Patent ID: 7910513

Claim:
A photocatalyst sheet comprising: a substrate made of glass fiber, a coated layer made of polytetrafluoroethylene (PTFE) coated on both sides of said substrate, and a photocatalyst-containing layer coated on at least one side of said coated layer, wherein said photocatalyst-containing layer contains tetrafluoroethylene-hexa-fluoropropylene copolymer (FEP) and apatite-coated photocatalyst particles having low water solubility, said photocatalyst particles contain titanium oxide, and said apatite is either of apatite hydroxide, apatite carbonate, apatite fluoride, or apatite chloride, or a mixture thereof, the particle diameter of said photocatalyst particles is 1 nm to 100 nm, the ratio of said apatite-coated photocatalyst particles to said photocatalyst-containing layer is 10-40 weight %, the coating quantity of said apatite coated on said photocatalyst particles is such that the weight loss ratio of the whole of said photocatalyst sheet is 10% or less when ultraviolet light of intensity of 18 mW/cm 2 is irradiated for one hour on the surface of said photocatalyst sheet, the water contact angle of said photocatalyst sheet surface is 130 degrees or less, whereby said coated layer can be peeled from said substrate when a pair of said photocatalyst sheets are mutually thermally welded to form a welded part and when said welded part is peeled off by a peeling test at the rate of 50 mm/min.