A photochromic article having improved photochromic equilibrium response is described. In particular, a photochromic compound is incorporated into or applied to an article, e.g., matrix, of a synthetic organic resin prepared from a composition comprising from about 55 to about 90 weight percent of a polyol(allyl carbonate), e.g., diethylene glycol bis(allyl carbonate), from about 10 to about 40 weight percent of an aliphatic polyurethan having terminal ethylenic unsaturation, e.g., an aliphatic polyesterurethan diacrylate, and from about 0 to about 5 weight percent of a difunctional monomer selected from the group consisting of allyl methacrylate and allyl acrylate. Such photochromic articles have an improved photochromic equilibrium response at ambient temperatures compared to the response of a comparable photochromic article prepared from a polyol(allyl carbonate) homopolymer, e.g., homopolymers of diethylene glycol bis(allyl carbonate), at the same ambient temperatures.
A photochromic composition which develops a neutral tint such as grey, green, brown or amber upon the irradiation with light including ultraviolet rays such as sunlight starting from the initial colorless state, maintaining a homogeneous color tone in the transient stage of developing color. The photochromic composition comprises 100 parts by weight of a fulgimide compound and/or a fulgide compound, and from 10 to 300 parts by weight of a chromene compound having a molar extinction coefficient of not smaller than 150 L/mol-cm for light of a wavelength of 400 nm.
Describes polymerizable organic resin compositions of from about 70 to 90 weight percent of a polyol(allyl carbonate), e.g., diethylene glycol bis(allyl carbonate), and from about 30 to 70 weight percent of aliphatic polyurethane having terminal allylic unsaturation. The polymerizable compositions have initiated pot life times of at least about 24 hours at 25.degree. C. and castings that have low yellowness (b*) values. Polymerizates prepared from such compositions may be used to prepare photochromic articles, e.g., lenses, by incorporating a photochromic substance, e.g., by thermal transfer, into the polymerizate.
The present invention relates to a novel photochromic polyurethane consisting essentially of an isocyanate reactive mixture consisting essentially of: i) from about 40 to about 85% by weight of one or more polyols having a nominal functionality of from 2 to 4 and molecular weights of from 500 to 6000 g/mole; ii) from about 15 to about 60% by weight of one or more diols or triols or mixtures thereof having a functionality of from 2 to 3 and molecular weights of from 62 to 499; b) an aliphatic polyisocyanate having a functionality ranging from about 2 to about 3; and c) a photochromic compound selected from a group consisting of spirooxazines, fulgides, fulgimides, and naphthopyrans, wherein the photochromic compound is present in an amount of 0.01 to 5 parts per hundred parts by weight of the isocyanate reactive mixture.
Describes organic resin compositions of from about 30 to 90 weight percent of a polyol(allyl carbonate), e.g., diethylene glycol bis(allyl carbonate), and from about 10 to 70, e.g., 10 to 30, weight percent of a mixture of aliphatic urethanes, the terminal portions of which contain allyl or acrylyl functional groups. Polymerizable compositions prepared from such compositions produce castings which have low yellowness (b*) values and which do not pre-release from the molds in which they are formed. Polymerizates prepared from such compositions may be used to prepare photochromic articles, e.g., lenses, by incorporating a photochromic substance, e.g., by thermal transfer, into the polymerizate.
A photochromic cured product exhibiting excellent photochromic properties such as a high color density and a high fading rate, as well as excellent base material properties such as a high hardness and a large heat resistance.
