Multilayer infrared reflecting film with high and smooth transmission in visible wavelength region and laminate articles made therefrom

• US 20050207002A1
• Filed: 05/20/2005
• Published: 09/22/2005
• Est. Priority Date: 01/15/2001
• Status: Active Grant

• Current Assignee: 3M Innovative Properties Company (3M Company)
• Original Assignee: 3M Innovative Properties Company (3M Company)
• Inventors: Liu, Yaoqi J., Ruff, Andrew T., Sievers, Jerry A.
• Granted Patent: US 7,236,296 B2
• Time in Patent Office: Days
• US Class Current: 359/359
• CPC Class Codes: B32B 17/10005 laminated safety glass or glazing
• CPC Class Codes: B32B 17/10761 containing vinyl acetal
• CPC Class Codes: B32B 17/10807 Making laminated safety glass or glazing; Apparatus therefor
• CPC Class Codes: B32B 17/10862 using pressing-rolls
• CPC Class Codes: B32B 2367/00 Polyesters, e.g. PET, i.e. polyethylene terephthalate
• CPC Class Codes: G02B 5/0841 comprising organic materials, e.g. polymers
• CPC Class Codes: G02B 5/282 reflecting for infrared and transparent for visible light, e.g. heat reflectors, laser protection

Abstract

A multilayer film article is disclosed. The film includes an infrared light reflecting multilayer film having alternating layers of a first polymer type and a second polymer type and an infrared light absorbing or reflecting layer adjacent the multilayer film. The film includes a multilayer stack composed of alternating optical layers of first and second diverse polymers A, B. The optical layers when counted from one end of a first effective optical packet form a plurality of unit cells each having six optical layers arranged in relative optical thicknesses in a first cyclic permutation of 7A1B1A7B1A1B. At normal incidence the first effective optical packet provides a reflection band at infrared wavelengths and substantially transmits light at visible wavelengths.

Claims

1. A multilayer film article comprising:

an infrared light reflecting multilayer film having alternating layers of a first polymer type and a second polymer type; and

an infrared light absorbing or reflecting layer adjacent the multilayer film.

2. A multilayer film article according to claim 1 wherein the infrared light absorbing layer comprises an infrared light absorbing pigment or dye.

3. A multilayer film article according to claim 1 wherein the infrared light reflecting layer comprises a metal.

4. A multilayer film article according to claim 1 wherein the infrared light reflecting layer comprises silver.

5. A multilayer film article according to claim 1 wherein the infrared light reflecting layer comprises a metal layer and an infrared light absorbing pigment or dye.

6. A multilayer film article according to claim 1 wherein the first polymer type comprises polyethylene terephthalate and the second polymer type comprises poly(methyl methacrylate) or a copolymer of poly(methyl methacrylate).

7. An optical body comprising at least a first effective optical packet of contiguous optical layers bounded by optically thick layers, the optical layers composed of alternating diverse materials A,B and an infrared light absorbing or reflecting layer is disposed an optically layer;

wherein the optical layers when counted from one end of the first effective optical packet form a plurality of unit cells each having six optical layers arranged in relative optical thicknesses in a first cyclic permutation of 7A1B1A7B1A1B; and

wherein at normal incidence the first effective optical packet provides a reflection band at infrared wavelengths and substantially transmits light at visible wavelengths.

8. An optical body according to claim 7 wherein the materials A,B have refractive indices that satisfy a relationship n_A>

n_B along at least one in-plane axis.

9. An optical body according to claim 7 wherein the optical body exhibits a variability in transmission over a visible wavelength range and a first optical layer disposed at the one end of the first effective optical packet and a second optical layer disposed at an opposite end of the first effective optical packet are selected from among the sequence of six optical layers 7A1B1A7B1A1B to reduce the variability in transmission.

10. An optical body according to claim 7 wherein the infrared light absorbing layer comprises an infrared light absorbing pigment or dye.

11. An optical body according to claim 7 wherein the infrared light reflecting layer comprises a metal.

12. An optical body according to claim 7 wherein the infrared light reflecting layer comprises silver.

13. An optical body according to claim 7 wherein the material A comprises polyethylene terephthalate and the material B comprises poly(methyl methacrylate) or a copolymer of poly(methyl methacrylate).

14. The optical body according to claim 7 wherein the optical body further comprises a first layer of glazing material.

15. The optical body of claim 7 wherein the optical body reflects at least 50% of light in a band at least 100 nm wide positioned between wavelengths from about 700 nm to about 2000 nm.

16. A film comprising an optical stack, the optical stack comprising an infrared light absorbing or reflecting layer disposed on at least one effective optical packet having a contiguous arrangement of unit cells of like design, the at least one effective optical packet including a first effective optical packet in which each unit cell has more than two optical layers of at least a first and second diverse material, such optical layers being arranged to exhibit within the packet a characteristic, with respect to a plane in the packet, selected from the group consisting of pseudo-symmetry, reverse symmetry, and reverse pseudo-symmetry and wherein at normal incidence the at least one effective optical packet provides a reflection band at infrared wavelengths and substantially transmits light at visible wavelengths.

17. A film according to claim 16 wherein the infrared light absorbing layer comprises an infrared light absorbing pigment or dye.

18. A film according to claim 16 wherein the infrared light reflecting layer comprises a metal.

19. A film according to claim 16 wherein the infrared light reflecting layer comprises silver.

20. A film according to claim 16 wherein the material A comprises polyethylene terephthalate and the material B comprises poly(methyl methacrylate) or a copolymer of poly(methyl methacrylate).

21. A film according to claim 16 wherein each unit cell in the first effective optical packet has six optical layers arranged with relative optical thicknesses of about 7A1B1A7B1A1B.