Mineral-filled polyamide molding compound

Abstract

To provide a mineral-filled thermoplastic polyamide molding compound with suitable mechanical properties for both automotive and electronics manufacturing, while imparting a deep black impression.SOLUTION: Provided is a mineral-filled thermoplastic polyamide molding compound comprising: (A) 20 to 89.9 wt% of at least one polyamide; (B) a mineral filler accounting for 10 to 55 wt%, composed of a mixture that includes 45 to 70 wt% (cryptocrystalline) silic acid B1, 5 to 15 wt% amorphous silic acid B2, and 20 to 40 wt% calcined kaolin B3, relative to 100 wt% of (B), the component (B) containing 5 to 20 wt% aluminum oxide and 80 to 95 wt% silicon oxide, relative to 100% of (B); (C) 0 to 15 wt% of glass and / or carbon fiber; (D) 0.1 to 5.0 wt% black colorant; and (E) 0 to 5.0 wt% additive.SELECTED DRAWING: None

Description

[Technical field]

[0001] The present invention relates to a thermoplastic mineral-filled polyamide moulding compound and to moulded articles produced therefrom having a particularly deep black impression. The present invention also relates to the use of a particular mineral filler in a black mineral-filled polyamide moulding compound, in particular a mineral filler consisting of a mixture of crystalline silicic acid, amorphous silicic acid and calcined kaolin, for improving the deep black impression. [Background technology]

[0002] Due to their good mechanical properties, chemical resistance, excellent processability and low specific gravity, thermoplastic polyamide materials have established a role in many sectors, in particular in the automotive sector but also in the electronics sector, e.g. for the manufacture of structural components for the housings of portable devices.

[0003] Black molding compounds are required in many applications. While glass-fiber filled polyamide molding compounds can give a sufficiently deep black impression, mineral filled polyamide molding compounds tend to have a dark grey appearance. This is where the present invention comes in. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] WO2018069055 [Patent Document 2] WO2016 / 202359 Summary of the Invention [Problem to be solved by the invention]

[0005] It is therefore an object of the present invention to provide a mineral-filled thermoplastic polyamide moulding compound which has suitable mechanical properties for the aforementioned applications but at the same time gives a deep black colour impression.

[0006] In particular, the object of the present invention is to provide a method for determining the lightness L determined in the CIELAB color space according to DIN EN ISO 11664-4:2020 on a plate of dimensions 60×60×2 mm. * but the color lightness L of up to 30 if gloss is also measured, or up to 12 if gloss is not measured. * The present invention relates to a mineral-filled polyamide molding compound. [Means for solving the problem]

[0007] This problem is solved by the subject matter of the claims, in particular by the thermoplastic polyamide moulding compounds modified according to the invention as defined in claim 1, by the moulded articles as defined in claim 15 and by the use of a mineral filler in a polyamide moulding compound as defined in claim 16 for improving the deep black colour impression, in which the mineral filler consists of a mixture of 45 to 70% by weight of (crypto) crystalline silicic acid (B1), 5 to 15% by weight of amorphous silicic acid (B2) and 20 to 40% by weight of calcined kaolin (B3), in each case relative to 100% by weight of (B), component (B) having an aluminium oxide content of 5 to 20% by weight and a silicon oxide content of 80 to 95% by weight, in each case relative to 100% of (B). DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0008] Thus, the essence of the present invention is finally the use of a mineral filler as a replacement for other mineral fillers in a thermoplastic black polyamide matrix, which has surprisingly been found to result in a very significant improvement of the deep black impression, the mineral filler consisting of a mixture of 45-70% by weight of (crypto)crystalline silicic acid (B1), 5-15% by weight of amorphous silicic acid (B2) and 20-40% by weight of calcined kaolin (B3), each relative to 100% by weight of (B), component (B) having an aluminum oxide content of 5-20% by weight and a silicon oxide content of 80-95% by weight, each relative to 100% by weight of (B). This is achieved without losing any of the favourable mechanical properties.

[0009] It is generally known from other fields that a filler consisting of a mixture of (crypto)crystalline silicic acid, amorphous silicic acid and calcined kaolin can be incorporated into polyamide materials, but this is not related to the improvement of the deep black impression, nor to the specific polyamide moulding compounds described herein.

[0010] In particular, reference should be made to the following documents regarding the prior art: WO2018069055 discloses flame-retardant thermoplastic polyamide molding compounds containing, in addition to a melamine compound, a mineral filler substantially composed of a mixture of (crypto)crystalline silicic acid, amorphous silicic acid and calcined kaolin. The molding compounds should have good mechanical properties and good flame retardancy. In particular, the addition of the mineral filler should allow a flame retardancy that results in the shortest possible afterburning time during the glow wire test. It is also emphasized that the molding compounds can be particularly well colored with bright colors.

[0011] The thermoplastic polyamide moulding compounds proposed herein for the present application are preferably flame retardant-free, in particular melamine-free. WO2016 / 202359 relates to the field of adhesives, in particular moisture-curing or hardening adhesives. The described adhesive provides high strength for bonding materials such as wood, concrete, plastic, stone, etc., and at the same time has high moisture resistance. Claimed is an adhesive comprising modified polyethers, fillers, adhesion promoters, and also one or more compounds selected from the group consisting of free radical scavengers, moisture scavengers, antioxidants, rheology modifiers, and catalysts. One of the preferred fillers is Neuburg Silicate Earth.

[0012] More particularly, the invention relates to a thermoplastic polyamide moulding compound comprising: (A) 20 to 89.9% by weight of at least one polyamide; (B) 10-55% by weight of a mineral filler, which consists of a mixture of 45-70% by weight of (crypto)crystalline silicic acid (B1), 5-15% by weight of amorphous silicic acid (B2) and 20-40% by weight of calcined kaolin (B3) relative to 100% by weight of (B), component (B) having an aluminum oxide content of 5-20% by weight and a silicon oxide content of 80-95% by weight relative to 100% by weight of (B); (C) 0 to 15% by weight of glass and / or carbon fiber; (D) 0.1 to 5.0% by weight of a black colorant; (E) 0 to 5.0% by weight of additives; The total of components (A) to (E) is 100% of the thermoplastic polyamide molding compound.

[0013] References to the individual concentration ranges of components (A) through (E), the sum of components (A) through (E), or the molding compound shall be considered equivalent for purposes of this invention. In the present invention, the term "polyamide" (abbreviation PA) is understood to be a generic term including homopolyamides and copolyamides. The selected notations and abbreviations for polyamides and their monomers correspond to those specified in ISO standard 16396-1 (2015(D)). The abbreviations used therein are used below as synonyms of the IUPAC names of the monomers, in particular the following abbreviations for the monomers are used: BAC stands for bis(aminomethyl)cyclohexane, which includes 1,3-bis(aminomethyl)cyclohexane (1,3-BAC) and 1,4-bis(aminomethyl)cyclohexane (1,4-BAC), MACM stands for bis(4-amino-3-methyl-cyclohexyl)methane (also known as 3,3'-dimethyl-4,4'-diaminodicyclohexylmethane, CAS number 6864-37-5), PACM stands for bis(4-aminocyclohexyl)methane (also known as 3,3'-dimethyl-4,4'-diaminodicyclohexylmethane, CAS number 6864-37-5), bis(4-amino-3,5-dimethyl-cyclohexyl)methane (also known as 3,3',5,5'-tetramethyl-4,4'-diaminodicyclohexylmethane, CAS number 65962-45-0), T stands for terephthalic acid (CAS number 100-21-0), and I stands for isophthalic acid (CAS number 121-95-5).

[0014] In comparison with semi-crystalline polyamides, amorphous polyamides have no or only a very low, barely detectable heat of fusion. In dynamic differential calorimetry (DSC) according to ISO 11357 (2013) at a heating rate of 20 K / min, amorphous polyamides exhibit the following behavior: preferably a heat of fusion of up to 5 J / g, particularly preferably up to 3 J / g, very particularly preferably 0 to 1 J / g. Amorphous polyamides do not have a melting point due to their amorphous nature.

[0015] In the context of the present invention, semicrystalline polyamides are polyamides which, in dynamic differential calorimetry (DSC) according to ISO 11357 (2013) at a heating rate of 20 K / min, preferably have a heat of fusion of more than 5 J / g, particularly preferably at least 25 J / g and very particularly preferably at least 30 J / g.

[0016] The color impression of the molded compound colored according to the present invention and the molded article produced therefrom can be described using the CIE standard color system. DIN EN ISO 11664-2020 (Parts 1 to 4) defines spectral value functions for use in colorimetry and describes the corresponding color measurements. The measurement is performed as the ratio of the reflection or transmission of the sample to a reference standard (= white standard), and thus is independent of the light source. L * , a * , and b * values can be determined from the spectral data using the standard color values shown in the table. The reflected or transmitted light is analyzed using a "monochromator" system consisting of a diffraction grating (prism) that splits the light and images it onto a photodiode array. The interaction (reflection) between the material surface and light can be directional or diffusive depending on the nature of the surface. Scattered light is the cause of a dark surface appearing bright when viewed. This is taken into account using a standard spherical shape. Gloss can be included or excluded by using the following measurement modes. Measurement mode A: Reflection, measurement geometry: D / 8°, light source: D65 / 10, gloss: included, calibration: UV calibration, measurement aperture: SAV; Measurement mode B: Reflection, measurement geometry: D / 8°, light source: D65 / 10, gloss: excluded, calibration: UV calibration, measurement aperture: SAV.

[0017] The term exclusion of gloss in relation to luminance measurement or luminance values shall be considered equivalent to the following phrases: exclusion of gloss, measurement without gloss, measurement without gloss content, matte.

[0018] The term inclusion of gloss in relation to luminance measurement values or luminance values shall be considered equivalent to the following phrases: gloss included, measurement with gloss, measurement with gloss content, glossy.

[0019] The use of the mineral filler (B) according to the invention makes it possible to produce colored mineral-filled thermoplastic molding compounds with a deep black color impression. In the CIELAB color space according to DIN EN ISO 11664-2020, measured without gloss content, the L * When measured including the gloss content, L values ​​of up to 30, preferably up to 28, particularly preferably up to 27 are achieved. * Value is achieved.

[0020] According to a first preferred embodiment, the moulding compound is characterised in that component (A) is present in the moulding compound in a proportion ranging from 28 to 84.9% by weight, preferably from 50 to 79.8% by weight.

[0021] In a preferred embodiment, component (A) may consist exclusively of a semicrystalline polyamide (A1), which is an aliphatic semicrystalline polyamide based on aliphatic dicarboxylic acids and aliphatic diamines and / or a partially aromatic semicrystalline polyamide based on dicarboxylic acids and diamines, the diacids or diamines containing aromatic structural units.

[0022] In a further preferred embodiment, component (A) may comprise a mixture of a semicrystalline polyamide (A1) and an amorphous polyamide (A2). Component (A) preferably comprises the following components: (A1) 20 to 100% by weight, preferably 40 to 85% by weight, of at least one aliphatic semicrystalline polyamide based on aliphatic dicarboxylic acids and aliphatic diamines and / or at least one partially aromatic semicrystalline polyamide based on dicarboxylic acids and diamines, (A2) 0 to 80% by weight, preferably 15 to 60% by weight, of at least one amorphous polyamide; The sum of the weight percentages of components (A1) and (A2) is 100 weight percentages of component (A).

[0023] The polyamides of components (A1) and (A2) are preferably of the AABB type, i.e. composed of dicarboxylic acids and diamines, with lactams and amino acids also being present as minor proportions.

[0024] Examples of diamines of component (A1) include the following monomers: 1,4-butanediamine, 2-methyl-1,5-pentanediamine, 2-butyl-2-ethyl-1,5-pentanediamine, 1,6-hexanediamine, 2,2,4-trimethylhexamethylenediamine, 2,4,4-trimethylhexamethylenediamine, 1,7-heptanediamine, 1,8-octanediamine, 2-methyl-1,8-octanediamine, 1,9-nonanediamine, 1,10-decanediamine. , 1,11-undecanediamine, 1,12-dodecanediamine, 1,13-tridecanediamine, 1,14-tetradecanediamine, 1,3-bis-(aminomethyl)cyclohexane, 1,4-bis-(aminomethyl)cyclohexane, m-xylylenediamine, and p-xylylenediamine may be used, with 1,6-hexanediamine, 1,10-decanediamine, 1,12-dodecanediamine, and 1,3-bis-(aminomethyl)cyclohexane being preferred.

[0025] Suitable dicarboxylic acids of component (A1) are, for example, the following monomers: adipic acid, suberic acid, azelaic acid, sebacic acid, undecanediacid, dodecanediacid, tridecanediacid, tetradecanediacid, pentadecanedioic acid, hexadecanedioic acid, heptadecanedioic acid, octadecanedioic acid, C36 dimer fatty acid, cis- and / or trans-cyclohexane-1,4-dicarboxylic acid and / or cis- and / or trans-cyclohexane-1,3-dicarboxylic acid, terephthalic acid, isophthalic acid, naphthalenedicarboxylic acid, in particular 1,5-naphthalenedicarboxylic acid and 2,6-naphthalenedicarboxylic acid, and mixtures thereof. Adipic acid, sebacic acid, tetradecanediacid, hexadecanedioic acid and dodecanediacid are preferred.

[0026] Furthermore, the polyamides (A1) and (A2) may also contain lactams or aminocarboxylic acids, in particular α,ω-amino acids or lactams having 6 to 12 carbon atoms, such as, for example, the following selections: m-aminobenzoic acid, p-aminobenzoic acid caprolactam (CL), α,ω-aminocaproic acid, α,ω-aminoheptanoic acid, α,ω-aminooctanoic acid, α,ω-aminononanoic acid, α,ω-aminodecanoic acid, α,ω-aminoundecanoic acid (AUA), laurinlactam (LL) and α,ω-aminododecanoic acid (ADA). Particularly preferred are caprolactam, aminocaproic acid, α,ω-aminoundecanoic acid, laurinlactam and α,ω-aminododecanoic acid. However, the proportion of these lactams or amino acids is preferably less than 50% by weight, particularly preferably less than 20% by weight and particularly preferably less than 10% by weight, based on the total mass of polyamide (A1).

[0027] The polyamide of component (A1) is preferably semicrystalline aliphatic polyamides selected from the group consisting of PA 6, 46, 56, 66, 66 / BAC6, 66 / 6, 69, 610, 612, 614, 616, 618, 810, 1010, 1012, 1212, 11, 12, 6 / 12, 66 / 6 / 610, with 66, 66 / BAC6 and 610 being preferred and 66 / BAC6, the BAC of which is equal to 1,3-BAC, being particularly preferred; and / or semicrystalline partially aromatic polyamides selected from the group consisting of PA 6T / 6I, 6T / 66, 6T / 6I / 66, 6T / 610, 6T / 612, 6T / 614, 6T / 616, 9T, 9MT (M=2-methyloctane-1,8-diamine), 10T, 11T, 10T / 6T, 11T / 6T, 12T, 10T / 6T, 11 / 10T, 12 / 10T, 11 / 9T, 12 / 9T, 10T / 1010, 10T / 612, in which the proportion of terephthalic acid based on the total dicarboxylic acid content is preferably greater than 50 mol%, particularly preferably greater than 55 mol%, and / or semi-crystalline polyamides having a melting point of at least 170°C, preferably in the range of 175-340°C, or, if aliphatic, preferably in the range of 175-265°C.

[0028] Very particular preference is given as component (A1) to polyamide 66 / BAC6 in a molar ratio of 66:BAC6 from 75:25 to 55:45, in particular from 70:30 to 60:40, the BAC being preferably 1,3-bis(aminomethyl)cyclohexane (1,3-BAC).

[0029] Furthermore, the polyamides of components (A), (A1) and (A2) preferably have a relative viscosity, measured in accordance with ISO 307 (2007) on m-cresol (0.5 g polymer in 100 ml m-cresol at 20° C.), in the range from 1.4 to 3.0, particularly preferably in the range from 1.45 to 2.70 and particularly preferably in the range from 1.50 to 2.40.

[0030] The polyamide of component (A2) is preferably is selected from the group consisting of amorphous polyamide 12 / MACMT, MACM10, MACM12, MACM14, MACM16, MACM18, MACMI / 12, PACM10, PACM12, PACM14, PACM16, PACM18, PACMI / 12, TMDC10, TMDC12, TMDC16, TMDC18, MACMT / MACMI / 12, PACMT / PACMI / 12, or mixtures thereof; and / or amorphous polyamides selected from the group consisting of MXDI, MXDI / 6I, MXD6 / MXDI, 6I, 6 / 6I, 6T / 6I, 10T / 10I, 3-6T (3-6=2,2,4- or 2,4,4-trimethylhexanediamine) or mixtures thereof, the 6T / 6I or 10T / 10I system having a proportion of 6T or 10T units of less than 50 mol %, the composition range of 6T:6I or 10T / 10I being preferred being 20:80 to 45:55, in particular 25:75 to 40:60, and / or an amorphous polyamide having a glass transition temperature (Tg) of more than 90°C, particularly preferably more than 110°C, particularly preferably more than 120°C.

[0031] Diamines for the amorphous polyamides of component (A2) are preferably selected from the group consisting of 1,6-diaminohexane, 1,10-diaminodecane, 1,12-diaminododecane, bis-(4-amino-3-methyl-cyclohexyl)-methane (MACM), bis-(4-amino-cyclohexyl)-methane (PACM), bis-(4-amino-3-ethyl-cyclohexyl)-methane (EACM), bis-(4-amino-3,5-dimethyl-cyclohexyl)-methane (TMDC), 2,6-norbornane diamine (2,6-bis-(aminomethyl)-norbornane), 1,3-diaminocyclohexane, 1,4-diaminocyclohexane, isophorone diamine, 1,3-bis-(aminomethyl)cyclohexane, 1,4-bis-(aminomethyl)cyclohexane, 2,2-(4,4'-diaminodicyclohexyl)propane, meta-xylylenediamine, para-xylylenediamine, and mixtures thereof. The diamine is particularly preferably selected from the group consisting of hexane-1,6-diamine, decane-1,10-diamine, bis-(4-amino-3-methyl-cyclohexyl)methane (MACM), and bis(4-amino-cyclohexyl)methane (PACM), and mixtures thereof.

[0032] The dicarboxylic acids for the polyamide (A2) are preferably selected from the group consisting of terephthalic acid, isophthalic acid, naphthalenedicarboxylic acid (NDA), in particular 1,5-naphthalenedicarboxylic acid and 2,6-naphthalenedicarboxylic acid, 1,6-hexanedioic acid (adipic acid), 1,9-nonanedioic acid, 1,10-decanedioic acid, 1,11-undecanedioic acid, 1,12-dodecanedioic acid, 1,13-tridecanedioic acid, 1,14-tetradecanedioic acid, 1,16-hexadecanedioic acid, 1,18-octadecanedioic acid, and mixtures thereof. Particularly preferred are 1,6-hexanedioic acid, 1,10-decanedioic acid, 1,12-dodecanedioic acid, terephthalic acid, isophthalic acid, and mixtures thereof. Furthermore, caprolactam and laurinlactam are preferred monomers for the preparation of the polyamides of component (A2).

[0033] According to the invention, the moulding compound comprises, besides the polyamide matrix, a certain proportion of a mineral filler as component (B). Preferably, the proportion of component (B) in the moulding compound is in the range from 15 to 50% by weight, preferably in the range from 20 to 45% by weight.

[0034] Surprisingly, particularly suitable as component (B) is a natural mineral filler, which consists of a mixture of finely divided (crypto)crystalline silicic acid, amorphous silicic acid and calcined layered kaolin. The mineral mixture is a deposit of non-agglomerated crystalline material that cannot be separated by physical methods. The silicic acid fraction has a rounded grain shape and consists of aggregated cryptocrystalline primary particles, the size of which is about 200 nm, and is coated with amorphous silicic acid like an opal. This structure results in a relatively high specific surface area and oil absorption value.

[0035] As component (B), the molding compound according to the invention contains 10 to 55% by weight, preferably 15 to 50% by weight, particularly preferably 20 to 45% by weight, of a mineral filler which consists essentially of a mixture of (crypto)crystalline silicic acid (B1), amorphous silicic acid (B2) and calcined kaolin (B3).

[0036] The mineral filler (B) contains a mixture of 45-70% by weight, preferably 53-65% by weight, of (B1), 5-15% by weight, preferably 7-12% by weight, of (B2), and 20-40% by weight, preferably 25-35% by weight, of (B3), relative to 100% by weight of (B).

[0037] Component (B) has an aluminum oxide content of 5-20% by weight, preferably 7-17% by weight, in particular 8-15% by weight, based on 100% by weight of (B). In addition, component (B) has a silica content of 80-95% by weight, preferably 83-93% by weight, in particular 85-92% by weight, based on 100% by weight of (B). Both the silicon oxide and aluminum oxide contents can be determined using XRF (X-ray fluorescence analysis) according to DIN 51001.

[0038] In a preferred embodiment, component (B) is a mineral filler consisting of a mixture of 45-70% by weight of (crypto)crystalline silicic acid (B1), 5-15% by weight of amorphous silicic acid (B2) and 20-40% by weight of calcined kaolin (B3), each relative to 100% by weight of (B), component (B) having an aluminum oxide content of 5-20% by weight and a silicon oxide content of 80-95% by weight relative to 100% by weight of (B).

[0039] Preferred components (B) have a BET specific surface area according to DIN ISO 9277 of 5 to 15 m 2 / g, preferably 6 to 10m 2 / g and / or an oil absorption according to DIN ISO 787 part 5 of 50 to 60 g / 100 g, preferably 52 to 58 g / 100 g.

[0040] For better compatibility with the polymer matrix, the mineral filler (B) can be surface-treated, preferably with silane compounds, particularly preferably with aminosilane compounds. Preferred silane compounds are trialkoxysilanes, dialkoxysilanes, epoxysilanes, vinylsilanes, (meth)acryloxysilanes, aminosilanes, and mercaptosilanes.

[0041] Suitable representatives of these silane compounds are, for example, γ-glycidoxypropylmethyl-dimethoxysilane, γ-glycidoxypropylmethyldiethoxysilane, vinylmethyldimethoxysilane, vinylmethyldiethoxysilane, γ-(meth)acryloxypropylmethyldimethoxysilane, γ-(meth)acryloxypropylmethyldiethoxysilane, ((meth)acryloxymethyl)methyldimethoxysilane, γ-aminopropylmethyldiethoxysilane, N-β-(aminoethyl)-γ-aminopropylmethyl-dimethoxysilane, N-β-(aminoethyl)-γ-aminopropylmethyldimethoxysilane, N-β-(aminoethyl)-γ-aminoisobutylmethyldimethoxysilane, γ-aminopropylmethyldi-methoxysilane, N-β-(aminoethyl)-γ-aminopropylmethyldiethoxysilane, 3-mercaptopropylmethyldimethoxysilane, γ-aminopropylmethyldimethoxysilane, Ethoxysilane, N-β-(aminoethyl)-γ-aminopropylmethyl-dimethoxysilane, N-β-(aminoethyl)-γ-aminopropylmethyldimethoxysilane, N-β-(aminoethyl)-γ-aminoisobutylmethyldimethoxysilane, γ-aminopropylmethyl-dimethoxysilane, N-β-(aminoethyl)-γ-aminopropylmethyldiethoxysilane, γ-aminopropyltriethoxysilane, γ-aminopropyltrimethoxysilane, N-β-(aminoethyl)-γ-aminopropyltrimethoxysilane, N-β-(aminoethyl)-γ-aminopropyltriethoxysilane, diethylenetriaminopropyltrimethoxysilane, bis-(γ-trimethoxysilylpropyl)amine, N-phenyl-γ-aminopropyltrimethoxysilane, γ-amino-3,3-dimethylbutyltrimethoxysilane, γ-aminobutyltriethoxysilane, polyazamidesilane.

[0042] Particularly preferred silane compounds are primary and secondary aminosilane compounds, such as aminopropyltrimethoxysilane, aminobutyltrimethoxysilane, aminopropyltriethoxysilane, aminobutyltriethoxysilane, bis(3-triethoxysilylpropyl)amine, and N-[3-(trimethoxysilyl)-propyl]-ethylenediamine.

[0043] Secondary aminosilanes are particularly preferred, with bis(3-triethoxysilylpropyl)amine and N-[3-(trimethoxysilyl)-propyl]-ethylenediamine being especially preferred.

[0044] The silane compounds are generally used for surface coating in an amount of 0.01 to 2% by weight, preferably 0.025 to 1.0% by weight, particularly preferably 0.05 to 0.5% by weight, based on component (B).

[0045] Particularly preferably, the mineral filler (B) according to the invention is surface-coated with primary and / or secondary aminosilanes, particularly preferably secondary aminosilanes, the amount of primary and / or secondary aminosilanes being 0.01 to 2.0% by weight, preferably 0.025 to 1.0% by weight, based on component (B).

[0046] In a preferred embodiment, component (B) is a mineral filler consisting of a mixture of 45 to 70% by weight of (crypto)crystalline silicic acid (B1), 5 to 15% by weight of amorphous silicic acid (B2) and 20 to 40% by weight of calcined kaolin (B3), each based on 100% by weight of (B), component (B) having an aluminum oxide content of 5 to 20% by weight and a silicon oxide content of 80 to 95% by weight based on 100% of (B), the mineral filler (B) being surface-coated with primary and / or secondary aminosilanes, particularly preferably secondary aminosilanes, the amount of primary and / or secondary aminosilanes being 0.01 to 2.0% by weight, preferably 0.025 to 1.0% by weight, based on component (B).

[0047] The polyamide moulding compound according to the invention can also contain reinforcing fibres, in particular glass fibres and / or carbon fibres, as component (C). Component (C) is contained in the moulding compound in an amount of 0 to 15% by weight, based on the sum of components (A) to (E). Particularly preferably, the moulding compound does not contain component (C), i.e. in this preferred embodiment, the moulding compound according to the invention does not contain any reinforcing fibres, i.e. does not contain glass fibres and / or carbon fibres.

[0048] The reinforcing fibres may be in the form of short fibres (chopped fibres) or long fibres (rovings). The reinforcing fibres C are preferably glass fibres. Suitable glass fibers have a diameter of 6 to 20 μm, preferably 6 to 17 μm, particularly preferably 6 to 13 μm, very particularly preferably 7 to 12 μm. The glass fibers can consist of all types of glass, for example D-, E-, ECR-, L-, S-, R-glass or any mixtures thereof. Glass fibers made of E-glass, ECR-glass or S-glass or mixtures of these fibers are preferred.

[0049] Suitable glass fibers have a cross-sectional area which may be circular or non-circular, and in the latter case have a dimensional ratio of the major cross-sectional axis to the minor cross-sectional axis of at least 2, preferably in the range of 2-5. The reinforcing fibres, in particular glass fibres, can be prepared with sizes suitable for thermoplastic materials, in particular polyamides, containing adhesion promoters based on amino or epoxy silane compounds.

[0050] In addition, the proposed moulding compound contains, besides the polyamide and the mineral filler according to the invention, at least one black colourant for colouring the moulding compound, more particularly as component (D), which is preferably present in the moulding compound in a proportion in the range from 0.1 to 3.0% by weight, preferably in the range from 0.1 to 2.0% by weight.

[0051] Component (D) is constructed by a colorant or a mixture of colorants suitable for coloring the polyamide molding compound dark or black. The colorant may be an organic or inorganic dye or pigment. A dye is a colorant that usually does not scatter light but absorbs light of certain specific visible wavelengths. Dyes often dissolve in the polymer matrix at certain concentrations. A pigment is an organic or inorganic dye that usually exists as individual particles insoluble in the polymer matrix.

[0052] According to the present invention, the colorant is used in an amount and combination sufficient to make the molding compound dark and opaque, particularly in an amount and combination sufficient to achieve the lightness value (L * , luminance) of the color described below. The specific amount of the colorant used depends, inter alia, on its solubility and absorption coefficient in the thermoplastic matrix and whether it is used in combination with one or more additional colorants.

[0053] Suitable colorants generally have a high absorption coefficient and high thermal stability in the visible wavelength range. A colorant has high thermal stability if no significant color shift or thermal degradation is observed during the production and processing of the colored molding compound by injection molding or extrusion in the temperature range of 230 to 300 °C. Furthermore, the colorant should not attack or degrade the polymer, which could lead to an unacceptable loss of mechanical properties or the formation of gaseous by-products during molding.

[0054] Regarding the present invention, the black colorant may also be derived from non-black, i.e., a mixture of colored pigments or dyes, provided that the mixture of individual colorants (dyes or pigments) results in black as a whole or enables the molding compound to be colored black.

[0055] Colorants (dyes and pigments) that may be preferably used as component (D) include carbon black, graphite, graphene, nigrosine, black pigments or dyes, and combinations of complementary pigments or dyes which, when mixed, allow a black coloring effect to be achieved, or mixtures of one or more of these colorants.

[0056] Particularly preferred for the combination of complementary pigments or dyes are the following dye mixtures (expressed as Color Index Common Names (CIGN)): Solvent Green 3 and Solvent Red 179 Solvent Red 52 and Solvent Blue 97 Solvent Green 3, Solvent Blue 97, and Solvent Red 179 The colorant is selected from the group consisting of:

[0057] Very particularly preferred colorants are the following components (expressed as Color Index Common Names (CIGN)): (D1) 20 to 40% by weight of Solvent Green 3 (D2) 10 to 30% by weight of Solvent Blue 97 (D3) 40 to 70% by weight of Solvent Red 179 The mixture (D) is the mixture (D), and the total of the components (D1) to (D3) is 100% by weight of the mixture (D). Preferably, the content of this colorant mixture D is 0.15 to 0.25% by weight based on the total of the components (A) to (E).

[0058] Another preferred colorant is carbon black. Carbon black, also known as technical carbon black, is a modified carbon with a high surface-to-volume ratio and is composed of on the order of 80-99.5% carbon by weight. The specific surface area of ​​technical carbon black is about 10-1500 m 2 / g (BET). Carbon black can be produced as gas carbon black, furnace carbon black, flame carbon black, cracked carbon black, or acetylene carbon black. The particle size ranges from 8 to 500 nm, typically 8 to 110 nm. Carbon black is also known as pigment black 7 or lamp black 6. Pigmented carbon black is a nanoparticle carbon black that is so fine that it gradually loses the brown base color of conventional carbon black.

[0059] The following black pigments: Iron oxide black (Fe 3 O 4 ), Spinel Black (Cu(Cr,Fe) 2 O 4 ), manganese black (a mixture of manganese dioxide, silica and iron oxide), cobalt black, and antimony black may also be used as colorants.

[0060] Nigrosine may also be used for black coloring. Nigrosine is a group of blue, black, or gray phenazine dyes (azine dyes) generally related to Induline in various forms (water-soluble, oil-soluble, alcohol-soluble). Nigrosine dyes are produced by, for example, reacting aniline, aniline hydrochloride, and nitrobenzene with metallic iron or copper and metal salts such as ferric chloride (FeCl 3 Nigrosine can be synthesized by oxidation and dehydration condensation by heating at a reaction temperature of 160-180°C in the presence of nigrosine. Depending on the reaction conditions, the raw materials used, the charge ratio, etc., nigrosine can be produced as a mixture of different compounds, for example, it is envisaged that nigrosine can be a mixture of different triphenazine oxazine compounds and phenazine azine compounds. Nigrosine can be used in the form of a free base or in the form of a salt (e.g., hydrochloride).

[0061] The nigrosines of the present invention may be black azine series mixtures described in the COLOUR INDEX as Cl Acid Black 2, Cl Solvent Black 5, Cl Solvent Black 5:1, Cl Solvent Black 5:2, and Cl Solvent Black 7 (Cl common names according to the COLOUR INDEX 3rd Edition).

[0062] Examples of commercially available Nigrosine dyes are Spirit Black SB, Spirit Black SSBB, Spirit Black AB (all classified as Cl Solvent Black 5); Nigrosine Base SA, Nigrosine Base SAP, Nigrosine Base SAP-L, Nigrosine Base EE, Nigrosine Base EE-L, Nigrosine Base EX, Nigrosine Base EX-BP (all classified as Cl Solvent Black 7), all products of Orient Chemical Industry Co., Ltd. Cl Solvent Black 7 (CAS number 8005-02-5) is preferably used.

[0063] The mentioned colorants can preferably be introduced into the moulding compounds according to the invention as masterbatches or concentrates based on polyamide (A), preferably polyamide (A1), the colorant content preferably ranging from 20 to 50% by weight. The aliphatic polyamides PA6, PA66, PA66 / BAC6, PA610, PA6 / 12, PA12 or mixtures thereof are preferably used as the basis for these masterbatches.

[0064] Preferably used as component (D) are black colorants selected from the group consisting of carbon black, graphite, graphene, nigrosine, black pigments, black dyes, or combinations of complementary pigments and / or dyes, or mixtures of one or more of these colorants.

[0065] Preferably, the polyamide moulding compound according to the invention has a colour lightness L measured in the CIE-LAB light space. * (brightness) is up to 28 if gloss is included, particularly preferably up to 27, and if gloss is excluded, the color lightness L* The colorant (component D) is applied so that the .gamma.-to-.gamma.-to-.gamma. is a maximum of 8, particularly preferably a maximum of 6.

[0066] Finally, the proposed moulding compound may also contain an additive as component (E). Component (E), which is different from components A to D, is preferably present in the moulding compound in a proportion ranging from 0 to 4.0% by weight, preferably from 0.1 to 3.0% by weight.

[0067] The additives of component (E) may be selected from the group consisting of stabilizers, anti-aging agents, antioxidants, anti-ozonants, light stabilizers, UV stabilizers, UV absorbers, UV blockers, inorganic heat stabilizers, in particular inorganic heat stabilizers based on copper halides and alkali halides, organic heat stabilizers, conductive additives, processing aids, nucleating agents, crystallization accelerators, crystallization retarders, flow aids, lubricants, release agents, plasticizers, marking agents, and mixtures thereof.

[0068] The moulding compound according to the invention preferably contains as component (E) at least one stabilizer selected from the group consisting of inorganic and organic stabilizers, in particular antioxidants, antiozonants, heat stabilizers, light stabilizers, UV stabilizers, UV absorbers or UV blockers. Preferably, the stabilizer C is a UV and / or heat stabilizer.

[0069] According to a preferred embodiment, component (E) may be selected from the following group: · A monovalent or divalent copper compound, especially a salt of monovalent or divalent copper with an inorganic or organic acid or a monovalent or divalent phenol, an oxide of monovalent or divalent copper, or a complex compound of a copper salt with ammonia, amine, amide, lactam, cyanide, or phosphine, preferably a Cu(I) or Cu(II) salt of hydrohalic acid or hydrocyanic acid, or a copper salt of an aliphatic carboxylic acid, particularly preferably CuCl, CuBr, CuI, CuCN, and Cu2O of monovalent copper compounds, and CuCl2, CuSO4, CuO, copper(II) acetate, or copper(II) stearate of divalent copper compounds, or a mixture of these compounds, and these copper compounds are used as such or preferably in the form of a concentrate. A concentrate means a polymer containing a copper salt or copper compound at a high concentration and preferably having the same or substantially the same chemical properties as component A1 or A2. In particular, the copper compound is preferably used in combination with other metal halides, including alkali metal halides such as Nal, KI, NaBr, and KBr, and the molar ratio of the metal halide to copper is 0.5 to 20, preferably 1 to 10, particularly preferably 2 to 7; · A stabilizer based on a secondary aromatic amine; · A stabilizer based on a sterically hindered phenol; · Phosphites and phosphonites, · A stabilizer selected from the group consisting of N,N'-oxamides, hydroxyphenyltriazines, hydroxyphenylbenzotriazoles, dibenzoylmethane, aminohydroxybenzoyl benzoates, hydroxybenzophenones, hindered amine light stabilizers (HALS), and · A mixture of the above stabilizers.

[0070] Particularly preferred examples of stabilizers related to secondary aromatic amines that can be used according to the present invention are an adduct of phenylenediamine and acetone (Naugard A), an adduct of phenylenediamine and linolenic acid, Naugard 445, N,N'-dinaphthyl-p-phenylenediamine, N-phenyl-N'-cyclohexyl-p-phenylenediamine, or a mixture of two or more of them.

[0071] Preferred examples of stabilizers based on sterically hindered phenols that can be used according to the invention are N,N'-hexamethylenebis-3-(3,5-di-tert-butyl-4-hydroxyphenyl)-propionamide, bis-(3,3-bis-(4'-hydroxy-3'-tert-butylphenyl)-butanoic acid)-glycol ester, 2,1'-thioethylbis-(3-(3,5-di.tert-butyl-4-hydroxyphenyl)-propionate, 4-4'-butylidene-bis-(3-methyl-6-tert.butylphenol), triethylene glycol 3-(3-tert-butyl-4-hydroxy-5-methylphenyl)propionate, or mixtures of two or more of these stabilizers.

[0072] Preferred phosphites and phosphonites are triphenyl phosphite, diphenyl alkyl phosphites, phenyl dialkyl phosphites, tris(nonylphenyl) phosphite, trilauryl phosphite, trioctadecyl phosphite, distearyl pentaerythritol diphosphite, tris(2,4-di-tert-butylphenyl) phosphite, diisodecyl pentaerythritol diphosphite, bis(2,4-di-tert-butylphenyl) pentaerythritol diphosphite, bis(2,6-di-tert-butyl-4-methylphenyl)-pentaerythritol diphosphite, diisodecyloxypentaerythritol diphosphite, bis(2,4-di-tert-butyl-6-methylphenyl)-pentaerythritol diphosphite, Taerythritol diphosphite, bis(2,4,6-tris-(tert-butyl-phenyl))pentaerythritol diphosphite, tristearyl sorbitol diphosphite, tetrakis(2,4-di-tert-butylphenyl)-4,4'-biphenylene diphosphonite, 6-isooctyloxy-2,4,8,10-tetra-tert-butyl-12H-dibenzo-[d,g]-1,3,2-dioxaphosphocin, 6-fluoro-2,4,8,10-tetra-tert-butyl-12-methyl-dibenzo[d,g]-1,3,2-dioxaphosphocin, bis(2,4-di-tert-butyl-6-methylphenyl)methyl phosphite, and bis(2,4-di-tert-butyl-6-methylphenyl)ethyl phosphite. In particular, tris[2-tert-butyl-4-thio(2'-methyl-4'-hydroxy-5'-tert-butyl)-phenyl-5-methyl]phenyl phosphite and tris(2,4-di-tert-butylphenyl)phosphite (Hostanox® PAR24: commercial product of Clariant, Basel).

[0073] A preferred embodiment of the heat stabilizer is Irgatec NC 66 (available from BASF) in combination with a copper stabilizer based on CuI and KI. Heat stabilizers based only on CuI and KI are particularly preferred.

[0074] According to a further preferred embodiment, the heat stabilizer of component (E) is selected from the group of phenolic heat stabilizers, phosphite heat stabilizers, amine heat stabilizers, or mixtures or combinations thereof, component (E) being particularly preferably selected from the following group: triethylene glycol bis(3-tert-butyl-4-hydroxy-5-methylphenyl)propionate, pentaerythritol tetrakis(3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate), N,N'-hexamethylene bis[3-(3,5-di-t-butyl-4-hydroxyphenyl)propionamide], tris(2,4-di-tert-butylphenyl)phosphite, tris(2,4-di-tert-butylphenyl)phosphite, or mixtures thereof.

[0075] Preferred organic stabilizers are phenolic and / or phosphite compounds, such as Irganox 1010, Irganox 1098, Hostanox PAR 24, or Irgafos 168. Particularly preferred as component (E) is a mixture of 10 parts by weight of a mixture of Irganox 1010 (CAS 6683-19-8, phenolic antioxidant) and Anox 20 (CAS 6683-19-8, phenolic antioxidant) in a ratio of 7:3, with 2 parts by weight of Hostanox PAR24 (CAS:31570-04-4, tris(2,4-ditert-butylphenyl)phosphite).

[0076] Preferred UV stabilizers are, for example, N-(2-ethoxyphenyl)-N'-(2-ethylphenyl)oxamide (Tinuvin 312), 2-(4,6-diphenyl-1,3,5-triazin-2yl)-5-hexyloxyphenol (Tinuvin 1577), 2-(4,6-diaryl-1,3,5-triazin-2yl)-5-(alkoxy-substituted)-phenol (Tinuvin 1600), 2-tert-butyl-6-(5-chlorobenzotriazol-2-yl)-4-methylphenol (Tinuvin 326), 2-(benzotriazol-2-yl)-4,6-bis(2-phenylpropan-2-yl)phenol (Tinuvin 234), bis(2,2,6,6,-tetramethyl-4-piperidyl)sebacate (Tinuvin 770). DF), N,N'-bis(2,2,6,6-tetramethyl-4-piperidinyl)isophthalamide (Nylostab S-EED), 2-(2-hydroxyphenyl)-benzotriazole derivatives (Tinuvin Carboprotect), 2-(benzotriazol-2-yl)-4,6-bis(2-methylbutan-2-yl)phenol (Tinuvin 328), 2-(benzotriazol-2-yl)-6-[[3-(benzotriazol-2-yl)-2-hydroxy-5-(2,4,4-trimethylpentan-2-yl)phenyl]methyl]-4-(2,4,4-trimethylpentan-2-yl)-phenol (Tinuvin 360), poly[[6-[(1,1,3,3-tetra-methylbutyl)amino]-1,3,5-triazine-2,4-diyl][(2,2,6,6-tetramethyl-4-piperidinyl)-imino]-1,6-hexanediyl[(2,2,6,6-tetramethyl-4-piperidinyl)-imino]]) (Chimassorb 944), 1-(4-methoxyphenyl)-3-(4-tert-butylphenyl)-propane-1,3-dione (Parsol 1789), and mixtures thereof.

[0077] In a preferred embodiment, the thermoplastic polyamide moulding compound according to the invention comprises (A) 28 to 84.9% by weight of component (A), (A1) 20 to 100% by weight, preferably 40 to 85% by weight, of at least one aliphatic semicrystalline polyamide based on an aliphatic dicarboxylic acid and an aliphatic diamine, (A2) 0 to 80% by weight, preferably 15 to 60% by weight, of at least one amorphous partially aromatic polyamide and / or at least one amorphous and / or microcrystalline polyamide; Component (A), wherein the sum of the weight percentages of components (A1) and (A2) is 100 weight percent of component (A); (B) 15-50% by weight of a mineral filler, which consists of a mixture of 45-70% by weight of (crypto)crystalline silicic acid (B1), 5-15% by weight of amorphous silicic acid (B2) and 20-40% by weight of calcined kaolin (B3) relative to 100% by weight of (B), component (B) having an aluminum oxide content of 5-20% by weight and a silicon oxide content of 80-95% by weight relative to 100% by weight of (B); (C) 0 to 15% by weight of glass and / or carbon fiber; (D) 0.1 to 3.0% by weight of a black colorant, preferably carbon black; (E) 0 to 4.0% by weight of additives; The total of A to E is 100% of the thermoplastic polyamide molding compound.

[0078] In a further preferred embodiment, the thermoplastic polyamide moulding compound according to the invention comprises (A) 50 to 79.8% by weight of component (A), (A1) 20 to 100% by weight, preferably 55 to 80% by weight, of at least one aliphatic semi-crystalline polyamide selected from the group consisting of 66, 66 / BAC6, 610, or mixtures thereof; (A2) 0 to 80% by weight, preferably 20 to 45% by weight, of at least one amorphous partially aromatic polyamide selected from the group consisting of 6T / 6I and / or 10T / 10I, each of which has a proportion of 6T or 10T units of less than 50 mol %, and / or at least one alicyclic polyamide selected from the group consisting of MACM12, PACM12, MACM12 / PACM12, MACM14, MACM16, or a mixture thereof; Component (A), wherein the sum of the weight percentages of components (A1) and (A2) is 100 weight percent of component (A); (B) 20-45% by weight of a mineral filler, which consists of a mixture of 45-70% by weight of (crypto)crystalline silicic acid (B1), 5-15% by weight of amorphous silicic acid (B2) and 20-40% by weight of calcined kaolin (B3), each relative to 100% by weight of (B), component (B) having an aluminum oxide content of 5-20% by weight and a silicon oxide content of 80-95% by weight relative to 100% by weight of (B); (D) 0.1 to 2.0% by weight of a black colorant, preferably carbon black; (E) 0.1 to 3.0% by weight of an additive; and the sum of (A), (B), (D), and (E) is 100% of the thermoplastic polyamide molding compound. In this preferred embodiment, the molding compound does not contain component (C), i.e., does not contain any glass fibers and / or carbon fibers.

[0079] Furthermore, the present invention relates to the use of a mineral filler consisting of a mixture of 45 to 70% by weight of (crypto)crystalline silica (B1), 5 to 15% by weight of amorphous silica (B2) and 20 to 40% by weight of calcined kaolin (B3), each relative to 100% by weight of (B), in which component (B) has an aluminum oxide content of 5 to 20% by weight and a silica content of 80 to 95% by weight relative to 100% of (B), for improving the impression of a deep black color in black mineral-filled polyamide moulding compounds, in which the lightness L of the color of the polyamide moulding compound, determined on a plate with dimensions 60 x 60 x 2 mm in the CIELAB colour space according to DIN EN ISO 11664-4:2020, is * but when gloss is included it is at most 30, preferably at most 28, particularly preferably at most 27, and when gloss is excluded it is at most 12, preferably at most 8, particularly preferably at most 6. Here too, the mineral filler according to the invention is preferably present in the polyamide moulding compound in a proportion in the range from 15 to 50% by weight, preferably in the range from 20 to 45% by weight, relative to the total weight of the polyamide moulding compound.

[0080] Further embodiments are set forth in the dependent claims. EXAMPLES

[0081] Description of the Preferred Embodiments The ingredients shown in Table 1 were compounded in the proportions shown in Tables 2 and 3 in a Werner and Pfleiderer twin-screw extruder with a screw diameter of 25 mm under the defined process parameters (see Table 4), with the polyamide granules and additives being metered into the feed zone, while the mineral filler was metered via a side feeder into the polymer melt 3 receiving unit upstream of the die. The compounds summarized in Tables 2 and 3 were drawn as strands through a die with a diameter of 3 mm and granulated after water cooling. The granulated material was dried at 100° C. in a vacuum of 30 mbar for 24 hours.

[0082] [Table 1]

[0083] [Table 2]

[0084] [Table 3]

[0085] [Table 4] The compounds were injected using an Arburg Allrounder 320-210-750 injection molding machine to form test specimens at predetermined cylinder temperatures of 240-280°C in zones 1-4 and a mold temperature of 100°C.

[0086] Measurement method Within the scope of this application, the following measurement methods were used: Melting point (Tm) and enthalpy of fusion (ΔHm): The melting point and enthalpy of fusion were determined on the granular material according to ISO 11357-3 (2013). DSC (Differential Scanning Calorimetry) measurements were performed at a heating rate of 20 K / min.

[0087] Glass transition temperature, Tg: The glass transition temperature, Tg, was determined on the granular material according to ISO 11357-2 (2013) using differential scanning calorimetry (DSC). This was done at a heating rate of 20 K / min for each of two heating cycles. After the first heating, the samples were quenched in dry ice. The glass transition temperature (T g ) was determined during the second heating. The midpoint of the glass transition range, designated as the glass transition temperature, was determined using the "half-height" method.

[0088] Relative viscosity, η rel : The relative viscosity was determined at 20 °C according to ISO 307 (2007). For this purpose, 0.5 g of polymer granules were weighed into 100 ml of m-cresol (unless otherwise specified) and the relative viscosity (RV) was determined according to section 11 of the standard: RV = t / t 0 was calculated according to

[0089] Tensile E Modulus: The tensile E modulus was determined according to ISO 527 (2012) at 23 °C and a pulling speed of 1 mm / min on ISO tensile bars (type A1, dimensions 170 × 20 / 10 × 4) according to the ISO / CD 3167 (2003) standard.

[0090] Stress at break and elongation at break: The determination of the breaking stress and the elongation at break was carried out according to ISO 527 (2012) at 23 °C and a tensile speed of 5 mm / min on ISO tensile bars type A1 (dimensions 170 × 20 / 10 × 4 mm) manufactured according to the ISO / CD 3167 (2003) standard.

[0091] Charpy impact strength: Charpy impact strength is ISO 179 / 2 * eU (1997, * 2 = instrumentation) at 23 °C on ISO test bars type B1 (dimensions 80 x 10 x 4 mm) manufactured according to the standard ISO / CD 3167 (2003).

[0092] Charpy notched impact strength: Charpy notched impact strength is ISO 179 / 2 * eA (1997, * 2 = instrumentation) at 23 °C on ISO test bars type B1 (dimensions 80 x 10 x 4 mm) manufactured according to the standard ISO / CD 3167 (2003).

[0093] Color measurement and brightness (color brightness L * ) Determination CIE L Standard and Test Plates * a * b *The values ​​were measured using a Datacolor spectrophotometer (instrument name: Datacolor 650) in front of a white-coated contrast sheet under the following measurement conditions in accordance with DIN EN ISO 11664-4:2020: measurement mode A: reflection, measurement geometry: D / 8°, light source: D 65 10, gloss: included, calibration: UV calibration, measurement aperture: SAV; measurement mode B: reflection, measurement geometry: D / 8°, light source: D 65 10, gloss: excluded, calibration: UV calibration, measurement aperture: SAV.

[0094] Discussion of results: All of the comparative examples CE1 to CE3 based on surface-coated kaolinite, i.e., prior art minerals, had a low color value including luster L * is greater than 30 and has no gloss * The color value L of the corresponding color plates is in the range of 16 to 18. When visually evaluated, the corresponding color plates have a dark gray appearance. In contrast, the color plates produced using the molding compounds of Examples E1 to E3 according to the present invention appear deep black. This is due to the low color value L of these examples. * This is also reflected in the σ σ, which is less than 27 when measured with gloss and less than 6 when measured without gloss. The mechanical properties of the moulding compounds according to the invention, in particular the E modulus and the stress at break, are at a good level, even if they are somewhat lower than in the comparative examples.

Claims

1. A thermoplastic polyamide molding compound comprising: A 20 to 89.9% by weight of at least one polyamide; B 10-55% by weight of a mineral filler, which consists of a mixture of 45-70% by weight of cryptocrystalline silicic acid B1, 5-15% by weight of amorphous silicic acid B2 and 20-40% by weight of calcined kaolin B3, each based on 100% by weight of B, said component B having an aluminum oxide content of 5-20% by weight and a silicon oxide content of 80-95% by weight, based on 100% by weight of B; C 0-15% by weight of glass fibers and / or carbon fibers; D 0.1 to 5.0 wt. % of a black colorant; E 0 to 5.0 wt. % of an additive; It consists of: The sum of A to E is 100% of the thermoplastic polyamide molding compound; The thermoplastic polyamide molding compounds have a color lightness L, determined in accordance with DIN EN ISO 11664-4:2020 in the CIELAB color space on a plate with dimensions 60 x 60 x 2 mm, of a maximum of 30 if gloss is also measured and a maximum of 12 if gloss is not measured. ＊ having Thermoplastic polyamide moulding compound.

2. 2. Thermoplastic polyamide moulding compound according to claim 1, characterised in that component A is present in a proportion ranging from 28 to 84.9% by weight, preferably from 50 to 79.8% by weight, relative to components A to E.

3. Component A is A1 20 to 100% by weight, preferably 40 to 85% by weight, of at least one aliphatic semicrystalline polyamide based on aliphatic dicarboxylic acids and aliphatic diamines and / or at least one partially aromatic semicrystalline polyamide based on dicarboxylic acids and diamines, A2 0 to 80% by weight, preferably 15 to 60% by weight, of at least one amorphous polyamide; It consists of: The sum of the weight percentages of components A1 and A2 is 100 weight percent of component A.

3. A thermoplastic polyamide moulding compound according to claim 1 or 2.

4. the polyamide of component A1 is a semicrystalline aliphatic polyamide selected from the group consisting of PA 6, 46, 56, 66, 66 / BAC6, 66 / 6, 69, 610, 612, 614, 616, 618, 810, 1010, 1012, 1212, 11, 12, 6 / 12, 66 / 6 / 610, with 66, 66 / BAC6 and 610 being preferred and 66 / BAC6, in which BAC is equal to 1,3-BAC, being particularly preferred; and / or semicrystalline partially aromatic polyamides selected from the group consisting of PA 6T / 6I, 6T / 66, 6T / 6I / 66, 6T / 610, 6T / 612, 6T / 614, 6T / 616, 9T, 9MT (M=2-methyloctane-1,8-diamine), 10T, 11T, 10T / 6T, 11T / 6T, 12T, 10T / 6T, 11 / 10T, 12 / 10T, 11 / 9T, 12 / 9T, 10T / 1010, 10T / 612, in which the proportion of terephthalic acid based on the total dicarboxylic acid content is preferably greater than 50 mol%, particularly preferably greater than 55 mol%, and / or semi-crystalline polyamides having a melting point of at least 170° C., preferably in the range of 175 to 340° C., or, if aliphatic, preferably in the range of 175 to 265° C.

4. A thermoplastic polyamide moulding compound according to claim 1 , characterized in that it is

5. The polyamide of component A2 is the amorphous polyamide is selected from the group consisting of 12 / MACMT, MACM10, MACM12, MACM14, MACM16, MACM18, MACMI / 12, PACM10, PACM12, PACM14, PACM16, PACM18, PACMI / 12, TMDC10, TMDC12, TMDC16, TMDC18, MACMT / MACMI / 12, PACMT / PACMI / 12, or mixtures thereof; and / or the amorphous polyamide is selected from the group consisting of MXDI, MXDI / 6I, MXD6 / MXDI, 6I, 6 / 6I, 6T / 6I, 10T / 10I, 3-6T (3-6=2,2,4- or 2,4,4-trimethylhexanediamine), or mixtures thereof, the 6T / 6I or 10T / 10I system having a proportion of 6T or 10T units of less than 50 mol %, the composition range of 6T:6I or 10T / 10I being preferred being 20:80 to 45:55, in particular 25:75 to 40:60, and / or an amorphous polyamide having a glass transition temperature (Tg) of more than 90° C., particularly preferably more than 110° C., particularly preferably more than 120° C.

5. A thermoplastic polyamide moulding compound according to claim 1 , characterized in that it is

6. 6. Thermoplastic polyamide moulding compound according to claim 1, characterized in that component B is present in a proportion in the range from 15 to 50% by weight, preferably in the range from 20 to 45% by weight, relative to components A to E.

7. 7. The thermoplastic polyamide moulding compound according to claim 1, wherein component B is surface-treated with silane compounds, preferably trialkoxysilanes, dialkoxysilanes, epoxysilanes, vinylsilanes, (meth)acryloxysilanes, aminosilanes and mercaptosilanes.

8. 8. The thermoplastic polyamide moulding compound according to claim 1, characterized in that component B is surface-coated with a primary and / or secondary aminosilane, particularly preferably a secondary aminosilane, the amount of which is 0.01 to 2.0% by weight, based on component B.

9. 9. Thermoplastic polyamide moulding compound according to claim 1, characterized in that component C is glass fibres.

10. Component D is present in a proportion in the range of 0.1 to 3.0% by weight, preferably in the range of 0.1 to 2.0% by weight, based on components A to E; and / or component D is selected from the group consisting of carbon black, graphite, graphene, nigrosine, black pigments, black dyes, or a combination of complementary pigments and / or dyes, or a mixture of one or more of these colorants.

10. A thermoplastic polyamide moulding compound according to claim 1 ,

11. Component E is present in an amount of 0 to 4.0% by weight, preferably 0.1 to 3.0% by weight, based on components A to E; and / or the additives of component E are selected from the group consisting of stabilizers, antiaging agents, antioxidants, antiozonants, light stabilizers, UV stabilizers, UV absorbers, UV blockers, inorganic heat stabilizers, in particular inorganic heat stabilizers based on copper halides and alkali halides, organic heat stabilizers, conductive additives, optical brighteners, processing aids, nucleating agents, crystallization accelerators, crystallization retarders, flow aids, lubricants, release agents, plasticizers, marking agents, and mixtures thereof.

11. A thermoplastic polyamide moulding compound according to claim 1 ,

12. A 8 to 84.9% by weight of component A, A1 20 to 100% by weight, preferably 40 to 85% by weight, of at least one aliphatic semicrystalline polyamide based on aliphatic dicarboxylic acids and aliphatic diamines, A2 0 to 80% by weight, preferably 15 to 60% by weight, of at least one amorphous polyamide; Component A, wherein the sum of the weight percentages of components A1 and A2 is 100 weight percent of component A; B 15-50% by weight of a mineral filler, which consists of a mixture of 45-70% by weight of cryptocrystalline silicic acid B1, 5-15% by weight of amorphous silicic acid B2 and 20-40% by weight of calcined kaolin B3, each based on 100% by weight of B, said component B having an aluminum oxide content of 5-20% by weight and a silicon oxide content of 80-95% by weight, based on 100% by weight of B; C 0-15% by weight of glass and / or carbon fibers; D 0.1 to 3.0 wt. % of a black colorant, preferably carbon black; E 0 to 4.0 wt. % of an additive; It consists of: The sum of A to E is 100% of the thermoplastic polyamide molding compound.

12. A thermoplastic polyamide moulding compound according to claim 1 ,

13. A 50 to 79.8% by weight of component A, 20 to 100% by weight, preferably 55 to 80% by weight, of at least one aliphatic semicrystalline polyamide selected from the group consisting of A1 66, 66 / BAC6, 610, or mixtures thereof, A2 0 to 80% by weight, preferably 20 to 45% by weight, of at least one amorphous partially aromatic polyamide selected from the group consisting of 6T / 6I and / or 10T / 10I, the proportion of 6T or 10T units being less than 50 mol %, respectively; Component A, wherein the sum of the weight percentages of components A1 and A2 is 100 weight percent of component A; B 20-45% by weight of a mineral filler, which consists of a mixture of 45-70% by weight of cryptocrystalline silicic acid B1, 5-15% by weight of amorphous silicic acid B2 and 20-40% by weight of calcined kaolin B3, each based on 100% by weight of B, said component B having an aluminum oxide content of 5-20% by weight and a silicon oxide content of 80-95% by weight, based on 100% by weight of B; D 0.1 to 2.0 wt. % of a black colorant, preferably carbon black; E 0.1 to 3.0 wt. % of an additive; It consists of: The sum of A, B, D, and E is 100% of said thermoplastic polyamide molding compound.

13. A thermoplastic polyamide moulding compound according to claim 1 ,

14. A color lightness L determined on a plate of dimensions 60 x 60 x 2 mm in the CIELAB color space according to DIN EN ISO 11664-4:2020 of maximum 28, preferably maximum 27, if gloss is also measured, or maximum 8, preferably maximum 6, if gloss is not measured. ＊ 14. The thermoplastic polyamide moulding compound according to claim 1, characterized in that it has

15. Moulded body comprising, preferably consisting of, the polyamide moulding compound according to any one of claims 1 to 14.

16. Use of a mineral filler in a black mineral-filled polyamide moulding compound for improving the deep black impression, the mineral filler consisting of a mixture of 45 to 70% by weight of cryptocrystalline silica B1, 5 to 15% by weight of amorphous silica B2 and 20 to 40% by weight of calcined kaolin B3, each based on 100% by weight of B, said component B having an aluminium oxide content of 5 to 20% by weight and a silicon oxide content of 80 to 95% by weight based on 100% by weight of B, the colour lightness L of said polyamide moulding compound being determined on a plate with dimensions 60x60x2 mm in the CIELAB colour space according to DIN EN ISO 11664-4:2020 ＊ is a maximum of 30, preferably a maximum of 28, if gloss is included, and a maximum of 12, preferably a maximum of 8, if gloss is excluded.

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