Hoya Corporation

Masahisa Kosaka

Yukio Kageyama

Shinsuke Itoh

Kazuo Inoue

Eiichi Yajima

Jian Jiang

Hajime Kamiya

Yoshitaka Kitahara

Tsuyoshi Ohkubo

Reisuke Okada

Kunio Sasaki

Tokio Suzuki

Koji Sato

Yoshiro Hirose

Mitsuo Sugimura

Takeshi Sakamoto

Tetsuo Ohsora

Kimio Nakamura

Tomoaki Yanagida

A plastic lens which absorbs ultraviolet light having wavelength of about 400 nm and suppresses coloring and a process for producing the lens. A plastic lens may be made from a composition which comprises (A) a lens material monomer comprising diethylene glycol bisallylcarbonate, (B) an organic peroxide-based polymerization initiator, (C) a cobalt compound represented by at least one of CoO.AlOand Co.AlO, and (D) at least one ultraviolet light absorbent selected from 2-hydroxy-4-octyloxy-benzophenone, 2,2',4,4&#x2032;-tetrahydroxy-4-octyloxybenzophenone and 2,2&#x2032;,4&#x2032;-trihydroxy-4-octyloxybenzophenone. A process for producing a plastic lens comprises mixing component (A), component (B), a cobalt fluid comprising component (C) in a dispersant and component (D) and a step of casting the mixed fluid into a mold and polymerizing the fluid to obtain a plastic lens.

Plastic lens and process for preparing the lens

A process for producing plastic lenses, having higher refractive index and Abbe's number without remarkably deteriorating basic physical properties such as mechanical strength, impact resistance and transparency, and plastic lenses. The process comprises mixing 1) a prepolymer with 2) a mixture comprising sulfur in an epithio group-containing compound and 3) a catalyst.

Process for producing plastic lens and plastic lens

Plastic lenses for spectacles having a high refractive index and a high Abbe's number, and having good transparency, heat resistance, mechanical strength and impact resistance are produced. Plastic lenses for spectacles are produced through polymerization of an epithio group-having compound (a), a polythiol compound (b) and a polyisocyanate compound (c) whereby the ratio (by mol) of the polythiol compound (b) to the polyisocyanate compound (c) is at least 1.2 calculated on the basis of &#x2014;SH and &#x2014;NCO groups. The invention also provides a process for preparing such lenses and a catalyst for use in said process.

Plastic lenses for spectacles

An optical material, particularly a plastic lens for spectacles, which absorbs almost all UV rays of up to around 400 nm or so and is not too yellow in color, is obtained by adding 2-(2-hydroxy-4-octyloxyphenyl)-benzotriazole to a diethylene glycol bisallylcarbonate monomer, a (thio)urethane monomer or an episulfide monomer, mixing them, and polymerizing the monomer.

Optical materials having good ultraviolet absorbability and method for producing them

The present invention provides a process for producing plastic lenses, which are transparent, less colored, are not remarkably deteriorated in basic physical properties such as mechanical strength and impact resistance, and have higher refractive index and Abbe's number, and plastic lenses.

Plastic lenses for spectacles having a high refractive index and a high Abbe's number, and having good transparency, heat resistance, mechanical strength and impact resistance are produced. Plastic lenses for spectacles are produced through polymerization of an epithio group-having compound (a), a polythiol compound (b) and a polyisocyanate compound (c) whereby the ratio (by mol) of the polythiol compound (b) to the polyisocyanate compound (c) is at least 1.2 calculated on the basis of &mdash;SH and &mdash;NCO groups. The invention also provides a process for preparing such lenses and a catalyst for use in said process.

Process for the production of polyurethane lens

A process for producing a polythiol oligomer having disulfide linkages by reacting polythiol (with the functionality of two or above) with sulfur in a molar ratio of m to (m-1) (where m is an integer of 2 to 21) in the presence of a basic catalyst, whereby the oligomers produced have a degree of oligomerization of m (wherein m is defined as above). Specifically disclosed is a process for reacting 2,5-dimercaptomethyl-1,4-dithiane (DMMD) with sulfur in a molar ratio 2:1 or 3:2 in the presence of a basic catalyst, thereby producing an oligomer represented by the below formula: ##STR1## (wherein n is an integer of up to 21). Also disclosed are optical polymers made with the oligomer and optical materials and devices made with the polymer.

Process of producing polythiol oligomer

The present invention relates to a process for the production of a polyurethane lens, which comprises the step (a) of providing a polyisocyanate compound and two or more polythiol compounds which have different reaction rates with the polyisocyanate compound and adding an alkyltin halide compound to the above polyisocyanate compound, and, after the step (a), the step (b) of mixing the polyisocyanate compound and the two or more polythiol compounds together with the alkyltin halide compound of the general formula (I) to allow them to react, and obtaining a polyurethane lens.

A polymer used for optical products wherein the polymer comprises 2,5-dimethyl-1,4-dithiane skeletons represented by formula (1): ##STR1## and 1,3,5-trimethylcyclohexane skeletons represented by formula (2): ##STR2## and a part of or all of bonds between the 2,5-dimethyl-1,4-dithiane skeleton and the 1,3,5-trimethylcyclohexane skeleton are thiourethane bonds. The polymer exhibits 1.63 or more of refractive index, 35 or more of Abbe's number and 100.degree. C. or more of second-order transition point. The polymer is prepared by polyaddition of 2,5-dimercaptomethyl-1,4-dithiane and 1,3,5-triisocyanatomethylcyclohexane.

Polymer for optical products and process for preparation thereof

The anti-reflection optical element of the present invention achieves reduction of surface reflection by providing a multi-layered anti-reflection film directly or indirectly on an optical component made of a plastic. The anti-reflection optical element of the present invention uses a multi-layered anti-reflection film comprising at least one high refractive index film layer which is a film of mixed metal oxides comprising tantalum oxide, zirconium oxide and yttrium oxide deposited by evaporation process, and thereby has solved the problems of conventional anti-reflection optical elements that their optical, mechanical and chemical properties are deteriorated with the lapse of time.

Growing community of inventors

Tokyo, Japan

Masahisa Kosaka