Curable photochromic composition including a segmented polymer
The present invention relates to a curable photochromic composition that includes: (a) a photochromic compound; and (b) a segmented polymer that includes active hydrogen groups, at least one first segment, and at least one second segment, in which, (i) each first segment independently includes a (meth)acrylic polymer segment, and (ii) each second segment independently includes at least one of, a polycarbonate segment, a polyester segment, a polyether segment, a polyurethane segment, and combinations of two or more thereof. The curable photochromic composition further includes (c) a curing agent having reactive functional groups that are reactive with the active hydrogen groups of the segmented polymer (a), in which the curing agent includes at least one of, a polyisocyanate, a polyisothiocyanate, and an aminoplast. The present invention also relates to photochromic articles that include at least one layer formed from the curable photochromic composition of the present invention.
1. A curable photochromic composition comprising:
(a) a photochromic compound;
(b) a segmented polymer comprising active hydrogen groups of at least one first segment, and at least one second segment, wherein:
(i) the at least one first segment in each case independently comprises a (meth)acrylic polymer segment, and
(ii) the at least one second segment in each case independently comprises at least one of a polycarbonate segment, a polyester segment, a polyether segment, and a polyurethane segment; and
(c) a curing agent comprising reactive functional groups that are reactive with the active hydrogen groups of the segmented polymer, wherein the curing agent comprises at least one of a polyisocyanate, and a polyisothiocyanate,
wherein,
the segmented polymer has an active hydrogen equivalent weight of from 1000 to 7000 g/eq, and
the active hydrogen groups of the segmented polymer are in each case independently selected from hydroxyl, thiol, primary amine, and secondary amine, and
wherein,
each reactive functional group of the curing agent is independently selected from isocyanate and isothiocyanate, and
a molar ratio of the reactive functional groups of the curing agent to the active hydrogen groups of the segmented polymer is at least 5:1.
2. The curable photochromic composition of claim 1 , wherein the active hydrogen groups of the segmented polymer are in each case hydroxyl.
3. The curable photochromic composition of claim 1 , wherein the at least one first segment and the at least one second segment are covalently bonded to each other by a linking group independently selected from the group consisting of a carboxylic acid ester linking group, a thioester linking group, an amide linking group, a urethane linking group, a thiourethane linking group, a urea linking group, a thiourea linking group, a carbonate linking group, an ether linking group, and a thioether linking group.
4. The curable photochromic composition of claim 1 , wherein the at least one second segment is present in the segmented polymer in an amount of from 60 percent by weight to 95 percent by weight, based on a total weight of the segmented polymer.
5. The curable photochromic composition of claim 4 , wherein the curable photochromic composition comprises a total amount of second segments of from 20 percent by weight to 50 percent by weight, based on a total solids weight of the curable photochromic composition.
6. The curable photochromic composition of claim 1 , wherein the at least one second segment in each case independently comprises at least one of said polycarbonate segment, a polycarbonate-polyester segment, a polycarbonate-polyurethane segment, and a polycarbonate-polyester-polyurethane segment.
7. The curable photochromic composition of claim 1 , wherein the molar ratio of the reactive functional groups of the curing agent to the active hydrogen groups of the segmented polymer is at least 6:1 and less than or equal to 60:1.
8. The curable photochromic composition of claim 1 , wherein the curing agent comprises the polyisocyanate, and the reactive functional groups of the curing agent are in each case selected from isocyanate.
9. The curable photochromic composition of claim 8 , wherein the polyisocyanate comprises at least one of linear or branched aliphatic polyisocyanates, cycloaliphatic polyisocyanates, dimers thereof, and trimers thereof.
10. The curable photochromic composition of claim 8 , wherein at least some of the reactive functional groups of the curing agent are blocked with a blocking agent, and the blocking agent is in each case independently selected from the group consisting of methylethyl ketoxime, pyrazole, and dialkyl pyrazole.
11. The curable photochromic composition of claim 1 , wherein the photochromic compound is selected from the group consisting of naphthopyrans, benzopyrans, phenanthropyrans, indenonaphthopyrans, spiro(indoline)naphthoxazines, spiro(indoline)pyridobenzoxazines, spiro(benzindoline)pyridobenzoxazines, spiro(benzindoline)naphthoxazines, spiro(indoline)-benzoxazines, fulgides, fulgimides, and mixtures of such photochromic compounds.
12. An article comprising:
(A) a substrate; and
(B) a photochromic layer over at least one surface of the substrate, wherein the photochromic layer is formed from the curable photochromic composition of claim 1 .
13. A photochromic multilayer article comprising at least one photochromic layer formed from the curable photochromic composition of claim 1 .