Process for producing self-dispersing and salt-sensitive polymer

Abstract

Disclosed is a process for producing a self-dispersing and salt-sensitive polymer by polymerizing the following monomers (A), (B) and (C) in a total concentration of 25 % by weight or above: (A) 35 to 65 % by weight of acrylic acid, (B) 10 to 45 % by weight of a vinyl monomer represented by the following general formula [I]: CH.sub.2 .dbd.C(R.sup.1)COOR.sup.2 [I] wherein R.sup.1 represents a hydrogen atom or a methyl group; and R.sup.2 represents an alkyl group having 8 to 12 carbon atoms, and (C) 20 to 45% by weight of a vinyl monomer represented by the following general formula [II]: CH.sub.2 .dbd.C(R.sup.3)COOR.sup.4 [II] wherein R.sup.3 represents a hydrogen atom or a methyl group; and R.sup.4 represents an alkyl group having 2 to 4 carbon atoms in a mixed solvent comprising 50 to 90% by weight of an organic solvent having a solubility parameter of 10 (cal/cm.sup.3).sup. 1/2 or below and miscible with water and 50 to 10% by weight of water, neutralizing 2 to 15 molar % of the acrylic acid moiety of the polymer, distilling off the organic solvent while water is left, and further adding water thereto. The polymer produced by the process is soluble in tap water, but insoluble in an aqueous salt solution of a low concentration such as 0.2% aqueous salt solution. In case the polymer is used as a binder for a non-woven fabric or paper, it exhibits satisfactory strength and permeability to a body fluid when the resultant product is wet with the body fluid.

Dependencies are inferred from the claim text.