| 摘要 |
The invention is directed to a UV light resistant, visibly transparent, urethane golf ball topcoat composition for use with UV curable inks and to golf balls incorporating such a topcoat. The topcoat includes an optical brightener that absorbs at least some ultraviolet light at wavelengths greater than about 350 nm, and emits visible light, and a light stabilizer package. The light stabilizer package includes at least one UV light absorber and, optionally, at least one light stabilizer, such as a HALS. The UV light absorber absorbs at least some UV light at wavelengths between about 200 nm and about 370 nm, and has an absorption peak at a wavelength between about 330 nm and about 360 nm and a UV light absorbance at a wavelength of about 350 nm that is at least about 3 times greater than the UV light absorbance at a wavelength of about 370 nm. The optical brightener is present in an amount sufficient to increase the brightness of the ball, and the light stabilizer is present in an amount sufficient to reduce or eliminate discoloration of the ball on exposure to UV light used to cure the UV curable ink. The invention also relates to a method of preventing discoloration of a golf ball upon UV curing. The method includes the steps of forming a golf ball having a cover and a core; the UV light resistant, visibly transparent, urethane golf ball topcoat composition of the invention by preparing a mixture of a polyol resin, a polyisocyanate, the optical brightener, the UV light absorber, and, optionally, the HALS. A topcoat is then formed on the golf ball with the urethane golf ball topcoat composition, and an image is formed on the topcoat with a UV curable ink. The ink is then cured by exposing the ink on the golf ball topcoat to UV light at a wavelength and in an amount and for a time sufficient to cure the ink, thereby curing the ink.
|
