ASA copolymer compositions with improved surface gloss
Patent Information
- Application Number
- DE202025100365
- Authority / Receiving Office
- DE · DE
- Patent Type
- Utility models
- Current Assignee / Owner
- Filing Date
- 2025-01-24
- Publication Date
- 2025-03-20
- Estimated Expiration
- 2035-01-31
Abstract
Description
[0001] The present invention relates to thermoplastic compositions containing acrylonitrile-styrene-acrylate graft copolymers and random copolymers of alkyl (meth)acrylate and vinyl aromatic monomers which have improved surface gloss.
[0002] Impact-modified thermoplastic compounds such as acrylonitrile styrene acrylate (ASA) and their blends with other thermoplastic polymers are used in many areas, including the automotive industry, the electronics industry, and household goods. The popularity of these thermoplastic polymer compounds can be attributed to their balanced properties such as good impact strength, melt flow, and high weather resistance.
[0003] WO 2021 / 074154 discloses molding compounds with high-gloss surfaces and improved weathering resistance compared to ASA polymers containing an acrylate-based graft copolymer as impact modifier, a polymer matrix based on a vinyl aromatic copolymer and a homopolymer of alkyl methacrylate or a copolymer of alkyl methacrylate with a vinyl aromatic monomer or vinyl cyanide.
[0004] US 2020 / 216656 and US 3,922,321 disclose impact-modified thermoplastic compositions, wherein the impact modifier contains acrylate monomers both in the graft shell of the impact modifier and in the polymer matrix.
[0005] WO 03 / 074608 discloses rubber-modified styrene compositions containing a matrix of a mixture of polymethyl methacrylate and a terpolymer of methyl methacrylate, styrene, and acrylonitrile. US 2021 / 0108070 discloses a thermoplastic resin composition comprising a matrix copolymer containing an alkyl (meth)acrylate, an aromatic vinyl-based monomer, and a vinyl cyano-based monomer, and an additive containing a polymer of an alkyl (meth)acrylate-based monomer unit.
[0006] Typical impact-modified thermoplastic ASA compositions (containing acrylate-based graft copolymers as impact modifiers and styrene-acrylonitrile copolymers as the polymer matrix) and articles made from them are generally opaque and typically have insufficient light transmission properties for applications requiring light transmission, such as backlit automotive parts. In particular, typical impact-modified thermoplastic compositions consisting of ASA graft copolymers as the impact modifier and styrene-acrylonitrile copolymers (SAN) as the polymer matrix are generally opaque.
[0007] WO 2023 / 041510 discloses an impact-modified thermoplastic composition with increased light transmittance, containing 25 to 45 wt.% of at least one acrylate-based graft copolymer and 25 to 75 wt.% of at least one random copolymer of alkyl (meth)acrylate and vinyl aromatic monomers. However, many applications require impact-modified thermoplastic compositions that combine the advantages of ASA graft copolymers with improved surface gloss.
[0008] Therefore, there is a need for impact-modified thermoplastic compositions that are better suited for applications requiring surface gloss while still retaining the advantageous properties of impact-modified ASA-based thermoplastic compositions.
[0009] An object of the invention is therefore to provide an impact-modified thermoplastic composition with improved surface gloss.
[0010] It has surprisingly been found that impact-modified thermoplastic compositions based on ASA graft copolymer and a matrix material containing at least one alkyl (meth)acrylate polymer have an improved surface gloss and are therefore more suitable for applications requiring a surface gloss if the ASA graft copolymer has at least a bimodal particle size distribution and the ASA graft copolymer with the higher average particle size is present in a larger weight ratio than the ASA graft copolymer with the lower average particle size.
[0011] One aspect of the invention is therefore a thermoplastic composition (P) comprising: a) 20 to 45% by weight, preferably 25 to 42% by weight, based on the total weight of the thermoplastic composition (P), of at least one graft copolymer (A) comprising (or consisting of): a1) a graft base (A1) containing at least one alkyl (meth)acrylate-based rubber, preferably a butyl acrylate-based rubber; and a2) a graft shell (A2) comprising at least one type of vinylaromatic repeating units, preferably styrene repeating units, and optionally at least one type of vinyl cyanide repeating units, preferably acrylonitrile repeating units, wherein the at least one graft copolymer (A) comprises: (Aa) at least one graft copolymer (Aa) having a volume-average particle size (D 50 ), measured by laser diffraction, from 30 to 340 nm, preferably from 50 to 320 nm, more preferably from 70 to 300 nm, more preferably from 80 to 250 nm, and (Ab) at least one graft copolymer (Ab) having a volume-average particle size (D 50 ), measured by laser diffraction, from 350 to 1000 nm, preferably from 380 to 800 nm, more preferably from 400 to 600 nm, more preferably from 450 to 550 nm, and wherein the weight ratio of the at least one graft copolymer (Aa) to the at least one graft copolymer (Ab) (weight ratio (Aa):(Ab)) is from 1:1 to 1:12, preferably from 1:1 to 1:10, particularly preferably from 1:1 to 1:7, in particular from 1:1 to 1:5; b) 20 to 75% by weight, preferably 21 to 70% by weight, based on the total weight of the thermoplastic composition (P), of at least one random copolymer (B) different from (A), comprising: b1) 10 to 55 wt.%, based on the total weight of the copolymer (B), of at least one type of alkyl (meth)acrylate repeating units (B1), preferably methyl methacrylate repeating units; and b2) 45 to 90% by weight, based on the total weight of the copolymer (B), of at least one type of vinylaromatic repeating units (B2), preferably styrene repeating units; and c) 0 to 60% by weight, preferably 0 to 50% by weight, based on the total weight of the thermoplastic composition (P), of at least one copolymer (C) different from (A) and (B), comprising: c1) 15 to 45% by weight, based on the total weight of the copolymer (C), of at least one type of vinyl cyanide repeating units (C1), preferably acrylonitrile repeating units; and c2) 55 to 85 wt.%, based on the total weight of the copolymer (C), of at least one type of vinylaromatic repeating units (C2), preferably of styrene repeating units.
[0012] Particle size measurements using laser diffraction are well known in the art and are described, for example, in “A Guidebook to Particle Size Analysis,” published by HORIBA Instruments, Inc., and in other literature. The volume-average particle size D used here is 50 is the mean particle size of the volume, ie 50% of the volume of all particles have a size equal to or smaller than the D 50 -value. The terms “volume-average particle size”, “D 50 “ and “volume average particle size” are used interchangeably in the present invention.
[0013] Preferably, the amount of acrylonitrile repeating units in the random copolymer (B) is less than 5 wt.%, based on the total weight of the copolymer (B).
[0014] It has been shown that the presence of homopolymers of methyl methacrylate, particularly poly(methyl methacrylate) (PMMA), can lead to a deterioration in impact strength. Therefore, the thermoplastic composition (P) does not contain homopolymers of methyl methacrylate.
[0015] In its natural state, the thermoplastic composition (P) does not contain pigments, dyes, light stabilizers, or UV absorbers. However, especially for outdoor applications, such as automotive parts, it is often important to increase the weather resistance of the thermoplastic composition (P). Therefore, in addition to the components (A), (B), and (C) described above, the thermoplastic composition may optionally contain: d) 0 to 4 wt.%, preferably 0.01 to 3.5 wt.%, particularly preferably 0.02 to 3 wt.%, based on the total weight of the thermoplastic composition (P), of at least one additive (D) selected from UV absorbers, light stabilizers and antioxidants.
[0016] In addition, articles made of thermoplastic compositions, including impact-modified compositions, are often colored, e.g., for aesthetic reasons, with dark colors being particularly popular in many applications, e.g., in the automotive industry, the electronics industry, or household goods.
[0017] EP-A 1685192 discloses a polymer composition used for laser marking based on a rubber latex, a black pigment, and a dye. US 2005 / 0014863 and US 7,077,898 disclose pigment-containing polymer compositions containing carbon black and another pigment.
[0018] WO 2015 / 036526 and US 2016 / 222185 (INEOS Styrolution) disclose deep-black, high-gloss thermoplastic molding compounds. These compositions are based on styrene copolymers, polymethyl methacrylate, polycarbonates, or polyester carbonates combined with carbon black and at least one dye soluble in the molding compounds. However, these compositions are not impact-modified.
[0019] The thermoplastic composition (P) can also be used in colored applications where impact-modified compositions are required. Therefore, in addition to the components (A), (B), (C), and optionally (D) described above, the thermoplastic composition may optionally contain: e) 0 to 5 wt.%, preferably 0.01 to 4 wt.%, more preferably 0.02 to 3 wt.%, more preferably 0.05 to 2 wt.%, based on the total weight of the thermoplastic composition (P), of at least one dye (E) selected from pigments and dyes.
[0020] In some embodiments, the thermoplastic composition (P) may optionally contain further components, e.g., further polymeric components or further additives.
[0021] Preferably, apart from the at least one graft copolymer (A), no further graft copolymers are present in the thermoplastic composition (P). Likewise preferably, with the exception of the at least one random copolymer (B), no further random copolymers containing alkyl (meth)acrylate repeat units and vinylaromatic repeat units are present in the thermoplastic composition (P). Likewise preferably, with the exception of the at least one copolymer (C), no further copolymers comprising vinyl cyanide repeat units and vinylaromatic repeat units are present in the thermoplastic composition (P).
[0022] Preferably, all three of these preferred conditions apply. More preferably, with the exception of the graft copolymer (A), the random copolymer (B), the copolymer (C), if present, the additive (D), if present and polymeric, and the dye (E), if present and polymeric, no other polymeric components are present in the thermoplastic composition (P). More preferably, the amounts of components (A), (B), (C), (D), (E), and optionally the lubricants amount to 100% by weight of the thermoplastic composition (P).
[0023] Those skilled in the art will understand that a particular repeating unit is the one obtainable by polymerizing the corresponding monomer. For example, vinyl aromatic repeating units are obtainable by polymerizing vinyl aromatic monomers, alkyl (meth)acrylate repeating units are obtainable by polymerizing alkyl (meth)acrylate monomers, and repeating units (B1), (B2), (C1), and (C2) are obtainable by polymerizing monomers (B1), (B2), (C1), and (C2), respectively. Furthermore, in certain cases, the terms "repeating unit" and "monomer" are used interchangeably.
[0024] The skilled person will understand that polymerization of certain repeating units means that the corresponding monomers are polymerized to form these repeating units, and that a polymer or copolymer containing certain monomers does not contain the monomers themselves (i.e., the unsaturated compounds), but the repeating units that can be obtained by polymerization of the corresponding monomers.
[0025] The term (meth)acrylate is to be understood as “acrylate and / or methacrylate”.
[0026] The individual components of the thermoplastic composition (P) according to the invention are described in more detail below. Graft copolymer (A)
[0027] The thermoplastic composition (P) contains 20 to 45 wt. %, preferably 25 to 42 wt. %, more preferably 30 to 40 wt. %, more preferably 33 to 38 wt. %, based on the total weight of the thermoplastic composition (P), of at least one graft copolymer (A). The at least one graft copolymer (A) has a multimodal particle size distribution, i.e., the particle size distribution has at least two local maxima.
[0028] According to the invention, the at least one graft copolymer (A) further comprises at least one graft copolymer (Aa) having a volume-average particle size (D 50), measured by laser diffraction, from 30 to 340 nm, preferably from 50 to 320 nm, more preferably from 70 to 300 nm, more preferably from 80 to 250 nm. The amount of the at least one graft copolymer (Aa) can be in the range from 1 to 35 wt.%, preferably 2 to 30 wt.%, particularly preferably 3 to 25 wt.%, based on the total weight of the thermoplastic composition (P).
[0029] According to the invention, the at least one graft copolymer (A) further comprises at least one graft copolymer (Ab) having a volume-average particle size (D 50), measured by laser diffraction, from 350 to 1000 nm, preferably from 380 to 800 nm, more preferably from 400 to 600 nm, more preferably from 450 to 550 nm. Preferably, the at least one graft copolymer (A) comprises at least 10 wt. %, preferably at least 12 wt. %, more preferably at least 13 wt. %, more preferably at least 14 wt. %, based on the total weight of the thermoplastic composition (P), of at least one graft copolymer (Ab) having a volume-average particle size (D 50 ), measured by laser diffraction, from 350 to 1000 nm, preferably from 380 to 800 nm, more preferably from 400 to 600 nm, more preferably from 450 to 550 nm.
[0030] According to one embodiment, the at least one graft copolymer (A) comprises at most 35% by weight, preferably at most 34% by weight, based on the total weight of the thermoplastic composition (P), of at least one graft copolymer (Ab) having a volume-average particle size (D 50 ), measured by laser diffraction, from 350 to 1000 nm, preferably from 380 to 800 nm, more preferably from 400 to 600 nm, more preferably from 450 to 550 nm.
[0031] Accordingly, the at least one graft copolymer (A) contains at least two graft copolymers (Aa) and (Ab), wherein at least one graft copolymer (Aa) has a D 50 from 30 to 340 nm, preferably from 50 to 320 nm, more preferably from 70 to 300 nm, more preferably from 80 to 250 nm, and at least one graft copolymer (Ab) has a D 50from 350 to 1000 nm, preferably from 380 to 800 nm, more preferably from 400 to 600 nm, more preferably from 450 to 550 nm. According to one embodiment of the invention, the volume-average particle size (D 50 ) of the at least one graft copolymer (Aa) and the volume-average particle size (D 50 ) of the at least one graft copolymer (Ab) by at least 100 nm, preferably by at least 150 nm, particularly preferably by at least 180 nm from each other
[0032] According to one embodiment, the thermoplastic composition (P) comprises 10 to 35 wt. %, more preferably 12 to 35 wt. %, more preferably 13 to 34 wt. %, more preferably 14 to 34 wt. %, based on the total weight of the thermoplastic composition (P), of at least one graft copolymer (Ab) having a volume-average particle size (D 50), measured by laser diffraction, from 350 to 1000 nm, more preferably 380 to 800 nm, preferably 400 to 600 nm, more preferably 450 to 550 nm, and 1 to 35 wt.%, preferably 2 to 30 wt.%, more preferably 3 to 25 wt.%, based on the total weight of the thermoplastic composition (P), of at least one graft copolymer (Aa) having a volume-average particle size (D 50 ) from 30 to 340 nm, preferably 50 to 320 nm, preferably 70 to 300 nm, more preferably 80 to 250 nm.
[0033] The weight ratio of the at least one graft copolymer (Aa) to the at least one graft copolymer (Ab), ie the weight ratio (Aa):(Ab) is 1:1 to 1:12, preferably 1:1 to 1:10, more preferably 1:1 to 1:7, in particular 1:1 to 1:5. It has been shown that the weight ratio (Aa):(Ab) of 1:1 to 1:7, in particular 1:1 to 1:5, leads to particularly good results with regard to impact strength and surface gloss of the thermoplastic composition (P).
[0034] In general, the graft copolymer (A) consists of a graft base (A1) comprising at least one alkyl (meth)acrylate-based rubber and a graft shell (A2) comprising at least one type of vinyl aromatic repeating units and optionally at least one type of vinyl cyanide repeating units.
[0035] Preferably, the at least one graft copolymer (A) (ie at least the graft copolymers (Aa) and (Ab)) consists of: a1) 40 to 90% by weight, more preferably 45 to 85% by weight, more preferably 50 to 80% by weight, based on the total weight of the graft copolymer (A), of a graft base (A1) comprising (or consisting of) at least one alkyl (meth)acrylate-based rubber; and a2) 10 to 60 wt.%, more preferably 15 to 55 wt.%, more preferably 20 to 50 wt.%, based on the total weight of the graft copolymer (A), of a graft shell (A2) comprising (or consisting of) at least one type of vinyl aromatic repeat units and optionally at least one type of vinyl cyanide repeat units.
[0036] In the graft base (A1), the at least one alkyl (meth)acrylate-based rubber is preferably a C1-C8 alkyl (meth)acrylate-based rubber, more preferably a C1-C8 alkyl acrylate-based rubber, more preferably a butyl acrylate-based rubber, in particular an n-butyl acrylate-based rubber.
[0037] The graft base (A1) may, for example, comprise (preferably consist of): a1-1) 65 to 99.99 wt.%, preferably 65 to 99.9 wt.%, more preferably 70 to 99.5 wt.%, more preferably 75 to 99 wt.%, more preferably 80 to 98 wt.%, based on the total weight of the graft base (A1), of at least one type of alkyl (meth)acrylate (A1-1), such as C1-C8 alkyl (meth)acrylate, preferably C1-C8 alkyl acrylate, more preferably butyl acrylate, in particular n-butyl acrylate; a1-2) 0 to 34.99 wt.%, preferably 0 to 29.9 wt.%, more preferably 0 to 29.5 wt.%, more preferably 0.5 to 24 wt.%, particularly preferably 1 to 18 wt.%, based on the total weight of the graft base (A1), of at least one type of monofunctional monomer (A1-2) which is copolymerizable with the at least one alkyl (meth)acrylate (A1-1), such as styrene, alpha-methylstyrene, acrylonitrile, methacrylonitrile, methyl methacrylate, maleic anhydride and N-phenylmaleimide, preferably styrene, α-methylstyrene or acrylonitrile, particularly preferably styrene; a1-3) 0.01 to 10 wt.%, preferably 0.1 to 9 wt.%, particularly preferably 0.5 to 7 wt.%, more preferably 1 to 6 wt.%, more preferably 2 to 5 wt.%, based on the total weight of the graft base (A1), of at least one type of bi- or polyfunctional crosslinking monomer (A1-3) which is copolymerizable with the at least one alkyl (meth)acrylate (A1-1), such as butadiene, isoprene, allyl (meth)acrylate, divinylbenzene, diallyl maleate, diallyl fumarate, diallyl phthalate, triallyl cyanurate, triallyl isocyanurate and dihydrodicyclopentadienyl acrylate (DCPA), preferably allyl (meth)acrylate, divinylbenzene, triallyl cyanurate, triallyl isocyanurate or DCPA, more preferably allyl (meth)acrylate or DCPA, more preferably DCPA.
[0038] In a preferred embodiment, the graft base (A1) comprises (or consists of) a1-1) 70 to 99.9 wt.% of at least one type of alkyl (meth)acrylate (A1-1), preferably butyl acrylate; a1-2) 0 to 29.5 wt. %, based on the total weight of the graft base (A1), of at least one type of monofunctional monomer (A1-2) which is copolymerizable with the at least one alkyl (meth)acrylate (A1-1), preferably styrene, alpha-methylstyrene and / or acrylonitrile; and a1-3) 0.1 to 10 wt.%, based on the total weight of the graft base (A1), of at least one type of bi- or polyfunctional crosslinking monomer (A1-3) which is copolymerizable with the at least one alkyl (meth)acrylate (A1-1).
[0039] In a further preferred embodiment, the graft base (A1) comprises (or consists of) 75 to 99 wt. %, based on the total weight of the graft base (A1), of butyl acrylate, in particular n-butyl acrylate; a1-2) 0 to 24.5 wt. %, based on the total weight of the graft base (A1), of styrene; and a1-3) 1 to 7 wt. %, based on the total weight of the graft base (A1), of DCPA.
[0040] The graft shell (A2) contains at least one type of vinylaromatic repeating units and optionally at least one type of vinyl cyanide repeating units. For certain purposes, the graft shell (A2) may also contain further monomers copolymerizable with the vinylaromatic repeating units, but preferably it contains no further monomers apart from the vinylaromatic repeating units and the vinyl cyanide repeating units. The vinylaromatic repeating units are preferably selected from styrene, alpha-methylstyrene, 2-methylstyrene, 3-methylstyrene, 4-methylstyrene, 2,4-dimethylstyrene, 2,5-dimethylstyrene, 2,6-dimethylstyrene, and 2,4,6-trimethylstyrene, more preferably styrene or alpha-methylstyrene repeating units, more preferably styrene repeating units. In preferred embodiments, at least 50 wt.%, preferably at least 70 wt.%, more preferably at least 90 wt.-% of the vinylaromatic repeat units in the graft shell (A2) are styrene. Particular preference is given to all vinylaromatic repeat units in the graft shell (A2) being styrene.
[0041] The vinyl cyanide repeating units in the graft shell (A2), if present, are preferably selected from methacrylonitrile and acrylonitrile repeating units, particularly preferably acrylonitrile repeating units.
[0042] In some embodiments, the graft shell (A2) contains only vinylaromatic repeat units, preferably styrene or alpha-methylstyrene repeat units, especially styrene repeat units. In some embodiments, the graft shell (A2) contains both vinylaromatic repeat units, especially styrene repeat units, and vinyl cyanide repeat units, especially acrylonitrile repeat units.
[0043] For example, the graft shell (A2) may comprise (or consist of) 50 to 100 wt.%, preferably 52 to 95 wt.%, particularly preferably 55 to 85 wt.%, particularly preferably 65 to 75 wt.%, based on the total weight of the graft shell (A2), of styrene or alpha-methylstyrene repeating units and 0 to 50 wt.%, preferably 5 to 48 wt.%, more preferably 15 to 45 wt.%, more preferably 25 to 35 wt.%, based on the total weight of the graft shell (A2), of acrylonitrile repeating units.
[0044] In addition, the graft shell (A2) may contain 0 to 20 wt.%, based on the total weight of the graft shell (A2), of further components selected from repeating units of monoethylenically unsaturated monomers such as maleic anhydride or N-phenylmaleimide and molecular weight regulators, e.g. thiol-based molecular weight regulators such as tert-dodecyl mercaptan.
[0045] The graft copolymer (A) can be prepared by any process known in the art. Preferably, the graft copolymer (A) is prepared by an emulsion polymerization process or a suspension polymerization process. The graft base (A1), comprising (or consisting of) repeating units (A1-1) and optionally (A1-2) and (A1-3), and its preparation are known and described in the literature, e.g., in DE-A 28 26 925, DE-A 31 49 358, and DE-A 34 14 118.
[0046] The graft polymerization reaction for synthesizing the graft shell (A2) can conveniently be carried out in the same vessel as the polymerization (preferably emulsion polymerization) for synthesizing the graft base (A1). Alternatively, the graft polymerization can also be carried out in a different vessel. Additives such as emulsifiers, pH buffers, and initiators can be added during the reaction. The monomers of the graft shell (A2), in particular the vinyl aromatic monomers and, if present, vinyl cyanide monomers, can be added to the reaction mixture all at once, continuously, or stepwise in several stages, preferably continuously during the polymerization. If the vinyl aromatic monomers and, if present, the vinyl cyanide monomers are added in several steps, a multilayer graft shell (A2) is typically obtained.
[0047] Suitable emulsifiers, buffers and initiators are described, for example, in WO 2015 / 150223 and WO 2015 / 078751.
[0048] In some preferred embodiments, the graft copolymer (A) is an acrylonitrile-styrene-acrylate (ASA) graft copolymer. In some preferred embodiments, the graft copolymer (A) is a styrene-acrylate graft copolymer.
[0049] The preparation of the graft copolymer (A) as used in the invention can be carried out, for example, as follows: To produce a first graft base (A1-a), a first basic rubber latex (L-A1-a) can be obtained by (co-)polymerization of the at least one alkyl (meth)acrylate monomer and one or more crosslinking agents (e.g. tricyclodecenyl acrylate) in an aqueous solution, which may contain further components such as one or more salts (e.g. C 12 - to C 18-paraffinsulfonic acid and / or sodium bicarbonate). The reaction temperature can, for example, be in the range from 55 to 70°C. In a preferred embodiment, a mass ratio of butyl acrylate:tricyclodecenyl acrylate in the range from 10:1 to 100:1, preferably from 40:1 to 80:1, is used for the polymerization. The mass ratios and definitions of the components are preferably as described here.
[0050] To produce a first graft copolymer (Aa), a first graft copolymer latex (LAa) can be obtained by (co-)polymerizing a basic rubber latex (e.g. a first basic rubber latex (L-A1-a) obtainable as described above) with styrene and optionally acrylonitrile to form a first graft shell (A2-a) in an aqueous solution which may contain further components such as one or more salts (e.g. sodium persulfate).
[0051] The reaction temperature can be in the range of 50 to 80 °C. Optionally, the resulting graft copolymer (Aa) can be coagulated from the latex (LAa). The coagulation can be carried out in a salt solution (e.g., a magnesium sulfate solution) at a temperature in the range of 50 to 80 °C. After coagulation, sintering can optionally be carried out (e.g., at a temperature in the range of 80 to 150 °C). The mass ratios and definitions of the components are preferably as described here. More specific examples can also be found in the following experimental section.
[0052] To prepare a second graft base (A1-b), a second basic rubber latex (L-A1-b) can be obtained by (co-)polymerization of butyl acrylate and one or more crosslinking agents (e.g., tricyclodecenyl acrylate) in the presence of a first basic rubber latex, as described above as (L-A1-a), in an aqueous solution containing further components such as one or more salts (e.g., sodium bicarbonate, sodium persulfate and / or C 12 - to C 18 -paraffinsulfonic acid). The reaction temperature can, for example, be in the range of 55 to 70 °C.
[0053] In a preferred embodiment, a mass ratio of butyl acrylate to tricyclodecenyl acrylate in the range of 10:1 to 100:1, preferably 40:1 to 80:1, is used for polymerization. The mass ratios and definitions of the components are preferably as described herein. More specific examples can also be found in the experimental section below.
[0054] To produce a second graft copolymer (Ab), a second graft rubber latex (LAb) can be obtained by (co)polymerizing a basic rubber latex (e.g., a second basic rubber latex (L-A1-b), obtainable as described above) with styrene and optionally acrylonitrile to form a graft shell (A2-b) in an aqueous solution, which may contain further constituents such as one or more salts (e.g., sodium persulfate). The reaction temperature can be in the range from 50 to 80°C. Optionally, the resulting graft copolymer (Ab) can be coagulated from the latex (LAb). Coagulation can take place in a salt solution (e.g., a magnesium sulfate solution) at a temperature in the range from 70 to 99°C. After coagulation, sintering can optionally take place (e.g., at a temperature in the range from 80 to 150°C). The mass ratios and definitions of the components are preferably as described here.More specific examples can also be found in the following experimental section. Statistical copolymer (B)
[0055] The thermoplastic composition (P) comprises 20 to 75 wt.%, preferably 21 to 70 wt.%, more preferably 22 to 65 wt.%, based on the total weight of the thermoplastic composition (P), of at least one random copolymer (B) comprising (or consisting of) at least one type of alkyl (meth)acrylate repeating units (B1) and at least one type of vinyl aromatic repeating units (B2).
[0056] For the purposes of the present invention, a random copolymer is a polymer comprising at least two different types of repeating units, with essentially all repeating units being arranged randomly. A random copolymer within the meaning of the present invention is not a graft copolymer or a block copolymer.
[0057] In general, the at least one type of alkyl (meth)acrylate repeating units (B1) is present in an amount of 10 to 55 wt.%, and the at least one type of vinyl aromatic repeating units (B2) is generally present in an amount of 45 to 90 wt.%, based on the total weight of the at least one random copolymer (B).
[0058] In the random copolymer (B), the at least one alkyl (meth)acrylate repeating units (B1) are preferably C1-C8 alkyl (meth)acrylate repeating units, more preferably C1-C8 alkyl methacrylate repeating units, more preferably C1-C4 alkyl methacrylate repeating units, in particular methyl methacrylate repeating units.
[0059] In preferred embodiments, at least 50 wt.%, preferably at least 70 wt.%, particularly preferably at least 90 wt.% of the alkyl (meth)acrylate repeat units (B1) are methyl methacrylate repeat units. Particularly preferably, all alkyl (meth)acrylate repeat units (B1) are methyl methacrylate repeat units.
[0060] The vinylaromatic repeat units (B2) are preferably selected from styrene, alpha-methylstyrene, 2-methylstyrene, 3-methylstyrene, 4-methylstyrene, 2,4-dimethylstyrene, 2,5-dimethylstyrene, 2,6-dimethylstyrene, and 2,4,6-trimethylstyrene, more preferably styrene or alpha-methylstyrene, more preferably styrene repeat units. In preferred embodiments, at least 50% by weight, preferably at least 70% by weight, more preferably at least 90% by weight of the vinylaromatic repeat units (B2) are styrene repeat units. Particular preference is given to all vinylaromatic repeat units (B2) being styrene repeat units.
[0061] Preferably, the amount of acrylonitrile repeat units in the random copolymer (B) is less than 5 wt.%, based on the total weight of the copolymer (B). This is typically the case when no such repeat units can be detected by NMR spectroscopy. Preferably, the amount of acrylonitrile repeat units is less than 2 wt.%.
[0062] It is more preferred that the random copolymer (B) does not contain any acrylonitrile repeating units. It is more preferred that the random copolymer (B) does not contain any cyanide group-containing monomers.
[0063] Optionally, the random copolymer (B) according to the present invention may also contain one or more crosslinking units, such as divinylbenzene or vinyl acrylate units, in its polymer chain. Preferably, such crosslinking agents make up no more than 25% by weight, more preferably no more than 10% by weight, frequently no more than 5% by weight, based on the total weight of the random copolymer (B). It is particularly preferred that the random copolymer (B) contains no crosslinking moieties. It is more preferred that the random copolymer (B) contains no repeating units other than the alkyl (meth)acrylate repeating units (B1) and the vinyl aromatic repeating units (B2). Furthermore, the random copolymer (B) is preferably not grafted onto or otherwise bonded to rubber polymers.
[0064] The random copolymer (B) according to the present invention may have a linear, cyclic, or branched structure. A cyclic structure is a copolymer chain in which both ends are connected to each other. The term "branched structure" can be broadly understood as any structure other than a simple linear or cyclic structure. Accordingly, in a polymer having a branched structure, there is at least one repeating unit connected to three or more other repeating units. Preferably, the random copolymer (B) used in the present invention is a substantially linear or cyclic copolymer, more preferably a substantially linear copolymer, especially a linear random copolymer.
[0065] Preferably, the melt flow index (MFI) (determined at a temperature of 200°C and a load of 5 kg according to ASTM D1238) of the random copolymer (B) according to the invention is less than 50 g / 10 min, more preferably less than 20 g / 10 min, more preferably less than 10 g / 10 min, often less than 5 g / 10 min. Preferably, ASTM D1238 in the 2013 version is used.
[0066] In general, the random copolymer (B) used in the present invention can be obtained by any suitable process known in the art. Numerous methods suitable for preparing such a random copolymer (B) are known to those skilled in the art. Known conventional polymerization processes can be used to prepare such a random copolymer (B). The random copolymer (B) is obtained, for example, in a known manner by bulk, solution, suspension, precipitation, or emulsion polymerization. Details of these processes can be found, for example, in Kunststoffhandbuch, ed. R. Vieweg and G. Daumiller, Vol. V "Polystyrol", Carl-Hanser-Verlag Munich, 1969, p. 118 ff.
[0067] The random copolymer (B) can be prepared, for example, by emulsion polymerization, solution polymerization, or bulk polymerization. Preferably, thermal or radical initiation (including living polymerization methods) can be used.
[0068] Alkyl (meth)acrylate monomers (B1) suitable for the preparation of a random copolymer (B) as well as numerous vinyl aromatic monomers (B2) are commercially available. Others can be easily obtained by standard chemical methods.
[0069] The copolymerization to produce the random copolymer (B) can optionally be carried out in the presence of, for example, one or more solvents and / or one or more initiators (e.g. one or more radical initiators).
[0070] The initiation of the copolymerization can be achieved, for example, by thermal decomposition of an initiator (e.g., an organic peroxide (e.g., dicumyl peroxide) or an azo compound), by photolysis (e.g., with metal iodides, metal alkyls or azo compounds (e.g., azoisobutylnitrile (AIBN)), a peroxide initiator (e.g., benzoyl peroxide), an initiator composition that enables a redox reaction (e.g., reduction of hydrogen peroxide or an alkyl hydrogen peroxide by means of iron ions or other reducing agents such as Cr 2+ , V 2+ , Ti 3+ , Co 2+ or Cu + ), persulfate activation, ionizing radiation (e.g. by means of α-, β-, γ- or X-rays), electrochemical activation, plasma activation, sonication (e.g. at about 16 kHz) or a ternary initiator (e.g. benzoyl peroxide-3,6-bis(o-carboxybenzoyl)-N-isopropylcarbazole-di-η 5-indenylzirconium dichloride, optionally in combination with a metallocene (e.g. indenylzirconium) and / or a peroxide (e.g. benzoyl peroxide).
[0071] In a preferred embodiment, the copolymerization comprises heating the reaction mixture comprising the alkyl (meth)acrylate monomers (B1) and the vinyl aromatic monomers (B2) to a temperature above 100 °C and / or adding one or more polymerization initiators to the reaction mixture.
[0072] The reaction mixture can be brought to conditions that allow chain extension of the polymer, or these conditions can be maintained. The temperature is adjusted, for example, according to the monomer / copolymer content of the reaction mixture. For example, the temperature can also be varied during the incubation, e.g., by continuously or gradually increasing it during the polymerization process.
[0073] Processes for preparing a random copolymer (B) as used in the present invention can be carried out as described in GB 464688, GB 531956, GB 863279 and WO 2003 / 051973.
[0074] For many applications, particularly low turbidity values are important to obtain highly transparent products. High turbidity values can occur, for example, if the concentration of at least one type of alkyl (meth)acrylate monomer (B1) is not constant during the copolymerization process.
[0075] For example, in a polymerization reactor, to switch from a product with a specific molar proportion of alkyl (meth)acrylate repeating units to another product with a different specific molar proportion of alkyl (meth)acrylate repeating units, the molar ratios of the at least one alkyl (meth)acrylate monomer (B1) and the at least one type of vinyl aromatic monomer (B2) in the reaction mixture must be changed. Initially, however, the alkyl (meth)acrylate monomers (B1) and the vinyl aromatic monomers (B2) are unevenly distributed in the reaction mixture, resulting in a random copolymer with a non-uniform chemical composition with respect to the molar ratio of the monomers (B1) and (B2).
[0076] The random copolymers (B) resulting from this transition phase of the polymerization process typically exhibit higher turbidity values, often exceeding 1.5%, and do not meet the product specifications for highly transparent random copolymers (B) required for many applications. After a steady state with a uniform distribution of monomers (B1) and (B2) in the reaction vessel is reached, a highly transparent random copolymer (B) is again obtained, typically exhibiting a turbidity value of less than or equal to 1.5%.
[0077] Accordingly, for many applications, polymer compositions (P) in which the random copolymer (B) has a low haze, e.g., less than or equal to 1.5%, are preferred. In other applications, low haze values are not important, and random copolymers (B) having a haze of more than 1.5% can be used. However, it has been shown that the technical effects of the present invention, in particular with regard to surface gloss, are achieved both for polymer compositions (P) in which the random copolymer (B) has a haze of less than or equal to 1.5% and for polymer compositions (P) in which the random copolymer (B) has a haze of more than 1.5%.
[0078] Unless otherwise stated, haze is the initial haze determined according to ASTM D1003 on 1 / 8-inch injection-molded sheets
[0079] According to one embodiment, the at least one random copolymer (B) can be selected from at least one random copolymer (Ba) having a turbidity of less than or equal to 1.5%, at least one random copolymer (Bb) having a turbidity of more than 1.5%, and mixtures of the random copolymers (Ba) and (Bb).
[0080] According to the invention, the random copolymer (Ba) is a random copolymer (B) as described herein, which has a turbidity of less than or equal to 1.5% and which is preferably obtained directly from the polymerization of a reaction mixture comprising at least one type of alkyl (meth)acrylate monomers (B1) and at least one type of vinyl aromatic monomers (B2), in particular in proportions suitable for complying with the specified turbidity value.
[0081] In some embodiments, the at least one random copolymer (Ba) comprises the at least one type of alkyl (meth)acrylate repeating units (B1) in an amount of 10 to 55 wt. %, preferably 12 to 52 wt. %, more preferably 15 to 48 wt. %, more preferably 18 to 46 wt. %, based on the total weight of the at least one random copolymer (Ba), and the at least one type of vinyl aromatic repeating units (B2) generally in an amount of 45 to 90 wt. %, preferably 48 to 88 wt. %, more preferably 52 to 85 wt. %, more preferably 54 to 82 wt. %, based on the total weight of the at least one random copolymer (Ba).
[0082] According to the invention, the random copolymer (Bb) is a random copolymer (B) as described herein, which has a turbidity of more than 1.5% and which can be obtained directly from the polymerization of a reaction mixture comprising at least one type of alkyl (meth)acrylate monomer (B1) and at least one type of vinyl aromatic monomer (B2), in particular in ratios suitable for maintaining the specified turbidity value. However, the random copolymer (Bb) can also arise during the production of the random copolymer (Ba) as an off-specification by-product, i.e., as post-industrial waste material, in particular as post-industrial waste material with a turbidity of more than 1.5%.
[0083] The random copolymer (Bb) is therefore preferably a post-industrial waste material. In some embodiments, the at least one random copolymer (Bb) comprises the at least one type of alkyl (meth)acrylate repeating units (B1) in an amount of 10 to 55 wt. %, preferably 12 to 52 wt. %, more preferably 15 to 48 wt. %, more preferably 18 to 46 wt. %, based on the total weight of the at least one random copolymer (Bb), and the at least one type of vinylaromatic repeating units (B2) generally in an amount of 45 to 90 wt. %, preferably 48 to 88 wt. %, more preferably 52 to 85 wt. %, more preferably 54 to 82 wt. %, based on the total weight of the at least one random copolymer (Bb).
[0084] According to one embodiment, the random copolymer (Bb) is preferably a post-industrial recycled random copolymer (Bb). According to the invention, the term "post-industrial recycled random copolymer (Bb)" refers to a random copolymer (Bb) obtained from the recycling of post-industrial waste. The term "post-industrial waste" refers to polymer waste originating from industrial processes.
[0085] The "post-industrial waste" comprises or consists, in particular, of at least one random copolymer (B) that does not meet the specifications of the random copolymer (Ba), particularly with regard to the homogeneous chemical composition and turbidity of the random copolymer (Bb). Often, the at least one type of alkyl (meth)acrylate repeating units (B1) in the random copolymer (Bb) is present in amounts that are too small or inhomogeneous to meet the specifications of the random copolymer (Ba).
[0086] According to one embodiment, the at least one random copolymer (B) comprises at least one random copolymer (Ba) having a turbidity value of less than or equal to 1.5%, which comprises the at least one type of alkyl (meth)acrylate repeating units (B1) in an amount of 10 to 55% by weight, preferably 12 to 52% by weight, more preferably 15 to 48% by weight, more preferably 18 to 46% by weight, based on the total weight of the at least one random copolymer (Ba), and the at least one type of vinyl aromatic repeating units (B2) generally in an amount of 45 to 90% by weight, preferably 48 to 88% by weight, preferably 52 to 85% by weight, particularly preferably 54 to 82% by weight, based on the total weight of the at least one random copolymer (Ba).
[0087] According to one embodiment, the at least one random copolymer (B) comprises at least one random copolymer (Bb) having a turbidity value of more than 1.5%, which comprises the at least one type of alkyl (meth)acrylate repeating units (B1) in an amount of 10 to 55 wt.%, preferably 12 to 52 wt.%, more preferably 15 to 48 wt.%, more preferably 18 to 46 wt.%, based on the total weight of the at least one random copolymer (Bb), and the at least one type of vinyl aromatic repeating units (B2) generally in an amount of 45 to 90 wt.%, preferably 48 to 88 wt.%, more preferably 52 to 85 wt.%, more preferably 54 to 82 wt.%, based on the total weight of the at least one random copolymer (Bb).
[0088] According to one embodiment, the at least one random copolymer (B) comprises a mixture of at least one random copolymer (Ba) and at least one copolymer (Bb) as defined herein.
[0089] In one embodiment, the random copolymer (Ba) comprises or consists of 10 to 55 wt. %, preferably 12 to 52 wt. %, more preferably 15 to 48 wt. %, more preferably 18 to 46 wt. %, based on the total weight of the at least one random copolymer (Ba), of methyl methacrylate and 45 to 90 wt. %, preferably 48 to 88 wt. %, more preferably 52 to 85 wt. %, more preferably 54 to 82 wt. %, based on the total weight of the at least one random copolymer (Ba), of styrene. Accordingly, preferred random copolymers (Ba) can be referred to as styrene-methyl methacrylate copolymers or SMMA copolymers.
[0090] The random copolymer (Bb) preferably comprises (or consists of) 10 to 55 wt. %, preferably 12 to 52 wt. %, particularly preferably 15 to 48 wt. %, particularly preferably 18 to 46 wt. %, based on the total weight of the at least one random copolymer (Bb), of at least one type of alkyl (meth)acrylate repeating units (B1), in particular methyl methacrylate, and 45 to 90 wt. %, preferably 48 to 88 wt. %, more preferably 52 to 85 wt. %, more preferably 54 to 82 wt. %, based on the total weight of the at least one random copolymer (Bb), of at least one type of vinyl aromatic repeating units (B2), in particular styrene. Accordingly, preferred random copolymers (Bb) can be referred to as styrene-methyl methacrylate copolymers or SMMA copolymers.
[0091] According to a preferred embodiment of the invention, the random copolymer (B) comprises or consists of at least one recycled random copolymer (Bb), preferably a recycled post-industrial random copolymer (Bb). The recycled random copolymer (Bb) can be obtained as a non-conforming (off-spec) by-product, i.e., as post-industrial waste material, during the production of the random copolymer (Ba). The random copolymer (Bb) is therefore preferably a recycled post-industrial waste material.
[0092] According to one embodiment, the thermoplastic composition (P) contains 20 to 75 wt.%, more preferably 20 to 50 wt.%, more preferably 20 to 40 wt.%, based on the total weight of the thermoplastic composition (P), of at least one post-industrial, recycled random copolymer (Bb).
[0093] Due to the nature and origin of the post-industrial recycled random copolymer (Bb), the composition of the post-industrial recycled random copolymer (Bb) is less fixed. Typically, the at least one type of alkyl (meth)acrylate repeating units (B1) are present in an amount of 10 to 55 wt. %, preferably 12 to 52 wt. %, more preferably 15 to 48 wt. %, more preferably 18 to 46 wt. %, based on the total weight of the at least one random copolymer (Bb), and the at least one type of vinyl aromatic repeating units (B2) are generally present in an amount of 45 to 90 wt. %, preferably 48 to 88 wt. %, more preferably 52 to 85 wt. %, more preferably 54 to 82 wt. %, based on the total weight of the at least one post-industrial recycled random copolymer (Bb).
[0094] According to one embodiment of the invention, the thermoplastic composition (P) contains 20 to 50 wt.%, preferably 20 to 30 wt.%, based on the total weight of the thermoplastic composition (P), of at least one random copolymer (Bb) from post-industrial recyclates. Optional copolymer (C)
[0095] According to an embodiment of the invention, in which the proportion of the thermoplastic composition (P) optionally comprises (or consists of) 0 to 60 wt.%, preferably 0 to 50 wt.%, more preferably 0 to 40 wt.%, more preferably 0 to 38 wt.%, based on the total weight of the thermoplastic composition (P), of at least one copolymer (C) comprising at least one type of vinyl cyanide repeating units (C1) and at least one type of vinyl aromatic repeating units (C2).
[0096] In general, the at least one type of vinyl cyanide repeating units (C1) is present in an amount of 15 to 45 wt.%, preferably 20 to 40 wt.%, particularly preferably 27 to 38 wt.%, based on the total weight of the copolymer (C), and the at least one type of vinyl aromatic repeating units (C2) is present in an amount of 55 to 85 wt.%, preferably 60 to 80 wt.%, particularly preferably 62 to 73 wt.%, based on the total weight of the copolymer (C).
[0097] Optionally, the copolymer (C) may contain further repeating units (C3) of monomers copolymerizable with the vinyl cyanide monomers (C1) and the vinyl aromatic monomers (C2), in amounts of up to 30 wt. %, preferably up to 20 wt. %, particularly preferably up to 10 wt. %, based on the total weight of the copolymer (C). If the further repeating units (C3) are present, their amount is preferably at least 1 wt. %, preferably at least 3 wt. %, more preferably at least 5 wt. %, based on the total weight of the copolymer (C). However, preferably no further repeating units (C3) are present in the copolymer (C).
[0098] The vinyl cyanide repeat units (C1) are preferably selected from methacrylonitrile and acrylonitrile, particularly preferably from acrylonitrile units. In preferred embodiments, at least 50 wt.%, preferably at least 70 wt.%, more preferably at least 90 wt.% of the vinyl cyanide repeat units (C1) are acrylonitrile repeat units. Particularly preferably, all vinyl cyanide repeat units (C1) are acrylonitrile repeat units.
[0099] The vinylaromatic repeat units (C2) are preferably selected from styrene, alpha-methylstyrene, 2-methylstyrene, 3-methylstyrene, 4-methylstyrene, 2,4-dimethylstyrene, 2,5-dimethylstyrene, 2,6-dimethylstyrene, and 2,4,6-trimethylstyrene, more preferably styrene or alpha-methylstyrene, more preferably styrene units. In preferred embodiments, at least 50% by weight, preferably at least 70% by weight, more preferably at least 90% by weight of the vinylaromatic repeat units (C2) are styrene repeat units. Particularly preferably, all vinylaromatic repeat units (C2) are styrene repeat units.
[0100] The further repeating units (C3), if present, can be obtained from any monomer copolymerizable with the vinyl cyanide monomers (C1) and the vinyl aromatic monomers (C2). The further repeating units (C3) can be selected, for example, from alkyl (meth)acrylate units and (meth)acrylic acid units or their salts, preferably from C1-C8 alkyl (meth)acrylate units, more preferably from C1-C8 methacrylate units, more preferably from methyl methacrylate units. Preferably, however, no further repeating units (C3) are present.
[0101] The copolymer (C) may be a random copolymer or a block copolymer, but is preferably a random copolymer. The copolymer (C) comprising or consisting of acrylonitrile and styrene repeating units may also be referred to as poly(styrene-acrylonitrile) (SAN). The copolymer (C) comprising or consisting of acrylonitrile and α-methylstyrene may also be referred to as poly(α-methylstyrene / acrylonitrile) (AMSAN).
[0102] For the purposes of the present invention, a block copolymer is a polymer comprising at least two different types of repeating units, wherein the repeating units are arranged in blocks, each block consisting essentially of the same type of repeating units and two adjacent blocks consisting of different types of repeating units. A block copolymer within the meaning of the present invention is neither a graft copolymer nor a random copolymer.
[0103] The weight-average molecular weight (determined by gel permeation chromatography relative to polystyrene as standard) of the copolymer (C) can be, for example, in the range from 15,000 to 200,000 g / mol, preferably in the range from 30,000 to 150,000 g / mol.
[0104] Among the above-mentioned copolymers (C), those with a viscosity number VN (determined according to DIN 53726 at 25°C, 0.5 wt.% in dimethylformamide) of 50 to 120 ml / g are preferred.
[0105] Unless otherwise defined, all measurement standards used here, such as DIN standards and ASTM standards, preferably refer to the version current in August 2021.
[0106] The copolymers (C), in particular SAN or AMSAN copolymers, are known, and the processes for their preparation, e.g. by radical polymerization, in particular by emulsion, suspension, solution and bulk polymerization, are also well documented in the literature. Optional additives (D)
[0107] The thermoplastic composition (P) optionally contains up to 4 wt.%, preferably 0.01 to 3.5 wt.%, more preferably 0.02 to 3 wt.%, based on the total weight of the thermoplastic composition (P), of at least one additive (D) selected from UV absorbers, light stabilizers and antioxidants.
[0108] The optional additives (D) can be provided as such or as a mixture with other components, e.g., as one or more masterbatches. Preferably, the optional additives (D) are provided as masterbatches of the respective additive (D) in a carrier, e.g., a polymeric carrier. More preferably, the optional additives (D) are provided as a masterbatch of the respective additive (D) in one or more of the polymeric components (A), (B), or, if present, (C). When the optional additives (D) are provided as a masterbatch, the amounts of additives stated here, based on the total weight of the thermoplastic composition (P), refer to the amounts of the respective additives as such. Accordingly, the amount of polymeric carrier in the masterbatch corresponds to the amount of the respective polymeric component (A), (B), or, if present, (C), or is considered as a further component.
[0109] When the optional additives (D) are provided as masterbatches, the concentration of an additive (D) in the respective masterbatch is preferably in a range from 1 to 90 wt.%, preferably from 10 to 80 wt.%, preferably from 20 to 60 wt.%, preferably from 30 to 50 wt.%, based on the total weight of the masterbatch.
[0110] The total amount of UV absorbers and light stabilizers, if present in the at least one additive (D), is preferably 0.1 to 2.7 wt.%, more preferably 0.2 to 2.5 wt.%, more preferably 0.3 to 2.3 wt.%, based on the total weight of the thermoplastic composition (P).
[0111] UV absorbers, if present in the at least one additive (D), are preferably organic UV absorbers, preferably from the group consisting of substituted benzotriazoles, substituted benzophenones, substituted triazines, oxalanilides, substituted resorcinols, salicylates and cyanoacrylates, particularly preferably from the group of 2-(2-hydroxyphenyl)-benzotriazoles, 2-hydroxybenzophenones, hydroxyphenyl-s-triazines and oxalanilides, in particular benzotriazoles.
[0112] Light stabilizers, if present in the at least one additive (D), are preferably hindered amine light stabilizers (HALS), preferably derivatives of 2,2,6,6-tetramethylpiperidine, more preferably derivatives of 2,2,6,6-tetramethyl-4-piperidyl-substituted organic compounds.
[0113] Suitable hindered amine light stabilizers are, for example, bis(2,2,6,6-tetramethylpiperidin-4-yl) sebacate (Tinuvin® 770 from BASF SE); bis(1,2,2,6,6-pentamethyl-4-piperidyl) sebacate (Tinuvin® 765 from BASF SE); N,N'-bisformyl-N,N'-bis-(2,2,6,6-tetramethyl-4-piperidinyl)-hexamethylenediamine (Uvinul® 4050 H from BASF SE); N,N'-bis(2,2,6,6-tetramethyl-4-piperidyl)isophthalamide (Nylostab® S-EED® from Clariant); 2,2,6,6-tetramethyl-4-piperidinyl stearate (Cyasorb® UV-3853 from Solvay); and sterically hindered amine with CAS registry number 71878-19-8 (Chimassorb® 944 from BASF SE).
[0114] If present, the hindered amine light stabilizer is preferably a derivative of bis(2,2,6,6-tetramethyl-4-piperidyl)dicarboxylic acid diesters, in particular bis(2,2,6,6-tetramethyl-4-piperidyl) sebacate.
[0115] For some applications where weathering stability is of little importance, the thermoplastic composition (P) does not contain UV absorbers or light stabilizers.
[0116] Antioxidants, if present in the at least one additive (D), are preferably compounds selected from monophosphite-based antioxidants, diphosphite-based antioxidants, and sterically hindered phenolic antioxidants. If one or more antioxidants are present, they are preferably selected from monophosphite-based antioxidants, such as trisubstituted monophosphite derivatives, diphosphite-based antioxidants, such as substituted pentaerythritol diphosphite derivatives, and sterically hindered phenolic antioxidants, such as 2,6-di-tert-butylphenol derivatives. Preferably, the antioxidants are one or more compounds selected from tri-phenyl-substituted monophosphite derivatives, di-phenyl-substituted pentaerythritol diphosphite derivatives and mono-substituted 2,6-di-tert-butylphenol derivatives.Preferably, the antioxidants are one or more of tris(2,4-di-tert-butylphenyl)phosphite, bis(2,4-di-tert-butylphenyl)pentaerythritol diphosphite and octa-decyl-3-[3,5-di-tert-butyl-4-hydroxyphenyl]propionate.
[0117] In some embodiments, the thermoplastic composition (P) does not contain antioxidants.
[0118] In some embodiments, the thermoplastic composition (P) contains a combination of UV absorbers, light stabilizers, and antioxidants, as described above as additives (D), in the amounts specified above. In other embodiments, the thermoplastic composition (P) contains no UV absorbers, light stabilizers, or antioxidants. In yet other embodiments, only antioxidants are present in the thermoplastic composition (P) as additives (D) in the amounts specified above. Optional dyes (E)
[0119] In embodiments in which the thermoplastic composition (P) must be colored, it is necessary that the thermoplastic composition contains pigments and / or dyes as colorants (E).
[0120] Therefore, the thermoplastic composition (P) optionally contains up to 5 wt.%, preferably 0.01 to 4 wt.%, more preferably 0.02 to 3 wt.%, more preferably 0.05 to 2 wt.%, based on the total weight of the thermoplastic composition (P), of at least one dye (E) selected from pigments and dyes.
[0121] The optional dyes (E) can be provided as such or as a mixture with other components, e.g., as one or more masterbatches. Preferably, the optional dyes (E) are provided as masterbatches of the respective dye (E) in a carrier, e.g., a polymeric carrier.
[0122] Preferably, the optional dyes (E) are provided as a masterbatch of the respective dye (E) in one or more of the polymeric components (A), (B) or, if present, (C). When the optional colorants (E) are provided as a masterbatch, the amounts of colorants stated here, based on the total weight of the thermoplastic composition (P), refer to the amounts of the respective colorants as such. Accordingly, the amount of polymeric carrier in the masterbatch corresponds to the amount of the respective polymeric component (A), (B) or, if present, (C) or is considered as a further component.
[0123] When the optional dyes (E) are provided as masterbatches, the concentration of a dye (E) in the respective masterbatch is preferably in a range from 1 to 90 wt.%, preferably from 10 to 80 wt.%, more preferably from 20 to 60 wt.%, more preferably from 30 to 50 wt.%, based on the total weight of the masterbatch.
[0124] In some applications, thermoplastic compositions must be colored and partially translucent at the same time, meaning that these colored thermoplastic compositions transmit visible light of certain wavelengths while absorbing light of others. This is the case, for example, with automotive parts exposed to backlighting.
[0125] For these applications, the total amount of colorants (E) is typically less than 2 wt.%, based on the total weight of the thermoplastic composition (P), and the colorants (E) do not contain carbon black. Preferably, the total amount of colorants (E) in this case is 0.01 to 1.5 wt.%, preferably 0.02 to 1 wt.%, more preferably 0.05 to 0.5 wt.%, based on the total weight of the thermoplastic composition (P). Furthermore, in this case, the thermoplastic composition preferably contains a single dye (E), particularly preferably a single dye.
[0126] For other applications, thermoplastic compositions and articles made from them are colored, e.g., for aesthetic reasons. Dark colors are particularly popular in many applications, such as the automotive industry, the electronics industry, or household goods. In such applications, the thermoplastic compositions are generally opaque.
[0127] The pigments present in the at least one dye (E) can be any pigments suitable for coloring thermoplastic compositions (P). The pigments can be, for example, organic or inorganic. Preferred pigments are phthalocyanines, ultramarine blue, iron oxides, and carbon black, but also the entire class of organic pigments. Carbon black is a preferred pigment when dark (e.g., deep black) compositions are required. Suitable carbon black can, for example, have a volume-average primary particle size D 50(measured by laser diffraction) of 5 to 100 nm, preferably 7 to 60 nm. In addition, suitable carbon black may have a carbon content of more than 95% and a specific surface area of more than 100 m 2 / g. Two examples of typical commercially available products are Black Pearls 880 (Cabot Corporation) or Printex 90 (Orion Engineered Carbons GmbH).
[0128] The dyes present in the at least one colorant (E) can be any dyes suitable for coloring thermoplastic compositions. The dyes soluble in the thermoplastic composition (P) can be selected, for example, from red dyes, green dyes, blue dyes, yellow dyes, magenta dyes, blue-green dyes, or any other color of dyes. Suitable dyes include, but are not limited to, Solvent Green, e.g., Solvent Green 3, Solvent Red, e.g., Solvent Red 179, and Solvent Yellow, e.g., Solvent Yellow 93. In dark thermoplastic compositions (P), when dyes are present, a combination of at least two dyes from different, in particular complementary, color families is preferably used as the colorant (E).
[0129] If a combination of at least two dyes is used, a dye that is soluble in the thermoplastic composition (P) can be a dye or a combination of dyes of any color (e.g., green). The additional dye should come from a different color family, in particular be a complementary color (e.g., reddish hues as a complementary color to green). Frequently, three different dye components are used. In one embodiment, the dyes consist of the commercial product Solvent Green 3. In one embodiment, the dyes consist of Solvent Red 179. The commercial product Solvent Yellow 93 can also be used (see 4-[(1,5-Dihydro-3-methyl-5-oxo-1-phenyl-4H-pyrazol-4-ylidene)methyl]-2,4-dihydro-5-methyl-2-phenyl-3H-pyrazol-3-one).
[0130] The amount of dyes, if present, is preferably 0.1 to 2 wt%, more preferably 0.2 to 1.5 wt%, more preferably 0.5 to 1 wt%, based on the total weight of the thermoplastic composition (P).
[0131] In some embodiments, the thermoplastic composition (P) contains no dyes. In some other embodiments, the thermoplastic composition (P) contains no UV absorbers or light stabilizers as additives (D) and no dyes (E). In other embodiments, the thermoplastic composition (P) contains no additives (D) and no dyes (E). In yet other embodiments, the thermoplastic composition (P) consists of components (A), (B), and (C). Other optional components
[0132] The thermoplastic composition (P) may optionally contain further components that differ from the at least one graft copolymer (A), the at least one random copolymer (B), the at least one copolymer (C), and the at least one additive (D). The further components can be selected, for example, from further polymeric components and / or further additives.
[0133] If further polymeric components are present in the thermoplastic composition (P), they preferably comprise no further graft copolymers besides the at least one graft copolymer (A), no random copolymers of alkyl (meth)acrylate monomers and vinyl aromatic monomers besides the at least one random copolymer (B), and no copolymers of vinyl cyanide monomers and vinyl aromatic monomers besides the copolymer (C). If further additives are present in the thermoplastic composition (P), they are not selected from UV absorbers, light stabilizers, antioxidants, pigments, or dyes.
[0134] Examples of further polymeric components are polyesters, polyethers, polycarbonates, polyamides, styrene homopolymers, and phenol-formaldehyde resins. The thermoplastic composition (P) preferably contains no further polymeric components. The further polymeric constituents also include polyester-modified polysiloxanes, in particular polyester-polysiloxane block copolymers, preferably [polyester-b-polysiloxane-b-polyester] triblock copolymers. Preferred examples of the polysiloxane moieties contained in the polyester-polysiloxane block copolymer are derived from poly(dimethylsiloxane), poly(diethylsiloxane), poly(dipropylsiloxane), poly(dibutylsiloxane), and mixtures thereof.
[0135] Examples of other additives include antistatic agents, flame retardants, stabilizers to improve thermal stability, stabilizers to increase hydrolysis and chemical resistance, agents to prevent thermal decomposition and, in particular, lubricants useful in the production of molded articles / plastics.
[0136] Examples of suitable antistatic agents are amine derivatives such as N,N-bis(hydroxyalkyl)alkylamines or -alkylenamines, polyethylene glycol esters, copolymers of ethylene oxide glycol and propylene oxide glycol (in particular two- or three-block copolymers of ethylene oxide blocks and propylene oxide blocks) as well as glycerol mono- and distearates and mixtures thereof.
[0137] Examples of suitable flame retardants that can be used are the halogen- or phosphorus-containing compounds known to those skilled in the art, magnesium hydroxide, but also other common compounds or mixtures thereof.
[0138] In addition to inorganic substances such as talc, glass beads or metal carbonates (e.g. MgCO3, CaCO3), polymer particles, especially spherical particles with diameters D 50 larger 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.
[0139] Examples of suitable anti-drip agents are polymers of polytetrafluoroethylene (Teflon) and polystyrene with ultra-high molecular weight (weight average molecular weight Mw over 2,000,000 g / mol).
[0140] Examples of fibrous / powdered fillers include carbon or glass fibers in the form of glass fabrics, glass mats, or glass fiber rovings, chopped glass, glass beads, and wollastonite, with glass fibers being particularly preferred. If glass fibers are used, they can be sized and bonded to improve compatibility with the blend components. The incorporated glass fibers can be in the form of short glass fibers or continuous filaments (rovings).
[0141] Suitable particulate fillers include carbon black, amorphous silica, magnesium carbonate, quartz flour, mica, bentonite, talc, feldspar or, in particular, calcium silicates such as wollastonite and kaolin.
[0142] Other suitable compounds include thiocarboxylic acid esters. Also suitable are C6-C 20 -Alkyl esters of thiopropionic acid, especially the stearyl esters and lauryl esters.
[0143] It is also possible to use the dilauryl ester of thiodipropionic acid (dilauryl thiodipropionate), the distearyl ester of thiodipropionic acid (distearyl thiodipropionate) or mixtures thereof.
[0144] Suitable lubricants and mold-release agents are stearic acids, stearyl alcohol, stearic acid esters, polyolefin waxes, and / or generally higher fatty acids, derivatives thereof, and corresponding fatty acid mixtures having 1 to 45 carbon atoms. In a further preferred embodiment, the composition comprises amide compounds having the formula R 1 -CONH-R 2 , where R 1 and R 2are each independently selected from aliphatic, saturated or unsaturated hydrocarbon groups having 1 to 30 carbon atoms, preferably 12 to 24 carbon atoms, in particular 16 to 20 carbon atoms. In a further preferred embodiment of the invention, the composition may additionally contain fatty acid ester compounds having the formula R 3 -CO-OR 4 contain, where 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.
[0145] Other additives are organic, inorganic or mixed phosphates, in particular an alkali or alkaline earth phosphate such as Ca3(PO4)2 and / or an organophosphate with alkyl or aryl groups having 1 to 12 carbon atoms.
[0146] These additional components can be added at any stage of the manufacturing process, but preferably at an early stage in order to benefit from the effects of the respective additional component at an early stage.
[0147] The optional further components can be provided as such or as a mixture with other components, e.g., as one or more masterbatches. Preferably, the optional further components are provided as masterbatches in a carrier, e.g., a polymer carrier. Even better, the optional further components are included as a masterbatch in one or more of the polymeric components (A), (B), or, if present, (C). If the optional further components are provided as a masterbatch, the amounts of the further components, based on the total weight of the thermoplastic composition (P), refer to the amounts of the respective further components as such. Accordingly, the amount of polymeric carrier in the masterbatch corresponds to the amount of the respective polymeric component (A), (B), or, if present, (C), or is considered as a further component.
[0148] If the optional further components are provided as masterbatches, their concentration in the respective masterbatch is preferably in a range from 1 to 90 wt.%, preferably from 10 to 80 wt.%, preferably from 20 to 60 wt.%, preferably from 30 to 50 wt.%, based on the total weight of the masterbatch.
[0149] The thermoplastic composition (P) preferably contains at least one lubricant, preferably at least one wax, more preferably at least one wax selected from amide waxes, such as ethylenebis(stearamide). If lubricants are present in the thermoplastic composition (P), their amount is preferably in the range from 0.0001 to 1 wt.%, preferably from 0.0005 to 0.5 wt.%, more preferably from 0.001 to 0.1 wt.%, more preferably from 0.005 to 0.05 wt.%, more preferably from 0.008 to 0.03 wt.%, more preferably from 0.01 to 0.02 wt.%, based on the total weight of the thermoplastic composition (P).
[0150] In some preferred embodiments, the thermoplastic composition (P) comprises no further components with the exception of the at least one graft copolymer (A), the at least one random copolymer (B), optionally the at least one copolymer (C), optionally the at least one additive (D) and optionally the at least one dye (E).
[0151] In other preferred embodiments, the thermoplastic composition (P) comprises no further components with the exception of the at least one graft copolymer (A), the at least one random copolymer (B), optionally the at least one copolymer (C), optionally the at least one additive (D), optionally the at least one dye (E) and optionally at least one lubricant, preferably ethylenebis(stearamide).
[0152] The thermoplastic composition (P) described above can be prepared by a process comprising the following steps: i) Provision of at least the following components: a) 20 to 45% by weight, preferably 25 to 42% by weight, based on the total weight of the components provided, of at least one graft copolymer (A) comprising (or consisting of): a1) a graft base (A1) containing at least one alkyl (meth)acrylate-based rubber, preferably a butyl acrylate-based rubber; and a2) a graft shell (A2) comprising at least one type of vinylaromatic repeating units, preferably styrene repeating units, and optionally at least one type of vinyl cyanide repeating units, preferably acrylonitrile repeating units, wherein the at least one graft copolymer (A) comprises: (Aa) at least one graft copolymer (Aa) having a volume-average particle size (D 50 ), measured by laser diffraction, from 30 to 340 nm, preferably from 50 to 320 nm, more preferably from 70 to 300 nm, more preferably from 80 to 250 nm, and (Ab) at least one graft copolymer (Ab) having a volume-average particle size (D 50 ), measured by laser diffraction, from 350 to 1000 nm, preferably from 380 to 800 nm, more preferably from 400 to 600 nm, more preferably from 450 to 550 nm, and wherein the weight ratio of the at least one graft copolymer (Aa) to the at least one graft copolymer (Ab) (weight ratio (Aa):(Ab)) is from 1:1 to 1:12, preferably from 1:1 to 1:10, more preferably from 1:1 to 1:7, in particular from 1:1 to 1:5; b) 20 to 75% by weight, preferably 21 to 70% by weight, based on the total weight of the components provided, of at least one random copolymer (B) different from (A), comprising: b1) 10 to 55 wt.%, based on the total weight of the copolymer (B), of at least one type of alkyl (meth)acrylate repeating units (B1), preferably methyl methacrylate repeating units; and b2) 45 to 90 wt.%, based on the total weight of the copolymer (B), of at least one type of vinylaromatic repeating units (B2), preferably styrene repeating units; c) 0 to 60% by weight, preferably 0 to 50% by weight, based on the total weight of the components provided, of at least one copolymer (C) different from (A) and (B), comprising: c1) 15 to 45% by weight, based on the total weight of the copolymer (C), of at least one type of vinyl cyanide repeating units (C1), preferably acrylonitrile repeating units; and c2) 55 to 85 wt.%, based on the total weight of the copolymer (C), of at least one type of vinylaromatic repeating units (C2), preferably styrene repeating units; d) 0 to 4% by weight, preferably 0.01 to 3.5% by weight, particularly preferably 0.02 to 3% by weight, based on the total weight of the components provided, of at least one additive (D) selected from UV absorbers, light stabilizers and antioxidants; and e) 0 to 5 wt.%, preferably 0.01 to 4 wt.%, more preferably 0.02 to 3 wt.%, more preferably 0.05 to 2 wt.%, based on the total weight of the components provided, of at least one dye (E) selected from pigments and dyes; ii) mixing the components provided in step i) to form a thermoplastic composition (P), provided that no homopolymers of methyl methacrylate are used in the process.
[0153] The components provided in step i) are preferably defined as the components of the thermoplastic composition described above. Preferably, only the at least one graft copolymer (A), the at least one random copolymer (B), the at least one copolymer (C), if present, the at least one additive (D), if present and polymeric, and the at least one colorant (E), if present and polymeric, are provided in step i) as polymeric components. Preferably, only the at least one graft copolymer (A), the at least one random copolymer (B), optionally the at least one copolymer (C), optionally the at least one additive (D), and optionally the at least one colorant (E) are provided in step i).
[0154] Each of the components (A) to (E) - as far as it is solid - can be provided in the form of particulate materials with different particle sizes and particle size distributions (e.g. as pellets, granules and / or powder).
[0155] The particulate materials (A) to (E) can be fed to a mixing device in the required amounts and ratios as previously indicated and, if appropriate, mixed prior to mixing step (ii) to obtain a homogeneous particulate material mixture. In a preferred embodiment, this may take 1 to 60, preferably 1 to 20, especially 2 to 10 minutes, depending on the amount of particulate material to be mixed.
[0156] In step ii), the homogeneous particle mixture thus obtained is then transferred into an optionally heatable mixing device and mixed therein, whereby a substantially molten polymer mixture is formed.
[0157] “Essentially molten” means that the polymer mixture, in addition to the predominantly molten (softened) fraction, may also contain a certain proportion of solid components, for example unmelted fillers and reinforcing material such as glass fibers, metal flakes or unmelted pigments, dyes, etc. “Melted” means that the polymer mixture has at least a low flowability, i.e. is softened at least to the extent that it has plastic properties.
[0158] Mixing devices known to those skilled in the art are used. Components (A) and (B) and, if present, (C), (D) and / or (E) can be mixed, for example, by jointly extruding, kneading, or rolling the aforementioned components.
[0159] Examples of mixing equipment for carrying out the process are discontinuously operating, heated internal kneaders with or without RAM, continuously operating kneaders, such as continuous internal kneaders, screw kneaders with axially oscillating screws, Banbury kneaders, extruders, but also rolling mills, mixing rolling mills with heated rollers and calenders.
[0160] Optionally, the process may comprise a further step (iii) of cooling the mixture obtained in step (ii) to temperatures below the glass transition point of components (A) to (E) to obtain the molding composition (P).
[0161] An extruder or kneader is preferably used as the mixing device. Single-screw or twin-screw extruders, for example, are particularly suitable for melt extrusion. A twin-screw extruder is preferred. In some cases, the mechanical energy applied by the mixing device during mixing is sufficient to melt the mixture, so the mixing device does not need to be heated. Otherwise, the mixing device is generally heated.
[0162] The temperature depends on the chemical and physical properties of components (A), (B), (C), (D), and (E) and should be selected so that a substantially molten polymer mixture is formed. On the other hand, the temperature should not be unnecessarily high to avoid thermal damage to the polymer mixture. However, the mechanical energy introduced can also be so high that the mixing device even requires cooling. The mixing apparatus is preferably operated at 150 to 400°C, more preferably at 170 to 300°C.
[0163] In a preferred embodiment, a heatable twin-screw extruder is used, and a speed of 50 to 150 rpm, preferably 60 to 100 rpm, is employed. In a preferred embodiment, an extrusion temperature of 170 to 270°C, preferably 210 to 250°C, is used to obtain the thermoplastic composition (P). The thermoplastic composition (P) can be used directly, e.g., in molding processes, preferably injection molding processes, or it can be processed into granules that can subsequently be subjected to molding processes. The molding processes are preferably carried out at temperatures of 170 to 270°C, in particular 210 to 250°C, to obtain a molded body.
[0164] The processing can be carried out by the known methods of thermoplastic processing, in particular the production can be carried out by thermoforming, extrusion, injection molding, calendering, blow molding, compression molding, press sintering, deep drawing or sintering, preferably by injection molding. Applications and properties
[0165] The present invention further relates to an article, in particular a molded article, containing the thermoplastic composition (P) described above. The molded article can be produced from the thermoplastic composition (P) in the presence or absence of other thermoplastic compositions.
[0166] Preferably, the molded article is produced in the absence of other thermoplastic compositions. Depending on the molded article and the desired properties, it may also contain additives that regulate the respective properties. Such additives are known in the art and may include all of the additives mentioned above.
[0167] The article, in particular the molded part, can be produced by all known thermoplastic processing methods. In particular, production can be carried out by thermoforming, extrusion, injection molding, calendering, blow molding, compression molding, press sintering, deep drawing, sintering, rotational molding, spraying, spinning, rolling, or weaving, preferably by extrusion or injection molding, particularly preferably by injection molding of the thermoplastic composition (P). In some embodiments, the articles can also be produced by coating finished products with the thermoplastic composition (P).
[0168] In particular, the thermoplastic composition (P) according to the invention can preferably be used for producing a translucent and / or colored molded article having a high surface gloss.
[0169] The invention therefore also relates to a translucent and / or colored molded article containing the thermoplastic composition (P) described above.
[0170] The thermoplastic composition (P) and the article, in particular the molded body, can advantageously be used as or for the production of components or articles for electronic devices, household goods, e.g., household appliances and electrical appliances, and automotive exterior and / or interior parts, in particular as or for the production of visible components or articles, such as trim strips and exterior panels, such as spoilers, window frames, cover strips, hoods, panels or parts of the radiator grille, antenna cover, side mirrors, or front or rear lights. A preferred application is the use as unpainted automotive exterior parts, such as front grilles or side mirrors.
[0171] The thermoplastic composition (P) according to the invention and the article obtained from the thermoplastic composition (P) according to the invention are characterized in that they exhibit improved surface gloss compared to thermoplastic compositions that have essentially the same composition but do not contain the ratio of graft copolymer (Aa) to graft copolymer (Ab) according to the invention. Preferably, the thermoplastic composition (P) simultaneously exhibits improved impact strength.
[0172] According to one embodiment, the thermoplastic composition (P) as well as the article obtained from the thermoplastic composition (P) has a surface gloss value, determined according to ASTM D523 at 20°, of more than 65, preferably more than 70, more preferably more than 75, often more than 80. Preferably, the surface gloss is determined on an injection-molded sample plate having a thickness of 3.175 mm (1 / 8 inch).
[0173] According to one embodiment, the thermoplastic composition (P) as well as the article obtained from the thermoplastic composition (P) has a surface gloss value, determined according to ASTM D523 at 60° of more than 75, preferably more than 80, more preferably more than 85, often more than 90. Preferably, the surface gloss is determined on an injection-molded sample plate having a thickness of 3.175 mm (1 / 8 inch).
[0174] According to one embodiment, the thermoplastic composition (P) and the article obtained from the thermoplastic composition (P) according to the invention have a Charpy notched impact strength, determined according to ISO 179 / 1eA, of more than 6 kJ / m 2 , preferably ≥ 6.2 kJ / m 2 , more preferably ≥ 6.5 kJ / m 2 , more preferably ≥ 6.8 kJ / m 2 . In some embodiments, the thermoplastic composition (P) and the article obtained from the thermoplastic composition (P) have a Charpy impact strength, determined according to ISO 179 / 1eA, of ≥ 7 kJ / m 2 .
[0175] The invention is explained in more detail by the claims and examples. ExamplesMaterialsGraft copolymer (Aa):
[0176] The graft copolymer (Aa) is a core-shell type impact modifier with a volume average particle size D 50, measured by laser diffraction with a Beckman Coulter LS 13 320 Laser Diffraction Particle Size Analyzer, of 100 nm, with a graft base based on poly(n-butyl acrylate) rubber and a graft shell based on poly(styrene-co-acrylonitrile), prepared according to the following procedure: A reaction vessel was filled with 90.2 parts by weight of demineralized water, 0.61 parts by weight of the sodium salt of a C 12 - to C 18 -paraffinsulfonic acid and 0.23 parts by weight of sodium bicarbonate. When the temperature in the reaction vessel reached 59°C, 0.16 parts by weight of sodium persulfate dissolved in 5 parts by weight of demineralized water was added. A mixture of 59.51 parts by weight of butyl acrylate and 1.21 parts by weight of tricyclodecenyl acrylate was added over a period of 210 minutes. The reaction was then continued for 60 minutes. The resulting latex (L-A1-a) had a total solids content of 39.6%.
[0177] A quantity of 151.9 parts by weight of the latex (L-A1-a) was added to a reaction vessel along with 92.2 parts by weight of demineralized water and 0.14 parts by weight of sodium persulfate dissolved in 3.22 parts by weight of demineralized water. A mixture of 31.18 parts by weight of styrene and 9.31 parts by weight of acrylonitrile was added at a temperature of 61°C over a period of 190 minutes, followed by a post-polymerization time of 60 minutes at 65°C. A polymer latex (LAa) with a total solids content of 35.5% was obtained.
[0178] After synthesis, the latex was coagulated with magnesium sulfate solution at a temperature of approximately 60 °C, followed by a sintering step at approximately 90 °C. The resulting slurry was centrifuged, yielding the graft copolymer (Aa) as a moist rubber powder. Graft copolymer (Ab):
[0179] The graft copolymer (Ab) is a core-shell type impact modifier with a volume average particle size D 50 , measured by laser diffraction using a Beckman Coulter LS 13 320 Laser Diffraction Particle Size Analyzer, of 500 nm with a poly(n-butyl acrylate) rubber-based graft base and a poly(styrene-co-acrylonitrile)-based graft shell, prepared according to the following procedure: A reaction vessel was filled with 70.66 parts by weight of demineralized water, 0.3 parts by weight of latex (L-A1-a), and 0.23 parts by weight of sodium bicarbonate. After heating the reaction vessel to 60°C, 0.16 parts by weight of sodium persulfate dissolved in 5 parts by weight of demineralized 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 over a period of 210 minutes.
[0180] Parallel to the first feed, a solution of 0.36 parts by weight of the sodium salt of a C12 to C18 paraffinsulfonic acid in 16.6 parts by weight of demineralized water was also added over a period of 210 minutes. After 200 minutes, starting with the feed, the temperature was increased to 65°C. The reaction was then continued at 65°C for 60 minutes. The resulting latex (L-A1-b) had a total solids content of 39.4%.
[0181] A quantity of 154 parts by weight of latex (L-A1-b) was added to a reaction vessel along with 88.29 parts by weight of demineralized water, 0.11 part by weight of the sodium salt of a C12 to C18 paraffinsulfonic acid, and 0.14 part by weight of sodium persulfate dissolved in 5.61 parts by weight of demineralized water. The reaction mixture was heated to 61°C. 13.16 parts by weight of styrene were added over a period of 60 minutes at a temperature of 61°C, followed by a post-polymerization period of 90 minutes during which the temperature was increased from 61°C to 65°C. A mixture of 20.5 parts by weight of styrene and 6.83 parts by weight of acrylonitrile was then added to the reaction over a period of 150 minutes. The reaction was continued at 65°C for another 60 minutes. A latex (LAb) with a total solids content of 35.2% was obtained. After synthesis, the latex was treated with magnesium sulfate solution at a temperature of approximately 10°C.88 °C, followed by a sintering step at approximately 130 °C. The resulting slurry was centrifuged, yielding the graft copolymer (Ab) as a moist rubber powder.
[0182] The preparation of the graft copolymers (Aa) and (Ab) was carried out, among other things, on a balance, where 1 part by weight corresponds to 10 g. Statistical copolymer (B):
[0183] The random copolymer (Ba) is the commercially available NAS® XC (INEOS Styrolution), a styrene-methyl methacrylate random copolymer with a methyl methacrylate content of 45 wt.% and a haze of less than 1.5%, determined according to ASTM D1003 on 1 / 8-inch injection-molded sheets.
[0184] The random copolymer (Bb) is a styrene-methyl methacrylate random copolymer recycled from post-industrial waste with a methyl methacrylate content in the range of 15 to 30 wt.% and a haze of more than 1.5%, determined according to ASTM D1003 on 1 / 8-inch injection-molded sheets. Copolymer (C)
[0185] The copolymer (C-1) is the commercially available Luran® VLR (INEOS Styrolution), a styrene-acrylonitrile copolymer with an acrylonitrile content of 33 wt.%, based on the total weight of the copolymer (C).
[0186] The copolymer (C-2) is the commercially available Luran® VLP (INEOS Styrolution), a styrene-acrylonitrile copolymer with an acrylonitrile content of 35 wt.%, based on the total weight of the copolymer (C). additives
[0187] Additive D-1 is ethylene bis(stearamide) wax.
[0188] Additive D-2 is a stabilizer blend of Tinuvin® 770 (BASF), Riasorb® UV-292 (Rianlon), Rianox® 1726 (Rianlon) and Irgafos® 168 (BASF).
[0189] Additive D-3 is a stabilizer blend of Tinuvin® 770 (BASF) and Cyasorb® UV-3853 (Syensqo).
[0190] Additive E is soot. Production of the thermoplastic composition (P) and the sample plates
[0191] Examples and comparative examples of thermoplastic compositions were prepared by compounding all the ingredients listed in the tables below in a twin-screw extruder (model ZSK26MC, Coperion GmbH, length: 1035 mm) at Tm=240°C according to the specific ratios given in the tables below. Sample plates (approximately 7.5 x 5 cm) with a thickness of 3.175 mm (1 / 8 inch) and other samples were produced by injection molding (Tm: 260°C).
[0192] The sample panels were tested for their surface gloss and impact resistance.
[0193] Surface gloss was determined according to ASTM D523 at angles of 20° and 60° on an injection-molded sample panel with a thickness of 3.175 mm (1 / 8 inch).
[0194] The Charpy notched impact strength was determined according to ISO 179 / 1eA.
[0195] The compositions of the tested thermoplastic compositions (examples and comparative examples) and the determined properties are listed in Tables 1 to 6. Table 1. Comparative examples CE1 to CE6 Examples Unit CE1 CE2 CE3 CE4 CE5 CE6 Aa % by weight 35 35 0 0 23,3 23,3 Away % by weight 0 0 35 35 11,7 11,7 Ba % by weight 65 39 65 39 65 39 C-1 % by weight 0 26 0 26 0 26 Ratio (Aa) / (Ab) -- - - - 2:1 2:1 Shine at 20° 21 57 61 58 42 66 Shine at 60° 50 89 86 86 85 88 Impact strength kJ / m 2 4,8 4,4 10,8 7,1 6,6 6,0
[0196] Comparative Examples CE1 and CE2 show that the thermoplastic compositions exhibit unsatisfactory surface gloss and impact strength in the absence of graft copolymer Ab. In the presence of graft copolymer Ab but without graft copolymer Aa, improved impact strength is observed, but the surface gloss value below 65 at 20°C is still unsatisfactory (cf. Comparative Examples CE3 and CE4). Slight improvements are observed for a thermoplastic composition containing graft copolymers Ab and Aa in combination with copolymer C-1 (cf. Comparative Examples CE5 and CE6). Table 2. Comparative examples CE7 to CE13. Examples Unit CE7 CE8 CE9 CE10 CE11 CE12 CE13 Aa % by weight 24,0 24,0 24,0 24,0 24,0 24,0 24,0 Away % by weight 10,0 10,0 10,0 10,0 10,0 10,0 10,0 Ba % by weight 38,2 33,2 28,2 0,0 0,0 0,0 0,0 Bb % by weight 25,0 30,0 35,0 59,0 25,0 30,0 35,0 C-1 % by weight 0,0 0,0 0,0 0,0 34,0 29,0 24,0 C-2 % by weight 0,0 0,0 0,0 4,2 4,2 4,2 4,2 E % by weight 1,8 1,8 1,8 1,8 1,8 1,8 1,8 D-1 % by weight 1,0 1,0 1,0 1,0 1,0 1,0 1,0 Ratio (Aa) / (Ab) 2,4:1 2,4:1 2,4:1 2,4:1 2,4:1 2,4:1 2,4:1 Shine at 20° 56 55 65 42 65 67 78 Shine at 60° 87 87 89 84 90 90 93 Impact strength kJ / m 2 5,2 5,2 5,6 5,0 6,0 4,2 6,0
[0197] The observations from Table 1 are confirmed by Comparative Examples CE7 to CE13 summarized in Table 2. In the absence of copolymer C, small amounts of graft copolymer Ab are insufficient to achieve good surface gloss and impact strength. When more than 10 wt.% of component C is used and the amount of random copolymer B is reduced, improved surface gloss and impact strength are observed, although these are still too low for many applications (cf. Comparative Examples CE11 to CE13). Table 3: Comparative examples CE14 to CE17. Examples Unit CE14 CE15 CE15 CE17 Aa % by weight 37.0 31.5 25.9 20.4 Away % by weight 0.0 5.6 11.1 16.7 Ba % by weight 63.0 63.0 63.0 63.0 Ratio (Aa) / (Ab) --- 5.7:1 2.3:1 1.2:1 Shine at 20° 21 27 22 37 Shine at 60° 52 68 63 74 Impact strength kJ / m 2 6.0 8.2 8.6 11.0
[0198] Comparative examples CE14 to CE17 show that increasing amounts of graft copolymer Aa lead to increased impact strength. However, if the ratio of Aa to Ab is too high (i.e., higher than 1:1), the surface gloss values remain at an unsatisfactory level. Table 4. Comparative examples CE18 to CE23 and examples E1 to E5. Examples Unit CE18 CE19 CE20 CE21 CE22 E1 Aa % by weight 34,0 31,0 28,5 25,4 22,0 18,0 Away % by weight 2,0 5,0 7,5 10,6 14,0 18,0 Bb % by weight 25,0 25,0 25,0 25,0 25,0 25,0 C-1 % by weight 32,8 32,8 32,8 32,8 32,8 32,8 C-2 % by weight 4,2 4,2 4,2 4,2 4,2 4,2 D-1 % by weight 0,3 0,3 0,3 0,3 0,3 0,3 E % by weight 1,8 1,8 1,8 1,8 1,8 1,8 Ratio (Aa) / (Ab) 17:1 6,2:1 3,8:1 2,4:1 1,6:1 1:1 Shine at 20° 66 76 80 80 85 87 Shine at 60° 89 92 93 93 95 95 Impact strength kJ / m 2 3,1 3,9 4,1 4,9 6,5 7,2 Table 4 (continued) Examples Unit E2 E3 E4 E5 CE23 Aa % by weight 14,0 10,0 6,0 3,0 0,0 Away % by weight 22,0 26,0 30,0 33,0 36,0 Bb % by weight 25,0 25,0 25,0 25,0 25,0 C-1 % by weight 32,8 32,8 32,8 32,8 32,8 C-2 % by weight 4,2 4,2 4,2 4,2 4,2 D-1 % by weight 0,3 0,3 0,3 0,3 0,3 E % by weight 1,8 1,8 1,8 1,8 1,8 Ratio (Aa) / (Ab) 1:1,6 1:2,6 1:5 1:11 - Shine at 20° 87 87 91 88 89 Shine at 60° 96 95 97 96 96 Impact strength kJ / m 2 8,4 8,1 7,4 6,5 4,2
[0199] A superior combination of surface gloss and impact strength is observed for thermoplastic compositions containing graft copolymers Ab and Aa, where the Aa:Ab weight ratio is in the range of 1:1 to 1:12 (cf. Table 4, Examples E1 to E5) and especially in the range of 1:1 to 1:5 (cf. Examples E1 to E4). Outside this range (i.e., below and above this range), the impact strength and surface gloss values are poorer. Table 5. Comparative examples CE24 to CE26 and examples E7 and E8. Examples Unit CE24 CE25 CE26 CE27 CE26 E7 E8 Aa % by weight 36,0 32,0 29,0 26,8 23,0 15,0 7,0 Away % by weight 2,0 6,0 9,0 11,2 15,0 23,0 31,0 Bb % by weight 25,0 25,0 25,0 25,0 25,0 25,0 25,0 C-1 % by weight 30,8 30,8 30,8 30,8 30,8 30,8 30,8 C-2 % by weight 4,2 4,2 4,2 4,2 4,2 4,2 4,2 D-1 % by weight 0,3 0,3 0,3 0,3 0,3 0,3 0,3 E % by weight 1,8 1,8 1,8 1,8 1,8 1,8 1,8 Ratio (Aa) / (Ab) 18:1 5,3:1 3,2:1 2,4:1 1,5:1 1:1,5 1:4,4 Shine at 20° 74 78 78 79 87 88 92 Gloss at 60° 91 92 92 93 95 95 97 Impact strength kJ / m 2 3,3 4,7 5,5 5,2 6,8 8,6 9,9
[0200] This trend is also confirmed with higher amounts of graft copolymers Ab and Aa (see Table 5, Examples E7 and E8) and in the presence of recycled random copolymers (Bb). Low amounts of graft copolymer Ab and high amounts of graft copolymer Aa lead to reduced impact strength and lower surface gloss (see Comparative Examples CE24 to CE27). In particular, the comparison of Comparative Example CE27 and Example E7 shows that changing the Aa:Ab ratio from 1.5:1 to 1:1.5 leads to a significant increase in impact strength. The use of 25 wt.% of the recycled random copolymer Bb also enables good overall properties with regard to impact strength and surface gloss. Table 6 Comparison examples CE27 to CE32 and examples E9 to E14. Examples Unit CE27 CE28 CE29 E9 E10 E11 Aa % by weight 27,4 25,4 26,8 14,0 10,0 6,0 Away % by weight 5,0 10,6 11,2 22,0 26,0 30,0 B- % by weight 62,8 59,2 57,2 59,2 59,2 59,2 C-1 % by weight 0,0 0,0 0,0 0,0 0,0 0,0 C-2 % by weight 0,0 0,0 0,0 0,0 0,0 0,0 D-1 % by weight 1,0 1,0 1,0 1,0 1,0 1,0 D-2 % by weight 1,2 1,2 1,2 1,2 1,2 1,2 E % by weight 1,6 1,6 1,6 1,6 1,6 1,6 Ratio (Aa) / (Ab) 5,5:1 2,4:1 2,4:1 1:1,6 1:2,6 1:5 Shine at 20° 34 49 51 84 82 83 Shine at 60° 80 84 85 93 93 93 Impact strength kJ / m 2 4,7 5,3 5,5 7,6 8,0 8,5 Table 6 (continued) Examples Unit CE30 CE31 CE32 E12 E13 E14 Aa % by weight 24,0 25,4 26,8 14,0 10,0 6,0 Away % by weight 9,6 10,6 11,2 22,0 26,0 30,0 B- % by weight 62,4 60,0 58,0 60,0 60,0 60,0 C-1 % by weight 0,0 0,0 0,0 0,0 0,0 0,0 C-2 % by weight 0,0 0,0 0,0 0,0 0,0 0,0 D-1 % by weight 1,0 1,0 1,0 1,0 1,0 1,0 D-2 % by weight 1,1 1,1 1,1 1,1 1,1 1,1 E % by weight 1,9 1,9 1,9 1,9 1,9 1,9 Ratio (Aa) / (Ab) 2,5:1 2,4:1 2,4:1 1:1,6 1:2,6 1:5 Shine at 20° 27 51 47 81 82 83 Shine at 60° 76 85 84 93 93 93 Impact strength kJ / m 2 5,0 5,3 5,7 7,4 7,7 7,9
[0201] The observations are also confirmed for a composition not containing copolymer C. A weight ratio of Aa:Ab in the range of 1:1 to 1:12, preferably 1:1 to 1:5, leads to better properties regarding impact resistance and surface gloss (cf. Examples E9 to E14).
[0202] Examples of articles in which the prepared compositions are used are: moldings, spoilers, window frames, cover strips, hoods, panels, parts of the grille, antenna covers, housings of side mirrors, front and rear lights and grilles for automotive applications. QUOTES CONTAINED IN THE DESCRIPTION
[0000] This list of documents submitted by the applicant was generated automatically and is included solely for the convenience of the reader. This list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions. Cited patent literature
[0000] WO 2021 / 074154
[0003] US 2020 / 216656
[0004] US 3,922,321
[0004] WO 03 / 074608
[0005] US 2021 / 0108070
[0005] WO 2023 / 041510
[0007] EP-A 1685192
[0017] US 2005 / 0014863
[0017] US 7,077,898
[0017] WO 2015 / 036526
[0018] US 2016 / 222185
[0018] DE-A 28 26 925
[0045] DE-A 31 49 358
[0045] DE-A 34 14 118
[0045] WO 2015 / 150223
[0047] WO 2015 / 078751
[0047] GB 464688
[0073] GB 531956
[0073] GB 863279
[0073] WO 2003 / 051973
[0073] Cited non-patent literature
[0000] ASTM D1238
[0065]
Claims
[1] A thermoplastic composition (P) comprising: a) 20 to 45% by weight, preferably 25 to 42% by weight, based on the total weight of the thermoplastic composition (P), of at least one graft copolymer (A) comprising (or consisting of): a1) a graft base (A1) containing at least one alkyl (meth)acrylate-based rubber, preferably a butyl acrylate-based rubber; and a2) a graft shell (A2) comprising at least one type of vinylaromatic repeating units, preferably styrene repeating units, and optionally at least one type of vinyl cyanide repeating units, preferably acrylonitrile repeating units, wherein the at least one graft copolymer (A) comprises: (Aa) at least one graft copolymer (Aa) having a volume-average particle size (D 50), measured by laser diffraction, from 30 to 340 nm, preferably from 50 to 320 nm, more preferably from 70 to 300 nm, more preferably from 80 to 250 nm, and (Ab) at least one graft copolymer (Ab) having a volume-average particle size (D 50 ), measured by laser diffraction, from 350 to 1000 nm, preferably from 380 to 800 nm, more preferably from 400 to 600 nm, more preferably from 450 to 550 nm, and wherein the weight ratio of the at least one graft copolymer (Aa) to the at least one graft copolymer (Ab) (weight ratio (Aa):(Ab)) is from 1:1 to 1:12, preferably from 1:1 to 1:10, particularly preferably from 1:1 to 1:7, in particular from 1:1 to 1:5; b) 20 to 75% by weight, preferably 21 to 70% by weight, based on the total weight of the thermoplastic composition (P), of at least one random copolymer (B) different from (A), comprising: b1) 10 to 55 wt.%, based on the total weight of the copolymer (B), of at least one type of alkyl (meth)acrylate repeating units (B1), preferably methyl methacrylate repeating units; and b2) 45 to 90 wt.%, based on the total weight of the copolymer (B), of at least one type of vinylaromatic repeating units (B2), preferably styrene repeating units; c) 0 to 60% by weight, preferably 0 to 50% by weight, based on the total weight of the thermoplastic composition (P), of at least one copolymer (C) different from (A) and (B), comprising: c1) 15 to 45% by weight, based on the total weight of the copolymer (C), of at least one type of vinyl cyanide repeating units (C1), preferably acrylonitrile repeating units; and c2) 55 to 85 wt.%, based on the total weight of the copolymer (C), of at least one type of vinylaromatic repeating units (C2), preferably of styrene repeating units. d) 0 to 4% by weight, preferably 0.01 to 3.5% by weight, particularly preferably 0.02 to 3% by weight, based on the total weight of the thermoplastic composition (P), of at least one additive (D) selected from UV absorbers, light stabilizers and antioxidants; and e) 0 to 5% by weight, based on the total weight of the thermoplastic composition (P), of at least one dye (E) selected from pigments and dyes, with the proviso that the thermoplastic composition (P) does not contain any homopolymers of methyl methacrylate, and wherein the components (A), (B), (C), (D) and (E) add up to 100% by weight. [2] Thermoplastic composition (P) according to claim 1, wherein the random copolymer (B) is selected from at least one random copolymer (Ba) having a turbidity of less than or equal to 1.5%, at least one random copolymer (Bb) having a turbidity of more than 1.5% and mixtures of random copolymers (Ba) and (Bb). [3] Thermoplastic composition (P) according to claim 1 or 2, wherein the at least one graft copolymer (A) comprises at least 10 wt.%, preferably at least 12 wt.%, more preferably at least 13 wt.%, more preferably at least 14 wt.%, based on the total weight of the thermoplastic composition (P), of at least one graft copolymer (Ab). [4] Thermoplastic composition (P) according to one of claims 1 to 3, wherein the at least one graft copolymer (A) comprises at most 35 wt.%, preferably at most 34 wt.%, based on the total weight of the thermoplastic composition (P), of the at least one graft copolymer (Ab). [5] Thermoplastic composition (P) according to one of claims 1 to 4, wherein the at least one graft copolymer (A) comprises 1 to 35 wt.%, preferably 2 to 30 wt.%, particularly preferably 3 to 25 wt.%, based on the total weight of the thermoplastic composition (P), of the at least one graft copolymer (Aa). [6] Thermoplastic composition (P) according to any one of claims 1 to 5, wherein the thermoplastic composition (P) comprises 20 to 50 wt.%, preferably 20 to 30 wt.%, based on the total weight of the thermoplastic composition (P), of at least one post-industrial recycled random copolymer (Bb). [7] Thermoplastic composition (P) according to one of claims 1 to 6, wherein the graft base (A1) is present in an amount of 40 to 90 wt.%, based on the total weight of the at least one graft copolymer (A), and the graft shell (A2) is present in an amount of 10 to 60 wt.%, based on the total weight of the at least one graft copolymer (A). [8] Thermoplastic composition (P) according to one of claims 1 to 7, wherein the graft shell (A2) contains 50 to 100 wt.%, preferably 55 to 85 wt.%, based on the total weight of the graft shell (A2), of styrene or alpha-methylstyrene and 0 to 50 wt.%, preferably 15 to 45 wt.%, based on the total weight of the graft shell (A2), of acrylonitrile. [9] Thermoplastic composition (P) according to one of claims 1 to 8, wherein the volume-average particle size (D 50 ) of the at least one graft copolymer (Aa) and the volume-average particle size (D 50) of the at least one graft copolymer (Ab) differ from each other by at least 100 nm, preferably by at least 150 nm, particularly preferably by at least 180 nm [10] An article, preferably a molded part, comprising the composition (P) according to any one of claims 1 to 9, preferably an automobile part, particularly preferably a colored automobile part.
Citation Information
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