Tokuyama Corporation

Kazuhiko Kuramoto

Satoshi Imura

Takashi Kobayakawa

Kazumasa Itonaga

Hironobu Nagoh

A polymerizable composition comprising at least two di(meth)acrylate compounds of the specific general formula (I), e.g., dimethacrylate compounds of polyethylene glycol adduct of 2,2-bis(4-hydroxyphenyl)propane, wherein the content of di(meth)acrylate compound of the general formula (I) in which m+n is 2 to 3 is 30 to 80 mol % and the content of di(meth)acrylate compound of the general formula (I) in which m+n is 6 to 12 is 20 to 50 mol %, and organic glass formed of a polymer from the polymerizable composition, the polymerizable composition being suitable as a transparent resin, particularly as a raw material for an ophthalmic lens which is free of optical strain, has sufficient hardness and is excellent in impact resistance and light resistance.

Polymerizable composition and organic glass

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

Kazuhiko Kuramoto