ocarbon group containing 1 to 10 carbon atoms containing no fluorine atoms or is a fluorine-containing organic group represented by the formula R2 OR1, wherein R1 represents a fluorine-containing organic group represented by the following formula: F-(Cg F2g O-)d -Ch F2h CH2 - where d represents an integer of from 1 to 5, g represents an integer of from 1 to 3, and h is an integer of 1 or 2, R2 rep