Flame retardant ultraviolet cured multi-layered film

• US 5,855,983 A
• Filed: 02/03/1995
• Issued: 01/05/1999
• Est. Priority Date: 02/03/1995
• Status: Expired due to Term

• Current Assignee: Minnesota Mining and Manufacturing Co (3M Company)
• Original Assignee: Minnesota Mining and Manufacturing Co (3M Company)
• Inventors: Williams, Todd R.
• Primary Examiner(s): LE, HOA T
• Application Number:
  US08/383,064
• Time in Patent Office: 1,432 Days
• Field of Search: 428/215, 428/412, 428/172, 428/520, 428/483, 428/920, 524/127, 524/143
• US Class Current: 428/172
• CPC Class Codes: B32B 2307/3065 Flame resistant or retardant, fire resistant or retardant
• CPC Class Codes: B32B 2363/00 Epoxy resins
• CPC Class Codes: B32B 2367/00 Polyesters, e.g. PET, i.e. polyethylene terephthalate
• CPC Class Codes: B32B 2369/00 Polycarbonates
• CPC Class Codes: B32B 2457/202 LCD, i.e. liquid crystal displays
• CPC Class Codes: B32B 27/08 of synthetic resin
• CPC Class Codes: B32B 27/18 characterised by the use of special additives
• CPC Class Codes: B32B 27/365 comprising polycarbonates
• CPC Class Codes: B32B 27/38 comprising epoxy resins
• CPC Class Codes: C09K 21/14 Macromolecular materials
• CPC Class Codes: G02B 5/045 Prism arrays
• CPC Class Codes: G02B 6/0053 Prismatic sheet or layer; Brightness enhancement element, sheet or layer
• CPC Class Codes: G02B 6/0065 Manufacturing aspects; Material aspects
• CPC Class Codes: G02F 1/133607 the light controlling member including light directing or refracting elements, e.g. prisms or lenses
• CPC Class Codes: Y10S 428/92 Fire or heat protection feature
• CPC Class Codes: Y10T 428/24612 Composite web or sheet
• CPC Class Codes: Y10T 428/24967 Absolute thicknesses specified
• CPC Class Codes: Y10T 428/31507 Of polycarbonate
• CPC Class Codes: Y10T 428/31797 Next to addition polymer from unsaturated monomers
• CPC Class Codes: Y10T 428/31928 Ester, halide or nitrile of addition polymer

Abstract

A flame resistant composite film includes a first layer and a second layer that are joined together. The first layer has a light transmission of at least 93 percent and is substantially constructed from a radiation-cured polymer and a flame retardant material. The second layer is constructed primarily from thermoplastic polymer resin. The first and second layer when taken as a whole have a flame retardancy sufficient to pass VTM-2 standard of Oct. 27, 1988, of Underwriters'"'"' Laboratories, Inc. Also, microstructured films comprising such flame retardant films, backlit displays comprising such microstructured films, and computers comprising such displays.

Claims

1. A flame resistant multi-layered film comprising:

a first layer and a second layer joined together,

the first layer being substantially composed of a polymerized (meth)acrylic-functional oligomeric composition and a flame retardant chemical and having a light transmission rate of at least 93 percent, and

the second layer substantially composed of thermoplastic polymer,

wherein the first and second layers have a combined flame retardancy sufficient to pass VTM-2 standard of Oct. 27, 1988, of Underwriters'"'"' Laboratories, Inc.

2. The film of claim 1 wherein the first layer is thinner than the second layer.

3. The film of claim 2 wherein said second layer is between 0.025 and 0.5 millmeter thick.

4. The film of claim 2 wherein the thickness of said first layer is not greater than 20 percent of the thickness of said second layer.

5. The film of claim 1 wherein the flame retardant chemical is a non-acrylate.

6. The film of claim 5 wherein the non-acrylate flame retardant chemical used in the first layer is cyclic phosphonate ester, halogenated phosphate ester, or combinations thereof.

7. The film of claim 6 wherein said first layer is the polymerized product of an oligomeric composition comprising less than 30 weight percent of said flame retardant chemical.

8. The film of claim 6 wherein said first layer is the polymerized product of an oligomeric composition comprising less than 10 weight percent of said flame retardant chemical.

9. The film of claim 1 wherein the polymerized oligomeric composition contains at least approximately 10 percent of a bromine substituted component.

10. The film of claim 1 wherein the polymerized oligomeric composition used in the first layer comprises at least one of the following:

bisphenol-A epoxy diacrylate, brominated bisphenol-A epoxy diacrylate, phenoxyethyl acrylate, tribromophenoxyethyl acrylate, tetrabromobisphenol-A diacrylate, benzyl acrylate, tetrabromobisphenol-A ethoxylated diacrylate, or combinations thereof.

11. The film of claim 1 wherein the second layer is formed from polyethylene-terephthalate or polycarbonate.

12. The film of claim 1 wherein said first layer further comprises a cross-linking agent.

13. The film of claim 8 wherein the cross-linking agent comprises at least one of the following:

1,4-butylene di-methacrylate or -acrylate;

ethylene di-methacrylate or -acrylate;

trimethylolpropane di- or tri-acrylate;

glyceryl di-acrylate or -methacrylate;

glyceryl tri-acrylate or -methacrylate;

glycidyl acrylate or methacrylate;

pentaerythritol triacrylate or trimethacrylate;

diallyl phthalate;

2,2-bis(4-methacryloxyphenyl)-propane;

diallyl adipate;

di(2-acryloxyethyl) ether;

dipentaerythritol pentacrylate;

neopentyl glycol diacrylate or dimethacrylate;

polypropylene glycol diacrylate or dimethacrylate;

1,3,5-tri-(2-(meth)acryloxyethyl)-s-triazine;

hexamethylene diacrylate or dimethacrylate;

poly(ethylenically unsaturated alkoxy) heterocycles;

adducts of poly(isocyanates) with hydroxy- and amino- functional acrylates, or combinations thereof.

14. The film of claim 1 wherein the second layer has a sputter etched surface adjacent to the first layer.

15. The film of claim 1 wherein a surface of the first layer has microstructures formed therein.

16. The film of claim 1 further comprising a photoinitiator.

17. The film of claim 1 wherein said flame retardant material is not chemically bound to said polymerized oligomeric composition.

18. A flame resistant brightness enhancement film for use in a liquid crystal display comprising:

a first layer being substantially constructed from a polymerized (meth)acrylic-functional oligomeric composition and a flame retardant material, the first layer having a light transmission rate of at least 93 percent, and

a second layer substantially composed of thermoplastic polymer resin,

the first and second layer being joined together and having a combined flame retardancy sufficient to pass VTM-2 standard of Oct. 27, 1988, of Underwriters'"'"' Laboratories, Inc.

19. The brightness enhancement film of claim 18 wherein the flame retardant material is a non-acrylate.

20. The brightness enhancement film of claim 19 wherein the non-acrylate flame retardant material used in the first layer is cyclic phosphonate ester, halogenated phosphate ester, or combinations thereof.

21. The brightness enhancement film of claim 20 wherein said first layer is the polymerized product of an oligomeric composition comprising less than 30 weight percent of said flame retardant chemical.

22. The brightness enhancement film of claim 20 wherein said first layer is the polymerized product of an oligomeric composition comprising less than 10 weight percent of said flame retardant chemical.

23. The brightness enhancement film of claim 18 wherein the second layer is thicker than the first layer.

24. The film of claim 23 wherein said second layer is between 0.025 and 0.5 millmeter thick.

25. The film of claim 23 wherein the thickness of said first layer is not greater than 20 percent of the thickness of said second layer.

26. The brightness enhancement film of claim 18 wherein the polymerized oligomeric composition used in the first layer comprises at least one of the following:

bisphenol-A epoxy diacrylate, brominated bisphenol-A epoxy diacrylate, phenoxyethyl acrylate, tribromophenoxyethyl acrylate, tetrabromobisphenol-A diacrylate, benzyl acrylate, tetrabromobisphenol-A ethoxylated diacrylate, or combinations thereof.

27. The brightness enhancement film of claim 18 wherein the second layer is formed from polyethylene terephthalate or polycarbonate.

28. The brightness enhancement film of claim 18 wherein said first layer further comprises a cross-linking agent.

29. The brightness enhancement film of claim 28 wherein the cross-linking agent comprises at least one of the following:

1,4-butylene di-methacrylate or -acrylate;

ethylene di-methacrylate or -acrylate;

trimethylolpropane di- or tri-acrylate;

glyceryl di-acrylate or -methacrylate;

glyceryl triacrylate or methacrylate;

glycidyl acrylate or methacrylate;

pentaerythritol triacrylate or trimethacrylate;

diallyl phthalate;

2,2-bis(4-methacryloxyphenyl)-propane;

diallyl adipate;

di(2-acryloxyethyl) ether;

dipentaerythritol pentacrylate;

neopentyl glycol diacrylate or dimethacrylate;

polypropylene glycol diacrylate or dimethacrylate;

1,3,5-tri-(2-(meth)acryloxyethyl)-s-triazine;

hexamethylene diacrylate or dimethacrylate;

poly(ethylenically unsaturated alkoxy) heterocycles;

adducts of poly(isocyanates) with hydroxy- and amino- functional acrylates, or combinations thereof.

30. The film of claim 18 wherein the second layer has a sputter etched surface adjacent to the first layer.

31. The film of claim 18 further comprising a photoinitiator.

32. The brightness enhancement film of claim 18 wherein said flame retardant material is not chemically bound to said polymerized oligomeric composition.