Abstract: Process for the preparation of styrenic polymers having an improved color stability by anionic polymerization wherein the obtained terminated polymer solution is fed to a dispersing device to which water is added, fed to a buffer vessel and then is impregnated in a static mixer by addition of further water, carbon dioxide and one or more stabilizers.

Abstract: The invention relates to a method for producing a polymer from a first component and a second component by means of a reactor (50), wherein reaction heat in the reactor (50) is discharged via an evaporative cooler (40), wherein gaseous exhaust vapour in the reactor (50) is supplied to the evaporative cooler (40), and condensed exhaust vapour is guided from the evaporative cooler (40) back into the reactor (50). In this way, the first component and/or second component are supplied at least partially via the evaporative cooler (40) and moved from the evaporative cooler (40) into the reactor (50). The invention also relates to a system for producing a polymer, comprising a reactor (50) and an evaporative cooler (40) for discharging reaction heat in the reactor (50). In addition, the evaporative cooler (40) has at least one filling opening (46) for filling in the first and/or second component.

Abstract: Process for the preparation of very low haze and color stable styrenic polymers by anionic polymerization wherein the obtained terminated polymer solution is passed through a first filter, fed to a dispersing device to which water is added, fed to a buffer vessel and then is impregnated in a static mixer by addition of further water, carbon dioxide and one or more stabilizers.

Abstract: Process for the preparation of styrenic polymers having an improved color stability by anionic polymerization wherein the obtained terminated polymer solution is fed to a dispersing device to which water is added, fed to a buffer vessel and then is impregnated in a static mixer by addition of further water, carbon dioxide and one or more stabilizers.

Abstract: The invention relates to a method for producing a polymer from a first component and a second component by means of a reactor (50), wherein reaction heat in the reactor (50) is discharged via an evaporative cooler (40), wherein gaseous exhaust vapour in the reactor (50) is supplied to the evaporative cooler (40), and condensed exhaust vapour is guided from the evaporative cooler (40) back into the reactor (50). In this way, the first component and/or second component are supplied at least partially via the evaporative cooler (40) and moved from the evaporative cooler (40) into the reactor (50). The invention also relates to a system for producing a polymer, comprising a reactor (50) and an evaporative cooler (40) for discharging reaction heat in the reactor (50). In addition, the evaporative cooler (40) has at least one filling opening (46) for filling in the first and/or second component.

Abstract: In a process for polymerizing dienes in a solvent comprising vinylaromatic monomers, the polymerization is carried out in the presence of a metal compound of Ti, Zr, Hf, V, Nb, Ta, Cr, Mo or W as catalyst and a Lewis acid as cocatalyst and, if desired, an alkylating agent and, if desired, a regulator. This process can be used for preparing high-impact polystyrene, acrylonitrile-butadiene-styrene copolymers or methyl methacrylate-butadiene-styrene copolymers.

Abstract: A process prepares impact-modified thermoplastic molding compositions which comprise a soft phase made from a rubber dispersed in a hard matrix composed of vinylaromatic monomers, where the hard matrix is prepared by anionic polymerization in the presence of a metal alkyl compound or a metal aryl compound of an element of the second or third main group, or of the second subgroup, of the Periodic Table.

Abstract: In the preparation of a rubber-modified molding material, in a first stage, a first mixture (A) contains at least one alkyl acrylate or methacrylate (a) of the formula (I) ##STR1## where R.sup.1 is hydrogen or methyl and R.sup.2 is alkyl of 1 to 32 carbon atoms, at least one first monomer (b) which forms free radicals on thermal decomposition and, if required, a second monomer (c) or a plurality thereof is polymerized, preferably with free radicals, to give a rubber (B),in a second stage, the resulting rubber (B) is mixed with a third monomer (d) or a plurality thereof, preferably dissolved or swollen therein, to form a second mixture (C), andin a third stage, the second mixture (C) is polymerized with free radicals to give the rubber-modified molding material (D).

Abstract: In the preparation of a rubber-modified molding material, in a first stage, a first mixture (A) contains at least one alkyl acrylate or methacrylate (a) of the formula (I) ##STR1## where R.sup.1 is hydrogen or methyl and R.sup.2 is alkyl of 1 to 32 carbon atoms, if required a first monomer (b) having two or more double bonds and, if required, also a second monomer (c) or a plurality thereof is polymerized, preferably with free radicals, to give a rubber (B), in a second stage, a third monomer (d) or a plurality thereof is added to the resulting rubber (B) to form a second mixture (C), whereby the rubber (B) is dissolved or swollen in the third monomer (d), with or with the addition of a solvent, and in a third stage, the second mixture (C) formed is polymerized with free radicals to give the rubber-modified molding material (D), and the mixture is reacted at >120.degree. C., during or after this polymerization, with a compound (e) which contains at least two peroxy groups.

Abstract: A molding composition based on an impact-modified thermoplastic A selected from ABS, ASA, impact-resistant polystyrene (HIPS) impact resistant polymethyl methacrylate, impact resistant PVC, polycarbonate, polyester carbonate, polyester, polyamide, polyphenylene ether, polyether ketone, polyether sulfone, polysulfone, polyoxyalkylene, polyarylene sulfide and also mixtures thereof containing a matting agent B composed of 30 to 80% by weight of an elastomeric grafting base B1 of 75 to 99.8% by weight of an alkyl acrylate having 1 to 8 carbon atoms in the alkyl radical (B11), 0.1 to 5% by weight of a polyfunctional, crosslinking monomer (B12) and 0.1 to 20% by weight of a monomer containing one or more acidic groups, or 49.9 to 99.9% by weight of one or more dienes (B111), up to 50% by weight of a further ethylenically unsaturated monomer (B112) and 0.1 to 20% by weight of a monomer containing one or more acidic groups (B113), and 20 to 70% by weight of a graft sheath B2 composed of 40 to 99.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: A rubber-modified, impactresistant acrylonitrile-butadiene-styrene (ABS) molding material, as obtained by polymerizing styrene and acrylonitrile in the presence of a preformed rubber, dissolved in monomeric styrene and acrylonitrile and, if necessary, a solvent, wherein the rubber is a styrene-butadiene block copolymer and at least one further polymer which is compatible with the styrene-butadiene block rubber or its polystyrene component and is incompatible with polystyrene-acrylonitrile.