To provide an emulsion polymn. compsn. which is suitable for producing impregnated paper excellent not only in dry tensile strength and wet strengths but also in folding strength and having balanced strengths by polymerizing a monomer mixture comprising a dialkylaminoalkyl (meth)acrylate, (meth) acrylamide, and itaconic acid in emulsion by using a nonionic emulsifier.
A monomer mixture is prepd. by compounding 0.1-10wt.% dialkylaminoalkyl (meth)acrylate, 0.1-30wt.% (meth)acrylamide, and 0.1-10wt.% itaconic acid. If necessary the mixture further contains 0-30wt.% 2-hydroxyethyl (meth)acrylate and 0-30wt.% sodium p-styrenesulfonate. An example of the nonionic emulsifier used is a polyoxyethylene alkyl ether. The emulsification is performed with a Homomixer, etc., and the polymn. is conducted usually at 50-90°C. Thus obtd. emulsion polymn. compsn. has an average particle size of 0.01-0.5μm and a viscosity of 10-10,000cP.
YAMAGUCHI TAKAHIRO
TSUKIYAMA FUMITOSHI
