To obtain the new subject polymer represented by a specific formula and useful as a dental filling material.
This new polymer is a (meth)acrylic ester polymer of formula I {A is a 3-20C aliphatic group (cross-linked with oxygen), a 7-26C araliphatic group or a 6-26C alicyclic group; (p) is 3-6; R1 is H or methyl; X is formulas II or III [(n) is 1-5, (m) is 0-5; R2 and R3 are each H, or H and methyl; Y is a 2-12C divalent aliphatic group (cross linked with oxygen)]}. The polymer is obtained by suspending or dissolving excess (meth)acrylic acid and a polyol in a solvent, adding an acid catalyst and a polymerization inhibitor, removing water by azeotrope from the suspension or solution with the added catalyst and the inhibitor, removing the unconverted (meth)acrylic acid by extraction therefrom after finishing the esterification, further removing the inhibitor by adding an absorbent from the product, and removing the solvent from the product after removing the initiator by distillation.
PODSZUN WOLFGANG DR (DE)
WINKEL JENS DR (DE)
| JPS62114932A | 1987-05-26 |
Next Patent: BENZANTHRONE DERIVATIVE AND ITS PRODUCTION