MULTILAYER FILM STACK

• US 20200132902A1
• Filed: 07/04/2018
• Published: 04/30/2020
• Est. Priority Date: 07/07/2017
• Status: Active Grant

• Current Assignee: Toyobo Company Limited
• Original Assignee: Toyobo Film Solutions Limited
• Inventors: HIROSE, Amane, TOJO, Mitsuo
• Granted Patent: US 11,442,209 B2
• Time in Patent Office: Days
• CPC Class Codes: B32B 2250/05 5 or more layers
• CPC Class Codes: B32B 2250/42 Alternating layers, e.g. ABAB(C), AABBAABB(C)
• CPC Class Codes: B32B 27/08 of synthetic resin
• CPC Class Codes: B32B 27/36 comprising polyesters
• CPC Class Codes: B32B 7/02 Physical, chemical or physicochemical properties
• CPC Class Codes: B32B 7/022 Mechanical properties
• CPC Class Codes: G02B 5/30 Polarising elements light-modulating devices with active elements G02F1/00
• CPC Class Codes: G02B 5/305 including organic materials, e.g. polymeric layers
• CPC Class Codes: G02B 5/3083 Birefringent or phase retarding elements G02B5/3008, G02B5/3016 take precedence; systems for polarisation control G02B27/286; manufacturing phase modulating patterns by lithographic processes G03F7/001
• CPC Class Codes: G02F 1/1335 Structural association of cells with optical devices, e.g. polarisers or reflectors
• CPC Class Codes: G02F 1/133536 Reflective polarizers G02F1/13362 takes precedence

Abstract

The invention provides a multilayer laminated film containing a multilayer laminated structure of alternately laminated first and second layers, and a thick film layer in contact therewith. The multilayer laminated structure has a layer thickness profile in terms of the physical thickness of repeating first and second layers. The layer thickness profile has a monotonously increasing thickness region and a thin layer region, which has at least three repeating units, a L2/L1 ratio of 0.85 or less, and a A2/L1 ratio of 0.70 or less, where L1 is the maximum repeating unit thickness in the monotonously increasing thickness region, L2 is the maximum repeating unit thickness in the thin layer region, and A2 is the average repeating unit thickness in the thin layer region. The thin layer region is on the thicker side of the monotonously increasing thickness region and in contact with the thick film layer.

Claims

1. A multilayer laminated film comprising a multilayer laminated structure in which a first layer containing a first resin and a second layer containing a second resin are alternately laminated, and a thick film layer in contact with the multilayer laminated structure,

wherein the multilayer laminated structure has a layer thickness profile in terms of a physical thickness of a repeating unit having one first layer and one second layer, and the layer thickness profile has a monotonously increasing thickness region and a thin layer region;

the thin layer region has at least three repeating units and is a region in which the L2/L1 ratio is 0.85 or less, where L2 is the maximum repeating unit thickness in the thin layer region, and L1 is the maximum repeating unit thickness in the monotonously increasing thickness region, and the A2/L1 ratio is 0.70 or less, where A2 is the average repeating unit thickness in the thin layer region, and L1 is the maximum repeating unit thickness in the monotonously increasing thickness region; and

the thin layer region is on the thicker side of the monotonously increasing thickness region and is present in contact with the thick film layer.

2. The multilayer laminated film according to claim 1, wherein the L2/S1 ratio exceeds 1.0, where L2 is the maximum repeating unit thickness in the thin layer region, and S1 is the minimum repeating unit thickness in the monotonously increasing thickness region.

3. The multilayer laminated film according to claim 1, wherein the first layer is birefringent, the second layer is isotropic, and the film is capable of reflecting light at a wavelength of 380 to 780 nm by optical interference of the layers.

4. A luminance-improving member comprising the multilayer laminated film according to claim 1.

5. A polarizer for a liquid crystal display, the polarizer comprising the multilayer laminated film according to claim 1.

6. The multilayer laminated film according to claim 2, wherein the first layer is birefringent, the second layer is isotropic, and the film is capable of reflecting light at a wavelength of 380 to 780 nm by optical interference of the layers.

7. A luminance-improving member comprising the multilayer laminated film according to claim 2.

8. A luminance-improving member comprising the multilayer laminated film according to claim 3.

9. A luminance-improving member comprising the multilayer laminated film according to claim 6.

10. A polarizer for a liquid crystal display, the polarizer comprising the multilayer laminated film according to claim 2.

11. A polarizer for a liquid crystal display, the polarizer comprising the multilayer laminated film according to claim 3.

12. A polarizer for a liquid crystal display, the polarizer comprising the multilayer laminated film according to claim 6.