Latex for high performance masking tape

摘要

This invention discloses a process for preparing a latex which is particularly beneficial for utilization in manufacturing high performance masking tape, which comprises the sequential steps of (1) terpolymerizing a vinyl aromatic monomer, an alkyl acrylate monomer, and an alkyl propenoic acid monomer in an aqueous polymerization medium by free radical polymerization to produce a seed polymer latex; (2) neutralizing the seed polymer latex to a pH of 6 to 9 by the addition of an alkali; (3) adding additional vinyl aromatic monomer and alkyl acrylate monomer to the neutralized seed polymer latex; and (4) allowing the additional vinyl aromatic monomer and alkyl acrylate monomer to polymerize in a second polymerization step to a solids content of 30% to 50% to produce the latex which is particularly beneficial for utilization in manufacturing high performance masking tape; wherein 30 percent to 50 percent of the total amount of vinyl aromatic monomer polymerized is polymerized in the first polymerization step; wherein 30 percent to 50 percent of the total amount of alkyl acrylate monomer polymerized is polymerized in the first polymerization step; wherein at least 90 percent of the total amount of the alkyl propenoic acid polymerized is polymerized in the first polymerization step; and wherein a total of from 25 phm to 39 phm of the vinyl aromatic monomer, from 60 phm to 70 phm of the alkyl acrylate, and from 1 phm to 5 phm of the alkyl propenoic acid is polymerized.