Abstract: A method of carrying out a continuous aqueous emulsion copolymerization using a single continuously stirred tank reactor to reduce the particle size distribution and the presence of over-sized particles comprises, slowly supplying to a reactor the materials used in the copolymerization, including the monomers which are copolymerized, while maintaining conditions causing copolymerization to proceed until the reactor is filled. The supply is continued while maintaining those conditions until the total supply is in the range of from about 1.5 to about 5 reactor volumes. The excess material in the reactor is removed therefrom and collected in one or more separate vessels, and the product of the copolymerization is then combined and mixed to form a uniform product. The composition copolymerized can be changed during the copolymerization. The emulsion copolymer product is particularly useful in latex paints where it improves the gloss and scrub resistance of the paint.

Abstract: An aqueous emulsion copolymer of monoethylenically unsaturated monomers which provide a copolymer having a glass transition temperature below 20.degree. C., is modified to include from about 0.3% to about 10% of a monoethylenically unsaturated copolymerizable polyether containing a chain of from about 6 to about 150 C.sub.2 -C.sub.4 oxyalkylene groups, the terminal hydroxy group provided by said chain of oxyalkylene groups being capped with a monofunctional hydrophobic group. These polyethers improve the brush drag of paints made with the emulsion copolymers, and in some instances the leveling is simultaneously improved.

Abstract: An aqueous latex is disclosed which possesses improved water resistance at reduced acrylic ester content for use in exterior latex paints. This latex comprises an aqueous emulsion copolymer of monomers consisting essentially of from 10% to 30% of vinylidene chloride together with 20% to about 50% of styrene, and from 40% to 60% of monoethylenic ester, preferably acrylic or methacrylic esters, the mixture of monomers providing the copolymer with a glass transition temperature in the range of -10.degree. C. to +10.degree. C., and from 0% to 10.0% of a monomer promoting adhesion, the proportions being based on the total weight of monomers copolymerized.

Abstract: An aqueous latex is disclosed which possesses improved water resistance for use in exterior paints. This latex comprises an aqueous emulsion copolymer of monomers consisting essentially of from 15% to 40% of vinylidene chloride together with a mixture of at least about 20% of vinyl acetate and monoethylenic ester, preferably acrylic or methacrylic esters, which provide the copolymer with a glass transition temperature in the range of -10.degree. C. to +10.degree. C., these monomers including from about 0.1% to 10.0% of a monomer promoting adhesion. The copolymerization is carried out in aqueous emulsion at a pH of 3-6 and the vinylidene chloride is preferably introduced at or near the bottom of a reactor maintained at atmospheric pressure. It is also preferred to introduce the vinylidene chloride after polymerization has been initiated with the other monomers.

Abstract: Ethylene and vinyl acetate are copolymerized in aqueous emulsion using redox catalysts by copolymerizing vinyl acetate and ethylene monomers in an emulsion containing at least 10% by weight of emulsified particles of a copolymer of ethylene and vinyl acetate, with the unreacted vinyl acetate and ethylene providing a concentration of at least 10% by weight of unreacted monomers in the emulsion together with redox catalysts to cause a vigorous exothermic reaction. The copolymer exhibits substantially increased insolubility in organic solvents and aqueous caustic.