DE3419377A1 - Poly(phenylene ether)- containing mixtures which are protected against thermooxidation, and the use thereof for the production of mouldings - Google Patents

Abstract

The invention relates to thermoplastic compositions comprising a poly(phenylene ether), optionally at least one styrene polymer, optionally conventional additives in conventional amounts, and additionally from 0.05 to 2% by weight of a stabiliser of the formula. <IMAGE> in which R<1>, R<2> and R<3> are identical or different and may be C4- to C20-alkyl, C5- to C8-cyloalkyl, optionally substituted C6- to C20-aryl or O-, S- or N- containing 5- to 6-membered heterocyclic radicals, and to the use of the mixtures for conversion into mouldings. In particular, the C6 to C20-aryl radicals are substituted by OH and/or C1- to C9-alkyl radicals, and the radicals R<1>, R<2> and R<3> are C4- to C12-alkyl, C5- to C6-cycloakyl and/or C6- to C20-aryl groups.

Description

^M OZ 0050/37132

Mixtures containing poly (phenylene ethers) protected against thermal oxidation and their use for the production of molded parts

The invention relates to thermoplastic mixtures consisting of (a) at least one poly (phenylene ether), (b) optionally at least a styrene polymer, (c) optionally customary additives in usual amounts and (d) additionally a stabilizer.

Such mixtures are unformed masses through Mixing of the mixture components come about according to conventional methods and which can be achieved by thermoplastic processing according to conventional processing methods can be processed into molded parts or semi-finished products within certain temperature ranges. The mixtures can be used as granules, them but can also be in powder form or otherwise preformed.

Thermoplastic mixtures of poly (phenylene ether), also poly (phenylene oxide) or polyphenylene ether for short and optionally styrene polymers, the usual additives and stabilizers contained in the usual amounts are well known from the literature (cf. US- - Patents 3 257 357, 3 306 874, 3 369 656, 3 383 435, 3 838 102, 4 128 and 4 128 603 as well as DE-Offenlegungsschriften 16 94 272, 19 32 234, 21 62 154, 24 34 848 and 30 43 893). With these compositions, the thermal oxidation sensitivity of the polyphenylene ether resins can contain Masses can be improved by mixing in stabilizers. Different phosphite stabilizers are recommended for this purpose (cf. US-PS-2,952,701, DE-OS-32 38 740 and DE-OS-32 41 542).

A disadvantage of all molding compositions containing polyphenylene oxide resins, however, is the pronounced instability when stored at temperatures above room temperature. The masses are subject to thermal oxidation and lose their good mechanical properties as a function of temperature and time and also experience significant discoloration. This is particularly true if the polyphenylene ether resin masses are not completely different from the by-products occurring during the polymerization, such as 3,3 ', 5 , 5'-Tetramethyldiphenoquinone and / or 3,3 ', 5.5 ^l -tetramethyl-4,4'-dihydroxibiphenyl have been freed and these by-products are contained in the masses to be processed. The object of the present invention was therefore to find stabilizers against the thermal oxidation of polyphenylene ether resins containing compositions which offer good protection against discoloration and against the drop in mechanical properties even if the polyphenylene ether resins contain significant amounts of 3.3 ', 5.5'- Contain tetramethyldiphenoquinone and / or 3,3 ', 5,5'-tetramethy1-4,4'-dihydroxibiphenyl.

BASF Aktiengesellschaft - * "- OZ 0050/37132

This object is achieved according to the invention in that the initially described Mixtures as stabilizers Compounds of the general formula (I)

05 OR ²

R ¹ - P ^ (D,

wherein R ¹ , R ² and R ^{3 are} identical or different and are C ₄ - to C ₂ Q-alkyl-, C ^ - to Cg _{-cycloalkyl, optionally substituted C 6} - to C ₂₀ -aryl- or O, S- or N-containing 5 to 6-membered heterocyclic radicals can be.

The Cg to C ₂₀ aryl radicals are preferably substituted by OH and / or C ₁ to C ₉ alkyl radicals.

Also preferred are compounds of the formula (I) in which the radicals R ¹ , R ² and R ^{3 are} C ₄ to C ₁₂
C2Q are aryl groups.

R ² and R ^{3 are} C ₄ to C ₁₂ alkyl, C ₅ to Cg cycloalkyl and / or Cg bis

The stabilizer (I) is preferred in amounts of 0.05 to 2, in particular 0.2 to 1 Gew.X, based on the weight of the mass in the mixture.

The polyphenylene ethers are compounds based on polyphenylene oxides disubstituted in the ortho position, the ether oxygen of one unit being bonded to the benzene nucleus of the adjacent unit. At least 50 units should be linked to one another. The polyphenylene ethers can carry hydrogen, halogen, hydrocarbons which do not have a tertiary hydrogen atom in the ortho position to oxygen, halogenated hydrocarbons, phenylene radicals and hydrocarbonoxy radicals. The following are particularly suitable: poly (2,6-dichloro-1,4-phenylene) ether, poly (2,6-diphenyl-1,4-phenylene) ether, poly (2,6-dimethoxy-l, 4-phenylene) ether, poly (2,6-dimethyl-1,4-phenylene) ether or poly (2,6-dibromo-1,4-phenylene) ether. The poly (2,6-dimethyl-1,4-phenylene) ether is preferably used. Very particularly preferably, poly (2,6-dimethyl-l, 4-phenylene) ether having an intrinsic viscosity between 0.4 and 0.7 dl / g (measured in chloroform at 30 ⁰ C).

The polyphenylene ethers can by self-condensation of the corresponding monohydric phenols under the action of oxygen in the presence of a catalyst system, as for example in US Patents 3,219,625, 3,306,874, 3,306,875, 3,956,442, 3,965,069, 3,972,851. In addition to the polyphenylene ethers, this always results

BASF Aktiengesellschaft - 3 "- OZ 0050/37132

0.1 to 2 wt. SK, based on the monomer, by-products such as 3,3 ', 5,5'Tetramethyldiphenoquinone and / or 3,3, 5,5'Tetramethyl-4,4- -dihydroxibiphenyl, which depending on the processing method in the polymer remain, or, as in the case of work-up by precipitation, from the polymer can be removed.

Any known styrene polymers may be used as optionally mixed-in styrene polymers Homopolymers and copolymers composed of alkenyl aromatic monomers can be used. The monovinyl aromatic compounds are used here in particular styrene into consideration, and also those alkylated in the nucleus or side chains Styrenes. However, styrene, p-methylstyrene and o ^ -Methylstyrene used.

Polar compounds such as acrylonitrile, Acrylic acid, (meth) acrylic acid alkyl esters with 1 to 8 carbon atoms in the alkyl radical and / or maleic acid are used. The proportion of comonomers is calculated in such a way that that the resulting copolymers with the polyphenylene ether resin compositions are homogeneously miscible. However, it is also possible to use non-polar comonomers to form statically or block-like copolymers. Examples are butadiene, isoprene, pentadiene and others.

Examples of suitable homo- and copolymers are polystyrene, poly-p- -methylstyrene, poly-o ^ -methylstyrene, styrene-ZoZ-methylstyrene copolymers, Styrene / acrylonitrile copolymers (SAN), styrene-methyl acrylate, styrene-butyl acrylate and styrene-methyl methacrylate copolymers, styrene / Butadiene copolymers, styrene / maleic anhydride copolymers, styrene / acrylonitrile / butadiene terpolymers (ABS), copolymers of ethylvinylbenzene and divinylbenzene and the like, block copolymers of A-B-A and A-B types, where A is polystyrene and B is an elastomeric diene, e.g. polybutadiene, radial teleblock copolymers of styrene and a conjugated diene, acrylic resin-modified styrene / butadiene resins and the like and mixtures of homopolystyrene and copolymers of the types mentioned above.

However, styrene polymers are also to be understood as meaning the polystyrenes which have been impact-modified by natural and / or synthetic rubbers. Be understood as rubbers polymers whose glass transition temperature should preferably be below ⁰ ° C, below -20 ⁰ C. Suitable rubbers for the purposes of the invention are, in addition to natural rubber, for example polybutadiene, polyisoprene and copolymers of butadiene and / or isoprene with styrene, alkyl esters or acrylic acid with 2 to 8 carbon atoms

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men in the alkyl radical, and with acrylonitrile, polymers of the alkyl esters of Acrylic acid with 2 to 8 carbon atoms in the alkyl radical, polyisobutylene and rubbers based on ethylene-propylene-diene.

All such styrene polymers are known per se, so that further Explanations are superfluous.

Polyphenylene ether and styrene polymer can be used in any weight ratio be present in the mixes. For optimum physical properties of the mixture, they are preferably in a proportion of 20: 1 up to 1:10, in particular 10: 1 to 1: 5 parts by weight are present.

The molding compositions can also contain one or more conventional non-resinous additives that are usually present in polyphenylene ether resin blends in order to have certain physical and chemical properties to improve the molded body produced therefrom. These agents include the usual flame retardants, plasticizers, lubricants and mold release agents, antistatic agents, Waxes, reinforcing fibers (e.g. glass fibers and graphite whiskers), mineral fillers, abrasion-resistant components, dyes and Pigments. Such agents are described, for example, in US Pat. No. 4,172,929 as additives for compositions containing polyphenylene ether resins. the Any additives used are in a total amount between 1 and 50, preferably 5 and 40% by weight, based on the weight of the Mixture, to develop their usual effects.

25th

The stabilizing compounds to be used according to the invention of the general Formula (I) are commercially available under the trade name “Irgafos P-EPQ” from Ciba Geigy and can be obtained according to those known to those skilled in the art Process as described e.g. in Houben-Weyl, Vol. 12/1, Thieme-Verlag, Stuttgart 1963, p. 324ff. Thus, the compounds of the general formula (I), hereinafter phosphonites referred to, e.g. through the reaction of dihalophosphines with hydroxy compounds, such as alcohols or phenols, in the presence of acid-binding agents such as tertiary amines, or by Grignard reaction or by reacting alkali or alkaline earth organyls with phosphorous acid triesters or phosphorous acid diester halides are produced. Representatives of these compounds are already used as stabilizers for polypropylene [see. Journal of Applied Polymer Science "27_ (1982), Pages 951ff] and other polymers [cf. EP-B] -5447].

40

Examples of the phosphonites to be used according to the invention are monophosphonites with R ¹ , R ² , R ³ = C ₁ - to C ₂ g-alkyl groups, such as nonyl, dodecyl, octadecyl or aryl groups, such as phenyl, nonylphenyl,

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2,4'-dimethylphenyl, 2,4-di-tert-butylphenyl, 3,5-dimethyl-4-hydroxyphenyl, 3,5-di-tert-butyl-4-hydroxyphenyl and cycloalkyl groups such as cyclohexyl or 3,3,5,5-tetramethylcyclohexyl or heterocyclic groups derived, for example, from imidazole. Particularly preferred, however Oiphosphonite are those in which R ¹ is a C ₂ - to C ₂ o ^A l ^| <ylylene, cycloalkylylene or arylylene group of hexylylene, nonylylene or cyclohexylylene, phenylylene or 4 ·, 4 '"- biphenylylene.

The following phosphonites are particularly preferably used: bis- (2,4-di- -tert.butylphenyD-phenylphosphonite, tris- (2,4-di-tert.butylphenyl) -phosphonite, Tetrakis- (2,4-di-tert-butyl-6-methylphenyl) -4,4'-biphenylylene-diphosphonite, Tetrakis- (2,4-di-tert-butylphenyl) -4,4'-biphenylylene-diphosphonite, Tetrakis- (2,4-dimethylphenyl) -1, 4-phenylylene-diphosphonite, tetrakis- (2,4-di-tert-butylphenyl) -1,6-hexylylene-diphosphonite and / or tetrakis (3,5-dimethyl-4-hydroxyphenyl) -4,4'-biphenylylene-diphosphonite, Tetrakis (3,5-di-tert-butyl-4-hydroxyphenyl) -4,4-biphenylylene-diphosphonite.

The diphosphonites tetrakis- (2,4-di-tert-butylphenyl) -4,4'-biphenylene-diphosphonite are particularly suitable, Tetrakis- (2,4-di-tert-butylphenyI) -I, 6-hexylylene-diphosphonite, Tetrakis (3,5-dimethyl-4-hydroxyphenyl) -4,4-biphenylylene-diphosphonite and tetrakis- (3,5-di-tert-butyl-4- -hydroxyphenyl) -4,4-biphenylylene-diphosphonite and tetrakis- (2,4-di- -tert.butyl) -l, 4-phenylylene-diphosphonite, again in particular the diphosphonite tetrakis- (3,5-dimethyl-4-hydroxyphenyl) -4,4-biphenylylene-diphosphonite ene and tetrakis (3,5-di-tert-butyl-4-hydroxylphenyl) -4,4-biphenylylene-diphosphonite the preference is to be given.

To be effective, the stabilizer compounds (I) should be used in amounts of at least 0.05 wt. SS, based on the total weight of the mixture, in available to the masses. For best results, using amounts in the range between 0.05 and 2 weight percent, are usually most preferred 0.2 to 1% by weight of the total mixture achieved.

The manner in which the mixtures according to the invention are prepared is not critical. In one procedure, the individual components are pre-mixed in a mixer and then assembled in an extruder at temperatures of 230 to 32O ⁰ C, usually the compounding is carried out on devices that allow homogeneous mixing, such as

40 kneaders, extruders or roller mixers.

The advantages achieved by the invention are in particular therein see that the compositions obtained have improved resistance to

BASF Aktiengesellschaft - fr'- 0.Z. 0050/37132

• τ

Thermal oxidation show what is in a light inherent color and good mechanical properties documented.

The mixtures according to the invention can be processed into customary molded parts by customary methods.

The following examples are provided for illustrative purposes only in no way limit the scope of the invention. Unless otherwise stated, all proportions are on a weight basis.

Example and comparative example

The agents and compositions listed in Table I below were pre-mixed by dry blending the ingredients in a fluid mixer, and then, made up at a temperature of 28O ⁰ C over a 53 mm twin-screw extruder from Werner and Pfleiderer, Stuttgart. To assess the thermal oxidative damage 200 mm at 28O ⁰ C 2 round slices were prepared from the blends on a SpritzguQmaschine type Arburg Allrounder. These are stored in a convection oven at 100 ⁰ C. The puncture resistance according to DIN 53443 were then determined at a test temperature of 28 ⁰ C on the test specimens. The percentage of penetration work remaining after 14 days was determined, the initial value of the unloaded samples being taken as 100 % . In addition, the white index of the sample

25 bodies determined after temperature storage.

As a polyphenylene ether (a) a poly (2,6-dimethyl-l, 4-phenylene) ether having an intrinsic viscosity of 0.50 dl / g (measured at 30 ⁰ C in chloroform) and a residual copper content of 5 ppm and a content of 3,3 ·, 5,5'-tetramethyl-4,4'-dihydroxybiphenyl of 0.9 wt. 515 used.

The styrene polymer (b) used was:

b ₁ ) an impact-modified polystyrene which was produced by mass suspension polymerization of 8% by weight of polybutadiene with a cis content of 96 % in the presence of styrene and had an average particle size of 1.5 μm;
b ₂ ) an ABA block copolymer consisting of a central polybutadiene block with a weight fraction of 70 % and external A blocks consisting of polystyrene with a total of 30 SS.

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The following agents were used as additives (c):

C ^) polyethylene wax

C ₂ ) tris-nonylphenyl phosphite (see US Pat. No. 2,952,701) C ₃ ) titanium dioxide

C ₄ ) triphenyl phosphate

C ₅ ) phenyl neopentylene glycol phosphite (cf. DE-OS 32 41 542)

The following compounds were used as stabilizers (Ia): 10

dj;) Tetrakis (2,4-di-tert-butylphenyl) -4,4'-biphenylylene diphosphonite d ₂ ) Tetrakis (3,5-dimethyl-4-hydroxyphenyl) -4 _f 4'-biphenylylene diphosphonite

Tabel example Composition of the molding compound

Components a) b) c) d)

Penetrability after storage for 14 days at

100 ° C (at 85th of the initial value)

White index before after Temperature storage

15 b _o 2 C ₁

15th

80

35

b ₂

50 b.

b _x
b,

0.5

₁ 2.5 C ₃

2 C ₁ 0.5 d ₂ 2.5 C ₃

2.4 C ₁

2.5 C ₃

0.1

15 b ₉ 1 C ₁ 1.5

₁ 2.5 C ₃

2 C ₁ 2.5 C ₃

40 b, 10 c
2 C ₁

2.5 C ₃

50 b _x 2 C ₁

b ₂ 2.5 C ₃

10 C ₄ 2 C ₁
2.5 ¹ C ₃

0.5 U ₁ 0.5 d _x

0.5 d ₂ 0.5 d ₂

94

98

22nd

21

24

20th

11th

15th

H * H U O

CD

Table (continued)

Example composition of the molding compound (%)

Components
a) b) c) d)

Comparative experiments
(not according to the invention)
A.

80

Penetrability after storage for 14 days at

100 ⁰ C (in % of the initial value)

White index
before after
Temperature storage

b ₂

0.5 C ₂ 2.5 C ₃

71

25th

31

80

b.

2 C ₁ 2.5 C, 0.5 C5

82

23

27

80

b.

2.5 C ₁ 2.5 C ₃

10

27

39

45

b.

2 C

0.5 C ₂ 2.5 C,

58

16

22nd

Claims (6)

BASF Aktiengesellschaft 0.Z. 0050/37132 claims 1. Thermoplastic mixtures consisting of (a) a poly (phenylene ether), (b) optionally at least one styrene polymer, (c) optionally customary additives in customary amounts and (d) an additional stabilizer of the general formula (I) OR ² OR ¹ - P ^/ (I), wherein R ¹ , R ² and R ^{3 are} identical or different and are C ₄ - to C ₂₀ - -alkyl-, Cc- to Cg-cycloalkyl-, optionally substituted Cg- to C ₂₀ -aryl- or O-, S- or N-containing 5 to 6-membered heterocyclic radicals can be. 2. Mixtures according to claim 1, characterized in that the Cg to C ₂ Q aryl radicals are substituted by OH and / or C ₁ to Cg alkyl radicals. 3. Mixtures according to claim 1, characterized in that the radicals R ¹ , R ² and R ^{3 are} C ₄ to C ₁₂ alkyl, C ₅ to Cg cycloalkyl and / or C ₆ to C ₂ Q Are aryl groups. 4. Mixtures according to claim 1, characterized in that the stabilizer (I) is contained in amounts of 0.05 to 2% by weight , based on the weight of the mixture. 5. Mixtures according to claim 1, characterized in that the stabilizer (I) is contained in amounts of 0.2 to 1 Gew.SS, based on the weight of the mixture. 6. Use of the mixtures according to claim 1 for thermoplastic processing to molded parts. 206/84 Fri / HB * § \ 23.05.84