Patent ID: 8053045

Claim:
A styrene-butadiene latex binder for ink-jet paper comprising the styrene-butadiene latex prepared from a styrene-butadiene seed having the particle size of 20-100 nm of 1-15 weight parts and a polymer based on total weight parts, wherein the polymer is prepared by emulsion polymerization of mixture comprising 20-85 weight parts of styrene monomer, 10-70 weight parts of butadiene monomer, 0.5-15 weight parts of vinyl cyan monomer, 0.1-1.5 weight parts of unsaturated carboxylic acid and 1-25 weight parts of a monomer copolymerizable with the above monomers, and wherein the styrene-butadiene latex is used with polyvinyl alcohol, has a glass transition temperature of 20-50° C. and a surface negative charge density of 50-200 μeq/g.