High performance photocurable optically clear adhesive

Patent metadata

Field	Value
Publication number	US-11511522-B2
Application number	US-201816486993-A
Country	US
Kind code	B2
Filing date	Feb 28, 2018
Priority date	Mar 3, 2017
Publication date	Nov 29, 2022
Grant date	Nov 29, 2022

Abstract

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.

First claim

What is claimed is:

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.

Assignees

• 3M Innovative Properties Company

Inventors

• Liu Lan Hong
• Xia Jianhui
• Klun Thomas P
• Kowitz David A
• Sherman Audrey A

Classifications

• B32B2457/20

  Displays, e.g. liquid crystal displays, plasma displays · CPC title

• B32B17/10 Primary

  of synthetic resin · CPC title

• C09J9/00

  Adhesives characterised by their physical nature or the effects produced, e.g. glue sticks (C09J7/00 takes precedence) · CPC title

• G02B1/04

  made of organic materials, e.g. plastics (G02B1/08 takes precedence) · CPC title

• B29C69/00

  Combinations of shaping techniques not provided for in a single one of main groups B29C39/00 - B29C67/00, e.g. associations of moulding and joining techniques; Apparatus therefore {(B29C48/001 takes precedence)} · CPC title