Homopolymer-random copolymer blends having a beneficial balance of optical and mechanical properties

Abstract

A single-phase polypropylene composition (PC) having a melt flow rate (MFR2) of 1.0 to 50.0 g / 10 min, the single-phase polypropylene composition (PC) comprising: a) 55.0 to 95.0 wt.-% of a random copolymer of propylene (R-PP), the random copolymer of propylene (R-PP) having an MFR2 of 1.0 to 30.0 g / 10 min, a comonomer content of 0.5 to 6.0 mol-%, and 0.1 to 1.4 mol-% of 2,1-regio defects ppm; and b) 5.0 to 45.0 wt.-% of a propylene homopolymer composition (H-PP) comprising a reactor blend of a propylene homopolymer and a polymeric nucleating agent present in an amount of 20 to 300 wt.-ppm, wherein the propylene homopolymer composition (H-PP) has an MFR2 of 10 to 100 g / 10min and is free of 2,1-regio defects; wherein the combined weight of the random copolymer of propylene (R-PP) and the propylene homopolymer composition (H-PP) is at least 95 wt.-%.

Description

Technical Field

[0001] The present invention relates to a monophasic polypropylene composition comprising a major amount of a random copolymer of propylene having a certain content of 2,1-regio defects and a minor amount of a propylene homopolymer composition without 2,1-regio defects, and to articles comprising between 90 and 100 wt% of the monophasic polypropylene composition. Background Art

[0002] Polymers are increasingly consumed in large quantities across a wide range of applications, including packaging for food and other goods, fibers, automotive components and various manufactured products.

[0003] In particular, polystyrene has long been used in thermoforming applications (e.g., cups and plates) due to its beneficial balance of mechanical and optical properties. Although well-suited for end-use applications, these polystyrene-based items are difficult to recycle. The primary components of post-consumer polymer waste are polypropylene and polyethylene, which are known to be immiscible with polystyrene, meaning that adding even very small amounts of polystyrene to a recycled blend primarily comprising polypropylene and / or polyethylene can have a detrimental effect on the homogeneity of the blend, thereby affecting its mechanical and optical properties.

[0004] Polypropylene-based materials offer great potential for mechanical recycling, as these materials are widely used in packaging. Considering the huge amount of waste collected compared to the amount of waste recycled into the stream, there is still great potential for the intelligent reuse of plastic waste streams and the mechanical recycling of plastic waste.

[0005] Therefore, providing polypropylene grades with the right balance of mechanical and optical properties for thermoforming applications would allow articles containing such polypropylene grades to be more easily recycled without the risk of contaminating existing polyolefin recycling processes.

[0006] In particular, it is known in the art that the haze of a polypropylene composition can be reduced by incorporating higher amounts of ethylene / α-olefin comonomer; however, this effect is generally accompanied by a reduction in the stiffness of the polypropylene composition. The development of polypropylene grades that exhibit an improved balance of stiffness and haze represents a significant development. Summary of the Invention

[0007] Thus, the present inventors have discovered that certain blends of single-site catalyzed propylene random copolymers with Ziegler-Natta catalyzed propylene homopolymers containing a polymeric nucleating agent can meet these demanding requirements.

[0008] Accordingly, the present invention is directed to a single-phase polypropylene composition (PC) having a melt flow rate (MFR2) measured according to ISO 1133 at 230 °C and 2.16 kg in the range of 1.0 to 50.0 g / 10 min, wherein the single-phase polypropylene composition (PC) comprises:

[0009] a) a random copolymer (R-PP) of 55.0 to 95.0 wt.-% relative to the total weight of the single-phase polypropylene composition (PC) of propylene and at least one comonomer selected from ethylene and C4 to C8 alpha-olefins, the propylene random copolymer (R-PP) having a melt flow rate (MFR2) measured according to ISO 1133 at 230 °C and 2.16 kg in the range of 1.0 to 30.0 g / 10 min, a quantitative 13 The comonomer content was determined by C-NMR spectroscopy and was in the range of 0.1 to 1.4 mol %. 13 2,1-regio defect content determined by C-NMR spectroscopy, and

[0010] b) 5.0 to 45.0 wt.-% relative to the total weight of the single-phase polypropylene composition (PC) of a propylene homopolymer composition (H-PP) comprising a reactor blend of a propylene homopolymer and a polymeric nucleating agent in an amount of 20 to 300 wt.-ppm relative to the total weight of the propylene homopolymer composition (H-PP), wherein the propylene homopolymer composition (H-PP) has a melt flow rate (MFR2) measured according to ISO 1133 at 230 °C and 2.16 kg in the range of 10 to 100 g / 10 min and does not contain 13 2,1-regio defects determined by C-NMR spectroscopy;

[0011] wherein the combined weight of the random copolymer of propylene (R-PP) and the propylene homopolymer composition (H-PP) is at least 95 wt.-%, relative to the total weight of the single-phase polypropylene composition (PC), and

[0012] The polymer nucleating agent comprises a monomer (I) of the following general formula

[0013] H2C=CH-CHR 1 R 2 (I)

[0014] where R 1 and R 2 is an alkyl group having one or more carbon atoms alone or forming an optionally substituted saturated, unsaturated or aromatic ring or fused ring system containing 4 to 20 carbon atoms.

[0015] The present invention also relates to an article comprising the single-phase polypropylene composition (PC) according to any of the preceding claims in an amount in the range of 90 to 100 wt.-%, more preferably in the range of 95 to 100 wt.-%, still more preferably in the range of 98 to 100 wt.-%, wherein the article is preferably selected from injection molded articles, thermoformed articles and films.

[0016] definition

[0017] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. Although any methods and materials similar or equivalent to those described herein can be used in practice to test the present invention, preferred materials and methods are described herein. In describing and claiming the present invention, the following terminology will be used in accordance with the definitions set forth below.

[0018] Unless expressly stated otherwise, the use of the terms "a," "an," etc. means one or more.

[0019] According to the present invention, the expression "propylene homopolymer" relates to a polypropylene which consists essentially of propylene units, i.e. a polypropylene which consists of at least 99.5 mol%, more preferably at least 99.8 mol%, such as at least 99.9 mol% of propylene units. In another embodiment, only propylene units are detectable, i.e. only propylene has been polymerized.

[0020] Propylene random copolymer is a copolymer of propylene monomer units and comonomer units, the comonomer units are preferably selected from ethylene and C4-C12 alpha-olefins, wherein the comonomer units are randomly distributed on the polymer chain. Propylene random copolymer can contain comonomer units from one or more comonomers having different carbon atom counts. Hereinafter, unless otherwise stated, amounts are given in mole %. Propylene random copolymer must contain at least 50 mole % propylene units.

[0021] For propylene homopolymers and propylene random copolymers, typically there is only one glass transition temperature. DETAILED DESCRIPTION

[0022] Random copolymer of propylene (R-PP)

[0023] The main component present in the monophasic polypropylene composition (PC) of the present invention is a random copolymer (R-PP) of propylene and at least one comonomer selected from ethylene and C4 to C8 alpha-olefins.

[0024] The random copolymer of propylene (R-PP) has a melt flow rate (MFR2) measured at 230°C and 2.16 kg according to ISO 1133 in the range of 1.0 to 30.0 g / 10 min, more preferably in the range of 3.0 to 20.0 g / 10 min, most preferably in the range of 5.0 to 10.0 g / 10 min.

[0025] The random copolymer of propylene (R-PP) preferably has a xylene cold soluble content (XCS), measured at 25°C, according to ISO 16152, in the range of 0.5 to 15.0 wt.-%, more preferably in the range of 0.6 to 8.0 wt.-%, most preferably in the range of 0.7 to 3.0 wt.-%.

[0026] The random copolymer of propylene (R-PP) is preferably polymerized in the presence of a single site catalyst (SSC).

[0027] The presence of 2,1-regio defects is a key indicator that the propylene polymer has been polymerized in the presence of a single-site catalyst. Therefore, the random copolymer of propylene (R-PP) is required to have a 2,1-regio defect in the range of 0.1 to 1.4 mol%, more preferably in the range of 0.2 to 1.0 mol%, most preferably in the range of 0.3 to 0.7 mol%. 13 2,1-regio defect content determined by C-NMR spectroscopy.

[0028] The random copolymer of propylene (R-PP) preferably has a melting temperature T in the range of 132 to 144°C, more preferably in the range of 134 to 142°C, most preferably in the range of 136 to 140°C. m .

[0029] The random copolymer of propylene (R-PP) preferably has a crystallization temperature T in the range of 95 to 105°C, more preferably in the range of 97 to 103°C, most preferably in the range of 98 to 102°C. c .

[0030] T m and T c Both are determined by differential scanning calorimetry (DSC) according to ISO 11357 / part 3 / method C2 in a heating / cooling / heating cycle at a scanning rate of 10°C / min in the temperature range of -30 to +225°C.

[0031] Preferably, the random copolymer of propylene (R-PP) has a glass transition temperature T 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 gSince the polypropylene composition is single-phase, the random copolymer of propylene (R-PP) must also be single-phase. Therefore, it is preferred that the glass transition temperature T g It is the only measurable glass transition temperature.

[0032] Preferably, the random copolymer of propylene (R-PP) has a number average molecular weight (Mn), determined by gel permeation chromatography, in the range of 60,000 to 100,000 g / mol, more preferably in the range of 65,000 to 95,000 g / mol, most preferably in the range of 70,000 to 90,000 g / mol.

[0033] Preferably, the random copolymer of propylene (R-PP) has a weight average molecular weight (Mw), determined by gel permeation chromatography (GPC), in the range of 170,000 to 310,000 g / mol, more preferably in the range of 190,000 to 290,000 g / mol, most preferably in the range of 210,000 to 270,000 g / mol.

[0034] Preferably, the random copolymer of propylene (R-PP) has a molecular weight distribution (Mw / Mn) determined by gel permeation chromatography (GPC) in the range of 2.0 to 5.0, more preferably in the range of 2.2 to 4.5, most preferably in the range of 2.5 to 4.0.

[0035] The random copolymer of propylene (R-PP) has a quantitative 13 Comonomer content was determined by C-NMR spectroscopy.

[0036] The comonomer is selected from ethylene and C4 to C8 alpha-olefins.

[0037] In one embodiment the random copolymer of propylene (R-PP) is a propylene ethylene random copolymer.

[0038] Quantitative determination of propylene-ethylene random copolymer 13 The ethylene content, as determined by C-NMR spectroscopy, is in the range of 2.0 to 6.0 mol %, more preferably in the range of 2.5 to 5.0 mol %, most preferably in the range of 3.0 to 4.0 mol %.

[0039] It is further preferred that the propylene-ethylene random copolymer comprises:

[0040] a) 51.0 to 75.0 wt.-% of a first propylene-ethylene random copolymer fraction (R-PP1), relative to the total weight of the propylene-ethylene random copolymer; and

[0041] b) 25.0 to 49.0 wt.-% of a second propylene-ethylene random copolymer fraction (R-PP2), relative to the total weight of the propylene-ethylene random copolymer.

[0042] Still further preferred, the propylene-ethylene random copolymer comprises:

[0043] a) 53.0 to 70.0 wt.-% of a first propylene-ethylene random copolymer fraction (R-PP1), relative to the total weight of the propylene-ethylene random copolymer; and

[0044] b) 30.0 to 47.0 wt.-% of a second propylene-ethylene random copolymer fraction (R-PP2), relative to the total weight of the propylene-ethylene random copolymer.

[0045] Still further preferred is that the propylene-ethylene random copolymer comprises:

[0046] a) 55.0 to 65.0 wt.-% of a first propylene-ethylene random copolymer fraction (R-PP1), relative to the total weight of the propylene-ethylene random copolymer; and

[0047] b) 35.0 to 45.0 wt.-% of a second propylene-ethylene random copolymer fraction (R-PP2), relative to the total weight of the propylene-ethylene random copolymer.

[0048] The combined weight of the first and second propylene-ethylene random copolymer fractions (R-PP1 + R-PP2) is at least 95 wt% relative to the total weight of the propylene-ethylene random copolymer (R-PP).

[0049] The first propylene-ethylene random copolymer fraction (R-PP1) has a quantitative 13 Ethylene content was determined by C-NMR spectroscopy.

[0050] The second propylene-ethylene random copolymer fraction (R-PP2) has a quantitative 13 Ethylene content was determined by C-NMR spectroscopy.

[0051] The ratio of the ethylene content of the propylene-ethylene random copolymer to the ethylene content of the first propylene-ethylene random copolymer fraction [C2(R-PP)] / [C2(R-PP1)] is preferably in the range of 1.10 to 2.00, more preferably in the range of 1.15 to 1.70, most preferably in the range of 1.20 to 1.40.

[0052] In an alternative embodiment, the random copolymer of propylene (R-PP) is a random copolymer of propylene and a comonomer selected from C4 to C8 α-olefins (hereinafter referred to as propylene-α-olefin random copolymer), more preferably a random copolymer of propylene and 1-hexene (hereinafter referred to as propylene-hexene random copolymer).

[0053] Quantitative determination of propylene-α-olefin random copolymers 13 The comonomer content, more preferably the 1-hexene content of the propylene-hexene random copolymer is in the range of 0.5 to 3.0 mol %, more preferably in the range of 0.8 to 2.0 mol %, most preferably in the range of 1.0 to 1.5 mol %, as determined by C-NMR spectroscopy.

[0054] It is further preferred that the propylene-α-olefin random copolymer, more preferably the propylene-hexene random copolymer comprises:

[0055] a) 25.0 to 45.0 wt.-% of a first propylene random copolymer fraction (R-PP1), relative to the total weight of the propylene random copolymer; and

[0056] b) 55.0 to 75.0 wt.-% of the second propylene random copolymer fraction (R-PP2), relative to the total weight of the propylene random copolymer.

[0057] Still further preferred is that the propylene-alpha olefin random copolymer, more preferably the propylene-hexene random copolymer comprises:

[0058] a) 30.0 to 43.0 wt.-% of a first propylene random copolymer fraction (R-PP1), relative to the total weight of the propylene random copolymer; and

[0059] b) 57.0 to 70.0 wt.-% of the second propylene random copolymer fraction (R-PP2), relative to the total weight of the propylene random copolymer.

[0060] Still further preferred is that the propylene-α-olefin random copolymer, more preferably the propylene-hexene random copolymer comprises:

[0061] a) 35.0 to 41.0 wt.-% of a first propylene random copolymer fraction (R-PP1), relative to the total weight of the propylene random copolymer; and

[0062] b) 59.0 to 65.0 wt.-% of the second propylene random copolymer fraction (R-PP2), relative to the total weight of the propylene random copolymer.

[0063] The combined weight of the first and second propylene random copolymer fractions (R-PP1 + R-PP2) is at least 95 wt.-%, relative to the total weight of the propylene-α-olefin random copolymer (R-PP), more preferably the propylene-hexene random copolymer (R-PP).

[0064] The first propylene random copolymer fraction (R-PP1) has a quantitative 13 The comonomer content, more preferably the 1-hexene content, is determined by C-NMR spectroscopy.

[0065] The second propylene random copolymer fraction (R-PP2) has a quantitative 13 The comonomer content, more preferably the 1-hexene content, is determined by C-NMR spectroscopy.

[0066] The ratio of the comonomer content of the propylene-α-olefin random copolymer to the comonomer content of the first propylene random copolymer fraction [C(R-PP)] / [C(R-PP1)] is preferably in the range of 1.5 to 3.0, more preferably in the range of 1.8 to 2.7, most preferably in the range of 2.0 to 2.5.

[0067] More preferably, the ratio of the 1-hexene content of the propylene-hexene random copolymer to the comonomer content of the first propylene random copolymer fraction [C(R-PP)] / [C(R-PP1)] is preferably in the range of 1.5 to 3.0, more preferably in the range of 1.8 to 2.7, most preferably in the range of 2.0 to 2.5.

[0068] Process for producing random copolymers of propylene (R-PP)

[0069] The process for preparing the random copolymer of propylene (R-PP) and the single site catalyst (SSC) will be described in further detail below.

[0070] As already indicated above the random copolymer of propylene (R-PP) is preferably produced in a sequential polymerization process.

[0071] The term "sequential polymerization system" means that the random copolymer of propylene (R-PP) is produced in at least two reactors connected in series. Thus, the polymerization system of the present invention comprises at least a first polymerization reactor (R1) and a second polymerization reactor (R2), and optionally a third polymerization reactor (R3). The term "polymerization reactor" should indicate that the main polymerization occurs. Thus, in the case where the process consists of two polymerization reactors, this definition does not exclude the option of the overall system including a prepolymerization step, for example, in a prepolymerization reactor. The term "consisting of" is a closed description only with respect to the main polymerization reactor.

[0072] Preferably, at least one of the two polymerization reactors (R1) and (R2) is a gas phase reactor (GPR). Still more preferably, the second polymerization reactor (R2) and the optional third polymerization reactor (R3) are gas phase reactors (GPR), i.e. a first gas phase reactor (GPR1) and a second gas phase reactor (GPR2). The gas phase reactor (GPR) according to the present invention is preferably a fluidized bed reactor, a fast fluidized bed reactor or a settled bed reactor or any combination thereof.

[0073] Thus, the first polymerization reactor (R1) is preferably a slurry reactor (SR) and can be any continuous or simple batch stirred tank reactor or loop reactor operating in bulk or slurry. Bulk refers to polymerization in a reaction medium comprising at least 60% (w / w) monomers. According to the present invention, the slurry reactor (SR) is preferably a (bulk) loop reactor (LR). Thus, in the polymer slurry in the loop reactor (LR), the first fraction (1) of the random copolymer of propylene (R-PP) is 100% by weight based on the total weight of the polymer slurry in the loop reactor (LR). st The average concentration of the first random propylene copolymer fraction (R-PP1) is typically from 15 to 55 wt-%. In a preferred embodiment of the present invention the average concentration of the first random propylene copolymer fraction (R-PP1) in the polymer slurry in the loop reactor (LR) is from 20 to 55 wt-%, and more preferably from 25 to 52 wt-%, based on the total weight of the polymer slurry in the loop reactor (LR).

[0074] Preferably, the propylene random copolymer of the first polymerization reactor (R1), i.e. the first propylene random copolymer fraction (R-PP1), more preferably the polymer slurry of the loop reactor (LR) comprising the first propylene random copolymer fraction (R-PP1), is fed directly to the second polymerization reactor (R2), i.e. to the (first) gas phase reactor (GPR1), without a flash step between stages. Such direct feeding is described in EP 887379A, EP 887380A, EP 887381A and EP 991684A. "Direct feeding" refers to a process in which the content of the first polymerization reactor (R1), i.e. the loop reactor (LR), i.e. the polymer slurry comprising the first propylene random copolymer fraction (R-PP1), is passed directly to the gas phase reactor of the next stage.

[0075] Alternatively, the propylene random copolymer of the first polymerization reactor (R1), i.e. the first propylene random copolymer fraction (R-PP1), more preferably the polymer slurry of the loop reactor (LR) comprising the first propylene random copolymer fraction (R-PP1), may also be directed to a flash step or through a further concentration step before being fed to the second polymerization reactor (R2), i.e. the gas phase reactor (GPR). Thus, this "indirect feeding" refers to a process in which the content of the first polymerization reactor (R1), i.e. the loop reactor (LR), i.e. the polymer slurry, is fed to the second polymerization reactor (R2), i.e. the (first) gas phase reactor (GPR1), via a reaction medium separation unit and the reaction medium as gas from the separation unit.

[0076] More specifically, the second polymerization reactor (R2) and any subsequent reactors, such as the third polymerization reactor (R3), are preferably gas phase reactors (GPR). Such gas phase reactors (GPR) can be any mechanically mixed or fluidized bed reactor. Preferably, the gas phase reactor (GPR) comprises 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 is a fluidized bed type reactor optionally having a mechanical stirrer.

[0077] Thus, in a preferred embodiment, the first polymerization reactor (R1) is a slurry reactor (SR), such as a loop reactor (LR), and the second polymerization reactor (R2) and any optional subsequent reactors (such as a third polymerization reactor (R3)) are gas phase reactors (GPR). Thus, for the process according to the present invention, at least two polymerization reactors connected in series are used, preferably two polymerization reactors (R1) and (R2) or three polymerization reactors (R1), (R2) and (R3), i.e. a slurry reactor (SR) (such as a loop reactor (LR)) and a (first) gas phase reactor (GPR1) and optionally a second gas phase reactor (GPR2). If desired, a prepolymerization reactor may be placed before the slurry reactor (SR).

[0078] The single-site catalyst (SSC) is fed to the first polymerization reactor (R1) and transferred to the subsequent reactors together with the polymer (slurry) obtained in the first polymerization reactor (R1). If the process also includes a prepolymerization step, it is preferred that all of the single-site catalyst (SSC) is fed to the prepolymerization reactor. Subsequently, the prepolymerization product containing the single-site catalyst (SSC) is transferred to the first polymerization reactor (R1).

[0079] A preferred multi-stage process is a "loop-gas phase" process such as that developed by Borealis A / S of Denmark (known as technology), for example the methods described in patent literature such as EP 0 887 379, WO 92 / 12182, WO 2004 / 000899, WO 2004 / 111095, WO 99 / 24478, WO 99 / 24479 or WO 00 / 68315.

[0080] Another suitable slurry-gas phase process is LyondellBasell Industries' method.

[0081] Particularly good results are obtained with careful choice of the temperature in the reactor.

[0082] Therefore, it is preferred that the operating temperature in the first polymerization reactor (R1) is in the range of 62 to 85°C, more preferably in the range of 65 to 82°C, still more preferably in the range of 67 to 80°C.

[0083] Alternatively or additionally to the previous paragraph, it is preferred that the operating temperature in the second polymerization reactor (R2) and the optional third reactor (R3) is in the range of 75 to 95°C, more preferably in the range of 78 to 92°C.

[0084] Preferably, the operating temperature in the second polymerization reactor (R2) is equal to or higher than the operating temperature in the first polymerization reactor (R1).

[0085] (a) the operating temperature in the first polymerization reactor (R1) is in the range of 62 to 85°C, more preferably in the range of 65 to 82°C, still more preferably in the range of 67 to 80°C, such as in the range of 70 to 80°C; and

[0086] (b) the operating temperature in the second polymerization reactor (R2) is in the range of 62 to 95°C, more preferably in the range of 65 to 92°C, still more preferably in the range of 67 to 88°C,

[0087] The condition is that the operating temperature in the second polymerization reactor (R2) is equal to or higher than the operating temperature in the first polymerization reactor (R1).

[0088] Typically, the pressure in the first polymerization reactor (R1), preferably the loop reactor (LR), is in the range of 20 to 80 bar, preferably in the range of 30 to 70 bar, for example in the range of 35 to 65 bar, while the pressure in the second polymerization reactor (R2), i.e. the (first) gas phase reactor (GPR1) and optionally any subsequent reactors, such as the third polymerization reactor (R3), e.g. the second gas phase reactor (GPR2), is in the range of 5 to 50 bar, preferably in the range of 15 to 40 bar.

[0089] Preferably, hydrogen is added to each polymerization reactor to control the molecular weight, ie the melt flow rate MFR2.

[0090] Preferably, the average residence time in the polymerization reactors (R1) and (R2) is relatively long. Typically, the average residence time (τ) is defined as the reaction volume (V R ) and the volumetric outflow rate of the reactor (Q o ) ratio (ie V R / Q o ), that is, τ=V R / Q o [τ=V R / Q o In the case of a loop reactor, the reaction volume (V R ) is equal to the reactor volume.

[0091] Thus, the average residence time (τ) in the first polymerization reactor (R1) is preferably at least 15 min, more preferably in the range of 15 to 80 min, still more preferably in the range of 20 to 60 min, such as in the range of 24 to 50 min, and / or the average residence time (τ) in the second polymerization reactor (R2) is preferably at least 70 min, more preferably in the range of 70 to 220 min, still more preferably in the range of 80 to 210 min, still more preferably in the range of 90 to 200 min, such as in the range of 90 to 190 min. Preferably, the average residence time (τ) in the third polymerization reactor (R3), if present, is preferably at least 30 min, more preferably in the range of 30 to 120 min, yet more preferably in the range of 40 to 100 min, such as in the range of 50 to 90 min.

[0092] As mentioned above, in addition to the (main) polymerization of the propylene random copolymer in the at least two polymerization reactors (R1, R3 and optionally R3), the preparation of the propylene random copolymer may also comprise a preceding prepolymerization in a prepolymerization reactor (PR) upstream of the first polymerization reactor (R1).

[0093] In the prepolymerization reactor (PR), polypropylene (pre-PP) is produced. The prepolymerization is carried out in the presence of a single-site catalyst (SSC). According to this embodiment, the single-site catalyst is introduced into the prepolymerization step. However, this does not exclude the option of adding, for example, an additional cocatalyst at a subsequent stage in the polymerization process, for example in the first reactor (R1). In one embodiment, if prepolymerization is used, all components of the single-site catalyst are added only to the prepolymerization reactor (PR).

[0094] The prepolymerization reaction is usually carried out at a temperature of 0 to 60°C, preferably 15 to 50°C, more preferably 20 to 45°C.

[0095] The pressure in the prepolymerisation reactor is not critical but must be high enough to keep the reaction mixture in the liquid phase. Thus, the pressure may be from 20 to 100 bar, for example from 30 to 70 bar.

[0096] In a preferred embodiment the prepolymerisation is carried out as bulk slurry polymerisation in liquid propylene, ie the liquid phase comprises mainly propylene, optionally with inert components dissolved therein. Furthermore, according to the present invention, as mentioned above, an ethylene feed is used during the prepolymerisation.

[0097] Other components may also be added to the prepolymerization stage. Thus, as is known in the art, hydrogen may be added to the prepolymerization stage to control the molecular weight of the polypropylene (pre-PP). In addition, antistatic additives may be used to prevent particles from adhering to each other or to the reactor walls.

[0098] The precise control of the prepolymerization conditions and reaction parameters is within the skill of the art.

[0099] Due to the process conditions defined above in the prepolymerization, a mixture (MI) of the single-site catalyst (SSC) and the polypropylene (pre-PP) produced in the prepolymerization reactor (PR) is preferably obtained. Preferably, the single-site catalyst (SSC) is (well) dispersed in the polypropylene (pre-PP). In other words, the single-site catalyst (SSC) particles introduced into the prepolymerization reactor (PR) are broken into smaller fragments, which are evenly distributed in the growing polypropylene (pre-PP). The size of the single-site catalyst (SSC) particles introduced and the size of the fragments obtained are not essential for the present invention and are within the scope of technical knowledge.

[0100] As mentioned above, if prepolymerization is used, the mixture (MI) of single site catalyst (SSC) and polypropylene (pre-PP) produced in the prepolymerization reactor (PR) is transferred to the first reactor (R1) after said prepolymerization. Typically, the total amount of polypropylene (pre-PP) in the final propylene copolymer (R-PP) is rather low and typically does not exceed 5.0 wt.-%, more preferably does not exceed 4.0 wt.-%, yet more preferably is in the range of 0.5 to 4.0 wt.-%, such as in the range of 1.0 to 3.0 wt.-%.

[0101] Propylene and other ingredients, such as single site catalyst (SSC), are introduced directly into the first polymerization reactor (R1) without using prepolymerization.

[0102] Therefore, the propylene random copolymer is preferably produced under the conditions stated above in a process comprising the steps of

[0103] (a) polymerizing propylene in a first polymerization reactor (R1), i.e. in a loop reactor (LR), to obtain a first random propylene copolymer fraction (R-PP1),

[0104] (b) transferring the first random propylene copolymer fraction (R-PP1) to a second polymerization reactor (R2),

[0105] (c) in a second polymerization reactor (R2), propylene is polymerized in the presence of the first propylene random copolymer fraction (R-PP1) to obtain a second propylene random copolymer fraction (R-PP2), wherein the first propylene random copolymer fraction (R-PP1) and the second propylene random copolymer fraction (R-PP2) form a random copolymer of propylene (R-PP).

[0106] The prepolymerization as described above may be carried out before step (a).

[0107] As indicated above, in the specific process for preparing the propylene random copolymer (R-PP) as defined above, a single site catalyst (SSC) should be used. Therefore, the single site catalyst (SSC) will now be described in more detail.

[0108] The single-site catalyst according to the present invention may be any supported metallocene catalyst suitable for producing highly isotactic polypropylene.

[0109] In a first embodiment, a single site catalyst (SSC) comprises a metallocene complex, a cocatalyst system comprising a boron-containing cocatalyst and / or an aluminoxane cocatalyst, and a silica support.

[0110] In particular, it is preferred that the single site catalyst (SSC) of the first embodiment comprises

[0111] (i) Metallocene complex having the general formula (II)

[0112]

[0113] wherein each X is independently a σ-donor ligand,

[0114] 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 or a C1-C ... 20 - a hydrocarbon group, or optionally two R' groups together can form a ring,

[0115] Each R 1 are independently identical or can be different and are hydrogen, linear or branched C1-C6-alkyl, C 7-20 -aralkyl, C 7-20 -alkylaryl or C 6-20 -aryl or OY group, where Y is C 1-10 -hydrocarbyl, and optionally two adjacent R 1 The groups can be part of a ring containing the phenyl carbon to which they are bonded,

[0116] Each R 2 are independently the same or can be different, and are CH2-R 8 Group, where R 8 H or linear or branched C 1-6 -alkyl, C 3-8 -cycloalkyl, C 6-10 -aryl,

[0117] R 3 is a straight or branched C1-C6-alkyl, C 7-20 -aralkyl, C 7-20 -alkylaryl or C6-C 20 -aryl,

[0118] R 4 C(R 9 )3 groups, wherein R 9 is a linear or branched C1-C6-alkyl group,

[0119] R 5 is hydrogen or an aliphatic C1-C12 radical optionally containing one or more heteroatoms from Groups 14 to 16 of the Periodic Table 20 -hydrocarbon group;

[0120] R 6 is hydrogen or an aliphatic C1-C12 radical optionally containing one or more heteroatoms from Groups 14 to 16 of the Periodic Table 20 - a hydrocarbon group; or

[0121] R 5 and R 6 can together form a 5-membered saturated carbocyclic ring, which is optionally substituted by n R 10 Group substitution, n is 0 to 4;

[0122] Each R 10 Same or different, and can be C1-C 20 -hydrocarbyl, or a C1-C ... 20 -hydrocarbon group;

[0123] R 7 is H or linear or branched C1-C6-alkyl or optionally substituted by 1 to 3 R 11 a radical-substituted aryl or heteroaryl group having 6 to 20 carbon atoms,

[0124] Each R 11 are independently identical or can be different and are hydrogen, linear or branched C1-C6-alkyl, C 7-20 -aralkyl, C 7-20 -alkylaryl or C 6-20 -aryl or OY group, where Y is C 1-10 - hydrocarbon group,

[0125] (ii) a cocatalyst system comprising a boron-containing cocatalyst and / or an aluminoxane cocatalyst, and

[0126] (iii) Silica support.

[0127] The term "σ-donor ligand" is well known to those skilled in the art, i.e., a group that binds to the metal via a σ bond. Thus, the anionic ligand "X" can independently be a halogen or selected from the group consisting of R', OR', SiR'3, OSiR'3, OSO2CF3, OCOR', SR', NR'2 or PR'2 groups, wherein R' is independently hydrogen, a linear or branched, cyclic or acyclic C1 to C 20 Alkyl, C2 to C 20 Alkenyl, C2 to C 20 Alkynyl, C3 to C 12 Cycloalkyl, C6 to C 20 Aryl, C7 to C 20 Aralkyl, C7 to C 20 Alkaryl, C8 to C 20 Aralkenyl, wherein the R' group can optionally contain one or more heteroatoms belonging to Groups 14 to 16. In a preferred embodiment, the anionic ligands "X" are identical and are halogen, such as Cl, or are methyl or benzyl.

[0128] Preferred monovalent anionic ligands are halogens, especially chloride (Cl).

[0129] More preferably, the metallocene catalyst has formula (IIa)

[0130]

[0131] Each R 1 are independently the same or can be different and are hydrogen or a linear or branched C1-C6 alkyl group, whereby at least one R of each phenyl group 1 Not hydrogen,

[0132] R′ is C1-C 10 a hydrocarbon group, preferably a C1-C4 hydrocarbon group, and more preferably a methyl group, and

[0133] 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.

[0134] Most preferably, X is chlorine, benzyl or methyl. Preferably, the two X groups are the same. The most preferred options are two chlorides, two methyls or two benzyls, especially two chlorides.

[0135] Preferred complexes of metallocene catalysts include:

[0136] rac-dimethylsilylenebis[2-methyl-4-(3',5'-dimethylphenyl)-5-methoxy-6-tert-butylinden-1-yl]zirconium dichloride,

[0137] Racemic-trans-dimethylsilanylidene[2-methyl-4-(4′-tert-butylphenyl)-inden-1-yl][2-methyl-4-(4′-tert-butylphenyl)-5-methoxy-6-tert-butylinden-1-yl]zirconium dichloride,

[0138] rac-trans-dimethylsilanylidene[2-methyl-4-(4′-tert-butylphenyl)-inden-1-yl][2-methyl-4-phenyl-5-methoxy-6-tert-butylinden-1-yl]zirconium dichloride,

[0139] Racemic-trans-dimethylsilylene[2-methyl-4-(3',5'-tert-butylphenyl)-1,5,6,7-tetrahydro-sym-indacene-1-yl][2-methyl-4-(3',5'-dimethyl-phenyl)-5-methoxy-6-tert-butylinden-1-yl]zirconium dichloride,

[0140] Racemic-trans-dimethylsilylene[2-methyl-4,8-bis-(4′-tert-butylphenyl)-1,5,6,7-tetrahydro-sym-indacene-1-yl][2-methyl-4-(3′,5′-dimethyl-phenyl)-5-methoxy-6-tert-butylinden-1-yl]zirconium dichloride,

[0141] Racemic-trans-dimethylsilylene[2-methyl-4,8-bis-(3',5'-dimethylphenyl)-1,5,6,7-tetrahydro-sym-indacen-1-yl][2-methyl-4-(3',5'-dimethylphenyl)-5-methoxy-6-tert-butylinden-1-yl]zirconium dichloride,

[0142] Racemic-trans-dimethylsilanylidene[2-methyl-4,8-bis-(3',5'-dimethylphenyl)-1,5,6,7-tetrahydro-sym-indacene-1-yl][2-methyl-4-(3',5'-5-di-tert-butyl-phenyl)-5-methoxy-6-tert-butylinden-1-yl]zirconium dichloride.

[0143] Particularly preferred is rac-trans-dimethylsilylene[2-methyl-4,8-bis-(3',5'-dimethylphenyl)-1,5,6,7-tetrahydro-sym-indacen-1-yl][2-methyl-4-(3',5'-dimethylphenyl)-5-methoxy-6-tert-butylinden-1-yl]zirconium dichloride(IIb)

[0144]

[0145] The complex compound of the present invention and the part required for the catalyst of the present invention can be synthesized by any method, and skilled organic chemists can design various synthesis schemes for the manufacture of necessary ligand materials. For example, WO2007 / 116034 discloses necessary chemistry. Synthesis schemes can also generally be found in WO 2002 / 02576, WO 2011 / 135004, WO 2012 / 084961, WO 2012 / 001052, WO 2011 / 076780, WO 2015 / 158790 and WO 2018 / 122134. With particular reference to WO 2019 / 179959, the most preferred catalyst of the present invention is described.

[0146] The catalyst can be used in a supported or unsupported form, preferably in a supported form in a first embodiment. The particulate support material used is preferably an organic or inorganic material, such as silicon dioxide, aluminum oxide or zirconium oxide or a mixed oxide, such as silicon dioxide-alumina, in particular silicon dioxide, aluminum oxide or silicon dioxide-alumina. Preferably, a silicon dioxide support is used. Those skilled in the art are aware of the procedures required for supporting metallocene catalysts.

[0147] Particularly preferably, the support is a porous material so that the complex can be loaded into the pores of the support, for example using methods similar to those described in WO 94 / 14856 (Mobil), WO 95 / 12622 (Borealis) and WO 2006 / 097497.

[0148] The average particle size of the silica support can generally be in the range of 10 to 100 μm. However, it has been shown that particular advantages can be achieved if the support has a median particle size d50 of 15 to 80 μm, preferably 18 to 50 μm.

[0149] The average pore size of the silica support can be in the range of 10 to 100 nm, with a pore volume of 1 to 3 mL / g.

[0150] Examples of suitable support materials are silicas such as ES757 produced and sold by PQ, Sylopol 948 produced and sold by Grace, or SUNSPERA DM-L-303 produced by AGC Si-Tech. The support can optionally be calcined before use in the catalyst preparation to achieve an optimal silanol group content.

[0151] The use of these supports is conventional in the art.

[0152] In a second alternative embodiment, the single site catalyst (SSC) comprises a metallocene complex and a cocatalyst system comprising a boron-containing cocatalyst and / or an aluminoxane cocatalyst.

[0153] In particular, it is preferred that the single site catalyst (SSC) of the second embodiment comprises:

[0154] (i) a complex having the formula (III):

[0155]

[0156] in

[0157] M is zirconium or hafnium;

[0158] Each X is a σ ligand;

[0159] 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-hydrocarbon group, a tri(C1-C20-alkyl)silyl group, a C6-C20-aryl group, a C7-C20-aralkyl group or a C7-C20-alkaryl group;

[0160] R 2 and R 2 ' are each independently a C1-C20 hydrocarbon group optionally containing one or more heteroatoms from Groups 14 to 16;

[0161] R 5 ' is a C1-20 hydrocarbon group optionally substituted by one or more halogen atoms and containing one or more heteroatoms of Groups 14 to 16;

[0162] R 6 and R 6 ' are each independently hydrogen or a C1-20 hydrocarbon group optionally containing one or more heteroatoms from Groups 14 to 16; wherein R 6 ' is preferably a tertiary alkyl group,

[0163] R 7 is hydrogen or a C1-20 hydrocarbon group optionally containing one or more heteroatoms from Groups 14 to 16;

[0164] R 7 ' is hydrogen;

[0165] Ar is independently optionally replaced by one or more R 1 a radical-substituted aryl or heteroaryl group having up to 20 carbon atoms;

[0166] Ar' is independently optionally replaced by one or more R 1 a radical-substituted aryl or heteroaryl group having up to 20 carbon atoms;

[0167] Each R 1 is a C1-20 hydrocarbon group, or two R 1 The group can be taken together with the Ar group to form a fused 5 or 6 membered non-aromatic ring which itself is optionally substituted by one or more R 4 group substitution;

[0168] Each R 4 is a C1-20 hydrocarbon group;

[0169] and

[0170] (ii) A co-catalyst comprising at least one or two compounds of Group 13 metals, such as Al and / or boron compounds.

[0171] The catalyst used in the second embodiment is in the form of solid particles. As mentioned above, it can be supported on a conventional carrier known to those skilled in the art. Preferably, the catalyst used does not contain an external carrier.

[0172] Ideally, the catalyst can be obtained by a process wherein

[0173] (a) forming a liquid / liquid emulsion system comprising a solution of catalyst components (i) and (ii) dispersed in a solvent to form dispersed droplets; and

[0174] (b) forming solid particles by solidifying the dispersed droplets.

[0175] The term C1-20 hydrocarbyl group includes C1-20 alkyl, C2-20 alkenyl, C2-20 alkynyl, C3-20 cycloalkyl, C3-20 cycloalkenyl, C6-20 aryl, C7-20 alkaryl or C7-20 aralkyl groups, or of course mixtures of these groups, such as cycloalkyl substituted by an alkyl group.

[0176] Unless otherwise stated, preferred C1-20 hydrocarbyl groups are C1-20 alkyl, C4-20 cycloalkyl, C5-20 cycloalkyl-alkyl, C7-20 alkaryl, C7-20 aralkyl or C6-20 aryl groups, especially C1-10 alkyl, C6-10 aryl or C7-12 aralkyl groups, for example C1-8 alkyl groups.

[0177] Most especially preferred hydrocarbyl groups are methyl, ethyl, propyl, isopropyl, tert-butyl, isobutyl, C5-6-cycloalkyl, cyclohexylmethyl, phenyl or benzyl.

[0178] When referring to the complex definition, the term halogen includes fluorine, chlorine, bromine and iodine groups, especially chlorine groups.

[0179] The oxidation state of a metal ion is primarily determined by the nature of the metal ion in question and the stability of the individual oxidation states of each metal ion.

[0180] It will be appreciated that in the complexes of the present invention, the metal ion M is coordinated by the ligand X to satisfy the valence state of the metal ion and fill its available coordination sites.

[0181] The nature of these σ-ligands can vary widely.

[0182] Such catalysts are described in WO 2013 / 007650, which is incorporated herein by reference.

[0183] Therefore, preferred complexes for use in the present invention have formula (IVa) or (IVb)

[0184]

[0185] in

[0186] M is zirconium or hafnium;

[0187] Each X is a sigma ligand, preferably each X is independently a hydrogen atom, a halogen atom, a C1-6 alkoxy group, a C1-6 alkyl group, a phenyl group or a benzyl group;

[0188] L is a divalent bridge selected from -R'2C-, -R'2C-CR'2-, -R'2Si-, -R'2Si-SiR'2-, and -R'2Ge-,

[0189] in

[0190] Each R' is independently a hydrogen atom, a C1-20 alkyl group, a C3-10 cycloalkyl group, a tri(C1-20-alkyl)silyl group, a C6-20 aryl group, a C7-20 aralkyl group, or a C7-20 alkaryl group;

[0191] Each R 2 or R 2 ' is a C1-10 alkyl group;

[0192] R 5 ' is a C1-10 alkyl group or Z'R 3 'group;

[0193] R 6 is hydrogen or C1-10 alkyl;

[0194] R 6 ' is a C1-10 alkyl group or a C6-10 aryl group; preferably a tertiary alkyl group;

[0195] R 7 is hydrogen, C1-6 alkyl or ZR 3 group;

[0196] R 7 ' is hydrogen;

[0197] Z and Z' are independently O or S;

[0198] R 3 ' is a C1-10 alkyl group or a C6-10 aryl group optionally substituted by one or more halogen groups;

[0199] R 3 is a C1-10-alkyl group;

[0200] Each n is independently 0 to 4, such as 0, 1 or 2;

[0201] And each R 1 are independently C1-20 hydrocarbon groups, such as C1-10 alkyl groups.

[0202] Further preferred complexes for use in the present invention have formula (Va) or (Vb):

[0203]

[0204] M is zirconium or hafnium;

[0205] Each X is a sigma ligand, preferably each X is independently a hydrogen atom, a halogen atom, a C1-6 alkoxy group, a C1-6 alkyl group, a phenyl group or a benzyl group;

[0206] L is a divalent bridge selected from -R'2C- or -R'2Si-, wherein each R' is independently a hydrogen atom, a C1-20 alkyl group or a C3-10 cycloalkyl group;

[0207] R 6 is hydrogen or C1-10 alkyl;

[0208] R 6 ' is a C1-10 alkyl group or a C6-10 aryl group, preferably a tertiary alkyl group;

[0209] R 7 is hydrogen, C1-6 alkyl or OC1-6 alkyl;

[0210] Z' is O or S;

[0211] R 3 ' is a C1-10 alkyl group or a C6-10 aryl group optionally substituted by one or more halogen groups;

[0212] n is independently 0 to 4, such as 0, 1 or 2; and each R 1 are independently C1-10 alkyl.

[0213] Further preferred complexes for use in the present invention have formula (VIa) or (VIb):

[0214]

[0215] M is zirconium or hafnium;

[0216] Each X is a sigma ligand, preferably each X is independently a hydrogen atom, a halogen atom, a C1-6-alkoxy group, a C1-6-alkyl group, a phenyl group or a benzyl group;

[0217] Each R' is independently a hydrogen atom, a C1-20 alkyl group or a C3-7 cycloalkyl group;

[0218] R 6 is hydrogen or a C1-10 alkyl group;

[0219] R 6 ' is a C1-10 alkyl group or a C6-10 aryl group, preferably a tertiary alkyl group;

[0220] R 7 is hydrogen, C1-6 alkyl or OC1-6 alkyl;

[0221] Z' is O or S;

[0222] R 3 ' is a C1-10 alkyl group or a C6-10 aryl group optionally substituted by one or more halogen groups;

[0223] n is independently 0, 1 to 2; and

[0224] Each R 1 are independently C3-8 alkyl groups.

[0225] Most particularly, the complexes used in the present invention have formula (VIIa) or (VIIb):

[0226]

[0227] wherein each X is a sigma ligand, preferably each X is independently a hydrogen atom, a halogen atom, a C1-6-alkoxy group, a C1-6-alkyl group, a phenyl group or a benzyl group;

[0228] R' is independently C1-6 alkyl or C3-10 cycloalkyl;

[0229] R 1 are independently C3-8 alkyl;

[0230] R6 is hydrogen or a C3-8 alkyl group;

[0231] R 6 ' is a C3-8 alkyl group or a C6-10 aryl group, preferably a tertiary C4-8 alkyl group;

[0232] R 3 ' is a C1-6 alkyl group or a C6-10 aryl group optionally substituted by one or more halogen groups; and

[0233] n is independently 0, 1 or 2.

[0234] Specific compounds according to the second embodiment include

[0235]

[0236] Most preferably, rac-trans-Me2Si(2-Me-4-(p-tBuPh)-Ind)(2-Me-4-Ph-5-OMe-6-tBu-Ind)ZrCl2 is used.

[0237] The synthesis of these materials is described in WO 2013 / 007650.

[0238] According to the present invention, a cocatalyst system comprising a boron-containing cocatalyst and / or an aluminoxane cocatalyst is used in combination with the metallocene catalyst complex defined above.

[0239] The aluminoxane cocatalyst may be an aluminoxane cocatalyst of formula (VIII):

[0240]

[0241] wherein n is generally 6 to 20 and R has the following meanings.

[0242] Aluminoxanes are formed upon partial hydrolysis of organoaluminum compounds, such as compounds having the formula AlR3, AlR2Y, and Al2R3Y3, wherein R can be, for example, C1-C 10 Alkyl, preferably C1-C5 alkyl, or C3-C 10 Cycloalkyl, C7-C 12 Aralkyl or alkaryl and / or phenyl or naphthyl, and wherein Y can be hydrogen, halogen, preferably chlorine or bromine, or C1-C 10 Alkoxy groups, preferably methoxy or ethoxy groups. The oxygen-containing aluminoxanes obtained are usually not pure compounds but mixtures of oligomers of formula (VI).

[0243] The preferred aluminoxane is methylaluminoxane (MAO).Since the aluminoxanes used as cocatalysts according to the invention are not pure compounds due to the way they are prepared, the molar concentrations of the aluminoxane solutions hereinafter are based on their aluminum content.

[0244] According to the present invention, a boron-containing cocatalyst may also be used instead of the aluminoxane cocatalyst, or the aluminoxane cocatalyst may be used in combination with the boron-containing cocatalyst.

[0245] It will be appreciated by those skilled in the art that where a boron-based cocatalyst is used, the complex is typically pre-alkylated by reacting the complex with an alkylaluminum compound such as TIBA. This procedure is well known and any suitable aluminum alkyl may be used, for example Al(C 1-6 Preferred alkylaluminum compounds are triethylaluminum, triisobutylaluminum, triisohexylaluminum, tri-n-octylaluminum and triisooctylaluminum.

[0246] Alternatively, when a borate cocatalyst is used, the metallocene catalyst complex is in its alkylated form, ie, for example, a dimethyl or dibenzyl metallocene catalyst complex may be used.

[0247] Boron-based cocatalysts of interest include cocatalysts of formula (IX)

[0248] BY3(IX)

[0249] wherein Y is the same or different and is a hydrogen atom, an alkyl group having 1 to about 20 carbon atoms, an aryl group having 6 to about 15 carbon atoms, an alkaryl group, an aralkyl group, a haloalkyl group, or a haloaryl group, wherein each of the alkaryl group, aralkyl group, haloalkyl group, or haloaryl group has 1 to 10 carbon atoms in the alkyl group and 6 to 20 carbon atoms in the aryl group, or fluorine, chlorine, bromine, or iodine. Preferred examples of Y are methyl, propyl, isopropyl, isobutyl, or trifluoromethyl, unsaturated groups (such as aryl or haloaryl groups, such as phenyl, tolyl, benzyl, p-fluorophenyl, 3,5-difluorophenyl, pentachlorophenyl, pentafluorophenyl, 3,4,5-trifluorophenyl, and 3,5-bis(trifluoromethyl)phenyl). Preferred options are trifluoroborane, triphenylborane, tri(4-fluorophenyl)borane, tri(3,5-difluorophenyl)borane, tri(4-fluoromethylphenyl)borane, tri(2,4,6-trifluorophenyl)borane, tri(pentafluorophenyl)borane, tri(tolyl)borane, tri(3,5-dimethyl-phenyl)borane, tri(3,5-difluorophenyl)borane and / or tri(3,4,5-trifluorophenyl)borane.

[0250] Tris(pentafluorophenyl)borane is particularly preferred.

[0251] However, preference is given to using borates, i.e. compounds containing borate ions. Such ionic promoters preferably contain non-coordinating anions, such as tetrakis(pentafluorophenyl)borate and tetraphenylborate. Suitable counterions are protonated amines or aniline derivatives, such as methylammonium, anilinium (the protonated form of aniline), dimethylammonium, diethylammonium, N-methylanilinium, diphenylammonium, N,N-dimethylanilinium, trimethylammonium, triethylammonium, tri-n-butylammonium, methyldiphenylammonium, pyridinium, p-bromo-N,N-dimethylanilinium or p-nitro-N,N-dimethylanilinium.

[0252] Preferred ionic compounds that can be used according to the present invention include:

[0253] triethylammonium tetra(phenyl)borate,

[0254] Tributylammonium tetra(phenyl)borate,

[0255] trimethylammonium tetra(tolyl)borate,

[0256] Tributylammonium tetra(tolyl)borate,

[0257] Tributylammonium tetrakis(pentafluorophenyl)borate,

[0258] tripropylammonium tetrakis(dimethylphenyl)borate,

[0259] Tributylammonium tetrakis(trifluoromethylphenyl)borate,

[0260] Tributylammonium tetrakis(4-fluorophenyl)borate,

[0261] N,N-dimethylcyclohexylammonium tetrakis(pentafluorophenyl)borate,

[0262] N,N-dimethylbenzylammonium tetrakis(pentafluorophenyl)borate,

[0263] N,N-dimethylanilinium tetra(phenyl)borate,

[0264] N,N-diethylanilinium tetra(phenyl)borate,

[0265] N,N-dimethylanilinium tetrakis(pentafluorophenyl)borate,

[0266] N,N-di(propyl)ammonium tetrakis(pentafluorophenyl)borate,

[0267] Di(cyclohexyl)ammonium tetrakis(pentafluorophenyl)borate,

[0268] triphenylphosphonium tetrakis(phenyl)borate,

[0269] triethylphosphonium tetra(phenyl)borate,

[0270] Diphenylphosphonium tetrakis(phenyl)borate,

[0271] tri(methylphenyl)phosphonium tetra(phenyl)borate,

[0272] tris(dimethylphenyl)phosphonium tetra(phenyl)borate,

[0273] triphenylcarbeniumtetrakis(pentafluorophenyl)borate,

[0274] or ferroceniumtetrakis(pentafluorophenyl)borate.

[0275] Triphenylcarbonium tetrakis(pentafluorophenyl)borate, N,N-dimethylcyclohexylammonium tetrakis(pentafluorophenyl)borate or N,N-dimethylbenzylammonium tetrakis(pentafluorophenyl)borate is preferred.

[0276] Surprisingly, it has been found that certain boron cocatalysts are particularly preferred. Thus, preferred borates for use in the present invention include trityl ions. Thus, the use of N,N-dimethylammonium-tetrakispentafluorophenylborate and Ph3CB(PhF5)4 and the like is particularly preferred.

[0277] According to the present invention, preferred cocatalysts are alumoxanes, more preferably methylalumoxane, combinations of alumoxanes with alkylaluminum, boron or borate cocatalysts, and combinations of alumoxanes with boron-based cocatalysts.

[0278] Suitable amounts of promoters are well known to those skilled in the art.

[0279] The molar ratio of boron to the metal ion of the metallocene may be in the range of 0.5:1 to 10:1 mol / mol, preferably in the range of 1:1 to 10:1 mol / mol, especially in the range of 1:1 to 5:1 mol / mol.

[0280] The molar ratio of Al in the aluminoxane to the metal ion of the metallocene may be in the range of 1:1 to 2000:1 mol / mol, preferably in the range of 10:1 to 1000:1 mol / mol, and more preferably in the range of 50:1 to 500:1 mol / mol.

[0281] Propylene homopolymer composition

[0282] The minor component present in the instant single-phase polypropylene composition (PC) is the propylene homopolymer composition (H-PP).

[0283] The propylene homopolymer composition (H-PP) comprises a reactor blend of a propylene homopolymer and a polymeric nucleating agent.

[0284] The polymeric nucleating agent is present in an amount in the range of 20 to 300 weight-ppm, more preferably in the range of 20 to 200 weight-ppm, most preferably in the range of 20 to 100 weight-ppm relative to the total weight of the propylene homopolymer composition (H-PP).

[0285] The polymeric nucleating agent comprises a monomer (I) having the general formula

[0286] H2C=CH-CHR 1 R 2 (I)

[0287] where R 1 and R 2 is a single alkyl group having one or more carbon atoms, or forms an optionally substituted saturated, unsaturated or aromatic ring or fused ring system containing 4 to 20 carbon atoms, whereby in R 1 and R 2 When forming an aromatic ring, -CHR 1 R 2 Some hydrogen atoms are absent.

[0288] Preferably, the monomer (I) of the polymeric nucleating agent is selected from the group consisting of vinylcyclohexane, vinylcyclopentane and 4-methylpent-1-ene, most preferably, the monomer is vinylcyclohexane.

[0289] Although other monomers may be present in the polymeric nucleating agent, most commonly propylene monomers, it is preferred that the polymeric nucleating agent consists of monomers having the general formula (I).

[0290] In a particularly preferred embodiment, the polymeric nucleating agent is a homopolymer of vinylcyclohexane (pVCH).

[0291] Since the propylene homopolymer composition (H-PP) is present in the form of a reactor blend of propylene homopolymer and polymeric nucleating agent, all polymer properties relevant for propylene homopolymers have been measured on the propylene homopolymer composition (H-PP).

[0292] The propylene homopolymer composition (H-PP) has a melt flow rate (MFR2) measured according to ISO 1133 at 230°C and 2.16 kg in the range of 10 to 100 g / 10 min, more preferably in the range of 30 to 90 g / 10 min, most preferably in the range of 50 to 80 g / 10 min.

[0293] Preferably, the propylene homopolymer composition (H-PP) has a xylene cold soluble content (XCS), measured according to ISO 16152 at 25°C, in the range of 0.5 to 4.0 wt.-%, more preferably in the range of 1.0 to 3.0 wt.-%, most preferably in the range of 1.5 to 2.0 wt.-%.

[0294] The propylene homopolymer composition (H-PP) is preferably polymerized in the presence of a Ziegler-Natta catalyst (ZNC).

[0295] The absence of 2,1-regio defects is a key indicator that the propylene polymer has been polymerized in the presence of a Ziegler-Natta catalyst. 13 2,1-regio defects determined by C-NMR spectroscopy.

[0296] Furthermore, it is preferred that the propylene homopolymer composition (H-PP) has a carbonyl group-containing copolymer in the range of 90.0 to 99.9%, more preferably in the range of 94.0 to 99.0%, most preferably in the range of 95.5 to 98.5%. 13 Isotactic pentad concentration [mmmm] determined by C-NMR spectroscopy.

[0297] It is especially preferred that the propylene homopolymer composition (H-PP) is polymerized in the presence of a Ziegler-Natta catalyst comprising no phthalate based electron donor.

[0298] Accordingly it is preferred that the propylene homopolymer composition (H-PP) is free from phthalates and their decomposition products.

[0299] Preferably, the propylene homopolymer composition (H-PP) has a melting temperature T in the range of 160 to 175 °C, more preferably in the range of 162 to 172 °C, most preferably in the range of 164 to 169 °C. m .

[0300] Preferably, the propylene homopolymer composition (H-PP) has a crystallization temperature T in the range of 125 to 135 °C, more preferably in the range of 127 to 133 °C, most preferably in the range of 128 to 132 °C. c .

[0301] Where T m and T c Both are determined by differential scanning calorimetry (DSC) according to ISO 11357 / part 3 / method C2 in a heating / cooling / heating cycle at a scanning rate of 10°C / min in the temperature range of -30 to +225°C.

[0302] Preferably, the propylene homopolymer composition (H-PP) has a glass transition temperature T 0 ... g .

[0303] Preferably, the propylene homopolymer composition (H-PP) has a number average molecular weight (Mn), determined by gel permeation chromatography (GPC), in the range of 15,000 to 35,000 g / mol, more preferably in the range of 17,000 to 30,000 g / mol, most preferably in the range of 19,000 to 25,000 g / mol.

[0304] Preferably, the propylene homopolymer composition (H-PP) has a weight average molecular weight (Mw), determined by gel permeation chromatography (GPC), in the range of 134,000 to 148,000 g / mol, more preferably in the range of 136,000 to 146,000 g / mol, most preferably in the range of 138,000 to 144,000 g / mol.

[0305] Preferably, the propylene homopolymer composition (H-PP) has a molecular weight distribution (Mw / Mn) determined by gel permeation chromatography (GPC) in the range of 4.0 to 20.0, more preferably in the range of 5.0 to 15.0, most preferably in the range of 5.5 to 10.0.

[0306] Preferably, the propylene homopolymer composition (H-PP) according to this invention is produced in the presence of

[0307] (a) a Ziegler-Natta catalyst (ZN-C) comprising a compound of a transition metal of Groups 4 to 6 of IUPAC (TC), a Group 2 metal compound (MC) and an internal donor (ID);

[0308] (b) optionally a co-catalyst (Co), and

[0309] (c) Optional external donor (ED).

[0310] Preferably the propylene homopolymer composition (H-PP) is produced in two reactors, ie is bimodal.

[0311] Process for producing a propylene homopolymer composition (H-PP)

[0312] The process for preparing the propylene homopolymer composition (H-PP) and the Ziegler-Natta catalyst (ZN-C) will be described in further detail below.

[0313] As already indicated above the propylene homopolymer composition (H-PP) is preferably produced in a sequential polymerization process.

[0314] In an alternative embodiment, a single polymerization process may be employed.

[0315] The term "sequential polymerization system" means that the propylene homopolymer composition (H-PP) is produced in at least two reactors connected in series. Thus, such a polymerization system comprises at least a first polymerization reactor (R1) and a second polymerization reactor (R2), and optionally a third polymerization reactor (R3). The term "polymerization reactor" should indicate that the main polymerization takes place. Thus, in case the process consists of two polymerization reactors, this definition does not exclude the option of the overall system including a prepolymerization step, for example in a prepolymerization reactor. The term "consisting of..." is a closed description only with respect to the main polymerization reactors.

[0316] The first polymerization reactor (R1) is preferably a slurry reactor (SR) and can be any continuous or simple batch stirred tank reactor or loop reactor operating in bulk or slurry. Bulk refers to polymerization in a reaction medium comprising at least 60% (w / w) monomers. According to the present invention, the slurry reactor (SR) is preferably a (bulk) loop reactor (LR). Thus, the average concentration of the propylene homopolymer composition (H-PP) or the first fraction of the propylene homopolymer composition (H-PP1) in the polymer slurry in the loop reactor (LR) (if a sequential process is used) is typically from 15 wt.-% to 55 wt.-%, based on the total weight of the polymer slurry in the loop reactor (LR). In a preferred embodiment of the present invention, the average concentration of the propylene homopolymer composition (H-PP) or the first fraction of the propylene homopolymer composition (H-PP1) in the polymer slurry in the loop reactor (LR) (if a sequential process is used) is from 20 wt.-% to 55 wt.-%, and more preferably from 25 wt.-% to 52 wt.-%, based on the total weight of the polymer slurry in the loop reactor (LR).

[0317] If further reactors are present, these reactors, such as the optional second polymerization reactor (R2) and the optional third polymerization reactor (R3), are gas phase reactors (GPR), i.e. a first gas phase reactor (GPR1) and a second gas phase reactor (GPR2). The gas phase reactor (GPR) according to the present invention is preferably a fluidized bed reactor, a fast fluidized bed reactor or a settled bed reactor or any combination thereof.

[0318] If a sequential process is used, the propylene homopolymer of the first polymerization reactor (R1), i.e. the first fraction (H-PP1) of the propylene homopolymer composition, more preferably the polymer slurry of the loop reactor (LR) containing the first fraction (H-PP1) of the propylene homopolymer composition, is fed directly to the second polymerization reactor (R2), i.e. to the (first) gas phase reactor (GPR1), without a flash step between stages. Such direct feeding is described in EP 887379A, EP 887380A, EP 887381A and EP 991684A. "Direct feeding" refers to a process in which the content of the first polymerization reactor (R1), i.e. the loop reactor (LR), i.e. the polymer slurry comprising the first fraction (H-PP1) of the propylene homopolymer composition, is passed directly to the gas phase reactor of the next stage.

[0319] Alternatively, the propylene homopolymer of the first polymerization reactor (R1), i.e. the first fraction (H-PP1) of the propylene homopolymer composition, more preferably the polymer slurry of the loop reactor (LR) containing the first fraction (H-PP1) of the propylene homopolymer composition, may also be directed to a flash step or through a further concentration step before being fed to the second polymerization reactor (R2), i.e. the gas phase reactor (GPR). Thus, this "indirect feeding" refers to a process in which the content of the first polymerization reactor (R1), i.e. the loop reactor (LR), i.e. the polymer slurry, is fed to the second polymerization reactor (R2), i.e. the (first) gas phase reactor (GPR1), via a reaction medium separation unit and the reaction medium as gas from the separation unit.

[0320] More specifically, the optional second polymerization reactor (R2) and any subsequent reactors, such as the third polymerization reactor (R3), are preferably gas phase reactors (GPR). Such gas phase reactors (GPR) can be any mechanically mixed or fluidized bed reactor. Preferably, the gas phase reactor (GPR) comprises a mechanically stirred fluidized bed reactor having a gas flow velocity of at least 0.2 m / s. Therefore, it should be understood that the gas phase reactor is a fluidized bed type reactor optionally having a mechanical stirrer.

[0321] Thus, when a sequential polymerization process is used, it is preferred that the first polymerization reactor (R1) is a slurry reactor (SR), such as a loop reactor (LR), and the second polymerization reactor (R2) and any optional subsequent reactors (such as a third polymerization reactor (R3)) are gas phase reactors (GPR). Thus, in this process, at least two polymerization reactors connected in series are used, preferably two polymerization reactors (R1) and (R2) or three polymerization reactors (R1), (R2) and (R3), i.e. a slurry reactor (SR) (such as a loop reactor (LR)) and a (first) gas phase reactor (GPR1) and optionally a second gas phase reactor (GPR2). If desired, a prepolymerization reactor may be placed before the slurry reactor (SR).

[0322] If any subsequent reactors are used, the Ziegler-Natta catalyst (ZN-C) is fed to the first polymerization reactor (R1) and transferred to the subsequent reactors together with the polymer (slurry) obtained in the first polymerization reactor (R1). If the process also includes a prepolymerization step, it is preferred that all of the Ziegler-Natta catalyst (ZN-C) is fed to the prepolymerization reactor. Subsequently, the prepolymerization product containing the Ziegler-Natta catalyst (ZN-C) is transferred to the first polymerization reactor (R1).

[0323] A preferred multi-stage process is a "loop-gas phase" process such as that developed by Borealis A / S of Denmark (known as technology), for example the methods described in patent literature such as EP 0 887 379, WO 92 / 12182, WO 2004 / 000899, WO 2004 / 111095, WO 99 / 24478, WO 99 / 24479 or WO 00 / 68315.

[0324] Another suitable slurry-gas phase process is the method.

[0325] Particularly good results are obtained with careful choice of the temperature in the reactor.

[0326] Therefore, it is preferred that the operating temperature in the first polymerization reactor (R1) is in the range of 62 to 85°C, more preferably in the range of 65 to 82°C, still more preferably in the range of 67 to 80°C.

[0327] Alternatively or additionally to the previous paragraph, it is preferred that the operating temperature in the optional second polymerization reactor (R2) and in the optional third reactor (R3) is in the range of 62 to 95°C, more preferably in the range of 67 to 92°C.

[0328] Preferably, the operating temperature in the optional second polymerization reactor (R2) is equal to or higher than the operating temperature in the first polymerization reactor (R1).

[0329] (a) the operating temperature in the first polymerization reactor (R1) is in the range of 62 to 85°C, more preferably in the range of 65 to 82°C, still more preferably in the range of 67 to 80°C, such as in the range of 69 to 80°C; and

[0330] (b) the operating temperature in the optional second polymerization reactor (R2) is in the range of 75 to 95°C, more preferably in the range of 78 to 92°C, still more preferably in the range of 78 to 88°C,

[0331] The proviso is that the operating temperature in the optional second polymerization reactor (R2) is equal to or higher than the operating temperature in the first polymerization reactor (R1).

[0332] Typically, the pressure in the first polymerization reactor (R1), preferably the loop reactor (LR), is in the range of 20 to 80 bar, preferably in the range of 30 to 70 bar, for example in the range of 35 to 65 bar, while the pressure in the optional second polymerization reactor (R2), i.e. the (first) gas phase reactor (GPR1) and optionally any subsequent reactors, such as the third polymerization reactor (R3), e.g. the second gas phase reactor (GPR2), is in the range of 5 to 50 bar, preferably in the range of 15 to 40 bar.

[0333] Preferably, hydrogen is added to each polymerization reactor to control the molecular weight, ie the melt flow rate MFR2.

[0334] Preferably, the average residence time in the polymerization reactors (R1) and (R2) is relatively long. Typically, the average residence time (τ) is defined as the reaction volume (V R ) and the volumetric outflow rate of the reactor (Q o ) ratio (ie V R / Q o ), that is, τ=V R / Q o [τ=V R / Q o In the case of a loop reactor, the reaction volume (V R ) is equal to the reactor volume.

[0335] Thus, the average residence time (τ) in the first polymerization reactor (R1) is preferably at least 15 min, more preferably in the range of 15 to 80 min, still more preferably in the range of 20 to 60 min, such as in the range of 24 to 50 min, and / or the average residence time (τ) in the second polymerization reactor (R2) (if present) is preferably at least 70 min, more preferably in the range of 70 to 220 min, still more preferably in the range of 80 to 210 min, still more preferably in the range of 90 to 200 min, such as in the range of 90 to 190 min. Preferably, the average residence time (τ) in the third polymerization reactor (R3) (if present) is preferably at least 30 min, more preferably in the range of 30 to 120 min, yet more preferably in the range of 40 to 100 min, such as in the range of 50 to 90 min.

[0336] As mentioned above, the preparation of the propylene homopolymer may comprise, in addition to the (main) polymerization of the propylene homopolymer in the at least one polymerization reactor (R1 and optionally R2 and R3), a preceding prepolymerization in a prepolymerization reactor (PR) upstream of the first polymerization reactor (R1).

[0337] In the prepolymerization reactor (PR), polypropylene (pre-PP) is produced. The prepolymerization is carried out in the presence of a Ziegler-Natta catalyst (ZN-C). According to this embodiment, the Ziegler-Natta catalyst (ZN-C), the cocatalyst (Co) and the external donor (ED) are all introduced into the prepolymerization step. However, this does not exclude the option of adding, for example, further cocatalyst (Co) and / or external donor (ED) at a subsequent stage in the polymerization process, for example in the first reactor (R1). In one embodiment, if prepolymerization is applied, the Ziegler-Natta catalyst (ZN-C), the cocatalyst (Co) and the external donor (ED) are only added to the prepolymerization reactor (PR).

[0338] The prepolymerization reaction is usually carried out at a temperature of 0 to 60°C, preferably 15 to 50°C, more preferably 20 to 45°C.

[0339] The pressure in the prepolymerisation reactor is not critical but must be high enough to keep the reaction mixture in the liquid phase. Thus, the pressure may be from 20 to 100 bar, for example from 30 to 70 bar.

[0340] In a preferred embodiment the prepolymerisation is carried out as bulk slurry polymerisation in liquid propylene, ie the liquid phase comprises mainly propylene, optionally with inert components dissolved therein. Furthermore, according to the present invention, as mentioned above, an ethylene feed is used during the prepolymerisation.

[0341] Other components may also be added to the prepolymerization stage. Thus, as is known in the art, hydrogen may be added to the prepolymerization stage to control the molecular weight of the polypropylene (pre-PP). In addition, antistatic additives may be used to prevent particles from adhering to each other or to the reactor walls.

[0342] The precise control of the prepolymerization conditions and reaction parameters is within the skill of those skilled in the art.

[0343] Due to the process conditions in the prepolymerization defined above, a mixture (MI) of the Ziegler-Natta catalyst (ZN-C) produced in the prepolymerization reactor (PR) and the polypropylene (pre-PP) is preferably obtained. Preferably, the Ziegler-Natta catalyst (ZN-C) is (well) dispersed in the polypropylene (pre-PP). In other words, the particles of the Ziegler-Natta catalyst (ZN-C) introduced into the prepolymerization reactor (PR) are broken into smaller fragments, which are evenly distributed in the growing polypropylene (pre-PP). The size of the particles of the Ziegler-Natta catalyst (ZN-C) introduced and of the fragments obtained are not essential for the present invention and are within the scope of the state of the art.

[0344] As mentioned above, if prepolymerization is used, the mixture (MI) of Ziegler-Natta catalyst (ZN-C) and polypropylene (pre-PP) produced in the prepolymerization reactor (PR) is transferred to the first reactor (R1) after said prepolymerization. Typically, the total amount of polypropylene (pre-PP) in the final propylene copolymer (R-PP) is rather low and typically does not exceed 5.0 wt.-%, more preferably does not exceed 4.0 wt.-%, yet more preferably is in the range of 0.5 to 4.0 wt.-%, such as in the range of 1.0 to 3.0 wt.-%.

[0345] Propylene and other ingredients, such as Ziegler-Natta catalyst (ZN-C), are introduced directly into the first polymerization reactor (R1) without using prepolymerization.

[0346] Thus, propylene homopolymers can be produced under the conditions set out above in a process comprising the steps of

[0347] (a) polymerizing propylene in a first polymerization reactor (R1), i.e. in a loop reactor (LR), to obtain a first fraction (H-PP1) of a propylene homopolymer composition,

[0348] (b) transferring the first fraction of the propylene homopolymer composition (H-PP1) to a second polymerization reactor (R2),

[0349] (c) in a second polymerization reactor (R2), polymerizing propylene in the presence of the first fraction of propylene homopolymer composition (H-PP1) to obtain a second fraction of propylene homopolymer composition (H-PP2) of propylene homopolymer, said first fraction of propylene homopolymer composition (H-PP1) and said second fraction of propylene homopolymer composition (H-PP2) forming a propylene homopolymer composition (H-PP).

[0350] In one embodiment, when a unimodal propylene homopolymer is desired, the propylene homopolymer is produced under the conditions stated above in a process comprising the following steps:

[0351] (a) polymerizing propylene in a first polymerization reactor (R1), i.e. in a loop reactor (LR), to obtain a propylene homopolymer (H-PP),

[0352] (b) removing the propylene homopolymer (H-PP) from the first polymerisation reactor.

[0353] The prepolymerization as described above may be carried out before step (a).

[0354] The catalyst used in the present invention is a solid Ziegler-Natta catalyst (ZN-C) comprising a compound (TC) of a transition metal of Groups 4 to 6 of the IUPAC, such as titanium, a Group 2 metal compound (MC) such as magnesium, and an internal donor (ID), which, as described in more detail below, is a non-phthalic compound, preferably a non-phthalic ester, and more preferably a diester of non-phthalic dicarboxylic acids. Thus, the catalyst is completely free of undesirable phthalic compounds. Furthermore, the solid catalyst preferably does not contain any external support material, such as silica or MgCl 2 , but is self-supported. Self-supported catalysts do not contain magnesium halide, since magnesium halide is formed during the reaction between the magnesium compound and TiCl 4 ; however, the presence of magnesium halide as an external support medium is preferably excluded.

[0355] The Ziegler-Natta catalyst (ZN-C) can be further defined by the manner in which it is obtained. Thus, the Ziegler-Natta catalyst (ZN-C) is preferably obtained by a process comprising the following steps:

[0356] a)

[0357] a1) providing a solution of at least a Group 2 metal alkoxide (Ax), which is the reaction product of a Group 2 metal compound (MC) and an alcohol (A), optionally in an organic liquid reaction medium, the alcohol (A) comprising at least one ether moiety in addition to a hydroxyl moiety;

[0358] or

[0359] a2) a solution of at least a Group 2 metal alkoxide (Ax') which is the reaction product of a Group 2 metal compound (MC) with an alcoholic mixture of an alcohol (A) and a monohydric alcohol (B) of the formula ROH, optionally in an organic liquid reaction medium;

[0360] or

[0361] a3) providing a solution of a mixture of a Group 2 alkoxide (Ax) and a Group 2 metal alkoxide (Bx), which is the reaction product of a Group 2 metal compound (MC) and a monohydric alcohol (B), optionally in an organic liquid reaction medium; and

[0362] b) adding said solution from step a) to at least one compound of a transition metal from Groups 4 to 6 (TC), and

[0363] c) obtaining solid catalyst component particles,

[0364] and adding a non-phthalic acid internal electron donor (ID) at any step prior to step c).

[0365] Preferably, an internal donor (ID) or a precursor thereof is added to the solution of step a).

[0366] According to the above procedure, the Ziegler-Natta catalyst (ZN-C) can be obtained by precipitation or by emulsion (liquid / liquid two-phase system)-solidification, depending on the physical conditions, especially the temperature used in steps b) and c).

[0367] In both methods (precipitation or emulsion-solidification), the catalyst chemistry is the same.

[0368] In the precipitation method, the combination of the solution of step a) and the at least one transition metal compound (TC) of step b) is carried out and the entire reaction mixture is maintained at a temperature of at least 50° C., more preferably in the range of 55 to 110° C., more preferably in the range of 70 to 100° C., to ensure complete precipitation of the catalyst components in the form of solid particles (step c).

[0369] In the emulsion-solidification process, in step b), the solution of step a) is added to at least one transition metal compound (TC), usually at a relatively low temperature, such as -10 to below 50° C., preferably -5 to 30° C. During the stirring of the emulsion, the temperature is usually maintained at -10 to below 40° C., preferably -5 to 30° C. The droplets of the dispersed phase of the emulsion form the active catalyst component. The solidification of the droplets (step c) is suitably carried out by heating the emulsion to a temperature of 70 to 150° C., preferably 80 to 110° C.

[0370] The present invention preferably uses a catalyst prepared by the emulsion-solidification method.

[0371] In a preferred embodiment, a solution of a2) or a3), ie a solution of (Ax') or a solution of a mixture of (Ax) and (Bx), is used in step a).

[0372] Preferably, the Group 2 metal (MC) is magnesium.

[0373] The alkoxymagnesium compounds (Ax), (Ax') and (Bx) can be prepared in situ in the first step (step a)) of the catalyst preparation process by reacting a magnesium compound with one or more of the above-mentioned alcohols, or the alkoxymagnesium compounds can be separately prepared alkoxymagnesium compounds, or they can even be commercially available ready-made alkoxymagnesium compounds and used as such in the catalyst preparation process of the present invention.

[0374] Illustrative examples of alcohol (A) are monoethers of dihydric alcohols (glycol monoethers). Preferred alcohols (A) are C2 to C4 glycol monoethers, wherein the ether moiety contains 2 to 18 carbon atoms, preferably 4 to 12 carbon atoms. Preferred examples are 2-(2-ethylhexyloxy)ethanol, 2-butoxyethanol, 2-hexyloxyethanol, 1,3-propylene glycol monobutyl ether, and 3-butoxy-2-propanol, with 2-(2-ethylhexyloxy)ethanol, 1,3-propylene glycol monobutyl ether, and 3-butoxy-2-propanol being particularly preferred.

[0375] Illustrative monohydric alcohols (B) have the formula ROH, where R is a linear or branched C6-C 10 The most preferred monohydric alcohol is 2-ethyl-1-hexanol or octanol.

[0376] Preferably, a mixture of Mg alkoxy compounds (Ax) and (Bx) or a mixture of alcohols (A) and (B), respectively, is used, employing a molar ratio of Bx:Ax or B:A of 8:1 to 2:1, more preferably 5:1 to 3:1.

[0377] The alkoxymagnesium compound may be the reaction product of one or more alcohols as defined above and a magnesium compound selected from the group consisting of dialkylmagnesium, alkylmagnesium alkoxy, dialkoxymagnesium, alkoxymagnesium halide and alkylmagnesium halide. The alkyl groups may be similar or different C1-C 20 Alkyl, preferably C2-C 10 Alkyl. When used, typical alkyl-alkoxy magnesium compounds are ethyl butoxy magnesium, butyl pentoxy magnesium, octyl butoxy magnesium and octyl octoxy magnesium. Dialkyl magnesium is preferably used. The most preferred dialkyl magnesium is butyl octyl magnesium or butyl ethyl magnesium.

[0378] It is also possible that the magnesium compound can react with alcohol (A) and alcohol (B) in addition to the reaction with the formula R" (OH) m If used, the preferred polyol is a C2 to C 10 A hydrocarbon residue, wherein m is an integer from 2 to 6.

[0379] Thus, the alkoxymagnesium compound of step a) is selected from the group consisting of dialkoxymagnesium, diaryloxymagnesium, alkoxymagnesium halide, aryloxymagnesium halide, alkylalkoxymagnesium, arylalkoxymagnesium and alkylaryloxymagnesium. In addition, mixtures of dihalide and dialkoxymagnesium can be used.

[0380] The solvent used to prepare the catalyst can be selected from aromatic and aliphatic linear, branched, and cyclic hydrocarbons having 5 to 20 carbon atoms, more preferably 5 to 12 carbon atoms, or mixtures thereof. Suitable solvents include benzene, toluene, cumene, xylene, pentane, hexane, heptane, octane, and nonane. Hexane and pentane are particularly preferred.

[0381] The magnesium compound is usually provided as a 10 to 50 wt% solution in the above solvents. Typical commercially available solutions of magnesium compounds, especially dialkylmagnesiums, are 20 to 40 wt% solutions in toluene or heptane.

[0382] The reaction for preparing the alkoxymagnesium compound can be carried out at a temperature of 40° C. to 70° C. The most suitable temperature is selected depending on the magnesium compound and the alcohol(s) used.

[0383] Preferably, the Group 4 to 6 transition metal compound is a titanium compound, most preferably a titanium halide such as TiCl4.

[0384] The internal donor (ID) used to prepare the catalyst used in the present invention is preferably selected from the group consisting of (diesters) of non-phthalic carboxylic (di)acids, 1,3-diethers, derivatives thereof, and mixtures thereof. Particularly preferred donors are diesters of monounsaturated dicarboxylic acids, in particular esters belonging to the group consisting of malonates, maleates, succinates, citraconic acid esters, glutarates, cyclohexene-1,2-dicarboxylates, and benzoates, and any derivatives and / or mixtures thereof, preferred examples being substituted maleates and citraconic acid esters, and most preferred being citraconate.

[0385] In the emulsion process, a two-phase liquid-liquid system can be formed by simple stirring and optionally adding (additional) solvents and additives, such as turbulence minimizing agents (TMAs) and / or emulsifiers and / or emulsion stabilizers, such as surfactants, which are used in a manner known in the art to promote the formation of the emulsion and / or stabilize the emulsion. Preferably, the surfactant is an acrylic acid or methacrylic acid polymer. Particularly preferred are unbranched C 12 to C 20 (Meth)acrylates such as poly(hexadecyl) methacrylate and poly(octadecyl) methacrylate and mixtures thereof. If used, the turbulence minimizing agent (TMA) is preferably selected from α-olefin polymers of α-olefin monomers having 6 to 20 carbon atoms, such as polyoctene, polynonene, polydecene, polyundecene or polydodecene or mixtures thereof. Most preferably, it is polydecene.

[0386] The solid particulate product obtained by precipitation or emulsion-solidification can be washed at least once, preferably at least twice, and most preferably at least three times with aromatic and / or aliphatic hydrocarbons, preferably toluene, heptane or pentane. The catalyst can be further dried, for example by evaporation or flushing with nitrogen, or it can be slurried into an oily liquid without any drying step.

[0387] The Ziegler-Natta catalyst is preferably in the form of particles, generally with an average particle size ranging from 5 to 200 μm, preferably from 10 to 100 μm. The particles are dense, low in porosity, and have a surface area of ​​less than 20 g / m 2 , more preferably less than 10 g / m 2 Typically, the amount of Ti in the catalyst composition is 1 to 6 wt%, the amount of Mg is 10 to 20 wt%, and the amount of the donor is 10 to 40 wt%.

[0388] Detailed descriptions of the preparation of the catalysts are disclosed in WO 2012 / 007430, EP 2610271, EP 261027 and EP 2610272, which are incorporated herein by reference.

[0389] Ziegler-Natta catalysts (ZN-C) are preferably used in association with an alkylaluminum cocatalyst and optionally an external donor.

[0390] As another component of the polymerization process of the present invention, an external donor (ED) is preferably present. Suitable external donors (ED) include certain silanes, ethers, esters, amines, ketones, heterocyclic compounds, and blends of these compounds. Particularly preferred is the use of silanes. Most preferably, silanes having the following general formula are used:

[0391] R a p R b q Si(OR c ) (4-p-q)

[0392] where R a 、R b and R c represents a hydrocarbon group, in particular an alkyl or cycloalkyl group,

[0393] And wherein p and q are numbers ranging from 0 to 3, and their sum p+q is equal to or less than 3. a 、R b and R c Can be selected independently of each other and can be the same or different. Specific examples of such silanes are (tert-butyl) 2Si(OCH 3 ) 2 , (cyclohexyl)(methyl)Si(OCH 3 ) 2 , (phenyl) 2Si (OCH 3 ) 2 and (cyclopentyl) 2Si (OCH 3 ) 2,

[0394] Alternatively, silanes of the following general formula may be used:

[0395] Si(OCH2CH3)3(NR 3 R 4 )

[0396] where R 3 and R 4 can be the same or different and represent a hydrocarbon group having 1 to 12 carbon atoms.

[0397] R 3 and R 4 are independently selected from the group consisting of a linear aliphatic hydrocarbon group having 1 to 12 carbon atoms, a branched aliphatic hydrocarbon group having 1 to 12 carbon atoms, and a cyclic aliphatic hydrocarbon group having 1 to 12 carbon atoms. 3 and R 4independently selected from the group consisting of methyl, ethyl, n-propyl, n-butyl, octyl, decyl, isopropyl, isobutyl, isopentyl, tert-butyl, tert-pentyl, neopentyl, cyclopentyl, cyclohexyl, methylcyclopentyl and cycloheptyl.

[0398] More preferably, R 3 and R 4 Both are the same, still more preferably, R 3 and R 4 Both are ethyl groups.

[0399] Particularly preferred external donors (ED) are dicyclopentyldimethoxysilane donors (D-donors) or cyclohexylmethyldimethoxysilane donors (C-donors).

[0400] In addition to the Ziegler-Natta catalyst (ZN-C) and the optional external donor (ED), a cocatalyst may also be used. Preferably, the cocatalyst is a compound of Group 13 of the Periodic Table (IUPAC), for example an organoaluminum, such as an aluminum compound, such as an alkylaluminum, an aluminum halide or an alkylaluminum halide compound. Therefore, in a specific embodiment, the cocatalyst (Co) is a trialkylaluminum, such as triethylaluminum (TEAL), a dialkylaluminum chloride or an alkylaluminum dichloride or a mixture thereof. In a specific embodiment, the cocatalyst (Co) is triethylaluminum (TEAL).

[0401] Preferably, the ratio between the cocatalyst (Co) and the external donor (ED) [Co / ED] and / or the ratio between the cocatalyst (Co) and the transition metal (TM) [Co / TM] should be carefully chosen.

[0402] therefore,

[0403] (a) the molar ratio of cocatalyst (Co) to external donor (ED) [Co / ED] must be in the range of 5 to 45, preferably in the range of 5 to 35, more preferably in the range of 5 to 25;

[0404] and optionally

[0405] (b) The molar ratio [Co / TC] of the co-catalyst (Co) to the titanium compound (TC) must be within the range of 80 or more and 500, preferably within the range of 100 to 350, and more preferably within the range of 120 to 300.

[0406] As stated above, the propylene homopolymer composition (H-PP) comprises a polymeric nucleating agent comprising a monomer (I) having the general formula

[0407] H2C=CH-CHR 1 R 2 (I)

[0408] where R 1 and R 2 is a single alkyl radical having one or more carbon atoms, or forms an optionally substituted saturated, unsaturated or aromatic ring or fused ring system containing 4 to 20 carbon atoms, whereby in R 1 and R 2 When forming an aromatic ring, -CHR 1 R 2 Some hydrogen atoms are absent.

[0409] Even more preferably, the monomer (I) of the polymeric nucleating agent is selected from the group consisting of vinylcyclohexane, vinylcyclopentane and 4-methylpent-1-ene, most preferably, the monomer is vinylcyclohexane.

[0410] Although other monomers may be present in the polymeric nucleating agent, most commonly propylene monomers, it is preferred that the polymeric nucleating agent consists of monomers having the general formula (I).

[0411] In a particularly preferred embodiment, the polymeric nucleating agent is a homopolymer of vinylcyclohexane (pVCH).

[0412] The polymeric nucleating agent is present in an amount in the range of 20 to 300 weight-ppm, more preferably in the range of 20 to 200 weight-ppm, most preferably in the range of 20 to 100 weight-ppm relative to the total weight of the propylene homopolymer composition (H-PP).

[0413] The nucleating agent is introduced into the propylene homopolymer composition (H-PP) during the polymerization process of the propylene homopolymer composition (H-PP), ie is present as a reactor blend.

[0414] Preferably, the polymeric nucleating agent is first introduced into the first propylene homopolymer (H-PP1) by polymerizing the above defined vinyl compound according to formula (I) as defined above, even more preferably vinylcyclohexane (VCH), in the presence of a catalyst system as described above comprising a solid Ziegler-Natta catalyst component, a cocatalyst and optionally an external donor, and the obtained reaction mixture of the polymer of the vinyl compound according to formula (I) as defined above, even more preferably vinylcyclohexane (VCH) polymer and the catalyst system is then used for the production of the propylene homopolymer composition (H-PP1).

[0415] A particularly preferred embodiment of the catalyst modification comprises the following steps:

[0416] - introducing a Ziegler-Natta type catalyst (ZN-C) as described above into the reaction medium,

[0417] - addition of cocatalyst (Co) and external donor (ED),

[0418] - feeding the monomer (I) to the stirred reaction medium in a monomer (I) / catalyst weight ratio ranging from 0.33 to 20, preferably from 0.33 to 10,

[0419] - polymerizing the vinyl compound in the presence of said Ziegler-Natta type catalyst (ZN-C), a cocatalyst (Co) and an external donor (ED) at a temperature comprised between 35 and 65° C., and

[0420] - continuing the polymerization until a maximum concentration of less than 2000, preferably less than 1000 weight-ppm by weight of unreacted monomers (I) is obtained,

[0421] - Producing a modified Ziegler-Natta catalyst system containing up to 20 g of vinyl compound per 1 g of solid catalyst.

[0422] The modified Ziegler-Natta catalyst comprises 25 to 95% by weight of isotactic polymer based on monomer (I), more preferably 50 to 90% by weight of isotactic polymer based on monomer (I), most preferably 60 to 80% by weight of isotactic polymer based on monomer (I).

[0423] Preferably, the ratio of polymeric nucleating agent to solid catalyst in the modified Ziegler-Natta catalyst ([pVCH] / [ZN]) is in the range of 0.33:1 to 20:1, more preferably in the range of 1.0:1 to 10:1, and most preferably in the range of 2.0:1 to 5.0:1.

[0424] The polymerization of vinyl compounds (e.g., VCH) can be carried out in any inert fluid in which the formed polymer (e.g., pVCH) is not soluble. It is important to ensure that the viscosity of the final catalyst / polymerized vinyl compound / inert fluid mixture is high enough to prevent sedimentation of the catalyst particles during storage and transportation.

[0425] The adjustment of mixture viscosity can be carried out before or after the polymerization of vinyl compounds. For example, polymerization can be carried out in low-viscosity oil, and after the polymerization of vinyl compounds, viscosity can be adjusted by adding high-viscosity substances. This high-viscosity substance can be "wax", such as oil or a mixture of oil and solid or high-viscosity substance (oil-grease). The viscosity of this viscous substance is generally 1000 to 15000 cP at room temperature. The advantage of using wax is to improve the storage of catalyst and the charging in the method. Owing to not needing washing, drying, screening and transfer, catalyst activity is maintained. The weight ratio between oil and solid or high-viscosity polymer is preferably less than 5: 1. In addition to viscous substances, liquid hydrocarbons (such as isobutane, propane, pentane and hexane) can also be used as the medium in the modification step.

[0426] The polypropylene produced using a catalyst modified with a polymerized vinyl compound is essentially free of free (unreacted) vinyl compounds. This means that the vinyl compounds should be completely reacted in the catalyst modification step.

[0427] In addition, the reaction time for modifying the catalyst by polymerizing the vinyl compound should be sufficient to allow the vinyl monomer to react completely, i.e., polymerization continues until the amount of unreacted vinyl compound in the reaction mixture (including the polymerization medium and reactants) is less than 0.5 weight %, particularly less than 2000 ppm by weight (as shown by analysis). Therefore, when the prepolymerized catalyst contains up to about 0.1 weight % vinyl compound, the final vinyl compound content in the polypropylene will be below the detection limit (<0.01 ppm by weight) using the GC-MS method. Typically, when operating on an industrial scale, a polymerization time of at least 30 minutes is required, preferably, the polymerization time is at least 1 hour, particularly at least 5 hours. Even polymerization times within the range of 6 to 50 hours can be used. Modification can be carried out at a temperature of 10 to 70° C., preferably 35 to 65° C.

[0428] This catalyst modification step is known as the BNT technique and is carried out during the above-mentioned prepolymerization step in order to introduce the polymer nucleating agent.

[0429] The general preparation of vinyl compounds (I) with such modified catalyst systems is disclosed, for example, in EP 1 028 984 or WO 00 / 6831.

[0430] Single-phase polypropylene composition (PC)

[0431] The single-phase polypropylene composition (PC) according to this invention comprises:

[0432] a) 55.0 to 95.0 wt.-% relative to the total weight of the monophasic polypropylene composition (PC) of a random copolymer of propylene (R-PP) as described above; and

[0433] b) 5.0 to 45.0 wt.-% relative to the total weight of the single-phase polypropylene composition (PC) of a propylene homopolymer composition (H-PP) as described above.

[0434] The combined weight of the random copolymer of propylene (R-PP) and the propylene homopolymer composition (H-PP) is at least 95 wt.-%, relative to the total weight of the single-phase polypropylene composition (PC).

[0435] It is further preferred that the single-phase polypropylene composition (PC) comprises:

[0436] a) 60.0 to 90.0 wt.-% relative to the total weight of the single-phase polypropylene composition (PC) of a random copolymer of propylene (R-PP) as described above; and

[0437] b) 10.0 to 40.0 wt.-% relative to the total weight of the single-phase polypropylene composition (PC) of a propylene homopolymer composition (H-PP) as described above.

[0438] Still further preferred, the single-phase polypropylene composition (PC) comprises:

[0439] a) 65.0 to 80.0 wt.-% relative to the total weight of the single-phase polypropylene composition (PC) of a random copolymer of propylene (R-PP) as described above; and

[0440] b) 20.0 to 35.0 wt.-% relative to the total weight of the single-phase polypropylene composition (PC) of a propylene homopolymer composition (H-PP) as described above.

[0441] In addition to the random copolymer of propylene (R-PP) and the propylene homopolymer composition (H-PP), the single-phase polypropylene composition (PC) may contain other additives known in the art; however, the remaining portion should not exceed 5.0 wt.%, such as not more than 3.0 wt.%, in the single-phase polypropylene composition (PC). For example, the single-phase polypropylene composition (PC) may additionally contain a small amount of additives (A) selected from the group consisting of antioxidants, stabilizers, fillers, colorants, nucleating agents and antistatic agents. Typically, they can be added during the mechanical blending of the random copolymer of propylene (R-PP) and the propylene homopolymer composition (H-PP).

[0442] These additives are generally commercially available and are described, for example, in "Plastic Additives Handbook" by Hans Zweifel, 5th edition, 2001, pages 871 to 873.

[0443] It will be appreciated that the amount of additive (A) given relative to the total weight of the single-phase polyolefin composition (PC) includes any carrier polymer, i.e. a masterbatch carrier polymer, used to introduce the additive into the single-phase polyolefin composition (PC). An example of such a carrier polymer is a polypropylene homopolymer in powder form.

[0444] In a specific embodiment the monophasic polypropylene composition (PC) consists of the random copolymer of propylene (R-PP), the propylene homopolymer composition (H-PP) and optional additives (A).

[0445] The single-phase polypropylene composition (PC) as part of the propylene homopolymer composition (H-PP) comprises a polymeric nucleating agent as defined above.

[0446] In addition to the polymeric nucleating agent present in the propylene homopolymer composition, further polymeric nucleating agents may or may not be present in the single-phase polypropylene composition. Preferably, the total content of polymeric nucleating agents comprising one or more monomers according to formula (I) is in the range of 1.0 to 100 weight-ppm, more preferably in the range of 1.5 to 50 weight-ppm, most preferably in the range of 2.0 to 20 weight-ppm relative to the total weight of the single-phase polypropylene composition (PC).

[0447] Since the single-phase polypropylene composition (PC) is not a heterophasic system comprising an elastomeric rubber layer, the single-phase polypropylene composition (PC) preferably does not have a glass transition temperature below -30°C, more preferably does not have a glass transition temperature below -25°C, most preferably does not have a glass transition temperature below -20°C.

[0448] The single-phase polypropylene composition (PC) has a melt flow rate (MFR2) measured according to ISO 1133 at 230°C and 2.16 kg in the range of 1.0 to 50.0 g / 10 min, more preferably in the range of 4.0 to 30.0 g / 10 min, most preferably in the range of 6.0 to 15.0 g / 10 min.

[0449] Preferably, the single-phase polypropylene composition (PC) has a quantitative 13 Total comonomer content C (PC) determined by C-NMR spectroscopy.

[0450] It is further preferred that the single-phase polypropylene composition (PC) is free of phthalates and their decomposition products.

[0451] Preferably, the single-phase polypropylene composition (PC) has a 80×10×4 mm2 compression ratio according to ISO 178 in the range of 1100 to 1900 MPa, more preferably in the range of 1200 to 1700 MPa, most preferably in the range of 1320 to 1500 MPa. 3 Flexural modulus measured on test bars.

[0452] Preferably, the single-phase polypropylene composition (PC) has an % RI in the range of 5 to 30%, more preferably in the range of 10 to 28%, most preferably in the range of 15 to 26% of the RI in a plate having the dimensions of 60×60×3 mm processed by injection moulding. 3The haze value is determined on a plate of 0.040 nm and measured according to ASTM D1003.

[0453] Preferably, the single-phase polypropylene composition (PC) has at least two observable melting peaks in a differential scanning calorimetry (DSC) curve measured according to ISO 11357 / part 3 / method C2 in a heating / cooling / heating cycle at a scanning rate of 10°C / min in a temperature range of -30 to +225°C, wherein the single-phase polypropylene composition has a first melting temperature T m1 , first heat of fusion H m1 , second melting temperature T m2 and the second heat of fusion H m2 .

[0454] Preferably, the first melting temperature T m1 In the range of 145 to 159°C, more preferably in the range of 150 to 159°C, most preferably in the range of 154 to 159°C.

[0455] Preferably, the first heat of fusion H m1 In the range of 20 to 100 J / g, more preferably in the range of 50 to 97 J / g, most preferably in the range of 80 to 95 J / g.

[0456] Preferably, the second melting temperature T m2 In the range of 125 to 136°C, more preferably in the range of 128 to 136°C, most preferably in the range of 130 to 135°C.

[0457] Preferably, the second heat of fusion H m2 In the range of 2.0 to 70 J / g, more preferably in the range of 2.0 to 40 J / g, most preferably in the range of 2.0 to 10 J / g.

[0458] Preferably, the single-phase polypropylene composition (PC) has a crystallization temperature T in the range of 115 to 130°C, more preferably in the range of 117 to 127°C, most preferably in the range of 119 to 125°C. c .

[0459] Products

[0460] The present invention also relates to an article comprising the single-phase polypropylene composition (PC) as described above.

[0461] The article comprises in the range of 90 to 100 wt.-%, more preferably 95 to 100 wt.-%, still more preferably 98 to 100 wt.-% of the single-phase polypropylene composition (PC).

[0462] The article is preferably selected from the group consisting of injection molded articles, thermoformed articles and films.

[0463] Example

[0464] A. Measurement Method

[0465] Unless defined otherwise, the following definitions of terms and assays apply to the above general description of the invention, including the claims, as well as to the following examples.

[0466] Quantification of microstructure by NMR spectroscopy

[0467] Quantitative nuclear magnetic resonance (NMR) spectroscopy was used to quantify the isotacticity and regioregularity of propylene homopolymers.

[0468] Use for 1 H and 13 Quantitative NMR spectra were recorded in solution on a Bruker Advance III 400 NMR spectrometer operating at 400.15 and 100.62 MHz, respectively. 13 C{ 1 H} NMR spectra. All spectra were obtained using 13 A C-optimized 10 mm extended temperature probe was used for recording at 125 °C, using nitrogen for all pneumatics.

[0469] For propylene homopolymers, approximately 200 mg of material was dissolved in 1,2-tetrachloroethane-d2 (TCE-d2). To ensure solution homogeneity, the NMR tube was further heated in a rotary oven for at least 1 hour after initial sample preparation in a heating block. After insertion into the magnet, the tube was rotated at 10 Hz. This setting was chosen primarily for the high resolution required for quantification of the tacticity distribution (Busico, V., Cipullo, R., Prog. Polym. Sci. 26 (2001) 443; Busico, V.; Cipullo, R., Monaco, G., Vacatello, M., Segre, AL, Macromolecules 30 (1997) 6251). Standard single-pulse excitation was employed, using NOE and a two-stage WALTZ16 decoupling scheme (Zhou, Z., Kuemmerle, R., Qiu, X., Redwine, D., Cong, R., Taha, A., Baugh, D. Winniford, B., J. Mag. Reson. 187 (2007) 225; Busico, V., Carbonniere, P., Cipullo, R., Pellecchia, R., Severn, J., Talarico, G., Macromol. Rapid Commun. 2007, 28, 11289). A total of 8192 (8k) transient signals were collected for each spectrum.

[0470] Quantification was performed using a proprietary computer program 13 C{ 1 The H} NMR spectra were processed, integrated and relevant quantitative properties were determined from the integration.

[0471] For propylene homopolymers, all chemical shifts are internally referenced to the methyl isotactic pentad (mmmm) at 21.85 ppm.

[0472] Characteristic signals corresponding to regio defects (Resconi, L., Cavallo, L., Fait, A., Piemontesi, F., Chem. Rev. 2000, 100, 1253; Wang, WJ., Zhu, S., Macromolecules 33 (2000), 1157; Cheng, HN, Macromolecules 17 (1984), 1950) or comonomers were observed.

[0473] The tacticity distribution was quantified by integration over the methyl region between 23.6 and 19.7 ppm, correcting for any sites not related to the stereo sequence of interest (Busico, V., Cipullo, R., Prog. Polym. Sci. 26 (2001) 443; Busico, V., Cipullo, R., Monaco, G., Vacatello, M., Segre, AL, Macromolecules 30 (1997) 6251).

[0474] Specifically, the quantitative effects of regio defects and comonomers on the tacticity distribution were corrected by subtracting representative regio defect and comonomer integrals from a specific integrated region of the stereo sequence.

[0475] Isotacticity is determined at the pentad level and reported as the percentage of isotactic pentad (mmmm) sequences over all pentad sequences:

[0476] [mmmm]% = 100*(mmmm / sum of all pentads).

[0477] The presence of a 2,1-erythro regio defect is indicated by the presence of two methyl sites at 17.7 and 17.2 ppm, confirmed by other characteristic sites. No characteristic signals corresponding to other types of regio defects were observed (Resconi, L., Cavallo, L., Fait, A., Piemontesi, F., Chem. Rev. 2000, 100, 1253).

[0478] The amount of 2,1-erythro regiodefects was quantified using the average integral of two characteristic methyl sites at 17.7 and 17.2 ppm:

[0479] P 21e =(I e6 +I e8 ) / 2.

[0480] The amount of 1,2 major propylene insertions was quantified based on the methyl region and corrected for sites not related to the major insertion and sites not included in this region:

[0481] P 12 =I CH3 +P 12e

[0482] The total amount of propene is quantified as the sum of the primary inserted propene and all other regio defects present:

[0483] P 总 =P 12 +P 21e

[0484] The mole percentage of 2,1-erythro regio defects relative to all propylene was quantified:

[0485] [21e] mol% = 100*(P 21e / P 总 )

[0486] Using the method of Wang et al. (Wang, WJ., Zhu, S., Macromolecules 33 (2000), 1157), the 13 C{ 1 The comonomer fraction is quantified by integrating multiple signals over the entire spectral region of the H spectrum. This method was chosen for its robustness and ability to account for the presence of regio defects when necessary. The integration region is slightly adjusted to improve applicability across the entire range of comonomer contents encountered.

[0487] For systems where only isolated ethylene is observed in PPEPP sequences, the method of Wang et al. was modified to reduce the influence of nonzero integrals at sites known to be absent. This approach reduces the overestimation of ethylene content in such systems and is achieved by reducing the number of sites used to determine absolute ethylene content to:

[0488] E=0.5(Sββ+Sβγ+Sβδ+0.5(Sαβ+Sαγ))

[0489] By using this set of sites, the corresponding integral equation becomes:

[0490] E=0.5(I H +I G +0.5(I C +I D ))

[0491] The same symbols used in the article by Wang et al. are used (Wang, WJ., Zhu, S., Macromolecules 33 (2000), 1157). The equations for absolute propylene content are not modified.

[0492] Calculate the mole percentage of comonomer incorporation from the mole fraction:

[0493] E [mol %] = 100 * fE

[0494] Calculate the weight percent of comonomer incorporation from the mole fraction:

[0495] E[weight%]=100*(fE*28.06) / ((fE*28.06)+((1-fE)*42.08)).

[0496] MFR2 (230°C) is measured according to ISO 1133 (230°C, 2.16 kg load).

[0497] Number average molecular weight (M n ), weight average molecular weight (M w ) and molecular weight distribution (MWD)

[0498] The molecular weight averages (Mw, Mn) and molecular weight distribution (MWD) (i.e., Mw / Mn (where Mn is the number average molecular weight and Mw is the weight average molecular weight)) were determined by gel permeation chromatography (GPC) according to ISO 16014-4:2003 and ASTM D6474-99. A PolymerChar GPC instrument equipped with an infrared (IR) detector, 3x Olexis and 1x Olexis guard columns from Polymer Laboratories, was used at 160° C. and a constant flow rate of 1 mL / min, using 1,2,4-trichlorobenzene (TCB, stabilized with 250 mg / L of 2,6-di-tert-butyl-4-methyl-phenol) as the solvent. 200 μl of sample solution was injected for each analysis. The column set was calibrated using a universal calibration (according to ISO 16014-2:2003) with at least 15 narrow MWD polystyrene (PS) standards ranging from 0.5 kg / mol to 11500 kg / mol. The Mark Houwink constants for PS, PE, and PP used were as described in accordance with ASTM D 6474-99. All samples were prepared by dissolving 5.0 to 9.0 mg of polymer in 8 mL (at 160° C.) of stabilized TCB (same as the mobile phase) in the autosampler of the GPC instrument at a maximum of 160° C. with constant gentle shaking for 2.5 hours (for PP) or 3 hours (for PE).

[0499] Xylene soluble fraction at room temperature (XCS, wt. %): the amount of polymer soluble in xylene is determined according to ISO 16152; 5th edition; 2005-07-01 at 25°C.

[0500] DSC analysis, melting temperature (T m ) and heat of fusion (H f ), crystallization temperature (T c ) and heat of crystallization (H c ): Measurements were performed on 5 to 7 mg samples using a TA Instrument Q200 Differential Scanning Calorimeter (DSC). The DSC was run according to ISO 11357 / Part 3 / Method C2 in a heating / cooling / heating cycle at a scan rate of 10°C / min over a temperature range of -30 to +225°C. The crystallization temperature (T c ) and heat of crystallization (Hc) are determined from the cooling step, while the melting temperature (T m ) and heat of fusion (Hf) are determined from the second heating step.

[0501] Glass transition temperature T gThe test results were determined by dynamic mechanical analysis according to ISO 6721-7. The test results were obtained by heating the compression molded specimens (40×10×1 mm2) 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.

[0502] Flexural modulus was measured according to ISO 178, Method A (3-point bend test) on 80 mm x 10 mm x 4 mm specimens. According to this standard, a test speed of 2 mm / min and a span length of 16 times the thickness were used. The test temperature was 23 ± 2°C. All materials were injection molded according to ISO 19069-2 using a melt temperature of 200°C, regardless of their melt flow rate.

[0503] The haze was obtained by injection molding a plate with a size of 60 × 60 × 1 mm. 3 The results were determined on plates and measured according to ASTM D1003.

[0504] B. Examples

[0505] For R-PP1, the catalyst used in the polymerization process was rac-trans-dimethylsilylene(2-methyl-4-phenyl-5-methoxy-6-tert-butyl-indenyl)(2-methyl-4-(4-tert-butylphenyl)indenyl)zirconium dichloride, as disclosed as D1 in WO 2020 / 245251 A1. The production of the metallocene catalyst was similar to D1, as used in WO 2020 / 245251 A1 for the preparation of IE1 and IE2 in Table 5.

[0506] For R-PP2, the catalyst used in the polymerization process was trans-dimethylsilylene[2-methyl-4,8-bis(3,5-dimethylphenyl)-1,5,6,7-tetrahydro-sym-indacene-1-yl][2-methyl-4-(3,5-dimethylphenyl)-5-methoxy-6-tert-butylinden-1-yl]zirconium dichloride, as disclosed as MC-2 in WO 2019 / 179959 A1. The production of the supported metallocene catalyst was similar to that of IE2 in WO 2019 / 179959 A1.

[0507] For H-PP1, the catalyst used in the polymerization process was an emulsion Ziegler-Natta catalyst, which was the same catalyst used in the polymerization of the inventive examples of WO 2017 / 148970 A1, except that 15.0 g of vinylcyclohexane (VCH) was added in the modification step instead of 5.0 g used in WO 2017 / 148970 A1.

[0508] In this catalyst, the internal donor is citraconate, the ratio of ZN-C:VCH is 1:3, and the external donor is di(cyclopentyl)dimethoxysilane (D-donor).

[0509] R-PP3 is commercially available from Borealis AG under the trade name RF490MO. The properties of the trade name are given in Table 2.

[0510] R-PP4 is commercially available from Borealis AG under the trade name RD734MO. The properties of the trade name are given in Table 2.

[0511] Both R-PP3 and R-PP4 are polymerized using Ziegler-Natta catalysts. R-PP3 contains pVCH because the catalyst has been prepolymerized with VCH, while R-PP4 does not contain pVCH.

[0512] R-PP1, R-PP2 and H-PP1 were polymerized according to the conditions given in Table 1.

[0513] Table 1: Polymerization conditions of propylene homopolymers and copolymers of the present invention

[0514]

[0515] Table 2: Polymer properties of inventive propylene homopolymers as well as inventive and comparative propylene copolymers

[0516]

[0517] Table 3: Composition, mechanical and optical properties of the inventive and comparative single-phase polypropylene compositions

[0518]

[0519] As can be seen in Table 3, the haze of inventive compositions IE1 to IE3, blends of SSC-catalyzed R-PP and ZN-catalyzed H-PP, is much lower than that of a comparable blend (CE2) in which the R-PP has been ZN-catalyzed. Furthermore, each of the inventive examples exhibits high stiffness. CE1 represents an attempt to replicate the favorable stiffness / optical property balance of the inventive blends of SSC-catalyzed R-PP and ZN-catalyzed H-PP. However, in the absence of an additional small-molecule nucleating agent, 1700 wt-ppm of an additional small-molecule nucleating agent must be used, the effect of which can be seen by comparing CE2 (without an additional nucleating agent) and CE3 (with a nucleating agent). Clearly, R-PP3, without a nucleating agent, has significantly inferior haze values. From a process perspective, avoiding such a small-molecule nucleating agent is advantageous; however, if further improvement is desired, the inventive examples could certainly be further nucleated.

[0520] It is generally believed that haze decreases with increasing comonomer content; therefore, it is surprising to find that the inventive examples have lower haze values ​​than that of CE1, even though the comonomer content is lower. Similarly, CE2 has a very similar comonomer content; however, the haze is worse, indicating the importance of SSC-catalyzed R-PP.

[0521] Furthermore, the low MFR2 of the present embodiments is useful in many applications, such as thermoforming.

Claims

1. A single-phase polypropylene composition (PC) having a melt flow rate (MFR2) measured according to ISO 1133 at 230 °C and 2.16 kg in the range of 1.0 to 50.0 g / 10 min, wherein the single-phase polypropylene composition (PC) comprises: a) 55.0 to 95.0 wt.-% relative to the total weight of the single-phase polypropylene composition (PC) of a propylene-ethylene random copolymer (R-PP) having a melt flow rate (MFR2) measured according to ISO 1133 at 230 °C and 2.16 kg in the range of 1.0 to 30.0 g / 10 min, 0.5 to 6.0 mol-% of a quantitative 13 The comonomer content was determined by C-NMR spectroscopy and was in the range of 0.1 to 1.4 mol %. 13 2,1-regio defect content determined by C-NMR spectroscopy, and b) 5.0 to 45.0 wt.-% relative to the total weight of the single-phase polypropylene composition (PC) of a propylene homopolymer composition (H-PP) comprising a reactor blend of a propylene homopolymer and a polymeric nucleating agent in an amount in the range of 20 to 300 wt.-ppm relative to the total weight of the propylene homopolymer composition (H-PP), wherein the propylene homopolymer composition (H-PP) has a melt flow rate (MFR2) measured according to ISO 1133 at 230 °C and 2.16 kg in the range of 10 to 100 g / 10 min and does not contain 13 2,1-regio defects determined by C-NMR spectroscopy; in, The combined weight of the propylene-ethylene random copolymer (R-PP) and the propylene homopolymer composition (H-PP) is at least 95 wt.-%, relative to the total weight of the single-phase polypropylene composition (PC), and The polymer nucleating agent comprises a monomer (I) of the following general formula: H2C=CH-CHR 1 R 2 (I) where R 1 and R 2 is an alkyl radical having one or more carbon atoms, or forming an optionally substituted saturated, aromatic or non-aromatic unsaturated ring or fused ring system containing 4 to 20 carbon atoms, whereby in R 1 and R 2 When forming an aromatic ring, -CHR 1 R 2 Some hydrogen atoms do not exist. wherein the single-phase polypropylene composition (PC) has a crystallization temperature T in the range of 115 to 130°C, determined by differential scanning calorimetry (DSC) according to ISO 11357 / part 3 / method C2 in a heating / cooling / heating cycle at a scanning rate of 10°C / min in the temperature range of -30 to +225°C c .

2. The single-phase polypropylene composition (PC) according to claim 1, wherein the monomer (I) of the polymeric nucleating agent is selected from the group consisting of vinylcyclohexane, vinylcyclopentane and 4-methylpent-1-ene.

3. The single-phase polypropylene composition (PC) according to claim 1, wherein the single-phase polypropylene composition (PC) does not have a glass transition temperature below -30°C.

4. The single-phase polypropylene composition (PC) according to claim 1, wherein the single-phase polypropylene composition (PC) comprises 60.0 to 90.0 wt.-% of the propylene-ethylene random copolymer (R-PP), 10.0 to 40.0 wt.-% of the propylene homopolymer composition (H-PP).

5. The single-phase polypropylene composition (PC) according to claim 1 , wherein the propylene homopolymer composition (H-PP) has a xylene cold soluble content (XCS) determined according to ISO 16152 at 25 °C in the range of 0.5 to 4.0 wt.-%, and / or wherein the propylene-ethylene random copolymer (R-PP) has a xylene cold soluble content (XCS) in the range of 0.5 to 15.0 wt.-%, measured at 25° C. according to ISO 16152.

6. The single-phase polypropylene composition (PC) according to claim 1 having a quantitative 13 Total comonomer content C (PC) determined by C-NMR spectroscopy.

7. The single-phase polypropylene composition (PC) according to claim 1, wherein the propylene homopolymer composition (H-PP) is free of phthalates and their decomposition products.

8. The single-phase polypropylene composition (PC) according to claim 1, wherein the random propylene-ethylene copolymer (R-PP) has an ethylene content in the range of 2.0 to 6.0 mol%.

9. The single-phase polypropylene composition (PC) according to claim 8, wherein the propylene-ethylene random copolymer (R-PP) comprises: a) 51.0 to 75.0 wt.-% of a first propylene-ethylene random copolymer fraction (R-PP1) relative to the total weight of the propylene-ethylene random copolymer, the first propylene-ethylene random copolymer fraction (R-PP1) having a quantitative 13 Ethylene content as determined by C-NMR spectroscopy; and b) 25.0 to 49.0 wt.-% of a second propylene-ethylene random copolymer fraction (R-PP2) relative to the total weight of the propylene-ethylene random copolymer, the second propylene-ethylene random copolymer fraction (R-PP2) having a quantitative 13 Ethylene content determined by C-NMR spectroscopy, in, The combined weight of the first and second propylene-ethylene random copolymer fractions (R-PP1+R-PP2) is at least 95 wt% relative to the total weight of the propylene-ethylene random copolymer (R-PP).

10. The single-phase polypropylene composition (PC) according to claim 1, wherein the propylene homopolymer composition (H-PP) has: i) Melting temperature T in the range of 160 to 175°C m and / or ii) a crystallization temperature T in the range of 125 to 135°C c ; Where T m and T c Both are determined by Differential Scanning Calorimetry (DSC) according to ISO 11357 / Part 3 / Method C2 in a heating / cooling / heating cycle at a scanning rate of 10°C / min in the temperature range of -30 to +225°C, and / or wherein the propylene-ethylene random copolymer (R-PP) has: i) Melting temperature T in the range of 132 to 144°C m and / or ii) a crystallization temperature T in the range of 95 to 105°C c ; Where T m and T c Both are determined by differential scanning calorimetry (DSC) according to ISO 11357 / part 3 / method C2 in a heating / cooling / heating cycle at a scanning rate of 10°C / min in the temperature range of -30 to +225°C.

11. The single-phase polypropylene composition (PC) according to claim 1 having a hardness in the range of 1100 to 1900 MPa according to ISO 178 or a hardness in the range of 80×10×4 mm2 injection molded according to ISO 19069-2. 3 Flexural modulus measured on test bars and / or in the range of 5 to 30% on plates processed from injection moulding with dimensions of 60 x 60 x 3 mm 3 The haze value is determined on a plate of 0.040 nm and measured according to ASTM D1003.

12. The single-phase polypropylene composition (PC) according to claim 1 , having at least two observable melting peaks in a differential scanning calorimetry (DSC) curve measured according to ISO 11357 / Part 3 / Method C2 in a heating / cooling / heating cycle at a scanning rate of 10°C / min in a temperature range of -30 to +225°C, wherein the single-phase polypropylene composition has a first melting temperature T m1 , first heat of fusion H m1 , second melting temperature T m2 and the second heat of fusion H m2 , the first melting temperature T m1 , the first heat of fusion H m1 The second melting temperature T m2 and the second heat of fusion H m2 At least one of the following falls within the range: i) a first melting temperature T in the range of 145 to 159°C m1 ; ii) a first heat of fusion H in the range of 20 to 100 J / g m1 ; iii) a second melting temperature T in the range of 125 to 136°C m2 ;and iv) a second heat of fusion H in the range of 2.0 to 70 J / g m2 .

13. An article comprising the single-phase polypropylene composition (PC) according to any of the preceding claims in an amount in the range of 90 to 100 wt.-%.

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