HK1117555A - Flame-resistant polycarbonate molding compositions - Google Patents

Description

Flame-resistant polycarbonate moulding materials

The present application is a divisional application of an invention patent application having the name "flame-retardant polycarbonate molding composition" with patent application No. 01805975.9, international application date 2/21/2001 (international application number PCT/EP 01/01925).

Technical Field

The invention relates to impact strength-improving polycarbonate compositions with a low fluorine content, which exhibit excellent flame retardancy even in thin wall thicknesses and particularly good chemical resistance and thermal stability.

Background

Chlorine-and bromine-free, flame-resistant, impact-strength-improved polycarbonate molding compositions are known.

EP-A0345522 describes polymer mixtures made from aromatic polycarbonates, ABS graft polymers and/or styrene-containing copolymers, which contain monophosphates to impart flame resistance. Furthermore, the polymer mixture contained Telfon as an antidrip agent in a concentration of 0.3% by weight.

U.S. Pat. Nos. 5,204,394 and 5,672,645 describe PC/ABS molding compositions which are rendered flame-resistant by oligomeric phosphoric acid esters or mixtures of oligomeric phosphoric acid esters and monophosphoric acid esters. The molding compositions also contain Telfon as an antidrip agent in a concentration of from 0.2 to 0.5 parts by weight, based on 100 parts by weight of the molding composition without Telfon.

JP-A11199768 describes PC/ABS blends which are provided with flame resistance with monomeric and oligomeric phosphoric acid esters, the flame resistance being significantly improved by the addition of inorganic fillers, such as talc. To prevent dripping of flaming substances, it is also necessary to add to the molding composition Telfon in a concentration of from 0.2 to 0.5 parts by weight, based on 100 parts by weight of PC + ABS. This corresponds in each case to a Teflon concentration > 0.15% by weight. JP-A11199768 also discloses flame-resistant PC/ABS moulding compositions based on triphenyl phosphate as flame retardant, which achieve the V-O standard in the UL94V test even without the addition of Teflon. The molding compositions comprise stabilized red phosphorus and relatively large amounts of talc, which have a relatively large adverse effect on the mechanical properties and the natural color of the polymer blends.

U.S. Pat. No. 5,5849827 describes PC/ABS moulding compositions which are rendered flame-resistant with resorcinol-based oligophosphates, in which the burning time (Nachbrenzenzeniten) is markedly reduced by the addition of low concentrations of nanoscale inorganic materials. This test shows that the tendency to drip burning substances cannot be reduced by means of nanoparticles, so that the addition of an antidrip agent, for example Teflon, is necessary in order to achieve the V-O standard in the UL94V test.

WO 99/07782 describes PC/ABS moulding compositions which are rendered flame-resistant with special oligophosphates derived from bisphenol A and which also contain synergistic amounts of nanoscale inorganic compounds. The molding compositions have improved weathering cracking (ESC) properties and high hot shape resistance. The molding composition contained Teflon at a concentration of 0.35%.

EP-A0754531 also describes, inter alia, flame-resistant PC/ABS moulding compositions which are rendered flame-resistant by oligomeric phosphoric acid esters of the bisphenol-A type or methyl-substituted derivatives thereof and which contain plate-like fillers, such as mica and/or glass flakes, optionally also in combination with glass fibres. The molding composition contained no Teflon. They also exhibit good rigidity and deformation stability (weakly deformable) and exhibit negligible deposit formation during injection molding. No information is disclosed about the flame resistance rating of PC/ABS moulding compositions, in particular about the dripping tendency of burning substances. The high inorganic filler content of the molding compositions has a negative effect on several mechanical properties. Thus resulting in insufficient impact strength in many applications, for example.

In some fields of plastics application, in particular in the power and electronics industry, it is required by customers or even by law for safety technical reasons not only to limit the chlorine and bromine content but also to limit the fluorine content. Thus, for example, a material is suitable as "halogen-free" according to DIN/VDE standard 0472, 815 only if the content of substances for halogen chlorine, bromine and iodine is 0.2% or less, calculated as chlorine, and the content of substances for fluorine is 0.1% or less.

WO 99/57198 describes PC/ABS moulding compositions which are rendered flame-resistant by resorcinol-derived oligophosphates (RDP) and which are halogen-free according to DIN/VDE-Standard 0472, section 815, owing to their low Teflon content of only 0.1 to an equivalent fluorine content of 0.076%. However, such molding compositions have poor ESC properties and poor heat distortion stability, in particular in extrusion applications, melt stability is often inadequate.

Disclosure of Invention

The object of the present invention is to provide molding compositions which meet DIN/VDE standard 0472, 815, with a fluorine content of < 0.1%, have excellent flame retardancy, good mechanical properties, improved thermal stability and improved ESC properties and can also be used in extrusion applications owing to their rheological properties (melt viscosity and stability).

It has now been found that polycarbonate compositions with improved impact strength, which are provided with flame retardancy by specific oligomeric phosphates derived from bisphenol a or similar diphenols and optionally additionally contain small amounts of inorganic materials, have the desired performance characteristics.

Accordingly, the present invention provides a polycarbonate composition comprising

A) At least one aromatic polycarbonate or polyester carbonate,

B) at least one impact modifier and

C) at least one phosphorus compound of the general formula I

Wherein

R¹、R²、R³And R⁴In each case independently of one another is C₁-C₈Alkyl and/or C optionally substituted by alkyl₅-C₆-cycloalkyl, C₆-C₁₀-aryl or C₇-C₁₂-an aralkyl group,

each n is independently 0 or 1,

q are each independently 0, 1, 2, 3 or 4,

n is a number from 0.1 to 30, preferably from 0.5 to 10, in particular from 0.7 to 5,

R⁵and R⁶Each independently is C₁-C₄-alkyl, preferably methyl, and

y represents C₁-C₇Alkylidene (Alkyliden), C₁-C₇Alkylene radical, C₅-C₁₂Cycloalkylene radical, C₅-C₁₂-cycloalkylidene, -O-, -S-, -SO-, SO₂or-CO-, wherein the molding composition is characterized in that it complies with DIN/VDE-Standard 0472, 815, part, i.e.contains 0.1% by weight or less of fluorine and 0.2% by weight or less of chlorine, bromine and iodine, based on the total composition.

The composition may optionally further comprise

D) A fluorinated polyolefinic compound as an anti-drip agent,

E) one of the other polymer components is selected from the group consisting of,

F) an inorganic material, and

G) conventional polymer additives, such as, for example, anti-drip agents, lubricants and mold release agents, nucleating agents, antistatic agents, stabilizers, dyes and pigments.

The compositions according to the invention are furthermore characterized in that they preferably meet the standard V-O by the UL94V test at a wall thickness of < 1.55 mm.

The fluorine content is preferably determined photometrically, as described in DIN/VDE-Standard 0472, 815.

Preferably, the molding composition comprises

A)60 to 98 parts by weight, preferably 70 to 95 parts by weight, particularly preferably 75 to 90 parts by weight, of at least one aromatic polycarbonate,

B)0.5 to 30, preferably 1 to 15, particularly preferably 2 to 10 parts by weight of at least one graft polymer comprising a rubber substrate,

C)1 to 20 parts by weight, preferably 2 to 15 parts by weight, of an oligomeric phosphoric acid ester based on bisphenol A,

D)0 to 0.13 part by weight of Teflon,

and

E) from 0 to 20 parts by weight, preferably from 0 to 10 parts by weight, in particular from 0 to 5 parts by weight, of a vinyl (co) polymer or polyalkylene terephthalate or mixtures thereof,

F)0 to 5 parts by weight, preferably 0 to 3 parts by weight, particularly preferably 0 to 1.5 parts by weight, of a finely divided particulate, platelet-shaped or fibrous inorganic material,

wherein the sum of the parts by weight of all components (A-F and optionally further components) is 100.

A more particularly preferred polycarbonate composition is characterized in that it meets the standard V-O by the UL94V test at a wall thickness of ≦ 1.6 mm.

Component A

The aromatic polycarbonates and/or aromatic polyester carbonates which are suitable according to component A are known from the literature or can be prepared by processes known from the literature (for the preparation of aromatic polycarbonates see, for example, Schnell, "Chemistry and Physics of Ploycarbonates", Interscience Publishers, 1964 and DE-AS 1495626, DE-OS 2232877, DE-OS 2703376, DE-OS 2714544, DE-OS 3000610, DE-OS 3832396; for the preparation of aromatic polyester carbonates see, for example, DE-OS 3077934).

The preparation of aromatic polycarbonates is carried out, for example, by reacting diphenols with carbonic acid halides, preferably phosgene, and/or with aromatic dicarboxylic acid dihalides, for example benzenedicarboxylic acid dihalides, in a phase interface process, optionally using chain terminators, for example monophenols, and optionally using trifunctional or more than trifunctional branching agents, for example triphenols or tetraphenols.

Diphenols for the production of the aromatic polycarbonates and/or aromatic polyester carbonates are preferably those of the formula (II)

Wherein

A represents a single bond, C₁-C₅Alkylene radical, C₂-C₅Alkylidene, C₅-C₆-cycloalkylidene, -O-, -SO-, -CO-, -S-, -SO₂-、C₆-C₁₂Arylene, other aromatic rings optionally containing hetero atoms possibly being linked to said C₆-C₁₂The arylene group is fused to the aromatic ring,

or a group of formula (III) or (IV)

B is in each case C₁-C₁₂-an alkyl group, preferably a methyl group,

x is in each case independently of one another 0, 1 or 2,

p is 1 or 0, and

R⁵and R⁶For each X¹Can be independently selected and is each independently hydrogen or C₁-C₆-an alkyl group, preferably hydrogen, methyl or ethyl,

X¹is carbon, and

m is an integer from 4 to 7, preferably 4 or 5, with the proviso that at least one atom X¹Upper R⁵And R⁶And is an alkyl group.

Preferred diphenols are hydroquinone, resorcinol, dihydroxydiphenols, bis-(hydroxyphenyl) -C₁-C₅-alkane, bis- (hydroxyphenyl) -C₅-C₆Cycloalkanes, bis- (hydroxyphenyl) -ethers, bis- (hydroxyphenyl) -sulfoxides, bis- (hydroxyphenyl) -ketones, bis- (hydroxyphenyl) -sulfones and α, α -bis- (hydroxyphenyl) -diisopropylbenzenes.

Particularly preferred diphenols are 4, 4 ' -dihydroxydiphenyl, bisphenol A, 2, 4-bis (4-hydroxyphenyl) -2-methylbutane, 1-bis- (4-hydroxyphenyl) -cyclohexane, 1-bis- (4-hydroxyphenyl) -3, 3, 5-trimethylcyclohexane, 4 ' -dihydroxydiphenyl sulfide, 4 ' -dihydroxydiphenyl-sulfone.

Especially preferred is 2, 2-bis- (4-hydroxyphenyl) -propane (bisphenol-a).

These diphenols may be used individually or as arbitrary mixtures.

The diphenols are known from the literature or are obtainable by processes known from the literature.

Suitable chain terminators for the preparation of the thermoplastic, aromatic polycarbonates are, for example, phenol and p-tert-butylphenol, but also long-chain alkylphenols, such as 4- (1, 3-tetramethylbutyl) -phenol according to DE-OS 2842005 or monoalkylphenols or dialkylphenols having a total of 8 to 20C atoms in the alkyl substituents, such as 3, 5-di-tert-butylphenol, p-isooctylphenol, 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 from 0.5 mol% to 10 mol%, based on the molar sum of the diphenols used.

The thermoplastic aromatic polycarbonate has an average weight average molecular weight (M)_wMeasured, for example, by ultracentrifugation or light scattering) is 10000-.

The thermoplastic, aromatic polycarbonates may be branched in a known manner and preferably by adding from 0.05 to 2.0 mol%, based on the sum of the moles of diphenols used, of trifunctional or more than trifunctional compounds, for example those having three or more phenolic groups.

Both homopolycarbonates and copolycarbonates are suitable. For the preparation of copolycarbonates according to the invention of component A, 1 to 25 wt.%, preferably 2.5 to 25 wt.% (based on the total amount of diphenols used) of polydiorganosiloxanes with hydroxy-aryloxy end groups may also be used. This is known (see, for example, US patent 3419634) or can be prepared by methods known from the literature. The preparation of polydiorganosiloxane-containing copolycarbonates is described, for example, in DE-OS 3334782.

Preferred polycarbonates, in addition to bisphenol A homopolycarbonates, are the copolycarbonates of bisphenol A with up to 15 mol%, based on the total moles of diphenols, of other diphenols mentioned as preferred or particularly preferred.

Aromatic dicarboxylic acid dihalides for the preparation 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 of between 1: 20 and 20: 1 are particularly preferred.

Furthermore, a carbonic acid halide, preferably phosgene, is used simultaneously as bifunctional acid derivative in the preparation of polyester carbonates.

As chain terminators for the preparation of the aromatic polyester carbonates, there are mentioned, in addition to the monophenols already mentioned, also their chlorocarbonic acid esters and the acid chlorides of aromatic monocarboxylic acids, which may optionally be substituted by C₁-C₂₂Alkyl substitution, and aliphatic C₂-C₂₂-a mono-acid chloride.

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

The aromatic polyester carbonates may also contain aromatic hydroxycarboxylic acids incorporated therein.

The aromatic polyester carbonates may be either linear or branched in a known manner (see also DE-OS 2940024 and DE-OS 3007934).

As branching agents, it is possible to use, for example, tri-or more functional acid chlorides such as 1, 3, 5-benzenetricarboxylic acid chloride, cyanuric acid trichloride, 3 '-, 4, 4' -benzophenonetetracarboxylic acid chloride, 1, 4, 5, 8-naphthalenetetracarboxylic acid chloride or 1, 2, 4, 5-benzenetetracarboxylic acid chloride in amounts of from 0.01 to 1.0 mol%, based on the diacid chloride used, or tri-or more functional phenols, such as phloroglucinol, 4, 6-dimethyl-2, 4, 6-tri- (4-hydroxyphenyl) -heptene-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, tris- (4-hydroxyphenyl) -phenylmethane, 2-bis [4, 4-bis (4-hydroxyphenyl) -cyclohexyl ] -propane, 2, 4-bis (4-hydroxyphenyl-isopropyl) -phenol, tetrakis- (4-hydroxyphenyl) -methane, 2, 6-bis (2-hydroxy-5-methyl-benzyl) -4-methylphenol, 2- (4-hydroxyphenyl) -2- (2, 4-dihydroxyphenyl) -propane, tetrakis- (4- [ 4-hydroxyphenyl-isopropyl ] -phenoxy) -methane, 1, 4-bis [4, 4' -dihydroxytriphenyl) -methyl ] -benzene, in amounts of from 0.01 to 1.0 mol%, based on the diphenols used. Phenolic branching agents may be added initially together with the diphenols, acid chloride branching agents may be added together with the acid dichlorides.

The content of carbonate structural units in the thermoplastic, aromatic polyester carbonates can be varied at will, preferably the content of carbonate groups is 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. The ester component and the carbonate component of the aromatic polyester carbonates may be present in the polycondensate either in the form of blocks or randomly.

Relative solution viscosity (. eta.) of aromatic polycarbonates and polyester carbonates_rel) From 1.18 to 1.4, preferably from 1.26 to 1.4, in particular from 1.28 to 1.35(0.5g of polycarbonate or polyestercarbonate in 100ml of methylene chloride solution at 25 ℃).

The thermoplastic, aromatic polycarbonates and polyester carbonates may be used individually or in any desired mixture with one another.

Component B

Component B comprises one or more graft polymers prepared from

B.15 to 95, preferably 30 to 90,% by weight of at least one vinyl monomer grafted on

295-5, preferably 70-10,% by weight of one or more graft bases having a glass transition temperature of < 10 ℃, preferably < 0 ℃, particularly preferably < -20 ℃.

The graft base B.2 generally has an average particle diameter (d)₅₀Value) of 0.05 to 10 μm, preferably 0.1 to 5 μm, particularly preferably 0.2 to 1 μm.

The monomers B.1 are preferably mixtures prepared from

B.1.150 to 99 parts by weight of vinylaromatic and/or ring-substituted vinylaromatic compounds (e.g. and preferably styrene,. alpha. -methylstyrene, p-methylstyrene) and/or methacrylic acid- (C)₁-C₈) Alkyl esters (e.g. and preferably methyl methacrylate, ethyl methacrylate) and

b.1.21 to 50 parts by weight of vinyl cyanides (unsaturated nitriles, such as and preferably acrylonitrile and methacrylonitrile) and/or (meth) acrylic acid (C)₁-C₈) Alkyl esters (such as and preferably methyl methacrylate, N-butyl acrylate, t-butyl acrylate) and/or derivatives (such as and preferably anhydrides and imides) of unsaturated carboxylic acids (such as and preferably maleic anhydride and/or N-phenyl-maleimide).

Preferred monomers B.1.1 are selected from at least one of the monomers styrene, alpha-methylstyrene and methyl methacrylate, and preferred monomers B.1.2 are selected from at least one of the monomers acrylonitrile, maleic anhydride and methyl methacrylate.

Particularly preferred monomers B.1.1 are styrene and B.1.2 acrylonitrile.

Suitable graft bases B.2 for the graft polymers B are, for example, diene rubbers, EP (D) M rubbers (ethylene-propylene rubbers and/or ethylene-propylene-diene rubbers), i.e.for example those based on ethylene/propylene and optionally diene, and also acrylate, polyurethane, silicone and ethylene/vinyl acetate rubbers.

Preferably, the graft base B.2 is a diene rubber (e.g.based on butadiene, isoprene, etc.) or a mixture of diene rubbers or copolymers of diene rubbers or mixtures thereof with other copolymerizable monomers (e.g.according to B.1.1 and B.1.2), with the proviso that the glass transition temperature of component B.2 is < 10 ℃, preferably < 0 ℃; particularly preferred is < -10 ℃.

Pure polybutadiene rubber is particularly preferred.

Particularly preferred polymers B are ABS (acrylonitrile-butadiene-styrene copolymer) -polymers (emulsion-, bulk-and suspension-ABS), such as those described, for example, in DE-a 2035390 (US-a 3644574) or in DE-a 2248242 (GB-a 1409275) or in Ullmann, enzyklopadie der Technischen Chemie, volume 19 (1980), page 280. The gel content of the graft base B.2 is at least 30% by weight, preferably at least 40% by weight (measured in toluene).

The graft copolymers B are prepared by free-radical polymerization, for example by emulsion, suspension, solution and bulk polymerization, preferably by emulsion or bulk polymerization.

Emulsion ABS is particularly preferred as component B.

ABS polymers which are prepared by redox initiation of an initiator system composed of organic hydroperoxides and ascorbic acid as described in U.S. Pat. No. 4,493,7285 are also particularly suitable graft rubbers.

Since it is known that the graft monomers do not have to be grafted onto the graft base in their entirety in the grafting reaction, the products of the invention which are obtained by (co) polymerization of the graft monomers in the presence of the graft base and occur simultaneously in the workup are also understood to be generic for graft polymers B.

Suitable acrylate rubbers according to B.2 of the polymers B are preferably polymers of alkyl acrylates, optionally containing up to 40% by weight, based on B.2, of other polymerizable, ethylenically unsaturated monomers. Preferred polymerizable acrylic esters are C₁-C₈Alkyl esters, such as methyl-, ethyl-, butyl-, n-octyl-and 2-ethylhexyl esters, and mixtures of these monomers.

Monomers having more than one polymerizable double bond can be copolymerized for crosslinking. Preferred examples of crosslinking monomers are esters of unsaturated monocarboxylic acids having 3 to 8C atoms with unsaturated monohydric alcohols having 3 to 12C atoms or with saturated polyols having 2 to 4 OH groups and 2 to 20C atoms, for example ethylene glycol dimethacrylate, allyl methacrylate; heterocyclic compounds having multiple degrees of unsaturation, such as trivinyl-and triallyl cyanurate; polyfunctional vinyl compounds, such as di-and trivinylbenzenes; and triallyl phosphate and diallyl phthalate.

Preferred crosslinking monomers are allyl methacrylate, ethylene glycol dimethacrylate, diallyl phthalate and heterocyclic compounds having at least 3 ethylenically unsaturated groups.

Particularly preferred crosslinking monomers are the cyclic monomers triallyl cyanurate, triallyl isocyanurate, triacryloylhexahydro-s-triazine, triallylbenzenes. The amount of crosslinking monomers is preferably from 0.02 to 5, in particular from 0.05 to 2,% by weight, based on the graft base B.2.

In the case of cyclic crosslinking monomers having at least 3 ethylenically unsaturated groups, it is advantageous to limit the amount to less than 1% by weight of the graft base B.2.

Preferred "other" polymerizable ethylenically unsaturated monomers which can optionally be used in addition to the acrylic esters for the preparation of the graft base B.2 are, for example, acrylonitrile, styrene, alpha-methylstyrene, acrylamide, vinyl-C₁-C₆Alkyl ethers, methyl methacrylate, butadiene. Preferred acrylate rubbers as graft base B.2 areAn emulsion polymer having a gel content of at least 60% by weight.

Further suitable graft bases for B.2 are silicone rubbers having graft-active sites, such as those described in DE-A3704657, DE-A3704655, DE-A3631540 and DE-A3631539.

The gel content of the graft base B.2 is determined at 25 ℃ in a suitable solvent (M.Hoffmann, H.Kr ö mer, R.Kuhn, Polymeranalytik I und II, Georg Thieme-Verlag, Stuttgart 1977).

Average particle diameter d₅₀Is a particle with a diameter above and below which 50% by weight of each particle is present. This value can be determined by ultracentrifugation assay (W.Scholtan, H.Lange, Kolloid, Z.und Z.Polymer 250(1972), 782-1796).

Component C

The inventive molding compositions comprise one or more phosphorus compounds of the formula (I) as flame retardants

Wherein the radicals have the abovementioned meanings in general.

Component C phosphorus compounds suitable for the invention are known (cf. for example Ullmanns Encyklopadie der Technischen Chemie, Vol. 18, p. 301, 1979; Houben-Weyl, Methoden der Organischen Chemie, Vol. 12/1, p. 43; Beilstein, Vol. 6, p. 177).

Preferred radicals R¹-R⁴Including, for example, methyl, propyl, isopropyl, butyl, t-butyl, octyl, phenyl, naphthyl, and C₁-C₄Alkyl-substituted aryl radicals, such as the tolyl, xylyl (Xylenyl), propylphenyl, butylphenyl and cumyl radical. Phenyl is particularly preferred.

R⁵And R⁶Preferably represents a methyl group.

Y preferably represents C₁-C₇Alkylene, especially isopropylidene or methylene.

q may be 0, 1, 2, 3 or 4, preferably q is 0, 1 or 2.

n may be 0 or 1, preferably n ═ 1.

N may be a value of from 0.1 to 30, preferably a value of from 0.5 to 10, in particular a value of from 0.7 to 5. As component C according to the invention, mixtures of various phosphoric esters according to formula (I) can be used. In this case, N may take the above value as an average value. Monophosphorus compounds (N ═ 0) may also be included in the mixtures.

Monophosphorus compounds of the formula (I) are, in particular, tributyl phosphate, triphenyl phosphate, tricresyl phosphate, diphenylcresyl phosphate, diphenyloctyl phosphate, diphenyl-2-ethylcresyl phosphate, tri- (isopropylphenyl) phosphate, dimethyl methylphosphonate, diphenyl methylphosphonate, diethyl phenylphosphonate, triphenylphosphine oxide or tricresylphosphine oxide. A particularly preferred monophosphorus compound is triphenyl phosphate.

The average value N can be determined as follows: the composition (molecular weight distribution) of the phosphate mixture is determined by suitable methods (gas chromatography (GC), High Pressure Liquid Chromatography (HPLC), Gel Permeation Chromatography (GPC)) and the average value of N is calculated therefrom.

Component D

The compositions of the present invention may also comprise fluorinated polyolefins as antidrip agents as component D. The amount of fluorinated polyolefin added must however be small enough to still meet the requirements of DIN/VDE-Standard 0472, 815, i.e.the fluorine content of the total composition cannot exceed 0.1% by weight.

Fluorinated polyolefins are generally known (see, for example, EP-A640655). Commercially available products such as Teflon from DuPont^®30N。

The fluorinated polyolefins may also be used in the form of coagulated mixtures of emulsions of fluorinated polyolefins with emulsions of graft polymers (B) or with emulsions of copolymers, preferably based on styrene/acrylonitrile, wherein the fluorinated polyolefins are mixed as an emulsion with an emulsion of graft polymer or copolymer and subsequently coagulated.

Furthermore, the fluorinated polyolefins may be used as a premix with the graft polymer (B) or preferably with a styrene/acrylonitrile-based copolymer. The powdered fluorinated polyolefins are mixed with the powder or granules of the graft polymer or copolymer and melt-compounded, generally at a temperature of 200 ℃ and 330 ℃ in conventional equipment, such as internal kneaders, extruders or twin-screw mixers.

The fluorinated polyolefins may also be used in the form of a masterbatch, which is prepared by emulsion polymerization of at least one monoethylenically unsaturated monomer in the presence of an aqueous dispersion of the fluorinated polyolefin. Preferred monomer components are styrene, acrylonitrile and mixtures thereof. The polymer is applied as a flowable powder after acid precipitation and subsequent drying.

The coagulum, premix and masterbatch generally have a solids content of from 5 to 95% by weight, preferably from 7 to 60% by weight, of fluorinated polyolefin.

Component E

The compositions of the present invention may also comprise other polymers as component (E).

Suitably, it is preferred that at least one member selected from the group consisting of vinyl aromatic compounds, vinyl cyanides (unsaturated nitriles), (meth) acrylic acid- (C)₁-C₈) Vinyl (co) polymers (E.1) of monomers of alkyl esters, unsaturated carboxylic acids and derivatives of unsaturated carboxylic acids, such as anhydrides and imides. Particularly suitable (co) polymers are those prepared by

E.1.150 to 99, preferably 60 to 90 parts by weight of vinylaromatic and/or ring-substituted vinylaromatic compounds, such as and preferably styrene,. alpha. -methylstyrene, p-methylstyrene) and/or methacrylic acid- (C)₁-C₈) Alkyl esters, such as and preferably methyl methacrylate, ethyl methacrylate), and

e.1.21 to 50, preferably 10 to 40 parts by weight of vinyl cyanides (unsaturated nitriles), such as acrylonitrile and methacrylonitrile and/or (meth) acrylic acid- (C)₁-C₈) Alkyl esters (such as and preferably methyl methacrylate, N-butyl acrylate, t-butyl acrylate) and/or unsaturated carboxylic acids (such as and preferably maleic acid) and/or derivatives (such as and preferably anhydrides and imides) of unsaturated carboxylic acids (such as and preferably maleic anhydride and N-phenyl maleimide).

The (co) polymers E.1 are resinous, thermoplastic and rubber-free.

Particular preference is given to copolymers of E.1.1 as styrene and E.1.2 as acrylonitrile.

The (co) polymers of E.1 are known and can be prepared by free-radical polymerization, in particular by emulsion, suspension, solution or bulk polymerization. The (co) polymers of component E.1 preferably have molecular weights Mw (weight average, determined by light scattering or sedimentation analysis) of 15,000-200,000.

Furthermore, polyalkylene terephthalates (E.2) are suitable, as described in EP-A-841187.

Preference is given to polyalkylene terephthalates which have been prepared from terephthalic acid and/or its reactive derivatives (e.g.its dialkyl esters) and ethylene glycol and/or butanediol-1, 4, and mixtures of these polyalkylene terephthalates.

Component F

Furthermore, inorganic materials, especially inorganic materials which improve the stability of the melt due to thixotropic effects, can be added to the polycarbonate composition. The inorganic material should be used in an amount that is beneficial or at least not detrimental to the mechanical properties of the material. In principle, all fine-grained inorganic materials are suitable for this. These inorganic materials are, for example, in the form of particles, flakes or fibers. Mention may be made here, by way of example, of chalk, quartz flour, titanium dioxide, silicates/aluminium silicates, such as talc, wollastonite, mica/layered clay minerals, montmorillonite, especially in organophilic form modified by ion exchange, kaolin, zeolites, vermiculite and also alumina, silica, magnesium hydroxide, aluminium hydroxide and glass fibers/glass flakes. Mixtures of various inorganic materials may also be employed.

The inorganic material may be surface treated, e.g. silanized, to ensure better polymer compatibility.

The inorganic materials may be used in concentrations of 0 to 5% by weight, preferably 0 to 3% by weight, in particular 0 to 1.5% by weight, based on the total composition.

Preference is given to using inorganic materials of platelet character, such as talc, mica/layered clay minerals, montmorillonite, especially organophilic forms modified by ion exchange, kaolin and vermiculite.

Talc is particularly preferred.

Talc means naturally occurring or synthetically prepared talc.

The chemical composition of the pure talc is 3 MgO.4SiO₂·H₂O, so that the MgO content is 31.9 wt.%, SiO₂The content was 63.4 wt.% and the chemically bound water content was 4.8 wt.%. It is a silicate of a layered structure.

Naturally occurring talc minerals generally do not have the above-mentioned ideal composition, because magnesium is partially exchanged for other elements, silicon is partially exchanged for e.g. aluminium and/or impure due to intergrowth with other minerals, such as dolomite, magnesite and chlorite. Such impure natural talc may also be used in the molding composition of the present invention, but high purity talc grades are preferred. Characterized in that the MgO content is 28 to 35 wt.%, preferably 30 to 33 wt.%, particularly preferably 30.5 to 32 wt.% and SiO₂The content is 55 to 65% by weight, preferably 58 to 64% by weight, particularly preferably 60 to 62.5% by weight. Furthermore, it is preferred that the talc grade has Al₂O₃The content is less than 5% by weight, particularly preferably less than 1% by weight, in particular less than 0.7% by weight.

It is particularly advantageous to use a catalyst having an average particle diameter d₅₀< 20 μm, preferably < 10 μm, particularly preferably < 5 μm, most preferably < 2.5 μm for grinding to talc in the form of fine particles.

Furthermore, mention may be made, as preferred inorganic components, of finely divided (nanoscale) inorganic compounds of metals from one or more of main groups 1 to 5 and transition groups 1 to 8 of the periodic Table of the elements, preferably from main groups 2 to 5 and transition groups 4 to 8, particularly preferably from main groups 3 to 5 and transition groups 4 to 8, with the elements oxygen, sulfur, boron, phosphorus, carbon, nitrogen, hydrogen and/or silicon.

Preferred compounds are, for example, oxides, hydroxides, hydrated/basic oxides, sulfates, sulfites, sulfides, carbonates, carbides, nitrates, nitrites, nitrides, borates, silicates, phosphates and hydrides.

Particularly preferred finely divided inorganic compounds are, for example, TiN, TiO₂、SnO₂、WC、ZnO、Al₂O₃、AlO(OH)、ZrO₂、SiO₂Iron oxide, BaSO₄Vanadium oxide, zinc borate, silicates, such as aluminium silicate, magnesium silicate. Mixtures and/or doped compounds may likewise be used. The nanoscale particles may be surface-modified with organic molecules.

Nanoscale AlO (OH) is particularly preferred.

The nano inorganic material has an average particle size of 200nm or less, preferably 150nm or less, especially 1-100 nm.

Particle size and particle diameter always refer to the average particle diameter d₅₀Measured by ultracentrifugation according to W.Scholtan et al, Kolloid-Z.und Z.Polymer 250(1972), pages 782-796.

The nano-inorganic compounds may be present in the form of a powder, paste, sol, dispersion or suspension. Powders can be obtained by precipitation from dispersions, sols or suspensions.

Component G

The moulding compositions according to the invention may contain further conventional additives in effective concentrations, for example anti-dripping agents other than component (D), flame retardants other than component (C), lubricants and mould release agents, nucleating agents, antistatic agents, stabilisers, dyes and pigments.

The molding compositions of the invention comprising components A to G and optionally further additives are prepared by mixing the components in a known manner in conventional apparatus, such as internal kneaders, extruders or twin-screw mixers, and are generally melt-compounded or melt-extruded at temperatures of 200 ℃ and 300 ℃.

The mixing of the individual components can be carried out in a known manner either sequentially or simultaneously and can be carried out both at about 20 ℃ and at higher temperatures.

Owing to their excellent flame resistance and also their good mechanical properties and their good processing behavior, the thermoplastic molding compositions according to the invention are suitable for the production of moldings of all types of molds, in particular those which are, of course, required to comply with DIN/VDE standard 0472, 815. The molded bodies can be produced in a known manner, for example by injection molding and extrusion processes.

Owing to their rheological properties, the molding compositions according to the invention are also particularly suitable for the production of sheets, profiles and moldings by extrusion, extrusion blow molding and deep drawing processes.

Examples of mouldings which can be prepared are: housing parts of various types, for example for household appliances, such as juice extractors, coffee machines, mixers; for electric motors, such as lawn mowers, drills, etc., and for office machines, such as monitors, (portable) computers, printers and copiers. Other possible fields of application are cover plates, window/door profiles and electronic device channels/pipes, cable ducts and electrical installation channels for electrical lines, bus bar covers and moldings, extruded profiles or sheets for the automotive/rail vehicle/aircraft sector (for example interior trim). Furthermore, the molding compositions can be used in the field of electronic engineering, for example for switches, sockets and slabs and for distribution cabinets and electricity meter boxes.

The invention also provides a process for the preparation of the composition, the use of the composition for the preparation of moulded bodies and the moulded bodies themselves.

Detailed Description

Examples

Component A

The branched polycarbonate based on bisphenol A had a relative solution viscosity of 1.32, measured in methylene chloride at 25 ℃ and at a concentration of 0.5g/100 ml.

Component B

From 45 parts by weight of styrene and acrylonitrile in a ratio of 72: 28 and 55 parts by weight of a particulate crosslinked polybutadiene rubber (average particle diameter d)₅₀0.3 to 0.4 μm) graft polymer prepared by emulsion polymerization.

Component C.1

Oligomeric phosphoric acid esters based on bisphenol-A

Component C.2

Resorcinol-based oligomeric phosphates (comparative)

To determine the number average N values for the given components c.1 and c.2, the content of oligomeric phosphate esters was first determined by HPLC measurement:

column type: LiChrosorp RP-8

Eluent in gradient elution: acetonitrile/water 50: 50-100: 0

Concentration: 5mg/ml

The weight-average N average value is then calculated in a known manner from the contents of the individual components (mono-and oligophosphates).

Component D.1

The polytetrafluoroethylene preparation (D.1) is prepared by coprecipitation of a mixture of an aqueous emulsion of the graft polymer (B) and an aqueous emulsion of a tetrafluoroethylene polymer. The weight ratio of graft polymer (B) to tetrafluoroethylene polymer in the coagulum was 90% by weight: 10% by weight. The tetrafluoroethylene polymer emulsion has a solids content of 60% by weight and an average PTFE particle diameter of 0.05 to 0.5. mu.m. The graft polymer emulsion had a solids content of 34% by weight and an average latex particle diameter of 0.3 to 0.4. mu.m.

For the preparation of (D.1), an emulsion of tetrafluoroethylene polymer (Teflon 30N from DuPont) was mixed with an emulsion of graft polymer (B) and stabilized with 1.8% by weight, based on polymer solids, of a phenolic anti-aging agent. The mixture was heated at 85-95 ℃ over MgSO₄The aqueous solution of (epsom salt) and acetic acid was coagulated at pH 4-5, filtered and washed to be substantially free of electrolytes, then most of the water was removed by centrifugation and dried to a powder at 100 ℃.

Component D.2

Blendex 449: a powdered PTFE article from General Electric Plastics, consisting of 50% by weight of PTFE contained in a SAN copolymer matrix.

Component F.1

Naintsch A3: finely ground high-purity talc from Naintsch minerals, Graz, Austria.

Component F.2

Pural 200: nanoscale AlO (OH) with Baume structure from Condea Chemie, Hamburg, Germany.

Component G.1

Phosphite stabilizer

Component G.2

Pentaerythritol tetrastearate was used as mold release agent.

Preparation and testing of the moulding compositions according to the invention

The mixing of the components A to G was carried out on a laboratory extruder type ZSK25 (Werner & Pfleiferer) at a mass temperature of 260 ℃, a flow rate of 15kg/h and a screw-conveying rotational frequency of 200U/min. Molded bodies were prepared on an injection molding machine (Arburg model 270E) at 260 ℃.

Fatigue crack resistance was measured using 80X 10X 4mm test strips. As test medium a mixture of 60 vol.% toluene and 40 vol.% isopropanol was used. The test specimens were pre-expanded (pre-tension 0.2-2.4%) through a circular arc template and placed in the test medium for 5 minutes at room temperature. Fatigue crack resistance was evaluated by edge fiber elongation (randfaserdehnnung), which is at least necessary to break the test strip within a 5 minute exposure time in the test medium.

Notched impact strength (a) determined at room temperature in accordance with ISO 180-1A_k)。

The Vicat B120-temperature is determined according to ISO 306 at a heating rate of 120K/h and a die load of 50N.

Flame retardancy was evaluated according to UL94V on test strips of 1.2 and 1.5mm thickness.

As a measure of the stability of the melt in the case of extrusion processing, the melt is subjected to a low shear range at 260 ℃ in accordance with DIN 54811 (shear rate of 100 s)^-1) The viscosity of the melt was measured.

The Melt Volume Ratio (MVR) was determined according to ISO 1133 at 260 ℃ with a mold load of 5 kg.

TABLE 1

Composition and Properties

examples/Components		V1＊	V2＊	V3＊	1	2	3	4
									A	Polycarbonate resin	84.2	84.2	84.2	84.2	84.2	84.2	82.75
B	Graft polymers	3.5	3.5	3.5	3.5	3.5	3.5	6.0
									C.1	BDP	-	-	-	10.0	10.0	10.0	10.0
C.2	RDP	10.0	10.0	10.0	-	-	-	-
									D.1	PTFE product (10%)	1.3	1.3	1.3	1.3	1.3	1.3	-
D.2	PTFE articles (50%)	-	-	-	-	-	-	0.25
									F.1	Talc	-	0.7	-	-	0.7	-	-
F.2	Nanoscale AlO (OH)	-	-	0.7	-	-	0.7	-
									G.1	Stabilizer	0.1	0.1	0.1	0.1	0.1	0.1	0.1
G.2	Release agent	0.2	0.2	0.2	0.2	0.2	0.2	0.2
									Performance ESC	Marginal fiber elongation at break [% ]]	0.6	1.0	0.8	1.4	2,2	1.8	1.8
ak(23℃)	[kJ/m2]	14.0	16.4	13.8	15.5	37.4	28.8	48.2
									Vicat B 120	[℃]	108	106	107	117	115	115	112
MVR[260℃/5kg]	[ml/10min]	15.0	12.5	12.3	10.4	8.8	9.4	9.2
									Viscosity of the melt [260 ℃ C., 100s ]-1]	[Pas]	772	933	980	1127	1236	1245	1227
UL94V at 1.5mm	Evaluation (Total post-combustion time)	V-O(5s)	V-O(7s)	V-O(3s)	V-O(6s)	V-O(7s)	V-O(2s)	V-O(10s)
									UL94V at 1.2mm	Evaluation (Total post-combustion time)	V-O(17s)	V-O(17s)	V-O(22s)	V-O(24s)	V-O(8s)	V-O(19s)	V-O(21s)

^*Control experiment

Table 1 shows that this is achieved by using bisphenol A-based oligophosphates (examples 1 to 3) instead of resorcinol-based oligophosphates (comparative examples V1 to V3)

a) The thermal shape invariance is improved,

b) the performance of the ESC is obviously improved,

c) the impact strength of the notch is improved and,

d) significantly improves melt stability in extrusion applications,

the flame retardancy was maintained at a good level without change. The Telfon content of all examples and comparative examples meets the DIN/VDE-Standard 0472, 815 section limits.

Furthermore, table 1 shows that the addition of small amounts of inorganic materials, such as talc or nanoscale alo (oh), further improves notched impact strength, ESC resistance and melt stability, and even flame retardant properties can be achieved in the case of talc. However, a corresponding improvement in the mechanical or rheological properties can also be achieved without the addition of inorganic materials by increasing the amount of graft polymer component (example 4).

Claims (24)

1. Composition comprising at least one polycarbonate, at least one impact modifier and at least one phosphorus-containing flame retardant of the general formula (I)

Wherein

R¹、R²、R³And R⁴Each independently is C₁-C₈-alkyl, optionally substituted by alkylC₅-C₆-cycloalkyl, C₆-C₁₀-aryl or C₇-C₁₂-an aralkyl group,

each n is independently 0 or 1,

q are each independently 0, 1, 2, 3 or 4,

n is a number from 0.1 to 30,

R⁵and R⁶Each independently is C₁-C₄-alkyl, and

y represents C₁-C₇Alkylidene, C₁-C₇Alkylene radical, C₅-C₁₂Cycloalkylene radical, C₅-C₁₂-cycloalkylidene, -0-, -S-, -SO-, SO₂or-CO-, wherein the molding composition is characterized by containing 0.1% by weight or less of fluorine, based on the total composition.

2. A composition according to claim 1, comprising 60 to 98% by weight of at least one aromatic polycarbonate, 0.5 to 30% by weight of at least one graft polymer, 1 to 20% by weight of at least one phosphorus-containing flame retardant of the formula (I) and 0 to 5% by weight of a particulate, platelet-shaped or fibrous inorganic material, the sum of the% by weight of the components being 100.

3. A composition according to claim 1, comprising 70 to 95% by weight of at least one aromatic polycarbonate, 1 to 15% by weight of at least one graft polymer, 2 to 15% by weight of at least one phosphorus-containing flame retardant of the formula (I) and 0 to 3% by weight of a particulate, platelet-shaped or fibrous inorganic material, where the sum of the% by weight of the components is 100.

4. The composition according to claim 1, comprising 75 to 90% by weight of at least one aromatic polycarbonate, 2 to 10% by weight of at least one graft polymer, 2 to 15% by weight of at least one phosphorus-containing flame retardant of the formula (I) and 0 to 1.5% by weight of a particulate, platelet-shaped or fibrous inorganic material, the sum of the% by weight of the components being 100.

5. Composition according to claims 1 to 4, further comprising a fluorinated polyolefin, optionally used in the form of a coagulum, premix or masterbatch with the graft polymer or vinyl (co) polymer, in an amount such that the fluorine content of the composition is < 0.1% by weight.

6. A composition according to claims 1 to 5, further comprising a vinyl (co) polymer, a polyalkylene terephthalate or a mixture thereof.

7. A composition according to claims 1 to 6, comprising a flame retardant of the formula I having an N value of from 0.7 to 5.

8. A composition according to claims 1 to 7, comprising as flame retardant a bisphenol A-based oligophosphate of formula

9. A composition according to claim 8, comprising as flame retardant a bisphenol A-based oligophosphate of formula

10. Composition according to claims 1 to 9, containing as impact modifier from 5 to 95% by weight of at least one vinyl monomer grafted on from 95 to 5% by weight of at least one graft base having a glass transition temperature of < 10 ℃.

11. A composition according to claim 10, comprising a graft polymer grafted to a diene rubber, EP (D) M rubber, acrylate rubber or silicone rubber.

12. A composition according to claim 10, comprising emulsion ABS or bulk ABS or a mixture thereof as impact modifier.

13. Compositions according to claims 1 to 12, further comprising other commercially available additives, such as other antidripping agents, other flame retardants, lubricants and mould release agents, nucleating agents, antistatic agents, stabilizers and dyes and pigments.

14. A composition according to claims 1-13, containing talc as inorganic material.

15. A composition according to claim 14, comprising Al, based on talc₂0₃High-purity talc in an amount of 1 wt.% or less.

16. A composition according to claim 14, comprising a compound having an average particle size d₅₀Finely divided talc of 2.5 μm or less.

17. A composition according to claims 1 to 13, comprising as inorganic material a finely divided powder having an average particle diameter of 100nm or less.

18. Polycarbonate molding composition according to one or more of the preceding claims, characterized in that the standard V-O is achieved by the UL94V test at a wall thickness of < 1.5 mm.

19. Polycarbonate molding composition according to one or more of the preceding claims, characterized in that the content of chlorine, bromine and iodine is less than or equal to 0.2% by weight, based on the total composition.

20. The use of inorganic materials for increasing the melt viscosity and the melt stability of chlorine-and bromine-free, impact-strength-improved polycarbonate moulding compositions.

21. Process for the preparation of polycarbonate moulding compositions according to one or more of the preceding claims, wherein the components are mixed and compounded at elevated temperature.

22. Use of polycarbonate moulding compositions according to one or more of the preceding claims for the production of moulded bodies or moulded parts.

23. Use of the polycarbonate moulding compositions according to one or more of the preceding claims for the production of profiles, plates, tubes and pipes by means of an extrusion process.

24. Moulded or moulded bodies and profiles, plates, tubes and pipes produced from the polycarbonate moulding compositions according to one or more of the preceding claims.