RU2810213C1 - Glass-fibre composite - Google Patents

Abstract

FIELD: composite materials.

SUBSTANCE: fibre-reinforced composite for automotive products is proposed, containing, based on the fibre-reinforced composite, from 59 to 90 wt.% of polypropylene, from 9.0 to 40 wt.% of glass fibres having an average length from 2.0 to 10.0 nm, and from 0.05 to 5.0 wt.% of compatibilizer, which is a polar modified polypropylene, wherein the total amount of polypropylene, glass fibre and compatibilizer in the fibre-reinforced composite is at least 95 wt.%, and polypropylene is characterized by a melting point from 152 to 160°C, ethylene comonomer content not more than 0.5 wt.%, polydispersity coefficient from 1.0 to less than 4.0, presence of 2,1-regiodefects in the range of 0.10 to 0.90%; a method for manufacturing the proposed fibre-reinforced composite and an automobile product containing the proposed fibre-reinforced composite.

EFFECT: production of glass-fibre polypropylene composites that have rigidity and high resistance to thermal deformation with a low level of pollutant release.

13 cl, 3 tbl, 4 ex

Description

The invention relates to a fiber-reinforced composite containing polypropylene and glass fiber, to the production of the specified fiber-reinforced composite, as well as to products containing the specified fiber-reinforced composite.

Polypropylene is a material used in a wide variety of technical applications, and reinforced polypropylenes in particular have gained relevance in areas that previously relied exclusively on non-polymeric materials, particularly metals. One specific example of reinforced polypropylenes is glass fiber reinforced polypropylene composites. Such materials allow you to control the properties of composites by choosing the type of polypropylene, the amount of glass fiber, and sometimes choosing the type of compatibilizer used. Accordingly, glass fiber reinforced polypropylene composites are now well-established materials for applications requiring high stiffness, thermal deformation resistance and impact resistance (examples include automotive load-bearing components in the engine compartment, support parts for polymer body panels, washing machine components and dishwashers). However, one of the disadvantages of commercially produced fiber-reinforced polypropylene composites is the relatively high release of pollutants from them, caused by a fairly large number of oligomers obtained as a by-product during the polymerization process.

Accordingly, there is a need for glass fiber reinforced polypropylene composites to be rigid and have fairly high resistance to thermal deformation coupled with low emission of pollutants.

The discovery of this invention is that the fiber reinforced polypropylene composite should contain polypropylene having a narrow molecular weight distribution and a relatively high melting point. It is preferable that the polypropylene has not been visbroken, that is, not modified in a radical-initiated process to reduce molecular weight.

Accordingly, this invention relates to a fiber reinforced polypropylene composite containing

(a) from 59 to 90 mass. %, based on fiber reinforced composite, polypropylene,

(b) from 9.0 to 40 wt. %, based on fiber reinforced composite, glass fiber, and

(c) from 0.05 to 5.0 wt. %, based on fiber-reinforced composite, compatibilizer,

where also

the total amount of polypropylene, glass fiber and compatibilizer in the fiber reinforced composite is at least 95 wt. %, while additionally polypropylene has

(i) melting point Tm, determined by DSC in accordance with ISO 11357-3 (heating and cooling rate 10°C/min), from 152 to 160°C,

(ii) the comonomer content, determined by ¹³ C-NMR spectroscopy, is not more than 0.5 wt. %, with the comonomer being ethylene,

(iii) a molecular weight distribution (MWD), determined by gel permeation chromatography (GPC), from 1.0 to less than 4.0, and

(iv) 2,1-regiodefects determined by ¹³ C-NMR spectroscopy, from 0.10 to 0.90%.

This invention particularly relates to a fiber reinforced polypropylene composite consisting of

(a) from 59 to 90 mass. %, based on fiber reinforced composite, propylene homopolymer,

(b) from 9.0 to 40 wt. %, based on fiber reinforced composite, glass fibers,

(c) from 0.05 to 5.0 wt. %, based on the fiber reinforced composite, compatibilizer, and

(d) from 0.1 to 5.0 wt. %, based on fiber reinforced composite, additives, where also

propylene homopolymer has

(i) melting point Tm, determined by DSC in accordance with ISO 11357-3 (heating and cooling rate 10°C/min), from 152 to 160°C,

(ii) comonomer content, determined by ¹³ C-NMR spectroscopy, not more than 0.5 wt. %, with the comonomer being ethylene,

(iii) a molecular weight distribution (MWD), determined by gel permeation chromatography (GPC), from 1.0 to less than 4.0, and

(iv) 2,1-regiodefects determined by ¹³ C-NMR spectroscopy, from 0.10 to 0.90%.

Preferred embodiments of the fiber reinforced composite are defined in the dependent claims.

The invention also relates to a method for making a fiber reinforced composite as defined herein, comprising the steps of adding

(a) polypropylene,

(b) fiberglass,

(c) a compatibilizer, and

(d) possibly additives

into an extruder and extruding these components to produce said fiber-reinforced composite.

Preferably, the polypropylene according to the invention is obtained by polymerizing propylene and optionally ethylene, more preferably propylene only, in the presence of a metallocene catalyst having formula (I)

where each of the R ¹ , which are independently the same or may be different, represents hydrogen or a linear or branched C ₁ -C ₆ alkyl group, and at least one R ¹ per phenyl group is not hydrogen,

R' represents a C ₁ -C ₁₀ hydrocarbyl group, preferably a C ₁ -C ₄ hydrocarbyl group and more preferably a methyl group and

X independently represents a hydrogen atom, a halogen atom, a C ₁ -C ₆ alkoxy group, a C ₁ -C ₆ alkyl group, a phenyl or a benzyl group.

Most preferably, X is chlorine, benzyl or a methyl group. It is preferable that both X groups be the same. The most preferred options are two chlorides, two methyl or two benzyl groups, especially two chlorides.

In addition, the invention relates to a product, preferably an automobile product, containing at least 90 wt. % fiber reinforced composite according to this invention.

The invention is described in more detail below.

Fiber reinforced composite

The invention relates to a fiber-reinforced composite containing polypropylene, glass fiber and a compatibilizer. It should be understood that fiber reinforced composite is known in the art. That is, polypropylene forms a continuous phase into which glass fibers are embedded. In case the glass fibers are short glass fibers, the fibers are dispersed in polypropylene, wherein the polypropylene plays the role of a continuous phase. The compatibilizer improves adhesion between non-polar polypropylene and polar glass fibers.

Accordingly, the invention provides a fiber reinforced polypropylene composite containing

(a) from 59 to 90 mass. %, based on fiber reinforced composite, polypropylene,

(b) from 9.0 to 40 wt. %, based on fiber reinforced composite, glass fiber, and

(c) from 0.05 to 5.0 wt. %, based on fiber-reinforced composite, compatibilizer,

where also

the total amount of polypropylene, glass fiber and compatibilizer in the fiber reinforced composite is at least 95 wt. %, preferably at least 98 wt. %.

In addition to these three components, typical additives may be present, which, for example, are added to increase the service life of polypropylene, that is, antioxidants (see definition of additives below).

Thus, in a preferred embodiment, the fiber reinforced composite of the present invention preferably comprises

(a) from 59 to 90 mass. %, based on fiber reinforced composite, polypropylene,

(b) from 9.0 to 40 wt. %, based on fiber reinforced composite, glass fibers,

(c) from 0.05 to 5.0 wt. %, based on the fiber reinforced composite, compatibilizer, and

(d) from 0.1 to 5.0 wt. %, based on fiber reinforced composite, additives, where also

the total amount of polypropylene, glass fiber, compatibilizer and additives in the fiber reinforced composite is at least 98 wt. %, preferably from 98 to 100 wt. %, for example from 99 to 100 wt. %.

The fiber reinforced composite preferably does not contain an elastomeric polymer. An elastomeric polymer is defined as a polymer that does not form a continuous phase within polypropylene. In other words, the elastomeric polymer is dispersed in the polypropylene, that is, it forms inclusions in the polypropylene. A polymer containing an elastomeric polymer in the form of inclusions as a second phase, in contrast, should be called heterophasic, and preferably does not form part of this invention. The presence of second phases or so-called inclusions is visible, for example, using high-resolution microscopy such as electron microscopy or atomic force microscopy, or using dynamic mechanical thermal analysis (DMTA). In particular, with DMTA, the presence of a multiphase structure can be identified by the presence of at least two different glass transition temperatures.

Therefore, in a specific embodiment, the fiber-reinforced composite according to the present invention preferably consists of

(a) from 59 to 90 mass. %, based on fiber reinforced composite, polypropylene,

(b) from 9.0 to 40 wt. %, based on fiber reinforced composite, glass fibers,

(c) from 0.05 to 5.0 wt. %, based on the fiber reinforced composite, compatibilizer, and

(d) from 0.1 to 5.0 wt. %, based on fiber reinforced composite, additives. The fiber reinforced composite according to the present invention is especially

has a low level of pollutant emissions. Accordingly, preferably the fiber reinforced composite has a VOC (volatile organic compound) value, determined in accordance with VDA 278, October 2011, below 12 μg/g, more preferably from 0.5 to 10 μg/g, even more preferably from 0 .8 to 8.0 µg/g.

In addition or alternative to the requirement of the previous paragraph, the fiber reinforced composite has a FOG value (low volatile or condensable organic compounds), determined in accordance with VDA 278, October 2011, below 75 µg/g, more preferably from 10 to 70 µg/g, even more preferably from 15 to 65 μg/g.

Furthermore, preferably the fiber reinforced composite has a tensile modulus, determined on injection molded specimens in accordance with ISO 527-1 at 1 mm/min, of 3500 to 7000 MPa, more preferably 3800 to 6500 MPa, e.g. from 4000 to 6300 MPa. In addition, the fiber reinforced composite preferably has an elongation at break in the same tensile test of greater than 2.0%, more preferably 2.1 to 10.0%, such as 2.2 to 8.0%.

In addition or alternative to the requirement of the previous paragraph, the fiber reinforced composite has a Charpy impact strength, determined in accordance with ISO 179-1eU at 23°C, from 30.0 to 75.0 kJ/m ² , more preferably from 35.0 to 70.0 kJ/ ^m2 , for example from 40.0 to 65.0 kJ/ ^m2 .

In a very specific embodiment, the fiber reinforced composite has a thermal distortion temperature (TST), measured in accordance with ISO 75 V at a load of 0.46 MPa, from 146 to 160°C, more preferably from 148 to 158°C, for example from 150 to 156°C.

Polypropylene

An essential component of this invention is polypropylene, which must be carefully selected to achieve the desired properties. Accordingly, the polypropylene of this invention requires a specific melting point and a fairly narrow molecular weight distribution (MWD).

Moreover, the polypropylene of this invention is prepared in the presence of a specific metallocene catalyst, as defined in more detail below. Unlike polypropylenes obtained in the presence of Ziegler-Natta catalysts, polypropylenes obtained in the presence of metallocene catalysts are characterized by incorrect introduction of monomer units during the polymerization process. Therefore, the polypropylene according to this invention has a certain amount of 2,1-regiodefects. That is, the polypropylene of this invention has 2,1-regiodefects from 0.10 to 0.90%, more preferably from 0.15 to 0.80%, determined by ¹³ C-NMR spectroscopy.

Accordingly, the polypropylene according to this invention has

(i) melting point Tm, determined by DSC in accordance with ISO 11357-3 (heating and cooling rate 10°C/min), from 152 to 160°C,

(ii) the comonomer content, determined by ¹³ C-NMR spectroscopy, is not more than 0.5 wt. %, with the comonomer being ethylene,

(iii) a molecular weight distribution (MWD), determined by gel permeation chromatography (GPC), from 1.0 to less than 4.0, and

(iv) 2,1-regiodefects determined by ¹³ C-NMR spectroscopy, from 0.10 to 0.90%.

More preferably, the polypropylene according to this invention has

(i) melting point Tm determined by DSC in accordance with ISO 11357-3 (heating and cooling rate 10°C/min), in the range from 153 to 159°C,

(ii) the comonomer content, determined by ¹³ C-NMR spectroscopy, is not more than 0.5 wt. %, with the comonomer being ethylene,

(iii) molecular weight distribution (MWD), determined by gel permeation chromatography (GPC), from 1.6 to less than 3.8, and

(iv) 2,1-regiodefects determined by ¹³ C-NMR spectroscopy, from 0.15 to 0.80%.

Particularly preferably, the polypropylene is single-phase, that is, it does not contain polymer components that do not mix with each other, as is the case with heterophasic propylene copolymers. As stated above, unlike single-phase systems, heterophasic systems contain a continuous polymer phase, like polypropylene, in which another immiscible polymer, like an elastomeric polymer, is dispersed as inclusions. These polypropylene systems containing a polypropylene matrix and inclusions as a second polymer phase, on the contrary, should be called heterophasic and preferably do not form part of this invention. The presence of second polymer phases or so-called inclusions is, for example, visible using high-resolution microscopy, such as electron microscopy or atomic force microscopy, or by dynamic mechanical thermal analysis (DMTA). In particular, with DMTA, the presence of a multiphase structure can be identified by the presence of at least two different glass transition temperatures.

Therefore, the polypropylene according to this invention is preferably a single-phase polypropylene having

(i) melting point Tm determined by DSC in accordance with ISO 11357-3 (heating and cooling rate 10°C/min), in the range from 152 to 160°C,

(ii) the comonomer content, determined by ¹³ C-NMR spectroscopy, is not more than 0.5 wt. %, with the comonomer being ethylene,

(iii) a molecular weight distribution (MWD), determined by gel permeation chromatography (GPC), from 1.0 to less than 4.0, and

(iv) 2,1-regiodefects determined by ¹³ C-NMR spectroscopy, from 0.10 to 0.90%.

Even more preferably, the polypropylene according to this invention is a single-phase polypropylene having

(i) melting point Tm, determined by DSC in accordance with ISO 11357-3 (heating and cooling rate 10°C/min), from 153 to 159°C,

(ii) the comonomer content, determined by ¹³ C-NMR spectroscopy, is not more than 0.5 wt. %, wherein the comonomer is ethylene, and

(iii) molecular weight distribution (MWD), determined by gel permeation chromatography (GPC), from 1.6 to less than 3.8, and

(iv) 2,1-regiodefects determined by ¹³ C-NMR spectroscopy, from 0.15 to 0.80%.

Particularly preferably, the single-phase polypropylene is a propylene homopolymer. A propylene homopolymer cannot, by definition, be heterophasic since it simply contains propylene polymer chains. In other words, the propylene homopolymer according to the present invention is always a single-phase polymer.

Therefore, preferably the single-phase polypropylene according to the invention is a propylene homopolymer having

(i) melting point Tm, determined by DSC in accordance with ISO 11357-3 (heating and cooling rate 10°C/min), from 152 to 160°C,

(ii) a molecular weight distribution (MWD), determined by gel permeation chromatography (GPC), from 1.0 to less than 4.0, and

(iii) 2,1-regiodefects determined by ¹³ C-NMR spectroscopy, from 0.10 to 0.90%.

Even more preferably, the single-phase polypropylene is a propylene homopolymer having

(i) melting point Tm determined by DSC in accordance with ISO 11357-3 (heating and cooling rate 10°C/min), in the range from 153 to 159°C,

(ii) molecular weight distribution (MWD), determined by gel permeation chromatography (GPC), from 1.6 to less than 3.8, and

(iii) 2,1-regiodefects determined by ¹³ C-NMR spectroscopy, from 0.15 to 0.80%.

As noted above, it is particularly preferred when the single-phase polypropylene is a propylene homopolymer. Accordingly, single-phase polypropylene, which is a propylene homopolymer, has

(i) melting point Tm, determined by DSC in accordance with ISO 11357-3 (heating and cooling rate 10°C/min), from 152 to 160°C,

(ii) 2,1-regiodefects ranging from 0.10 to 0.90% determined by ¹³ C-NMR spectroscopy, and

(iii) molecular weight distribution (MWD), determined by gel permeation chromatography (GPC), from 1.0 to less than 4.0.

Even more preferably, the single-phase polypropylene is a propylene homopolymer having

(i) melting point Tmelting temperature determined by DSC in accordance with ISO 11357-3 (heating and cooling rate 10°C/min), e from 153 to 159°C,

(ii) 2,1-regiodefects ranging from 0.15 to 0.80% determined by ¹³ C-NMR spectroscopy, and

(iii) molecular weight distribution (MWD), determined by gel permeation chromatography (GPC), from 1.6 to less than 3.8.

The polypropylene of this invention also preferably has a very low cold xylene solutes (CXS) content, which cannot be achieved using Ziegler-Natta catalysts. Thus, in a preferred embodiment, the polypropylene, more preferably single-phase polypropylene, according to this invention has a cold xylene solubles (CSCS) proportion, measured according to ISO 16152 (25°C), from 0.05 to 1.00 wt. %, more preferably from 0.10 to 0.90 wt. %, for example from 0.15 to 0.85 wt. %.

Accordingly, it is preferable

(a) polypropylene, more preferably single-phase polypropylene, has

(i) melting point Tm, determined by DSC in accordance with ISO 11357-3 (heating and cooling rate 10°C/min), from 152 to 160°C,

(ii) the comonomer content, determined by ¹³ C-NMR spectroscopy, is not more than 0.5 wt. %, with the comonomer being ethylene,

(iii) the proportion of cold xylene solubles (CSCS), measured in accordance with ISO 16152 (25°C), from 0.05 to 1.00 mass. %, And

(iv) molecular weight distribution (MWD), determined by gel permeation chromatography (GPC), from 1.0 to less than 4.0, or

(b) polypropylene, more preferably single-phase polypropylene, has

(i) melting point Tm, determined by DSC in accordance with ISO 11357-3 (heating and cooling rate 10°C/min), from 152 to 160°C,

(ii) the comonomer content, determined by ¹³ C-NMR spectroscopy, is not more than 0.5 wt. %, with the comonomer being ethylene,

(iii) 2,1-regiodefects from 0.10 to 0.90%, determined by ¹³ C-NMR spectroscopy,

(iv) the proportion of cold xylene solubles (CSCS), measured in accordance with ISO 16152 (25°C), from 0.05 to 1.00 wt. %, And

(v) molecular weight distribution (MWD), determined by gel permeation chromatography (GPC), ranging from 1.0 to less than 4.0.

Even more preferable

(a) polypropylene, preferably single-phase polypropylene, according to this invention has

(i) melting point Tm determined by DSC in accordance with ISO 11357-3 (heating and cooling rate 10°C/min) from 153 to 159°C,

(ii) the comonomer content, determined by ¹³ C-NMR spectroscopy, is not more than 0.5 wt. %, with the comonomer being ethylene,

(iii) the proportion of cold xylene solubles (CSCS), measured in accordance with ISO 16152 (25°C), from 0.05 to 1.00 mass. %, And

(iv) molecular weight distribution (MWD), determined by gel permeation chromatography (GPC), from 1.6 to less than 3.8,

or

(b) polypropylene, preferably single-phase polypropylene, according to this invention has

(i) melting point Tm, determined by DSC in accordance with ISO 11357-3 (heating and cooling rate 10°C/min), from 153 to 159°C,

(ii) the comonomer content, determined by ¹³ C-NMR spectroscopy, is not more than 0.5 wt. %, with the comonomer being ethylene,

(iii) 2,1-regiodefects from 0.15 to 0.80%, determined by ¹³ C-NMR spectroscopy,

(iv) the proportion of cold xylene solubles (CSCS), measured in accordance with ISO 16152 (25°C), from 0.05 to 1.00 wt. %, And

(v) molecular weight distribution (MWD), determined by gel permeation chromatography (GPC), from 1.6 to less than 3.8.

As noted above, it is particularly preferable that the single-phase polypropylene is a propylene homopolymer. Accordingly, single-phase polypropylene, which is a propylene homopolymer, has

(i) melting point Tm, determined by DSC in accordance with ISO 11357-3 (heating and cooling rate 10°C/min), from 152 to 160°C,

(ii) the proportion of cold xylene solubles (CSCS), measured in accordance with ISO 16152 (25°C), from 0.10 to 0.90 wt. -%, And

(iii) molecular weight distribution (MWD), determined by gel permeation chromatography (GPC), from 1.0 to less than 4.0.

Even more preferably, the propylene homopolymer has

(i) melting point Tm, determined by DSC in accordance with ISO 11357-3 (heating and cooling rate 10°C/min), from 152 to 160°C,

(ii) 2,1-regiodefects from 0.10 to 0.90%, determined by ¹³ C-NMR spectroscopy,

(iii) the proportion of cold xylene solubles (CSCS), measured in accordance with ISO 16152 (25°C), from 0.10 to 0.90 wt. %, And

(iv) molecular weight distribution (MWD), determined by gel permeation chromatography (GPC), from 1.0 to less than 4.0.

In a very preferred embodiment, the present invention is directed to a propylene homopolymer having

(i) melting point Tm, determined by DSC in accordance with ISO 11357-3 (heating and cooling rate 10°C/min), from 153 to 159°C,

(ii) the proportion of cold xylene solubles (CSCS), measured in accordance with ISO 16152 (25°C), from 0.10 to 0.90 wt. %, And

(iii) molecular weight distribution (MWD), determined by gel permeation chromatography (GPC) from 1.6 to less than 3.8.

Accordingly, it is particularly preferred that the propylene homopolymer has

(i) melting point Tm, determined by DSC in accordance with ISO 11357-3 (heating and cooling rate 10°C/min), from 153 to 159°C,

(ii) 2,1-regiodefects in the range from 0.15 to 0.80%, determined by ¹³ C-NMR spectroscopy,

(iii) the proportion of cold xylene solubles (CSCS), measured in accordance with ISO 16152 (25°C), from 0.10 to 0.90 wt. %, And

(iv) molecular weight distribution (MWD), determined by gel permeation chromatography (GPC), ranging from 1.6 to less than 3.8.

In addition, preferably the polypropylene according to this invention has a certain molecular weight. Accordingly, preferably the polypropylene according to the present invention has a melt flow index MFR ₂ (230°C, 2.16 kg), measured according to ISO 1133, from 5.0 to 500 g/10 min, preferably from 5.5 to 300 g/10 min , more preferably from 6.0 to 250 g/10 min.

Therefore, preferably polypropylene, more preferably single-phase polypropylene, has

(i) melting point Tm, determined by DSC in accordance with ISO 11357-3 (heating and cooling rate 10°C/min), from 152 to 160°C,

(ii) the comonomer content, determined by ¹³ C-NMR spectroscopy, is not more than 0.5 wt. %, with the comonomer being ethylene,

(iii) the proportion of cold xylene solubles (CSCS), measured in accordance with ISO 16152 (25°C), from 0.05 to 1.00 mass. %,

(iv) melt flow index PTR ₂ (230°C, 2.16 kg), measured in accordance with ISO 1133, from 5.0 to 500 g/10 min, and

(v) molecular weight distribution (MWD), determined by gel permeation chromatography (GPC), from 1.0 to less than 4.0.

In a specific embodiment, the polypropylene, preferably single-phase polypropylene, according to this invention has

(i) melting point Tm, determined by DSC in accordance with ISO 11357-3 (heating and cooling rate 10°C/min), from 153 to 159°C,

(ii) the comonomer content, determined by ¹³ C-NMR spectroscopy, is not more than 0.5 wt. %, with the comonomer being ethylene,

(iii) 2,1-regiodefects from 0.15 to 0.80%, determined by ¹³ C-NMR spectroscopy,

(iv) the proportion of cold xylene solubles (CSCS), measured in accordance with ISO 16152 (25°C), from 0.05 to 1.00 wt. %,

(v) melt flow index PTR ₂ (230°C, 2.16 kg), measured in accordance with ISO 1133, from 5.0 to 500 g/10 min, and

(vi) molecular weight distribution (MWD), determined by gel permeation chromatography (GPC), from 1.6 to less than 3.8.

As noted above, it is particularly preferable that the single-phase polypropylene is a propylene homopolymer. Accordingly, preferably single-phase polypropylene, which is a homopolymer of propylene, has

(i) melting point Tm, determined by DSC in accordance with ISO 11357-3 (heating and cooling rate 10°C/min), from 153 to 159°C,

(ii) the proportion of cold xylene solubles (CSCS), measured in accordance with ISO 16152 (25°C), from 0.10 to 0.90 wt. %,

(iii) melt flow index PTR ₂ (230°C, 2.16 kg), measured in accordance with ISO 1133, from 5.0 to 500 g/10 min, and

(iv) molecular weight distribution (MWD), determined by gel permeation chromatography (GPC), from 1.6 to less than 3.8.

Accordingly, it is particularly preferable that the propylene homopolymer has

(i) melting point Tm, determined by DSC in accordance with ISO 11357-3 (heating and cooling rate 10°C/min), from 153 to 159°C,

(ii) 2,1-regiodefects from 0.15 to 0.80%, determined by ¹³ C-NMR spectroscopy,

(iii) the proportion of cold xylene solubles (CSCS), measured in accordance with ISO 16152 (25°C), from 0.10 to 0.90 wt. %,

(iv) melt flow index PTR ₂ (230°C, 2.16 kg), measured in accordance with ISO 1133, from 5.0 to 500 g/10 min, and

(v) molecular weight distribution (MWD), determined by gel permeation chromatography (GPC), from 1.6 to less than 3.8.

As noted above, preferably the polypropylene of the invention is produced using a specific metallocene catalyst. Accordingly, in a preferred embodiment, polypropylene, more preferably single-phase polypropylene, is obtained by polymerizing propylene and optionally ethylene in the presence of a metallocene catalyst having formula (I)

where each of the R ¹ , which are independently the same or may be different, represents hydrogen or a linear or branched C ₁ -C ₆ alkyl group, and at least one R ¹ per phenyl group is not hydrogen,

R' represents a C ₁ -C ₁₀ hydrocarbyl group, preferably a C ₁ -C ₄ hydrocarbyl group and more preferably a methyl group and

X independently represents a hydrogen atom, a halogen atom, a C ₁ -C ₆ alkoxy group, a C ₁ -C ₆ alkyl group, a phenyl or a benzyl group.

Below, the term “formula (I)” means a metallocene catalyst as defined in the previous paragraph.

Therefore, it is particularly preferable that polypropylene, more preferably single-phase polypropylene, has

(i) melting point Tm, determined by DSC in accordance with ISO 11357-3 (heating and cooling rate 10°C/min), from 152 to 160°C,

(ii) the comonomer content, determined by ¹³ C-NMR spectroscopy, is not more than 0.5 wt. %, with the comonomer being ethylene,

(iii) 2,1-regiodefects from 0.10 to 0.90%, determined by ¹³ C-NMR spectroscopy,

(iv) the proportion of cold xylene solubles (CSCS), measured in accordance with ISO 16152 (25°C), from 0.05 to 1.00 wt. %,

(v) melt flow index PTR ₂ (230°C, 2.16 kg), measured in accordance with ISO 1133, from 5.0 to 500 g/10 min, and

(vi) molecular weight distribution (MWD), determined by gel permeation chromatography (GPC), from 1.0 to less than 4.0,

wherein the polypropylene, more preferably single-phase polypropylene, is obtained by polymerizing propylene and optionally ethylene in the presence of a metallocene catalyst having formula (I) as defined above.

Even more preferably polypropylene, preferably monophasic polypropylene, according to the invention has

(i) melting point Tm, determined by DSC in accordance with ISO 11357-3 (heating and cooling rate 10°C/min), from 153 to 159°C,

(ii) the comonomer content, determined by ¹³ C-NMR spectroscopy, is not more than 0.5 wt. %, with the comonomer being ethylene,

(iii) 2,1-regiodefects from 0.15 to 0.80%, determined by ¹³ C-NMR spectroscopy,

(iv) the proportion of cold xylene solubles (CSCS), measured in accordance with ISO 16152 (25°C), from 0.05 to 1.00 wt. %,

(v) melt flow index PTR ₂ (230°C, 2.16 kg), measured in accordance with ISO 1133, from 5.0 to 500 g/10 min, and

(vi) molecular weight distribution (MWD), determined by gel permeation chromatography (GPC), from 1.6 to less than 3.8,

wherein polypropylene, more preferably single-phase polypropylene, is produced by polymerization of propylene and optionally ethylene in the presence of a metallocene catalyst having formula (I) as defined above.

In a particular preferred embodiment, the single-phase polypropylene is a propylene homopolymer. Accordingly, preferably the propylene homopolymer has

(i) melting point Tm, determined by DSC in accordance with ISO 11357-3 (heating and cooling rate 10°C/min), from 153 to 159°C,

(ii) 2,1-regiodefects from 0.15 to 0.80%, determined by ¹³ C-NMR spectroscopy,

(iii) the proportion of cold xylene solubles (CSCS), measured in accordance with ISO 16152 (25°C), from 0.10 to 0.90 wt. %,

(iv) melt flow index PTR ₂ (230°C, 2.16 kg), measured in accordance with ISO 1133, from 5.0 to 500 g/10 min, and

(v) molecular weight distribution (MWD), determined by gel permeation chromatography (GPC), from 1.6 to less than 3.8,

wherein the propylene homopolymer is obtained by polymerizing propylene in the presence of a metallocene catalyst having formula (I) as defined above.

Moreover, preferably the polypropylene is not visbreaked. Visbreaking, or controlled degradation by a radical-initiated process initiated by peroxides or other radical sources, is typically used to increase melt flow index and thus reduce molecular weight and narrow molecular weight distribution. However, destruction, that is, visbreaking, of the polymer occurs when peroxides are used. Visbreaking, as well as the use of peroxides, can increase pollutant emission values (in terms of VOCs or FOG) due to an undesirable side reaction leading to an increase in the number of oligomers. In addition, the presence of peroxides can cause unwanted discoloration of polypropylene. In other words, whether polypropylene has been visbroken can be identified by the decomposition products of peroxides or other radical sources, as well as by discoloration of the polypropylene. Therefore, whenever the term “visbroken-free” or “not visbroken” is used, it is understood that the melt flow index, molecular weight and molecular weight distribution of the polypropylene have not been altered by chemical or physical treatment and, in addition, the polypropylene is free from degradation products peroxides or other sources of radicals.

Accordingly, preferably the polypropylene has not been visbroken and has

(i) melting point Tm, determined by DSC in accordance with ISO 11357-3 (heating and cooling rate 10°C/min), from 152 to 160°C,

(ii) the comonomer content, determined by ¹³ C-NMR spectroscopy, is not more than 0.5 wt. %, with the comonomer being ethylene,

(iii) 2,1-regiodefects from 0.10 to 0.90%, determined by ¹³ C-NMR spectroscopy,

(iv) the proportion of cold xylene solubles (CSCS), measured in accordance with ISO 16152 (25°C), from 0.05 to 1.00 wt. %,

(v) melt flow index PTR ₂ (230°C, 2.16 kg), measured in accordance with ISO 1133, from 5.0 to 500 g/10 min, and

(vi) molecular weight distribution (MWD), determined by gel permeation chromatography (GPC), from 1.0 to less than 4.0,

wherein the polypropylene is optionally obtained by polymerizing propylene and optionally ethylene in the presence of a metallocene catalyst having formula (I) as defined above.

Even more preferably, the polypropylene according to the previous paragraph is non-visbreaked single-phase polypropylene.

Even more preferably, the single-phase polypropylene of this invention is a non-visbroken single-phase polypropylene having

(i) melting point Tm, determined by DSC in accordance with ISO 11357-3 (heating and cooling rate 10°C/min), from 153 to 159°C,

(ii) the comonomer content, determined by ¹³ C-NMR spectroscopy, is not more than 0.5 wt. %, with the comonomer being ethylene,

(iii) 2,1-regiodefects from 0.15 to 0.80%, determined by ¹³ C-NMR spectroscopy,

(iv) the proportion of cold xylene solubles (CSCS), measured in accordance with ISO 16152 (25°C), from 0.05 to 1.00 wt. %,

(v) melt flow index PTR ₂ (230°C, 2.16 kg), measured in accordance with ISO 1133, from 5.0 to 500 g/10 min, and

(vi) molecular weight distribution (MWD), determined by gel permeation chromatography (GPC), from 1.6 to less than 3.8,

wherein the non-visbreaked single-phase polypropylene is produced by polymerizing propylene and optionally ethylene in the presence of a metallocene catalyst having formula (I) as defined above.

More preferably, the single-phase polypropylene of this invention is a non-visbreaked propylene homopolymer. Accordingly, preferably the non-visbroken propylene homopolymer of the present invention has

(i) melting point Tm, determined by DSC in accordance with ISO 11357-3 (heating and cooling rate 10°C/min), from 153 to 159°C,

(ii) 2,1-regiodefects from 0.15 to 0.80%, determined by ¹³ C-NMR spectroscopy,

(iii) the proportion of cold xylene solubles (CSCS), measured in accordance with ISO 16152 (25°C), from 0.10 to 0.90 wt. %,

(iv) melt flow index PTR ₂ (230°C, 2.16 kg), measured in accordance with ISO 1133, from 5.0 to 500 g/10 min, and

(v) molecular weight distribution (MWD), determined by gel permeation chromatography (GPC), from 1.6 to less than 3.8,

wherein the optionally non-visbroken propylene homopolymer is obtained by polymerizing propylene in the presence of a metallocene catalyst having formula (I) as defined above.

The following describes in detail the polymerization to produce polypropylene.

The polypropylene according to this invention can be produced in a single reactor or in a reactor cascade of two or more reactors, preferably two reactors. Polymerization processes suitable for producing polypropylene according to this invention are known in the art. They include at least one polymerization step, where the polymerization is usually carried out in solution, suspension, bulk or gas phase. Typically, the polymerization process includes additional polymerization steps or reactors. In one particular embodiment, the method includes at least one bulk polymerization reactor zone and optionally at least one gas phase reactor zone, each zone containing at least one reactor and all reactors arranged in cascade. In one particularly preferred embodiment, the polymerization process includes at least one bulk polymerization reactor and optionally at least one gas phase reactor, arranged in this order. The process may further include pre- and post-reactors. Pre-reactors typically include pre-polymerization reactors. In these types of processes, it is preferable to use higher polymerization temperatures to achieve the special properties of the polymer. Typical temperatures in these processes are 70°C or higher, preferably 75°C or higher. Higher polymerization temperatures, as noted above, can be used in some or all of the reactors of the reactor cascade.

A preferred multi-stage process is a loop reactor-gas phase reactor process such as that developed by Borealis (known as BORSTAR® technology), described for example in patent literature such as EP 0887379, WO 92/12182, WO 2004/000899, WO 2004/111095, WO 99/24478, WO 99/24479 or WO 00/68315. Another suitable slurry-gas phase process is the Spheripol® process from Basell.

As noted above, the polypropylene according to this invention is particularly produced by a polymerization process using a metallocene catalyst having formula (I)

where each of the R ¹ , which are independently the same or may be different, represents hydrogen or a linear or branched C ₁ -C ₆ alkyl group, and at least one R ¹ per phenyl group is not hydrogen,

R' represents a C ₁ -C ₁₀ hydrocarbyl group, preferably a C ₁ -C ₄ hydrocarbyl group and more preferably a methyl group and

X independently represents a hydrogen atom, a halogen atom, a C ₁ -C ₆ alkoxy group, a C ₁ -C ₆ alkyl group, a phenyl or a benzyl group.

Most preferably, X is chlorine, benzyl or a methyl group. Preferably both groups X are the same. The most preferred options are two chlorides, two methyl or two benzyl groups, especially two chlorides.

Specific preferred metallocene catalysts according to the invention include:

rac-anti-dimethylsilanediyl[2-methyl-4,8-bis-(4'-tert-butylphenyl)-1,5,6,7-tetrahydro-8-indacen-1-yl][2-methyl-4- (3',5'-dimethylphenyl)-5-methoxy-6-tert-butylinden-1-yl]zirconium dichloride

rac-anti-dimethylsilanediyl[2-methyl-4,8-bis-(3',5'-dimethylphenyl)-1,5,6,7-tetrahydro-8-indacen-1-yl][2-methyl-4 -(3',5'-dimethylphenyl)-5-methoxy-6-tert-butylinden-1-yl]zirconium dichloride

rac-anti-dimethylsilanediyl[2-methyl-4,8-bis-(3',5'-dimethylphenyl)-1,5,6,7-tetrahydro-8-indacen-1-yl][2-methyl-4 -(3',5'-ditert-butylphenyl)-5-methoxy-6-tert-butylinden-1-yl]zirconium dichloride

or their corresponding zirconium dimethyl analogues.

The most preferred catalyst is rac-anti-dimethylsilanediyl[2-methyl-4,8-bis-(3',5'-dimethylphenyl)-1,5,6,7-tetrahydro-8-indacen-1-yl][2 -methyl-4-(3',5'-dimethylphenyl)-5-methoxy-6-tert-butylinden-1-yl]zirconium dichloride

The ligands needed to form the complexes and hence the catalysts of the invention can be synthesized by any method, and a skilled organic chemist is able to develop various synthetic protocols for the preparation of the required ligand materials. For example, WO 2007/116034 describes the required chemistry. Synthesis protocols can also generally be found in WO 2002/02576, WO 2011/135004, WO 2012/084961, WO 2012/001052, WO 2011/076780, WO 2015/158790 and WO 2018/122134. Of particular note is WO 2019/179959, which describes the most preferred catalyst of this invention. The examples section also provides sufficient guidance to the qualified person.

Cocatalyst

To form the active catalytic molecule it is generally necessary to use a cocatalyst, as is well known in the art.

According to the present invention, a cocatalyst system containing a boron cocatalyst and/or an alumoxane cocatalyst is used in combination with a metallocene catalyst complex as defined above.

The aluminoxane co-catalyst may be a co-catalyst of formula (III):

where n is typically between 6 and 20, and R has the meaning given below.

Alumoxanes are obtained by partial hydrolysis of organoaluminum compounds, for example compounds of the formula AlR ₃ , AlR ₂ Y and Al ₂ R ₃ Y ₃ , where R can be, for example, C ₁ -C ₁₀ -alkyl, preferably C ₁ -C ₃ -alkyl, or C ₃ -C ₁₀ -cycloalkyl, C ₇ -C ₁₂ -arylalkyl or -alkylaryl and/or phenyl or naphthyl, and where Y may be hydrogen, halogen, preferably chlorine or bromine, or C ₁ -C ₁₀ -alkoxyl, preferably methoxyl or ethoxyl. The resulting oxygen-containing alumoxanes are generally not pure compounds, but mixtures of oligomers of formula (III).

A preferred alumoxane is methylaluminoxane (MAO). Since the alumoxanes used according to the invention as co-catalysts are not, due to their method of preparation, pure compounds, the molarity of the alumoxane solutions is further based on their aluminum content.

According to the present invention, instead of an alumoxane co-catalyst, a boron-containing co-catalyst can also be used, or an aluminoxane co-catalyst can be used in combination with a boron-containing catalyst.

One skilled in the art will appreciate that when boron-based cocatalysts are used, it is common to pre-alkylate the complex by reacting it with an alkylaluminum compound such as triisobutylaluminum (TIBA). This procedure is well known and any suitable aluminum alkyl can be used, for example Al(C ₁ -C ₆ alkyl) ₃ . Preferred alkylaluminum compounds are triethylaluminum, triisobutyl aluminum, triisohexyl aluminum, tri-n-octylaluminum and triisooctylaluminum.

Alternatively, when a borate cocatalyst is used, the metallocene catalyst complex is in its alkylated form, that is, for example, a dimethyl or dibenzyl metallocene catalyst complex can be used.

Boron-based cocatalysts of interest include cocatalysts of formula (IV)

BY ₃ (IV)

where Y are the same or different and represent a hydrogen atom, an alkyl group of 1 to about 20 carbon atoms, an aryl group of 6 to about 15 carbon atoms, an alkylaryl, arylalkyl, haloalkyl or haloaryl group, each having from 1 to 10 carbon atoms in an alkyl radical and from 6 to 20 carbon atoms in an aryl radical, or fluorine, chlorine, bromine or iodine. Preferred examples of Y are methyl, propyl, isopropyl, isobutyl or trifluoromethyl, unsaturated groups such as aryl or haloaryl, for example phenyl, tolyl, benzyl groups, p-fluorophenyl, 3,5-difluorophenyl, pentachlorophenyl, pentafluorophenyl, 3,4, 5-trifluorophenyl and 3,5-di(trifluoromethyl)phenyl. Preferred options are trifluoroborane, triphenylborane, tris(4-fluorophenyl)borane, tris(3,5-difluorophenyl)borane, tris(4-fluoromethylphenyl)borane, tris(2,4,6-trifluorophenyl)borane, tris(pentafluorophenyl)borane , tris(tolyl)borane, tris(3,5-dimethylphenyl)borane, tris(3,5-difluorophenyl)borane and/or tris(3,4,5-trifluorophenyl)borane.

Particular preference is given to tris(pentafluorophenyl)borane.

However, it is preferable if borates are used, that is, compounds containing the borate 3+ ion. Such ionic cocatalysts preferably contain a non-coordinating anion such as tetrakis(pentafluorophenyl)borate and tetraphenylborate. Suitable counterions are protonated amine or aniline derivatives such as methylammonium, anilinium, dimethylammonium, diethylammonium, N-methylanilinium, diphenyl ammonium, N,N-dimethylanilinium, trimethylammonium, triethylammonium, tri-n-butylammonium, methyldiphenylammonium, pyridinium, p-bromo -N,N-dimethylanilinium or p-nitro-N,N-dimethylanilinium.

Preferred ionic compounds that can be used according to this invention include:

triethylammonium tetra(phenyl)borate,

tributylammonium tetra(phenyl)borate,

trimethylammonium tetra(tolyl)borate,

tributylammonium tetra(tolyl)borate,

tributylammonium tetra(pentafluorophenyl)borate,

tripropylammonium tetra(dimethylphenyl)borate,

tributyl ammonium tetra(trifluoromethylphenyl)borate,

tributylammonium tetra(4-fluorophenyl)borate,

N,N-dimethylcyclohexylammonium tetrakis(pentafluorophenyl)borate,

N,N-dimethylbenzylammonium tetrakis(pentafluorophenyl)borate,

N,N-dimethylanilinium tetra(phenyl)borate,

N,N-diethylanilinium tetra(phenyl)borate,

N,N-dimethylanilinium tetrakis(pentafluorophenyl)borate,

N,N-di(propyl)ammonium tetrakis(pentafluorophenyl)borate,

di(cyclohexyl)ammonium tetrakis(pentafluorophenyl)borate,

triphenylphosphonium tetrakis(phenyl)borate,

triethylphosphonium tetrakis(phenyl)borate,

diphenylphosphonium tetrakis(phenyl)borate,

tri(methylphenyl)phosphonium tetrakis(phenyl)borate,

tri(dimethylphenyl)phosphonium tetrakis(phenyl)borate,

triphenylcarbenium tetrakis(pentafluorophenyl)borate,

or ferrocenium tetrakis(pentafluorophenyl)borate.

Preference is given to triphenylcarbenium tetrakis(pentafluorophenyl)borate,

N,N-dimethylcyclohexylammonium tetrakis(pentafluorophenyl)borate or

N,N-dimethylbenzylammonium tetrakis(pentafluorophenyl)borate.

It has been surprisingly discovered that certain boron-containing cocatalysts are particularly preferred. The preferred borates used in the invention contain trityl ion. Thus, it is therefore particularly preferred to use N,N-dimethylammonium tetrakispentafluorophenylborate and Ph ₃ CB(PhF ₅ ) ₄ and analogs thereof.

According to the present invention, preferred cocatalysts are alumoxanes, more preferably methylaluminoxanes, combinations of alumoxanes with Al-alkyl, boron-containing or borate cocatalysts, and combinations of alumoxanes with boron-based cocatalysts.

Suitable amounts of cocatalyst a are well known to those skilled in the art.

The molar ratio of boron to metal ion in the metallocene may be from 0.5:1 to 10:1 mol/mol, preferably from 1:1 to 10:1, especially from 1:1 to 5:1 mol/mol.

The molar ratio of Al in the alumoxane to metal ion in the metallocene may be from 1:1 to 2000:1 mol/mol, preferably from 10:1 to 1000:1, and more preferably from 50:1 to 500:1 mol/mol.

The catalyst can be used in supported or unsupported form, preferably in supported form. The particulate support material used is preferably an organic or inorganic material such as silica, alumina or zirconia, or a mixed oxide such as an aluminosilicate, in particular silica, alumina or aluminosilicate. Preferred is the use of silica as the carrier. One skilled in the art will know the procedures required to apply the metallocene catalyst.

Particularly preferably, the support is a porous material so that the complex can be loaded into the pores of the support, for example, using a process similar to that described in WO 94/14856 (Mobil), WO 95/12622 (Borealis) and WO 2006/097497.

The average particle size of the silica carrier may typically be from 10 to 100 microns. However, it has turned out that particular advantages can be obtained if the carrier has an average particle size of from 15 to 80 μm, preferably from 18 to 50 μm.

The average pore size of the silica carrier can be from 10 to 100 nm, and the pore volume can be from 1 to 3 ml/g.

Examples of suitable support materials are, for example, ES757 manufactured and sold by PQ Corporation, Sylopol 948 manufactured and sold by Grace, or SUNSPERA DM-L-303 silica manufactured by AGC Si-Tech Co. The supports can, if necessary, be calcined before their use in catalyst preparation to achieve optimal silanol group content.

The use of these media is common in the art.

Fiberglass

The second essential component in a fiber reinforced composite is glass fiber. The glass fibers can be any type of glass fibers, such as long glass fibers or short glass fibers. However, it is particularly preferred that the glass fibers are short glass fibers, also known as cut glass fibers or chopped glass filaments.

The short glass fibers used in the fiber reinforced composite preferably have an average fiber length of 2.0 to 10.0 mm, more preferably 2.0 to 8.0 mm, even more preferably 2.0 to 5.0 mm.

Also preferably, the short glass fibers used in the fiber reinforced composite preferably have an average diameter of 5 to 20 µm, more preferably 8 to 18 µm, even more preferably 8 to 15 µm.

Preferably, the short glass fibers have an aspect ratio, defined as the ratio between the average fiber length and the average fiber diameter, from 150 to 600, preferably from 200 to 500, more preferably from 250 to 400. The aspect ratio is the ratio between the average length and the average diameter of the fibers .

Compatibilizer

Another component present in fiber reinforced composite is a compatibilizer, or also called a coupling agent or adhesion promoter. As noted above, the compatibilizer improves adhesion between non-polar polypropylene and polar glass fibers.

The compatibilizer according to this invention is preferably a polar modified polypropylene. Polar modified polypropylene, such as polar modified propylene homopolymer or polar modified copolymer, is highly compatible with the fiber reinforced polypropylene composite of the present invention.

From a structural point of view, polar modified polypropylenes are preferably selected from graft copolymers or block copolymers.

In this context, preference is given to polarly modified polypropylenes containing groups derived 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, as well as ionic connections.

Specific examples of these polar compounds are unsaturated cyclic anhydrides and their aliphatic diesters, as well as diacid derivatives. In particular, maleic anhydride and compounds selected from C ₁ -C ₁₀ linear and branched dialkyl maleates, C ₁ -C ₁₀ linear and branched dialkyl fumarates, itaconic anhydride, C ₁ -C ₁₀ linear and branched dialkyl esters of itaconic acid, maleic acid can be used , fumaric acid, itaconic acid and mixtures thereof.

In a particular preferred embodiment of this invention, the polar modified polypropylene is maleic anhydride grafted polypropylene, where the polypropylene is either a propylene-ethylene copolymer or a propylene homopolymer. It is particularly preferred that the polar modified polypropylene is maleic anhydride grafted polypropylene, wherein the polypropylene is a propylene homopolymer.

Polar modified polypropylene, especially maleic anhydride grafted polypropylene, can be produced in a simple manner by reaction extrusion of polypropylene, for example with maleic anhydride in the presence of free radical generators (such as organic peroxides), as described, for example, in EP 0572028.

The amount of groups derived from polar compounds, for example, the amount of maleic anhydride, in polar modified polypropylene ranges from 0.1 to 5.0 wt. %, preferably from 0.5 to 4.0 wt. %, and more preferably from 0.5 to 3.0 wt. %.

Preferably, the polar modified polypropylene, for example maleic anhydride grafted polypropylene, has a melt flow index MFR ₂ (190°C, 2.16 kg), measured in accordance with ISO 1133, of at least 50 g/10 min, more preferably at least at least 80 g/10 min, even more preferably from 50 to 500 g/10 min, and even more preferably from 80 to 250 g/10 min.

Supplements

The fiber reinforced composite according to the present invention may further contain additives. Typical additives are acid scavengers, antioxidants, dyes, light stabilizers, glidants, anti-scratch agents, dispersants, processing aids, lubricants, pigments, etc.

Such additives are produced industrially and are described, for example, in the “Plastic Additives Handbook”, 6th edition 2009 of Hans Zweifel (p. 1141 - 1190).

Supplements are usually supplied in the form of a masterbatch (master batch). A masterbatch is a composition in which an additive or mixture of additives is dispersed in a sufficiently large amount in a polymer. Accordingly, the term "additive" according to this invention also includes carrier materials, in particular polymeric carrier materials in which the "active additive" or "mixture of active additives" is dispersed.

Method for producing fiber-reinforced composite

The fiber reinforced composite is produced as is well known in the art. Accordingly, the fiber reinforced composite is produced by a process comprising the steps of adding

polypropylene,

fiberglass,

compatibilizer, and

perhaps additives

into an extruder and extruding them to obtain said fiber-reinforced composite,

wherein preferably the polypropylene is obtained by polymerizing propylene and optionally ethylene in the presence of a metallocene catalyst having formula (I), preferably having formula (II).

For extrusion, that is, melt mixing, of the individual components of the composite, a conventional compounding or mixing device, for example a Banbury mixer, 2-roll rubber mixer, Bass mixer or twin-screw extruder, can be used. The fiber reinforced composite extracted from the extruder/mixer is usually in pellet form. These granules are then preferably further processed, for example by injection molding, to produce composite articles and products according to the invention.

Particularly preferably, the fiber-reinforced composite according to the present invention is produced by melt mixing the individual components in an extruder, preferably a twin-screw extruder.

In particular, preferably the fiber reinforced composite according to the present invention is produced by a process comprising the steps

(a) feeding the polypropylene, compatibilizer and possibly additives into an extruder, preferably a twin screw extruder,

(b) melt mixing the composition obtained in step (a) at a temperature of from 200 to 270°C,

(c) feeding the (short) glass fibers into an extruder, preferably a twin-screw extruder, containing the composition obtained in step (b), and

(d) melt mixing the composition obtained in step (c) at a temperature of from 200 to 270°C, thereby obtaining a fiber reinforced composite,

wherein preferably the polypropylene is obtained by polymerizing propylene and optionally ethylene in the presence of a metallocene catalyst having formula (I), preferably having formula (II).

Products

The invention also relates to a product, preferably an automobile product, containing at least 90 wt. %, more preferably at least 95 wt. %, even more preferably consisting of a fiber-reinforced composite according to this invention.

Particularly preferred automotive products are instrument panels and dashboard supports, bumper supports, load-bearing components for doors and rear doors, under-hood components such as fans and battery holders, and underbody protection elements.

Particularly Preferred Embodiments Based on the information presented above, the present invention is particularly

refers to the following incarnations.

Thus, in a preferred embodiment, the fiber reinforced composite

according to the invention contains

(a) from 59 to 90 mass. %, based on fiber reinforced composite, propylene homopolymer,

(b) from 9 to 40 mass. %, based on fiber reinforced composite, short glass fibers,

(c) from 0.05 to 5.0 wt. %, based on the fiber reinforced composite, compatibilizer, and

(d) from 0.1 to 5.0 wt. %, based on fiber reinforced composite, additives, where also

the total amount of propylene homopolymer, short glass fibers, compatibilizer and additives in the fiber reinforced composite is from 98 to 100 wt. %,

additionally

propylene homopolymer has

(i) melting point Tm, determined by DSC in accordance with ISO 11357-3 (heating and cooling rate 10°C/min), from 152 to 160°C,

(ii) 2,1-regiodefects from 0.10 to 0.90%, determined by ¹³ C-NMR spectroscopy,

(iii) the proportion of cold xylene solubles (CSCS), measured in accordance with ISO 16152 (25°C), from 0.10 to 0.90 wt. %,

(iv) melt flow index PTR ₂ (230°C, 2.16 kg), measured in accordance with ISO 1133, from 5.0 to 500 g/10 min, and

(v) molecular weight distribution (MWD), determined by gel permeation chromatography (GPC), from 1.0 to less than 4.0,

and preferably the propylene homopolymer is not visbreaked. In another preferred embodiment, the fiber reinforced composite according to the invention contains

(a) from 59 to 90 mass. %, based on fiber reinforced composite, propylene homopolymer,

(b) from 9.0 to 40 wt. %, based on fiber reinforced composite, short glass fibers,

(c) from 0.05 to 5.0 wt. %, based on the fiber reinforced composite, compatibilizer, and

(d) from 0.1 to 5.0 wt. %, based on fiber reinforced composite, additives, where also

the total amount of propylene homopolymer, short glass fibers, compatibilizer and additives in the fiber reinforced composite is from 98 to 100 wt. %,

additionally

propylene homopolymer has

(i) melting point Tm, determined by DSC in accordance with ISO 11357-3 (heating and cooling rate 10°C/min), from 153 to 159°C,

(ii) 2,1-regiodefects from 0.15 to 0.80%, determined by ¹³ C-NMR spectroscopy,

(iii) the proportion of cold xylene solubles (CSCS), measured in accordance with ISO 16152 (25°C), from 0.10 to 0.90 wt. %,

(iv) melt flow index PTR ₂ (230°C, 2.16 kg), measured in accordance with ISO 1133, from 5.0 to 500 g/10 min, and

(v) molecular weight distribution (MWD), determined by gel permeation chromatography (GPC), from 1.6 to less than 3.8,

and preferably the propylene homopolymer is not visbreaked. In yet another preferred embodiment, the fiber reinforced composite according to the invention preferably contains

(a) from 59 to 90 mass. %, based on fiber reinforced composite, propylene homopolymer,

(b) from 9.0 to 40 wt. %, based on fiber reinforced composite, short glass fibers,

(c) from 0.05 to 5.0 wt. %, based on the fiber reinforced composite, compatibilizer, and

(d) from 0.1 to 5.0 wt. %, based on fiber reinforced composite, additives, where also

the total amount of propylene homopolymer, short glass fibers, compatibilizer and additives in the fiber reinforced composite is in the range of 98 to 100 wt. %,

additionally

propylene homopolymer has

(i) melting point Tm, determined by DSC in accordance with ISO 11357-3 (heating and cooling rate 10°C/min), from 153 to 159°C,

(ii) 2,1-regiodefects from 0.15 to 0.80%, determined by ¹³ C-NMR spectroscopy,

(iii) the proportion of cold xylene solubles (CSCS), measured in accordance with ISO 16152 (25°C), from 0.10 to 0.90 wt. %,

(iv) melt flow index PTR ₂ (230°C, 2.16 kg), measured in accordance with ISO 1133, from 5.0 to 500 g/10 min, and

(v) molecular weight distribution (MWD), determined by gel permeation chromatography (GPC), from 1.6 to less than 3.8,

and preferably the propylene homopolymer is not visbroken,

additionally

- short glass fibers have an average fiber length from 2.0 to 10.0 mm and an average diameter from 5 to 20 µm, and

- the compatibilizer is polypropylene grafted with maleic anhydride, where the polypropylene grafted with maleic anhydride has a maleic anhydride content of 0.1 to 5 wt. %.

The invention is described below by way of examples.

EXAMPLES

1. Determination methods

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

a) Melt flow index Melt flow index (MFR ₂ ) is determined in accordance with ISO 1133 and indicated in g/10 min. MFR ₂ of polypropylene is determined at a temperature of 230°C and at a load of 2.16 kg.

i) Thermal Distortion Temperature B (TDB) Thermal Distortion Temperature B (TDB) was determined in accordance with ISO 75 B at 0.45 MPa using 80 x 10 x 4 mm ³ injection molded test rods in accordance with EN ISO 1873-2.

c) Proportion of cold xylene soluble substances (XCSW, wt. %) The amount of polymer soluble in xylene is determined at 25.0 °C according to ISO

16152; 1st edition; 2005-07-01.

d) Melting temperature Tmelt and crystallization temperature Tcr Melting temperature Tmelt is determined by differential scanning

calorimetry (DSC) in accordance with ISO 11357-3 using a TA-Instruments 2920 Dual-Cell with an RSC refrigeration unit and a data transfer station. A heating and cooling rate of 10°C/min is used in a heating/cooling/heating cycle between +23 and +210°C. The crystallization temperature (Tcr) is determined in the cooling stage, while the melting temperature (Tm) and enthalpy of fusion (Nmel) are determined in the second heating stage.

f) Tensile modulus Tensile modulus and elongation at break are measured in accordance with ISO 527-2 using injection molded specimens as described in EN ISO 1873-2 (dog bone shape 1 B, thickness 4 mm) .

f) Charpy impact strength

Charpy impact strength was measured in accordance with ISO 179 leU at +23°C using test specimens in the form of injection molded rods 80×10×4 mm ³ prepared in accordance with EN ISO 1873-2.

g) Quantitative assessment of copolymer microstructure using ¹³ C-NMR

spectroscopy

Quantitative nuclear magnetic resonance (NMR) spectroscopy has been used to quantify the comonomer content of polymers. Quantitative NMR spectra of ^13C { ^1H } were recorded in dissolved form using a Bruker Advance III 400 NMR spectrometer operating at a frequency of 400.15 and 100.62 MHz for ^1H and ^13C , respectively. All spectra were recorded using a ¹³ C optimized 10 mm extended temperature probe at 125 C using nitrogen gas for the entire pneumatic system. Approximately 200 mg of the substance was dissolved in 3 ml of 1,2-tetrachloroethane-d ₂ (TX3-d ₂ ) along with chromium(III) acetylacetonate (Cr(acac) ₃ ) to obtain a 65 mM solution of the relaxant in the solvent (Singh, G., Kothari, A., Gupta, V., Polymer Testing 28 5 (2009), 475). To ensure a homogeneous solution, after initial sample preparation in the heat block, the NMR ampoule was further heated in a rotary oven for at least 1 hour. After insertion into the magnet, the ampoule was rotated at a speed of 10 Hz. This setup was chosen primarily because of its high resolution and was necessary for accurate ethylene quantification. Standard single-pulse excitation without NOE (Nuclear Overhauser Effect) was used using optimized apex angle, 1 s recirculation delay and WALTZ 16 two-level decoupling circuit (Zhou, Z., Kuemmerle, R., Qiu, X., Redwine, D., Cong , R, Taha, A., Baugh, D. Winniford, V., J. Mag. Reson. 187 (2007) 225; Busico, V., Carbonniere, P., Cipullo, R., Pellecchia, R., Severn , J., Talarico, G, Macromol. Rapid Commun. 2007, 28, 1128). A total of 6144 (6 k) transitions were obtained in the spectrum. Quantitative ¹³ C{ ¹ H} NMR spectra were processed, integrated, and the corresponding quantitative properties were determined from integrals using proprietary computer programs. All chemical shifts were indirectly assigned to the central methylene group of the ethylene block (EEE) at 30.00 ppm. using solvent chemical shift. This approach made it possible to obtain comparable assignments, even when this structural link was missing. Characteristic signals consistent with the incorporation of ethylene were observed (Cheng, N. N., Macromolecules 17 (1984), 1950).

In the presence of observed characteristic signals corresponding to 2,1-erythro-regiodefects (as described in the works of L. Resconi, L. Cavallo, A. Fait, F. Piemontesi, Chem. Rev. 2000, 100 (4), 1253, Cheng, H. N., Macromolecules 1984, 17, 1950, and W-J. Wang and S. Zhu, Macromolecules 2000, 33 1157), correction was required taking into account the influence of regional defects on the determined properties. No characteristic signals corresponding to other types of regional defects were observed.

The comonomer fraction was quantified using the method of Wang et. al. (Wang, W. J., Zhu, S., Macromolecules 33 (2000), 1157) by integrating multiple signals across the entire spectral region in the ¹³ C{ ¹ H} spectra. This method was chosen due to its reliability and ability to take into account the presence of regional defects when necessary. The integration ranges have been slightly adjusted to increase applicability over the entire detection range of comonomer content.

For systems where only isolated ethylene in PPEPP sequences was observed, the method of Wang et al. was modified to reduce the influence of non-zero integrals for sites not known to be present. This approach reduced the overestimation of ethylene content for such systems and was achieved by reducing the number of sites used to determine absolute ethylene content to the following:

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

using the same notation as in the paper by Wang et al. (Wang, W-J., Zhu, S., Macromolecules 33 (2000), 1157). The equations used to estimate the absolute propylene content were not modified.

The molar percentage of comonomer incorporation was calculated from the molar fraction:

The mass percentage of comonomer incorporation was calculated from the molar fraction:

h) Number average molecular weight (Mn), mass average molecular weight (Mw) and molecular weight distribution (Mw/Mn)

Number average molecular weight (Mn), mass average molecular weight (Mw) and molecular weight distribution (Mw/Mn) were determined using gel permeation chromatography (GPC) in accordance with ISO 16014-4:2003 and ASTM D 6474-99. A PolymerChar GPC instrument equipped with an infrared (IR) detector was used with 3 x Olexis and 1 x Olexis Guard columns from Polymer Laboratories and 1,2,4-trichlorobenzene (TCB, stabilized with 250 mg/L 2,6-di-tert-butyl -4-methyl-phenol) as solvent at 160°C and at a constant flow rate of 1 ml/min. For one analysis, 200 μl of sample solution was injected. The column set was calibrated using a universal calibration (according to ISO 16014-2:2003) using at least 15 narrow MWD polystyrene (PS) standards ranging from 0.5 kg/mol to 11,500 kg/mol. The Mark-Houwink constants used for PS, PE and PP are as described in ASTM D 6474-99. All samples were prepared by dissolving 5.0 - 9.0 mg of polymer in 8 ml (at 160°C) of stabilized TCB (same as mobile phase) for 2.5 hours for PP or 3 hours for PE at max. 160°C With continuous gentle shaking in the autosampler of the GPC device.

i) VOC and FOG

VOC values and FOG values were measured in accordance with VDA 278 (October 2011; Thermal desorption analysis of organic emissions for the characterization of non-metallic materials for vehicles, VDA Verband der Automobilindustrie) after sample preparation in the form of injection molded plates in accordance with EN ISO 19069 -2:2016. These records were packaged in aluminum composite foil immediately after production and the films were sealed.

According to VDA 278 of October 2011, the VOC value is defined as “the total amount of highly volatile and moderately volatile substances. It is calculated as toluene equivalent. The method described in this recommendation allows the determination and analysis of substances in the boiling/eluting range to n-pentacosane (C ₂₅ ).”

The FOG value is defined as “the total amount of low volatility species that elute with retention time from n-tetradecane (inclusive).” It is calculated as hexadecane equivalent. Substances in the boiling range of n-alkanes from “C ₁₄ ” to “C ₃₂ ” were identified and analyzed.

j) Fogging

Fogging was measured in accordance with DIN 75201:2011-11, method B (gravimetric method) on direct-compression specimens (diameter 80 mm +/- 1 mm, thickness < 1 cm) cut from an injection molded plate. In this method, the mass in mg of condensation formed by fogging on aluminum foil is determined by weighing the foil before and after the fogging test. The term "fog" refers to the fraction of volatile substances condensed on glass parts, such as, for example, a vehicle windshield.

k) Average fiber diameter

The average fiber diameter is determined in accordance with ISO 1888:2006(E), method B, microscope magnification 1000.

2. Preparation of polypropylenes a) Preparation of a single-site catalytic system 1

Catalytic complex The following metallocene complex was used, described in WO 2019/179959:

Preparation of MAO on a silica support

A steel reactor equipped with a mechanical stirrer and a filter mesh was purged with nitrogen, and the reactor temperature was set at 20°C. DM-L-303 silica from AGC Si-Tech Co, pre-calcined at 600°C (5.0 kg), was then added from the feed drum, followed by careful pressurization and release of the pressure with nitrogen using manual valves. Toluene (22 kg) was then added. The mixture was stirred for 15 minutes. After this, 30 wt.% was added to the top of the reactor through the feed line. % solution of MAO in toluene (9.0 kg) from Lanxess for 70 minutes. The reaction mixture was then heated to 90°C and stirred at 90°C for an additional two hours. The suspension was allowed to settle and the mother liquor was filtered. The catalyst was washed twice with toluene (22 kg) at 90°C, followed by precipitation and filtration. The reactor was cooled to 60°C and the solid was washed with heptane (22.2 kg). Finally, the MAO-treated SiO ₂ was dried at 60° under a stream of nitrogen for 2 hours and then for 5 hours in a vacuum (-0.5 barg (-50 kPa g)) with stirring. The MAO-treated support was collected as a free-flowing white powder containing 12.2% Al by weight.

Preparation of single-site catalyst system 1

30 wt. was added to a steel reactor under a nitrogen atmosphere through a burette. % MAO in toluene (0.7 kg) at 20°C. Toluene (5.4 kg) was then added with stirring.

The metallocene complex described in section 2a) above (93 g) was added from a metal can followed by rinsing with 1 kg of toluene. The mixture was stirred for 60 minutes at 20°C. Trityltetrakis(pentafluorophenyl)borate (91 g) was then added from a metal can, followed by rinsing with 1 kg of toluene. The mixture was stirred for 1 hour at room temperature. The resulting solution was added to the stirred precipitate of MAO supported on silica, prepared as described above, for 1 hour. The precipitate was left to stand for 12 hours, followed by drying under a stream of N ₂ at 60°C for 2 hours and an additional 5 hours in vacuum (-0.5 barg (-50 kPa excess)) with stirring.

The dried catalyst was taken in the form of a pink free-flowing powder containing 13.9% Al and 0.11% Zr.

b) Preparation of single-site catalyst system 2

Catalytic Complex The following metallocene complex was used, described in WO 2013/007650:

Preparation of MAO on a silica support

A steel reactor equipped with a mechanical stirrer and a filter mesh was flushed with nitrogen, and the reactor temperature was set at 20°C. DM-L-303 silica from AGC Si-Tech Co, pre-calcined at 600°C (7.4 kg), was then added from the feed drum, followed by careful pressurization and release of the pressure with nitrogen using manual valves. Toluene (32.2 kg) was then added. The mixture was stirred (40 rpm) for 15 minutes. Next, 30 wt. was added through a 12 mm line to the top of the reactor. % solution of MAO in toluene (17.5 kg) from Lanxess for 70 minutes. The reaction mixture was then heated to 90°C and stirred at 90°C for an additional two hours. The suspension was allowed to settle and the mother liquor was filtered. The MAO-treated silica support was washed twice with toluene (32.2 kg) at 90°C, followed by precipitation and filtration. The reactor was cooled to 60°C and the solid was washed with heptane (32.2 kg). Finally, the MAO-treated SiO ₂ was dried at 60°C for 2 h under a nitrogen flow of 2 kg/h, a pressure of 0.3 barg (30 kPa g), and then for 5 hours in vacuum (-0. 5 barg (-50 kPa gauge)) with stirring at 5 rpm. The MAO-treated carrier was collected as a free-flowing white powder containing 12.7% Al by weight.

Preparation of single-site catalyst system 2:

In a nitrogen-filled glovebox, 0.25 mL of a solution of MAO (30 wt%, in toluene, AXION 1330 CA Lanxess) in dry toluene (1 mL) was added to an aliquot of the metallocene complex described in section 2b above (30.0 mg, 38 µmol). The mixture was stirred for 60 minutes at room temperature. Next, the solution was slowly added to 1.0 g of MAO-treated silica, prepared as described above, which was placed in a glass flask. The mixtures were left to stand overnight, washed with 5 ml of toluene and then vacuum dried for 1 hour to obtain 1.1 g of catalyst as a pink free-flowing powder.

Catalytic system 2 has an Al content of 12.5 wt. %, Zr content 0.248 wt. % and Al/Zr molar ratio 170 mol/mol.

c) Preparation of Ziegler-Natta catalyst system 3

The Ziegler-Natta catalytic system was used

Chemicals used:

20% solution in toluene of butyl ethyl magnesium (Mg(Bu)(Et), BEM), supplied by Chemtura

2-ethylhexanol supplied by Amphochem

3-Butoxy-2-propanol - (DOWANOL™ PnB), available from Dow

bis(2-ethylhexyl)citraconate supplied by SynphaBase

TiCU supplied by Millenium Chemicals

Toluene supplied by Aspokem

Viscoplex® 1-254, supplied by Evonik

Heptane supplied by Chevron

Preparation of Mg alkoxy compound

A solution of Mg alkoxide was prepared by adding, with stirring (70 rpm), a mixture of 4.7 kg of 2-ethylhexanol and 1.2 kg of butoxypropanol to 11 kg of 20 wt. % solution of butylethylmagnesium (Mg(Bu)(Et)) in toluene in a 20-liter stainless steel reactor. During addition, the reactor contents were maintained below 45°C. After addition was complete, stirring (70 rpm) of the reaction mixture was continued at 60°C for 30 minutes. After cooling to room temperature, 2.3 kg of donor bis(2-ethylhexyl)citraconate was added to the Mg alkoxide solution, maintaining the temperature below 25°C. Mixing was continued for 15 minutes with stirring (70 rpm).

Preparation of Solid Catalytic Component 20.3 kg of TiCl ₄ and 1.1 kg of toluene were added to a 20 L stainless steel reactor. While stirring at 350 rpm and maintaining the temperature at 0° C., 14.5 kg of the prepared Mg alkoxy compound was added over 1.5 hours. 1.7 L of Viscoplex® 1-254 and 7.5 kg of heptane were added, and after 1 hour of stirring at 0°C, the temperature of the resulting emulsion was raised to 90°C over 1 hour. After 30 minutes, stirring was stopped, the catalyst drops solidified, and the resulting catalyst particles were allowed to settle. After sedimentation (1 hour), the supernatant was pumped out. The catalyst particles were then washed with 45 kg of toluene at 90°C for 20 minutes, followed by two washes with heptane (30 kg, 15 min). During the first wash with heptane, the temperature dropped to 50°C, and during the second wash, to room temperature.

The catalyst thus obtained was used together with triethylaluminum (TEA) as a cocatalyst and dicyclopentyldimethoxysilane (D-donor) as a donor. The following ratio was used:

TEA/Ti: 250 mol/mol

TEA/Donor: 10 mol/mol

Inventive Examples IE1 and IE2 and Comparative Examples CE1 and CE2 were prepared by compounding on a co-rotating twin screw extruder (ZSK 40 from Coperion) with a mixing screw typical for glass fiber blends and an L/D ratio of 43. The following process parameters were used :

- productivity 100 kg/h

- screw rotation speed 100 - 150 rpm

- cylinder temperature 220 - 250°C, increases from the feed zone and decreases again towards the die plate

- spun plate with 4 mm diameter holes and 3 strands Polypropylene and additives other than short glass fibers were fed into

extruder and mixed in the melt in the 2nd cylinder. The first mixing zone for mixing polypropylene and additives is located between the 3rd and 5th cylinders. Short glass fibers were added to the 6th cylinder using a side feeder. The second mixing zone for dispersing the glass fiber is located between the 7th and 12th cylinders.

The composites and their properties are presented in Table 3.

The glass fiber used is the commercial product ECS03T-480H from Nippon Electric Glass, which has an average fiber length of 3.0 mm and an average diameter of 10 μm.

During compounding, the following combination of additives was used: 0.2 wt. % tris(2,4-di-tert-butylphenyl)phosphite (CAS-No. 31570-04-4, sold as Irgafos 168 from BASF AF, Germany), 0.1 wt. % pentaerythrityl-tetrakis(3-(3',5'-di-tert-butyl-4-hydroxyphenyl)-propionate (CAS-No. 6683-19-8, sold as Irganox 1010 from BASF AG, Germany) and 0. 2 wt.% carbon black superconcentrate “Plasblak PPP6331” from Cabot Corporation, Germany.

The compatibilizer is industrial polypropylene grafted with maleic anhydride “Scona TPPP 8112 GA” from BYK with a maleic anhydride content of 1.4 wt. % and MTR ₂ more than 80 g/10 min.

Claims (41)

1. Fiber reinforced composite for automotive products, including (a) from 59 to 90 mass. %, based on fiber reinforced composite, polypropylene, (b) from 9.0 to 40 wt. %, based on the fiber reinforced composite, of short glass fibers having an average length of 2.0 to 10.0 nm, and (c) from 0.05 to 5.0 wt. %, based on the fiber-reinforced composite, compatibilizer, which is polar modified polypropylene, where additionally the total amount of polypropylene, glass fiber and compatibilizer in the fiber reinforced composite is at least 95 wt. %, in addition, polypropylene also has (i) melting point Tm, determined by differential scanning calorimetry (DSC) in accordance with ISO 11357-3, using a heating and cooling rate of 10°C/min, from 152 to 160°C, (ii) the comonomer content, determined by ¹³ C-NMR spectroscopy, is not more than 0.5 wt. %, with the comonomer being ethylene, (iii) molecular weight distribution (MWD), determined by gel permeation chromatography (GPC), from 1.0 to less than 4.0, where the molecular weight distribution is Mw/Mn, where Mw is the weight average molecular weight and Mn represents the number average molecular weight, and (iv) 2,1-regiodefects determined by ¹³ C-NMR spectroscopy, from 0.10 to 0.90%. 2. The fiber-reinforced composite according to claim 1, wherein the polypropylene has a cold xylene solubilities (CSCS) content, measured according to ISO 16152 at 25°C, from 0.05 to 1.0 wt. %. 3. A fiber-reinforced composite according to claim 1 or 2, wherein the polypropylene forms a continuous phase into which the fibers are embedded. 4. The fiber-reinforced composite according to claim 1 or 2, wherein the polypropylene has a melt flow index MFR ₂ measured in accordance with ISO 1133 under a load of 2.16 kg at 230 ° C, from 5.0 to 500 g/10 min. 5. The fiber-reinforced composite according to claim 1 or 2, wherein the polypropylene is single-phase polypropylene. 6. The fiber-reinforced composite according to claim 1 or 2, wherein the fiber-reinforced composite consists of (a) from 59 to 90 mass. %, based on fiber reinforced composite, polypropylene, (b) from 9.0 to 40 wt. %, based on fiber reinforced composite, glass fibers, (c) from 0.05 to 5.0 wt. %, based on the fiber reinforced composite, compatibilizer, and (d) from 0.1 to 5.0 wt. %, based on fiber reinforced composite, additives. 7. Fiber-reinforced composite according to claim 1 or 2, in which the polypropylene is not visbreaked. 8. A fiber-reinforced composite according to claim 1 or 2, wherein the polypropylene is obtained by polymerizing propylene or propylene and ethylene in the presence of a metallocene catalyst having formula (I) , where each of the R ¹ , which are independently the same or may be different, represents hydrogen or a linear or branched C ₁ -C ₆ alkyl group, and at least one R ¹ per phenyl group is not hydrogen, R' represents a C ₁ -C ₁₀ hydrocarbyl group and X independently represents a hydrogen atom, a halogen atom, a C ₁ -C ₆ alkoxy group, a C ₁ -C ₆ alkyl group, a phenyl or a benzyl group. 9. The fiber-reinforced composite according to claim 1 or 2, wherein the glass fibers have an average diameter of 5 to 20 μm. 10. Fiber-reinforced composite according to claim 1 or 2, where the compatibilizer is polypropylene grafted with maleic anhydride. 11. The fiber-reinforced composite according to claim 10, wherein the maleic anhydride-grafted polypropylene has a maleic anhydride content of 0.1 to 5.0 wt. % and melt flow index PTR ₂ measured in accordance with ISO 1133 with a load of 2.16 kg at 190°C, ranging from 80 to 250 g/10 min. 12. A method for producing a fiber-reinforced composite according to any of the preceding claims, comprising the steps of adding (a) polypropylene, (b) glass fiber, (c) a compatibilizer and (d) possibly additives into an extruder and extruding them to obtain said fiber-reinforced composite, wherein polypropylene is obtained by polymerization of propylene or propylene and ethylene in the presence of a metallocene catalyst having formula (I) , where each of the R ¹ , which are independently the same or may be different, represents hydrogen or a linear or branched C ₁ -C ₆ alkyl group, and at least one R ¹ per phenyl group is not hydrogen, R' represents a C ₁ -C ₁₀ hydrocarbyl group and X independently represents a hydrogen atom, a halogen atom, a C ₁ -C ₆ alkoxy group, a C ₁ -C ₆ alkyl group, a phenyl or a benzyl group. 13. Automotive product containing at least 90 wt. % fiber reinforced composite according to any one of claims 1 to 11.