Thermoplastic molding compositions with improved weathering resistance

Abstract

The present invention relates to a thermoplastic molding composition having improved weathering resistance and a process for its preparation. The present invention further relates to injection-molded and extruded parts consisting of the thermoplastic molding composition.

Description

Technical Field

[0001] The present invention relates to a thermoplastic molding composition having improved weathering resistance and a process for its preparation. The present invention further relates to injection-molded and extruded parts consisting of the thermoplastic molding composition. Background Art

[0002] Thermoplastic polymers, for example polymethyl methacrylate (PMMA), polyester, polycarbonate and polymeric amide, use various soluble organic dyes and optionally use organic or inorganic pigment colored conventionally.Typically, pyrenone (perinone) type, azo type and anthraquinone type solvent dyes are used for this purpose because of their commercially available properties and bright color. " soluble " as the term used in the application shows that described dyestuff can be dissolved in the described thermoplastic polymer matrix as follows, and described amount is that described dyestuff is used for painted amount.Therefore, as the term used in the application " thermoplastic molding composition " refers to following thermoplastic composition, this thermoplastic composition comprises carbon black and the organic dye that are evenly distributed in the described thermoplastic polymer matrix.

[0003] Molding compositions for outdoor applications are exposed to high levels of solar UV radiation and elevated temperatures and therefore need to exhibit adequate weathering stability. The long-term weathering stability of thermoplastic molding compositions depends not only on the intrinsic stability of the underlying thermoplastic polymer, but also on various polymer additives, such as organic dyes and, if present, organic or inorganic pigments, as well as UV absorbers, UV stabilizers, etc.

[0004] For aesthetic reasons, molding compositions for various outdoor applications are often colored black or light gray. Such molding compositions typically contain a combination of carbon black and at least one soluble organic dye, typically a red dye. Such a combination is known to impart an aesthetically appealing appearance to the resulting composition.

[0005] Due to the presence of carbon black, black or light gray thermoplastic molding compositions tend to absorb significant amounts of solar infrared (IR) radiation, and in outdoor applications, temperatures of 60° C. or even higher may be reached. The combination of solar UV radiation and elevated temperatures is particularly harmful to molding compositions and often leads over time to undesirable discoloration effects (e.g., yellowing of polymeric materials) and decomposition of soluble organic dyes. Therefore, there is a strong need for weather-resistant black or light gray thermoplastic molding compositions for use in outdoor applications.

[0006] WO 2012 / 080397 A2 describes glazing materials that exhibit high transmission in the visible range and low transmission in the IR range. These materials include:

[0007] a. at least one transparent thermoplastic,

[0008] b. at least one inorganic IR absorber,

[0009] c. Nanoscale carbon black, and

[0010] d. At least one colorant.

[0011] WO 2012 / 080397 A2 proposes the use of pyrenone dyes as red colorants Red EG (Solvent Red 135) and as a blue colorant Blue L 6385 (Pigment Blue 60). The document reports that the obtained material has high weather resistance.

[0012] WO 2015 / 036526 A1 describes a black thermoplastic molding composition with high gloss, comprising:

[0013] a. 90 to 99.5% by weight of one or more styrenic copolymers,

[0014] b. 0.01 to 5% by weight of carbon black pigment,

[0015] c. 0.1 to 1.5% by weight of at least two dyes soluble in the molding composition,

[0016] d. 0 to 5% by weight of one or more additional substances.

[0017] The composition is reported to have a deep black color with an L*-value of 0.5 to 2.0 measured according to DIN 5033 and a high gloss of greater than 98 measured according to DIN 67530.

[0018] JP 2016-037518 A discloses a black methacrylic resin molding composition with high weather resistance and shielding properties. The composition generally comprises three or more dyes selected from red, yellow, green, blue and violet dyes. The dye can be selected from anthraquinone dyes, heterocyclic compound dyes and pyrene dyes. JP 2016-037518 A recommends the use of red dyes such as Solvent Red 52, 111, 135, 145, 146, 149, 150, 151, 155, 179, 180, 181, 196, 197, 207, Disperse Red 22, 60, 191 and the like. Examples of blue dyes include Solvent Blue 35, 45, 78, 83, 94, 97, 104, 105. Examples of suitable yellow dyes include Disperse Yellow 160, 54, 160 and Solvent Yellow 33. Examples of green dyes include, for example, Solvent Green 3, 20, and 28, etc. Examples of violet dyes include, for example, Solvent Violet 28, 13, 31, 35, and 36.

[0019] To date, commercially available monoazo dyes containing at least one heteroaromatic moiety have not been used in combination with carbon black for coloring thermoplastic polymers such as polyalkyl (meth)acrylates. This is because monoazo solvent dyes have been found to have only moderate thermal and weathering stability, and therefore molding compositions containing any combination of monoazo solvent dyes and carbon black would not be expected to be suitable for outdoor use.

[0020] Insufficient weathering stability of pigmented molding compositions often leads to undesirable color changes when exposed to solar radiation. Therefore, the weathering stability of a given molding composition can often be estimated by measuring the color of a sample of such molding composition in the CIELAB color space before and after exposure to a weathering test. The color difference, i.e., the difference between the two colors, can be used as an indicator of the weathering stability. Summary of the Invention

[0021] Purpose of the Invention

[0022] It is therefore an object of the present invention to provide a novel gray or black thermoplastic composition having improved long-term thermal and weathering stability, an aesthetically pleasing appearance, and a high gloss. It is further desirable that the molding composition retain its favorable optical properties even when exposed to elevated temperatures and / or high shear forces, for example, during the injection molding of parts with complex geometries.

[0023] A further object of the present invention was to provide a process for producing grey or black thermoplastic compositions having improved long-term thermal and weathering stability in a particularly efficient manner.

[0024] Finally, the present invention aims to provide grey or black mouldings, in particular those with complex geometries, having these advantageous properties. SUMMARY OF THE INVENTION

[0026] The present invention is based on the surprising finding that thermoplastic molding compositions comprising a combination of a monoazo dye containing at least one heteroaromatic moiety and carbon black have significantly higher long-term thermal and weathering stability than comparable molding compositions containing other types of dyes, such as conventional pyrenone-based dyes. Due to the excellent solubility of the monoazo dye containing at least one heteroaromatic moiety in the thermoplastic polymer used, complete and uniform dissolution occurs in the polymer matrix, and the resulting thermoplastic molding compositions have excellent optical properties, low haze, high gloss, and an aesthetically pleasing appearance.

[0027] Therefore, in a first aspect thereof, the present invention relates to a thermoplastic molding composition comprising:

[0028] a) 90.0 to 99.99989 wt % of a thermoplastic polymer;

[0029] b) 0.0001 to 5.0 wt. % carbon black; and

[0030] c) 0.00001 to 5.0% by weight of a monoazo dye comprising at least one heteroaromatic moiety.

[0031] Furthermore, the present invention provides a process for producing a thermoplastic molding composition as defined above, wherein the process comprises the following steps:

[0032] a) providing a thermoplastic polymer; and

[0033] b) adding at least one coloring composition comprising carbon black and a monoazo dye comprising at least one heteroaromatic moiety to the thermoplastic polymer obtained in step a), wherein the coloring composition is preferably a liquid composition or a masterbatch. Detailed Description of the Invention

[0035] The monoazo dyes used in the present invention are well known to those skilled in the art and are derivatives of diazene (diimine) "HN=NH" in which both hydrogen atoms are replaced by aromatic or heteroaromatic moieties (IUPAC Recommendations 1995, published in Pure & Appl. Chem., Vol. 67, No. 819, pp. 1307-1375, 1995). In other words, the chemical structure of all monoazo dyes contains a chemical moiety "-N=N-".

[0036] The term "heteroaromatic moiety" as used in this application is also well known and generally refers to a 5-membered or 6-membered aromatic moiety containing at least one heteroatom in its structure. Typically, the heteroatom is a N, O, S, Se or Te atom, more preferably a N, O or S atom, and even more preferably a N atom. Specific examples of the heteroaromatic moiety include, for example, furan, thiophene, pyran, pyrrole, imidazole, pyrazole, 3H-pyrazol-3-one, pyrazolin-5-one, pyridine, pyrazine, pyrimidine, pyridazine, thiazole, Azoles, isothiazoles, isothiazoles Azoles, thiadiazoles, Other examples of heteroaromatic moieties include, for example, indolizine, purine, pteridine, carboline, pyrroloimidazole, pyrrolotriazole, pyrazoloimidazole, pyrazolotriazole, pyrazolopyrimidine, pyrazolotriazine, triazolopyridine, tetrazoindene, imidazoimidazole, imidazopyridine, imidazopyrazine, imidazopyrimidine, imidazopyridazine, Azolopyridine, Azolopyrazine, Azolopyrimidine, oxazolopyridazine, thiazolopyridine, thiazolopyrazine, thiazolopyrimidine, thiazolopyridazine, pyridopyrazine, pyradinopyrazine, pyradinopyrazine, naphthyridine, imidazotriazine and 1-H-perimidin.

[0037] The heteroaromatic moiety is usually substituted with one or more substituents, which may be alkyl, alkenyl, alkynyl, aryl, amino, alkoxy, aryloxy, acyl, alkoxycarbonyl, aryloxycarbonyl, acyloxy, acylamino, alkoxycarbonylamino, aryloxycarbonylamino, sulfonylamino, sulfamoyl, carbamoyl, alkylthio, arylthio, sulfonyl, cyano, heterocyclic groups, and halogen atoms. More preferred are alkyl, alkenyl, aryl, alkoxy, aryloxy, cyano, heterocyclic groups, and halogen atoms, even more preferred are alkyl, aryl, alkoxy, aryloxy, and aromatic heterocyclic groups, and particularly preferred are alkyl, aryl, alkoxy, and aromatic heterocyclic groups.

[0038] Specific examples of monoazo dyes for use in the present invention include, but are not limited to:

[0039] Disperse Yellow 241 (5-[(3,4-dichlorophenyl)azo]-1,2-dihydro-6-hydroxy-1,4-dimethyl-2-oxonicotinonitrile),

[0040] Solvent Black 3 (2,3-dihydro-2,2-dimethyl-6-((4-(phenylazo)-1-naphthyl)azo)-1H-perylene),

[0041] Solvent Red 195 (methyl cyano-5-[[5-cyano-2,6-bis[(3-methoxypropyl)amino]-4-methylpyridin-3-yl]azo]-3-methyl-2-thiophenecarboxylate),

[0042] Solvent Yellow 16 (5-methyl-2-phenyl-4-phenylazo-4H-pyrazol-3-one),

[0043] Solvent Yellow 18 (4-[(2,4-dimethylphenyl)azo]-2,4-dihydro-5-methyl-2-phenyl-3H-pyrazol-3-one),

[0044] Solvent Yellow 21 (3-[(1-oxonaphthalene-2-ylidene)methylhydrazinylidene]-1-prop-2-enylindol-2-one),

[0045] Solvent Yellow 72 (4-((o-methoxyphenyl)azo)-3-methyl-1-phenyl-2-pyrazol-5-one),

[0046] Solvent Yellow 82,

[0047] Solvent Yellow 16 (5-methyl-2-phenyl-4-phenylazo-4H-pyrazol-3-one).

[0048] In a preferred embodiment of the present invention, the monoazo dye is Solvent Red 195. Compared to comparable poly(meth)acrylate-based molding compositions containing other red solvent dyes of the prior art (e.g., red pyrene dyes), thermoplastic molding compositions comprising a combination of Solvent Red 195 and carbon black surprisingly exhibit significantly higher weathering stability and thermal stability, in addition to an aesthetically pleasing appearance. Advantageously, the thermoplastic molding compositions of the present invention comprising Solvent Red 195 are substantially free of other red solvent dyes. Red solvent dyes within the meaning of the present invention are those designated as Solvent Red, Acid Red, or Modern Red according to the Color Index (CI). In particular, the thermoplastic molding compositions of the present invention comprising Solvent Red 195 typically contain less than 0.1% by weight, more preferably less than 0.01% by weight, even more preferably less than 0.001% by weight, still even more preferably less than 0.0001% by weight, yet more preferably less than 0.00001% by weight, and most preferably less than 0.000001% by weight of other red solvent dyes, based on the weight of the thermoplastic molding composition.

[0049] The concentration of the monoazo dye containing at least one heteroaromatic moiety in the thermoplastic molding composition depends on the desired perceived color. The concentration is generally in the range of 0.00001 to 5.0 wt. %, preferably 0.0001 to 4.0 wt. %, more preferably 0.001 to 3.0 wt. %, based on the weight of the thermoplastic molding composition. If other dyes are present, the sum of the dye concentrations is preferably in the range of 0.00001 to 5.0 wt. %, preferably 0.0001 to 4.0 wt. %, more preferably 0.001 to 3.0 wt. %, based on the weight of the thermoplastic molding composition.

[0050] In order to impart a black or light grey colour to the moulding composition, at least one carbon black is used. The average primary particle size of the carbon black pigment is generally in the range of 5.0 to 100.0 nm, more preferably in the range of 7.0 to 60.0 nm. The average particle size d 50 The determination can be made by methods known to those skilled in the art, for example by photon correlation spectroscopy according to DIN ISO 13320 (1999) using commercially available instruments (for example the LS 13 320 laser diffraction particle size analyzer from Beckman Coulter Inc.). It has further been shown to be advantageous with regard to the coloring properties to select a particle having a particle size of 50 to 500 nm as measured by the BET method, ISO 9277. 2 / g, such as 70 to 200m 2 / g of carbon black particles. The carbon black can be treated or untreated. For example, the carbon black can be treated with a specific gas or organic substance (e.g., butyl lithium). Such treatment allows the surface to be modified or functionalized. This can further improve compatibility with the corresponding polymer matrix used.

[0051] The carbon blacks suitable for use within the scope of the present invention differ from so-called conductive carbon blacks in that they have only low or no electrical conductivity. In contrast to the carbon blacks used here, conductive carbon blacks have a specific morphology and superlattice to achieve high electrical conductivity. In contrast, the carbon black particles used here can be easily dispersed in thermoplastics, so that there are almost no cohesive areas of carbon black, from which a corresponding electrical conductivity could arise. Suitable carbon blacks within the scope of the present invention are commercially available under a large number of trade names and in a large number of forms (e.g. pellets or powders). For example, suitable carbon blacks are available under the trade name BLACK Obtained in the form of wet processed pellets under the name and Obtained, and in flocculent form under the name and Available - They are all available from Cabot Corporation. 60 and 90 (Orion Engineered Carbons GmbH) is also suitable for this purpose.

[0052] The concentration of carbon black in the thermoplastic molding composition depends primarily on the desired L* value in the color space of CIELAB 1976. The concentration is preferably in the range from 0.0001 to 5.0% by weight, preferably from 0.001 to 4.0% by weight, more preferably from 0.005 to 3.0% by weight, further preferably from 0.001 to 2% by weight, further preferably from 0.01 to 1% by weight, based on the weight of the thermoplastic molding composition.

[0053] Besides the monoazo dye comprising at least one heterocyclic moiety and carbon black, the thermoplastic molding composition of the invention may further comprise:

[0054] at least one other dye selected from the group consisting of pyrene dyes, quinophthalone dyes and anthraquinone dyes;

[0055] at least one phthalocyanine pigment; or

[0056] Any mixture of the above substances.

[0057] As skilled colorists readily appreciate, the properties of these dyes that preferably cover complementary color regions are selected in a manner that their combination produces black. An example of a simple combination that produces black is a red monoazo dye comprising at least one heteroaromatic structure portion and its complementary green dye. Green solvent dyes within the meaning of the present invention are those that are designated as solvent green, acid green or modern green according to the color index (CI). For example, dyestuff Solvent Red 195 can be used in combination with known dyestuff Solvent Green 28 to realize black coloring. In the present invention, a yellow monoazo dye comprising at least one heteroaromatic structure portion and a combination of complementary blue dyes can also be used to produce black. An example of such a combination is the combination of Solvent Yellow 82 and Solvent Blue 104, both of which are known per se.

[0058] In addition, if desired glossy jet black appearance, thermoplastic molding composition of the present invention can advantageously comprise at least three different dyes that cover complementary color regions.Therefore can avoid undesirable black chromaticity or adjust these chromaticities in the desired direction. An example is the combination of Solvent Red 195 with Solvent Green 28 and Solvent Yellow 114. Yellow solvent dyes within the meaning of the present invention are those yellow solvent dyes that are designated as Solvent Yellow, Acid Yellow or Modern Yellow according to the Color Index (CI). The combination of red monoazo dye Solvent Red 195 with yellow dye Solvent Yellow 114 and green dye Solvent Green 28 is another example of the combination with advantageous properties.

[0059] Anthraquinone dyes are dyes having an anthraquinone moiety in their structure. Examples of suitable anthraquinone dyes include (color index CI) solvent yellow 117, 163, 167, 189; solvent orange 77, 86; solvent red 111, 143, 145, 146, 150, 151, 155, 168, 169, 172, 175, 181, 207, 222, 227, 230, 245, 247; solvent violet 11, 13, 14, 26, 31, 36, 37, 38, 45, 47, 48, 51, 59, 60; solvent blue 14, 18, 35, 36, 45, 58, 59, 5 9:1, 63, 68, 69, 78, 79, 83, 94, 98, 100, 101, 102, 104, 105, 111, 112, 122, 128, 132, 136, 139; Solvent Green 3, 28, 29, 32, 33; Acid Red 80; Acid Green 25, 27, 28, 41; Acid Violet 34; Acid Blue 25, 27, 40, 45, 78, 80, 112; Disperse Yellow 51; Disperse Violet 26, 27; Disperse Blue 1, 14, 56, 60; Direct Blue 40; Modern Red 3, 11; Modern Blue 8.

[0060] Examples of pyrenone dyes suitable for use in the present invention include (Color Index CI) Solvent Orange 60, 78, 90; Solvent Red 135, 162, 179; Solvent Violet 29 and the like.

[0061] Suitable quinophthalone dyes include (Color Index CI) Solvent Yellow 33, 114, 128, 129, Disperse Yellow 14, 49, 54 and the like.

[0062] The phthalocyanine pigments used in the present invention are not particularly limited and include, in particular, metal-free phthalocyanines, cobalt phthalocyanines, copper phthalocyanines, nickel phthalocyanines, iron phthalocyanines, manganese phthalocyanines, and zinc phthalocyanines. Thermoplastic molding compositions containing copper phthalocyanines exhibit particularly high heat and weather resistance and a strong depth of color. Suitable copper phthalocyanine pigments can be selected, for example, from Pigment Blue 1, 2, 15, 15:1, 15:2, 15:3, 15:4, 15:6, 16, 17:1, 56, 60, and 63, as well as Pigment Green 7 and 36.

[0063] The thermoplastic molding composition of the invention may also contain at least one inorganic pigment. The inorganic pigment may be selected, for example, from barium sulfate, zinc oxide, iron oxide, magnesium titanate, calcium sulfate, calcium carbonate, magnesium carbonate, titanium dioxide, carbon black and dolomite.

[0064] The choice of thermoplastic polymer for use in the present invention is not particularly limited, as long as the thermoplastic polymer is suitable for coloring and thermoplastic processing, in particular for injection molding and extrusion. For example, the thermoplastic polymer can be advantageously selected from polyalkyl (meth) acrylates, polymethylmethacrylimide, polyalkyl (meth) acrylate copolymers, polystyrene, polystyrene copolymers, acrylonitrile copolymers, polycarbonate, polyester (preferably polyethylene terephthalate), polyamide, polyvinylidene fluoride or mixtures thereof.

[0065] Preferably, the thermoplastic polymer is selected from polyalkyl (meth)acrylates, polymethylmethacrylimide, polyalkyl (meth)acrylate copolymers, polystyrene, polystyrene copolymers, acrylonitrile copolymers, polycarbonate, polyester (preferably polyethylene terephthalate), polyvinylidene fluoride, or mixtures thereof. More preferably, the thermoplastic polymer is selected from polyalkyl (meth)acrylates, polymethylmethacrylimide, polyalkyl (meth)acrylate copolymers, polycarbonate, or mixtures thereof.

[0066] Preferably, the thermoplastic polymer itself is substantially transparent before being colored. The term "substantially transparent" as used in the present application means that the material has a transmittance (D) of at least 50%, preferably at least 60%, more preferably at least 70%, even more preferably at least 80% and particularly preferably at least 90%, measured according to standard ISO 13468-2 (2006) on a sample with a thickness of 2.0 mm. 65 ).

[0067] Polyalkyl (meth)acrylate

[0068] Polyalkyl (meth)acrylates are generally obtained by free-radical polymerization of mixtures which generally comprise an alkyl (meth)acrylate, typically methyl methacrylate (a), and at least one further (meth)acrylate (b). These mixtures generally comprise at least 50% by weight, preferably at least 60% by weight, particularly preferably at least 80% by weight and even more preferably at least 90% by weight of methyl methacrylate (a), based on the weight of the monomers. The amount of methyl methacrylate (a) generally used is from 50.0% to 99.9% by weight, preferably from 80.0% to 99.9% by weight and particularly preferably from 90.0% to 99.9% by weight, based on the weight of the monomers.

[0069] These mixtures for preparing polyalkyl (meth)acrylates may also contain other (meth)acrylates (b) that are copolymerizable with methyl methacrylate (a). As used herein, the term "(meth)acrylate" ((meth)acrylate) is intended to encompass methacrylates, acrylates, and mixtures thereof. (Meth)acrylates may be derived from saturated alcohols such as methyl acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, n-butyl (meth)acrylate, tert-butyl (meth)acrylate, isobutyl (meth)acrylate, pentyl (meth)acrylate, and 2-ethylhexyl (meth)acrylate; or from unsaturated alcohols such as oleyl (meth)acrylate, 2-propynyl (meth)acrylate, allyl (meth)acrylate, vinyl (meth)acrylate; and aryl (meth)acrylates such as benzyl (meth)acrylate or phenyl (meth)acrylate; (meth)acrylates may be derived from (meth)acrylates, such as cycloalkyl (meth)acrylates, such as 3-vinylcyclohexyl (meth)acrylate and bornyl (meth)acrylate; hydroxyalkyl (meth)acrylates, such as 3-hydroxypropyl (meth)acrylate, 3,4-dihydroxybutyl (meth)acrylate, 2-hydroxyethyl (meth)acrylate and 2-hydroxypropyl (meth)acrylate; diol di(meth)acrylates, such as 1,4-butanediol (meth)acrylate; (meth)acrylates of ether alcohols, such as tetrahydrofurfuryl (meth)acrylate and vinyloxyethoxyethyl (meth)acrylate; amides and nitriles of (meth)acrylic acid, etc.

[0070] The amount of (meth)acrylic comonomer (b) generally used is 0.1 to 50.0% by weight, preferably 1.0 to 20.0% by weight, and particularly preferably 1.0 to 10.0% by weight, based on the weight of the monomers, and the compounds mentioned here can be used individually or in the form of a mixture.

[0071] The polymerization reaction is usually initiated by known free radical initiators. Preferred initiators include, in particular, the azo initiators known to those skilled in the art, and peroxide compounds such as, for example, methyl ethyl ketone peroxide, acetylacetone peroxide, dilauroyl peroxide, tert-butyl 2-ethylperhexanoate, ketone peroxide, methyl isobutyl ketone peroxide, cyclohexanone peroxide, dibenzoyl peroxide, tert-butyl peroxybenzoate, tert-butyl peroxyisopropyl carbonate, 2,5-bis(2-ethylhexanoylperoxy)-2,5-dimethylhexane, tert-butyl 2-ethylperoxyhexanoate, tert-butyl 3,5,5-trimethylperoxyhexanoate, dicumyl peroxide, 1,1-bis(tert-butylperoxy)cyclohexane, 1,1-bis(tert-butylperoxy)-3,3,5-trimethylcyclohexane, cumyl hydroperoxide, tert-butyl hydroperoxide, bis(4-tert-butylcyclohexyl) peroxydicarbonate or mixtures thereof.

[0072] The composition to be polymerized may contain not only the methyl methacrylate (a) and (meth)acrylate (b) described above, but also other unsaturated monomers which can be copolymerized with the methyl methacrylate and the (meth)acrylate mentioned above, either alone or by using other monomers which facilitate copolymerization. These include, in particular, 1-olefins such as 1-hexene, 1-heptene; branched olefins such as vinylcyclohexane, 3,3-dimethyl-1-propene, 3-methyl-1-diisobutylene, 4-methyl-1-pentene; acrylonitrile; vinyl esters such as vinyl acetate; styrene, substituted styrenes having alkyl substituents in the side chains such as α-methylstyrene and α-ethylstyrene, maleic acid derivatives such as maleic anhydride, methylmaleic anhydride, maleimide, methylmaleimide; and dienes such as divinylbenzene.

[0073] These comonomers (c) are generally used in amounts of 0.0 to 35.0% by weight, preferably 0.0 to 30.0% by weight and particularly preferably 0.0 to 25.0% by weight, based on the weight of the monomers, and the compounds mentioned here can be used individually or in the form of mixtures.

[0074] Further preference is given to polyalkyl (meth)acrylates obtainable by polymerizing a composition having as polymerizable component:

[0075] (a) 50.0% to 99.9% by weight of methyl methacrylate

[0076] (b) 0.1 to 50.0 wt% of acrylic acid esters of C1-C4 alcohols

[0077] (c) 0.0% to 35.0% by weight of a monomer copolymerizable with monomers (a) and (b).

[0078] In yet another embodiment, preferred are polyalkyl (meth)acrylates composed of 85.0 to 99.5% by weight of methyl methacrylate and 0.5 to 15.0% by weight of methyl acrylate, the amounts being based on 100% by weight of the polymerizable components. Particularly advantageous copolymers are those obtainable by copolymerizing 90.0 to 99.5% by weight of methyl methacrylate and 0.5 to 10.0% by weight of methyl acrylate, the amounts being based on 100% by weight of the polymerizable components. For example, the polyalkyl (meth)acrylate may comprise 91.0% by weight of methyl methacrylate and 9.0% by weight of methyl acrylate, 96.0% by weight of methyl methacrylate and 4.0% by weight of methyl acrylate, or 99.0% by weight of methyl methacrylate and 1.0% by weight of methyl acrylate. The polyalkyl (meth)acrylate typically has a Vicat softening point VSP (ISO 306:2013, method B50) of at least 90°C, preferably from 95°C to 112°C.

[0079] The weight-average molecular weight Mw of the polyalkyl (meth)acrylates is generally in the range from 50,000 g / mol to 300,000 g / mol. Particularly advantageous mechanical properties are achieved with polyalkyl (meth)acrylates having an average molecular weight Mw in the range from 50,000 g / mol to 200,000 g / mol, preferably from 80,000 g / mol to 180,000 g / mol, determined in each case by GPC against PMMA calibration standards and THF as eluent.

[0080] In a particularly preferred embodiment, the polyalkyl (meth)acrylate is obtainable by polymerizing the following composition, the polymerizable component of which comprises, based on the weight of the polymerizable composition:

[0081] (a) 80.0% to 99.9% by weight of methyl methacrylate, and

[0082] (b) 0.1 to 20.0 wt% of an acrylic acid ester of a C1-C4 alcohol.

[0083] Corresponding copolymers are available, for example, under the trademark Commercially available from GmbH.

[0084] Poly(meth)acrylimide

[0085] The poly(meth)acrylimide (PMMI) that can be used in the present invention comprises at least 25 wt. %, preferably at least 50 wt. %, most preferably at least 70 wt. %, based on the weight of the poly(meth)acrylimide, of repeating units of formula (I):

[0086]

[0087] where R 1 and R 2 are independently selected from hydrogen and methyl groups, R 1 and R 2 preferably represents a methyl group, and R 3 is hydrogen or a C1-C4 alkyl group, preferably a methyl group.

[0088] Processes for the preparation of PMMI are disclosed, for example, in EP-A 216 505, EP-A 666 161 or EP-A 776 910, the entire disclosure of which is incorporated herein by reference.

[0089] The starting material for preparing PMMI comprises the following polymer, this polymer is derived from alkyl methacrylate, and is usually composed of greater than 50.0 weight %, preferably greater than 80.0 weight %, particularly preferably 95.0 weight % to 100.0 weight % of alkyl methacrylate units having 1 to 4 carbon atoms in the alkyl group. Preferred is methyl methacrylate. Preferred polymer is composed of at least 80.0 weight %, preferably greater than 90.0 weight %, more preferably greater than 95.0 weight %, more preferably greater than 99.0 weight % of methyl methacrylate, wherein pure methyl methacrylate is most preferably used. Available comonomers comprise any monomer capable of copolymerizing with methyl methacrylate, in particular alkyl methacrylate, acrylonitrile or methacrylonitrile, acrylamide or methacrylamide, styrene or also maleic anhydride having 1 to 4 carbon atoms in the alkyl group. Preference is given to thermoplastically processable polymers of this type having a reduced viscosity in the range of 20 ml / g to 92 ml / g, preferably 50 ml / g to 80 ml / g (measured according to ISO 8257 (2006) Part 2). They are used in the form of powders or granules having a median particle size of about 0.03 mm to 3 mm.

[0090] Typically, the PMMI for use in the present invention has a mass average molar weight Mw of 80,000 to 200,000 g / mol, preferably 90,000 to 150,000 g / mol, as determined by GPC using PMMA as a standard. Commercially available from GmbH. Suitable products include, but are not limited to, those commercially available from GmbH TT50, TT70, 8805, 8813, 8817.

[0091] polycarbonate

[0092] Polycarbonates can also be used as thermoplastic polymers in the process of the present invention. Polycarbonates can be formally considered as polyesters formed from carbonic acid and aliphatic or aromatic dihydroxy compounds. They can be easily obtained by reacting diethylene glycol (diglycol) or bisphenols with phosgene or carbonic acid diesters through polycondensation or transesterification.

[0093] Polycarbonates derived from bisphenols are preferred. These bisphenols include, in particular, 2,2-bis(4-hydroxyphenyl)propane (bisphenol A), 2,2-bis(4-hydroxyphenyl)butane (bisphenol B), 1,1-bis(4-hydroxyphenyl)cyclohexane (bisphenol C), 2,2'-methylenediphenol (bisphenol F), 2,2-bis(3,5-dibromo-4-hydroxyphenyl)propane (tetrabromobisphenol A), and 2,2-bis(3,5-dimethyl-4-hydroxyphenyl)propane (tetramethylbisphenol A). Such aromatic polycarbonates are typically prepared by interfacial polycondensation or transesterification. By selecting the bisphenols, the properties of the polycarbonate can be adjusted to the desired purpose.

[0094] Scattering particles

[0095] In some embodiments of the present invention, the thermoplastic molding composition may further comprise organic or inorganic scattering particles dispersed in the matrix of the thermoplastic polymer. Although the nature of the scattering particles is not particularly limited, they are generally selected so that the refractive index of the scattering particles differs from the refractive index of the polymer matrix by at least 0.01. The refractive index can be measured at 23° C. at the Na D-line of 589 nm as specified in standard ISO 489 (1999).

[0096] The scattering particles generally have a weight-average particle diameter of 0.01 μm to 100.0 μm. The weight-average particle diameter of the scattering particles—denoted as the so-called volume-average d50 The value (i.e., the particle size at which 50% by volume of the particles have a particle size below the specified average particle size) can be measured according to the laser diffraction measurement standard ISO 13320-1 (2009). Typically, the size of the scattered particles is determined in each case by laser light scattering (at room temperature, 23° C.) in dry powder form using a Beckman Coulter LS 13 320 laser diffraction particle size analyzer, cyclone dry powder system. The measurements are performed as described in the manual. For the computer-assisted analysis model, Mie was used.

[0097] Inorganic scattering particles may include conventional inorganic sunscreens such as barium sulfate, calcium carbonate, titanium dioxide, or zinc oxide.

[0098] Organic scattering particles are typically spherical scattering beads composed of a cross-linked polymer material (e.g., polyalkyl (meth)acrylate, silicone, polystyrene, etc.). For the purposes of the present invention, the term "spherical" means that the scattering beads preferably have a spherical shape, but it will be clear to those skilled in the art that, as a result of the preparation process, scattering beads may have other shapes, or the shape of the scattering beads may deviate from the ideal spherical shape. Therefore, the term "spherical" means that the ratio of the largest dimension to the smallest dimension of the scattering beads is no greater than 4, preferably no greater than 2, with each of these dimensions being measured through the center of gravity of the scattering bead. Based on the number of scattering beads, at least 70% are preferably spherical, and in particular at least 90%.

[0099] The preferred scattering beads composed of cross-linked polystyrene may be trademarked SBX-4, SBX-6, SBX-8 and SBX-12 is commercially available from Sekisui Plastics Co., Ltd.

[0100] Other particularly preferred spherical plastic particles used as scattering agents include crosslinked silicones. The silicone scattering agents used particularly preferably in the present invention can be used as 120 and 3120 is available from Momentive Performance Materials Inc.

[0101] Impact modifiers

[0102] If described thermoplastic molding composition comprises impact modifier, then the mechanical property of described thermoplastic molding composition can be adjusted to the purpose of hope in addition.It is well known that the impact modifier used in the present invention itself can have different chemical compositions and different polymer architectures.Described impact modifier can be crosslinked or thermoplastic.In addition, described impact modifier can be in granular form, as core-shell or as core-shell-shell particle.Typically, granular impact modifier has between 20nm to 500nm, preferably between 50nm to 450nm, more preferably between 100nm to 400nm and most preferably between 150nm to 350nm average particle diameter.In this article, " granular impact modifier " means the crosslinked impact modifier with core, core-shell, core-shell-shell or core-shell-shell-shell structure usually. The average particle diameter of the particulate impact modifier can be determined by methods known to those skilled in the art, for example by photon correlation spectroscopy in accordance with standard DIN ISO 13321 (1996).

[0103] In the simplest case, the particulate impact modifier is a crosslinked particle obtained by emulsion polymerization, having an average particle diameter in the range of 10 nm to 250 nm, preferably 20 nm to 100 nm, and more preferably 30 nm to 90 nm. These particles are generally composed of at least 20.0% by weight, preferably 20.0% to 99.0% by weight, particularly preferably 30.0% to 98.0% by weight, of butyl acrylate, and 0.1% to 2.0% by weight, preferably 0.5% to 1.0% by weight, of a crosslinking monomer, for example a polyfunctional (meth)acrylate, such as allyl methacrylate, and, if appropriate, further monomers, for example 0.0% to 10.0% by weight, preferably 0.5% to 5.0% by weight, of a C1-C4 alkyl methacrylate, for example ethyl acrylate or butyl methacrylate, preferably methyl acrylate, or other vinyl-polymerizable monomers, for example styrene.

[0104] Other preferred impact modifiers are polymer particles which may have a core-shell or core-shell-shell structure and are obtained by emulsion polymerization (see, for example, EP-A 0 113 924, EP-A 0 522 351, EP-A 0 465 049 and EP-A 0 683 028). The present invention generally requires that these emulsion polymers have a suitable average particle diameter in the range of 20 nm to 500 nm, preferably between 50 nm and 450 nm, more preferably between 150 nm and 400 nm, and most preferably between 200 nm and 350 nm.

[0105] The three-layer or three-phase structure with a core and two shells can have the following composition. The innermost (hard) shell can, for example, be composed of methyl methacrylate, a small proportion of comonomers (e.g. ethyl acrylate) and a certain proportion of crosslinking agents (e.g. allyl methacrylate). The middle (soft) shell can, for example, be composed of a copolymer comprising butyl acrylate and, if appropriate, styrene, while the outermost (hard) shell is identical to the matrix polymer, thus providing compatibility with the matrix and good bonding. The proportion of polybutyl acrylate in the core or shell of the impact modifier of the two-layer or three-layer core-shell structure is decisive for the impact-modifying effect and is preferably in the range of 20.0% to 99.0% by weight, particularly preferably in the range of 30.0% to 98.0% by weight, even more preferably in the range of 40.0% to 97.0% by weight, based on the total weight of the impact modifier.

[0106] Thermoplastic impact modifiers have a different mechanism of action than particulate impact modifiers. They are usually mixed with a matrix material. When microdomains are formed, as occurs, for example, when block copolymers are used, the preferred size of these microdomains (which can be determined, for example, by electron microscopy) corresponds to the preferred size of the core-shell particles.

[0107] There are various classes of thermoplastic impact modifiers. One example of these is aliphatic thermoplastic polyurethanes (TPUs), such as those commercially available from Covestro AG. Products. For example, TPU WDP 85784A, WDP 85092A, WDP 89085A and WDP 89051D, all of which have a refractive index between 1.490 and 1.500, are particularly suitable as impact modifiers.

[0108] Another class of thermoplastic polymers useful as impact modifiers according to the present invention are methacrylate-acrylate block copolymers, especially acrylic TPEs, which comprise a PMMA-poly-n-butyl acrylate-PMMA triblock copolymer and which can be The product is commercially available from Kuraray under the name of .The poly-n-butyl acrylate blocks form nano-domains with a size of 10 nm to 20 nm in the polymer matrix.

[0109] The thermoplastic polymers used in the present invention may further comprise conventional additives / auxiliaries of any type. These include, in particular, antistatic agents, antioxidants, mold release agents, flame retardants, lubricants, flow improvers, fillers, UV absorbers, light stabilizers, and organophosphorus compounds (e.g., phosphites or phosphonates), pigments, agents providing weather resistance, and plasticizers. The selection and amount of additives can be adjusted according to the intended use. The thermal stability and weathering stability of the resulting thermoplastic molding composition should not be excessively impaired by these additives.

[0110] When the thermoplastic polymer is a polyalkyl (meth)acrylate, the thermoplastic molding composition of the present invention generally has a melt flow rate MVR of 0.5 to 10.0 g / 10 min, measured at 230° C. with a 3.8 kg load in accordance with ISO 1133 (2011). Therefore, the thermoplastic molding composition can be advantageously used for injection molding as well as for extrusion.

[0111] The jet-black thermoplastic molding compositions of the present invention generally have L* values ​​according to DIN 5033 of from 0.4 to 2. If desired, the compositions can often have L* values ​​as low as 0.4 to 1, in particular 0.4 to 0.9. The gloss (R 60°; measured according to DIN 67530 (1982)) of such molding compositions is generally at least 60, more preferably at least 70, even more preferably at least 80, and particularly preferably at least 90.

[0112] Insufficient weathering stability of thermoplastic molding compositions often leads to undesirable color changes when exposed to elevated temperatures. Therefore, the weathering stability of a given molding composition can often be estimated by measuring the color of a sample of such molding composition in the CIELAB color space before and after exposure to a weathering test. The color difference, i.e., the difference between the two colors, can be used as an indicator of the weathering stability.

[0113] In a preferred embodiment, the color difference ΔE of the molding composition after 3000 hours of artificial weathering (CIELAB 1976 (D65, 10°) determined in accordance with DIN 6174) is less than 3.0, preferably less than 2.5, particularly preferably less than 2.0. The corresponding test is carried out under the following conditions:

[0114] Instrument: Xenotest Beta LM / 1

[0115] Filter: Xenochrome 300 filter system, daylight (ISO 4892-2)

[0116] Irradiance: 60W / m 2(300-400nm)

[0117] Temperature: Chamber 38±3℃, Black Standard 65±3℃

[0118] Humidity: 65±10 ％ RH

[0119] 102 minutes drying, 18 minutes water spraying

[0120] Process for producing thermoplastic molding compositions

[0121] Another embodiment of the present invention relates to a process for producing a thermoplastic molding composition as defined above, wherein said process comprises the following steps:

[0122] a) providing a thermoplastic polymer; and

[0123] b) adding at least one coloring composition comprising carbon black and a monoazo dye comprising at least one heteroaromatic moiety to the thermoplastic polymer obtained in step a), wherein the coloring composition is preferably a liquid composition or a masterbatch.

[0124] In one embodiment, in step b), a single coloring composition is added to the thermoplastic polymer obtained in step a), wherein the formulation comprises the monoazo dye in combination with carbon black. In yet another embodiment, two or more coloring compositions may be added in step b), wherein one formulation may comprise the monoazo dye and the other formulation may comprise carbon black. If two or more coloring compositions are added in step b), they may be added in any order or simultaneously.

[0125] The coloring composition may be, for example, a liquid composition or a masterbatch. If the coloring composition is added to the thermoplastic polymer in the form of a liquid composition, the liquid composition typically comprises:

[0126] 1.0 to 30.0 wt. %, preferably 5.0 to 25.0 wt. %, more preferably 1.0 to 20.0 wt. % of a dispersing additive,

[0127] 0.05 to 10.0% by weight, preferably 0.1 to 5.0% by weight, of carbon black,

[0128] 0.5 to 50.0% by weight, preferably 5.0 to 40.0% by weight, of a monoazo dye, and

[0129] 0.0 to 50.0 wt %, preferably 0.0 to 10.0 wt %, more preferably 0.0 to 5.0 wt % of auxiliary additives, and

[0130] Liquids, such as demineralized water or organic solvents,

[0131] The total weight of the components of the liquid composition is 100 weight %.

[0132] Examples of the organic solvent include, but are not limited to, well-known organic solvents such as acetone, methyl ethyl ketone, methyl n-butyl ketone, methyl isobutyl ketone, ethyl isobutyl ketone, tetrahydrofuran, dioxane, dimethylformamide, diethylformamide, dimethylacetamide, diethylacetamide, N-methylpyrrolidone, methanol, ethanol, isopropanol, ethylene glycol, propylene glycol, 2-methoxy-2-propanol and tetraethylene glycol dimethyl ether or mixtures thereof.

[0133] The choice of the dispersing additive is not particularly limited as long as the additive does not adversely affect the properties of the resulting thermoplastic molding composition. The use of pH-independent dispersing additives has been shown to be particularly advantageous with regard to color uniformity and thermal stability of the resulting thermoplastic molding composition.

[0134] For example, the dispersing additive can be a high molecular weight copolymer comprising at least maleic anhydride, styrene and an aminopolyether as monomer units. Alternatively, the dispersing additive can also be a copolymer of methacrylic acid and a hydrophobic methacrylate. As used herein, the term "hydrophobic methacrylate" preferably refers to an ester formed by methacrylic acid and an alcohol having at least 3 and no more than 24 carbon atoms. In addition, the dispersing additive can also be a copolymer of a polyether, preferably a copolymer of ethylene oxide, propylene oxide and / or butylene oxide, and styrene oxide.

[0135] Suitable dispersing additives include, for example, polyacrylates commercially available from BASF SE. Ultra4550 (previously 4550). This polymer consists essentially of the monomers α-methylstyrene, 2-ethylhexyl acrylate and poly(ethylene glycol) methyl ether (MPEG) methacrylate. Other examples of suitable dispersing additives are available from Evonik Industries AG. Dispers 750W and 755W, and from BYK-Chemie GmbH 190.

[0136] Optionally, to minimize undesirable discoloration of the molding composition at elevated temperatures, the dispersing additive can be selected such that, in dry form, the weight loss during isothermal thermogravimetric analysis (TGA) at 260° C. for 15 minutes does not exceed 15.0% by weight, preferably 0.0 to 10.0% by weight, more preferably 0.0 to 7.0% by weight, even more preferably 0.0 to 5.0% by weight, and particularly preferably 0.0 to 4.0% by weight. The isothermal thermogravimetric analysis is performed using an automatic thermobalance (e.g., a Q5000 IR from TA Instruments) with a heating rate of 5 K / min up to 260° C. and subsequent isothermal analysis at 260° C. for 15 minutes. Prior to the TGA analysis, the sample is dried to constant mass in a drying oven. In the case of bead polymers as dispersing aids, the TGA is performed on solid bead polymers. In other words, in the case of alkaline aqueous solutions of the bead polymers, the solid bead polymers used to prepare these solutions are analyzed.

[0137] In addition to dispersing additives, the liquid formulations may also contain auxiliary additives such as agents to prevent spoilage or bacterial decomposition, fungicides, leveling agents, thickeners and defoamers.

[0138] In some embodiments, for example, if the liquid formulation contains a pigment or a pigment mixture, in particular if its concentration is less than 10.0% by weight, viscosity adjustment may be advantageous to prevent the pigment or pigment mixture from settling. This is preferably accomplished by adding one or more thickeners. Preferred thickeners include, in particular, cellulose, in particular ethylcellulose. As another possibility, polymers containing carboxylate groups, which are available as water-soluble or alkali-soluble solid products, as colloidal solutions or as aqueous dispersions, such as homopolymers and copolymers based on vinyl acetate and crotonic acid or partially hydrolyzed poly(meth)acrylates, can be used as thickeners. Homopolymers and copolymers of acrylic acid and / or methacrylic acid in the form of their sodium salts are particularly preferred.

[0139] The proportion of ethylenically unsaturated, free-radically polymerizable carboxylic acids is preferably not less than 6.0% by weight and not more than 80.0% by weight, preferably from 10.0 to 80.0% by weight, and in particular from 20.0 to 80.0% by weight, based on the total weight of the monomers used to prepare the thickener. Acrylic acid and / or methacrylic acid and maleic acid are preferred, with fumaric acid, itaconic acid or crotonic acid also being suitable.

[0140] The comonomers involved in forming the thickener can be monomers with high or low water solubility, ethylenically unsaturated, and free-radically polymerizable. Ethylene and alkyl acrylates and / or alkyl methacrylates, particularly those having 1 to 4 carbon atoms in the alkyl group, have a favorable effect. Their proportion is preferably 20.0 to 90.0 wt %, more preferably 20.0 to 80.0 wt %, based on the total weight of the monomers used to prepare the thickener. Other useful comonomers are, for example, styrene, acrylonitrile, or vinyl acetate. Comonomers with higher hydrophilicity or water solubility, such as acrylamide and / or methacrylamide or hydroxyalkyl acrylate and / or hydroxyalkyl methacrylate, can also be used, for example, in a proportion of about 30.0 wt %, preferably up to 10.0 wt %, based on the total weight of the monomers used to prepare the thickener.

[0141] The thermoplastic polymer can also be colored by adding a coloring composition in the form of a masterbatch to the thermoplastic polymer obtained in step a). A masterbatch is understood to mean a formulation comprising a polymer molding material, the monoazo dye, and / or carbon black. The concentration of the coloring agent in the masterbatch is adjusted so that the desired color impression is produced when the masterbatch is used to color the uncolored thermoplastic polymer obtained in step a).

[0142] The masterbatch added in step b) generally comprises:

[0143] 0.01 to 40.0% by weight of said monoazo dye,

[0144] 0.01 to 10.0% by weight of carbon black,

[0145] 50.0 to 99.99% by weight of said thermoplastic polymer,

[0146] 0.0 to 10.0 wt. % of at least one auxiliary additive.

[0147] The thermoplastic polymer in the masterbatch can be substantially the same as described above. The selection of the thermoplastic polymer in the masterbatch is not particularly limited, as long as the thermoplastic polymer is suitable for coloring and thermoplastic processing, in particular for injection molding and extrusion. For example, the thermoplastic polymer can advantageously be selected from poly (meth) alkyl acrylates, polymethyl methacrylimide, poly (meth) alkyl acrylate copolymers, polystyrene, polystyrene copolymers, acrylonitrile copolymers, polycarbonate, polyester (preferably polyethylene terephthalate), polyamide, polyvinylidene fluoride or mixtures thereof.

[0148] The thermoplastic polymer can also be colored by adding neat coloring preparations as available from the manufacturer and carbon black to the thermoplastic polymer obtained from step a).

[0149] The present inventors have further found that the coloring formulation used in step b) should advantageously comprise an aluminum compound less than 100ppm and a silicon compound less than 300ppm. This effectively prevents the formation of undesirable dark particles in the molding composition. Without wishing to be bound by theory, the present inventors have found that compounds of aluminum and silicon, even in amounts as low as several hundred ppm, appear to form chelate-type chemical complexes with monoazo dyes comprising at least one heteroaromatic structural portion. Unlike free monoazo dyes, such chemical complexes are substantially insoluble in the thermoplastic polymer matrix and result in the formation of undesirable dark particles in the resulting molding. In particular, if components with complex geometries are manufactured by injection molding, it is often necessary to use elevated temperatures to ensure that the viscosity of the polymer melt is sufficiently low. The combination of elevated temperatures and high shear forces in the presence of aluminum or silicon (silicone) during injection molding appears to promote the formation of such undesirable dark particles.

[0150] The inventors have further discovered that the optical properties and thermal stability of the thermoplastic molding composition can be even further improved if the coloring formulation has a dry form weight loss of no more than 15.0% by weight, preferably 0.0 to 10.0% by weight, more preferably 0.0 to 7.0% by weight, even more preferably 0.0 to 5.0% by weight, and particularly preferably 0.0 to 4.0% by weight, within 15 minutes of isothermal thermogravimetric analysis (TGA) at 260° C. Without wishing to be bound by theory, it appears that coloring formulations with particularly low dry form weight loss often produce particularly low amounts of by-products that have low solubility in the thermoplastic polymer and are responsible for the formation of various optical defects in the final thermoplastic molding composition.

[0151] The method for preparing the thermoplastic molding composition according to the present invention can be implemented by conventional introduction methods in which the thermoplastic polymer and the liquid composition or masterbatch are combined, mixed, and homogenized. This can be carried out in the melt under the action of shear forces. Optionally, the combination and mixing prior to melt homogenization can be carried out using a powder premix, in particular when a masterbatch containing the monoazo dye and / or carbon black is introduced.

[0152] Described thermoplastic polymer and described masterbatch, described liquid composition or as the pure colored preparation that obtains from manufacturer can be merged, mixed, homogenized, and then extrude in conventional equipment, described conventional equipment for example screw type extruder (for example twin screw extruder, ZSK), kneader, Brabender or Banbury grinding mill.After described extrusion, can be with extrudate cooling and granulation.Also can with independent component premix and subsequently individually and / or equally as mixture add remaining parent material.Term " colored preparation " as used in the application refers to the material that can be used as " dyestuff " commercially available from manufacturer.Colored preparation is basically made up of the corresponding monoazo dye with different chemical purity.

[0153] In yet another embodiment, the thermoplastic polymer may be provided in the form of a hot melt and the liquid composition or the masterbatch added thereto.This method is particularly advantageous for coloring thermoplastic polymers directly after their preparation.

[0154] Typically, if the thermoplastic polymer is a polyalkyl (meth)acrylate, step b) is carried out in an extruder, preferably at a temperature in the range of 200° C. to 320° C., more preferably 230° C. to 300° C., since the molding composition has excellent thermal stability and dark particles are not undesirably formed at this stage.

[0155] Use of thermoplastic molding compositions

[0156] In another aspect of the present invention, the present invention relates to a process for producing a molding, wherein the process comprises an injection molding step of the thermoplastic molding composition at a temperature in the range of 200° C. to 320° C., preferably 230° C. to 300° C., wherein the thermoplastic molding composition is injected into a mold from which the molding can be produced, wherein the thermoplastic molding composition comprises a monoazo dye comprising at least one heteroaromatic moiety, and

[0157] The thermoplastic molding composition comprises:

[0158] less than 100 ppm, preferably less than 50 ppm, of aluminum or its compounds, and

[0159] Less than 300 ppm, preferably less than 200 ppm, of silicon or its compounds.

[0160] When the thermoplastic polymer is a polyalkyl (meth)acrylate, the temperature of the molten molding composition during the injection molding process of the present invention is preferably 210 to 320°C, and more preferably 240 to 270°C, without intending to be limiting. Furthermore, the temperature of the injection molding nozzle is preferably 230 to 270°C, and more preferably 240 to 250°C, and the temperature of the injection mold is preferably 40 to 80°C, and more preferably 50 to 60°C. The temperature of the injection molding cylinder is preferably 220 to 260°C, and more preferably 230 to 250°C. In the method of the present invention, the molding composition is injected into the mold at a pressure in the range of 50 to 1000 bar. A specific embodiment herein applies the pressure in stages, with the pressure in the first stage being 50 bar and the pressure in the second stage being 400 bar.

[0161] The injection rate can also be graded, ranging from 0.01 m / s to 0.1 m / s in the first stage, from 0.1 m / s to 1 m / s in the second stage, and from 0.05 m / s to 0.5 m / s in a possible third stage. The metering stroke here is preferably 1 to 4 times the screw diameter.

[0162] Importantly, the method of the present invention is well-suited for producing complex moldings, such as those with variable thickness and / or perforations. Thickness differences in the corresponding injection mold, and particularly in the perforations, i.e., in the area around which the melt is injected into the mold, can have a significant effect on the rheological properties of the material as it fills one or more mold cavities. For the purposes of the present invention, a complex molding is a molded article having one or more of the characteristics described below.

[0163] In one embodiment of the method according to the invention, the complex molding has varying wall thicknesses. The resulting complex molding is preferably a molding whose wall thickness is in the range of 1 to 30 mm and can vary within the complex molding. For example, the variation in wall thickness can be described by a difference between the minimum and maximum wall thickness of the complex molding, which difference is greater than 1 mm, preferably greater than 5 mm, and particularly preferably greater than 10 mm. The ratio of maximum to minimum wall thickness is preferably in the range of >1:20, more preferably >1:10, particularly preferably >1:4, and most preferably >1:2.

[0164] In another embodiment of the method according to the invention, the complex molded part has at least one perforation. The wall thickness of the complex molded part is zero at the location of the perforation. The molding composition surrounding the perforation can form a uniform or variable wall thickness in the surrounding area, preferably within the ranges specified above.

[0165] Another embodiment of the above-described method produces a complex molded part having at least one non-planar surface. This surface is preferably of convex or concave design.

[0166] Another aspect of the present invention relates to a method for producing an extruded part, wherein the method comprises an extrusion process of a thermoplastic molding composition at a temperature in the range of 200° C. to 320° C., preferably 230° C. to 300° C., wherein the thermoplastic molding composition is melted and die-cast into the final part,

[0167] wherein the thermoplastic molding composition comprises a monoazo dye comprising at least one heteroaromatic moiety, and the thermoplastic molding composition comprises

[0168] less than 100 ppm, preferably less than 50 ppm, of aluminum or its compounds, and

[0169] Less than 300 ppm, preferably less than 200 ppm, of silicon or its compounds.

[0170] The content of aluminum and silicon in the coloring preparation can be easily determined by methods such as atomic emission spectroscopy. For example, the sample can be digested and mineralized using a microwave pressure digestion system MARS 5PLUS / MARS 6 and then analyzed using an atomic emission spectrometer iCAP available from ThermoFischer Scientific. TM The analysis was performed using a 7400 ICP-OES analyzer.

[0171] The extrusion of thermoplastic polymers is well known and is described, for example, in the following document: Kunststoffextrusionstechnik II (Plastics Extrusion Technology II), Hanser Verlag, 1986, pages 125 et seq. In the process according to the invention, a hot melt is extruded from the nozzle of an extruder into the gap between two calendering rolls. The optimum temperature of the melt depends, for example, on the composition of the mixture and can therefore vary within a wide range. The preferred temperature of the polyalkyl (meth)acrylate molding compound at the nozzle inlet is in the range of 150 to 300° C., particularly preferably in the range of 180 to 270° C., and very particularly preferably in the range of 200 to 220° C. The temperature of the calendering rolls is preferably less than or equal to 150° C., preferably between 60° C. and 140° C.

[0172] The thermoplastic molding compositions of the invention can advantageously be used to produce moldings having a light gray or jet black appearance and high gloss for use in motor vehicles, household appliances, electrical equipment, decorative strips and exterior cladding, exterior areas of motor vehicles, for example A-pillar, B-pillar, C-pillar or D-pillar cladding, spoilers, window frames, cover strips, hoods and panels, or as components of radiator grilles, antenna claddings, side mirrors or headlights or taillights. DETAILED DESCRIPTION

[0173] Example

[0174] Test Method

[0175] Color measurements were performed using a spectrophotometer Color Eye 7000A available from X-Rite Inc., Grand Rapids, United States. Subsequently, the color coordinates (L*, a*, and b*) of the samples were measured using a spectrophotometer according to standard DIN 5033 (2017) parts 1-4, and the color difference ΔECIELAB 1976 (D 65 , 10°).

[0176] For transparent color (YD 65 / 10°>1, measured as transmittance according to DIN 5033 (2017) Parts 1-4, 7), ΔE is determined via transmittance measurement. 65 / 10°≤1, measured as transmittance according to DIN 5033 (2017) parts 1-4, 7), ΔE is determined via reflectance measurement.

[0177] Weathering tests were performed using the following parameters:

[0178] Xenotest (xenon lamp aging test)

[0179] ·Device: Xenotest Beta LM / 1

[0180] Filter: Xenochrome 300 filter system, daylight (ISO 4892-2)

[0181] Irradiance: 60W / m 2 (300-400nm)

[0182] Temperature: Chamber 38±3℃, Black Standard 65±3℃

[0183] Humidity: 65±10%RH

[0184] 102 minutes drying, 18 minutes water spraying

[0185] Suntest (sun aging test)

[0186] ·Device: Xenotest Beta LM / 1

[0187] Filter: Xenochrome 300 filter system, daylight (ISO 4892-2)

[0188] Irradiance: 60W / m 2 (300-400nm)

[0189] Temperature: Chamber 38±3℃, Black Standard 65±3℃

[0190] Humidity: 65±10%RH

[0191] No drizzle cycle

[0192] In the 750-hour Suntest, samples having a ΔE greater than 0.4 were evaluated as samples having low weathering stability, samples having a ΔE between 0.1 and 0.4 were evaluated as samples having medium weathering stability, and samples having a ΔE lower than 0.1 were evaluated as samples having excellent weathering stability.

[0193] In the 3000-hour Xenotest, samples having a ΔE greater than 3 were evaluated as samples having low weathering stability, samples having a ΔE between 2 and 3 were evaluated as samples having medium weathering stability, and samples having a ΔE lower than 2 were evaluated as samples having excellent weathering stability.

[0194] The thermoplastic molding compositions of Examples 1 to 5 were prepared as follows:

[0195] A mixture is prepared in a tumble mixer using the polymer granules and the coloring preparation or masterbatch from the manufacturer, which is metered by means of a funnel into the granules from Mörfelden. The pelletizer was placed in the feed zone of a single-screw extruder 30ESE from Herbert Stork Maschinenbau GmbH. Extrusion was carried out at 250° C. The degassing zone was connected to a vacuum pump. A pelletizer was connected downstream of the extruder.

[0196] In a second processing step, samples were injection molded from the granules thus obtained. In each example, individual samples with a thickness of 3.0 mm were injection molded at 260° C. on an Arburg Allrounder 320C from ARBURG GmbH & Co KG, Lossburg, under the following conditions:

[0197] Injection time: 0.92 seconds

[0198] Material temperature: 250℃

[0199] Barrel temperature: 250 to 220°C

[0200] Mold temperature: 70℃

[0201] Switching from injection to holding pressure at 600 bar internal mold pressure

[0202] Total cycle time: 40 seconds

[0203] Injection molding with a closed vented barrel.

[0204] Example 1 (comparison)

[0205] Pyrenone-type solvent dyes Red E2G (Solvent Red 179) was purchased from Lanxess Deutschland GmbH, Cologne.

[0206] Commercially available from Polymethyl methacrylate from GmbH The thermoplastic molding composition obtained contained 0.1% by weight of Solvent Red 179 and 0.0001% by weight of Color Black FW1 (Pigment Black 7).

[0207] The injection molded samples were subjected to the Suntest as described above for 750 hours. After the Suntest, the sample had a ΔE (transmittance) of 0.81, which indicates low weathering stability.

[0208] Example 2 (comparison)

[0209] Pyrenone-type solvent dyes Red EG (Solvent Red 135) was purchased from Lanxess Deutschland GmbH, Cologne.

[0210] Commercially available from Polymethyl methacrylate from GmbH The thermoplastic molding composition obtained contained 0.1% by weight of Solvent Red 135 and 0.0001% by weight of Color Black FW1 (Pigment Black 7).

[0211] The injection molded samples were subjected to the Suntest as described above for 750 hours. After the Suntest, the sample had a ΔE (transmittance) of 0.18, which indicates moderate weathering stability.

[0212] Example 3 (present invention)

[0213] Monoazo dyes Red 454 (Solvent Red 195) was purchased from BASF SE, Ludwigshafen.

[0214] Commercially available from Polymethyl methacrylate from GmbH The thermoplastic molding composition obtained contained 0.1% by weight of Solvent Red 195 and 0.0001% by weight of Color Black FW1 (Pigment Black 7).

[0215] The injection molded samples were subjected to the Suntest as described above for 750 hours. After the Suntest, the sample had a ΔE (transmittance) of 0.09, which indicates excellent weathering stability.

[0216] Example 4 (present invention)

[0217] Commercially available from Polymethyl methacrylate from GmbH 8N is used as the thermoplastic material. The thermoplastic molding composition is prepared from a mixture having the following composition:

[0218] 98.63% by weight 8N

[0219] 0.67 wt% of a masterbatch containing 0.1 wt% of Red 454 (Solvent Red 195) available from BASF SE, Ludwigshafen

[0220] 0.37 wt% of a masterbatch containing 1.0 wt% of Color Black FW1 (Pigment Black 7) obtained from The Cary Company of Addison, USA

[0221] 0.33 wt% of a masterbatch containing 1.0 wt% of Blue 7080W (Pigment Blue 15:3), available from BASF SE, Ludwigshafen

[0222] The injection molded samples had an aesthetically pleasing appearance.

[0223] The sample was subjected to 3000 hours of Xenotest as described above. After the Xenotest, the sample had a ΔE (transmittance) of 1.9, which indicates excellent weathering stability.

[0224] Example 4A (comparative, without carbon black)

[0225] Commercially available from Polymethyl methacrylate from GmbH 8N is used as the thermoplastic material. The thermoplastic molding composition is prepared from a mixture having the following composition:

[0226] 99% by weight 8N

[0227] 0.67 wt% of a masterbatch containing 0.1 wt% of Red 454 (Solvent Red 195) available from BASF SE, Ludwigshafen

[0228] 0.33 wt% of a masterbatch containing 1.0 wt% of Blue 7080W (Pigment Blue 15:3), available from BASF SE, Ludwigshafen

[0229] The sample was subjected to 3000 hours of Xenotest as described above. After the Xenotest, the sample had a ΔE (transmittance) of 4.0, which indicates insufficient weathering stability.

[0230] Example 5 (present invention)

[0231] Commercially available from Polymethyl methacrylate from GmbH 8N is used as the thermoplastic material. The thermoplastic molding composition is prepared from a mixture having the following composition:

[0232] 95.9% by weight 8N

[0233] 0.2 wt% of a masterbatch containing 10.0 wt% of Red 454 (Solvent Red 195) available from BASF SE, Ludwigshafen

[0234] 0.2 wt% of a masterbatch containing 10.0 wt% of 140 (Pigment Black 7) available from The Cary Company, Addison, USA

[0235] 2.6 wt% masterbatch containing 10.0 wt% Blue 690 (Solvent Blue 104) available from BASF SE, Ludwigshafen

[0236] 0.5 wt% masterbatch containing 10.0 wt% Yellow G (Solvent Yellow 114) available from Lanxess Deutschland GmbH, Cologne

[0237] 0.6 wt% of a masterbatch containing 1.0 wt% of Green G (Solvent Green 28) available from Lanxess Deutschland GmbH, Cologne

[0238] The injection molded samples had an aesthetically pleasing appearance.

[0239] The sample was subjected to 3000 hours of Xenotest as described above. After the Xenotest, the sample had a ΔE (reflectance) of 0.4, which indicates excellent weathering stability.

[0240] Example 6 (present invention)

[0241] Commercially available from Polymethyl methacrylate from GmbH 8N is used as the thermoplastic material. The thermoplastic molding composition is prepared from a mixture having the following composition:

[0242] 99.344% by weight 8N

[0243] 0.32 wt% of a masterbatch containing 0.01 wt% of Red 454 (Solvent Red 195) available from BASF SE, Ludwigshafen

[0244] 0.176 wt% of a masterbatch containing 0.1 wt% of Color Black FW1 (Pigment Black 7) obtained from The Cary Company, Addison, USA.

[0245] 0.16 wt% of a masterbatch containing 0.1 wt% of Blue 7080W (Pigment Blue 15:3), available from BASF SE, Ludwigshafen

[0246] The injection molded samples had an aesthetically pleasing appearance.

[0247] The sample was subjected to 3000 hours of Xenotest as described above. After the Xenotest, the sample had a ΔE (transmittance) of 0.4, which indicates excellent weathering stability.

[0248] Example 7 (present invention)

[0249] Commercially available from Polymethyl methacrylate from GmbH 8N is used as the thermoplastic material. The thermoplastic molding composition is prepared from a mixture having the following composition:

[0250] 98.864% by weight 8N

[0251] 0.145 wt% of a masterbatch containing 10 wt% of Red 454 (Solvent Red 195) available from BASF SE, Ludwigshafen

[0252] 0.377 wt% of a masterbatch containing 1 wt% of Yellow G (Solvent Yellow 114) from Lanxess AG, Leverkusen,

[0253] 0.322 wt% of a masterbatch containing 0.1 wt% of Color Black FW1 (Pigment Black 7) obtained from The Cary Company of Addison, USA

[0254] 0.292 wt% of a masterbatch containing 0.1 wt% of Blue 7080W (Pigment Blue 15:3), available from BASF SE, Ludwigshafen

[0255] The injection molded samples had an aesthetically pleasing appearance.

[0256] The sample was subjected to 3000 hours of Xenotest as described above. After the Xenotest, the sample had a ΔE (transmittance) of 1.1, which indicates excellent weathering stability.

[0257] Example 7A (comparative, without monoazo dye)

[0258] Solvent Red 179 was used instead of Solvent Red 195 (the monoazo dye used in Example 7 of the present invention).

[0259] Commercially available from Polymethyl methacrylate from GmbH 8N is used as the thermoplastic material. The thermoplastic molding composition is prepared from a mixture having the following composition:

[0260] 98.9945% by weight 8N

[0261] 0.0145% by weight of Macrolexred E2G as pure colorant (Solvent Red 179) from Lanxess AG, Leverkusen

[0262] 0.377 wt% of a masterbatch containing 1 wt% of Yellow G (Solvent Yellow 114) from Lanxess AG, Leverkusen,

[0263] 0.322 wt% of a masterbatch containing 0.1 wt% of Color Black FW1 (Pigment Black 7) obtained from The Cary Company of Addison, USA

[0264] 0.292 wt% of a masterbatch containing 0.1 wt% of Blue 7080W (Pigment Blue 15:3), available from BASF SE, Ludwigshafen

[0265] The sample was subjected to 3000 hours of Xenotest as described above. After the Xenotest, the sample had a ΔE (transmittance) of 5.4, which indicates insufficient weathering stability.

[0266] Example 7B (comparative, without carbon black)

[0267] Commercially available from Polymethyl methacrylate from GmbH 8N is used as the thermoplastic material. The thermoplastic molding composition is prepared from a mixture having the following composition:

[0268] 99.186% by weight 8N

[0269] 0.145 wt% of a masterbatch containing 10 wt% of Red 454

[0270] (Solvent Red 195) available from BASF SE, Ludwigshafen. 0.377 wt% masterbatch containing 1 wt% Yellow G (Solvent Yellow 114) from Lanxess AG, Leverkusen

[0271] 0.292 wt% of a masterbatch containing 0.1 wt% of Blue 7080W (Pigment Blue 15:3), available from BASF SE, Ludwigshafen

[0272] The sample was subjected to 3000 hours of Xenotest as described above. After the Xenotest, the sample had a ΔE (transmittance) of 3.8, which indicates insufficient weathering stability.

[0273] Example 8 (present invention)

[0274] Commercially available from Polymethyl methacrylate from GmbH 7N is used as the thermoplastic material. The thermoplastic molding composition is prepared from a mixture having the following composition:

[0275] 97.99% by weight 7N

[0276] 0.38 wt% of a masterbatch containing 10 wt% of Red 454 (Solvent Red 195) available from BASF SE, Ludwigshafen

[0277] 0.45 wt% of a masterbatch containing 10 wt% of Yellow G (Solvent Yellow 114) from Lanxess AG, Leverkusen

[0278] 0.38 wt% of a masterbatch containing 10 wt% of Color Black FW1 (Pigment Black 7) obtained from The Cary Company of Addison, USA

[0279] 0.3 wt% of a masterbatch containing 10 wt% of Blue 640 (Solvent Blue 104) available from BASF SE, Ludwigshafen

[0280] 0.5 wt% of a masterbatch containing 10 wt% of 645T (Pigment Brown 43) available from Lanxess AG, Leverkusen

[0281] The injection molded samples had an aesthetically pleasing appearance.

[0282] The sample was subjected to 3000 hours of Xenotest as described above. After the Xenotest, the sample had a ΔE (reflectance) of 0.51, which indicates excellent weathering stability.

[0283] Example 8A (comparative, without monoazo dye)

[0284] Solvent Red 179 was used instead of Solvent Red 195 (the monoazo dye used in Example 8 of the present invention).

[0285] Commercially available from Polymethyl methacrylate from GmbH 7N is used as the thermoplastic material. The thermoplastic molding composition is prepared from a mixture having the following composition:

[0286] 98.332% by weight 7N

[0287] 0.038% by weight of Macrolexred E2G as pure colorant (Solvent Red 179) from Lanxess AG, Leverkusen

[0288] 0.45 wt% of a masterbatch containing 10 wt% of Yellow G (Solvent Yellow 114) from Lanxess AG, Leverkusen

[0289] 0.38 wt% of a masterbatch containing 10 wt% of Color Black FW1 (Pigment Black 7) obtained from The Cary Company of Addison, USA

[0290] 0.3 wt% of a masterbatch containing 10 wt% of Blue 640 (Solvent Blue 104) available from BASF SE, Ludwigshafen

[0291] 0.5 wt% of a masterbatch containing 10 wt% of 645T (Pigment Brown 43) available from Lanxess AG, Leverkusen

[0292] The sample was subjected to 3000 hours of Xenotest as described above. After the Xenotest, the ΔE (reflectance) of the sample was 0.9, which shows that the weathering stability is worse than that of Example 8.

[0293] Example 8B (comparative, no carbon black) -

[0294] Commercially available from Polymethyl methacrylate from GmbH 7N is used as the thermoplastic material. The thermoplastic molding composition is prepared from a mixture having the following composition:

[0295] 98.37% by weight 7N

[0296] 0.38 wt% of a masterbatch containing 10 wt% of Red 454 (Solvent Red 195) available from BASF SE, Ludwigshafen

[0297] 0.45 wt% of a masterbatch containing 10 wt% of Yellow G (Solvent Yellow 114) from Lanxess AG, Leverkusen

[0298] 0.3 wt% of a masterbatch containing 10 wt% of Blue 640 (Solvent Blue 104) available from BASF SE, Ludwigshafen

[0299] 0.5 wt% of a masterbatch containing 10 wt% of 645T (Pigment Brown 43) available from Lanxess AG, Leverkusen

[0300] The sample was subjected to 3000 hours of Xenotest as described above. After the Xenotest, the ΔE (reflectance) of the sample was 1.0, which shows that the weathering stability is worse than that of Example 8.

[0301] Example 9 (present invention)

[0302] Commercially available from Polymethyl methacrylate from GmbH 7N is used as the thermoplastic material. The thermoplastic molding composition is prepared from a mixture having the following composition:

[0303] 98.52% by weight 7N

[0304] 0.25 wt% of a masterbatch containing 10 wt% of Red 454 (Solvent Red 195) available from BASF SE, Ludwigshafen

[0305] 0.3 wt% of a masterbatch containing 10 wt% of Yellow G (Solvent Yellow 114) from Lanxess AG, Leverkusen

[0306] 0.5 wt% masterbatch containing 10 wt% Color Black FW1 (Pigment Black 7) available from The Cary Company, Addison, USA

[0307] 0.43 wt% of a masterbatch containing 10 wt% of Yellow K2111 FG (Pigment Brown 24) available from BASF SE, Ludwigshafen

[0308] The injection molded samples had an aesthetically pleasing appearance.

[0309] The sample was subjected to 3000 hours of Xenotest as described above. After the Xenotest, the sample had a ΔE (reflectance) of 0.70, which indicates excellent weathering stability.

[0310] Example 9A (comparative, without carbon black)

[0311] Commercially available from Polymethyl methacrylate from GmbH 7N is used as the thermoplastic material. The thermoplastic molding composition is prepared from a mixture having the following composition:

[0312] 99.02% by weight 7N

[0313] 0.25 wt% of a masterbatch containing 10 wt% of Red 454 (Solvent Red 195) available from BASF SE, Ludwigshafen

[0314] 0.3 wt% of a masterbatch containing 10 wt% of Yellow G (Solvent Yellow 114) from Lanxess AG, Leverkusen

[0315] 0.43 wt% of a masterbatch containing 10 wt% of Yellow K2111 FG (Pigment Brown 24) available from BASF SE, Ludwigshafen

[0316] The sample was subjected to 3000 hours of Xenotest as described above. After the Xenotest, the ΔE (reflectance) of the sample was 1.2, which shows that the weathering stability is worse than that of Example 9.

[0317] Example 10 (present invention)

[0318] Commercially available from Polymethyl methacrylate from GmbH 7H is used as the thermoplastic material. The thermoplastic molding composition is prepared from a mixture having the following composition:

[0319] 98.1% by weight 7H

[0320] 0.2 wt% of a masterbatch containing 10 wt% of Red 454 (Solvent Red 195) available from BASF SE, Ludwigshafen

[0321] 0.67 wt% of a masterbatch containing 10 wt% of Yellow G (Solvent Yellow 114) from Lanxess AG, Leverkusen

[0322] 0.7 wt% of a masterbatch containing 10 wt% of 140V (Pigment Black 7) available from The Cary Company, Addison, USA

[0323] 0.33 wt% of a masterbatch containing 10 wt% of Green G (Solvent Green 28) from Lanxess AG, Leverkusen

[0324] The injection molded samples had an aesthetically pleasing appearance.

[0325] The sample was subjected to 3000 hours of Xenotest as described above. After the Xenotest, the sample had a ΔE (reflectance) of 0.61, which indicates excellent weathering stability.

Claims

1. A thermoplastic molding composition comprising: a) 90.0 to 99.99989 wt % of a thermoplastic polymer; b) 0.0001 to 5.0 wt. % carbon black; and c) 0.00001 to 5.0% by weight of a monoazo dye comprising at least one heteroaromatic moiety; The thermoplastic polymer is polymethyl methacrylate having a weight average molecular weight Mw of 80,000 to 180,000 g / mol and is obtained by polymerizing the following polymerizable composition, the polymerizable component of which comprises, based on the weight of the polymerizable composition: (i) 50.0 to 99.9% by weight of methyl methacrylate, (ii) 0.1 to 50.0% by weight of acrylic acid esters of C1-C4 alcohols, (iii) 0.0 to 35.0 wt. % of at least one other monomer copolymerizable with monomers (i) and (ii); and The monoazo dye is selected from: 5-[(3,4-dichlorophenyl)azo]-1,2-dihydro-6-hydroxy-1,4-dimethyl-2-oxonicotinonitrile, 2,3-Dihydro-2,2-dimethyl-6-((4-(phenylazo)-1-naphthyl)azo)-1H-perylene, Methyl cyano-5-[[5-cyano-2,6-bis[(3-methoxypropyl)amino]-4-methylpyridin-3-yl]azo]-3-methyl-2-thiophenecarboxylate, 5-methyl-2-phenyl-4-phenylazo-4H-pyrazol-3-one, 4-[(2,4-dimethylphenyl)azo]-2,4-dihydro-5-methyl-2-phenyl-3H-pyrazol-3-one, 3-[(1-oxonaphthalene-2-ylidene)methylhydrazide]-1-prop-2-enylindol-2-one, 4-((o-methoxyphenyl)azo)-3-methyl-1-phenyl-2-pyrazolin-5-one, and 5-Methyl-2-phenyl-4-phenylazo-4H-pyrazol-3-one.

2. The thermoplastic molding composition according to claim 1, wherein the carbon black has a weight average particle size of 5.0 to 100.0 nm and a particle size of 50 to 500 nm as determined by the BET method. 2 / g specific surface area.

3. The thermoplastic molding composition according to claim 1 or 2, wherein the carbon black has a weight average particle size of 7.0 to 60.0 nm and a particle size of 50 to 500 nm as determined by the BET method. 2 / g specific surface area.

4. The thermoplastic molding composition according to claim 1 or 2, wherein the composition further comprises: at least one dye selected from the group consisting of pyrene dyes, quinophthalone dyes, and anthraquinone dyes; at least one phthalocyanine pigment; or Mixtures of the above substances.

5. The thermoplastic molding composition according to claim 1 or 2, wherein the thermoplastic polymer is obtained by polymerizing the following polymerizable composition, the polymerizable component of the polymerizable composition comprising, based on the weight of the polymerizable composition: (i) 80.0 to 99.9% by weight of methyl methacrylate, (ii) 0.1 to 20.0% by weight of acrylic acid esters of C1-C4 alcohols, (iii) 0.0 to 35.0% by weight of at least one other monomer copolymerizable with monomers (i) and (ii).

6. The thermoplastic molding composition according to claim 1 or 2, wherein the thermoplastic polymer comprises a polymer matrix and scattering particles dispersed in the polymer matrix, wherein the weight average particle diameter of the scattering particles is 0.01 μm to 100.0 μm and the refractive index of the scattering particles differs from the refractive index of the polymer matrix by at least 0.

01.

7. The thermoplastic molding composition according to claim 1 or 2, wherein the thermoplastic molding composition has a melt flow rate of 0.5 to 10.0 g / 10 minutes measured at 230°C with a load of 3.8 kg.

8. A process for producing a thermoplastic molding composition according to any one of claims 1 to 7, wherein the process comprises the following steps: a) providing a thermoplastic polymer; and b) adding at least one coloring composition comprising carbon black and a monoazo dye comprising at least one heteroaromatic moiety to the thermoplastic polymer obtained in step a), wherein the coloring composition is a liquid composition or a masterbatch.

9. The method of claim 8, wherein the coloring composition is a liquid composition comprising: 1.0 to 30.0% by weight of a dispersing additive, 0.05 to 10.0% by weight of carbon black, 0.5 to 50.0% by weight of said monoazo dye, and 0.0 to 50.0% by weight of auxiliary additives, and liquid, The total weight of the components is 100% by weight.

10. The method according to claim 9, wherein the liquid is demineralized water or an organic solvent.

11. The method of claim 8, wherein the coloring composition is a masterbatch comprising: 0.01 to 40.0% by weight of said monoazo dye, 0.01 to 10.0% by weight of carbon black, 50.0 to 99.98% by weight of a thermoplastic polymer, 0.0 to 10.0% by weight of auxiliary additives.

12. The method according to any one of claims 8 to 11, wherein the coloring composition comprises: Less than 100 ppm of aluminum or its compounds, and Less than 300 ppm of silicon or its compounds; and / or The coloring composition has a weight loss on drying of no more than 15% by weight in isothermal thermogravimetric analysis at 260°C for 60 minutes.

13. The method according to any one of claims 8 to 11, wherein the coloring composition comprises Less than 50 ppm of aluminum or its compounds, and less than 200 ppm of silicon or its compounds; and / or The coloring composition has a loss in dry form of 0.0 to 7 weight percent by isothermal thermogravimetric analysis at 260° C. for 60 minutes.

14. The process according to any one of claims 8 to 11, wherein step b) is performed in an extruder.

15. The process according to any one of claims 8 to 11, wherein step b) is performed in an extruder at a temperature ranging from 200°C to 320°C.

16. A method for producing a molded part, wherein the method comprises the step of injection molding the thermoplastic molding composition according to any one of claims 1 to 7 at a temperature in the range of 200° C. to 320° C., wherein the thermoplastic molding composition is injected into a mold capable of producing the molded part, wherein the thermoplastic molding composition comprises: a) 90.0 to 99.99989 wt % of a thermoplastic polymer; b) 0.0001 to 5.0 wt. % carbon black; and c) 0.00001 to 5.0% by weight of a monoazo dye comprising at least one heteroaromatic moiety.

17. The method according to claim 16, wherein the step of injection molding is performed at a temperature in the range of 230°C to 300°C.

18. A method for producing an extruded part, wherein the method comprises extruding the thermoplastic molding composition according to any one of claims 1 to 7 at a temperature in the range of 200°C to 320°C, wherein the thermoplastic molding composition is melted and die-cast into the final part, wherein the thermoplastic molding composition comprises: a) 90.0 to 99.99989 wt % of a thermoplastic polymer; b) 0.0001 to 5.0 wt. % carbon black; and c) 0.00001 to 5.0% by weight of a monoazo dye comprising at least one heteroaromatic moiety.

19. The method according to claim 18, wherein the extrusion process is carried out at a temperature ranging from 230°C to 300°C.

20. The method of claim 18, wherein the extrusion has varying wall thicknesses, one or more perforations, at least one non-planar surface, or a combination of these features.

21. Mouldings or extrusions obtainable by the process according to any one of claims 16 to 20.

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