摘要：

A stable polyvinyl acetate emulsion is obtained by polymerising vinyl acetate in an aqueous medium containing a hydrophilic colloidal emulsifier to obtain an emulsion in which x (the average size of polyvinyl acetate particle in microns) and y (the percentage emulsifier by weight of the polyvinyl acetate) are equal to or less than those which satisfy the equation x(y-0.5) = 9, x not being greater than 5 and y being not greater than 10, and adding to this emulsion with stirring 3-25 per cent (of weight of emulsion) of a conditioning agent which is one or more solvents or plasticisers for polyvinyl acetate having a solubility in water of not more than 10 per cent. The combination of solvents and/or plasticisers may have as a whole the required solubility. Conditioners specified are benzene, toluene, xylene, ethyl and butyl acetates, cyclohexanone, glycol esters and ethers, dibutyl or di-ethyl phthalate, butyl b -hydroxy butyrate, ethanol ethyl ether, triethylene glycol-2-ethyl butyrate and hexoate, liquid copolymers of vinyl acetate with butyl or octyl crotonate. Pigments such as titanium dioxide, iron oxides, mineral black, ultramarine blue, bone black, venetian red, and fillers such as bentonite and diatomaceous earth, and dyes, resins, and oils may be added. Water may be added to the solvent or plasticiser and the mixture added to the resin emulsion, which may be polymerised according to Specification 568,884, using two emulsifiers such as hydrolysed polyvinyl acetate, gum arabic and gum tragacanth, while the sodium salt of the sulphonic acid of dioctyl succinic ester may be added as a surface depressant. The emulsions may be used to coat paper, wood, metals, textiles and regenerated cellulose.

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