PROBLEM TO BE SOLVED: To provide a composition for photocatalyst coating, which is used suitably as a window material of an ultraviolet light irradiation device or the like when breeding water of aqueous organisms such as cultured fishes and ornamental fishes is sterilized with ultraviolet light and which is suitable for producing an ultraviolet light transmission window material which shows self cleaning properties and has a photocatalytic function.SOLUTION: The composition for photocatalyst coating is prepared by blending a composite photocatalyst particle with a binder such as silica sol, which particle is obtained by pulverizing a cured body obtained by curing a curable composition containing a photocatalytic substance 1 such as TiO2 fine particle and the binder. The binder is used, whose cured body 7 shows transmittance to ultraviolet rays 11, 12 and excited light of the photocatalytic substance. The prepared composition for photocatalyst coating is applied to the outside surface of a window material main body 5 consisting of a substance such as sapphire exhibiting transmittance to ultraviolet ray having 200-400 nm and excited light of the photocatalytic substance. The applied composition is cured to form a photocatalyst coating layer 6, which is used as the window material of the ultraviolet light irradiation device 8.SELECTED DRAWING: Figure 2COPYRIGHT: (C)2016,JPO&INPIT【課題】養殖魚や観賞魚などの水性生物の飼育水を紫外線殺菌するときの紫外線照射装置などの窓材として好適に使用される、セルフクリーニング性発現させる光触媒機能を有する紫外線透過性窓材を製造するのに好適な光触媒コーティング用組成物を提供する。【解決手段】TiO2微粒子などの光触媒物質1’と、その硬化体7が紫外線11,12及び該光触媒物質の励起光に対して透過性を有するシリカゾル等のバインダーとを含んでなる硬化性組成物を硬化させて得た硬化体を粉砕して得た複合光触媒粒子を、硬化体が紫外線及び前記光触媒物質の励起光に対して透過性を有するシリカゾル等のバインダーに配合して光触媒コーティング用組成物を調製し、これを波長200~400nmの紫外線及び光触媒物質の励起光を透過するサファイア等の物質からなる窓材本体5の外側表面に塗布して硬化させて光触媒コート層6を形成して窓材とする紫外線照射装置8。【選択図】図2
