| 摘要 |
1,162,409. Aqueous polymeric dispersions; reacting addition polymers with isocyanatecontaining polymers. FARBENFABRIKEN BAYER A.G. 18 Sept., 1967 [30 Sept., 1966], No. 42362/67. Headings C3G, C3P, C3R and C3T. [Also in Division D1] Aqueous polymeric dispersions are prepared by reacting (1) an aqueous dispersion of a polymer or copolymer of olefinically unsaturated monomers containing groups capable of reacting with NCO groups with (ii) product obtained by reacting a high M.W. compound which contains at least two active hydrogen atoms with an excess of polyisocyanate, the proportions of (i) and (ii) being such that no free NCO groups are present in the resulting dispersion. Suitable monomers which may be used to form the polymer or copolymer (i) areα,#-definically unsaturated monocarboxylic acids and their esters and amides and acrylontrile and methacrylonitrile, aromatic vinyl compounds, aliphatic vinyl compounds, conjugated diolefins, methylol compounds of acrylamide and methacrylamide and Mannich bases of acrylamide and methacrylamide. Exemplified polymers (i) are derived from butyl acrylate/styrene/acrylamide, and styrene/butyl acrylate/acrylamide grafted on to polybutadiene. The product (ii) is suitably prepared by reacting a polyether, polyester or polysiloxane which contains at least two active hydrogen atoms with excess of an aliphatic cycloaliphatic or aromatic diisocyanate. The product (ii) may be prepared in the form of an aqueous emulsion to which may be added an anionic, cationic or non-ionic emulsifying agent and then added to the aqueous dispersion of the polymers or copolymers (i). Alternatively the product (i) may be emulsified directly into the aqueous polymer or copolymer dispersion. |
