Hoya Corporation

Kunio Sasaki

Kazuo Inoue

Masahiro Nakagawa

Masahisa Kosaka

Eiichi Yajima

Yoshiro Hirose

Mitsuo Sugimura

Takeshi Sakamoto

The present invention is concerned with a coating composition for a hard coat layer of a plastic lens, which comprises (A) a hydrolyzate of a specific alkoxysilane compound, (B) fine particles of an oxide of silicon, aluminum, tin, antimony, zirconium, tungsten or titanium or composite fine particles made of oxides of any two oxides of these, (C) a polyurethane and (D) a curing agent, and the coating composition is applied onto a plastic lens surface to give a scratch-resistant plastic lens.

Coating composition and method for preparing the same, and scuff-resistant plastic lense

A dyeing method for dyeing plastic lenses or the like employed as lenses for eye glasses and exhibiting excellent dyeability. The lens is dipped into a dyeing solution while being moved by a combination of a small-amplitude short-cycle time up and down reciprocating motion superimposed on a large-amplitude long-cycle time up and down reciprocating motion. The lens is minutely oscillated according to the small-amplitude short-cycle time up and down reciprocating motion while being periodically moved up and down in the dyeing solution according to the large-amplitude long-cycle time up and down reciprocating motion. The lowest position of the lens obtained by the large-amplitude long-cycle time up and down reciprocating motion is raised gradually. Also disclosed is a dyeing apparatus which is used to carry out that dyeing method.

Lens dyeing method and lens dyeing aparatus: dyeing lenses to give a

A polyurethane lens is produced by (a) adding to a monomer mixture comprising a polyisocyanate and a polythiol, a phosphoric acid ester represented by the general formula (I) ##STR1## (R.sub.1 and R.sub.2 which may be the same or different are each an alkyl group of 1-8 carbon atoms) and then (b) subjecting the monomer mixture containing the phosphoric acid ester, obtained in the step (a) to cast polymerization in a mold for plastic lens production. Said polyurethane lens has good releasability from mold, is free from color unevenness after tinting and cloudiness, and possesses high refractive index (N.sub.D) and high optical dispersion.

Process for producing polyurethane lens

Growing community of inventors

Akishima, Japan

Kunio Sasaki