Hoya Corporation

Shinya Miyajima

Takaaki Kubotera

Shinichi Yamashita

Hiroshi Futami

Misa Mishina

Yoko Sakai

A method of dyeing a plastic lens including applying a sublimation dye to a dyeing substrate, holding the dyeing substrate on a holding member, holding a plastic lens on the holding member at a position above the dyeing substrate, evacuating a vacuum vessel which accommodates the holding member, transferring the dyeing substrate from the holding member to a heating device provided in the vacuum vessel, so that the dyeing substrate is held to be heatable by the heating device, by vertically moving at least one of the holding member and the heating device, bringing the plastic lens in close proximity to the dyeing substrate by vertically moving at least one of the holding member and the heating device which holds the dyeing substrate, and dyeing the target surface of the plastic lens with the sublimation dye by sublimating the sublimation dye by heating the dyeing substrate using the heating device.

Method for dyeing plastic lens

A process which enables a plastic lenses having a refractive index of 1.7 or greater and, in particular, plastic lenses having a refractive index of 1.7 to 1.8 to be dyed uniformly to a great density without unevenness, which is, specifically, a process for producing a dyed plastic lens which comprises conducting following steps (1), (2) and (3) in this order: Step (1): a step comprising coating a substrate at 60&#xb0; C. or lower with an ink comprising a sublimation dye; Step (2): a step comprising decreasing content of water in the ink comprising sublimation dye coating the substrate to 50% by mass or less of the entire ink; and Step (3): a step comprising, after placing a plastic lens in a manner such that a face for dying of the lens and a face of the substrate coated with the ink comprising a sublimation dye face each other, sublimating the sublimation dye in the ink comprising a sublimation dye coating the substrate by heating the substrate obtained after Step (2) under a degree of vacuum of about 1&#xd7;10Pa or smaller to dye the plastic lens.

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Tokyo, Japan

Shinya Miyajima