EP4619465A1 - Mixed metal-oxide compositions as stabilizer for flame retardant polyamides - Google Patents

Abstract

A thermoplastic moulding composition comprising a thermoplastic polyamide, red phosphorous and a mixed metal oxide comprising Cu and Cr, a process for producing the thermoplastic moulding composition, the use of the thermoplastic moulding composition for producing moulded articles, fibres, films or extruded articles, moulded articles, fibres, films or extruded articles made of the thermoplastic moulding composition and the use of a mixed metal oxide comprising Cu and Cr in form of their oxides for stabilization of red phosphorous as flame retardant in polyamide compositions while maintaining the electrical properties of the polyamide compositions.

Description

Mixed metal-oxide compositions as stabilizer for flame retardant polyamides

Description

The present invention relates to a thermoplastic moulding composition comprising a thermoplastic polyamide, red phosphorous and a mixed metal oxide comprising Cu and Cr, a process for producing the thermoplastic moulding composition, the use of the thermoplastic moulding composition for producing moulded articles, fibres, films or extruded articles, moulded articles, fibres, films or extruded articles made of the thermoplastic moulding composition and the use of a mixed metal oxide comprising Cu and Cr in form of their oxides for stabilization of red phosphorous as flame retardant in polyamide compositions while maintaining the electrical properties of the polyamide compositions.

Addition of red phosphorus to thermoplastics, especially to reinforced or filled polyamides, is known to lead to effective fire protection (DE-A-1931387). However, under unfavorable conditions, e.g. elevated temperature or moisture, or presence of alkali or oxygen, red phosphorus tends to form decomposition products, such as phosphine and acids of mono- to pentavalent phosphorus. Although red phosphorus incorporated within thermoplastics, e.g. within polyamides, has substantial protection from thermal oxidation as a consequence of embedment into the polymer, formation of decomposition products can nevertheless still occur here over prolonged periods. This is disadvantageous because if pellets are not correctly processed in the injection-molding process, the resultant phosphine can cause odor problems and is moreover toxic. The phosphorus acids produced at the same time can deposit on the surface of mouldings, a particular result being that the mouldings have reduced tracking resistance. There has therefore been no lack of attempts to improve the stability of red phosphorus used as flame retardant for plastics. By way of example, a stabilizing effect can be achieved via addition of oxides or hydroxides of zinc, of magnesium, or of copper. In DE-A-2625691 , in addition to said stabilization via metal oxides, a polymer is used to coat the phosphorus particles. However, said coating or encapsulation process is very complicated, and the stabilizing effect of the system is moreover not always satisfactory.

US 4187207 A relates to a composition of matter comprising a polyamide, an amount of red phosphorous sufficient to flameproof said polyamide and an amount of cadmium oxide sufficient to retard the liberation of phosphine during heating of said polyamide.

US 2013/0072606 A1 relates to a thermoplastic moulding composition comprising a thermoplastic polyamide, red phosphorus and a stabilizer mixture composed of elemental Ag and ZnO.

WO 2013/124128 A1 relates to a thermoplastic moulding composition comprising a thermoplastic polyamide, red phosphorus, a catalyst comprising a mixture of CuO and ZnO and a support material.

US 3883475 A relates to a moulding composition of thermoplastic material containing from red phosphorus and a substance binding hydrogen phosphide selected from the group consisting of M0S2, HgO, PbC>2, AgNOs, HgCh FeCh 6 H2O, CuO, and active carbon.

It is mentioned in US 3883475 A that it is remarkable that many other compounds with active surface such as aluminium oxide, silica, or molecular sieves are not suitable, or only suitable in much higher concentrations, for the binding of the hydrogen phosphide in moulding compositions of thermoplastic materials.

However, for example in the application of polyamides in the battery technology and propulsion technology of electric vehicles not only the fire protection of polyamides, especially of reinforced or filled polyamides, is of relevance, but also its electrical properties.

The present invention was therefore based on the object of providing thermoplastic moulding compositions which comprise red phosphorus with effective stabilization as flame retardant, i.e. exhibit less phosphorus acid deposition, and also less phosphine formation, while maintaining the electrical properties, e.g. the tracking index. The stabilizers are moreover intended to feature good stability during processing and particularly homogeneous processability in the plastics melt.

The object is achieved by a thermoplastic moulding composition comprising a) from 10 to 99.85% by weight of at least one thermoplastic polyamide, as component A), b) from 0.1 to 60% by weight of red phosphorous, as component B), c) from 0.05 to 20% by weight of at least one mixed metal oxide comprising Cu and Cr in form of their oxides, as component C), d) from 0 to 40% by weight of at least one impact modifier, as component D), e) from 0 to 60% by weight of at least one filler, as component E), f) from 0 to 40% by weight of at least one further additive, as component F), where the total of the percentages by weight of components A), B), C), optionally D), optionally

E) and optionally F) is 100% by weight.

The object is further achieved by a process for producing the inventive thermoplastic moulding composition comprising the step of mixing the components A), B), C) and optionally D), optionally E) and optionally F).

The object is further achieved by the use of the inventive thermoplastic moulding composition for producing moulded articles, fibres, films or extruded articles.

The object is further achieved by moulded articles, fibres, films or extruded articles made of the inventive thermoplastic moulding composition.

The object is further achieved by the use of a mixed metal oxide comprising Cu and Cr in form of their oxides for stabilization of red phosphorous as flame retardant in polyamide compositions while maintaining the electrical properties, e.g. the tracking index, of the polyamide compositions while maintaining the electrical properties of the polyamide compositions.

It has been found by the inventors that red phosphorus is not only effectively stabilized in polyamide compositions by a mixed metal oxide comprising Cu and Cr in form of their oxides, but the electrical properties of said polyamide compositions, e.g. the tracking index, are maintained. This is surprising, since it is generally known that other metal oxides or metal salts negatively affect the electrical properties.

In the context of the present invention, “at least one” means either exactly one or a mixture of two or more different components.

Component A)

As component A), the thermoplastic moulding composition contains 10 to 99.85% by weight, preferably 20 to 98% by weight, more preferably 30 to 90% by weight, based on the total amount of components A), B), C), optionally D), optionally E) and optionally F) of at least one thermoplastic polyamide.

If components D, E) or F), or combinations thereof are present in the thermoplastic moulding composition, the maximum amount of component A) is decreased by the minimum amount of each of components D), E), F), or a combination thereof.

The polyamides A) of the inventive moulding compositions generally have a viscosity number of 90 to 350 ml/g, preferably from 100 to 240 ml/g. The viscosity number (VN) of the polyamides and polyamide compositions according to the present invention is determined according to EN ISO 307:2019 in sulphuric acid (0.5% [m/v] of polyamide in 96 wt.-% [m/m] sulphuric acid at 25 °C), unless indicated otherwise.

Preference is given to semicrystalline or amorphous polyamides with a molecular weight (weight average) of at least 5000, described by the way of example in the following US patents: 2071250, 2071251 , 2130523, 2130948, 2241322, 2312966, 2512606, and 3393210.

Examples of these are polyamides that derive from lactams having from 7 to 13 ring members, e.g. polycaprolactam, polycaprylolactam, and polylaurolactam, and also polyamides obtained via reaction of dicarboxylic acids with diamines.

Dicarboxylic acids which may be used are alkane dicarboxylic acids having from 6 to 12, in particular from 6 to 10 carbon atoms, and aromatic dicarboxylic acids. Merely as examples, those that may be mentioned here are adipic acid, azelaic acid, sebacic acid, dodecanedioic acid and terephthalic and/or isophthalic acid. Particularly suitable diamines are alkane diamines having from 6 to 12, in particular 6 to 8 carbon atoms, and also m-xylylene diamine, di[4-aminophenyl]methane, di[4-aminocyclohexyl]me- thane, 2,2-di[4-aminophenyl]propane, 2,2-di[4-aminocyclohexyl]propane and 1 ,5-diamino-2- methylpantane.

Preferred polyamides are polyhexamethylene adipamid, polyhexamethylene sebacamid, and polycaprolactam, and also PA 6/66 copolyamides, in particular having a proportion of 5 to 95 wt% of caprolactam units (e.g. Ultramid® C31 from BASF SE).

Other suitable polyamides are obtainable from uj-aminoalkyl nitriles, e.g. aminocapronitrile (PA 6) and adiponitrile with hexamethylene diamine (PA 66) via what is known as direct polymerization in the presence of water, for example as described in DE-A 10313681 , EPA 1198491 and EP 0 922 065.

Mention may also be made of polyamides obtainable, by way of example, via condensation of 1 ,4-diaminobutane with adipic acid at an elevated temperature (PA 46). Preparation processes for polyamides of this structure are described by way of example in EP-A 38094, EP-A 38582, and EP-A 39524.

Other suitable examples are polyamides obtainable via copolymerization of two or more of the above-mentioned monomers, and mixtures of two or more polyamides in any desired mixing ratio. Particular preference is given to mixtures of PA 66 with other polyamides, in particular blends of PA 6 and PA 66, and to PA6/66 copolyamides and PA 66/6 copolyamides.

Other copolyamides which have proven particularly advantageous are semiaromatic copolyamides, such as PA 6/6T and PA 66/6T, where the triamine content of these is preferably less than 0.5 wt%, more preferably less than 0.3 wt% (see EP-A 299444). Other polyamides resistant to high temperatures are known from EP-A 1994075 (PA 6T/6I/MXD6).

The processes described in EP-A 129195 and EP-A 129196 can be used to prepare the preferred semiaromatic copolyamides with low triamine content.

The following list, which is not comprehensive, comprises polyamides A) mentioned above and other polyamides A) useful for the purposes of the present invention, and the monomers comprised:

AB polymers:

PA 4 Pyrrolidone

PA 6 e-Caprolactam

PA 7 Ethanolactam

PA 8 Caprylolactam

PA 9 9-Aminopelargonic acid

PA 11 11 -Aminoundecanoic acid PA 12 Laurolactam

AA/BB polymers:

PA 46 Tetramethylenediamine, adipic acid

PA 66 Hexamethylenediamine, adipic acid

PA 69 Hexamethylenediamine, azelaic acid

PA 610 Hexamethylenediamine, sebacic acid

PA 612 Hexamethylenediamine, decanedicarboxylic acid

PA 613 Hexamethylenediamine, undecanedicarboxylic acid

PA 1212 1 ,12-Dodecanediamine, decanedicarboxylic acid

PA 1313 1 ,13-Diaminotridecane, undecanedicarboxylic acid

PA 6T Hexamethylenediamine, terephthalic acid

PA MXD6 m-Xylylenediamine, adipic acid

AA/BB polymers:

Hexamethylenediamine, isophthalic acid

Trimethylhexamethylenediamine, terephthalic acid

(see below)

(see PA 6 and PA 6T)

(see PA 6 and PA 66)

(see PA 6 and PA 12)

(see PA 66, PA 6 and PA 610)

(see PA 6I and PA 6T)

Diaminodicyclohexylmethane, laurolactam as PA 6I/6T + diaminodicyclohexylmethane

Laurolactam, dimethyldiaminodicyclohexylmethane, isophthalic acid Laurolactam, dimethyldiaminodicyclohexylmethane, terephthalic acid Phenylenediamine, terephthalic acid

Preferred polyamides A) are PA 6, PA 66, PA 46, PA 6/66, PA 66/6, PA 6/636, PA 6T/6, PA 6T/6I, PA 6T/6I/66, PA 9T, PA 6T/66 or mixtures thereof.

Most preferred are PA 6, PA 66, PA 6/66 and PA 66/6 as well as PA 6/636, or mixtures thereof.

Most preferred are PA 6, PA 66 or mixtures thereof.

Suitable copolyamides are constructed from:

A1 ) 20.0 to 90.0 wt% of units derived from terephthalic acid and hexamethylene diamine,

A2) 0 to 50.0 wt% of units derived from e-caprolactam,

A3) 0 to 80.0 wt% of units derived form adipic acid and hexamethylene diamine,

A4) 0 to 40.0 wt% of further polyamide-forming monomers, wherein the proportion of component A2) or A3) or A4), or mixtures thereof is at least 10.0 wt%. Component A1) comprises 20.0 to 90.0 wt% of units derived from terephthalic acid and hexamethylene diamine.

In addition to the units derived from terephthalic acid and hexamethylene diamine, the copolyamides optionally comprise units derived from e-caprolactam and/or units derived from adipic acid and hexamethylene diamine and/or units derived from further polyamide-forming monomers.

Aromatic dicarboxylic acids A4) comprise 8 to 16 carbon atoms. Suitable aromatic dicarboxylic acids include for example isophthalic acid, substituted terephthalic and isophthalic acids, such as 3t-butylisophthalic acid, polycyclic dicarboxylic acids, for example 4,4’- and 3,3’-diphenyldi- carboxylic acid, 4,4’- and 3,3’-diphenylmethanedicarboxylic acid, 4,4’- and 3,3’-sulphodiphenyl- carboxylic acid, 1 ,4- or 2,6-naphthalenedicarboxylic acid, phenoxyterephthalic acid, whereby isophthalic acid is particularly preferred.

Further, polyamide-forming monomers A4) may be derived from dicarboxylic acids having 4 to 16 carbon atoms and aliphatic or cycloaliphatic diamines having 4 to 16 carbon atoms, and also from aminocarboxylic acids/corresponding lactams having 7 to 12 carbon atoms. Examples of suitable monomers of these types are suberic acid, azelaic acid and sebacic acid as representatives of aliphatic dicarboxylic acids, 1 ,4-butanediamine, 1 ,5-pentandiamine, piperazine, 4,4’- diaminodicyclohexylmethane, 2,2-(4,4’-diaminodicyclohexylpropane) and 3,3’-dimethyl-4,4’-dia- minodicyclohexylmethane or meta-xylylenediamine as representatives of diamines and caprolactam, enantholactam, uj-aminoundecanoic acid and laurolactam as representatives of lac- tams/aminocarboxylic acids.

Examples for such copolyamides are more particularly elucidated in DE-A 102009 011668.

As component A) the thermoplastic moulding materials can comprise at least one copolyamide produced by polymerization of the components

A’) 15% to 84% by weight of at least one lactam,

B’) 16% to 85% by weight of a monomer mixture (M) comprising the components

B1 ’) at least one C32-C4o-dimer acid and

B2’) at least one C4-Ci2-diamine, wherein the percentages by weight of the components A’) and B’) are in each case based on the sum of the percentages by weight of the components A’) and B’).

In the context of the present invention the terms "component A’)" and "at least one lactam" are used synonymously and therefore have the same meaning.

The same applies for the terms "component B’)" and "monomer mixture (M)". These terms are likewise used synonymously in the context of the present invention and therefore have the same meaning. According to the invention the at least one copolyamide is produced by polymerization of 15% to 84% by weight of the component A') and 16% to 85% by weight of the component B'), preferably by polymerization of 40% to 83% by weight of the component A') and 17% to 60% by weight of the component B') and especially preferably by polymerization of 60% to 80% by weight of the component A) and 20% to 40% by weight of the component B'), wherein the percentages by weight of the components A') and B') are in each based on the sum of the percentages by weight of the components A') and B').

The sum of the percentages by weight of the components A') and B') is preferably 100% by weight.

It will be appreciated that the weight percentages of the components A') and B') relate to the weight percentages of the components A') and B') prior to the polymerization, i.e. when the components A') and B') have not yet reacted with one another. During the polymerization of the components A') and B') the weight ratio of the components A') and B') may optionally change.

According to the invention the at least one copolyamide is produced by polymerization of the components A') and B'). The polymerization of the components A') and B') is known to those skilled in the art. The polymerization of the components A') with B') is typically a condensation reaction. During the condensation reaction the component A') reacts with the components B1') and B2') present in the component B') and optionally with the component B3') described hereinbelow which may likewise be present in the component B'). This causes amide bonds to form between the individual components. During the polymerization the component A') is typically at least partially in open chain form, i.e. in the form of an amino acid.

The polymerization of the components A') and B') may take place in the presence of a catalyst. Suitable catalysts include all catalysts known to those skilled in the art which catalyze the polymerization of the components A') and B'). Such catalysts are known to those skilled in the art. Preferred catalysts are phosphorus compounds, for example sodium hypophosphite, phosphorous acid, triphenylphosphine or triphenyl phosphite.

The polymerization of the components A') and B') forms the at least one copolyamide which therefore comprises units derived from the component A') and units derived from the component B'). Units derived from the component B') comprise units derived from the components B1') and B2') and optionally from the component B3').

The polymerization of the components A') and B') forms the copolyamide as a copolymer. The copolymer may be a random copolymer. It may likewise be a block copolymer.

Formed in a block copolymer are blocks of units derived from the component B') and blocks of units derived from the component A'). These appear in alternating sequence. In a random copolymer units derived from the component A') alternate with units derived from the component B'). This alternation is random. For example two units derived from the component B') may be followed by one unit derived from the component A') which is followed in turn by a unit derived from the component B') and then by a unit comprising three units derived from the component A')-

It is preferable when the at least one copolyamide is a random copolymer.

Production of the at least one copolyamide preferably comprises steps of:

I) polymerizing the components A') and B') to obtain at least a first copolyamide,

II) pelletizing the at least one first copolyamide obtained in step I) to obtain at least one pelletized copolyamide,

III) extracting the at least one pelletized copolyamide obtained in step II) with water to obtain at least one extracted copolyamide,

IV) drying the at least one extracted copolyamide obtained in step III) at a temperature (TT) to obtain the at least one copolyamide,

The polymerization in step I) may be carried out in any reactor known to those skilled in the art. Preference is given to stirred tank reactors. It is also possible to use auxiliaries known to those skilled in the art, for example defoamers such as polydimethylsiloxane (PDMS), to improve reaction management.

In step II) the at least one first copolyamide obtained in step I) may be pelletized by any methods known to those skilled in the art, for example by strand pelletization or underwater pelletization.

The extraction in step III) may be effected by any methods known to those skilled in the art.

During the extraction in step III) byproducts typically formed during the polymerization of the components A') and B') in step I) are extracted from the at least one pelletized copolyamide.

In step IV) the at least one extracted copolyamide obtained in step III) is dried. Processes for drying are known to those skilled in the art. According to the invention the at least one extracted copolyamide is dried at a temperature (TT). The temperature (TT) is preferably above the glass transition temperature (TG<O) of the at least one copolyamide and below the melting temperature (TM(C>) of the at least one copolyamide.

The drying in step IV) is typically carried out for a period in the range from 1 to 100 hours, preferably in the range from 2 to 50 hours and especially preferably in the range from 3 to 40 hours. It is thought that the drying in step IV) further increases the molecular weight of the at least one copolyamide.

The at least one copolyamide typically has a glass transition temperature (TG<O). The glass transition temperature (TG<O) is for example in the range from 20 °C to 50 °C, preferably in the range from 23 °C to 47 °C and especially preferably in the range from 25 °C to 45 °C determined according to ISO 11357-2:2014.

In the context of the present invention the glass transition temperature (TG<O) of the at least one copolyamide is based, in accordance with ISO 11357-2:2014, on the glass transition temperature (TG<O) of the dry copolyamide.

In the context of the present invention “dry” is to be understood as meaning that the at least one copolyamide comprises less than 1 % by weight, preferably less than 0.5% by weight and especially preferably less than 0.1 % by weight of water based on the total weight of the at least one copolyamide. “Dry" is more preferably to be understood as meaning that the at least one copolyamide comprises no water and most preferably that the at least one copolyamide comprises no solvent.

In addition, the at least one copolyamide typically has a melting temperature (TM<O). The melting temperature (TM<O) of the at least one copolyamide is, for example, in the range from 150 to 210 °C, preferably in the range from 160 to 205 °C and especially preferably in the range from 160 to 200 °C determined according to ISO 11357-3:2014.

The at least one copolyamide generally has a viscosity number (VN(c>) in the range from 150 to 300 ml/g determined in a 0.5% by weight solution of the at least one copolyamide in a mixture of phenol/o-dichlorobenzene in a weight ratio of 1 : 1 .

It is preferable when the viscosity number (VN(c>) of the at least one copolyamide is in the range from 160 to 290 mL/g and particularly preferably in the range from 170 to 280 mL/g determined in a 0.5% by weight solution of the at least one copolyamide in a mixture of phenol/o-dichloro- benzene in a weight ratio of 1 : 1 .

Component A’)

According to the invention the component A’) is at least one lactam.

In the context of the present invention "at least one lactam” is understood as meaning either precisely one lactam or a mixture of 2 or more lactams.

Lactams are known per se to those skilled in the art. Preferred according to the invention are lactams having 4 to 12 carbon atoms. In the context of the present invention "lactams" are to be understood as meaning cyclic amides having preferably 4 to 12 carbon atoms, particularly preferably 5 to 8 carbon atoms, in the ring.

Suitable lactams are for example selected from the group consisting of 3-aminopropanolactam (propio-3-lactam; p-lactam; p-propiolactam), 4-aminobutanolactam (butyro-4-lactam; y-lactam; y-butyrolactam), aminopentanolactam (2-piperidinone; 6-lactam; 6-valerolactam), 6-aminohexa- nolactam (hexano-6-lactam; e-lactam; e-caprolactam), 7-aminoheptanolactam (heptano-7-lac- tam; ^-lactam; ^-heptanolactam), 8-aminooctanolactam (octano-8-lactam; r]-lactam; q-octanolac- tam), 9-aminononanolactam (nonano-9-lactam; 0-lactam; 0-nonanolactam), 10-aminodecano- lactam (decano-10-lactam; uj-decanolactam), 11-aminoundecanolactam (undecano-11 -lactam; uj-undecanolactam) and 12-aminododecanolactam (dodecano-12-lactam; uj-dodecanolactam).

The present invention therefore also provides a process where the component A’) is selected from the group consisting of 3-aminopropanolactam, 4-aminobutanolactam, 5-aminopentanolac- tam, 6-aminohexanolactam, 7-aminoheptanolactam, 8-aminooctanolactam, 9-aminononanolac- tam, 10-aminodecanolactam, 11-aminoundecanolactam and 12-aminododecanolactam.

The lactams may be unsubstituted or at least monosubstituted. If at least monosubstituted lactams are used, the nitrogen atom and/or the ring carbon atoms thereof may bear one, two, or more substituents selected independently of one another from the group consisting of Ci- to Cw-alkyl, Cs- to Ce-cycloalkyl, and C5- to Cw-aryl.

Suitable Ci- to Cw-alkyl substituents are, for example, methyl, ethyl, propyl, isopropyl, n-butyl, sec-butyl, and tert-butyl. A suitable C5- to Ce-cycloalkyl substituent is for example cyclohexyl. Preferred C5- to Cw-aryl substituents are phenyl or anthranyl.

It is preferable to employ unsubstituted lactams, y-lactam (y-butyrolactam), 6-lactam (6- valerolactam) and e-lactam (e-caprolactam) being preferred. Particular preference is given to 6- lactam (6-valerolactam) and e-lactam (e-caprolactam), e-caprolactam being especially preferred.

Monomer mixture (M)

According to the invention the component B’) is a monomer mixture (M). The monomer mixture (M) comprises the components B1'), at least one C32-C4o-dimer acid, and B2'), at least one C4- Cw-diamine.

In the context of the present invention a monomer mixture (M) is to be understood as meaning a mixture of two or more monomers, wherein at least components BT) and B2’) are present in the monomer mixture (M).

In the context of the present invention the terms "component B1 ’)" and "at least one C32-C4o-di- mer acid" are used synonymously and therefore have the same meaning. The same applies for the terms "component B2’)" and "at least one C4-Ci2-diamine". These terms are likewise used synonymously in the context of the present invention and therefore have the same meaning.

The monomer mixture (M) comprises, for example, in the range from 45 to 55 mol% of the component BT) and in the range from 45 to 55 mol% of the component B2’) in each case based on the sum of the mole percentages of the components BT) and B2’), preferably based on the total amount of substance of the monomer mixture (M).

It is preferable when the component B’) comprises in the range from 47 to 53 mol% of component BT) and in the range from 47 to 53 mol% of component B2’) in each case based on the sum of the mole percentages of the components BT) and B2’), preferably based on the total amount of substance of the component B’).

It is particularly preferable when the component B’) comprises in the range from 49 to 51 mol% of the component BT) and in the range from 49 to 51 mol% of the component B2’) in each case based on the sum total of the mole percentages of the components BT) and B2'), preferably based on the total amount of substance of the component B’).

The mole percentages of the components BT) and B2’) present in the component B’) typically sum to 100 mol%.

The component B’) may additionally comprise a component B3’), at least one C4-C2o-diacid.

In the context of the present invention, the terms "component B3’)" and "at least one C4-C2o-di- acid" are used synonymously and therefore have the same meaning.

When the component B’) additionally comprises the component B3’) it is preferable when component B’) comprises in the range from 25 to 54.9 mol% of the component B1 ’), in the range from 45 to 55 mol% of the component B2’) and in the range from 0.1 to 25 mol% of the component B3’) in each case based on the total amount of substance of the component B’).

It is particularly preferable when the component B’) then comprises in the range from 13 to 52.9 mol% of the component BT), in the range from 47 to 53 mol% of the component B2’) and in the range from 0.1 to 13 mol% of the component B3’) in each case based on the total amount of substance of the component B’).

It is most preferable when the component B’) then comprises in the range from 7 to 50.9 mol% of the component BT), in the range from 49 to 51 mol% of the component B2’) and in the range from 0.1 to 7 mol% of the component B3’) in each case based on the total amount of substance of the component B’).

When component B’) additionally comprises the component B3’) the mole percentages of the components BT), B2') and B3') typically sum to 100 mol%. The monomer mixture (M) may further comprise water.

The components BT) and B2') and optionally B3') of the component B’) can react with one another to obtain amides. This reaction is known per se to those skilled in the art. The component B’) may therefore comprise components BT), B2’) and optionally B3’) in fully reacted form, in partially reacted form or in unreacted form. It is preferable when the component B’) comprises the components BT), B2’) and optionally B3’) in unreacted form.

In the context of the present invention "in unreacted form” is thus to be understood as meaning that the component B1 ’) is present as the at least one C32-C4o-dimer acid and the component B2’) is present as the at least one C4-Ci2-diamine and optionally the component B3’) is present as the at least one C4-C2o-diacid.

If the components BT) and B2’) and optionally B3’) have at least partly reacted the components BT) and B2’) and any B3’) are thus at least partially in amide form.

Component BT)

According to the invention the component BT) is at least one C32-C4o-dimer acid.

In the context of the present invention "at least one C32-C4o-dimer acid" is to be understood as meaning either precisely one C32-C4o-dimer acid or a mixture of two or more C32-C4o-dimer acids.

Dimer acids are also referred to as dimer fatty acids. C32-C4o-dimer acids are known per se to those skilled in the art and are typically produced by dimerization of unsaturated fatty acids. This dimerization may be catalyzed by argillaceous earths for example.

Suitable unsaturated fatty acids for producing the at least one C32-C4o-dimer acid are known to those skilled in the art and are for example unsaturated Ci6-fatty acids, unsaturated Cis-fatty acids and unsaturated C2o-fatty acids.

It is therefore preferable when the component BT) is produced from unsaturated fatty acids selected from the group consisting of unsaturated C -fatty acids, unsaturated C -fatty acids and unsaturated C2o-fatty acids, wherein the unsaturated C -fatty acids are particularly preferred.

A suitable unsaturated Cw-fatty acid is palmitoleic acid ((9Z)-hexadeca-9-enoic acid) for example.

Suitable unsaturated Cw-fatty acids are for example selected from the group consisting of pe- troselic acid ((6Z)-octadeca-6-enoic acid), oleic acid ((9Z)-octadeca-9-enoic acid), elaidic acid ((9E)-octadeca-9-enoic acid), vaccenic acid ((11 E)-octadeca-11-enoic acid), linoleic acid ((9Z,12Z)-octadeca-9,12-dienoic acid), a-linolenic acid ((9Z,12Z,15Z)-octadeca-9,12,15-trienoic acid), y-linolenic acid ((6Z,9Z,12Z)-octadeca-6,9,12-trienoic acid), calendulic acid ((8E,10E,12Z)-octadeca-8,10,12-trienoic acid), punicic acid ((9Z,11 E,13Z)-octadeca-9,11 ,13- trienoic acid), a-eleostearic acid ((9Z,11 E,13E)-octadeca-9,11 ,13-trienoic acid) and p-eleos- tearic acid ((9E,11 E,13E)-octadeca-9,11 , 13-trienoic acid). Particular preference is given to unsaturated C -fatty acids selected from the group consisting of petroselic acid ((6Z)-octadeca-6- enoic acid), oleic acid ((9Z)-octadeca-9-enoic acid), elaidic acid ((9E)-octadeca-9-enoic acid), vaccenic acid ((11 E)-octadeca-11-enoic acid), linoleic acid ((9Z,12Z)-octadeca-9,12-dienoic acid).

Suitable unsaturated C2o-fatty acids are for example selected from the group consisting of gado- leic acid ((9Z)-eicosa-9-enoic acid), ecosenoic acid ((11Z)-eicosa-11-enoic acid), arachidonic acid ((5Z,8Z,11Z,14Z)-eicosa-5,8,11 ,14-tetraenoic acid) and timnodonic acid ((5Z,8Z,11Z, 14Z,17Z)-eicosa-5, 8,11 ,14, 17-pentaenoic acid).

The component BT) is especially preferably at least one Cse-dimer acid.

The at least one Cse-dimer acid is preferably produced from unsaturated C -fatty acids. It is particularly preferable when the Cse-dimer acid is produced from

C -fatty acids selected from the group consisting of petroselic acid ((6Z)-octadeca-6-enoic acid), oleic acid ((9Z)-octadeca-9-enoic acid), elaidic acid ((9E)-octadeca-9-enoic acid), vaccenic acid ((11 E)-octadeca-11-enoic acid) and linoleic acid ((9Z,12Z)-octadeca-9,12-dienoic acid).

Production of the component B1') from unsaturated fatty acids may also form trimer acids and residues of unconverted unsaturated fatty acid may also remain.

The formation of trimer acids is known to those skilled in the art.

According to the invention the component BT) preferably comprises not more than 0.5% by weight of unreacted unsaturated fatty acid and not more than 0.5% by weight of trimer acid, particularly preferably not more than 0.2% by weight of unreacted unsaturated fatty acid and not more than 0.2% by weight of trimer acid, in each case based on the total weight of component BT).

Dimer acids (also known as dimerized fatty acids or dimer fatty acids) are thus to be understood as meaning generally, and especially in the context of the present invention, mixtures produced by oligomerization of unsaturated fatty acids. They are producible for example by catalytic dimerization of plant-derived unsaturated fatty acids, wherein the starting materials employed are in particular unsaturated Ci6- to C2o-fatty acids. The bonding proceeds primarily by the Diels-Alder mechanism, and results, depending on the number and position of the double bonds in the fatty acids used to produce the dimer acids, in mixtures of primarily dimeric products having cy- cloaliphatic, linear aliphatic, branched aliphatic, and also Ce-aromatic hydrocarbon groups between the carboxyl groups. Depending on the mechanism and/or any subsequent hydrogenation, the aliphatic radicals may be saturated or unsaturated and the proportion of aromatic groups may also vary. The radicals between the carboxylic acid groups then comprise 32 to 40 carbon atoms for example. Production preferably employs fatty acids having 18 carbon atoms so that the dimeric product thus has 36 carbon atoms. The radicals which join the carboxyl groups of the dimer fatty acids preferably comprise no unsaturated bonds and no aromatic hydrocarbon radicals.

In the context of the present invention production thus preferably employs C -fatty acids. It is particularly preferable to employ linolenic, linoleic and/or oleic acid.

Depending on reaction management the above described oligomerization affords mixtures which comprise primarily dimeric, but also trimeric, molecules and also monomeric molecules and other by-products. Purification by distillation is customary. Commercial dimer acids generally comprise at least 80% by weight of dimeric molecules, up to 19% by weight of trimeric molecules, and at most 1 % by weight of monomeric molecules and of other by-products.

It is preferable to use dimer acids that consist to an extent of at least 90% by weight, preferably to an extent of at least 95% by weight, very particularly preferably to an extent of at least 98% by weight, of dimeric fatty acid molecules.

The proportions of monomeric, dimeric, and trimeric molecules and of other by-products in the dimer acids may be determined by gas chromatography (GC), for example. The dimer acids are converted to the corresponding methyl esters by the boron trifluoride method (cf. DIN EN ISO 5509) before GC analysis and then analyzed by GC.

In the context of the present invention it is thus a fundamental feature of “dimer acids” that production thereof comprises oligomerization of unsaturated fatty acids. This oligomerization forms predominantly, i.e. preferably to an extent of at least 80% by weight, particularly preferably at least 90% by weight, very particularly preferably at least 95% by weight and in particular at least 98% by weight, dimeric products. The fact that the oligomerization thus forms predominantly dimeric products comprising precisely two fatty acid molecules justifies this designation which is in any case commonplace. An alternative expression for the relevant term “dimer acids” is thus “mixture comprising dimerized fatty acids”.

The dimer acids to be used are obtainable as commercial products. Examples include Radiacid 0970, Radiacid 0971 , Radiacid 0972, Radiacid 0975, Radiacid 0976, and Radiacid 0977 from Oleon, Pripol 1006, Pripol 1009, Pripol 1012, and Pripol 1013 from Croda, Empol 1008, Empol 1012, Empol 1061 , and Empol 1062 from BASF SE, and Unidyme 10 and Unidyme Tl from Arizona Chemical.

The component B1') has an acid number in the range from 190 to 200 mg KOH/g for example. Component B2')

According to the invention the component B2') is at least one C4-Ci2-diamine.

In the context of the present invention "at least one C4-Ci2-diamine" is to be understood as meaning either precisely one C4-Ci2-diamine or a mixture of two or more C4-Ci2-diamines.

In the context of the present compound, "C4-Ci2-diamine" is to be understood as meaning aliphatic and/or aromatic compounds having four to twelve carbon atoms and two amino groups (- NH2 groups). The aliphatic and/or aromatic compounds may be unsubstituted or additionally at least monosubstituted. If the aliphatic and/or aromatic compounds are additionally at least monosubstituted, they may bear one, two or more substituents that do not take part in the polymerization of the components A’) and B’). Such substituents are for example alkyl or cycloalkyl substituents. These are known per se to those skilled in the art. The at least one C4-C12- diamine is preferably unsubstituted.

Suitable components B2’) are for example selected from the group consisting of 1 ,4-diaminobu- tane (butane-1 ,4-diamine; tetramethylenediamine; putrescine), 1 ,5-diaminopentane (pentamethylenediamine; pentane-1 ,5-diamine; cadaverine), 1 ,6-diaminohexane (hexamethylenediamine; hexane-1 ,6-diamine), 1 ,7-diaminoheptane, 1 ,8-diaminooctane, 1 ,9-diaminononane, 1 ,10-dia- minodecane (decamethylenediamine), 1 ,11 -diaminoundecane (undecamethylenediamine) and 1 ,12-diaminododecane (dodecamethylenediamine).

It is preferable when the component B2’) is selected from the group consisting of tetramethylenediamine, pentamethylenediamine, hexamethylenediamine, decamethylenediamine and dodecamethylenediamine.

Component B3')

According to the invention the component B3’) optionally present in the component B’) is at least one C4-C2o-diacid.

In the context of the present invention, "at least one C4-C2o-diacid" is to be understood as meaning either precisely one C4-C2o-diacid or a mixture of two or more C4-C2o-diacids.

In the context of the present invention "C4-C2o-diacid" is to be understood as meaning aliphatic and/or aromatic compounds having two to eighteen carbon atoms and two carboxyl groups (- COOH groups). The aliphatic and/or aromatic compounds may be unsubstituted or additionally at least monosubstituted. If the aliphatic and/or aromatic compounds are additionally at least monosubstituted, they may bear one, two or more substituents that do not take part in the polymerization of components A’) and B’). Such substituents are for example alkyl or cycloalkyl substituents. These are known to those skilled in the art. Preferably, the at least one C4-C2o-di- acid is unsubstituted.

Suitable components B3’) are for example selected from the group consisting of butanedioic acid (succinic acid), pentanedioic acid (glutaric acid), hexanedioic acid (adipic acid), heptanedioic acid (pimelic acid), octanedioic acid (suberic acid), nonanedioic acid (azelaic acid), decanedioic acid (sebacic acid), undecanedioic acid, dodecanedioic acid, tridecanedioic acid, tetradecanedioic acid and hexadecanedioic acid.

It is preferable when the component B3’) is selected from the group consisting of pentanedioic acid (glutaric acid), hexanedioic acid (adipic acid), decanedioic acid (sebacic acid) and dodecanedioic acid.

Most preferably, component A) is selected from the group consisting of PA 6, PA 66, PA 46, PA 6/66, PA 66/6, PA 6/6.36, PA610, PA 6T/6, PA 6T/6I, PA 6T/6I/66, PA 9T and PA 6T/66, more preferably from PA 6, PA 6.6, PA 66/6, PA 6/6.6 and mixtures thereof, and most preferably PA 6 and PA 66 and mixtures thereof.

Component B)

As component B), the thermoplastic moulding composition contains from 0.1 to 60% by weight, preferably 0.5 to 40% by weight, more preferably 1 to 15% by weight, based on the total amount of components A), B), C), optionally D), optionally E) and optionally F) of red phosphorous.

Preferred as component B) is elemental red phosphorus.

The red phosphorous is preferably used in untreated form, especially in combination with glass fiber-reinforced molding compositions.

However, the phosphorus may be surface-treated, for example with “phlegmatizing agents” like low-molecular-weight liquid substances, such as silicone oil, paraffin oil, or esters of phthalic acid (in particular dioctyl phthalate, see EP 176 836) or adipic acid, or with polymeric or oligomeric compounds, e.g. with phenolic resins or aminoplastics, or else with polyurethanes (see EP-A 384 232, DE-A 196 48 503). Amounts comprised of the these “phlegmatizing agents” are generally from 0.05 to 5% by weight, based on 100% by weight of B).

Concentrates (masterbatches) of red phosphorus are also suitable as flame retardant, e.g. in a polyamide or elastomer. Also in said masterbatches the red phosphorous is preferably used in untreated form. Particularly suitable concentrate polymers are polyolefin homopolymers and polyolefin copolymers. However, the proportion of the concentrate polymer - if no polyamide is used as thermoplastic - should not exceed 35% by weight, based on the weight of components A) and B) in the moulding compositions of the invention. Preferred concentrate compositions comprise

B1 ) from 30 to 90% by weight, preferably from 45 to 70% by weight, of a polyamide or elastomer, and

B2) from 10 to 70% by weight, preferably from 30 to 55% by weight, of red phosphorus.

Suitable elastomers B1 ) are the elastomers mentioned as component D) below, e.g. polyolefin homopolymers and polyolefin copolymers which may be grafted for example with maleic anhydride.

Suitable polyamides B1 ) are mentioned above (see component A)). The polyamide B1 ) used for the concentrate (masterbatch) can differ from component A) or can preferably be identical with component A), in order that no adverse effect on the molding composition results from any incompatibility or melting-point differences.

The average particle size (d50) of the phosphorus particles dispersed in the molding compositions is preferably in the range from 0.0001 to 0.5 mm; in particular from 0.001 to 0.2 mm, determined by laser diffraction according to ISO 13320:2009.

Component C)

As component C), the thermoplastic moulding composition contains from 0.05 to 20% by weight, preferably from 0.07 to 5% by weight, more preferably from 0.1 to 3% by weight, and most preferably from 0.5 to 2% by weight based on the total amount of components A), B), C), optionally D), optionally E) and optionally F), of at least one mixed metal oxide comprising Cu and Cr in form of their oxides.

The mixed metal oxide comprising Cu and Cr in form of their oxides according to the present invention can comprise - in addition to Cu and Cr - further metals, generally in form of their oxides, like Mn, Fe, Al and/or Co.

Preferably, component C) comprises c1 ) from 15 to 25, preferably 17 to 22 parts by weight of Cu; c2) from 20 to 40, preferably 25 to 38 parts by weight of Cr; c3) from 0.5 to 15, preferably 5 to 13 parts by weight of Fe; c4) from 0 to 20 parts by weight of Mn, Al and/or Co; wherein components c1), c2), c3) and optionally c4) are present in form of their oxides and the amounts of components c1 ), c2), c3) and optionally c4) are calculated on the respective metals.

More preferably component C) is present in form of a spinel structure, preferably of the general formula CuCr2O4, most preferably, component C) is copper chromite. The copper chromite may comprise further metals, generally in form of their oxides, like Mn, Fe, Al and/or Co, as mentioned above. Component C) preferably has a BET surface area of 1 to 200 m²/g, preferably 1 .5 to 100 m²/g, more preferably 10 to 80 m²/g according to ISO 9277:2010, under nitrogen (BET method).

Component C) has a mean primary particle diameter of 0.05 to 200 pm, preferably 0.1 to 50 pm, more preferably 0.5 to 25 pm, determined by dynamic light scattering according to ISO22412:2017.

A suitable component C) is commercially available, for example as Pigment Black 28 (C.L 77428), e.g. from The Shepherd Color company.

Component D)

As component D), the thermoplastic moulding composition contains from 0 to 40% by weight, preferably from 1 to 30% by weight, and more preferably from 2 to 20% by weight, based on the total amount of components A), B), C), optionally D), optionally E) and optionally F), of at least one impact modifier.

The “impact modifier” is often also termed elastomeric polymer, elastomer, or rubber.

If component D) is present, the maximum amount of component A) is decreased by the minimum amount of component D), so that the total amount of components A) to F) is still 100 wt%.

These are very generally copolymers for example composed of at least two of the following monomers: ethylene C3-i2-olefins, carboxylic esters like Ci-is-alkyl (meth)acrylates, carboxylic acids like (meth)acrylic acid, carboxylic acid anhydrides like maleic anhydride, chloroprene, vinyl acetate, styrene, acrylonitrile, carboxamides, carboximides, amino group comprising compounds, hydroxy group comprising compounds, epoxy group comprising compounds.

Polymers of this type are described, for example, in Houben-Weyl, Methoden der organischen Chemie, Vol. 14/1 (Georg-Thieme-Verlag, Stuttgart, Germany, 1961), pages 392-406, and in the monograph by C. B. Bucknall, “Toughened Plastics” (Applied Science Publishers, London, UK, 1977). Some preferred types of such elastomers are described below.

Preferred types of such elastomers are those known as ethylene-propylene (EPM) and etylene- propylene-diene (EPDM) rubbers.

EPM rubbers generally have practically no residual double bonds, whereas EPDM rubbers may have from 1 to 20 double bonds per 100 carbon atoms.

Examples which may be mentioned of diene monomers for EPDM rubbers are conjugated dienes, such as isoprene and butadiene, non-conjugated dienes having from 5 to 25 carbon atoms, such as 1 ,4-pentadiene, 1 ,4-hexadiene, 1 ,5-hexadiene, 2,5-dimethyl-l,5-hexadiene and 1 ,4-octadiene, cyclic dienes, such as cyclopentadiene, cyclohexadienes, cyclooctadienes and dicyclopentadiene, and also alkenylnorbornenes, such as 5-ethylidene-2-norbornene, 5-butyli- dene-2-norbornene, 2-methallyl-5-norbornene and 2-isopropenyl-5-norbornene, and trie clodienes, such as 3-methyltricyclo-[5.2.1 ,02’6]-3,8-decadiene, and mixtures of these. Preference is given to 1 ,5-hexadiene, 5-ethylidenenorbornene and dicyclopentadiene.

The diene content of the EPDM rubbers is preferably from 0.5 to 50% by weight, in particular from 1 to 8% by weight, based on the total weight of the rubber.

EPM rubbers and EPDM rubbers may preferably also have been grafted with reactive carboxylic acids or with derivatives of these. Examples of these are acrylic acid, methacrylic acid and derivatives thereof, e.g. glycidyl (meth)acrylate, and also maleic anhydride.

Copolymers of ethylene with acrylic acid and/or methacrylic acid and/or with the esters of these acids are another group of preferred rubbers. The rubbers may also comprise dicarboxylic aids, such as maleic acid and fumaric acid, or derivatives of these acids, e.g. esters and anhydrides, and/or monomers comprising epoxy groups. These monomers comprising dicarboxylic acid derivatives or comprising epoxy groups are preferably incorporated into the rubber by adding to the monomer mixture monomers comprising dicarboxylic acid groups and/or epoxy groups and having the general formulae I or II or III or IV

(I)

R¹ (COOR²) = C(COOR³)R⁴

(II) where R¹ to R⁹ are hydrogen or alkyl groups having from 1 to 6 carbon atoms, and m is a whole number from 0 to 20, g is a whole number from 0 to 10 and p is a whole number from 0 to 5.

The radicals R¹ to R⁹ are preferably hydrogen, where m is 0 or 1 and g is 1 . The corresponding compounds are maleic acid, fumaric acid, maleic anhydride, allyl glycidyl ether and vinyl glycidyl ether. Preferred compounds of the formulae I, II and IV are maleic acid, maleic anhydride and (meth)acrylates comprising epoxy groups, such as glycidyl acrylate and glycidyl methacrylate, and the esters with tertiary alcohols, such as tert-butyl acrylate. Although the latter have no free carboxy groups, their behavior approximates to that of the free acids and they are therefore termed monomers with latent carboxy groups.

The copolymers are advantageously composed of from 50 to 98% by weight of ethylene, from 0.1 to 20% by weight of monomers comprising epoxy groups and/or methacrylic acid and/or monomers comprising anhydride groups, the remaining amount being (meth)acrylates.

Particular preference is given to copolymers composed of from 50 to 98% by weight, in particular from 55 to 95% by weight, of ethylene, from 0.1 to 40% by weight, in particular from 0.3 to 20% by weight, of glycidyl acrylate and/or glycidyl methacrylate, (meth)acrylic acid and/or maleic anhydride, and from 1 to 45% by weight, in particular from 5 to 40% by weight, of n-butyl acrylate and/or 2- ethylhexyl acrylate.

Other preferred (meth)acrylates are the methyl, ethyl, propyl, isobutyl and tert-butyl esters.

Comonomers which may be used alongside these are vinyl esters and vinyl ethers.

The ethylene copolymers described above may be prepared by processes known per se, preferably by random copolymerization at high pressure and elevated temperature. Appropriate processes are well-known.

Other preferred elastomers are emulsion polymers whose preparation is described, for example, by Blackley in the monograph “Emulsion Polymerization”. The emulsifiers and catalysts which can be used are known per se.

In principle it is possible to use homogeneously structured elastomers or else those with a shell structure. The shell-type structure is determined by the sequence of addition of the individual monomers. The morphology of the polymers is also affected by this sequence of addition.

Monomers which may be mentioned here, merely as examples, for the preparation of the rubber fraction of the elastomers are acrylates, such as n-butyl acrylate and 2-ethylhexyl acrylate, corresponding methacrylates, butadiene and isoprene, and also mixtures of these. These monomers may be copolymerized with other monomers, such as styrene, acrylonitrile, vinyl ethers and with other acrylates or methacrylates, such as methyl methacrylate, methyl acrylate, ethyl acrylate or propyl acrylate.

The soft or rubber phase (with a glass transition temperature of below 0°C) of the elastomers may be the core, the outer envelope or an intermediate shell (in the case of elastomers whose structure has more than two shells). Elastomers having more than one shell may also have more than one shell composed of a rubber phase.

If one or more hard components (with glass transition temperatures above 20°C) are involved, besides the rubber phase, in the structure of the elastomer, these are generally prepared by polymerizing, as principal monomers, styrene, acrylonitrile, methacrylonitrile, a-methylstyrene, p-methylstyrene, or acrylates or methacrylates, such as methyl acrylate, ethyl acrylate or methyl methacrylate. Besides these, it is also possible to use relatively small proportions of other comonomers.

It has proven advantageous in some cases to use emulsion polymers which have reactive groups at their surfaces. Examples of groups of this type are epoxy, carboxy, latent carboxy, amino and amide groups, and also functional groups which may be introduced by concomitant use of monomers of the general formula where the substituents can be defined as follows:

R¹⁰ is hydrogen or a Ci-C4-alkyl group,

R¹¹ is hydrogen, a Ci-Cs-alkyl group or an aryl group, in particular phenyl,

R¹² is hydrogen, a Ci-Cw-alkyl group, a Ce-Ci2-aryl group, or — OR¹³,

R¹³ is a Ci-Cs-alkyl group or a Ce-Ci2-aryl group, which can optionally have substitution by groups that comprise O or by groups that comprise N,

X is a chemical bond, a (Ci-Cw-alkylene group, or a Ce-Ci2-arylene group, or

Y is O-Z or NH-Z, and

Z is a Ci-Cw-alkylene or Ce-Ci2-arylene group.

The graft monomers described in EP-A 208 187 are also suitable for introducing reactive groups at the surface.

Other examples which may be mentioned are acrylamide, methacrylamide and substituted acrylates or methacrylates, such as (N-tert-butylamino)ethyl methacrylate, (N,N-dimethylamino)ethyl acrylate, (N,N-dimethylamino) methyl acrylate and (N,N-diethylamino)ethyl acrylate. The particles of the rubber phase may also have been crosslinked. Examples of crosslinking monomers are 1 ,3-butadiene, divinylbenzene, diallyl phthalate and dihydrodicyclopentadienyl acrylate, and also the compounds described in EP-A 50 265.

It is also possible to use the monomers known as graft-linking monomers, i.e. monomers having two or more polymerizable double bonds which react at different rates during the polymerization. Preference is given to the use of compounds of this type in which at least one reactive group polymerizes at about the same rate as the other monomers, while the other reactive group (or reactive groups), for example, polymerize(s) significantly more slowly. The different polymerization rates give rise to a certain proportion of unsaturated double bonds in the rubber. If another phase is then grafted onto a rubber of this type, at least some of the double bonds present in the rubber react with the graft monomers to form chemical bonds, i.e. the phase grafted on has at least some degree of chemical bonding to the graft base.

Examples of graft-linking monomers of this type are monomers comprising allyl groups, in particular allyl esters of ethylenically unsaturated carboxylic acids, for example allyl acrylate, allyl methacrylate, diallyl maleate, diallyl fumarate and diallyl itaconate, and the corresponding monoallyl compounds of these dicarboxylic acids. Besides these there is a wide variety of other suitable graft-linking monomers. For further details reference may be made here, for example, to U.S. Pat. No. 4,148,846.

The proportion of these crosslinking monomers in the impact-modifying polymer is generally up to 5% by weight, preferably not more than 3% by weight, based on the impact-modifying polymer.

Some preferred emulsion polymers are listed below. Mention may first be made here of graft polymers with a core and with at least one outer shell, and having the following structure:

Type Monomers for the core Monomers for the envelope

I 1,3-butadiene, isoprene, styrene, acrylonitrile, methyl n-butyl acrylate, methacrylate ethylhexyl acrylate, or a mixture of these

Type Monomers for the core Monomers for the envelope

II as I, but with as I concomitant use of crosslinking agents

III as I or II n-butyl acrylate, ethyl acrylate, methyl acrylate, 1,3-butadiene, isoprene, ethylhexyl acrylate

IV as I or II as I or III, but with concomitant use of monomers having reactive groups, as described herein

V styrene, acrylonitrile, first envelope composed of monomers methyl methacrylate, or as described under I and II for the core, a mixture of these second envelope as described under I or IV for the envelope Instead of graft polymers whose structure has more than one shell, it is also possible to use homogeneous, i.e. single-shell, elastomers composed of 1 ,3-butadiene, isoprene and n-butyl acrylate or of copolymers of these. These products, too, may be prepared by concomitant use of crosslinking monomers or of monomers having reactive groups.

Examples of preferred emulsion polymers are n-butyl acrylate-(meth)acrylic acid copolymers, n- butyl acrylateglycidyl acrylate or n-butyl acrylate-glycidyl methacrylate copolymers, graft polymers with an inner core composed of n-butyl acrylate or based on butadiene and with an outer envelope composed of the abovementioned copolymers, and copolymers of ethylene with comonomers which supply reactive groups.

The elastomers described may also be prepared by other conventional processes, e.g. by suspension polymerization.

Preference is also given to silicone rubbers, as described in DE-A 37 25 576, EP-A235 690, DE-A38 00 603 and EP-A 319 290.

Particularly preferred impact modifiers D) are ethylene copolymers, as described above, which comprise functional monomers.

The proportion of the functional monomers is from 0.1 to 20% by weight, preferably from 0.2 to 10% by weight, and in particular from 0.3 to 3.5% by weight, based on 100% by weight of D).

Particularly preferably, component D) is at least one copolymer composed of i) 80 to 99.9% by weight, preferably 90 to 99.8% by weight, more preferably 96.5 to 99.7% by weight of ethylene, as component i), and ii) 0.1 to 20% by weight, preferably 0.2 to 10% by weight, more preferably 0.3 to 3.5% by weight of at least one functional monomer different from ethylene, as component ii), wherein the sum of components i) and ii) is 100% by weight, wherein the copolymer may also be additionally grafted with maleic anhydride.

The functional monomers are preferably selected from the group consisting of C3-i2-olefins, carboxylic esters like Ci-is-alkyl (meth)acrylates, carboxylic acids like (meth)acrylic acid, carboxylic acid anhydrides like maleic anhydride, chloroprene, vinyl acetate, styrene, acrylonitrile, carboxamides, carboximides, amino group comprising compounds, hydroxy group comprising compounds, epoxy group comprising compounds, and mixtures thereof.

The term “(meth)acryl” means “methacryl or acryl”, e.g. “(meth)acrylic acid” means “methacrylic acid or acrylic acid”. Particularly preferred monomers are composed of an ethylenically unsaturated mono- or dicarboxylic acid or of a functional derivative of this type of acid. In principle any of the primary, secondary, and tertiary Ci-C -alkyl esters of (meth)acrylic acid is suitable, but preference is given to esters having from 1 to 12 carbon atoms, in particular having from 2 to 10 carbon atoms.

Examples of these are methyl, ethyl, propyl, n-butyl, isobutyl, and tert-butyl, 2-ethylhexyl, octyl, and decyl (meth)acrylates. Among these, particular preference is given to n-butyl acrylate and 2-ethylhexyl acrylate.

Instead of the esters or in addition to these, it is also possible that the olefin polymers comprise acid-functional and/or latent acid-functional monomers of ethylenically unsaturated mono- or dicarboxylic acids, or comprise monomers having epoxy groups.

Other examples that may be mentioned of monomers are (meth)acrylic acid, tertiary alkyl esters of said acids, in particular tert-butyl acrylate, and dicarboxylic acids, such as maleic acid and fumaric acid, and derivatives of said acids, and also monoesters of these.

Latent acid-functional monomers are compounds which form free acid groups under the polymerization conditions and, respectively, during incorporation of the olefin polymers into the molding compositions. Examples of these that may be mentioned are anhydrides of dicarboxylic acids having up to 20 carbon atoms, in particular maleic anhydride, and tertiary C2-Ci2-alkyl esters of the abovementioned acids, in particular tert-butyl acrylate and tert-butyl methacrylate.

The acid-functional or latent acid-functional monomers and the monomers comprising epoxy groups are preferably incorporated into the olefin polymers via addition of compounds of the general formulae l-IV to the monomer mixture.

Preferred impact modifiers are ethylene-propylene rubbers, ethylene-propylene-diene-rubbers, ethylene-butyl acrylate copolymers, copolymers of ethylene and/or propylene and maleic anhydride, ethylene-butyl acrylate-acrylic acid-maleic anhydride copolymers and mixtures thereof.

The melt index of ethylene copolymers described above is generally in the range from 1 to 80 g/10 min (measured at 190°C with 2.16 kg load).

The molar mass of said ethylene copolymers is from 10 000 to 500 000 g/mol, preferably from 15 000 to 400 000 g/mol (Mn, determined by means of GPC in 1 ,2,4-trichlorobenzene with PS calibration).

In one particular embodiment, ethylene-a-olefin copolymers are used which have been produced by means of what are known as “single site catalysts”. Further details can be found in U.S. Pat. No. 5,272,236. In this case, the molecular weight distribution of the ethylene-a-olefin copolymers is narrow for polyolefins, being smaller than 4, preferably smaller than 3.5. Further suitable impact modifiers are for example polyethylenes comprising a butyl acrylate comonomer, polyolefin elastomers like ethylene copolymers functionalized with maleic anhydride, ethylene (meth)acrylate copolymers grafted with maleic anhydride, polyolefin elastomers like ethylene copolymers grafted with maleic anhydride, ethylene (meth)acrylate copolymers, triblock copolymers based on styrene and ethylene/butylene grafted with maleic anhydride, and random terpolymers of ethylene, acrylic ester and maleic anhydride.

Examples of suitable commercial elastomers useful as impact modifiers are obtainable for example from Lyondellbasell under the designations Lucalen A2540D and Lucalen A2700M. Lu- calen A2540D is a low density polyethylene comprising a butyl acrylate comonomer. It has a density of 0.923 g/cm³ and a Vicat softening temperature of 85 °C and a melting temperature of 103 °C at a butyl acrylate proportion of 6.5% by weight. Lucalen A2700M is a low density polyethylene likewise comprising a butyl acrylate comonomer. It has a density of 0.924 g/cm³, a Vicat softening temperature of 60 °C and a melting temperature of 95 °C.

The polymer resin Exxelor™ VA 1801 from ExxonMobil is a semicrystalline ethylene copolymer functionalized with maleic anhydride by reactive extrusion and having an intermediate viscosity. The polymer backbone is fully saturated. The density is 0.880 g/cm³ and the proportion of maleic anhydride is typically in the range from 0.5% to 1 .0% by weight. Further suitable polymer resins are Exxelor™ VA 1850 and VA 1803 from ExxonMobil.

The polymer resin Fusabond® A560 from Dow is a chemically modified ethylene acrylate copolymer, Fusabond® N493 from Dow is a maleic anhydride grafted low Tg ethylene copolymer, Fusabond® N416 from Dow is a chemically modified ethylene elastomer and Surlyn® from Dow are ionomers built from ethylene-methacrylic acid copolymers.

The polymer resin Kraton® FG 1901 from Kraton® Corporation is a linear triblock copolymer based on styrene and ethylene/butylene with a polystyrene content of 30%. Kraton® FG 1924 from Kraton® Corporation is a linear triblock copolymer based on styrene and ethylene/butylene with a polystyrene content of 13 wt.%. Kraton® G 1567 from Kraton® Corporation is a linear triblock copolymer based on styrene and ethylene/butylene with a polystyrene content of 13 wt.%.

The polymer resins Lotader® 4503, 4700 and 4720 from Arkema are random terpolymers of ethylene, acrylic ester and maleic anhydride. The Lotader® 3, 5 and 8 series from Arkema are random terpolymers of ethylene, acrylic ester and maleic anhydride.

The polymer resins Tafmer® M series from Mitsui are acid modified a-olefin copolymer grades grafted with polar groups (MA 8510 and MA 9015, MH 7510, 7010, MD 715 and MH 7020, MH 5010, MH 5020, MH 5040). The polymer resin N413® from NINGBO, CHINA is a polyolefin elastomer as resin with maleic ahhydride grafting.

The polymer resin KT-915® from Shenyang Ketong Plastic Co., Ltd is a maleic anhydride grafted polyolefin elastomer.

The polymer resins Fine-Blend® CMG5805 and CMG5805-L from Fine-Blend are polyolefine elastomers grafted with maleic anhydride.

It is also possible, of course, to use mixtures of the types of rubber listed above.

Component E)

As component E), the thermoplastic moulding composition contains from 0 to 60% by weight, preferably from 0 to 50% by weight, based on the total amount of components A), B), C), optionally D), optionally E) and optionally F), of at least one filler, preferably at least one fibrous and/or particulate filler, as component E).

If component E) is present, the maximum amount of component A) is decreased by the minimum amount of component E), so that the total amount of components A) to F) is still 100 wt%.

Preferably, component E) is present in an amount of from 5 to 60 wt%, more preferably 10 to 50 wt%, based on the total amount of components A), B), C), optionally D), optionally E) and optionally F).

It is possible to use mixtures of two or more different fibrous and/or particulate fillers.

Component E) is preferably selected from the group consisting of carbon fibres, glass beads, e.g. solid or hollow glass beads, glass fibres, ground glass, amorphous quartz glass, aluminum borosilicate glass having an alkali content of about 1 % (E glass), amorphous silica, quartz flour, alkaline earth metal silicate, especially calcium silicate, calcium metasilicate, magnesium carbonate, kaolin, calcined kaolin, chalk, kyanite, powdered or milled quartz, mica, phlogopite, barium sulfate, feldspar, wollastonite, montmorillonite, boehmite, bentonite, vermiculite, hectorite, laponite®, pseudoboehmite of formula AIO(OH), magnesium carbonate, talc, aramid fibres, potassium titanate fibres, barium carbonate, alkaline earth metal oxide, metallic fibres, ceramic fibres, titanium dioxide, aluminum oxide, plaster, zirconium oxide, antimony oxide, clay, silica-alu- mina, sericite, diatomite, silica stone, carbon black, glassy hollow microspheres (Shirasu® balloon), red oxide, zinc oxide, and mixtures thereof.

Other fillers which may be mentioned are lamellar or acicular fillers, the amounts of these preferably being from 0.1 to 10% - if present. Materials preferred for this purpose are boehmite, bentonite, montmorillonite, vermiculite, hectorite, and laponite®. The lamellar nanofillers are organically modified by prior art methods, to give them good compatibility with the organic binder. Addition of the lamellar or acicular fillers to the inventive thermoplastic moulding compositions gives a further increase in mechanical strength.

For the purposes of the invention, acicular mineral fillers are mineral fillers with strongly developed acicular character. An example is acicular wollastonite. The mineral preferably has an L/D (length to diameter) ratio of from 8:1 to 35: 1 , preferably from 8: 1 to 11 : 1 . The mineral filler may optionally have been pretreated with the abovementioned silane compounds, but the pretreatment is not essential.

Preferred fibrous or particulate fillers E) are glass fibres. The glass fibres are generally chopped fibres, also called short fibres, having a length in the range from 0.1 to 1 mm, long fibres having a length in the range from 1 to 50 mm, and continuous fibres having a length l>50 mm. Continuous fibres are used in the form of rovings or fabric in fibre-reinforced plastics.

Also available are ground glass fibres, the length of which after grinding is typically in the range from 70 to 200 pm.

Particular preference being given to glass fibres in the form of rovings or in the forms of chopped glass as described above.

More preferred glass fibres to be used as component E) are chopped long glass fibres having an average starting length to be determined by laser diffraction-particle size analysis (laser granulometry/laser diffractometry) according to ISO 13320:2009 in the range from 1 to 50 mm, more preferably in the range from 1 to 10 mm, most preferably in the range from 2 to 7 mm. Most preferred glass fibres for use as component E) have an average fibre diameter to be determined by laser diffractometry according to ISO 13320:2009 in the range from 7 to 18 pm, more preferably in the range from 9 to 15 pm.

In a preferred embodiment, the glass fibres for use with preference as component E) are modified with a suitable size system or an adhesion promoter/adhesion promoter system. Preference is given to using a size system or an adhesion promoter based on silane, to improve compatibility with the thermoplastic.

Suitable silane compounds have the general formula (II):

(X— (C H 2)n)k^— S i— (O— Cm H 2m+ 1 )4-k

CH₂ — CH CH₂ — CH— CH₂— O —

O O

X is -NH2, HO-, carboxyl, or n is an integer from 2 to 10, preferably 3 to 4, m is an integer number from 1 to 5, preferably 1 to 2, and k is an integer from 1 to 3, preferably 1 . Preferred silane compounds are aminopropyltrimethoxysilane, aminobutyltrimethoxysilane, aminopropyltriethoxysilane and aminobutyltriethoxysilane, and also the corresponding silanes which comprise a glycidyl group or a carboxyl group as substituent X.

For the modification of the glass fibres for use with preference as component E), the adhesion promoter, preferably the silane compounds of formula (II), is used preferably in amounts of 0.01 % to 2% by weight, more preferably in amounts of 0.025% to 1 .5% by weight and most preferably in amounts of 0.05% to 1% by weight, based in each case on 100% by weight of component E).

The glass fibres to be used with preference as component E), as a result of the processing to give the thermoplastic moulding composition, may be shorter in the composition than the glass fibres originally used. Thus, the arithmetic average of the glass fibre length after processing, to be determined by high-resolution X-ray computed tomography, is frequently only in the range from 150 pm to 300 pm.

Those skilled in the art distinguish between different types of glass fibres, some of which are listed here by way of example (https://polser.com/en/frp/fibreglass-types): Flour (F2) -0,4 0-0,1 j - |

Particular preference being given to glass fibres in the form of E glass. These can be used as rovings or in the commercially available forms of chopped glass, whereby suitable rovings and chopped glass fibres are described above. Said E glass fibres are modified with a suitable size system or an adhesion promoter/adhesion promoter system. Preference is given to using a size system or an adhesion promoter based on silane, to improve compatibility with the thermoplastic. Suitable silane compounds are mentioned above.

It is further possible to use as component E) non-fibrous and non-foamed milled glass having a particle size distribution to be determined by laser diffractometry according to ISO 13320:2009 having a dgo in the range from 5 to 250 pm, preferably in the range from 10 to 150 pm, more preferably in the range from 15 to 80 pm, most preferably in the range from 16 to 25 pm. With regard to the dgo values, their determination and their significance, reference is made to Chemie Ingenieur Technik (72) pp. 273-276, 3/2000, Wiley-VCH Verlags GmbH, Weinheim, 2000, according to which the dgo value is that particle size below which 90% of the amount of particles lie (volume distribution).

It is preferable in accordance with the invention when the non-fibrous and non-foamed milled glass has a particulate, non-cylindrical shape and has a length to thickness ratio to be determined by laser diffractometry according to ISO 13320:2009 of less than 5, preferably less than 3, more preferably less than 2. It will be appreciated that the value of zero is impossible. The non-foamed and non-fibrous milled glass is additionally characterized in that it generally does not have the glass geometry typical of fibrous glass with a cylindrical or oval cross section having a length to diameter ratio (L/D ratio) to be determined by laser diffractometry according to ISO 13320:2009 greater than 5.

The non-foamed and non-fibrous milled glass is preferably obtained by grinding glass with a mill, preferably a ball mill, and more preferably with subsequent sifting or sieving. Preferred starting materials for the milling of the non-fibrous and non-foamed milled glass for use as component E) in one embodiment also include glass wastes as generated as unwanted by product and/or as off-spec primary product (called offspec material) especially in the production of glass products. These especially include waste glass, recycled glass and broken glass as can be obtained especially in the production of window or bottle glass, and in the production of glass containing fillers and reinforcers, especially in the form of what are called melt cakes. The glass may be coloured, but preference is given to non-coloured glass as the starting material for use as component E).

As component F), the thermoplastic moulding composition contains from 0 to 40% by weight, preferably from 0 to 30% by weight, based on the total amount of components A), B), C), optionally D), optionally E) and optionally F), of at least one further additive, as component F).

If component F) is present, the maximum amount of component A) is decreased by the minimum amount of component F), so that the total amount of components A) to F) is still 100 wt%. Component F) is preferably selected from one or more elements of the group consisting of lubricants and mould-release agents as component F1), oxidation retarders and heat stabilizers as component F2), colourants as component F3) and conventional processing aids as component F4), such as agents to counteract decomposition by ultraviolet light, nucleating agents, plasticizers.

Component F1 )

As component F1 ), the thermoplastic moulding composition contains 0 to 3 wt%, preferably 0.05 to 1 .5 wt%, more preferably from 0.1 to 1 w%, based on the total amount of components A), B), C), optionally D), optionally E) and optionally F), of at least one lubricant and/or mould-release agent.

Preference as lubricant is given to the salts of Al, of alkali metals, or of alkaline earth metals, or esters or amides of fatty acids having from 10 to 44 carbon atoms, preferably having from 12 to 44 carbon atoms.

The metal ions are preferably alkaline earth metal and Al or Zn, particular preference being given to Ca.

Preferred metal salts are Ca stearate and Ca montanate, and also Al distearate.

It is also possible to use a mixture of various salts, in any desired mixing ratio.

The carboxylic acids can be monobasic or dibasic. Examples which may be mentioned are pelargonic acid, palmitic acid, lauric acid, margaric acid, dodecanedioic acid, behenic acid, and particularly preferably stearic acid, capric acid, and also montanic acid (a mixture of fatty acids having from 30 to 40 carbon atoms).

The aliphatic alcohols can be monohydric to tetrahydric. Examples of alcohols are n-butanol, n- octanol, stearyl alcohol, ethylene glycol, propylene glycol, neopentyl glycol, pentaerythritol, preference being given to glycerol and pentaerythritol.

The aliphatic amines can be mono- to tribasic. Examples of these are stearylamine, ethylenediamine, propylenediamine, hexamethylenediamine, di(6-aminohexyl)amine, particular preference being given to ethylenediamine and hexamethylenediamine. Preferred esters or amides are correspondingly glycerol distearate, glycerol tristearate, ethylenediamine distearate, glycerol monopalmitate, glycerol trilaurate, glycerol monobehenate, and pentaerythritol tetrastearate.

It is also possible to use a mixture of various esters or amides, or of esters with amides in combination, in any desired mixing ratio. Materials used as mould-release agents are usually long-chain carboxylic acids, and also their soaps, esters or amides, other materials used are waxes like polar or nonpolar polyethylene waxes, ester waxes and amide waxes, as well as mould-release agent combinations based on an amide wax, on an ester wax and/or on a saponified wax, combinations based on at least one fatty acid amide ester wax, natural and/or synthetic silica and a montan wax, and combinations comprising at least one amide wax, at least one ester wax and/or at least one saponified wax.

Component F2)

As component F2), the thermoplastic moulding composition contains 0 to 3 wt%, preferably 0.01 to 2.5 wt%, more preferably from 0.02 to 2 wt%, most preferably 0.05 to 1 wt%, based on the total amount of components A), B), C), optionally D), optionally E) and optionally F), of at least one oxidation retarder and/or heat stabilizer.

The heat stabilizers are preferably selected from copper compounds, amines like secondary aromatic amines, e.g. 4-amino-2,2,6,6-tetramethylpiperidine (TAD) and diphenylamines, sterically hindered phenols, phosphites, phosphonites, hydroquinones and mixtures thereof.

As component F2), 0.05 to 3 wt%, preferably 0.1 to 2 wt%, in particular 0.1 to 1 wt% of at least one sterically hindered phenol antioxidant can be employed.

This component F2) preferably has a molecular weight of more than 500 g/mol, more preferably of more than 1000 g/mol. Additionally, component H should preferably exhibit a high thermal stability, e.g. maximum of 5% weight loss, more preferably maximum of 2% weight loss, measured under nitrogen at 300 °C within a TGA (thermogravimetric analysis) experiment (40 °C to 120 °C with 10 °C/min, isothermal the later temperature for 15 min followed by 120 °C to 600 °C at 20 °C/min).

Component F2) has preferably at least one, more preferably at least two phenol groups substituted by at least one branched C3-i2-alkyl group as sterically hindering group. The substituted phenol groups are covalently linked with the structure of component F2).

Suitable sterically hindered phenols F2) are in principle all of the compounds which have a phenolic structure and which have at least one bulky group on the phenolic ring. A bulky group is for example a branched C3-i2-alkyl group, preferably a branched Cs-e-alkyl group, more preferably an isopropyl or tert.-butyl group.

It is preferable to use, for example, compounds of the formula where:

R¹ and R² are an alkyl group, a substituted alkyl group, or a substituted triazole group, and where the radicals R¹ and R² may be identical or different, and R³ is an alkyl group, a substituted alkyl group, an alkoxy group, or a substituted amino group. The alkyl and alkoxy residues have preferably 1 to 12 carbon atoms, more preferably 1 to 6 carbon atoms. Substituents are preferably Ci-12-alkyl , more preferably Ci-6-alkyl, most preferably Ci-4-alkyl. At least one of R¹ to R³ is preferably a bulky group as defined above.

Antioxidants of the abovementioned type are described by way of example in DE-A 27 02 661 (US-A 4 360 617).

Another group of preferred sterically hindered phenols is provided by those derived from substituted phenylcarboxylic acids, in particular from substituted phenylpropionic acids, which preferably have at least one bulky group on the phenyl group. They contain at least one, preferably two covalently linked substituted phenylcarboxylic acid unit(s) in their structure, which preferably have at least one bulky group on the phenyl group.

Preferred phenylcarboxylic acids are phenyl-Ci-12-carboxylic acids, more preferably phenyl-C2-6- carboxylic acids. The phenyl group is preferably a phenol group having at least one bulky group on the phenolic ring, as indicated above. Thus, the above-mentioned sterically hindered phenols are preferably covalently linked with a Ci-12-alkane carboxylic acid, more preferably a linear C2-6- alkane carboxylic acid.

Particularly preferred compounds from this class are compounds of the formula where R⁴, R⁵, R⁷, and R⁸, independently of one another, are Ci-Cs-alkyl groups which themselves may have substitution (at least one of these being a bulky group), and R⁶ is a divalent aliphatic radical which has from 1 to 10 carbon atoms and whose main chain may also have C- O bonds. At least one of R⁴ to R⁸ is a bulky group as defined above.

Preferred compounds corresponding to these formulae are

(Irganox® 245 from BASF SE)

(Irganox® 259 from BASF SE)

All of the following should be mentioned as examples of sterically hindered phenols:

2,2’-methylenebis(4-methyl-6-tert-butylphenol), 1 ,6-hexanediol bis[3-(3,5-di-tert-butyl-4-hydroxy- phenyl)propionate], pentaerythrityl tetrakis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate] (Ir- ganox® 1010 from BASF SE), distearyl 3,5-di-tert-butyl-4-hydroxybenzylphosphonate, 2,6,7-tri- oxa-1 -phosphabicyclo[2.2.2]oct-4-ylmethyl 3,5-di-tert-butyl-4-hydroxyhydrocinnamate, 3,5-di- tert-butyl-4-hydroxyphenyl-3,5-distearylthiotriazylamine, 2-(2’-hydroxy-3’-hydroxy-3’,5’-di-tert- butylphenyl)-5-chlorobenzotriazole, 2,6-di-tert-butyl-4-hydroxymethylphenol, 1 ,3,5-trimethyl- 2,4,6-tris(3,5-di-tert-butyl-4-hydroxybenzyl)benzene, 4,4’-methylenebis(2,6-di-tert-butylphenol), 3,5-di-tert-butyl-4-hydroxybenzyldimethylamine.

Compounds which have proven particularly effective and which are therefore used with preference are 2,2’-methylenebis(4-methyl-6-tert-butylphenol), 1 ,6-hexanediol bis(3,5-di-tert-butyl-4- hydroxyphenyl)propionate (Irganox® 259), pentaerythrityl tetrakis[3-(3,5-di-tert-butyl-4-hydroxy- phenyl)propionate], and also N,N’-hexamethylenebis-3,5-di-tert-butyl-4-hydroxyhydrocinnamide (Irganox® 1098), and the products Irganox® 245 and Irganox® 1010 described above from BASF SE, which have particularly good suitability.

In some instances, sterically hindered phenols having not more than one sterically hindered group in ortho-position with respect to the phenolic hydroxy group have proven particularly advantageous; in particular when assessing colourfastness on storage in diffuse light over prolonged periods.

Furthermore, it is advantageous to employ sterically hindered phenol antioxidants which also have a sufficiently high molecular weight, preferably of more than 500 g/mol and especially a molecular weight above 1000 g/mol. Furthermore, they preferably exhibit a high thermal stability measured by TGA (thermogravimetric analysis) of less than 2% degradation up until 300 °C under nitrogen atmosphere.

The moulding compositions of the invention can comprise, as component E3), from 0.05 to 3% by weight, preferably from 0.1 to 1.5% by weight, and in particular from 0.1 to 1 % by weight, of at least one copper stabilizer, preferably of a Cu(l) halide, in particular in a mixture with an alkali metal halide, preferably KI, in particular in the ratio 1 :4, or of a sterically hindered phenol, or a mixture of these. Preferred salts of monovalent copper used are cuprous acetate, cuprous chloride, cuprous bromide, and cuprous iodide. The materials comprise these in amounts of from 5 to 500 ppm of copper, preferably from 10 to 250 ppm, based on polyamide.

The advantageous properties are in particular obtained if the copper is present with molecular distribution in the polyamide. This is achieved if a concentrate comprising the polyamide, and comprising a salt of monovalent copper, and comprising an alkali metal halide in the form of a solid, homogeneous solution is added to the moulding composition. By way of example, a typical concentrate is composed of from 79 to 95% by weight of polyamide and from 21 to 5% by weight of a mixture composed of copper iodide or copper bromide and potassium iodide. The copper concentration in the solid homogeneous solution is preferably from 0.3 to 3% by weight, in particular from 0.5 to 2% by weight, based on the total weight of the solution, and the molar ratio of cuprous iodide to potassium iodide is from 1 to 11 .5, preferably from 1 to 5.

Suitable polyamides for the concentrate are homopolyamides and copolyamides, in particular PA6 and PA6.6.

According to a preferred embodiment of the present invention, the moulding compositions are free from copper, specifically from copper stabilizers, such as Cu/(l)halides, and combinations of Cu(l)halides with alkali metal halides.

More preferably, the thermoplastic moulding compositions of the present inventions are metal halide-free. Metal halide-free systems, so-called electro-friendly systems, are of high interest, since electro-mobility, electrification and connectivity are an increasing trend in almost all industries.

Therefore, the thermoplastic moulding composition is preferably free from metal halides, specifically Cu halides and alkali metal halides.

Component F3)

As component F3), the thermoplastic moulding composition contains 0 to 5 wt%, preferably 0.05 to 3 wt%, more preferably from 0.1 to 2 wt%, most preferably 0.25 to 1 wt%, based on the total amount of components A), B), C), optionally D), optionally E) and optionally F), of at least one colourant.

Colourants in the meaning of the present inventions are pigments or dyes or mixtures thereof.

Preferred colourants F3) are nigrosins.

Nigrosins are generally a group of black or gray phenazine dyes (azine dyes) related to the in- dulines and taking various forms (water-soluble, oleosoluble, spirit-soluble), used in wool dyeing and wool printing, in black dyeing of silks, and in the colouring of leather, of shoe creams, of varnishes, of plastics, of stoving lacquers, of inks, and the like, and also as microscopy dyes.

Nigrosins are obtained industrially via heating of nitrobenzene, aniline, and aniline hydrochloride with metallic iron and FeCh (the name being derived from the Latin niger=black).

The nigrosins can be used in the form of free base or else in the form of salt (e.g. hydrochloride).

Further details concerning nigrosins can be found by way of example in the electronic encyclopedia Rompp Online, Version 2.8, Thieme-Verlag Stuttgart, 2006, keyword “Nigrosin”.

Other suitable colourants are are inorganic pigments, such as titanium dioxide, ultramarine blue, iron oxide, and carbon black, and also organic pigments, such as phthalocyanines, quinacrido- nes, perylenes, and also dyes, such as anthraquinones.

Component F4)

As component F4), the thermoplastic moulding composition contains 0 to 5 wt%, preferably 0.05 to 3 wt%, more preferably from 0.1 to 2 wt%, most preferably 0.25 to 1 wt%, based on the total amount of components A), B), C), optionally D), optionally E) and optionally F), of at least one conventional processing aid.

Examples for conventional processing aids as component F4) are agents to counteract decomposition by ultraviolet light, nucleating agents, plasticizers, etc.

Agents to counteract decomposition by ultraviolet light are UV stabilizers. Suitable UV stabilizers are known in the art and for example various substituted resorcinols, salicylates, benzotriazoles, andbenzophenones. Nigrosine can also be employed.

Examples for materials useful as nucleating agents are sodium phenylphosphinate, aluminum oxide, silicon dioxide and also preferably talc powder.

Suitable plasticizers are described in Kunststoff-Handbuch, Band VI Polyamide, Carl Hanser Verlag Munchen 1966, Section 3.4.2.1 . b) on pages 238 and 239 in connection with Table 7 describes suitable plasticizers. They can be divided in aromatic hydroxy compounds, sulfonamides and further plasticizers like lactams, lactones, alcohols etc.

Suitable plasticizers are for example poly(trimethylene ether) glycol (PPD), preferably poly(tri- methylene ether) glycol (PPD) having a number average molecular weight of 255 and poly(tri- methylene ether) glycol benzoate (PPDB), N-butyl benzene sulfonamide (NBBS), polyethylene glycol dibenzoate (M_n = 410), poly(1 ,2-propylene glycol)dibenzoate (M_n = 400), monomeric am- ides, specifically sulfonamides, for example N-alkyl aryl sulfonamides, p-alkyl benzene sulfonamides and guanidine-based compounds, a mixture of lactam compounds and polyethylene glycol, an aromatic ester of poly(trimethylene ether) glycol with a number average molecular weight of 1000 or less or compounds of the general formula (1).

Ri-O-(CH₂CH₂-O-)_nR₂ (1) with n = 1 to 10

Ri, R₂ independently H, Ci-i₂-alkyl, phenyl or tolyl, having a boiling point of more than 250 °C.

A preferred plasticizer of general formula (1) is based on triethylene glycol, tetraethylene glycol, pentaethylene glycol or mixtures thereof. Most preferred is tetraethylene glycol. Therefore, n most preferably has a value of from 3.8 to 4.2, most preferably of 4.

Tetraethylene glycol is non-toxic and has a high plasticizing efficiency. When compared with sulfonamides and lactams, only half the amount of tetraethylene glycol is necessary to achieve the same plasticizing effect and the same decrease of the glass transition temperature. Therefore, in a preferred embodiment, the thermoplastic moulding composition comprises a compound of formula (1) as plasticizer, in the case that a plasticizer is present as component F4).

Compositions

The compositions according to the present invention are characterized by effective fire protection and at the same time good electrical properties obtained by effectively stabilizing red phosphorous in polyamide by a mixed metal oxide comprising Cu and Cr in form of their oxides which does not negatively affect the electrical properties.

The weight ratio between component B) and component C) is preferably 1.5 to 100 : 1 , more preferably 2 to 90 : 1 , most preferably 4 to 80 : 1.

The inventive thermoplastic moulding composition therefore comprises a) from 10 to 99.85% by weight, preferably 20 to 98% by weight, more preferably 30 to 90% by weight, of at least one thermoplastic polyamide, as component A), b) from 0.1 to 60% by weight, preferably 0.5 to 40% by weight, more preferably 1 to 15% by weight, of red phosphorous, as component B), c) from 0.05 to 20% by weight, preferably from 0.07 to 5% by weight, and more preferably from 0.1 to 2% by weight, of at least one mixed metal oxide comprising Cu and Cr in form of their oxides, as component C), d) from 0 to 40% by weight, preferably from 1 to 30% by weight, and more preferably from 2 to 20% by weight, of at least one impact modifier, as component D), e) from 0 to 60% by weight, preferably 0 to 50% by weight, of at least one filler, as component E), f) from 0 to 40% by weight, preferably from 0 to 30% by weight, of at least one further additive, as component F), where the total of the percentages by weight of components A), B), C), optionally D), optionally E) and optionally F) is 100% by weight, wherein component C) preferably comprises c1) from 15 to 25 parts by weight of Cu; c2) from 20 to 40 parts by weight of Cr; c3) from 0.5 to 15 parts by weight of Fe; c4) from 0 to 20 parts by weight of Mn, Al and/or Co; wherein components d ), c2), c3) and optionally c4) are present in form of their oxides and the amounts of components d ), c2), c3) and optionally c4) are calculated on the respective metals, more preferably component C) is present in form of a spinel structure.

Suitable and preferred components A), B), C), D), E) and F) and amounts of said components in the inventive thermoplastic moulding composition are mentioned above.

The inventive thermoplastic moulding composition is a filled composition, i.e. comprising 5 to 60 wt%, more preferably 10 to 50 wt%, of at least one filler, preferably at least one fibrous and/or particulate filler, as component E), or a non filled composition, i.e comprising 0% by weight of a filler, as component E).

In one embodiment, the thermoplastic moulding composition of the present invention is a filled composition comprising a) from 10 to 94.85% by weight, preferably 20 to 88% by weight, more preferably 30 to 88% by weight, of at least one thermoplastic polyamide, as component A), b) from 0.1 to 60% by weight, preferably 0.5 to 40% by weight, more preferably 1 to 15% by weight, of red phosphorous, as component B), c) from 0.05 to 20% by weight, preferably from 0.07 to 5% by weight, and more preferably from 0.1 to 2% by weight, of at least one mixed metal oxide comprising Cu and Cr in form of their oxides, as component C), d) from 0 to 40% by weight, preferably from 1 to 30% by weight, and more preferably from 2 to 20% by weight, of at least one impact modifier, as component D), e) from 5 to 60% by weight, preferably 10 to 50% by weight, of at least one filler, as component E), f) from 0 to 40% by weight, preferably from 0 to 30% by weight, of at least one further additive, as component F), where the total of the percentages by weight of components A), B), C), D) optionally E) and optionally F) is 100% by weight, wherein component C) preferably comprises c1) from 15 to 25 parts by weight of Cu; c2) from 20 to 40 parts by weight of Cr; c3) from 0.5 to 15 parts by weight of Fe; c4) from 0 to 20 parts by weight of Mn, Al and/or Co; wherein components d ), c2), c3) and optionally c4) are present in form of their oxides and the amounts of components d ), c2), c3) and optionally c4) are calculated on the respective metals, more preferably component C) is present in form of a spinel structure.

Suitable and preferred components A), B), C), D), E) and F) and amounts of said components in the inventive thermoplastic moulding composition are mentioned above.

The thermoplastic moulding compositions of the invention feature good flame retardancy and excellent phosphorus stability and at the same time good electrical properties, especially a good tracking resistance.

The flame retardancy of the moulding composition was determined according to method UL94- V (Underwriters Laboratories Inc. Standard of Safety, "Test for Flammability of Plastic Materials for Parts in Devices and Appliances", pages 14 to 18, Northbrook 1998). The glow-wire resistance was determined as the Glow-Wire Flammability Index (GWFI) according to I EC 60695- 2-12 as of 2019. The inventive moulding compositions comply with the requirements placed upon heat resistance and glow-wire resistance (UL 94/1.6 mm V-0 and GWFI 960°C at 0.8 mm).

Additionally, the inventive moulding compositions have a tracking resistance (CTI) of at least 450V, preferably 475V, more preferably 490V. The CTI value (tracking resistance) indicates a material’s tendency to form a creepage path when exposed to contamination and high humidity. The better a material can resist destruction thanks to high field strengths and creepage currents, the more likely it is to be used in electrical applications. Measurements are made according to I EC 60112 (Method for determining the test number and the comparative tracking path index of solid insulating materials).

The thermoplastic moulding compositions of the invention can be produced by processes known per se, by mixing the starting components in conventional mixing apparatus, such as screw-based extruders, Brabender mixers, or Banbury mixers, and then extruding the same. The extrudate can be cooled and pelletized. It is also possible to premix individual components and then to add the remaining starting materials individually and/or likewise in the form of a mixture. The mixing temperatures are generally from 230 to 320°C.

In another preferred mode of operation, components B) to C) and also, if present, D) and E) can be mixed with a prepolymer, compounded, and pelletized. The resultant pellets are then solidphase condensed under an inert gas continuously or batchwise at a temperature below the melting point of component A) until the desired viscosity has been reached.

The thermoplastic moulding compositions of the invention feature good flame retardancy and excellent phosphorus stability and at the same time good electrical properties. These materials are therefore suitable for producing fibers, foils, and moldings of any type. Some examples are mentioned hereinafter: plug connectors, plugs, plug parts, cable harness components, circuit mounts, circuit mount components, three-dimensionally injection-molded circuit mounts, electrical connector elements, and mechatronic components.

The mouldings or semifinished products to be produced in the invention from the thermoplastic moulding compositions can be used by way of example in the motor vehicle industry, electrical industry, electronics industry, telecommunications industry, information technology industry, entertainment industry, or computer industry, in vehicles and other conveyances, in ships, in spacecraft, in households, in office equipment, in sports, in medicine, and also generally in articles and parts of buildings which require increased fire protection.

Improved-flow polyamides can be used in the kitchen and household sector for producing components for kitchen equipment, e.g. fires, smoothing irons, buttons, and also for garden- and leisure-sector applications.

Examples

The following components were used:

Component a:

Nylon-6, 6 with intrinsic viscosity IV 150 mL/g, measured in 0.5% by weight solution in 96% by weight sulfuric acid at 25° C. to ISO 307 (using Ultramid® A27 from BASF SE).

Component b:

50% concentrate of red phosphorus of average particle size (d50) from 10 to 30 pm in an olefin polymer made of: 59.8% by weight of ethylene, 35% by weight of n-butyl acrylate, 4.5% by weight of acrylic acid, and 0.7% by weight of maleic anhydride (component D) with melt index MFI (190/2.16) 10 g/10 min. The copolymer was produced via copolymerization of the monomers at elevated temperature and elevated pressure.

The d50 value is determined by laser diffraction according to ISO 13320:2009.

Component c: commercially available copper chromite black spinell (CAS: 68186-91 -4). Composition: 19,5 weight-% Cu, 33,0 weight-% Cr and 12.2 weight-% Fe and 0,55 weight-% Mn. Cu, Cr, Fe and Mn are present in form of their oxides (the total of copper chromite black spinell is 100 wt%) and the amounts of Cu, Cr, Fe and Mn are calculated on the respective metals. c/1 = commercially available Cu-(l)-oxide (CAS: 1317-39-1 ).

Component d: commercially available zinc oxide (for comparison).

Component e:

Standard chopped glass fiber for polyamides, length=4.5 mm, diameter=10 pm.

Component f/1 : N,N'-Hexamethylenebis-3,5-di-tert-butyl-4-hydroxyhydrocinnamide (Irganox® 1098)

Component f/2: commercially available Ca-stearate

Component f/3: 30% concentrate of carbon black in PA6 (Ultramid® B27)

In order to provide evidence of the phosphorus stability improvements and the good electrical properties described in the invention, appropriate plastics molding compositions were manufactured via compounding. To this end, the individual components were mixed in a ZSK 26 (Berstorff) twin-screw extruder with throughput 20 kg/h and a flat temperature profile at about 270°C, extruded in the form of strand, cooled until pelletizable, and pelletized.

The test specimens for the study set out in Table 1 were injection-molded in an Arburg 420C injection-molding machine at a melt temperature of about 270°C and mold temperature of about 80°C.

The flame retardancy of the molding compositions was determined firstly by the UL 94 V method (Underwriters Laboratories Inc. Standard of Safety, "Test for Flammability of Plastic Materials for Parts in Devices and Appliances”, p. 14 to p. 18 Northbrook 1998).

Glow - wire resistance GWFI (glow - wire flammability index) was tested in accordance with DIN EN 60695-2-12 on plaques. The GWFI test is a general suitability test for plastics in contact with parts that carry an electrical potential. The temperature determined is the highest at which one of the following conditions is met in three successive tests: (a) no ignition of the specimen or (b) afterflame time or afterglow time 30 s after end of exposure to the glow wire, and no ignition of the underlay.

The CTI (tracking resistance) was measured according to I EC 60112 (Method for determining the test number and the comparative tracking path index of solid insulating materials).

Testing of Plastics Parts for Phosphorus Deposition:

A plastics specimen (125x12.5x1.6 mm) was halved, and each half was placed in a 10 ml glass beaker. A silver contact material (10x50x0.125 mm) was placed in a short test tube. The three specimens were then placed in a 100 ml screw-cap bottle, 5 ml of water was added, and the sealed system was placed in a drying oven at 70° C. After 28 days, the test tube was removed and filled to the top with water, and the entire contents were placed in a glass beaker. 5 ml of cone, hydrochloric acid were added to this, and the mixture was evaporated almost to dryness. The metal specimen was then removed and rinsed with water; 1 ml of sulfuric acid was admixed with the residue, and the mixture was again evaporated almost to dryness. 20 ml of water is then used for dilution, 4 ml of 5% potassium peroxodisulfate solution are added, and the mixture is heated for 30 minutes. Phosphorus was then determined photometrically by using molybdenum blue, in pg of phosphorus/plastics specimen. The table gives the constitutions of the molding compositions and the results of the measurements.

Table 1

*When the amount of Cu-(l)-oxide in comparative example 3 is increased, the CTI becomes worse and the compositions are not useful. Based on the data in Table 1 it is obvious that the addition of the mixed oxide based on copper and chromium strongly reduces the deposition of phosphorus while keeping the electrical properties (CTI value) at a high level.

Claims

Claims

1 . A thermoplastic moulding composition comprising a) from 10 to 99.85% by weight of at least one thermoplastic polyamide, as component A), b) from 0.1 to 60% by weight of red phosphorous, as component B), c) from 0.05 to 20% by weight of at least one mixed metal oxide comprising Cu and Cr in form of their oxides, as component C), d) from 0 to 40% by weight of at least one impact modifier, as component D), e) from 0 to 60% by weight of at least one filler, as component E), f) from 0 to 40% by weight of at least one further additive, as component F), where the total of the percentages by weight of components A), B), C), optionally D), optionally E) and optionally F) is 100% by weight.

2. The thermoplastic moulding composition according to claim 1 , wherein component A) is selected from aliphatic and semiaromatic polyamides, preferably from PA 6, PA 66, PA 46, PA 6/66, PA 66/6, PA 6/636, PA610, PA 6T/6, PA 6T/6I, PA 6T/6I/66, PA 9T and PA 6T/66 and mixtures thereof, more preferably from PA 6, PA 66, PA 66/6, PA 6/66,

PA 6/636 and mixtures thereof, and most preferred are PA 6 and PA 66 and mixtures thereof.

3. The thermoplastic moulding composition according to claim 1 or 2, wherein the amount of component B) is from 0.5 to 20% by weight, preferably from 1 to 15% by weight.

4. The thermoplastic moulding composition according to any one of claims 1 to 3, wherein component C) comprises c1) from 15 to 25 parts by weight of Cu; c2) from 20 to 40 parts by weight of Cr; c3) from 0.5 to 15 parts by weight of Fe; c4) from 0 to 20 parts by weight of Mn, Al and/or Co; wherein components c1), c2), c3) and optionally c4) are present in form of their oxides and the amounts of components c1), c2), c3) and optionally c4) are calculated on the respective metals, preferably component C) is present in form of a spinel structure.

5. The thermoplastic moulding composition according to any one of claims 1 to 4, wherein component C) is copper chromite.

6. The thermoplastic moulding composition according to any one of claims 1 to 5, wherein component C) has a BET surface area of 1 to 200 m²/g, preferably 1.5 to 100 m²/g according to ISO 9277:2010, under nitrogen.

7. The thermoplastic moulding composition according to any one of claims 1 to 6, wherein component C) has a mean primary particle diameter of 0.05 to 200 pm, preferably 0.1 to 50 |jm, more preferably 0.5 to 25 pm, determined by dynamic light scattering according to ISO22412:2017. The thermoplastic moulding composition according to any one of claims 1 to 7, wherein component D) is at least one copolymer composed of i) 80 to 99.9% by weight of ethylene, as component i), and ii) 0.1 to 20% by weight of at least one functional monomer different from ethylene, as component ii), wherein the copolymer may also be additionally grafted with maleic anhydride. The thermoplastic moulding composition according to claim 8, wherein component ii) is selected from the group consisting of C3-12-0I efins, carboxylic esters like Ci-is-alkyl (meth)acrylates, carboxylic acids like (meth)acrylic acid, carboxylic acid anhydrides like maleic anhydride, chloroprene, vinyl acetate, styrene, acrylonitrile, carboxamides, car- boximides, amino group comprising compounds, hydroxy group comprising compounds, epoxy group comprising compounds, and mixtures thereof. The thermoplastic moulding composition according to any one of claims 1 to 9, wherein component E) is at least one fibrous or particulate filler or a mixture thereof, preferably, component E) is selected from the group consisting of carbon fibres, glass beads, e.g. solid or hollow glass beads, glass fibres, ground glass, amorphous quartz glass, aluminum borosilicate glass having an alkali content of about 1 %, amorphous silica, quartz flour, alkaline earth metal silicate, especially calcium silicate, calcium metasilicate, magnesium carbonate, kaolin, calcined kaolin, chalk, kyanite, powdered or milled quartz, mica, phlogopite, barium sulfate, feldspar, wollastonite, montmorillonite, boehmite, bentonite, vermiculite, hectorite, laponite®, pseudoboehmite of formula AIO(OH), magnesium carbonate, talc, aramid fibres, potassium titanate fibres, barium carbonate, alkaline earth metal oxide, metallic fibres, ceramic fibres, titanium dioxide, aluminum oxide, plaster, zirconium oxide, antimony oxide, clay, silica-alumina, sericite, diatomite, silica stone, carbon black, glassy hollow microspheres, red oxide, zinc oxide, and mixtures thereof. The thermoplastic moulding composition according to any one of claims 1 to 10, wherein component F) is selected from one or more elements of the group consisting of lubricants and mould-release agents as component F1 ), oxidation retarders and heat stabilizers as component F2), colourants as component F3) and conventional processing aids as component F4), such as agents to counteract decomposition by ultraviolet light, nucleating agents, plasticizers. A process for producing the thermoplastic moulding composition according to any one of claims 1 to 11 comprising the step of mixing the components A), B), C) and optionally D), optionally E) and optionally F).

13. The use of the thermoplastic moulding composition according to any one of claims 1 to 11 or obtained by the process according to claim 12 for producing moulded articles, fibres, films or extruded articles. 14. Moulded articles, fibres, films or extruded articles made of the thermoplastic moulding composition according to any one of claims 1 to 11 or obtained by the process according to claim 12.

15. Use of a mixed metal oxide comprising Cu and Cr in form of their oxides for stabilization of red phosphorous as flame retardant in polyamide compositions while maintaining the electrical properties of the polyamide compositions.