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US 6,444,146 B2Granted
Process for production of optical material
AssigneeMitsubishi Gas Chemical Company, Inc.
InventorsYuichi Yoshimura, Motoharu Takeuchi
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Abstract
An improved process for producing optical materials with minimized yellowing is described. The process is characterized by polymerizing/curing a composition for optical materials after adding a bluing agent. With the use of the bluing agent, the yellowing is minimized even when a large amount of an ultraviolet light absorber is used to improve a light resistance of the resultant optical material, thereby enabling the production of optical materials having a colorless and transparent appearance and excellent optical properties.
Claims10
A process for producing an optical material, comprising:
- adding a bluing agent to a composition for optical materials comprising a compound having a radical represented by the formula (I):
- wherein R1 is C1-C10 hydrocarbon group;
- R2, R3 and R4 are each independently C1-C10 hydrocarbon group or hydrogen;
- Y is O, S, Se or Te;
- p is 0 or 1;
- m is an integer of 1 to 5;
- and n is an integer of 0 to 5, thereby preparing a molding composition;
- and
- subjecting the molding composition to polymerization and curing in a mold.
6 more elements
Dependencies are inferred from the claim text.