Composition for forming film

摘要

A substrate is surface treated using a composition for forming a film that comprises (A) an organoalkoxysilane, (B) an organopolysiloxane having a silicon-bonded hydrogen atom, and (C) a condensation reaction catalyst. This composition for forming a film can form a highly hydrophobic water repellent film provided with sufficient water shedding performance. It is possible to provide a highly hydrophobic substrate such as a heat dissipating body.

主权项

1. A composition for forming a film comprising:
(A) an organoalkoxysilane; (B) an organopolysiloxane having a silicon-bonded hydrogen atom, wherein: the organopolysiloxane having a silicon-bonded hydrogen atom is represented by average unit formula (1):
[R1R2R3SiO1/2]2[R4HSiO2/2]m[R52SiO2/2]n  (1) wherein R1, R2, and R3 are each independently a monovalent hydrocarbon group or hydrogen atom; R4 and R5 are each independently a monovalent hydrocarbon group; m is 0 or a positive number; n is a positive number; (m+n) is in a range of 5 to500; [m/(m+n)] is in a range of 0 to 0.3; with the proviso that, however, when m>0, the number of hydrogen atoms bonded to a silicon atom of a terminal silyl group is in a range of 0 to 2, and when m=0, the number of hydrogen atoms bonded to a silicon atom of a terminal silyl group is 1 or 2; (C) a condensation reaction catalyst; and (D) a silicone resin represented by the following average formula (2):
[R6SiO3/2]a[R7R8pSiO(3-p)/2]b  (2) wherein, R6 and R7 are each independently a monovalent hydrocarbon group; R8 is an alkoxy group or a hydroxyl group; however, at least 70 mol % of R8 are alkoxy groups; p is a number in a range of 1≦p<3; a is 0 or a positive number; b is a positive number; and 0.5≦b/(a+b) ≦1.0.