| 摘要 |
PURPOSE:To impart not only color developability and lightfastness but also excellent surface strength to pressure-sensitive copying paper, by using special synthetic copolymer latex as the binder of the coupler composition of the pressure-sensitive copying paper. CONSTITUTION:In order to improve color developability and lightfastness, a synthetic copolymer latex film is adjusted by a chain transfer agent so as to set a swelling index to 10 or less. As an emulsifier, an anionic one is optimum and, as an org. coupler, aromatic carboxylic acid, a phenol resin or a copolymer of aromatic carboxilic acid and aldehyde or acetylene or a multivalent metal salt thereof are designated. The synthetic copolymer latex is prepared by a method wherein 41pts.of butadiene, 10pts. of acrylonitile, 12pts. of methacrylonitrile, 0.4pts. of itaconic acid, 5pts. of methyl methacrylate, 27.6pts. of styrene, 0.9pts. of sodium bicarbonate, 0.9pts. of sodium persulfate, 0.5pts. of sodium alkylbenzenesulfonate and 15pts. of polymerization water are charged in a 5l autoclave and reacted at 80 deg.C for 9hr under stirring in a nitrogen atmo sphere. The polymerisation conversion ratio of the monomers is 99.0% and a pref. average particle size is about 1,600Angstrom . |
