摘要:
A process for the continuous preparation of rubber-modified polymers of vinyl-aromatics, wherein a mixture which contains a monomeric aromatic vinyl compound and from 3 to 30% by weight, based on the monomer, of an elastomeric polymer, with or without a solvent, is polymerized, in the presence of a free radical initiator and in the presence or absence of a mercaptan as chain transfer agent, at from 80.degree. to 180.degree. C., with stirring, in a cascade of two or more isothermally operated reaction zones and of one or more additional reaction zones which can be operated isothermally or with a rising temperature profile in such a way that the residence time of the reactants in the first reaction zone is .ltoreq.35 minutes. The polymer obtained is freed from vinyl-aromatic monomer, and from any solvent, in a devolatilization zone. The product is useful for the production of injection moldings.
摘要:
Polyphenylene ethers are prepared from monohydric phenols, which possess alkyl substituents in the two ortho-positions and, if desired, in the meta-position, but not in the para-position, by an oxidative coupling reaction with oxygen at from 15.degree. to 50.degree. C. and under from 1 to 10 bar in the presence of a catalyst complex, of a solvent and, if required, of an activator, by a method in which the conversion of the phenols is carried out in two more reaction zones, in which some or all of the solvent, the catalyst complex and the phenols and, where relevant, the activator is initially taken and is circulated by means of a conveying unit, and about 60-100% of the stoichiometric amount of oxygen required for the oxidative coupling is introduced into the first reaction zone and from 0 to about 40% of the said stoichiometric amount is introduced into the second reaction zone.
摘要:
Thermoplastic molding materials based on styrene polymers modified to be impact resistant with EPDM rubbers and polyphenylene ethers wherein the particles of the flexible components of the impact resistant styrene polymer have an average particle diameter range of 0.3 to 0.7 microns.
摘要:
The catalyst is removed in the preparation of high molecular weight polyphenylene ethers from monohydric phenols, which are alkyl-substituted at the two ortho-positions but not at the para-position and may or may not be alkyl-substituted at the meta-position, by an oxidative coupling reaction with oxygen at from 15.degree. to 50.degree. C. in the presence of a catalyst complex obtained from a copper salt and an organic amine, in the presence of from 1 to 20 parts by weight of a solvent per part by weight of the monomeric phenol, and in the presence or absence of an activator, and removal of the metal component of the catalyst from the polyphenylene ether solution with a complex-forming or chelate-forming compound in aqueous solution, in the presence or absence of reducing and stabilizing substances and assistants for accelerating the interphase reactions and for phase separation, by a method in which the continuous removal of the copper catalyst is carried out in one or more mixer-settler stages at a phase volume ratio of the organic phase to the aqueous phase of from 1:0.1 to 1:1.0, preferably from 1:0.4 to 1:0.6.
摘要:
A thermoplastic molding material consists of from 10 to 90 parts by weight of a polycarbonate A and from 90 to 10 parts by weight of a graft copolymer B having a mean particle size of from 200 to 700 nm (d.sub.50 value of the integral mass distribution). The graft polymer B is formed from an elastomer (rubber) (b.sub.1), which accounts for from 10 to 80% by weight, and a grafted shell (b.sub.2), which accounts for from 90 to 20% by weight, the percentages in each case being based on (B).The elastomer (b.sub.1) is composed of from 50 to 99.9% by weight of an alkyl acrylate, where alkyl is of 1 to 8 carbon atoms, and from 0.1 to 5% by weight of a copolymerizable polyfunctional crosslinking monomer.The grafted shell (b.sub.2) is produced in three stages and contains, as graft monomers,(b.sub.2 a.sub.1) from 5 to 40% by weight of a monoethylenically unsaturated aromatic hydrocarbon of not more than 12 carbon atoms, in the first stage,(b.sub.2 a.sub.2) from 15 to 50% by weight of a mixture of a monoethylenically unsaturated aromatic hydrocarbon of not more than 12 carbon atoms and a copolymerizable ethylenically unsaturated monomer, in a weight ratio of from 90:10 to 60:40, in the second stage, and(b.sub.2 a.sub.3) from 10 to 85% by weight of an alkyl (meth)acrylate in the third stage, the percentages in each case being based on (b.sub.2).
摘要:
The use of tricyclodecenyl alcohol in place of other crosslinking agents for crosslinking the soft component of impact-resistant polystyrene based on a polystyrene-grafted poly(alkyl acrylate) improves the flow of mixtures of the said polystyrene with polyphenylene ethers.
摘要:
Thermoplastic molding materials contain a blend of a polyphenylene ether with a copolymer which consists of monovinyl-aromatic monomers, alkyl acrylates where alkyl is of not more than 8 carbon atoms and, if required, an elastomer component having a glass transition temperature of .ltoreq.0.degree. C.
摘要:
A thermoplastic molding material based on a styrene polymer which has been made impact-resistant, and on a polyphenylene ether, wherein the impact-resistant styrene polymer comprises a soft component which has a mean particle diameter of greater than 0.3 .mu.m and contains an acrylic ester polymer as the elastomeric component. The novel molding materials possess improved flow and give moldings having improved aging resistance.
摘要:
Molding materials containing high molecular weight polyphenylene ethers are produced by a process in which a solution of a polyphenylene ether in an organic solvent, together with another polymer, is freed of solvent by multi-stage evaporation.The solvent is preferably an aromatic compound from the class comprising the hydrocarbons, halohydrocarbons, ethers or esters, the ratio of the other polymer to the polyphenylene ether is advantageously from 99:1 to 20:80 parts by weight, the other polymer is, in particular, a homopolymer or copolymer of styrene or of a homolog thereof, which may be modified with rubber, and the multi-stage evaporation process preferably comprises not less than two and not more than four working up stages.The evaporation is carried out in general at from 120.degree. to 280.degree. C. and under a pressure of from 1 to 3,000 mbar, advantageously in the presence of assistants which reduce the partial pressure, eg. water and/or methanol.
摘要:
The invention relates to a process for the manufacture of impact resistant thermoplastic molding materials wherein potassium salts of saturated or unsaturated fatty acids with 10 to 30 carbon atoms are used as emulsifier.