| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a high-performance copolymer latex giving coated paper excellent in physical properties such as pick strength, wet pick strength, and blister resistance and exhibiting excellent backing roll staining resistance in paper coating. <P>SOLUTION: The copolymer latex is a conjugate diene copolymer latex prepared by emulsion polymerization of a conjugate diene monomer and other copolymerizable monomers by a multistep polymerization method. In the method: at least the conjugate diene monomer is included in both of a first process and a second process; a monomer mixture (A) added in the first process contains 25-50 wt.% of a vinyl cyanide monomer; an SPA of a copolymer obtained from a composition of the monomer mixture (A) and an SPB of a copolymer obtained from a composition of a monomer mixture (B) added in the second process satisfy an equation (1): 1.2<(SPA)-(SPB)<3; and a weight ratio (A)/(B) of the monomer mixture (A) to the monomer mixture (B) ranges from 3/7 to 7/3. <P>COPYRIGHT: (C)2012,JPO&INPIT |
