GB475162A - Manufacture of emulsions and dispersions - Google Patents

Abstract

Water soluble or partly water soluble partial esters, acetals, and ethers of polyvinyl alcohols are obtained by incomplete esterification, acetalization or etherification of polyvinyl alcohols or by the partial saponification of their esters, acetals or ethers to the stage at which solubility in water results. A vinyl compound may also be polymerized in the presence of a polymerized fatty oil or fatty oil capable of polymerizing and the product partly saponified. Partly saponified polyvinyl acetate, polyvinyl butyrate, polymeric vinyl ethylether and formaldehyde polyvinylacetal are mentioned, and are used as emulsifying agents for insoluble condensation and polymerization, products which may be produced at the same time as the emulsification is effected. In examples: (1) chloroprene is polymerized in the presence of water and a partly saponified polyvinyl acetate; the stability of the resulting latex can be increased by adding ammonia, formaldehyde or polybasic sodium phosphate; (2) vinyl butyrate is polymerized in the presence of water, benzoylperoxide and a partly saponified polyvinylbutyrate; (3) a latex is produced by polymerizing vinyl acetate in the presence of water, ethylphthalate, benzoylperoxide and a partly saponified polymeric vinylethylether; (4) chloroprene and ethylacrylate are condensed in the presence of water, hydrogen peroxide and a polyvinylacetate, which has been saponified until it is soluble in water; (5) a latex is obtained by polymerizing styrol in the presence of water, hydrogen peroxide and a partly saponified formaldehyde polyvinylacetal.ALSO:Emulsions or dispersions are made by means of partial esters of a polyvinyl alcohol, preferably used in a concentration of less than 1,0 per cent of the substance to be emulsified: (b) partial acetals or ethers of a polyvinyl-alcohol used in a concentration of 1 per cent or below of the substance to be emulsified, or (c) products resulting from the partial saponification of products obtained by polymerization of a vinyl compound in the presence of a polymerized fatty oil or a fatty oil capable of polymerizing, e.g. linseed stand oil, in a concentration of 1 per cent or below of the substance to be emulsified. The emulsifying agents, which may be used in association with soaps, turkey red oils, polyvinyl alcohol, gelatine, pectins, starch products, solvents or plasticizing agents, may be used for emulsifying oils, rubber, synthetic polymerization products and natural and artificial resins, e.g. shellac, aldehyde resins, phenol-aldehyde resins, polyvinyl acetate, polyacrylic esters, aldehyde-urea resins and polybacic acid-alcohol condensation products. The emulsion may be produced during the production of the insoluble condensation and polymerization products in statu nascendi, but in this case, when partial esters of polyvinylalcohol are used for the emulsification, the quantity employed is not more than 4,0 per cent of the substance to be polymerized. In examples: (1) chloroprene is polymerized in the presence of water and a partly saponified polyvinyl acetate; the stability of the resulting latex can be increased by adding ammonia, formaldehyde or polybasic sodium phosphate: (2) vinyl butyrate is polymerized in the presence of water, benzoylperoxide and a partly saponified polyvinylbutyrate: (3) a latex is produced by polymerizing vinyl acetate in the presence of water, ethylphthalate benzoylperoxide and a partly saponified polymeric vinylethylether: (4) chloroprene and ethylacrylate are condensed in the presence of water, hydrogen peroxide and a polyvinylacetate which has been saponified until it is soluble in water: (5) a latex giving coatings having good electrical insulation is obtained by polymerizing styrol in the presence of water, hydrogen peroxide and a partly saponified formaldehyde polyvinylacetal.