Patent ID: 7129367

Claim:
A phosphine compound of formula (1), wherein R 1 is a hydrogen atom, an alkyl group, a cycloalkyl group or a phenyl group which may be substituted; R 2 and R 3 are each, the same or different, an alkyl group, a cycloalkyl group or a phenyl group which may be substituted; R 4 and R 5 are each, the same or different, a hydrogen atom, an alkyl group, a cycloalkyl group or a phenyl group which may be substituted; R 6 , R 7 , R 8 and R 9 are each, the same or different, an alkyl group, a cycloalkyl group, a phenyl group which may be substituted, an alkoxyl group, a dialkylamino group, a halogen atom, a benzyl group, a naphthyl group or a halogenated alkyl group; R 6 and R 7 , or R 8 and R 9 each may be combined to form, a fused ring, a trimethylene group, a tetramethylene group or a methylenedioxy group; p, q, r and s are each an integer of from 0 to 5; and p+q, and r+s are each in the range of from 0 to 5.