| 摘要 |
1,217,373. Polymer emulsion. E.I. DUPONT DE NEMOURS & CO. 28 Aug., 1968 [30 Aug., 1967], No. 41171/68. Heading C3P. A mechanically and freeze-thaw stable emulsion comprises an aqueous phase having dispersed therein an iminated copolymer containing at least 0À2% of a protective colloid selected from a water soluble cellulose derivative and a water-soluble polyvinyl alcohol, wherein the copolymer being derived from a vinyl ester of a lower (C 1 -C 8 ) carboxylic acid, ethylene and at least one monomer containing both polymerizable olefinic unsaturation and a carboxyl group is prepared in the presence of the protective colloid and contains, prior to imination, 0À01- 1À0 milliequivalent of acid per gram of polymer. Preferably the copolymer is iminated with an alkylene imine such as ethylene or propylene imine. In the examples, ethylene, vinyl acetate and (meth)acrylic acid are continuously copolymerized in an aqueous phase in the presence of potassium hydroxide or sodium bicarbonate, ammonium persulphate, and hydroxyethylcellulose or polyvinyl alcohol, and anionic surfactants. The copolymer prepared in this manner is then iminated by treatment at an elevated temperature with ethyleneimine. The products may be used in coating compositions. |
