Tokuyama Corporation

Kazumasa Itonaga

Satoshi Imura

Takashi Kobayakawa

Kazuhiko Kuramoto

Hironobu Nagoh

Process for production of photochromic cured product

A photochromic composition comprising (A) 100 parts by weight of a compound having at least one epoxy group in the molecule and (B) 0.0001 to 10,000 parts by weight of a photochromic compound. The compound (A) is represented by the following general formula ##STR1## wherein A is a residue of an n-valent alcoholic hydroxyl-containing compound, a residue of an n-valent phenolic-hydroxyl-containing compound, or a residue of an n-valent carboxylic acid, R.sup.1 is a hydrogen atom or a methyl group, and n is an integer of 1 to 4. Examples of the (B) photochromic compound include fulgide compounds, spirooxazine compounds and chromene compounds. A polymer obtained by polymerizing the above photochromic composition of the invention by a radical polymerization method has a good durability of photochromic properties, and also possesses a dark color-forming density, a fast color fading speed, is transparent, and has a high surface hardness. Thus, especially, the polymer is suitable for use as a photochromic lens.

Photochromic composition

A photochromic composition comprising (A) 100 parts by weight of a compound having at least one epoxy group in the molecule and (B) 0.0001 to 10,000 parts by weight of a photochromic compound. The compound (A) is represented by the following general formula ##STR1## wherein A is a residue of an n-valent alcoholic hydroxyl-containing compound, a residue of an n-valent phenolic-hydroxyl-containing compound, or a residue of an n-valent carboxylic acid, R.sup.1 is a hydrogen atom or a methyl group, and n is an integer of 1 to 4. Examples of the (A) compound include alcoholic hydroxyl-containing compounds such as monohydric, dihydric or trihydric alcohols, reaction products of phenolic hydroxyl-containing compounds such as phenol or hydroquinone with epichlorohydrin, or reaction products of carboxylic acids such as benzoic acid, or terephthalic acid with epichlorohydrin. Examples of the (B) photochromic compound include fulgide compounds, spirooxazine compounds and chromene compounds. A polymer obtained by polymerizing the above photochromic composition of the invention by a radical polymerization method has a good durability of photochromic properties, and also possesses a dark color-forming density, a fast color fading speed, is transparent, and has a high surface hardness. Thus, especially, the polymer is suitable for use as a photochromic lens.

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Tokuyama, Japan

Kazumasa Itonaga