Multicomponent, multilayer polymeric reflective bodies

• US 5,262,894 A
• Filed: 02/10/1992
• Issued: 11/16/1993
• Est. Priority Date: 06/20/1989
• Status: Expired due to Term

• Current Assignee: 3M Innovative Properties Company (3M Company)
• Original Assignee: The Dow Chemical Company (Dow, Inc.)
• Inventors: Wheatley, John A., Schrenk, Walter J.
• Primary Examiner(s): Arnold, Bruce Y.
• Assistant Examiner(s): Nguyen, Thong
• Application Number:
  US07/833,272
• Time in Patent Office: 645 Days
• Field of Search: 359/580-588, 359/883, 359/884, 359/554-556, 359/359, 359/491, 428/212, 428/213, 428/131, 428/156, 215/246, 206/807, 528/204
• US Class Current: 359/586
• CPC Class Codes: B32B 2307/416 Reflective
• CPC Class Codes: B32B 2551/00 Optical elements
• CPC Class Codes: B32B 27/08 of synthetic resin
• CPC Class Codes: B32B 27/302 comprising aromatic vinyl (co)polymers, e.g. styrenic (co)polymers
• CPC Class Codes: B32B 27/308 comprising acrylic (co)polymers
• CPC Class Codes: B32B 27/365 comprising polycarbonates
• CPC Class Codes: B32B 33/00 Layered products characterised by particular properties or particular surface features, e.g. particular surface coatings; Layered products designed for particular purposes not covered by another single class
• CPC Class Codes: B32B 7/023 Optical properties
• CPC Class Codes: G02B 1/04 made of organic materials, e.g. plastics G02B1/08 takes precedence
• CPC Class Codes: G02B 1/08 made of polarising materials
• CPC Class Codes: G02B 5/0841 comprising organic materials, e.g. polymers
• CPC Class Codes: G02B 5/0883 with a refractive index gradient rugate filters G02B5/289
• CPC Class Codes: G02B 5/26 Reflecting filters G02B5/28 takes precedence
• CPC Class Codes: G02B 5/305 including organic materials, e.g. polymeric layers
• CPC Class Codes: G02F 1/133545 Dielectric stack polarisers

Abstract

A multicomponent, multilayered, highly reflective polymeric body which is thermoformable and capable of being fabricated into films, sheets and a variety of parts while maintaining a uniform reflective appearance is provided. The reflective polymeric body includes at least first, second, and third diverse polymeric materials having a sufficient number of alternating layers of the polymeric materials such that a portion of the light incident on the body is reflected. A sufficient number of the individual layers of the body have optical thicknesses of not more than 0.09 micrometers or not less than 0.45 micrometers, such that there is an absence of visibly perceived color in the body. The polymeric materials having the highest and lowest refractive indices differ from each other in refractive index by at least about 0.03. The reflective body may be fabricated into mirrors, noncorroding metallic appearing articles and parts, reflectors, reflective lenses, and the like.

Claims

1. A reflective polymer body of at least first, second, and third diverse polymeric materials, the body comprising a sufficient number of alternating layers of said polymeric material such that a portion of the light incident on said body is reflected but such that essentially no visibly perceived iridescence is reflected, a sufficient number of the individual layers of said body (1) having an optical thickness of not more than 0.09 micrometers or not less than 0.45 micrometers, with at least one of said individual layers having an optical thickness of not more than 0.09 micrometers, or (2) having an optical thickness of not less than 045 micrometers, and wherein said polymeric materials having the highest and lowest refractive indices differ from each other by at least about 0.03.

2. The reflective polymeric body of claim 1 wherein said first polymeric material comprises polystyrene, said second polymeric material comprises a copolymer of styrene and methacrylic acid, and said third polymeric material comprises polymethyl methacrylate.

3. The reflective polymeric body of claim 1 in which said body comprises at least 500 layers.

4. The reflective polymeric body of claim 1 in which said polymeric body is thermoformable.

5. The reflective polymeric body of claim 1 including a coloring agent incorporated into at least one layer of said polymeric body.

6. The reflective polymeric body of claim 5 in which said coloring agent is selected from the group consisting of pigments and dyes.

7. The reflective polymeric body of claim 6 wherein said coloring agent is incorporated into at least one surface layer of said polymeric body.

8. The reflective polymeric body of claim 6 wherein said coloring agent is incorporated into at least one interior layer of said polymeric body.

9. The reflective polymeric body of claim 1 in which at least one surface layer has a brushed or roughened surface.

10. The reflective polymeric body of claim 1 in which at least one surface layer has been etched to provide a matte or pewter finish.

11. The reflective polymeric body of claim 1 in which at least one surface layer has been embossed.

12. The reflective polymeric body of claim 1 in which said body is extruded as a profile.

13. The reflective body of claim 1 in which said body is post formed into a profile.

14. The reflective polymeric body of claim 12 in which said body is in the form of a tube.

15. The reflective body of claim 1 in which said body is a blow-molded container.

16. The reflective polymeric body of claim 1 in which said first, second, and third polymeric materials are elastomers.

17. The reflective polymeric body of claim 1 in which said polymeric body is in the form of a sheet having two major surfaces.

18. The reflective polymeric body of claim 1 which includes a gas or moisture barrier layer as an exterior layer of said body.

19. The reflective polymeric body of claim 17 in which said body includes a permanent protective skin layer on at least one major surface thereof.

20. The reflective body of claim 1 in which said polymeric body includes first, second, and third diverse polymeric materials of alternating layers in a pattern ABCB.

21. The reflective polymeric body of claim 20 in which said first polymeric material is thiodiphenyl copolycarbonate, said second polymeric material is polycarbonate, and said third polymeric material is polymethyl methacrylate.

22. A mirror like polymeric article having at least first and second major surfaces, said article comprising a sufficient number of alternating layers of at least first, second, and third polymeric materials such that at least 30% of light incident on said article is reflected, but such that essentially no visibly perceived iridescence is reflected, a sufficient number of the individual layers of said mirror like article (1) having an optical thickness of not more than 0.09 micrometers or not less than 0.45 micrometers, with at least one of said individual layers having an optical thickness of not more than 0.09 micrometers, or (2) having an optical thickness of not less than 0.45 micrometers, and wherein said polymeric materials having the highest and lowest refractive indices differ from each other by at least about 0.03, and wherein a light absorbent layer in included as one of said major surfaces or as an interior layer.

23. A birefringent light polarizer which reflects light anisotropically, comprising multiple layers of at least first, second, and third diverse polymeric materials, a sufficient number of the individual layers of said polarizer having (1) an optical thickness of not more than 0.09 micrometers or not less than 0.45 micrometers, with at least one of said individual layers having an optical thickness of not more than 0.09 micrometers, or (2) having an optical thickness of not less than 0.45 micrometers, and wherein at least two of said polymeric materials differ from each other in refractive index by at least about 0.03 in one plane of the polarizer.

24. The birefringent light polarizer of claim 23 in which the difference in refractive index between said polymeric materials is caused by stretching said polymeric materials in a uniaxial direction to orient said polymeric materials.