Patent ID: 8101701

Claim:
A fumaric acid derivative having a hydrophilic group (R) and a silicon-containing alkyl group, which is represented by formula (1): wherein Y 1 is O or NR 1 (R 1 is selected from the group consisting of hydrogen, C 1-3 alkyl and aryl); R is selected from the group represented by the following formula: Y 2 is selected from linear or branched C 3-10 alkylene, phenylene, cyclohexylene, —(CH 2 CH 2 O) o —CH 2 CH 2 CH 2 — (o is an integer from 1 to 10), or a group represented by any one of the following formulae: X 1 , X 2 and X 3 are independently selected from the group consisting of methyl, trimethylsiloxy, and organosiloxy with 18 Si atoms or less.