Adhesive blends, articles, and methods

• US 7,927,703 B2
• Filed: 04/11/2003
• Issued: 04/19/2011
• Est. Priority Date: 04/11/2003
• Status: Expired due to Fees

• Current Assignee: 3M Innovative Properties Company (3M Company)
• Original Assignee: 3M Innovative Properties Company (3M Company)
• Inventors: Lu, Ying-Yuh, Zhou, Zhiming, Xia, Jianhui
• Primary Examiner(s): Seidleck; James
• Assistant Examiner(s): HAIDER, SAIRA BANO
• Application Number:
  US10/411,933
• Publication Number:
  US 20040202879A1
• Time in Patent Office: 2,930 Days
• Field of Search: 428/412, 428/514, 428/516, 428/500, 428/523, 428/515, 525/222, 525/55, 525/228, 156/331, 156/327, 156/332
• US Class Current: 428/412
• CPC Class Codes: B32B 2307/7246 Water vapor barrier
• CPC Class Codes: B32B 2551/00 Optical elements
• CPC Class Codes: B32B 27/08 of synthetic resin
• CPC Class Codes: B32B 27/308 comprising acrylic (co)polymers
• CPC Class Codes: B32B 27/365 comprising polycarbonates
• CPC Class Codes: B32B 7/12 using interposed adhesives or interposed materials with bonding properties
• CPC Class Codes: C08L 2666/04 Macromolecular compounds according to groups C08L7/00 - C08L49/00, or C08L55/00 - C08L57/00; Derivatives thereof
• CPC Class Codes: C09J 133/00 Adhesives based on homopolymers or copolymers of compounds having one or more unsaturated aliphatic radicals, each having only one carbon-to-carbon double bond, and at least one being terminated by only one carboxyl radical, or of salts, anhydrides, esters, amides, imides, or nitriles thereof; Adhesives based on derivatives of such polymers
• CPC Class Codes: C09J 133/06 of esters containing only carbon, hydrogen and oxygen, the oxygen atom being present only as part of the carboxyl radical
• CPC Class Codes: C09J 201/02 characterised by the presence of specified groups , e.g. terminal or pendant functional groups
• CPC Class Codes: C09J 2433/00 Presence of (meth)acrylic polymer
• CPC Class Codes: C09J 7/10 without carriers
• CPC Class Codes: C09J 7/35 Heat-activated
• CPC Class Codes: Y10T 428/2804 Next to metal
• CPC Class Codes: Y10T 428/2848 Three or more layers
• CPC Class Codes: Y10T 428/2891 including addition polymer from alpha-beta unsaturated carboxylic acid [e.g., acrylic acid, methacrylic acid, etc.] Or derivative thereof
• CPC Class Codes: Y10T 428/31507 Of polycarbonate
• CPC Class Codes: Y10T 428/31855 Of addition polymer from unsaturated monomers
• CPC Class Codes: Y10T 428/31909 Next to second addition polymer from unsaturated monomers
• CPC Class Codes: Y10T 428/31938 Polymer of monoethylenically unsaturated hydrocarbon

Abstract

Described are adhesive compositions containing a mixture of a pressure sensitive adhesive, a high Tg polymer, and a crosslinker to form a compatibilized blend that is optically clear. Methods of using the adhesive compositions, and multilayer assemblies such as optical elements prepared using the adhesives, are also provided.

Claims

1. An adhesive composition comprising a blend of:

a majority of a pressure sensitive adhesive component comprising at least one polymer with an acid functionality, wherein the pressure sensitive adhesive is formed from alkyl (meth)acrylate monomers having an alkyl group comprising from 4 to 12 carbon atoms,

a high Tg polymer with a glass transition temperature greater than 20°

C. and a weight average molecular weight greater than 100,000 wherein the high Tg polymer is a basic copolymer, and wherein the high Tg polymer comprises a copolymer formed from methyl methacrylate, butyl methacrylate, and dimethylamino ethylmethacrylate; and

a crosslinker;

wherein the functionality of the pressure sensitive adhesive component and the functionality of the high Tg polymer form an acid-base interaction when mixed, and after aging at 80°

C. and 90% relative humidity for 500 hours, the composition is optically clear on visual observation so that the composition exhibits a luminous transmission of at least about 90% and a haze of less than about 2% when measured according to ASTM-D 1003-95.

2. The adhesive composition of claim 1, wherein the high Tg polymer has a glass transition temperature greater than 50°

C.

3. The adhesive composition of claim 2 wherein the pressure sensitive adhesive component is present in an amount ranging from about 70 to 90 percent by weight, and the high Tg polymer is present in an amount ranging from about 10 to 30 percent by weight based on a total weight of the pressure sensitive adhesive component and the high Tg polymer.

4. The adhesive composition of claim 3 comprising an activatable crosslinker, said activatable crosslinker being capable of being activated by heat or light and being selected from the group consisting of multifunctional aziridine, benzophenones, triazines, monoethylenically unsaturated mono-, di-, and trialkoxy silane compounds, diacrylates, triacrylates, and tetraacrylates, isocyanates, epoxies, and mixtures thereof.

5. The adhesive composition of claim 4 comprising a multifunctional aziridine crosslinker.

6. The adhesive composition of claim 5 wherein the multifunctional aziridine crosslinker comprises 1,1′

-(1,3-phenylene dicarboxyl)-bis-(2-methylaziridine).

7. The adhesive composition of claim 6 wherein the pressure sensitive adhesive component comprises a copolymer with an weight average molecular weight less than 800,000.

8. The adhesive composition of claim 1 wherein the adhesive composition is a pressure sensitive adhesive.

9. An article comprising the adhesive composition of claim 1 coated on at least one surface of a substrate.

10. The article of claim 9 wherein the substrate is selected from the group consisting of a release liner, a film, and a rigid material.

11. A multi-layer assembly comprising the adhesive composition of claim 1;

wherein the adhesive composition is optically clear, and wherein the adhesive composition bonds at least two layers together comprising a low moisture vapor transfer layer and an outgassing layer, said outgassing layer comprising a material selected from the group consisting of a polycarbonate and a poly(methyl methacrylate), and said low moisture vapor transfer layer being selected from the group consisting of a metallized polymeric film, an infrared reflecting film, a multilayer optical film, and a polymeric film layer coated with a conductive layer, and

wherein after aging at 80°

C. and 90% relative humidity for 500 hours, the bond between the outgassing layer and the low moisture vapor transfer layer does not delaminate or bubble, and the composition remains optically clear so that the composition exhibits a luminous transmission of at least about 90% and a haze of less than about 2% when measured according to ASTM-D 1003-95.

12. The multilayer assembly of claim 11 wherein the assembly comprises a conductive optical element comprising a rigid polycarbonate layer adhered with the adhesive to a surface of a polymeric film layer, an opposite surface of the polymeric film layer being coated with a conductive layer.

13. The multi-layer assembly of claim 11 comprising an activatable crosslinker, said activatable crosslinker being capable of being activated by heat or light and being selected from the group consisting of multifunctional aziridine, benzophenones, triazines, monoethylenically unsaturated mono-, di-, and trialkoxy silane compounds, diacrylates, triacrylates, and tetraacrylates, isocyanates, epoxies, and mixtures thereof.

14. The adhesive composition of claim 1 wherein the pressure sensitive adhesive component is present in an amount ranging from about 70 to 90 percent by weight, and the high Tg polymer is present in an amount ranging from about 10 to 30 percent by weight based on a total weight of the pressure sensitive adhesive component and the high Tg polymer.

15. The adhesive composition of claim 14 wherein the pressure sensitive adhesive component is formed from (i) isooctyl acrylate monomer and acrylic acid monomer.

16. The adhesive composition of claim 15 wherein the crosslinker comprises 1,1′

-(1,3-phenylene dicarboxyl)-bis-(2-methylaziridine).

17. The adhesive composition of claim 14 wherein the pressure sensitive adhesive component comprises a copolymer with an weight average molecular weight less than 800,000.

18. The adhesive composition of claim 17 wherein the pressure sensitive adhesive component comprises a copolymer with an weight average molecular weight less than 600,000.