Patent ID: 8575265
Filing Date: 2013-11-05
Classification: C08F

Abstract:
1. A polymerization method for acrylic latex without emulsifier, comprising the following steps (1)-(4): (1) preparing a reaction system comprising 40 to about 58 wt % of pure water, 2-9 wt % of carboxylic acid monomer A with carbon-carbon double bond polymerizable functional groups, and 40-50 wt % of methacrylate alkane or acrylate alkane monomer B; (2) adjusting the pH of the reaction system of step (1) to within a pH range of 9.0-13.0 by adding 0.2-2 wt % of an inorganic alkaline solution; (3) obtaining an aqueous resin latex by adding 0.2-1.0 wt % of an initiator of emulsification polymerization to the reaction system of step (2), maintaining the reaction system at a temperature of 70-95° C. and stirring the reaction system at a rotating speed of 150-300 rpm, wherein the initiator of emulsification polymerization is a persulfate selected from the group consisting of sodium persulfate, potassium persulfate, ammonium persulfate, and any combination thereof; and (4) adjusting the pH value of the aqueous resin latex of step (3) to within a pH range of 7.0-9.5 by adding an organic amine selected from the group consisting of trimethyl amine, monoethanolamine, dimethyl ethanolamine, 2-amino-2-methyl propanol, and any combination thereof, thereby obtaining an ultra-thin aqueous acrylic polymer of uniformly distributed particles having a diameter of 100-130 nm.