CA2024729A1

CA2024729A1 - Stabilized thermoplastic molding materials based on polyphenylene ethers and polyamides

Info

Publication number: CA2024729A1
Application number: CA002024729A
Authority: CA
Inventors: Klaus Muehlbach; Bertram Ostermayer
Original assignee: Individual
Current assignee: BASF SE
Priority date: 1989-09-07
Filing date: 1990-09-06
Publication date: 1991-03-08
Also published as: DE59003322D1; EP0416435B1; DE3929686A1; ES2059939T3; EP0416435A1

Abstract

- 27 - O.Z. 0050/41085 Abstract of the Disclosure: Thermoplastic molding materials containing, as essential components, A) from 10 to 89.9 % by weight of a thermoplastic polyamide, B) from 10 to 89.9 % by weight of a modified poly-phenylene ether, C) from 0.1 to 8 % by weight of a metal sulfide and, in addition, D) from n to 40 % by weight of a fibrous or particulate filler or a mixture thereof, E) from 0 to 25 % by weight of an impact-modifying rubber and F) from 0 to 25 % by weight of a flameproofing agent.

Description

2~72~
o.z. 0050/41085 Stabilized thermop~astic moldin~ material~ based on polyphenylene ether~ and polyamides The present invention xelate~ to thermopla~tic molding material~ containing, as essential components, S A) from 10 to 89.9 % by weight of a thermoplastic polyamide, B) from 10 to 89.9 ~ by weight of a modif_ed poly-phenylene ether, C) from 0.1 to 8 % by weight of a metal sulfide and, in addition, D) from 0 to 40 ~ by weight of a fibrous or particulate filler or a mixture thereof, E) from 0 to 25 % by weight of an impact-modifying rubber and F) from 0 to 25 % by weight of a flameproofing agent.
The present invention furthermore relates to the use of these molding materials for the production of molding~, and to moldings obtainable using these molding materials as e~sential componentq.
Blends of modified polyphenylene ether3 and polyamide~, containing or not containing fillers, are di~closed in WO 85/05 372, EP-A-260 123, WO 87~05 304, EP-A-46 040 and WO 86/02 986.
US 4,255,321 disclose~ mixture~ of polyphenylene ethers and high impact poly tyrene which contain metal sulfide~ as oxygen stabilizers for the polymers.
In addition, DE-A-34 43 154, EP-A 221 341 and WO
83/03 834 disclose thermoplastic molding materials which are ba~ed on unmodified polyphenylene ether~ and poly-amides and may contain small amounts of metal -~ulfides.
Although the mechanical properties of the blends known hitherto have been improved in pointQ, it must, however, be accepted that other mechanical properties have at the 3ame time worsened. In particular, a balanced mechanical property profile is essential in moldings for motor vehicle since high toughness is required, for example, in the ca~e of multiaxial load.

2~2 -~ 72~
- 2 - O.Z. 0050/41085 In addition, the processability of these blends is inadequate.
It was therefore an object of the present inven-tion to provide thermoplastic molding materials which have good free-flowing properties and multiaxial touqh-ness.
We have found tha~ this ob~ect is achieved by the molding materials defined at the outset.
The subclaims deal with preferred materials of this type and their ~se.
The polyamides present in the material~ as component A) are known per se and include partially crystalline and amorphous resins having molecular weights (weight averages) of S000 or more, usually known as nylon. Polyamides of this type are de~cribed, for ex-ample, in US Patents 2,071,250, 2,071,251, 2,130,523, 2,130,948, 2,241,322, 2,312,966, 2,512,606 and 3,393,210.
The polyamides can be prepared, for example, by condensing equimolar amounts of a saturated or aromatic dicarboxylic acid having from 4 to 12 carbon atom~ with a saturated or aromatic diamine having up to 14 carbon atom~ or by conden~ing ~-aminocarboxylic acids or by polyaddition of lactam~.
Example~ of polyamides are polyhexamethyleneadip-amide (nylon 66), polyhexamethyleneazelaamide (nylon 69),polyhexamethylene~ebacamide (nylon 610), polyhexamethyl-enedodecanediamide (nylon 612), the polyamide~ obtained by ring opening of lactam~, such as polycaprolactam and polylaurolactam, and poly-ll-aminoundecanoic acid and polyamide~ made from di(p aminocyclohexyl)methane and dodecanedioic acid.
It is also possible to use, ccording to the invention, polyamides prepared by copolycondensation of two or more of the abovementioned polymers or their component~, eg. copolymers made from adipic acid, i~ophthalic acid or terephthslic acid and hexamethylene-diamine or copolymer~ made from caprolactam, terephthalic 2~2~72~
_ 3 _ o.z. 0050/41085 acid and hexamethylenediamine. Partially aromatic copolyamides of this type contain, as component al), from 40 to 90 % by weight of units clerived from terephthalic acid and hexamethylenediamine. A small proportion of the S terephthalic acid, preferably not more than lO ~ by weight of all the aromatic dicarboxylic acids employed, may be replaced by .isophthalic acid or other aromatic dicarboxylic acids, preferably those in which the car-boxyl is in the para-position.
In addition to the units derived from tereph-thalic acid and hexamethylenediamine, the partially aromatic copolyamides contain units derived from ~-caprolactam (a2) and/or units derived from adipic acid and hexamethylenediamine (a3).
lS The proportion of units derived from ~-caprolac-tam is up to 50 % by weight, preferably from 20 to S0 %
by weight, in particular from 25 to 40 ~ by weight, while the proportion of unit~ derived from adipic acid and hexamethylenediamine is up to 60 % by weight, preferably from 30 to 60 ~ by weight, in particular from 3S to 55 %
by weight.
The copolyamide~ may contain both units derived from ~-caprolactam and those derived from adipic acid and hexamethylenediamine; in this case, it must be ensured 2S that the proportion of units which are free from aromatic groups is lO ~ by weight or more, preferably 20 % by weight or more, but the ratio of units derived from ~-caprolactam to tho~e derived from adipic acid and hexa-methylenediaminQ is not sub~ect to any particular limitation.
It has proven particularly advantageous for many applications to use polyamides containing from 50 to 80 %
by weight, in particular from 60 to 75 % by weight~ of units derived from terephthalic acid and hexamethylene-diamine (units al)) and from 20 to 50 % by weight, preferably from 25 to 40 ~ by weight, of unit~ derived from ~-caprolactam (units az)).

'7 2 9 _ 4 _ o.z. 0050/41085 -The partially aromatic copolyamides can be prepared, for example, by the process described in EP-A-129 195 and EP 129 196.
Preference is given to linear polyamides having a melting point of above 200C.
Preferred polyamides are polyhexamethyleneadip-amide, polyhexamethylenesebacamide, polycaprolactam, nylon 6/6T and nylon 66/6T. The polyamides generally have a relative viscosity of from 2.0 to 5, determined in 1 ~
strength by weight solution in 96 ~ sulfuric acid at 23C, corresponding to a molecular weight of from about 15,000 to 45,000. Preference is given to polyamide~
having a relative viscosity of from 2.4 to 3.5, in particular from 2.5 to 3.4.
Other examples of polyamides are those obtain-able, for example, by condensing 1,4-diaminobutane with adipic acid at elevated temperature (nylon 4,6). Prepar-ation processes for polyamides of this structure are described, for example, in EP-A 38 094~ EP-A-38 582 and EP-A-39 524.
~he proportion of polyamides A) in the molding materials according to the invention is from 10 to 89.9~
by weight, preferably from 25 to 71.8 % by weight, in particular from 20 to 50 ~ by weight.
The molding materials according to the invention contain, as componen~ B), from 10 to 89.9 ~ by weight, preferably from 25 to 71.8 ~ by weight, in particular from 20 to 50 % by weight, of a modified polyphenylene ether.
Polyphenylene ethers generally have a moleculax wei~ht (weight average) in the range from 10,000 to 80,000, preferably from 20,000 to 60,000.
This correspond~ to a reduced specific viscosity ~r~d of from 0.2 to 0.9 dl/g, preferably from 0.35 to 0.8 dl/g, in particular from 0.45 to 0.6 dl/g, measured in 1 ~ strength by weight solution in chloroform at 25C
in accordance with DIN 53 726.

2 ~ 2 ~ r~ 2 ~
_ 5 _ O. Z . 0050/41085 The unmodified polypheny:Lene ethers bl) are known per se and are preferably prepared by oxidative coupling of o-disubsti~uted phenols.
Examples of substituents are halogen atom~, such as chlorine or bromine, and alkyl radicals having from 1 to 4 carbon atoms and preferably containing no ~-tertiary hydrogen, eg. methyl, ethyl, propyl or butyl. The alkyl radicals m~y in turn be substituted by halogen, such a~
chlorine or bromine, or by hydroxyl. Further examples of po~sible substituents are alkoxy, preferably having up to 4 carbon atoms, or phenyl which is unsubstituted or substituted by halogen and/or alkyl. Copolymers of different phenols, for example copolymer~ of 2,6-dLme-thylphenol and 2,3,6-trimethylphenol, are also ~uitable.
It is of course also possible to employ mixtures of different polyphenylene ethers.
Preferred polyphenylene ethers are those which are compatible with vinyl-aromatic polymers, ie. are fully or substantially soluble therein (cf. A. Noshay, Block Copolymer~, pages 8 to 10, Academic Pre s, 1977, and O. Olabisi, Polymer-Polymer Miscibility, 1979, pages 117 t~ 189).
Examples of polyphenylene ethers are poly(2,6-dilauryl-1,4-phenylene) ether, poly(2,6-diphenyl-1,4-phenylene) ether, poly(2,6-dimethoxy-1,4-phenylene) ether, poly(2,6-diethoxy-1,4 polyphenylene) ether, poly(2-methoxy-6-ethoxy-1,4-phenylene) ether, poly(2-ethyl-6-~tearyloxy-1,4-phenylene) ether, polyt2,6-dichloro-1,4-phenylene)ether,poly(2-methyl-6-phenylene-1,4-phenylene) ether, poly~2,6-dibenzyl-1,4-phenylene) ether, poly(2-ethoxy-1,4-phenylene) ether, poly(2-chloro-1,4-phenylene) ether and poly(2,5-dibromo-1,4-phenylene) ether. Preference is given to polyphenylene ethers in which the sub tituents ara alkyl having from 1 to 4 carbon atoms, such a~ poly(2,6-dimet~yl-1,4-phenylene) ether, poly(2,6-diethyl-1,4-phenylene) ether, poly(2-methyl-6-ethyl-1,4-phenylene) ether, poly(2-2~ 7~
- 6 - O.Z. 0050/41085 methyl-6-propyl-1,4~phenylene) ether, poly(2,6-dipropyl-1,4-phenylene) ether and poly(2-ethyl-6-propyl-1,4-phenylene) ether.
Graft polymers made from polyphenylene ethers and vinyl-aromatic polymers such as styrene, ~-methylstyrene, vinyltoluene and chlorostyrene are also suitable.
Functionalized or modified polyphenylene ethers B) are known per se, for example from WO-A 86/02086, WO-A 87/00540, EP-A-222 246, EP-A-223 116 and EP-A-254 048.
The polyphenylene ether bl) is usually modified by incorporating one or more carbonyl, carboxylic acid, acid anhydride, acid amide, acid imide, carboxylic acid ester, carboxylate, amino, hydroxyl, epoxy, oxazoline, urethane, urea, lactam or halobenzyl groups, ~hus ensur-ing adequate compatibility with the 2nd polymer of the mixture, the polyamide.
The modification is generally carried out by reacting a polyphenylene ether bl) with a modifier con-taining one or more of the abovementioned groups, insolution (WO-A 86/2086), in aqueous dispersion, in the gas phase (EP-A-25 200) or in the melt, if desired in the presence of suitable vinyl-aroma~ic polymer~ or impact modifier~, it al~o being po~sible for free-radical initiators to be present.
Examples of suitable modifiers (b3) are maleic acid, methyl maleic acid, itaconic acid, tetrahydro-phthalic acid, the anhydrides and imides thereof, fumaric acid, the monoesters and diester~ of the e acid~, for example of C~- and C2-C8-alkanols (monomer b3~), the monoamidos and diamides of these acids, such as N-phenyl-maleimide (monomers b32), maleic hydrazide, the acyl chloride of trimellitic anhydrid~, ben~ene-1,2-(dicar-boxylic anhydride)-4-(carboxylic acetic anhydride), chloroethanoylsuccinaldehyde, chloroformylsuccinaldehyde, citric acid And hydroxysuccinic acid. Example~ of monomer~ b33~ are N-vinylpyrrolidone and 2 ~
- 7 - O.Z~ 0050/41085 ~meth)acryloylcaprolactam.
The preferred component B) in the molding materials according to the invention is a modified pol~phenylene ether obtainable by reacting bl) from 9.g4 to 99.94 ~ by weight of Pn unmodified polyphenylene ether, b2) from 0 to 90 ~ by weight of a vinyl-aromatic polymer, b3) from 0.05 to 10 % by weight of one or more compound~
from the group formed by b31) an l,~-unsaturated dicarbonyl compound, b32~ an amide-containing monomer having a polymeriz-able double bond and b33) a lactam-containing monomer having a polymeriz-able double bond, b4) from 0 to 80 ~ by weight of other graft-active monomers and b5) from 0.01 to 0.09 % by weight of a free-radical initiator, 20 the percentages by weight being based on the ~um of bl) to b5), for from 0.5 to 15 minutes at from 240 to 375C
in a suitable mixer and kneader, such as a twin-screw extruder.
The vinyl-aromatic polymer ~b2) should preferably 25 be compatible with the polyphenylene ether employed.
The molecular weight of these conventional polymers i8 generally in the range from 1500 to 2,000,000, preferably in the range from 70,000 to 1,000,000.
Example-~ of preferred vinyl-aromatic polymers which are compatible with polyphenylene ethers are given in the abovementioned monograph by Olabisi, pages 224 to 230 and 245. A~ representatives only, vinyl-aromatic polymers made from styrene~ chlorostyrene, ~-methyl-35 styrene and p-m~thylstyrene are mentioned here; in minor amounts (preferably not more than 20 % by weight, in particular not more than 8 % by weight), comonomer~

2~ ~ 72~
- 8 - O.Z. 0050/41085 such as (meth)acrylonitrile or (meth)acrylates may also participate in the synthesis. Particularly preferred vinyl-aromatic polymers are polystyrene and Lmpact-modified polystyrene. :[t is of course also possible to employ mixtures of these polymers. The preparation is preferably carried out by the process described in EP-A-302 485.
If desired, further comonomers b4) which react with or graft onto components bl and, if used, b2) under the preparation conditions can also be employed in the preparation of the modified polyphenylene ether B.
Examples which may be mentioned are acrylic acid, meth-acrylic acid, acrylates, methacrylates and vinyl-aromatic monomers such as styrene, ~-methylstyrene and vinyl-toluene, to mention but a few.
The proportion of component b4) is from 0 to 80 %by weight, preferably from 0 to 45 % by weight, in particular not more than 20 % by weight, based on the sum of components b1) to b5). Particularly preferred molding materials contain no component b4).
Examples of free-radical initiators (b5) are:
di(2,4-dichlorobenzoyl) peroxide, tert.-butyl peroxide, di(3,5,5-trimethylhexanoyl) peroxide, dilauroylperoxide, didecanoyl peroxide, dipropionyl peroxide, dibenzoyl peroxide, tert.-butyl peroxy-2-ethylhexanoate, tert.-butyl peroxydiethylacetate, tert.-butyl peroxyisobutyr-ate, 1,1-di-tert.-butylperoxy-3,3,5-trimethylcyclohexane, tert.-butyl peroxyi~opropylcarbonate, tert.-butylperoxy-3,3,5-trimeth.ylhexanoate, tert.-butyl peracetate, tert.-butyl perbenzoate, butyl 4,4-di-tert.-butyl peroxyvaler-ate, 2,2-di-tert.-butylperoxybutane, dicumyl peroxide, tert.-butylcumyl peroxide, 1,3-di(tert.-butylperoxyiso-propyl)benzene and di-tert.-butyl peroxide. Organic hydroperoxides, such a~ diisopropylbenzene monohydro-peroxide, cumene hydroperoxide, tert.-butyl hydroperox-ide, p-menthyl hydroperoxide and pinane hydroperoxide, and highly branched alkanes of the general structure 2~2~29 - 9 - O.Z. 0050/41085 R4 Rl where Rl to R6 are alkyl ha~ing from 1 to 8 carbon atoms, alkoxy having from 1 to 8 carbon atoms, aryl, such as phenyl or naphthyl, or 5- or 6-membered heterocyclic rings having a ~-electron system and nitrogen, oxygen or sulfur as heteroatoms, are also suitable. The substitu-ent3 R1 to R5 may themselves contain functional groups as sub~tituents, such as carboxyl, carboxyl derivatives, hydroxyl, amino, thiol or epoxide groups. Examples are 2,3-dLmethyl-2,3-diphenylbutane, 3,4-dLmethyl-3,4-di-phenylhexane and 2,2,3,3-tetraphenylbutane.
The molding materials according to the invention contain, as component C), from 0.1 to 8 % by weight, preferably from 0.2 to 4 ~ by weigh~, in particular from 0.25 to 3 ~ by weight, of a metal ~ulfide.
Suitable sulfides are alkali metal and alkaline earth metal sulfides, e.g. sodium sulfide, potassium sulfide, calcium sulfide and barium sulfide, and metal sulfides from the sub-group~ of the Periodic Table, such as manganese sulfide, iron sulfide, nickel sulfide, copper sulfide and cadmium sulfide, and particularly preferably zinc sulfide.
Commercially available zinc sulfide generally contains 97 % by weight or more of zinc sulfide in addition to small amounts of barium sulfate and zinc oxide.
It u~ually ha~ a zinc blende or wurzite structure and a den~ity, in general, of from 2 to 5 g/cm3, in particular from 4 to 5 g/cm3.
It i8 also possible to use mixtures of metal sulfides with oxideq in a mixing ratio of, in general, from 8:2 to 2:8.
In general, the metal sulfides in powder form can easily be incorporated into the molding materials according to the in~ention. Preference is given to 2 ~ r~ 2 ~
- lO - O.Z. 0050/41085 concentrates of the metal sulfide, for example in a polyamide, since this allow~ better dispersion of the pigment to be achieved.
The molding materials according to the invention contain, as component D), from 0 to 40 ~ by weight, preferably from 10 to 35 % by weight, of fibrous or particulate fillers or mixtures thereof. Examples of fillers are carbon or glass fibers in the form of woven glass fabrics, glass mats or glass rovings, glass beads, and wollastonite.
Preferred fibrous reinforcing materials (com-ponent C) are carbon fibers, potassium titanate whiskers, aramid fibers and, particularly preferably, glass fibers.
When gla~s fiberY are used, they may be provided with a size and coupling agent in order to impart better com-patibi~ity with the thermoplastic polyamide (A) or the polyphenylene ether (B). In general, the carbon fiber~
and glass fibers used have a diameter in the range from 6 to 20 ~m.
These glass fibers can be incorporated either in the form of short glass fiber~ or continuous extrudates (rovings). In the finished injection molding, the mean length of the glass fibers is preferably in the range from 0.08 to 0.5 mm.
~5 Suitable particulate fillers are amorphouq silica, asbesto3, magne#ium carbonate, chalk , powdered quartz, mica, talc, feldspar and, in particular, calcium ~ilicate~ such a~ wollastonite and kaolin (in particular calcined kaolin).
Examples of preferred combinations of fillers are 20 ~ by weight of glass fibers with 15 % by weight of wollastonite and 15 % by weight of glas~ fiber~ with 15 %
by waight of wollastonite.
In addition to the es~ential component~ A), B) and C), the molding materials according to the invention can contain from 0 to 25 % by weight, preferably from 3 to 20 % by weight, of an impact-modifying rubber. Con-~ O.Z. 0050/41085 ventional impact modifiers E) which are suitable for polyamides (component A) and rubbers E) which are usually used for the impact modification of polyphenylene ether~
B) can be used.
The preferred rubber-ela~tic polymers E) for polyamides A) are those which have reactive group~ at the surface.
Examples of groups of this type are epoxy, carboxyl, latent carboxyl, amino or amide groups, and functional groups which can be introduced by carrying out the polymerization in the presence of monomerq of the general formula R10 Rll CH 2=C--X~C--R12 ll where the substituent can have the following meanings:
Rl~ is hydrogen or C~-C4-alkyl, Rll is hydrogen, Cl-C8-alkyl or aryl, in particular phenyl, Rl2 is hydrogen, C1-C10-alkyl, C6-C12-aryl or oR13, Rl3 is Cl-C~-alkyl or C6-Cl2-aryl, which is unsubstituted or substituted by O~ or N containing groups, X i8 a chemical bond, C1-C10-alkylene, C6-Cl2-arylene or R

_c--Y
Y i8 O-Z or NH-Z and Z i~ C1-C10-alkylene or Cs-Cl2-arylene.
The graft monomer~ described in EP-A 208 187 are also suitable for introducing reactive groups at the surface.
Examples of monomers using which the abovemen-tioned functional groups can be introduced are glycidyl methacrylate, glycidyl acrylate, allyl glycidyl ether, vinyl glycidyl e~her, glycidyl itaconate, acrylic acid, methacrylic acid and the metal, in partlcular alkali metal, and ammonium salts thereof, maleic acid, fumaric 2~7~
- 12 - O.Z. 0050/41085 acid, itaconic acid, vinylbenzoic acid, vinylphthalic acid, monoesters of these acids with alcohols ROH where R has up to 29 carbon atoms and is, for example, methyl, ethyl, propyl, isopropyl, n-butyl, i-butyl, hexyl, cyclohexyl, octyl, 2-ethylhexyl, decyl, stearyl, methoxy-ethyl, ethoxyethyl or hydroxyethyl. Although maleic anhydride and esters of acrylic acid or methacrylic acid with tertiary alcohols, for example tert.-butyl acrylate, do not have any free carboxyl groups, they behave in a similar manner to the free acids and are therefore regarded as monomers having latent acid groups.
Further examples are acrylamide, methacrylamide and substituted esters of acrylic acid or methacrylic acid, such as (N-t-butylamino)ethyl methacrylate, (N,N-dimethylamino)ethyl acrylate, (N,N-dimethylamino)methyl acrylate and (N,N-diethylamino)ethyl acrylate.
The proportion of groups derived from the above-mentioned monomers is generally from 0.5 to 40 % by weight, preferably from 0.5 to 25 ~ by weight, based on the total weight of the rubber.
These monomers can either be copolym~rized with the other monomers during preparation of the rubber or grafted onto a pre-exi~ting, unmodified rubber (if necessary in the presence of initiator~, for example free-radical initiators).
The rubbers are generally polymers preferably built up from two or more of the following monomer~ as the principal component~: ethylene, propylene, butadiene, isobutene, i30prene, chloroprene, vinyl acetate, styrene, acrylonitrile, methacrylic acid, acrylic acid and acrylate~ and methacrylates having from 1 ~o 18 carbon atoms in the alcohol component.
A first preferred group comprises the ethylene-propylene (EPM) and ethylene-propylene-diene (EPDM) rubbers, which preferably h~ve an ethylene:
propylene ratio in the range from 40:60 to 90:10.
The Mooney viRcositie~ (MLl+4flQ0C) of uncro~s-2~7~
- 13 - O.Z. 0050/4108S
linXed EPM and EPDM rubbers of this type (gel contents generally less than I % by weigh~) are preferably in the range from 25 to 100, in particular from 35 to 90 (meas-ured in accordance with DIN 53 523 on the large rotor after a running time of 4 minutes at 100C).
EPM rubbers generally have virtually no double bonds, while EPDM rubbers may contain from 1 to 20 double bonds per 100 carbon atom3.
Examples of diene monomers for EPDM rubbers are conjugated dienes, such as isoprene and butadiene, non-con~ugated diene~ having from 5 to 25 carbon atoms, such as penta-1,4-diene, hexa-1,4-diene, hexa-1,5-diene, 2,5-dimethylhexa-1,5-diene and octa-1,4-diene, cyclic diene~, such as cyclopentadiene, cyclohexadienes, cyclooctadienes and dicyclopentadiene, and alkenylnorbornenes, such as 5-ethylidene-2-norbornene, 5-butylidene-2-norbornene, 2-methallyl-5-norbornene and 2-isopropenyl-5-norbornene, and tricyclodienes, such as 3-methyltricyclo-[5.2.1Ø2.6]-3,8-decadiene, and mixtures thereof.
Preference is given to hexadiene-1,5,5-ethylidenenorbor-nene and dicyclopentadiene. The diene content of the EPDM
rubbers is generally from 0.5 to 50 ~ by weight, in particular from 3 to 15 % by weight, based on the total weight of the rubber.
EPM and EPDM rubbers are usually grafted with the - abovementioned monomers carrying reactive group~, of which only acrylic acid, methacrylic acid and derivatives thereof, and maleic anhydride are mentioned here.
A further group of rubbers comprise~ copolymer~
of ~-olefin , preferably ethylene, with ester~ of acrylic or methacrylic acid, for example with the methyl, ethyl, propyl, n-, i- or t-butyl and 2-ethylhexyl esters. In addition, the rubbers may also contain the abovementioned reactive gxoup~, for example in the form of dicarboxylic acids, derivatives of these aclds, vinyl esters and vinyl ether~.
The ethylene content of the copolymers i~ gener-2~2~2~

- 14 - O.Z. 5050/41085 ally in the range from 50 to 98 % by weight, and the proportions of epoxide-contain:ing monomers and of the acrylate and/or methacrylate are each in the range from 1 to 49 % by weight.
Preference is given to olefin polymers comprising from 50 to 98.9 ~ by weight, in particular from 60 to 95 ~ by weight, of ethylene, from 0.1 to 20 ~ by weight, in particular from 0.15 to 15 ~ by weight, of glycidyl acrylate and~or glycidyl methacrylate, acrylic acid and/or maleic anhydride, and from 1 to 45 ~ by weight, in particular fxom 10 to 35 % by weight, of n-butyl acrylate and/or 2-ethylhexyl acrylate.
The above-described ethylene copolymers can be prepared by conventional processes, preferably by random copolymerization under superatmospheric pressure and at elevated temperature. Appropriate processes are described in the literature.
The melt flow index of the ethylene copolymers is generally in the range from 1 to 80 g/10 min (measured at 190C under a load of 2.16 kg).
Suitable elastomers for the impact modification of polyamide are furthermore graft copolymers/ containing reactive group~, with butadiene, butadieneJ~tyrene, butadiene/acrylonitrile and acrylate rubbers aQ the graft base, as deQcribed, for example, in DE-A 16 9~ 173, DE-A 23 48 377, DE-A 24 44 584 and DE-A-27 26 256, in particular the ABS polymer~, as de~cribed in DE-A-20 35 390, DE-A-22 48 242 and EP-A-22 216.
The rubber E may be a graft polymer comprising from 25 to 98 % by weight of an acrylate rubber having a glass transition temperature of below -20C as the graft baQe ~base polymer) and ?~ ~ 2 ~
- 15 - O.Z. 0050/41085 from 2 to 75 ~ by weight of a copolymerizable, ~thylenically unsaturated monomer whose homopolymers and copolymers have a glass transition temperature of greater than 25C, as the graft shell.
The graft base is an acrylate or methacrylate rubber containing up to 40 ~ by weight of further co-monomers. The Cl-C3-e~ter~ of acrylic acid or methacrylic acid and the halogenated derivatives thereof, and aromatic acrylates and mixtures thereof are usually employed.
Specific exampleR of comonomers in the graft base are acrylonitrile, methacrylonitrile, styrene, ~-methylstyr-ene, ac~ylamide~, methacrylamides and vinyl Cl-C~-alkyl ethers.
The graft base may be uncrosslinked or partially or fully crosslinked, which is achieved, for example, by copolymerizing preferably from 0.02 to 5 ~ by weight, in particular from 0.05 to 2 % by weight, of a crosslinking monomer containing more than one double bond. Suitable crosslinking monomer~ are described, for example, in DE-A 27 2~ 256 and EP-A 50 265.
Preferred crosslinking monomers are triallyl cyanurate, triallyl isocyanurate, triacryloylhexahydro-s-triazine and triallylbenzenes.
If ths crosslinking monomerR contain more than 2 polymerizable double bond~, it i~ advantageous to limit their amount to not more than 1 ~ by weight, based on the graft base.
Highly ~uitable graft bases are emulsion polymers having a gal content of grea~er than 60 ~ by weight (determined in dimethylformamide at 25C by the method of M. Hoffmann, H. Rr~mer, R. Kuhn, Polymeranalytik, Georg-Thieme-Verlag, Stuttgart, 1977).
Other ~uitable graft ba3e~ are acrylate rubbers 3S having a diene core, as described, for example, in EP-A 50 262.
Particularly sui~able graft monomer-~ are styrene, 2~2~ 1~2~

- 16 - O.Z. 0050/41085 ~-methylstyrene, acrylonitrile, methacrylonitrile and methyl methacrylate, or mixtures thereof, in particular those comprisiny styrene and acrylonitrile in the weight ratio from 1:1 to 9:1.
The reactive groups can be introduced into the graft copolymers by, for example, carrying out the preparation of the graft shell in the presence of the appropriate monomers. In this case, the proportion thereof in the graft monomer mixture is preferably from 0.5 to 30 % by weight, in particular from 1 to 25 % by weight. It is also possible to apply the appropriate monomers separately as the final graft shell.
The graft yield, ie. the quotient of the amount of grafted-on monomers and the amount of graft monomers employed, is generally in the range from 20 to 90 ~.
Examples of rubbers are those which are used for the impact modification of polyphenylene ethers B).
Examples which may be mentioned are thermoplastic rubbers, such as polybutadiene, polybutene, polyisoprene, acrylonitrile-butadiene, ethylene-propylene, polyesteror ethylene rubbers, and elastomeric copolymers made from ethylene and esters of (meth)acrylic acid, for example ethylene-butyl acrylate copolymers, furthermore ionomers, polyoctenylenes, graft rubbers having a graft core made from butadiene or isoprene or alkyl ~meth)acrylates and a graft shell made from styrene and/or ~-methyl~tyrene, and preferably ~tyrene-butadiene block copolymer3, including A~, A~A and ~BAB block copolymer~, which may al~o have indi3tinct transitions, star block copolymers and the like, analogous isoprene block copolymers and (partially) hydrogenated block copolymers. These rubber~
can also be employed in the form of a graft with vinyl-aromatic monomers, such a~ styrene (EP-A 234 063 and US-A 4,681,915).
The rubber~ E preferably have a gla~ transition temperature of below ~30C, in particular below -40C. It is of course al~o possible to employ mixtures of the 2~ 72~3 - 17 - O.Z. 0050/41085 abovementioned types of rubber.
The molding materials according to the invention may furthermore contain flameproofing agents F) in amounts of from 0 to 25 ~ by weight, preferably up to 15 ~ by weight, based on the total weight of the molding materials.
All known flameproofing agents are suitable, eg.
polyhalobiphenyl, polyhalobiphenyl ether, polyhalo-phthalic acid and derivatives thereof, polyhalooligo-carbonates and polyhalopolycarbonates, the correspondingbromine compound~ being particularly effective.
Examples of these are polymer~ of 2,6,2',6'-tetrabromobisphenol A, of tetrabromophthalic acid, of 2,6-dibromophenol and of 2,4,6-tribromophenol and deriv-atives thereof.
A preferred flameproofing agent F~ is elementalred phosphorus, which can generally be phlegmatized or coated with, for example, polyurethanes or other amino plastic~. In addition, concentrates of red phosphorus in, for example, a polyamide, elastomer or polyolefin are also suitable.
Particular preference i~ given to 1,2,3,4,7,8,9,-10,13,13,14,14-dodecachloro-1,4,4a,5,6,6a,7,10,10a,11,-12,12a-dodecahydro-1,4:7,10-dimethanodibenzo(a,e)cyclo-octane (Dechlorane~ Plus, Occidental Chemical Corp.) and,if desired, a synergi~t, for example antimony trioxide.
Other cuitable phosphorus compounds are organo-phosphoru~ compound~, such a~ phosphonates, phosphinate~, phosphinites, phosphine oxides, phosphines, pho~phites or phosphates. A ~pecific example i triphenylpho~phine oxide, which can be used alone or mixed with hexabromo-benzene or a chlorinated biphenyl or red pho~phoru~ and, if desired, antimony oxide.
Typical preferred phosphorus compounds which can be u~ed according ~o the pre~ent invention are tho~e of the general formula 2~72~
- 18 - O.Z. 0050/~1085 ~o-I~OQ
o~
where Q is hydrogen or identical or different hydrocarbon radicals or halogenated hydrocarbon radicals, such a~
alkyl, cycloalkyl, aryl, alkyl-substituted aryl and aryl-substituted alkyl, with the proviso that one or more of the radicals Q is aryl. Example~ of suitable phosphate~
of this type are phenyl bisdodecyl phosphate, phenyl bisneopentyl phosphate, phenyl ethylene hydrogen phos-phate, phenyl bis(3,5,5'-trLmethylhexyl) phosphate, ethyl diphenyl phosphate, 2-ethylhexyl di(p-tolyl) phosphate, diphenyl hydrogen phosphate, bis(2-ethylhexyl) phenyl pho~phate, tri(nonylphenyl) phosphate, phenyl methyl hydrogen phosphate, di(dodecyl) p-tolyl phosphate, tricresyl pho~phate, triphenyl phosphate, dibutyl phenyl phosphate and diphenyl hydrogen phosphate. The preferred phosphates are those in which each Q i aryl. The most preferred phosphate is triphenyl phosphate. The combin-ation of triphenyl pho~phate with hexabromobenzene and antimony trioxide is also preferred.
Other suitabls flameproofing agent~ are compounds which contain phosphorus-nitrogen bond~, such as phospho-nitrile chloride, phosphori~ acid e~ter amides, phoc-phoric acid ester amine~, phosphoric acid amides, phosphonic acid amides, pho~phinic acid amide~, tris-(aziridinyl) phosphine oxide and tetrakis(hydroxymethyl)-phosphonium chloride. The ma~ority of these flame-inhibiting additives are commercially available.
Other ~uitable halogen-containing flameproofing agents are tetrabromoben~ene, hexachlorobenzene, hexa-bromobenzene, and halogenated polystyrene~ and polyphenylene ethers.
It is also pos~iblo to use the halogenated phthalimides de cribed in DE-A-l9 46 924, of which N,N'-ethylenebistetrabromophthalimide, in pasticular, has - 19 - O.Z. 0050/41085 achieved Lmportance.
In addition to the essential components A), B) and C) and, if desired, D), E) and F), the molding mater-ials according to the invention can also contain conven-S tional additives and processing aids, whose proportion isgenerally up to 20 % by weight, preferably up to 10 % by weight, based on the total weight of components A) to F).
Examples of conventional additives are stabiliz-ers, antioxidants, thermal stabilizers, W stabilizers, lubricants, mold release agents, dyes, pigments and plasticizers.
Examples of antioxidants and thermal stabilizers which can be added to the thermoplastic materials accord-ing to the invention are halides of metals of group I of the Periodic Table, eg. ~odium halides, potassium halides and lithium halides, if desired in combination with copper(I) halides, eg. chlorides, bromides or iodides. It is also possible to use zinc fluoride, zinc chloride, sterically hindered phenols, hydroquinone~, substituted representa~ive~ of thi~ group, and mixtures of these compounds, preferably in concentration~ of up to 1 % by weight, based on the weight of the mixture.
Examples of W 4tabilizers are various substituted resorcinols, salicylates, benzotriazole~ and benzophe-nones, which are generally employed in amounts of up to2 % by weight.
Materials for increasing the screening against electromagnetic waves, such as metal flakes, metal powders, metal fibers and metal-coated fillers, can also be used.
Lubricants and mold release agents, which are generally added to the thermopla~tic material in amounts of up to 1 ~ by weight, are stearic acid, stearyl alcohol, alkyl stearates, alkyl ~tearamides and esters of pentaerythritol with long-chain fatty acid~.
The additiveY al~o include ~tabilizers which prevent decomposition of the red phosphorus (component F) 2~L~ ~ 2~
- 20 - O.Z. 0050/41085 in khe pre~ence of moisture and atmospheric oxysen.
Examples are compounds of cadmium, zinc, aluminum, silver, iron, copper, antimony, tin, magnesium, man-ganese, vanadium and boron. Examples of particularly suitable compounds are oxides of the metals mentioned, furthermore carbonates or o~ycarbonates, hydroxides and salts of organic or inorganic acids, such as acetates, pho~phates, hydrogen phosphates and sulfates.
The thermoplastic molding materials according to the invention can be prepared by conventional processes by mixing and subsequently extruding the starting com-ponents in conventional mixers, such as screw extruder~, preferably twin-screw extruders, Brabender mills or Banburry mills, and kneaders. After extrusion, the extrudate i~ cooled and comminuted.
In order to obtain the mo~t homogeneous molding material possible, vigorous mixing i~ necessary. To this end, mean mixing times of from 0.2 to 30 minute~ at from 280 to 380C are generally necessary. The ~equence of mixing of the components may be varied; for example, it is po~sible to pre-mix two or three components, or to mix all the components together. It may be advantageous to prepare the modified polyphenylene ether B2 in a first zone of an extruder and to mix it with the other com-ponents of the molding material according to the inven-tion in one or more ~ub~equent zones. A proces~ of this type i~ described in DE-A 37 02 5B2.
The molding materials according to the invention have good toughness, in particular multiaxial toughness, combined with good processability.
This property profile makes the moldings which can be produced from ~he molding materials according to the invention particularly suitable for motor vehicle part~, ~ports equipment, and electronic and electrical components.

2~24 729 - 21 - O.Z. 0050/41085 EXAMPLES
Component A1) Poly-~-caprolactam having a Fikentscher K value of 73, measured in l ~ strength by weight solution of 96 % by weight sulfuric acid at 25C, corresponding to ~rel f 2.7.
Component A2) Polyhexamethyleneadipamide having a R value of 76, corresponding to a relative viscosity ~r~l of 2.95.
Component A3) Polyhexamethyleneadipamide having a K value of 60, corresponding to qr~l Of 2.05.
Component (Bl) A modified polyphenylene ether comprising 90 g by weight of poly(2,6-dLmethyl-1,4-phenylene) ether (~r~d = ~ 59 dl/g, measured in 1 % strength by weight solution in chloroform at 25C), 8 ~ by weight of polystyrene (melt flow index MFI at 200~C and a load of 5 kg: 24 g/10 min), 1.95 % by weight of fumaric acid and 0.05 % by weight of 3,4-dimethyl-3,4-diphenylhexane (initiator) wa~ prepared by mixing the component~ at from 290 to 310C in a twin screw extruder with subsequent dega~sing.
The melt was p2s~ed through a water bath, granulated and dried.
Component (Bl*) (for comparison) An unmodified polyphenylene ether having a mean molecular weight (weight average) ~ of 30,000 and ~rad = 0.59 dl/g.
Component C1) Zinc sulfide having a density of 4.1 g/cm3.
Component C2) Zinc ~ulfide pigment having a mean particle size of 0.35 ~m.

2~2~72~
- 22 - O.Z. 0050/41085 Component E1) A styrene-butadiene-styrene three-blockcopolymer having a styrene content of 30 ~ by weight.
Component E2) A two-block copolymer of styrene and hydrogenated polybutadiene having a styrene content of 35 % by weight;
n~mber average molecular weight ~ = 95,000.
Component E3) An ethylene copolymer comprising:
70 % by weiqht of ethylene, 25 % by weight of n-butyl acrylate and 5 ~ by weight of acrylic acid.
MFI = 11 g/10 min (190C/2.16 kg) (DIN 53 735) Preparation of the molding materials Components A), B) and C) and, if desired, D) to F) were mixed in a twin-screw extruder at a barrel temperature of 290C. The melt wa~ passed through a water bath and granulated. The dried granules were in~ection-molded at 280C to form dumbbell te~t specimens and a~
300C to form circular di~ks (60 x 2 mm).
The penetration energy was determined on circular disk~ in accordance with DIN 53 443; the modulus of ela~ticity was determined on dumbbell te~t specLmens in accordance with DIN 53 437.
The melt flow index (MFI) wa~ determined in accordance with DIN 53 735 at 275C and a load of 10 kg.
Th~ compositions of the molding material~ and the results of the measurements are shown in the table.
As can be seen, the melt flow index and the penetration energy are clearly superior in the examples according to the invention compared with the comparative examples.

~2~72~
- 23 C). Z . 0050/41085 ~ I
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202~ ~729 - 24 - O.Z. 0050/41085 Key to table:
***) in addition 0.3 % by weight of 2-(2-hydroxy-5-methylphenyl)benzotriazole **) for comparison Example 6 additionally contained, in accordance with DE-A-3 443 154, 5 ~ by weight of styrene-maleic anhydride copolymer (92/8~ and 10 % by weight of triphenylphosphine oxide Example 7 contained, in accordance with Example 10 of EP-A-221,341, 10.4 ~ by weight of a styrene-acrylamide copolymer (90/10) Example 8 contained, in accordance with WO 83/0 38 34, 20 ~ by weight of triphenyl phosphate.
Examples 9 to 11 contained, in accordance with US 4,255,321, impact-modified polystyrene containing 8 % by weight of polybutadiene rubber (VN = 70 ml/g of the matrix tyrene in accordance with DIN 53 726), 9 = 49.5 ~ by weight, 10 = 50 ~ by weight, 11 = 49 ~ by weight.

Claims

1. A thermoplastic molding material containing, as essential components, A) from 10 to 89.9 % by weight of a thermoplastic polyamide, B) from 10 to 89.9 % by weight of a modified poly-phenylene ether, C) from 0.1 to 8 % by weight of a metal sulfide and, in addition, D) from 0 to 40 % by weight of a fibrous or particulate filler or a mixture thereof, E) from 0 to 25 % by weight of an impact-modifying rubber and F) from 0 to 25 % by weight of a flameproofing agent.

2. A thermoplastic molding material as claimed in claim 1, containing from 25 to 71.8 % by weight of A), from 25 to 71.8 % by weight of B), from 0.2 to 4 % by weight of C) and from 3 to 20 % by weight of E).

3. A thermoplastic molding material as claimed in claim 1, in which component C) is zinc sulfide.

4. A thermoplastic molding material as claimed in claim 1, in which component B) is a modified poly-phenylene ether prepared from b1) from 9.94 to 99.95 % by weight of a polyphenylene ether, b2) from 0 to 90 % by weight of a vinyl-aromatic polymer, b3) from 0.05 to 10 % by weight of one or more compounds from the group formed by b31) an .alpha.,.beta.-unsaturated dicarbonyl compound, b32) an amide-containing monomer having a polymeriz-able double bond and b33) a lactam-containing monomer having a polymeriz-able double bond, b4) from 0 to 80 % by weight of further graft-active - 26 - O.Z. 0050/41085 monomers and b5) from 0.01 to 0.09 % by weight of a free-radical initiator.
4. A filler-containing thermoplastic molding material as claimed in claim 1, in which the filler comprises glass fibers, wollastonite, carbon fibers or a mixture thereof.

5. A molding obtainable from a thermoplastic molding material as claimed in claim 1.