Abstract:
PROBLEM TO BE SOLVED: To provide a polymer having sufficient gel-proof performance as compared with a conventional polymer.SOLUTION: The (meth)acrylic copolymer is characterized by comprising, based on 100 mol% of the total monomer, (a) a structural unit originating from 20-50 mol% of methacrylic acid (salt), (b) a structural unit originating from 50-80 mol% of acrylic acid (salt), as indispensable structural units, and having 2,000-4,000 of a weight average molecular weight and including sulfur atoms in the molecules.
Abstract:
PROBLEM TO BE SOLVED: To provide a production method for polymer emulsion, capable of much decreasing coarse particles; and to provide a water-based inkjet recording liquid attaining stable discharge by much decreasing clogging at nozzles, and attaining physical properties required after discharge, especially an excellent OD value and abrasion resistance.SOLUTION: There is provided a production method for a polymer emulsion which polymer emulsion is provided by adding a monomer pre-emulsion to a polymerization field not containing the monomer pre-emulsion, and performing radical polymerization, wherein the monomer pre-emulsion uses a radical polymerizable unsaturated monomer comprising as an essential ingredient a radical polymerizable unsaturated monomer having a specific amount of alkoxysilyl groups, a specific amount of an emulsifier, water and a water-based polymerization initiator and has 0.5-10 μm volume-average particle diameter of monomer liquid drops measured by a number counting method, and the polymer emulsion has ≤5.0×10/cmof super coarse particles of ≥1.5 μm in the polymer emulsion in terms of 0.1% nonvolatile matter concentration.