Curable adhesive compositions

1. A curable adhesive composition, comprising:

at least one high index-high viscosity component having a refractive index, before curing, of at least 1.56 at 25° C., and a viscosity, before curing, of at least 15,000 cP at 25° C.;

a photoinitiator; and

5 wt% to 25% of at least one naphthalene component selected from the group consisting of 1-chloro naphthalene; 1-bromo naphthalene; and 1-naphthaldehyde;

wherein the adhesive composition has a refractive index, after curing, in a range from 1.64 to 1.74;

wherein the high index-high viscosity component is selected from the group consisting of:

brominated aromatic urethane acrylate;

tribromophenyl acrylate; and

9,9-bis{4-(2-cryloloxyethoxy)phenyl}fluorene.

2. The composition of claim 1 , wherein the aromatic urethane acrylate is a brominated aromatic urethane acrylate.

3. The composition of claim 1 , further comprising at least one vinyl resin.

4. The composition of claim 1 , further comprising at least one sulfur component.

5. The composition of claim 4 , wherein the sulfur component is selected from the group consisting of:

1,2-bis(2-mercapto ethylthio)-3-mercapto propane;

trimethylolpropane tris(3-mercaptopropionate);

2-mercaptoethylthio-3-propanthiol sulfide;

pentaerythritol tetrakis(2-mercaptopropoinate);

2,2′-thiodiethanethiol;

trimethyloltris(3-mercaptopropoinate)oethylthio-3 propanthiol sulfide;

2,5-dimercaptomethyl-1,4-dithiane;

4,5-(mercaptomethylthio)-1,3-dithiolane;

4,6-(mercaptomethylthio)-1,3-dithiane;

1,1,3,3-tetra(mercaptomethylthio)propane;

2,3-episulfide propanyl disulfide; and

2,3-episulfide propanyl sulfide.

6. The composition of claim 1 , further comprising at least one acrylic component.

7. The composition of claim 6 , wherein the acrylic component is selected from the group consisting of:

polyethylene glycol o-phenyl phenyl ether acrylate;

urethane acrylate;

aliphatic urethane acrylate;

2(2-ethoxyethoxy)ethyl acrylate;

2-phenoxyethyl acrylate;

ethoxylated (4) trimethylolpropane triacrylate;

ethoxylated (6) trimethylolpropane triacrylate;

isobornyl acrylates;

glycidyl methacrylate;

1,6 hexanediol diacrylate;

alkoxylated phenol acrylate;

alkoxylated phenol diacrylate;

2 hydroxyethyl acrylate;

phenyl thioethyl acrylate;

alkoxylated nonylphenol acrylate;

ethoxlyated tribromo phenyl acrylate;

tetrahydrofurfuryl acrylate;

tetrahydrofurfuryl methacrylate; and

polyethylene glycol (200) diacrylate.

8. The composition of claim 7 , wherein the composition comprises urethane acrylate.

9. The composition of claim 1 , further comprising a bisphenol A component.

10. The composition of claim 9 , wherein the bisphenol A component is selected from the group consisting of:

ethoxylated (10) bisphenol A diacrylate;

ethoxylated (4) bisphenol A diacrylate;

ethoxylated (4) bisphenol A dimethacrylate

diallylether bisphenol A; and

ortho diallyl bisphenol A.

11. A curable adhesive composition, comprising:

at least one high index-high viscosity component having a refractive index, before curing, of at least 1.56 at 25° C., and a viscosity, before curing, of at least 15,000 cP at 25° C.,

a photoinitiator, and

a naphthalene component selected from the group consisting of: 1-Chloro naphthalene, 1-Bromo naphthalene, and 1-Naphthaldehyde,

wherein the adhesive composition has a refractive index, after curing, of greater than 1.50;

wherein the high index-high viscosity is selected from the group consisting of:

brominated aromatic urethane acrylate,

tribromophenyl acrylate; and

9,9-bis-{4-(2-acryloxyloxyethoxy)phenyl}fluorene.

12. The composition of claim 1 , further comprising at least one epoxy resin.

13. The composition of claim 12 , wherein the epoxy resin is selected from the group consisting of:

poly[(phenyl glycidyl ether)-co-formaldehyde]oligomeric epoxide; and

epoxy acrylates.

14. The composition of claim 1 , wherein the photoinitiator comprises one or more of:

a radical photoinitiator,

a cationic photoinitiator, and

an anionic photoinitiator.

15. A The composition of claim 14 , wherein the photoinitiator comprises at least one radical photoinitiator selected from the group consisting of:

bis(2,3,6-trimethlbenzoyl)-phenylphosphineoxide;

1-hydroxcyclohexylphenylketone;

2-hydroxy-2-methyl-1-phenyl-propan-1-one;

bis(2,6-dimethoxy bezoyl)-2,4,4-trimethylpenty 1 phospheine oxide;

2,4,6-trimethylbezoyldiphenylphosphine;

2,2-dimethoxy-2-phenylacetophenone;

4-(2-hydroxyethoxy)phenyl-(2-hydroxy-2-methlpropyl)ketone;

2-methyl thioxanthone;

2-isopropyl thioxanthone;

2-chloro thioxanthone;

xanthone;

benzophenone;

2-methyl-1-[4-methylthio)phenyl]-2-morpholino propan-1-one; and

2-benzyl-2-N,N-dimethlamino-1-(-morpholinophenyl)-1-butanone.

16. The composition of claim 15 , wherein the photoinitiator comprises at least one radical photoinitiator selected from the group consisting of:

bis(2,3,6-trimethlbenzoyl)-phenylphosphineoxide;

1-hydroxcyclohexylphenylketone; and

2-hydroxy-2-methyl-1-phenyl-propan-1-one.

17. The composition of claim 14 , wherein the photoinitiator comprises at least one cationic photoinitiator selected from the group consisting of:

triaryl sulfonium salt hexafluoroantimonate;

triaryl sulfonium hexafluorophosphate;

bis(4-diphenylsulfonio)-phenyl]sufid-bis-hexafluorophosphate;

di(alkylphenyl)iodonium salt;

diaryl iodonium hexafluoroantimonate; and

iron-arene complex.

18. A curable adhesive composition, comprising:

at least one high index-high viscosity component having a refractive index, before curing, of at least 1.56 at 25° C., and a viscosity, before curing, of at least 15,000 cP at 25° C., and

a photoinitiator, wherein the photoinitiator comprises at least one anionic photoinitiator selected from the group consisting of:

0-nitrobenzyl derivatives;

metal amine complexes;

(cyclopentadienyl)ruthenium complexes; and

(cyclopentadienyl)osmium complexes,

wherein the adhesive composition has a refractive index, after curing, of greater than 1.50;

wherein the high index-high viscosity is selected from the group consisting of:

brominated aromatic urethane acrylate,

tribromophenyl acrylate; and

9,9-bis-{4-(2-acryloxyloethoxy)phenyl}fluorene.

19. The composition of claim 1 , wherein the photoinitiator comprises at least one additive selected from the group consisting of a co-catalyst, a phosphine, and an amine.

20. The composition of claim 19 , wherein the photoinitiator comprises at least one additive selected from the group consisting of:

tera alkylphosphonium bromide;

tera alkylphosphonium chloride;

triphenyl phosphine;

trimethoxy phenyl phosphine;

trichloro phenyl phosphine;

alkyl amine primary;

dialkyl amine; and

trialkyamine.

21. The composition of claim 1 , wherein the adhesive composition is curable by ultraviolet radiation.

22. The composition of claim 1 , wherein the adhesive composition comprises:

0.01 wt % to 5 wt % of the photoinitiator; and

1 wt % to 70 wt % of the at least one high index-high viscosity component.

23. The composition of claim 22 , wherein the photoinitiator comprises at least one of bis(2,3,6-trimethlbenzoyl)-phenylphosphineoxide, triaryl sulfonium salt hexafluoroantimonate, and triaryl sulfonium hexafluorophosphate.

24. The composition of claim 22 , wherein the adhesive composition further comprises 10 wt % to 95 wt % of at least one vinyl resin.

25. The composition of claim 1 , wherein the adhesive composition comprises 2 wt % to 50 wt % of at least one acrylic component selected from the group consisting of polyethylene glycol o-phenyl phenyl ether acrylate; urethane acrylate; acrylic oligomer; isobornyl acrylates; phenylthioethylacrylate; and ethoxlyated tribromo phenyl acrylate.

26. The composition of claim 5 , wherein the adhesive composition comprises 1 wt % to 30 wt % of the at least one sulfur component, wherein the at least one sulfur component is selected from the group consisting of 1,2-bis(2-mercapto ethylthio)-3-mercapto propane; trimethylolpropane tris(3-mercaptopropionate); 2-mercaptoethylthio-3-propanthiol sulfide; pentaerythritol tetrakis(2-mercaptopropoinate); and 2,2′-thiodiethanethiol.

27. A curable adhesive composition, comprising:

at least one high index-high viscosity component having a refractive index, before curing, of at least 1.56 at 25° C., and a viscosity, before curing, of at least 15,000 cP at 25° C.,

a photoinitiator, and

a bisphenol A component selected from the group consisting of diallylether bisphenol A; and ortho diallyl bisphenol A,

wherein the adhesive composition, after curing, has a refractive index of 1.60 to 1.74;

wherein the high index-high viscosity is selected from the group consisting of:

brominated aromatic urethane acrylate,

tribromophenyl acrylate; and

9,9-bis-{4-(2-acryloxyloxyethoxy)phenyl}fluorene.

28. The composition of claim 1 , wherein the adhesive composition comprises:

0.01 wt % to 5 wt % of the photoinitiator;

10 wt % to 60 wt % of the at least one high index-high viscosity component; and

1 wt % to 60 wt % of at least one acrylic component selected from the group consisting of 2(2-ethoxyethoxy)ethyl acrylate; 2-phenoxyethyl acrylate; ethoxylated (4) trimethylolpropane triacrylate; ethoxylated (6) trimethylolpropane triacrylate; alkoxylated phenol acrylate; 2 hydroxyethyl acrylate; polyethylene glycol o-phenyl phenyl ether acrylate; urethane acrylate; isobornyl acrylates; and alkoxylated nonylphenol acrylate.

29. The composition of claim 28 , wherein the adhesive composition comprises:

0.01 wt % to 5 wt % of the photoinitiator, wherein the photoinitiator is selected from the group consisting of bis(2,3,6-trimethlbenzoyl)-phenylphosphineoxide; 1-hydroxcyclohexylphenylketone; and 2-hydroxy-2-methyl-1-phenyl-propan-1-one; and

10 wt % to 60 wt % of the at least one high index-high viscosity component, wherein the at least one high index-high viscosity component is selected from the group consisting of brominated aromatic urethane acrylates; and

1 wt % to 60 wt % of the at least one acrylic component, wherein the at least one acrylic component is selected from the group consisting of 2(2-ethoxyethoxy)ethyl acrylate; 2-phenoxyethyl acrylate; ethoxylated (4) trimethylolpropane triacrylate; ethoxylated (6) trimethylolpropane triacrylate; alkoxylated phenol acrylate; and 2 hydroxyethyl acrylate.

30. The composition of claim 1 , further comprising a sulfur component selected from the group consisting of 2-mercaptoethylthio-3-propanthiol sulfide; 2,2′-thiodiethanethiol; and trimethyloltris(3-mercaptopropoinate)oethylthio-3 propanthiol sulfide.

31. The composition of claim 1 , further comprising an epoxy resin selected from the group consisting of epoxy acrylates.

32. The composition of claim 1 , further comprises a bisphenol A component selected from the group consisting of ethoxylated (10) bisphenol A diacrylate; ethoxylated (4) bisphenol A diacrylate; and ethoxylated (4) bisphenol A dimethacrylate.

33. The composition of claim 1 , further comprising triallyl isocyanurate.

34. A curable adhesive composition, comprising:

0.01 wt % to 5 wt % of at least one photoinitiator;

5 wt % to 80 wt % of at least one acrylic component selected from the group consisting of acrylic oligomer; ethoxylated (4) trimethylolpropane triacrylate; ethoxylated (6) trimethylolpropane triacrylate; glycidyl methacrylate; 1,6 hexanediol diacrylate; alkoxylated phenol acrylate; alkoxylated phenol diacrylate; 2 hydroxyethyl acrylate; alkoxylated nonylphenol acrylate; ethoxylated (10) bisphenol A diacrylate; 2-phenoxyethyl acrylate; isobornyl acrylates; tetrahydrofurfuryl acrylate; tetrahydrofurfuryl methacrylate; and

a sulfur component selected from the group consisting of trimethylolpropane tris(3-mercaptopropionate) and pentaerythritol tetrakis(2-mercaptopropoinate),

wherein the adhesive composition, after curing, has a refractive index of 1.49 to 1.55.

35. The composition of claim 34 , wherein the at least one acrylic component is selected from the group consisting of aliphatic urethane acrylate; ethoxylated (4) trimethylolpropane triacrylate; ethoxylated (6) trimethylolpropane triacrylate; glycidyl methacrylate; 1,6 hexanediol diacrylate; alkoxylated phenol acrylate; 2 hydroxyethyl acrylate; alkoxylated nonylphenol acrylate; and ethoxylated (10) bisphenol A diacrylate; aliphatic urethane acrylate; and polyethylene glycol (200) diacrylate.

36. The composition of claim 34 , further comprising 10 wt % to 50 wt % of at least one high index-high viscosity component selected from the group consisting of

brominated aromatic urethane acrylate;

tribromophenyl acrylate; and

9,9-bis{4-(2-cryloyloxyethoxy)phenyl}fluorene.