WO2012022669A2 - Nanocomposite blends with polyesters - Google Patents

Abstract

Thermoplastic moulding compounds comprising A) 10% to 98.95% by weight of at least one thermoplastic polyester, B) 0.05% to 30% by weight of at least one nanoparticulate oxide and/or oxide hydrate of at least one metal or semimetal, having a number-weighted average diameter of the primary particles of 0.5 to 50 nm and a hydrophobic particle surface, C) 1% to 60% by weight of at least one graft polymer, composed of c₁) 20% to 80% by weight of a graft base which is composed of a rubber-elastic polymer based on alkyl acrylates having 1 to 8 C atoms in the alkyl radical and/or dienes having a glass transition temperature of below 10°C, c₂) 20% to 80% by weight of a graft comprising c₂₁) 60% to 95% by weight of styrene or substituted styrenes of the general formula I in which R is an alkyl radical having 1 to 8 C atoms or a hydrogen atom and R¹ is an alkyl radical having 1 to 8 C atoms and n has a value of 1, 2 or 3, and c₂₂) 5% to 40% by weight of at least one unsaturated nitrile, D) 0% - 60% by weight of further additives, the sum of the percentages by weight of components A) to D) making 100%.

Description

 Nanocomposite blends with polyesters

description

The invention relates to thermoplastic molding compositions comprising

A) from 10 to 98.95% by weight of at least one thermoplastic polyester, B) from 0.05 to 30% by weight of at least one nanoparticulate oxide and / or hydrated oxide of at least one metal or half metal having a number-weighted mean diameter of the primary particles of 0.5 to 50 nm and a hydrophobic particle surface,

1 to 60 wt .-% of at least one graft polymer, composed of

20 to 80 wt .-% of a graft base of a rubber-elastic polymers based on alkyl acrylates having 1 to 8 carbon atoms in the alkyl radical and / or dienes having a glass transition temperature of below 10 ° C.

20 to 80 wt .-% of a graft

C21) from 60 to 95% by weight of styrene or substituted styrenes of the general formula I

worin R einen Alkylrest mit 1 bis 8 C-Atomen oder ein Wasserstoffatom und R¹ ei nen Alkylrest mit 1 bis 8 C-Atomen darstellen und n den Wert 1 , 2 oder 3 hat und

in which R is an alkyl radical having 1 to 8 C atoms or a hydrogen atom and R ^{1 is} an alkyl radical having 1 to 8 C atoms and n is 1, 2 or 3 and

From 5 to 40% by weight of at least one unsaturated nitrile,

D) 0-60 wt .-% of other additives, wherein the sum of the weight percent of components A) to D) gives 100%.

Furthermore, the invention relates to the use of the thermoplastic molding compositions for the production of fibers, films and moldings as well as fibers, films and moldings, which are obtainable from the thermoplastic molding compositions according to the invention. The modification of polyesters with rubbers is known. Among others, rubbers based on ASA and / or ABS are also suitable for this purpose.

For example, polyesters and nanoparticles are made of e.g. CN-A 10/1423656, CN-A 1/687230 and 10/1407630.

The mechanical properties of the known blends, which contain a combination of rubber and nanoparticles, are in need of improvement.

 The object of the present invention was therefore to provide blends of polyester with ASA / ABS rubbers which should have good processability and at the same time improved mechanical properties (in particular impact strength) with nanoparticles.

Accordingly, the molding compositions defined above were found. Preferred embodiments are given in the subclaims.

As component (A), the molding compositions according to the invention contain from 10 to 98.95, preferably from 20 to 94 and in particular from 30 to 90,% by weight of at least one thermoplastic

Polyester.

Generally, polyesters A) based on aromatic dicarboxylic acids and an aliphatic or aromatic dihydroxy compound are used.

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

Such polyalkylene terephthalates are known per se and described in the literature.

They contain an aromatic ring in the main chain, that of the aromatic

Dicarboxylic acid is derived. The aromatic ring may also be substituted, e.g.

by halogen, such as chlorine and bromine, or by C 1 -C 4 -alkyl groups, such as methyl, ethyl, 25-i or n-propyl and n, i and t-butyl groups, respectively.

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

As 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 obtained by aliphatic or cycloaliphatic dicarboxylic acids, such as adipic acid, azelaic acid, sebacic acid,

35 dodecanedioic and cyclohexanedicarboxylic acids are replaced.

Of the aliphatic dihydroxy compounds are diols having 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.

Particularly preferred polyesters (A) are polyalkylene terephthalates which are derived from alkanediols having 2 to 6 C atoms. Of these, in particular, polyethylene terephthalate, polypropylene terephthalate and polybutylene terephthalate or mixtures thereof are preferred. Preference is furthermore given to PET and / or PBT which 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 (measured in a 0.5 wt .-% solution in a Phenollo- Dichlorbenzolgemisch (weight ratio 1: 1 at 25 ° C.) according to ISO 1628. Particular preference is given to 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 of polyester. A 44 01 055. The carboxyl end group content is usually determined by titration methods (eg potentiometry).

Particularly preferred molding compositions contain as component A) a mixture of polyesters which are different from P8T, such as, for example, polyethylene terephthalate (PET). The proportion z.8. of the polyethylene terephthalate is preferably in the mixture up to 50, especially-1 -0 to 35 wt .-%, based on 100 wt .-% A).

Furthermore, it is advantageous to use PET recyclates (also termed scrap PET), optionally mixed with polyalkylene terephthalates such as PBT.

Recyclates are generally understood as:

1) so-called Post Industrial Recyclate: these are production waste in polycondensation or in processing, e.g. Sprues in injection molding processing, start-up goods in injection molding or extrusion or edge sections of extruded sheets or foils.

2) Post Consumer Recyclate: These are plastic items that are collected and processed after use by the end user. By far the dominating items in terms of volume are blow-molded PET bottles for mineral water, soft drinks and juices.

Both types of recycled material can be present either as regrind or in the form of granules. In the latter case, after the separation and purification in an extruder, the tubes are recycled. the melted and granulated. This usually facilitates the handling, the flowability and the metering for further processing steps.

Both granulated and as regrind present recyclates can be used, the maximum edge length should be 10 mm, preferably less than 8 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 derived from aromatic dicarboxylic acids and aromatic dihydroxy compounds.

Suitable aromatic dicarboxylic acids are the compounds already described for the polyalkylene terephthalates. Preference is given to using mixtures of 5 to 100 mol% of isophthalic acid and 0 to 95 mol% of terephthalic acid, in particular mixtures of about 80% of terephthalic acid with 20% of isophthalic acid to approximately equivalent mixtures of these two acids.

The aromatic dihydroxy compounds preferably have the general formula

in der Z eine Alkylen- oder Cycloalkylengruppe mit bis zu 8 C-Atomen, eine Arylengruppe mit bis zu 12 C-Atomen, eine Carbonylgruppe, eine Sulfonylgruppe, ein Sauerstoff- oder Schwefel- atom oder eine chemische Bindung darstellt und in der m den Wert 0 bis 2 hat. Die Verbindungen können an den Phenylengruppen auch Ci-Cö-Alkyl- oder Alkoxygruppen und Fluor, Chlor oder Brom als Substituenten tragen.

in which Z represents an alkylene or cycloalkylene group having up to 8 C atoms, an arylene group having up to 12 C atoms, a carbonyl group, a sulfonyl group, an oxygen or sulfur atom or a chemical bond and in the m the value 0 to 2 has. The compounds may also carry C 1 -C 6 -alkyl or alkoxy groups and fluorine, chlorine or bromine as substituents on the phenylene groups.

As a parent of these compounds his example

dihydroxydiphenyl,

Di (hydroxyphenyl) alkane,

Di (hydroxyphenyl) cycloalkane,

Di (hydroxyphenyl) sulfide,

Di (hydroxyphenyl) ether,

ketone di- (hydroxyphenyl),

di- (hydroxyphenyl) sulfoxide,

a, a'-di- (hydroxyphenyl) -dialkylbenzol,

Di (hydroxyphenyl) sulfone, di (hydroxybenzoyl) benzene Resorcinol and

 Hydroquinone and their nuclear alkylated or ring-halogenated derivatives called. Of these will be

4,4'-dihydroxydiphenyl,

2,4-di- (4'-hydroxyphenyl) -2-methylbutane

a, a'-di- (4-hydroxyphenyl) -p-diisopropylbenzene,

2,2-di- (3'-methyl-4'-hydroxyphenyl) propane and

2,2-di- (3'-chloro-4'-hydroxyphenyl) propane, and in particular 2,2-di- (4'-hydroxyphenyl) propane

 2,2-di- (3 ', 5-dichlordihydroxyphenyl) propane,

 1,1-di- (4'-hydroxyphenyl) cyclohexane,

 3,4'-dihydroxybenzophenone,

 4,4'-dihydroxydiphenylsulfone and

2,2-di (3 ', 5'-dimethyl-4'-hydroxyphenyl) propane or mixtures thereof are preferred.

Of course, it is also possible to use mixtures of polyalkylene terephthalates and fully aromatic polyesters. These generally contain from 20 to 98% by weight of the polyalkylene terephthalate and from 2 to 80% by weight of the wholly aromatic polyester.

Of course, polyester block copolymers such as copolyetheresters may also be used. Such products are known per se and are known in the literature, e.g. in US Pat. No. 3,651,014. Also in the trade, corresponding products are available, e.g. Hytrel® (DuPont).

worin Q eine Einfachbindung, eine d- bis Ce-Alkylen-, eine C2- bis C3-Alkyliden-, eine C3- bis Cö-Cycloalkylidengruppe, eine CQ- bis Ci2-Arylengruppe sowie -O-, -S- oder -SO2- bedeutet und m eine ganze Zahl von 0 bis 2 ist. Die Diphenole können an den Phenylenresten auch Substituenten haben wie C1 - bis C_ß-Alkyl oder C1 - bis Cö-Alkoxy. As a polyester to be understood according to the invention also halogen-free polycarbonates. Suitable halogen-free polycarbonates are, for example, those based on diphenols of the general formula

in which Q denotes a single bond, a C 1 - to C 6 -alkylene, a C 2 - to C 3 -alkylidene, a C 3 - to C 6 -cycloalkylidene group, a C 2 - to C 12 -arylene group and -O-, -S- or -SO 2 - and m is an integer from 0 to 2. The diphenols may on the phenylene radicals also have substituents such as C 1 - to C _ß -alkyl or C1 - to Coe-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. Particularly preferred are 2,2-bis (4-hydroxyphenyl) propane and 1, 1-bis (4-hydroxyphenyl) cyclohexane, and 1, 1-bis (4-hydroxyphenyl) -3,3,5-trimethyl - cyclohexane.

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

The suitable polycarbonates may be branched in a known manner, preferably by the incorporation of from 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.

Particularly suitable polycarbonates have proven, the relative viscosities r _re i from 1.10 to 1.50, in particular from 1.25 to 1.40. This corresponds to average molecular weights M w (weight average) of from 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 phase boundary process or with phosgene by the homogeneous phase process (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 respect polydiorganosiloxanhaltigen polycarbonates see, for example, DE-OS 33 34 782).

Suitable chain terminators include phenol, pt-butylphenol but also long-chain alkylphenols such as 4- (1, 3-tetramethyl-butyl) -phenol, according to DE-OS 28 42 005 or monoalkylphenols or dialkylphenols having a total of 8 to 20 carbon atoms in the alkyl substituents according to DE-A 3506472, such as p-nonylphenyl, 3,5-di-t-butylphenol, pt-octylphenol, p-dodecylphenol, 2- (3,5-dimethylheptyl) -phenol and 4- ( 3,5-dimethylheptyl) -phenol. Halogen-free polycarbonates in the context of the present invention means that the polycarbonates are composed of halogen-free diphenols, halogen-free chain terminators and optionally halogen-free branching agents, the content of minor ppm amounts of saponifiable chlorine resulting, for example, from the preparation of the polycarbonates with phosgene the interfacial process, is not to be regarded as halogen-containing in the context of the invention. Such polycarbonates with ppm contents of saponifiable chlorine are halogen-free polycarbonates in the context of the present invention.

As further suitable components A) may be mentioned amorphous polyester carbonates, wherein phosgene against aromatic dicarboxylic acid units such as isophthalic acid and / or terephthalic acid units, was replaced in the preparation. For further details, reference is made at this point to EP-A 71 1 810.

Further suitable copolycarbonates with cycloalkyl radicals as monomer units are described in EP-A 365 916.

Furthermore, bisphenol A can be replaced by bisphenol TMC. Such polycarbonates are available under the trademark APEC HT® from Bayer. The content of component B) is 0.05 to 30, preferably 0.05 to 10 and in particular 1 to 5 wt .-%, based on A) to D).

According to the invention, component B) is at least one nanoparticulate oxide and / or hydrated oxide of at least one metal or semimetal having a number-weighted mean diameter of the primary particles of 0.5 to 50 nm and a hydrophobic particle surface.

 Corresponding oxides and / or oxide hydrates with a hydrophobic particle surface are known per se to the person skilled in the art.

Component B) can be characterized in particular by at least one of the following features a) and / or b): a) component B) is at least one nanoparticulate oxide and / or hydrated oxide of at least one metal or semimetal having a number-weighted mean diameter of the primary particles of 0 , 5 to 50 nm. B) Component B) has a methanol wettability of at least 50%.

The methanol wettability is a measure of how hydrophobic an oxide and / or hydrated oxide of at least one metal or semi-metal is. In the process, oxides and / or oxide hydrates are wetted using a methanol / water mixture. The proportion of methanol in the mixture, expressed in weight percent, is a measure of the water repellency of the metal oxide. The higher the proportion of methanol, the more hydrophobic the substance is. The degree of hydrophobicity is determined by titration. For this purpose, 0.2 g of the sample are weighed in a 250 ml separating funnel and 50 ml ultrapure water added. The oxide or hydrated oxide with hydrophobic surface remains on the surface of the water. Methanol is now added from a burette. In doing so, the separating funnel is shaken with a circular hand movement so that no swirls are created in the liquid. In this way, methanol is added until the powder is wetted. This can be seen from the decrease in the total powder from the water surface. The consumption of methanol is converted into wt .-% methanol and indicated as a value for the methanol wettability.

The number-weighted average diameter of the primary particles is determined in the thermoplastic molding composition by transmission electron microscopy and subsequent image analysis analysis on the basis of a statistically significant number of samples. Corresponding methods are known to the person skilled in the art.

Oxides with a hydrophobic particle surface generally have a BET surface area according to DIN 66131 of at most 300 m ² / g. Component B) preferably has a BET specific surface area to DIN 66131 of 50 to 300 m ² / g, in particular from 100 to 250 m ² / g. Preferably, the metal and / or semimetal according to component B) is silicon. The thermoplastic molding compositions of the invention preferably contain as component B) a nanoparticulate oxide and / or hydrated oxide of silicon having a number-weighted mean diameter of the primary particles of 0.5 to 50 nm, in particular 1 to 20 nm. Component B) is particularly preferably flame-pyrolytically produced nanoparticulate silicon - dioxide whose surface is hydrophobically modified.

Component B) particularly preferably has a number-weighted mean diameter of the primary particles of from 1 to 20 nm, preferably from 1 to 15 nm.

In a preferred embodiment, component B) is hydrophobically modified by a surface modifier, preferably an organosilane.

The surface modification can be carried out by contacting the nanoparticles, preferably as a suspension or as such, with a surface modifier, for example by spraying.

In particular, the nanoparticles can first be sprayed with water and then with the surface modifier. The spraying can also be done in reverse order. The water used may be acidified with an acid, for example hydrochloric acid, to a pH of 7 to 1. If several surface modifiers can be used, they can be applied as a mixture or separately, simultaneously or sequentially.

The surface modifier (s) may be dissolved in suitable solvents. After the spraying is finished, mixing can be continued for 5 to 30 minutes. Preferably, the mixture is then thermally treated at a temperature of 20 to 400 ° C over a period of 0.1 to 6 hours. The thermal treatment can be carried out under protective gas, such as nitrogen. An alternative method of surface modification of the silicas may be carried out by treating the silicas with the surface modifier in vapor form and then thermally treating the mixture at a temperature of 50 to 800 ° C for a period of 0.1 to 6 hours. The thermal treatment can be carried out under protective gas, such as nitrogen. The temperature treatment can also be carried out in several stages at different temperatures. The application of the surface modifier (s) can be done with single, dual or ultrasonic nozzles.

The surface modification can be carried out continuously or batchwise in heatable mixers and dryers with sprayers. Suitable devices may be, for example: plowshare mixers, plate, fluidized bed or fluid bed dryers.

In the context of the present invention advantageously usable surface modifiers are described in DE 10 2007 035 951 A1 in paragraph [0015]. Preferably can be used as surface modifiers following silanes: octyl tyltrimethoxysilan, octyltriethoxysilane, hexamethyldisilazane, 3-Methacrylxypropyltrimethoxysilan, 3-methacryloxypropyltriethoxysilane, hexadecyltrimethoxysilane, hexadecyltriethoxysilane, methylpolysiloxane di-, glycidyloxypropyltrimethoxysilane, glycidyloxypropyltriethoxysilane, Nonafluo- rohexyltrimethoxysilan, Tridecaflourooctyltrimethoxysilan, Tridecaflourooctyltriethoxysilan, amino nopropyl-triethoxysilane , Hexamethyldisilazane.

Hexamethyldisilazane, hexadecyltrimethoxysilane, dimethylpolysiloxane, octyltrimethoxysilane and octyltriethoxysilane are particularly preferably used. In particular, hexamethyldisilazane, octyltrimethoxysilane and hexadecyltrimethoxysilane are used, most preferably hexamethyldisilazane.

One or a mixture of different graft copolymers are used as component C) in the molding compositions according to the invention in amounts of from 1 to 60% by weight, based on the sum of components A to D. Preferred molding compositions of the invention comprise from 5 to 50, particularly preferably from 6 to 45,% by weight of at least one graft copolymer. Risates C, which is different from possible further rubbery polymers D).

The graft polymers C are composed of

Ci) 20 to 80 wt .-%, preferably 50 to 70 wt .-% of a graft base of a rubber-elastic polymers based on alkyl acrylates having 1 to 8 carbon atoms in the alkyl radical and / or dienes having a glass transition temperature of below 10 ° C.

From 20 to 80% by weight, preferably from 30 to 50% by weight, of a grafting pad

60 to 95 wt .-%, preferably 70 to 85 wt .-% styrene or substituted styrenes of the general formula I.

worin R einen d- bis Ce-Alkylrest, bevorzugt Methyl oder Ethyl, oder Wasserstoff bedeutet und R¹ einen d- bis Ce-Alkylrest, bevorzugt Methyl oder Ethyl, darstellt und n den Wert 1 , 2 oder 3 hat oder deren Mischungen und

wherein R is a d- to Ce-alkyl radical, preferably methyl or ethyl, or hydrogen and R ^{1 is} a d- to Ce-alkyl radical, preferably methyl or ethyl, and n has the value 1, 2 or 3 or mixtures thereof and

5 to 40 wt .-%, preferably 15 to 30 wt .-% of at least one unsaturated nitrile, preferably acrylonitrile or methacrylonitrile or mixtures thereof.

Suitable polymers for the grafting base Ci are those whose glass transition temperature is below 10 ° C., preferably below 0 ° C., particularly preferably below -20 ° C. These are e.g. Elastomers based on d- to Ce-alkyl esters of acrylic acid and / or dienes, which may optionally contain further comonomers.

Preference is given to graft bases ci, which are composed of

C11) 70 to 99.9 wt .-%, preferably 99 wt .-% of at least one alkyl acrylate having 1 to 8 carbon atoms in the alkyl radical, preferably n-butyl acrylate and / or 2-ethyl-hexyl acrylate, in particular n-butyl acrylate alone Alkyl acrylate, isoprene or butadiene as Dienmonome- re

C12) 0 to 30 wt .-%, in particular 20 to 30 wt .-% of a further copolymerizable monoethylenically unsaturated monomers such as butadiene, isoprene, styrene, acrylonitrile, methyl methacrylate or vinyl methyl ether or mixtures thereof C13) 0.1 to 5 wt .-%, preferably 1 to 4 wt .-% of a copolymerizable, polyfunctional, preferably bi- or tri-functional, causing the crosslinking monomers.

Suitable bi- or polyfunctional crosslinking monomers C13) are monomers which preferably contain two, optionally also three or more, ethylenic double bonds which are capable of copolymerization and are not conjugated in the 1, 3-positions. Suitable crosslinking monomers are, for example, divinylbenzene, diallyl maleate, diallyl fumarate, dialyl phthalate, triallyl catechurate or triallyl isocyanurate. The acrylic acid ester of tricyclodecenyl alcohol has proven to be a particularly favorable crosslinking monomer (cf.

DE-A 12 60 135).

This type of graft base is known per se and described in the literature, for example in DE-A 31 49 358. Of the graft C2, preference is given to those in which C21 is styrene or α-methylstyrene or mixtures thereof and C22 is acrylonitrile or methacrylonitrile , The preferred monomer mixtures used are, in particular, styrene and acrylonitrile or α-methylstyrene and acrylonitrile. The graft coatings are obtainable by copolymerization of components C21 and C22.

The grafting base Ci of the graft polymers C), which is composed of the components cn optionally C12, and C22, is also referred to as ASA rubber. Their preparation is known per se and described for example in DE-A 28 26 925, DE-A 31 49358 and DE-A 34141 18. If the grafting base is composed of dienes, this is referred to as ABS rubber, s. DE-A 22 44 519.

The preparation of the graft polymers C can be carried out, for example, by the methods described in DE-PS 12 60135 or WO 2008/101888. The structure of the graft (graft) of the graft polymers can be carried out in one or two stages.

 In the case of the single-stage construction of the graft, a mixture of the monomers C21 and C22 in the desired weight ratio in the range 95: 5 to 50:50, preferably from 90:10 to 65:35 in the presence of the elastomer Ci, in per se known manner (see, eg

DE-OS 28 26 925), preferably in emulsion polymerized.

In the case of a two-stage structure of the graft shell C2, the 1st stage generally constitutes 20 to 70% by weight, preferably 25 to 50% by weight, based on C2. For their preparation, preferably only styrene or substituted styrenes or mixtures thereof (C21) are used.

The second stage of the graft shell generally makes 30 to 80 wt .-%, in particular 50 to

75 wt .-%, each based on C2, from. For their preparation, mixtures of the monomers nomeren C21 and the nitriles C22 in the weight ratio C21 / C22 of generally 90:10 to 60:40, in particular 80:20 to 70:30 applied.

The conditions of the graft polymerization are preferably selected such that particle sizes of 50 to 700 nm (dso-the integral mass distribution) result. Measures for this are known and e.g. described in DE-OS 2826925.

The seed latex process can be used to directly produce a coarse-particle rubber dispersion.

In order to obtain products which are as tough as possible, it is often advantageous to use a mixture of at least two graft polymers having different particle sizes.

To achieve this, the particles of the rubber are prepared in a known manner, e.g. by agglomeration, increased so that the latex bimodal (50 to 180 nm and 200 to 700 nm) is constructed.

In a preferred embodiment, a mixture of two graft polymers having particle diameters (d.sub.50 value of the integral mass distribution) of from 50 to 180 nm or from 200 to 700 nm in a weight ratio of from 70:30 to 30:70 is used.

The chemical structure of the two graft polymers is preferably the same, although the shell of the coarse-particulate graft polymer can be constructed in two stages in particular.

Mixtures of the components, the latter having a coarse and fine graft polymer, are e.g. described in DE-OS 3615607. Mixtures of the components, the latter having a two-stage graft shell, are known from EP-A 1 1 1 260. As component D), the molding compositions according to the invention may contain from 0 to 60, in particular up to 50% by weight of further additives.

 As component D), the molding compositions according to the invention 0 to 5, preferably 0.05 to 3 and in particular 0.1 to 2 wt .-% of at least one ester or amide of saturated or unsaturated aliphatic carboxylic acids having 10 to 40, preferably 16 to 22 C Atoms containing aliphatic saturated alcohols or amines having 2 to 40, preferably 2 to 6 carbon atoms.

The carboxylic acids can be 1- or 2-valent. 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 montanic acid (mixture of fatty acids having 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 of these are stearylamine, ethylenediamine, propylenediamine, hexamethylenediamine, di (6-aminohexyl) amine, ethylenediamine and hexamethylenediamine being particularly preferred. Accordingly, preferred esters or amides are glycerin distearate, glycerol tristearate, ethylenediamine distearate, glycerin monopalmitate, glycerol trilaurate, glycerin monobehenate and pentaerythritol tetrastearate.

It is also possible to use mixtures of different esters or amides or esters with amides in combination, the mixing ratio being arbitrary.

Other conventional additives D) are, for example, in amounts of up to 40, preferably up to 30 wt .-% of elastomeric polymers (often also referred to as impact modifiers, elastomers or rubbers), which are different from C).

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 having 1 to 18 carbon atoms in the alcohol component.

Such polymers are z.8. 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).

Fibrous or particulate fillers D) which may be mentioned 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 may be used in amounts of up to 50% by weight. , in particular up to 40%.

Preferred fibrous fillers are carbon fibers, aramid fibers and potassium titanate fibers, with glass fibers being particularly preferred as E glass. These can be used as rovings or cut glass in the commercial forms. The fibrous fillers can be surface-pretreated for better compatibility with the thermoplastic with a silane compound.

Suitable silane compounds are those of the general formula

(X- (CH 2) n) k ^~ S i- (0-Cm H 2m + 1) 4-k where the substituents have the following meanings: X is 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 3, preferably 1

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 wt .-% (based on E) for surface coating.

Also suitable are acicular mineral fillers.

In the context of the invention, the term "needle-shaped mineral fillers" is understood to mean a mineral filler with a pronounced, needle-like character. An example is needle-shaped wollastonite. Preferably, the mineral has an LID (length: diameter ratio of 8: 1 to 35: 1, preferably 8: 1 to 1: 1: 1) The mineral filler may optionally be pretreated with the silane compounds mentioned above, but the pretreatment is not Other suitable fillers are kaolin, causticized kaolin, wollastonite, talc and chalk. As component D), the thermoplastic molding compositions according to the invention may contain conventional processing aids such as stabilizers, antioxidants, agents against thermal decomposition and decomposition by ultraviolet light, lubricants and mold release agents, colorants such as dyes and pigments, nucleating agents, plasticizers, etc. included.

Examples of antioxidants and heat stabilizers sterically hindered phenols and / or phosphites, hydroquinones, aromatic secondary amines such as diphenylamines, various substituted representatives of these groups and mixtures thereof in concentrations up to 1 wt .-%, based on the weight of the thermoplastic molding compositions mentioned.

As UV stabilizers, which are generally used in amounts of up to 2 wt .-%, based on the molding composition, various substituted resorcinols, salicylates, Benzotriazo- le and benzophenones may be mentioned. It is possible to add inorganic pigments such as titanium dioxide, ultramarine blue, iron oxide and carbon black, furthermore organic pigments such as phthalocyanines, quinacridones, perylenes and also dyes such as nigrosine and anthraquinones as colorants. As nucleating agents, sodium phenylphosphinate, alumina, silica and preferably talc may be used.

Other lubricants and mold release agents are usually used in amounts of up to 1 wt .-%. Preferred are long-chain fatty acids (eg stearic acid or behenic acid), their salts (eg Ca or Zn stearate) or montan waxes (mixtures of straight-chain, saturated carboxylic acids with chain lengths of 28 to 32 C atoms) and Ca or Na montanate and also low molecular weight polyethylene or polypropylene waxes.

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

The molding compositions according to the invention may still contain from 0 to 2% by weight of fluorine-containing ethylene polymer. These are polymers of ethylene with a fluorine content of 55 to 76 wt .-%, preferably 70 to 76 wt .-%.

Examples of these are polytetrafluoroethylene (PTFE), tetrafluoroethylene-hexafluoropropylene copolymers or tetrafluoroethylene copolymers with smaller amounts (generally up to 50% by weight) of copolymerizable ethylenically unsaturated monomers. These are e.g. by Schildknecht in "Vinyl and Related Polymers", Wiley-Verlag, 1952, pages 484 to 494 and by Wall in "Fluoropolymers" (Wiley Interscience, 1972).

These fluorine-containing ethylene polymers are homogeneously distributed in the molding compositions and preferably have a particle size dso (number average) in the range of 0.05 to 1 ° μΐτι, in particular from 0.1 to 5 μΐη. These small particle sizes can be achieved particularly preferably by using aqueous dispersions of fluorine-containing ethylene polymers and incorporating them into a polyester melt.

The thermoplastic molding compositions according to the invention can be prepared by processes known per se, in which the starting components are mixed in conventional mixing devices, such as screw extruders, Brabender mills or Banbury mills, and then extruded. After extrusion, the extrudate can be cooled and comminuted. It is also possible to premix individual components and then to add the remaining starting materials individually and / or likewise mixed. The mixing temperatures are usually 230 to 290 ° C.

According to a further preferred procedure, the components B) and C) and optionally D) can be mixed with a polyester prepolymer, formulated and granulated. the. The resulting granules are then condensed in solid phase under inert gas continuously or discontinuously at a temperature below the melting point of component A) to the desired viscosity. The novel thermoplastic molding compositions are distinguished by good processing and good flowability combined with good mechanical properties.

These are suitable for the production of fibers, films and moldings of any kind, in particular for applications as plugs, switches, housing parts, housing cover, headlight background (Bezel), shower head, fittings, irons, rotary switches, stove knobs, fryer covers, door handles, ( Rear) mirror housings, (rear) windscreen wipers, fiber optic sheathings.

In the E / E area, the flow-improved polyester can be used to produce plugs, plug connectors, plug connectors, wiring harness components, circuit carriers, circuit carrier components, three-dimensional injection-molded circuit boards, electrical connection elements, mechatronic components or optoelectronic components.

The interior of the car includes use for dashboards, steering column switches, seat parts, headrests, center consoles, transmission components and door modules, in the car exterior for door handles, headlight components, exterior mirror components, windscreen wiper components, windscreen wiper protection housings, grille, roof rails, sunroof frames and exterior body parts possible. For the kitchen and household sector, the use of the flow-improved polyester for the production of components for kitchen appliances, such as z. Fryers, irons, buttons, as well as applications in the garden leisure area, z.8. Components for irrigation systems or garden tools possible.

 In the field of medical technology, inhaler housings and their components can be more easily realized by means of flow-improved polyesters.

Examples

Component A / 1:

Polybutylene terephthalate with a viscosity number VZ of 120 ml / g and a carboxyl end group content of 34 meq / kg (Ultradur® B 2550 from BASF AG) (VZ measured in

0.5% strength by weight solution of phenol / o-dichlorobenzene), 1: 1 mixture at 25 ° C.

Component B-1: Aerosil® R8200, a hydrophobically modified flame-pyrolytically produced S1O2 of average particle size (transmission electron microscopy) of 15 nm with a hexamethyldisilazane hydrophobized particle surface, a BET specific surface area of about 160 m ² / g and a pH of 4% -iger dispersion of at least 5. B 1 a as a 20% by weight batch in component A)

 B 1 b as a 20% strength by weight batch in component C)

 B 1 c as a 20% by weight batch in component C / 1V)

Component B-2 (comparative experiment): Aerosil® 380, an unmodified flame-pyrolytic S1O2 of average particle size (transmission electron microscopy) of 7 nm with hydrophilic particle surface and BET surface area of about 380 m ² / g and a pH at 4%. iger dispersion of 3.7 to 4.7.

B 2a: as a 20% strength by weight batch in component A)

B 2b: as a 20% by weight batch in component C)

Component C:

By means of emulsion polymerization using potassium peroxodisulfate as the initiator, 50% by weight of n-butyl acrylate and 50% by weight of a grafting pad of styrene-acrylonitrile (75:25) were prepared. The mean particle size was 150 nm (measured by ultracentrifuge).

Component C / 1V (for comparison)

By mass polymerization was a styrene-acrylonitrile copolymer with 75 wt .-% of styrene and 25 wt .-% of acrylonitrile and a viscosity number of 80 ml / g (determined according to DIN 53726 or DIN EN ISO 1628-2 in 0.5 wt. % DMF solution at 25 ° C). The molecular weight (Mn) is about 85,000 g / mol (GPC in THF with PS calibration: Stationary phase: 5-styrene-divinylbenzene gel columns (PLgel Mixed-B, Polymer Laboratories); TH F 1, 2 ml / min ).

The molding compositions were prepared as follows:

All samples were prepared by compounding in the melt in a twin-screw extruder ZSK-18 at 260 ° C at a rate of 5 kg / h.

The test specimens used to determine the properties were obtained by injection molding (injection temperature 260 ° C, melt temperature 80 ° C). The Charpy impact strength was determined unnotched at -30 ° C according to ISO 179-2 / 1 eU and notched according to ISO 179-1 / 1 eA and the tensile test according to ISO 527-1.

The properties of various comparative experiments and examples according to the invention and the corresponding compositions of the molding compositions are shown in Table 1.

Claims

claims 1 . Thermoplastic molding compositions containing A) from 10 to 98.95% by weight of at least one thermoplastic polyester, B) from 0.05 to 30% by weight of at least one nanoparticulate oxide and / or hydrated oxide of at least one metal or semimetal having a number-average mean diameter of the primary particles of from 0.5 to 50 nm and a hydrophobic particle surface, C) 1 to 60 wt .-% of at least one graft polymer, composed of Ci) 20 to 80 wt .-% of a graft base of a rubber-elastic polymers based on alkyl acrylates having 1 to 8 carbon atoms in the alkyl radical and / or dienes having a glass transition temperature of below 10 ° C. C2) 20 to 80 wt .-% of a graft C21) from 60 to 95% by weight of styrene or substituted styrenes of the general formula I

wherein R is an alkyl radical having 1 to 8 carbon atoms or a hydrogen atom and R ^{1 is} an alkyl radical having 1 to 8 carbon atoms and n is 1, 2 or 3, and C22) from 5 to 40% by weight of at least one unsaturated nitrile, D) from 0 to 60% by weight of further additives, the sum of the percentages by weight of components A) to D) being 100%. Thermoplastic molding compositions according to claim 1, wherein component B) has a methanol wettability of at least 50%. Thermoplastic molding compositions according to claims 1 or 2, wherein component B) has a BET specific surface area according to DIN 66131 of 50 to 300 m ² / g. Thermoplastic molding compositions according to claims 1 to 3, comprising as component B) an amorphous oxide and / or hydrated oxide of silicon having a number-weighted average diameter of the primary particles of 0.5 to 50 nm. Thermoplastic molding compositions according to claims 1 to 4, wherein component B) has a number-weighted mean diameter of the primary particles of 1 to 20 nm, preferably of 1 to 10 nm. Thermoplastic molding compositions according to claims 1 to 5, wherein component B) is hydrophobically modified by a silane, preferably hexamethyldisilazane. Thermoplastic molding compositions according to claims 1 to 6, wherein component B) is flame-pyrolytically produced silicon dioxide whose surface is hydrophobically modified. Use of thermoplastic molding compositions according to claims 1 to 7 for the production of fibers, films and moldings. Fibers, films and moldings, obtainable from the thermoplastic molding compositions according to claims 1 to 7.