EP1095098A1

EP1095098A1 - Flame-resistant polycarbonate abs moulding materials

Info

Publication number: EP1095098A1
Application number: EP99929192A
Authority: EP
Inventors: Thomas Eckel; Michael Zobel; Dieter Wittmann
Original assignee: Bayer AG
Current assignee: Bayer AG
Priority date: 1998-06-26
Filing date: 1999-06-12
Publication date: 2001-05-02
Also published as: AU4609199A; KR100617431B1; CA2336252A1; HK1039138A1; CN1307609A; JP2002519463A; WO2000000543A1; DE19828538A1; US6747078B1; KR20010053163A; AR016727A1; BR9911580A; CN1146629C; JP2010065237A; TW565590B

Abstract

The present invention relates to thermoplastic polycarbonate moulding materials containing phosphazenes and special graft polymers that are produced by means of redox initiator systems. The inventive moulding materials are characterized by substantially improved mechanical properties.

Description

Flame retardant polycarbonate / ABS molding compounds

The present invention relates to thermoplastic polycarbonate molding compositions which contain phosphazenes and special graft polymers prepared by means of redox initiator systems and are distinguished by significantly improved mechanical properties.

DE-A-196 16 968 describes polymerizable phosphazene derivatives, processes for their preparation and their use as curable binders for lacquers, coatings, fillers, fillers, adhesives, moldings or films.

WO 97/40 092 describes flame-retardant molding compositions made of thermoplastic polymers and unsubstituted phosphazenes of the PN _n type. _x Hi _y described.

EP-A-728 811 describes a thermoplastic mixture consisting of aromatic polycarbonate, graft copolymer, copolymer and phosphazenes, which have good flame retardant properties, impact resistance and heat resistance.

A combination of phosphazenes and the special graft polymers is not described in WO 97/40 092 or in EP-A-728 811.

In EP-A-315 868 (= US-A-4,937,285) molding compositions made of thermoplastic

Described polycarbonates containing redox graft polymers. The addition of phosphazenes is not mentioned.

The object of the present invention is to provide flame-retardant polycarbonate / ABS molding compositions with very good mechanical properties, such as notched impact strength, stress crack resistance, flame resistance and weld line strength. speed. This range of properties is particularly required for applications in the field of data technology, such as for thin-walled housings for monitors, printers and others.

It has now been found that PC / ABS molding compositions which contain phosphazenes and a graft polymer prepared by means of a redox initiator system have the desired properties.

The invention therefore relates to thermoplastic molding compositions

A) 40 to 99, preferably 60 to 98.5 parts by weight of aromatic polycarbonate and / or polyester carbonate

B) 0.5 to 60, preferably 1 to 40, in particular 2 to 25 parts by weight of graft polymer, characterized in that the graft polymers B consist of

B.l) 5 to 95, preferably 30 to 80 wt .-% of one or more vinyl monomers and

B.2) 95 to 5, preferably 20 to 70% by weight of one or more particulate diene rubbers with a glass transition temperature <10 ° C., preferably <0 ° C., particularly preferably <-20 ° C., which are produced by emulsion polymerization, an initiator system consisting of an organic hydroperoxide and ascorbic acid being used for the graft polymerization,

C) 0 to 45, preferably 0 to 30, particularly preferably 2 to 25 parts by weight of at least one thermoplastic polymer selected from the group of thermoplastic vinyl (co) polymers and polyalkylene terephthalates, D) 0.1 to 50, preferably 2 to 35, in particular 5 to 25 parts by weight of at least one component selected from the group of the phosphazenes of the formulas

wherein

R is the same or different and represents amino, in each case optionally halogenated, preferably with fluorine halogenated C, - to C ₈ - alkyl, or C, - to Cg-alkoxy, in each case optionally substituted by alkyl, preferably C1-C ₄ - alkyl, and / or halogen, preferably chlorine and / or bromine, substituted C ₅ - to Cg-cycloalkyl, Cg to C _2υ aryl, preferably phenyl or naphthyl, C ₆ - to C ₂ o-aryloxy, preferably phenoxy, naphthyloxy, or C ₇ - to C _j2 -aralkyl, preferably phenyl-C _] -C -alkyl,

k for 0 or a number from 1 to 15, preferably for a number from 1 to

10 stands,

E) 0 to 5 parts by weight, preferably 0.1 to 1 part by weight, particularly preferably 0.1 to 0.5 part by weight of fluorinated polyolefin. Component A

Aromatic polycarbonates and / or aromatic polyester carbonates according to component A which are suitable according to the invention are known from the literature or can be prepared by processes known from the literature (for the production of aromatic polycarbonates see, for example, Schnell, "Chemistry and Physics of Polycarbonates", Interscience Publishers, 1964 and DE-AS 1 495 626 , DE-OS 2 232 877, DE-OS 2 703 376, DE-OS 2 714 544, DE-OS 3 000 610, DE-OS 3 832 396; for the production of aromatic polyester carbonates e.g. DE-OS 3 077 934 ).

Aromatic polycarbonates are produced e.g. by reacting diphenols with carbonic acid halides, preferably phosgene and / or with aromatic dicarboxylic acid dihalides, preferably benzenedicarboxylic acid dihalogenides, according to the phase interface method, if appropriate using chain terminators, for example monophenols and if appropriate using trifunctional or more than trifunctional branching agents or triphenols, for example triphenols.

Diphenols for the production of aromatic polycarbonates and / or aromatic

Polyester carbonates are preferably those of the formula (II)

in which A is a single bond, C] -C ₅ alkylene, C ₂ -C5 alkylidene, C ₅ -C6 cycloalkylene, -O-, -SO-, -CO-, -S-, -SO ₂ -, Cg -C ^ aryls, to which further aromatic rings optionally containing heteroatoms can be condensed,

or a radical of the formula (III) or (IV)

R ⁵ 'R ^β

B each C ₁ -C ₂ alkyl, preferably methyl, halogen, preferably chlorine and / or bromine

x each independently of one another 0, 1 or 2,

p are 1 or 0, and

R ⁵ and R ^{6 can be} selected individually for each X ¹ , independently of one another hydrogen or -CC ₆ alkyl, preferably hydrogen, methyl or ethyl,

X ¹ carbon and

m is an integer from 4 to 7, preferably 4 or 5, with the proviso that at least one atom X ¹ , R ⁵ and R ^{6 are} simultaneously alkyl. Preferred diphenols are hydroquinone, resorcinol, dihydroxydiphenols, bis (hydroxyphenyl) -C i -C ₅ alkanes, bis (hydroxyphenyl) -C ₅ -C6 cycloalkanes, bis (hydroxyphenyl) ether, bis (hydroxyphenyl) sulfoxides, bis (hydroxyphenyl) ketones, bis (hydroxyphenyl) sulfones and α, α-bis (hydroxyphenyl) diisopropyl benzenes and their core-brominated and / or core-chlorinated derivatives.

Particularly preferred diphenols are 4,4'-dihydroxydiphenyl, bisphenol-A, 2,4-bis (4-hydroxyphenyl) -2-methylbutane, 1,1-bis (4-hydroxyphenyl) cyclohexane, 1,1-bis - (4-hydroxyphenyl) -3.3.5-trimethylcyclohexane, 4,4'-dihydroxydiphenyl sulfide, 4,4'-dihydroxydiphenyl sulfone and their di- and tetrabrominated or chlorinated

Derviates such as 2,2-bis (3-chloro-4-hydroxyphenyl) propane, 2,2-bis (3,5-dichloro-4-hydroxyphenyl) propane or 2,2-bis (3,5 -dibromo-4-hydroxyphenyl) propane.

2,2-bis (4-hydroxyphenyl) propane (bisphenol-A) is particularly preferred.

The diphenols can be used individually or as any mixtures.

The diphenols are known from the literature or can be obtained by processes known from the literature.

Chain terminators suitable for the production of the thermoplastic, aromatic polycarbonates are, for example, phenol, p-chlorophenol, p-tert-butylphenol or 2,4,6-tribromophenol, but also long-chain alkylphenols, such as 4- (1,3-tetramethylbutyl) -phenol according to DE-OS 2 842 005 or monoalkylphenol or dialkylphenols with a total of 8 to 20 carbon atoms in the alkyl substituents, such as 3,5-di-tert-butylphenol, p-iso-octylphenol, p-tert. -Octylphenol, p-dodecylphenol and 2- (3,5-dimethylheptyl) phenol and 4- (3,5-dimethylheptyl) phenol. The amount of chain terminators to be used is generally between 0.5 mol% and 10 mol%, based on the molar sum of the diphenols used in each case. The thermoplastic, aromatic polycarbonates have average weight-average molecular weights (M _w , measured, for example, by means of an ultracentrifuge or scattered light measurement) of 10,000 to 200,000, preferably 20,000 to 80,000.

The thermoplastic, aromatic 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 trifunctional or more than trifunctional compounds, for example those with three and more phenolic groups.

Both homopolycarbonates and copolycarbonates are suitable. To produce copolycarbonates according to component A according to the invention, 1 to 25% by weight, preferably 2.5 to 25% by weight (based on the total amount of diphenols to be used) of polydiorganosiloxanes with hydroxy-aryloxy end groups can also be used. These are known (see, for example, US Pat. No. 3,419,634) or can be produced by processes known from the literature. The production of polydiorganosiloxane-containing copolycarbonates is e.g. B. described in DE-OS 3 334 782.

In addition to the bisphenol A homopolycarbonates, preferred polycarbonates are the copolycarbonates of bisphenol A with up to 15 mol%, based on the molar sum of diphenols, of other diphenols mentioned as preferred or particularly preferred, in particular 2,2-bis (3, 5-dibromo-4-hydroxyphenyl) propane.

Aromatic dicarboxylic acid dihalides for the production of aromatic polyester carbonates are preferably the diacid dichlorides of isophthalic acid, terephthalic acid, diphenyl ether-4,4'-dicarboxylic acid and naphthalene-2,6-dicarboxylic acid.

Mixtures of the diacid dichlorides of isophthalic acid and terephthalic acid in a ratio between 1:20 and 20: 1 are particularly preferred. In the production of polyester carbonates, a carbonic acid halide, preferably phosgene, is additionally used as a bifunctional acid derivative.

In addition to the monophenols already mentioned, their chain terminators for the production of the aromatic polyester carbonates are their chlorocarbonic acid esters and the acid chlorides of aromatic monocarboxylic acids, which may be substituted by C _r C ₂₂ alkyl groups or by halogen atoms, and aliphatic C ₂ -C ₂₂ - Monocarboxylic acid chlorides into consideration.

The amount of chain terminators is in each case 0.1 to 10 mol%, based on moles of diphenols in the case of the phenolic chain terminators and on moles of dicarboxylic acid dichlorides in the case of monocarboxylic acid chloride chain terminators.

The aromatic polyester carbonates can also contain aromatic hydroxycarboxylic acids.

The aromatic polyester carbonates can be linear or branched in a known manner (see also DE-OS 2 940 024 and DE-OS 3 007 934).

For example, 3- or polyfunctional carboxylic acid chlorides, such as trimesic acid trichloride, cyanuric acid trichloride, 3,3 '-, 4,4'-benzophenonetetracarboxylic acid tetrachloride, 1, 4,5,8-naphthalenetetracarboxylic acid tetrachloride or pyromellitic acid tetrachloride, can be used as branching agents in amounts of 0.01 up to 1.0 mol% (based on the dicarboxylic acid dichlorides used) or 3- or polyfunctional phenols, such as phloroglucin, 4,6-dimethyl-2,4,6-tri- (4-hydroxyphenyl) -hepten-2 , 4,4-dimethyl-2,4-6-tri- (4-hydroxyphenyl) heptane, 1,3,5-tri- (4-hydroxyphenyl) benzene, 1,1,1-tri- (4- hydroxyphenyl) ethane, tri- (4-hydroxyphenyl) phenylmethane, 2,2-bis [4,4-bis (4-hydroxyphenyl) cyclohexyl] propane, 2,4-bis (4th -hydroxyphenyl-isopropyl) phenol, tetra- (4-hydroxyphenyl) methane, 2,6-bis (2-hydroxy-5-methyl-benzyl) -4-methylphenol, 2- (4-hydroxyphenyl) -2 - (2,4-dihydroxyphenyl) propane, tetra- (4- [4-hydroxy- phenyl-isopropyl] phenoxy) methane, 1,4-bis [4,4'-dihydroxytriphenyl) methyl] benzene, in amounts of 0.01 to 1.0 mol%, based on the diphenols used . Phenolic branching agents can be introduced with the diphenols, acid chloride branching agents can be introduced together with the acid dichlorides.

The proportion of carbonate structural units in the thermoplastic, aromatic polyester carbonates can vary as desired. The proportion of carbonate groups is preferably up to 100 mol%, in particular up to 80 mol%, particularly preferably up to 50 mol%, based on the sum of ester groups and carbonate groups.

Both the ester and the carbonate content of the aromatic polyester carbonates can be present in the form of blocks or randomly distributed in the polycondensate.

The relative solution viscosity (η _re ,) of the aromatic polycarbonates and polyester carbonates is in the range from 1.18 to 1.4, preferably 1.22 to 1.3 (measured on

Solutions of 0.5 g polycarbonate or polyester carbonate in 100 ml methylene chloride solution at 25 ° C).

The thermoplastic, aromatic polycarbonates and polyester carbonates can be used alone or in any mixture with one another.

Component B

Component B comprises one or more graft polymers of

B.l 5 to 95, preferably 30 to 80 wt .-%, of at least one vinyl monomer

B.2 95 to 5, preferably 70 to 20% by weight of one or more particulate diene rubbers with glass transition temperatures <10 ° C, preferably <0 ° C, particularly preferably <-20 ° C, which are produced by emulsion polymerization using an initiator system made from organic hydroperoxide and ascorbic acid.

The graft base B.2 generally has an average particle size (d ₅₀ value) of 0.05 to 5 μm, preferably 0.10 to 0.6 μm, particularly preferably 0.20 to 0.40 μm.

Monomers B.l are preferably mixtures of

Bl .l 50 to 99 parts by weight of vinyl aromatics and / or core-substituted vinyl aromatics (such as styrene, α-methylstyrene, p-methylstyrene, p-chlorostyrene) and / or methacrylic acid (C, -C ₈ ) - Alkyl esters (such as methyl methacrylate, ethyl methacrylate) and

B.l .2 1 to 50 parts by weight of vinyl cyanide (unsaturated nitriles such as acrylonitrile and

Methacrylonitrile) and / or (meth) acrylic acid (C, -C ₈ ) alkyl esters (such as

Methyl methacrylate, n-butyl acrylate, t-butyl acrylate) and / or derivatives (such as

Anhydrides and imides) of unsaturated carboxylic acids (for example maleic anhydride and N-phenyl-maleimide).

Preferred monomers B.l.l are selected from at least one of the monomers styrene, α-methylstyrene and methyl methacrylate, preferred monomers B.l.2 are selected from at least one of the monomers acrylonitrile, maleic anhydride and methyl methacrylate.

Particularly preferred monomers are B.l.l styrene and B.l.2 acrylonitrile.

Preferred graft bases B.2 are diene rubbers (for example based on butadiene, isoprene etc.) or mixtures of diene rubbers or copolymers of diene rubbers or their mixtures with other copolymerizable monomers (For example according to B1 and B1), with the proviso that the glass transition temperature of component B.2 is below <10 ° C, preferably <0 ° C, particularly preferably <-10 ° C.

Pure polybutadiene rubber is particularly preferred.

Graft polymers of are particularly preferred

a) 40 to 90% by weight of particulate diene rubber with an average particle diameter of 0.1 to 0.6 μm and

b) 60 to 10% by weight of styrene, acrylonitrile, methyl methacrylate or mixtures thereof by emulsion graft polymerization,

which is characterized in that an initiator system composed of an organic hydroperoxide and ascorbic acid is used for graft polymerization to achieve a graft yield of> 60% by weight, preferably> 75% by weight, in particular> 85% by weight (based on monomers Bl or b) used.

According to a preferred embodiment, the graft polymerization of

Monomers a) in aqueous emulsion in the presence of an emulsion of the rubber polymer b) at temperatures of 40 to 70 ° C, in particular 50 to 70 ° C, by using an initiator system made of organic hydroperoxide (I) iπ ascorbic acid (II), in which generally 0.3 to 1.5 parts by weight (I) and 0.1 to 1 part by weight (II), in each case based on 100 parts by weight of graft monomers, and the weight ratio (I) :( II) 0, 3 to 15, in particular 1 to 10, preferably 3 to 8, is (cf. DE-A-37 08 913 (= US-A-4.859.744) and EP-A-315 868 (= US-A-4.937. 285)).

The rubbers are generally partially crosslinked and have gel contents of 10 to 90% by weight, in particular 40 to 80% by weight, and are particulate with them average particle sizes (d ₅₀ values) of 0.1 to 0.6 μm, in particular 0.2 to 0.4 μm. Such particulate rubbers are known. They are produced by emulsion polymerization and are usually in the form of latices.

The graft polymers are in aqueous emulsion by polymerizing the

Monomers are prepared on a rubber present in an aqueous emulsion. Surface-active auxiliaries are usually used, emulsifiers or dispersants and, if appropriate, additives in order to adjust certain pH values and electrolyte contents in the graft polymerization. Under certain circumstances, the emulsion graft polymerization can also be carried out without the addition of an emulsifier, in particular when working with small amounts of monomer, based on the amount of rubber, or when the amounts of emulsifier already present in the rubber emulsion (latex) are already sufficient to effect the graft polymerization of the To ensure monomers in the emulsion state with sufficient emulsion stability.

Anionic emulsifiers, preferably alkali salts of fatty acids, resin acids, disproportionated resin acids, alkyl sulfonic acids, aryl sulfonic acids, are particularly suitable. They are used in amounts of up to 5% by weight, preferably up to 2.5% by weight, based on the monomers to be polymerized.

Suitable hydroperoxides are, for example, cumene hydroperoxide, tert-butyl hydroperoxide, hydrogen peroxide, preferably cumene hydroperoxide and tert-butyl hydroperoxide, ie hydroperoxides with long half-lives.

An aqueous emulsion of a partially cross-linked diene rubber is grafted discontinuously or continuously in an aqueous emulsion; at polymerization temperatures of 40 to 70 ° C, in particular 50 to 70 ° C, the rubber emulsion is mixed with the graft monomers and, if appropriate, additional emulsifier and hydroperoxide and ascorbic acid solutions. The proportions as described above must be observed. In exceptional cases, the Polymerization as a further component of the starter system, catalytically small amounts of heavy metal cations, in particular Fe, are added, especially when diene rubber emulsions must be used which already contain large amounts of complexing agents. The process is normally carried out without the addition of iron ions; this method is preferred and allows technically advantageous the production of graft polymers that are practically free or low in heavy metals, since it is known that such traces of metal can have a disadvantageous effect on the application properties of plastics. The process works with aqueous solutions of ascorbic acid and aqueous solutions of hydroperoxide; It is advantageous to feed not enough water-soluble hydroperoxides, such as cumene hydroxide, into the polymerization system in the form of an aqueous emulsion. The same emulsifier is advantageously used in such emulsions as in graft polymerization.

The hydroperoxide and the ascorbic acid can be metered into the graft polymerization in portions or continuously. In a preferred variant, the hydroperoxide is initially charged in the reactors with the rubber to be grafted; the graft monomers and the remaining ascorbic acid, hydroperoxide and, if appropriate, emulsifier are fed separately into the reactor with the progressive polymerization of the graft monomers.

The amounts of hydroperoxide and ascorbic acid are critical. If hydroperoxide and / or ascorbic acid is overdosed, the graft polymerization is impaired. The yield of graft drops; the molecular weight of the grafted and free resin decreases; Exceeding or exceeding the amounts of hydroperoxide and ascorbic acid can also have a sensitive effect on monomer conversion and emulsion stability, so that the technical implementation of the graft polymerization becomes impossible. In order to optimize the implementation of the process, the structure of the graft polymers and their physical properties, a temperature of 40 to 70 ° C. and the amounts of hydroperoxide / ascorbic acid given above must be observed during the graft polymerization. In the case of graft polymerization up to monomer conversions of greater than 90% by weight, in particular greater than 98% by weight, storage-stable graft polymer emulsions with polymer contents of 25 to 50% by weight are obtained; the graft polymer itself can easily be isolated from the emulsions by known coagulation processes (for example by means of acids or salts). If one wants to combine the graft polymers with thermoplastic resins, which are themselves in the form of an emulsion, the graft polymer emulsion can be mixed with the resin emulsion and coagulated together.

The gel content of the graft base B.2 is determined at 25 ° C. in a suitable solvent (M. Hoffmann, H. Krömer, R. Kuhn, Polymeranalytik I and II, Georg Thieme-Vlag, Stuttgart 1977).

The average particle size d ₅₀ is the diameter above and below which 50% by weight of the particles lie. It can be measured using an ultracentrifuge

(W. Scholtan, H. Lange, Kolloid, Z. and Z. Polymer 250 (1972), 782-1796).

Component C

Component C comprises one or more thermoplastic vinyl (co) polymers C.1 and / or polyalkylene terephthalates C.2.

Suitable as (co) polymers C.1 are polymers of at least one monomer from the group of the vinyl aromatics, vinyl cyanides (unsaturated nitriles),

(Meth) acrylic acid (C, -C ₈ ) alkyl esters, unsaturated carboxylic acids and derivatives (such as anhydrides and imides) of unsaturated carboxylic acids. (Co) polymers of are particularly suitable

C.1.1 50 to 99, preferably 60 to 80 parts by weight of vinyl aromatics and / or nucleus-substituted vinyl aromatics such as, for example, styrene, α-methylstyrene, p- Methylstyrene, p-chlorostyrene) and / or methacrylic acid (C, -C ₄ ) alkyl esters such as methyl methacrylate, ethyl methacrylate), and

C.1.2 1 to 50, preferably 20 to 40 parts by weight of vinyl cyanides (unsaturated nitriles) such as acrylonitrile and methacrylonitrile, and / or (meth) acrylic acid (C, - C _g) alkyl (such as methyl methacrylate, n-butyl acrylate, t-butyl acrylate) and / or unsaturated carboxylic acids (such as maleic acid) and / or derivatives (such as anhydrides and imides) of unsaturated carboxylic acids (for example maleic anhydride and N-phenyl-maleimide).

The (co) polymers C.l are resin-like, thermoplastic and rubber-free.

The copolymer of C.I. 1 styrene and C.1.2 acrylonitrile is particularly preferred.

The (co) polymers according to C.l are known and can be radicalized

Produce polymerization, in particular by emulsion, suspension, solution or bulk polymerization. The (co) polymers according to component C. 1 preferably have molecular weights M _w (weight average, determined by light scattering or sedimentation) between 15,000 and 200,000.

The polyalkylene terephthalates of component C.2 are reaction products from aromatic dicarboxylic acids or their reactive derivatives, such as dimethyl esters or anhydrides, and aliphatic, cycloaliphatic or araliphatic diols and mixtures of these reaction products.

Preferred polyalkylene terephthalates contain at least 80% by weight, preferably at least 90% by weight, based on the dicarboxylic acid component of terephthalic acid residues and at least 80% by weight, preferably at least 90 mol%, based on the diol component of ethylene glycol and / or butanediol -l, 4 residues. In addition to terephthalic acid residues, the preferred polyalkylene terephthalates can contain up to 20 mol%, preferably up to 10 mol%, of residues of other aromatic or cycloaliphatic dicarboxylic acids with 8 to 14 C atoms or aliphatic dicarboxylic acids with 4 to 12 C atoms, such as, for example Residues of phthalic acid, isophthalic acid, naphthalene-2,6-dicarboxylic acid, 4,4'-diphenyldicarboxylic acid, succinic acid, adipic acid, sebacic acid, azelaic acid, cyclohexane-diacetic acid.

In addition to ethylene glycol or butanediol 1,4-residues, the preferred polyalkylene terephthalates can contain up to 20 mol%, preferably up to 10 mol%, other aliphatic diols with 3 to 12 carbon atoms or cycloaliphatic diols with 6 to 21 Contain carbon atoms, e.g. Residues of 1,3-propanediol, 2-ethyl-1,3-propanediol, neopentyl glycol, 1,5-pentanediol, 1,6-hexanediol, 1,4-cyclohexane-dimethanol, 2,4-3, 3-ethylpentanediol, 2-methylpentanediol 2,4,2,2,4-trimethylpentanediol-1,3,2-ethylhexanediol-1,3,2,2-diethylpropanediol-1,3, hexanediol-2,5,4,4-di- (β-hydroxyethoxy ) benzene, 2,2-bis (4-hydroxycyclohexyl) propane, 2,4-dihydroxy-l, l, 3,3-tetramethyl-cyclobutane, 2,2-bis

(4-β-hydroxyethoxy-phenyl) propane and 2,2-bis (4-hydroxypropoxyphenyl) propane (DE-OS 2 407 674, 2 407 776, 2 715 932).

The polyalkylene terephthalates can be prepared by incorporating relatively small amounts of trihydric or tetravalent alcohols or 3- or 4-basic carboxylic acids, e.g. according to DE-OS

1,900,270 and U.S. Patent 3,692,744. Examples of preferred branching agents are trimesic acid, trimellitic acid, trimethylolethane and -propane and pentaerythritol.

Particular preference is given to polyalkylene terephthalates which have been prepared solely from terephthalic acid and its reactive derivatives (for example its dialkyl esters) and ethylene glycol and / or 1,4-butanediol, and mixtures of these polyalkylene terephthalates. Mixtures of polyalkylene terephthalates contain 1 to 50% by weight, preferably 1 to 30% by weight, polyethylene terephthalate and 50 to 99% by weight, preferably 70 to 99% by weight, polybutylene terephthalate.

The polyalkylene terephthalates preferably used generally have an intrinsic viscosity of 0.4 to 1.5 dl / g, preferably 0.5 to 1.2 dl / g, measured in phenol / o-dichlorobenzene (1: 1 parts by weight) at 25 ° C. in the Ubbelohde viscometer.

The polyalkylene terephthalates can be prepared by known methods (see e.g. Kunststoff-Handbuch, Volume VIII, p. 695 ff, Carl-Hanser-Verlag, Munich 1973).

Component D

Phosphazenes according to component D, which are used according to the present invention, are linear phosphazenes according to formula (Ia) and cyclic phosphazenes according to formula (Ib)

in which

R and k have the meaning given above. Examples include:

Propoxyphosphazen, phenoxyphosphazen, methylphenoxyphosphazen, aminophosphazen and fluoroalkylphosphazenes.

Phenoxyphosphazene is preferred.

The phosphazenes can be used alone or as a mixture. The radical R can always be the same or 2 or more radicals in the formulas (Ia) and (Ib) can be different.

The phosphazenes and their preparation are described, for example, in EP-A-728 811, DE-A-1 961 668 and WO 97/40 092.

Component E

The fluorinated polyolefins E are of high molecular weight and have glass transition temperatures of above -30 ° C., generally above 100 ° C., fluorine contents, preferably from 65 to 76, in particular from 70 to 76% by weight, average particle diameter d ₅₀ of 0, 05 to 1,000, preferably 0.08 to 20 μm. In general, the fluorinated polyolefins E have a density of 1.2 to 2.3 g / cm ³ . Preferred fluorinated polyolefins E are polytetrafluoroethylene, polyvinylidene fluoride, tetrafluoroethylene (hexafluoropropylene and ethylene / tetrafluoroethylene copolymers. The fluorinated polyolefins are known (cf. "Vinyl and Related Polymers" from Schildknecht, John Wiley & Sons, Inc., New York, 1962 , Pages 484-494; "Fluoropolymers" by Wall,

Wiley-Interscience, John Wiley & Sons, Inc., New York, Vol. 13, 1970, pages 623-654; "Modem Plastics Encyclopedia", 1970-1971, volume 47, No. 10A, October 1970, Mc Graw-Hill, Inc., New York, pages 134 and 774; "Modern Plastica Encyclopedia", 1975-1976, October 1975, volume 52, No. 10A, Mc Graw-Hill, Inc., New York, pages 27, 28 and 472 and U.S. Patents 3,671,487, 3,723,373 and 3 838 092). They can be prepared by known processes, for example by polymerizing tetrafluoroethylene in an aqueous medium with a free radical-forming catalyst, for example sodium, potassium or ammonium peroxydisulfate at pressures from 7 to 71 kg / cm ² and at temperatures from 0 to 200 ° C, preferably at temperatures from 20 to 100 ° C. (For more details see e.g. US patent

2 393 967). Depending on the form of use, the density of these materials can be between 1.2 and 2.3 g / cm ³ , the average particle size between 0.5 and 1000 μm.

Fluorinated polyolefins E preferred according to the invention are tetrafluoroethylene polymers with average particle diameters of 0.05 to 20 μm, preferably 0.08 to

10 microns, and a density of 1.2 to 1.9 g / cm ³ and are preferably used in the form of a coagulated mixture of emulsions of tetrafluoroethylene polymers E with emulsions of graft polymers B.

Suitable fluorinated polyolefins E that can be used in powder form are tetrafluoroethylene polymers with average particle diameters of 100 to 1,000 μm and densities of 2.0 g / cm ³ to 2.3 g / cm ³ .

To produce a coagulated mixture of B and E, an aqueous emulsion (latex) of a graft polymer B with a finely divided emulsion of a

Tetrafluoroethylene polymer E mixed; Suitable tetrafluoroethylene polymer emulsions usually have solids contents of 30 to 70% by weight, in particular 50 to 60% by weight, preferably 30 to 35% by weight.

The quantity in the description of component B can be the proportion of

Include graft polymer for the coagulated blend of graft polymer and fluorinated polyolefins.

The equilibrium ratio of graft polymer B to tetrafluoroethylene polymer E in the emulsion mixture is 95: 5 to 60:40. Then the

Emulsion mixture coagulated in a known meadow, for example by spray drying NEN, freeze drying or coagulation by adding inorganic or organic salts, acids, bases or organic, water-miscible solvents, such as alcohols, ketones, preferably at temperatures from 20 to 150 ° C, in particular from 50 to 100 ° C. If necessary, drying can be carried out at 50 to 200 ° C., preferably 70 to 100 ° C.

Suitable tetrafluoroethylene polymer emulsions are commercially available products and are offered, for example, by DuPont as Teflon® 30 N.

The molding compositions according to the invention can contain at least one of the customary additives, such as lubricants and mold release agents, nucleating agents, antistatic agents, stabilizers and dyes and pigments.

The molding compositions according to the invention can contain up to 35% by weight, based on the total molding composition, of a further flame retardant which may have a synergistic action. Organic halogen compounds such as decabromobisphenyl ether, tetrabromobisphenol, inorganic halogen compounds such as ammonium bromide, nitrogen compounds such as melamine, melamine formaldehyde resins, inorganic hydroxide compounds such as Mg, Al hydroxide, inorganic compounds such as antimony oxides, barium metaborate, hydroxoantimonate, zirconium oxide, zirconium oxide, zirconium oxide and zirconium oxide, zirconium oxide, zirconium oxide, zirconium oxide, zirconium oxide, zirconium oxide, zirconium oxide, zirconium oxide, zirconium oxide, zirconium oxide, zirconium oxide, zirconium oxide, zirconium oxide, zirconium oxide, zirconium oxide, zirconium oxide, zirconium oxide, zirconium oxide, zirconium oxide, zirconium oxide, zirconium oxide, zirconium oxide, zirconium oxide, zirconium oxide, zirconium oxide, zirconium oxide, zirconium oxide, being used as examples of further flame retardants , Ammonium molybdate, zinc borate, ammonium borate, barium metaborate, talc, silicones, silicon dioxide and tin oxide and siloxane compounds.

The molding compositions according to the invention containing components A to E and optionally other known additives such as stabilizers, dyes, pigments, lubricants and mold release agents, nucleating agents and antistatic agents are prepared by mixing the respective constituents in a known manner and at temperatures from 200 ° C. to 300 ° C in conventional units such as internal kneaders, extruders and twin-screw extruders, melt-compounded and melt-extruded, wherein component E is preferably used in the form of the coagulated mixture already mentioned.

The individual constituents can be mixed in a known manner both successively and simultaneously, both at about 20 ° C. (room temperature) and at a higher temperature.

Due to their excellent flame resistance and their very good mechanical properties, the thermoplastic molding compositions according to the invention are suitable for the production of moldings of any kind, in particular those with increased

Breaking resistance requirements.

The molding compositions of the present invention can be used for the production of moldings of any kind. In particular, moldings can be produced by injection molding. Examples of moldings that can be produced are: housing parts each

Type, e.g. for household appliances such as juicers, coffee machines, mixers, for office machines such as monitors, printers, copiers, or cover plates for the construction sector and parts for the motor vehicle sector. They can also be used in the field of electrical engineering because they have very good electrical properties.

The molding compositions according to the invention can furthermore be used, for example, for the production of the following moldings or moldings:

1. Interior fittings for rail vehicles (FR) 2. Hub caps

3. Housing of electrical devices containing small transformers

4. Housing for devices for information dissemination and transmission

5. Housing and cladding for medical purposes

6. Massagers and housings therefor 7. Toy vehicles for children

8. Flat wall elements 9. Housing for safety devices

10.Rear spoiler

11. Thermally insulated transport containers

12. Device for keeping or caring for small animals 13. Molded parts for sanitary and bathing equipment

14. Cover grille for fan openings

15. Molded parts for garden and tool sheds

16. Housing for garden tools

Another form of processing is the production of molded articles by deep drawing from previously produced sheets or foils.

Another object of the present invention is therefore also the use of the molding compositions according to the invention for the production of moldings of any kind, preferably those mentioned above, and the molded articles from the inventive ones

Molding compounds.

Example

Component A

Linear polycarbonate based on bisphenol A with a relative solution viscosity of 1.252, measured in CH2CI2 as a solvent at 25 ° C and a concentration of 0.5 g / 100 ml.

Component B

Graft base:

B.2 emulsion of a partially cross-linked, coarse-particle polybutadiene with an average particle diameter of 0.40 μm (d ₅₀ value), a gel content of

89% by weight. The emulsion contains 50% by weight polymer solid.

Production of the graft polymers:

Ba) graft polymer composed of 55% by weight of diene rubber (B.2) and 45% by weight

SAN copolymer according to DE-A-37 08 913.

A mixture of 200 parts by weight of the latex (B.2) and 149 parts by weight of water are placed in a reactor and heated to 60 to 62 ° C. At this temperature, the following two solutions or emulsions are introduced into the reactor in the following order:

1. 0.0836 parts by weight of cumene hydroperoxide

6.9600 parts by weight of water 0.0600 parts by weight of Na salt of C _{] 4} -C ₁₆ alkylsulfonic acids 2. 0.0557 parts by weight of ascorbic acid 6.9600 parts by weight of water.

The following feeds are then metered into the reactor with stirring at an internal temperature of 60 to 62 ° C. within 4 hours:

ZI) 39.05 parts by weight of water

4.00 parts by weight Na salt of the disproportionated abietic acid 3.10 parts by weight ln sodium hydroxide solution 0.62 parts by weight cumene hydroperoxide

Z2) 59 parts by weight of styrene

23 parts by weight of acrynitrile

Z3) 39.800 parts by weight of water

0.105 parts by weight of ascorbic acid

The mixture is then polymerized at 60 to 62 ° C for 6 hours. The monomer conversion is greater than 97% by weight.

After stabilization with 1.2 parts by weight of phenolic antioxidant, per 100 parts by weight of graft polymer, the graft polymer is isolated by coagulation with an acetic acid / Mg sulfate mixture, washed and dried to a powder.

The SAN grafting proceeded with a grafting yield of 89% by weight.

The graft yield was determined by fractional segregation with the segregating liquids dimethylformamide / methylcyclohexane in the ultracentrifuge and by determining the amounts and the chemical Composition of the fractions thus obtained (see R. Kuhn, Makromol-Chemie 177, 1525 (1976)).

Bb) graft polymer composed of 55% by weight of diene rubber (B.2) and 45% by weight of SAN copolymer

(Comparative example)

The following are placed in a reactor:

1,500 parts by weight of emulsion B.2 and 1,030 parts by weight of water. After heating to 65 ° C., a starter solution consisting of 3 parts by weight of potassium peroxydisulfate in 50 parts by weight of water is fed. The following two solutions are then fed into the reactor at 65 ° C. within 6 hours:

1. 442 parts by weight of styrene 172 parts by weight of acrylonitrile

2. 1,000 parts by weight of water and 13 parts by weight of sodium salt of disproportionated abiettic acid

10 parts by weight in sodium hydroxide solution

The mixture is then polymerized by stirring at 65 ° C within 4 hours. The monomer conversion is greater than 98% by weight. The graft polymer is stabilized and isolated in accordance with regulation Ba).

The SAN grafting proceeded with a grafting yield of 55% by weight. The graft yield was determined as for Ba). Component C

Styrene / acrylonitrile copolymer with a styrene / acrylonitrile weight ratio of 72:28 and an intrinsic viscosity of 0.55 dl / g (measurement in dimethylformamide at 20 ° C).

Component D

Phenoxyphosphazen of the formula

Commercial product: P-3800, Nippon Soda Co., Ltd., Japan

Component E

Tetrafluoroethylene polymer as a coagulated mixture of a SAN graft polymer emulsion according to component B above in water and a tetrafluoroethylene polymer emulsion in water. The weight ratio of graft polymer B to tetrafluoroethylene polymer E in the mixture is 90% by weight to 10% by weight. The tetrafluoroethylene polymer emulsion has a solids content of 60% by weight, the average particle diameter is between 0.05 and 0.5 μm. The SAN graft polymer emulsion has a solids content of 34% by weight and an average latex particle diameter of d ₅₀ = 0.28 μm. Manufacture of E

The emulsion of the tetrafluoroethylene polymer (Teflon 30 N from DuPont) is mixed with the emulsion of the SAN graft polymer B and stabilized with 1.8% by weight, based on polymer solids, of phenolic antioxidants. At 85 to 95 ° C, the mixture is coagulated with an aqueous solution of MgSO4 (Epsom salt) and acetic acid at pH 4 to 5, filtered and washed until practically free of electrolytes, then freed from the main amount of water by centrifugation and then at 100 ° C dried a powder. This powder can then be compounded with the other components in the units described.

Production and testing of the molding compositions according to the invention

The components are mixed on a 3-1 kneader. The moldings are produced on an Arburg 270 E injection molding machine at 260 ° C.

The heat resistance according to Vicat B is determined in accordance with DIN 53 460 (ISO 306) on rods measuring 80 x 10 x 4 mm.

To determine the weld line strength, the impact strength according to DIN 53 453 is measured on the weld line of test specimens injected on both sides (processing temperature 260 ° C) of the dimension 170 x 10 x 4 mm.

The stress crack behavior (ESC behavior) was investigated on bars measuring 80 x 10 x 4 mm, processing temperature 260 ° C. A mixture of 60 vol.% Toluene and 40 vol.% Isopropanol was used as the test medium. The test specimens were pre-stretched using a circular arch template (pre-stretching in percent) and stored in the test medium at room temperature. The stress cracking behavior was assessed via the cracking or breaking depending on the pre-stretching in the test medium. The composition and properties are summarized in Table 1 below.

Table: Molding compounds and their properties

When using the special graft polymer in polycarbonate molding compounds produced by means of a redox initiator system, significant improvements in mechanical properties are shown in the presence of phenoxyphosphazene as a flame retardant

Characteristics. High values for impact strength, weld line strength and good stress crack resistance are prerequisites for use in thin-walled housing parts.

Claims

claims

1. Containing thermoplastic molding compositions

A) 40 to 99 parts by weight of aromatic polycarbonate and / or polyester carbonate

B) 0.5 to 60 parts by weight of graft polymer, characterized in that the graft polymer B consists of

B.l) 5 to 95 wt .-% one or more vinyl monomers and

B.2) 95 to 5% by weight of one or more particulate diene rubbers with a glass transition temperature <10 ° C., which are produced by emulsion polymerization, an initiator system comprising an organic hydroperoxide and ascorbic acid being used for the graft polymerization,

C) 0 to 45 parts by weight of at least one thermoplastic polymer selected from the group of thermoplastic vinyl (co) polymers and polyalkylene terephthalates,

D) 0.1 to 50 parts by weight of at least one component selected from the group of the phosphazenes of the formulas

wherein

R is in each case identical or different and for amino, in each case optionally halogenated C 1 -C 6 -alkyl or C _r 1 -C ₈ -

Alkoxy, in each case optionally substituted by alkyl and / or halogen, C ₅ - to Cg-cycloalkyl, C ₆ to C ₂₀ aryl, Cg to C ₂₀ aryloxy or C ₇ to C ₁₂ aralkyl,

k represents 0 or a number from 1 to 15,

E) 0 to 5 parts by weight of fluorinated polyolefin.

2. Molding compositions according to claim 1, containing

60 to 98.5 parts by weight of A,

1 to 40 parts by weight B, 0 to 30 parts by weight C,

2 to 35 parts by weight of D, 0.1 to 1 part by weight of E.

3. Molding compositions according to claim 1 and 2, containing 2 to 25 parts by weight of C.

4. Molding compositions according to claims 1 to 3, containing 5 to 25 parts by weight of D.

5. Molding compositions according to the preceding claims, wherein vinyl monomers B.l mixtures

B1 to 50 to 99 parts by weight of vinyl aromatics and / or nucleus-substituted vinyl aromatics and / or methacrylic acid (C i -C ₈ ) alkyl esters and

Bl2 1 to 50 parts by weight of vinyl cyanides and / or (meth) acrylic acid (C _j - Cg) alkyl esters and / or derivatives of unsaturated carboxylic acids.

6. Molding compositions according to the preceding claims, wherein the graft base is selected from diene rubbers or mixtures of diene rubbers or copolymers of diene rubbers or their mixtures with other copolymerizable monomers.

7. Molding compositions according to the preceding claims, wherein the graft base is a polybutadiene rubber.

8. Molding compositions according to the preceding claims, wherein the grafting yield in the polymerization is> 60% by weight.

9. Molding compositions according to the preceding claims, wherein the grafting yield is> 75% by weight.

10. Molding compositions according to the preceding claims, wherein the graft yield is> 85% by weight.

11. Molding compositions according to the preceding claims, wherein the hydroperoxides used are cumene hydroperoxide, tert-butyl hydroperoxide and / or hydrogen peroxide.

12. Molding compositions according to the preceding claims, wherein component D is selected from the group consisting of propoxyphosphazen, phenoxyphosphazen, methylphenoxyphosphazen, aminophosphazen and fluoroalkylphosphazenes.

13. Molding compositions according to the preceding claims, containing at least one additive selected from the group of lubricants and mold release agents, nucleating agents, antistatic agents, stabilizers, dyes and pigments.

14. Molding compositions according to the preceding claims, containing others

Flame retardants, which are different from component D.

15. A method for producing molding compositions according to claim 1, wherein components A to E and optionally further additives are mixed and melt-compounded.

16. Use of the molding compositions according to claim 1 for the production of molded bodies.

17. Molded body produced from molding compositions according to claims 1 to 15.

18. Housing parts according to claim 17.