An object of the present invention is to provide a novel polyvinyl
alcohol-based resin excellent in viscosity stability of an aqueous
solution, high-speed coatability, reactivity with a crosslinking agent
and water solubility. The invention relates to a polyvinyl alcohol-based
resin comprising a structural unit having a carboxyl group-containing
long-chain alkyl group on a side chain, which is represented by the
general formula (1):
[KA 1]
##STR00001##
wherein R.sup.1 and R.sup.2 each independently represents a hydrogen atom
or an alkyl group, R.sup.4, R.sup.5 and R.sup.6 each independently
represents a hydrogen atom or an alkyl group, R.sup.3 represents a
hydrogen atom, an alkyl group or an alkali metal, and n represents a
positive integer.