Benzothiazol-2-ylazo-phenyl compound as dye, compositions including the dye, and method of determining degree of cure of such compositions

1. A compound represented by formula:

wherein

R is hydrogen or alkyl;

X is alkylene;

Y is a bond, ether, thioether, amine, amide, ester, thioester, carbonate, thiocarbonate, carbamate, thiocarbamate, urea, thiourea, alkylene, arylalkylene, alkylarylene, or arylene, wherein alkylene, arylalkylene, alkylarylene, and arylene are optionally at least one of interrupted or terminated by at least one of an ether, thioether, amine, amide, ester, thioester, carbonate, thiocarbonate, carbamate, thiocarbamate, urea, or thiourea; and

Z is an acrylate, a methacrylate, an acrylamide, a methacrylamide, a styrenyl, or a terminal alkenyl having at least three carbon atoms.

2. The compound of claim 1 , wherein Z is acrylate, methacrylate, or styrenyl.

3. The compound of claim 2 , wherein Y is a bond, —O—, —O—C(O)—, —O—C(O)—NR 1 —, or alkylene optionally at least one of interrupted or terminated by at least one ether, ester, carbonate, or carbamate, and wherein R 1 is hydrogen, alkyl, aryl, arylalkylenyl, or alkylarylenyl.

4. The compound of claim 3 , wherein —X—Y—Z is —CH 2 CH 2 —O—C(O)—CH═CH 2 , —CH 2 CH 2 —O—C(O)—C(CH 3 )═CH 2 , or —CH 2 CH 2 —O—C(O)—C 6 H 4 —CH═CH 2 .

5. A composition comprising the compound of claim 1 , a free radical initiator, and a diluent.

6. The composition of claim 5 , wherein the free-radical initiator is an organic peroxide.

7. The composition of claim 5 , wherein the free-radical initiator is a photoinitiator.

8. A composition comprising the compound of claim 1 and a curable polymeric resin.

9. The composition of claim 8 , wherein the curable polymeric resin is an unsaturated polyester resin.

10. The composition of claim 8 , further comprising at least one of styrene monomer, a substituted styrene monomer, an acrylate monomer, a methacrylate monomer, an acrylamide monomer, or a methacrylamide monomer.

11. The composition of claim 8 , further comprising at least one of ceramic beads, polymer beads, silica, hollow ceramic elements, hollow polymeric elements, alumina, zirconia, mica, dolomite, woolasonite, fibers, talc, calcium carbonate, sodium metaborate, or clay.

12. A method for indicating extent of cure of a curable polymeric resin, the method comprising:

providing a composition comprising a curable polymeric resin, a free-radical initiator, and a compound of claim 1 in an amount sufficient to provide the composition with a first absorbance at a wavelength in a range from 400 nanometers to 700 nanometers; and

allowing the composition to cure to provide a cured composition, wherein the cured composition has a second absorbance at the wavelength that is different from the first absorbance, and

determining a difference between the first absorbance and the second absorbance, wherein the difference between the first absorbance and the second absorbance indicates the extent of cure of the curable polymeric resin.

13. The method of claim 12 , wherein the difference between the first absorbance and the second absorbance is visually determined.

14. The method of claim 12 , wherein providing the composition comprises mixing the curable polymeric resin with a curative comprising the free-radical initiator and the compound or wherein providing the composition comprises mixing the curable polymeric resin and the compound and then combining the free-radical initiator with the curable polymeric resin and the compound, and wherein mixing is carried out until the composition is uniformly colored.

15. The method of claim 12 , wherein the curable polymeric resin is an unsaturated polyester resin, and wherein the composition further comprises at least one of styrene monomer, a substituted styrene monomer, an acrylate monomer, a methacrylate monomer, an acrylamide monomer, or a methacrylamide monomer.

16. The method of claim 12 , wherein the free-radical initiator is an organic peroxide.

17. The method of claim 12 , wherein the free-radical initiator is a photoinitiator.

18. The method of claim 12 , wherein Z in the compound represented by formula:

is acrylate, methacrylate, or styrenyl.

19. The method of claim 18 , wherein Y in the compound represented by formula:

is a bond, —O—, —O—C(O)—, —O—C(O)—NR 1 —, or alkylene optionally at least one of interrupted or terminated by at least one ether, ester, carbonate, or carbamate, and wherein R 1 is hydrogen, alkyl, aryl, arylalkylenyl, or alkylarylenyl.

20. The method of claim 19 , wherein —X—Y—Z in the compound represented by formula:

is —CH 2 CH 2 —O—C(O)—CH═CH 2 , —CH 2 CH 2 —O—C(O)—C(CH 3 )═CH 2 , or —CH 2 CH 2 —O—C(O)—C 6 H 4 —CH═CH 2 .