DE4013112A1 - Thermoplastic moulding compsns. - contg. thio:xanthone as heat-stabiliser in mixt. of ABS and aromatic polycarbonate - Google Patents

Abstract

Compsns. (I) contain (A) ABS; (B) aroamtic, thermoplastic polycarbonate (II), and (C) 0.01-15% (all pts. wt.) on (A) + (B), thioxanthone of formula (III) m, n = 1-4; X, Y = H, 1-5C alkyl, or halogen. Compsns. contg. (A) 100-20 pts. ABS of compsn. (A1) 5-10% graft copolymer prepd. by graft polymerisation of ?

Description

The present invention relates to thermoplastic Molding compositions containing

• I. ABS plastics and
• II. Thermoplastic, aromatic polycarbonates,

which are characterized in that they are a thioxane thon of the general formula I

included in what

m, n = 1-4 and
x, y independently of one another = H, C _1-5 alkyl, halogen,

in amounts of 0.01-15% by weight, preferably 0.05-10% by weight, in particular 0.1-3 wt .-% based on the plastics.

The ABS polymers I according to the invention contain 5-100% by weight of a graft polymer (A) and 95-0% by weight of a thermoplastic copolymer (Resin) (B).

Graft polymers (A) are within the meaning of the invention those in which a rubber is either a mono mer from the series styrene, methyl methacrylate or a Monomer mixture of 95-50% by weight styrene, α-methylstyrene, core substituted styrene, methyl methacrylate or Mixtures thereof and 5-50% by weight (meth) acrylonitrile, Maleic anhydride, N-substituted maleimides or Mixtures thereof are graft polymerized. Suitable Rubbers are in particular polybutadiene, butadiene / Styrene copolymers with up to 30% by weight of one lower alkyl esters of acrylic or methacrylic acid (e.g. Methyl acrylate, ethyl acrylate, methyl methacrylate and Ethyl methacrylate.

Other suitable rubbers are e.g. B. polyisoprene or Polychloroprene. Alkyl acrylate are also suitable rubbers based on C₁-C₈ alkyl acrylates, ins special ethyl, butyl, ethylhexyl acrylate. These Alkyl acrylate rubbers can optionally be up to 30% by weight of monomers such as vinyl acetate, acrylonitrile, styrene, Methyl methacrylate, vinyl ether copolymerized. These alkyl acrylate rubbers can still be smaller  Amounts (up to 5% by weight) of crosslinking ethylenic contain unsaturated monomer. Such are e.g. B. alkylene diol di (meth) acrylates, polyester di (meth) - acrylate, di-, tri-vinylbenzene, triallyl cyanurate, allyl (meth) acrylate, butadiene, isoprene etc. Such alkyl acrylates are known. Acrylic rubbers as a graft The basis can also be products that a ver wetting diene rubber from one or more con conjugated dienes, such as polybutadiene, or a copoly merisat of a conjugated diene with an ethylenic unsaturated monomer, such as styrene and / or acrylonitrile, included as the core.

Diene monomer rubbers are preferred.

The graft copolymers (A) contain 10-95% by weight, in particular 20-70% by weight, rubber and 90-5% by weight, in particular 80-30% by weight, graft-copolymerized mono mere. The rubbers lie in this graft mixed poly Merisaten in the form of at least partially cross-linked part Chen an average particle diameter (d₅₀) of 0.09 up to 5 µm, in particular from 0.1-1 µm. Such Graft copolymers can be replaced by free radicals Graft copolymerization of monomers from the series Styrene, α-methylstyrene, nucleus-substituted styrene, (Meth) acrylonitrile, methyl methacrylate, maleic anhydride, N-subst. Maleimide in the presence of those to be grafted Rubbers are made. Preferred manufacturing are procedures for such graft copolymers  the emulsion, solution, bulk or suspension poly merization.

The copolymers (B) can be obtained from the graft monomers be constructed for (A) or similar monomers, ins especially from at least one monomer from the series Styrene, α-methylstyrene, halostyrene, acrylonitrile, Methacrylonitrile, methyl methacrylate, maleic anhydride, N-subst. Maleimide in the presence of those to be grafted Rubbers are made. Preferred manufacturing The processes for such graft copolymers are Emulsion, solution, bulk or suspension poly merization.

The copolymers (B) can be made from the graft monomers for (A) or similar monomers, in particular at least one styrene monomer, α-methylstyrene, halostyrene, acrylonitrile, metha crylonitrile, methyl methacrylate, maleic anhydride, Vinyl acetate and N-substituted maleimide. It deals are preferably copolymers of 95-50% by weight Styrene, α-methylstyrene, maleic anhydride or mixtures therefrom with 5-50% by weight of acrylonitrile, methacrylonitrile, Methyl methacrylate, maleic anhydride or mixtures from it. Such copolymers are also created during grafting mixed polymerization as by-products. It is usual, in addition to the copolymers contained in the graft polymer to mix separately prepared copolymers.  

These do not have to match those in the graft polymers lying grafted resin parts chemically identical be.

Suitable copolymers made separately are resin well-behaved, thermoplastic and rubber-free; it's ins special copolymers of styrene and / or α-methylstyrene with acrylonitrile, optionally in a mixture with methyl methacrylate.

Particularly preferred copolymers consist of 20- 40% by weight of acrylonitrile and 80-60% by weight of styrene or α-methyl styrene. Such copolymers are known and can in particular by radical polymers tion, in particular by emulsion, suspension, Prepare solution or bulk polymerization. The Copolymers preferably have molecular weights of 15,000 to 2.10⁵.

For the molding compositions according to the invention can reason In addition, all thermoplastic polycarbonates are used will.

Aromatic polycarbonates in the sense of the invention (II) homopolycarbonates and copolycarbonates are ver stood who z. B. one or more of the following Underlying diphenols:

Hydroquinone
Resorcinol
Dihydroxybiphenyls
Bis (hydroxyphenyl) alkanes
Bis (hydroxyphenyl) cycloalkanes
Bis (hydroxyphenyl) sulfides
Bis (hydroxyphenyl) ether
Bis (hydroxyphenyl) ketones
Bis (hydroxyphenyl) sulfoxides
Bis (hydroxyphenyl) sulfones
α, α′-bis (hydroxyphenyl) diisopropylbenzenes,

and their nuclear alkylated and nuclear halogenated Ver bonds. These and other suitable diphenols are e.g. B. in U.S. Patents 30 28 365, 29 99 835, 31 48 172, 32 75 601, 29 91 273, 32 71 367, 30 62 781 and 29 99 846, in German Offenlegungsschriften 15 70 703, 20 63 050, 20 63 052, 22 11 956, 22 11 957, the french Patent 15 61 518 and the monograph "H. Schnell, Chemistry and Physics of Polycarbonates, Interscience Publishers, New York, 1964 ".

Preferred diphenols are e.g. B .:

4,4'-dihydroxybiphenyl
2,2-bis (4-hydroxyphenyl) propane
2,4-bis (4-hydroxyphenyl) -2-methylbutane
1,1-bis (4-hydroxyphenyl) cyclohexane
α, α'-bis (4-hydroxyphenyl) -p-diisopropylbenzene
2,2-bis (3-methyl-4-hydroxyphenyl) propane
2,2-bis (3-chloro-4-hydroxyphenyl) propane
Bis (3,5-dimethyl-4-hydroxyphenyl) methane
2,2-bis (3,5-dimethyl-4-hydroxyphenyl) propane
Bis (3,5-dimethyl-4-hydroxyphenyl) sulfone
2,4-bis (3,5-dimethyl-4-hydroxyphenyl) -2-methylbutane
1,1-bis (3,5-dimethyl-4-hydroxyphenyl) cyclohexane
α, α′-bis (3,5-dimethyl-4-hydroxyphenyl) -p-diisopropylbenzene
2,2-bis (3,5-dichloro-4-hydroxyphenyl) propane
2,2-bis (3,5-dibromo-4-hydroxyphenyl) propane
1,1-bis (4-hydroxyphenyl) -3,3,5-trimethylcyclohexane, P.

Particularly preferred diphenols are e.g. B .:

2,2-bis (4-hydroxyphenyl) propane
2,2-bis (3,5-dimethyl-4-hydroxyphenyl) propane
2,2-bis (3,5-dichloro-4-hydroxyphenyl) propane
2,2-bis (3,5-dibromo-4-hydroxyphenyl) propane
1,1-bis (4-hydroxyphenyl) cyclohexane
1,1-bis (4-hydroxyphenyl) -3,3,5-trimethylcyclohexane, P.

Preferred aromatic polycarbonates are those which one or more of the diphenols mentioned as preferred underlie. Copolycarbonates are particularly preferred, those 2,2-bis (4-hydroxyphenyl) propane and one the other diphenols mentioned as particularly preferred underlie. Poly are also particularly preferred carbonates based solely on 2,2-bis (4-hydroxyphenyl) - propane or 2,2-bis (3,5-dimethyl-4-hydroxyphenol) propane.  

The aromatic polycarbonates can according to known Ver drive are manufactured, e.g. B. a melt transesterification from bisphenol and diphenyl carbonate and in solution Bisphenols and phosgene. The solution can be homogeneous ("Pyridine process"), or heterogeneous ("two-phase limit surface process "). According to the invention, polycarbonates, those in solution, especially after the two-phase limit surface processes have been produced, especially suitable.

The aromatic polycarbonates can be incorporated small amounts, preferably amounts between 0.05 and 2.0 mol% (based on diphenols used) three or more than three-functional compounds, e.g. B. those with three or more than three phenolic Hydroxy groups can be branched.

Polycarbonates of this type are e.g. B. in the DE-OS 15 70 533, 15 95 762, 21 16 974, 21 13 347, 25 00 092, GB-PS 10 79 821, the US-PS 35 44 514 described.

Some of the usable compounds with three or more as three phenolic hydroxy groups are, for example Phloroglucin, 4,6-dimethyl-2,4,6-tri- (4-hydroxyphenyl) - heptene-2,4,6-dimethyl-2,4,6-tri- (4-hydroxyphenyl) heptane, 1,3,5-tri- (4-hydroxyphenyl) benzene, 1,1,1-tri- (4- hydroxyphenyl) ethane, tri- (4-hydroxyphenyl) phenyl metane, 2,2-bis- [4,4-bis- (4-hydroxyphenyl) cyclohexyl] - propane, 2,4-bis (4-hydroxyphenyl-isopropyl) phenol, 2,6- Bis- (2'-hydroxy-5'-methyl-benzyl) -4-methylphenol, 2- (4-  Hydroxyphenyl) -2- (2,4-dihydroxyphenyl) propane and 1,4- Bis-84.4 '' - dihydroxytriphenyl-methyl) benzene. Some of the other three-functional compounds are 2,4- Dihydroxybenzoic acid, trimesic acid, cyanuric chloride and 3,3-bis (4-hydroxyphenyl) -2-oxo-2,3-dihydroindole.

The aromatic polycarbonates should generally have average weight-average molecular weights _w of 10,000 to over 200,000, preferably from 20,000 to 80,000 (determined by measuring the relative viscosity in CH₂Cl₂ to 25 ° C at a concentration of 0.5 % By weight).

In the case of polycarbonate mixtures, the high molecular weight polycarbonates with _w from 10,000 to 200,000 can also contain small amounts of low molecular weight polycarbonates, e.g. B. mixed with an average degree of polymerization of 2-20.

When processing mixtures of aromatic poly Carbonates and ABS plastics can be used in particular the production of large parts at Temperaturbe loads up to 300 ° C surface defects in the form of Blocks or streaks appear.

According to EP-A 23 291, the use of esters is known of phosphorous acid as stabilizers. For temperatures The stabilization achieved here is <280 ° C not sufficient (see comparative experiment 2).  

It has now been shown that the addition of thioxanthone general formula I in amounts of 0.01 to 15% by weight, or 0.05-10% by weight, in particular 0.1-3% by weight, of poly carbonate-ABS molding compounds leads to products that significantly higher temperature limit show improved flowability at the same time.

The thioxanthones which can be used according to the invention are in Principle known and in principle known methods producible (see: Houben-Weyl, methods of organization African chemistry, volume 712a, p. 426). You will i. a. at the curing of paints containing unsaturated groups used as photoinitiators by UV rays (see: R. Hulman, P. Oldring, UV + EB Curing, Formu lations for printing inks, coatings and paints, Selec tive Industrials Training Associates Limited, London, US 1988, published by: SITA-Technology). Your effect as Thermal stabilizers are completely unexpected and new. Examples of the thioxanthones according to the invention are: 2-methylthioxanthone, 2-isopropylthioxanthone, 2-chlorothio xanthon.

The molding compositions according to the invention can be mixed of the individual components can be obtained. In a before The latices are the preferred manufacturing method of the graft polymer (A) and optionally that of Rubber (A2) and the copolymer (B) mixed and the solids precipitated and dried together. The powder mixture thus obtained is then with the Polycar bonat mixed. The individual components of the Invention  but molding compounds can also be made separately and then mixed on known mixers. Suitable for this are, for. B. mixing rolling mills, Screw extruder or internal mixer.

The incorporation of the stabilizers according to the invention can be done by known techniques in any way respectively. So the stabilizers z. B. via kneader or screw machines both beforehand into the individual components of the mixture as well as directly at thermo plastic processing of the individual components for Total mix or even retrospectively in the total mix yourself.

The present invention thus also relates to Process for incorporating additives in ABS / PC form masses, which is characterized in that thioxane thones of the general formula I in amounts of 0.01- 15% by weight, preferably 0.05-10% by weight, in particular 0.1- 3% by weight based on the plastics, before, during or after manufacturing the ABS / PC blends in the Melt clogs.

The molding compositions according to the invention can still for ABS and / or PC additives in the usual for these Plastic usual amount turned in a known manner be working. Common additives are, for example Pigments, flame retardants, stabilizers, flow medium, lubricant, mold release agent and / or anti statica.  

The present invention thus also relates to Process for producing the mold according to the invention compositions additionally comprising at least one additive selected from pigments, flame retardants, stabilizers, Plasticizers, lubricants, mold release agents and / or antistatic agents, which is characterized in that that the additional additives together with the Thioxanthone before, during or after manufacture ABS / PC mixtures are added in the melt.

The present invention thus includes the ABS / PC molding compounds according to the invention, which except the at least one additive selected from pigments, Flame retardants, stabilizers, flow agents, lubricants agents, mold release agents and / or antistatic agents hold.

The molding compositions of the present invention can be used for Manufacture of moldings of all types can be used. In particular, molded bodies can be produced by injection molding be put. Examples of moldings that can be produced are: Housing parts of all types (e.g. for household appliances such as juicers, coffee machines, mixers) or covers plates for the construction sector and parts for the motor vehicle sector. You will also be in the field of electrical engineering used because they have very good electrical properties of molded parts by deep drawing from beforehand manufactured sheets or foils.

Examples Polymers and polycondensates used or Stabilizers

• A. Aromatic polycarbonate from 2,2-bis (4-hydroxy phenyl) propane (bisphenol A) with a relative Viscosity of 1.26, measured in CH₂Cl₂ at 25 ° C (0.5% by weight solution).
• B. styrene-acrylonitrile copolymer with a styrene Acrylonitrile ratio of 70:30 and a limit viscosity of (η) = 0.55 dl / g (measurement in Dimethylformamide at 20 ° C).
• C. SAN graft polymer of 50% by weight styrene-acrylic nitrile mixture (in a weight ratio of 72:28) 50% particulate polybutadiene of a medium Particle size (d₅₀) of 0.4 µm, obtained by Emulsion polymerization.
• D. 2-isopropylthioxanthone.
• E. Phosphoric acid esters of bis-82-hydroxy-3-cyclo hexyl-5-methylphenyl) methane (stabilizer according to EP-A 2 32 919).

The molding compositions of the examples below were based on a twin-screw extruder from Werner & Pfleiderer the designation ZSK 53 at 240 ° C by mixing the ABS  Polymer with the polycarbonate component and Stabilizer manufactured.

The properties of the molding compositions were as follows Methods determined:

• 1. The viscosity was high using a capillary pressure viscometer determined at 260 ° C. The Ver Ratio of length to thickness of the capillary was 30th
• 2. The optical assessment was carried out on spritz cast round plates (80 × 2 mm). Based on was a rating scale of 1-4. Here means 1: flawless surface; 2: minor upper surface disorders; 3: severe surface defects, no longer justifiable; 4: strong streaks.

Examples 1-3

Claims (3)

1. Thermoplastic molding compositions containing (I) an ABS plastic and (II) an aromatic, thermoplastic polycarbonate, characterized in that the molding compositions are a thioxanthone of the general formula whereinm, n = 1-4 and
x, y independently of one another = H, C _1-5 -alkyl, halogen, in amounts of 0.01-15% by weight, preferably 0.05-10% by weight, in particular 0.1-3% by weight. -% based on the plastics. 2. Thermoplastic molding compositions containing:

• I. 100-20 parts by weight of an ABS polymer of the following composition:
  • A. 5-100 wt .-%, preferably 5-80 wt .-%, of a graft copolymer, Herge provides by graft polymerization of
    • A1) 10-95% by weight, preferably 10-80% by weight, of a mixture of
      • A1.1) 50-90% by weight of styrene, α-methylstyrene, nucleus-substituted styrene or methyl methacrylate or mixtures thereof and
      • A1.2) 50-10% by weight (meth) acrylonitrile, methyl methacrylate, maleic anhydride, N-substituted maleimide or mixtures thereof
    • A2) 90-5% by weight, preferably 90-20% by weight, of a rubber with a glass transition temperature T _G 0 ° C. and
  • B. 95-0 wt .-%, preferably 95-20 wt .-%, of a thermoplastic copolymer
    • B1) 90-50% by weight of styrene, α-methylstyrene, nucleus-substituted styrene or methyl methacrylate or mixtures thereof and
    • B2) 50-10% by weight (meth) acrylonitrile, methyl methacrylate, maleic anhydride, N-substituted maleimide or mixtures thereof
• II. 0-80 parts by weight of an aromatic polycarbonate
• III. 0-5 parts by weight, preferably 0.01-3 parts by weight, of a customary additive or a customary additive mixture
• IV. 0.01-15% by weight, preferably 0.05-10% by weight, in particular 0.1-3% by weight, based on 100 parts by weight of I, II and III, of a thio xanthone of the general formula I, wherein m, n = 1-4 and x, y independently of one another = H, C _1-5 alkyl, halogen.

3. Process for the preparation of the invention Molding compositions according to claims 1 and 2.