摘要:
In a process for preparing thermoplastic molding compositions by a) polymerizing, in aqueous emulsion, dienes, C1-C12-alkyl acrylates or mixtures of these, where from 0 to 30% by weight of these monomers may have been replaced by other copolymerizable monomers, and where from 0 to 10 by weight of these monomers may have been replaced by crosslinking monomers, to give a rubber latex with a glass transition temperature below −10° C., b) agglomerating, at least to some extent, the rubber latex obtained in a), by adding, as agglomerating agent, a dispersion of a polymer made from 80 to 100% by weight of C1-C12-alkyl acrylates and from to 20% by weight of comonomers forming water-soluble polymers, where from 0 to 50% by weight of these monomers may have been replaced by other copolymerizable monomers, c) polymerizing, in aqueous emulsion, from 10 to 90 parts by weight of styrene, &agr;-methylstyrene, (meth)acrylonitril, C1-C12-alkyl acrylate, C1-C6-alkyl methacrylate or mixtures of these, where up to 30% by weight of these monomers may have been replaced by other copolymerizable monomers, in the presence of from 10 to 90% by weight of the agglomerated latex obtained in b), based on the solid, to give a graft polymer, the agglomerating agent is prepared by polymerizing the monomers mentioned in b) in the presence of from 0.001 to 10% by weight of a molecular weight regulator, based on the amount of the monomers mentioned in b).
摘要:
A thermoplastic molding composition having little intrinsic color is produced from a graft copolymer and a thermoplastic polymer. The graft copolymer is produced from a soft elastomeric particulate graft base obtained by polymerization of a conjugated diene alone or with a small amount of a monoethylenically unsaturated monomer, upon which is grafted a vinylaromatic monomer and acrylonitrile and optionally another monoethylenically unsaturated monomer. The thermoplastic polymer is a copolymer of a vinylaromatic monomer and acrylonitrile and optionally an additional monoethylenically unsaturated monomer. The thermoplastic molding composition has a low level of intrinsic color coupled with good mechanical properties and can be processed by, for example, extrusion, injection molding, calendaring, blow molding, compression molding, or sintering.
摘要:
A particulate polymer P having an average particle diameter d50 of from 0.1 to 50 &mgr;m is prepared by a process in which an emulsion E is prepared from one or more monomers M, which are polymerizable by free radical polymerization to give the polymer P, water, and at least one protective colloid PC by the action of high shear forces, and the emulsion E is subjected to polymerization in a reactor with the use of a free radical polymerization initiator RI wherein, based on the emulsion E, not more than 75% by weight of the emulsion E (initially taken portion of E) are initially taken in the reactor at the beginning of the polymerization and at least 25% by weight of the emulsion E (feed portion of E) are not fed to the reactor until after the beginning of the polymerization.
摘要:
Rubber-modified molding materials having improved impact strength in combination with good flow behavior can be prepared by special graft polymerization of monomers forming hard graft shells, such as styrene and acrylonitrile, in the presence of an elastomeric acrylate macromonomer copolymer dissolved or swollen in these monomers, the graft polymerization being carried out, to a conversion of more than 15% by weight of the monomers, by thermal or free radical mass or solution polymerization.
摘要:
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).
摘要:
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.
摘要:
A process is proposed for coagulation of an aqueous polymer dispersion, which comprises, during or after the coagulation, converting the dissolved coagulation salt into an insoluble form.
摘要:
Halogen-free antidrip agents for thermoplastic molding materials contain polymers based on vinylaromatic monomers and having molecular weights (M.sub.w) of at least 800 000 g/mol and a narrow molecular weight distribution.
摘要:
Molding materials modified with acrylic rubber are prepared by means of groups which are incorporated in the acrylic rubber and are decomposed by a redox component to give free radicals.
摘要:
Particulate elastomeric graft polymers which are suitable for improving the quality of macromolecular base materials B consist ofa) a grafting core comprising an elastomeric polymer P.sub.K, the particles having a mean particle diameter of from 1 to 150 .mu.m, andb) one or more shells, the outer shell S.sub.a consisting of a polymer P.sub.a which is compatible or partly compatible with the base material B.