DE2119301B2 - Thermoplastic compounds with high impact strength - Google Patents

Description

The invention relates to thermoplastic compositions with high impact resistance made from mixtures of polyphenylene ethers with a rubber-modified polystyrene and or a polystyrene and a rubber.

High molecular weight polyphenylene ethers are technical high-performance thermoplastics with relatively high melt viscosities and softening points above 275 ° C ". They are suitable for numerous technical applications where resistance at high temperatures is important. They can be processed into foils, fibers and molded parts.

Certain properties of the polyphenylene ethers are undesirable for some technical applications. For example, molded parts made from polyphenylene ethers are somewhat brittle due to their poor impact strength. In addition, the processing as a melt is due to the relatively high melt viscosities and softening points because of the high temperatures that soften the polymer are required, and the problems associated therewith, e.g. B. instability and discoloration, uninteresting. Processing as a melt also requires specially designed process equipment for use at elevated temperatures.

The US-PS 33 83 435 describes a method for improving the processability of polyphenylene ethers in the melt. For this purpose, the polyphenylene ethers with polystyrene resins, preferably rubber-modified high-impact polystyrenes, mixed. Mixtures of poly (2,6-dialkyl-1,4-phenylene) ethers Using a high impact polystyrene are technically important because with them both an improvement the processability of the polyphenylene ethers as a melt as well as an improvement in the impact strength the molded parts produced from the mixtures is achieved.

It is generally known. d; eat the properties from blow / practice polystyrolhar / .cn largely from the number. Size and type of dispersing in the resin depend on elastomeric particles. There is an optimal particle size in the range of 2 to 5 or 10 microns for kaulschukmodili / .icrtes schbg / ähes polystyrene mil a relatively narrow size distribution within this range (see, for example, Encyclopedia of Polymer Science and Technology, Vol. 13, 1970. p. 392 and GB-PS 1127 820 and 1174 214).

It has now surprisingly been found that mixtures based on a polyphenylene ether with a rubber modified polystyrene or with a styrene resin and a rubber considerably have better impact strengths if the particle size of the dispersed elastomeric phase falls below an average maximum of about 2 μ is maintained. Impact resistance is essential higher than comparable mixtures in which the mean particle size is above about 2, e.g. B. about 6 µ, is increased, i.e. H. is within the range that has been designated as the optimum so far. About that in addition, the appearance of the surface, especially the gloss, as well as the resistance wedge against Aggressive solutions like Ben / in surprisingly improved.

The invention relates to thermoplastic compositions with high impact strength from mixtures a polyphenylene ether with a rubber-modified polystyrene and or a polystyrene and a rubber, which is characterized in that it contains 0.1 to 30 weight per unit of a disperse elastomeric phase made of natural or synthetic rubbers or those with grafted polystyrene contain, the particles of which have a mean diameter of a maximum of about 2 μ.

Preferred embodiment of the invention are such thermoplastic compositions. 111 which the polystyrene resin on a chewing-free basis 20 to 80 percent by weight of the total weight of the polyslyrolic resin on a rubber-free basis and the polyphenylene ether.

The thermoplastic compositions generally exist from a mixture of two phases, a closed phase from a polyphylene oxide resin / and sylrol resin in which a disperse phase of particles of the elastomer is embedded. in various Particles made of polystyrene resins can also be used, depending on how the masses are manufactured and polyphenylene ether resins are present in the disperse phase. In any case, the Size of the particles according to known methods, e.g. B. by phase contrast microscopy, the particularly is appropriate, or can be measured by microfiltration and similar known methods.

The polystyrene resin and the elastomer can be used with the polyphenylene ether as separate components be put together. Since apparently comparable with lower amounts of the elastomer Impact strengths are achieved, is preferably a rubber-modified polystyrene resin / with the Polyphenylene ether combined. The first method is the particle size of the elastomeric phase adjusted by mechanical mixing of rubber, slyrole resin and polyphenylene oxide, z. B. downsized. In the / wide method, the particle size of the elastomer is, for example by polymerizing styrene in the presence of dissolved rubber under known conditions set, with a disperse elastomeric phase, for example from grafted crosslinked Chewable particles in polystyrene, which represents the closed phase, is disporgicrt. Has become a product

ijann combined with the polyphenylene ether, whereby The size of the particle in general: in the final Mass remains unchanged.

The polyphenylene ethers upon which the egg discovery is dependent is, are well known and are for example in US-PS 33 06 874, 33 06 875 3257 357 and 32 57 358.

A preferred group of polyphenylene ethers consists of recurring structural units Formula,

-ο- <

in which the ether oxygen atom of a unit is attached to the Benzene ring bound to the neighboring unit is, π is a positive integer of at least 50 and each radical Q is a monovalent substituent from the Group hydrogen, halogen, of tertiary i <carbon atoms free hydrocarbon radicals, halogenated hydrocarbon radicals with at least 2 carbon atoms between the halogen atom and the phenyl nucleus, hydrocarbonoxy radicals and halocarbonoxy radicals with at least 2 carbon atoms between the halogen atom and the phenyl nucleus. Numerous Examples of polyphenylene ethers falling under the above formula are in those mentioned above U.S. Patent Specified.

For the purposes of the invention, a group of polyphenylene ethers of the formula above preferred, in which each radical Q is an alkyl radical having 1 to 4 carbon atoms.

These include, for example

Poly (2,6-dimethyl-1,4-phenylene) ether,
Poly (2,6-diethyl-1,4-phenylene) ether,
Poly (2-methyl-6-ethyl-1,4-phenylene) ether,
Poly (2-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.

Poly (2,6-dimethyll, 4-phenylene) ether is particularly preferred, which easily forms a compatible single-phase mass with polystyrenes over the entire range of proportions.

The term "polystyrene" used here has the same meaning as in the above US-PS 33 83 435. These polystyrenes can be combined with the polyphenylene ether. In general for this purpose, polystyrenes are selected which contain at least 25 percent by weight of polymer units, those of a vinyl aromatic monomer, e.g. B. a monomer of the formula

RC = CH ₂

in which R is a hydrogen atom, a lower alkyl radical, for example with 1 to 4 carbon atoms or a halogen atom, Z is a hydrogen atom, a vinyl resl. is a halogen atom or a lower alkyl resi and ρ is 0 or an integer from 1 to 5 stein, are derived. Suitable polyslyrole resins are, for example, the homopolymer of styrene, polychlorostyrene and poly - «- methylstyrene, styrene-containing copolymers, eg. B. styrene-acrylonitrile-Conolyrnert, copolymers of Ätbylvinylbenzol and divinylbenzene and

Terpolymers of styrene, acrylonitrile and «-methylstyrene. Preferred of the polystyrene resins of this class are homopolystyrene, poly-u-methylstyrene, Styrene-acrylonitrile copolymers ^ styrene-fi-methylstyrene copolymers, Styrene-methyl methacrylate copolymers

ίο and poly-u-chlorostyrene. It is particularly preferred Homopolystyrene.

The term "rubber" used here includes natural and synthetic polymeric materials, at room temperature, e.g. B. at 20 to 25 C, are elastomers. The expression "rubber" thus includes natural or synthetic rubbers of the type generally used in manufacture used by high impact polymers. All of these rubbers form a two-phase system with the resin, e.g. B. a polystyrene resin, and make the disperse fine-grained phase in the blow / ead Polystyrene resin composition. Suitable rubbers for the purposes of the invention are, for example, natural rubber and polymerized diene rubbers. / .. B.

Polybutadiene and polyisoprene, and copolymers of these dienes with vinyl monomers. ? .. B. vinyl aromatic monomers such as styrene. Suitable rubbers or rubber-like copolymers are, for example, natural crepe rubber, synthetic SBR rubber, which contains 40 to 98 percent by weight butadiene and 60 to 2 percent by weight styrene and has been produced by emulsion polymerization by hot or cold methods, and synthetic GR N rubber with 65 up to 82 percent by weight of butadiene and 35 to 18 percent by weight of acrylonitrile and synthetic caulks, for example made from butadiene. Butadiene-styrene or isoprene can be produced, for example, by processes in which heterogeneous catalyst systems, e.g. B. aluminum trialkyl and a titanium halide can be used. Also suitable as synthetic rubbers for the polymer mixtures according to the invention are elastomeric modified diene homopolymers, e.g. B. polybutadienes and polychlorobutadienes with terminal hydroxyl and carboxyl groups, 7. B. polychloroprene, polyisobutylene and copolymers of isobutylene with butadiene or isoprene, polyisoprene, copolymers of ethylene and propylene and their interpolymers with butadiene, thioicol rubber. Polysulfide rubbers, acrylic rubbers, polyurethane rubbers, copolymers of dienes, e.g. B. butadiene and isoprene, with various comonomers, e.g. B. unsaturated alkyl esters. z. B. methyl methacrylate, unsaturated ketones. ? .. B. methyl isopropyl ketone, vinyl heterocycles, e.g. B.

Vinyl pyridine, polyether rubbers and epichlorohydrin rubbers. Are preferred as rubbers Polybutadiene and rubber-like copolymers of butadiene with styrene. These preferred rubbers are used on a large scale for the manufacture of rubber-modified, impact-resistant polystyrene resins in the current range of particle sizes mentioned in the above publications of elastomers used.

The expression »jacket-modified polyslyrole-

i> 5 resin «denotes a class of compounds that represent a two-phase system in which the rubber is in the form of separate particles in a Polystyrene resin matrix is dispersed. The particles

can be formed by mechanically mixing the rubber and the polystyrene resin. In this In this case, particles of the rubber form the disperse elastomeric phase. On the other hand - and it will preferably - the two-phase system consists of interpolymers of a Styrdmonomer and one Elastomers or rubber. These high impact polystyrenes are becoming common on an industrial scale produced by grafting onto rubber in the presence of polymerizing styrene. These systems consist of a closed phase of polymerized styrene monomer, in the rubber or the elastomer as a discontinuous elastomeric phase with or without grafted chains of polymerized styrene monomer is dispersed. The particles can also be entrapped polymerized Contain styrene monomer. This has some influence on their size.

Process for the production of rubber-modified Controlled particle size polystyrenes are known. GB-PS 1174 214 describes the Polymerization of rubber in monomeric styrene. This polymerization is called block polymerization carried out with the mixture during the initial stages to form the desired Particle size is stirred. Then the intensity of the stirring is reduced and the polymerization accomplished. In the Bender process ...!. Appl Polymer Sci .. 9, 2887 (1965), is a block prepolymerization of rubber in monomeric styrene carried out with stirring until the desired particle size has been obtained, whereupon water and surfactants are added and the Polymerization in suspension is completed

In these resins, the elastomer is preferably of butadiene, a builder-styrene copolymer or mixtures thereof. These materials can be prepared by known methods, e.g. B. the above Process are produced. They are also available commercially from a number of sources.

In US-PS 33 83435 it is found that PoIyphenylenäther and polystyrene resins can be combined with one another in all proportions and that the products have a unique combination of thermodynamic properties. the Mixtures according to the invention can therefore contain 1 to 99 percent by weight of polyphenylene ether and 99 Contains up to 1% polystyrene resin on a rubber-free basis. In general, mixtures are preferred, in which the rubber-free polystyrene resin is 20 to 80 percent by weight of the polystyrene and of the polyphenylene ether, because after shaping it has the best combination of impact strength, Surface appearance and solvent resistance. Particularly beneficial and preferred are mixtures in which the rubber-free polystyrene resin is 40 to 60 percent by weight of the total weight of polystyrene and polyphenylene ether. properties such as flexural strength, tensile strength, hardness and especially impact strength have preferred in these Mixes their maximum.

The rubber content, i.e. H. the weight fraction of the disperse elastomeric phase can vary, where fts however, no benefit is obtained above a maximum of about 30% of the total mass of the mass is gone out. If the proportion of the elastomeric phase falls below about 0.1 percent by weight, the impact strength becomes worse. The preferred proportion of the elastomeric phase is about 1 to 15 percent by weight, the higher proportion being used when the rubber is mechanically Mixing is dispersed- If, as is preferred, the rubber is in the form of an elastomeric When styrene-rubber graft copolymers are present, the lower amounts can be advantageous. In in all cases the preferred amount of elastomeric phase ranges between 1.5 and 6% des Total weight of the mass. The impact strength is clearly optimal with higher proportions, however other properties, e.g. B. Solvent Resistance and appearance of molded parts. As with the rubber particles grafted on Mixtures are obtained which have better impact strengths than those of mechanically mixed, d. H. non-grafted particles made mixtures at the optimum level of 1.5 to 6 percent by weight have, the mixtures according to the invention, which have a one-part elastomeric phase with grafted Contain styrene, particularly preferred.

The process by which the mixtures according to the invention are based on polyphenylene ether, polystyrene and rubber is not critically important provided that it is Method is possible, the maximum mean particle size of the elastomeric particles to 2 μ, preferably to 0.5 to 2 μ. to decrease or to hold at these values. A method is preferred in which the polyphenylene ether with polystyrene and a rubber or with a rubber-modified one Polystyrene mixed by any conventional mixing method and the resultant Mixture is processed for example by extrusion and hot forming.

Of course, other additives, e.g. B. Plasticizers, pigments, flame retardants, reinforcing fillers. 7. B. Glass thread or fibers and stabilizers are added.

Within the scope of the invention, others can also Polymers, e.g. B. polyamides. Polyolefins and polystyrene added to the blends. For example it was found that mixtures of polyphenylene oxide with equal proportions of polystyrene and rubber-modified polystyrene with a particle size of the elastomer of 1 to 2 μ impact strengths which are comparable to those of known mixtures that have the same content of polyphenylene ethers, but in which all of the polystyrene resin is rubber-modified and has an elastomer particle size of about 4 μ. These mixtures are not only more economical to produce than the known mixtures, but also have better looking surfaces even after injection molding.

The invention is further illustrated by the following examples, in which preferred embodiments to be discribed. Unless otherwise stated, all blends are made by Mixtures of polyphenylene ethers. of styrene resin and rubber or high impact polystyrene and possibly other components by a single screw press with an uneven pitch The extrusion temperature is kept between about 232 and 2S8 ° C.

All parts are parts by weight. The strands emerging from the extruder are made according to the usual Process cooled, chopped into granules, extruded, chopped into granules and test bars pressed.

example 1

22.7 kg of a mixture of the following compositions are prepared:

Poly (2,6-dimethyl-1,4-phenylene) -

ether ¹ ) 45 parts

Rubber modified

Polystyrene ² ) 55 parts

Polyethylene 1.5 parts

Tridecyl phosphite 0.5 part ' ⁵

Acrawax 0.25 parts

Titanium dioxide 2 parts

M PPO-PoK phernlenather in granular form. made by the Applicant

Polystyrene with high impact strength in granular form with a disperse clastomeric phase with an average particle size of 1 to 2 tons and a polybutadiene content of 9 percent by weight

The mixture is extruded in a 63.5 mm Prodex extruder. The strands obtained are cooled, chopped into granules and pressed into test sticks. The mean particle size of the elastomeric Phase in the mixture remains 1 to 2 μ.

The following physical properties are determined:

Notched Izod impact strength .... 0.79 mkg /

25.4 mm notch

Gardner impact strength wedge 277 cmkg

Elongation at break 48%

Dimensional stability in the

Heat (18.6 kg / cm ² ) 123 ° C

Tensile strength at the

Yield strength 668 kg / cm ²

Tensile strength at break 591 kg / cm ²

45 "gloss value 62

Flexural modulus 24 607 kg / cm ²

Flexural strength 1916 kg / cm ²

For comparison purposes, the experiment described above is repeated, but using a rubber-modified polystyrene of high impact strength, which is a disperse elastomeric phase of a contains mean particle size of about 6 μ (range 2 to μ) and a polybutadiene content of about Instead of the rubber-modified polystyrene of Example 1, the weight percent contains after mixing, an elastomeric phase with a particle size of about 6 microns. The following physical Properties are determined:

1 zod impact strength 0.25 mkg

25.4 mm notch

Gardner impact strength .... 230 _o cmkg

Elongation at break 51%

Dimensional stability in the

Heat (18.6 kg 'cm ² ) 131 ¹ C

Tensile strength at the

Yield strength 682 kg cm

i bi Bh577 k cm

35

40 Comparison of the results can be a significant improvement in impact resistance determined during the Izod TCST and Gardner test as well as the appearance of the surface (recognizable from the gloss value) in the mixture containing the particles 1-2 μ, in comparison to the mixture containing particles 6μ in diameter.

Example 2

22.7 kg of a self-extinguishing (flame-retardant) mixture of the following composition manufactured:

Poly (2,6-dimethyl-

1,4-phenylene) ether (PPO) 50 parts

Rubber modified

Polystyrene (see example 1,

Note 2) 50 parts

Polyethylene 1.5 parts

Triphenyl phosphate 3.0 parts

Tridecyl phosphite 1.0 part

Zinc sulfide 1.5 parts

Containing 30% styrene

Soot premix 0.5 parts

After extruding on a 63.5mm Prodex extruder the strands are cooled, chopped up and pressed into test rods by conventional methods. The mean particle size in the elastomeric phase is 1 to 2 μ. The following physical properties are determined:

Notched Izod impact strength .... 0.71 mkg '

25.4 mm notch
Gardncr impact strength .... 202 cmkg

Elongation at break "49%

Dimensional stability in the

Heat (18.6 kg / cm ² ) 122 ° C

Tensile strength at the

Yield strength 640 kg cm ²

Tensile strength at break .... 577 kg / cm ²

Flexural modulus 24 030 kg cm ²

Flexural strength 1,829 kg / cm ²

For comparison purposes, the one described above is used Experiment repeated, but using impact-resistant polystyrene, which is a disperse contains elastomeric phase with an average particle diameter of 6 μ (range 2 to 10 μ), instead of the rubber-modified polystyrene of Example 1. The final mixture has one thing Particle size in the same range. The following physical properties are determined:

Notched Izod impact strength 0.25 mkg /

25.4 mm notch
Gardner impact strength .... 138 cmkg

Elongation at break 40%

Dimensional stability in the

Heat (18.6 kg / cm ² ) 121 C

Tensile strength at the

Yield strength 657 kg cm ²

Tensile strength at break .... 584 kg cm ²

Flexural modulus 23 852 kg cm ²

Flexural strength 2 170 kg cm ²

Stg
Tensile strength at break

45 'glossy word 59

Flexural modulus 26 717 kg cm ²

Flexibility! 2 142 kg cm

A comparison of the results shows a ^{substantial improvement of 577 kg cm 2} 65 in the notched impact strength in the case of mixtures containing a dispersed elastomer in the form of particles with a maximum diameter of 2 μ.

509 541/31

Example 3

22.7 kg of a self-extinguishing (flame-retardant) mixture of the following composition created:

Polyphenylene ether 40 parts

High impact polystyrene (as in Example 1) .. 60 parts

Polyethylene 1.5 parts

Tridecyl phosphite 0.5 parts

Triphenyl phosphate 9 parts

Polytetrafluoroethylene 0.1 part

After extruding on a 63.5mm Prodex extruder the strands are cooled, chopped up and pressed into test rods by conventional methods. The mean particle size in the elastomeric phase is 1 to 2 μ. The following physical properties are determined:

Notched Izod impact strength 0.73 mkg /

25.4 mm notch

Gardner impact strength> 276 cmkg

Elongation at break 55%

Dimensional stability in the

Heat (18.6 kg cm ² ) 104 ⁰ C

Tensile strength at the

Yield strength 562 kg / cm ²

Tensile strength at break 522 kg / cm ²

45 ° gloss value 61.5

For comparison purposes, the experiment described above is repeated, but using of a polystyrene of high impact strength with an average particle size of 6 μ (range up to 10 μ) instead of the rubber-modified polystyrene of Example 1. The final mixture has a particle size in this range. The following physical properties are determined:

Notched Izod impact strength 0.25 mkg /

25.4 mm notch

Gardner impact strength 58 cmkg

Elongation at break 42%

Dimensional stability in the

Heat (18.6 kg / cm ² ) 99 ^C C

Tensile strength at the

Yield strength 605 kg 'cm ²

Tensile strength at break 506 kg / cm ²

A comparison of the results shows a significant improvement in the notched impact strength of mixtures, which is a dispersed elastomer in the form of particles with a maximum diameter of 2 μ contain.

Example 4

22.7 kg of a mixture of the following composition are produced:

Polyphenylene ether (PPO) 30 parts

Impact-resistant polystyrene as in

Example 1 70 parts

Polyethylene 1.5 parts

Tridecyl phosphite 0.5 parts

Triphenyl phosphate 6 parts

weight percent styrene resin (rubber-free basis), based on on bound styrene resin (rubber-free) and polyphenylene ether, and about 5.8% dispersed elastomers Phase with a particle size of 1 to 2 μ, has a higher notched impact strength (0.68 versus 0.235 mkg / 25.4 mm notch) than similar known mixtures made from rubber-modified Polystyrene can be produced with a particle size of 2 to 10 μ (USA. Patent 33 83 435). the

ίο the following physical properties are determined:

Notched Izod impact strength .... 0.68 mkg /

25.4 mm notch

Dimensional stability in the

Heat (18.6 kg cm ² ) 108 ^° C

Elongation at break 44%

Tensile strength at the
Yield strength 527 kg / cm ²

B e i s ρ i e 1 5

22.7 kg of a mixture of the following composition are made:

Polyphenylene ether (PPO) 25 parts

Impact-resistant polystyrene as in

Example 1 75 parts

Polyethylene 1.5 parts

Tridecyl phosphite 0.5 parts

_o triphenyl phosphate 6 parts

After being extruded in a 63.5 mm Prodex extruder, the strands are cooled to give granules chopped up and pressed into test strips. The dispersed particles of the elastomeric phase have a more moderate Diameter between 1 and 2 μ. The following physical properties are determined:

Notched Izod impact strength 0.55 mkg /

25.4 mm notch

Elongation at break 34%

Dimensional stability in the

Heat (18.6 kgem ² ) 106 "C

Tensile strength at the

Yield strength 527 kg / cm ²

Tensile strength at break 506 kg / cm ²

A similar well-known mix, but one

impact-resistant polystyrene with a particle size of 2

to 10 μ contained (US-PS 33 83 435, Example 7 and

Fig. 18), had a notched impact strength of only about 0.235 mkg / 25.4 mm notch.

Test bars produced from the products of Examples 1 and 2, which at 1% deformation in gasoline were immersed showed no catastrophic damage after 15 minutes if the particle size averaged 1 to 2 μ (impact-resistant polystyrene as in Example 1).

In contrast, all the test failed rods (complete destruction), which were prepared from the Mi mixtures in which the Teilchei f> o were greater (mean particle size of 6 μ, the region '. To 10 μ), in less than 15 seconds at 1 % Deformation in gasoline.

Example 6

After extrusion in a 63.5 mm Prodex 65 I in mixture is produced, the 50 parts of PoIj

In an extrusion press, the strands are ether (2.6-dimethyl-1.4-phenykn) ether. 45 parts crystalline

drive cooled, chopped into granules and test polystyrene and 5 parts polybutadiene rubber eni

bars pressed! This mixture, which holds about 68 First, the rubber and the kr

Stalline polystyrene mixed intensively in a Banbury mixer until the rubber particles hit one average diameter of 1 to 2 μ have been crushed. Then the mixture is common extruded with the polyphenylene ether, a uniformly mixed mass in which the elastomeric particles have a size of 1 to 2 μ, is obtained. This mass results in molded parts with high impact strength and improved gloss when chilled, chopped into granules and is processed by extrusion or injection molding.

Example 7

The experiment described in Example 1 is repeated, but instead of that with polybutadiene modified polystyrene a polystyrene is used that contains 9 percent by weight of an elastomeric phase contains, which is made of a rubber-like styrene-butadiene copolymer, which contains 77 percent by weight butadiene units and 23 percent by weight styrene units, has been formed. The final mixture has a particle size between 0.5 and 2 μ. the Notched impact strength is high and comparable to that of the product of Example 1.

Example 8

Three mixtures are made from the following ingredients:

mixture

ABC

Parts

Poly (2,6-dimethyl-1,4-phenylene) - 40 40 40 ether (PPO)

Rubber modified

Polystyrene

Particle size

3 to 8 μ 65 -

3 to 10 μ - 65

1 to 2 μ _. _ 65

35

45

mixture B. A. 0.25 Notched Izod toughness, 0.235 mkg / 25.4mm notch 633 Tensile strength at the 675 Yield strength, kg / cm ² 534 Tensile strength at break, 548 kg cm ^a 46 Strain, % 36

0.53

640

520

47 The values show that Mixture C has a much higher notched impact strength than Mixture A and B. They indicate that these properties can be achieved with the same rubber content if Elastomer particles in a size of 1 to 2 μ instead of a range of 3 to 10 μ, as is the case with commercially available rubber-modified polystyrenes is common and so far in known mixtures Base of polyphenylene ethers was used.

Example 9

Mixtures are prepared in the manner described in Example 1, but with half of the rubber-modified high-impact polystyrene of Example 1 is replaced by crystalline polystyrene. The mixtures have the following composition:

mixture E. F. D. Parts 45 45 Poly (2,6-dimethyl- 45 1,4-phenylene) ether (PPO) - 27.5 Rubber modified 55 Polystyrene of example 1, Particle size 1 to 2 μ 55 - From US-PS 33 83435, - Example 7, particle size 2 to 10 μ - 27.5 Crystalline polystyrene - 1.5 1.5 Polyethylene 1.5 0.5 0.5 Tridecyl phosphite 0.5 0.25 0.25 Acrawax 0.25

All of the above polystyrenes contained 7.5 percent by weight Kauls chuk.

The three blends were made on a 19.05 mm extruder (Wayne) extruded and pressed in a 25g (Newbury) press. The individual mixes contain a dispersed clastomeric gel with a small particle diameter corresponding to the of the rubber-modified styrene resin. The following properties are determined:

Titanium dioxide 2 2 2

After extrusion, the mixtures contain dispersed elastomer particles with the same Diameter as in the raw materials. Test specimens produced from the mixtures have the following properties:

mixture E. F. D. 0.25 0.23i Notched Izod 0.79 ability, mkg / 25.4mm notch 2600 2350 Melt viscosity (poise) 2540 51 59 Strain, % 48 131 138 Dimensional stability in 123 of warmth, ⁰ C

The results show that by mixing the impact-resistant polystyrene with a particle size of 1 to 2 μ with a substantial proportion of rubber-free styrene resin (Mixture F), costs are greatly reduced, but the strength properties of Mixture B, which have twice the rubber content of Mixture F had maintained

will. It is noteworthy that the mixture F has a higher dimensional stability under heat than the mixture E.

Example 10

The following polyphenylene ethers are used instead of poly (2,6-dimethyl-1,4-phenylene) ethers in the im Example 1 uses the mixture described:

Poly (2,6-diethyl-1,4-phenylene) ether, poly (2-methyl-6-ethyl-1,4-phenylene) ether, Poly (2-methyl-6-propyl-1,4-phenylene) ether, poly (2,6-dipropyl-1,4-phenylene) ether, Poly (2-ethyl-6-propyl-1,4-phenylene) ether.

The final mixes have similar properties like the mixture prepared according to Example 1.

Example 11

The following polystyrene resins are used instead of the crystalline homopolystyrene in mixtures of the composition mentioned in Example 6: Poly-u-methylstyrene,
Styrene-acrylonitrile copolymer

(27% acrylonitrile),

Styrene-u-methyl-etyrene-copolymers,
Styrene-methyl methacrylate copolymer,
Poly-a-chlorostyrene,
Siyrol-acrylonitrile- <i-methylstyrene-terpolymer.

The mixtures obtained have properties similar to those of the mixture described in Example 6.

The following rubbers are used in mixtures of those mentioned in Example 6 instead of the polybutadiene Composition used:

Natural crepe rubber,
Styrene-butadiene copolymer (23.5% styrene),
Acrylonitrile-butadiene copolymer

(18% acrylonitrile),
Methyl isopropenyl ketone butadiene

Copolymer (50% methyl isopropenyl ketone). Ethylene-propylene-butadiene terpolymer.

The mixtures obtained have similar properties Shafts like the mixture described in Example 6

Claims (2)

Patent claims: 1. Thermoplastic compositions with high impact strength from mixtures of a polyphenylene ether with a rubber-modified polystyrene and / or a polystyrene and a rubber, characterized in that that they contain 0.1 to 30 percent by weight of a disperse elastomeric phase of natural or synthetic Contain rubbers or those with grafted polystyrene, their particles have a mean diameter of a maximum of about 2 μ. 2. Thermoplastic composition according to claim 1, characterized in that the polystyrene resin on a rubber-free basis, 20 to 80 percent by weight of the total weight of the polystyrene resin rubber-free base and polyphenylene ether.