Polymeric reflective materials utilizing a back light source

• US 5,353,154 A
• Filed: 11/02/1992
• Issued: 10/04/1994
• Est. Priority Date: 11/02/1992
• 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., Lutz, William G., Motter, Gregg A.
• Primary Examiner(s): NOT, DEFINED
• Application Number:
  US07/969,907
• Time in Patent Office: 701 Days
• Field of Search: 359/580, 359/581, 359/582, 359/584, 359/586, 359/588, 428/212, 428/213, 264/171, 385/131
• US Class Current: 359/582
• CPC Class Codes: B29C 43/00 Compression moulding, i.e. applying external pressure to flow the moulding material; Apparatus therefor by liberation of internal stresses B29C61/006
• CPC Class Codes: B29C 51/08 Deep drawing or matched-mould forming, i.e. using mechanical means only
• CPC Class Codes: B29C 51/14 using multilayered preforms or sheets
• CPC Class Codes: B29K 2033/12 Polymers of methacrylic acid esters, e.g. PMMA, i.e. polymethylmethacrylate
• CPC Class Codes: B29K 2075/00 Use of PU, i.e. polyureas or polyurethanes or derivatives thereof, as moulding material
• CPC Class Codes: B29K 2995/002 Coloured
• CPC Class Codes: B29K 2995/0026 Transparent
• CPC Class Codes: B29K 2995/003 Reflective
• CPC Class Codes: B29K 2995/0031 Refractive
• CPC Class Codes: B29L 2031/747 Lightning equipment
• CPC Class Codes: F21S 41/28 Cover glass
• CPC Class Codes: F21S 43/20 characterised by refractors, transparent cover plates, light guides or filters
• CPC Class Codes: F21S 43/33 characterised by their material, surface treatment or coatings
• CPC Class Codes: F25D 23/02 Doors; Covers F25D23/08 takes precedence locks or fastenings E05B65/0042
• CPC Class Codes: G02B 1/10 Optical coatings produced by application to, or surface treatment of, optical elements G02B1/08 takes precedence
• CPC Class Codes: G02B 5/287 comprising at least one layer of organic material
• CPC Class Codes: Y10T 428/2495 Thickness [relative or absolute]

Abstract

A multilayered reflective body which is thermoformable and capable of being fabricated into a number of parts while maintaining a uniform reflective appearance is provided. The reflective polymeric body is formed from at least two diverse polymeric materials which differ in refractive index and which are arranged in substantially parallel alternating layers. The polymeric body is reflective in appearance yet is transparent or, colored if a coloring agent is included, upon illumination from a back light source. The polymeric body has application in variety of areas such as in an automobile lighting lens which is reflective and thereby indiscernible yet transmissive upon exposure to a back light source. Additionally, various parts of consumer appliances, for example a refrigerator door, can be formed from the polymeric body.

Claims

1. A multilayer reflective polymeric body of at least first and second diverse polymeric materials arranged in substantially parallel alternating layers, said body having first and second major surfaces, wherein said first and second polymeric materials differ from each other in refractive index by at least 0.03, said body including a sufficient number of layers such that said body reflects at least 40% of light impinging on said first major surface thereof such that when said body is viewed in reflection it displays a substantially uniform reflective appearance, said body transmitting at least 5% of light directed through said body from said second major surface, said reflective polymeric body further including a coloring agent incorporated in or present on at least one of said first and second major surfaces such that when said body is illuminated, said body exhibits the color of said coloring agent, and wherein at least one of said first and second major surfaces has indicia printed thereon, which indicia is concealed from view on said reflective body when viewed in reflection, but which is displayed when said body is illuminated.

2. A multilayer reflective polymeric body of at lest first and second diverse polymeric materials arranged in substantially parallel alternating layers wherein said first and second polymeric materials differ from each other in refractive index by at least 0.03, said body having first and second major surfaces, means for projecting an image onto said first major surface of said body, and means for directing light through said body from said second major surface, said body including a sufficient number of layers such that said body reflects at least 40% of light impinging on said first major surface thereof while transmitting at least 5% of light directed through said body from said second major surface so as to illuminate said image on said first major surface.

3. In a combination, a multilayer reflective polymeric body of at least first and second diverse polymeric materials arranged in substantially parallel alternating layers which define at least one edge of said body, and means for illuminating said edge of said body, said body further having first and second major surfaces substantially parallel to said layers, said body including a coloring agent incorporated in or present on at least one of said layers, wherein said first and second polymeric materials differ from each other in refractive index by at least 0.03, said body including a sufficient number of layers such that said body reflects at least 40% of light impinging on said first major surface thereof while transmitting at least 5% of light directed through said edge of said body, at least one of said first and second major surfaces includes irregularities thereon such that when said edge is illuminated, said body exhibits the color of said coloring agent.