Styrene copolymer composition having PMMA and improved weather resistance

Abstract

The present invention relates to a thermoplastic molding composition (P) comprising: (A) a thermoplastic polymer composition (A) including: (A-1) 10 to 50% by weight of a graft copolymer (A-1), (A-2) 1 to 50% by weight of a thermoplastic polymer matrix (A-2) based on one or more vinyl aromatic copolymers, (A-3) 20 to 50% by weight of a polymerized alkyl methacrylate component (A-3), and (A-4) 0 to 45% by weight of a comonomer copolymerized with the polymerized alkyl methacrylate component (A-3), wherein the sum of (A-1), (A-2), (A-3) and optionally the comonomer (A-4) is 83.2 to 99.8% by weight; (B) a hindered amine light stabilizer composition (B) comprising at least two of substances (B-1) to (B-3): (B-1) 0 to 0.9% by weight of at least one hindered amine light stabilizer having a dipiperidine structure with at least one alkyl group at each of the 2- and 6-positions of the dipiperidine structure, (B-2) 0 to 0.9% by weight of a mixture of hindered amine light stabilizers having a monopiperidine structure with at least one alkyl group at each of the 2- and 6-positions of the monopiperidine structure, and (B-3) 0 to 2% by weight of at least one hindered amine light stabilizer having a polymeric structure containing a piperidine group with at least one alkyl group at each of the 2- and 6-positions of the piperidine group, (C) 0 to 5% by weight of one or more other additives (C) different from (B); and (D) 0 to 10% by weight of a colorant, dye and / or pigment (D) different from (C); wherein components (A) to (D) total 100% by weight of the molding composition (P).

Description

[0001] Description of the Invention

[0002] Impact-modified molding compositions, such as acrylonitrile styrene acrylate (ASA), and their blends with other thermoplastic polymers, have a wide range of applications, such as in the automotive industry, the electronics industry, or household goods. The popularity of these thermoplastic polymer compositions can be attributed to their combination of good impact strength, melt flow characteristics, and high weathering stability.

[0003] An important application area of ASA polymers is the unpainted exterior parts of automobiles, such as the front grille or side mirrors, which are usually painted black. In such parts, automobile manufacturers not only require the main material properties, such as impact and thermal properties, but also a certain degree of stability in the surface appearance when exposed to ultraviolet light and weathering conditions for a long time (thousands of hours). Automobile manufacturers (such as Volkswagen) often use laboratory weathering exposure tests to simulate years of outdoor exposure and then usually judge the surface appearance performance by changes in surface color or gloss. Here, the laboratory method PV3929 (Artificial accelerated aging and aging testing of polymers) is one of the most difficult to comply with and the most demanding requirements.

[0004] In more traditional designs, the unpainted exterior parts of automobiles are usually decorated with a granular low-gloss surface texture. However, in recent years, there has been an obvious new design trend for automobile exterior parts, that is, the surface of such exterior parts is high-gloss or a combination of high-gloss and low-gloss parts. This has led to an increasing demand for thermoplastic compositions with high surface appearance stability in the high-gloss surface area. The high-gloss surface in the present invention is defined as a surface with a glossiness higher than 75 gloss units measured at a 60° measurement angle according to DIN EN ISO 2813 (2015 edition).

[0005] However, the currently available state-of-the-art technology cannot achieve sufficient weathering stability for ASA polymers with a high-gloss surface. Compared with a rough textured surface, visible changes in the surface appearance of a high-gloss surface can be observed in a significantly shorter time when it undergoes weathering.

[0006] Ultraviolet stabilizers, such as hindered amine light stabilizer (HALS) compounds or ultraviolet absorbers, are usually used in ASA formulations for outdoor applications. Some documents such as US 4,692,486, US 9,701,813, EP-B 2593510, and DE-A10316198 teach HALS stabilizers and their combinations as UV absorbers and light stabilizers. However, in our research, we found that ASA compositions using the ultraviolet stabilizer formulations described in the prior art cannot simultaneously meet the requirements of low mold deposit formation and high weather resistance required for high-gloss exterior applications.

[0007] Surprisingly, it has been found that adding poly(alkyl methacrylate) in an amount of more than 20 wt.-% to a molding composition, in particular to an ASA formulation, is a very effective method for improving weather resistance. That is, it improves the stability of uncoated high-gloss surface parts of the ASA formulation when exposed to PV3929 conditions for 3200 hours.

[0008] Accordingly, a first aspect of the present invention relates to a molding composition (P) comprising:

[0009] (A) at least one thermoplastic polymer composition (A), comprising:

[0010] (A-1) based on the total weight of the molding composition (P), 10 to 50 wt.%, preferably 15 to 45 wt.%, more preferably 20 to 45 wt.% of at least one graft copolymer (A-1),

[0011] (A-2) based on the total weight of the molding composition (P), 1-50 wt.-%, preferably 5-50 wt.-% of at least one thermoplastic polymer matrix (A-2), which is based on one or more vinyl aromatic copolymers,

[0012] (A-3) based on the total weight of the molding composition (P), 20 to 50 wt.%, preferably 25 to 40 wt.% of at least one polymerized alkyl methacrylate component (A-3), preferably methyl methacrylate, which is present in a homopolymer of one or more alkyl methacrylates and / or a copolymer of an alkyl methacrylate and one or more comonomers (A-4), and

[0013] (A-4) based on the total weight of the molding composition (P), 0 to 45 wt.% of at least one comonomer copolymerized with at least one polymerized alkyl methacrylate component (A-3), the comonomer (A-4) being selected from vinyl aromatic monomers, preferably styrene, or vinyl cyanides, preferably acrylonitrile, wherein the sum of (A-1), (A-2), (A-3) and optionally comonomer (A-4) is 83.2 to 99.8 wt.%, based on the total weight of the molding composition (P);

[0014] (B) a hindered amine light stabilizer composition (B) comprising at least two of substances (B-1) to (B-3):

[0015] (B-1) Based on the total weight of the molding composition (P), 0 to 0.9% by weight, preferably 0.1 to 0.9% by weight, more preferably 0.2 to 0.9% by weight of at least one hindered amine light stabilizer having a dipiperidine structure, having an alkyl group at each of the 2- and 6-positions of the dipiperidine structure and having no saturated or unsaturated C12-C21 ester moiety (i.e., a saturated or unsaturated ester moiety having 12 to 21 carbon atoms) at one of the 3-, 4-, or 5-positions of the piperidine structure, wherein the molecular weight of the at least one hindered amine light stabilizer having a dipiperidine structure is 200 - 550 g / mol,

[0016] (B-2) Based on the total weight of the molding composition (P), 0 to 0.9% by weight, preferably 0.1 to 0.9% by weight, more preferably 0.2 to 0.9% by weight, especially 0.2 to 0.6% by weight of a mixture of hindered amine light stabilizers having a monopiperidine structure, having at least one alkyl group at each of the 2- and 6-positions of the monopiperidine structure and having a saturated or unsaturated C12-C21 ester moiety at at least one of the 3-, 4-, or 5-positions of the monopiperidine structure, and

[0017] (B-3) Based on the total weight of the molding composition (P), 0 to 2% by weight, preferably 0.1 to 2% by weight, more preferably 0.2 to 2% by weight of at least one hindered amine light stabilizer having a polymer structure, the polymer structure of which contains piperidine groups, having at least one alkyl group at each of the 2- and 6-positions of the piperidine groups and having no saturated or unsaturated C12-C21 ester moiety at one of the 3-, 4-, or 5-positions of the piperidine groups, wherein the molecular weight of the at least one hindered amine light stabilizer having a polymer structure is 1000 - 4000 g / mol, preferably 1500 - 4000 g / mol, more preferably 2000 - 4000 g / mol, provided that the total amount of the at least one hindered amine light stabilizer composition (B) present in the molding composition (P) is at least 0.2% by weight, based on the total weight of the molding composition (P);

[0018] (C) 0 to 5% by weight, preferably 0.05 to 5% by weight of one or more other additives (C) different from (B); and

[0019] (D) 0 to 10% by weight, preferably 0.1 to 10% by weight of colorants, dyes, and / or pigments (D) different from (C);

[0020] wherein components (A) to (D) total to 100% by weight of the molding composition (P).

[0021] In the present application, the positions at which the carbon atoms in the piperidine moiety and the substituents are attached are numbered according to the following general chemical structure, wherein the nitrogen atom is numbered as position 1:

[0022]

[0023] The molding composition (P) comprises the components of a thermoplastic polymer composition (A) and a stabilizer composition (B).

[0024] In a further preferred embodiment, the present invention relates to a molding composition (P), wherein the hindered amine light stabilizer composition (B) comprises:

[0025] (B-1) Based on the total weight of the molding composition (P), 0.1 to 0.9% by weight, preferably 0.2 to 0.9% by weight, more preferably 0.2 to 0.6% by weight, of a compound represented by the following formula (I):

[0026]

[0027] In a further preferred embodiment, the present invention relates to a molding composition (P), wherein the hindered amine light stabilizer composition (B) comprises:

[0028] (B-2) Based on the total weight of the molding composition (P), 0.1 to 0.9% by weight, preferably 0.2 to 0.9% by weight, more preferably 0.2 to 0.6% by weight, of a compound represented by the following formula (II):

[0029]

[0030] In a further preferred embodiment, the present invention relates to a molding composition (P), wherein the hindered amine light stabilizer composition (B) comprises:

[0031] (B-3) Based on the total weight of the molded article, 0 to 2.0% by weight, preferably 0.1 - 2.0% by weight, more preferably 0.2 - 2.0% by weight, especially 0.2 - 1.0% by weight, of a compound represented by the following formula (III):

[0032]

[0033] In a further embodiment, the present invention relates to a molding composition (P) as defined above, wherein the at least one graft copolymer (A-1) comprises or consists of an acrylonitrile styrene acrylate (ASA) copolymer, which comprises rubber particles having an average particle size d 50 of 50 - 1000 nm, the average particle size being determined by measurement of scattered light.

[0034] In another embodiment, the present invention relates to a molding composition (P) as defined above, wherein the at least one thermoplastic matrix (A-2) comprises a copolymer containing at least one vinyl cyanide repeating unit and at least one vinyl aromatic repeating unit.

[0035] In a further embodiment, the invention relates to a molding composition (P) as defined above, wherein the at least one thermoplastic polymer composition (A) comprises at least one copolymer (A-2), the copolymer (A-2) comprising:

[0036] 18 to 45% by weight of at least one vinyl cyanide repeating unit; and

[0037] 55 to 82% by weight of at least one vinyl aromatic repeating unit.

[0038] In a further embodiment, the invention relates to a molding composition (P) as defined above, wherein the graft copolymer (A-1) comprises rubber particles having a binary or ternary size distribution, comprising:

[0039] (A-1a) at least one graft copolymer (A-1a), the average particle size d of the rubber particles in the ASA copolymer of which 50 is 50 - 150 nm; and

[0040] (A-1b) at least one graft copolymer (A-1b), the average particle size d of the rubber particles in the ASA copolymer of which 50 is 200 to 750 nm.

[0041] In a further embodiment, the invention relates to a molding composition (P) as defined above, wherein the polymerized alkyl methacrylate component (A-3) comprises a poly(alkyl methacrylate) polymer, preferably a poly(methyl methacrylate) homopolymer, or consists thereof.

[0042] In an alternative embodiment, the invention relates to a molding composition (P) as defined above, wherein the polymerized alkyl methacrylate component (A-3) comprises (or consists of) a copolymer of at least one alkyl methacrylate monomer (preferably methyl methacrylate) and at least one vinyl aromatic comonomer (preferably styrene), preferably a poly(styrene-methyl methacrylate) copolymer.

[0043] In another alternative embodiment, the invention relates to a molding composition (P) as defined above, wherein the polymerized alkyl methacrylate component (A-3) comprises (or consists of) at least one copolymer copolymerized from an alkyl methacrylate monomer (preferably methyl methacrylate), at least one vinyl aromatic comonomer (preferably styrene), and vinyl cyanide (preferably acrylonitrile), and optionally other comonomers, preferably a poly(styrene-acrylonitrile-methyl methacrylate) terpolymer.

[0044] In another alternative embodiment, the present invention relates to a molding composition (P) as defined above, wherein the molded article produced from the molding composition (P) exhibits a glossiness above 75 gloss units before any aging exposure, and after 3200 hours of artificial weathering according to PV3929, the measured color shift dE is lower than dE = 6, preferably lower than dE = 3, relative to the unexposed surface, wherein the glossiness is measured at a measurement angle of 60° according to DIN EN ISO 2813.

[0045] On the other hand, the present invention relates to a method for preparing the aforementioned molding composition (P), which method comprises at least the following steps:

[0046] (i) adding a predetermined amount of components (A) to (D) to a mixing device; and

[0047] (ii) mixing components (A) to (D) in the mixing device at a temperature above the glass transition point of component (A) to obtain the molding composition (P).

[0048] On the other hand, the present invention relates to a method for improving the weather resistance of a high-gloss surface molded article (T), wherein at least a part of the surface of the surface molded article (T) has a glossiness above 75 gloss units before artificial weathering, and the glossiness is measured at a measurement angle of 60° according to DIN EN ISO 2813, wherein the method comprises the step of mixing components (A) to (D) as described above, and wherein the high-gloss surface molded article (T) made of the molding composition (P) has the following properties:

[0049] After 3200 hours of artificial weathering according to PV3929, the color shift of the high-gloss surface molded article (T) produced from the molding composition (P) is less than 25% of the color shift of the high-gloss surface molded article produced from a comparative molding composition (P'), both molded and evaluated under the same conditions,

[0050] wherein the comparative molding composition (P') is obtained by mixing components (A) to (D) contained in the above-mentioned molding composition (P), except that the content of the polymerized alkyl methacrylate component (A-3) in the comparative molding composition (P') is less than 20% by weight.

[0051] On the other hand, the present invention relates to a molded article (T) having a high-gloss surface area with a glossiness above 75 gloss units prepared from the thermoplastic molding composition (P) as described above, wherein the gloss level is measured at a measurement angle of 60° according to DIN EN ISO 2813.

[0052] On the other hand, the present invention relates to the use of a molded article (T) having a high-gloss surface prepared from the thermoplastic molding composition (P) as described above for unpainted exterior parts, preferably for automotive applications, wherein the high-gloss surface has a glossiness higher than 75 gloss units, and the glossiness is measured at an angle of 60° according to DIN EN ISO 2813.

[0053] Graft copolymer (Component A-1)

[0054] The molding composition (P) according to the present invention comprises (or consists of) at least one thermoplastic polymer composition (A), which thermoplastic polymer composition (A) comprises at least one graft copolymer (A-1) and at least one thermoplastic matrix (A-2), which is based on one or more vinyl aromatic copolymers, and at least one polymerized alkyl methacrylate component (A-3).

[0055] In a preferred embodiment, the graft copolymer (A-1) is a rubber-modified copolymer comprising repeating units of acrylonitrile and styrene. In a preferred embodiment, a copolymer of acrylonitrile and styrene graft-polymerized on rubber particles is used, and the rubber particles are derived from the polymerization of a monomer composition comprising at least one conjugated diene monomer or at least one acrylate monomer.

[0056] In a further preferred embodiment, the at least one graft copolymer (A-1) used comprises (or consists of):

[0057] A-1.1 20 to 90% by weight, preferably 40 to 90% by weight, particularly preferably 45 to 85% by weight, very particularly preferably 50 to 80% by weight, based on the weight of the total graft copolymer (A-1), of a graft matrix, which consists of one or more of the following monomers:

[0058] A-1.11 Based on the total weight of the graft matrix (A-1.1), 65 to 100% by weight or 65 to 99.99% by weight, preferably 75 to 99.99% by weight, particularly preferably 80 to 99.98% by weight, of at least one C 1 to C 8 alkyl (meth)acrylate, in particular n-butyl acrylate and / or 2-ethylhexyl acrylate,

[0059] 0 to 35% by weight, preferably 0 to 25% by weight, particularly preferably 0 to 20% by weight, of at least one other comonomer, based on the total weight of the graft matrix (A-1.1), selected from: styrene, α-methylstyrene, acrylonitrile, methacrylonitrile, methyl methacrylate, maleic anhydride and N-phenylmaleimide, preferably styrene and α-methylstyrene, particularly preferably styrene;

[0060] 0 to 10% by weight or 0.01 to 10% by weight, preferably 0.01 to 5% by weight, particularly preferably 0.02 to 2% by weight, of one or more polyfunctional crosslinking monomers, based on the total weight of the graft matrix (A-1.1), selected from allyl (meth)acrylate, divinylbenzene, diallyl maleate, diallyl fumarate, diallyl phthalate, triallyl cyanurate, triallyl isocyanurate and dicyclopentadienyl diacrylate (DCPA), with a content of at least 0.1% by weight when component A-1.11 is an acrylate;

[0061] 10 to 80% by weight, preferably 10 to 60% by weight, more preferably 15 to 55% by weight, very particularly preferably 20 to 50% by weight, based on the weight of the total graft copolymer (A-1), of the weight of at least one graft layer, which consists of one or more of the following monomers:

[0062] 65 to 95% by weight, preferably 70 to 90% by weight, particularly preferably 75 to 85% by weight, of at least one vinyl aromatic monomer, preferably styrene and / or α-methylstyrene, in particular styrene, based on the total weight of the graft layer (A-1.2);

[0063] 5 to 35% by weight, preferably 10 to 30% by weight, particularly preferably 15 to 25% by weight, of acrylonitrile and / or methacrylonitrile, preferably acrylonitrile, based on the total weight of the graft layer (A-1.2); and

[0064] 0 to 30% by weight, preferably 0 to 20% by weight, particularly preferably 0 to 15% by weight, based on the total weight of the graft copolymer (A-1), of at least one other component, selected from:

[0065] at least one monoolefinically unsaturated monomer selected from the following: methyl methacrylate, maleic anhydride and N-phenylmaleimide, preferably methyl methacrylate and / or

[0066] at least one molecular weight regulator, in particular a thiol-based molecular weight regulator, such as tert-dodecyl mercaptan.

[0067] Particularly preferred polyfunctional crosslinking monomer A-1.13 is allyl (meth)acrylate and / or dicyclopentadienyl diacrylate (DCPA), more preferably DCPA.

[0068] Preferably, the graft copolymer (A-1) is usually prepared by emulsion polymerization or suspension polymerization. The graft matrix A-1.1 comprising monomers A-1.11, A-1.12 and optionally A-1.13 (or consisting thereof) and its preparation method are known and described in the literature, for example, DE-A 28 26 925, DE-A 31 49 358 and DE-A 34 14 118.

[0069] The graft polymerization for synthesizing the graft shell A-1.2 and the emulsion polymerization for synthesizing the graft matrix A-1.1 can be conveniently carried out in the same container. Additives such as emulsifiers, pH buffers and initiators can be added during the reaction. The monomers of the graft shell, especially monomers A-1.21 and A-1.22, can be added to the reaction mixture all at once, or added stepwise in several steps during the polymerization, preferably in a continuous manner. When monomers A-1.21 and / or A-1.22 are added in several steps, a multi-layered graft shell A-1.2 is usually obtained.

[0070] For suitable emulsifiers, buffers and initiators, see the descriptions in WO 2015 / 150223 and WO 2015 / 078751.

[0071] In a preferred embodiment, the styrene-based graft copolymer (A-1) is acrylonitrile styrene acrylate (ASA) and its mixtures.

[0072] In a more preferred embodiment, the graft copolymer (A-1) according to the present invention is particularly preferably an ASA copolymer, which comprises (or consists of):

[0073] A-1.1 Based on the total weight of the styrene-based graft copolymer (A-1), 40 to 90% by weight of the graft matrix, the composition of which is:

[0074] A-1.11 Based on the total weight of the graft matrix (A-1.1), 65 - 99.9% by weight, preferably 90 - 99.5% by weight, of at least one C 1 -C 8 alkyl (meth)acrylate, preferably n-butyl acrylate and / or 2-ethylhexyl acrylate, especially n-butyl acrylate,

[0075] A-1.12 Based on the total weight of the graft matrix (A-1.1), 0 to 35% by weight, preferably 1 to 10% by weight, of styrene,

[0076] A-1.3 Based on the total weight of the graft matrix (A-1.1), 0.1 to 5% by weight, preferably 0.5 to 5% by weight, particularly 0.5 to 3% by weight, most preferably 1 to 2.5% by weight, of at least one polyfunctional crosslinking monomer selected from allyl (meth)acrylate, divinylbenzene, diallyl maleate, diallyl fumarate, diallyl phthalate, triallyl cyanurate, triallyl isocyanurate, and dicyclopentadienyl diacrylate (DCPA), preferably selected from allyl (meth)acrylate and DCPA, particularly DCPA, and

[0077] A-1.2 Based on the total weight of the styrenic graft copolymer (A-1), 10 - 60% by weight of the graft, which comprises (or consists of):

[0078] A-1.21 Based on the total weight of the graft layer (A-1.2), 65 - 95% by weight of styrene;

[0079] A-1.22 Based on the total weight of the graft layer (A-1.2), 5 to 35% by weight of acrylonitrile, and

[0080] A-1.3 Based on the total weight of the styrenic graft copolymer (A-1), 0 to 30% by weight of methyl methacrylate (MMA).

[0081] In a preferred embodiment, the at least one graft copolymer (A-1) is, or comprises, acrylonitrile styrene acrylate (ASA), and the average particle diameter d 50 of the rubber particles in the ASA copolymer is 50 to 1000 nm, preferably 60 to 60 nm, wherein the average particle diameter is determined by measurement of scattered light.

[0082] Generally, the average particle diameter can be measured by measurement of scattered light, i.e., by turbidimetry (see Lange, "Journal of Colloid and Polymer Science", 1968, 223(1): 24 - 30), or by ultracentrifugation (see Scholtan and Lange, "Journal of Colloid and Polymer Science", 1972, 250(8): 782 - 796), or using hydrodynamic chromatography HDC (see W. Wohlleben, H. Schuch, "Measurement of the Particle Size Distribution of Polymer Latices", 2010, eds.: L. Gugliotta, J. Vega, pp. 129 - 153).

[0083] In a preferred embodiment, the graft copolymer (A-1) has a bimodal or trimodal size distribution, comprising (or consisting of):

[0084] (A-1a) At least one graft copolymer (A-1a) having an average particle diameter d50 of the rubber particles in the ASA copolymer of 50 - 150 nm; and

[0085] (A-1b) At least one graft copolymer (A-1b), wherein the average particle size d50 of the rubber particles in the ASA copolymer is 200 - 750 nm.

[0086] In a further preferred embodiment, the graft copolymer (A-1) comprises a binary or ternary size distribution, comprising (or consisting of):

[0087] (A-1a) At least one graft copolymer (A-1a), wherein the average particle size d50 of the rubber particles in the ASA copolymer is 50 - 150 nm or 70 - 100 nm; and

[0088] (A-1b) At least one graft copolymer (A-1b), wherein the average particle size d50 of the rubber particles in the ASA copolymer is 200 - 750 nm or 400 - 600 nm.

[0089] In a preferred embodiment, the first base rubber latex (L1) can be obtained by (co)polymerization of butyl acrylate and one or more crosslinking agents (such as tricyclodecenyl acrylate) in an aqueous solution, which aqueous solution may contain additional components, such as one or more salts (such as C12 - to C18 - paraffin sulfonic acid and / or sodium bicarbonate). The reaction temperature can be in the range of 55 to 70 °C. In a preferred embodiment, the mass ratio of butyl acrylate : tricyclodecenyl acrylate for the polymerization is in the range of 10:1 to 100:1, preferably 40:1 to 80:1. The mass ratio of the components and the definition of the components are preferably as described herein. The following experimental section also provides more specific examples.

[0090] In a preferred embodiment, the first graft rubber latex (component A-1a) can be obtained by (co)polymerization of a base rubber latex (such as the first base rubber latex L1 obtained as described above) with styrene and acrylonitrile in an aqueous solution, which may contain additional components, such as one or more salts (such as sodium persulfate). The reaction temperature can be in the range of 50 to 80 °C. Optionally, the obtained graft latex can be coagulated. The coagulation can be achieved in a salt solution (such as magnesium sulfate solution) at a temperature in the range of 50 to 80 °C. Sintering can be optionally carried out after coagulation (such as at a temperature in the range of 80 to 150 °C). The mass ratio of the components and the definition of the components are preferably as described herein. The following experimental section also provides more specific examples.

[0091] In a preferred embodiment, the second base rubber latex (L2) can be obtained by (co)polymerizing butyl acrylate and one or more crosslinking agents (such as tricyclodecenyl acrylate) in an aqueous solution in the presence of, for example, the first base rubber latex L1 as described above. The aqueous solution may contain other components such as one or more salts (such as sodium bicarbonate, sodium persulfate, and / or C12-C18-alkanesulfonic acid). The reaction temperature can be in the range of 55 to 70 °C. In a preferred embodiment, the mass ratio of butyl acrylate to tricyclodecenyl acrylate for the polymerization is in the range of 10:1 to 100:1, preferably 40:1 to 80:1. The mass ratios of the components and the definitions of the components are preferably as described herein. The following experimental section also provides more specific examples.

[0092] In a preferred embodiment, the second graft rubber latex (component A-1b) can be obtained by (co)polymerizing a base rubber latex (for example, the second base rubber latex L2 obtained as described above) with styrene and acrylonitrile in an aqueous solution, which may contain additional components such as one or more salts (such as sodium persulfate). The reaction temperature can be in the range of 50 to 80 °C. Optionally, the obtained graft latex can be coagulated. Coagulation can be achieved in a salt solution (such as a magnesium sulfate solution) in the temperature range of 70 to 99 °C. Sintering can be optionally carried out after coagulation (for example, at a temperature in the range of 80 to 150 °C). The mass ratios of the components and the definitions of the components are preferably as described herein. The following experimental section also provides more specific examples.

[0093] Thermoplastic matrix (component A-2)

[0094] In a preferred embodiment, the at least one thermoplastic matrix (A-2) comprises a copolymer containing at least one vinyl cyanide repeating unit and at least one vinyl aromatic repeating unit. In a preferred embodiment, throughout the present invention, the vinyl cyanide repeating unit is derived from acrylonitrile. In a preferred embodiment, throughout the present invention, the vinyl aromatic repeating unit is derived from styrene, α-methylstyrene, or a combination thereof.

[0095] In a more preferred embodiment, the at least one thermoplastic matrix (A-2) comprises a copolymer containing acrylonitrile repeating units and at least one vinyl aromatic repeating unit selected from styrene, α-methylstyrene, and combinations thereof, especially styrene. A copolymer containing acrylonitrile and styrene or consisting of acrylonitrile and styrene can also be referred to as poly(styrene-acrylonitrile) (SAN). A copolymer containing acrylonitrile and α-methylstyrene or consisting of them can also be referred to as poly(α-methylstyrene / acrylonitrile) (AMSAN).

[0096] Poly(styrene-acrylonitrile) (SAN) and / or poly(α-methylstyrene / acrylonitrile) (AMSAN) copolymers can be used as the thermoplastic polymer (A-2). Generally, any SAN and / or AMSAN copolymer known in the art can be used in the present invention.

[0097] In a preferred embodiment, the at least one thermoplastic polymer composition (A) comprises at least one copolymer (A-2) comprising (or consisting of):

[0098] Based on the total weight of (A-2), 18 to 45% by weight of at least one vinyl cyanide repeating unit, in particular acrylonitrile; and

[0099] Based on the total weight of (A-2), 55 to 82% by weight of at least one vinyl aromatic repeating unit, in particular a vinyl aromatic repeating unit derived from styrene and / or α-methylstyrene,

[0100] In a preferred embodiment, the SAN and AMSAN copolymers of the present invention comprise:

[0101] Based on the total weight of the SAN and / or AMSAN copolymer, 50 - 99% by weight of at least one component selected from styrene and α-methylstyrene; and

[0102] Based on the total weight of the SAN and / or AMSAN copolymer, 1 - 50% by weight of acrylonitrile.

[0103] The weight average molecular weight of the SAN or AMSAN copolymer (determined by gel permeation chromatography relative to polystyrene as the standard) can be in the range of 15,000 to 200,000 g / mol, preferably in the range of 30,000 to 150,000 g / mol.

[0104] In a preferred embodiment, the SAN or AMSAN copolymer contains 60 to 95% by weight of styrene and / or α-methylstyrene, and 40 to 5% by weight of acrylonitrile.

[0105] In a preferred embodiment, SAN or AMSAN can be used, in which the proportion of incorporated acrylonitrile monomer units is ≤ 36% by weight.

[0106] In a preferred embodiment, a copolymer of styrene and acrylonitrile of the SAN or AMSAN type can be used, which incorporates a relatively small amount of acrylonitrile (not exceeding 35% by weight, based on the total weight of the SAN and / or AMSAN copolymer).

[0107] In the above embodiments, the most preferred SAN or AMSAN copolymers are those having a viscosity value VN (measured in dimethylformamide at 0.5 wt% at 25 °C according to DIN 53726) of 50 - 120 ml / g.

[0108] As used herein, unless otherwise defined, all measurement specifications, such as DIN specifications and PV specifications, preferably refer to the latest version in August 2019.

[0109] Copolymers of SAN or AMSAN components are known, and their preparation methods, such as by free radical polymerization, especially by emulsion, suspension, solution, and bulk polymerization, are well documented in the literature.

[0110] Polymerized alkyl methacrylates (component (A-3)) and potential comonomers

[0111] Any poly(alkyl methacrylate) homopolymer is suitable for use as component (A-3) within the scope of the present invention. Particularly suitable are poly(alkyl methacrylates) in which the alkyl group is a saturated straight-chain or branched-chain C 1 to C 10 alkyl group, preferably a straight-chain or branched-chain C 1 to C 5 alkyl group, more preferably a straight-chain or branched-chain C 1 to C 3 alkyl group and mixtures thereof. In a more preferred embodiment, the alkyl group is selected from methyl and ethyl. Thus, in one embodiment of the present invention, the poly(alkyl methacrylate) is selected from poly(methyl methacrylate), poly(ethyl methacrylate), and mixtures thereof.

[0112] In a more preferred embodiment of the present invention, the poly(alkyl methacrylate) comprises or consists of poly(methyl methacrylate). Poly(methyl methacrylate) is commercially available from Evonik, a German company, under the trade names 6N, 7N or 8N.

[0113] In addition to the above poly(alkyl methacrylate) homopolymers, component (A-3) may also comprise (or consist of) a copolymer of a polymerizable alkyl methacrylate with a polymerizable vinyl aromatic comonomer and / or a vinyl cyanide comonomer.

[0114] Suitable polymerizable alkyl methacrylates include alkyl methacrylates in which the alkyl group is a saturated straight-chain or branched-chain C 1 to C 10 alkyl group, preferably a straight-chain or branched-chain C 1 to C 5 alkyl group, more preferably a straight-chain or branched-chain C 1to C 3 alkyl and mixtures thereof.

[0115] Suitable vinyl aromatic comonomers include, in particular, styrene, α-methylstyrene and mixtures thereof. In a preferred embodiment, the vinyl aromatic comonomer is styrene. Suitable vinyl cyanide comonomers include, in particular, acrylonitrile.

[0116] In a preferred embodiment, component (A-3) comprises or consists of poly(methyl methacrylate).

[0117] In a further preferred embodiment, component (A-3) comprises or consists of poly(styrene-methyl methacrylate) (SMMA). SMMA can be composed of any monomer moieties as long as it is mainly composed of styrene and methyl methacrylate. In a preferred embodiment, the at least one SMMA comprises 20 to 80% by weight of styrene, preferably 30 to 80% by weight of styrene, more preferably 40 to 80% by weight of styrene, and even more preferably 50 to 80% by weight of styrene. SMMA can be a random polymer or a block polymer. In a preferred embodiment, the at least one SMMA is a random polymer.

[0118] In a further preferred embodiment, component (A-3) comprises or consists of a poly(styrene-acrylonitrile-methyl methacrylate) terpolymer. Preferably, the terpolymer comprises 20 to 75% by weight, preferably 40 to 70% by weight, more preferably 65 to 70% by weight of methyl methacrylate, 10 to 50% by weight, preferably 20 to 30% by weight of styrene, and 0.05 to 10%, more preferably 7 to 10% by weight of acrylonitrile.

[0119] In a further preferred embodiment, component (A-3) comprises a mixture comprising at least two polymers selected from poly(methyl methacrylate), poly(styrene-methyl methacrylate) (SMMA) and poly(styrene-acrylonitrile-methyl methacrylate) terpolymer.

[0120] Thermoplastic polymer composition (A)

[0121] In a preferred embodiment, at least one thermoplastic polymer composition (A) comprises (or consists of):

[0122] (A-1) Based on the total weight of the molding composition (P), 10 to 50% by weight, preferably 15 to 45% by weight, more preferably 20 to 45% by weight of at least one graft copolymer (A-1);

[0123] (A-2) 1 to 50% by weight, preferably 5 to 50% by weight, based on the total weight of the molding composition (P), of at least one thermoplastic polymer matrix (A-2) based on one or more vinyl aromatic copolymers; and

[0124] (A-3) 20 to 50% by weight, preferably 25 to 40% by weight, based on the total weight of the molding composition (P), of at least one polymerized alkyl methacrylate component (A-3), which is preferably present in a homopolymer of one or more alkyl methacrylates and / or a copolymer of an alkyl methacrylate with one or more comonomers (A-4), and

[0125] (A-4) 0 to 45% by weight, based on the total weight of the molding composition (P), of at least one comonomer copolymerizable with the at least one polymerized alkyl methacrylate component (A-3), the comonomer (A-4) being selected from vinyl aromatic monomers, preferably styrene, or vinyl cyanides, preferably acrylonitrile,

[0126] wherein the sum of (A-1), (A-2), (A-3) and optionally the comonomer (A-4) is 83.2 to 99.8% by weight, based on the total weight of the molding composition (P).

[0127] In another preferred embodiment, the at least one thermoplastic polymer composition (A) comprises or consists of:

[0128] (A-1) 10 to 50% by weight, preferably 15 to 45% by weight, more preferably 20 to 45% by weight, based on the total weight of the molding composition (P), of at least one graft copolymer (A-1);

[0129] (A-2) 1 to 50% by weight, preferably 5 to 50% by weight, based on the total weight of the molding composition (P), of at least one thermoplastic polymer matrix (A-2) based on one or more vinyl aromatic copolymers; and

[0130] (A-3) 20 to 50% by weight, preferably 25 to 40% by weight, based on the total weight of the molding composition (P), of at least one polymerized alkyl methacrylate component (A-3), preferably methyl methacrylate present in one or more alkyl methacrylate homopolymers;

[0131] wherein the amounts of (A-1), (A-2) and (A-3) together total 100% by weight of (A).

[0132] In another preferred embodiment, the at least one thermoplastic polymer composition (A) comprises or consists of:

[0133] (A-1) At least one graft copolymer (A-1) in an amount of 10 to 50% by weight, preferably 15 to 45% by weight, more preferably 20 to 45% by weight, based on the total weight of the molding composition (A);

[0134] (A-2) At least one molding matrix (A-2) in an amount of 1 - 50% by weight, preferably 5 - 50% by weight, based on the total weight of the thermoplastic polymer composition (A), which is based on one or more vinyl aromatic copolymers;

[0135] (A-3) At least one polymerized alkyl methacrylate component (A-3) in an amount of 20 - 50% by weight, preferably 25 - 40% by weight, based on the total weight of the molding composition (A), preferably methyl methacrylate present in a copolymer of one or more alkyl methacrylates and one or more comonomers (A-4); and

[0136] (A-4) At least one comonomer (A-4) in an amount of 1 to 45% by weight, based on the total weight of the molding composition (P), which is selected from vinyl aromatic monomers, preferably styrene, or vinyl cyanides, preferably acrylonitrile, wherein the comonomer (A-3) copolymerizes with the polymerized alkyl methacrylate component (A-3) to form a copolymer;

[0137] wherein the sum of (A-1), (A-2), (A-3) and optionally the comonomer (A-4) is 83.2 to 99.8% by weight, based on the total weight of the molding composition (P).

[0138] In another preferred embodiment, the at least one thermoplastic polymer composition (A) comprises or consists of:

[0139] (A-1) At least one graft copolymer (A-1) in an amount of 10 to 50% by weight, preferably 15 to 45% by weight, more preferably 20 to 45% by weight, based on the total weight of the molding composition (P);

[0140] (A-2) At least one thermoplastic polymer matrix (A-2) in an amount of 1 - 50% by weight, preferably 5 - 50% by weight, based on the total weight of the molding composition (P), which is based on one or more vinyl aromatic copolymers;

[0141] (A-3) At least one polymerized alkyl methacrylate component (A-3) in an amount of 20 to 50% by weight, preferably 25 to 40% by weight, based on the total weight of the molding composition (P), preferably methyl methacrylate present in a mixture comprising homopolymers of one or more alkyl methacrylates and copolymers of one or more alkyl methacrylates and one or more comonomers (A-4); and

[0142] (A-4) 1 to 45% by weight, based on the total weight of the moulding composition (P), of at least one comonomer (A-4) selected from vinylaromatic monomers, preferably styrene, or vinyl cyanides, preferably acrylonitrile, where the comonomer (A-4) forms a copolymer with the polymerized alkyl methacrylate component (A-3);

[0143] where the sum of (A-1), (A-2), (A-3) and optionally the comonomer (A-4) is 83.2 to 99.8% by weight, based on the total weight of the moulding composition (P).

[0144] Hindered amine light stabilizer composition (Component B)

[0145] According to the invention, the moulding composition (P) comprises at least one hindered amine light stabilizer composition (B) which comprises at least two of the substances (B-1) to (B-3):

[0146] (B-1) 0 to 0.9% by weight, preferably 0.1 to 0.9% by weight, more preferably 0.2 to 0.9% by weight, based on the total weight of the moulding composition (P), of at least one hindered amine light stabilizer having a dipiperidine structure, having an alkyl group at the 2- and 6-positions of the dipiperidine structure and not containing any saturated or unsaturated C12-C21 ester moieties at one of the 3-, 4- or 5-positions of the piperidine structure, where the at least one hindered amine light stabilizer having a dipiperidine structure has a molecular weight of 200 - 550 g / mol,

[0147] (B-2) 0 to 0.9% by weight, preferably 0.1 to 0.9% by weight, more preferably 0.2 to 0.9% by weight, in particular 0.2 to 0.6% by weight, based on the total weight of the moulding composition (P), of a mixture of hindered amine light stabilizers having a monopiperidine structure, having at least one alkyl group at the 2- and 6-positions of the monopiperidine structure and having a saturated or unsaturated C12-C21 ester moiety at at least one of the 3-, 4- or 5-positions of the piperidine structure, and

[0148] (B-3) 0 to 2% by weight, preferably 0.1 to 2% by weight, more preferably 0.2 to 2% by weight, based on the total weight of the moulding composition (P), of at least one hindered amine light stabilizer having a polymeric structure, the polymeric structure of which comprises piperidine groups, having at least one alkyl group at the 2- and 6-positions of the piperidine groups and not containing any saturated or unsaturated C12-C21 ester moieties at one of the 3-, 4- or 5-positions of the piperidine groups, where the at least one hindered amine light stabilizer having a polymeric structure has a molecular weight of 1000 - 4000 g / mol, preferably 1500 - 4000 g / mol, more preferably 2000 - 4000 g / mol,

[0149] Provided that the amount of the at least one hindered amine light stabilizer composition (B) present in the molding composition (P) is at least 0.2% by weight (based on the total weight of the molding composition (P)),

[0150] wherein the sum of (B-1), (B-2) and (B-3) is 100% by weight of the total weight of the at least one hindered amine light stabilizer composition (B).

[0151] Suitable hindered amine light stabilizers include a piperidine structure having at least one alkyl group at each of the 2- and 6-positions of the piperidine structure. Particularly preferred is having two alkyl groups at each of the 2- and 6-positions of the piperidine structure. In a more preferred embodiment, the alkyl group is selected from C 1 -C 5 alkyl groups, especially C 1 -C 3 alkyl groups.

[0152] The hindered amine light stabilizer (B-1) of the molding composition (P) according to the present invention is at least one compound having a dipiperidine structure, having at least one alkyl group at each of the 2- and 6-positions of the dipiperidine structure and not containing any saturated or unsaturated C 12 -C 21 ester moiety at one of the 3-, 4- or 5-positions of the piperidine structure, wherein the molecular weight of the at least one hindered amine light stabilizer having a dipiperidine structure is 200-550 g / mol. Suitable hindered amine light stabilizers (B-1) include compounds having two piperidine structures, the two piperidine structures being linked by a C 3 -C 11 -saturated or -unsaturated diester moiety, the diester moiety being bonded to one of the 3-, 4- or 5-positions of the piperidine structure.

[0153] In a further preferred embodiment, the hindered amine light stabilizer (B-1) comprises a compound having two piperidine structures, the two piperidine structures being linked by a C 3 -C 11 -saturated diester moiety, especially a C 6 -C 10 -saturated diester moiety, the diester moiety being bonded to one of the 3-, 4- or 5-positions of the piperidine structure. And not containing any saturated or unsaturated C 12 -C 21 ester moiety at one of the 3-, 4- or 5-positions of the piperidine structure.

[0154] Particularly preferred hindered amine light stabilizers having a dipiperidine structure suitable for use as component (B-1) according to the present invention are represented by the chemical formula (I):

[0155]

[0156] This sterically hindered amine (bis(2,2,6,6-tetramethylpiperidin-4-yl) sebacate, CAS 52829-07-9) and its preparation are known to those skilled in the art and are described in the literature (see, for example, US Patent 4,396,769 and the references cited therein). It is sold by BASF SE under 770, with a molecular weight of 481 g / mol.

[0157] Other suitable examples of component (B-1) are: bis(1,2,2,6,6-pentamethyl-4-piperidyl) sebacate (CAS 41556-26-7, 765 from BASF SE, molecular weight (MW) = 509 g / mol); N,N'-biformyl-N,N'-bis-(2,2,6,6-tetramethyl-4-piperidyl)-hexamethylenediamine (CAS 124172-53-8, 4050H from BASF SE, MW = 450 g / mol); N,N'-bis(2,2,6,6-tetramethyl-4-piperidyl) isophthalamide (CAS 42774-15-2, MW = 443 g / mol) from Clariant.

[0158] The hindered amine light stabilizer (B-2) of the molding composition (P) according to the invention is at least one compound having a monopiperidine structure, with at least one alkyl group at each of the 2- and 6-positions of the monopiperidine structure and at least one saturated or unsaturated C 12 -C 21 ester moiety at at least one of the 3-, 4- or 5-positions of the monopiperidine structure. Such hindered amine stabilizers can exist as a mixture of substances with different fatty acid chains. Preferably, the ester moiety comprises or consists of a saturated ester moiety. Even more preferably, at least one of the 3-, 4- or 5-positions of the monopiperidine structure, especially at least the 4-position, comprises or consists of a C 15 -C 20 -saturated ester moiety.

[0159] Particularly preferred hindered amine light stabilizers having a monopiperidine structure suitable for use as component (B-2) according to the invention are represented by the chemical formula (II):

[0160]

[0161] This sterically hindered amine (2,2,6,6 - tetramethyl - 4 - piperidyl stearate, CAS 167078 - 06 - 0, or 86403 - 32 - 9, or 24860 - 22 - 8) and its preparation are known to those skilled in the art and are described in the literature (Carlsson et al., Can. Journal of Polymer Science, Polymer Chemistry Edition (1982), 20(2), 575 - 82). It is sold by Solvay under UV - 3853. This substance with a molecular weight below 516 g / mol is a waxy viscous product with a melting point of about 30 °C. Since it is difficult to exist in pure solid form during the mixing of thermoplastic compositions, this product is usually supplied and used as a masterbatch. In a preferred embodiment, this substance is thus added in the form of a masterbatch, which, based on the total weight of the masterbatch, contains 20 - 70 wt%, preferably 40 - 60 wt% of 2,2,6,6 - tetramethyl - 4 - piperidyl stearate and a copolymer of vinyl aromatic olefin and acrylonitrile as the matrix polymer. Preferably, the matrix polymer is selected from poly(styrene - acrylonitrile) (SAN), poly(α - methylstyrene / acrylonitrile) (AMSAN) and / or poly(styrene - methyl methacrylate) (SMMA).

[0162] The hindered amine light stabilizer (B - 3) of the molding composition (P) according to the invention is at least one compound having a polymeric structure comprising piperidine groups, each having at least one alkyl group at the 2 - and 6 - positions of the piperidine group. And at one of the 3 -, 4 - or 5 - positions of the piperidine group, it does not contain any saturated or unsaturated C 12 -C 21 ester group (i.e., ester moieties). The hindered amine light stabilizer (B - 3) having a polymeric structure is defined as comprising at least two, preferably at least three repeating units derived from polymerizable monomers, and having a molecular weight of 1000 - 4000 g / mol, preferably 1500 - 4000 g / mol, more preferably 2000 - 4000 g / mol.

[0163] Particularly preferred hindered amine light stabilizers having a polymeric structure containing piperidine groups and suitable for use as component (B - 3) of the present invention are represented by chemical formula (III):

[0164]

[0165] This sterically hindered amine (CAS 71878 - 19 - 8) and its preparation are known to those skilled in the art and are described in the literature (see, for example, EP - A - 93 693 and the references cited therein). It is sold by BASF SE under 944 for sale, with a molecular weight of 2100 - 3000 g / mol.

[0166] Other suitable examples of component (B-3) are: 1,6-hexanediamine, N,N'-bis(2,2,6,6-tetramethyl-4-piperidinyl)-polymer with 2,4,6-trichloro-1,3,5-triazine, reaction product with N-butyl-1-butylamine and N-butyl-2,2,6,6-tetramethyl-4-piperidinamine (CAS 192268-64-7, BASF SE 2020, molecular weight = 2600 - 3400 g / mol); polymer of dimethyl succinate and 4-hydroxy-2,2,6,6-tetramethyl-1-piperidinoethanol (CAS 65447-77-0, BASF SE 622, MW = 3100–4000 g / mol); reaction product of C20-24α-polymer of olefin with maleic anhydride and 2,2,6,6-tetramethyl-4-piperidinamine (CAS 152261-33-1, 5050H, BASFSE, MW = 3000–4000 g / mol); 1,3,5-Triazine-2,4,6-triamine, N2,N2”-1,2-ethanediylbis[N2-[3-[[4,6-bis[butyl(1,2,2,6,6-pentamethyl-4-piperidinyl)amino]-1,3,5-triazine-2-yl]amino]propyl]-N',N”-dibutyl-N',N”-bis(1,2,2,6,6-pentamethyl-4-piperidinyl)-(CAS 106990-43-6, SABO S.p.A. UV 119, MW = 2286 g / mol); poly[(6-morpholino-s-triazine-2,4-diyl)[2,2,6,6-tetramethyl-4-piperidinyl)imino]-hexamethylene[(2,2,6,6-tetramethyl-4-piperidinyl)imino]] (CAS 82451-48-7 or 90751-07-8, Solvay UV-3346, MW = 1600 g / mol); 1,6-hexanediamine, N,N'-bis(2,2,6,6-tetramethyl-4-piperidinyl)-polymer with morpholine-2,4,6-trichloro 1,3,5-triazine (CAS 193098-40-7 or 219920-30-6, Solvay UV-3529).

[0167] Optionally, based on the total weight of the molding composition (P), the hindered amine light stabilizer (B-1) is present in the molding composition in an amount of 0 to 0.9% by weight, preferably 0.1 to 0.9% by weight, more preferably 0.2 to 0.9% by weight, even more preferably 0.2 to 0.6% by weight, especially 0.4 to 0.6% by weight.

[0168] Optionally, based on the total weight of the molding composition (P), the hindered amine light stabilizer (B-2) is present in the molding composition in an amount of 0 to 0.9% by weight, preferably 0.1 to 0.9% by weight, more preferably 0.2 to 0.9% by weight, even more preferably 0.2 to 0.6% by weight, especially 0.2 to 0.5% by weight.

[0169] The hindered amine light stabilizer (B-3) is optionally present in the molding composition in an amount of 0 to 2.0% by weight, preferably 0.1 to 2.0% by weight, more preferably 0.2 to 2.0% by weight, especially 0.2 to 1.0% by weight based on the total weight of the molding composition (P).

[0170] In one embodiment, the present invention relates to a molding composition (P), wherein the hindered amine light stabilizing composition (B) comprises:

[0171] (B-1) Based on the total weight of the molding composition (P), a compound of formula (I) in an amount of 0 to 0.9% by weight, preferably 0.1 to 0.9% by weight, more preferably 0.2 to 0.9% by weight, even more preferably 0.2 to 0.6% by weight, especially 0.4 to 0.6% by weight:

[0172]

[0173] In one embodiment, the present invention relates to a molding composition (P), wherein the hindered amine light stabilizing composition (B) comprises:

[0174] (B-2) Based on the total weight of the molding composition (P), a composition in an amount of 0 to 0.9% by weight, preferably 0.1 to 0.9% by weight, more preferably 0.2 to 0.9% by weight, even more preferably 0.2 to 0.6% by weight, especially 0.2 to 0.5% by weight, which comprises at least one compound of formula (II):

[0175]

[0176] In one embodiment, the present invention relates to a molding composition (P), wherein the hindered amine light stabilizing composition (B) comprises:

[0177] (B-3) 0 to 2.0% by weight, preferably 0.1 - 2.0% by weight, more preferably 0.2 - 2.0% by weight, in particular 0.2 - 1.0% by weight, based on the total weight of the molding composition (P), of a compound of formula (III):

[0178]

[0179] In one embodiment of the present invention, the molding composition (P) comprises at least one hindered amine light stabilizer composition (B), which comprises:

[0180] (B-1) 0.1 to 0.9% by weight, preferably 0.2 to 0.9% by weight, more preferably 0.2 to 0.6% by weight, in particular 0.4 to 0.6% by weight, based on the total weight of the molding composition (P), of at least one hindered amine light stabilizer having a dipiperidine structure, having at least one alkyl group at each of the 2- and 6-positions of the dipiperidine structure and not containing any saturated or unsaturated C12 - C21 ester moiety at one of the 3-, 4- or 5-positions of the piperidine structure, wherein the at least one hindered amine light stabilizer having a dipiperidine structure has a molecular weight of 200 - 550 g / mol,

[0181] (B-2) 0.1 to 0.9% by weight, preferably 0.2 to 0.9% by weight, more preferably 0.2 to 0.6% by weight, in particular 0.2 to 0.5% by weight, based on the total weight of the molding composition (P), of a mixture of hindered amine light stabilizers having a monopiperidine structure, having at least one alkyl group at each of the 2- and 6-positions of the monopiperidine structure and having a saturated or unsaturated C12 - C21 ester moiety at at least one of the 3-, 4- or 5-positions of the monopiperidine structure, and

[0182] (B-3) 0 to 2.0% by weight, preferably 0.1 to 2.0% by weight, more preferably 0.2 to 2.0% by weight, in particular 0.2 to 1.0% by weight, based on the total weight of the molding composition (P), of at least one hindered amine light stabilizer having a polymer structure, the polymer structure comprising piperidine groups, having at least one alkyl group at each of the 2- and 6-positions of the piperidine group and not containing any saturated or unsaturated C12 - C21 ester moiety at one of the 3-, 4- or 5-positions of the piperidine group, wherein the at least one hindered amine light stabilizer having a polymer structure has a molecular weight of 1000 - 4000 g / mol, preferably 1500 - 4000 g / mol, more preferably 2000 - 4000 g / mol.

[0183] In one embodiment of the present invention, the molding composition (P) comprises at least one hindered amine light stabilizer composition (B), which comprises:

[0184] (B-1) From 0.1 to 0.9% by weight, preferably from 0.2 to 0.9% by weight, more preferably from 0.2 to 0.6% by weight, in particular from 0.4 to 0.6% by weight, of a compound of formula (I) based on the total weight of the moulding composition (P):

[0185]

[0186] (B-2) From 0.1 to 0.9% by weight, preferably from 0.2 to 0.9% by weight, more preferably from 0.2 to 0.6% by weight, in particular from 0.2 to 0.5% by weight, of at least one compound of formula (II) based on the total weight of the moulding composition (P): and,

[0187]

[0188] (B-3) From 0 to 2.0% by weight, preferably from 0.1 to 2.0% by weight, more preferably from 0.2 to 2.0% by weight, in particular from 0.2 to 1.0% by weight, of at least one hindered amine light stabilizer having a polymeric structure, the polymeric structure comprising piperidine groups, each having at least one alkyl group in the 2- and 6-positions of the piperidine group and having no saturated or unsaturated C12-C21 ester moiety at one of the 3-, 4- or 5-positions of the piperidine group, wherein the at least one hindered amine light stabilizer having a polymeric structure has a molecular weight of 1000 - 4000 g / mol, preferably 1500 - 4000 g / mol, more preferably 2000 - 4000 g / mol, and is preferably a compound of formula (III):

[0189]

[0190] Based on the total weight of the moulding composition (P), the at least one hindered amine light stabilizer composition (B) is present in the moulding composition (P) in an amount of at least 0.2% by weight, preferably 0.3% by weight, in particular 0.4% by weight. However, based on the total weight of the moulding composition (P), the at least one hindered amine light stabilizer composition (B) is present in the moulding composition (P) in an amount of at most 4.0% by weight, preferably 3.0% by weight.

[0191] Other additives (optional component C)

[0192] As used herein, the one or more additional additives (C) can be any additives that are useful for the moulding composition (P) and are not included in components (A), (B) or (D). For example, the additional additives (C) can be selected from plasticizers, aliphatic amide waxes, aliphatic fatty acid esters and additional UV stabilizers not included in component (B).

[0193] Optionally, various additives can be added to the molding composition in an amount of 0 to 5% by weight, typically 0.1 to 5% by weight, as auxiliaries and processing additives. Suitable additives (C) include all substances commonly used for processing or finishing polymers.

[0194] Additive (C) can be added in the form of a masterbatch, a masterbatch containing additive (C) in a polymer matrix. In a preferred embodiment, additive (C) is added in the form of a masterbatch, which, based on the total amount of the masterbatch, contains 20 - 70% by weight, preferably 40 - 60% by weight of additive (C) or a mixture thereof, and 30 - 80% by weight, preferably 40 - 60% by weight of a copolymer of vinyl aromatic olefin and acrylonitrile as the matrix polymer. Preferably, the matrix polymer is selected from poly(styrene - acrylonitrile) (SAN), poly(α - methylstyrene / acrylonitrile) (AMSAN), and / or poly(styrene - methyl methacrylate) (SMMA).

[0195] Examples of additive (C) include, for example, antistatic agents, antioxidants, flame retardants, stabilizers for improving thermal stability, stabilizers for improving light stability, stabilizers for improving hydrolysis resistance and chemical resistance, thermal decomposition inhibitors, especially lubricants, which can be used for the production of molded articles / products. These further added substances can be mixed at any stage of the manufacturing operation, but are preferably mixed at an early stage in order to benefit from the stabilizing effect (or other specific effects) of the added substances as early as possible.

[0196] Examples of suitable antistatic agents include amine derivatives such as N,N - bis(hydroxyalkyl)alkylamine or - alkyleneamine, polyethylene glycol esters, copolymers of ethylene glycol and propylene glycol (especially diblock or triblock copolymers of ethylene oxide blocks and propylene oxide blocks), glycerol monostearate and distearate, and mixtures thereof.

[0197] Examples of suitable antioxidants include sterically hindered monocyclic or polycyclic phenolic antioxidants, which can contain various substituents and can also be bridged by substituents. These include not only monomeric compounds but also oligomeric compounds that can be composed of multiple phenolic units. Hydroquinones and hydroquinone analogs are also suitable, as are substituted compounds and antioxidants based on tocopherols and their derivatives. Mixtures of different antioxidants can also be used. In principle, any commercially common or suitable compound for styrene copolymers can be used, such as those from the series of antioxidants. In addition to the phenolic antioxidants cited by way of example above, co - stabilizers, especially phosphorus - or sulfur - containing co - stabilizers, can also be used. These phosphorus - or sulfur - containing co - stabilizers are known to those skilled in the art.

[0198] Examples of suitable flame retardants that can be used include halogen - or phosphorus - containing compounds known to those skilled in the art, magnesium hydroxide, and other commonly used compounds or mixtures thereof.

[0199] Examples of suitable light stabilizers include various substituted resorcinols, salicylates, benzotriazoles, and benzophenones. Suitable matting agents include not only inorganic substances such as talc, glass beads, or metal carbonates (e.g., MgCO 3 , CaCO 3 ), but also polymer particles, especially spherical particles with a diameter D50 greater than 1 μm based on, for example, methyl methacrylate, styrene compounds, acrylonitrile, or mixtures thereof. Polymers containing copolymerized acidic and / or basic monomers can also be used.

[0200] Examples of suitable anti - dripping agents include polytetrafluoroethylene (Teflon) polymers and ultra - high molecular weight polystyrene (weight - average molar mass Mw higher than 2,000,000 g / mol).

[0201] Examples of fibrous / powdery fillers include carbon or glass fibers in the form of glass fabrics, glass mats, or filament glass rovings, chopped glass, glass beads, and wollastonite, with glass fibers being particularly preferred. When using glass fibers, they can be treated with sizing agents and coupling agents to improve their compatibility with the blend components. The incorporated glass fibers can be in the form of short glass fibers or continuous filaments (rovings).

[0202] Examples of suitable particulate fillers include carbon black, amorphous silica, magnesium carbonate, quartz powder, mica, bentonite, talc, feldspar, or especially calcium silicates such as wollastonite and kaolin.

[0203] Examples of suitable stabilizers include hindered phenols, as well as vitamin E and / or compounds with a similar structure, and butylated condensation products of p - cresol and dicyclopentadiene. Other HALS stabilizers (hindered amine light stabilizers), benzophenones, resorcinols, salicylates, and benzotriazoles not listed above as component B are also suitable.

[0204] Other suitable compounds include, for example, thioesters. (C 6 - C 20 ) alkyl esters of thiodipropionic acid can also be used, especially stearyl esters and lauryl esters.

[0205] Dilauryl thiodipropionate, distearyl thiodipropionate, or mixtures thereof can also be used. Examples of other additives include UV absorbers such as 2H - benzotriazol - 2 - yl-(4 - methylphenol).

[0206] Suitable lubricants and release agents include stearic acid, stearyl alcohol, stearates and / or conventional higher fatty acids, their derivatives and corresponding fatty acid mixtures containing 1 to 45 carbon atoms. In a further preferred embodiment, the composition contains an amide compound having the formula R 1 -CONH-R 2 wherein R 1 and R 2 are each independently selected from aliphatic, saturated or unsaturated hydrocarbon groups having 1 to 30 carbon atoms, preferably 12 to 24 carbon atoms, especially 16 to 20 carbon atoms. In another preferred embodiment of the present invention, the composition may additionally contain a fatty acid ester compound having the formula R 3 -CONH-R 4 wherein R 3 and R 4 are each independently selected from aliphatic, saturated or unsaturated hydrocarbon groups having 1 to 45 carbon atoms, preferably 15 to 40 carbon atoms, especially 25 to 35 carbon atoms. Ethylene bis(stearamide) is also particularly suitable.

[0207] In a further preferred embodiment, the molding composition (P) may contain organic, inorganic or mixed phosphates, especially alkali metal or alkaline earth metal phosphates such as Ca 3 (PO 4 ) 2 and / or organic phosphates having an alkyl or aryl group including 1 to 12 carbon atoms.

[0208] In a further preferred embodiment, the molding composition (P) may further contain a polyester-modified polysiloxane, especially a polyester-polysiloxane-block copolymer, preferably a [polyester-b-polysiloxane-b-polyester] triblock copolymer. Preferred examples of the polysiloxane moiety contained in the polyester-polysiloxane-block copolymer are derived from poly(dimethylsiloxane), poly(diethylsiloxane), poly(dipropylsiloxane), poly(dibutylsiloxane) and mixtures thereof.

[0209] Colorants, dyes and pigments (optional component D)

[0210] As described above, the molding composition (P) may further comprise from 0 to 10% by weight, typically from 0.1 to 5% by weight, of dyes, pigments or colorants, which may be added in the form of a masterbatch comprising a polymer matrix and the dyes, pigments or colorants therein. In a preferred embodiment, the dyes, pigments or colorants are added in the form of a masterbatch which, based on the total amount of the masterbatch, comprises from 20 to 70% by weight of dyes, pigments, colorants or mixtures thereof and from 30 to 80% by weight of a copolymer of vinyl aromatic olefin and acrylonitrile as matrix polymer. Preferably, the matrix polymer is selected from poly(styrene-acrylonitrile) (SAN), poly(α-methylstyrene / acrylonitrile) (AMSAN) and / or poly(styrene-methyl methacrylate) (SMMA).

[0211] Examples of suitable pigments as optional component D include titanium dioxide, phthalocyanine, ultramarine, iron oxide and carbon black, as well as the entire class of organic pigments. Examples of suitable colorants include all dyes which can be used for transparent, translucent or opaque coloring of polymers, in particular dyes suitable for coloring styrene copolymers.

[0212] Preparation of the molding composition (P)

[0213] According to the process of the invention, any procedural steps suitable for carrying out the claimed process may be employed.

[0214] In a preferred embodiment, the mixing step of the components comprises at least the following steps:

[0215] (i) adding a predetermined amount of components (A) to (D) to an optionally heatable mixing device; and

[0216] (ii) mixing components (A) to (D) in the optionally heatable mixing device at a temperature above the glass transition point of components (A) to (D) to obtain the molding composition (P).

[0217] Optionally, a step of preparing a homogeneous mixture of particulate materials of components (A) to (D) may be carried out prior to step (ii). However, when such pre-mixing is not carried out, homogeneous mixing can generally also be achieved in the optionally heatable mixing device.

[0218] Each of components (A) to (D)—in solid form—may be provided in the form of particulate materials having different particle sizes and particle size distributions (e.g., as pellets, granules and / or powders).

[0219] The particulate materials (A) to (D) can be added to the mixing device in the required amounts and ratios as described above and, optionally, mixed before the mixing step (ii) to obtain a homogeneous mixture of particulate materials. In a preferred embodiment, this may take from 1 to 60 minutes, preferably from 1 to 20 minutes, particularly 2 to 10 minutes, depending on the amount of particulate materials to be mixed.

[0220] The homogeneous mixture of particulate materials thus obtained is then transferred to an optionally heatable mixing device and mixed therein to produce a polymer mixture which is substantially a liquid melt.

[0221] "Substantially a liquid melt" means that the polymer mixture and the predominantly liquid melt (softened) portion may further contain a certain amount of solid components, such as unmelted fillers and reinforcing materials, such as glass fibers, metal flakes, or unmelted pigments, colorants, etc. "Liquid melt" means that the polymer mixture has at least low fluidity and is thus at least softened to a plastic state.

[0222] Mixing devices which can be used are those known to the person skilled in the art. Components (A) and (B) and - if included - (C) and / or (D) can be mixed, for example, by co-extrusion, kneading or rolling, and the abovementioned components must already have been separated from the aqueous dispersion or aqueous solution during polymerization.

[0223] Examples of mixing devices for carrying out the process include discontinuous operation, heatable internal kneading devices (with or without RAM), continuous operation kneaders, such as continuous operation internal kneading machines, screw kneaders with axially oscillating screws, Banbury kneaders, and in addition extruders, as well as roller mills, with heated rollers and mixing calenders, and rolling mills.

[0224] Optionally, the process can include a further step (iii) of cooling the blend obtained in step (ii) to a temperature below the glass transition point of components (A) to (D) to obtain the molding composition (P).

[0225] Preferred mixing devices are extruders or kneaders. Particularly suitable for melt extrusion are single-screw or twin-screw extruders, preferably twin-screw extruders. In some cases, the mechanical energy introduced by the mixing device during mixing is sufficient to melt the mixture, which means that the mixing device does not have to be heated. Otherwise, the mixing device generally has to be heated.

[0226] The setting of the temperature is determined by the chemical and physical properties of the polymer composition (A) and components (B), (C), and (D). The selected temperature should be such that a polymer mixture that is substantially a liquid melt is produced. On the other hand, the temperature should not be too high to prevent thermal damage to the polymer mixture. However, the mechanical energy introduced may also be high enough that the mixing device even needs to be cooled. The mixing device is generally operated at 150 to 400 °C, preferably 170 to 300 °C.

[0227] In a preferred embodiment, a heatable twin-screw extruder is used, at a speed of 50 to 150 rpm, preferably 60 to 100 rpm. In a preferred embodiment, an extrusion temperature of 170 to 270 °C, preferably 210 to 250 °C, is employed to obtain the molding composition (P). The molding composition (P) can be used directly, for example, for the molding process, preferably the injection molding process, or can be processed into pellets, and then the molding process can be carried out on them. The molding process is preferably carried out at a temperature of 170 to 270 °C, especially 210 to 250 °C, to produce molded articles.

[0228] Processing can be carried out using known thermoplastic processing methods, in particular, it can be carried out by thermoforming, extrusion, injection molding, calendering, blow molding, compression molding, pressure sintering, deep drawing, or sintering, preferably injection molding.

[0229] Applications and properties

[0230] The present invention further relates to articles, especially molded articles (T), which are prepared from the molding composition (P), or from a polymer composition comprising a combination of the molding composition (P) with another thermoplastic polymer as described above. The articles, especially the molded articles, can be prepared by any known thermoplastic processing method. In particular, the preparation can be carried out by thermoforming, extrusion, injection molding, calendering, blow molding, compression molding, pressure sintering, deep drawing, or sintering, preferably injection molding.

[0231] In particular, the molding composition (P) according to the present invention can preferably be used to prepare a molded article (T) which is prepared from the thermoplastic molding composition (P) as described above and has a high-gloss surface with a glossiness higher than 75 gloss units, wherein the glossiness is measured at a measurement angle of 60° according to DIN EN ISO 2813.

[0232] Therefore, the present invention also relates to a molded article (T) prepared from the thermoplastic molding composition (P) as described above, especially a molded article (T) having a high-gloss surface with a glossiness higher than 75 gloss units, wherein the glossiness is measured at a measurement angle of 60° according to DIN EN ISO 2813.

[0233] The molding composition (P) and articles, in particular molded articles (T), can advantageously be used for manufacturing parts or articles for electronic devices, household articles, and external and / or internal automotive components, in particular for manufacturing visible components or articles. A preferred application is for unpainted automotive exterior parts, such as front grilles or side mirrors.

[0234] Molded articles (T) with a high-gloss surface prepared from the thermoplastic molding composition (P) as described above, having a glossiness higher than 75 gloss units, have various applications. However, the preferred application is for unpainted exterior parts, preferably in the automotive field. Wherein the glossiness is measured at a measurement angle of 60° according to DIN EN ISO 2813.

[0235] Automobile manufacturers who use unpainted high-gloss parts in external applications generally require that after 3200 hours of weathering under PV3929 conditions, only slight appearance changes occur on the surface. The maximum acceptable color shift in appearance change for automobile manufacturers is generally in the range of dE < 6, so this standard is used as the definition of acceptable appearance change in the present invention.

[0236] The molding composition (P) according to the present invention is characterized by the specific properties exhibited by the high-gloss surface of the molded article produced therefrom. In particular, the high-gloss surface exhibits a glossiness higher than 75 gloss units before any weathering exposure, and after 3200 hours of artificial weathering according to PV3929, a color shift lower than dE = 6, preferably lower than dE = 3, is measured relative to the unexposed surface, where the glossiness is measured at a measurement angle of 60° according to DIN EN ISO 2813.

[0237] The present invention also relates to a method for improving the weather resistance of a high-gloss surface molded article (T). Before the molding composition (P) undergoes artificial weathering, the glossiness level of at least a part of the surface area of the molded article (T) is above 75 gloss units, where the glossiness is measured at a measurement angle of 60° according to DIN EN ISO 2813,

[0238] Wherein the method includes the step of mixing components (A) to (D) as described above, and wherein the high-gloss surface molded article (T) made from the molding composition (P) exhibits the following characteristics:

[0239] The high-gloss surface molded article made from the molding composition (P), after 3200 hours of artificial weathering according to PV3929, has a 25% reduction in color shift compared to the high-gloss surface molded article made from a comparative molding composition (P') molded and evaluated under the same conditions.

[0240] The comparative molding composition (P') is obtained by mixing the components (A) to (D) contained in the molding composition (P) as described above, except that the content of the polymerized alkyl methacrylate component (A-3) in the comparative molding composition (P') is less than 20% by weight.

[0241] The present invention is further illustrated by the claims and the examples. Examples

[0242] Composition

[0243] Component A The thermoplastic polymer composition (A) is acrylonitrile-styrene acrylate (ASA), i.e., impact-modified poly(styrene-acrylonitrile) (SAN), which includes (A-1a) and (A-1b) grafted onto a butyl acrylate (BA) core SAN (BA-g-SAN)) having the following specified properties:

[0244] Thermoplastic matrix polymer component A-2a: AMSAN (30% by weight ACN, 70% by weight α-methylstyrene, VN 57 ml / g),

[0245] Thermoplastic matrix polymer component A-2b: SAN (35% by weight ACN, VN 80 ml / g) Thermoplastic matrix polymer component A-3: poly(methyl methacrylate): from Evonik 6N

[0246] Component B1 Hindered amine light stabilizer (HALS) from BASF 770

[0247] Component B2 Hindered amine light stabilizer (HALS) UV-3853 from Solvay, as a 50% by weight masterbatch in AMSAM (30% by weight acrylonitrile, 70% by weight α-methylstyrene, viscosity value 57 ml / g)

[0248] Component C1 Hindered amine light stabilizer (HALS) from BASF 944

[0249] Component C2 Di(2-propylheptyl) phthalate (DPHP) is a plasticizer.

[0250] Component D1 Carbon black Black from Cabot 880, as a 30% by weight masterbatch in SAN, containing 24% acrylonitrile, viscosity value 64 ml / g

[0251] Comparative component E:

[0252] PMMA U470 is dark black and commercially available from Romira GmbH. According to Romira's technical data sheet, Rotec PMMA U470 is a PMMA compound. As can be seen from TEM imaging, the material is impact-modified but does not contain any acrylonitrile and thus no ASA, which can be seen from the absence of a corresponding signal in the IR spectrum in the wavelength band from 2210 cm -1 to 2260 cm -1 -1.

[0253] Advertisements from Romira GmbH state that the material is used for high-gloss automotive exterior applications in black and unpainted.

[0254] Preparation of the base latex L1:

[0255] 90.2 parts by weight of softened water, 0.61 parts by weight of sodium C12- to C18-alkanesulfonate, and 0.23 parts by weight of sodium bicarbonate are added to a reaction vessel. When the temperature in the reaction vessel reaches 59 °C, 0.16 parts by weight of sodium persulfate dissolved in 5 parts by weight of softened water is added. A mixture of 59.51 parts by weight of butyl acrylate and 1.21 parts by weight of tricyclodecenyl acrylate is added within 210 minutes. The reaction is then continued for 60 minutes. Finally, the total solids content of the polymer dispersion is 39.6%, and the particle size of the latex particles is 75 nm (determined by turbidimetry).

[0256] Preparation of the graft latex (component A-1a):

[0257] 151.9 parts by weight of the base latex, 92.2 parts by weight of softened water, and 0.14 parts by weight of sodium persulfate dissolved in 3.22 parts by weight of softened water are added to a reaction vessel. A mixture of 31.18 parts by weight of styrene and 9.31 parts by weight of acrylonitrile is added at a temperature of 61 °C over a period of 190 minutes, followed by a post-polymerization time of 60 minutes at a temperature of 65 °C.

[0258] A polymer dispersion with a total solids content of 35.5% is obtained. The diameter of the latex particles is 87 nm (determined by turbidimetry). After synthesis, the latex is coagulated with a magnesium sulfate solution at a temperature of approximately 60 °C, followed by a sintering step at a temperature of approximately 90 °C. The resulting slurry is centrifuged to obtain a wet rubber powder, which is further processed.

[0259] Preparation of the base latex L2:

[0260] 70.66 parts by weight of softened water, 0.3 parts by weight of latex L1, and 0.23 parts by weight of sodium bicarbonate were added to a reaction vessel. After heating the reaction vessel to 60 °C, 0.16 parts by weight of sodium persulfate dissolved in 5 parts by weight of softened water was added to the reaction mixture. A mixture of 59.51 parts by weight of butyl acrylate and 1.21 parts by weight of tricyclodecenyl acrylate was added within 210 minutes.

[0261] Simultaneously with the first feed, 0.36 parts by weight of sodium C12-C18-alkane sulfonate (solution in 16.6 parts by weight of softened water) was also added within 210 minutes. Starting from the beginning of the feed, after 200 minutes, the temperature was raised to 65 °C. Then the reaction was continued at 65 °C for 60 minutes. Finally, the total solid content of the polymer dispersion was 39.4%, and the particle size of the latex particles was 440 nm (determined by turbidimetry).

[0262] Preparation of graft latex (component A-1b):

[0263] 154 parts by weight of base latex was added to a reaction vessel together with 88.29 parts by weight of softened water, 0.11 parts by weight of C 12 to C 18 -alkane sulfonate and 0.14 parts by weight of sodium persulfate dissolved in 5.61 parts by weight of softened water. The reaction mixture was heated to 61 °C. Within 60 minutes, 13.16 parts by weight was added at a temperature of 61 °C, and then a post-polymerization time of 90 minutes was carried out, during which the temperature rose from 61 to 65 °C.

[0264] Then a mixture of 20.5 parts by weight of styrene and 6.83 parts by weight of acrylonitrile was added to the reaction within 150 minutes. The reaction was continued at 65 °C for 60 minutes. A polymer dispersion with a total solid content of 35.2% was obtained. The diameter of the latex particles was 500 nm (determined by turbidimetry). After synthesis, the latex was coagulated with a magnesium sulfate solution at a temperature of about 88 °C, and then a sintering step was carried out at a temperature of about 130 °C. The resulting slurry was centrifuged to obtain wet rubber powder, which was further processed

[0265] Preparation of molding composition (P) and test specimens

[0266] Examples and comparative examples of the molding composition were prepared by mixing all components at Tm = 240 °C according to the specific ratios given in Table 1 using a twin-screw extruder (model ZSK26MC, Coperion GmbH, length: 1035 mm). Sample plates (7.5 x 5 cm) and other samples were prepared by injection molding (Tm: 260 °C).

[0267] Table 1. Composite formulation

[0268]

[0269]

[0270] The comparative examples and their molding compounds do not belong to the present invention and are used for comparison.

[0271] Here, each BA-g-SAN (i.e., components A-1a and A-1b) contains approximately 60 parts of n-butyl acrylate (BA) containing a crosslinking agent, approximately 40 parts of SAN (styrene:acrylonitrile mass ratio of 1:3 to 1:4), and approximately 1 part of other monomers such as dicyclopentadienyl acrylate (DCPA) or tricyclodecenyl acrylate.

[0272] Weathering conditions

[0273] The performance of the sample plates was tested for weathering conditions according to the following test procedures.

[0274] Simulating a humid and warm climate according to ISO 4892-2A, the parameters are as follows:

[0275] Volkswagen standard PV 3929 (simulating a dry and hot climate):

[0276] Black label 90 ± 2 °C (dry phase: 50 ± 2 °C), relative humidity: 20 ± 10%;

[0277] Irradiation: 0.6 W / m 2 , wavelength 340 nm

[0278] The test results were evaluated according to the color measurement standard of DIN 6174. The gloss was measured at a 60° measurement angle according to DIN EN ISO 2813. All descriptions of gloss and gloss measurement in the present invention are based on the above conditions. The evaluation results are shown in Table 2.

[0279] Table 2: Aging results

[0280]

[0281] For all high-gloss test panels of comparative examples (Comparative Examples 1 to 5) where the content of component (A-3) is less than 20% by weight of the total weight of the composition, they were exposed for 3200 hours according to PV3929. The weathering results are shown in Table 1. Although these formulations have good stability in terms of ultraviolet irradiation, they show unsatisfactory weathering results.

[0282] The color shift is higher than dE = 10, so it does not meet the technical requirements for automotive exterior applications, indicating that further improvement is needed.

[0283] The high-gloss test panel of Comparative Example 6, which contains a poly(methyl methacrylate) compound that does not belong to the present invention (containing more than 20% by weight of component (A-3) but not containing components (A-1) and (A-2)), the weather resistance results after exposure for 3200 hours according to PV3929 are shown in Table 1, showing a color shift with dE of 7 or more, and thus cannot meet the above technical requirements.

[0284] As shown in Table 1, the high-gloss test panel of Example 1 unexpectedly showed significantly improved weather resistance results (compared with the weather resistance results of the comparative examples) after exposure for 3200 hours according to PV3929. The color shift dE of the test panel of Example 1 after 3200 h was lower than dE = 2.

[0285] The measured color shift dE of Example 1 of the present invention was less than 25% of the color shifts measured in Comparative Example 1 and Comparative Example 2. Therefore, the high-gloss weather resistance stability of the examples according to the formulation of the present invention after 3200 hours of aging can meet the technical requirements of the high-gloss surface outlined in the present invention.

Claims

1. A thermoplastic molding composition (P), comprising: (A) At least one thermoplastic polymer composition (A), comprising: (A-1) Based on the total weight of the molding composition (P), 10 to 50 wt% of at least one graft copolymer (A-1), wherein the graft copolymer (A-1) is a rubber-modified copolymer comprising repeating units of acrylonitrile and styrene, (A-2) Based on the total weight of the molding composition (P), 1 - 50 wt% of at least one thermoplastic polymer matrix (A-2), which is based on one or more vinyl aromatic copolymers, (A-3) Based on the total weight of the molding composition (P), 20 to 50 wt% of at least one polymerized alkyl methacrylate component (A-3), which is present in the form of homopolymers of one or more alkyl methacrylates, or copolymers of alkyl methacrylates with one or more comonomers (A-4), or a combination of homopolymers of one or more alkyl methacrylates and copolymers of alkyl methacrylates with one or more comonomers (A-4), and (A-4) Based on the total weight of the molding composition (P), 0 to 45 wt% of at least one comonomer copolymerized with the at least one polymerized alkyl methacrylate component (A-3), wherein the comonomer (A-4) is selected from vinyl aromatic monomers or vinyl cyanides, wherein the sum of (A-1), (A-2), (A-3) and optionally comonomer (A-4) is 83.2 to 99.8 wt%, based on the total weight of the molding composition (P); (B) A hindered amine light stabilizer composition (B), which comprises at least two of substances (B-1) to (B-3): (B-1) Based on the total weight of the molding composition (P), 0 to 0.9 wt% of at least one hindered amine light stabilizer having a dipiperidine structure, having an alkyl group at each of the 2- and 6-positions of the dipiperidine structure and not containing at one of the 3-, 4- or 5-positions of the dipiperidine structure wherein the at least one hindered amine light stabilizer having a dipiperidine structure has a molecular weight of 200 - 550 g / mol, (B-2) Based on the total weight of the molding composition (P), 0 to 0.9 wt% of a mixture of hindered amine light stabilizers having a monopiperidine structure, having at each of the 2- and 6-positions of the monopiperidine structure Any saturated or unsaturated C 12 -C 21 ester moiety, wherein the molecular weight of the at least one hindered amine light stabilizer having a polymeric structure is 1000 - 4000 g / mol, provided that the amount of the hindered amine light stabilizer composition (B) present in the molding composition (P) is at least 0.2 wt%, based on the total weight of the molding composition (P); (C) 0 to 5 wt% of one or more other additives (C) different from (B); and One alkyl group less and having a saturated or unsaturated C at one of the 3, 4 or 5 positions of the monopiperidine structure 12 -C 21 ester moiety, and (B-3) Based on the total weight of the molding composition (P), 0 to 2% by weight of at least one hindered amine light stabilizer having a polymeric structure, the polymeric structure comprising a piperidine group having at least one alkyl group at each of the 2- and 6-positions of the piperidine group and not containing any saturated or unsaturated C 12 -C 21 ester moiety (D) 0 to 10 wt% of a colorant; wherein components (A) to (D) total to 100 wt% of the molding composition (P).

2. The molding composition (P) according to claim 1, wherein the hindered amine light stabilizer composition (B) comprises: (B-1) Based on the total weight of the molding composition (P), 0.1 to 0.9 wt% of the compound represented by formula (I) ​ ​ ​ Object:

3. The molding composition (P) according to claim 1 or 2, wherein the hindered amine light stabilizer composition (B) comprises: (B-2) 0.1 to 0.9% by weight, based on the total weight of the molding composition (P), of a compound represented by formula (II):

4. The molding composition (P) according to claim 1 or 2, wherein the hindered amine light stabilizer composition (B) comprises: (B-3) 0 to 2.0% by weight, based on the total weight of the molding composition (P), of a compound represented by chemical formula (III):

5. The molding composition (P) according to claim 1 or 2, wherein the at least one thermoplastic polymer matrix (A-2) comprises at least one copolymer containing vinyl cyanide repeating units and at least one vinyl aromatic repeating unit.

6. The molding composition (P) according to claim 1 or 2, wherein the at least one thermoplastic polymer composition (A) comprises at least one copolymer (A-2), the copolymer (A-2) comprising: 18 to 45% by weight of at least one vinyl cyanide repeating unit; and 55 to 82% by weight of at least one vinyl aromatic repeating unit.

7. The molding composition (P) according to claim 1 or 2, wherein the graft copolymer (A-1) comprises rubber particles having a bimodal or trimodal size distribution, which comprises: (A-1a): at least one graft copolymer, wherein the average particle size d of the rubber particles in the ASA copolymer 50 is 50 - 150 nm; and (A-1b): At least one graft copolymer, the average particle size d of rubber particles in the ASA copolymer 50 is 200 - 750 nm.

8. The molding composition (P) according to claim 1 or 2, wherein the polymerized alkyl methacrylate component (A-3) comprises, or consists of, a poly(alkyl methacrylate) polymer.

9. The molding composition (P) according to claim 1 or 2, wherein the polymerized alkyl methacrylate component (A-3) comprises, or consists of, at least one copolymer formed by copolymerizing an alkyl methacrylate monomer with at least one vinyl aromatic comonomer.

10. The molding composition (P) according to claim 1 or 2, wherein the polymerized alkyl methacrylate component (A-3) comprises, or consists of, at least one copolymer formed by copolymerizing an alkyl methacrylate monomer, at least one vinyl aromatic comonomer, a vinyl cyanide, and an optional other comonomer (A-4).

11. The molding composition (P) according to claim 1 or 2, wherein the molded article produced from the molding composition (P) exhibits a glossiness higher than 75 gloss units before any aging exposure, and after 3200 hours of artificial weathering according to PV3929, with reference to the unexposed surface, shows a color shift dE lower than dE = 6, wherein the glossiness is measured at a measurement angle of 60° according to DIN EN ISO 2813.

12. The molding composition (P) according to claim 1 or 2, wherein the colorant in component (D) is a dye and / or a pigment.

13. A method for preparing the thermoplastic molding composition (P) according to claim 1 or 2, the method at least comprises the following steps: (i) adding a predetermined amount of components (A) to (D) to a mixing device; and (ii) Mix components (A) to (D) in the mixing device at a temperature above the glass transition point of component (A) to obtain the molding composition (P).

14. A method for improving the weather resistance of a high-gloss surface molded article (T), wherein, before any artificial weathering, the gloss of at least a part of the surface of the molded article exceeds 75 gloss units, and the gloss is measured at a measurement angle of 60° according to DIN EN ISO 2813. The method includes the step of mixing components (A) to (D) according to claim 1 or 2, and the high-gloss surface molded article (T) made of the molding composition (P) has the following properties: The color shift of the high-gloss surface molded article (T) produced from the molding composition (P) after 3200 hours of artificial weathering according to PV3929 is less than 25% of the color shift of the high-gloss surface component produced from the comparative molding composition (P'), and both are molded and evaluated under the same conditions. wherein, The comparative molding composition (P') is obtained by compounding components (A) to (D) contained in the molding composition (P) according to claim 1 or 2, and the content of the polymeric alkyl methacrylate component (A-3) in the comparative molding composition (P') is less than 20% by weight.

15. A high-gloss surface molded article (T) prepared from the thermoplastic molding composition (P) according to claim 1 or 11, and comprising a high-gloss surface area with a gloss higher than 75 gloss units, wherein the gloss is measured at a measurement angle of 60° according to DIN EN ISO 2813.

16. A use of a molded article (T) having a high-gloss surface with a gloss higher than 75 gloss units, prepared from the thermoplastic molding composition (P) according to claim 1 or 2, in the field of unpainted exterior components, wherein the gloss is determined at a measurement angle of 60° according to DIN EN ISO 2813.

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