PRODUCTION OF STYRENE-ACRYLIC ACID COPOLYMER AND PAPER OR THE LIKE UTILIZING THE AQUEOUS SOLUTION OF THE COPOLYMER SALT

摘要

PROBLEM TO BE SOLVED: To obtain an aqueous solution of a salt having high transparency by neutralizing the copolymer formed in the emulsion polymerization of the styrene-acrylic acid system of a high styrene ratio. SOLUTION: During the emulsion polymerization, the monomers of styrene and acrylic acid are continuously fed into the polymerization system, as the amount of unreacted styrene is suppressed to <=0.6 wt.% in the system to produce a styrene-acrylic acid copolymer comprising 40-90 wt.% of styrene and 60-10 wt.% of acrylic acid. The unreacted styrene monomer in the polymerization system is controlled to <= a specific amount and the styrene that is suppressed its feed rate is accelerated its dissolution rate and promptly copolymerizes with the water-soluble acrylic acid to give the polymer that substantially has no styrene to styrene linked area whereby an alkali salt aqueous solution of high transparency can be smoothly produced.