High performance photocurable optically clear adhesive

Patent metadata

Field	Value
Publication number	US-2020017720-A1
Application number	US-201816486993-A
Country	US
Kind code	A1
Filing date	Feb 28, 2018
Priority date	Mar 3, 2017
Publication date	Jan 16, 2020
Grant date	—

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

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 2000 g/mol or less, a poly(propylene oxide) diol having a number average molecular weight of about 2000 g/mol or less, and a polycaprolactone diol having a number average molecular weight of about 2000 g/mol or less.

3 . The optically clear, curable adhesive of claim 1 , wherein the diisocyanate is an aliphatic diisocyanate.

4 . (canceled)

5 . The optically clear, curable adhesive of claim 1 , further comprising a hydroxyfunctional monomer with an aromatic moiety.

6 . 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.

7 . 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.

8 . The optically clear, curable adhesive of claim 1 , wherein the polyvinylbutyral has a polyvinyl acetate weight percent of between about 1% and about 8%.

9 . The optically clear, curable adhesive of claim 1 , wherein the optically clear, curable adhesive comprises between about 30% and about 70% by weight polyvinylbutyral.

10 . 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.

11 . 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.

12 . The optically clear, curable adhesive of claim 1 , wherein the (meth)acrylate monomer comprises at least one of monofunctional or difunctional acrylates.

13 . 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.

14 . The optically clear laminate of claim 13 , wherein the diol is selected from one of a poly(tetramethylene oxide) diol having a number average molecular weight of about 2000 g/mol or less, a poly(propylene oxicde) diol having a number average molecular weight of about 2000 g/mol or less and a polycaprolactone diol having a number average molecular weight of about 2000 g/mol or less.

15 . The optically clear laminate of claim 13 , wherein the diisocyanate is an aliphatic diisocyanate.

16 . The optically clear laminate of claim 13 , wherein the polyvinylbutyral has a weight average molecular weight between about 10,000 g/mol and about 25,000 g/mol.

17 . The optically clear laminate of claim 13 , wherein the polyurethane (meth)acrylate has a weight average molecular weight between about 2,745 g/mol and about 63,000 g/mol.

18 . The optically clear laminate of claim 13 , wherein the polyvinylbutyral has a polyvinyl acetate weight percent of between about 1% and about 8%.

19 . The optically clear laminate of claim 13 , wherein the optically clear, curable adhesive comprises between about 30% and about 70% by weight polyvinylbutyral.

20 . The optically clear laminate of claim 13 , wherein the optically clear, curable adhesive comprises between about 10% and about 60% by weight polyurethane (meth)acrylate.

21 . The optically clear laminate of claim 13 , wherein the optically clear, curable adhesive comprises between about 10% and about 60% by weight (meth)acrylate monomer.

Assignees

• 3M Innovative Properties Co

Inventors

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

Classifications

• B32B2367/00

  Polyesters, e.g. PET, i.e. polyethylene terephthalate · CPC title

• C09J4/06 Primary

  {Organic non-macromolecular compounds having at least one polymerisable carbon-to-carbon unsaturated bond} in combination with a macromolecular compound other than an unsaturated polymer of groups C09J159/00 - C09J187/00 · CPC title

• B32B7/12

  using interposed adhesives or interposed materials with bonding properties · CPC title

• B32B2255/26

  Polymeric coating · CPC title

• B32B27/32

  comprising polyolefins {(comprising vinyl (co)polymers or acrylic (co)polymers B32B27/30)} · CPC title