GB834900A - Emulsions - Google Patents

Abstract

Vinyl esters of fatty acids, e.g. vinyl acetate and vinyl propionate, are polymerized and copolymerized, e.g. with vinyl propionate, vinyl butyrate, dibutyl maleate, dibutyl fumarate, dibutyl itaconate, ethyl acrylate, butyl acrylate and methacrylic acid, in aqueous emulsion in the presence of (1) a water-soluble colloidal emulsifying agent, and (2) a water-immiscible non-ionic surface-active agent containing a polyalkylene oxide chain and compatible with the resulting vinyl ester polymer. (1) May be hydroxyethyl cellulose or polyvinyl alcohol. (2) May be polypropylene glycols, reaction products thereof with ethylene oxide and reaction products of alkyl phenols, e.g. octyl, nonyl and decyl phenols with ethylene oxide. Other emulsifying and dispersing agents, e.g. organic sulphonates such as sodium dodecyl benzene sulphonate, sodium octyl sulphosuccinate, sodium N-methyl-N-palmitoyl tauride, and watermiscible non-ionic surface-active agents such as reaction products of ethylene oxide with polypropylene glycol, nonyl phenol, trimethylnonyl phenol, oleyl alcohol and tallow alcohols may be present. Catalyst, e.g. hydrogen peroxide and potassium persulphate and redox systems comprising hydrogen peroxide and an iron salt, zinc formaldehyde sulphoxylate or a titanous salt, potassium persulphate and sodium bisulphite or a bromate and a bisulphite, may be used and the polymerization conducted at elevated temperatures at subatmospheric, atmospheric or superatmospheric pressures. The pH may be adjusted by adding alkaline substances, e.g. sodium bicarbonate, and chelating and sequestering agents, e.g. imino-triacetic acid, ethylene diamine tetra-acetic acid and their alkali metal salts may be added before, during or after polymerization. The monomers may be added gradually during polymerization and part of the catalyst may be added towards the end of the reaction. The pH and water content of the emulsion may be adjusted after polymerization. Pigments, e.g. titanium dioxide, lithopone, whiting, antimony oxide, barytes, diatomaceous silica, talc, clay, mica, iron oxides, cadmium red, cadmium yellow, toluidine red, hausa yellow, benzidine yellow, dinitraniline orange, chromium oxide green, phthalocyanine green, phthalocyanine blue, carbon black, lamp black, metal, e.g. aluminium and copper, flakes and powders and luminous pigments, plasticizers, e.g. dibutyl phthalate, dioctylphthalate, tricresyl phosphate, dioctyl sebacate, dioctyl adipate, polyester resins, chlorinated diphenyls, mildew preventives such as blends of mercury salts with sodium o-phenyl phenate, ethylene glycol, ethyl ether of diethylene glycol, defoaming agents and methyl cellulose may be incorporated and the emulsions used as paints.