Ultraviolet radiation absorbing coating composition and its production

PURPOSE: To obtain the subject composition having resistance to ultraviolet radiation and abrasion resistance by partially hydrolyzing a specified organoalkoxysilane and reacting the hydrolyzate with a titanium alkoxide. CONSTITUTION: An organoalkoxysilane (A) of the formula: R x Si(OR') 4-x (wherein R is an organic radical; R' is a low-molecular-weight alkyl; and x is 0-4), a titanium alkoxide or colloidal titania (B) is added to the hydrolyzate and reacted with component A, water (C) is added to hydrolyze the composition, and the resulting hydrolyzate is dried. Next, the composition is subjected to the step of heating the composition to at least 750°C to attain an absorbance at 320 nm of at least 0.5 per μm of the thickness of the coating to obtain the objective composition. The molar ratio of the titania to the silica in the reaction product should be 0.1-0.5. COPYRIGHT: (C)1994,JPO