Photochromic polyurethane laminate
View Patent ↗Photochromic polyurethane laminates and methods for the formation of same wherein the photochromic polyurethane layer of the laminate has been crosslinked with a isocyanate-active prepolymer using a crosslinking agent. The crosslinking agent is formulated to have at least three functional groups that are reactive with functional groups of the polyurethane or of the isocyanate-active prepolymer.
1. A photochromic polyurethane laminate for use in an optical article comprising:
a first resin sheet;
a second resin sheet;
a photochromic polyurethane layer disposed between said first and second resin sheet;
said photochromic polyurethane layer formed from a composition comprising a prepolymer, di(trimethylolpropane), and one or more photochromic compounds;
said prepolymer formed from a composition comprising:
a polycarbonate polyol having a number average molecular weight of about 800 gram per mole and an OH number of 138 milligrams KOH per gram;
a polyether polyol having a number average molecular weight of about 1,000 gram per mole and an OH number of 115 milligrams KOH per gram; and
an aliphatic diisocyanate.
2. A photochromic polyurethane laminate according to claim 1 wherein said polycarbonate polyol has a formula:
where n is equal to an integer from 3 to 6 or a combination thereof, and “x” is an integer that makes the molecular weight of the polycarbonate polyol approximately equal to 800.
3. A photochromic polyurethane laminate according to claim 1 wherein said polyether polyol has a formula:
HO—[(CR1R2M) n O] x H
where R1 and R2 are a hydrogen or an alkyl group, where “n” is equal to an integer from 3 to 6, and “x” is an integer that makes the molecular weight of the said polyether polyol approximately equal to 1,000 and where “M” has a formula:
(CH2) y
where “y” is an integer from 1 to 6.
4. A photochromic polyurethane laminate according to claim 1 wherein said photochromic polyurethane layer is formed from a composition further comprising a chain extender.
5. A photochromic polyurethane laminate according to claim 4 wherein said chain extender is 1,4-butanediol.
6. The photochromic polyurethane according to claim 1 wherein said aliphatic diisocyanate comprises 4,4′-dicyclohexylmethanediisocyanate.
7. A photochromic polyurethane laminate for use in an optical article comprising:
a photochromic polyurethane layer disposed on a surface of a resin sheet;
said photochromic polyurethane layer formed from a composition comprising a prepolymer, a chain extender, di(trimethylolpropane) as a crosslinking agent, and one or more photochromic compounds;
said prepolymer formed from a composition comprising:
a polycarbonate polyol having a number average molecular weight of about 800 gram per mole and an OH number of 138 milligrams KOH per gram;
a polyether polyol having a number average molecular weight of about 1,000 gram per mole and an OH number of 115 milligrams KOH per gram; and
an aliphatic diisocyanate.
8. The photochromic polyurethane laminate according to claim 7 wherein the resin sheet is a polycarbonate resin sheet.
9. A photochromic polyurethane laminate according to claim 7 wherein said polycarbonate polyol has a formula:
where n is equal to an integer from 3 to 6 or a combination thereof, and “x” is an integer that makes the molecular weight of the said polycarbonate polyol approximately equal to 800.
10. A photochromic polyurethane laminate according to claim 7 wherein said polyether polyol has a formula:
HO—[(CR1R2M) n O] x H
where R1 and R2 are a hydrogen or an alkyl group, where “n” is equal to an integer from 3 to 6, and “x” is an integer that makes the molecular weight of the said polyether polyol approximately equal to 1,000 and where “M” has a formula:
(CH2) y
where “y” is an integer from 1 to 6.
11. The photochromic polyurethane according to claim 7 wherein said aliphatic diisocyanate comprises 4,4′-dicyclohexylmethanediisocyanate.
12. A photochromic polyurethane laminate according to claim 7 wherein said chain extender is 1,4-butanediol.