Patent ID: 7341775

Claim:
A composition for forming porous film, comprising a surfactant and a solution comprising polymer obtainable by hydrolyzing and condensing, in the presence of the surfactant, one or more alkoxysilanes represented by Formula (1) and one or more alkoxysilanes represented by Formula (2): (R 1 ) m Si(OR 2 ) 4-m (1) R 3 Si(R 4 ) n (OR 5 ) 3-n (2) wherein R 1 represents a straight chain or branched alkyl group having 1 to 7 carbons or an aryl group wherein the alkyl or aryl group may be substituted or non-substituted and when there are R 1 s, the R 1 s are independently the same or different; R 2 represents an alkyl group having 1 to 4 carbons and when there are R 2 s, the R 2 s are independently the same or different; R 3 represents a straight chain or branched alkyl group having 8 to 30 carbons; R 4 represents a monovalent hydrocarbon group which may be substituted or non-substituted and when there are R 4 s, the R 4 s are independently the same or different; R 5 represents an alkyl group having 1 to 4 carbons and when there are R 5 s, the R 5 s are independently the same or different; m is an integer of 0 to 3; and n is an integer of 0 to 2, wherein the one or more alkoxysilanes represented by Formula (1) comprise one or more tetraalkoxysilanes wherein m=0 and one or more alkoxysilanes wherein m=1, 2 or 3, and wherein said one or more alkoxysilanes represented by Formula (2) is present in an amount of 0.01 to 10 parts by weight to 100 parts by weight of said one or more alkoxysilanes represented by Formula (1).