Abstract: A process for producing impact-resistant moulding compositions, which is characterised in that a monomer mixture comprising 90 to 20 parts by weight of an aromatic monoalkenyl compound, 10 to 50 parts by weight of an ethylenically unsaturated nitrile, 0 to 30 parts by weight of other copolymerisable compounds is polymerised by a radical mechanism in the presence of 15 to 50 parts by weight, per 100 parts by weight of monomers, of a soluble, gel-free butadiene polymer, and in the presence of 50 to 200 parts by weight, per 100 parts by weight of monomers, of a solvent, wherein the solvent is selected from the group comprising an aliphatic (C1-C8) or cycloaliphatic alcohol, ketone, ether, ester, nitrile (A) or mixtures thereof or a mixture of (A) with an aliphatic (C4-C10), cycloaliphatic or aromatic hydrocarbon (B) in an A:B weight ratio of 100:0 to 30:70, and the polymerisation is conducted as far as a polymer content of the total mixture of 30 to 70% by weight, with thorough mixing and optionally with

Abstract: A method of producing ABS moulding compositions wherein a solution of polymers in group (A) solvents is gradually supplied to a polymerizing mixture of previously-formed soluble rubber, aromatic mono-alkenyl compounds, ethylenically unsaturated nitrites, optional other copolymerizable compounds and optionally a group (B) solvent or a mixture of group (A) and group (B) solvents, the gradual addition of the polymer solution to the polymerizing mixture being started before the beginning of phase inversion and at a monomer conversion rate of 5 to 15% and a viscosity of the polymerizing mixture of less than 20 Pa.sec with simultaneous continuation of polymerization, the group (A) solvent is an aliphatic (C.sub.1 -C.sub.8) or cycloaliphatic alcohol, ketone, ether, ester and/or nitrile, and the group (B) solvent is an aliphatic (C.sub.4 -C.sub.10), cycloaliphatic and/or aromatic hydrocarbon.

Abstract: Thermoplastic moulding compositions ofA. 90 to 30 parts by weight of a copolymer prepared by solution or bulk polymerization of a.sub.1 30 to 45% by weight of .alpha.-methylstyrene, a.sub.2 26 to 35% by weight of acrylonitrile and a.sub.3 44 to 20% by weight of styrene and/or p-methylstyrene, and with a content of incorporated acrylonitrile of 27-30% by weight,B. 5 to 60 parts by weight of a random copolymer of b.sub.1 18 to 24% by weight of maleic anhydride and b.sub.2 82 to 76% by weight of styrene and/or p-methylstyrene andC. 5 to 40 parts by weight of a graft polymer of 70 to 30% by weight of a mixture of c.sub.1 a vinylaromatic and/or C.sub.1 -C.sub.4 -alkyl and c.sub.2 acrylonitrile, on 30 to 70% by weight of a rubber with a glass transistion temperature of less than -10.degree. C.

Abstract: The invention relates to new cross-linked copolymers of N-vinyl pyrrolidone, N-alkyl-N-vinyl carboxylic acid amides, methacrylates and optionally further copolymerizing monomers of a specific composition. the copolymers have a water absorption capacity of up to about 80% by weight, based on the hydrated state, and are suitable for the production of shaped articles which are in contact with living tissue in use. Examples include soft contact lenses and scleral lenses of high mechanical strength, in particular thin to very thin lenses for prolonged wear.

Abstract: Process for the preparation of thermoplastic copolymers of .alpha.-methylstyrene and acrylonitrile by continuous bulk copolymerization ofA. 30 to 50 mol % of .alpha.-methylstyrene andB. 70 to 50 mol % of acrylonitrileat temperatures from 60.degree. to 120.degree. C. with average residence times of 4 to 12 hours in the presence of initiators which supply free radicals, carried out in at least two continuously operated mixed tank reactors, characterized in that 100 molar parts of a monomer mixture ofA.sub.0. 34 to 52 mol % of .alpha.-methylstyrene andB.sub.0. 66 to 48 mol % of acrylonitrileare fed continuously into the first tank reactor per unit time, and, with back-mixing, are copolymerized up to a conversion of 5 to 30 molar parts to give a copolymer of the compositionA.sub.1. 49 to 53 mol % of .alpha.-methylstyrene andB.sub.1. 51 to 47 mol % of acrylonitrile,and the mixture consisting of 70 to 95 molar parts of the monomers A and B and 5 to 30 molar parts of the copolymer of the composition A.sub.1 -B.sub.

Abstract: The optical contact objects contain a wettable, optionally crosslinked copolymer comprising the components N-vinylcarboxamide, (meth)acrylates of a polysiloxane and, optionally, vinyl monomers.

Abstract: Thermoplastic, high-impact moulding compositions of (A) 5 to 80 parts by weight of a graft product of 70 to 30% by weight of a mixture of an aromatic vinyl compound and acrylonitrile and/or methacrylonitrile on 30 to 70% by weight of a rubber having a glass transition temperature of below -10.degree. as the graft base and (B) 20 to 95 parts by weight of a terpolymer of styrene and/or .alpha.-methylstyrene, p-methylstyrene and acrylonitrile and/or methacrylonitrile, the terpolymer having been produced by mass polymerization.

Abstract: This invention relates to thermoplastic moulding compounds free from nitrile groups, containing a mixture of randomly structured copolymers containing methyl methacrylate, maleic acid anhydride and aromatic vinyl compounds, aromatic polycarbonate resins and an elastomer grafted with methyl methacrylate.

Abstract: This invention relates to thermoplastic moulding compounds which are free from nitrile groups, obtained from randomly structured aromatic vinyl copolymers containing N-phenyl- or methyl-maleimide, aromatic polycarbonate resins and an elastomer grafted with methyl methacrylate.

Abstract: The discharge apparatus comprises an at least four-shaft screw pump having engaging shafts (1,2,3,4) which rotate in opposite directions in pairs. The viscous product to be processed is caught up over a large area and removed by the screws. A double shaft screw pump is connected downstream of the actual collection zone as a pressure build-up zone. The two center screws (2, 3) of the collection zone merge equiaxially into the screw shafts (2a, 3a) of the pressure build-up zone. The collection zone and the pressure build-up zone are combined into one constructional unit. At least one screw shaft is driven. The resulting high viscosity product strands (7) are caught up by the screws in the collection zone and are moved on into the pressure build-up zone. The double shaft screw pump is used for the build up of a high operational pressure and thus provides the prerequisite for the subsequent connection of further procedural stages.

Abstract: Contact lenses prepared from a polymer alloy essentially free from low molecular weight plasticizers and which comprises(A) 97-80% by weight of one or more cellulose esters of one or more aliphatic carboxylic acids, and(B) 3-30% by weight of an aliphatic polymeric compound having ester moieties, carbonate moieties or both ester and carbonate moieties in the polymer chain and having an average molecular weight of 2,000 to 300,000, with less than 2% by weight of compounds having a molecular weight below 500.

Abstract: Contact lenses and implants for human medicine can be fabricated from a polymer blend comprising 98-80% by weight of component A and 2-20% by weight of component B wherein:component A is a cellulose ester of an aliphatic carboxylic acid with up to 40% by weight of total component A of an ethylene/vinyl acetate copolymer having 30-98% by weight, relative to ethylene/vinyl acetate, of incorporated vinyl acetate andcomponent B is a homopolymer or copolymer of water-soluble vinyl monomers and up to 10% by weight relative to the total polymer B of multifunctional crosslinker vinyl compounds.

Abstract: This invention relates to a process for carrying out reactions which primarily occur during the transport of compounds in the liquid phase or at the liquid-gas interface. Starting components are reacted with one another and/or with gases of the inner space in a multi-phase flow tube having a liquid ring flow which may contain dissolved and/or dispersed constituents. Any necessary heat exchange takes place between the liquid and the wall of the tube or the gases.

Abstract: Contact lenses and contact shells of light-refracting material consisting essentially of a copolymer of(I) from 40 to 90% by weight of methyl methacrylate and(II) from 10 to 60% by weight of methyl acrylate and/or esters corresponding to formula (1): ##STR1## in which R represents H or CH.sub.3,R' represents H, CH.sub.3 or C.sub.2 H.sub.5 andn=1 or 2,the sum of I and II amounting to 100% by weight.

Abstract: A thermoplastic moulding composition comprising:(1.) 80 to 20 parts by wt. of a thermoplastic polycarbonate based on a dihydroxy diaryl alkane,(2.) 20 to 80 parts by wt. of a graft polymer of2.2. a monomer mixture, polymerized onto2.1. a diene rubber with a glass transition temperature below -30.degree. C., of2.2.1. 95 to 50% by wt. of styrene, methyl methacrylate or a mixture thereof; and2.2.2. 50 to 5% by wt. of acrylonitrile, methacrylonitrile or a mixture thereof,the ratio by wt. of rubber (2.1) to monomer mixture (2.2.) being in the range of from 80:20 and 10:90, and the moulding composition containing from 5 to 35% by wt. of the rubber (2.1.), and(3.) 5 to 75 parts by wt. of a copolymer which is chemically uniform in structure and which comprises:(3.1.) 93 to 50 parts by wt. of styrene, methyl methacrylate or a mixture thereof;(3.2.) 40 to 5 parts by weight of acrylonitrile, methacrylonitrile or a mixture thereof; and(3.3.) 2 to 30 parts by wt. of maleic acid anhydride.

Abstract: A thermoplastic moulding composition comprising:(1) 80 to 20 parts by weight of a thermoplastic polycarbonate based on a dihydroxy diarylalkane,(2) 0 to 60 parts by weight of a graft copolymer of a(2.2) monomer mixture of(2.2.1) 95 to 50% by weight of styrene, methyl methacrylate or a mixture thereof; and(2.2.2) 50 to 5% by weight of acrylonitrile, methacrylonitrile or a mixture thereof,polymerized onto(2.1) a rubber which has a glass temperature below -20.degree. C., and which contains less than 30 C.dbd.C-double bonds per 1,000 carbon atoms, the moulding composition containing from 0 to 35% by weight of the rubber (2.1), and(3) 5 to 75 parts by weight of a copolymer which is chemically uniform in structure and comprises:(3.1) 95 to 50% by weight of styrene, methyl methacrylate or a mixture thereof;(3.2) 40 to 5% by weight of acrylonitrile, methacrylonitrile or a mixture thereof; and(3.3) 2 to 30% by weight of maleic acid anhydride, the sum of 3.1, 3.2 and 3.3 being equal to 100% by weight.

Abstract: This invention relates to a process for producing a homopolymer or co-polymer of an aromatic vinyl monomer by anionically polymerizing a monomer mixture in the absence of oxygen in a tubular coil evaporator.

Abstract: Contact lenses and scleral lenses formed of mixtures consisting essentially of(1) from 99 to 70% by weight of a cellulose ester of one or more aliphatic carboxylic acids, and(2) from 1 to 30% by weight of an ethylene/vinyl acetate copolymer containing from 30 to 98% by weight of incorporated vinyl acetate.

Abstract: A process for the production of thermoplastically processible moulding materials based on vinyl polymers of high chemical and molecular uniformity and having residual monomer contents of less than 0.1 mol % which comprises the steps of:(i) mass homogeneous phase polymerization of at least one vinyl monomer in a stirred continuously charged tank reactor to a conversion of from 25 to 60 mol %;(ii) directly concentrating the syrup consisting of residual monomers and vinyl polymer dissolved therein obtained from step (i) in a spiral tube evaporator at a temperature of from 60.degree. to 250.degree. C. and at a pressure of 100 m bar to 35 bar to obtain a solid content of vinyl polymer of from 40 to 90 mol %;(iii) directly charging the concentrate obtained from step (ii) to the inlet zone of a screw evaporator which consists of at least two sequential zones in order to effect further concentration, in which a first zone at a pressure of from 10 to 300 m bar and at a temperature of from 100.degree. to 250.degree. C.

Abstract: A thermoplastic moulding composition comprising a polymer mixture of (A) 25 to 95% by weight of a graft polymer of 70 to 30% by weight of a mixture of styrene (95 to 50% by weight) and acrylonitrile (5 to 50% by weight) on 30 to 70% by weight of polybutadiene or a butadiene-styrene copolymer, and (B) 5 to 75% by weight of a terpolymer containing 10 to 30 parts by weight of acrylonitrile, 7.5 to 15 parts by weight of maleic acid anhydride, and 82.5 to 55 parts by weight of styrene in copolymerized form.