

The glass transition temperature Tg was determined by dynamic mechanical analysis according to ISO 6721-7. The measurements were done in torsion mode on compression.

MFR₂ (230℃) was measured according to ISO 1133 (230℃, 2.16 kg load) .

MFR₂ (190℃) was measured according to ISO 1133 (190℃, 2.16 kg load) .

The xylene cold solubles (XCS, wt. -％) were determined at 25℃ according to ISO 16152； first edition； 2005-07-01

Quantification of comonomer content by FTIR spectroscopy

The comonomer content is determined by quantitative Fourier transform infrared spectroscopy (FTIR) after basic assignment calibrated via quantitative ¹³C nuclear magnetic resonance (NMR) spectroscopy in a manner well known in the art. Thin films are pressed to a thickness of between 100-500 μm and spectra recorded in transmission mode.

Specifically, the ethylene content of a polypropylene-co-ethylene copolymer is determined using the baseline corrected peak area of the quantitative bands found at 720-722 and 730-733 cm^-1. Quantitative results are obtained based upon reference to the film thickness.

Tensile strength was measured according to ISO 527-2 (cross head speed ＝ 50 mm/min； 23℃) using injection molded specimens as described in EN ISO 1873-2 (dog bone shape, 4 mm thickness) .

Elongation at breakwas measured according to ISO 527-2 (cross head speed ＝ 50 mm/min； 23℃) using injection molded specimens as described in EN ISO 1873-2 (dog bone shape, 4 mm thickness) .

Flexural modulus was measured according to ISO 178.

Charpy notched impact strength was determined according to ISO 179 /1eA at 23℃. The impact strength was determined by using injection molded test specimens of 80 x 10 x 4 mm³ prepared in accordance with EN ISO 19069-2.

Charpy unnotched impact strength was determined according to ISO 179 /1eU at 23℃by using injection molded test specimens of 80 x 10 x 4 mm³ prepared in accordance with EN ISO 19069-2.

Average fiber diameter was determined according to ISO 1888: 2006 (E) , Method B, microscope magnification of 1000.

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

Aging properties were determined by heating in an oven at a temperature of 150℃, and lasting for 1000h.

Odor test: according to PV3900 of Volkswagen (Germany)

Testing setsa) heat chamber with air circulation according to DIN 50011-12； accuracy class 2 b) 1 or 3 litre glass testing cup with unscented sealing and lid； the cup, the sealing and the lid have to be cleaned before use.

50 +/-5 g sample is put in 1 litre glass cup and then heated for 2 hours at 80+/-2℃ in the heat chamber. The sample is taken away from the heat chamber, and conditioned at room temperature till it is cooled to 65℃, and then the test is conducted.

Analysis

The rating of smell for all samples is accomplished by the scale as given in table below. Grades are given from 1 to 6, whereby half grades are possible.

Table 1: Rating of smell

Grade	Rating
1	not noticeable
2	noticeable； undisturbing
3	clearly noticeable； but not yet disturbing
4	Disturbing
5	severely disturbing
6	Intolerable

The result is given as an average value, rounded by half grades.

2. Examples

The following inventive examples IE1 and IE2 were preparedby compounding on a co-rotating twin-screw extruder with an L/D ratio of 44: 1 and D of 35mm. The temperature profiles used for inventive examples IE1 and IE2 and further processing characteristics are set out in tables 3a and 3b.

Table 2: Overview of the composition for inventive examples IE1 and IE2

		IE1	IE2
H-PP1	[wt. -％]	46.5	49.5
H-PP2	[wt. -％]	20.0	10.0
EC	[wt. -％]	--	7.0
Compatibilizer	[wt. -％]	1.0	1.0
Glass fibers	[wt. -％]	30.0	30.0
AO 1	[wt. -％]	0.6	0.6
AO 2	[wt. -％]	0.2	0.2
AO 3	[wt. -％]	0.4	0.4
Demoulding agent	[wt. -％]	0.3	0.3
Additives*	[wt. -％]	1.0	1.0

* includes carbon black in a propylene homopolymer carrier.

H-PP1 is the commercial propylene homopolymer HJ311Al of Borouge Pte Ltd having a melt flow rate MFR₂ (230 ℃) of 60 g/10min, free of glyceryl monostearate (GMS) ；

H-PP2 is the commercial propylene homopolymer HD915CF ofBorealis AG having a melt flow rate MFR₂ (230 ℃) of 8 g/10min and a melting temperature of 168 ℃, prepared by BNT technology of Borealis, free of glyceryl monostearate (GMS) ；

Compatibilizer is the commercial maleic anhydride grafted copolymer of propylene and ethylene, “FH118” of Nengzhiguang Co. Ltd., NingPo, China； having a free maleic anhydride level of 50 ppm,

Glass fibers are the commercial glass fibers “T438H” of Tianshan Glassfiber Co. Ltd (Shandong, China) , having an average diameter of 10 to 14 μm；

AO 1 is the commercial antioxidant “Irganox 3114” of BASF being the sterically hindered phenolic antioxidant 1, 3, 5-tris (3’ , 5’ -di-tert. butyl-4’ -hydroxybenzyl) -isocyanurate；

AO 2 is the commercial antioxidant “Irgafos 168” of BASF being the phosphorous-based antioxidant tris (2, 4-di-t-butylphenyl) phosphite；

AO 3 is the commercial antioxidant “Irganox 1010” of BASF being the sterically hindered phenolic antioxidant pentaerythrityl-tetrakis (3- (3’ , 5’ -di-tert. butyl-4-hydroxyphenyl) -propionate；

Demoulding agent is the commercial blend of 50 wt. -％ultra-high molecular weight silicone polymer with 50 wt. -％polyproyplene homopolymer carrier, “MB50-001” of Dow Corning, free of glyceryl monostearate (GMS) ；

EC is the commercial elastomeric ethylene/butylene copolymer "Tafmer DF640" of Mitsui Chemicals, Japan, having MFR₂ of 4 g/10 min (190℃/2.16 kg) , a glass transition temperature of >-70 ℃ and a density of 0.864 g/cm³ .

Table 3a: temperature (℃) of each zone of twin-screw extruder and other processing conditions for inventive example IE1

Table 3b: temperature (℃) of each zone of twin-screw extruder and other processing conditions for inventive example IE2

The mechanical and odor characteristics of the inventive examples IE1 and IE2 and a comparative example CE are indicated in table 4 below. The comparative example CE comprises a polypropylene homopolymer containing 0.3 wt. -％glyceryl monostearate (GMS) , 30 wt. -％glass fibers, the sulphurous-based antioxidant “di-stearyl-thio-di-propionate” (DSTDP) , and a propylene polymer grafted with maleic anhydride containing 150ppm free maleic anhydride as compatilizer.

Table 4: Mechanical and odor characteristics

The glass fiber reinforced composition of the present invention has a greatly improved odor, a high stiffness, and an improved toughness. It can meet typical odor requirements for car interior articles, and has a high melt flow rate suitable for improved processing. Thus, it can be also used for preparing thin wall automobile parts with low odor and high strength.

Claims

Glass fiber reinforced composition comprising

(a) from 50 to 80 wt. -％， based on the total weight of the composition， of a propylene homopolymers (H-PP) ， having a melt flow rate MFR₂ (230 ℃， 2.16 kg) measured according to ISO 1133 in the range from 5 to 70 g/10 min，

(b) from 15 to 35 wt. -％， based on the total weight of the composition， of glass fibers (GF) ，

(c) optionally from 3 to 10 wt. -％， based on the total weight of the composition， of an elastomeric ethylene copolymer (EC) comprising one or more comonomer units derived from C₄ to C₈ α-olefins，

(d) from 0.8 to 1.5 wt. -％， based on the total weight of the composition， of a polar modified polypropylene (PMP) as compatibilizer，

(e) from 0.5 to 1.5 wt. -％， based on the total weight of the composition， of one or more antioxidant (s) being free of sulphur atom (s) ，

(f) from 0.2 to 0.5 wt. -％， based on the total weight of the composition， of a demoulding agent， and

(g) from 0.5 to 2 wt. -％， based on the total weight of the composition， of one or more additives.
Glass fiber reinforced composition according to claim 1， wherein the propylene homopolymer (H-PP) has

a) a comonomer content of ≤ 2.0 wt. -％， based on the total weight of the propylene homopolymer (H-PP) ， and/or

b) a xylene cold soluble (XCS) content below 2.5 wt. -％， based on the total weight of the propylene homopolymer (H-PP) .
Glass fiber reinforced composition according to claim 1 or 2， wherein the propylene homopolymer (H-PP) is a mixture of at least two propylene homopolymers，

preferably two propylene homopolymers， more preferably the mixture comprises two propylene homopolymers and one propylene homopolymer (H-PP1) has a melt flow rate MFR₂ (230 ℃， 2.16 kg) measured according to ISO 1133 in the range from 5 to 30 g/10 min and the other propylene homopolymer (H-PP2) has a melt flow rate MFR₂ (230 ℃， 2.16 kg) measured according to ISO 1133 in the range from ＞ 30 to 70 g/10 min.
Glass fiber reinforced composition according to claim 3， wherein the mixture of two propylene homopolymers comprises the two propylene homopolymers in a weight ratio from 5∶1 to 1.2∶1， preferably from 3∶1 to 1.5∶1.
Glass fiber reinforced composition according to any one of the preceding claims 3 or 4， wherein the mixture of at least two propylene homopolymers comprises one propylene homopolymer being alpha-nucleated， preferably the propylene homopolymer (H-PP1) having a melt flow rate MFR₂ (230 ℃， 2.16 kg) measured according to ISO 1133 in the range from 5 to 30 g/10 min is alpha-nucleated.
Glass fiber reinforced composition according to any one of the preceding claims， wherein the glass fibers (GF) have a fiber average diameter in the range of 5 to 30 μm and/or an average fiber length from 0.1 to 20 mm.
Glass fiber reinforced composition according to any one of the preceding claims， wherein the elastomeric ethylene copolymer (EC)

a) comprises the one or more comonomer units in an amount from 20 to 40 wt. -％， based on the total weight of the elastomeric ethylene copolymer (EC) ， and/or

b) has a melt flow rate MFR₂ (190 ℃， 2.16 kg) in the range from 1 to 40 g/10 min.
Glass fiber reinforced composition according to any one 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， oxazoline and epoxides， and also ionic compounds.
Glass fiber reinforced composition according to any one of the preceding claims， wherein the polar modified polypropylene (PMP) is a propylene polymer grafted with maleic anhydride， preferably a propylene polymer grafted with maleic anhydride containing ≤ 100 ppm， based on the total weight of the polar modified polypropylene (PMP) ， of free maleic anhydride.
Glass fiber reinforced composition according to any one of the preceding claims， wherein the one or more antioxidant (s) is/are selected from phenolic antioxidants (AO) ， phosphorous-based antioxidants (AO) and mixtures thereof， preferably the phenolic antioxidant is a sterically hindered phenol (SHP) ， like 1， 3， 5-tris (3’， 5’-di-tert butyl-4’-hydroxybenzyl) -isocyanurate， or pentaerythrityl-tetrakis (3- (3’， 5’-di-tert butyl-4-hydroxyphenyl) -propionate， and/or the phosphorous-based antioxidant is tris (2， 4-di-t-butylphenyl) phosphite.
Glass fiber reinforced composition according to any one of the preceding claims， wherein the demoulding agent is free of glyceryl monostearate， more preferably free of alkane glyceryl ester.
Glass fiber reinforced composition according to any one of the preceding claims， wherein the demoulding agent is a silicone rubber.
Glass fiber reinforced composition according to any one of the preceding claims， wherein the composition is free of glyceryl monostearate， more preferably free of alkane glyceryl ester.
Automotive article comprising the glass fiber reinforced composition according to any one of the preceding claims.
Automotive article according to claim 14， wherein the automotive articles is a car interior article.
Process for the preparation of the glass fiber reinforced composition according to any one of the preceding claims 1 to 13 comprising the steps of adding

(a) from 50 to 80 wt. -％， based on the total weight of the composition， of a propylene homopolymer (H-PP) ， having a melt flow rate MFR₂ (230 ℃， 2.16 kg) measured according to ISO 1133 in the range from 5 to 70 g/10 min，

(b) from 15 to 3 5 wt. -％， based on the total weight of the composition， of glass fibers (GF) ，

(c) optionally from 3 to 10 wt. -％， based on the total weight of the composition， of an elastomeric ethylene copolymer (EC) comprising one or more comonomer units derived from C₄ to C₈ α-olefins，

(d) from 0.8 to 1.5 wt. -％， based on the total weight of the composition， of a polar modified polypropylene (PMP) as compatibilizer，

(e) from 0.5 to 1.5 wt. -％， based on the total weight of the composition， of one or more antioxidant (s) being free of sulphur atom (s) ，

(f) from 0.2 to 0.5 wt. -％， based on the total weight of the composition， of a demoulding agent， and

(g) from 0.5 to 2 wt. -％， based on the total weight of the composition， of one or more additives，

to an extruder and extruding the same obtaining said glass fiber reinforced composition.