| 摘要 |
PROBLEM TO BE SOLVED: To obtain a well-balanced copolymer latex having a high adhesion strength and a high blister resistance by intermittently increasing the rate of addingα-methylstyrene dimer and continuing the addition at least a predetermined rate for at least a predetermined time. SOLUTION: In the production of a diene copolymer latex by emulsion- polymerizing 100 pts.wt. monomer mixture of (A) 20 to 70wt.% conjugated diene monomer, (B) 0.5 to 10wt.% ethylenic unsatd. carboxylic acid monomer and (C) 20 to 29.5wt.% copolymerizable vinyl monomer in the presence ofα- methylstyrene dimer (hereinafter referred to as 'α-MSD'), (1) the addition rate ofα-MSD is intermittently increased in the polymn. step by at least 0.3 pt.wt. per unit time and (2) 0.2 to 3 pts.wt.α-MSD (for 100 pts.wt. whole monomer mixture) is added at a rate of at least 0.3 pt.wt. per unit time within 2hr in the polymn. step after the addition rate has been intermittently increased.
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