To obtain a water-repelling coating material which does not cause the generation of defective coating films due to air bubbles or the high viscosity of the coating material and can correspond to a dipping coating method and a brush-coating method, by formulating specific tetrafluoroethylene resin powder, a specified silicone resin binder, and the like, and adjusting the total specific gravity change rate to a specific value or smaller.
This water-repelling coating material has a total specific gravity change rate of ≤10%, and comprises tetrafluoroethylene resin powder in whose IR light absorption spectrum the ratio of the strength of a peak near to 1,800 cm-1 exhibiting a carbonyl group as a terminal group to the strength of a peak near to 500 cm-1 due to C-F bonds is ≤0.05, a silicone resin binder containing one or more kinds of polyorganosiloxanes and their partial fluoridation products, and an organic solvent which comprises one or more solvents selected from fluorinated solvents, hydrocarbon-based solvents, alcoholic solvents, toluene and xylene, and has a surface tension of 16 to 22 dyne/cm and a specific gravity of 0.6 to 1.6 at 25°C.
TSUKAMOTO YASUHIRO
MATSUDA CHIEMI
YANAGAWA TSUTOMU
FUJINO MASAYA
OTA TAKEHITO
NIPPON TELEGRAPH & TELEPHONE