POLYAMIDE COMPOSITIONS

Description

[0001] The present invention relates to a method for reducing the abrasiveness of polyamide compositions containing aluminium oxide or the use of aluminium oxide surface-treated with at least one aminosilane in thermally conductive polyamide compositions for reducing abrasion in processing machines and processing tools and corresponding compositions, molding compounds to be produced therefrom and products based thereon. State of the art

[0002] The use of aluminum oxide as an abrasive is well known to those in the field. Aluminum oxide is obtained from bauxite by digesting it with sodium hydroxide according to the Bayer process. By removing the water, for example by calcination, sintering, or calcination, aluminum oxide is obtained. A distinction is made between cubic γ-Al₂O₃, so-called alumina, which serves as a starting material for ceramic and aluminum production, and rhombohedral / trigonal α-Al₂O₃, known as the mineral corundum, sapphire, or, when chromium-doped, ruby.

[0003] Due to its thermodynamic stability, α-Al 2 O 3 with a density of 3.98, a Mohs hardness of 9 and a melting point of 2053°C is preferably used as an abrasive.

[0004] In WO2010 / 025857A1, the aluminum oxide used in the production of abrasives is surface-treated with organic silane and incorporated into a synthetic resin matrix. The examples explicitly mention 3-aminopropyltriethoxysilane and 3-methacryloxypropyltrimethoxysilane as silanes.

[0005] The increase in thermal conductivity of polyamide-based molding compounds and products manufactured from them by adding aluminum oxide (Al₂O₃) is known to those skilled in the art from WO2009 / 019186 A1. However, due to its Mohs hardness of 9 and the resulting high wear in processing machinery, especially the tools of injection molding machines, aluminum oxide has not yet become established for the production of thermally conductive plastic compositions. Furthermore, it has been found that the use of aluminum oxide leads to a significant embrittlement of the compound or the products manufactured from it and also has a negative impact on the deformation resistance, elongation at break, and impact strength of polyamide-based products.

[0006] Elongation at break is a material property that indicates the permanent elongation of a sample after fracture, relative to the initial gauge length, and thus represents an essential parameter for characterizing the deformability or ductility of a material (see: http: / / de.wikipedia.org / wiki / Bruchdehnung). Elongation at break is measured in a tensile test according to ISO 527, for example, on injection-molded specimens. Impact strength, on the other hand, describes a material's ability to absorb impact energy without fracturing. Impact strength is calculated as the ratio of impact energy to the cross-sectional area of ​​the specimen (unit: kJ / m²). Impact strength can be determined using various types of impact bending tests (Charpy, Izod). Impact strength is measured according to ISO 180-1U, for example, on injection-molded specimens.

[0007] (see here: http: / / de.wikipedia.org / wiki / Schlagz%C3%A4higkeit). Object of the present invention

[0008] The object of the present invention was to provide thermally conductive and electrically insulating polyamide compositions containing aluminium oxide for this purpose, with improved mechanical properties and acceptable or, if necessary, improved thermal conductivity and improved abrasion behavior compared to the above-cited WO 2009 / 019186 A1, while otherwise having a comparable composition with regard to further additives.

[0009] A reduction in mechanical properties is acceptable according to the invention if it only occurs significantly after exposure to elevated temperatures over longer periods, where elevated temperatures mean T > 100°C and longer periods mean t > 1000 h.

[0010] The wear behavior of processing machines, hereinafter referred to as "abrasion", in particular in extruders and in injection molding machines, was investigated within the scope of the present invention in accordance with the wear test of the German Plastics Institute DKI Darmstadt. (Publication FG Plastics, "New and further development of model testing methods for corrosive / abrasive wear in plastics processing", project no. AiF 12245N (DKI 18 / 0-87), duration 01.12.1999 to 28.02.2003) recreated.

[0011] Low wear or good wear behavior (=abrasion) in processing machines or processing tools means, within the scope of the present invention, that only a technically acceptable material removal occurs during injection molding of the polyamide composition under investigation in 100 shots (1 shot = 3D), with an injection speed v from v = 30 mm / s and a screw diameter D of D = 35 mm, at a melt temperature of 290°C through a nozzle consisting of two metal plates (steel: 1.2738) with the slot width b = 12 mm, the slot length I = 12 mm and the slot height h = 0.4 mm can be observed.V describes the volume flow that passes through the platelets during the injection molding process. Material removal from the steel 1.2738 (short name 40CrMnNiMo8-6-4 and Italian name 40CrMnNiMo8-6-4) used in the present invention is described. Data sheet Dörrenberg Edelstahl GmbH, Engelskirchen, dated 02 / 2017 A composition with a chemical composition of C = 0.4%, Mn = 1.5%, Cr = 1.9%, Ni = 1.0%, Mo = 0.2% of less than 200 mg is considered technically acceptable within the meaning of the present invention in order to enable the user / processor to process aluminum oxide-containing polyamide compositions in the injection molding process when using a suitably hardened and, if necessary, surface-coated steel. Fig. 2 and Fig. 3 show schematic representations of the wear apparatus used according to the invention for determining the abrasion, as well as the plate arrangement and geometry of the measuring device used according to the invention.

[0012] If the expert knows the number of shots, the shot speed, and the shot quantity (shot quantity = screw feed = 3D = 3 times screw diameter), he can calculate V = volume. V = 3 D ⋅ π ⋅ D 2 2 Calculate the amount of material forced through the metal slot. The apparent shear rate. γ̇ ap Can the expert use the formula γ ˙ ap = 6 ⋅ V ˙ b ⋅ h 2 with the V = Volume melt flow V ˙ = v ⋅ π D 2 2 , the slot width b, the slot height h, The screw diameter D and the injection speed v can also be calculated. The material removal can be determined by weighing the metal plates before and after the test.

[0013] Good mechanical properties within the meaning of the present invention mean an elongation at break of at least 1.5% measured according to ISO 527 on freshly injection-molded specimens, wherein the elongation at break is the last recorded strain value before a stress drop to less than or equal to 10% of the yield strength occurs. The elongation at break is specified as a dimensionless quantity or as a percentage (%). For fractures above the yield strength, the nominal elongation at break is specified. This is the last recorded nominal elongation value before a stress drop to less than or equal to 10% of the yield strength occurs. The nominal elongation is determined from the measurements taken between the clamping jaws. See: https: / / de.wikipedia.org / wiki / Bruchdehnung?veaction=edit§ion=6#Definition_2

[0014] High impact strength within the meaning of the present invention means an impact strength of at least 20 kJ / m² measured according to ISO 180-1U on freshly injection-molded specimens. A thermal conductivity acceptable for a product according to the present invention is a thermal conductivity of at least 0.8 W / mK measured according to ISO 22007-4 on freshly injection-molded specimens both in and perpendicular to the flow direction of the specimen under investigation.

[0015] Electrically insulating within the meaning of the present invention means that the volume resistance of freshly injected test specimens, measured according to IEC60093, is greater than 10⁹ Ωm.

[0016] Polyamides are industrially produced with varying viscosities. Commonly used polyamides for polyamide 6, polyamide 66, and their copolyamides have solution viscosities in the range of 140–155 ml / g, measured according to ISO 307 in 96% sulfuric acid. Low-viscosity polyamides are used less frequently. Their solution viscosity, measured in 96% sulfuric acid according to ISO 307, is <135 ml / g. Preferably, the solution viscosity of low-viscosity polyamides is in the range of 95 to 135 ml / g.

[0017] Surprisingly, it was found that polyamide compositions and products manufactured from them, whose thermal conductivity is improved by a high aluminum oxide content, exhibit significantly less tool abrasion during injection molding in processing machines, while maintaining their mechanical properties, if the aluminum oxide is surface-treated with at least one aminosilane before being processed into a molding compound within the polyamide, and if a low-viscosity polyamide matrix is ​​used for processing into the molding compound. Since it is known to those skilled in the art that abrasion depends on the filler content of a compound, the inventive effect must be tested on compositions that, apart from the aluminum oxide, contain the same amounts of additives. Solution to the problem:

[0018] The present invention relates to a method for reducing the abrasiveness of thermally conductive polyamide compositions and molding compounds produced therefrom, characterized in that aluminum oxide, the surface of which is surface-treated with at least one aminosilane, is brought into contact with a polyamide composition and the polyamide composition is based on a low-viscosity polyamide with a solution viscosity measured in a 0.5 wt% solution in 96% sulfuric acid according to ISO 307 of <135 ml / g and the aluminum oxide has a monomodal, volume-mean particle size distribution to be determined according to ISO 13320 by laser diffraction and a volume-mean particle size d50 in the range of 0.1 to 50 µm.where a monomodal particle size distribution exists if the plot of the volume of the aluminum oxide particle sizes in [%] on the Y-axis of a histogram against the size class in micrometers [µm] on the X-axis of a histogram forms only one maximum in the form of a Gaussian curve and any further maxima that may occur do not exceed a volume of 1%.

[0019] The invention further relates to the use of aluminum oxide surface-treated with at least one aminosilane for reducing abrasion in processing machines during the processing of polyamide compositions and polyamide molding compounds based thereon with low-viscosity polyamide, the polyamide having a solution viscosity of <135 ml / g as measured in a 0.5 wt.% solution in 96% sulfuric acid according to ISO 307, wherein the aluminum oxide has a monomodal, volume-average particle size distribution according to ISO 13320 and a volume-average particle size d50 in the range of 0.1 to 50 µm, and a monomodal particle size distribution is present if the plot of the volume of the aluminum oxide particle sizes in [%] on the Y-axis of a histogram against the size class in micrometers [µm] on the X-axis of a histogram forms only one maximum in the form of a Gaussian curve, and any further maxima that may occur do not exceed a volume of 1%.

[0020] Within the scope of the present invention, aluminium oxide without aminosilane surface treatment and a polyamide matrix with commercially available viscosity are considered as a reference.

[0021] The invention also relates to compositions, molding compounds to be produced therefrom and products based thereon containing on a) 100 mass fractions of polyamide, preferably polyamide 6 and / or caprolactam-based copolyamides and / or polyamide 66, with a solution viscosity measured at 25°C according to ISO 307 in a 0.5 wt% solution in 96% sulfuric acid of less than 135 ml / g, b) 125 to 600 mass fractions of aluminum oxide (Al₂O₃) surface-treated with at least one aminosilane, having a monomodal, volume-average particle size distribution to be determined according to ISO 13320 by laser diffraction and a volume-average particle size d50 in the range of 0.1 to 50 µm, wherein a monomodal particle size distribution is present if the plot of the volume of the aluminum oxide particle sizes in [%] on the Y-axis of a histogram against the size class in micrometers [µm] on the X-axis of a histogram shows only a maximum in the form of a a Gaussian curve is formed and any further maxima that may occur do not exceed a volume of 1%.

[0022] In one embodiment, the compositions according to the invention and the molding compounds and products to be produced therefrom contain, in addition to components a) and b), at least one thermostabilizer as component c). Thus, the present invention relates to compositions and molding compounds to be produced therefrom and products based thereon, wherein based on a) 100 mass fractions of polyamide, preferably polyamide 6 and / or caprolactam-based copolyamides and / or polyamide 66, with a solution viscosity measured at 25°C according to ISO 307 in a 0.5 wt% solution in 96% sulfuric acid of less than 135 ml / g, b) 125 to 600 mass fractions of aluminum oxide Al₂O₃ surface-treated with at least one aminosilane, with a monomodal, volume-average particle size distribution to be determined according to ISO 13320 by laser diffraction and a volume-average particle size d₅₀ in the range of 0.1 to 50 µm, wherein a monomodal particle size distribution is present if the plot of the volume of the aluminum oxide particle sizes in [%] on the Y-axis of a histogram against the size class in micrometers [µm] on the X-axis of a histogram shows only a maximum in the form of a a Gaussian curve and any further maxima that may occur do not exceed a volume of 1%, c) 0.13 to 12.5 mass fractions of at least one thermostabilizer selected from the group of sterically hindered phenols, sterically hindered phosphites, sterically hindered phosphates, hydroquinones, aromatic secondary amines, substituted resorcinols, salicylates, benzotriazoles, benzophenones, polyhydric alcohols or copper halides are used.

[0023] In one embodiment, the compositions according to the invention and the molding compounds and products to be produced therefrom contain, in addition to components a), b) and c), at least one demolding agent and / or nucleating agent as component d). Thus, the present invention relates to compositions and molding compounds to be produced therefrom and products based thereon, wherein based on a) 100 mass fractions of polyamide, preferably polyamide 6 and / or caprolactam-based copolyamides and / or polyamide 66, with a solution viscosity measured at 25°C according to ISO 307 in a 0.5 wt% solution in 96% sulfuric acid of less than 135 ml / g, b) 125 to 600 mass fractions of aluminum oxide Al₂O₃ surface-treated with at least one aminosilane, with a monomodal, volume-average particle size distribution to be determined according to ISO 13320 by laser diffraction and a volume-average particle size d₅₀ in the range of 0.1 to 50 µm, wherein a monomodal particle size distribution is present if the plot of the volume of the aluminum oxide particle sizes in [%] on the Y-axis of a histogram against the size class in micrometers [µm] on the X-axis of a histogram shows only a maximum in the form of a a Gaussian curve and any further maxima that may occur do not exceed a volume of 1%, c) 0.13 to 12.5. Mass fractions of at least one thermostabilizer selected from the group consisting of sterically hindered phenols, sterically hindered phosphites, sterically hindered phosphates, hydroquinones, aromatic secondary amines, substituted resorcinols, salicylates, benzotriazoles, benzophenones, polyhydric alcohols or copper halides, and d) 0.001 to 10 mass fractions of at least one demolding agent and / or nucleating agent are used.

[0024] In one embodiment, the compositions according to the invention and the molding compounds and products to be produced therefrom contain at least one additive other than components b), c) and d). Thus, the present invention relates to compositions and molding compounds to be produced therefrom and products based thereon, wherein based on a) 100 mass fractions of polyamide, preferably polyamide 6 and / or caprolactam-based copolyamides and / or polyamide 66, with a solution viscosity measured at 25°C according to ISO 307 in a 0.5 wt% solution in 96% sulfuric acid of less than 135 ml / g, b) 125 to 600 mass fractions of aluminum oxide Al₂O₃ surface-treated with at least one aminosilane, with a monomodal, volume-average particle size distribution to be determined according to ISO 13320 by laser diffraction and a volume-average particle size d₅₀ in the range of 0.1 to 50 µm, wherein a monomodal particle size distribution is present if the plot of the volume of the aluminum oxide particle sizes in [%] on the Y-axis of a histogram against the size class in micrometers [µm] on the X-axis of a histogram shows only a maximum in the form of a a Gaussian curve and any further maxima that may occur do not exceed a volume of 1%, c) 0.13 to 12.5. Mass fractions of at least one thermostabilizer selected from the group consisting of sterically hindered phenols, sterically hindered phosphites, sterically hindered phosphates, hydroquinones, aromatic secondary amines, substituted resorcinols, salicylates, benzotriazoles, benzophenones, polyhydric alcohols, or copper halides; d) 0.001 to 10 mass fractions of at least one demolding agent and / or nucleating agent; and e) 0.001 to 150 mass fractions of at least one additive different from components b), c), and d).

[0025] In one embodiment, the present invention relates to compositions and molding compounds to be produced therefrom and products based thereon, wherein based on a) 100 mass fractions of polyamide, preferably polyamide 6 and / or caprolactam-based copolyamides and / or polyamide 66, with a solution viscosity measured at 25°C according to ISO 307 in a 0.5 wt% solution in 96% sulfuric acid of less than 135 ml / g, b) 125 to 600 mass fractions of aluminum oxide Al₂O₃ surface-treated with at least one aminosilane, with a monomodal, volume-average particle size distribution to be determined according to ISO 13320 by laser diffraction and a volume-average particle size d₅₀ in the range of 0.1 to 50 µm, wherein a monomodal particle size distribution is present if the plot of the volume of the aluminum oxide particle sizes in [%] on the Y-axis of a histogram against the size class in micrometers [µm] on the X-axis of a histogram shows only a maximum in the form of a a Gaussian curve and any further maxima that may occur do not exceed a volume of 1%, c) 0.13 to 12.5. Mass fractions of at least one thermostabilizer selected from the group consisting of sterically hindered phenols, sterically hindered phosphites, sterically hindered phosphates, hydroquinones, aromatic secondary amines, substituted resorcinols, salicylates, benzotriazoles, benzophenones, polyhydric alcohols, or copper halides; d) 0.001 to 10 mass fractions of talc and / or at least one demolding agent; and e) 0.001 to 150 mass fractions of at least one further additive different from components b), c), and d).

[0026] Preferably, a composition according to the invention or molding compounds and products based thereon to be produced therefrom have a thermal conductivity to be determined according to ISO 22007-4 in the range of 0.8 to 10 W / m·K, particularly preferably in the range of 0.8 to 8 W / m·K, most preferably in the range of 1 to 6 W / m·K, both in and perpendicular to the flow direction of the specimen to be examined.

[0027] The preparation of the compositions according to the invention for further use is carried out by mixing the components a) and b), which are used as starting materials, and optionally the additional components c) to e) in at least one mixing tool. This yields molding compounds based on the compositions according to the invention as intermediate products. These molding compounds can consist either exclusively of the aforementioned components or can contain additional components.

[0028] In the context of the present invention, particularly in formulas (I) and (II), "alkyl" denotes a straight-chain or branched saturated hydrocarbon group. If, for example, an alkyl group with 1 to 4 carbon atoms is used, it can be referred to as a "low alkyl group" and preferably comprises methyl (Me), ethyl (Et), propyl, in particular n-propyl and isopropyl, butyl, in particular n-butyl, isobutyl, sec-butyl, tert-butyl.

[0029] "Cycloalkyl" is derived from cycloalkanes, which are a class of ring-shaped, saturated hydrocarbons. The rings can carry side chains. In the systematics of organic chemistry, they are classified as alicyclic compounds. Cycloalkanes without side chains form a homologous series with the general formula CnH2n, where n ≥ 3. Thus, the smallest cycloalkane is cyclopropane. The corresponding formula for an unsubstituted cycloalkyl group without a side chain is CnH2n-1.

[0030] For the avoidance of doubt, it should be noted that the scope of this invention encompasses all listed, general, or preferred definitions and parameters in any combination. Unless otherwise specified, cited standards apply in the version valid on the filing date. Unless otherwise specified, percentages are weight percentages. Polyamides to be used according to the invention, in particular polyamide 6 and / or caprolactam-based copolyamides and / or polyamide 66, with a solution viscosity of less than 135 ml / g as measured at 25°C according to ISO 307 in a 0.5 wt% solution in 96% sulfuric acid, are, within the scope of the present invention, so-called low-viscosity polyamides. Preferred embodiments of the invention Component a)

[0031] The polyamides used according to the invention, preferably polyamide 6 and / or caprolactam-based copolyamides and / or polyamide 66, have a solution viscosity of <135 ml / g when measured at 25°C according to ISO 307 in a 0.5 wt% solution in 96% sulfuric acid. For the viscosity measurement of polyamide in sulfuric acid, an Ubbelohde viscometer according to DIN 51 562, Part 1, with capillary II is used. The measurements are carried out at 25°C (± 0.02°C). See: Viscosity measurement of polyamide, A guide, SI Analytics GmbH, Mainz, 2012, Xylem Inc.

[0032] Preferably, component a) is a low-viscosity polyamide with a solution viscosity determined in a 0.5 wt% solution in 96 wt% sulfuric acid at 25°C according to ISO 307 in the range of 80 to 135 ml / g, particularly preferably in the range of 90 to 130 ml / g, most preferably in the range of 90 to 125 ml / g, and particularly preferably in the range of 95 to 115 ml / g.

[0033] The polyamides to be used according to the invention are preferably semicrystalline polyamides which, according to DE 10 2011 084 519 A1, have a fusion enthalpy in the range of 4 to 25 J / g, measured using the DSC method according to ISO 11357 during the second heating and integration of the melting peak.

[0034] Preferably, the polyamides used as component a) have a melting point of at least 180°C. Polyamide 6 (PA 6) or polyamide 66 (PA 66) or a co-polyamide of PA6 or PA66 are particularly preferred. PA 6 is especially preferred.

[0035] The designation of the polyamides used in this application complies with international standards, specifically DIN 7728, where the first digit(s) indicate the number of carbon atoms in the starting diamine and the last digit(s) indicate the number of carbon atoms in the dicarboxylic acid. If only one digit is given, as in the case of PA 6, this indicates that the compound is based on an α,ω-aminocarboxylic acid or the lactam derived from it, in the case of PA 6, ε-caprolactam. For further information, see H. Domininghaus, Die Kunststoffe und ihreeigenschaften (Plastics and their Properties), 8th edition, 2012, pages 605–607, VDI-Verlag. .

[0036] The polyamides to be used in the thermoplastic molding compounds according to the invention can be produced by various processes and synthesized from different building blocks. A multitude of methods are known for the production of polyamides, whereby, depending on the desired end product, different monomer building blocks as well as various chain regulators for adjusting a target molecular weight or monomers with reactive groups for subsequent post-treatments are used.

[0037] The technically relevant processes for producing the polyamides used according to the invention mostly proceed via polycondensation in the melt. Within the scope of the present invention, the hydrolytic polymerization of lactams is also understood as polycondensation. Component b)

[0038] Preferably, component b) is α-Al 2 O 3 surface-treated with at least one aminosilane.

[0039] For component b), Al₂O₃ [CAS 1344-28-1] is particularly preferred, with a monomodal, volume-averaged particle size distribution determined by laser diffraction according to ISO 13320. The data obtained by laser diffraction are evaluated using a volume-related histogram with a logarithmic abscissa. For this purpose, the particle sizes are divided into size classes. Each decade is represented by a

[0040] The measuring range is divided from 0.01 µm to 10000 µm into 18 size classes. This results in 108 size classes, the width of which is given by the formula for size class y. y = 0 , 01 ⋅ e ln 10 • x 18 − 0 , 01 ⋅ e ln 10 • x − 1 18 corresponds to where x describes the continuous number of size classes in the range from 1 to 108.

[0041] For a definition of the term "monomodal", please refer to: https: / / de.wikipedia.org / wiki / Partikelgr%C3%B6%C3%9Fenverteilung

[0042] According to the invention, a monomodal particle size distribution exists when the plot of the volume of the aluminium oxide particle sizes in [%] (= Y-axis in the histogram) against the size class in micrometers [µm] (= X-axis in the histogram) preferably forms only one maximum in the form of a Gaussian curve and any further maxima that may occur do not exceed a volume of 1%.

[0043] An aluminum oxide powder used within the scope of the present invention, with a monomodal, volume-average particle size distribution to be determined by laser diffraction according to ISO 13320, is CT 3000 SG from Almatis GmbH, with a d50 value of 0.5 µm and a BET surface area of ​​7.8 m² / g.

[0044] Fig. 1Figure 1 shows a histogram of the monomodal particle size distribution of another surface-treated aluminum oxide used in the present invention, determined by laser diffraction according to ISO 13320. 3-Aminopropyltrimethoxysilane was used for this purpose. 3-Aminopropyltriethoxysilane can also be used. The histogram of the Fig. 1 The size classes in µm (x-axis) are plotted against the volume in %. The d10 is 0.582 µm, the d50 is 1.95 µm, and the d90 is 4.79 µm. Monomodal aluminum oxides are also marketed by Nabaltec AG, Schwandorf, under the brand name Nabalox®.

[0045] The term "particle size distribution" is borrowed from statistics. There, frequencies and frequency distributions of an arbitrary characteristic, such as manufacturing tolerances, are considered. In the field of particle technology and particle measurement technology, or dispersion analysis, the equivalent diameter of a particle is chosen as the characteristic. The particle size distribution, often also referred to as grain size distribution, is derived from the general frequency distribution used in statistics. The density distribution of particle sizes usually exhibits the form of a Gaussian bell curve. If the density distribution of particle sizes has only one maximum, it is called a monomodal distribution. With two maxima, the distribution is bimodal. The abscissa value of the largest maximum is called the mode. The particle size distribution is determined by laser diffraction according to ISO 13320.For the measurement, the optical material properties for aluminium oxide were used within the scope of the present invention and evaluated according to the Mie theory; see: . https: / / de.wikipedia.org / wiki / Laserbeugungs-Partikelgr%C3%B6%C3%9Fenanalyse.

[0046] d10, d50 and d90 are the diameters at which 10%, 50% (median) and 90% of the particles, respectively, have a smaller diameter relative to the total volume.

[0047] The technical-grade aluminum oxide preferably used in the present invention has a α-Al₂O₃ content of more than 70%. Particularly preferred is an aluminum oxide with a α-Al₂O₃ content of over 90%. Most preferred is an aluminum oxide with a α-Al₂O₃ content of over 95%. According to the invention, α-Al₂O₃ with less than 5 wt.% impurities is particularly preferred, and most preferred is one with less than 1 wt.% impurities.

[0048] For component b), a surface-treated aluminum oxide in powder form is preferably used. Preferred powders have a volume-average particle size d50 of a maximum of 100 µm, as determined according to ISO 13320, and a volume-average particle size d50 in the range of 0.1 to 50 µm, preferably a volume-average particle size d50 in the range of 0.5 to 10 µm, and particularly preferably a volume-average particle size d50 in the range of 0.5 to 5 µm.

[0049] The particle size d10 to be determined according to ISO13320 for component b) is preferably in the range of 0.01 to 20 µm, particularly preferably in the range of 0.05 to 10 µm, most preferably in the range of 0.1 to 5 µm and particularly preferably in the range of 0.5 to 2µm.

[0050] The particle size d90 to be determined according to ISO13320 is preferably a maximum of 200µm for component b), particularly preferably in the range of 1 to 100 µm, most preferably in the range of 1.5 to 50 µm, and particularly preferably in the range of 2 to 10 µm.

[0051] According to the invention, component b) comprises an aluminum oxide with a monomodal, volume-average particle size distribution determined by laser diffraction according to ISO 13320, with a d50 in the range of 0.1 to 50 µm, a d10 in the range of 0.01 to 20 µm, and a d90 in the range of 1 to 100 µm. The invention therefore particularly preferably relates to compositions and molding compounds and products made therefrom, with the proviso that component b) comprises an aluminum oxide with a monomodal, volume-average particle size distribution determined by laser diffraction according to ISO 13320, with a d50 in the range of 0.1 to 50 µm, a d10 in the range of 0.01 to 20 µm, and a d90 in the range of 1 to 100 µm.

[0052] In particular, and especially preferably, component b) uses an aluminum oxide with a monomodal, volume-average particle size distribution determined according to ISO 13320 by laser diffraction, with a d50 in the range of 0.5 to 5 µm, a d10 in the range of 0.5 to 2 µm, and a d90 in the range of 2 to 10 µm. The invention therefore relates particularly preferably to compositions and molding compounds and products made therefrom, with the proviso that component b) uses an aluminum oxide with a monomodal, volume-average particle size distribution determined according to ISO 13320 by laser diffraction, with a d50 in the range of 0.5 to 5 µm, a d10 in the range of 0.5 to 2 µm, and a d90 in the range of 2 to 10 µm.

[0053] The Al₂O₃ particles to be used for component b) according to the invention can be in different shapes, which can be described by the aspect ratio. Particles with an aspect ratio of 1 to 100 are preferred, particularly preferably 1 to 30, and most preferably 1 to 10. EP 3 164 694 A1 describes several methods for determining the aspect ratio. In camera-based methods, the particles are imaged as two-dimensional images on the camera sensor. If the sensor is a CCD matrix or a CMOS image sensor, appropriate image processing software is used to determine the particle shape. DE 198 02 141 C1 describes a solution with a matrix camera, and EP 1 972 921 A1 describes a solution with two cameras. If the sensor is a CCD array, the imaged particle area is composed from the measured chord lengths at a known particle velocity.Corresponding devices and methods are listed in DE 10 2009 056 503 A1 (with sensor array), DE 10 2004 056 520 A1 (with CCD array), DE 43 13 688 A1 (with CCD array), DE 41 19 240 C2 (with CCD array), DD 278 859 A1 (with CCD line sensor), DD 260 764 A1 (with CCD line sensor) and DD 232760 A1 (with single-row television camera). DE 196 28 348 C1 proposes determining the particle shape using a single array of individual optical fibers, with a second optical fiber array being used to determine the velocity. Diffraction-based methods utilize the dependence of the particle diffraction pattern on the particle shape. In this process, the particles are irradiated with coherent light, and the light intensity distribution of the diffraction pattern is measured with a suitable receiver. The distribution of light intensity in the diffraction pattern depends on the shape of the particles. Solutions for this are provided in DE 694 06 683 T2 (with ring sensor) and DE 102 18 413 B4. .Document DE 41 29 105 A1 discloses a method for determining particle shape using scattered light measurement. Since the methods mentioned differ only in terms of complexity, a person skilled in the art can freely choose from these methods described in the prior art.

[0054] According to the invention, the Al₂O₃ to be used for component b) is provided with at least one surface modification based on at least one aminosilane. Surface modifications are defined as silane-based organic coupling agents that are intended to improve the bonding to the thermoplastic matrix.

[0055] Preferred surface treatment agents or surface modifications are aminosilanes with the general molecular formula (RO) 3 -Si-(CH 2 ) n -X wherein R represents an organic residue selected from the group methyl, ethyl, i-propyl and methoxymethyl, n represents an integer from 0 to 12 - including final values ​​- and X represents a residue NR 1< R 2< and R 1< and R 2< each independently represent hydrogen, a C 1 -C 6 alkyl residue or a C 6 -C 9 cycloalkyl residue.

[0056] Preferably, at least one aminosilane selected from the group consisting of 3-aminopropyltriethoxysilane [CAS 919-30-2], 3-aminopropyltrimethoxysilane [CAS 13822-56-5], N-(2-aminoethyl)-3-aminopropyltrimethoxysilane [CAS 1760-24-3], N-(2-aminoethyl)-3-aminopropyltriethoxysilane [CAS 5089-72-5], 3-(N-cyclohexylamino)propyltrimethoxysilane [CAS 3068-78-8], and N,N-(diethylaminomethyl)triethoxysilane [CAS 15180-47-9] is used for the surface treatment or surface modification of the aluminium oxide.

[0057] According to the invention, silane-based surface modifications and their production are in principle known to those skilled in the art. US 7,547,743 B2 known, the content of which, with regard to the production of organopolysiloxanes disclosed therein, is fully encompassed by the present application.

[0058] Preferably, the aminosilane used for surface modification is applied in amounts in the range of 0.05 to 5 mass parts, particularly preferably in amounts in the range of 0.1 to 1 mass parts, based on 100 mass parts of aluminium oxide.

[0059] The surface treatment or modification of the aluminum oxide with aminosilane can be carried out immediately before the aluminum oxide is used, or previously surface-treated aluminum oxide can be used. The aminosilanes mentioned above react upon contact with the aluminum oxide to form silanols, and the respective alcohol residue is cleaved off. This is related to Fig. 1The compounds discussed were 3-Aminopropyltrimethoxysilane or 3-Aminopropyltriethoxysilane, both of which are converted to 3-Aminopropylsilanol upon contact with the aluminum oxide, with the alcohol residue being cleaved off.

[0060] According to the invention, the application of the aminosilane to the aluminum oxide can be carried out in the manner described in WO 2009 / 156342 A1 by first placing the aminosilane in demineralized water (DI = fully demineralized water) to form silanol and stirring at a temperature in the range of 23 to 27 °C (room temperature). The quantities used are based on the mass fractions mentioned above. The aluminum oxide is then added, the suspension is stirred at temperatures in the range of 75 to 100 °C, the surface-treated aluminum oxide is filtered off, and washed with demineralized water. The surface is then dried at temperatures of approximately 120 °C and tempered at 200 °C. A technical method for the surface treatment of aluminum oxide with silanes is described in EP 1 628 916 B1, the content of which is fully encompassed by the present application.In this process, pyrogenic aluminum oxide is sprayed with the surface modifier at room temperature, and the mixture is then thermally treated at a temperature of 50 to 400 °C for a period of 1 to 6 hours. Alternatively, the pyrogenic aluminum oxide is treated with the surface modifier in vapor form, and the mixture is then thermally exposed at a temperature in the range of 50 to 800 °C for a period of 0.5 to 6 hours. The thermal treatment can be carried out under a protective gas, such as nitrogen. The surface treatment according to EP 1 628 916 B1 can be carried out continuously or discontinuously in heated mixers and dryers with spray devices. Suitable devices include, for example, plowshare mixers or plate, cyclone, or fluidized bed dryers. Component c)

[0061] The thermostabilizer to be used in the compositions according to the present invention comprises thermostabilizers selected from the group consisting of sterically hindered phenols, sterically hindered phosphites, sterically hindered phosphates, hydroquinones, aromatic secondary amines, substituted resorcinols, salicylates, benzotriazoles, benzophenones, polyhydric alcohols, and copper halides. In one embodiment, various substituted representatives of all the aforementioned thermostabilizers and mixtures thereof are also used.

[0062] The copper halides are preferably used in combination with alkali and / or alkaline earth metal halides. A preferred copper halide is copper iodide. Preferred alkali halides are potassium iodide, potassium bromide, or sodium chloride. A preferred alkaline earth halide is calcium chloride. In one embodiment, the copper halide is used in combination with manganese chloride.

[0063] Tripentaerythritol or dipentaerythritol, especially dipentaerythritol, are preferably used as the polyhydric alcohol.

[0064] Particularly preferred is the use of at least one compound from the series of sterically hindered phenols, sterically hindered phosphites, polyhydric alcohols, or copper halides as a thermostabilizer.

[0065] Particularly preferred as thermostabilizers are sterically hindered phenols and / or phosphites, especially sterically hindered phenols. In particular, the sterically hindered phenol N,N'-hexamethylene-bis[3-(3,5-di-t-butyl-4-hydroxyphenyl)propionamide [CAS 23128-74-7], offered as Ultranox®< 1098 by BASF SE, Ludwigshafen, is used as a thermostabilizer for component c).

[0066] According to the invention, preferred are compositions, molding compounds to be produced therefrom and products based thereon containing on a) 100 mass fractions of at least one polyamide, preferably polyamide 6 and / or caprolactam-based copolyamides and / or polyamide 66, with a solution viscosity measured at 25°C according to ISO 307 in a 0.5 wt% solution of 96% sulfuric acid of less than 135 ml / g, b) 125 to 600 mass fractions of Al₂O₃ surface-treated with at least one aminosilane, having a monomodal, volume-average particle size distribution to be determined according to ISO 13320 by laser diffraction and a volume-average particle size d50 in the range of 0.1 to 50 µm, wherein a monomodal particle size distribution is present if the plot of the volume of the aluminum oxide particle sizes in [%] on the Y-axis of a histogram against the size class in micrometers [µm] on the X-axis of a histogram shows only a maximum in the form of a Gaussian curve and any further maxima that may occur do not exceed a volume of 1%, and c) 0.13 to 12.5 mass fractions of N,N'-hexamethylene-bis[3-(3,5-di-t-butyl-4-hydroxyphenyl)propionamide. .

[0067] The invention particularly preferably relates to a method for reducing the abrasiveness of thermally conductive and simultaneously thermostabilized polyamide compositions, characterized in that the Al 2 O 3 to be used, the surface of which is surface-treated with at least one aminosilane, is brought into contact with a polyamide composition which contains at least one thermostabilizer from the group of sterically hindered phenols and / or phosphites, in particular preferably sterically hindered phenols and in particular most preferably with N,N'-hexamethylene-bis[3-(3,5-di-t-butyl-4-hydroxyphenyl)propionamide.

[0068] The invention further relates to the use of Al 2 O 3 surface-treated with at least one aminosilane for reducing abrasion in processing machines for processing polyamide compositions, and the aluminum oxide is used in combination with at least one thermostabilizer from the group of sterically hindered phenols and / or phosphites, in particular preferably sterically hindered phenols and in particular most preferably with N,N'-hexamethylene-bis[3-(3,5-di-t-butyl-4-hydroxyphenyl)propionamide. Component d)

[0069] In one embodiment, at least one demolding means or at least one nucleating means is used as component d).

[0070] According to the invention, nucleating agents preferably used as component d) are sodium or calcium phenylphosphinate, silicon dioxide, or talc, particularly preferably talc. Talc is a magnesium silicate hydrate with the chemical composition Mg3[Si4O10(OH)2].

[0071] According to the invention, the demolding agents preferably used as component d) are preferably long-chain fatty acids, their salts, as well as their ester derivatives or amide derivatives, montan wax esters and their salts, as well as low molecular weight polyethylene or polypropylene waxes in oxidized and non-oxidized form.

[0072] The preferred fatty acid is stearic acid. Preferred salts of the fatty acids are calcium stearate or zinc stearate. Preferred ester derivatives of the fatty acids are stearyl stearate or glycerol tristearate. Preferred montan wax esters are esters of montanic acids with multifunctional alcohols, especially ethylene glycol.

[0073] Preferred lubricating and / or demolding agents according to the invention are further the group of esters or amides of saturated or unsaturated aliphatic carboxylic acids with 8 to 40 C atoms with aliphatic saturated alcohols or amines with 2 to 40 C atoms.

[0074] In a further preferred embodiment, the molding compounds according to the invention contain mixtures of the aforementioned lubricating and / or demolding agents. The montan wax esters and their salts, which are particularly preferred for use, improve the flowability of plastics such as polyamides solely through internal lubrication, without reducing the molecular weight of the polymer.

[0075] In particular, esters of montanic acid with multifunctional alcohols, offered by Clariant GmbH as Licowax ®< E (CAS No: 73138-45-1), are especially preferred.

[0076] In one embodiment, the present invention relates to compositions and molding compounds to be produced therefrom and products based thereon, wherein based on a) 100 mass fractions of polyamide, preferably polyamide 6 and / or caprolactam-based copolyamides and / or polyamide 66, with a solution viscosity measured at 25°C according to ISO 307 in a 0.5 wt.% solution in 96% sulfuric acid of less than 135 ml / g, b) 125 to 600 mass fractions of Al₂O₃ surface-treated with at least one aminosilane, having a monomodal, volume-average particle size distribution to be determined according to ISO 13320 by laser diffraction and a volume-average particle size d₅₀ in the range of 0.1 to 50 µm, wherein a monomodal particle size distribution is present if the plot of the volume of the aluminum oxide particle sizes in [%] on the Y-axis of a histogram against the size class in micrometers [µm] on the X-axis of a histogram shows only a maximum in the form of a Gaussian curve forms and any further maxima that may occur do not exceed a volume of 1%, c) 0.13 to 12.5. Mass fractions of at least one thermostabilizer selected from the group consisting of sterically hindered phenols, sterically hindered phosphites, sterically hindered phosphates, hydroquinones, aromatic secondary amines, substituted resorcinols, salicylates, benzotriazoles, benzophenones, polyhydric alcohols, or copper halides; d) 0.001 to 10 mass fractions of at least one ester of montanic acid with multifunctional alcohols and / or talc.

[0077] According to the invention, preferred are compositions, molding compounds to be produced therefrom and products based thereon containing on a) 100 mass fractions of at least one polyamide, preferably polyamide 6 and / or caprolactam-based copolyamides and / or polyamide 66, with a solution viscosity measured at 25°C according to ISO 307 in a 0.5 wt.% solution in 96% sulfuric acid of less than 135 ml / g, b) 125 to 600 mass fractions of Al₂O₃ surface-treated with at least one aminosilane, having a monomodal, volume-average particle size distribution to be determined according to ISO 13320 by laser diffraction and a volume-average particle size d50 in the range of 0.1 to 50 µm, wherein a monomodal particle size distribution is present if the plot of the volume of the aluminum oxide particle sizes in [%] on the Y-axis of a histogram against the size class in micrometers [µm] on the X-axis of a histogram shows only a maximum in the form of a Gaussian curve and any further maxima that may occur do not exceed a volume of 1%, and c) 0.13 to 12.5 mass fractions of N,N'-hexamethylene-bis[3-(3,5-di-t-butyl-4-hydroxyphenyl)propionamide, and d) 0.001 to 10 mass fractions of at least one ester of montanic acid with multifunctional alcohols and / or talc.

[0078] In one embodiment, the present invention relates to compositions and molding compounds to be produced therefrom and products based thereon, wherein based on a) 100 mass fractions of polyamide, preferably polyamide 6 and / or caprolactam-based copolyamides and / or polyamide 66, with a solution viscosity measured at 25°C according to ISO 307 in a 0.5 wt% solution in 96% sulfuric acid of less than 135 ml / g, b) 125 to 600 mass fractions of Al₂O₃ surface-treated with at least one aminosilane, having a monomodal, volume-average particle size distribution to be determined according to ISO 13320 by laser diffraction and a volume-average particle size d50 in the range of 0.1 to 50 µm, wherein a monomodal particle size distribution is present if the plot of the volume of the aluminum oxide particle sizes in [%] on the Y-axis of a histogram against the size class in micrometers [µm] on the X-axis of a histogram shows only a maximum in the form of a a Gaussian curve and any further maxima that may occur do not exceed a volume of 1%, c) 0.13 to 12.5. Mass fractions of at least one thermostabilizer selected from the group consisting of sterically hindered phenols, sterically hindered phosphites, sterically hindered phosphates, hydroquinones, aromatic secondary amines, substituted resorcinols, salicylates, benzotriazoles, benzophenones, polyhydric alcohols, or copper halides; d) 0.001 to 10 mass fractions of at least one ester of montanic acid with multifunctional alcohols and / or talc; and e) 0.001 to 150 mass fractions of at least one further additive different from components b), c), and d).

[0079] According to the invention, preferred are compositions, molding compounds to be produced therefrom and products based thereon containing on a) 100 mass fractions of at least one polyamide, preferably polyamide 6 and / or caprolactam-based copolyamides and / or polyamide 66, with a solution viscosity measured at 25°C according to ISO 307 in a 0.5 wt.% solution in 96% sulfuric acid of less than 135 ml / g, b) 125 to 600 mass fractions of Al₂O₃ surface-treated with at least one aminosilane, having a monomodal, volume-average particle size distribution to be determined according to ISO 13320 by laser diffraction and a volume-average particle size d50 in the range of 0.1 to 50 µm, wherein a monomodal particle size distribution is present if the plot of the volume of the aluminum oxide particle sizes in [%] on the Y-axis of a histogram against the size class in micrometers [µm] on the X-axis of a histogram shows only a maximum in the form of a Gaussian curve and any further maxima that may occur do not exceed a volume of 1%, and c) 0.13 to 12.5 mass fractions of N,N'-hexamethylene-bis[3-(3,5-di-t-butyl-4-hydroxyphenyl)propionamide, and d) 0.001 to 10 mass fractions of at least one ester of montanic acid with multifunctional alcohols and / or talc.

[0080] In one embodiment, the present invention relates to compositions and molding compounds to be produced therefrom and products based thereon, wherein based on a) 100 mass fractions of polyamide, preferably polyamide 6 and / or caprolactam-based copolyamides and / or polyamide 66, with a solution viscosity measured according to ISO 307 in a 0.5 wt% solution in 96% sulfuric acid of less than 135 ml / g . b) 125 to 600 mass fractions of Al₂O₃ surface-treated with at least one aminosilane, with a monomodal, volume-average particle size distribution to be determined by laser diffraction according to ISO 13320, and a volume-average particle size d₅₀ in the range of 0.1 to 50 µm, wherein a monomodal particle size distribution is present if the plot of the volume of the aluminum oxide particle sizes in [%] on the Y-axis of a histogram against the size class in micrometers [µm] on the X-axis of a histogram forms only one maximum in the form of a Gaussian curve and any further maxima that may occur do not exceed a volume of 1%, c) 0.13 to 12.5. Mass fractions of at least one thermostabilizer selected from the group consisting of sterically hindered phenols, sterically hindered phosphites, sterically hindered phosphates, hydroquinones, aromatic secondary amines, substituted resorcinols, salicylates, benzotriazoles, benzophenones, polyhydric alcohols, or copper halides; d) 0.001 to 10 mass fractions of at least one ester of montanic acid with multifunctional alcohols and / or talc; and e) 0.001 to 150 mass fractions of at least one further additive different from components b), c), and d).

[0081] In one embodiment, component d) can be omitted. In this case, a composition, molding compound, or product contains components a), b), c), and e). Component e)

[0082] Further additives to be used as component e) may be different from those in components b), c), and d) and belong to the groups of UV stabilizers, gamma-ray stabilizers, hydrolysis stabilizers, antistatic agents, emulsifiers, plasticizers, heat conductivity additives, processing aids, impact modifiers or elastomer modifiers, fillers and reinforcing agents, lubricants, flame retardants, dyes, or pigments. The aforementioned and other suitable additives are state of the art and can be found, for example, in the Plastics Additives Handbook, 5th Edition, Hanser-Verlag, Munich, 2001, pages 80-84, 546-547, 688, 872-874. , 938, 966 can be found. The additives to be used as component e) can be used alone or in mixtures or in the form of masterbatches.

[0083] According to the invention, UV stabilizers preferably to be used as component e) are preferably substituted resorcinols, salicylates, benzotriazoles or benzophenones.

[0084] Impact modifiers or elastomer modifiers to be used as component e) according to the invention are preferably copolymers, preferably composed of at least two monomers from the group consisting of ethylene, propylene, butadiene, isobutene, isoprene, chloroprene, vinyl acetate, styrene, acrylonitrile, and acrylic or methacrylic esters with 1 to 18 carbon atoms in the alcohol component. The copolymers may contain compatibilizing groups, preferably maleic anhydride or epoxide.

[0085] The dyes or pigments to be used as component e) according to the invention are preferably inorganic pigments, particularly preferably titanium dioxide, ultramarine blue, iron oxide, zinc sulfide or carbon black, as well as organic pigments, particularly preferably phthalocyanines, quinacridones, perylene, and dyes, particularly preferably nigrosine or anthraquinones as colorants, as well as other colorants. Carbon black and / or nigrosine are particularly preferred.

[0086] The fillers and reinforcing materials to be used as component e) according to the invention are preferably fibrous, needle-shaped, or particulate fillers and reinforcing materials other than aluminum oxide. Particularly preferred are carbon fibers, glass beads, amorphous silica, calcium silicate, calcium metasilicate, magnesium carbonate, kaolin, calcined kaolin, chalk, powdered quartz, mica, phlogopite, barium sulfate, feldspar, wollastonite, kyanite, aluminum silicate, montmorillonite, magnesium oxide, zinc oxide, boron nitride, graphite, carbon nanotubes, graphene, iron oxides, ferrites, magnetite, copper, aluminum, titanium dioxide, or glass fibers, most preferably glass fibers, and especially preferably glass fibers made of E-glass. In a preferred embodiment, the fibrous or particulate reinforcing materials are provided with suitable surface modifications, in particular surface modifications containing silane compounds, to improve their compatibility with thermoplastics.

[0087] Thermal conductivity additives to be used as component e) according to the invention are preferably selected from the group consisting of aluminium silicate, in particular kyanite, montmorillonite, magnesium oxide, zinc oxide, boron nitride, graphite, carbon nanotubes, graphene, iron oxides, ferrites, magnetite, copper, aluminium and titanium dioxide.

[0088] Flame retardants to be used as component e) according to the invention are preferably mineral flame retardants, nitrogen-containing flame retardants or phosphorus-containing flame retardants.

[0089] Preferred nitrogen-containing flame retardants are the reaction products of trichlorotriazine, piperazine, and morpholine [CAS 1078142-02-5], in particular MCA PPM Triazine HF from MCA Technologies GmbH, Biel-Benken, Switzerland, as well as melamine cyanurate and condensation products of melamine such as melem, melam, melon, or higher-condensed compounds of this type. Preferred inorganic nitrogen-containing compounds are ammonium salts.

[0090] Furthermore, salts of aliphatic and aromatic sulfonic acids and mineral flame retardant additives such as aluminum hydroxide, Ca-Mg carbonate hydrates (e.g. DE-A 4 236 122) may also be used. ) as a flame retardant of component e).

[0091] For component e), flame retardant synergists from the group of oxygen-, nitrogen- or sulfur-containing metal compounds are also suitable, with zinc-free compounds being particularly preferred, especially molybdenum oxide, magnesium oxide, magnesium carbonate, calcium carbonate, calcium oxide, titanium nitride, magnesium nitride, calcium phosphate, calcium borate, magnesium borate or mixtures thereof.

[0092] In an alternative embodiment, zinc-containing compounds can also be used as component e), if required. These preferably include zinc oxide, zinc borate, zinc stannate, zinc hydroxystannate, zinc sulfide and zinc nitride, or mixtures thereof.

[0093] Preferred phosphorus-containing flame retardants to be used as component e) are organic metal phosphinates, in particular aluminum tris(diethyl phosphinate), aluminum salts of phosphonic acid, red phosphorus, inorganic metal hypophosphites, in particular aluminum hypophosphite, other metal phosphonates, in particular calcium phosphonate, derivatives of 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxides (DOPO derivatives), resorcinol bis-(diphenyl phosphate) (RDP), including oligomers, and bisphenol A bis-diphenyl phosphate (BDP), including oligomers, furthermore melamine pyrophosphate and melamine polyphosphate, furthermore melamine poly(aluminum phosphate), melamine poly(zinc phosphate) or phenoxyphosphazene oligomers and mixtures thereof.

[0094] Other flame retardants to be used as component e) are carbon formers, particularly preferably phenol-formaldehyde resins, polycarbonates, polyimides, polysulfones, polyethersulfones or polyetherketones, as well as anti-drip agents, in particular tetrafluoroethylene polymers.

[0095] The flame retardants to be used as component e) can be added in pure form, as well as via masterbatches or compacts.

[0096] In an alternative embodiment, the flame retardants to be used as component e) can also be halogenated flame retardants, if required, taking into account the disadvantages of losing the halogen-free status of the flame retardants. Preferred halogenated flame retardants are commercially available organic halogen compounds, particularly preferably ethylene-1,2-bistetrabromophthalimide, decabromodiphenylethane, tetrabromobisphenol A epoxy oligomer, tetrabromobisphenol A oligocarbonate, tetrachlorobisphenol A oligocarbonate, polypentabrombenzyl acrylate, brominated polystyrene, or brominated polyphenylene ethers, which can be used alone or in combination with synergists, in particular antimony trioxide or antimony pentoxide. Among the halogenated flame retardants, brominated polystyrene is particularly preferred. Brominated polystyrene is commercially available in various product grades. Examples include, for example...Firemaster ®< PBS64 from Lanxess, Cologne, Germany and Saytex ®< HP-3010 from Albemarle, Baton Rouge, USA.

[0097] Among the flame retardants to be used as component e), aluminium tris(diethylphosphinate)] [CAS 225789-38-8] and the combination of aluminium tris(diethylphosphinate) and melamine polyphosphate or the combination of aluminium tris(diethylphosphinate) and at least one aluminium salt of phosphonic acid are particularly preferred, the latter combination being especially preferred.

[0098] Suitable aluminum tris(diethylphosphinate) products include, for example, Exolit® < OP1230 or Exolit® < OP1240 from Clariant International Ltd., Muttenz, Switzerland. Melamine polyphosphate is commercially available in various grades. Examples include Melapur® < 200 / 70 from BASF, Ludwigshafen, Germany, and Budit® < 3141 from Budenheim, Budenheim, Germany.

[0099] Preferred aluminum salts of phosphonic acid are selected from the group primary aluminum phosphonate [Al(H₂PO₃)₃], basic aluminum phosphonate [Al(OH)H₂PO₃)₂·2H₂O], Al₂(HPO₃)₃·xAl₂O₃·nH₂O with x in the range of 2.27 to 1 and n in the range of 0 to 4, Al₂(HPO₃)₃·(H₂O)q (Z1) with q in the range of 0 to 4, in particular aluminum phosphonate tetrahydrate [Al₂(HPO₃)₃·4H₂O] or secondary aluminum phosphonate [Al₂(HPO₃)₃], Al₂Mz(HPO₃)y(OH)v·(H₂O)w (Z2) wherein M represents at least one alkali metal ion and z in the range of 0.01 to 1.5, y in the range of 2.63 - 3.5, v in the range of 0 to 2 and w in the range of 0 to 4, and Al 2 (HPO 3 ) u (H 2 PO 3 ) t · (H 2 O) s (Z3) wherein u is in the range of 2 to 2.99, t in the range of 2 to 0.01 and s in the range of 0 to 4, wherein in formula (Z2) z, y and v and in formula (Z3) u and t can only take such numbers that the corresponding aluminium salt of phosphonic acid as a whole is uncharged.Preferred alkali metals in formula (Z2) are sodium and potassium. The described aluminum salts of phosphonic acid can be used individually or in a mixture. Particularly preferred aluminum salts of phosphonic acid are selected from the group consisting of primary aluminum phosphonate [Al(H₂PO₃)₃], secondary aluminum phosphonate [Al₂(HPO₃)₃], basic aluminum phosphonate [Al(OH)H₂PO₃)₂·2H₂O], aluminum phosphonate tetrahydrate [Al₂(HPO₃)₃·4H₂O], and Al₂(HPO₃)₃·xAl₂O₃·nH₂O, where x is in the range of 2.27 to 1 and n is in the range of 0 to 4. Particularly preferred are secondary aluminum phosphonate [Al₂(HPO₃)₃], [CAS 71449-76-8] and secondary aluminum phosphonate tetrahydrate [Al₂(HPO₃)₃·4H₂O], [CAS 156024-71-4], in particular secondary aluminium phosphonate [Al 2 (HPO 3 ) 3 ].

[0100] The production of the aluminium salts of phosphonic acid to be used as flame retardants of component e) is described, for example, in WO 2013 / 083247 A1.

[0101] Furthermore, the present invention relates to a method for producing molding compounds according to the invention, wherein components a) to c), and optionally d) and optionally e), are mixed or blended in corresponding mass proportions in at least one mixing unit. Preferably, the components to be used are kneaded, compounded, extruded, or rolled to form a molding compound. This is preferably carried out at a temperature in the range of 230 to 400°C, particularly preferably by compounding on a co-rotating twin-screw extruder or Buss kneader. It can be advantageous to premix individual components.

[0102] The subject of the present application also includes the use or processing of the molding compounds to be produced from the components to be used according to the invention in the extrusion process, in blow molding processes or in injection molding for the production of products, preferably molded parts or semi-finished products, in particular by means of injection molding.

[0103] The inventive methods for manufacturing products by means of extrusion, blow molding or injection molding are carried out at melt temperatures in the range of 230 to 330°C, preferably from 250 to 300°C and optionally additionally at pressures of a maximum of 2500 bar, preferably at pressures of a maximum of 2000 bar, particularly preferably at pressures of a maximum of 1500 bar and most preferably at pressures of a maximum of 750 bar.

[0104] In extrusion, also known as extrusion pressing, solid to viscous thermoplastic molding compounds are continuously forced under pressure out of a shaping opening, preferably called a nozzle, die, or cutting tip. This process produces products with a cross-section equal to the opening and theoretically any length. (http: / / de.wikipedia.org / wiki / Extrusion_(Verfahrenstechnik). The basic process steps of the profile extrusion process, a form of extrusion, are: 1. Plasticizing and supplying the thermoplastic melt in an extruder, 2. Extrusion of the thermoplastic melt strand through a calibration sleeve that has the cross-section of the profile to be extruded, 3. Cooling of the extruded profile in a calibration table, 4. Further transport of the profile with a take-up unit behind the calibration table, 5. Cutting of the previously continuous profile to length in a cutting unit, 6. Collection of the cut profiles on a collection table.

[0105] A description of the profile extrusion of polyamide 6 and polyamide 66 can be found in Kunststoff-Handbuch 3 / 4, Polyamide, Carl Hanser Verlag, Munich 1998, pages 374-384. .

[0106] The blow molding process is used, for example, in http: / / www.blasformen.com / The process is described below. In blow molding, the first step involves drawing in plastic granules through a heated extruder, compacting them, degassing them, heating them, plasticizing them, and homogenizing them into a plastic strand. In the next step, the molten plastic is fed into a die head flanged to the extruder. There, the molten plastic is formed into a tube that exits vertically downwards from a nozzle. The tube diameter is adjusted to the desired part by using mandrels and nozzles of varying sizes, which are flanged to the die head. The tube thickness and the resulting weight of the blow-molded parts are predetermined by selecting different diameter differences between the mandrel and nozzle.

[0107] Injection molding is characterized by the fact that the raw material, i.e., the thermoplastic molding compound to be processed containing the components to be used according to the invention, preferably in granular form, is melted (plasticized) in a heated cylindrical cavity and injected as injection material under pressure into a temperature-controlled cavity. After the compound has cooled (solidified), the injection-molded part is demolded. One distinguishes

[0108] 1. Plasticizing / Melting 2. Injection phase (filling process) 3. Holding phase (due to thermal contraction during crystallization) 4. Demolding.

[0109] An injection molding machine consists of a clamping unit, the injection unit, the drive, and the control system. The clamping unit includes fixed and movable mounting plates for the mold, an end plate, as well as columns and the drive for the movable mold mounting plate (toggle joint or hydraulic clamping unit).

[0110] An injection unit comprises the electrically heated cylinder, the screw drive (motor, gearbox), and the hydraulics for moving the screw and injection unit. The injection unit's function is to melt, meter, inject, and compress the powder or granules (due to contraction). The problem of melt backflow within the screw (leakage) is solved by non-return valves.

[0111] In the injection mold, the flowing melt of the molding compound containing the components to be processed and the components to be inserted according to the invention is dissolved, cooled, and thus the component to be manufactured is produced. At least two mold halves are always necessary for this. The following functional complexes are distinguished in injection molding: Gating system, mold-forming inserts, venting, machine and force absorption, demolding system and motion transmission, temperature control

[0112] In contrast to injection molding, extrusion involves inserting an endless strand of the molding compound used according to the invention into the extruder, where the extruder is a machine for producing products based on thermoplastic molded parts. A distinction is made between single-screw extruders and twin-screw extruders, as well as their respective subgroups: conventional single-screw extruders, conveying single-screw extruders, counter-rotating twin-screw extruders, and co-rotating twin-screw extruders.

[0113] Extrusion plants for the production of profiles consist of: extruder, profile tool, calibration, cooling section, caterpillar and roller take-off, cutting device and tipping trough.

[0114] The present invention therefore also relates to products, preferably molded parts, molded bodies or semi-finished products, obtainable by extrusion or injection molding of the molding compounds according to the invention, comprising at least the components a), b) and c) and optionally d) and optionally e).

[0115] The present invention relates to the use of electrically insulating but thermally conductive products, preferably molded parts, molded bodies, or semi-finished products, manufactured by extrusion or injection molding from molding compounds containing at least components a), b), and c), and optionally d) and optionally e), for electrical or electronic components. These products according to the invention can preferably be used in the automotive, electrical, electronics, telecommunications, solar, information technology, and computer industries, as well as in household appliances, sports, medicine, and the entertainment industry. In particular, products according to the invention can be used for applications where improved thermal conductivity and good mechanical properties are required. The use of these products for molded parts in electrical engineering and in vehicles, especially components in motor vehicles, is preferred for such applications.

[0116] The present invention therefore also relates to the use of the thermoplastic molding compounds according to the invention for the production of molded parts and semi-finished products and products to be manufactured therefrom, preferably molded parts for motor vehicles. Examples:

[0117] The individual components a), b), c), and, where applicable, d) and e) were mixed in a Coperion Werner & Pfleiderer (Stuttgart, Germany) ZSK 26 Compounder twin-screw extruder at a temperature of approximately 280°C, discharged as a strand into a water bath, cooled until suitable for granulation, and then granulated. The granules were dried at 70°C in a vacuum drying oven until a constant weight was achieved.

[0118] The granules were then processed on an Arburg SG370-173732 injection molding machine at melt temperatures between 270 and 300°C and mold temperatures between 80 and 100°C into shoulder bars (4 mm thick according to ISO 528), flat bars (80 mm x 10 mm x 4 mm), and plates measuring 60 mm x 40 mm x 2 mm. The plates were subsequently milled to dimensions of 12.7 mm x 12.7 mm x 2 mm.

[0119] The mechanical properties of the products manufactured from the molding compounds were determined in the tensile test according to ISO 527 and in the impact test according to ISO180-1U; the thermal conductivity was determined on plates with dimensions of 12.7 mm · 12.7 mm · 2 mm according to ISO 22007-4.

[0120] The wear behavior of processing machines, hereinafter referred to as "abrasion", in particular extruders and injection molding machines, was determined based on the wear test of the DKI Darmstadt. (Publication FG Plastics, project number 12245) - New wear-resistant devices, project no. AiF 12245N (DKI 18 / 0-87), duration 01.12.1999 to 28.02.2003)The abrasion was recreated. The abrasion was determined gravimetrically based on the material removal caused by the injection molding of 100 shots (1 shot = 3D) of a polyamide-based composition, with an injection speed of v = 30 mm / s and a screw diameter of D = 35 mm, at a melt temperature of 290°C, through a nozzle consisting of two metal plates (steel: 1.2738) with dimensions 12 x 12 and a slot width of 0.4 mm. Materials used:

[0121] Component a): Linear polyamide 6 with a viscosity index determined in a 0.5 wt% solution in 96% sulfuric acid at 25°C, according to ISO 307, of 108 ml / g. Component b): 3-Aminopropyltriethoxysilane surface-treated, monomodal aluminum oxide CT 3000 SG from Almatis GmbH with a d50 value of 0.5 µm and a BET surface area of ​​7.8 m² / g. Thermostabilizer: Ultranox® < 1098 from BASF SE. Talc: Mistron® < R10 microtalc from Imerys. Montan wax ester: Licowax® < E from Clariant GmbH. Carbon black: RKK Raven® < 2000 from Colloids. Nigrosine: Solvent black 7. Surface treatment with 3-aminopropyltriethoxysilane

[0122] The application of the aminosilane to the aluminum oxide CT 3000 SG from Almatis GmbH, with a d50 value of 0.5 µm and a BET surface area of ​​7.8 m² / g, was carried out in the manner described in WO 2009 / 156342 A1. First, 0.6 g of 3-aminopropyltriethoxysilane was mixed with 100 g of Al₂O₃ to form silanol in deionized water (250 ml deionized water to 100 g Al₂O₃) and stirred at 25 °C (room temperature) for 30 minutes. Then, the aluminum oxide was added, the suspension was stirred at 80 °C, the surface-treated aluminum oxide was filtered off, and the surface was washed with deionized water. The surface-treated aluminium oxide was then dried for 5 hours at temperatures of about 120 °C and tempered for 30 minutes at 200 °C.

[0123] The in Table 1 The composition shown was processed in the manner described above, with the values ​​given in percent by weight. Table 1 ingredient Example 1 polyamide 22 Aluminum oxide surface-treated with aminosilane 77 Thermostabilizer 0,5 microtalc 0,01 Montan wax ester 0,2 Nigrosine 0,14 soot 0,15 Measurement result Impact strength IZOD unnotched [kJ / m2] 35 Elongation at break [%] 2,4 Thermal conductivity perpendicular to the flow direction of the test specimen [W / mK] 1,6 Thermal conductivity in the flow direction of the test specimen [W / mK] 1,7 Abrasion [mg] 62 Abrasion test

[0124] The abrasion test was performed according to the regulations in the Publication FG Plastics, "New and further development of model testing methods for corrosive / abrasive wear in plastics processing", project no. AiF 12245N (DKI 18 / 0-87), duration 01.12.1999 to 28.02.2003 (see description) was carried out and a material removal of 62 mg was determined by differential weighing of the metal plates before and after the experiment for Example 1. A material removal of only 62 mg represents low abrasion. For the purposes of this invention, abrasion with material removal of <200 mg is considered acceptable.

[0125] The mechanical properties, with an elongation at break of 2.4% measured according to ISO 527 on freshly injected specimens and an impact strength of 35 kJ / mol measured according to ISO 180-1U on freshly injected specimens, are good mechanical properties in the sense of the present invention and significantly exceed the requirements of 1.5% elongation at break measured according to ISO 527 on freshly injected specimens and an impact strength of 20 kJ / m² measured according to ISO 180-1U on freshly injected specimens, and also do not represent a deterioration compared to the prior art.

[0126] The thermal conductivity of 1.6 W / mK measured perpendicular to the flow direction of the specimen according to ISO 22007-4 and 1.7 W / mK measured in the flow direction of the specimen according to ISO 22007-4 are acceptable thermal conductivities in the sense of the present invention and exceed the requirements of at least 0.8 W / mK set out in the problem of the present invention.

Claims

1. Compositions, moulding compounds producible therefrom and products based thereupon containing per a) 100 parts by mass of at least one polyamide, preferably polyamide 6 and / or caprolactam-based copolyamides and / or polyamide 66, having a solution viscosity measured at 25°C according to ISO 307 in a 0.5% by weight solution in 96% sulfuric acid of <135 ml / g, b) 125 to 600 parts by mass of aluminium oxide surface-treated with at least one aminosilane having a monomodal volume-average particle size distribution determinable by laser diffraction according to ISO 13320 and a volume-average particle size d50 in the range from 0.1 to 50 µm, wherein a monomodal particle size distribution is present if the plot of the volume of the aluminium oxide particle sizes in [%] on the Y-axis of a histogram against the size class in micrometres [µm] on the X-axis of a histogram forms only one maximum in the form of a Gaussian curve and if any further maxima do not exceed a volume of 1%.

2. Compositions, moulding compounds producible therefrom and products based thereupon according to Claim 1, characterized in that as surface treatment agent of the aluminium oxide at least one aminosilane of general empirical formula         (RO)3-Si-(CH2)n-X is employed, wherein R represents an organic radical selected from the group of methyl, ethyl, i-propyl and methoxymethyl, n is an integer from 0 to 12 inclusive and X represents a radical NR1R2 and R1 and R2 each independently represent hydrogen, a C1-C6-alkyl radical or a C6-C9-cycloalkyl radical.

3. Compositions, moulding compounds producible therefrom and products based thereupon according to Claim 2, characterized in that for the surface treatment of the aluminium oxide is at least one aminosilane is employed from the group of 3-aminopropyltriethoxysilane, 3-aminopropyltrimethoxysilane, N-(2-aminoethyl)-3-aminopropyltrimethoxysilane, N-(2-aminoethyl)-3-aminopropyltriethoxysilane, 3-(N-cyclohexylamino)propyltrimethoxysilane and N,N-(diethylaminomethyl)triethoxysilane.

4. Compositions, moulding compounds producible therefrom and products based thereupon according to any of Claims 1 to 3, characterized in that these additionally c) 0.13 to 12.5 parts by mass of at least one heat stabilizer selected from the group of sterically hindered phenols, sterically hindered phosphites, sterically hindered phosphates, hydroquinones, aromatic secondary amines, substituted resorcinols, salicylates, benzotriazoles, benzophenones, polyhydric alcohols or copper halides.

5. Compositions and moulding compounds producible therefrom and products based thereupon according to Claim 4, characterized in that these additionally contain d) 0.001 to 10 parts by mass of at least one demoulding agent.

6. Compositions and moulding compounds producible therefrom and products based thereupon according to Claim 4, characterized in that these additionally contain d) 0.001 to 10 parts by mass of at least one nucleating agent, preferably talc.

7. Compositions and moulding compounds producible therefrom and products based thereupon according to Claim 4, characterized in that these additionally contain d) 0.001 to 10 parts by mass of at least one nucleating agent and at least one demoulding agent, wherein the employed nucleating agent is preferably talc.

8. Compositions and moulding compounds producible therefrom and products based thereupon according to Claims 5 and 7, characterized in that the employed demoulding agents are long-chain fatty acids, salts thereof and also ester or amide derivatives thereof, montan wax esters and salts thereof and also low molecular weight polyethylene waxes or polypropylene waxes in oxidized and non-oxidized form.

9. Compositions and moulding compounds producible therefrom and products based thereupon according to Claim 7, characterized in that the employed demoulding agents are esters or amides of saturated or unsaturated aliphatic carboxylic acids having 8 to 40 carbon atoms with aliphatic saturated alcohols or amines having 2 to 40 carbon atoms.

10. Compositions and moulding compounds producible therefrom and products based thereupon according to any of Claims 4 to 9, characterized in that alternatively or in addition to component d) these contain e) 0.001 to 150 parts by mass of at least one further additive.

11. Compositions and moulding compounds producible therefrom and products based thereupon according to any of Claims 1 to 10, characterized in that employed component b) is α-Al2O3 surface-treated with at least one aminosilane.

12. Process for reducing the abrasiveness of thermally conductive polyamide compositions and moulding compounds producible therefrom, characterized in that aluminium oxide surface-treated with at least one aminosilane is brought into contact with a polyamide composition and the polyamide composition is based on a low-viscosity polyamide having a solution viscosity measured in a 0.5% by weight solution in 96% sulfuric acid according to ISO307 of <135 ml / g and the aluminium oxide has a monomodal volume-average particle size distribution determinable by laser diffraction according to ISO 13320 and a volume-average particle size d50 in the range from 0.1 to 50 µm, wherein a monomodal particle size distribution is present if the plot of the volume of the aluminium oxide particle sizes in [%] on the Y-axis of a histogram against the size class in micrometres [µm] on the X-axis of a histogram forms only one maximum in the form of a Gaussian curve and if any further maxima do not exceed a volume of 1%.

13. Use of aluminium oxide surface-treated with at least one aminosilane for reducing abrasion in processing machines during processing of polyamide compositions based on a low-viscosity polyamide and polyamide moulding compounds based thereupon, wherein the polyamide has a solution viscosity measured in a 0.5% by weight solution in 96% sulfuric acid according to ISO307 of <135 ml / g, wherein the aluminium oxide has a monomodal volume-average particle size distribution determinable by laser diffraction according to ISO 13320 and a volume-average particle size d50 in the range from 0.1 to 50 µm and a monomodal particle size distribution is present if the plot of the volume of the aluminium oxide particle sizes in [%] on the Y-axis of a histogram against the size class in micrometres [µm] on the X-axis of a histogram forms only one maximum in the form of a Gaussian curve and if any further maxima do not exceed a volume of 1%.