Patent ID: 8802968

Claim:
A fluororesin film comprising: an ethylene/tetrafluoroethylene copolymer as the main component, and titanium oxide composite particles, wherein: each titanium oxide composite particle comprises (i) a silica-covered titanium oxide particle and (ii) a hydrophobizing agent covering the silica-covered titanium oxide particle; the surface of the fluororesin film in contact with air has an arithmetic mean roughness Ra, as stipulated by JIS B0601, of from 0.5 to 3 μm; the silica-covered titanium oxide particles comprise from 1.5 to 5 parts by mass of silica, calculated as SiO 2 , per 100 parts by mass of the titanium oxide particles; the silica-covered titanium oxide particles have a difference (Δ 300-100 ) in the Karl Fischer water content between 300° C. and 100° C. of at most 0.5%; the titanium oxide composite particles comprise from 0.5 to 10 parts by mass of the hydrophobizing agent per 100 parts by mass of the silica-covered titanium oxide particles; the fluororesin film has a thickness of from 12 to 100 μm; the fluororesin film has an initial breaking strength of 52 to 65 MPa; and the fluororesin film has an initial breaking extension of 290 to 350%.