A surface treatment agent containing a
hydrocarbon-terminal-group-containing compound of the following formula makes it possible to form a cured film that is exceptional in water repellency, slipperiness,
dirt removability, and abrasion resistance, particularly
steel wool abrasion resistance and wet abrasion resistance. (R1 is a C12-80 monovalent
hydrocarbon group that includes a C12 or higher monovalent or
divalent linear unsubstituted
aliphatic saturated hydrocarbon group and does not contain a
hydrocarbon branched structure, R2 is H, a
halogen atom, a hydroxyl group, a siloxy group, an -OSi(CH3)3 group, an -OSi(C2H5)3 group, an amino group, an SH group, a monovalent hydrocarbon group, R1, -V-Z-(Y-A)m, or -Y-A, U is a
single bond, C, or a trivalent or tetravalent
organic group, V is a
single bond or a
divalent hydrocarbon group, Z is a
single bond, C, Si, N, S, or a trivalent to octavalent
organic group, Y is a single bond or a
divalent hydrocarbon group, A is a monovalent reactive group, k is 0, 1, or 2, and m is 1-7.)