Tinting plastic articles
OwnerChristophe U. Ryserinventor
Life of this patent
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Abstract
Plastic articles, especially plastic optical lenses are tinted by immersing the plastic article in an aqueous dispersion of tinting agent and exposing the dispersion and immersed article to microwave radiation to bring the dispersion to ebullition; the ebullition is maintained for at least 2 seconds with transfer of tinting agent from the dispersion to the article to tint the article; the tinted article is removed from the dispersion and rinsed with water. The method achieves tinting in significantly shorter times than conventional methods and employs water-based dispersions thereby avoiding emission of vapors of organic solvents.
Claims22
A method of tinting a tintable plastic optical lens, said lens being of thermoplastic or a thermoset plastic comprising:
- i) immersing a tintable thermoplastic or thermoset plastic optical lens in an aqueous dispersion of a tinting agent, said dispersion and lens being supported on a rotatable platform, and said tinting agent being a high energy dye or a UV dye which withstands temperatures of 90° C. to 135° C.;
- ii) exposing said aqueous dispersion with said immersed optical lens to microwave radiation to bring said dispersion to a quiescent boil, while rotating said platform,
- iii) maintaining said quiescent boil for a time period of at least about 2 seconds, while rotating said platform, with transfer of tinting agent from said dispersion to said optical lens to effect tinting,
- iv) removing the resulting tinted optical lens from said dispersion;
- and
- v) rinsing the tinted optical lens with water to remove residual dispersion.
Dependencies are inferred from the claim text.