Patent ID: 10759926

Abstract:
A polymer latex, including a polymerization step of polymerizing a monomer in organic solvent to thereby obtain polymer solution of synthetic polyisoprene and/or styrene-isoprene-styrene block copolymer, antioxidant addition step of adding antioxidant to the polymer solution of synthetic polyisoprene and/or styrene-isoprene-styrene block copolymer at proportion of 0.01-1.00 parts by weight per 100 parts by weight of the synthetic polyisoprene and/or styrene-isoprene-styrene block copolymer, and emulsification step of emulsifying the polymer solution which the antioxidant is added, in water in the presence of a surfactant, to thereby obtain polymer latex, wherein the emulsification performs in the emulsification step so the ratio D75/D25 of the volume particle size D75 at a cumulative frequency of 75% to the volume particle size D25 at a cumulative frequency of 25% of a particle of the synthetic polyisoprene and/or styrene-isoprene-styrene block copolymer included in the polymer latex is 1.90 or more and 2.30 or less.