USE OF POLYHYDRIC ALCOHOLS TO INCREASE THE IMPACT RESISTANCE OF A WELDED JOINT AFTER THERMAL AGING IN POLYAMIDES

Abstract

The invention relates to the use of polyhydric alcohols having more than two hydroxyl groups in polyamide compositions comprising at least one polyamide to increase the impact strength of a welded joint after thermal aging of shaped articles produced from the polyamide composition in which, during injection molding, at least two flow fronts of the molten polyamide composition meet and form at least one welded joint.

Description

[0001] Use of polyhydric alcohols to increase weld line strength after heat aging in polyamides

[0002] Description

[0003] The invention relates to the use of polyhydric alcohols with more than two hydroxyl groups and a corresponding process.

[0004] Polyamides are among the most widely produced polymers worldwide and, in addition to their main applications in films, fibers, and molded parts (materials), serve a multitude of other purposes. Among the polyamides, polyamide 6 (polycaprolactam, PA 6) and polyamide 66 (nylon, polyhexamethylene adipamide, PA 66) are the most commonly produced polymers. Most technically important polyamides are semi-crystalline thermoplastic polymers characterized by high temperature resistance.

[0005] Polyamide molded parts can be produced, for example, by injection molding. This process typically results in (dynamic) weld lines. A fundamental distinction is made between static and dynamic weld lines. Static weld lines occur, for example, during the welding process when joining thermoplastic molded parts. A dynamic weld line in a plastic component during the injection molding process arises from the confluence of at least two melt flows, for example, behind cavities, due to wall thickness differences, or through multiple gates or injection points of the mold. When two flow fronts meet, a weld line is formed at the point of confluence.

[0006] These seams are called weld lines or flow lines. Visually, they appear as lines. A weld line is therefore a frequently visible surface effect on injection-molded parts.

[0007] A weld line is a potential weak point in a component. Here, the flow fronts meet perpendicularly due to volume expansion and weld together. The lower the pressure and temperature, the lower the weld line's strength. Reinforcing fibers often align parallel to the weld line due to the shear forces and flow conditions during the injection molding process. If the melt has cooled so much that the colliding melt fronts can no longer weld completely, the weld line is often visible on the surface as a V-shaped notch. Should tensile stresses occur in this area, the notch effect leads to a stress concentration at the weld line, which then acts as a predetermined breaking point.

[0008] WO 2010 / 014801 discloses the production of heat-resistant polyamide molded parts in which polyhydric alcohols, such as pentaerythritol, dipentaerythritol, tripentaerythritol, ditrimethylolpropane, D-mannitol, D-sorbitol, or xylitol, are added to the polyamide. Polyamide mixtures can also be used. According to the exemplary embodiments, the polyamide mixtures contain a larger proportion of at least a partially aromatic polyamide and a smaller proportion of an aliphatic polyamide. WO 201 194553 describes corresponding polyhydroxy polymers for comparable applications.

[0009] EP-B-2 307 480 concerns heat-resistant thermoplastic articles with co-stabilizers. The articles are manufactured from polyamide compositions containing at least one polyhydric alcohol with more than two hydroxyl groups and a number-average molecular weight (Mc). n) of less than 2,000 as well as co-stabilizers selected from secondary arylamines and hindered amine light stabilizers (HALS) and mixtures thereof. Reinforcing agents are also included in the polyamide resin.

[0010] The molded bodies produced from polyamides by injection molding should exhibit good mechanical properties even after prolonged heat aging at high temperatures.

[0011] The object of the present invention is to provide polyamide compositions suitable for the production of injection-molded components which exhibit increased weld seam strength after heat aging.

[0012] The object is achieved according to the invention by using polyhydric alcohols with more than two hydroxyl groups in polyamide compositions containing at least one polyamide to increase the weld line strength after heat aging of molded parts produced by injection molding from the polyamide composition, wherein at least two flow fronts of the molten polyamide composition meet during injection molding and form at least one weld line.

[0013] The problem is further solved by a method for increasing the weld line strength after heat aging of molded parts made from polyamide compositions by injection molding, in which 0.1 to 10 wt.%, based on the total polyamide composition, of at least one polyhydric alcohol with more than two hydroxyl groups is added to the polyamide composition before the molded parts are produced, and the polyamide composition thus obtained is injection molded to produce the molded parts, wherein at least two flow fronts of the molten polyamide composition meet during injection molding and form at least one weld line.

[0014] According to the invention, it has been found that by using polyhydric alcohols with more than two hydroxyl groups in polyamide compositions containing at least one polyamide, the weld line strength increases after heat aging of molded parts produced by injection molding from the polyamide composition. Weld line strength is a specific criterion for molded parts produced by injection molding, where at least two flow fronts of the molten polyamide composition meet during injection molding and form at least one weld line. According to the invention, the term "weld line" refers to a dynamic weld line as described above. The term "weld line" can also be replaced by "flow line" or "weld line." The essential point is that the weld line is formed by the injection molding of the polyamide composition. Weld lines are frequently the weak points of the injection-molded part.Particularly if the polyamide composition cools too quickly on the mold wall of the injection mold, the flowing material cannot bond optimally. This leads to the formation of weld lines or small notches, which then represent a weak point in the injection-molded part. Under mechanical stress, fracture often occurs along the weld line / flow seam, or a fracture may begin in this area. Therefore, weld line strength is important for the overall strength of the injection-molded part.

[0015] The mechanical properties of injection-molded parts often deteriorate during heat aging, which occurs over the part's service life. Therefore, increasing weld line strength after heat aging is particularly important for injection-molded parts.

[0016] The use of polyhydric alcohols in polyamide compositions typically impairs the mechanical properties, particularly during extrusion and injection molding into shaped parts. This is due, firstly, to the chemical degradation of the base polymer by the alcohol (reduction of the viscosity number), and secondly, to the tendency of short-chain alcohols to migrate at certain concentrations and combinations (see also EP 1 797 132 B1).

[0017] However, according to the invention, it was found that the weld line strength after heat aging can be increased by adding polyhydric alcohols. Furthermore, the surface quality could be improved by using high-molecular-weight alcohols, such as polyvinyl alcohol copolymers, through reduced migration. Ideally, these copolymers have a minimum flow rate (MFR) (210 °C / 2.16 kg) between 2 and 20 g / 10 min.

[0018] The additional use of heat stabilizers, selected from copper compounds, secondary aromatic amines, sterically hindered phenols, phosphites, phosphonites, and mixtures thereof, can be advantageous. The polyhydric alcohols exhibit a weld strength-enhancing effect, particularly during heat aging at temperatures of at least 140 °C, for example, from 180 °C to 220 °C. The additional heat stabilizers can further increase weld strength at lower temperatures, for example, up to 150 °C, or even at 140 °C. Thus, by combining the polyhydric alcohols with the aforementioned additional heat stabilizers, an increase in weld strength after heat aging can be achieved over a wide temperature range.Furthermore, combining polyamides with copolyamides or terpolyamides and polyhydric alcohols yields polyamide compositions that exhibit good weld line strengths, which do not diminish significantly even after prolonged heat aging. These effects are particularly pronounced when combining aliphatic polyamide with aliphatic copolyamide or terpolyamide.

[0019] In the use or method according to the invention, a polyamide composition is preferably used, containing

[0020] a) 30 to 99.9 wt.% of at least one polyamide as component A),

[0021] b) 0 to 60 wt.% glass fibers as component B),

[0022] c) 0 to 2 wt.% heat stabilizers selected from copper compounds, secondary aromatic amines, sterically hindered phenols, phosphites, phosphonites and mixtures thereof as component C),

[0023] d) 0.1 to 10 wt% of at least one polyhydric alcohol with more than two hydroxyl groups as component D),

[0024] e) 0 to 20 wt% other additives as component E),

[0025] where the quantities specified, the sum of which equals 100% by weight, refer to the entire composition.

[0026] According to one embodiment of the invention, the polyamide composition contains a maximum of 2.9 wt.%, particularly preferably a maximum of 2.0 wt.%, and in particular a maximum of 1.5 wt.% of impact modifiers, such as those described, for example, in US 2013 / 02531 15 A1.

[0027] Preferably, the polyamide composition also does not contain ethylene ionomer resins, such as those described in US 4,885,340.

[0028] According to one embodiment of the invention, the polyamide molding compound preferably does not contain monoepoxy or carbonate compounds such as those described as compounds (C) of general formula (I) in US 4,885,340.

[0029] According to one embodiment of the invention, the polyhydric alcohol is not glycerin.

[0030] The polyamide compositions used according to the invention contain 30 to 99.9 wt.%, preferably 40 to 99.5 wt.%, in particular 50 to 98.5 wt.% of component A).

[0031] They also contain 0 to 60 wt.%, preferably 0 to 40 wt.%, particularly 0 to 30 wt.% of component B). If component B) is present, the minimum amount is preferably 5 wt.%, particularly preferably at least 10 wt.%, particularly at least 15 wt.%. In this case, the range is 5 to 60 wt.%, preferably 10 to 40 wt.%, particularly preferably 15 to 30 wt.% of component B). Component C) is used in an amount of 0 to 2 wt.%, preferably 0 to 1 wt.%, particularly preferably 0 to 0.5 wt.%. If component C) is also used, the lower limit is preferably 0.01 wt.%, particularly preferably 0.02 wt.%, particularly 0.05 wt.%. In this case, the resulting quantity ranges are from 0.01 to 2 wt.%, preferably 0.02 to 1 wt.%, and particularly preferably 0.05 to 0.5 wt.%.

[0032] Component D) is present in an amount of 0.1 to 10 wt.%, preferably 0.5 to

[0033] 5 wt.%, in particular 1.5 to 3 wt.% used.

[0034] Component E) is used in an amount of 0 to 20 wt.%, preferably 0 to 10 wt.%, and in particular 0 to 5 wt.%. If component E) is also used, the lower limit is preferably 0.1 wt.%, particularly preferably at least 0.2 wt.%, and in particular at least 0.3 wt.%. In this case, the ranges are 0.1 to 20 wt.%, preferably 0.2 to 10 wt.%, and in particular 0.3 to 5 wt.%, and in particular 0.3 to 2 wt.%.

[0035] If components B), C) and / or E) are present, the maximum quantity of component A) is reduced accordingly by the minimum quantities of the respective components or the sum of these minimum quantities. For example, if component B) is present in a minimum quantity of 5% by weight, the maximum quantity of component A) is reduced to 94.9% by weight.

[0036] If the minimum quantities of components C) and E) of 0.01 and 0.1 wt.% respectively are also present, the maximum quantity of component A) is reduced accordingly to 94.7 wt.%. The same procedure applies to the other quantity ranges, so that the total quantity of components A) to E) always adds up to 100 wt.%.

[0037] The polyamide composition used according to the invention contains, as component A), at least one synthetic polyamide. The term "synthetic polyamide" is used broadly within the scope of the invention. It generally encompasses polymers that contain at least one component suitable for polyamide formation, selected from dicarboxylic acids, diamines, salts of at least one dicarboxylic acid and at least one diamine, lactams, ρ-amino acids, aminocarboxylic acid nitriles, and mixtures thereof. In addition to the components suitable for polyamide formation, the synthetic polyamides according to the invention may also contain polymerized monomers that can be copolymerized with them. The term "synthetic polyamide" does not include natural polyamides such as peptides and proteins, e.g., hair, wool, silk, and egg white.

[0038] For the designation of the polyamides, the invention uses, in part, industry-standard abbreviations consisting of the letters PA followed by numbers and letters. Some of these abbreviations are standardized in DIN EN ISO 1043-1. Polyamides derived from aminocarboxylic acids of the type H2N-(CH2) x Polyamides derived from -COOH or the corresponding lactams are designated as PA Z, where Z denotes the number of carbon atoms in the monomer. For example, PA 6 stands for the polymer of e-caprolactam or co-aminocaproic acid. Polyamides derived from diamines and dicarboxylic acids of the types H2N-(CH2) x - NH2 and HOOC-(CH2) yCopolyamides derived from -COOH are designated as PA Z1Z2, where Z1 denotes the number of carbon atoms in the diamine and Z2 the number of carbon atoms in the dicarboxylic acid. To designate copolyamides, the components are listed in order of their molecular weight, separated by slashes. For example,

[0039] PA 66 / 610 is the copolyamide of hexamethylenediamine, adipic acid, and sebacic acid. The following letter abbreviations are used for the monomers with an aromatic or cycloaliphatic group used according to the invention:

[0040] T = Terephthalic acid, I = Isophthalic acid, MXDA = m-Xylylenediamine, IPDA = Isophorone diamine, PACM = 4,4'-Methylenebis(cyclohexylamine), MACM = 2,2'-Dimethyl-4,4'-methylenebis-(cyclohexylamine).

[0041] In the following, the term "Ci-C4 alkyl" encompasses unsubstituted, straight-chain, and branched Ci-C4 alkyl groups. Examples of Ci-C4 alkyl groups include, in particular, methyl, ethyl, propyl, isopropyl, n-butyl, isobutyl, sec-butyl, and tert-butyl (1,1-dimethylethyl).

[0042] In the aliphatic dicarboxylic acids, cycloaliphatic dicarboxylic acids, aromatic dicarboxylic acids, and monocarboxylic acids mentioned below, the carboxyl groups can be present in non-derivatized form or as derivatives. In dicarboxylic acids, none, one, or both carboxyl groups can be present as derivatives. Suitable derivatives include anhydrides, esters, acid chlorides, nitriles, and isocyanates. Preferred derivatives are anhydrides or esters. Anhydrides of dicarboxylic acids can be monomeric or polymeric. Preferred esters are alkyl esters and vinyl esters, particularly Ci-C4 alkyl esters, especially the methyl or ethyl esters. Dicarboxylic acids are preferably present as mono- or dialkyl esters, particularly mono- or di-Ci-C4 alkyl esters, especially monomethyl esters, dimethyl esters, monoethyl esters, or diethyl esters. Dicarboxylic acids are further preferably present as mono- or divinyl esters.Dicarboxylic acids are still preferably present as mixed esters, especially preferably mixed esters with different Ci-C4 alkyl components, in particular methyl ethyl esters.

[0043] The components suitable for polyamide formation are preferably selected from among

[0044] pA) unsubstituted or substituted aromatic dicarboxylic acids and derivatives of unsubstituted or substituted aromatic dicarboxylic acids,

[0045] pB) unsubstituted or substituted aromatic diamines,

[0046] pC) aliphatic or cycloaliphatic dicarboxylic acids,

[0047] pD) aliphatic or cycloaliphatic diamines,

[0048] pE) Monocarboxylic acids,

[0049] pF) Monoamines,

[0050] pG) at least trivalent amines, pH) lactams,

[0051] Pl) π-Amino acids,

[0052] pK) from pA) to pl) different, thus co-condensable compounds.

[0053] A suitable embodiment is aliphatic polyamides. For aliphatic polyamides of type PA Z1 Z2 (such as PA 66), the requirement is that at least one of the components pC) or pD) must be present and neither of the components pA) nor pB) may be present. For aliphatic polyamides of type PA Z (such as PA 6 or PA 12), the requirement is that at least the component pH) must be present.

[0054] Another suitable embodiment is semi-aromatic polyamides. For semi-aromatic polyamides, the requirement is that at least one of the components pA) or pB) and at least one of the components pC) or pD) must be present.

[0055] The aromatic dicarboxylic acids pA) are preferably selected from unsubstituted or substituted phthalic acid, terephthalic acid, isophthalic acid, naphthalenedicarboxylic acids or diphenyldicarboxylic acids and the derivatives and mixtures of the aforementioned aromatic dicarboxylic acids.

[0056] Substituted aromatic dicarboxylic acids (pA) preferably have at least one (e.g., 1, 2, 3, or 4) Ci-C4 alkyl group. In particular, substituted aromatic dicarboxylic acids (pA) have one or two Ci-C4 alkyl groups. These are preferably selected from methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, and tert-butyl, especially methyl, ethyl, and n-butyl, and in particular methyl and ethyl, and specifically methyl. Substituted aromatic dicarboxylic acids (pA) may also bear other functional groups that do not interfere with amidation, such as 5-sulfoisophthalic acid, its salts, and derivatives. A preferred example is the sodium salt of dimethyl 5-sulfoisophthalic acid ester.

[0057] The aromatic dicarboxylic acid pA) is preferably selected from unsubstituted terephthalic acid, unsubstituted isophthalic acid, unsubstituted naphthalenedicarboxylic acids, 2-chloroterephthalic acid, 2-methylterephthalic acid, 5-methylisophthalic acid and 5-sulfoisophthalic acid.

[0058] Terephthalic acid, isophthalic acid or a mixture of terephthalic acid and isophthalic acid is particularly preferred as the aromatic dicarboxylic acid pA).

[0059] Preferably, the semi-aromatic polyamides have a proportion of aromatic dicarboxylic acids of at least 50 mol%, particularly preferably 70 mol% to 100 mol%, relative to all dicarboxylic acids. In a particular embodiment, the semi-aromatic polyamides have a proportion of terephthalic acid or isophthalic acid or a mixture of terephthalic acid and isophthalic acid of at least 50 mol%, preferably 70 mol% to 100 mol%, relative to all dicarboxylic acids. The aromatic diamines pB) are preferably selected from bis-(4-aminophenyl)methane, 3-methylbenzidine, 2,2-bis-(4-aminophenyl)propane, 1,1-bis-(4-aminophenyl)cyclohexane, 1,2-diaminobenzene, 1,4-diaminobenzene, 1,4-diaminonaphthalene, 1,5-diaminonaphthalene, 1,3-diaminotoluene, m-xylylenediamine, N,N'-dimethyl-4,4'-biphenyldiamine, bis-(4-methyl-aminophenyl)methane, 2,2-bis-(4-methylaminophenyl)propane or mixtures thereof.

[0060] The aliphatic or cycloaliphatic dicarboxylic acids (pC) are preferably selected from oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, cortic acid, azelaic acid, sebacic acid, undecan-α,co-dicarboxylic acid, dodecan-α,co-dicarboxylic acid, maleic acid, fumaric acid or itaconic acid, cis- and trans-cyclohexane-1,2-dicarboxylic acid, cis- and trans-cyclohexane-1,3-dicarboxylic acid, cis- and trans-cyclohexane-1,4-dicarboxylic acid, cis- and trans-cyclopentane-1,2-dicarboxylic acid, cis- and trans-cyclopentane-1,3-dicarboxylic acid and mixtures thereof.

[0061] The aliphatic or cycloaliphatic diamines (pD) are preferably selected from ethylenediamine, propylenediamine, tetramethylenediamine, heptamethylenediamine, hexamethylenediamine, pentamethylenediamine, octamethylenediamine, nonamethylenediamine, decamethylenediamine, undecamethylenediamine, dodecamethylenediamine, 2-methylpentamethylenediamine, 2,2,4-trimethylhexamethylenediamine, 2,4,4-trimethylhexamethylenediamine, 5-methylnonamethylenediamine, 2,4-dimethyloctamethylenediamine, 5-methylnonanediamine, bis-(4-aminocyclohexyl)methane, 3,3'-dimethyl-4,4'diaminodicyclohexylmethane and mixtures thereof.

[0062] Particularly preferred is the diamine pD) selected from hexamethylenediamine, 2-methylpentamethylenediamine, octamethylenediamine, nonamethylenediamine, 2-methyl-1,8-octamethylenediamine, decamethylenediamine, undecamethylenediamine, dodecamethylenediamine, bis-(4-aminocyclohexyl)methane, 3,3'-dimethyl-4,4'diaminodicyclohexylmethane and mixtures thereof.

[0063] In a special embodiment, the semi-aromatic polyamides contain at least one diamine (pD) polymerized, selected from hexamethylenediamine, bis-(4-aminocyclohexyl)methane (PACM), 3,3'-dimethyl-4,4'diaminodicyclohexylmethane (MACM), isophoronediamine (IPDA) and mixtures thereof.

[0064] In a special version, the semi-aromatic polyamides contain exclusively hexamethylenediamine polymerized as diamine (pD).

[0065] In another special version, the semi-aromatic polyamides contain exclusively bis-(4-aminocyclohexyl)-methane polymerized as diamine pD).

[0066] In another special formulation, the semi-aromatic polyamides contain exclusively 3,3'-dimethyl-4,4'-diaminodicyclohexylmethane (MACM) as the diamine pD. In another special formulation, the semi-aromatic polyamides contain exclusively isophorone diamine (IPDA) as the diamine pD.

[0067] The aliphatic and semi-aromatic polyamides can contain at least one monocarboxylic acid (pE) polymerized into the structure. The monocarboxylic acids (pE) serve as end caps for the polyamides produced according to the invention. In principle, all monocarboxylic acids capable of reacting with at least some of the available amino groups under the reaction conditions of the polyamide condensation are suitable. Suitable monocarboxylic acids (pE) include aliphatic, alicyclic, and aromatic monocarboxylic acids. These include acetic acid, propionic acid, and n-, iso-, or tert-alpha amino acids.- Butyric acid, valeric acid, trimethylacetic acid, caproic acid, enanthic acid, caprylic acid, pelargonic acid, capric acid, undecanoic acid, lauric acid, tridecanoic acid, myristic acid, palmitic acid, stearic acid, pivalic acid, cyclohexanecarboxylic acid, benzoic acid, methylbenzoic acids, α-naphthalenecarboxylic acid, β-naphthalenecarboxylic acid, phenylacetic acid, oleic acid, ricinoleic acid, linoleic acid, linolenic acid, erucic acid, fatty acids from soy, linseed, castor and sunflower, acrylic acid, methacrylic acid, Versatic. ® -acids, cook ® -Acids and mixtures thereof.

[0068] If unsaturated carboxylic acids or their derivatives are used as monocarboxylic acids (pE), it may be useful to work in the presence of commercially available polymerization inhibitors.

[0069] The monocarboxylic acid pE) selected from acetic acid, propionic acid, benzoic acid and mixtures thereof is particularly preferred.

[0070] In a special version, the aliphatic and semi-aromatic polyamides contain propionic acid exclusively polymerized as the monocarboxylic acid (pE).

[0071] In another special version, the aliphatic and semi-aromatic polyamides contain exclusively benzoic acid polymerized as the monocarboxylic acid (pE).

[0072] In another special version, the aliphatic and semi-aromatic polyamides contain exclusively acetic acid polymerized as the monocarboxylic acid pE).

[0073] The aliphatic and semi-aromatic polyamides can contain at least one monoamine (pF) polymerized within them. The aliphatic polyamides contain only aliphatic or alicyclic monoamines polymerized within them. The monoamines (pF) serve as end caps in the polyamides produced according to the invention. In principle, all monoamines capable of reacting with at least some of the available carboxylic acid groups under the reaction conditions of the polyamide condensation are suitable. Suitable monoamines (pF) are aliphatic monoamines, alicyclic monoamines, and aromatic monoamines. These include methylamine, ethylamine, propylamine, butylamine, hexylamine, heptylamine, octylamine, decylamine, stearylamine, dimethylamine, diethylamine, dipropylamine, dibutylamine, cyclohexylamine, dicyclohexylamine, aniline, toluidine, diphenylamine, naphthylamine, and mixtures thereof.

[0074] For the production of aliphatic and semi-aromatic polyamides, at least one trivalent amine (pG) can additionally be used. These include N'-(6-aminohexyl)hexane-1,6-diamine, N'-(12-aminododecyl)dodecane-1,12-diamine, N'-(6-aminohexyl)dodecane-1,12-diamine, N'-[3-(aminomethyl)-3, 5, 5-trimethylcyclohexyl]hexane-1 ,6-diamine, N'-[3-(aminomethyl)-3,5,5-trimethyl-cyclohexyl]dodecane-1,12-diamine, N'-[(5-amino-1,3,3-trimethyl-cyclohexyl)-methyl]hexane-1,6-diamine, N'-[(5-amino-1,3, 3-trimethylcyclohexyl)methyl]dodecane-1,12-diamine, 3-[[[3-(aminomethyl)-3,5,5-trimethyl-cyclohexyl]amino]methyl]-3,5,5-trimethyl-cyclohexanamine, 3-[[(5-amino-1 ,3,3-trimethyl-cyclohexyl)methylamino]methyl]-3,5,5-trimethyl-cyclohexanamine, 3-(Aminomethyl)-N-[3-(aminomethyl)-3,5,5-trimethyl-cyclohexyl]-3,5,5-trimethyl-cyclohexanamine. Preferably, no trivalent amines (pG) are used.

[0075] Suitable lactams (pH) are e-caprolactam, 2-piperidone (d-valerolactam), 2-pyrrolidone (g-butyrolactam), capryllactam, enanthlactam, lauryllactam and mixtures thereof.

[0076] Suitable w-amino acids (pl) are 6-aminocaproic acid, 7-aminoheptanoic acid, 1-aminoundecanoic acid, 12-aminododecanoic acid and mixtures thereof.

[0077] Suitable compounds ranging from pA) to pl) that are co-condensable (pK) are at least trivalent carboxylic acids, diaminocarboxylic acids, etc.

[0078] Suitable compounds (pK) also include 4-[(Z)-N-(6-Aminohexyl)-C-hydroxy-carbonimido-yl]benzoic acid, 3-[(Z)-N-(6-Aminohexyl)-C-hydroxy-carbonimidoyl]benzoic acid, (6Z)-6-(6-Aminohexylimino)-6-hydroxy-hexanecarboxylic acid, 4-[(Z)-N-[(5-Amino-1,3,3-trimethyl-cyclohexyl)-methyl]-C-hydroxy-carbonimidoyl]benzoic acid, 3-[(Z)-N-[(5-Amino-1,3,3-trimethyl-cyclohexyl)-methyl]-C-hydroxy-carbonimidoyl]benzoic acid, 4-[(Z)-N-[3-(Aminomethyl)-3,5,5-trimethyl-cyclo- hexyl]-C-hydroxy-carbonimidoyl]benzoic acid, 3-[(Z)-N-[3-(Aminomethyl)-3,5,5-trimethyl-cyclo- hexyl]-C-hydroxy-carbonimidoyl]benzoic acid and mixtures thereof.

[0079] Preferably, polyamide A is selected from PA 4, PA 5, PA 6, PA 7, PA 8, PA 9, PA 10,

[0080] PA 1 1 , PA 12, PA 46, PA 66, PA 666, PA 69, PA 610, PA 612, PA 96, PA 99, PA 910, PA 912, PA 1212, PA 6.T, PA 9.T, PA8.T, PA 10.T, PA 12.T, PA 6.I, PA 8.I, PA 9.I, PA 10.1, PA 12.1, PA 6.T / 6, PA 6. T / 10, PA 6.T / 12, PA 6.T / 6.I, PA6.T / 8.T, PA 6.T / 9.T, PA 6.T / 10T, PA 6.T / 12.T, PA 12.T / 6.T, PA 6.T / 6.I / 6, PA 6.T / 6.I / 12, PA 6.T / 6.1 / 6.10, PA 6. T / 6.1 / 6.12, PA 6. T / 6.6,

[0081] PA 6.T / 6.10, PA 6. T / 6.12, PA 10.T / 6, PA 10.T / 1 1 , PA 10.T / 12, PA 8.T / 6.T, PA 8. T / 66,

[0082] PA 8.T / 8.I, PA 8.T / 8.6, PA 8.T / 6.I, PA 10.T / 6.T, PA 10.T / 6.6, PA 10.T / 10.I, PA 10T / 10.I / 6.T,

[0083] PA 10. T / 6.1, PA 4.T / 4.I / 46, PA 4.T / 4.I / 6.6, PA 5.T / 5.I, PA 5.T / 5.I / 5.6, PA 5.T / 5.I / 6.6,

[0084] PA 6.T / 6.I / 6.6, PA MXDA.6, PA IPDA.I, PA IPDA.T, PA MACM.I, PA MACM.T, PA PACM.I,

[0085] PA PACM.T, PA MXDA.I, PA MXDA.T, PA 6.T / IPDA.T, PA 6.T / MACM.T, PA 6.T / PACM.T, PA 6.T / MXDA.T, PA 6.T / 6.I / 8.T / 8.I, PA 6. T / 6.1 / 10. T / 10.1, PA 6.T / 6.I / IPDA.T / IPDA.I,

[0086] PA 6.T / 6.I / MXDA.T / MXDA.I, PA 6.T / 6.I / MACM.T / MACM.I, PA 6.T / 6.I / PACM.T / PACM.I,

[0087] PA 6.T / 10.T / IPDA.T, PA 6.T / 12.T / IPDA.T, PA 6.T / 10.T / PACM.T, PA 6.T / 12.T / PACM.T,

[0088] PA 10.T / IPDA.T, PA 12.T / IPDA.T and copolymers and mixtures thereof.

[0089] In a preferred embodiment, the polyamide composition used according to the invention contains as component A) at least one aliphatic polyamide or consists of aliphatic polyamide.

[0090] The aliphatic polyamide is then preferably selected from PA 4, PA 5, PA 6, PA 7, PA 8, PA 9, PA 10, PA 11, PA 12, PA 46, PA 66, PA 666, PA 69, PA 610, PA 612, PA 96,

[0091] PA 99, PA 910, PA 912, PA 1212, and copolymers and mixtures thereof.

[0092] In particular, the aliphatic polyamide A) is selected from PA 6, PA 66 or PA 12. A special embodiment is polyamide compositions in which component A) contains PA 6 or PA 66 or consists of PA 6, PA 66 or mixtures thereof.

[0093] A semi-aromatic polyamide or copolyamide is preferably selected from PA 6.T, PA 9.T, PA 10.T, PA 12.T, PA 6.I, PA 9.I, PA 10.1, PA 12.1, PA 6.T / 6.I, PA 6.T / 6, PA6.T / 8.T,

[0094] PA 6.T / 10T, PA 10.T / 6.T, PA 6.T / 12.T, PA12.T / 6.T, PA IPDA.I, PA IPDA.T, PA 6.T / IPDA.T,

[0095] PA 6.T / 6.I / IPDA.T / IPDA.I, PA 6.T / 10.T / IPDA.T, PA 6.T / 12.T / IPDA.T, PA 6.T / 10.T / PACM.T,

[0096] PA 6.T / 12.T / PACM.T, PA 10.T / IPDA.T, PA 12.T / IPDA.T and copolymers and mixtures thereof.

[0097] The following information is given for the number-average molecular weight M n and the weight-mean molecular weight M wWithin the scope of this invention, the determination is carried out by gel permeation chromatography (GPC). For calibration, PMMA, for example, was used as a polymer standard with low polydispersity.

[0098] The synthetic polyamide A) preferably has a number-average molecular weight M n in a range of 8000 to 50000 g / mol, particularly preferably from 10000 to 35000 g / mol.

[0099] The synthetic polyamide A) preferably has a weight-average molecular weight M n in a range of 15000 to 200000 g / mol, particularly preferably from 20000 to 125000 g / mol.

[0100] The polyamides preferably exhibit a polydispersity PD (= M w / M n ) of at most 6, particularly preferably of at most 5, especially of at most 3.5.

[0101] The present invention also relates to the use of special polyamide compositions based on aliphatic polyamides and copolyamides / terpolyamides. When using a polyamide mixture of aliphatic polyamide A1) and aliphatic copolyamide or terpolyamide A2), the weight ratio of A1) to A2) is preferably 55:45 to 95:5. The polyamide mixture then forms component A).

[0102] In the polyamide compositions used according to the invention, the polyamide mixture A) contains aliphatic polyamide A1) and aliphatic copolyamide or terpolyamide A2). The corresponding components can be selected from the components listed above.

[0103] Preferably the aliphatic polyamide A1 ) is selected from: PA 4, PA 5, PA 6, PA 7, PA 8, PA 9, PA 10, PA 11 , PA 12, PA 46, PA 66, PA 69, PA 610, PA 612, PA 96, PA 99, PA 910,

[0104] PA 912, PA 1212.

[0105] Particularly preferred is the aliphatic polyamide A1) selected from polyamide 6, polyamide 66 and mixtures thereof.

[0106] The aliphatic copolyamide or terpolyamide A2) is preferably composed of the monomers of two or three polyamides selected from PA 4, PA 5, PA 6, PA 7, PA 8, PA 9, PA 10, PA 11, PA 12, PA 46, PA 66, PA 69, PA 610, PA 612, PA 96, PA 99, PA 910, PA 912, PA 1212.

[0107] Specific examples of copolyamides are PA 66 / 6, PA 66 / 68, PA 66 / 610, PA 66 / 612,

[0108] PA 66 / 10, PA 66 / 12, PA 6 / 68, PA 6 / 610, PA 6 / 612, PA 6 / 10, PA 6 / 12. Examples of suitable terpolymers are PA 6 / 66 / 610, PA 6 / 66 / 69, PA 6 / 66 / 11, PA 6 / 66 / 12, PA 6 / 610 / 11, PA 6 / 610 / 12, 6 / 66 / PACM.

[0109] Preferably, the aliphatic copolyamide is a PA 6 / PA 66 copolymer.

[0110] Suitable aliphatic polyamides and copolyamides / terpolyamides are also mentioned in EP-B-1 060 216.

[0111] The weight ratio of aliphatic polyamide A1) to aliphatic copolyamide or terpolyamide A2) is 55:45 to 95:5, preferably 60:40 to 90:10, particularly 70:30 to 90:10.

[0112] Preferably, the crystallization point (crystallization temperature) of the polyamide mixture A) should be below the crystallization points (crystallization temperatures) of the aliphatic polyamide A1) and the aliphatic copolyamide / terpolyamide A2). Similarly, in the use and method according to the invention, the crystallization point of the mixture of the at least one polyamide and at least one copolyamide or terpolyamide should preferably be below the crystallization points of the at least one polyamide and at least one copolyamide or terpolyamide. Thus, the addition of the copolyamide / terpolyamide preferably has a crystallization point-reducing effect in the polyamide composition. The reduction or lowering of the crystallization point can be determined by DSC measurement (differentiating scanning calorimetry).

[0113] The polyamide compositions according to the invention may optionally contain glass fibers as component B). If glass fibers are present, the maximum permissible quantity of component A) is reduced by the minimum amount of glass fibers present.

[0114] Specifically, cut glass fibers are used. In particular, component B) comprises glass fibers, preferably short fibers. These preferably have a length in the range of 2 to 50 mm and a diameter of 5 to 40 pm. Alternatively, continuous fibers (rovings) can be used. Fibers with circular and / or non-circular cross-sectional areas are suitable, the latter having a dimensional ratio of the main cross-sectional axis to the secondary cross-sectional axis that is preferably > 2, more preferably in the range of 2 to 8, and most preferably in the range of 3 to 5.

[0115] In a specific embodiment, component B) comprises so-called "flat glass fibers". These have a specifically oval or elliptical cross-sectional area, or an elliptical fiber with constrictions (so-called "cocoon" fiber), or a rectangular or nearly rectangular cross-sectional area. Glass fibers with a non-circular cross-sectional area and a dimension ratio of more than 2, preferably from 2 to 8, and particularly from 3 to 5, are preferably used.

[0116] To reinforce the molding compounds according to the invention, mixtures of glass fibers with circular and non-circular cross-sections can also be used. In a special embodiment, the proportion of flat glass fibers, as defined above, predominates, i.e., they make up more than 50 wt.% of the total mass of the fibers.

[0117] If glass fiber rovings are used as component B), these preferably have a diameter of 10 to 20 pm, more preferably 12 to 18 pm. The cross-section of the glass fibers can be round, oval, elliptical, nearly rectangular, or rectangular. So-called flat glass fibers with a cross-sectional axis ratio of 2 to 5 are particularly preferred. E-glass fibers are used in particular. However, all other types of glass fibers, such as A-, C-, D-, M-, S-, and R-glass fibers, or any mixtures thereof or mixtures with E-glass fibers, can also be used.

[0118] The polyamide molding compounds according to the invention can be produced by known methods for manufacturing long-fiber-reinforced rod-shaped granules, in particular by pultrusion processes in which the continuous fiber strand (roving) is completely impregnated with the polymer melt and subsequently cooled and cut. The long-fiber-reinforced rod-shaped granules obtained in this way, which preferably have a granule length of 3 to 25 mm, particularly 4 to 12 mm, can be further processed into molded parts using conventional processing methods, such as injection molding or compression molding.

[0119] As component C), the polyamide compositions according to the invention may optionally contain one or more heat stabilizers.

[0120] As component C), the molding compounds according to the invention may preferably contain 0.01 to 2 wt.%, particularly preferably 0.02 to 1 wt.%, in particular 0.05 to 0.5 wt.% at least a heat stabilizer, based on the total weight of the composition.

[0121] The heat stabilizers are preferably selected from copper compounds, secondary aromatic amines, sterically hindered phenols, phosphites, phosphonites and mixtures thereof.

[0122] If a copper compound is used, the amount of copper is preferably 0.003 to 0.5 wt.%, in particular 0.005 to 0.3 wt.% and most preferably 0.01 to 0.2 wt.%, based on the total weight of the composition.

[0123] If stabilizers based on secondary aromatic amines are used, the amount of these stabilizers is preferably 0.2 to 2 wt.%, particularly preferably 0.2 to 1.5 wt.%, based on the total weight of the composition.

[0124] If stabilizers based on sterically hindered phenols are used, the amount of these stabilizers is preferably 0.07 to 1.5 wt.%, particularly preferably 0.1 to 1 wt.%, based on the total weight of the composition.

[0125] If stabilizers based on phosphites and / or phosphonites are used, the amount of these stabilizers is preferably 0.1 to 1.5 wt.%, particularly preferably 0.2 to 1 wt.%, based on the total weight of the composition.

[0126] Suitable compounds C) of mono- or divalent copper are, for example, salts of mono- or divalent copper with inorganic or organic acids or mono- or divalent phenols, the oxides of mono- or divalent copper, or the complex compounds of copper salts with ammonia, amines, amides, lactams, cyanides, or phosphines, preferably Cu(l) or Cu(ll) salts of hydrohalic acids, hydrocyanic acids, or the copper salts of aliphatic carboxylic acids. Particularly preferred are the monovalent copper compounds CuCl, CuBr, Cul, CuCN, and Cu₂O, as well as the divalent copper compounds CuCl₂, CuSO₄, CuO, copper(ll) acetate, or copper(ll) stearate.

[0127] The copper compounds are commercially available or their preparation is known to those skilled in the art. The copper compound can be used as such or in the form of concentrates. A concentrate is understood to be a polymer, preferably of the same chemical nature as component A), which contains the copper salt in a high concentration. The use of concentrates is a common procedure and is particularly frequently employed when very small quantities of a starting material need to be dosed. Advantageously, the copper compounds are used in combination with other metal halides, especially alkali halides, such as Nal, Kl, NaBr, and KBr, wherein the molar ratio of metal halide to copper halide is 0.5 to 20, preferably 1 to 10, and particularly preferably 3 to 7.

[0128] Particularly preferred examples of stabilizers based on secondary aromatic amines that can be used according to the invention are adducts of phenylenediamine with acetone (Naugard). ® A) Adducts of phenylenediamine with linolenic acid, 4,4 , -Bis(a,a-dimethylbenzyl)diphenylamine (Naugard ® 445), N,N'-Dinaphthyl-p-phenylenediamine, N-Phenyl-N'-cyclohexyl-p-phenylenediamine or mixtures of two or more of these.

[0129] Preferred examples of stabilizers based on sterically hindered phenols that can be used according to the invention are N^'-hexamethylene-bis-S-^S-di-tert-butyl^-hydroxypheny-propionamide (Irganox ® 1098), Bis-(3,3-bis-(4'-hydroxy-3'-tert-butylphenyl)-butanoic acid) glycol ester, 2,1'-Thioethylbis-(3-(3,5-di.tert-butyl-4-hydroxyphenyl)-propionate, 4,4'-Butylidene-bis-(3-methyl-6-tert-butylphenol), Triethylene glycol-3-(3-tert-butyl-4-hydroxy-5-methylphenyl)-propionate or mixtures of two or more of these stabilizers.

[0130] Bevorzugte Phosphite und Phosphonite sind Triphenylphosphit, Diphenylalkylphosphit, Phe- nyldialkylphosphit, Tris(nonylphenyl)phosphit, Trilaurylphosphit, Trioctadecylphosphit, Distearyl- pentaerythritoldiphosphit, Tris(2,4-di-tert-butylphenyl)phosphit, Diisodecylpentaerythritoldiphos- phit, Bis(2,4-di-tert-butylphenyl)pentaerythritoldiphosphit, Bis(2,6-di-tert-butyl-4-methylphenyl)- pentaerythritoldiphosphit, Diisodecyloxypentaerythritoldiphosphit, Bis(2,4-di-tert-butyl-6- methylphenyl)pentaerythritoldiphosphit, Bis(2,4,6-tris-(tert-butylphenyl))pentaerythritoldiphos- phit, Tristearylsorbitoltriphosphit, Tetrakis-(2,4-di-tert-butylphenyl)-4,4'-biphenylendiphosphonit, 6-lsooctyloxy-2,4,8,10-tetra-tert-butyl-12H-dibenz-[d,g]-1 ,3,2-dioxaphosphocin, 6-Fluoro- 2,4,8,10-tetra-tert-butyl-12-methyl-dibenz[d,g]-1 ,3,2-dioxaphosphocin, Bis(2,4-di-tert-butyl-6-me- thylphenyl)methylphosphit und Bis(2,4-di-tert-butyl-6-methylphenyl)ethylphosphit.In particular, Tris[2-tert-butyl-4-thio(2'-methyl-4'-hydroxy-5'-tert-butyl)-phenyl-5-methyl]phenylphosphite and Tris(2,4-di-tert-butylphenyl)phosphite (Hostanox. ® PAR24: commercial product from BASF SE).

[0131] A preferred embodiment of the heat stabilizer consists of a combination of organic heat stabilizers (in particular Hostanox). ® PAR 24 and Irganox ® 1010), a bisphenol A-based epoxide (especially Epikote ® 1001) and a copper stabilization based on Cul and Kl. A commercially available stabilizer mixture consisting of organic stabilizers and epoxides is, for example, Irgatec. ®NC66 from BASF SE. Heat stabilization based exclusively on Cul and Kl is particularly preferred. In addition to the addition of copper or copper compounds, the use of other transition metal compounds, especially metal salts or metal oxides of groups VB, VIB, VI1B, or VIIIB of the periodic table, is excluded. Furthermore, transition metals of groups VB, VIB, VIIB, or VIIIB of the periodic table, such as iron or steel powder, are preferably not added to the molding compound according to the invention. The use of Irganox is also particularly preferred. ® 1098.

[0132] The use of copper compounds, especially monovalent copper compounds, and stabilizers based on sterically hindered phenols, such as Irganox, is particularly preferred. ® 1098, and mixtures thereof. The particularly preferred amount used is in the range of 0.05 to 0.5 wt.%, specifically 0.07 to 0.2 wt.%.

[0133] Component D) uses at least one polyhydric alcohol with more than two hydroxyl groups. Suitable polyols are described, for example, in WO 2010 / 014801; see in particular page 14, line 29, to page 16, line 7.

[0134] The polyhydric alcohols can be selected from aliphatic hydroxyl compounds with more than two hydroxyl groups, aliphatic-cycloaliphatic compounds with more than two hydroxyl groups, cycloaliphatic compounds with more than two hydroxyl groups, aromatic compounds and saccharides.

[0135] An aliphatic chain in polyhydric alcohols can contain heteroatoms in addition to carbon, such as nitrogen, oxygen, or sulfur atoms. A cycloaliphatic ring in a polyhydric alcohol can be a monocycle or part of a dicyclic or polycyclic ring system. It can be carbocyclic or heterocyclic. The polyhydric alcohols can contain one or more substituents, such as ethers, carboxylic acids, carboxylic amides, or carboxylic ester groups, or they can be polyvinyl alcohol copolymers, e.g., ethylene-vinyl alcohol copolymers. Ideally, these copolymers have a minimum MFR (210 °C /

[0136] 2.16 kg) between 2 and 20 g / 10 min.

[0137] Examples of suitable polyhydric alcohols, preferably with a number-average molecular weight (M n) von weniger als 2000, sind Triole, wie Glyzerin, Trimethylolpropan, 2,3-Di-(2‘- hydroxyethyl)cyclohexan-1-ol, Hexan-1 ,2,6-triol, 1 ,1 ,1-tris(Hydroxymethyl)ethan, 3-(2‘-Hy- droxyethoxy)propan-1 ,2-diol, 3-(2‘-Hydroxypropoxy)propan-1 ,2-diol, 2-(2‘-Hydroxyethoxy)- hexan-1 ,2-diol, 6-(2‘-Hydroxypropoxy)hexan-1 ,2-diol, 1 ,1 ,1-tris-[(2‘-Hydroxyethoxy)me- thyl]ethan, 1 ,1 ,1-tris-[(2‘-Hydroxypropoxy)methyl]propan, 1 ,1 ,1-tris-(4‘-Hydroxyphenyl)ethan,

[0138] 1,1,1-tris-(hydroxyphenyl)propane, 1,1,3-tris-(dihydroxy-3-methylphenyl)propane, 1,1,4-tris-(dihydroxyphenyl)butane, 1,1,5-tris-(hydroxyphenyl)-3-methylpentane, di-trimethylopropane, trimethylolpropane ethoxylates or Trimethylolpropane propoxylates, polyols such as pentaerythritol, dipentaerythritol and tripentaerythritol, and saccharides such as cyclodextrin, D-mannose, glucose, galactose, sucrose, fructose, ylose, arabinose, D-mannitol, D-sorbitol, D- or L-arabitol, yylitol, iditol, talitol, allitol, altritol, Guilite, erythritol, threitol and D-Gulon-y-lactone. In preferred polyhydric alcohols, the hydroxyl groups are each bonded to carbon atoms that are separated from each other by at least one atom, preferably a carbon atom. Accordingly, the polyhydric alcohol is preferably pentaerythritol, dipentaerythritol, tripentaerythritol, trimethylolpropane, D-mannitol, D-sorbitol, or xylitol. Dipentaerythritol and / or tripentaerythritol are particularly preferred.The most preferred form is dipentaerythritol.

[0139] Component E) in the polyamide compositions may contain further additives. When component E) is used, the upper limit for component A) is reduced accordingly.

[0140] Component E) of the compositions according to the invention contains 0 to 20 wt.%, preferably 0 to 10 wt.%, in particular 0 to 5 wt.% of further additives. When such additives are used, the minimum amount is 0.1 wt.%, preferably 1 wt.%, in particular 3 wt.%.

[0141] When component E is used in conjunction with component A, the upper limit for component A is reduced accordingly. For example, with a minimum quantity of 0.1 wt% of component E, the upper limit for the quantity of component A is 89.88 wt%.

[0142] Other possible additives include various fillers and reinforcing materials for glass fibers, various thermoplastic polymers or other additives for component A).

[0143] The term "filler and reinforcing material" (= possible component E)) is broadly understood within the scope of the invention and includes particulate fillers, fibrous materials, and any intermediate forms. Particulate fillers can exhibit a wide range of particle sizes, from dust-like to coarse-grained particles. Organic or inorganic fillers and reinforcing materials are suitable. For example, inorganic fillers such as kaolin, chalk, wollastonite, talc, calcium carbonate, silicates, titanium dioxide, zinc oxide, graphite, glass particles, etc., can be used. B. glass spheres, nanoscale fillers such as carbon nanotubes, nanoscale layered silicates, nanoscale aluminum oxide (Al2O3), nanoscale titanium dioxide (T1O2), graphene, permanently magnetic or magnetizable metal compounds and / or alloys, layered silicates and nanoscale silicon dioxide (S1O2).The fillers may also be surface-treated.

[0144] The layered silicates used in the molding compounds according to the invention can include, for example, kaolins, serpentines, talc, mica, vermiculite, illite, smectite, montmorillonite, hectorite, double hydroxides, or mixtures thereof. The layered silicates can be surface-treated or untreated.

[0145] Furthermore, one or more fibrous materials may be used. These are preferably selected from known inorganic reinforcing fibers, such as boron fibers, carbon fibers, silica fibers, ceramic fibers and basalt fibers; organic reinforcing fibers, such as aramid fibers, polyester fibers, nylon fibers, polyethylene fibers and natural fibers, such as wood fibers, flax fibers, hemp fibers and sisal fibers.

[0146] The use of carbon fibers, aramid fibers, boron fibers, metal fibers or potassium titanate fibers is particularly preferred.

[0147] The thermoplastic polymers, different from component A), are preferably selected from among

[0148] - Homo- or copolymers containing, in polymerized form, at least one monomer selected from C2-C10 monoolefins, such as ethylene or propylene, 1,3-butadiene, 2-chloro-1,3-butadiene, vinyl chloride, vinylidene chloride, vinylidene fluoride, tetrafluoroethylene, glycidyl acrylate, glycidyl methacrylate, acrylates and methacrylates with alcohol components of branched and unbranched Ci-Cio alcohols, vinyl aromatics, such as styrene, acrylonitrile, methacrylonitrile, α,β-ethylene unsaturated mono- and dicarboxylic acids, and maleic anhydride;

[0149] - Homo- and copolymers of vinyl acetals,

[0150] - Polyvinyl esters,

[0151] - Polyvinylpyrrolidone or polyvinylpyrrolidone copolymers (PVP)

[0152] - Polycarbonates (PC),

[0153] - Polyesters, such as polyalkylene terephthalates, polyhydroxyalkanoates (PHA), polybutylene succinates (PBS), polybutylene succinate adipates (PBSA),

[0154] - Polyethers,

[0155] - Polyetherketones,

[0156] - thermoplastic polyurethanes (TPU),

[0157] - Polysulfides,

[0158] - Polysulfones,

[0159] - Polyethersulfones,

[0160] - Cellulose alkyl esters

[0161] and mixtures thereof.

[0162] Examples include polyacrylates with the same or different alcohol residues from the group of C4-C8 alcohols, especially butanol, hexanol, octanol and 2-ethylhexanol, polymethyl methacrylate (PMMA), methyl methacrylate-butyl acrylate copolymers, acrylonitrile-butadiene-styrene copolymers (ABS), ethylene-propylene copolymers, ethylene-propylene-diene copolymers (EPDM), polystyrene (PS), styrene-acrylonitrile copolymers (SAN), acrylonitrile-styrene acrylate (ASA), styrene-butadiene-methyl methacrylate copolymers (SBMMA), styrene-maleic anhydride copolymers, styrene-methacrylic acid copolymers (SMA), polyoxymethylene (POM), polyvinyl alcohol (PVAL), polyvinyl acetate (PVA), and polyvinyl butyral (PVB). Polycaprolactone (PCL), polyhydroxybutyric acid (PHB), polyhydroxyvaleric acid (PHV), polylactic acid (PLA), ethylcellulose (EC), cellulose acetate (CA), cellulose propionate (CP) or cellulose acetate / butyrate (CAB).Preferably, the thermoplastic polymer contained in the molding compound according to the invention is at least one polyvinyl chloride (PVC), polyvinyl butyral (PVB), homo- and copolymers of vinyl acetate, homo- and copolymers of styrene, polyacrylates, thermoplastic polyurethanes (TPU) or polysulfides.

[0163] It may be advantageous to use nigrosine (Solvent Black 7, CAS No. 8005-02-5) and / or Solvent Black 28 (CAS No. 12237-23-91) and optionally combine it with at least one other colorant. Component E) is then preferably selected from non-nucleating colorants different from C). These include non-nucleating dyes, non-nucleating pigments, and mixtures thereof. Examples of non-nucleating dyes are Solvent Yellow 21 (marketed as Oracet). ® Yellow 160 FA from BASF SE (available in [location]) or Solvent Blue 104 (marketed as Solvaperm) ®Blue 2B from Clariant is available). Examples of non-nucleating pigments include Pigment Brown 24 (marketed as Sicotan). ® Yellow K 201 1 FG (available from BASF SE). Small amounts of at least one white pigment are also suitable as component E). Suitable white pigments are titanium dioxide (Pigment White 6), barium sulfate (Pigment White 22), zinc sulfide (Pigment White 7), etc. In a special embodiment, the molding compound according to the invention contains as component E)

[0164] 0.001 to 0.5 wt% of at least one white pigment. For example, the molding compound may contain 0.05 wt% titanium dioxide of the brand Kronos 2220 from the company Kronos.

[0165] The type and amount added depends on the hue, i.e., the desired shade of black. For example, Solvent Yellow 21 can be used to adjust the shade of black in the CIELAB color space to, for example, b. * = -1 ,0 in the direction of +b *, i.e., shifted towards yellow. This method is known to experts as color nuance. The measurement is carried out according to DIN 6174 "Colorimetric determination of color values ​​and color distances in the approximately uniform CIELAB color space" or its successor standard.

[0166] Carbon black can also be used as component E). For example, the compositions according to the invention contain 0.01 to 1 wt.%, preferably 0.03 to 0.5 wt.%, and particularly 0.05 to 0.3 wt.%, carbon black. Carbon black, also known as industrial carbon black, is a modification of carbon with a high surface area to volume ratio and consists of 80 to 99.5 wt.% carbon. The specific surface area of ​​industrial carbon black is approximately 10 to 1500 m². 2 / g (BET). The carbon black can be produced as gas black, furnace black, flame black, split black, or acetylene black. The grain diameter ranges from 8 to 500 nm, typically 8 to 110 nm. Carbon black is also referred to as Pigment Black 7 or Lamp Black 6. Colored carbon blacks are nanoparticle carbon blacks that, due to their fineness, increasingly lose the brown base color of conventional carbon blacks.

[0167] Suitable preferred additives E) are lubricants, flame retardants, light stabilizers (UV stabilizers, UV absorbers or UV blockers), dyes, nucleating agents, metallic pigments, metal flakes, metal-coated particles, antistatic agents, conductivity additives, demolding agents, optical brighteners, defoamers, etc. The molding compositions according to the invention preferably contain 0 to 15 wt.%, particularly preferably 0 to 10 wt.%, based on the total weight of the composition, at least one flame retardant as additive E). If the molding compositions according to the invention contain at least one flame retardant, then preferably in an amount of 0.01 to 15 wt.%, particularly preferably 0.1 to 10 wt.%, based on the total weight of the composition. Suitable flame retardants include halogenated and halogen-free flame retardants and their synergists (see also Gächter / Müller, 3rd edition, 1989, Hanser Verlag, chapter 11).Preferred halogen-free flame retardants are red phosphorus, phosphinic acid or diphosphinic acid salts and / or nitrogen-containing flame retardants, such as melamine, melamine cyanurate, melamine sulfate, melamine borate, melamine oxalate, melamine phosphate (primary, secondary) or secondary melamine pyrophosphate, neopentyl glycol boric acid melamine, guanidine and derivatives thereof known to those skilled in the art, as well as polymeric melamine phosphate (CAS No. 56386-64-2 or 218768-84-4 and EP-A-1 095 030), ammonium polyphosphate, trishydroxyethyl isocyanurate (optionally also ammonium polyphosphate in a mixture with trishydroxyethyl isocyanurate) (EP-A-058 456 7). Further N- or P-containing flame retardants or PN condensates suitable as flame retardants can be found in DE-A-10 2004 049 342, as well as the usual synergists such as oxides or borates. Suitable halogenated flame retardants include, for example,oligomeric brominated polycarbonates (BC 52 Great Lakes) or polypentabrombenzyl acrylates with N greater than 4 (FR 1025 Dead sea bromine), reaction products of tetrabromobisphenol-A with epoxides, brominated oligomeric or polymeric styrenes, dechlorane, which are mostly used with antimony oxides as synergists (for details and other flame retardants: see DE-A-10 2004 050 025).

[0168] The polyamide molding compounds are produced according to methods known per se. This includes mixing the components in their respective weight proportions. Preferably, the components are mixed at elevated temperatures by joint blending, mixing, kneading, extrusion, or rolling. The mixing temperature is preferably in the range of 220 °C to 340 °C, particularly preferably from 240 °C to 320 °C, and especially from 250 °C to 300 °C. Suitable methods are known to those skilled in the art.

[0169] Molded body

[0170] Molded bodies are produced from the polyamide compositions used according to the invention by injection molding, wherein at least two flow fronts of the molten polyamide composition meet during injection molding and form at least one weld line.

[0171] This means the molded parts have at least one weld line resulting from the injection molding process. Injection molding can be carried out using known methods and is described, for example, in "Coloring Plastics," VDI-Verlag, ISBN 3-18-404014-3. Typically, at least two gate points are provided in the mold during injection molding, resulting in at least two flow fronts of the molten polyamide compound. Depending on the size and shape of the molded part, significantly more gate points may be provided. The at least two flow fronts can also be created by flowing around a cavity or core in the mold.

[0172] The molded parts produced according to the invention can be single-piece or multi-piece. In the case of a multi-piece structure, the individual molded parts must be subsequently joined together, for example by welding, such as friction welding, hot gas welding or laser transmission welding.

[0173] The polyamide molded bodies obtainable according to the inventive method are further advantageously suitable for use in automotive applications, for electrical and electronic components, especially also in the high temperature range.

[0174] A special embodiment is formed bodies in the shape of or as part of a component for the automotive sector, in particular selected from cylinder head covers, engine covers, charge air cooler housings, charge air cooler flaps, intake pipes, intake manifolds, connectors, gears, fan wheels, coolant boxes, housings or housing parts for heat exchangers, coolant coolers, charge air coolers, thermostats, water pumps, heater cores, fastening parts.

[0175] In the car interior, it is used for dashboards, steering column switches, seat parts, headrests, center consoles, transmission components and door modules; in the car exterior for A-,

[0176] B-, C- or D-pillar covers, spoilers, door handles, exterior mirror components, windshield wiper components, windshield wiper protection housings, decorative grilles, cover strips, roof rails, window frames, sunroof frames, antenna covers, front and rear lights, engine covers, cylinder head covers, intake pipes, windshield wipers and body exterior parts are possible.

[0177] Another special embodiment is shaped bodies as such or as part of an electrical or electronic passive or active component, a printed circuit board, a part of a printed circuit board, a housing component, a film, a conductor, in particular in the form of or as part of a switch, a plug, a socket, a distributor, a relay, a resistor, a capacitor, a coil or a coil former, a lamp, a diode, an LED, a transistor, a connector, a regulator, an integrated circuit (IC), a processor, a controller, a memory and / or a sensor.

[0178] For kitchen and household applications, polyamides can be used to manufacture components for kitchen appliances, such as deep fryers, irons, and knobs, as well as for garden applications, such as components for irrigation systems or garden tools. The polyamide composition for manufacturing molded parts is produced using methods known per se. Reference is made here to the aforementioned methods for producing the polyamide composition. This includes mixing the components in the corresponding weight proportions. Preferably, the components are mixed at elevated temperatures by joint blending, mixing, kneading, extrusion, or rolling. The mixing temperature is preferably in the range of 220 to 340 °C, particularly preferably from 240 to 320 °C, and especially from 250 to 300 °C. It can be advantageous to premix individual components.It is also possible to produce the molded parts directly from a dry blend of premixed components and / or individual components, prepared at a temperature significantly below the melting point of the polyamide. The mixing temperature is preferably 0 to 100 °C, particularly preferably 10 to 50 °C, and especially ambient temperature (25 °C). The molding compounds are processed into molded parts by injection molding. They are particularly suitable, for example, for materials for lids, housings, attachments, and sensors, for instance, for automotive, electrical, electronic, telecommunications, information technology, computer, household, sports, medical, or entertainment applications.

[0179] The molded parts produced by injection molding from the polyamide compositions used according to the invention exhibit a significantly increased weld line strength after heat aging over a wide temperature range, particularly after heat aging at 180 °C for 500 hours. The tensile strength of the molded parts, and especially of the weld line, is largely retained or only slightly reduced after heat treatment for 500 hours at 180 °C.

[0180] The heat aging process is carried out analogously to common specifications from the automotive industry.

[0181] Thus, the weld line strength after oxidative and thermal aging can be significantly improved by using the described polyamide molding compounds, especially when combined with copolyamides / terpolyamides. This eliminates the disadvantages of the

[0182] WO 2010 / 014801 and EP-B-2 307 480 describe the molding compounds for relevant applications.

[0183] The invention is explained in more detail by the following examples.

[0184] Examples

[0185] The following raw materials were used: A1: Polyamide-6: Ultramid ® B27 of BASF SE, melting point: 222 °C, viscosity number (0.5% in 96% H2SO4): 150 cm 3 / g. The viscosity number of the polyamide was determined in accordance with ISO 307 at 25 °C.

[0186] B: Fiber optic: OCV-995, Manufacturer: Nippon Electric Glass (Malaysia) SDN. BHD., mean diameter: 10.5 µm, length: 3 mm

[0187] C: Irganox ® 1098, Manufacturer: BASF SE

[0188] D: polyhydric alcohol:

[0189] Charmor ® PP100: Mixture of pentaerythritol (CAS No. 116-77-5) and various other compounds

[0190] Polyalcohols and esters. Manufacturer: Perstorp

[0191] Charmor ® DP40 :2,2,2",2"-Tetrakis(hydroxymethyl)-3,3"-oxydipropan-1-ol.

[0192] Manufacturer: Perstorp

[0193] EPVOH: Ethylene polyvinyl alcohol (CAS No. 26221-27-2)

[0194] Cul / Kl: Mixture of copper iodide (CAS No. 7681-65-4) and potassium iodide (CAS No.: 7681-11-0)

[0195] E: Lubricant: Calcium stearate (CAS No. 1592-23-0).

[0196] EBS: Distearylethylenediamide (CAS No. 110-30-5)

[0197] Colorant: Nigrosine (CAS No. 8005-02-5, Solvent black 7)

[0198] The ingredients listed in Table 1 below, with the exception of the glass fibers (separately dosed via hot feed), were premixed in a tumbling mixer for 10 minutes and then extruded and granulated using a twin-screw extruder with a diameter of 25 mm and an L / D ratio of 44 at a cylinder temperature of 300 °C. The natural-colored polyamide granules were previously dried in a drying oven at 100 °C for four hours, resulting in a moisture content of less than 0.1%. The resulting granules were injection-molded into standard ISO dog bones at a melt temperature of 290 °C and evaluated both visually and metrologically.The standard ISO dog bones, 4 mm thick and 150 mm long, were manufactured using injection points located opposite each other at the ends of the dog bone. This allowed the injected polyamide to flow from the outside to the center of the dog bone, forming a weld line in the middle of the molded part. The weld line strength was determined by a standardized tensile stress test. The mechanical properties were determined according to DIN ISO 527, 179-2 / 1 eU, and 179-2 / 1 eAf, as amended in 2017. The quantities given in the table are wt.%.

[0199] Heat aging was carried out according to typical automotive standards. A convection oven was heated to the appropriate temperature. Before each step, the samples were dried at 80 °C for 48 hours under reduced pressure. They were then stored in the heated oven for the specified time. Table 1

[0200]

[0201] The dry as molded (DAM) dog bones show only slightly different fracture strains.

[0202] The effects of polyhydric alcohols become strongly apparent during heat aging at 180 °C.

[0203] The results for combinations of polyol and Irganox ® 1098 of the examples E1 and E3 are better than the results of the comparison example C1. After aging at 180 °C, the compositions of examples E5 and E6 show the best values ​​for fracture stress.

Claims

Patent claims 1. Use of polyhydric alcohols with more than two hydroxyl groups in polyamide compositions containing at least one polyamide to increase weld line strength after heat aging of molded parts produced by injection molding from the polyamide composition, wherein at least two flow fronts of the molten polyamide composition meet and form at least one weld line during injection molding.

2. A method for increasing weld line strength after heat aging of molded parts produced from polyamide compositions by injection molding, in which 0.1 to 10 wt.%, based on the total polyamide composition, of at least one polyhydric alcohol with more than two hydroxyl groups is added to the polyamide composition before the molded parts are produced, and the polyamide composition thus obtained is injection molded to produce the molded parts, wherein at least two flow fronts of the molten polyamide composition meet during injection molding and form at least one weld line.

3. Use according to claim 1 or method according to claim 2, characterized in that a polyamide composition is used, comprising a) 30 to 99.9 wt.% of at least one polyamide as component A), b) 0 to 60 wt.% glass fibers as component B), c) 0 to 2 wt.% heat stabilizers selected from copper compounds, secondary aromatic amines, sterically hindered phenols, phosphites, phosphonites and mixtures thereof as component C), d) 0.1 to 10 wt% of at least one polyhydric alcohol with more than two hydroxyl groups as component D), e) 0 to 20 wt% other additives as component E), where the quantities specified, the sum of which equals 100% by weight, refer to the entire composition.

4. Use or method according to claim 3, characterized in that component D) in the polyamide composition is selected from: pentaerythritol, dipentaerythritol, tripentaerythritol, di-trimethylolpropane, D-mannitol, D-sorbitol and xylitol or polyvinyl alcohol copolymers.

5. Use or method according to claim 3 or 4, characterized in that in the polyamide composition the polyamide A) is aliphatic and is selected from PA 4, PA 5, PA 6, PA 7, PA 8, PA 9, PA 10, PA 11, PA 12, PA 46, PA 66, PA 69, PA 610, PA 612, PA 96, PA 99, PA 910, PA 912, PA 1212.

6. Use or method according to claim 5, characterized in that the aliphatic polyamide A) in the polyamide composition is selected from PA 6, PA 66 and mixtures thereof.

7. Use or method according to any one of claims 3 to 6, characterized in that the polyamide composition contains an aliphatic copolyamide or terpolyamide composed of the monomers of two or three polyamides selected from PA 4, PA 5, PA 6, PA 7, PA 8, PA 9, PA 10, PA 11, PA 12, PA 46, PA 66, PA 69, PA 610, PA 612, PA 96, PA 99, PA 910, PA 912, PA 1212.

8. Use or method according to claim 7, characterized in that the aliphatic copolyamide in the polyamide composition is a PA 6 / PA 66 copolymer.

9. Use or method according to any one of claims 3 to 8, characterized in that in the polyamide composition, component A) is a mixture of aliphatic polyamide A1) and aliphatic copolyamide or terpolyamide A2), wherein the weight ratio of A1) to A2) is 55:45 to 95:

5.

10. Use or method according to claim 9, characterized in that the crystallization point of the mixture of the at least one polyamide and the at least one copolyamide or terpolyamide in the polyamide composition lies below the crystallization points of the at least one polyamide and at least one copolyamide or terpolyamide.

1. Use or method according to any one of claims 3 to 10, characterized in that the polyamide composition contains 0.05 to 2 wt.% of component C).

12. Use or method according to any one of claims 3 to 11, characterized in that component C) in the polyamide composition is selected from copper compounds, sterically hindered phenols and mixtures thereof.

13. Use or method according to any one of claims 3 to 12, characterized in that the polyamide composition contains 5 to 60 wt.% of component B).

14. Use or method according to any one of claims 3 to 13, characterized in that the polyamide composition contains a maximum of 2.9 wt.% impact modifiers.

15. Use or method according to any one of claims 3 to 14, characterized in that the polyamide composition does not contain ethylene ionomer resins.