PURPOSE: To obtain a copolymer excellent in adhesion to dentin, insolubility in saliva and useful as a base of a dental lining material, comprising specified three kinds of structural units.
CONSTITUTION: A styrene/maleic anhydride copolymer is obtained by copolymerizing styrene with maleic anhydride at a molar ratio of 0.4W0.8:0.6W0.2. This copolymer and an aminosalicylic acid such as p- aminosalicylic acid are added to a solvent such as dimethyl sulfoxide and are reacted with each other at room temperature to 150°C for 1hrW1day in an oxygenfree atmosphere to obtain a copolymer comprising structural units (A) of formula I, structural units (B) of formula II and structural units (C) of formula III and having a such a constitution that the molar ratio of units A to units B and C is 0.4W0.8:0.6W0.2 and the molar ratio of units B to units C is 0.4W0.9:0.6W1 and a weight-average MW of 2,000W500,000.
HIGAKI TATSUHIKO
YAMAUCHI JUNICHI
