Fiber-reinforced composition comprising propylene random copolymer

Abstract

The present invention relates to a fiber-reinforced polypropylene composition (C) comprising a propylene random copolymer (P), fibers (F) and an adhesion promoter (AP), and an article comprising the fiber-reinforced polypropylene composition (C).

Description

Technical Field

[0001] The present invention relates to a fiber-reinforced polypropylene composition (C) comprising a propylene random copolymer (P), fibers (F) and an adhesion promoter (AP), and an article comprising the fiber-reinforced polypropylene composition (C). Background Art

[0002] Fiber-reinforced materials are widely used in various applications, especially in engineering, where higher stiffness, higher heat distortion temperature (HDT) and good impact resistance are seen as benefits. Polypropylene is one of the most popular base polymers due to its versatility, low cost and low density. It can meet most target properties. Polypropylene produced in the presence of metallocene catalysts is a promising candidate due to additional benefits such as controlled molecular weight distribution, good comonomer incorporation and low emissions. However, current grades have inherent disadvantages because stiffness and HDT are often not high enough. Excellent impact properties are also required in some specialized applications, such as automotive exteriors.

[0003] Therefore, there is a need in the art for a fiber reinforced polypropylene material that combines good rigidity and impact properties with low emissions. In addition, injection molding requires excellent flow properties.

[0004] It is therefore an object of the present invention to provide a high flow fiber reinforced polypropylene composition characterized by balanced stiffness and impact properties and low emissions. Summary of the Invention

[0005] This object is achieved by a fiber-reinforced polypropylene composition (C) comprising, based on the total weight of the fiber-reinforced composition (C),

[0006] a) 57.0 to 95.0 wt.% of a random propylene copolymer (P), wherein the comonomer is selected from ethylene and / or at least one C4 to C12 α-olefin, the random propylene copolymer (P) having

[0007] i) a melt flow rate MFR2 (230° C., 2.16 kg) determined according to ISO 1133 in the range of 45 to 150 g / 10 min, and

[0008] ii) a melting temperature Tm, determined according to differential scanning calorimetry (DSC), in the range of 125 to 150° C.,

[0009] b) 5.1 to 40.0% by weight of fibers (F), and

[0010] c) Optionally 0.1 to 5.0% by weight of an adhesion promoter (AP).

[0011] According to one embodiment of the present invention, the propylene random copolymer (P) has at least 0.4 mol% of 1,2-erythro regio defects. A preferred embodiment of the present invention relates to a fiber reinforced composition (C) comprising, based on the total weight of the fiber reinforced composition (C),

[0012] a) 57.0 to 94.9 wt.% of a random propylene copolymer (P), wherein the comonomer is selected from ethylene and / or at least one C4 to C12 α-olefin, the random propylene copolymer (P) having

[0013] i) a melt flow rate MFR2 (230° C., 2.16 kg) determined according to ISO 1133 in the range of 45 to 150 g / 10 min, and

[0014] ii) a melting temperature Tm, determined according to differential scanning calorimetry (DSC), in the range of 125 to 150° C.,

[0015] iii) an amount of 1,2-erythro regio defects of at least 0.4 mol %,

[0016] b) 5.0 to 40.0 wt. % of fibers (F), and

[0017] c) 0.1 to 5.0% by weight of an adhesion promoter (AP).

[0018] According to another embodiment of the present invention the propylene random copolymer (P) comprises

[0019] i) a first random propylene copolymer (P1), and

[0020] ii) a second random propylene copolymer (P2) having a higher comonomer content than the first random propylene copolymer (P1),

[0021] wherein the weight ratio between the first propylene random copolymer (P1) and the second propylene random copolymer (P2) is in the range of 20 / 80 to 60 / 40, and the combined amount of the first propylene random copolymer (P1) and the second propylene random copolymer (P2) is at least 95.0 wt.-%, based on the propylene random copolymer (P).

[0022] According to other embodiments of the present invention the random propylene copolymer (P) has a comonomer content in the range of 1.0 to 6.0 mol-%.

[0023] According to another embodiment of the present invention the first random propylene copolymer (P1) has a comonomer content in the range of 0.4 to 2.5 mol-% and the second random propylene copolymer (P2) has a comonomer content in the range of 2.8 to 7.0 mol-%.

[0024] According to one embodiment of the present invention, the comonomer is at least one C4 to C12 α-olefin. Particularly preferably, the comonomer is 1-hexene or 1-butene.

[0025] According to one embodiment of the present invention the propylene random copolymer (P) has a xylene soluble content (XCS) determined according to ISO 16152 (25°C) in the range of 3.0 to 15.0 wt.-%, based on the total weight of the propylene random copolymer.

[0026] According to another embodiment of the present invention the propylene random copolymer (P) has been visbroken with a visbreaking ratio [final MFR2 (230°C / 2.16 kg) / initial MFR2 (230°C / 2.16 kg)] of at least 5.0, wherein "final MFR2 (230°C / 2.16 kg)" is the MFR2 (230°C / 2.16 kg) of the propylene random copolymer (P) after visbreaking and "initial MFR2 (230°C / 2.16 kg)" is the MFR2 (230°C / 2.16 kg) of the propylene random copolymer (P) before visbreaking. MFR2 (230°C / 2.16 kg) is determined according to ISO 1133.

[0027] According to a further embodiment of the present invention the propylene random copolymer (P) has a melt flow rate MFR2 (230°C, 2.16 kg) determined according to ISO 1133 before visbreaking in the range of 0.5 to 10.0 g / 10 min.

[0028] According to another embodiment of the present invention, the fibers (F) are glass fibers (GF), preferably short glass fibers (SGF), having an average length of 2.0 to 10.0 mm, and / or an average diameter of 5 to 20 μm.

[0029] According to one embodiment of the present invention, the adhesion promoter (AP) is a polar modified polypropylene (PM-PP) which is a propylene homopolymer or copolymer grafted with maleic anhydride, the polar modified polypropylene (PM-PP) having a melt flow rate MFR2 (230° C., 2.16 kg), measured according to ISO 1133, of 20.0 to 400 g / 10 min.

[0030] According to other embodiments of the present invention, the fiber reinforced composition (C) has a melt flow rate MFR2 (230° C., 2.16 kg), determined according to ISO 1133, in the range of 8.0 to 60.0 g / 10 min.

[0031] According to another embodiment of the present invention the random propylene copolymer (P) is obtained in the presence of a solid catalyst system (SCS) comprising a metallocene compound.

[0032] It is particularly preferred that the metallocene compound has the formula (I)

[0033] R n (Cp)2MX2(I)

[0034] in

[0035] each Cp is independently an unsubstituted or substituted and / or fused cyclopentadienyl ligand, such as a substituted or unsubstituted cyclopentadienyl, substituted or unsubstituted indenyl or substituted or unsubstituted fluorenyl ligand; the optional substituent(s) are preferably independently selected from halogen, hydrocarbon (e.g., C1-C20-alkyl, C2-C20-alkenyl, C2-C20-alkynyl, C3-C12-cycloalkyl, C6-C20-aryl or C7-C20-aralkyl), C3-C12-cycloalkyl containing 1, 2, 3 or 4 heteroatoms in the ring portion, C6-C20-heteroaryl, C1-C20-haloalkyl, -SiR"3, -OSiR"3, -SR", -PR"2, OR" or -NR"2,

[0036] Each R" is independently hydrogen or a hydrocarbon group, such as a C1-C20-alkyl, C2-C20-alkenyl, C2-C20-alkynyl, C3-C12-cycloalkyl or C6-C20-aryl group; or, for example in the case of -NR"2, the two substituents R" may form a ring together with the nitrogen atom to which they are attached, such as a five-membered ring or a six-membered ring;

[0037] R is a bridge of 1 to 3 atoms, for example a bridge of 1 to 2 carbon atoms and 0 to 2 heteroatoms, wherein the heteroatom(s) may be, for example, one or more Si, Ge and / or O atoms, wherein each bridge atom may independently carry a substituent, such as a C1-C20-alkyl, tri(C1-C20-alkyl)silyl, tri(C1-C20-alkyl)siloxy or C6-C20-aryl substituent); or a bridge of 1 to 3, for example 1 or 2, heteroatoms, such as one or more silicon, germanium and / or oxygen atoms, for example -SiR 10 2, where each R 10 independently C1-C20-alkyl, C3-12-cycloalkyl, C6-C20-aryl or tri(C1-C20-alkyl)silyl residues, such as trimethylsilyl;

[0038] M is a transition metal of Group 4, such as Zr or Hf, especially Zr;

[0039] each X is independently a σ-ligand such as H, halogen, C1-C20-alkyl, C1-C20-alkoxy, C2-C20-alkenyl, C2-C20-alkynyl, C3-C12-cycloalkyl, C6-C20-aryl, C6-C20-aryloxy, C7-C20-aralkyl, C7-C20-aralkenyl, -SR", -PR", -SiR", -OSiR", -NR", or -CH2-Y, wherein Y is C6-C20-aryl, C6-C20-heteroaryl, C1-C20-alkoxy, C6-C20-aryloxy, NR", -SR", -PR", -SiR", or -OSiR",

[0040] Each of the above ring moieties, alone or as part of another moiety such as a substituent for Cp, X, R" or R, may also be substituted, for example by C1-C20-alkyl which may contain Si and / or O atoms;

[0041] n is 1 or 2.

[0042] The present invention also relates to an article comprising a fiber-reinforced composition (C) according to any one of claims 1 to 14.

[0043] Hereinafter, the present invention will be described in more detail. DETAILED DESCRIPTION

[0044] Fiber-reinforced composition (C)

[0045] The fiber reinforced composition (C) according to the present invention comprises a propylene random copolymer (P), fibers (F) and an adhesion promoter (AP).

[0046] In particular, the fiber-reinforced composition (C) comprises, based on the total weight of the fiber-reinforced composition (C),

[0047] a) 57.0 to 95.0 wt%, preferably 60.0 to 90.0 wt%, more preferably 65.0 to 85.0 wt%, still more preferably 70.0 to 80.0 wt% of a propylene random copolymer (P), and

[0048] b) 5.0 to 40.0 wt. %, preferably 8.0 to 37.0 wt. %, more preferably 11.0 to 32.0 wt. %, still more preferably 15.0 to 27.0 wt. % of fibers (F).

[0049] According to a preferred embodiment of the present invention, the fiber-reinforced composition (C) further comprises an adhesion promoter (AP).

[0050] Therefore, it is preferred that the fiber-reinforced composition (C) comprises, based on the total weight of the fiber-reinforced composition (C),

[0051] a) 57.0 to 94.9 wt%, preferably 60.0 to 90.0 wt%, more preferably 65.0 to 85.0 wt%, still more preferably 70.0 to 80.0 wt% of a propylene random copolymer (P),

[0052] b) 5.0 to 40.0 wt. %, preferably 8.0 to 37.0 wt. %, more preferably 11.0 to 32.0 wt. %, still more preferably 15.0 to 27.0 wt. % of fibers (F), and

[0053] c) 0.1 to 5.0 wt. %, preferably 0.5 to 4.0 wt. %, more preferably 0.8 to 3.5 wt. %, still more preferably 1.0 to 3.0 wt. % of an adhesion promoter (AP).

[0054] In addition, the fiber reinforced composition (C) according to the present invention may contain additives (AD). In one embodiment, the fiber reinforced composition (C) comprises, preferably consists of, the following components based on the total weight of the fiber reinforced composition (C),

[0055] a) 57.0 to 94.8 wt%, preferably 60.0 to 90.0 wt%, more preferably 65.0 to 85.0 wt%, still more preferably 70.0 to 80.0 wt% of a propylene random copolymer (P),

[0056] b) 5.0 to 40.0 wt. %, preferably 8.0 to 37.0 wt. %, more preferably 11.0 to 32.0 wt. %, still more preferably 15.0 to 27.0 wt. % of fibers (F), and

[0057] c) 0.1 to 5.0 wt. %, preferably 0.5 to 4.0 wt. %, more preferably 0.8 to 3.5 wt. %, still more preferably 1.0 to 3.0 wt. % of an adhesion promoter (AP),

[0058] d) 0.01 to 2.5% by weight of additives (AD), wherein the amount of components a) to d) is preferably selected to be 100% by weight.

[0059] Therefore, it is preferred that the fiber-reinforced composition (C) comprises, preferably consists of, the following components based on the total weight of the fiber-reinforced composition (C):

[0060] a) 57.0 to 92.4 wt.%, preferably 60.0 to 90.0 wt.%, more preferably 65.0 to 85.0 wt.%, still more preferably 70.0 to 80.0 wt.% of a propylene random copolymer (P),

[0061] b) 5.0 to 40.0 wt. %, preferably 8.0 to 37.0 wt. %, more preferably 11.0 to 32.0 wt. %, still more preferably 15.0 to 27.0 wt. % of fibers (F),

[0062] c) 0.1 to 5.0 wt. %, more preferably 1.0 to 3.0 wt. % of an adhesion promoter (AP), and

[0063] d) 0.01 to 2.5% by weight of additives (AD).

[0064] Additives (AD) are described in more detail below.

[0065] Preferably, the fiber reinforced composition (C) according to the present invention does not contain other polymers other than the propylene random copolymer (P) and the adhesion promoter (AP) in an amount of more than 5.0 wt.-%, preferably more than 3.0 wt.-%, more preferably more than 2.5 wt.-%, based on the total weight of the fiber reinforced composition (C). An additional polymer that may be present in such low amounts is polyethylene, which is a reaction by-product obtained by preparing the propylene random copolymer (P). Therefore, it is particularly understood that the fiber reinforced composition (C) contains as polymer compounds only the propylene random copolymer (P), the adhesion promoter (AP) and, optionally, the amounts of polyethylene mentioned in this paragraph.

[0066] It is particularly preferred that the fiber reinforced composition (C) of the present invention does not contain any one or more elastomeric polymers in an amount exceeding 5.0% by weight, preferably exceeding 3.0% by weight, more preferably exceeding 2.5% by weight, based on the total weight of the fiber reinforced composition (C). In particular, it is preferred that the fiber reinforced composition (C) of the present invention does not contain any ethylene propylene rubber (EPR) in an amount exceeding 5.0% by weight, preferably exceeding 3.0% by weight, more preferably exceeding 2.5% by weight, based on the total weight of the fiber reinforced composition (C). Therefore, it is preferred that the fiber reinforced composition has a xylene soluble content (XCS) determined according to ISO 16152 (25° C.) in the range of 3.0 to 15.0% by weight, more preferably in the range of 3.5 to 12.0% by weight, still more preferably in the range of 4.0 to 10.0% by weight, such as in the range of 4.5 to 9.5% by weight, based on the total weight of the fiber reinforced composition (C).

[0067] Preferably, the fiber reinforced composition (C) has a melt flow rate MFR2 (230°C, 2.16 kg) determined according to ISO 1133 in the range of 8.0 to 60.0 g / 10 min, more preferably in the range of 10.0 to 50.0 g / 10 min, still more preferably in the range of 12.0 to 40.0 g / 10 min, such as in the range of 14.0 to 30.0 g / 10 min.

[0068] Furthermore, it is preferred that the fiber reinforced composition (C) has a melting temperature as determined by differential scanning calorimetry (DSC) of equal to or lower than 155°C, more preferably in the range of 125 to 150°C, still more preferably in the range of 130 to 145°C, such as in the range of 132 to 140°C.

[0069] With regard to mechanical properties, it is preferred that the fiber reinforced composition (C) has a tensile modulus determined according to ISO 527-1A in the range of 2500 to 6000 MPa, more preferably in the range of 2800 to 5500 MPa, still more preferably in the range of 3000 to 5200 MPa, such as in the range of 3200 to 5000 MPa, and / or a tensile strength determined according to ISO 527-2 in the range of 40 to 100 MPa, preferably in the range of 40 to 80 MPa, more preferably in the range of 42 to 70 MPa, yet more preferably in the range of 45 to 68 MPa, such as in the range of 50 to 65 MPa.

[0070] Additionally or alternatively to the previous paragraph, it is preferred that the fiber-reinforced composition (C) has a thermal conductivity of at least 25.0 kJ / m 2 , more preferably at least 30.0 kJ / m 2 , still more preferably 35.0 kJ / m 2 , such as at least 40.0 kJ / m 2 The reasonable upper limit of the Charpy unnotched impact strength measured at 23°C according to ISO 179 is 100 kJ / m 2 .

[0071] Furthermore, it is preferred that the fiber reinforced composition (C) has a heat distortion temperature (HDT) measured according to ISO 75A of at least 110°C, more preferably at least 115°C, still more preferably at least 120°C, such as at least 125°C. A reasonable upper limit for the heat distortion temperature (HDT) measured according to ISO 75A is 155°C.

[0072] Furthermore, it is preferred that the fiber-reinforced composition (C) contains low amounts of volatile compounds (VOCs) as determined according to VDA 278, less than 25 μg / g, more preferably less than 20 μg / g, still more preferably less than 15 μg / g, such as less than 12 μg / g.

[0073] Likewise, it is preferred that the fiber-reinforced composition (C) contains low amounts of moderately volatile compounds (FOG) as determined according to VDA 278, less than 80 μg / g, more preferably less than 75 μg / g, still more preferably less than 45 μg / g, such as less than 40 μg / g.

[0074] The fiber reinforced composition (C) is preferably obtained by melt blending the propylene random copolymer (P), the fibers (F), optionally the adhesion promoter (AP) and optionally the additives (AD).

[0075] Hereinafter, the components of the fiber-reinforced composition (C) are described in more detail.

[0076] Propylene random copolymer (P)

[0077] The fiber-reinforced composition (C) of the present invention comprises a propylene random copolymer (P).

[0078] In particular, the propylene random copolymer (P) is a copolymer of propylene and ethylene and / or at least one C4 to C12 alpha-olefin. Therefore, the propylene random copolymer (P) includes monomers copolymerizable with propylene selected from ethylene and C4 to C12 alpha-olefins. Preferably, one or more comonomers are selected from ethylene and C4 to C6 alpha-olefins, such as 1-butene and / or 1-hexene. Especially preferably, the propylene random copolymer according to the present invention includes propylene and monomers copolymerizable with propylene selected from the group consisting of ethylene, 1-butene and 1-hexene, more preferably composed of propylene and monomers copolymerizable with propylene selected from the group consisting of ethylene, 1-butene and 1-hexene. More specifically, in addition to propylene, the propylene random copolymer of the present invention (P) comprises units derived from ethylene, 1-butene and / or 1-hexene.

[0079] According to a preferred embodiment of the present invention, the comonomer is 1-hexene. Therefore, it is especially preferred that the propylene random copolymer (P) comprises units derived only from propylene and 1-hexene. In other words, it is preferred that only propylene and 1-hexene are polymerized.

[0080] The term "random copolymer" is preferably understood according to IUPAC (Pure Applied Chemistry, Vol. 68, No. 8, pp. 1591-1595, 1996). Preferably, the molar concentration of the comonomer dyad (e.g., 1-hexene dyad) obeys the relationship

[0081] [HH]<[H]2

[0082] in

[0083] [HH] is the mole fraction of adjacent comonomer units, such as adjacent 1-hexene units, and

[0084] [H] is the mole fraction of the total comonomer units in the polymer, such as the mole fraction of the total 1-hexene units.

[0085] Preferably, the random propylene copolymer (P) has a comonomer content, more preferably a 1-hexene content, in the range of 1.0 to 6.0 mol-%, more preferably in the range of 1.5 to 5.2 mol-%, yet more preferably in the range of 2.0 to 4.7 mol-%, like in the range of 2.2 to 4.2 mol-%.

[0086] Additionally it is preferred that the random propylene copolymer (P) is bimodal.

[0087] In particular, it is preferred that the propylene random copolymer (P) comprises

[0088] i) a first random propylene copolymer (P1), and

[0089] ii) a second random propylene copolymer (P2) having a higher comonomer content, preferably a 1-hexene content, than the first random propylene copolymer (P1),

[0090] The combined amount of the first random propylene copolymer (P1) and the second random propylene copolymer (P2) is at least 95.0 wt.%, more preferably 97.0 wt.%, still more preferably 99.0 wt.%, like 99.9 wt.%, based on the random propylene copolymer (P). It is especially preferred that the random propylene copolymer essentially consists of, preferably consists of, the first random propylene copolymer (P1) and the second random propylene copolymer (P2).

[0091] With regard to the term "random copolymer", reference is made to the definition provided above.

[0092] Preferably, the weight ratio between the first random propylene copolymer (P1) and the second random propylene copolymer (P2) is in the range of 20 / 80 to 60 / 40, more preferably in the range of 30 / 70 to 55 / 45, still more preferably in the range of 40 / 60 to 50 / 50.

[0093] The second random propylene copolymer (P2) preferably has a higher comonomer content, such as 1-hexene content, than the first random propylene copolymer (P1). Preferably, the ratio C(P2) / C(P1) is in the range of 1.1 to 10.0, more preferably in the range of 2.0 to 7.5, yet more preferably in the range of 3.0 to 6.2, wherein C(P2) is the comonomer content, preferably 1-hexene content, in [mol%] of the second random propylene copolymer (P2) and C(P1) is the comonomer content, preferably 1-hexene content, in [mol%] of the first random propylene copolymer (P2).

[0094] It is especially preferred that the first random propylene copolymer (P1) has a comonomer content, preferably a 1-hexene content, in the range of 0.4 to 2.5 mol-%, more preferably in the range of 0.5 to 2.0 mol-%, still more preferably in the range of 0.6 to 1.6 mol-%.

[0095] The second random propylene copolymer (P2) preferably has a comonomer content, preferably 1-hexene content, in the range of 2.8 to 7.0 mol-%, more preferably in the range of 3.0 to 6.0 mol-%, still more preferably in the range of 3.2 to 5.0 mol-%.

[0096] Preferably, the propylene random copolymer (P) has an amount of 1,2-erythro regio defects of at least 0.4 mol%, more preferably in the range of 0.4 to 1.2 mol%. Without being bound by theory, the large amount of misintercalation of propylene and / or 1-hexene and / or 1-butene in the polymer chain indicates that the propylene random copolymer (P) is produced in the presence of a single-site catalyst, preferably a metallocene catalyst. It is known in the art that propylene random copolymers produced in the presence of a Ziegler-Natta catalyst can have 1,2-erythro regio defects far below 0.4 mol%, and are typically substantially free of 1,2-erythro regio defects.

[0097] Furthermore, it is preferred that the random propylene copolymer (P) according to this invention has a rather high melt flow rate. Accordingly, the random propylene copolymer (P) has a melt flow rate MFR2 (230°C, 2.16 kg), measured according to ISO 1133, in the range of 45.0 to 150 g / 10 min, preferably in the range of 50.0 to 130 g / 10 min, more preferably in the range of 55.0 to 110 g / 10 min, yet more preferably in the range of 60.0 to 100 g / 10 min.

[0098] In this regard it is preferred that the random propylene copolymer (P) is visbroken.

[0099] Visbreaking the propylene random copolymer (P) by heating or using a peroxide under more controlled conditions will narrow the molar mass distribution (MWD) and reduce the molar mass M, corresponding to an increase in MFR2, due to easier cleavage or shearing of long molecular chains. MFR2 increases with increasing the amount of peroxide used. Unless otherwise specified, throughout the present invention, the melt flow rate (MFR2) (230°C / 2.16kg) of the propylene random copolymer (P) is preferably the melt flow rate (230°C / 2.16kg) after visbreaking.

[0100] Preferred mixing equipment suitable for visbreaking are discontinuous and continuous kneaders, twin-screw extruders and single-screw extruders with special mixing sections, and co-kneaders.

[0101] Visbreaking can be performed in any known manner, such as by using a peroxide visbreaking agent. Typical visbreaking agents are 2,5-dimethyl-2,5-bis(tert-butylperoxy)hexane (DHBP) (sold, for example, under the trade names Luperox 101 and Trigonox 101), 2,5-dimethyl-2,5-bis(tert-butylperoxy)hexyne-3-ol (DYBP) (sold, for example, under the trade names Luperox 130 and Trigonox 145), dicumyl peroxide (DCUP) (sold, for example, under the trade names Luperox DC and Perkadox BC), di-tert-butyl peroxide (DTBP) (sold, for example, under the trade names Trigonox B and Luperox Di), tert-butylcumyl peroxide (BCUP) (sold, for example, under the trade names Trigonox T and Luperox 801), and bis(tert-butylperoxyisopropyl)benzene (DIPP) (sold, for example, under the trade names Perkadox 14S and Luperox DC). Suitable amounts of peroxide to be used according to the present invention are in principle known to the skilled person and can be easily calculated based on the amount of propylene random copolymer (P) to be visbroken, the MFR2 (230°C / 2.16 kg) value of the propylene random copolymer (P) to be visbroken and the desired target MFR2 (230°C / 2.16 kg) of the product to be obtained. Thus, typical amounts of peroxide visbreaking agents are from 0.005 to 0.7 wt.-%, more preferably from 0.01 to 0.4 wt.-%, based on the total amount of propylene random copolymer (P) used.

[0102] Typically, the visbreaking according to the invention is carried out in an extruder, so that under suitable conditions, an increase in the melt flow rate is obtained. During visbreaking, the chains of the higher molar mass of the starting product are statistically broken more frequently than the molecules of the lower molar mass, which, as described above, leads to an overall decrease in the average molecular weight and an increase in the melt flow rate.

[0103] Thus, the melt flow rate MFR2(initial) (230°C / 2.16 kg) of the propylene random copolymer (P), i.e. the melt flow rate before visbreaking, is much lower, such as in the range of 0.5 to 10.0 g / 10 min. For example, before visbreaking, the melt flow rate MFR2(initial) (230°C / 2.16 kg) of the propylene random copolymer (P) is in the range of 0.8 to 8.0 g / 10 min, such as in the range of 1.0 to 6.0 g / 10 min.

[0104] In one embodiment of the present invention the propylene random copolymer (P) has been visbroken with a visbreaking ratio [final MFR2 (230°C / 2.16 kg) / initial MFR2 (230°C / 2.16 kg)] of at least 5.0, wherein "final MFR2 (230°C / 2.16 kg)" is the MFR2 (230°C / 2.16 kg) of the propylene random copolymer (P) after visbreaking and "initial MFR2 (230°C / 2.16 kg)" is the MFR2 (230°C / 2.16 kg) of the propylene random copolymer (P) before visbreaking. Preferably, the propylene random copolymer (P) has been visbroken with a visbreaking ratio [final MFR2 (230°C / 2.16 kg) / initial MFR2 (230°C / 2.16 kg)] of 5.0 to 100, wherein "final MFR2 (230°C / 2.16 kg)" is the MFR2 (230°C / 2.16 kg) of the propylene homopolymer after visbreaking and "initial MFR2 (230°C / 2.16 kg)" is the MFR2 (230°C / 2.16 kg) of the propylene homopolymer before visbreaking. More preferably, the propylene random copolymer (P) has been visbroken with a visbreaking ratio [final MFR2 (230°C / 2.16 kg) / initial MFR2 (230°C / 2.16 kg)] of 10 to 80, still more preferably of 20 to 70, wherein "final MFR2 (230°C / 2.16 kg)" is the MFR2 (230°C / 2.16 kg) of the propylene random copolymer (P) after visbreaking and "initial MFR2 (230°C / 2.16 kg)" is the MFR2 (230°C / 2.16 kg) of the propylene random copolymer (P) before visbreaking.

[0105] The melting temperature Tm of the propylene random copolymer (P), determined according to differential scanning calorimetry (DSC), is in the range of 125 to 150°C, preferably in the range of 128 to 145°C, more preferably in the range of 130 to 142°C, still more preferably in the range of 132 to 140°C.

[0106] The random propylene copolymer (P) is further characterized by the amount of xylene cold solubles (XCS). Preferably, the random propylene copolymer (P) has a xylene soluble content (XCS) determined according to ISO 16152 (25°C) in the range of 3.0 to 15.0 wt.-%, more preferably in the range of 3.5 to 12.0 wt.-%, yet more preferably in the range of 4.0 to 10.0 wt.-%, such as in the range of 5.0 to 9.0 wt.-%. According to another preferred embodiment, the random propylene copolymer (P) has a xylene soluble content (XCS) determined according to ISO 16152 (25°C) in the range of 0.1 to 15.0 wt.-%, more preferably in the range of 0.1 to 12.0 wt.-%, yet more preferably in the range of 0.1 to 10.0 wt.-%, such as in the range of 0.1 to 9.0 wt.-%.

[0107] A low amount of xylene cold solubles (XCS) additionally indicates that the random propylene copolymer (P) preferably does not contain elastomeric (co)polymers forming inclusions as a second phase for improving the mechanical properties. Polymers containing elastomeric (co)polymers as insertions of a second phase would be referred to as heterophasic and are preferably not part of the present invention. The presence of second phases or so-called inclusions is visible, for example, by high-resolution microscopy, such as electron microscopy or atomic force microscopy, or by dynamic mechanical thermal analysis (DMTA). In particular, in DMTA, the presence of a heterophasic structure can be identified by the presence of at least two different glass transition temperatures.

[0108] Accordingly it is preferred that the random propylene copolymer (P) according to this invention does not have a glass transition temperature below -30°C, preferably below -25°C, more preferably below -20°C.

[0109] According to another preferred embodiment of the present invention, the comonomer of the propylene random copolymer is 1-butene. Therefore, it is particularly preferred that the propylene random copolymer (P) comprises units derived only from propylene and 1-butene. In other words, it is preferred that only propylene and 1-butene are polymerized.

[0110] In another preferred embodiment, the propylene random copolymer (P) has a 1-butene content in the range of 1.0 to 6.0 mol-%, more preferably in the range of 1.5 to 5.2 mol-%, still more preferably in the range of 2.0 to 5.2 mol-%, such as in the range of 3.5 to 5.0 mol-%. In another preferred embodiment, the comonomer of the propylene random copolymer is 1-butene, and the propylene random copolymer (P) has a 1-butene content in the range of 1.0 to 6.0 mol-%, more preferably in the range of 1.5 to 5.2 mol-%, yet more preferably in the range of 2.0 to 5.2 mol-%, such as in the range of 3.5 to 5.0 mol-%.

[0111] According to another preferred embodiment of the present invention, the comonomer of the propylene random copolymer is 1-butene, and the propylene random copolymer (P) comprises

[0112] i) a first random propylene copolymer (P1) having a comonomer content in the range of 2.0 to 6.0 mol-%, preferably in the range of 2.5 to 5.5 mol-%, more preferably in the range of 3.0 to 5.0 mol-%, e.g. 4.0 to 4.5 mol-%, and

[0113] ii) a second random propylene copolymer (P2) having a comonomer content in the range of 4.0 to 10.0 mol-%, preferably in the range of 5.0 to 9.0 mol-%, more preferably in the range of 5.5 to 8.0 mol-%, like 6.0 to 7.0 mol-%.

[0114] According to another preferred embodiment of the present invention, the comonomer of the propylene random copolymer is 1-butene and the propylene random copolymer (P) has a xylene soluble content (XCS), determined according to ISO 16152 (25°C), in the range of 0.1 to 5.0 wt.-%, preferably in the range of 0.2 to 3.0 wt.-%, more preferably in the range of 0.3 to 2.0 wt.-%, based on the total weight of the propylene random copolymer (P).

[0115] According to another preferred embodiment of the present invention, the comonomer of the random propylene copolymer is 1-butene, and the random propylene copolymer (P) has a melt flow rate MFR2 (230°C, 2.16 kg), determined according to ISO 1133, in the range of 45.0 to 150.0 g / 10 min, preferably in the range of 50.0 to 130.0 g / 10 min, more preferably in the range of 55.0 to 110.0 g / 10 min, yet more preferably in the range of 60.0 to 100.0 g / 10 min.

[0116] The random propylene copolymer (P) is in particular obtainable, preferably obtainable, by the process defined in detail below.

[0117] The process for preparing the random propylene copolymer (P) is preferably a sequential polymerization process comprising at least two reactors connected in series, wherein the process comprises the following steps

[0118] (A) polymerizing propylene and a comonomer selected from ethylene and C4 to C12 α-olefins, preferably 1-hexene or 1-butene, in a first reactor (R-1) being a slurry reactor (SR), preferably a loop reactor (LR), to obtain a first propylene random copolymer (P1) as defined in the present invention,

[0119] (B) transferring the first random propylene copolymer (P1) and unreacted comonomers from the first reactor (R-1) to a second reactor (R-2) which is a gas phase reactor (GPR-1),

[0120] (C) feeding propylene and a comonomer selected from ethylene and C4 to C12 α-olefins, preferably 1-hexene or 1-butene, to the second reactor (R-2),

[0121] (D) polymerizing propylene and a comonomer selected from ethylene and C4 to C12 α-olefins, preferably 1-hexene or 1-butene, in the presence of the first propylene random copolymer (P1) in the second reactor (R-2) to obtain the second propylene random copolymer (P2) as defined in the present invention, the first propylene random copolymer (P1) and the second propylene random copolymer (P2) forming the propylene random copolymer (P) as defined in the present invention, wherein further

[0122] In the first reactor (R-1) and the second reactor (R-2), the polymerization is carried out in the presence of a solid catalyst system (SCS) comprising

[0123] (i) Transition metal compound of formula (I)

[0124] R n (Cp)2MX2(I)

[0125] in

[0126] "M" is zirconium (Zr) or hafnium (Hf),

[0127] Each "X" is independently a monovalent anionic sigma-ligand,

[0128] each "Cp" is a cyclopentadienyl-type organic ligand independently selected from the group consisting of unsubstituted or substituted and / or fused cyclopentadienyl, substituted or unsubstituted indenyl or substituted or unsubstituted fluorenyl, said organic ligand being coordinated to the transition metal (M),

[0129] "R" is a divalent bridging group connecting the organic ligand (Cp),

[0130] "n" is 1 or 2, preferably 1, and

[0131] (ii) optionally a promoter (Co) comprising an element (E) from Group 13 of the Periodic Table (IUPAC), preferably a promoter (Co) comprising an Al and / or B compound.

[0132] Concerning the definitions of the propylene random copolymer (P), the first propylene random copolymer (P1) and the second propylene random copolymer (P2), reference is made to the definitions given above.

[0133] The solid catalyst system (SCS) is defined in more detail below.

[0134] Due to the use of a solid catalyst system (SCS) in a sequential polymerization process, random propylene copolymers (P) as defined above can be produced. In particular, since a propylene copolymer, i.e., a first random propylene copolymer (P1), is produced in a first reactor (R-1) and this propylene copolymer, in particular the unreacted comonomer, is transferred to a second reactor (R-2), it is possible to produce copolymers (P) with a high comonomer content in a sequential polymerization process. Conventionally, the production of propylene copolymers with a high comonomer content in a sequential polymerization process leads to fouling or, in severe cases, blockage of the transfer lines, as unreacted comonomer typically condenses in the transfer lines. However, with the new process, the increased conversion of the comonomer, and thus better incorporation into the polymer chains, leads to higher comonomer contents and reduced stickiness.

[0135] The term "sequential polymerization process" means that the propylene random copolymer (P) is produced in at least two reactors connected in series. More precisely, the term "sequential polymerization process" in this application means that the polymer from the first reactor (R-1) and the unreacted comonomer are conveyed directly to the second reactor (R-2). Therefore, a decisive aspect of the process of the present invention is that the propylene random copolymer (P) is produced in two different reactors, wherein the reaction material from the first reactor (R-1) is conveyed directly to the second reactor (R-2). Therefore, the process of the present invention comprises at least a first reactor (R-1) and a second reactor (R-2). In a specific embodiment, the process of the present invention consists of two polymerization reactors (R-1) and (R-2). The term "polymerization reactor" is intended to indicate that the main polymerization takes place. Therefore, in case the process consists of two polymerization reactors, this definition does not exclude the option of the overall process including a prepolymerization step, for example in a prepolymerization reactor. The term "consisting of..." is only a closed expression with respect to the main polymerization reactor.

[0136] The first reactor (R-1) is a slurry reactor (SR) and can be any continuous or simple batch stirred tank reactor or loop reactor operating in slurry. According to the present invention, the slurry reactor (SR) is preferably a loop reactor (LR).

[0137] The second reactor (R-2) and any subsequent reactors are gas phase reactors (GPR). Such gas phase reactors (GPR) can be any mechanically mixed or fluidized bed reactor. Preferably, one or more gas phase reactors (GPR) comprise a mechanically stirred fluidized bed reactor having a gas velocity of at least 0.2 m / s. Therefore, it should be understood that the gas phase reactor (GPR) is a fluidized bed type reactor preferably with a mechanical stirrer.

[0138] The conditions in each reactor (temperature, pressure, reaction time, monomer feed) depend on the desired product as known to those skilled in the art. As described above, the first reactor (R-1) is a slurry reactor (SR), such as a loop reactor (LR), and the second reactor (R-2) is a gas phase reactor (GPR-1). Subsequent reactors (if present) are also gas phase reactors (GPR).

[0139] A preferred multi-stage process is a "loop-gas phase" process, such as that developed by Borealis A / S of Denmark (known as technology), described, for example, in patent literature, such as EP 0 887 379 or WO 92 / 12182.

[0140] Multimodal polymers can be produced according to several processes as described, for example, in WO 92 / 12182, EP 0 887 379 and WO 98 / 58976. The contents of these documents are included herein by reference.

[0141] Preferably, in the process of the present invention for producing the propylene random copolymer (P) as defined above, the conditions for the first reactor (R-1), i.e. the slurry reactor (SR), e.g. the loop reactor (LR), of step (A) may be the following:

[0142] - a temperature in the range of 40°C to 110°C, preferably between 60°C and 100°C, more preferably in the range of 65 to 90°C,

[0143] - a pressure in the range of 20 to 80 bar, preferably between 40 and 70 bar,

[0144] Hydrogen can be added for controlling the molar mass in a manner known per se.

[0145] Subsequently, the reaction mixture from step (A) is transferred to the second reactor (R-2), i.e. the gas phase reactor (GPR-1), i.e. to step (D), wherein the conditions in step (D) are preferably the following:

[0146] - a temperature in the range of 50°C to 130°C, preferably between 60°C and 100°C,

[0147] - a pressure in the range of 5 to 50 bar, preferably between 15 and 40 bar,

[0148] Hydrogen can be added for controlling the molar mass in a manner known per se.

[0149] The residence time can be varied in the two reactor zones.

[0150] In one embodiment of the process for producing the random propylene copolymer (P), the residence time in the slurry reactor (SR), e.g. the loop (LR), is in the range of 0.2 to 4.0 hours, e.g. 0.3 to 1.5 hours, while the residence time in the gas phase reactor (GPR) is typically 0.2 to 6.0 hours, such as 0.5 to 4.0 hours.

[0151] If desired, the polymerization can be carried out in a known manner under supercritical conditions in the first reactor (R-1), ie in the slurry reactor (SR), such as in the loop reactor (LR).

[0152] The conditions in the other gas phase reactors (GPR), if present, are similar to those of the second reactor (R-2).

[0153] The process of the present invention may also comprise a prepolymerization prior to the polymerization in the first reactor (R-1). The prepolymerization can be carried out in the first reactor (R-1), but preferably, the prepolymerization is carried out in a separate reactor, the so-called prepolymerization reactor.

[0154] The random propylene copolymer (P) according to this invention is produced in the presence of a solid catalyst system (SCS) comprising a transition metal compound.

[0155] The transition metal compound has the formula (I)

[0156] R n (Cp)2MX2(I)

[0157] in

[0158] each Cp is independently an unsubstituted or substituted and / or fused cyclopentadienyl ligand, such as a substituted or unsubstituted cyclopentadienyl, substituted or unsubstituted indenyl or substituted or unsubstituted fluorenyl ligand; the optional substituent(s) are preferably independently selected from halogen, hydrocarbon (e.g., C1-C20-alkyl, C2-C20-alkenyl, C2-C20-alkynyl, C3-C12-cycloalkyl, C6-C20-aryl or C7-C20-aralkyl), C3-C12-cycloalkyl containing 1, 2, 3 or 4 heteroatoms in the ring portion, C6-C20-heteroaryl, C1-C20-haloalkyl, -SiR"3, -OSiR"3, -SR", -PR"2, OR" or -NR"2,

[0159] Each R" is independently hydrogen or a hydrocarbon group, such as a C1-C20-alkyl, C2-C20-alkenyl, C2-C20-alkynyl, C3-C12-cycloalkyl or C6-C20-aryl group; or, for example in the case of -NR"2, the two substituents R" may form a ring together with the nitrogen atom to which they are attached, such as a five-membered ring or a six-membered ring;

[0160] R is a bridge of 1 to 3 atoms, for example a bridge of 1 to 2 carbon atoms and 0 to 2 heteroatoms, wherein the heteroatom(s) may be, for example, one or more Si, Ge and / or O atoms, wherein each bridge atom may independently carry a substituent, such as a C1-C20-alkyl, tri(C1-C20-alkyl)silyl, tri(C1-C20-alkyl)siloxy or C6-C20-aryl substituent); or a bridge of 1 to 3, for example 1 or 2, heteroatoms, such as one or more silicon, germanium and / or oxygen atoms, for example -SiR 10 2, where each R 10 independently C1-C20-alkyl, C3-12-cycloalkyl, C6-C20-aryl or tri(C1-C20-alkyl)silyl residues, such as trimethylsilyl;

[0161] M is a transition metal of Group 4, such as Zr or Hf, especially Zr;

[0162] each X is independently a σ-ligand such as H, halogen, C1-C20-alkyl, C1-C20-alkoxy, C2-C20-alkenyl, C2-C20-alkynyl, C3-C12-cycloalkyl, C6-C20-aryl, C6-C20-aryloxy, C7-C20-aralkyl, C7-C20-aralkenyl, -SR", -PR", -SiR", -OSiR", -NR", or -CH2-Y, wherein Y is C6-C20-aryl, C6-C20-heteroaryl, C1-C20-alkoxy, C6-C20-aryloxy, NR", -SR", -PR", -SiR", or -OSiR",

[0163] Each of the above ring moieties, alone or as part of another moiety such as a substituent for Cp, X, R" or R, may also be substituted, for example by C1-C20-alkyl which may contain Si and / or O atoms;

[0164] n is 1 or 2.

[0165] Suitably, in each X such as -CH2-Y, each Y is independently selected from C6-C20-aryl, NR"2, -SiR"3 or -OSiR"3. Most preferably, X such as -CH2-Y is benzyl. Each X different from -CH2-Y is independently halogen, C1-C20-alkyl, C1-C20-alkoxy, C6-C20-aryl, C7-C20-arylalkenyl or -NR"2 as defined above, for example -N(C1-C20-alkyl).

[0166] Preferably, each X is halogen, methyl, phenyl or -CH2-Y, and each Y is independently as defined above.

[0167] Cp is preferably cyclopentadienyl, indenyl or fluorenyl, optionally substituted as defined above. Ideally Cp is cyclopentadienyl or indenyl.

[0168] In suitable subgroups of compounds of formula (I), each Cp independently carries 1, 2, 3 or 4 substituents as defined above, preferably 1, 2 or 3, such as 1 or 2 substituents, which are preferably selected from C1-C20-alkyl, C6-C20-aryl, C7-C20-aralkyl (wherein the aromatic ring alone or as part of another moiety may also be substituted as indicated above), -OSiR"3, where R" is as indicated above, preferably C1-C20-alkyl.

[0169] R″ is preferably a methylene, ethylene or silyl bridge, wherein the silyl group may be substituted as defined above, for example (dimethyl)Si═, (methylphenyl)Si═, (methylcyclohexyl)silyl═ or (trimethylsilylmethyl)Si═; n is 0 or 1. Preferably, R″ is not hydrogen.

[0170] Specific subgroups include the well-known metallocenes of Zr and Hf with two η5-ligands bridged with a cyclopentadienyl ligand, which is optionally substituted with a silanoxy or alkyl group (e.g., C1-6-alkyl) as defined above, or with two bridged indenyl ligands, which are optionally substituted with a silanoxy or alkyl group, e.g., as defined above, in any ring portion, e.g., in the 2-, 3-, 4-, and / or 7-positions. Preferred bridges are ethylene or -SiMe2.

[0171] The preparation of metallocene can be carried out according to or be similar to known methods in the literature and is within the skill range of those skilled in the art. Therefore, about preparation, referring to for example EP-A-129 368, wherein the metal atom has-NR " The example of the compound of part is referring to especially in WO-A-985683 1 and WO-A-0034341. About preparation, also referring to for example EP-A-260130, WO-A-9728170, WO-A-9846616, WO-A-9849208, WO-A-9912981, WO-A-9919335, WO-A-9856831, WO-A-00 34341, EP-A-423 101 and EP-A-537 130.

[0172] Complex compound of the present invention is preferably asymmetric. This only means that the two indenyl ligands forming the metallocene are different, i.e. each indenyl ligand carries a set of chemically different or differently positioned substituents relative to the other indenyl ligand. More precisely, they are chiral, racemic bridged bis-indenyl metallocenes. Although complex compound of the present invention can be in its cis configuration ideally, they are in its trans configuration. For purposes of the present invention, racemic-trans refers to that the two indenyl ligands are oriented in opposite directions relative to the cyclopentadienyl-metal-cyclopentadienyl plane, while racemic-cis refers to that the two indenyl ligands are oriented in the same direction relative to the cyclopentadienyl-metal-cyclopentadienyl plane.

[0173] Preferred complexes of the present invention have formula (II') or (II)

[0174]

[0175] in

[0176] M is Zr;

[0177] Each X is a sigma ligand, preferably each X is independently a hydrogen atom, a halogen atom, a C1-C6 alkoxy group, a C1-C6 alkyl group, a phenyl group or a benzyl group;

[0178] L is a divalent bridge selected from -R'2C-, -R'2C-CR'2, -R'2Si-, -R'2Si-SiR'2-, -R'2Ge-, wherein each R' is independently a hydrogen atom, a C1-C20 alkyl group, a C3-C10 cycloalkyl group, a tri(C1-C20-alkyl)silyl group, a C6-C20-aryl group, a C7-C20 aralkyl group;

[0179] Each R 2 or R 2 ' is a C1-C10 alkyl group;

[0180] R 5' is C1-C10 alkyl or Z'R 3 'group;

[0181] R 6 is hydrogen or C1-C10 alkyl;

[0182] R 6 ' is a C1-C10 alkyl group or a C6-C10 aryl group;

[0183] R 7 is hydrogen, C1-C6 alkyl or ZR 3 group;

[0184] R 7 ' is hydrogen or C1-C10 alkyl;

[0185] Z and Z' are independently O or S;

[0186] R 3 ' is a C1-C10 alkyl group, or a C6-C10 aryl group, which is optionally substituted by one or more halogen groups;

[0187] R 3 is a C1-C10 alkyl group;

[0188] Each n is independently 0 to 4, such as 0, 1 or 2;

[0189] and each R 1 and independently a C1-C20 hydrocarbon group, such as a C1-C10 alkyl group.

[0190] Particularly preferred compounds of the present invention include:

[0191] rac-Dimethylsilylenebis[2-methyl-4-(4-tert-butylphenyl)-1,5,6,7-tetrahydro-s-indacen-1-yl]zirconium dichloride

[0192] rac-dimethylsilylenebis(2-methyl-4-phenyl-5-methoxy-6-tert-butylinden-1-yl)zirconium dichloride

[0193] Racemic-trans-Me2Si(2-Me-4-Ph-6-tBu-Ind)(2-Me-4-Ph-5-OMe-6-tBu-Ind)ZrCl2

[0194] Racemic-trans-Me2Si(2-Me-4-(p-tBuPh)-Ind)(2-Me-4-Ph-5-OMe-6-tBu-Ind)ZrCl2

[0195] Racemic-trans-Me2Si(2-Me-4-(3,5-di-tBuPh)-6-tBu-Ind)(2-Me-4-Ph-5-OMe-6-tBu-Ind)ZrCl2

[0196] Racemic-trans-Me2Si(2-Me-4-(p-tBuPh)-Ind)(2-Me-4-Ph-5-OC6F5)-6-iPr-Ind)ZrCl2

[0197] Racemic-trans-Me(CyHex)Si(2-Me-4-Ph-6-tBu-Ind)(2-Me-4-Ph-5-OMe-6-tBu-Ind)ZrCl2

[0198] Racemic-trans-Me2Si(2-Me-4-(3,5-di-tBuPh)-7-Me-Ind)(2-Me-4-Ph-5-OMe-6-tBu-Ind)ZrCl2

[0199] Racemic-trans-Me2Si(2-Me-4-(3,5-di-tBuPh)-7-OMe-Ind)(2-Me-4-Ph-5-OMe-6-tBu-Ind)ZrCl2

[0200] Racemic-trans-Me2Si(2-Me-4-(p-tBuPh)-6-tBu-Ind)(2-Me-4-Ph-5-OMe-6-tBu-Ind)ZrCl2

[0201] Racemic-trans-Me2Si(2-Me-4-(p-tBuPh)-Ind)(2-Me-4-(4-tBuPh)-5-OMe-6-tBu-Ind)ZrCl2

[0202] Racemic-trans-Me2Si(2-Me-4-(p-tBuPh)-Ind)(2-Me-4-(3,5-tBu2Ph)-5-OMe-6-tBu-Ind)ZrCl2

[0203] rac-trans-Me2Si(2-Me-4-(p-tBuPh)-Ind)(2-Me-4-Ph-5-OtBu-6-tBu-Ind)ZrCl2.

[0204] The most preferred metallocene complex (procatalyst) is rac-trans-dimethylsilylene(2-methyl-4-phenyl-5-methoxy-6-tert-butyl-indenyl)(2-methyl-4-(4-tert-butylphenyl)indenyl)zirconium dichloride.

[0205] In addition to the metallocene complex (procatalyst), the metallocene catalyst also comprises a cocatalyst as defined in WO 2015 / 011135 A1. Therefore, the preferred cocatalyst is methylaluminoxane (MAO) and / or a borate ester, preferably trityl tetrakis(pentafluorophenyl)borate.

[0206] It is particularly preferred that the metallocene catalyst is unsupported, ie no external support is used. With regard to the preparation of such metallocene complexes, reference is again made to WO 2015 / 011135 A1.

[0207] Fiber (F)

[0208] An essential component of the fiber-reinforced composition (C) of the present invention is the fiber (F).

[0209] Preferably, the fibers (F) are selected from the group consisting of glass fibers, carbon fibers, polymer fibers, metal fibers, mineral fibers, ceramic fibers, and mixtures thereof. More preferably, the fibers (F) are glass fibers and / or carbon fibers.

[0210] It is particularly preferred that the fibers (F) are glass fibers (GF). Preferably, the glass fibers (GF) are cut glass fibers, also known as short glass fibers (SGF) or chopped strands, and / or long glass fibers (LGF), preferably long glass fibers (LGF) obtained from glass roving.

[0211] It is particularly preferred that the fibers (F) are short glass fibers (SGF).

[0212] The chopped or short glass fibers (SGF) used in the fiber-reinforced composition (C) preferably have an average length in the range of 2.0 to 10.0 mm, more preferably in the range of 2.3 to 9.0 mm, still more preferably in the range of 2.5 to 8.0 mm, such as in the range of 3.0 to 7.0 mm.

[0213] The chopped or short glass fibers (SGF) used in the fiber-reinforced composition (C) preferably have an average diameter of 5 to 20 μm, more preferably 6 to 18 μm, still more preferably 8 to 16 μm.

[0214] Preferably, the short glass fibers (SGF) have an aspect ratio of 125 to 650, preferably 150 to 500, more preferably 200 to 450. The aspect ratio is the relationship between the average length and the average diameter of a fiber.

[0215] Adhesion Promoter (AP)

[0216] According to the present invention, the fiber reinforced polypropylene composition (C) may further comprise an adhesion promoter (AP). In case the fibers (F) are glass fibers and / or carbon fibers, it is preferred that the fiber reinforced polypropylene composition (C) comprises an adhesion promoter (AP).

[0217] The adhesion promoter (AP) is designated as a polar modified polypropylene (PM-PP) homopolymer or copolymer.

[0218] Polar modified polypropylene (PM-PP) homopolymers or copolymers contain low molecular weight compounds with reactive polar groups. Most preferred are modified polypropylene homopolymers and copolymers such as propylene and ethylene or other α-olefins (e.g. C4 to C 10 Copolymers of propylene (α-olefins) are preferred because they are highly compatible with the propylene polymer (P) of the fiber-reinforced polypropylene composition (C) of the present invention.

[0219] In terms of structure, the polar modified polypropylene (PM-PP) homopolymer or copolymer is preferably selected from grafted homopolymers or copolymers.

[0220] In this context it is preferred that the polar modified polypropylene (PM-PP) homo- or copolymer contains groups derived from polar compounds, in particular selected from the group consisting of anhydrides, carboxylic acids, carboxylic acid derivatives, primary and secondary amines, hydroxyl compounds, oxazolines and epoxides and ionic compounds.

[0221] Specific examples of the polar compound are unsaturated cyclic anhydrides and aliphatic diesters and diacid derivatives thereof. In particular, maleic anhydride and a compound 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 dialkyl itaconic acid esters, acrylic acid, maleic acid, fumaric acid, itaconic acid, and mixtures thereof can be used.

[0222] Particular preference is given to using polypropylene homo- or copolymers grafted with maleic anhydride or acrylic acid as polar-modified polypropylene (PM-PP) homo- or copolymers, ie adhesion promoters (AP).

[0223] Modified polymers, i.e. adhesion promoters, can be produced in a simple manner by reactive extrusion of polymers, for example with maleic anhydride or acrylic acid in the presence of free radical generators such as organic peroxides, as disclosed, for example, in US Pat. No. 4,506,056, US Pat. No. 4,753,997 or EP 1 805 238.

[0224] The preferred amount of groups derived from polar compounds in the polar modified polypropylene (PM-PP) homopolymer or copolymer (i.e., adhesion promoter (AP)) is 0.5 to 5.0 wt. %. For example, the amount may be in the range of 0.5 to 4.5 wt. %, preferably in the range of 0.5 to 4.0 wt. %, more preferably in the range of 0.5 to 3.5 wt. %.

[0225] The preferred value of the melt flow rate MFR2 (230°C) of the polar modified polypropylene (PM-PP) homopolymer or copolymer (i.e. the adhesion promoter (AP)) is from 20.0 to 400 g / 10 min. It is particularly preferred that the polar modified polypropylene (PM-PP) homopolymer or copolymer has a melt flow rate MFR2 (230°C) in the range of 40.0 to 300 g / 10 min, more preferably in the range of 50.0 to 250 g / 10 min.

[0226] In a preferred embodiment of the present invention, the adhesion promoter (AP) is a maleic anhydride-modified polypropylene homopolymer or copolymer and / or an acrylic acid-modified polypropylene homopolymer or copolymer. Preferably, the adhesion promoter (AP) is a maleic anhydride-modified polypropylene homopolymer and / or an acrylic acid-modified polypropylene homopolymer, and preferably a maleic anhydride-modified polypropylene homopolymer. For example, suitable polar modified polypropylene (PM-PP) homopolymers or copolymers include, for example, polypropylene homopolymer grafted with maleic anhydride (PP-g-MAH) and polypropylene homopolymer grafted with acrylic acid (PP-g-AA).

[0227] According to another preferred embodiment of the present invention the adhesion promoter (AP) is a propylene random copolymer (P) grafted with maleic anhydride as described above.

[0228] Additives (AD)

[0229] In addition to the propylene random copolymer (P), the fibers (F) and the adhesion promoter (AP), the fiber-reinforced composition (C) of the present invention may include additives (AD). Typical additives are acid scavengers, antioxidants, colorants, light stabilizers, plasticizers, slip agents, anti-scratch agents, dispersants, processing aids, lubricants, pigments, etc.

[0230] Such additives are commercially available and are described, for example, in the “Plastic Additives Handbook” by Hans Zweifel, 6th edition, 2009 (pp. 1141 to 1190).

[0231] Furthermore, the term "additive (AD)" according to the present invention also comprises support materials, in particular polymeric support materials.

[0232] Polymer carrier materials

[0233] Preferably, the fiber-reinforced composition (C) of the present invention does not contain (a) other polymers other than the random propylene copolymer (P) and the adhesion promoter (AP) in an amount of more than 5.0 wt.-%, preferably more than 3.0 wt.-%, more preferably more than 2.0 wt.-%, based on the total weight of the fiber-reinforced composition (C). Any polymer serving as a carrier material for the additive (AD) is not counted towards the amount of the polymer compound indicated in the present invention, but rather towards the amount of the corresponding additive.

[0234] The polymer carrier material of the additive (AD) is a carrier polymer to ensure uniform distribution in the fiber-reinforced polypropylene composition (C) of the present invention. The polymer carrier material is not limited to a specific polymer. The polymer carrier material can be an ethylene homopolymer, an ethylene copolymer obtained by ethylene and an α-olefin comonomer (such as a C3 to C8 α-olefin comonomer), a propylene homopolymer and / or a propylene copolymer obtained by propylene and an α-olefin comonomer (such as ethylene and / or a C4 to C8 α-olefin comonomer). Preferably, the polymer carrier material does not contain monomer units derived from styrene or its derivatives.

[0235] Products

[0236] The present invention also relates to an article, such as an injection molded article, comprising a fiber-reinforced composition (C) as defined above. The present invention particularly relates to an article, such as an injection molded article, comprising at least 60 wt.%, more preferably at least 80 wt.%, still more preferably at least 90 wt.%, such as at least 95 wt.% or at least 99 wt.% of a fiber-reinforced polypropylene composition (C) as defined above. In a particularly preferred embodiment, the present invention relates to an article, such as an injection molded article, consisting of a fiber-reinforced composition (C) as defined above.

[0237] Preferably, the article is an automotive article, such as an injection molded automotive article.

[0238] Further implementation plans

[0239] [1] A fiber-reinforced composition (C), based on the total weight of the fiber-reinforced composition (C)

[0240] a) 57.0 to 95.0 wt.% of a random propylene copolymer (P), wherein the comonomer is selected from ethylene and / or at least one C4 to C12 α-olefin, the random propylene copolymer (P) having

[0241] i) a melt flow rate MFR2 (230° C., 2.16 kg) determined according to ISO 1133 in the range of 45 to 150 g / 10 min, and

[0242] ii) a melting temperature Tm, determined according to differential scanning calorimetry (DSC), in the range of 125 to 150° C.,

[0243] b) 5.0 to 40.0 wt. % of fibers (F), and

[0244] c) Optionally 0.1 to 5.0% by weight of an adhesion promoter (AP).

[0245] [2] The fiber-reinforced composition (C) according to [1], wherein the propylene random copolymer (P) has an amount of 1,2-erythro regio defects of at least 0.4 mol%.

[0246] [3] The fiber-reinforced composition (C) according to [1] or [2], wherein the propylene random copolymer (P) comprises

[0247] i) a first random propylene copolymer (P1), and

[0248] ii) a second random propylene copolymer (P2) having a higher comonomer content than the first random propylene copolymer (P1),

[0249] wherein the weight ratio between the first propylene random copolymer (P1) and the second propylene random copolymer (P2) is in the range of 20 / 80 to 60 / 40, and the combined amount of the first propylene random copolymer (P1) and the second propylene random copolymer (P2) is at least 95.0 wt.-%, based on the propylene random copolymer (P).

[0250] [4] The fiber-reinforced composition (C) according to any one of [1] to [3], wherein the propylene random copolymer (P) has a comonomer content in the range of 1.0 to 6.0 mol%.

[0251] [5] The fiber-reinforced composition (C) according to any one of [1] to [4], wherein

[0252] i) the first random propylene copolymer (P1) has a comonomer content in the range of 0.4 to 2.5 mol-%, and

[0253] ii) The second random propylene copolymer (P2) has a comonomer content in the range of 2.8 to 7.0 mol-%.

[0254] [6] The fiber-reinforced composition (C) according to any one of [1] to [5], wherein the comonomer is 1-hexene.

[0255] [7] The fiber reinforced composition (C) according to any of [1] to [6], wherein the random propylene copolymer (P) has a xylene soluble content (XCS) determined according to ISO 16152 (25°C) in the range of 3.0 to 15.0 wt.-%, based on the total weight of the random propylene copolymer (P).

[0256] [8] The fiber reinforced composition (C) according to any one of [1] to [6], wherein the propylene random copolymer (P) has been visbroken with a visbreaking ratio [final MFR2 (230°C / 2.16 kg) / initial MFR2 (230°C / 2.16 kg)] of at least 5.0, wherein "final MFR2 (230°C / 2.16 kg)" is the MFR2 (230°C / 2.16 kg) of the propylene random copolymer (P) after visbreaking and "initial MFR2 (230°C / 2.16 kg)" is the MFR2 (230°C / 2.16 kg) of the propylene random copolymer (P) before visbreaking.

[0257] [9] The fiber-reinforced composition (C) according to [8], wherein the propylene random copolymer (P) has a melt flow rate MFR2 (230° C., 2.16 kg) measured according to ISO 1133 before visbreaking in the range of 0.5 to 10.0 g / 10 min.

[0258]

[10] The fiber-reinforced composition (C) according to any one of [1] to [9], wherein the fiber (F) is a glass fiber (GF), preferably a short glass fiber (SGF), having

[0259] i) an average length of 2.0 to 10.0 mm, and / or

[0260] ii) an average diameter of 5 to 20 μm.

[0261]

[11] The fiber-reinforced composition (C) according to any one of [1] to

[10] , wherein the adhesion promoter (AP) is a polar-modified polypropylene (PM-PP), the polar-modified polypropylene (PM-PP) being a propylene homopolymer or copolymer grafted with maleic anhydride, the polar-modified polypropylene (PM-PP) having a melt flow rate MFR2 (230°C, 2.16 kg) measured according to ISO 1133 of 20.0 g / 10 min to 400 g / 10 min.

[0262]

[12] The fiber-reinforced composition (C) according to any one of [1] to

[11] , wherein the fiber-reinforced composition (C) has a melt flow rate MFR2 (230°C, 2.16 kg) measured according to ISO 1133 in the range of 8.0 to 60.0 g / 10 min.

[0263]

[13] The fiber-reinforced composition (C) according to any one of [1] to

[12] , wherein the propylene random copolymer (P) is obtained in the presence of a solid catalyst system (SCS) comprising a metallocene compound.

[0264]

[14] The fiber-reinforced composition (C) according to claim

[13] , wherein the metallocene compound has the formula (I)

[0265] R n (Cp)2MX2(I)

[0266] in

[0267] each Cp is independently an unsubstituted or substituted and / or fused cyclopentadienyl ligand, such as a substituted or unsubstituted cyclopentadienyl, substituted or unsubstituted indenyl or substituted or unsubstituted fluorenyl ligand; the optional substituent(s) are preferably independently selected from halogen, hydrocarbon (e.g., C1-C20-alkyl, C2-C20-alkenyl, C2-C20-alkynyl, C3-C12-cycloalkyl, C6-C20-aryl or C7-C20-aralkyl), C3-C12-cycloalkyl containing 1, 2, 3 or 4 heteroatoms in the ring portion, C6-C20-heteroaryl, C1-C20-haloalkyl, -SiR"3, -OSiR"3, -SR", -PR"2, OR" or -NR"2,

[0268] Each R" is independently hydrogen or a hydrocarbon group, such as a C1-C20-alkyl, C2-C20-alkenyl, C2-C20-alkynyl, C3-C12-cycloalkyl or C6-C20-aryl group; or, for example in the case of -NR"2, the two substituents R" may form a ring together with the nitrogen atom to which they are attached, such as a five-membered ring or a six-membered ring;

[0269] R is a bridge of 1 to 3 atoms, for example a bridge of 1 to 2 carbon atoms and 0 to 2 heteroatoms, wherein the heteroatom(s) may be, for example, one or more Si, Ge and / or O atoms, wherein each bridge atom may independently carry a substituent, such as a C1-C20-alkyl, tri(C1-C20-alkyl)silyl, tri(C1-C20-alkyl)siloxy or C6-C20-aryl substituent); or a bridge of 1 to 3, for example 1 or 2, heteroatoms, such as one or more silicon, germanium and / or oxygen atoms, for example -SiR 10 2, where each R 10 independently C1-C20-alkyl, C3-12-cycloalkyl, C6-C20-aryl or tri(C1-C20-alkyl)silyl residues, such as trimethylsilyl;

[0270] M is a transition metal of Group 4, such as Zr or Hf, especially Zr;

[0271] each X is independently a σ-ligand such as H, halogen, C1-C20-alkyl, C1-C20-alkoxy, C2-C20-alkenyl, C2-C20-alkynyl, C3-C12-cycloalkyl, C6-C20-aryl, C6-C20-aryloxy, C7-C20-aralkyl, C7-C20-aralkenyl, -SR", -PR", -SiR", -OSiR", -NR", or -CH2-Y, wherein Y is C6-C20-aryl, C6-C20-heteroaryl, C1-C20-alkoxy, C6-C20-aryloxy, NR", -SR", -PR", -SiR", or -OSiR",

[0272] Each of the above ring moieties, alone or as part of another moiety such as a substituent for Cp, X, R" or R, may also be substituted, for example with C1-C20-alkyl groups which may contain Si and / or O atoms;

[0273] n is 1 or 2.

[0274]

[15] An article comprising the fiber-reinforced composition (C) according to any one of [1] to

[14] .

[0275] The present invention will now be described in more detail by way of the examples provided below.

[0276] Example

[0277] A. Measurement Method

[0278] Unless defined otherwise, the following definitions of terms and assay methods apply to the above general description of the invention as well as to the following examples.

[0279] 1-Hexene comonomer content of propylene-1-hexene copolymer (P)

[0280] Use for 1 H and 13 Quantitative measurements were recorded in the melt on a Bruker Avance III 500 NMR spectrometer operating at 500.13 and 125.76 MHz, respectively. 13 C{ 1 H} NMR spectroscopy. Nitrogen was used for all pneumatic devices and the temperature was 180 °C. 13All spectra were recorded using a C-optimized 7 mm magic angle spinning (MAS) probe. Approximately 200 mg of material was loaded into a 7 mm outer diameter zirconium oxide MAS rotor and spun at 4 kHz. This setup was chosen primarily for the high sensitivity required for rapid identification and accurate quantification (Klimke, K., Parkinson, M., Piel, C., Kaminsky, W., Spiess, H.W., Wilhelm, M., Macromol. Chem. Phys. 2006; 207: 382., Parkinson, M., Klimke, K., Spiess, H.W., Wilhelm, M., Macromol. Chem. Phys. 2007; 208: 2128., Castignolles, P., Graf, R., Parkinson, M., Wilhelm, M., Gaborieau, M., Polymer 50 (2009) 2373). Standard single pulse excitation was used with a short recycle delay of 3 s using NOE (Klimke, K., Parkinson, M., Piel, C., Kaminsky, W., Spiess, H.W., Wilhelm, M., Macromol. Chem. Phys. 2006; 207:382., Pollard, M., Klimke, K., Graf, R., Spiess, H.W., Wilhelm, M., Sperber, O., Piel, C., Kaminsky, W., Macromolecules 2004; 37:813.) and RS-HEPT decoupling scheme (Filip, X., Tripon, C., Filip, C., J. Mag. Resn. 2005, 176, 239., Griffin, J.M., Tripon, C., Samoson, A., Filip, C., and Brown, S.P., Mag. Res. in 2006). Chem. 200745, S1, S198). A total of 16,384 (16k) transient signals were collected for each spectrum.

[0281] Quantitative 13 C{ 1 H} NMR spectra were processed, integrated and relevant quantitative properties determined from the integration. All chemical shifts were internally referenced to the methyl isotactic pentad (mmmm) at 21.85 ppm.

[0282] A characteristic signal corresponding to the incorporation of 1-hexene was observed, and the comonomer content was quantified in the following manner.

[0283] The amount of 1-hexene incorporated into the PHP isolated sequence was quantified using the integration of the αB4 site at 44.2 ppm and taking into account the number of reported sites per comonomer:

[0284] H=IαB4 / 2

[0285] The amount of 1-hexene incorporated in the PHHP bicontinuous sequence was quantified using the integration of the ααB4 site at 41.7 ppm and taking into account the number of reporter sites for each comonomer:

[0286] HH=2*IααB4

[0287] When bicontinuous incorporation is observed, the amount of 1-hexene incorporated in the PHP isolated sequence needs to be compensated due to the overlap of the αB4 and αB4B4 signals at 44.4 ppm:

[0288] H=(IαB4–2*IααB4) / 2

[0289] The total 1-hexene content was calculated based on the sum of isolated and continuously incorporated 1-hexene:

[0290] H total = H + HH

[0291] When no sites indicating continuous incorporation were observed, the total 1-hexene comonomer content was calculated based solely on this amount:

[0292] H total = H

[0293] Characteristic signals indicative of regional 2,1-erythro defects were observed (Resconi, L., Cavallo, L., Fait, A., Piemontesi, F., Chem. Rev. 2000, 100, 1253).

[0294] The presence of Pαβ (21e8) and Pαγ (21e6) methyl sites at 17.7 and 17.2 ppm indicates the presence of 2,1-erythro regiodefects, which is confirmed by other characteristic signals.

[0295] The total amount of inserted secondary (2,1-erythro)propylene was quantified based on the αα21e9 methylene site at 42.4 ppm:

[0296] P21=Iαα21e9

[0297] The total amount of inserted primary (1,2) propene was quantified based on the main Sαα methylene site at 46.7 ppm and compensating for the relative amounts of 2,1-erythro, αB4, and ααB4B4 methylene units of propene that were not accounted for (note that H and HH count the number of hexene monomers per sequence rather than the number of sequences):

[0298] P12=I S αα+2*P21+H+HH / 2

[0299] The total amount of propene is quantified as the sum of inserted primary (1,2) and secondary (2,1-erythro) propene:

[0300] Ptotal=P12+P21=I S αα+3*Iαα21e9+(IαB4–2*IααB4) / 2+IααB4

[0301] This simplifies to:

[0302] Ptotal=I S αα+3*Iαα21e9+0.5*IαB4

[0303] The total mole fraction of 1-hexene in the polymer was then calculated as:

[0304] fH=Htotal / (Htotal+Ptotal)

[0305] The complete integrated equation for the mole fraction of 1-hexene in the polymer is:

[0306] fH=(((IαΒ4–2*IααΒ4) / 2)+(2*IααΒ4)) / ((ISαα+3*Iαα21e9+0.5*IαB4)+((IαΒ4–2*IααΒ4) / 2)+(2*IααΒ4))

[0307] This simplifies to:

[0308] fH=(IαΒ4 / 2+IααΒ4) / (ISαα+3*Iαα21e9+IαB4+IααB4)

[0309] The total comonomer incorporation of 1-hexene in mole percent is calculated from the mole fractions in the usual manner:

[0310] H [mol %] = 100 * fH

[0311] The total comonomer incorporation of 1-hexene in weight percent was calculated from the mole fractions in the standard manner:

[0312] H [wt%] = 100*(fH*84.16) / ((fH*84.16)+((1-fH)*42.08)).

[0313] Calculation of the comonomer content of the second random propylene copolymer (P2):

[0314]

[0315] in

[0316] w(P1) is the weight fraction of the first propylene random copolymer (P1),

[0317] w(P2) is the weight fraction of the second propylene random copolymer (P2),

[0318] C(P1) is the first propylene random copolymer (P1), i.e. the product of the first reactor (R1) 13 Comonomer content [in mol %] measured by C NMR spectroscopy,

[0319] C(P) is the product obtained in the second reactor (R2), i.e. a mixture of the first propylene random copolymer (P1) and the second propylene random copolymer (P2) [propylene random copolymer (P)]. 13 Comonomer content [in mol %] measured by C NMR spectroscopy,

[0320] C(P2) is the calculated comonomer content [in mol %] of the second random propylene copolymer (P2).

[0321] 1-Butene comonomer content of propylene-1-butene copolymer (P)

[0322] Record, process and reference quantification as described above 13 C{ 1 H} NMR spectroscopy.

[0323] A characteristic signal corresponding to 1-butene incorporation was observed, and the comonomer content was quantified in the following manner.

[0324] The amount of 1-butene incorporated into the PPBPP isolated sequence was quantified using the integration of the αB2 site at 43.6 ppm and taking into account the number of reported sites for each comonomer:

[0325] B=Iα / 2

[0326] The amount of 1-butene incorporated in the PPBBPP bicontinuous sequence was quantified using the integration of the ααB2B2 sites at 40.5 ppm and taking into account the number of reporter sites for each comonomer:

[0327] BB=2*Iαα

[0328] When bicontinuous incorporation is observed, the amount of 1-butene incorporated in the PPBPP isolated sequence needs to be compensated due to the overlap of the αB2 and αB2B2 signals at 43.9 ppm:

[0329] B=(Iα–2*Iαα) / 2

[0330] The total 1-butene content was calculated based on the sum of isolated and continuously incorporated 1-butene:

[0331] B 总 =B+BB

[0332] The amount of propene was quantified based on the relative amounts of the αB2 and ααB2B2 methylene units of the main Sαα methylene site at 46.7 ppm and compensating for the unaccounted for propene (note that B and BB are calculated based on the number of butane monomers per sequence rather than the number of sequences):

[0333] P 总 =I S αα+B+BB / 2

[0334] In cases where characteristic signals corresponding to regio defects were observed (Resconi, L., Cavallo, L., Fait, A., Piemontesi, F., Chem. Rev. 2000, 100, 1253), compensation of the erroneously inserted propylene units was used for Ptot.

[0335] In the presence of 2,1-erythro misinsertion, the ninth carbon (S) from the microstructure unit with a chemical shift at 42.5 ppm was selected. 21e9 ) signal (Resconi, L., Cavallo, L., Fait, A., Piemontesi, F., Chem. Rev. 2000, 100, 125). In this case:

[0336] P 总 =ISαα+B+BB / 2+3*I(S 21e9 )

[0337] The total mole fraction of 1-butene in the polymer is then calculated as:

[0338] fB=(B 总 / (B 总 +P 总 )

[0339] The total comonomer incorporation of 1-butene in mole percent is calculated from the mole fractions in the usual manner:

[0340] B [mol %] = 100 * fB

[0341] The total comonomer incorporation of 1-butene in weight percent was calculated from the mole fractions in the standard manner:

[0342] B [weight %] = 100*(fB*56.11) / ((fB*56.11)+((1-fB)*42.08)).

[0343] Melt flow rate (MFR)

[0344] The melt flow rate MFR2 is measured at 230° C. for propylene copolymers under a load of 2.16 kg and at 190° C. for ethylene copolymers under a load of 2.16 kg. The melt flow rate is the amount of polymer in grams which is extruded in 10 minutes by a test apparatus conforming to ISO 1133 at a temperature of 230° C. or 190° C. under a load of 2.16 kg.

[0345] Xylene cold solubles (XCS, wt. %): The xylene cold solubles (XCS) content is determined according to ISO 16152; 1st edition; 2005-07-01 at 25°C.

[0346] Melting temperature T m , crystallization temperature T c Measurements were performed on 5 to 7 mg samples using a Mettler TA820 Differential Scanning Calorimeter (DSC). The DSC was operated according to ISO 11357 / Part 3 / Method C2 using a heating / cooling / heating cycle over a temperature range of -30 to +225°C at a scan rate of 10°C / min. The crystallization temperature was determined from the cooling step, while the melting temperature was determined from the second heating step.

[0347] All mechanical measurements were carried out after the specimens had undergone a conditioning time of 96 hours (at 23° C. and 50% relative humidity).

[0348] The glass transition temperature Tg was determined by dynamic mechanical analysis according to ISO 6721-7. Compression molded specimens (40×10×1 mm2) were heated between −100° C. and +150° C. at a heating rate of 2° C. / min and a frequency of 1 Hz. 3 ) are measured in torsion mode.

[0349] The Charpy unnotched impact strength is determined according to ISO 179-1 / 1eU at 23° C. by using injection molded test specimens (80×10×4 mm) prepared according to EN ISO 1873-2.

[0350] Tensile properties were measured on 4 mm thick injection molded dog-bone specimens prepared according to EN ISO 1873-2. Tensile modulus was measured according to ISO 527-1A at a strain rate of 1 mm / min and 23°C, and tensile strength and elongation at break (strain) were measured according to ISO 527-2 at a strain rate of 50 mm / min and 23°C.

[0351] Heat Deflection Temperature (HDT):

[0352] HDT was prepared according to ISO 1873-2 on a 80 × 10 × 4 mm 3 The test is carried out according to ISO 75, condition A, with a nominal surface stress of 1.80 MPa on horizontally supported specimens.

[0353] VOC / Fog emissions are measured according to VDA 278:2002 on injection molded specimens and pelletized compounds. Volatile organic compounds are measured in toluene equivalents per gram. Fogging is measured in hexadecane equivalents per gram.

[0354] The measurements were performed using a TDSA supplied by Gerstel, using Helium 5.0 as carrier gas and a column HP Ultra 2 of 50 m length, 0.32 mm diameter and 0.52 μm with a 5% phenyl-methyl-siloxane coating.

[0355] VOC analysis was performed according to the instrument settings 1 listed in the standard using the following key parameters: flow mode splitless, final temperature 90°C; final time 30 min, rate 60 K / min. The cooling trap was purged with a flow mode split ratio of 1:30 at a heating rate of 12 K / s and a final time of 5 min over a temperature range of -150°C to +280°C. The following GC settings were used for the analysis: isothermal at 40°C for 2 min, heating to 92°C at 3 K / min, then heating to 160°C at 5 K / min, then heating to 280°C at 10 K / min, isothermal for 10 min; flow rate 1.3 ml / min.

[0356] Fog analysis was performed according to the instrument settings listed in the standard, using the following key parameters: splitless flow mode at 60 K / min; final temperature 120°C; and final time 60 min. The cold trap was purged at a heating rate of 12 K / s over a temperature range of -150°C to +280°C, using a flow mode split ratio of 1:30. The following GC settings were used for the analysis: isothermal at 50°C for 2 min, heating at 25 K / min to 160°C, then heating at 10 K / min to 280°C and isothermal for 30 min; flow rate 1.3 ml / min.

[0357] 2. Examples

[0358] Catalyst preparation

[0359] Metallocene (MC1) (rac-trans-dimethylsilylene(2-methyl-4-phenyl-5-methoxy-6-tert-butyl-indenyl)(2-methyl-4-(4-tert-butylphenyl)indenyl)zirconium dichloride) has been synthesized as described in WO 2013 / 007650.

[0360] The catalyst was prepared using a catalyst system comprising metallocene MC1, MAO, and trityl tetrakis(pentafluorophenyl)borate according to Catalyst 3 of WO 2015 / 11135, with the proviso that the surfactant was 2,3,3,3-tetrafluoro-2-(1,1,2,2,3,3,3-heptafluoropropoxy)-1-propanol. This catalyst was used to prepare random propylene copolymers PI and P-II.

[0361] Preparation of random propylene copolymer (PI)

[0362] The random propylene copolymer (PI) was produced in a sequential process comprising a loop reactor and a gas phase reactor. The reaction conditions are summarized in Table 1.

[0363] Table 1: Preparation of random propylene copolymer (PI)

[0364] PI Prepolymerization temperature [℃] 20 pressure [kPa] 5053 Catalyst feed [g / h] 2.1 TEAL / C3 [g / t] 0 C3 feed [kg / h] 67.3 H2 feed [g / h] 0.6 Dwell time [h] 0.4 Ring pipe (R1) temperature [℃] 70 pressure [kPa] 4949 H2 / C3 ratio [mol / kmol] 0.1 C6 / C3 ratio [mol / kmol] 8.0 <![CDATA[MFR2 (Slurry Phase)]]> [g / 10min] 2.5 C6 (ring pipe) [mol%] 0.86 Ring pipe [h] 0.7 Split ratio (loop pipe) [weight%] 47

[0365] Table 1: (Continued)

[0366] GPR(R2) temperature [℃] 80 pressure [kPa] 2500 H2 / C3 ratio [mol / kmol] 0.9 C6 / C3 ratio [mol / kmol] 9.1 Calculated C6(GPR) [mol%] 3.8 Dwell time [h] 2.4 Flow split ratio (GPR) [weight%] 53 C6(total) [mol%] 2.4 XCS (total) [weight%] 8.8 1,2e regional defects [mol%] 0.8 <![CDATA[MFR2 (Copolymer)]]> [g / 10min] 1.5 Tm [℃] 135 Tg [℃] 2.0

[0367] The resulting copolymer was then visbroken in a co-rotating twin-screw extruder at 210 to 230°C using a masterbatch of 5 wt% 2,5-dimethyl-2,5-di-(tert-butylperoxy)hexane and polypropylene (POX). The resulting modified propylene random copolymer (mP-I) had a melt flow rate (MFR2) of 79 g / 10 min (230°C, 2.16 kg). This represents a visbreaking ratio of 52.7.

[0368] Preparation of random propylene copolymer (P-II)

[0369] The random propylene copolymer (P-II) was produced in a sequential process comprising a loop reactor and a gas phase reactor. The reaction conditions are summarized in Table 2.

[0370] Table 2: Preparation of random propylene copolymer (P-II)

[0371] P-II Prepolymerization temperature [℃] 20 pressure [kPa] 4135 Catalyst feed [g / h] 2.6 TEAL / C3 [g / t] 0 C3 feed [kg / h] 70.0 H2 feed [g / h] 0.1 Dwell time [h] 0.4 Ring pipe (R1) temperature [℃] 68 pressure [kPa] 4897 H2 / C3 ratio [mol / kmol] 0.23 C4 / C3 ratio [mol / kmol] 48.0 <![CDATA[MFR2 (Slurry Phase)]]> [g / 10min] 70.6 C4 (ring pipe) [mol%] 4.4 Dwell time [h] 0.5 Split ratio (ring pipe) [weight%] 49

[0372] Table 2: (Continued)

[0373] GPR(R2) temperature [℃] 80 pressure [kPa] 2498 H2 / C3 ratio [mol / kmol] 2.3 C4 / C3 ratio [mol / kmol] 40.2 Calculated C4(GPR) [mol%] 6.6 Dwell time [h] 2.3 Flow split ratio (GPR) [weight%] 51 C4(total) [mol%] 5.5 XCS (total) [weight%] 0.4 1,2e regional defects [mol%] 0.9 <![CDATA[MFR2 (Copolymer)]]> [g / 10min] 94 Tm [℃] 140 Tg [℃] -2.0

[0374] The obtained copolymers were compounded without visbreaking and stabilized using a basic antioxidant combination.

[0375] P-II is a C3C4 random copolymer having a melt flow rate MFR2 (230°C, 2.16 kg) of 94 g / 10 min, a C4 comonomer content of 5.5 mol%, and no nucleating agent. P-II has a melting temperature Tm of 140°C as measured by differential scanning calorimetry (DSC) and a crystallization temperature Tc of 105°C as measured by differential scanning calorimetry (DSC).

[0376] Preparation of fiber-reinforced composition (C)

[0377] The fiber-reinforced composition (C) was obtained by melt blending the modified propylene random copolymer (mP-I) or propylene random copolymer (P-II) with glass fiber (GF), adhesion promoter (AP) and additive (AD) in a co-rotating twin-screw extruder. The compositions and properties of the inventive examples and comparative examples are summarized in Table 3.

[0378] Table 3: Composition and properties of the present invention and comparative examples

[0379] CE1 IE1 IE2 IE3 CE2 mP-I [weight%] 77.5 76.0 74.5 P-II 77.1 hP [weight%] 76.0 GF [weight%] 20.0 20.0 20.0 20.0 20.0 AP1 [weight%] 1.5 1.5 1.5 AP2 [weight%] 3.0 AD1 [weight%] 2.5 2.5 2.5 2.5 AD2 1.4 MFR [g / 10min] 18 18 19 29 18 Tensile modulus [MPa] 3647 3748 3706 4519 5200 tensile strength [MPa] 55.8 63.1 62.3 86.0 94.9 Elongation at break [％] 2.5 4.8 5.1 3.4 2.9 simply supported beam notch <![CDATA[[kJ / m 2 ]]]> 20.3 52.7 57.3 51.4 47.3 HDT [℃] 127 127 127 138 161 Tc [℃] 99 99 99 110 123 Tc [℃] 99 99 99 110 123

[0380] Table 3: (Continued)

[0381] Tm [℃] 136 136 135 141 164 Hm J / g 57 57 55 59 94 VOC μg / g 1 11 1 2 25 Fog μg / g 35 72 35 38 215

[0382] hP is a commercial propylene homopolymer HJ120UB from Borealis AG produced with a Ziegler-Natta catalyst, having a melt flow rate MFR2 (230°C) of 75 g / 10 min, a 3 Density determined according to ISO 1183-187, glass transition temperature Tg of +2°C.

[0383] GF is a commercial product ECS 03T-480H of Nippon Electric Glass Co., Ltd., which has a filament diameter of 10.5 μm and a filament bundle length of 3 mm.

[0384] AP1 is Scona's adhesion promoter SCONA TPPP 8112GA, which is a polypropylene functionalized with maleic anhydride, having a maleic anhydride content of 1.4 wt% and an MFR (190°C, 2.16 kg) above 80 g / 10 min, corresponding to an MFR2 (230°C, 2.16 kg) of about 50 g / 10 min.

[0385] AP2 is a MAH-grafted copolymer of propylene and 1-hexene, obtained by grafting the propylene random copolymer (P) described above with 0.7 wt% maleic anhydride in the presence of 1000 ppm of POX in a co-rotating twin-screw extruder. AP2 has a melt flow rate (MFR2) of 72 g / 10 min (230°C, 2.16 kg).

[0386] AD1 is a masterbatch consisting of 8.0 wt% of tris(2,4-di-tert-butylphenyl)phosphite (Kinox-68-G from HPL Additives), 8.0 wt% of pentaerythritol tetrakis(3-(3',5'-di-tert-butyl-4-hydroxyphenyl)propionate (Irganox 1010FF from BASF), 20.0 wt% of carbon black from Borealis (39.5 wt% masterbatch) and 64.0 wt% of propylene homopolymer HC001A from Borealis, which has a mass fraction of 905 kg / m 3 The composite had a density determined according to ISO 1183-187 of 5.5 and an MFR of 3.2 g / 10 min (230° C., 2.16 kg).

[0387] AD2 is a masterbatch consisting of 14.3 wt% tris(2,4-di-tert-butylphenyl)phosphite (Kinox-68-G from HPL Additives), 14.3 wt% pentaerythritol tetrakis(3-(3',5'-di-tert-butyl-4-hydroxyphenyl)propionate (Irganox 1010FF from BASF), 35.7 wt% carbon black from Borealis (39.5 wt% masterbatch) and 35.7 wt% propylene homopolymer HC001A from Borealis, which has a mass fraction of 905 kg / m 3 The composite had a density determined according to ISO 1183-187 of 5.5 and an MFR of 3.2 g / 10 min (230° C., 2.16 kg).

Claims

1. A fiber-reinforced composition (C), comprising: a) 57.0 to 94.9 wt.% of a random propylene copolymer (P), wherein the comonomer is selected from ethylene and / or at least one C4 to C12 α-olefin, said random propylene copolymer (P) having i) a melt flow rate MFR2, measured according to ISO 1133 at 230°C under a load of 2.16 kg, in the range of 45 to 150 g / 10 min, and ii) a melting temperature Tm, determined according to differential scanning calorimetry (DSC), in the range of 125 to 150° C., iii) an amount of 1,2-erythro regio defects of at least 0.4 mol %, b) 5.0 to 40.0% by weight of fibers (F), and c) 0.1 to 5.0 wt. % adhesion promoter (AP).

2. The fiber reinforced composition (C) according to claim 1, wherein the propylene random copolymer (P) has an amount of 1,2 erythro regio defects in the range of 0.4 to 1.2 mol%.

3. The fiber-reinforced composition (C) according to claim 1 or 2, wherein the propylene random copolymer (P) comprises i) a first propylene random copolymer (P1), and ii) a second random propylene copolymer (P2) having a higher comonomer content than said first random propylene copolymer (P1), wherein the weight ratio between the first propylene random copolymer (P1) and the second propylene random copolymer (P2) is in the range of 20 / 80 to 60 / 40, and the combined amount of the first propylene random copolymer (P1) and the second propylene random copolymer (P2) is at least 95.0 wt.%, based on the propylene random copolymer (P).

4. The fiber reinforced composition (C) according to claim 1 or 2, wherein the propylene random copolymer (P) has a comonomer content in the range of 1.0 to 6.0 mol%.

5. The fiber-reinforced composition (C) according to claim 1 or 2, wherein the comonomer is at least one C4 to C12 α-olefin.

6. The fiber-reinforced composition (C) according to claim 5, wherein the comonomer is 1-hexene.

7. The fiber-reinforced composition (C) according to claim 3, wherein i) the first random propylene copolymer (P1) has a comonomer content in the range of 0.4 to 2.5 mol%, and ii) The second random propylene copolymer (P2) has a comonomer content in the range of 2.8 to 7.0 mol-%.

8. The fiber reinforced composition (C) according to claim 1 or 2, wherein the random propylene copolymer (P) has a xylene soluble content (XCS) determined according to ISO 16152 at 25°C in the range of 3.0 to 15.0 wt.-%, based on the total weight of the random propylene copolymer (P).

9. The fiber-reinforced composition (C) according to claim 5, wherein the comonomer is 1-butene.

10. The fiber-reinforced composition (C) according to claim 9, wherein the propylene random copolymer (P) comprises i) a first propylene random copolymer (P1) having a comonomer content in the range of 2.0 to 6.0 mol%, and ii) A second random propylene copolymer (P2) having a comonomer content in the range of 4.0 to 10.0 mol%.

11. The fiber reinforced composition (C) according to claim 9, wherein the random propylene copolymer (P) has a xylene soluble content (XCS) determined according to ISO 16152 at 25°C in the range of 0.1 to 5.0 wt.-%, based on the total weight of the random propylene copolymer (P).

12. The fiber-reinforced composition (C) according to claim 1 or 2, wherein the fiber (F) is glass fiber (GF).

13. The fiber-reinforced composition (C) according to claim 12, wherein the glass fiber (GF) is a short glass fiber (SGF) having i) an average length of 2.0 to 10.0 mm, and / or ii) average diameter of 5 to 20 µm.

14. The fiber-reinforced composition (C) according to claim 1 or 2, wherein the adhesion promoter (AP) is a polar-modified polypropylene (PM-PP), which is a propylene homopolymer or copolymer grafted with maleic anhydride, and has a melt flow rate MFR2 measured according to ISO 1133 at 230°C under a load of 2.16 kg of 20.0 to 400 g / 10 min.

15. The fiber-reinforced composition (C) according to claim 1 or 2, wherein the fiber-reinforced composition (C) has a melt flow rate MFR2 measured according to ISO 1133 at 230°C under a load of 2.16 kg in the range of 8.0 to 60.0 g / 10 min.

16. Fiber reinforced composition (C) according to claim 1 or 2, wherein the propylene random copolymer (P) is obtained in the presence of a solid catalyst system (SCS) comprising a metallocene compound.

17. The fiber-reinforced composition (C) according to claim 16, wherein the metallocene compound has the formula (I) R n (Cp)2MX2(I) in Each Cp is independently an unsubstituted or substituted and / or fused cyclopentadienyl ligand; Each R" is independently hydrogen or a hydrocarbon group; or in the case of -NR"2, the two substituents R" may form a ring together with the nitrogen atom to which they are attached; R is a bridge of 1 to 3 atoms; M is a transition metal of Group 4; Each X is independently a σ-ligand; Each of the above ring moieties, alone or as part of another moiety such as a substituent for Cp, X, R" or R, can also be substituted; n is 1 or 2.

18. The fiber-reinforced composition (C) according to claim 17, wherein each Cp is independently a substituted or unsubstituted cyclopentadienyl, substituted or unsubstituted indenyl, or substituted or unsubstituted fluorenyl ligand; optionally, one or more substituents are independently selected from halogen, hydrocarbyl, C3-C12-cycloalkyl containing 1, 2, 3, or 4 heteroatoms in the ring portion, C6-C20-heteroaryl, C1-C20-haloalkyl, -SiR"3, -OSiR"3, -SR", -PR"2, OR" or -NR"2; Each R" is independently C1-C20-alkyl, C2-C20-alkenyl, C2-C20-alkynyl, C3-C12-cycloalkyl or C6-C20-aryl; or in the case of -NR"2, the two substituents R" can form a five-membered ring or a six-membered ring together with the nitrogen atom to which they are attached; R is a bridge of 1 to 2 carbon atoms and 0 to 2 heteroatoms, wherein the heteroatoms are Si, Ge and / or O atoms, wherein each bridge atom may independently carry a substituent; or a bridge of 1 to 3 heteroatoms, wherein the heteroatoms are silicon, germanium and / or oxygen atoms; M is Zr or Hf; each X is independently H, halogen, C1-C20-alkyl, C1-C20-alkoxy, C2-C20-alkenyl, C2-C20-alkynyl, C3-C12-cycloalkyl, C6-C20-aryl, C6-C20-aryloxy, C7-C20-aralkyl, C7-C20-aralkenyl, -SR", -PR", -SiR", -OSiR", -NR", or -CH2-Y, wherein Y is C6-C20-aryl, C6-C20-heteroaryl, C1-C20-alkoxy, C6-C20-aryloxy, NR", -SR", -PR", -SiR", or -OSiR", Each of the above mentioned ring moieties can also be substituted by C1-C20-alkyl groups which may contain Si and / or O atoms.

19. The fiber-reinforced composition (C) according to claim 18, wherein Optionally, one or more substituents are C1-C20-alkyl, C2-C20-alkenyl, C2-C20-alkynyl, C3-C12-cycloalkyl, C6-C20-aryl or C7-C20-aralkyl; R is a bridge of 1 to 2 carbon atoms and 0 to 2 heteroatoms, where each bridge atom can independently carry a C1-C20-alkyl, tri(C1-C20-alkyl)silyl, tri(C1-C20-alkyl)siloxy or C6-C20-aryl substituent).

20. The fiber-reinforced composition (C) according to claim 19, wherein R is –SiR 10 2 bridges, where each R 10 are independently C1-C20-alkyl, C3-12-cycloalkyl, C6-C20-aryl or tri(C1-C20-alkyl)silyl residues.

21. The fiber-reinforced composition (C) according to claim 19, wherein R is –SiR 10 2 bridges, where each R 10 is independently trimethylsilyl.

22. An article comprising the fiber-reinforced composition (C) according to any one of claims 1 to 21.

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