摘要:
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.
摘要:
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.
摘要:
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.
摘要:
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.
摘要:
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. concentrates the vinyl polymer to a solid content of from 80 to 99 mol-%, and each subsequent zone at a pressure of 1 to 200 m bar and at a temperature of 150.degree. to 250.degree. C. concentrates the vinyl polymer to a solid content of at least 99.9 %; and(iv) recycling the residual monomers from step (ii) and the residual monomers from said first zone of the screw evaporator to the stirred and charged tank reactor without intermediate cleaning.
摘要:
The optical contact objects contain a wettable, optionally crosslinked copolymer comprising the components N-vinylcarboxamide, (meth)acrylates of a polysiloxane and, optionally, vinyl monomers.
摘要:
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.
摘要:
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.
摘要:
Powdered coating agent for use in the sprayed powder process comprising a mixture ofA. free hydroxyl groups containing copolymers having been reacted with an acid anhydride;B. a cross-linker such as triglycidyl isocyanurate or bis- or tris-oxazolines and optionallyC. auxiliary agents such as pigments and levelling agents.The copolymer contains polymerized units of30 to 85% by weight of styrene or derivatives thereof or methylmethacrylate or mixtures thereof;5 to 60% by weight of acrylic or methacrylic esters excepted methylmethacrylate and10 to 30% by weight of hydroxyalkylester of acrylic or methacrylic acid, said copolymer having been reacted with an aliphatic or cycloaliphatic dicarboxylic acid anhydride;4 to 20 parts by weight of the cross-linker are employed for 96 to 80 parts by weight of the acidified copolymer.
摘要:
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 the subsequent addition of a regulator and initiator, so that the isolated thermoplastic moulding composition contains 20 to 40% by weight of butadiene polymer.