Patent ID: 7211543

Claim:
A photocatalyst composition comprising: (A) modified photocatalyst particles, said modified photocatalyst particles (A) being prepared by subjecting particles of a photocatalyst (a) to a modification treatment with at least one modifier compound (b) selected from the group consisting of different compounds each of which independently comprises at least one structural unit selected from the group consisting of a triorganosilane unit represented by formula (1), a monooxydiorganosilane unit represented by formula (2), and a dioxyorganosilane unit represented by formula (3): R 3 Si— (1) wherein each R independently represents a straight chain or branched C 1 –C 30 alkyl group, a C 5 –C 20 cycloalkyl group, a straight chain or branched C 1 –C 30 fluoroalkyl group, a straight chain or branched C 2 –C 30 alkenyl group or a C 1 –C 20 alkoxy group, —(R 2 SiO)— (2) wherein each R is as defined for formula (1), and wherein R is as defined for formula (1), and (B) a binder component which comprises a phenyl group-containing silicone (BP), optionally containing an alkyl group, represented by formula (4): R 1 p R 2 q X r SiO (4-p-r)/2 (4) wherein: the or each R 1 represents a phenyl group, and the or each R 2 independently represents a straight chain or branched C 1 –C 30 alkyl group, a C 5 –C 20 cycloalkyl group or a straight chain or branched C 2 –C 30 alkenyl group; the or each X independently represents a hydrogen atom, a hydroxyl group, a C 1 –C 20 alkoxy group, a C 1 –C 20 acyloxy group, an aminoxy group, a C 1 –C 20 oxime group or a halogen atom; and p, q and r satisfy the following relationships: 0<p<4, 0≦q<4, 0≦r<4, 0<(p+q+r)<4, and 0.05≦p/(p+q)≦1.