Patent GB-598257-A (GB)
Title: Improvement in vinyl resin suspensions
IPC: C08K5/01
Filed: 1945-05-18
Abstract: Stable hydrocarbon suspensions of vinyl resins are produced by grinding below 50 DEG C., dried coagulated particles of a high molecular weight and substantially toluene-insoluble vinyl resin, made by aqueous emulsion polymerisation or copolymerisation of a monomeric substance predominantly vinyl chloride, in a liquid blend containing 20 to 80 per cent. by weight of aromatic hydrocarbons and 20 to 80 per cent. aliphatic or alicyclic hydrocarbons and a plasticizer or its equivalent, until the average particle diameter is below 5 microns.  The vinyl chloride may be liquified under pressure, emulsified with specified agents preferably below 50 DEG C. and polymerised with catalysts, e.g., peroxy compounds.  The polymers, coagulated by freezing or adding electrolytes, washed and dried, may be dispersed, preferably with a ball or buhrstone mill, in a 50-90 per cent. aromatic blende, preferably using 5-25 p.c. of alcohol ethers as dispersing agents. The plasticisers are preferably 35-40 p.c. of high boiling active polymer solvents but more volatile solvents may be used.  Vinyl chloride-acetate copolymers may be used. Soluble resins preferably compatible with the polymers, e.g., alkyd, phenol-formaldehyde polystyrene, polyisobutylene, acrylic or methacrylic resins, waxes, pigments, lubricants, heat and ligh stabilizers, antimony, phthalic esters, alkyl phosphates &c. may be added to improve film stability, waterproofing, fireproofing, coating &c. properties of the dispersions.  Examples are given. The dispersions may be used to form shaped flexible articles, films, filaments; in shoe manufacture; as adhesives and printing pastes; for coating cloth, paper, cellulose film, fibre filaments, metal articles, foils, wires; or for lining or caulking tanks, batteries, plating cells.  The coatings are preferably baked at 230-450 DEG F. to fuse the film, e.g., using portable infra red lamps.ALSO:Stable hydrocarbon suspensions of vinyl resins suitable for making films are produced by grinding below 50 DEG  C., dried coagulated particles of a high molecular weight and substantially toluene-insoluble vinyl resin, made by aqueous emulsion polymerization or copolymerization of a monomeric substance predominantly vinyl chloride, in a liquid blend containing 20 to 80 per cent by weight of aromatic hydrocarbons and 20 to 80 per cent aliphatic or alicyclic hydrocarbons and a plasticizer or its equivalent, until the average particle diameter is below 5 microns.  The polymers, may be dispersed in a 50-90 per cent aromatic blend, preferably using alcohol ethers as dispersing agents. Vinyl chloride acetate copolymers may be used.  Soluble resins preferably compatible with the polymers, e.g. alkyd, phenol-formaldehyde, polystyrene, polyisobutylene, acrylic or methacrylic resins, waxes, pigments, lubricants, heat and light stabilisers, antimony oxide, phthalic esters, or alkyl phosphates may be added to improve film stability, waterproofing, fireproofing, or coating properties of the dispersions.  Examples are given.  The dispersions may be used to form films, filaments or other articles. The dispersion may be cast upon a regenerated cellulose sheet and the film layer may be dried and then fused by passing through an oven at 230-450 DEG  F.  The film may subsequently be stripped from the casting surface.