EP1592737A1

EP1592737A1 - Hydrolysis-resistant polyesters

Info

Publication number: EP1592737A1
Application number: EP04706134A
Authority: EP
Inventors: Dietrich Scherzer; Jochen Engelmann; Motonori Yamamoto
Original assignee: BASF SE
Current assignee: BASF SE
Priority date: 2003-02-03
Filing date: 2004-01-29
Publication date: 2005-11-09
Also published as: CA2514589A1; MXPA05007517A; IL169537A0; US20060142442A1; KR20050107406A; PL378401A1; DE10304341A1; JP2006517605A; WO2004069912A1

Abstract

The invention relates to the use of epoxidised natural oils or fatty acid esters or the mixtures thereof (constituents B) for producing hydrolysis-resistant thermoplastic polyester moulding materials (A).

Description

Hydrolysis-resistant polyester

description

The invention relates to the use of epoxidized natural oils or fatty acid esters or their mixtures (component B) for the production of hydrolysis-resistant thermoplastic polyester molding compositions (A).

The invention further relates to the use of epoxidized natural oils or fatty acid esters or their mixtures to increase the resistance to hydrolysis of molded parts made of thermoplastic polyesters A).

In addition, the invention relates to the molded parts of any type obtainable according to the use according to the invention.

Because of their properties, polyesters are resistant to numerous chemicals. However, the resistance to hydrolysis is still in need of improvement since it essentially influences the shrinkage (dimensional stability) and the mechanical properties of the component.

EP-A 794974 discloses polycarbodiimides as hydrolysis stabilizers. In addition to the much higher costs, the toxicity of such compounds is problematic during processing.

Epoxidized vegetable oils and fatty acid esters are known as (co) stabilizers for PVC with regard to color and as plasticizers: Gächter / Müller, Kunststoffadditive 3rd edition, pp. 317, 318 and 399 and 400, Carl Hanser Verlag 1989.

Such additives for polyester are known from US Pat. No. 3,886,105, but in connection with thermal degradation and melt stability of the polymer matrix.

The object of the present invention was therefore to provide molding compositions and molded parts made of polyesters which can be used at higher service temperatures and which are largely stable to hydrolysis.

Accordingly, the uses defined at the outset were found. Preferred embodiments can be found in the subclaims. As component (A), the molding compositions which can be used according to the invention contain 29 to 99.9, preferably 40 to 95.5 and in particular 40 to 80% by weight of a thermoplastic polyester.

Polyesters A) based on aromatic dicarboxylic acids and an aliphatic or aromatic dihydroxy compound are generally used.

A first group of preferred polyesters are polyalkylene terephthalates, in particular with 2 to 10 carbon atoms in the alcohol part.

Such polyalkylene terephthalates are known per se and are described in the literature. They contain an aromatic ring in the main chain, which comes from the aromatic dicarboxylic acid. The aromatic ring can also be substituted, for example by halogen such as chlorine and bromine or by dC ₄ alkyl groups such as methyl, ethyl, i- or n-propyl and n-, i- or t-butyl groups.

These polyalkylene terephthalates can be prepared in a manner known per se by reacting aromatic dicarboxylic acids, their esters or other ester-forming derivatives with aliphatic dihydroxy compounds.

Preferred dicarboxylic acids are 2,6-naphthalenedicarboxylic acid, terephthalic acid and isophthalic acid or mixtures thereof. Up to 30 mol%, preferably not more than 10 mol%, of the aromatic dicarboxylic acids can be replaced by aliphatic or cycloaliphatic dicarboxylic acids such as adipic acid, azelaic acid, sebacic acid, dodecanedioic acids and cyclohexanedicarboxylic acids.

Of the aliphatic dihydroxy compounds are diols with 2 to 6 carbon atoms, in particular 1, 2-ethanediol. 1,3-propanediol, 1,4-butanediol, 1,6-hexanediol, 1,4-hexanediol, 1,4-cyclohexanediol, 1,4-cyclohexanedimethanol and neopentyl glycol or mixtures thereof are preferred.

Particularly preferred polyesters (A) are polyalkylene terephthalates which are derived from alkanediols having 2 to 6 G-aiornene. Of these, particularly preferred are polyethylene terephthalate, polypropylene terephthalate and polybutylene terephthalate or mixtures thereof. PET and / or PBT are preferred because they contain up to 1% by weight, preferably up to 0.75% by weight, of 1,6-hexanediol and / or 2-methyl-1,5-pentanediol as further monomer units. The viscosity number of the polyesters (A) is generally in the range from 50 to 220, preferably from 80 to 160 ml / g (measured in a 0.5% strength by weight solution in a phenol / o-dichlorobenzene mixture (weight ratio 1: 1 at 25oC) according to ISO 1628.

Particularly preferred are polyesters whose carboxyl end group content is up to 100 meq / kg, preferably up to 50 meq / kg and in particular up to 40 meq / kg polyester. Such polyesters can be produced, for example, by the process of DE-A 4401 055. The carboxyl end group content is usually determined by titration methods (e.g. potentiometry).

Particularly preferred molding compositions contain, as component A), a mixture of polyesters other than PBT, such as, for example, polyethylene terephthalate (PET). The proportion e.g. The polyethylene terephthalate in the mixture is preferably up to 50, in particular 10 to 35,% by weight, based on 100% by weight of A).

Furthermore, it is advantageous to use PET recyclates (also called scrap PET), optionally in a mixture with polyalkylene terephthalates such as PBT.

Recyclates are generally understood to mean:

1) so-called post industrial recyclate: this is production waste from polycondensation or processing e.g. Sprues in injection molding processing, approach goods in injection molding processing or extrusion or edge sections of extruded sheets or foils.

2) Post consumer recyclate: these are plastic articles that are collected and processed by the end consumer after use. The most dominant item in terms of quantity are blow-molded PET bottles for mineral water, soft drinks and juices.

Both types of recyclate can either be in the form of regrind or in the form of granules. In the latter case, the pipe cyclates are melted and granulated in an extruder after separation and cleaning. This usually facilitates handling, free-flowing properties and the metering wedge for further processing steps.

Recyclates, both granulated and in the form of regrind, can be used, the maximum edge length being 6 mm, preferably less than 5 mm. Due to the hydrolytic cleavage of polyesters during processing (due to traces of moisture), it is advisable to pre-dry the recyclate. The residual moisture content after drying is preferably <0.2%, in particular <0.05%.

Another group to be mentioned are fully aromatic polyesters which are derived from aromatic dicarboxylic acids and aromatic dihydroxy compounds.

Aromatic dicarboxylic acids which are suitable are the compounds already described for the polyalkylene terephthalates. Mixtures of 5 to 100 mol% isophthalic acid and 0 to 95 mol% terephthalic acid, in particular mixtures of approximately 80% terephthalic acid with 20% isophthalic acid to approximately equivalent mixtures of these two acids, are used.

The aromatic dihydroxy compounds preferably have the general formula

in which Z represents an alkylene or cycloalkylene group with up to 8 C atoms, an arylene group with up to 12 C atoms, a carbonyl group, a sulfonyl group, an oxygen or sulfur atom or a chemical bond and in which m is the value Has 0 to 2. The compounds can also carry CC ₆ alkyl or alkoxy groups and fluorine, chlorine or bromine as substituents on the phenylene groups.

As the stem body of these compounds, for example

dihydroxydiphenyl,

Di (hydroxyphenyl) alkane,

Di (hydroxyphenyl) cycloalkane,

Di (hydroxyphenyl) sulfide,

Di (hydroxyphenyl) ether,

Di- (hydroxyphenyl) ketone, di- (hydroxyphenyl) sulfoxide, α, α'-di- (hydroxyphenyl) dialkylbenzene,

Di (hydroxyphenyl) sulfone, di (hydroxybenzoyl) benzene

Resorcinol and

Hydroquinone and their core alkylated or nuclear halogenated derivatives called.

Of these will be 4,4'-dihydroxydiphenyl, 2,4-di- (4'-hydroxyphenyl) -2-methylbutane α, α'-di- (4-hydroxyphenyl) -p-diisopropylbenzene, 2,2-di- (3'- methyl-4'-hydroxyphenyl) propane and 2,2-di- (3'-chloro-4'-hydroxyphenyl) propane,

as well as in particular

2,2-di- (4'-hydroxyphenyl) propane 2,2-di- (3 ', 5-dichlorodihydroxyphenyl) propane, 1, 1 -di (4'-hydroxyphenyl) cyclohexane, 3,4'-dihydroxybenzophenone, ^{4,4-dihydroxydiphenyl} and 2,2-di (3 ', 5'-dimethyl-4'-hydroxyphenyl) propane

or mixtures thereof are preferred.

Mixtures of polyalkylene terephthalates and fully aromatic polyesters can of course also be used. These generally contain 20 to 98% by weight of the polyalkylene terephthalate and 2 to 80% by weight of the fully aromatic polyester.

Of course, polyester block copolymers such as copolyether esters can also be used. Such products are known per se and are known in the literature, e.g. in US-A 3,651,014. Corresponding products are also available commercially, e.g. Hytrel® (DuPont).

According to the invention, polyester should also be understood to mean halogen-free polycarbonates. Suitable halogen-free polycarbonates are, for example, those based on diphenols of the general formula

wherein Q is a single bond, a C to G ₈ alkylene, a C ₂ to C ₃ alkylidene, a C ₃ to Ces cycloalkylidene group, a C ₆ to C ₁₂ arylene group and -O-, -S - or - SO ₂ - and m is an integer from 0 to 2.

The diphenols can also have substituents on the phenylene radicals, such as d- to C ₆ -alkyl or C to C ₆ -alkoxy. Preferred diphenols of the formula are, for example, hydroquinone, resorcinol, 4,4'-dihydroxydiphenyl, 2,2-bis (4-hydroxyphenyl) propane, 2,4-bis (4-hydroxyphenyl) -2-methylbutane, 1, 1 bis (4-hydroxyphenyl) -cyclohexane. 2,2-bis (4-hydroxyphenyl) propane and 1,1-bis (4-hydroxyphenyl) cyclohexane, and 1,1-bis (4-hydroxyphenyl) -3,3,5- are particularly preferred. trimethylcyclohexane.

Both homopolycarbonates and copolycarbonates are suitable as component A; in addition to the bisphenol A homopolymer, the copolycarbonates of bisphenol A are preferred.

The suitable polycarbonates can be branched in a known manner, preferably by incorporating 0.05 to 2.0 mol%, based on the sum of the diphenols used, of at least trifunctional compounds, for example those having three or more than three phenolic compounds OH groups.

Polycarbonates which have relative viscosities rj _re i of 1.10 to 1.50, in particular of 1.25 to 1.40, have proven particularly suitable. This corresponds to average molecular weights M _w (weight average) of 10,000 to 200,000, preferably from 20,000 to 80,000 g / mol.

The diphenols of the general formula are known per se or can be prepared by known processes.

The polycarbonates can be prepared, for example, by reacting the diphenols with phosgene by the interfacial process or with phosgene by the process in a homogeneous phase (the so-called pyridine process), the molecular weight to be set in each case being achieved in a known manner by a corresponding amount of known chain terminators. (With regard to polycarbonates containing polydiorganosiloxane, see for example DE-OS 3334782).

Suitable chain terminators are, for example, phenol, pt-butylphenol, but also long-chain alkylphenols such as 4- (1,3-tetramethylbutyl) phenol, according to DE-OS 2842 005 or monoalkylphenols or dialkylphenols with a total of 8 to 20 carbon atoms in the alkyl substiluents DE-A 3506472, such as p-nonylphenyl, 3,5-di-t-butylphenol, pt-octylphenol, p-dodecylphenol, 2- (3,5-dimethyl-heptyl) -phenol and 4- (3,5-dimethylheptyl -phenol.

Halogen-free polycarbonates in the sense of the present invention means that the polycarbonates consist of halogen-free diphenols, haiogen-free chain terminators and halogen-free branching agents are optionally built up, the content of minor ppm amounts of saponifiable chlorine, resulting, for example, from the production of the polycarbonates with phosgene by the phase boundary process, not to be regarded as containing halogen in the sense of the invention. Such polycarbonates with ppm contents of saponifiable chlorine are halogen-free polycarbonates in the sense of the present invention.

Amorphous polyester carbonates may be mentioned as further suitable components A), phosgene being replaced by aromatic dicarboxylic acid units such as isophthalic acid and / or terephthalic acid units during the preparation. For further details, reference is made to EP-A 711 810.

Further suitable copolycarbonates with cycloalkyl radicals as monomer units are described in EP-A 365916.

Bisphenol A can also be replaced by Bisphenol TMC. Such polycarbonates are available under the trademark APEC HT® from Bayer.

As component B), the molding compositions which can be used according to the invention contain 0.01 to 10, preferably 0.5 to 7 and in particular 1 to 5% by weight of epoxidized natural oils or fatty acid esters or mixtures thereof.

As component B), preference is given to using epoxidized compounds whose epoxy groups are not terminally bound (so-called “internal” epoxy groups located in the hydrocarbon chain).

The content of epoxy groups is preferably from 1 to 20, preferably from 4 to 15 and in particular from 6 to 12% by weight, based on the respective component B).

Preferred natural oils are olive oil, linseed oil, palm oil. Peanut oil, coconut oil, tung oil, turnip oil, castor oil, cod liver oil or their mixtures, with soybean oil being particularly preferred.

The molecular weight of such oils is preferably from 500 to 1000, in particular from 600 to 900. Such linseed or soybean oils are mixtures of tri-fatty acid glycerides, the C ₁₈ carboxylic acid component predominating.

The epoxidized fatty acid esters can generally be prepared from these natural oils, according to methods familiar to the person skilled in the art. Esters of saturated or unsaturated aliphatic carboxylic acids with 10 to 40, preferably 16 to 22, carbon atoms with aliphatic saturated alcohols with 2 to 40, preferably 2 to 6, carbon atoms are preferably used.

The carboxylic acids can be 1- or 2-valent. Examples include pelargonic acid, palmitic acid, lauric acid, margaric acid, dodencandioic acid, behenic acid and particularly preferably stearic acid, capric acid and montanic acid (mixture of fatty acids with 30 to 40 carbon atoms, linoleic acid, linolenic acid and elostearic acid , Called oleic acid.

The aliphatic alcohols can be 1- to 4-valent. Examples of alcohols are n-butanol, n-octanol, stearyl alcohol, ethylene glycol, propylene glycol, neopentyl glycol, pentaerythritol, myricyl alcohol, cetyl alcohol, glycerol being preferred.

Mixtures of different esters and / or oils can also be used.

Component B) preferably contains unsaturated fatty acid components, corresponding to an iodine number (according to DIN 53995) from 130 to 180 and in particular from 120 to 200 mg iodine per gram of substance.

The introduction of the epoxy function into the oils or / and esters mentioned above takes place via reaction of these with epoxidizing agents e.g. Peracids such as peracetic acid. Such implementations are known to the person skilled in the art, which is why further information on this is unnecessary.

The usable molding compositions according to the invention can contain 0 to 70, in particular up to 50% by weight of further additives as component C).

As component C), the molding compositions according to the invention can contain 0 to 5, in particular 0.01 to 5, preferably 0.05 to 3 and in particular 0.1 to 2% by weight of at least one ester or amide of saturated or unsaturated aliphatic carboxylic acids with 10 to 40 , preferably contain 16 to 22 carbon atoms with aliphatic saturated alcohols or amines with 2 to 40, preferably 2 to 6, carbon atoms. These differ from B) because they do not contain epoxy functions.

The carboxylic acids can be 1- or 2-valent. Examples include pelargonic acid, palmitic acid, lauric acid, margaric acid, dodecanedioic acid, behenic acid and particularly preferably stearic acid, capric acid and montanic acid (mixture of fatty acids with 30 to 40 carbon atoms). The aliphatic alcohols can be 1- to 4-valent. Examples of alcohols are n-butanol, n-octanol, stearyl alcohol, ethylene glycol, propylene glycol, neopentyl glycol, pentaerythritol, with glycerol and pentaerythritol being preferred.

The aliphatic amines can be 1- to 3-valent. Examples include stearylamine, ethylenediamine, propylenediamine, hexamethylenediamine, di (6-aminohexyt) amine, with ethylenediamine and hexamethylenediamine being particularly preferred. Preferred esters or amides are correspondingly glycerol distearate, glycerol tristearate, ethylenediamine distearate, glycerol monopalmitate, glycerol trilaurate, glycerol monobehenate and pentaerythritol tetrastearate.

Mixtures of different esters or amides or esters with amides can also be used in combination, the mixing ratio being arbitrary. It is particularly advantageous to add this component C) in amounts of 0.1 to 0.8, in particular 0.5 to 0.7,% by weight, based on A), when at least 80% of the desired final viscosity of component A has been reached ) and subsequent compounding with the other components B) to C).

Additional additives C) are, for example, in amounts of up to 40, preferably up to 30% by weight of rubber-elastic polymers (often also referred to as impact modifiers, elastomers or rubbers).

In general, these are copolymers which are preferably composed of at least two of the following monomers: ethylene, propylene, butadiene, isobutene, isoprene, chloroprene, vinyl acetate, styrene, acrylonitrile and acrylic or methacrylic acid esters with 1 to 18 C- Atoms in the alcohol component.

Such polymers are e.g. in Houben-Weyl, Methods of Organic Chemistry, Vol. 14/1 (Georg-Thieme-Verlag, Stuttgart, 1961). Pages 392 to 406 and in the monograph by C.B. Bucknall, 'Toughened Plastics' (Applied Science Publishers, London, 1977).

Some preferred types of such elastomers are presented below.

Preferred types of such elastomers are the so-called ethylene-propylene (EPM) or ethylene-propylene-diene (EPDM) rubbers.

EPM rubbers generally have practically no more double bonds, while EPDM rubbers can have 1 to 20 double bonds / 100 carbon atoms. Examples of diene monomers for EPDM rubbers are conjugated dienes such as isoprene and butadiene, non-conjugated dienes having 5 to 25 carbon atoms such as penta- 1,4-diene, hexa-1,4-diene, hexa-1,5 -diene, 2,5-dimethylhexa-1,5-diene and octa-1,4-diene, cyclic dienes such as cyclopentadiene, cyclohexadienes, cyclooctadienes and dicyclopentadiene and alkenylnorbornenes such as 5-ethylidene-2-norbornene, 5-butylidene 2-norbomen, 2-methallyl-5-norbomen, 2-isopropenyl-5-norbornene and tricyclodienes such as 3-methyl-tricyclo (5.2.1.0.2.6) -3,8-decadiene or mixtures thereof. Hexa-1,5-diene, 5-ethylidene norbornene and dicyclopentadiene are preferred. The diene content of the EPDM rubbers is preferably 0.5 to 50, in particular 1 to 8,% by weight, based on the total weight of the rubber.

EPM or EPDM rubbers can preferably also be grafted with reactive carboxylic acids or their derivatives. Here are e.g. Acrylic acid, methacrylic acid and their derivatives, e.g. Glycidyl (meth) acrylate, as well as maleic anhydride.

Another group of preferred rubbers are copolymers of ethylene with acrylic acid and / or methacrylic acid and / or the esters of these acids. In addition, the rubbers can also contain dicarboxylic acids such as maleic acid and fumaric acid or derivatives of these acids, e.g. Contain esters and anhydrides, and / or monomers containing epoxy groups. These monomers containing dicarboxylic acid derivatives or epoxy groups are preferably incorporated into the rubber by adding monomers of the general formulas I or II or III or IV containing dicarboxylic acid or epoxy groups to the monomer mixture:

R ¹ C (COOR ² ) = C (COOR ³ ) R ⁴ (I)

R

(II)

CO O

CH ₂ = CR ^§ - COO (-CH,) - CH CHR ⁸ (IV)

\ /

O where R to R ^{9 are} hydrogen or alkyl groups having 1 to 6 carbon atoms and m is an integer from 0 to 20, g is an integer from 0 to 10 and p is an integer from 0 to 5.

The radicals R ¹ to R ^{9 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 formulas I, II and IV are maleic acid, maleic anhydride and epoxy group-containing esters of acrylic acid and / or methacrylic acid, such as glycidyl acrylate, glycidyl methacrylate and the esters with tertiary alcohols, such as t-butyl acrylate. Although the latter have no free carboxyl groups, their behavior comes close to that of the free acids and is therefore referred to as monomers with latent carboxyl groups.

The copolymers advantageously consist of 50 to 98% by weight of ethylene, 0.1 to 20% by weight of monomers containing epoxy groups and / or monomers containing methacrylic acid and / or monomers containing acid anhydride groups and the remaining amount of (meth) acrylic acid esters.

Copolymers of are particularly preferred

50 to 98, in particular 55 to 95% by weight of ethylene,

0.1 to 40, in particular 0.3 to 20% by weight of glycidyl acrylate and / or glycidyl methacrylate, (meth) acrylic acid and / or maleic anhydride, and

1 to 45, in particular 10 to 40% by weight of n-butyl acrylate and / or 2-ethylhexyl acrylate.

Further preferred esters of acrylic and / or methacrylic acid are the methyl, ethyl, propyl and i- or t-butyl esters.

In addition, vinyl esters and vinyl ethers can also be used as comonomers.

The ethylene copolymers described above can be prepared by processes known per se, preferably by random copolymerization under high pressure and elevated temperature. Appropriate methods are generally known. Preferred elastomers are also emulsion polymers, the preparation of which is described, for example, by Blackley in the monograph "Emulsion Polymerization". The emulsifiers and catalysts that can be used are known per se.

In principle, homogeneous elastomers or those with a shell structure can be used. The shell-like structure is determined by the order of addition of the individual monomers; The morphology of the polymers is also influenced by this order of addition.

Only representative here are monomers for the production of the rubber part of the elastomers, such as acrylates. n-Butyl acrylate and 2-ethylhexyl acrylate, corresponding methacrylates, butadiene and isoprene and mixtures thereof. These monomers can be combined with other monomers such as e.g. Styrene, acrylonitrile, vinyl ethers and other acrylates or methacrylates such as methyl methacrylate, methyl acrylate, ethyl acrylate and propyl acrylate can be copolymerized.

The soft or rubber phase (with a glass transition temperature of below 0 ° C) of the elastomers can represent the core, the outer shell or a middle shell (in the case of elastomers with more than two-shell structure); in the case of multi-layer elastomers, several shells can also consist of a rubber phase.

If, in addition to the rubber phase, one or more hard components (with glass transition temperatures of more than 20 ° C) are involved in the construction of the elastomer, these are generally obtained by polymerizing styrene, acrylonitrile, methacrylonitrile, α-methylstyrene, p-methylstyrene, acrylic acid esters and methacrylic acid esters such as methyl acrylate, ethyl acrylate and methyl methacrylate as main monomers. In addition, smaller proportions of further comonomers can also be used here.

In some cases it has proven advantageous to use emulsion polymers which have reactive groups on the surface. Such groups are e.g. Epoxy, carboxyl, latent carboxyl, amino or amide groups as well as functional groups by the use of monomers of the general formula

can be introduced where the substituents can have the following meanings:

R ^{0 is} hydrogen or ad- to C ₄ -alkyl group,

R ^{11 is} hydrogen, ad- to C ₈ -alkyl group or an aryl group, in particular phenyl,

R ^{12 is} hydrogen, ad to d ₀ alkyl, a C ₆ to C ₁₂ aryl group or -OR ¹³

R ^{13 is} a C 1 to C ₈ alkyl or C ₆ to C ₁₂ aryl group, which may optionally be substituted by O- or N-containing groups,

X is a chemical bond, ad to C ₁₀ alkylene or C ₆ -C ₂ arylene group or

O

- C - Y Y O-Z or NH-Z and

Z is a d- to Cι ₀ alkylene or C ₆ - to Cι ₂ arylene group.

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

Further examples include acrylamide, methacrylamide and substituted esters of acrylic acid or methacrylic acid such as (Nt-butylamino) ethyl methacrylate, (N, N-dimethylamino) ethyl! Acrylate, (N, N-dimethylamino) methyl acrylate and (N , N-Diethylamino) ethyl acrylate called.

The particles of the rubber phase can also be crosslinked. Monomers acting as crosslinking agents are, for example, buta-1,3-diene, divinylbenzene, diallyl phthalate and dihydrodicyclopentadienyl acrylate and the compounds described in EP-A 50265.

So-called graft-linking monomers can also be used, ie monomers with two or more polymerizable double bonds which react at different rates during the polymerization. Compounds are preferably used in which at least one reactive group polymerizes at approximately the same rate as the other monomers, while the other reactive group (or reactive groups), for example polymerizes much slower (polymerize). The different polymerization rates result in a certain proportion of unsaturated double bonds in the rubber. If a further phase is subsequently grafted onto such a rubber, the double bonds present in the rubber react at least partially with the graft monomers to form chemical bonds, ie the grafted phase is at least partially linked to the graft base via chemical bonds.

Examples of such graft-crosslinking monomers are monomers containing allyl groups, in particular allyl esters of ethylenically unsaturated carboxylic acids such as allyl acrylate, allyl methacrylate, diallyl maleate, diallyl fumarate, diallyl itaconate or the corresponding monoallyl compounds of these dicarboxylic acids. There are also a large number of other suitable graft-crosslinking monomers; for further details, reference is made here, for example, to US Pat. No. 4,148,846.

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

Instead of graft polymers with a multi-layer structure, homogeneous, i.e. single-shell elastomers of buta-1, 3-diene, isoprene and n-butyl acrylate or their copolymers are used. These products can also be produced by using crosslinking monomers or monomers with reactive groups.

Examples of preferred emulsion polymers are n-butyl acrylate (meth) acrylic acid copolymers, n-butyl acrylate / glycidyl acrylate or n-butyl acrylate glycidyl methacrylate copolymers, graft polymers with an inner core made of n-butyl acrylate or based on butadiene and an outer shell from the above mentioned copolymers and copolymers of ethylene with comonomers which provide reactive groups.

The elastomers described can also be made by other conventional methods, e.g. by suspension polymerization.

Silicone rubbers as described in DE-A 3725576, EP-A 235690, DE-A 3800 603 and EP-A 319290 are also preferred.

Mixtures of the rubber types listed above can of course also be used. The fibrous or particulate fillers C) are carbon fibers, glass fibers, glass spheres, amorphous silica, asbestos, calcium silicate, calcium metasilicate, magnesium carbonate, kaolin, chalk, powdered quartz, mica, barium sulfate and feldspar, which are present in amounts of up to 50% by weight. -%, in particular 1 to 50%, preferably 5 to 40 and in particular 15 to 35 wt .-% are used.

Carbon fibers, aramid fibers and potassium titanate fibers may be mentioned as preferred fibrous fillers, glass fibers being particularly preferred as E-glass. These can be used as rovings or cut glass in the commercially available forms.

The fibrous fillers can be surface-pretreated with a silane compound for better compatibility with the thermoplastic.

Suitable silane compounds are those of the general formula

(X- (CH ₂ ) n) k-Si- (OC _m H _2r n + l) -

in which the substituents have the following meaning:

X NH ₂ -, CH, - CH-, HO-,

\ /

O

n is an integer from 2 to 10, preferably 3 to 4 m is an integer from 1 to 5, preferably 1 to 2 k is an integer from 1 to

Preferred silane compounds are aminopropyltrimethoxysilane, aminobutyltrimethoxysilane, aminopropyltriethoxysilane, aminobutyltriethoxysilane and the corresponding silanes which contain a glycidyl group as substituent X.

The silane compounds are generally used in amounts of 0.05 to 5, preferably 0.5 to 1.5 and in particular 0.8 to 1% by weight (based on C) for the surface coating.

Acicular mineral fillers are also suitable.

For the purposes of the invention, acicular mineral fillers are understood to be mineral fillers with a pronounced acicular character. As an game is called needle-shaped wollastonite. The mineral preferably has a UT - (length diameter) ratio of 8: 1 to 35: 1, preferably 8: 1 to 11: 1. The mineral filler may optionally have been pretreated with the abovementioned silane compounds; however, pretreatment is not essential.

Kaolin, calcined kaolin, wollastonite, talc and chalk may be mentioned as further fillers.

As component C), the thermoplastic molding compositions which can be used according to the invention can contain customary processing aids such as stabilizers, oxidation retardants, agents against heat decomposition and decomposition by ultraviolet light, further lubricants and mold release agents, colorants such as dyes and pigments, nucleating agents, plasticizers, flame retardants, etc.

Various substituted resorcinols, salicylates, benzotriazoles and benzophenones may be mentioned as UV stabilizers, which are generally used in amounts of up to 2% by weight, based on the molding composition.

Suitable stabilizers are preferably organic phosphonites C) of the general formula I.

wherein

m 0 or 1, n 0 or 1, y is an oxygen, sulfur or 1,4-phenylene bridge or a bridge member of the formula -CH (R ² ) -; all RO and R -O groups independently of one another, the residue of an aliphatic, alicyclic or aromatic alcohol which may contain up to three hydroxyl groups, but the hydroxyl groups are not arranged such that they can be part of a phosphorus-containing ring ( referred to as monovalent RO groups), or two RO or R -O groups bonded to a phosphorus atom, each independently of one another together the remainder of an aliphatic, alicyclic or aromatic alcohol with a total of up to three hydroxyl groups (referred to as divalent RO or R ¹ -O groups), R ^{2 is} hydrogen, dC ₈ alkyl or a group of the formula COOR ³ and R ^{3 is} Cι- ₈ alkyl ,

Preference is given to at least one RO and at least R ¹ -O group, a phenol radical which, in the 2-position, bears a sterically hindered group, in particular t-butyl radicals.

It is particularly preferred tetrakis (2,4-di-tert-butyl-phenyl) -biphenyls diphosphonite, which is commercially available as Irgaphos® ^® PEPQ Ciba Geigy AG.

When RO and R ¹ are -ivalent radicals, they are preferably derived from dihydric or trihydric alcohols.

R is preferably R ¹ and this is alkyl, aralkyl (preferably optionally substituted phenyl or phenylene), aryl (preferably optionally substituted phenyl) or a group of the formula a

wherein the cores A and B can carry further substituents and Y 'is an oxygen or sulfur bridge or a bridge member of the formula -CH (R ³ ) -,

R ^{2 is} hydrogen, dC ₈ alkyl or a group of the formula -COOR ³ and

R ^{3 is} C ₈ alkyl and n is 0 or 1 (referred to as divalent R ').

Particularly preferred radicals R are the radicals R ", where this d-22-alkyl, phenyl, the 1 to 3 substituents from the series cyano- ₂₂ alkyl, C 1-4 alkoxy, benzyl, phenyl, 2-2.6, 6-tetramethyl! -Piperidyl-4-, hydroxy, _8- alkylphenyl, carboxyl, -C (CH ₃ ) 2-C ₆ H ₅ , - COO-Cι. ₂₂ -alkyl, CH ₂ CH ₁₂ -COOH , -CH ₂ CH ₂ COO-, d- ₂ 2-alkyl or -CH2-Sd-22-alkyl, or a group of the formula i to vii.

(i) (ü) (iii)

(Iv)

(V)

(vi) (vii)

or two R "together form a group of formula viii

mean where R ^{8 is} hydrogen or d. ₂₂ alkyl,

R ^{6 is} hydrogen, d- ₄ alkyl or -CO-d. ₈ alkyl,

R ^{4 is} hydrogen or alkyl;

R ^{5 is} hydrogen, C ₂₂ alkyl, C ₂₂ alkoxy, benzyl, cyano, phenyl, hydroxyl, C ₈ - alkylphenyl, C. ₂₂ -alkoxycarbonyl, d- ₂₂ -alkoxycarbonylethyl, carboxyethyl, 2,2,6,6-tetramethylpiperidyl-4- or a group of the formula -CH ₂ -S-Cι. ₂ alkyl or -C (CH ₃ ) ₂ -C ₆ H ₅ and

R ^{7 is} hydrogen, d- ₂₂ alkyl, hydroxy or alkoxy and

Y 'and n have the meanings given above.

Particularly preferred as radicals R are the radicals R ", which are one of the formulas a to g

correspond to what

R ^{9 is} hydrogen, Cι. ₈ alkyl, ds-alkoxy, phenyl, d. _8- alkylphenyl or phenyl-d. ₈ -

Alkylphenyl or phenyl-d- ₄ -alkyl, R ¹⁰ and R ¹¹ independently of one another, hydrogen, d- ₂₂ -alkyl, phenyl or d- ₈ -

Alkylphenyl, R ^{12 is} hydrogen or Cι. ₈ alkyl and R ¹³ cyan, carboxyl or d- ₈ alkoxycarbonyl mean.

Among the groups of the formula a are 2-tert-butylphenyl, 2-phenylphenyl, 2- (1 ', 1'-dimethyl-propyl) -phenyl, 2-cyclohexylphenyl, 2-tert-butyl-4-methylphenyl, 2,4-di-tert-amylphenyl, 2,4-di-tert-butylphenyl, 2,4-di-phenylphenyl, 2,4-di-tert-octylphenyl, 2-tert-butyl-4- phenylphenyl, 2,4-bis (1 ', 1' dimethylpropyl) phenyl, 2- (1 'phenyl-1' methylethyl) phenyl, 2,4 bis (1 'phenyl) 1'-methylethyl) phenyl and 2,4-di-tert-butyl-6-methylphenyl are preferred.

Processes for the preparation of the phosphonites C) can be found in DE-A 4001 397, which can be present in the molding compositions in amounts of from 0.001 to 5, preferably from 0.01 to 3,% by weight. Inorganic compounds of phosphoric acid may be mentioned as further phosphorus-containing stabilizers in the abovementioned amounts, alkaline earth metals and alkali metals being preferred. Zinc phosphate or zinc dihydrogen phosphate are particularly preferred.

Inorganic pigments such as ultramarine blue, iron oxide, zinc sulfide, titanium dioxide and carbon black, organic pigments such as phthalocyanines, quinacridones, perylenes and dyes such as anthraquinones can also be added as colorants.

Sodium phenylphosphinate, aluminum oxide, silicon dioxide and preferably talc are used as nucleating agents.

Other lubricants and mold release agents, which are usually used in amounts of up to 1% by weight, are preferably long-chain fatty acids (e.g. stearic acid or behenic acid), their salts (e.g. Ca or Zn stearate) or montan waxes (mixtures of straight-chain, saturated Carboxylic acids with chain lengths of 28 to 32 carbon atoms) or their salts with (earth) alkali metals, preferably Ca montanate and / or sodium montanate) and low molecular weight polyethylene or polypropylene waxes.

Examples of plasticizers are phthalic acid dioctyl ester, phthalic acid dibenzyl ester, phthalic acid butyl benzyl ester, hydrocarbon oils, N- (n-butyl) benzenesulfonamide.

The thermoplastic molding compositions which can be used according to the invention can be prepared by processes known per se, in which the starting components are mixed in customary mixing devices, such as screw extruders, Brabender mills or Banbury mills, and then extruded. After extrusion, it can Extrudate cooled and crushed. Individual components can also be premixed and then the remaining starting materials can be added individually and / or also mixed. The mixing temperatures are usually 230 to 290 ° C.

According to a preferred procedure, components B) to C) can be mixed with a polyester prepolymer, made up and granulated. The granules obtained are then condensed in the solid phase under inert gas continuously or batchwise at a temperature below the melting point of component A) to the desired viscosity.

The molding compositions which can be used according to the invention are distinguished by a substantially improved resistance to hydrolysis.

They are suitable for the production of fibers, foils and molded parts of any kind which have an increased resistance to hydrolysis. These applications are, in particular, bristles for toothbrushes, paper screen fabrics, films and molded parts which can be sterilized with superheated steam, pipes, molded parts and profiles for the automotive sector which are exposed to elevated temperatures and moisture, and polyester molding compounds for coating paper and cardboard, for the production of films, profiles and pipes and polyester molding compounds for the production of technical functional parts by injection molding, for example automotive components, parts for the electrical industry and parts with high heat and hydrolysis resistance as well as external vehicle parts such as bumpers and spoilers, petrol and oil-resistant technical components with good paintability, housing and switch covers , Plug connections, switches, motor housings, headlight parts and electrical components such as microswitches, capacitor cups, switch parts, circuit breaker housings, circuit boards.

Examples

Component A ^ polybutylene terephthalate (PBT) with a viscosity number of 130 ml / g and a carboxyl end group content of 25 meq / kg (VZ measured in 0.5% by weight solution of phenol / o-dichlorobenzene, 1: 1 mixture at 35oC according to ISO 1628), containing 0.65% by weight, based on A ¹ , of pentaerythritol tetrastearate (component C1).

Component A ₂ : PBT with a VN of 107 ml / g (without component F1)

Component B ^ epoxidized soybean oil (epoxy content: approx. 8% by weight) (Edenol ^® D81 from Cognis GmbH) Component B ₂ : epoxidized soybean oil (epoxy content: approx. 8% by weight)

(Merginat ^® ESB from Harburger Fettchemie Brinkmann &

Mergeil GmbH)

Component B ₃ : epoxidized linseed oil (epoxy content: approx. 9% by weight)

(Merginat ^® ELO from Harburger Fettchemie Brinkmann &

Mergeil GmbH)

Component B: for comparison according to EP 794 974 carbodiimide based on 1, 3 bis (1-isocyanato-1-methylethyl) benzene in polyethylene terephthalate (Stabaxol ^® MBPET 5010 from Rheinchemie GmbH)

Weight ratio: PCDI: PET 15%: 85%

Component C ₂ : chopped glass fibers with an average length of 4 mm (epoxysilanized size)

Component C ₃ : talc

Production of molding compounds

Components A) to C) were mixed in the proportions given in the table on an extruder at 260 ° C., homogenized, granulated and dried. Charpy test specimen: 80 x 10 x 4 mm ³ , tensile test: switch rod according to DIN

The modulus of elasticity, elongation at break was determined in accordance with ISO 527-2, Charpy in accordance with ISO 179 / 1eU.

The melt index was determined by MVR measurement at 275 ° C or 250 ° C / 2.16 kg load.

The composition of the molding compounds and the results of the measurements can be found in the table.

Claims

claims

1. Use of epoxidized natural oils or fatty acid esters or their mixtures (component B) for the production of hydrolysis-resistant thermoplastic polyester molding compositions (A).

2. Use of epoxidized natural oils or fatty acid esters or their mixtures to increase the resistance to hydrolysis of molded parts made of thermoplastic polyesters A).

3. Use according to claims 1 or 2, in which component B) has a content of 1 to 20 wt .-% of epoxy groups.

4. Use according to claims 1 to 3, in which the epoxy groups of component B) are not terminally bound.

5. Use according to claims 1 to 4, wherein the polyester molding compositions may contain up to 70% by weight, based on the molding compositions from A) to C), of further additives (C).

6. Use according to claims 1 to 5, wherein the amount of component B) is 0.01 to 10 wt .-% based on A) to C).

7. Use according to claims 1 to 6, wherein component A) is composed of epoxidized olive oil, linseed oil, soybean oil, palm oil, peanut oil, coconut oil, tung oil, cod liver oil or mixtures thereof.

8. Use according to claims 1 to 6, wherein the epoxidized fatty acid esters B) are composed of saturated or unsaturated aliphatic carboxylic acids having 10 to 40 carbon atoms with aliphatic saturated alcohols having 2 to 40 carbon atoms.

9. Hydrolysis-resistant moldings, fibers and films obtainable in accordance with usage claims 1 to 8

10. Injection molded articles, coated articles, articles for electrical and electronic use, automotive components, available in accordance with use claims 1 to 8.