DE2119301A1 - Thermoplastic compounds with high impact strength - Google Patents

Description

PATENT MNWAL! DR. EQQt = Rr 01 IQTf] I

Cologne, April 19 = 1971 Eg / Ax

General Electric Company, 1 River Road, Schenectady 5, New ^v ork (USA).

Thermoplastic compounds with high impact strength

The invention relates to thermoplastic resin mixtures, in particular to impact-resistant thermoplastic mixtures which a polyphenylene ether and a rubber-modified polystyrene resin or a polystyrene resin and a rubber contain.

High molecular weight polyphenylene ethers are technical high-performance thermoplastics with relatively high melt viscosities and softening points that are 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.

For example, certain properties of the polyphenylene ethers are undesirable for some technical applications molded parts made of Polyphenylenätherη are somewhat brittle Reason for poor impact strength. In addition, processing as a melt is due to the relatively high Melt viscosities and softening points because of the high temperatures required to soften the polymer and the associated problems, e.g. instability and discoloration, are of no interest. The processing

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Processing as a melt also requires specially designed process equipment for use at elevated temperatures.

The U.SoA. Patent 3,383,435 "describes a method for improving the processability of polyphenylene ethers in the melt ₀ this purpose, the polyphenylene ether with polystyrene resins, preferably rubber-modified impact-resistant polystyrenes, mixed" blends of poly (2,6-dialkyl-1, 4-phenylene ethers with an impact-resistant polystyrene are technically important because they both improve the processability of the polyphenylene ethers as a melt and improve the impact strength of the molded parts made from the mixtures »

It is well known that the properties of high-impact polystyrene resins largely depend on the number The size and type of elastomeric particles dispersed in the resin depend on «There is an optimal particle size in the Range from 2 to 5 or 10yU for rubber modified impact-resistant polystyrene with a relatively narrow size distribution within this range (see for example Encyclopedia of Polymer Science and Technology, Volume 13, 1970, page 392, and British patents 1 127 820 and 1 174 214).

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 have significantly better impact strengths if the particle size of the dispersed elastomeric phase is kept at an average maximum of about 2 α . The impact strength is much higher than comparable © *! Mixtures in which the mean particle size is about 2 _S z «B. about β μ is increased, cLh. lies within the range which has previously been referred to as the optimum. Be beyond

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the appearance of the surface, especially the gloss, as well the resistance to aggressive solvents such as gasoline surprisingly improved.

The invention relates to thermoplastic compositions with high impact strength that contain a polyphenylene ether and

a) a polystyrene resin and a rubber,

b) a rubber modified polystyrene resin or

c) contain a mixture of (a) and (b) and have a disperse phase of finely divided elastomer, the particles of which have a maximum mean diameter of about 2 μm, preferably about 0.5 to 2 μm.

The thermoplastic compositions generally consist of a mixture of two phases, a closed phase made of a polyphenylene oxide resin and styrene resin, in which a disperse phase of particles of the elastomer is embedded is. Particles can also be used to varying degrees, depending on how the masses are manufactured of polystyrene resins and polyphenylene ether resins are present in the disperse phase. In any case, the size can of the particles by known methods, e.g. by phase contrast microscopy, which is particularly useful, or can be measured by microfiltration as well as by similar known methods.

The polystyrene resin and the elastomer can be combined with the polyphenylene ether as separate components will. Since apparently comparable impact strengths are achieved with lower amounts of the elastomer is preferably a rubber modified one Polystyrene resin combined with the polyphenylene ether. The first method is the particle size of the elastomeric Phase adjusted by mechanical mixing of rubber, styrene resin and polyphenylene oxide resin, e.g. reduced in size. In the second method, the particle size of the elastomer is determined, for example, by polymer

1 0 9 8 A 5/1 8 5 1

sation of styrene in the presence of dissolved chewing gum set under known conditions, a disperse elastomeric phase, for example from grafted crosslinked rubber particles in polystyrene, which is the closed phase, is dispersed o The product is then combined with the polyphenylene ether, the size of the particle generally being in the final Mass remains unchanged.

The polyphenylene ethers to which the invention is directed are well known and ₀ S ₀ A. Patents 3,306,874, 3,306,875, 3,257,357 and 3,257,358, for example, described in U.

A preferred group of polyphenylene ethers consists of repeating structural units of the formula

in which the ether oxygen atom of one unit is bonded to the benzene ring of the next adjacent unit, η a positive integer of at least 50 and each radical Q is a monovalent substituent from the group hydrogen, Halogen, hydrocarbon radicals free of tertiary a-carbon atoms, Halocarbon 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 the UoS.Ao patent documents mentioned above specified.

For the purposes of the invention, a group of polyphenylene ethers is used of the formula above, in which each radical Q is an alkyl radical having 1 to 4 carbon atoms. 109845/1 851

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-propy1-1, 4-phenylene) ether _e Particularly "preferred is the poly (2,6-dimethyl-1,4-phenylene) ether, which easily forms a compatible single-phase compound with polystyrenes over the entire range of proportions"

The term "polystyrene" used herein has the same meaning Meaning as in the UoSoAo patent mentioned above 3 383 435 β These polystyrenes can be mixed with the polypnenylene ether be combined. In general, polystyrenes are chosen for this purpose, which have at least 25% by weight of polymer units contain derived from a vinyl aromatic monomer, e.g., a monomer of the formula

in which R is a hydrogen atom, a lower alkyl radical, for example with 1 to 4 carbon atoms or a halogen atom, Z a hydrogen atom, a vinyl radical, a halogen atom or is a lower alkyl radical and ρ is 0 or an integer from 1 to 5, are derived. Suitable polystyrene resins are for example the homopolymers of styrene, polychlorostyrene and poly-α-methylstyrene, styrene-containing Copolymers, e.g., styrene-acrylonitrile copolymers, copolymers of ethylvinylbenzene and divinylbenzene, and Terpolymers of styrene, acrylonitrile and α-methylstyrene Preferred of the polyetyrene resins of this class are homopolystyrene, poly-α-methylstyrene, styrene-acrylonitrile copolymers, Styrene-α-methylstyrene copolymers, styrene-methyl methacrylate copolymers and poly-α-chlorostyrene. Homopolystyrene is particularly preferred.

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As used herein the term "rubber" includes natural and synthetic polymeric materials which are solid at room temperature, for example _e at 20 to 25 ° C, elastomers ,, the term "rubber" thus comprises natural or synthetic rubbers of the type which is generally used for the Production of impact-resistant polymers is used, All these rubbers form a two-phase system with the resin, Z ₀ B ₀ a polystyrene resin, and represent the disperse, finely divided phase in the impact-resistant polystyrene resin composition. Suitable rubbers for the purposes of the invention are, for example, natural rubber and polyme

"ized diene rubbers, for example polybutadiene and polyisoprene, and copolymers of these dienes with vinyl monomers, for example vinyl aromatic monomers such as styrene. Suitable rubbers or rubber-like copolymers are, for example, natural crepe rubber, synthetic SBR rubber, the 40 to 98 wt. - $> butadiene and 60 to 2 wt · - ^ styrene and having been prepared by emulsion polymerization on a hot or cold process, synthetic GR-N rubber with 65 to 82 wt -i> butadiene and 35 to 18 wt .- ^ acrylonitrile and synthetic rubbers, for example. from butadiene, butadiene-styrene or isoprene, for example, by processes in which heterogeneous catalyst systems, e.g. aluminum trialkyl and a titanium halide, are used.In addition, elastomeric modified diene homopolymers, e.g. polybutadienes and polychlorobutadienes with terminal hydroxyl, are suitable as synthetic rubbers for the polymer mixtures according to the invention - and carboxyl groups, e.g. polychlo roprene, polyisobutylene and copolymers of isobutylene with butadiene or isoprene, polyisoprene, copolymers of ethylene and propylene and their interpolymers with butadiene, iDhiokol rubbers, polysulphide rubbers, acrylic rubbers, polyurethane rubbers, e.g. , z »£. Methyl methacrylate, unsaturated ketones, e.g. methyl isopropenyl ketone,

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Viny! .Heterocycles, e.g. vinyl pyridine, polyether rubbers and epichlorohydrin rubbers. Preferred rubbers are polybutadiene and rubbery copolymers of Butadiene with styrene. These "preferred rubbers" are widely used in the manufacture of rubber-modified rubbers impact-resistant polystyrene resins in the wide range of those mentioned in the publications mentioned above Particle sizes of the elastomers used.

The term "rubber modified polystyrene resin" denotes a class of compounds that represent a two-phase system in which the rubber is in the form of separate particles is dispersed in a polystyrene resin matrix. The particles can be caused by mechanical Mixing the rubber and the polystyrene resin can be formed. In this case, particles form the rubber the disperse elastomeric phase. On the other hand - and this is preferred - the two-phase system consists of interpolymers a styrene monomer and an elastomer or rubber. These high-impact polystyrenes are usually produced on an industrial scale by grafting made on rubber in the presence of polymerizing styrene. These systems consist of a closed Phase of the polymerized styrene monomer in which the rubber or the elastomer as discontinuous elastomeric phase is dispersed with or without grafted chains of polymerized styrene monomer. the Particles can also contain entrapped polymerized styrene monomer. This has a certain influence on their size.

Processes for the production of rubber-modified polystyrenes with controlled particle size are known. British patent specification 1,174,214 describes the polymerization of rubber in monomeric styrene. These Polymerization is carried out as a bulk polymerization, with the mixture forming during the initial stages the desired particle size is stirred «, then the

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The stirring intensity is reduced and the polymerization is completed. In the Bender, JOAppl »Polymer Sei «, 9_, 2887 (1965) is a block prepolymerization of Rubber carried out in monomeric styrene with stirring until the desired particle size has been obtained, whereupon water and surfactants are added and the suspension polymerization is completed will.

In these resins, the elastomer is preferably butadiene, a butadiene-styrene copolymers or "mixtures derived These materials the above procedures can be prepared by known methods, for example _e. They are also available commercially from a number of sources, e.g. "B" from Foster Grant, Inc, UoS.Α., as Product No. _n 834- "

U.S. Patent 3,383,435 states that polyphenylene ethers and polystyrene resins can be combined in all proportions and that the products have a single combination of thermodynamic properties. The mixtures according to the invention can therefore contain 1 to 99% by weight of polyphenylene ether and 99 to 1% of polystyrene resin on a rubber-free basis. In general, mixtures are preferred in which the polystyrene resin constitutes on rubber-free basis 20 to 80 Gewe- $ of polystyrene and of polyphenylene ether, because they have the best combination of impact resistance, appearance after molding the surface and resistance to solvents ₀ particularly advantageous and preferred Mixtures in which the rubber-free polystyrene resin accounts for 40 to 60 GeWo of the total weight of polystyrene and polyphenylene ether, properties such as flexural strength, tensile strength, hardness and, in particular, impact strength have their maximum in these preferred mixtures.

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The rubber content, ie the proportion by weight of the disperse elastomeric phase, can vary, but no advantage is achieved if a maximum of about 30% of the total weight of the composition is exceeded. If the proportion of the elastomeric phase is below about 0.1 -. Drops $>, the impact resistance is inferior The preferred proportion of the elastomeric phase is about 1 to 15 wt * ~ $, wherein the higher proportion is used when the rubber by mechanical Mixing is dispersed If, as is preferred, the rubber is in the form of an elastomeric styrene-rubber graft copolymer, the lower amounts may be advantageous. In all cases the preferred amount of the elastomeric phase is in the range between 1.5 and 6% Total weight of the masses Although the impact strength is clearly optimal with higher proportions, other properties, Z ₈ Be solvent resistance and the appearance of molded parts, are impaired. Since mixtures are obtained with the grafted rubber particles, mixed the better impact resistance than those made from mechanical, d _e h. Mixtures prepared from ungrafted particles have the optimum proportion of 1.5 to 6 wt .- $, the mixtures according to the invention, which contain a finely divided elastomeric phase with grafted styrene, are particularly preferred.

The method by which the polyphenylene ether, polystyrene and rubber-based mixtures according to the invention are prepared is not critically important, provided that it is possible in this method to reduce the maximum mean particle size of the elastomeric particles to 2 × _f, preferably to 0.5 to 2 u, decrease or hold at these values. A process is preferred in which the polyphenylene ether is mixed and mixed with polystyrene and a rubber or with a rubber-modified polystyrene by any conventional mixing methods

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the mixture formed in this way is processed, for example, by extrusion and hot forming »

Of course, the mixtures of the invention other additives, Z ₀ B z _o be added ₀ plasticizers, pigments, fire-retarding agents, reinforcing fillers, _e B glass fiber or fibers and stabilizers according to ,,

In the context of the invention also other polymers, Z can ₀ B. polyamides, polyolefins and polystyrene, blends are added. For example, it has been 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 jx have impact strengths which are comparable to those of known mixtures which have the same content of poly-phenylene ether, but in which all of the polystyrene resin is rubber modified and has an elastomer particle size of about 4M. These mixtures are not only more economical to produce than the known mixtures, but also have better-looking surfaces after injection molding.

The invention is further illustrated by the following examples, in which preferred embodiments are described will. Unless otherwise stated, all blends are made by adding blends of the polyphenyl enäth er s, styrene resin and rubber or impact-resistant polystyrene and optionally others Ingredients are given through a single screw press with uneven pitch, the extrusion temperature is maintained between about 252 and 288 C. All parts are parts by weight. The strands emerging from the extrusion press are cooled using conventional methods, chopped into granules, extruded, chopped into granules and pressed into test bars.

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45 Parts 55 η 1.5 η 0.5 η 0.25 H 2 Il

example 1

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

Poly (2,6-dimethyl-1,4-phenylene) ether ^ ■ *

() Rubber modified polystyrene

Acrawax polyethylene tridecyl phosphite Titanium dioxide

(1) PPO polyphenylene ether in granulate form, manufactured from the applicant

(2) polystyrene with high impact strength in granular form with a disperse elastomeric phase with an average particle size of 1-2 / u and a polybutadiene content of 9 wt .- #; Product Ur ₀ 834 of Foster-Grant Inc ·

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

The following physical properties are trmitte.it:

Notched Izod Impact Strength
25th 0.79 mkg /
, 4 mm notch Gardner impact strength 277 cmkg Elongation at break 4856 Dimensional stability in the heat
(18.6 kg / cm ² ) 123 ⁰ C Tensile strength at the yield point 668 kg / cm ² Tensile strength at break 591 kg / cm ² 45 ° gloss value 62 Bending module 24607 kg / cm ² Flexural strength 1916 kg / cm ²

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For comparison purposes, the experiment described above is repeated, but using a rubber-modified polystyrene of high impact strength, which contains a disperse elastomeric phase with a mean particle size of about 6 ix (range 2 "to 10 a) and a polybutadiene content of about 9 wt .- ^ (product ' ¹ HT-Oi'', manufacturer Monsanto) instead of the rubber-modified polystyrene "No. ₀ 834" (manufacturer Foster-Grant). After mixing, the pale contains an elastomeric phase with a particle size of about 6 * u The following physical Properties are determined:

Notched Izod impact strength 0.25 mkg / 25.4 mm notch

G-ardner-Schlag tenacity 230 cmkg Elongation at break Dimensional stability in the heat
(18.6 kg / cm ² ) 131 ° 0 Tensile strength at the yield point 682 kg / cm Tensile strength at break
45 ° flatness value 577 kg / cm ²
59 Bending module 26717 kg / cm ² Flexural strength 2142 kg / cm ²

A comparison of the results allows a substantial improvement in the "impact strength" determined in the Izod test and Gardner test and in the appearance of the surface (recognizable from the gloss value) for the mixture which contains the particles from 1 to 2 α in comparison the mixture, which contains particles 6 α in diameter, recognize o

Example 2

22.7 kg of a self-extinguishing (flame-retardant) mixture of the following composition are produced: Poly (2,6-dimethyl-1,4-phenylene ether (PPO) 50 parts Kattchuk-modified polystyrene (No. 834) 50 ^M polyethylene 1.5 "

iriphenyl phosphate 3.0 "

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Tridecyl phosphite 1.0 part

Zinc sulfide 1.5 "

30 $ soot premix containing styrene 0.5 " ($ 30 Styrene Master Batch Black)

After extrusion in a 63.5 mm Prodex extruder, the strands are cooled, chopped up and pressed into test bars using conventional methods. The mean particle size in the elastomeric phase is 1 to 2 a. The following physical properties are determined »

Notched Izod impact strength 0.71 mkg / 25.4 mm notch Gardner impact strength 202 cmkg

Elongation at break 49 $

Dimensional stability in the heat

(18.6 kg / cm ² ) 122 ° 0

Tensile strength at the yield point 640 kg / cm

Tensile strength at break 577 kg / cm

Flexural modulus 24030 kg / cm

Flexural strength 1829 kg / cm ²

For comparison purposes, the experiment described above is repeated, but using high-impact polystyrene HT-91 »which contains a disperse elastomeric phase with an average particle diameter of 6 a (range 2 to 10 μm) instead of rubber-modified polystyrene No. 834. The final mixture will have a particle size in the same range. The following physical properties are determined:

Notched Izod impact strength 0.25 mgk / 25.4 mm notch Gardner impact strength I38 cmkg

Elongation at break 40 $

Dimensional stability under heat (18.6 kg / cm ² )

Tensile strength at the yield point Tensile strength at break
Bending module
Flexural strength

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121 ⁰ O 657 kg / om 584 kg / cm 23852 kg / cm 2170 kg / cm ²

40 Parts 60 Il 1.5 η 0.5 Il 9 Il 0.1 Il

A comparison of the results shows a significant improvement in the notched impact strength of the mixtures containing a dispersed elastomer in the form of particles with a maximum diameter of 2 x «

Example 3

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

Polyphenylene ether

High Impact Polystyrene (# 834)

* Polyethylene tridecyl phosphite triphenyl phosphate

PoIyte metraf1uoräthyleη

After extrusion in a 63.5mm Prodex extruder the strands are cooled, chopped up and pressed into test rods using conventional methods. The mean particle size in the elastomeric phase is 1 to 2 ju. the The following physical properties are determined: Notched Izod impact strength 0.73 mkg / 25.4 mm notch Gardner impact strength> 276 crakg

Elongation at break 55 $

* Dimensional stability in the heat

(18.6 kg / cm ² ) 104 C

Tensile strength at the yield point 562 kg / cm Tensile strength at break 522 "

45 ° gloss value 61.5

For comparison purposes, the experiment described above is repeated, but without using high-impact polystyrene with an average particle size of 6a (range 2 to 10 u) ("HT-91"), manufacturer Monsanto) instead of the rubber-modified polystyrene (No. .834 »Manufacturer Foster-Grant). The final mixture has a particle size in this range · The following physical properties are determined »

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58 G mkg $ 42 kg / cm 99 ⁽ kg / cm 605 506

Notched Izod impact strength 0.25 mkg / 25.4 mm notch

G-ardner impact strength elongation at break

Dimensional stability under heat (18.6 kg / cm ² )

Tensile strength at the yield point Tensile strength at break

A comparison of the results shows a significant improvement in notched impact strength at mixtures containing a dispersed elastomer in the form of particles having a maximum diameter of 2 u.

Example 4

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

Polyphenylene ether (PPO) 30 parts

High impact polystyrene (No. 834) 70 "

Polyethylene 1.5 "

Tridecyl phosphite 0.5 "

Triphenyl phosphate 6 "

After extrusion in a 63.5 mm Prodex extruder, the strands are cooled by conventional methods, chopped into granules and pressed into test bars. This mixture, which contains about 68% by weight of styrene resin (rubber-free basis), based on bound styrene resin (rubber-free) and polyphenylene ether, and about 5.8 $ dispersed elastomeric phase with a particle size of 1 to 2 x , has a higher notched impact strength ( 0.68 versus 0.235 mkg / 25.4 mm notch) than similar known mixtures made of rubber-modified polystyrene with a particle size of 2 to 10 a. (SA patent 3,383,435). 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 / cnr) 108 ⁰ C

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Elongation at break

Tensile strength at the yield point 527 kg / cm

Example 5

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

Polyphenylene ether (PPO) 25 parts

High impact polystyrene (# 834) 75 "

Polyethylene 1.5 "

Tridecyl 0.5 ^M

Triphenyl phosphate 6 ^M

After extrusion in a 63.5 mm Prodex extruder, the strands are cooled and chopped into granules and pressed into test bars »The dispersed particles of the elastomeric phase have · a mean diameter between 1 and 2 u. The following physical properties ^ shafts are determined:

Notched Izod toughness 0.55 mkg / 25.4 mm notch Elongation at break

Dimensionally stable in the warmth 106 ⁰ C (18.6 kg / cm ^ T 527 kg / cm tensile strenght at the yield point 506 kg / cm tensile strenght at break

A similar known mixture, but which is an impact-resistant polystyrene with the trade name "HT-88" (manufacturer Monsanto) with a particle size of 2 to 10µ (üoS.Α "patent 3 383 435, example 7 and Pig. 18), had a notched impact strength of only about 0.235 mkg / 25.4 mm notch «

Test bars prepared from the products of Examples 1 and 2, which were immersed in 1 * $ Deformier ung into gasoline, showed after 15 minutes no catastrophic damage when the particle size was an average of 1 to 2 ix (impact polystyrene Nr.834, Foster Grant).

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In contrast, all of the test specimens failed (complete destruction), which were prepared from the mixtures in which the particles were larger (impact polystyrene "HT-91", Monsanto) in less than 15 seconds at \ i "deformation in gasoline ·

Example 6

A mixture is produced that contains 50 parts of poly (2,6-dimethyl-1,4-phenylene) ether, 45 parts of crystalline polystyrene and 5 parts of polybutadiene rubber. »First, the rubber and the crystalline polystyrene are thoroughly mixed in a Banbury mixer, until the rubber particles have been comminuted to an average diameter of 1 to 2 JU. Subsequently, the mixture is extruded together with the polyphenylene ether, whereby a uniformly mixed mass in which the elastomer particles and a size of 1 to 2 are., Is obtained. This compound produces molded parts with high impact strength and improved gloss when it is cooled, chopped into granules and processed by extrusion or injection molding.

Example 7

The experiment described in Example 1 is repeated, but instead of the one modified with polybutadiene Polystyrene a polystyrene is used, the 9 wt, - # contains an elastomeric phase, which consists of a rubbery styrene-butadiene copolymer, the 77 wt «- # butadiene units and 23, wt .-? 6 contains styrene units, has been formed. The final mixture has a particle size between 0.5 and 2μ is high and comparable to that of the product of Example 1.

Example 8

Three mixtures are made from the following ingredients:

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Parts

Mixed breed AB Q

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

ether (PPO) 40 40 40

Rubber modified polystyrene

825 TV, 3-8 α (Cosden) 65 - - ■ »Dylene 601», 3-1Om (Koppers) - 65 "PRZ 1005", 1-2 a. (Koppers) - 65

All of the above polystyrenes contained 7.5% by weight Rubbers

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

Mix . A BC

Notched Izod impact strength,

mkg / 25.4 mm notch 0.235 0.25 0.53

Tensile strength at yield point, kg / cm ²

Tensile strength at break, kg / cm

) Elongation, i>

675 633 640 548 534- 520 36 46 47

The values show that mixture C has a much higher notched impact strength than mixtures A and B. They show that these properties can be achieved with the same rubber content, e.g. in the elastane particle size of 1 to 2 a instead of an Esreich from 3 to 10 a _s as is customary with commercially available rubber modified polystyrenes and has been used in known mixtures based on polyphanylene ethers up to now.

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Example 9

Mixtures are made in the manner described in Example 1 " produced, but with half of the chewing-stick modified impact resistant polystyrene No. 834 (Foster-Grant) by crystalline polystyrene (Monsanto HH-101) is replaced. The mixtures have the following composition:

Parts of mixture D E F

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

ether (PPO) 45 4-5 45

Rubber modified polystyrene

No. 834, 1-2 a (Poster Grant) 55 27.5

HT-91, 2-10 β (Monsanto) 55

Crystalline polystyrene (HH-101, Monsanto) polyethylene
Tridecyl phosphite Acrawax
Titanium dioxide

After extrusion, the mixtures contain dispersible

yawed elastomer particles of the same diameter as in the starting materials test specimens produced from the mixtures have the following properties:

Mixture I) E F

Notched Izod impact strength, mkg / 25.4mm notch melt viscosity (poise) elongation, #

Dimensional stability in heat, ⁰ C

The results show that 834, the cost is greatly reduced by mixing the impact-modified polystyrene Nr * with a particle size of 1 to 2 A with a significant proportion of rubber-free styrenic resin (mixture F), but the strength properties of the mixture B, which

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- 1 - 27.5 1 , 5 O , 5 1.5 O , 5 O , 5 0.5 O , 25 , 25 0.25 2 2 2

0.79 0.25 0.235 2540 2600 2350 48 51 59 123 131 138

twice the rubber content of mixture F , can be maintained. It is "noteworthy that the mixture I has a higher dimensional stability under heat than the mixture Eo

Example 11

The following polyphenylene ethers are used in place of Poly (2,6-dimethyl-1,4 ~ phenylene) ether used in the mixture described in Example 1:

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-phe nyIe η) ether Poly (2-ethyl-6-propyl-1,4-phenylene) ether

The final mixtures have similar properties to the mixture prepared according to Example 1,

Example 12

The following polystyrene resins are used instead of the crystalline homopolystyrene in mixtures of those in Example 6 mentioned composition used:

Poly-α-methylstyrene

Styrene-acrylonitrile copolymer ($ 27 acrylonitrile) "styrene-α-methylstyrene copolymer

Styrene-methyl methacrylate copolymer poly-α-chlorostyrene oil
Styrene-acrylonitrile-α-methylstyrene terpolymer

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

The following rubbers are used in place of the polybutadiene in mixtures of the composition mentioned in Example 6:
Natural Crepe Chews ch uk
. Styrene-butadiene copolymer ($ 23.5 styrene)

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Acrylonitrile Butadiene Copolymer ($ 18 Acrylonitrile) Methyl isopropenyl ketone butadiene copolymer (5Ο5έ methyl isopropenyl ketone) Ethylene-propylene-butadiene terpolymer

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

109845/1851

Claims (10)

Claims 1) Thermoplastic compositions of high impact strength, containing a polyphenylene ether and a) a polystyrene resin and a rubber, b) a rubber modified polystyrene resin or c) a mixture of (a) and (b), characterized in that the masses contain a dispersed, finely divided elastomeric phase, the particles of which have a maximum mean diameter of about 2 u . » " 2) impact-resistant thermoplastic compositions according to claim 1, characterized in that the dispersed elastomer Particles have a mean diameter of about 0.5 "to 2 η« 3) impact-resistant thermoplastic compositions according to claim 1 or 2, characterized in that the polystyrene resin rubber-free base 20 Ms 80% by weight, preferably 40 Ms 60% by weight of the total weight of the polystyrene resin on a rubber-free basis and made of polyphenylene ether « 4) Impact-resistant thermoplastic compositions according to claim 1 "to ) 3, characterized in that the elastomeric phase 0.1 to $ 30, preferably 1 to 15-6, especially 0.5 makes up to 65ε of the total weight of the mass, 5) Impact-resistant thermoplastic compositions according to claim 1 to 4, containing a polyphenylene ether, a polystyrene resin and a rubber, characterized in that the elastomeric phase consists of rubber particles " 6) Impact-resistant thermoplastic compositions according to claim 1 to 4, containing a polyphenylene ether and a rubber-modified one Polystyrene, characterized in that the elastomeric phase consists of rubber parts with made of grafted polystyrene. 109845/18 5 1 7) impact-resistant thermoplastic compositions according to claim 1 "to 6, characterized in that they contain polybutadiene as rubber» 8) impact-resistant thermoplastic compositions according to claim 1 to 6, characterized in that the elastomeric phase consists of a styrene-butadiene graft copolymer. 9) impact-resistant thermoplastic compositions according to claim 1 to 8, characterized in that the polyphenylene ether from recurring structural units of the formula consists in which the ether oxygen atom of a unit bonded to the benzene ring of the next adjacent unit, η is a positive integer of at least 50 and each Q is a monovalent substituent from the group hydrogen, halogen, hydrocarbon radicals which are free of tertiary oc-carbon atoms are, halogenated hydrocarbon radicals with at least 2 carbon atoms between the halogen atom and the Phenyl nucleus, hydrocarbonoxy radicals and halogenated hydrocarbonoxy radicals with at least 2 carbon atoms is between the halogen atom and the phenyl nucleus 10) impact-resistant thermoplastic compositions according to claim 9, characterized in that Q is an alkyl radical with 1 to 4 carbon atoms, preferably a methyl radical. 1 0 9 8 A 5/1 8 5 1