Resin composition, optical compensation film using same, and production method for same

Patent metadata

Field	Value
Publication number	US-9932488-B2
Application number	US-201414895360-A
Country	US
Kind code	B2
Filing date	Jun 4, 2014
Priority date	Jun 7, 2013
Publication date	Apr 3, 2018
Grant date	Apr 3, 2018

Abstract

A resin composition including from 30 to 99 wt % of a cellulose-based resin represented by the following formula (1) and from 70 to 1 wt % of a fumaric acid ester polymer containing 30 mol % or more of a fumaric acid diester residue unit represented by the following formula (2); an optical compensation film using the same; and a production method of the optical compensation film.

(wherein R 1 to R 3 represent a substituent having a carbon number of 1 to 12, and R 4 and R 5 represent an alkyl group having a carbon number of 1 to 12).

First claim

The invention claimed is:

1. A resin composition, comprising:
from 30 to 99 wt % of a cellulose-based resin as a cellulose ether, represented by the following formula (1), wherein carboxymethyl cellulose, methyl cellulose, hydroxyethyl cellulose, and hydroxypropyl cellulose are excluded; and
from 70 to 1 wt % of a fumaric acid ester polymer containing from 30 to 95 mol % of a fumaric acid diester residue unit represented by the following formula (2) and from 70 to 5 mol % of a furamic acid monoester residue unit represented by the following formula (3):

wherein each of R 1 , R 2 and R 3 independently represents a substituent having a carbon number of 1 to 12:

wherein R 4 and R 5 represent an alkyl group having a carbon number of 1 to 12,

wherein R 6 represents an alkyl group having a carbon number of 1 to 12.

2. The resin composition according to claim 1 ,
wherein the fumaric acid monoester residue unit is a fumaric acid monoester residue unit selected from the group consisting of a monomethyl fumarate residue unit, a monoethyl fumarate residue unit, a monoisopropyl fumarate residue unit, a mono-n-propyl fumarate residue unit, a mono-n-butyl fumarate residue unit and a mono-2-ethylhexyl fumarate residue unit.

3. The resin composition according to claim 1 , wherein the fumaric acid ester polymer further comprises from 30 to 0.5 mol % of a residue unit selected from the group consisting of an acrylic acid ester residue unit represented by the following formula (4), a methacrylic acid ester residue unit represented by the following formula (5), an acrylic acid amide residue unit represented by the following formula (6) and a methacrylic acid amide residue unit represented by the following formula (7):

wherein each of R 7 , R 8 , R 9 and R 10 independently represents an alkyl group having a carbon number of 1 to 12, an alkylene group or an ether group.

4. The resin composition according to claim 1 , wherein an etherification degree, which is a substitution degree, of the cellulose-based resin as a cellulose ether represented by the formula (1) is from 1.5 to 3.0.

5. An optical compensation film, which is formed using the resin composition according to claim 1 and has a thickness of from 5 to 200 μm.

6. An optical compensation film, which is formed using the resin composition according to claim 1 and has a thickness of from 20 to 60 μm.

7. The optical compensation film according to claim 5 , wherein an in-plane retardation (Re) represented by the following expression (1) is from 80 to 300 nm and an Nz coefficient represented by the following expression (2) is from 0.35 to 0.65:
Re =( ny−nx ) xd   (1)

Nz =( ny−nz )/( ny−nx )  (2),

wherein nx represents a refractive index in a fast axis direction in a film plane; ny represents a refractive index in a slow axis direction in a film plane; nz represents a refractive index outside a film plane; and d represents a film thickness.

8. The optical compensation film according to claim 5 , wherein the in-plane retardation (Re) represented by the expression (1) is from 50 to 200 nm and the Nz coefficient represented by the expression (2) is from −0.2 to 0.2.

9. The optical compensation film according to claim 5 , wherein the in-plane retardation (Re) represented by the expression (1) is from 0 to 20 nm and an out-of-plane retardation (Rth) represented by the following expression (3) is from −150 to 20 nm:
Rth =[( nx+ny )/2− nz]×d   (3),

wherein nx represents a refractive index in a fast axis direction in a film plane; ny represents a refractive index in a slow axis direction in a film plane; nz represents a refractive index outside a film plane; and d represents a film thickness.

10. The optical compensation film according to claim 5 , wherein a light transmittance is 85% or more.

11. The optical compensation film according to claim 5 , wherein a haze is 1% or less.

12. The optical compensation film according to claim 5 , wherein a ratio Re(450)/Re(550) between a retardation at 450 nm and a retardation at 550 nm is 0.60<Re(450)/Re(550)<1.05.

13. A method for producing an optical compensation film according to claim 7 , the method comprising:
dissolving, in a solvent, a resin composition comprising from 30 to 99 wt % of a cellulose-based resin as a cellulose ether, represented by the following formula (1), and from 70 to 1 wt % of a fumaric acid ester polymer comprising 30 mol % or more of a fumaric acid diester residue unit represented by the following formula (2);
casting an obtained resin solution on a base material; and
after drying, separating a resulting film from the base material:

wherein each of R 1 , R 2 and R 3 independently represents a substituent having a carbon number of 1 to 12:

wherein R 4 and R 5 represent an alkyl group having a carbon number of 1 to 12.

14. The production method of an optical compensation film according to claim 13 , wherein an etherification degree of the cellulose-based resin as a cellulose ether represented by the formula (1) is from 1.5 to 3.0.

15. A method for producing an optical compensation film by using the resin composition according to claim 2 .

16. A method for producing an optical compensation film according to claim 7 , comprising:
subjecting a film having a thickness of 10 to 200 μm obtained by casting to uniaxial stretching or unbalanced biaxial stretching.

17. A method for producing an optical compensation film according to claim 7 , comprising:
subjecting a film having a thickness of 30 to 100 μm obtained by casting to uniaxial stretching or unbalanced biaxial stretching.

Assignees

• Tosoh Corp

Inventors

• Ito Masayasu
• Toyomasu Shinsuke
• Kitagawa Takahiro

Classifications

• C08J7/0427

  with only one layer of a composition containing a polymer binder (with more layers C08J7/042) · CPC title

• C08J5/18

  Manufacture of films or sheets · CPC title

• C08L1/26

  Cellulose ethers · CPC title

• C08J2431/06

  Homopolymers or copolymers of esters of polycarboxylic acids · CPC title

• C08L35/00

  Compositions of homopolymers or copolymers of compounds having one or more unsaturated aliphatic radicals, each having only one carbon-to-carbon double bond, and at least one being terminated by a carboxyl radical, and containing at least one other carboxyl radical in the molecule, or of salts, anhydrides, esters, amides, imides or nitriles thereof; Compositions of derivatives of such polymers · CPC title