Multilayer optical film having high heat resistance and method for manufacturing the same

Patent metadata

Field	Value
Publication number	US-9541689-B2
Application number	US-201214375588-A
Country	US
Kind code	B2
Filing date	Dec 27, 2012
Priority date	Feb 20, 2012
Publication date	Jan 10, 2017
Grant date	Jan 10, 2017

Abstract

Disclosed is a multilayer optical film having a structure in which a first resin layer and a second resin layer are alternately laminated, wherein the first resin layer comprises a crystalline naphthalene dicarboxylic-acid polyester and the second resin layer comprises polyethylene terephthalate glycol (PETG). Also disclosed is a method for manufacturing a multilayer optical film comprising (a) melting extrusion a first resin comprising a crystalline naphthalene dicarboxylic-acid polyester and a second resin comprising PETG respectively and then alternately laminating the first resin and the second resin; and (b) elongating the laminated sheet in step (a) and then thermosetting them.

First claim

The invention claimed is:

1. A multilayer optical film having a structure in which a first resin layer and a second resin layer are alternately laminated,
wherein the first resin layer comprises a crystalline naphthalene dicarboxylic-acid polyester and the second resin layer comprises polyethylene terephthalate glycol (PETG),
wherein the crystalline naphthalene dicarboxylic-acid polyester of the first resin layer is polyethylenenaphthalate (PEN) manufactured by polycondensation of naphthalatedicarboxylic-acid and ethyleneglycol,
wherein a glass transfer temperature of the second resin layer is 100 to 140° C., and
wherein the PETG of the second resin layer comprises an amount of cyclohexanedimethanol (CHDM) of 60% to 70%.

2. A multilayer optical film according to claim 1 , wherein a refractive index difference of the first resin layer and the second resin layer is 0.05 to 0.2.

3. A multilayer optical film according to claim 1 , wherein the PETG of the second resin layer comprises a component manufactured from ethylene glycol (EG), 1,4-cyclohexanedimethanol (CHDM), and terephthalic acid (TPA).

4. A multilayer optical film according to claim 1 , wherein the PETG of the second resin layer comprises a compound represented by the formulae:

5. A multilayer optical film according to claim 1 , wherein the first resin layer and the second resin layer have thicknesses from 100 to 500 nm.

6. A multilayer optical film according to claim 1 , wherein the first resin layer and the second resin layer have thicknesses from 200 to 300 nm.

7. A method for manufacturing a multilayer optical film comprising the step of:
(a) melting extrusion a first resin comprising a crystalline naphthalene dicarboxylic-acid polyester and a second resin comprising PETG respectively and then alternately laminating the first resin and the second resin; and
(b) elongating the laminated sheet in the step (a) and then thermosetting the laminated sheet,
wherein the crystalline naphthalene dicarboxylic-acid polyester of the first resin is polyethylenenaphthalate (PEN) manufactured by polycondensation of naphthalatedicarboxylic-acid and ethyleneglycol,
wherein a glass transfer temperature of the second resin is 100 to 140° C.,
wherein the PETG of the second resin comprises an amount of cyclohexanedimethanol (CHDM) of 60% to 70%
wherein laminated sheet in the step (b) is elongated in at least one direction among a longitudinal direction or a vertical direction, and
wherein a temperature of the melted extrusion is 280 to 300° C.

8. A method for manufacturing a multilayer optical film according to claim 7 , after elongating process in the step (b), wherein a refractive index difference of the first resin layer and the second resin layer in an elongation direction is greater than a refraction difference of the first resin layer and the second resin layer in a non-elongation direction.

9. A method for manufacturing a multilayer optical film according to claim 8 , wherein the refractive index difference of the first resin layer and the second resin layer in the elongation direction is 0.3 or more.

10. A method for manufacturing a multilayer optical film according to claim 7 , wherein a temperature of the elongated in the longitudinal direction and the vertical direction is 150 to 180° C.

11. A method for manufacturing a multilayer optical film according to claim 7 , wherein a temperature of the elongation in the longitudinal direction and the vertical direction is a glass transfer temperature (Tg) of the PETG +30° C. or less.

12. A method for manufacturing a multilayer optical film according to claim 7 , wherein a temperature of the elongation in the longitudinal direction and the vertical direction is a glass transfer temperature (Tg) of the PETG +10° C. or less.

Assignees

• Lg Hausys Ltd

Inventors

• Lee Eung Kee
• Lee Min Hee
• Shin Chang Hak
• Park Ku Il

Classifications

• B32B2038/0028

  Stretching, elongating · CPC title

• B32B27/08 Primary

  of synthetic resin · CPC title

• G02B5/305 Primary

  including organic materials, e.g. polymeric layers · CPC title

• G02B1/04

  made of organic materials, e.g. plastics (G02B1/08 takes precedence) · CPC title

• C08L67/02

  Polyesters derived from dicarboxylic acids and dihydroxy compounds (C08L67/06 takes precedence) · CPC title