Multilayer light-reflecting film

• US RE31,780 E
• Filed: 08/08/1983
• Issued: 12/25/1984
• Est. Priority Date: 12/26/1979
• Status: Expired due to Term

• Current Assignee: Mearl Corporation
• Original Assignee: Mearl Corporation
• Inventors: Cooper, Scott A., Shetty, Ramakrishna, Pinsky, Jules
• Primary Examiner(s): HERBERT JR, THOMAS
• Application Number:
  US06/521,127
• Time in Patent Office: 505 Days
• Field of Search: 428/212, 428/213, 428/392, 428/480, 428/483, 264/171, 264/173, 350/166
• US Class Current: 428/212
• CPC Class Codes: B32B 7/02 Physical, chemical or physicochemical properties
• CPC Class Codes: G02B 5/287 comprising at least one layer of organic material
• CPC Class Codes: Y10T 428/24942 including components having same physical characteristic in differing degree
• CPC Class Codes: Y10T 428/2495 Thickness [relative or absolute]
• CPC Class Codes: Y10T 428/31786 Of polyester [e.g., alkyd, etc.]
• CPC Class Codes: Y10T 428/31797 Next to addition polymer from unsaturated monomers

Abstract

Improvements in multilayer light-reflecting film are effected by the use of thermoplastic polyester as the high refractive index component of a system in which two or more resinous materials form a plurality of layers.

Claims

1. A transparent thermoplastic resinous laminate film of at least 10 very thin layers of substantially uniform thickness, said layers being generally parallel, the contiguous adjacent layers being of different transparent thermoplastic resinous materials one of which is a .Iadd.terephthalate .Iaddend.thermoplastic polyester or copolyester resin having a refractive index of 1.55-1.61 and the adjacent resinous material having a refractive index which is lower by at least about 0.03, the contiguous adjacent layers differing in refractive index by at least about 0.03.

2. The transparent thermoplastic resinous laminate film of claim 1, wherein said polyester or copolyester is selected from the group consisting of poly(ethylene terephthalate), and a copolyester of cyclohexanedimethanol and an acid comprising terephthalate acid.

3. The transparent thermoplastic resinous laminate film of claim 1 having at least 35 layers.

4. The transparent thermoplastic resinous laminate film of claim 3 having at least about 70 layers.

5. The transparent thermoplastic resinous laminate film of claim 4 wherein said adjacent resinous material has a refractive index which is lower by at least about 0.06.

6. The transparent thermoplastic resinous laminate film of claim 1, wherein said polyester is polybutylene terephthalate.

7. The transparent thermoplastic resinous laminate film of claim 6, wherein said other resinous material is polymethyl methacrylate.

8. The transparent thermoplastic resinous laminate film of claim 1 wherein the outermost layers of said film comprise an impact modified acrylic resin and the thickness of each of the outermost layers is at least 5% of the total thickness of the film.

9. The transparent thermoplastic resinous laminate film of claim 8 wherein said impact modified acrylic resin is a terpolymer of methyl methacrylate, butadiene and acrylonitrile, or methyl methacrylate combined with an elastomer.

10. The transparent thermoplastic resinous laminate film of claim 9 wherein said polyester or copolyester resin is polybutylene terephthlate and adjacent other resin is polymethyl methacrylate.

11. The transparent thermoplastic resinous laminate film of claim 10 of at least 70 substantially uniformly thick layers.