VINYLPYRROLIDONE COPOLYMER AND PROCESS FOR PRODUCTION THEREOF

摘要

The invention provides a vinylpyrrolidone copolymer comprising N-vinylpyrrolidone and a hydroxyl-bearing (meth)acrylate as the essential constituent components, which can give excellent crosslinked coating films; and a process which enables easy production of the copolymer. The vinylpyrrolidone copolymer is one which comprises constituent units derived from N-vinylpyrrolidone and constituent units derived from a hydroxyl-bearing (meth)acrylate at a specific ratio and has a Fikentscher K value of 12 or above and a water-insolubles content of 0.5% by mass or below (in terms of solid matter) and which satisfies the requirement that the contents of iron, nickel, chromium, sodium and potassium are each 500ppb or below (by mass; the same applies hereinafter) or the requirement that a 10% aqueous solution of the copolymer exhibits an electric conductivity of 35µS/cm or below.