High performance photocurable optically clear adhesive
The present invention is an optically clear, curable adhesive including a polyvinylbutyral, a polyurethane (meth)acrylate, a (meth)acrylate monomer, and a photoinitiator. The polyvinylbutyral has a dynamic viscosity of between about 9 and about 13 mPa·s and a polyvinyl alcohol weight percent of less than about 18%. The polyurethane (meth)acrylate includes the reaction product of a diol, at least one diisocyanate, and a hydroxyfunctional (meth)acrylate or an isocyanatofunctional (meth)acrylate. When the optically clear, curable adhesive is placed between two transparent substrates and made into a laminate, the laminate has a haze of less than about 6%, a transmission of greater than about 88%, and an optical clarity of greater than about 98% when cured. The optically clear, curable adhesive also has a peel adhesion of at least about 100 g/cm based on ASTM 3330 when cured.
1. An optically clear, curable adhesive comprising:
a polyvinylbutyral having a dynamic viscosity of between about 9 and about 30 mPa·s and having a polyvinyl alcohol weight percent of between about 14% and about 21%;
a polyurethane (meth)acrylate comprising the reaction product of:
a diol;
at least one diisocyanate; and
a hydroxyfunctional (meth)acrylate or an isocyanatofunctional (meth)acrylate;
a (meth)acrylate monomer; and
a photoinitiator;
wherein when the optically clear, curable adhesive is placed between two transparent substrates and made into a laminate, the laminate has a haze of less than about 6%, a transmission of greater than about 88% and optical clarity of greater than about 98% when cured, and
wherein the optically clear, curable adhesive has a peel adhesion of at least about 100 g/cm based on ASTM 3330 when cured.
2. The optically clear, curable adhesive of claim 1 , wherein the diol is selected from one of a poly(tetramethylene oxide) diol having a number average molecular weight of about 2,000 g/mol or less, a poly(propylene oxide) diol having a number average molecular weight of about 2,000 g/mol or less, and a polycaprolactone diol having a number average molecular weight of about 2,000 g/mol or less.
3. The optically clear, curable adhesive of claim 1 , wherein the at least one diisocyanate is an aliphatic diisocyanate.
4. The optically clear, curable adhesive of claim 1 , further comprising a hydroxyfunctional monomer with an aromatic moiety.
5. The optically clear, curable adhesive of claim 1 , wherein the polyvinylbutyral has a weight average molecular weight between about 10,000 g/mol and about 25,000 g/mol.
6. The optically clear, curable adhesive of claim 1 , wherein the polyurethane (meth)acrylate has a weight average molecular weight between about 2,745 g/mol and about 63,000 g/mol.
7. The optically clear, curable adhesive of claim 1 , wherein the polyvinylbutyral has a polyvinyl acetate weight percent of between about 1% and about 8%.
8. The optically clear, curable adhesive of claim 1 , wherein the optically clear, curable adhesive comprises between about 30% and about 70% by weight polyvinylbutyral.
9. The optically clear, curable adhesive of claim 1 , wherein the optically clear, curable adhesive comprises between about 10% and about 60% by weight polyurethane (meth)acrylate.
10. The optically clear, curable adhesive of claim 1 , wherein the optically clear, curable adhesive comprises between about 10% and about 60% by weight (meth)acrylate monomer.
11. The optically clear, curable adhesive of claim 1 , wherein the (meth)acrylate monomer comprises at least one of monofunctional or difunctional acrylates.
12. An optically clear laminate comprising:
a first substrate;
a second substrate; and
an optically clear, curable adhesive positioned between the first substrate and the second substrate, the optically clear, curable adhesive comprising:
a polyvinylbutyral having a dynamic viscosity of between about 9 and about 30 mPa·s and having a polyvinyl alcohol weight percent of between about 14% and about 21%;
a polyurethane (meth)acrylate comprising the reaction product of:
a diol;
at least one diisocyanate; and
a hydroxyfunctional (meth)acrylate or an isocyanatofunctional (meth)acrylate;
a (meth)acrylate monomer; and
a photoinitiator;
wherein when the optically clear, curable adhesive is placed between two transparent substrates and made into a laminate, the laminate has a haze of less than about 6%, a transmission of greater than about 88% and optical clarity of greater than about 98% when cured, and
wherein the optically clear, curable adhesive has a peel adhesion of at least about 100 g/cm based on ASTM 3330 when cured.
13. The optically clear laminate of claim 12 , wherein the diol is selected from one of a poly(tetramethylene oxide) diol having a number average molecular weight of about 2,000 g/mol or less, a poly(propylene oxicde) diol having a number average molecular weight of about 2,000 g/mol or less and a polycaprolactone diol having a number average molecular weight of about 2,000 g/mol or less.
14. The optically clear laminate of claim 12 , wherein the at least one diisocyanate is an aliphatic diisocyanate.
15. The optically clear laminate of claim 12 , wherein the polyvinylbutyral has a weight average molecular weight between about 10,000 g/mol and about 25,000 g/mol.
16. The optically clear laminate of claim 12 , wherein the polyurethane (meth)acrylate has a weight average molecular weight between about 2,745 g/mol and about 63,000 g/mol.
17. The optically clear laminate of claim 12 , wherein the polyvinylbutyral has a polyvinyl acetate weight percent of between about 1% and about 8%.
18. The optically clear laminate of claim 12 , wherein the optically clear, curable adhesive comprises between about 30% and about 70% by weight polyvinylbutyral.
19. The optically clear laminate of claim 12 , wherein the optically clear, curable adhesive comprises between about 10% and about 60% by weight polyurethane (meth)acrylate.
20. The optically clear laminate of claim 12 , wherein the optically clear, curable adhesive comprises between about 10% and about 60% by weight (meth)acrylate monomer.