Film obtained from silsesquioxane polymer and method of preparing same

A method of preparing a cured film, comprising applying a coating of a composition to a substrate, heating said coating at a temperature lower than 300° C. but not lower than 40° C. in air or in an inert atmosphere for a period of time sufficient to form a precursor film on said substrate, and curing said precursor film at a temperature of 300-1500° C. in an inert atmosphere, said composition comprising a hydrosilylated polymer obtained by reacting at least one hydridosilsesquioxane compound of the following formula (1):

• (HSiO3/2)n (1)
• wherein n is an integer of 4-1000, with at least one compound of the following formula (2)
• R1—C≡C—R2 (2)
• wherein R1 represents a hydrogen atom, a monovalent organic group or a monovalent organosilicon group and R2 represents a hydrogen atom or a group of the formula:
• —(R′)q—C≡C—R
• where R′ represents a divalent organic group or a divalent organometallic group, R represents a monovalent organic group or a monovalent organosilicon group and q is 0 or 1
• with the proviso that when R1 is a hydrogen atom R2 a hydrogen atom,
• so that said cured film shows an IR spectrum having absorption peaks at 2200-2400 cm−1 and 850-930 cm−1, wherein the absorbance of the peak at 2200-2400 cm−1 of the coating after said curing is not greater than 70% of the absorbance of the peak at 2200-2400 cm−1 of the coating before said curing, and wherein the absorbance of the peak at 850-930 cm−1 of the coating after said curing is not greater than 70% of the absorbance of the peak at 850-930 cm−1 of the coating before said curing.