Flame-retardant grey polyamide compounds and their use

Description

[0001] The present invention relates to flame-retardant polyamide compositions and molded parts produced therefrom.

[0002] Flammable plastics generally require flame retardants to meet the stringent flame protection requirements demanded by plastics processors and, in some cases, by legislators. Non-halogenated flame retardant systems, which produce little or no fumes, are preferred – also for environmental reasons.

[0003] Among these flame retardants, the salts of phosphinic acids (phosphinates) have proven to be particularly effective for thermoplastic polymers (DE 2 252 258 A and DE 2 447 727 A).

[0004] Furthermore, synergistic combinations of phosphinates with certain nitrogen-containing compounds are known to act more effectively as flame retardants in a whole range of polymers than the phosphinates alone (WO-2002 / 28953 A1 as well as DE 197 34 437 A1 and DE 197 37 727 A1).

[0005] From US patent 7,420,007 B2, it is known that dialkylphosphinates containing a small amount of selected telomeres are suitable as flame retardants for polymers, whereby the polymer is subject to only a very small degree of degradation when the flame retardant is incorporated into the polymer matrix.

[0006] Flame retardants often need to be added in high doses to ensure sufficient flame resistance of the plastic according to international standards. Due to their chemical reactivity, which is necessary for flame retardancy at high temperatures, flame retardants, especially at higher doses, can impair the processing stability of plastics. This can lead to increased polymer degradation, crosslinking reactions, outgassing, or discoloration.

[0007] Polyamide molding compounds are known from WO 2014 / 135256 A1 which exhibit significantly improved thermal stability, reduced migration tendency and good electrical and mechanical properties.

[0008] Colored polyamide compositions have also been described. WO 2010 / 089241 A1 discloses thermoplastic molding compounds that contain a gray or black colored fibrous filler and a gray or black colorant. This document mentions that polyamides can also be used as thermoplastic polymers. EP 1 121 388 B1 discloses polyamide compositions stabilized with copper complexes and organic halogen compounds that can be colored with conventional pigments. DE 43 01 541 A1 describes flame-retardant, black-colored polyamide molding compounds that contain polyamide, red phosphorus, and a colorant. Finally, WO 2014 / 044471 A1 discloses flame-retardant polyamides with a light color. These have a slight reddish inherent color and can be colored more effectively for light and gray applications.

[0009] When using red phosphorus or combinations of halogenated aromatics with antimony trioxide as flame retardants and conventionally used colorant mixtures for greying, it has been found that the greying of the molding compounds and molded parts has an undesirable reddish tint.

[0010] So far, there is a lack of flame-retardant phosphinate-containing polyamide compositions that achieve all the required properties simultaneously, such as good electrical values ​​(GWFI, CTI), a grey color without a red tint (color), and effective flame protection characterized by the shortest possible afterburn times (UL-94, afterburn time).

[0011] It was therefore an object of the present invention to provide flame-retardant polyamide compositions based on phosphinate-containing flame retardant systems which have all the aforementioned properties simultaneously and which in particular have a grey color without a reddish tint and a high level of flame protection, characterized by the shortest possible afterburn times.

[0012] The invention relates to flame-retardant polyamide compositions containing Polyamide with a melting point of less than or equal to 290 °C, preferably less than or equal to 280 °C and most preferably less than or equal to 250 °C, as component A, fillers and / or reinforcing materials, preferably glass fibers, as component B, phosphinic acid salt of formula (I) as component C wherein R 1 and R 2 represent ethyl, M is Al, Fe, TiO p or Zn, m 2 to 3, preferably 2 or 3, means, and p = 4 − m / 2 ist Compound selected from the group of Al, Fe, TiO p- or Zn salts of ethylbutylphosphinic acid, dibutylphosphinic acid, ethylhexylphosphinic acid, butylhexylphosphinic acid and / or dihexylphosphinic acid, with component D being a phosphonic acid salt of formula II, and component E being a compound consisting of Al, Fe, TiO p- or Zn salts of ethylbutylphosphinic acid, dibutylphosphinic acid, ethylhexylphosphinic acid, butylhexylphosphinic acid and / or dihexylphosphinic acid. wherein R 3 means Ethyl, Met Al, Fe, TiO q or Zn, n 2 to 3, preferably 2 or 3, and q = 4 − n / 2 ist Melamine polyphosphate with a mean degree of condensation of 2 to 200 as component F, grey colorant as component G, and inorganic phosphonate as component H.

[0013] In the polyamide composition according to the invention, the proportion of component A is typically 25 to 95 wt.%, preferably 25 to 75 wt.%.

[0014] In the polyamide composition according to the invention, the proportion of component B is typically 1 to 45 wt.%, preferably 20 to 40 wt.%.

[0015] In the polyamide composition according to the invention, the proportion of component C is typically 1 to 35 wt.%, preferably 5 to 20 wt.%.

[0016] In the polyamide composition according to the invention, the proportion of component D is typically 0.01 to 3 wt.%, preferably 0.05 to 1.5 wt.%.

[0017] In the polyamide composition according to the invention, the proportion of component E is typically 0.001 to 1 wt.%, preferably 0.01 to 0.6 wt.%.

[0018] In the polyamide composition according to the invention, the proportion of component F is typically 1 to 25 wt.%, preferably 2 to 10 wt.%.

[0019] In the polyamide composition according to the invention, the proportion of component G is typically 0.01 to 20 wt.%, preferably 0.01 to 10 wt.% and in particular 0.1 to 8 wt.%.

[0020] Component H is typically present in an amount of 0.005 to 10 wt.%, in particular in an amount of 0.02 to 5 wt.%.

[0021] The percentages given for the proportions of components A to H refer to the total amount of the polyamide composition.

[0022] Flame-retardant polyamide compositions are preferred, in which The proportion of component A is 25 to 95 wt.%, the proportion of component B is 1 to 45 wt.%, the proportion of component C is 1 to 35 wt.%, the proportion of component D is 0.01 to 3 wt.%, the proportion of component E is 0.001 to 1 wt.%, the proportion of component F is 1 to 25 wt.%, the proportion of component G is 0.01 to 20 wt.%, and the proportion of component H is 0.005 to 10 wt.% where the percentages refer to the total amount of the polyamide composition.

[0023] Flame-retardant polyamide compositions are particularly preferred where The proportion of component A is 25 to 75 wt.%, the proportion of component B is 20 to 40 wt.%, the proportion of component C is 5 to 20 wt.%, the proportion of component D is 0.05 to 1.5 wt.%, the proportion of component E is 0.01 to 0.6 wt.%, the proportion of component F is 2 to 10 wt.%, the proportion of component G is 0.1 to 8 wt.%, and the proportion of component H is 0.02 to 5 wt.%. where the percentages refer to the total amount of the polyamide composition.

[0024] Preferred salts of component C are those in which M m+< Zn 2+< , Fe 3+< or especially Al 3+< .

[0025] Preferred salts of component D are zinc, iron or especially aluminum salts.

[0026] Preferred salts of component E are those in which Met n+< Zn 2+< , Fe 3+< or especially Al 3+< .

[0027] Flame-retardant polyamide compositions are particularly preferred in which M and Met represent Al, m and n are 3 and in which the compounds of component D are present as aluminium salts.

[0028] The flame-retardant polyamide compositions described above contain inorganic phosphonate as component H.

[0029] The use of the inorganic phosphonates or salts of phosphorous acid (phosphites) used as component H according to the invention as flame retardants is known. WO 2012 / 045414 A1 discloses flame retardant combinations that contain not only phosphinic acid salts but also salts of phosphorous acid (= phosphites).

[0030] Preferably the inorganic phosphonate (component H) corresponds to the general formulas (IV) or (V) [(HO)PO 2 ] 2-< p / 2 Kat p+< (IV) [(HO) 2 PO] -< p Kat p+< (V) wherein Kat is a p-valent cation, in particular a cation of an alkali metal, alkaline earth metal, an ammonium cation and / or a cation of Fe, Zn or in particular of Al including the cations Al(OH) or Al(OH) 2, and p means 1, 2, 3 or 4.

[0031] Preferably, the inorganic phosphonate (component H) is aluminum phosphite [Al(H₂PO₃)₃], secondary aluminum phosphite [Al₂(HPO₃)₃], basic aluminum phosphite [Al(OH)(H₂PO₃)₂*2aq], aluminum phosphite tetrahydrate [Al₂(HPO₃)₃*4aq], aluminum phosphonate, Al₇(HPO₃)₉(OH)₆(1,6-hexanediamine)₁₅*12H₂O, Al₂(HPO₃)₃<*xAl₂O₃*nH₂O with x = 2.27 - 1 and / or Al₄H₆P₁₆O₁₈.

[0032] The inorganic phosphonate (component H) is preferably also aluminum phosphite of formulas (VI), (VII) and / or (VIII) Al₂(HPO₃)³x(H₂O)q (VI), where q means 0 to 4, Al₂.00Mz(HPO₃)y(OH)vx(H₂O)w (VII), where M means alkali metal cations, z means 0.01 to 1.5, y means 2.63 to 3.5, v means 0 to 2, and w means 0 to 4, Al₂.00(HPO₃)u(H₂PO₃)tx(H₂O)s (VIII), where u means 2 to 2.99, t means 2 to 0.01, and s means 0 to 4, and / or aluminum phosphite [Al(H₂PO₃)³ ], to secondary aluminum phosphite [Al 2 (HPO 3 ) 3 ], to basic aluminum phosphite [Al(OH)(H 2 PO 3 ) 2 *2aq], to aluminum phosphite tetrahydrate [Al 2 (HPO 3 ) 3 *4aq], to aluminum phosphonate, to Al 7 (HPO 3 ) 9 (OH) 6 (1,6-hexanediamine) 1.5 *12H 2 O, to Al 2 (HPO 3 ) 3< *xAl 2 O 3 *nH 2 O with x = 2.27 - 1 and / or Al 4 H 6 P 16 O 18 .

[0033] Preferred inorganic phosphonates (component H) are salts that are insoluble or sparingly soluble in water.

[0034] Particularly favored inorganic phosphonates are aluminum, calcium, and zinc salts.

[0035] Particularly preferably, component H is a reaction product of phosphorous acid and an aluminum compound.

[0036] Particularly preferred components H are aluminium phosphites with CAS numbers 15099-32-8, 119103-85-4, 220689-59-8, 56287-23-1, 156024-71-4, 71449-76-8 and 15099-32-8.

[0037] The preferred aluminum phosphites are produced by reacting an aluminum source with a phosphorus source and optionally a template in a solvent at 20–200 °C for up to 4 days. For this purpose, the aluminum source and phosphorus source are mixed for 1–4 hours, heated under hydrothermal conditions or by reflux, filtered, washed, and dried, for example, at 110 °C.

[0038] Preferred sources of aluminum are aluminum isopropoxide, aluminum nitrate, aluminum chloride, aluminum hydroxide (e.g., pseudoboehmite).

[0039] Preferred sources of phosphorus are phosphorous acid, (acidic) ammonium phosphite, alkali phosphites or alkaline earth phosphites.

[0040] Preferred alkali phosphites are disodium phosphite, disodium phosphite hydrate, trisodium phosphite, potassium hydrogen phosphite.

[0041] Preferred disodium phosphite hydrate is Brüggolen ®< H10 from Brüggemann.

[0042] Preferred templates are 1,6-hexanediamine, guanidine carbonate, or ammonia.

[0043] The preferred alkaline earth phosphite is calcium phosphite.

[0044] The preferred ratio of aluminum to phosphorus to solvent is 1:1:3.7 to 1:2.2:100 mol. The ratio of aluminum to template is 1:0 to 1:17 mol. The preferred pH of the reaction solution is 3 to 9. The preferred solvent is water.

[0045] Particularly preferred in the application is the use of the same salt of phosphinic acid as of phosphorous acid, e.g. aluminium diethylphosphinate together with aluminium phosphite or zinc diethylphosphinate together with zinc phosphite.

[0046] In a preferred embodiment, the flame-retardant polyester compositions described above contain as component H a compound of formula (III) wherein MeFe, TiOr, Zn or in particular Al, o 2 to 3, preferably 2 or 3, means, and r = 4 − o / 2 ist .

[0047] Preferred compounds of formula III are those in which Me° +< Zn 2+< , Fe 3+< or especially Al 3+< .

[0048] Preferably flame-retardant polyamide compositions according to the invention have a Comparative Tracking Index, measured according to the International Electrotechnical Commission Standard IEC-60112 / 3, of greater than or equal to 500 volts.

[0049] Also preferred flame-retardant polyamide compositions according to the invention achieve a rating of V0 according to UL-94, particularly measured on molded parts from 3.2 mm to 0.4 mm thick.

[0050] Other preferred flame-retardant polyamide compositions according to the invention have a Glow Wire Flammability Index according to IEC-60695-2-12 of at least 960 °C, in particular measured on molded parts of 0.75 - 3 mm thickness.

[0051] The polyamide compositions according to the invention contain as component A one or more polyamides with a melting point of less than or equal to 290 °C. The melting point is determined by differential scanning calorimetry (DSC) at a heating rate of 10 K / second.

[0052] The polyamides of component A are generally aliphatic homo- or copolyamides derived from (cyclo)aliphatic dicarboxylic acids or their polyamide-forming derivatives, such as their salts, and from (cyclo)aliphatic diamines or from (cyclo)aliphatic aminocarboxylic acids or their polyamide-forming derivatives, such as their salts.

[0053] The polyamides used as component A according to the invention are thermoplastic polyamides.

[0054] Thermoplastic polyamides, according to Hans Domininghaus in "Die Kunststoffe und ihreeigenschaften", 5th edition (1998), page 14, are understood to be polyamides whose molecular chains have no or more or less long and varying numbers of side branches, which soften when heated and are almost infinitely malleable.

[0055] The polyamides used as component A according to the invention can be produced by various processes and synthesized from very different building blocks. Depending on the specific application, they can be combined alone or in combination with processing aids, stabilizers, or polymeric alloying partners, preferably elastomers, to form materials with specifically tailored combinations of properties. Mixtures with proportions of other polymers, preferably polyethylene, polypropylene, or ABS, are also suitable, optionally including one or more compatibilizers. The properties of the polyamides can be improved by adding elastomers, for example, with regard to impact strength, especially when, as in this case, glass fiber-reinforced polyamides are used. The multitude of possible combinations enables a very large number of products with a wide variety of properties.

[0056] A variety of processes have become known for the production of polyamides, whereby different monomer building blocks, various chain regulators to adjust a desired molecular weight or monomers with reactive groups for later intended post-treatments are used depending on the desired end product.

[0057] The technically relevant processes for the production of polyamides mostly involve polycondensation in the melt. In this context, the hydrolytic polymerization of lactams is also understood as polycondensation.

[0058] Polyamides preferably used as component A are semi-crystalline aliphatic polyamides which can be produced starting from aliphatic diamines and aliphatic dicarboxylic acids and / or cycloaliphatic lactams with at least 5 ring members or corresponding amino acids.

[0059] Suitable starting materials include aliphatic dicarboxylic acids, preferably adipic acid, 2,2,4- and 2,4,4-trimethyladipic acid, azelaic acid and / or sebacic acid; aliphatic diamines, preferably tetramethylenediamine, hexamethylenediamine, 1,9-nonanediamine, 2,2,4- and 2,4,4-trimethylhexamethylenediamine; the isomeric diaminodicyclohexylmethanes, diaminodicyclohexylpropanes, bis-aminomethylcyclohexane; aminocarboxylic acids, preferably aminocaproic acid; or the corresponding lactams. Copolyamides consisting of several of the aforementioned monomers are also included. Caprolactams are particularly preferred, and ε-caprolactam is especially preferred.

[0060] The aliphatic homo- or copolyamides used according to the invention are preferably polyamide 12, polyamide 4, polyamide 4.6, polyamide 6, polyamide 6.6, polyamide 6.9, polyamide 6.10, polyamide 6.12, polyamide 6.66, polyamide 7.7, polyamide 8.8, polyamide 9.9, polyamide 10.9, polyamide 10.10, polyamide 11 or polyamide 12. These are known, for example, under the trade names Nylon® (DuPont), Ultramid® (BASF), Akulon® K122 (DSM), Zytel® 7301 (DuPont), Durethan® B 29 (Bayer) and Grillamid® (Ems Chemie).

[0061] Compounds based on PA6, PA6.6 and other aliphatic homo- or copolyamides are particularly suitable, in which 3 to 11 methylene groups are added to one polyamide group in the polymer chain.

[0062] Flame-retardant polyamide compositions are preferred in which component A is one or more polyamides selected from the group consisting of PA 6, PA 6.6, PA 4.6, PA 12, PA 6.10.

[0063] Flame-retardant polyamide compositions are particularly preferred in which polyamide 6.6 or polymer mixtures of polyamide 6.6 and polyamide 6 are used as component A.

[0064] Particularly preferred are flame-retardant polyamide compositions in which component A consists of at least 75 wt.% polyamide 6.6 and at most 25 wt.% polyamide 6.

[0065] Component B consists of fillers and / or preferably reinforcing materials, preferably glass fibers. Mixtures of two or more different fillers and / or reinforcing materials can also be used.

[0066] Preferred fillers are mineral particulate fillers based on talc, mica, silicate, quartz, titanium dioxide, wollastonite, kaolin, amorphous silicas, nanoscale minerals, particularly preferably montmorillonite or nano-boehmite, magnesium carbonate, chalk, feldspar, glass beads and / or barium sulfate. Mineral particulate fillers based on talc, wollastonite and / or kaolin are particularly preferred.

[0067] Furthermore, needle-shaped mineral fillers are particularly preferred. According to the invention, needle-shaped mineral fillers are defined as mineral fillers with a pronounced needle-shaped character. Needle-shaped wollastonites are preferred. The mineral preferably has a length-to-diameter ratio of 2:1 to 35:1, particularly preferably 3:1 to 19:1, and most preferably 4:1 to 12:1. The mean particle size of the needle-shaped mineral fillers used as component B according to the invention is preferably less than 20 µm, particularly preferably less than 15 µm, and most preferably less than 10 µm, as determined using a CILAS granulometer.

[0068] The components B preferably used according to the invention are reinforcing materials. These can be, for example, reinforcing materials based on carbon fibers and / or glass fibers.

[0069] In a preferred embodiment, the filler and / or reinforcing material can be surface-modified, preferably with an adhesion promoter or adhesion promoter system, particularly preferably silane-based. Especially when using glass fibers, polymer dispersions, film formers, branching agents, and / or glass fiber processing aids can also be used in addition to silanes.

[0070] The glass fibers preferably used as component B according to the invention can be short glass fibers and / or long glass fibers. Cut fibers can be used as short or long glass fibers. Short glass fibers can also be used in the form of ground glass fibers. In addition, glass fibers can also be used in the form of continuous fibers, for example in the form of rovings, monofilaments, filament yarns or twisted strands, or glass fibers can be used in the form of textile fabrics, for example as glass fabric, glass braid or glass mat.

[0071] Typical fiber lengths for short glass fibers before incorporation into the polyamide matrix range from 0.05 to 10 mm, preferably from 0.1 to 5 mm. After incorporation into the polyamide matrix, the length of the glass fibers has decreased. Typical fiber lengths for short glass fibers after incorporation into the polyamide matrix range from 0.01 to 2 mm, preferably from 0.02 to 1 mm.

[0072] The diameter of individual fibers can vary widely. Typical diameters of individual fibers range from 5 to 20 µm.

[0073] The optical fibers can have any cross-sectional shape, for example, round, elliptical, n-sided, or irregular cross-sections. Optical fibers with monolobal or multilobal cross-sections can be used.

[0074] Glass fibers can be used as continuous fibers or as cut or ground glass fibers.

[0075] The glass fibers themselves, regardless of their cross-sectional area and length, can be selected, for example, from the group consisting of E-glass fibers, A-glass fibers, C-glass fibers, D-glass fibers, M-glass fibers, S-glass fibers, R-glass fibers, and / or ECR-glass fibers, with E-glass fibers, R-glass fibers, S-glass fibers, and ECR-glass fibers being particularly preferred. The glass fibers are preferably provided with a sizing coating, which preferably contains polyurethane as a film former and aminosilane as an adhesion promoter.

[0076] Particularly preferred E-glass fibers have the following chemical composition: SiO2 50-56%; Al2O3 12-16%; CaO 16-25%; MgO ≤ 6%; B2O3 6-13%; F ≤ 0.7%; Na2O 0.3-2%; K2O 0.2-0.5%; Fe2O3 0.3%.

[0077] R-glass fibers, which are particularly preferred, have the following chemical composition: SiO2 50-65%; Al2O3 20-30%; CaO 6-16%; MgO 5-20%; Na2O 0.3-0.5%; K2O 0.05-0.2%; Fe2O3 0.2-0.4%; TiO2 0.1-0.3%.

[0078] Particularly preferred ECR glass fibers have the following chemical composition: SiO2 57.5-58.5%; Al2O3 17.5-19.0%; CaO 11.5-13.0%; MgO 9.5-11.5%.

[0079] The salts of diethylphosphinic acid used as component C according to the invention are known flame retardants for polymer molding compounds.

[0080] Salts of diethylphosphinic acid containing the phosphinic acid and phosphonic acid salts used as components D and E according to the invention are also known flame retardants. The preparation of these combinations is described, for example, in US 7,420,007 B2.

[0081] The salts of diethylphosphinic acid of component C used according to the invention can contain small amounts of salts of component D and of salts of component E, for example up to 10 wt.% of component D, preferably 0.01 to 6 wt.%, and in particular 0.2 to 2.5 wt.% thereof, and up to 10 wt.% of component E, preferably 0.01 to 6 wt.%, and in particular 0.2 to 2.5 wt.% thereof, based on the amount of components C, D and E.

[0082] The salts of ethylphosphonic acid used as component E according to the invention are also known as additives to diethyl phospinates in flame retardants for polymeric molding compounds, for example from WO 2016 / 065971 A1.

[0083] The use of melamine polyphosphate derivatives with a degree of condensation of 20 or greater than or equal to 20, which are used as component F according to the invention, as flame retardants is also known. For example, DE 10 2005 016 195 A1 discloses a stabilized flame retardant containing 99 to 1 wt.% melamine polyphosphate and 1 to 99 wt.% additive with reserve alkalinity. This document also discloses that this flame retardant can be combined with phosphinic acid and / or a phosphinic acid salt.

[0084] Preferred flame-retardant polyamide compositions according to the invention contain as component F a melamine polyphosphate, the average degree of condensation of which is 20 to 200, in particular 40 to 150.

[0085] In another preferred range, the average degree of condensation is 2 to 100.

[0086] Further preferred flame-retardant polyamide compositions according to the invention contain as component F a melamine polyphosphate which has a decomposition temperature of greater than or equal to 320 °C, in particular of greater than or equal to 360 °C and most preferably of greater than or equal to 400 °C.

[0087] Preferably, melamine polyphosphates are used as component F, which are known from WO 2006 / 027340 A1 (corresponding to EP 1 789 475 B1) and WO 2000 / 002869 A1 (corresponding to EP 1 095 030 B1).

[0088] Preferably, melamine polyphosphates are used whose average degree of condensation is between 20 and 200, in particular between 40 and 150, and whose melamine content is 1.1 to 2.0 mol, in particular 1.2 to 1.8 mol per mole of phosphorus atom.

[0089] Melamine polyphosphates are also preferably used, whose mean condensation level (number average) is >20, whose decomposition temperature is greater than 320 °C, whose molar ratio of 1,3,5-triazine compound to phosphorus is less than 1.1, in particular 0.8 to 1.0, and whose pH value of a 10% suspension in water at 25 °C is 5 or higher, preferably 5.1 to 6.9.

[0090] In another preferred embodiment, components C, D, E and F are in particle form, wherein the mean particle size (d 50 ) is 1 to 100 µm.

[0091] The polyamide compositions according to the invention contain grey colorants as component G.

[0092] In general, a colouring agent is understood to be all colouring substances according to DIN ISO 18451, which can be divided into inorganic and organic colouring agents as well as natural and synthetic ones (see Römpp's Chemistry Lexicon, 1981, 8th edition, p. 1237).

[0093] According to DIN ISO 18451, a distinction is made between dyes and pigments, the latter being insoluble in plastics, while dyes are soluble.

[0094] The grey colouring agent used as component G according to the invention generally consists of a mixture of black and white pigments or dyes.

[0095] White pigments or dyes result in varying matte shades of black pigments or black dyes, producing a gray coloration. Suitable white pigments are generally known; see, for example, B.R. Gächter and H. Müller, Taschenbuch der Kunststoffadditive (Pocketbook of Plastic Additives), Carl Hanser Verlag, 1983, pp. 494–510. Preferred pigments include white pigments such as zinc oxide, zinc sulfide, lead white (2 PbCO₃ · Pb(OH)₂), lithopone, antimony white, barium sulfate, and titanium dioxide. Of the two most common crystal modifications (rutile and anatase) of titanium dioxide, the rutile form is particularly used to nuance the molding compounds according to the invention.

[0096] Furthermore, it is possible to achieve the grey color of the polyamide compositions by using complementary colored pigments or dyes.

[0097] The dyes and pigments preferably used for the production of component G include carbon black, graphite, graphene, nigrosine, bone char, black pigments or combinations of complementary red to yellow pigments with green, blue or violet pigments or mixtures of one or more of these compounds, each mixed with white pigment or white dye to produce the grey color.

[0098] Suitable carbon blacks for the production of component G include, in particular, carbon blacks with a pore volume (DBP dibutyl phthalate adsorption) according to DIN ISO 18451 of at least 30 ml / 100 g, preferably of at least 50 ml / 100 g.

[0099] Other carbon blacks preferably used for the production of component G have a specific surface area according to BET (according to ISO 4652) of at least 20 to 1000 m² / g, preferably 30 to 300 m² / g.

[0100] Other carbon blacks preferably used for the production of component G have a mean primary particle size of 5 to 50 nm, in particular of 10 to 35 nm.

[0101] Such carbon black types are available, for example, under the brands Printex ®< XE2 (Evonik GmbH) or Ketjenblack ®< EC 600JD (Akzo), as well as furnace blacks such as Printex ®< 90, 75, 80, 85, 95 and 60-A.

[0102] Graphite can also be used to produce component G. It can be ground into smaller particles. The particle size is typically in the range of 0.01 µm to 1 mm, preferably in the range of 1 to 250 µm. Graphites are very soft (Mohs hardness 1) and have a grayish to black color.

[0103] Other examples of blackening agents suitable for the production of component G are graphenes. Commercially available graphenes include, for example, the Vor-x® products (Vorbeck Materials). The thickness of graphenes is typically 1 to 5 nm, the diameter 20 to 1000 nm, and the specific surface area according to BET 500 to 1000 m² / g (N₂).

[0104] Nigrosines are preferred blackening agents used in the production of component G. These are generally understood to be a group of black or gray phenazine dyes (azines) related to the indulines, available in various forms. Nigrosines can be water-soluble, fat-soluble, or alcohol-soluble. Industrially, nigrosines are produced by heating nitrobenzene, aniline, and aniline hydrochloride with metallic iron and FeCl₃.

[0105] Nigrosine can be used as a free base or as a salt (e.g., as hydrochloride).

[0106] Bone char or bone black can also be used to produce component G. Bone char can be produced by heating defatted bone meal to approximately 700 °C in the absence of air. A mixture of bone char and sugar or syrup, when carbonized with concentrated sulfuric acid, yields so-called bone black or Cologne black. Finely ground bone char is suitable for coloring thermoplastic molding compounds. Modified bone chars can also be used as component G. For example, if mineral components are dissolved from the bone char using hydrochloric acid, a blacker bone char remains, which, when mixed with a little Prussian blue, is available as lacquer black or Parisian black.

[0107] Suitable colorants that can be used as component G are generally classified according to the Colour Index (CI), whereby a CI designation enabling unambiguous assignment is added in addition to systematic or trivial names.

[0108] Black color pigments that can be used as component G in combination with white pigments, such as titanium dioxide, barium sulfate or zinc sulfide, according to the invention, are, for example, iron oxide black (Fe 3 O 4 ), spinel black (Cu, (Cr, Fe) 2 O 4 ), manganese black (mixture of manganese dioxide, silicon dioxide and iron oxide ), cobalt black or antimony black.

[0109] Furthermore, it is possible to achieve the grey color of the polyamide composition according to the invention by using complementary colored pigments.

[0110] For this purpose, red to yellow pigments are used with correspondingly complementary green, blue or violet pigments or mixtures thereof to achieve a grey color of the polyamide composition, as desired.

[0111] Copper phthalocyanine pigments, which exhibit a green or blue color, are among the preferred pigments. The green color is generally achieved by substituting hydrogen atoms with chlorine atoms on the macrocyclic tetraam.

[0112] Other suitable pigments include manganese violet pigments (pyrophosphates of ammonium and manganese(III) of the formula MnNH₄P₂O₇, which produce bluer or redder tones by varying their stoichiometric composition), ultramarine pigments (sodium and aluminum silicates), and blue and green pigments based on, for example, chromium oxides or cobalt oxides with a spinel structure. Such pigments are commercially available under the trade names Heliogen® - blue, Heliogen® - green, Sicopal® - green, and Sicopal® - blue (trademarks of BASF SE), as well as ultramarine, chromium oxide, and manganese violet pigments.

[0113] Preferred pigments according to CI Part 1 are Pigment blue 15, Pigment blue 15:2, Pigment blue 15:4, Pigment blue 16, Pigment blue 28, Pigment blue 29, Pigment blue 36, Pigment green 17, Pigment green 24, Pigment green 50, Pigment violet 15 and Pigment violet 16, with Pigment blue 15:1 and 15:3 as well as Pigment green 7 and 36 being particularly preferred.

[0114] Preferably used as component G are mixtures of white pigments with black pigments or dyes, wherein the white pigments are selected from the group consisting of zinc oxide, zinc sulfide, lead white, lithopone, antimony white, barium sulfate and / or titanium dioxide, and wherein the black pigments or dyes are selected from the group consisting of carbon black, graphite, graphene, nigrosine, bone char, black color pigments or combinations of complementary red to yellow pigments with green, blue or violet pigments or mixtures of one or more of these compounds.

[0115] The polyamide compositions according to the invention preferably have a grey coloration, which is characterized by the numbers 7000 to 7048 of the RAL color chart, in particular by RAL 7035.

[0116] Particularly preferred as component G are mixtures of titanium dioxide with black pigments, especially with carbon black, which are used particularly in polyamide compositions used in the electronics sector (the so-called "electrogrey").

[0117] One particularly preferred component G is the pigment paste Elektrograu RAL 7032 from Brohl Chemie.

[0118] Other preferred components G are combinations of titanium dioxide with yellow, red, and black pigments, resulting in a color shade according to RAL 7032. Such combinations are described, for example, in DE 4104681 A1.

[0119] The polyamide compositions according to the invention can contain further additives as component I. Preferred components I within the meaning of the present invention are antioxidants, UV stabilizers, gamma-ray stabilizers, hydrolysis stabilizers, co-stabilizers for antioxidants, antistatic agents, emulsifiers, nucleating agents, plasticizers, processing aids, impact modifiers, various dyes from component G, various pigments from component G, and / or further flame retardants that differ from components C, D, E, F, and H.

[0120] This includes in particular phosphates, such as melamine poly(metal phosphates). Preferred metals for this purpose are the elements of Group 2, Group 3, Group 2, Group 4, and Group VIIIa of the periodic table, as well as cerium and / or lanthanum.

[0121] Melamine poly(metal phosphates) are preferably melamine poly(zinc phosphates), melamine poly(magnesium phosphates) and / or melamine poly(calcium phosphates).

[0122] Preferred are (melamine) 2 Mg(HPO 4 ) 2 , (melamine) 2 Ca(HPO 4 ) 2 , (melamine) 2 Zn(HPO4) 2 , (melamine) 3 Al(HPO 4 ) 3 , (melamine) 2 Mg(P 2 O 7 ), (melamine) 2 Ca(P 2 O 7 ), (melamine) 2 Zn(P 2 O 7 ), (melamine) 3 Al(P 2 O 7 ) 3 / 2 .

[0123] Preferably melamine poly(metal phosphates) known as hydrogen phosphate or pyrophosphate metallates with complex anions having a four- or six-bonded metal atom as a coordination center with bidentate hydrogen phosphate or pyrophosphate ligands.

[0124] Melamine-intercalated aluminium, zinc or magnesium salts of condensed phosphates are also preferred, bis-melamine zinc diphosphate and / or bis-melamine alumotriphosphate are particularly preferred.

[0125] Preferred are salts of the elements of the 2nd main group, the 3rd main group, the 2nd transition group, the 4th transition group and transition group VIIIa of the periodic table as well as of cerium and / or lanthanum with anions of the oxo acids of the fifth main group (phosphates, pyrophosphates and polyphosphates).

[0126] Preferably, aluminum phosphates, aluminum monophosphates, aluminum orthophosphates (AlPO4), aluminum hydrogen phosphate (Al2(HPO4)3) and / or aluminum dihydrogen phosphate are used.

[0127] Calcium phosphate, zinc phosphate, titanium phosphate and / or iron phosphate are also preferred.

[0128] Calcium hydrogen phosphate, calcium hydrogen phosphate dihydrate, magnesium hydrogen phosphate, titanium hydrogen phosphate (TIHC) and / or zinc hydrogen phosphate are preferred.

[0129] Preferably, aluminum dihydrogen phosphate, magnesium dihydrogen phosphate, calcium dihydrogen phosphate, zinc dihydrogen phosphate, zinc dihydrogen phosphate dihydrate and / or aluminum dihydrogen phosphate are used.

[0130] Calcium pyrophosphate, calcium dihydrogen pyrophosphate, magnesium pyrophosphate, zinc pyrophosphate and / or aluminum pyrophosphate are particularly preferred.

[0131] The aforementioned and other similar phosphates are offered, for example, by JM Huber Corporation, USA, under the Safire® products; these include types APP Type II, AMPP, MPP, MPyP, PiPyP, PPaz, Safire®< 400, Safire®< 600, EDAP and others.

[0132] Other phosphates are mentioned, for example, in JP-A-2004204194, DE-A-102007036465 and EP-A-3133112 and are expressly included among the usable components I.

[0133] Preferably, the quantitative ratio of components C (phosphinic acid salt), F (melamine polyphosphate) and I (additive) is as follows, if the latter is the metal phosphates described above and, in particular, aluminum phosphates are present in the mixture: Component C 98 - 54 wt.%, Component F 33 - 1 wt.%, Component I 13 - 1 wt.%, based on a total of 100 wt.% of these three components only.

[0134] The other additives are known as additives to polyamide compositions per se and can be used alone or in mixtures or in the form of masterbatches.

[0135] The aforementioned components A, B, C, D, E, F, G, and H, and optionally I, can be processed in a wide variety of combinations to form the flame-retardant polyamide composition according to the invention. It is possible, for example, to mix the components into the polyamide melt at the beginning or end of the polycondensation process, or in a subsequent compounding process. Furthermore, there are processing methods in which individual components are added later. This is particularly common when using pigment or additive masterbatches. Additionally, it is possible to drum components, especially powdered components, onto the polymer granules, which may be warm from the drying process.

[0136] Two or more of the components of the polyamide compositions according to the invention can also be combined by mixing before being incorporated into the polyamide matrix. Conventional mixing units can be used for this purpose, in which the components are mixed in a suitable mixer, e.g. for 0.01 to 10 hours at 0 to 300 °C.

[0137] Granules can also be produced from two or more of the components of the polyamide compositions according to the invention, which can then be incorporated into the polyamide matrix.

[0138] For this purpose, two or more components of the polyamide composition according to the invention can be processed with granulation aids and / or binders in a suitable mixer or granulation tray to form granules.

[0139] The raw product initially produced can be dried in a suitable dryer or tempered for further grain formation.

[0140] The polyamide composition according to the invention, or two or more components thereof, can be produced in one embodiment by roll compaction.

[0141] The polyamide composition according to the invention, or two or more components thereof, can be produced in one embodiment by mixing, extruding, cutting (or optionally breaking and classifying) and drying (and optionally coating) the ingredients.

[0142] The polyamide composition according to the invention, or two or more components thereof, can be produced in one embodiment by spray granulation.

[0143] The flame-retardant polymer molding compound according to the invention is preferably in granular form, e.g. as an extrudate or as a compound. The granules preferably have a cylindrical shape with a circular, elliptical or irregular base, a spherical shape, a cushion shape, a cubic shape, a cuboid shape, or a prism shape.

[0144] Typical length-to-diameter ratios of the granules are 1 to 50 to 50 to 1, preferably 1 to 5 to 5 to 1.

[0145] The granules preferably have a diameter of 0.5 to 15 mm, particularly preferably of 2 to 3 mm and preferably a length of 0.5 to 15 mm, particularly preferably of 2 to 5 mm.

[0146] The invention also relates to molded parts made from the flame-retardant polyamide composition described above, comprising components A, B, C, D, E, F, G and H and optionally I.

[0147] The molded parts according to the invention can be of any shape. Examples include fibers, films or molded bodies, obtainable from the flame-retardant polyamide molding compounds according to the invention by any molding process, in particular by injection molding or extrusion.

[0148] The flame-retardant polyamide molded parts according to the invention can be manufactured using any molding process. Examples include injection molding, compression molding, foam injection molding, gas-assisted injection molding, blow molding, film casting, calendering, laminating, or coating at higher temperatures with the flame-retardant polyamide molding compound.

[0149] The molded parts are preferably injection molded parts or extruded parts.

[0150] The flame-resistant polyamide compositions according to the invention are suitable for the production of fibers, films and molded parts, in particular for applications in the electrical and electronics sector.

[0151] The invention preferably relates to the use of the flame-retardant polyamide compositions according to the invention in or for connectors, live parts in power distributors (RCD protection), circuit boards, potting compounds, power plugs, circuit breakers, lamp housings, LED housings, capacitor housings, coil formers and fans, protective contacts, plugs, in / on circuit boards, housings for plugs, cables, flexible printed circuit boards, charging cables for mobile phones, motor covers or textile coatings.

[0152] The invention also preferably relates to the use of the flame-retardant polyamide compositions according to the invention for the production of molded parts in the form of components for the electrical / electronics sector, in particular for parts of printed circuit boards, housings, films, cables, switches, distributors, relays, resistors, capacitors, coils, lamps, diodes, LEDs, transistors, connectors, controllers, storage devices and sensors, in the form of large-area components, in particular housing parts for control cabinets and in the form of elaborately designed components with sophisticated geometry.

[0153] The wall thickness of the molded bodies according to the invention can typically be up to 10 mm. Molded bodies with a wall thickness of less than 1.5 mm are particularly suitable, more preferably with a wall thickness of less than 1 mm, and most preferably with a wall thickness of less than 0.5 mm.

[0154] The following examples illustrate the invention without limiting it. 1. Components used

[0155] Commercially available polyamides (component A): Polyamide 6.6 (PA 6.6-GV; melting range of 255-260 °C): Ultramid® < A27 (BASF) Polyamide 6 (melting range of 217-222 °C): Durethan® < B29 (Lanxess) Polyamide 6T / 6.6 (melting range of 310-320 °C): Vestamid® < HT plus 1000 (Evonik)

[0156] Optical fibers (component B): PPG HP 3610 optical fibers, 10µm diameter, 4.5 mm length (PPG, NL),

[0157] Flame retardant FM 1 (components C, D and E): Aluminum salt of diethylphosphinic acid containing 0.9 mol% of aluminum ethyl butylphospinate and 0.5 mol% of aluminum ethylphosphonate, prepared according to Example 3 of US 7,420,007 B2

[0158] Flame retardant FM 2 (components C, D and E): Aluminum salt of diethylphosphinic acid containing 2.7 mol% of aluminum ethyl butylphospinate and 0.8 mol% of aluminum ethylphosphonate, prepared according to Example 4 of US 7,420,007 B2

[0159] Flame retardant FM 3 (components C, D and E): Aluminum salt of diethylphosphinic acid containing 0.5 mol% of aluminum ethyl butylphospinate and 0.05 mol% of aluminum ethylphosphonate, prepared according to the process of US 7,420,007 B2

[0160] Flame retardant FM 4 (components C, D and E): Aluminum salt of diethylphosphinic acid containing 10 mol% of aluminum ethyl butylphospinate and 5 mol% of aluminum ethylphosphonate, prepared according to the process of US 7,420,007 B2

[0161] Flame retardant FM 5 (component C): Aluminum salt of diethylphosphinic acid produced in analogy to Example 1 of DE 196 07 635 A1

[0162] Flame retardant FM 6 (components C and E): Aluminum salt of diethylphosphinic acid containing 8.8 mol% of aluminum ethylphosphonate

[0163] Flame retardant FM 7 (component H): Aluminium salt of phosphonic acid produced according to Example 1 of DE 102011120218 A1

[0164] Flame retardant FM 8 (component F): Melamine polyphosphate produced according to the example of WO 2000 / 002869 A1. Flame retardant FM 9 (not according to the invention): Melamine polyphosphate with a mean degree of condensation of 18 produced by analogy to WO 2000 / 002869 A1.

[0165] Flame retardant FM 10 (not according to the invention): Red phosphorus (Exolit® < RP 607, Clariant)

[0166] Flame retardant FM 11 (not according to the invention): Bromopolystyrene (Saytex® < HP 3010, Albemarle) mixed with antimony trioxide masterbatch 80% in PA 6 (Campine) in a ratio of 75%:25% Grey dye (component G)

[0167] Pigment granules in polyamide, electric grey RAL 7032 (Lifocolor, Lichtenfels, Germany) 2. Production, processing and testing of flame-retardant polyamide molding compounds

[0168] The flame retardant components were mixed with the colorant in the ratios specified in the tables and incorporated via the side feed of a twin-screw extruder (type Leistritz ZSE 27 / 44D) at temperatures of 260 to 310 °C into PA 6.6, at 250 to 275 °C into PA 6, and at 310 to 330 °C into PA 6T / 6.6. The glass fibers were added via a second side feed. The homogenized polymer strand was withdrawn, cooled in a water bath, and then granulated.

[0169] After sufficient drying, the molding compounds were processed into test specimens on an injection molding machine (Arburg 320 C Allrounder type) at melt temperatures of 250 to 320 °C and tested for flame retardancy and classified according to the UL 94 test (Underwriters Laboratories). In addition to the classification, the afterburn time was also recorded.

[0170] The Comparative Tracking Index of the molded parts was determined according to the International Electrotechnical Commission standard IEC-60112 / 3.

[0171] The Glow Wire Flammability Index (GWIT index) was determined according to the standard IEC-60695-2-12.

[0172] The color of the molded part was visually assessed. This meant: 1 = Grey coloring without a red tint, 2 = Grey coloring with a slight red tint and 3 = Grey coloring with a distinct red tint.

[0173] Unless otherwise stated, all tests in each series were conducted under identical conditions (such as temperature programs, screw geometries and injection molding parameters) for comparability. Examples 1-5, 1a, 1b, 5a and comparison examples V1-V3 with PA 6.6

[0174] The results of the tests with PA 6.6 molding compounds are listed in the examples in the table below. All quantities are given as wt.% and refer to the polyamide molding compound including flame retardants, additives, and reinforcing agents. Table 1: PA 6.6 GF 30 test results (1-4, 1a and 1b not claimed; 5 and 5a according to the invention; V1-V3 comparisons; nb = not determined; na = not claimed) Example No. 1 (na) 2 (na) 3 (na) 4 (na) 5 V1 V2 V3 V4 V5 1a (na) 1b (na) 5a A: Polyamide 6.6 51 52,5 51 48 51 51 51 51 51 51 51 48 48 B: GF, HP3610 30 30 30 30 30 30 30 30 30 30 30 30 30 C+D+E: FM 1 12 - - - - - - - - - 8 16 - C+D+E: FM 2 - 12 - - 10 - 12 - - - - - 10 C+D+E: FM 3 - - 12 - - - - - - - - - - C+D+E: FM 4 - - - 12 - - - - - - - - - C: FM 5 - - - - - - - - - 12 - - - C+E: FM 6 - - - - - 12 - - - - - - - H: FM 7 - - - - 2 - - - - - - - 5 F: FM 8 5 5 5 5 5 5 - 5 5 5 9 4 5 Comparison: FM 9 - - - - - - 5 - - - - - - Comparison: FM 10 - - - - - - - 12 - - - - - Comparison: FM 11 - - - - - - - - 12 - - - - G: 2 0,5 2 5 2 2 2 2 2 2 2 2 2 UL 94 0.4 mm / time [sec.] V-0 / 25 V-0 / 20 V-0 / 25 V-0 / 40 V-0 / 10 V-0 / 45 nb V-0 / 40 V-0 / 35 V-0 / 50 V-0 / 28 V-0 / 28 V-0 / 10 GWFI [ °C] 960 960 960 960 960 960 nb 850 900 960 960 960 960 CTI [Volts] 600 600 600 600 600 500 nb 600 450 500 600 600 600 Color 1 1 1 1 1 1 nb 3 2 1 1 1 1

[0175] The polyamide compositions of Examples 1 to 5, 1a, 1b and 5a are molding compounds that achieve UL 94 V-0 fire rating at 0.4 mm, simultaneously exhibit CTI 600 volts and GWFI 960 °C, and display a consistent gray color without any reddish tint. The addition of component H in Examples 5 and 5a of the invention leads to a further improvement in flame retardancy, expressed by a reduced afterburn time.

[0176] The omission of component D in comparison example V1 resulted in a longer afterburn time and a reduction in the CTI value compared to examples 1-4.

[0177] Replacing component F with a component with a lower degree of condensation in comparison example V2 resulted in the polyamide strand foaming up during production and no measurements could be taken.

[0178] The use of red phosphorus instead of components C, D and E in comparison example V3 resulted in a distinct reddish tint to the color of the molded parts.

[0179] The use of bromopolystyrene / antimony trioxide masterbatch in PA 6 instead of components C, D, and E in comparison example V4 also resulted in a significant reddish tint to the color of the molded parts. Furthermore, the CTI value decreased considerably.

[0180] The omission of components D and E in comparison example V5 resulted in a longer afterburn time and a reduction in the CTI value compared to examples 1-4. Examples 6-10 and comparison examples V6-V10 with PA 6.6 / PA 6

[0181] The results of the tests with PA 6 / PA6.6 molding compounds are listed in the examples in the table below. All quantities are given as wt.% and refer to the polyamide molding compound including flame retardants, additives, and reinforcing agents. Table 2: PA 6 / PA 6.6 GF 30 Test results (6-9 not claimed; 10 according to the invention; V6-V10 comparisons; nb = not determined) Example No. 6 (na) 7 (na) 8 (na) 9 (na) 10 V6 V7 V8 V9 V10 A: Polyamide 6.6 36 36 36 36 36 36 36 36 36 36 A: Polyamide 6 15 15 15 15 15 15 15 15 15 15 B: GF, HP3610 30 30 30 30 30 30 30 30 30 30 C+D+E: FM 1 12 - - - - - - - - - C+D+E: FM 2 - 12 - - 10 - 12 - - - C+D+E: FM 3 - - 12 - - - - - - - C+D+E: FM 4 - - - 12 - - - - - - C: FM 5 - - - - - - - - - 12 C+E: FM 6 - - - - - 12 - - - - H: FM 7 - - - - 2 - - - - - F: FM 8 5 5 5 5 5 5 - 5 5 5 Comparison: FM 9 - - - - - - 5 - - - Comparison: FM 10 - - - - - - - 12 - - Comparison: FM 11 - - - - - 12 - G 2 2 2 2 2 2 2 2 2 2 UL 94 0.4 mm / time [sec.] V-0 / 29 V-0 / 23 V-0 / 44 V-0 / 28 V-0 / 14 V-0 / 47 nb V-0 / 50 V-0 / 35 V-0 / 50 GWFI [ °C] 960 960 960 960 960 960 nb 850 900 960 CTI [Volts] 600 600 600 600 600 500 nb 600 450 500 Color 1 1 1 1 1 1 nb 3 2 1

[0182] The polyamide compositions of Examples 6 to 10 are molding compounds that achieve UL 94 V-0 fire rating at 0.4 mm, simultaneously exhibit CTI 600 volts and GWFI 960 °C, and display a consistent gray color without any reddish tint. The addition of component H in Example 10 of the invention leads to a further improvement in flame retardancy, expressed by a reduced afterburn time.

[0183] The omission of component D in comparison example V6 resulted in a longer afterburn time and a reduction in the CTI value compared to examples 6-9.

[0184] Replacing component F with a component with a lower degree of condensation in comparison example V7 resulted in the polyamide strand foaming up during production and no measurements could be taken.

[0185] The use of red phosphorus instead of components C, D and E in comparison example V8 resulted in a distinct reddish tint to the color of the molded parts.

[0186] The use of bromopolystyrene / antimony trioxide masterbatch in PA 6 instead of components C, D, and E in comparison example V9 also resulted in a significant reddish tint to the color of the molded parts. Furthermore, the CIT value decreased considerably.

[0187] The omission of components D and E in comparison example V10 resulted in a longer afterburn time and a reduction in the CTI value compared to examples 6-9. Comparison examples V11-V17 with PA 6T / 6.6

[0188] The results of the tests with PA 6T / 6.6 molding compounds are listed in the examples in the table below. All quantities are given as wt.% and refer to the polyamide molding compound including flame retardants, additives, and reinforcing agents. Table 3: PA 6T / 6.6 GF 30 test results (nb = not determined) Example No. V11 V12 V13 V14 V15 V16 V17 A: Polyamide 6T / 6.6 51 51 51 51 51 51 51 B: Fiber optics HP361 30 30 30 30 30 30 30 C+D+E: FM 1 12 - - - - - - C+D+E: FM 2 - 12 - - 10 - - C+D+E: FM 3 - - 12 - - - - C+D+E: FM 4 - - - 12 - - - C: FM 5 - - - - - - 12 H: FM 7 - - - - 2 - - F: FM 8 5 5 5 5 5 5 5 Comparison: FM 10 - - - - - 12 - G: 2 2 2 2 2 2 2 UL 94 0.4 mm / time [sec.] nb nb nb nb nb nb nb GWFI [ °C] nb nb nb nb nb nb nb MVR [cm³ / 10 min.] nb nb nb nb nb nb nb Color nb nb nb nb nb nb nb CTI [Volts] nb nb nb nb nb nb nb

[0189] None of the PA molding compounds used in the comparison examples V11-V17 could be used to produce test specimens, as the PA molding compounds proved to be unprocessable. The polyamide strands foamed up during production, and no test specimens suitable for the measurements could be produced. Comparison examples V18-V22 with PA 6.6

[0190] Table 4 shows that only with the combination of flame retardants according to the invention can polyamide compositions be produced which exhibit the properties V-0, GWFI 960, CTI 600 and a gray color without a reddish tint. With melamine polyphosphate alone or with polybromobromide with antimony trioxide, V-0 can be achieved, but not a deep gray color. Table 4: Comparison examples of polyamide 6.6 GF results (nk = unclassifiable) Example No. V18 V19 V20 V21 V22 A: Polyamide 6.6 43 51 43 51 43 B: Fiber optics HP361 30 30 30 30 30 Comparison: FM 8 25 17 5 5 5 Comparison: FM 9 - - 25 17 - Comparison: FM 11 25 G: 2 2 2 2 2 UL 94 0.4 mm / time [sec.] V-0 / 45 nk V-0 / 43 nk V-0 / 23 GWFI [ °C] 960 750 960 700 960 Color 2 2 2 2 2 CTI [Volts] 500 500 350 500 350

Claims

1. Flame-retardant polyamide compositions comprising - polyamide having a melting point of not more than 290°C as component A, - fillers and / or reinforcers as component B, - phosphinic salt of the formula (I) as component C in which R1 and R2 are ethyl, M is Al, Fe, TiOp or Zn, m is 2 to 3, and p = 4 − m / 2 - compound selected from the group of the Al, Fe, TiOp and Zn salts of ethylbutylphosphinic acid, of dibutylphosphinic acid, of ethylhexylphosphinic acid, of butylhexylphosphinic acid and / or of dihexylphosphinic acid as component D - phosphonic salt of the formula II as component E in which R3 is ethyl, Met is Al, Fe, TiOq or Zn, n is 2 to 3, and q = 4 − n / 2 - melamine polyphosphate having an average degree of condensation of 2 to 200 as component F, - gray colorant as component G, and - inorganic phosphonate as component H.

2. Flame-retardant polyamide compositions according to Claim 1, characterized in that M and Met are Al, m and n are 3, and component D is an aluminum salt.

3. Flame-retardant polyamide compositions according to at least one of Claims 1 and 2, characterized in that - the proportion of component A is 25% to 95% by weight, - the proportion of component B is 1% to 45% by weight, - the proportion of component C is 1% to 35% by weight, - the proportion of component D is 0.01% to 3% by weight, - the proportion of component E is 0.001% to 1% by weight, - the proportion of component F is 1% to 25% by weight, - the proportion of component G is 0.01% to 20% by weight, and - the proportion of component H is 0.005% to 10% by weight, where the percentages are based on the total amount of the polyamide composition.

4. Flame-retardant polyamide compositions according to Claim 3, characterized in that - the proportion of component A is 25% to 75% by weight, - the proportion of component B is 20% to 40% by weight, - the proportion of component C is 5% to 20% by weight, - the proportion of component D is 0.05% to 1.5% by weight, - the proportion of component E is 0.01% to 0.6% by weight, - the proportion of component F is 2% to 10% by weight, - the proportion of component G is 0.1% to 8% by weight, and - the proportion of component H is 0.02% to 5% by weight, where the percentages are based on the total amount of the polyamide composition.

5. Flame-retardant polyamide compositions according to Claim 1, characterized in that the inorganic phosphonate is a compound of the formula (III) in which Me is Fe, TiOr, Zn or especially Al, o is 2 to 3, and r = 4 − o / 2 , where the compound of the formula III is present in an amount of 0.005% to 10% by weight, especially in an amount of 0.02% to 5% by weight, based on the total amount of the polyamide composition.

6. Flame-retardant polyamide compositions according to at least one of Claims 1 to 5, characterized in that they have a comparative tracking index measured according to International Electrotechnical Commission Standard IEC-60112 / 3 of not less than 500 volts.

7. Flame-retardant polyamide compositions according to at least one of Claims 1 to 6, characterized in that they attain a V-0 assessment according to UL-94 from thickness 3.2 mm to 0.4 mm.

8. Flame-retardant polyamide compositions according to at least one of Claims 1 to 7, characterized in that they have a glow wire flammability index according to IEC-60695-2-12 of not less than 960°C at thickness 0.75-3 mm.

9. Flame-retardant polyamide compositions according to at least one of Claims 1 to 8, characterized in that component A is one or more polyamides selected from the group consisting of PA 6, PA 6,6, PA 4,6, PA 12, PA 6,10.

10. Flame-retardant polyamide compositions according to Claim 9, characterized in that component A is nylon-6,6 or comprises polymer mixtures of nylon-6,6 and nylon-6.

11. Flame-retardant polyamide compositions according to Claim 10, characterized in that component A consists to an extent of at least 75% by weight of nylon-6,6 and to an extent of at most 25% by weight of nylon-6.

12. Flame-retardant polyamide compositions according to at least one of Claims 1 to 11, characterized in that glass fibers are used as component B.

13. Flame-retardant polyamide compositions according to at least one of Claims 1 to 12, characterized in that components C, D, E and F are in particulate form, where the median particle size d50 of these components is 1 to 100 µm.

14. Flame-retardant polyamide compositions according to at least one of Claims 1 to 13, characterized in that the average degree of condensation of the melamine polyphosphate is 2 to 100.

15. Flame-retardant polyamide compositions according to at least one of Claims 1 to 14, characterized in that the melamine polyphosphate has a breakdown temperature of not less than 320°C.

16. Flame-retardant polyamide compositions according to at least one of Claims 1 to 15, characterized in that component G is a blend of black and white pigments or dyes or is a blend of complementary-colored pigments or dyes.

17. Flame-retardant polyamide compositions according to Claim 16, characterized in that component G is a blend of white pigments with black pigments or dyes, where the white pigments are selected from the group of zinc oxide, zinc sulfide, white lead, lithopone, antimony white, barium sulfate and / or titanium dioxide and where the black pigments or dyes are selected from the group of carbon black, graphite, graphene, nigrosins, bone charcoal, black color pigments or of combinations of complementary-colored red to yellow pigments with green, blue or violet pigments or mixtures of one or more of these compounds.

18. Flame-retardant polyamide compositions according to at least one of Claims 1 to 17, characterized in that they comprise further additives as component I, where the further additives are selected from the group consisting of antioxidants, UV stabilizers, gamma ray stabilizers, hydrolysis stabilizers, costabilizers for antioxidants, antistats, emulsifiers, nucleating agents, plasticizers, processing auxiliaries, impact modifiers, dyes other than component G, pigments other than component G and / or further flame retardants other than components C, D, E, F and H.

19. Use of the polyamide compositions according to any of Claims 1 to 18 for production of fibers, films and shaped bodies, especially for applications in the electricals and electronics sector.