摘要:
A method for making a diester of oxalic acid which comprises oxidatively carbonylating an alcohol having 1 to 10 carbon atoms with carbon monoxide and with oxygen at a pressure from 1 to 700 bars and at a temperature from 20.degree. C. to 250.degree. C. in a reaction phase comprising said alcohol having dissolved therein a catalyst system consisting essentially of, as cations, ions of palladium(II) and copper ions in a molar ratio of at least 0.2 and, as anions, halide ions and carboxylate ions having 1 to 6 carbon atoms, the amounts of all ions in said catalyst system being such that the solution of the cations and anions in the alcohol has a formal pH value, as determined electrometrically, between 8 and 5.
摘要:
Rubber-modified, impact-resistant molding materials contain, based on the sum of A, B1 and B2,A: from 70 to 98% by weight of a polymer matrix A formed by free radical polymerization of a mixture of from 60 to 90% by weight of styrene and from 10 to 40% by weight of acrylonitrile,B1: from 1 to 29% by weight of a particulate, first graft copolymer B1 which is distributed in the matrix A and consists of a grafting base of polybutadiene and grafts of a copolymer of styrene and acrylonitrile having a mean particle size of about 100-500 nm, andB2: from 1 to 29% by weight of a particulate, second graft copolymer B2 distributed in the matrix A and consisting of a grafting base of polybutadiene and grafts of a copolymer of styrene and acrylonitrile having a mean particle size of from 600 to 10,000 nm, as obtained if both graft copolymers have been prepared by solution and/or mass polymerization and have been incorporated in the polymer matrix in a conventional manner.
摘要:
A process for the continuous preparation of ABS polymers by free-radical-initiated polymerization of, in particular, styrene and acrylonitrile in the presence of polybutadiene, in the presence or absence of a solvent, in a reactor cascade comprising at least 3 stirred reactors operating essentially without back-mixing, at least some of which contain internal cooling tubes for dissipating the heat of polymerization, at from 50 to 180.degree. C., phase inversion taking place in one of the reactors which contains means for generating a high shear force, and an apparatus for carrying out the process comprising an essentially cylindrical/tubular vessel jacket and a cylindrical internal element connected to a stirrer shaft by rotational force and having an external diameter which is slightly less than the internal diameter of the vessel jacket.
摘要:
Flame retarded polyacrylimide or polymethacrylimide resin foams containing at least 70 percent by weight of cyclic acrylimide or methacrylimide units and incorporating at least 1 percent by weight of phosphorus, present at least partially in the form of a phosphorus compound, XCH.sub.2 --PO(OR).sub.2, wherein R is methyl, ethyl, or chloromethyl, and X is hydrogen, halogen, hydroxyl, or RO--CO--.
摘要:
Thermoplastic material comprising:A) 20-80% polycarbonateB) 10-60% styrenic/nitrile copolymerC) 5-30% ABS or MBS with a median particle size of 0.2-0.5 micronsD) 20-60% ASA with a median particle size of 0.4-0.7 microns.
摘要:
Thermoplastic molding materials which are free of cyanuric acid or cyanuric acid derivatives contain as essential components,(A) from 5 to 95% by weight of a toughened polyamide ofa1) from 70 to 98% by weight, based on (A), of a polyamide anda2) from 2 to 30% by weight, based on (A), of an emulsion polymer whose particles do not have a hard outer shell, and(B) from 5 to 95% by weight of a functionalized polyphenylene ether.
摘要:
A molding material is described which contains, in each based on the sum of A, B and C,A. from 5 to 95, in particular from 20 to 80, % by weight of a copolymer comprisinga) from 1 to 95% by weight of styrene,b) not more than 40% by weight of acrylonitrile andc) from 5 to 98% by weight of an amide of methacrylic acid of the formula I ##STR1## where R is primary, secondary or tertiary alkyl, cycloalkyl, aryl or aralkyl of 1 or 6 or 7, respectively, to 12 carbon atoms, with the proviso that, when alkyl is methyl or isopropyl, the copolymer has a styrene content of less than 75% by weight,B. from 5 to 60, in particular from 10 to 40, % by weight of a graft polymer B, prepared by emulsion polymerization of a mixture of styrene and acrylonitrile in the weight ratio from 60:40 to 90:10 in the presence of, based on the amount of expected copolymer, from 40 to 80, in particular from 50 to 70, % by weight of a conventional particulate, partially crosslinked diene rubber or acrylate rubber, andC. Not more than 90, in particular from 10 to 40, % by weight of a further thermoplastic resin C.
摘要:
Reinforced thermoplastic molding materials containing, as essential components,(A) from 40 to 94 parts by weight of a polymer component of(a.sub.1) from 10 to 90% by weight of polyphenylene ether and(a.sub.2) from 10 to 90% by weight, based in each case on A, of a styrene polymer toughened with an acrylate rubber or with an unhydrogenated or hydrogenated polymer of a conjugated diene,(B) from 1 to 20 parts by weight of a copolymer of(b.sub.1) from 70 to 99.9% by weight of a monomer from the group consisting of styrene, .alpha.-methylstyrene and styrene alkylated in the nucleus or a mixture of these monomers,(b.sub.2) from 0.1 to 30% by weight of one or more compounds from the group consisting of tert-butyl acrylate and tert-butyl methacrylate, or one or more compounds from the group of compounds of the general formula I ##STR1## where R.sup.1 is hydrogen or methyl and R.sup.2, R.sup.3 and R.sup.4 are each an alkyl or alkoxy group of not more than 4 carbon atoms, or of the general formula II ##STR2## where n is an integer from 1 to 4 and R.sup.5, R.sup.6 and R.sup.7 are each one of the radicals stated for R.sup.2 or are each --O(CH.sub.2 --CH.sub.2 --O).sub.m R.sup.8, where R.sup.8 is C.sub.1 -C.sub.4 -alkyl and m is 1, 2, 3 or 4, and(b.sub.3) from 0 to 10% by weight, based on the copolymer, of a further ethylenically unsaturated monomer which is copolymerizable with b.sub.1 and b.sub.2, and(C) from 5 to 50 parts by weight of a reinforcing agent, the number of parts by weight being based on 100 parts by weight of the sum of A, B and C,are prepared and used for the production of moldings.
摘要:
A process for the continuous preparation of high-impact polystyrene-acrylonitrile (ABS) by free radical-initiated polymerization of a mixture of from 60 to 90% by weight of at least one vinylaromatic monomer and from 10 to 40% by weight of least one further ethylenically unsaturated monomer, in the presence of from 5 to 30% by weight, based on the sum of the monomers, of polybutadiene having a solution viscosity (5% strength by weight in styrene at 25.degree. C.) from 25 to 95 mPa.s and in the presence or absence of a solvent, in at least three consecutive reactors operated essentially without back-mixing, at from 50.degree. to 170.degree. C., phase inversion taking place in one of the reactors, involves carrying out the polymerization as far as phase inversion at 90.degree. C. or below and initiating the polymerization by free radicals from the decomposition of tert-butyl peresters whose half life period at 90.degree. C. is not more than 20 minutes, the polybutadiene content, based on the total reaction mixture, being at least 10% by weight and at most 25% of the total amount of chain-transfer agent (regulator) required being added up to the time of phase inversion and the remainder being added thereafter.
摘要:
Impact-resistant polystyrene acrylonitrile (ABS) is prepared by free radical polymernation of monomeric styrene and acrylonitrile or equivalents thereof in the presence of preformed, dissolved polbutadiene as a grafting base, the solvents used being in particular ethylbenzene and, at least from time to time, the monomers, and phase inversion taking place when the process has progressed to a certain point, in two or more reaction zones, by a continuous process in which the first reaction zone is present at least in duplicate and is in the form of a stirred kettle in each case, so that one stirred kettle is operated batchwise and alternately with the other in such a way that the reaction mixture is polymerized until phase inversion is complete or the initiator has been consumed, and the particular kettle content is then fed continuously to a second reaction zone in the form of a tube reactor.