To make water drops hard to stick and stay, and for this reason, make lime deposit hard to generate by microscopically dispersing hydrophilic parts of photocatalyst oxide particles, and water repellent parts of a water repellent fluororesin on the surface of the apron part of a bathtub.
On the surface of a bathtub apron part, a surface layer which has a structure wherein parts presenting hydrophilic property where photocatalyst oxide particles are exposed so as to come into contact with the outside air, and part presenting water repellent property where a water repellent fluororesin is exposed so as to come into contact with the outside air, are microscopically dispersed on the surface, and the contact angle with water of the surface of which, is 90° or higher, is formed. For the photocatalyst oxide, e.g. an oxide such as anatase-type titanium dioxide, rutile-type titanium dioxide, and zinc oxide can be used. For a light source to be used for the optical excitation of the photocatalyst, e.g. a fluorescent lamp, an incandescent lamp, a metal halide lamp, and a mercury lamp, can be used. For the water repellent fluororesin e.g. polytetrafluoroethylene, polychlorotrifluoroethylene, and polyhexafluoropropylene, etc., can be used.
HAYAKAWA MAKOTO
Next Patent: MANUFACTURE OF ABSORBENT PAPER