Mineral-filled polyamide molding compound

Abstract

The invention relates to a mineral-filled thermoplastic polyamide moulding compound, consisting of: A 20 wt.% to 89.9 wt.% of at least one polyamide; b 10 wt.% to 55 wt.% of a mineral filler consisting of a mixture of 45 wt.% to 70 wt.% of (implicit) silicic acid B1, 5 wt.% to 15 wt.% of amorphous silicic acid B2 and 20 wt.% to 40 wt.% of calcined kaolin (B3), respectively, with respect to 100 wt.% of B, component B having an aluminum oxide content of 5 wt.% to 20 wt.% and a silicon oxide content of 80 wt.% to 95 wt.%, with respect to 100% of B; c from 0 wt.% to 15 wt.% of glass fibers and / or carbon fibers; d from 0.1 wt.% to 5.0 wt.% of a black colorant; e from 0 wt.% to 5.0 wt.% of an additive; wherein the sum of A to E provides 100% of the thermoplastic polyamide molding compound, and wherein the maximum value of the color brightness L * of the thermoplastic polyamide molding compound is 30 if gloss is also measured, and the maximum value of the color brightness L * of the thermoplastic polyamide molding compound is 12 if gloss is not measured.

Description

Technical Field

[0001] The invention relates to thermoplastic, mineral-filled polyamide moulding compounds and mouldings produced therefrom, which have a particularly dark black appearance. The invention also relates to the use of specific mineral fillers, in particular a mineral filler consisting of a mixture of crystalline silicic acid, amorphous silicic acid and calcined kaolin, in black-coloured mineral-filled polyamide moulding compounds to improve the dark black appearance. Background Art

[0002] Thermoplastic polyamide materials have established their position for the production of structural components in many fields, especially in the automotive field, and in the electronics field, such as in housings for portable devices, due to their good mechanical properties, chemical resistance, good processability, low specific gravity, etc.

[0003] Many applications require black-pigmented molding compounds. While glass-fiber-filled polyamide molding compounds can achieve a sufficiently dark black appearance, mineral-filled polyamide molding compounds often have an anthracite-gray appearance. This is where the present invention comes into play. Summary of the invention

[0004] It was therefore an object of the present invention to provide mineral-filled thermoplastic polyamide moulding materials which have mechanical properties suitable for the applications mentioned but which at the same time also produce a deep black visual impression.

[0005] In particular, the object of the present invention is to provide mineral-filled polyamide molding compounds whose color lightness L*, measured in accordance with DIN EN ISO 11664-4:2020 in the CIELAB color space on a plate with dimensions of 60 mm×60 mm×2 mm, is a maximum of 30 if the gloss is also measured and a maximum of 12 if the gloss is not measured. This problem is solved by the subject matter of the claims, in particular by a modified thermoplastic polyamide molding compound according to the invention as claimed in claim 1, a molding as claimed in claim 15 and the use of a mineral filler as claimed in claim 16 in a polyamide molding compound for improving the deep black appearance, the 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), relative to 100% by weight of (B), wherein component (B) has an aluminum oxide content of 5% to 20% by weight and a silicon oxide content of 80% to 95% by weight, relative to 100% by weight of (B).

[0006] The core of the invention is therefore the surprising discovery that the use of 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), respectively, relative to 100% by weight of (B), wherein component (B) has an aluminum oxide content of 5 to 20% by weight and a silicon oxide content of 80 to 95% by weight, respectively, relative to 100% by weight of (B), in a thermoplastic black polyamide matrix, as an alternative to other mineral fillers, leads to a very significant improvement in the perception of a deep black color. This core is achieved without any loss of advantageous mechanical properties.

[0007] It is generally known from other fields that fillers consisting of mixtures of (crypto)crystalline silicic acid, amorphous silicic acid and calcined kaolin can be admixed into polyamide materials, but this has no bearing on improving the deep black appearance nor on the specific polyamide moulding materials as described here.

[0008] In particular, the following documents should be referenced in conjunction with the prior art:

[0009] WO2018069055 discloses flame-retardant thermoplastic polyamide molding compounds, which, in addition to a melamine compound, contain a mineral filler consisting essentially of a mixture of (crypto)crystalline silicic acid and amorphous silicic acid and calcined kaolin. The molding compound should have good mechanical properties and good flame retardancy. In particular, the addition of the mineral filler should make it flame-retardant so that the continuous burning time in the glow-wire test is as short as possible. It is also emphasized that the molding compound can be particularly well pigmented to light colors.

[0010] The thermoplastic polyamide moulding materials proposed in the context of the present application are preferably free of flame retardants, in particular free of melamine compounds.

[0011] WO2016 / 202359 relates to the field of adhesives, in particular to the field of moisture-curing adhesives or curing adhesives. The adhesives described provide high-strength bonding for materials such as wood, concrete, plastics, stone, etc., while having high moisture resistance. What is claimed is an adhesive comprising a modified polyether, a filler, an adhesion promoter and one or more compounds selected from free radical scavengers, moisture scavengers, antioxidants, rheology modifiers and catalysts. One of the preferred fillers is Neuburg Silicate Earth.

[0012] More specifically, the present invention relates to a thermoplastic polyamide molding compound consisting of:

[0013] (A) 20% to 89.9% by weight of at least one polyamide;

[0014] (B) 10 to 55% by weight of 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), relative to 100% by weight of (B), wherein component (B) has an aluminum oxide content of 5 to 20% by weight and a silicon oxide content of 80 to 95% by weight, relative to 100% by weight of (B);

[0015] (C) 0 to 15 wt % of glass and / or carbon fibers;

[0016] (D) 0.1 wt % to 5.0 wt % of a black colorant;

[0017] (E) 0 wt % to 5.0 wt % of additives;

[0018] A thermoplastic polyamide molding compound in which the sum of components (A) to (E) is 100%.

[0019] Within the scope of the present invention, references to individual concentration ranges of components (A) to (E), the sum of components (A) to (E) or the molding materials are regarded as equivalent. DETAILED DESCRIPTION

[0020] For the purposes of the present invention, the term "polyamide" (abbreviated PA) is understood as a general term including homopolyamides and copolyamides. The symbols and abbreviations of polyamides and their monomers are consistent with those specified in ISO Standard 16396-1 (2015 (D)). The abbreviations used therein are used as synonyms for the IUPAC names of the monomers hereinafter, and the following monomer abbreviations are specifically used: BAC stands for bis(aminomethyl)cyclohexane, including 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 No. 6864-37-5) , PACM represents bis(4-amino-cyclohexyl)methane (also known as 4,4'-diaminodicyclohexylmethane, CAS No. 1761-71-3), TMDC represents bis(4-amino-3,5-dimethyl-cyclohexyl)methane (also known as 3,3',5,5'-tetramethyl-4,4'-diaminodicyclohexylmethane, CAS No. 65962-45-0), T represents terephthalic acid (CAS No. 100-21-0), and I represents isophthalic acid (CAS No. 121-95-5).

[0021] Compared to semicrystalline polyamides, amorphous polyamides have no heat of fusion 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 properties: the heat of fusion is preferably a maximum of 5 J / g, particularly preferably a maximum of 3 J / g, very particularly preferably 0 J / g to 1 J / g. Amorphous polyamides have no melting point due to their amorphous nature.

[0022] In the context of the present invention, semicrystalline polyamides are polyamides which have a heat of fusion of preferably more than 5 J / g, particularly preferably at least 25 J / g, very particularly preferably at least 30 J / g, according to dynamic differential calorimetry (DSC) according to ISO 11357 (2013) at a heating rate of 20 K / min.

[0023] The color perception of the molding materials colored according to the invention and the moldings produced therefrom can be described using the CIE standard color system. DIN EN ISO 11664-2020 (Parts 1 to 4) specifies the spectral value functions used in colorimetry and describes the corresponding color measurements. The measurement is carried out as the reflectance or transmittance of the sample relative to a reference standard (= white standard) and is therefore independent of the light source. The L* value, a* value and b* value can be determined from the spectral data using a list of standard color values. The reflected or transmitted light is analyzed using a "monochromator" system consisting of an optical diffraction grating (prism), which separates the light and images it onto a photodiode array. The interaction (reflection) of the material surface with the light can be directional or diffuse, depending on the nature of the surface. Scattered light makes dark surfaces appear brighter. This is taken into account using a standard spherical geometry. Gloss can be included or excluded by using the following measurement modes:

[0024] Measuring mode A: Reflection, Measuring geometry: D / 8°, Illuminant: D 65 10, Gloss: Included, Calibration: UV calibration, Measuring aperture: SAV;

[0025] Measuring mode B: Reflection, Measuring geometry: D / 8°, Illuminant: D 65 10, Gloss: Exclusion, Calibration: UV calibration, Measuring aperture: SAV.

[0026] The term gloss excluded, when used in conjunction with a brightness measurement or brightness value, shall be considered equivalent to the following expressions: gloss excluded, measurement excluding gloss, measurement excluding gloss content, matte.

[0027] The term including gloss when used in conjunction with a brightness measurement or brightness value shall be considered equivalent to the following expressions: including gloss, including measurement of gloss, including measurement of gloss content, and glossy.

[0028] According to the invention, the use of mineral fillers (B) enables the production of pigmented mineral-filled thermoplastic molding compounds with a deep black appearance. In the CIELAB color space according to DIN EN ISO 11664-2020, when measured without gloss content, the L* value is not more than 12, preferably not more than 8, particularly preferably not more than 6. When measured with gloss content, the L* value is at most 30, preferably at most 28, particularly preferably at most 27.

[0029] According to a first preferred embodiment, the molding compound is characterized in that component (A) is present in the molding compound in a proportion of 28% to 84.9% by weight, preferably 50% to 79.8% by weight.

[0030] In a preferred embodiment, component (A) may consist exclusively of semicrystalline polyamide (A1). Polyamide (A1) 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, wherein the diacid or the diamine contains aromatic structural units.

[0031] In other preferred embodiments, component (A) may comprise a mixture of semi-crystalline polyamide (A1) and amorphous polyamide (A2). Component (A) preferably consists of the following components:

[0032] (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 and / or at least one partially aromatic semicrystalline polyamide based on a dicarboxylic acid and a diamine.

[0033] (A2) 0 to 80% by weight, preferably 15 to 60% by weight, of at least one amorphous polyamide,

[0034] The sum of the weight % of component (A1) and component (A2) is 100 weight % of component (A).

[0035] The polyamides of component (A1) and component (A2) are preferably of the AABB type, ie are composed of dicarboxylic acids and diamines, wherein lactams and amino acids may also be present as components in minor proportions.

[0036] For example, the following monomers can be used as the diamine of component (A1): 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, 1,1 0-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, among which 1,6-hexanediamine, 1,10-decanediamine, 1,12-dodecanediamine and 1,3-bis-(aminomethyl)cyclohexane are preferred.

[0037] For example, the following monomers are suitable as dicarboxylic acids of component (A1): adipic acid, suberic acid, azelaic acid, sebacic acid, undecanedioic acid, dodecanedioic acid, tridecanedioic acid, tetradecanedioic acid, pentadecanedioic acid, hexadecanedioic acid, heptadecanedioic acid, octadecanedioic acid, C36 dimer fatty acids, 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 of these dicarboxylic acids. Preference is given to adipic acid, sebacic acid, tetradecanedioic acid, hexadecanedioic acid and dodecanedioic acid.

[0038] In addition, polyamide (A1) and polyamide (A2) may also contain lactams or aminocarboxylic acids, in particular α,ω-amino acids or lactams having 6 to 12 carbon atoms, wherein the following selection is given as an example: 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), laurolactam (LL) and α,ω-aminododecanoic acid (ADA). Caprolactam, aminocaproic acid, α,ω-aminoundecanoic acid, laurolactam and α,ω-aminododecanoic acid are particularly preferred. However, the proportion of these lactams or amino acids relative to the total weight of polyamide (A1) is preferably less than 50% by weight, particularly preferably less than 20% by weight, particularly preferably less than 10% by weight.

[0039] The polyamide of component (A1) is preferably

[0040] Semicrystalline aliphatic polyamides selected from the group consisting of PA 6, PA 46, PA 56, PA 66, PA 66 / BAC6, PA 66 / 6, PA 69, PA 610, PA 612, PA 614, PA 616, PA 618, PA 810, PA 1010, PA 1012, PA 1212, PA 11, PA 12, PA 6 / 12, PA 66 / 6 / 610, of which PA 66, PA 66 / BAC6 and PA 610 are preferred, and PA 66 / BAC6 in which BAC is identical to 1,3-BAC is particularly preferred,

[0041] and / or a semicrystalline partially aromatic polyamide selected from the group consisting of PA 6T / 6I, PA 6T / 66, PA 6T / 6I / 66, PA 6T / 610, PA 6T / 612, PA 6T / 614, PA 6T / 616, PA 9T, PA9MT (M = 2-methyloctane-1,8-diamine), PA 10T, PA 11T, PA 10T / 6T, PA 11T / 6T, PA 12T, PA 10T / 6T, PA 11 / 10T, PA 12 / 10T, PA11 / 9T, PA 12 / 9T, PA 10T / 1010, PA 10T / 612, wherein the proportion of terephthalic acid relative to the total content of dicarboxylic acids is preferably greater than 50 mol%, particularly preferably greater than 55 mol%,

[0042] and / or a semi-crystalline polyamide having a melting point of at least 170°C, preferably from 175°C to 340°C, or if the semi-crystalline polyamide is an aliphatic semi-crystalline polyamide, preferably from 175°C to 265°C.

[0043] Very particular preference is given as component (A1) to polyamide 66 / BAC6 in a molar ratio of 75:25 to 55:45, in particular 70:30 to 60:40, wherein BAC is preferably 1,3-bis(aminomethyl)cyclohexane (1,3-BAC).

[0044] Furthermore, the relative viscosity of the polyamides of components (A), (A1) and (A2), measured in m-cresol (0.5 g polymer in 100 ml m-cresol, 20° C.) according to ISO 307 (2007), is preferably 1.4 to 3.0, particularly preferably 1.45 to 2.70, particularly preferably 1.50 to 2.40.

[0045] The polyamide of component (A2) is preferably

[0046] is selected from 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 of these polyamides,

[0047] and / or from the group consisting of amorphous polyamides MXDI, MXDI / 6I, MXD6 / MXDI, 6I, 6 / 6I, 6T / 6I, 10T / 10I, 3-6T (3-6=2,2,4-trimethylhexanediamine or 2,4,4-trimethylhexanediamine) or mixtures of these polyamides, wherein the system 6T / 6I or 10T / 10I has a proportion of 6T units or 10T units of less than 50 mol %, and wherein the composition of 6T / 6I or 10T / 10I is preferably from 20:80 to 45:55, particularly preferably from 25:75 to 40:60,

[0048] and / or an amorphous polyamide having a glass transition temperature (Tg) of above 90°C, particularly preferably above 110°C, particularly preferably above 120°C.

[0049] The diamines of the amorphous polyamide of component (A2) are preferably selected from the group consisting of 1,6-hexanediamine, 1,10-decanediamine, 1,12-dodecanediamine, 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-norbornene diamine (2,6-bis-(aminomethyl)norbornene), 1,3-cyclohexanediamine, 1,4-cyclohexanediamine, isophoronediamine, 1,3-bis-(aminomethyl)cyclohexane, 1,4-bis-(aminomethyl)cyclohexane, 2,2-(4,4′-diaminodicyclohexyl)propane, m-xylylenediamine, p-xylylenediamine and mixtures of these diamines. The diamine is particularly preferably selected from 1,6-hexanediamine, 1,10-decanediamine, bis-(4-amino-3-methyl-cyclohexyl)-methane (MACM) and bis(4-amino-cyclohexyl)methane (PACM) and mixtures of these diamines.

[0050] The dicarboxylic acids used for the polyamide (A2) are preferably selected from terephthalic acid, isophthalic acid, naphthalene dicarboxylic acid (NDA), in particular 1,5-naphthalene dicarboxylic acid and 2,6-naphthalene dicarboxylic acid, 1,6-hexanedioic acid (adipic acid), 1,9-nonane dicarboxylic acid, 1,10-decanedioic acid, 1,11-undecane dicarboxylic acid, 1,12-dodecane dicarboxylic acid, 1,13-tridecane dicarboxylic acid, 1,14-tetradecane dicarboxylic acid, 1,16-hexadecanedioic acid, 1,18-octadecane dicarboxylic acid and mixtures of these dicarboxylic acids. Particular preference is given to 1,6-hexanedioic acid, 1,10-decanedioic acid, 1,12-dodecane dicarboxylic acid, terephthalic acid, isophthalic acid and mixtures of these dicarboxylic acids. Furthermore, caprolactam and laurolactam are preferred monomers for the production of the polyamide of component (A2).

[0051] According to the invention, in addition to the polyamide matrix, the molding compound also has a certain proportion of mineral fillers as component (B). Preferably, the proportion of component (B) in the molding compound is 15% to 50% by weight, preferably 20% to 45% by weight.

[0052] Surprisingly, naturally occurring mineral fillers which consist of a mixture of particulate, (crypto)crystalline and amorphous silicic acid and calcined layered kaolin are particularly suitable as component (B). The mineral mixture is a loose heap of crystalline matter which cannot be separated physically. The silicic acid portion has a rounded grain shape and consists of aggregated cryptocrystalline primary particles with a size of about 200 nm and is coated with opal-like amorphous silicic acid. This structure results in relatively high specific surface areas and oil absorption values.

[0053] As component (B), the molding material 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) and amorphous silicic acid (B2) and calcined kaolin (B3).

[0054] The mineral filler (B) contains a mixture of 45% to 70% by weight, preferably 53% to 65% by weight, of (B1), 5% to 15% by weight, preferably 7% to 12% by weight, of (B2) and 20% to 40% by weight, preferably 25% to 35% by weight, of (B3), based on 100% by weight of (B).

[0055] Component (B) has an aluminum oxide content of 5 to 20% by weight, preferably 7 to 17% by weight, and in particular 8 to 15% by weight, relative to 100% by weight of (B). In addition, component (B) has a silicon dioxide content of 80 to 95% by weight, preferably 83 to 93% by weight, and in particular 85 to 92% by weight, relative to 100% by weight of (B). The contents of silicon oxide and aluminum oxide can both be determined using XRF (X-ray fluorescence analysis) according to DIN 51001.

[0056] 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), relative to 100% by weight of (B), wherein component (B) has an aluminum oxide content of 5% to 20% by weight and a silicon oxide content of 80% to 95% by weight, relative to 100% by weight of (B).

[0057] Preferred components (B) have a 5 m 2 / g to 15m 2 / g, preferably 6m 2 / g to 10m 2 The invention further comprises a BET specific surface area of ​​50 to 60 g / 100 g, preferably 52 to 58 g / 100 g, according to DIN ISO 787, part 5.

[0058] In order to achieve better compatibility with the polymer matrix, the mineral filler (B) may be surface treated, preferably with silane compounds, particularly preferably with aminosilane compounds.

[0059] Preferred silane compounds are trialkoxysilane, dialkoxysilane, epoxysilane, vinylsilane, (meth)acryloxysilane, aminosilane and mercaptosilane.

[0060] Suitable representatives of these silane compounds are, for example, γ-glycidyloxypropylmethyldimethoxysilane, γ-glycidyloxypropylmethyldiethoxysilane, vinylmethyldimethoxysilane, vinylmethyldiethoxysilane, γ-(meth)acryloxypropylmethyldimethoxysilane, γ-(meth)acryloxypropylmethyldiethoxysilane, ((meth)acryloxymethyl)methyldimethoxysilane, γ-aminopropylmethyldiethoxysilane, N-β-(aminoethyl)-γ-aminopropylmethyldimethoxysilane, N-β-(aminoethyl)-γ-aminopropylmethyldimethoxysilane, N-β-(aminoethyl)-γ-aminopropylmethyldimethoxysilane, γ-aminopropylmethyldimethoxysilane, N-β-(aminoethyl)-γ-aminopropylmethyldiethoxysilane, 3-mercaptopropylmethyldimethoxysilane, γ-aminopropylmethyldiethoxysilane, Silane, N-β-(aminoethyl)-γ-aminopropylmethyldimethoxysilane, N-β-(aminoethyl)-γ-aminopropylmethyldimethoxysilane, N-β-(aminoethyl)-γ-aminoisobutylmethyldimethoxysilane, γ-aminopropylmethyldimethoxysilane, N-β-(aminoethyl)-γ-aminopropylmethyldiethoxysilane, γ-aminopropyltriethoxysilane, γ-aminopropyltrimethoxysilane, N-β- (Aminoethyl)-γ-aminopropyltrimethoxysilane, N-β-(aminoethyl)-γ-aminopropyltriethoxysilane, diethylenetriaminopropyltrimethoxysilane, bis(γ-trimethoxy-silylpropyl)amine, N-phenyl-γ-aminopropyltrimethoxysilane, γ-amino-3,3-dimethylbutyltrimethoxysilane, γ-aminobutyltriethoxysilane, polyazamidesilane.

[0061] 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.

[0062] Secondary aminosilanes are particularly preferred, with bis(3-triethoxysilylpropyl)amine and N-[3-(trimethoxysilyl)-propyl]-ethylenediamine being particularly preferred.

[0063] 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, in particular 0.05 to 0.5% by weight, respectively, relative to component (B).

[0064] The mineral filler (B) according to the invention is particularly preferably surface-coated with primary and / or secondary aminosilanes, particularly preferably with 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, relative to component (B).

[0065] 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), relative to 100% by weight of (B), wherein component (B) has an aluminum oxide content of 5% to 20% by weight and a silicon oxide content of 80% to 95% by weight, relative to 100% by weight of (B), and wherein the mineral filler (B) is surface-coated with primary and / or secondary aminosilanes, particularly preferably with secondary aminosilanes, wherein the amount of primary and / or secondary aminosilanes is 0.01% to 2.0% by weight, preferably 0.025% to 1.0% by weight, relative to component (B).

[0066] The polyamide molding compound according to the invention may also contain reinforcing fibers, in particular glass fibers and / or carbon fibers, as component (C). The amount of component (C) contained in the molding compound is 0% to 15% by weight relative to the sum of components (A) to (E). Particularly preferably, the molding compound does not contain component (C), i.e. in this preferred embodiment, the molding compound according to the invention does not contain any reinforcing fibers, i.e., does not contain glass fibers and / or carbon fibers.

[0067] The reinforcing fibers may be in the form of short fibers (chopped fibers) or continuous fibers (rovings). The reinforcing fibers C are preferably glass fibers.

[0068] Suitable glass fibers have a diameter of 6 μm to 20 μm, preferably 6 μm to 17 μm, particularly preferably 6 μm to 13 μm, very particularly preferably 7 μm to 12 μm. The glass fibers can consist of all types of glass, such as D glass, E glass, ECR glass, L glass, S glass, R glass or any mixtures of these glasses. Glass fibers made of E glass, ECR glass or S glass or mixtures of these fibers are preferred.

[0069] Suitable glass fibers have a cross-section that may be circular or non-circular, wherein in the latter case the ratio of the size of the major cross-sectional axis to the minor cross-sectional axis is at least 2, preferably 2 to 5.

[0070] The reinforcing fibers, in particular glass fibers, can provide a sizing suitable for thermoplastics, in particular polyamides, which contain an adhesion promoter based on amino or epoxysilane compounds. In addition to the polyamide according to the invention and the mineral filler, the proposed molding compound also contains at least one black colorant for coloring the molding compound, more specifically as component (D). Component (D) is preferably present in the molding compound in a proportion of 0.1% to 3.0% by weight, preferably 0.1% to 2.0% by weight.

[0071] Component (D) consists of a colorant or a mixture of colorants, which is suitable for coloring the polyamide molding compound to a dark or black color. The colorant can be organic or inorganic, and can be a dye or a pigment. A dye is a colorant that generally does not scatter light, but absorbs light of a specific visible wavelength. The dye is generally soluble in a polymer matrix at a certain concentration. A pigment is an organic or inorganic dye, which is generally present as discrete particles that are insoluble in the polymer matrix.

[0072] According to the invention, the amount and combination of colorants used are sufficient to darken and opacify the molding compound, in particular to achieve the color lightness values ​​(L*, brightness) described below. The specific amount of colorant used depends on its solubility and extinction coefficient in the thermoplastic matrix, and whether it is used in combination with one or more than one other colorant.

[0073] Suitable colorants generally have a high extinction coefficient in the visible wavelength range and high thermal stability. 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 at temperatures between 230°C and 300°C. In addition, the colorant should not attack or degrade the polymer, which can lead to unacceptable loss of mechanical properties or the formation of gaseous by-products during the molding process.

[0074] In the context of the present invention, black colorants can also come from mixtures of non-black, ie colored pigments or colored dyes if the mixture of these individual colorants (dyes or pigments) leads to an overall black color or to a black coloring of the molding compound.

[0075] Colorants (dyes and pigments) that can be preferably used as component (D) include carbon black, graphite, graphene, aniline black, black pigments or dyes and combinations of complementary color pigments or dyes which, when mixed, allow a black coloring effect to be achieved, or mixtures of one or more than one of these colorants.

[0076] For the combination of complementary color pigments or dyes, particular preference is given to colorants selected from the following dye mixtures (expressed as Color Index General Names (CIGN)):

[0077] Solvent Green 3 and Solvent Red 179

[0078] Solvent Red 52 and Solvent Blue 97

[0079] Solvent Green 3, Solvent Blue 97 and Solvent Red 179.

[0080] Very particularly preferred colorants are mixtures (D) of the following components (expressed as Color Index General Names (CIGN)):

[0081] (D1) 20 to 40 wt% of Solvent Green 3

[0082] (D2) 10 to 30 wt% of Solvent Blue 97

[0083] (D3) 40 to 70 wt % of Solvent Red 179

[0084] A mixture (D) wherein the sum of components (D1) to (D3) is 100 wt %. Preferably, the content of the colorant mixture D is 0.15 wt % to 0.25 wt % relative to the sum of components (A) to (E).

[0085] Another preferred colorant is carbon black. Carbon black, also known as industrial carbon black, is a modification of carbon with a high surface area to volume ratio, containing 80% to 99.5% by weight of carbon. The specific surface area of ​​industrial carbon black is about 10 m 2 / g to 1500m 2 / g (BET). Carbon black can be produced as gas phase carbon black, furnace carbon black, flame carbon black, pyrolysis carbon black or acetylene carbon black. The crystallite diameter is 8nm to 500nm, usually 8nm to 110nm. Carbon black is also called pigment black7 or lamp black6. Colored carbon black is a nanoparticle carbon black that gradually loses the brown basic tone of traditional carbon black due to its fineness.

[0086] The following black pigments may also be used as colorants: iron oxide black (Fe3O4), spinel black (Cu(Cr,Fe)2O4), manganese black (a mixture of manganese dioxide, silicon dioxide and iron oxide), cobalt black and antimony black.

[0087] Nigrosine can also be used for black coloring. Nigrosine is generally a group of blue, black or gray phenazine dyes (azine dyes) related to induline in various forms (water-soluble, oil-soluble, alcohol-soluble). Nigrosine dyes can be synthesized by, for example, heating aniline, aniline hydrochloride and nitrobenzene in the presence of metallic iron or metallic copper and metal salts such as ferric chloride (FeCl3) at a reaction temperature of 160°C to 180°C, oxidizing and dehydrating condensation. Depending on the reaction conditions, the raw materials used, the charge ratio, etc., Nigrosine is produced as a mixture of different compounds; for example, it is assumed that Nigrosine can be a mixture of different triphenazinoxazine 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).

[0088] The aniline black of the present invention may be a black azine series mixture, which is described in the Color Index as CI Acid Black 2, CI Solvent Black 5, CI Solvent Black 5:1, CI Solvent Black 5:2, CI Solvent Black 7 (CI common names according to the Color Index 3rd Edition).

[0089] Examples of commercially available nigrosine dyes are alcohol soluble nigrosine SB, alcohol soluble nigrosine SSBB, alcohol soluble nigrosine AB (all belonging to CI Solvent Black 5); oil soluble nigrosine SA, oil soluble nigrosine SAP, oil soluble nigrosine SAP-L, oil soluble nigrosine EE, oil soluble nigrosine EE-L, oil soluble nigrosine EX, oil soluble nigrosine EX-BP (all belonging to CI Solvent Black 7), all of which are products of Orient Chemical Industrie, Ltd. Preferably, CI Solvent Black 7 (CAS No. 8005-02-5) is used.

[0090] The colorant can be introduced into the molding material according to the invention as a masterbatch or concentrate, preferably based on polyamide (A), preferably polyamide (A1), wherein the content of colorant is preferably 20% to 50% by weight. Preferably, aliphatic polyamides PA6, PA66, PA66 / BAC6, PA610, PA6 / 12, PA12 or mixtures of these polyamides are used as the basis for these masterbatches.

[0091] Used as component (D) is a black colorant preferably selected from carbon black, graphite, graphene, aniline black, black pigments, black dyes or combinations of complementary color pigments and / or dyes or a mixture of one or more than one of these colorants.

[0092] Preferably, the polyamide molding material according to the invention is provided with a colorant (component D) in such a way that the value of the color lightness L* (brightness) measured in the CIE-LAB light space is at most 28, particularly preferably at most 27, if gloss is included, and at most 8, particularly preferably at most 6, if gloss is excluded.

[0093] Last but not least, the proposed molding materials may also contain additives as component (E). In contrast to components A to D, component (E) is preferably present in the molding material in a proportion of 0% to 4.0% by weight, preferably 0.1% to 3.0% by weight.

[0094] The additives of component (E) can be selected from: stabilizers, anti-aging agents, antioxidants, anti-ozonants, light stabilizers, UV stabilizers, UV absorbers, UV blockers, inorganic heat stabilizers, especially inorganic heat stabilizers based on copper halides and alkali halides, organic heat stabilizers, conductive additives, processing aids, nucleating agents, crystallization promoters, crystallization retarders, flow aids, lubricants, mold release agents, plasticizers, marking agents and mixtures of these additives.

[0095] The molding compound according to the invention preferably contains at least one stabilizer as component (E) selected from inorganic stabilizers and organic stabilizers, in particular antioxidants, antiozonants, heat stabilizers, light stabilizers, UV stabilizers, UV absorbers or UV blockers. Preferably, stabilizer C is a UV stabilizer and / or a heat stabilizer.

[0096] According to a preferred embodiment, component (E) may be selected from:

[0097] Copper or divalent copper compounds, in particular salts of copper or divalent copper with inorganic or organic acids or monohydric or dihydric phenols, copper or divalent copper oxides, or complexes of copper salts with ammonia, amines, amides, lactams, cyanides or phosphines, preferably Cu(I) or Cu(II) salts of hydrohalic acids, hydrocyanic acid or copper salts of aliphatic carboxylic acids, with particular preference given to copper compounds CuCl, CuBr, CuI, CuCN and Cu2O, and divalent copper compounds CuCl2, CuSO4, CuO, copper(II) acetate or copper(II) stearate or mixtures of these compounds, wherein these copper compounds are used as such or preferably in the form of concentrates. A concentrate is understood to mean a polymer containing a high concentration of copper salts or copper compounds, which preferably have the same or essentially the same chemical properties as component A1 or component A2. In particular, the copper compound is preferably used in combination with other metal halides, including alkali metal halides such as NaI, KI, NaBr, KBr, wherein the molar ratio of metal halide to copper is 0.5 to 20, preferably 1 to 10, particularly preferably 2 to 7;

[0098] Stabilizers based on aromatic secondary amines;

[0099] Stabilizers based on sterically hindered phenols;

[0100] Phosphites and phosphonites,

[0101] a stabilizer selected from N,N'-oxamide, hydroxyphenyltriazine, hydroxybenzotriazole, dibenzoylmethane, aminohydroxybenzoylbenzoate, hydroxybenzophenone, hindered amine light stabilizer (HALS), and

[0102] Mixtures of the above stabilizers.

[0103] Particularly preferred examples of stabilizers related to aromatic secondary amines that can be used according to the invention are adducts of phenylenediamine and acetone (Naugard A), adducts of phenylenediamine and linolenic acid, Naugard 445, N,N'-dinaphthyl-p-phenylenediamine, N-phenyl-N'-cyclohexyl-p-phenylenediamine or mixtures of two or more of these stabilizers.

[0104] 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)-butyric acid)-ethylene glycol ester, 2,1'-thioethylbis-(3-(3,5-di-tert-butyl-4-hydroxyphenyl) propionate, 4-4'-butylene-bis-(3-methyl-6-tert-butylphenol), triethylene glycol 3-(3-tert-butyl-4-hydroxy-5-methylphenyl) propionate or a mixture of two or more of these stabilizers.

[0105] Preferred phosphites and phosphonites are triphenylphosphite, diphenylalkylphosphites, phenyldialkylphosphites, tri(nonylphenyl)phosphite, trilaurylphosphite, tri(octadecyl)phosphite, distearylpentaerythritol diphosphite, tri(2,4-di-tert-butylphenyl)phosphite, diisodecylpentaerythritol diphosphite, bis(2,4-di-tert-butylphenyl)pentaerythritol diphosphite, bis(2,6-di-tert-butyl-4-methylphenyl)pentaerythritol diphosphite, diisodecylpentaerythritol diphosphite, bis(2,4-di-tert-butyl-6-methylphenyl)pentaerythritol diphosphite , bis(2,4,6-tri-(tert-butylphenyl))pentaerythritol diphosphite, tristearyl sorbitol diphosphite, tetrakis(2,4-di-tert-butylphenyl)-4,4'-biphenylene diphosphite, 6-isooctyloxy-2,4,8,10-tetra-tert-butyl-12H-dibenzo[d,g]-1,3,2-dioxaphosphite, 6-fluoro-2,4,8,10-tetra-tert-butyl-12-methyl-dibenzo[d,g]-1,3,2-dioxaphosphite, 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 ( PAR24: Commercial product of Clariant, Basel).

[0106] A preferred embodiment of the heat stabilizer is a combination of Irgatec NC 66 (available from BASF) and a copper stabilizer based on CuI and KI. Heat stabilizers based solely on CuI and KI are particularly preferred.

[0107] According to other preferred embodiments, the heat stabilizer of component (E) is selected from phenol-based heat stabilizers, phosphite-based heat stabilizers, amine-based heat stabilizers, or mixtures or combinations of these heat stabilizers, wherein component (E) is particularly preferably selected from: triethylene glycol bis(3-tert-butyl-4-hydroxy-5-methylphenyl) propionate, pentaerythritol tetrakis(3-(3,5-di-tert-butyl-4-hydroxyphenyl) propionate), N,N'-hexamethylenebis[3-(3,5-di-tert-butyl-4-hydroxyphenyl) propionamide], tris(2,4-di-tert-butylphenyl) phosphite, tris(2,4-di-tert-butylphenyl) phosphite, or mixtures thereof.

[0108] Preferred organic stabilizers are phenolic compounds and / or phosphite compounds, such as Irganox 1010, Irganox 1098, Hostanox PAR 24 or Irgafos 168. As component (E), a mixture of 10 parts by weight of Irganox 1010 (CAS 6683-19-8, phenolic antioxidant) and Anox 20 (CAS 6683-19-8, phenolic antioxidant) in a ratio of 7:3 and 2 parts by weight of Hostanox PAR 24 (CAS: 31570-04-4, tris(2,4-di-tert-butylphenyl)phosphite) is particularly preferred.

[0109] Preferred UV stabilizers are selected from, for example, N-(2-ethoxyphenyl)-N'-(2-ethylphenyl)oxalamide (Tinuvin 312), 2-(4,6-diphenyl-1,3,5-triazine-2-yl)-5-hexyloxyphenol (Tinuvin 1577), 2-(4,6-diaryl-1,3,5-triazine-2-yl)-5-(substituted alkoxy)-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-piperidinyl) sebacate (Tinuvin 236). 770DF), 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-methylbutyl-2-yl)phenol (Tinuvin328), 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-tetramethylbutyl)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 of these UV stabilizers.

[0110] In a preferred embodiment, the thermoplastic polyamide molding compound according to the invention consists of:

[0111] (A) 28 to 84.9 wt% of component (A), which consists of:

[0112] (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;

[0113] (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 polyamide and / or microcrystalline polyamide,

[0114] wherein the sum of the weight % of component (A1) and component (A2) is 100 weight % of component (A);

[0115] (B) 15 to 50% by weight of 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), relative to 100% by weight of (B), wherein component (B) has an aluminum oxide content of 5 to 20% by weight and a silicon oxide content of 80 to 95% by weight, relative to 100% by weight of (B);

[0116] (C) 0 to 15 wt % of glass fibers and / or carbon fibers;

[0117] (D) 0.1 to 3.0 wt % of a black colorant, preferably carbon black;

[0118] (E) 0 wt % to 4.0 wt % of additives;

[0119] The sum of (A) to (E) is 100% of thermoplastic polyamide molding compound.

[0120] In other preferred embodiments, the thermoplastic polyamide molding compound according to the invention consists of:

[0121] (A) 50% to 79.8% by weight of component (A), which consists of:

[0122] (A1) 20 to 100% by weight, preferably 55 to 80% by weight, of at least one aliphatic semi-crystalline polyamide selected from polyamide 66, polyamide 66 / BAC6, polyamide 610 or mixtures thereof;

[0123] (A2) 0 to 80 wt. %, preferably 20 to 45 wt. %, of at least one amorphous partially aromatic polyamide selected from 6T / 6I and / or 10T / 10I, wherein the proportion of 6T units or 10T units is less than 50 mol %, and / or at least one cycloaliphatic polyamide selected from MACM12, PACM12, MACM12 / PACM12, MACM14, MACM16 or mixtures thereof,

[0124] wherein the sum of the weight % of component (A1) and component (A2) is 100 weight % of component (A);

[0125] (B) 20 to 45% by weight of 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), relative to 100% by weight of (B), wherein component (B) has an aluminum oxide content of 5 to 20% by weight and a silicon oxide content of 80 to 95% by weight, relative to 100% by weight of (B);

[0126] (D) 0.1 to 2.0 wt % of a black colorant, preferably carbon black;

[0127] (E) 0.1 wt % to 3.0 wt % of additives;

[0128] The sum of (A), (B), (D) and (E) is 100% of the thermoplastic polyamide moulding material. In this preferred embodiment, the moulding material contains no component (C), ie it contains no glass fibres and / or carbon fibres.

[0129] The invention further relates to the use of a mineral filler in a black-pigmented, mineral-filled polyamide moulding material for improving the deep black appearance, the 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), relative to 100% by weight of (B), wherein component (B) has an aluminium oxide content of 5% to 20% by weight and a silicon oxide content of 80% to 95% by weight, relative to 100% by weight of (B), wherein the colour brightness L* of the polyamide moulding material is 0.0447 W / m2 according to DIN EN ISO 9001:2003. 11664-4:2020, measured in the CIELAB color space on a plate with dimensions of 60 mm×60 mm×2 mm, the value of the color lightness L* of the polyamide molding compound, if gloss is included, is at most 30, preferably at most 28, particularly preferably at most 27, and if gloss is excluded, the value of the color lightness L* of the polyamide molding compound is at most 12, preferably at most 8, particularly preferably at most 6. In this case, the proportion of the mineral filler according to the invention in the polyamide molding compound is preferably 15% by weight to 50% by weight, preferably 20% by weight to 45% by weight, relative to the total weight of the polyamide molding compound.

[0130] Further embodiments are given in the dependent claims.

[0131] Example

[0132] The components listed in Table 1 were mixed in the proportions shown in Table 2 and Table 3 in a twin-screw extruder from Werner and Pfleiderer with a screw diameter of 25 mm under specific process parameters (see Table 4), wherein the polyamide granules and additives were metered into the feed zone, and the mineral filler was metered into the polymer melt of the three housing units located upstream of the die via a side feeder. The compounds listed in Table 2 and Table 3 were pulled out of a die with a diameter of 3 mm in the form of strands and pelletized after water cooling. The granular material was dried at 100° C. in a vacuum of 30 mbar for 24 hours.

[0133] Table 1: Materials used in Examples and Comparative Examples

[0134]

[0135]

[0136] Table 2: Moulding materials according to the invention

[0137]

[0138] Table 3: Molding materials of comparative examples

[0139]

[0140]

[0141] Table 4: Mixing process parameters

[0142] parameter Temperature curve [℃] Temperature zone 1 80 to 100 Temperature zone 2 230 to 250 Temperature zones 3 to 10 250 to 260 Temperature zone 11 250 to 270 Temperature zone 12 230 to 270 Die head temperature 260 to 280 Melting temperature 250 to 280 Output [kg / h] 8 to 12 Screw speed [rpm] 150 to 200

[0143] These compounds were injection molded into test specimens using an Arburg Allrounder 320-210-750 injection molding machine at specified barrel temperatures in zones 1 to 4 of 240°C to 280°C and a mold temperature of 100°C.

[0144] Measurement method

[0145] The following measurement methods were used within the scope of this application:

[0146] Melting point (Tm) and melting enthalpy (ΔHm):

[0147] Melting points and enthalpy of fusion were determined on granular materials according to ISO 11357-3 (2013).DSC (Differential Scanning Calorimetry) measurements were performed at a heating rate of 20 K / min.

[0148] Glass transition temperature, Tg:

[0149] Glass transition temperature T g The granular material was measured using differential scanning calorimetry (DSC) according to ISO 11357-2 (2013). Both heating cycles were carried out at a heating rate of 20 K / min. After the initial heating, the sample was quenched in dry ice. The glass transition temperature (T g ). Use the "half-height" method to determine the center point of the glass transition range, which is the glass transition temperature.

[0150] Relative viscosity, η rel :

[0151] The relative viscosity is determined according to ISO 307 (2007) at 20° C. For this purpose, 0.5 g of polymer particles are weighed into 100 ml of m-cresol (unless otherwise stated) and the relative viscosity (RV) is calculated according to RV=t / t0 according to section 11 of the standard.

[0152] Tensile modulus of elasticity:

[0153] The tensile modulus of elasticity was determined according to ISO 527 (2012) at 23°C at a tensile rate of 1 mm / min on an ISO tensile bar (type A1, dimensions 170×20 / 10×4) according to ISO / CD 3167 (2003) standard.

[0154] Breaking stress and breaking elongation:

[0155] Stress at break and elongation at break were determined according to ISO 527 (2012) at 23°C with a tensile rate of 5 mm / min on an ISO tensile bar of type A1 (dimensions 170 mm x 20 / 10 mm x 4 mm) manufactured according to ISO / CD 3167 (2003) standard.

[0156] Impact strength according to Charpy:

[0157] The Charpy impact strength is measured according to ISO 179 / 2*eU (1997, *2=instrumented) at 23°C on a B1 type ISO test bar (dimensions 80 mm×10 mm×4 mm) manufactured according to ISO / CD3167 (2003) standard.

[0158] Notched impact strength according to Charpy:

[0159] The Charpy notched impact strength is measured according to ISO 179 / 2*eA (1997, *2=instrumented) at 23°C on a B1 type ISO test bar (dimensions 80 mm×10 mm×4 mm) manufactured according to ISO / CD 3167 (2003) standard.

[0160] Color measurement and determination of lightness (color brightness L*)

[0161] The CIE L*a*b* values ​​of the reference and test color charts were measured in accordance with DIN EN ISO 11664-4:2020 using a spectrophotometer from Datacolor (instrument name: Datacolor 650) in front of a white coated comparison plate under the following measuring conditions; Measuring mode A: Reflection, Measuring geometry: D / 8°, Illuminant: D 65 10, Gloss: Included, Calibration: UV Calibration, Measuring aperture: SAV; Measuring mode B: Reflection, Measuring geometry: D / 8°, Illuminant: D 65 10, Gloss: Excluded, Calibration: UV Calibration, Measuring aperture: SAV.

[0162] Results and Discussion:

[0163] Comparative Examples CE1 to CE3, based on surface-coated kaolinite, a mineral of the prior art, all have values ​​of color lightness L* including gloss of more than 30 and values ​​of color lightness L* excluding gloss of 16 to 18. Visual evaluation of the corresponding color plates shows a coal-grey appearance. In contrast, the colored plates produced with the molding compounds according to Examples E1 to E3 of the invention exhibit a deep black color. This is also reflected in the color lightness L* of these examples, which have values ​​of color lightness L* below 27 when including gloss measurement and below 6 when excluding gloss measurement. The mechanical properties of the molding compounds according to the invention are at a good level, even though the modulus of elasticity and, in particular, the stress at break are slightly lower than for 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 to 55% by weight of a mineral filler consisting of a mixture of, relative to 100% by weight of B, 45 to 70% by weight of cryptocrystalline silicic acid B1, 5 to 15% by weight of amorphous silicic acid B2 and 20 to 40% by weight of calcined kaolin B3, wherein component B, relative to 100% by weight of B, has an aluminum oxide content of 5 to 20% by weight and a silicon oxide content of 80 to 95% by weight; C 0 to 15 wt % of glass fibers and / or carbon fibers; D 0.1 wt % to 5.0 wt % of a black colorant; E 0 to 5.0 wt% of additives; Thermoplastic polyamide molding compound wherein the sum of A to E is 100%, And wherein the color brightness L* of the thermoplastic polyamide molding material is measured in the CIELAB color space on a flat plate with dimensions of 60 mm×60 mm×2 mm according to DIN EN ISO 11664-4:2020, if the gloss is also measured, the maximum value of the color brightness L* of the thermoplastic polyamide molding material is 30, if the gloss is not measured, the maximum value of the color brightness L* of the thermoplastic polyamide molding material is 12.

2. The thermoplastic polyamide molding compound according to claim 1, characterized in that Component A is present in a proportion of 28% by weight to 84.9% by weight, preferably 50% by weight to 79.8% by weight, relative to components A to E.

3. Thermoplastic polyamide molding compound according to any one of the preceding claims, characterized in that Component A consists of: 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 and / or at least one partially aromatic semicrystalline polyamide based on a dicarboxylic acid and a diamine; A2 0 to 80 wt. %, preferably 15 to 60 wt. %, of at least one amorphous polyamide, The total weight percent of component A1 and component A2 is 100 weight percent of component A.

4. Thermoplastic polyamide molding compound according to any one of the preceding claims, characterized in that The polyamide of component A1 is a semicrystalline aliphatic polyamide selected from the group consisting of PA 6, PA 46, PA 56, PA 66, PA 66 / BAC6, PA 66 / 6, PA 69, PA 610, PA 612, PA 614, PA 616, PA 618, PA 810, PA 1010, PA 1012, PA 1212, PA 11, PA 12, PA 6 / 12, PA 66 / 6 / 610, of which PA 66, PA 66 / BAC6 and PA 610 are preferred and PA 66 / BAC6 in which BAC is equivalent to 1,3-BAC is particularly preferred, and / or is a semicrystalline partially aromatic polyamide selected from the group consisting of PA 6T / 6I, PA 6T / 66, PA 6T / 6I / 66, PA6T / 610, PA 6T / 612, PA 6T / 614, PA 6T / 616, PA 9T, PA 9MT (M = 2-methyloctane-1,8-diamine), PA 10T, PA 11T, PA 10T / 6T, PA 11T / 6T, PA 12T, PA 10T / 6T, PA 11 / 10T, PA 12 / 10T, PA 11 / 9T, PA 12 / 9T, PA 10T / 1010, PA 10T / 612, wherein the proportion of terephthalic acid relative to the total dicarboxylic acid content is preferably greater than 50 mol %, particularly preferably greater than 55 mol %, and / or It is a semi-crystalline polyamide having a melting point of at least 170°C, preferably from 175°C to 340°C, or if it is an aliphatic semi-crystalline polyamide, preferably from 175°C to 265°C.

5. Thermoplastic polyamide molding compound according to any one of the preceding claims, characterized in that Polyamide component A2 Selected from 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 of these polyamides, and / or from the group consisting of amorphous polyamides MXDI, MXDI / 6I, MXD6 / MXDI, 6I, 6 / 6I, 6T / 6I, 10T / 10I, 3-6T (3-6=2,2,4-trimethylhexanediamine or 2,4,4-trimethylhexanediamine) or mixtures of these polyamides, wherein the proportion of 6T units or 10T units in the system 6T / 6I or 10T / 10I is less than 50 mol % and wherein the composition of 6T / 6I or 10T / 10I is preferably from 20:80 to 45:55, particularly preferably from 25:75 to 40:60, and / or It is an amorphous polyamide having a glass transition temperature (Tg) of above 90°C, particularly preferably above 110°C, particularly preferably above 120°C.

6. Thermoplastic polyamide molding compound according to any one of the preceding claims, characterized in that Component B is present in a proportion of 15% to 50% by weight, preferably 20% to 45% by weight, relative to components A to E.

7. Thermoplastic polyamide molding compound according to any one of the preceding claims, characterized in that Component B is surface-treated with a silane compound, preferably trialkoxysilane, dialkoxysilane, epoxysilane, vinylsilane, (meth)acryloxysilane, aminosilane and mercaptosilane.

8. Thermoplastic polyamide molding compound according to any one of the preceding claims, characterized in that Component B is surface-coated with primary and / or secondary aminosilanes, particularly preferably with secondary aminosilanes, wherein the amount of primary and / or secondary aminosilanes, relative to component B, is 0.01% to 2.0% by weight.

9. Thermoplastic polyamide molding compound according to any one of the preceding claims, characterized in that Component C is glass fiber.

10. The molding compound according to any one of the preceding claims, characterized in that Component D is present in a proportion of 0.1% to 3.0% by weight, preferably 0.1% to 2.0% by weight, relative to components A to E; and / or Component D is selected from the group consisting of carbon black, graphite, graphene, aniline black, black pigments, black dyes, or combinations of complementary color pigments and / or dyes, or mixtures of one or more than one of these colorants.

11. Thermoplastic polyamide molding compound according to any one of the preceding claims, characterized in that Relative to components A to E, component E is present in a proportion of 0% to 4.0% by weight, preferably 0.1% to 3.0% by weight; and / or The additives of component E are selected from the group consisting of stabilizers, anti-aging agents, antioxidants, anti-ozonants, light stabilizers, UV stabilizers, UV absorbers, UV blockers, inorganic heat stabilizers, especially inorganic heat stabilizers based on copper halides and alkali halides, organic heat stabilizers, conductive additives, optical brighteners, processing aids, nucleating agents, crystallization promoters, crystallization retarders, flow aids, lubricants, mold release agents, plasticizers, marking agents and mixtures of these additives.

12. Thermoplastic polyamide molding compound according to any one of the preceding claims, characterized in that The molding compound is composed of: A 28% to 84.9% by weight of component A, which consists of: A1 20 to 100% by weight, preferably 40 to 85% by weight, of at least one aliphatic semicrystalline polyamide based on aliphatic dicarboxylic acid and aliphatic diamine; A2 0 to 80 wt. %, preferably 15 to 60 wt. %, of at least one amorphous polyamide, wherein the sum of the weight % of component A1 and component A2 is 100 weight % of component A; B 15 to 50% by weight of a mineral filler consisting of a mixture of, relative to 100% by weight of B, 45 to 70% by weight of cryptocrystalline silicic acid B1, 5 to 15% by weight of amorphous silicic acid B2 and 20 to 40% by weight of calcined kaolin B3, wherein component B, relative to 100% by weight of B, has an aluminum oxide content of 5 to 20% by weight and a silicon oxide content of 80 to 95% by weight; C 0 to 15 wt % of glass fibers and / or carbon fibers; D 0.1 wt % to 3.0 wt % of a black colorant, preferably carbon black; E 0 to 4.0 wt% of additives; The total of A to E is 100% of thermoplastic polyamide molding compound.

13. Thermoplastic polyamide molding compound according to any one of the preceding claims, characterized in that The molding compound is composed of: A 50% to 79.8% by weight of component A, which consists of: A1 20 to 100% by weight, preferably 55 to 80% by weight, of at least one aliphatic semicrystalline polyamide chosen from polyamide 66, polyamide 66 / BAC6, polyamide 610 or a mixture of these polyamides; A2 0 to 80 wt. %, preferably 20 to 45 wt. %, of at least one amorphous partially aromatic polyamide selected from 6T / 6I and / or 10T / 10I, wherein the proportion of 6T units or 10T units in 6T / 6I and 10T / 10I is less than 50 mol %, respectively, wherein the sum of the weight % of component A1 and component A2 is 100 weight % of component A; B 20 to 45% by weight of a mineral filler consisting of a mixture of 45 to 70% by weight of cryptocrystalline silicic acid B1, 5 to 15% by weight of amorphous silicic acid B2 and 20 to 40% by weight of calcined kaolin B3, relative to 100% by weight of B, wherein component B, relative to 100% by weight of B, has an aluminum oxide content of 5 to 20% by weight and a silicon oxide content of 80 to 95% by weight; D 0.1 wt % to 2.0 wt % of a black colorant, preferably carbon black; E 0.1 wt % to 3.0 wt % of additives; The total of A, B, D and E is 100% of the thermoplastic polyamide molding compound.

14. Thermoplastic polyamide molding compound according to any one of the preceding claims, characterized in that The color brightness L* of the polyamide molding material is measured in the CIELAB color space according to DIN EN ISO 11664-4:2020 on a flat plate with dimensions of 60 mm×60 mm×2 mm. If the gloss is also measured, the maximum value of the color brightness L* of the polyamide molding material is 28, preferably a maximum value of 27. If the gloss is not measured, the maximum value of the color brightness L* of the polyamide molding material is 8, preferably a maximum value of 6. 15 . A molded body comprising the polyamide molding compound according to claim 1 and preferably consisting of the polyamide molding compound.

16. Use of a mineral filler in a black-pigmented, mineral-filled polyamide molding compound for improving the deep black appearance, the mineral filler consisting of a mixture of 45 to 70 wt. % cryptocrystalline silicate B1, 5 to 15 wt. % amorphous silicate B2 and 20 to 40 wt. % calcined kaolin B3, relative to 100 wt. % B, wherein component B, relative to 100 wt. % B, has an aluminum oxide content of 5 to 20 wt. % and a silicon oxide content of 80 to 95 wt. %, wherein the color lightness L* of the polyamide molding compound is determined in accordance with DIN EN ISO 11664-4:2020 in the CIELAB color space on a plate with dimensions of 60 mm×60 mm×2 mm, and if gloss is included, the color lightness L* of the polyamide molding compound is a maximum of 30, preferably a maximum of 28, and if gloss is excluded, the color lightness L* of the polyamide molding compound is a maximum of 12, preferably a maximum of 8.

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