Aqueous dispersed solution of substituted succinic anhydride and process

Abstract

An aqueous dispersed solution of a substituted succinic anhydride which comprises an aqueous soluble copolymer (A) having 50 percent or more by mol of (meth)acrylamide (a) 1 percent or more by mol of N,N-dialkylamino.alkyl(meth)acrylamide (b) as monomer ingredients, aqueous soluble copolymer (B) having 50 percent or more by mol of (meth)acrylamide (a), 1 percent or more by mol of N,N-dialkylamino.alkyl(metho)acrylamide (b) and 49 percent or less by mol of other copolymer monomer (c) as monomer ingredients, or both of the dqueous soluble copolymer (A) and the aqueous soluble copolymer (B), and a process for producing an aqueous dispersed solution of a substituted succinic anhydride prepared by dispersing the aqueous soluble copolymer (A) or the aqueous soluble copolymer (B) or a mixture (C) of 99 to 99.9 percent by weight of the substituted succinic anhydride (d) and 10 to 0.1 percent by weight of an oil-in-water type surfactant (e) in aqueous solution containing both the aqueous soluble copolymer (A) and the aqueous soluble copolymer (B). Thus, the aqueous dispersion can provide an excellent sizing effect in case applied as a sizing agent in paper making process but also hs preferable dilute dispersibility of aqueous dispersion, does not possibly contaminate wires, rolls and carpets of a paper making machine when applied as a sizing agent in the practical paper making process with properties of capable of continuously operating for a long period of time.