PHOTOCURABLE COMPOSITION AND SEALING MATERIALS AND GASKETS MADE BY USING THE SAME

摘要

A photocurable composition comprising (A) 100 parts by mass of a urethane oligomer having an unsaturated group which is represented by the general formula (I) [wherein R<SUP>1</SUP> is a residue derived from a monool having at least either of (meth)acryloyl and vinyl by the removal of hydroxyl; R<SUP>2</SUP> is a residue derived from an organic diisocyanate by the removal of isocyanate groups; R<SUP>3</SUP> is a residue derived from a polyester diol having a number-average molecular weight of 1 x 10<SUP>3</SUP> to 1 x 10<SUP>4</SUP> and either a cyclic group or a branched chain group by the removal of hydroxyl, a residue derived from a polyether diol having a number-average molecular weight of 1 x 10<SUP>3</SUP> to 1 x 10<SUP>4</SUP> by the removal of hydroxyl, or a residue derived from a diol having an aliphatic group by the removal of hydroxyl; A is a residue derived from a diamine by the removal of hydrogen or a residue derived from a diol by the removal of hydrogen; and p and r are each 0 to 7, and q is 0 to 3, with the proviso that when q is 0, 1 < p + r < 10] and which has a number-average molecular weight of 5 x 10<SUP>3</SUP> to 5 x 10<SUP>4</SUP> and (B) 0.5 to 5 parts by mass of a thixotropic agent, which composition exhibits excellent sealing properties and improved thixotropy and can give highly accurate extrudates; sealing materials containing the composition; and gaskets made by using the same. [Chemical formula 1] R<SUP>1</SUP>-O-CONH-R<SUP>2</SUP>-NHCO-(-O-R<SUP>3</SUP>-O-CONH-R<SUP>2</SUP>-NHCO)<SUB>p</SUB>-(-A-CONH-R<SUP>2</SUP>-NHCO-)<SUB>q</SUB>-(-O-R<SUP>3</SUP>-O-CONH-R<SUP>2</SUP>-NHCO-)<SUB>r</SUB>-O-R<SUP>1</SUP> (I)