Optical film, polarizing plate equipped with the optical film, liquid crystal display device, and method for producing an optical film

Patent metadata

Field	Value
Publication number	US-9766378-B2
Application number	US-201514864236-A
Country	US
Kind code	B2
Filing date	Sep 24, 2015
Priority date	Sep 26, 2014
Publication date	Sep 19, 2017
Grant date	Sep 19, 2017

Abstract

An optical film (polarizing plate protecting film) is equipped with a substrate and a hard coat layer provided on the substrate. The hard coat layer is a layer obtained by curing a photocurable composition on the substrate. The photocurable composition includes an epoxide represented by Chemical Formula I below, a bisphenol compound, and a cationic photopolymerization initiator.

First claim

What is claimed is:

1. An optical film comprising:
a substrate; and
a hard coat layer provided on the substrate;
the hard coat layer being a layer obtained by curing a photocurable composition on the substrate;
the photocurable composition including an epoxide represented by Chemical Formula I below, a bisphenol compound represented by General Formula II-1 below, and a cationic photopolymerization initiator:

and

wherein R 1 is hydrogen and R 2 is a methyl group, and X represents a divalent linking group formed by at least one species selected from among a single bond, a hydrocarbon group having a carbon number within a range from 1 to 15, an oxygen atom, a sulfur atom, and a sulfonyl group.

2. An optical film as defined in claim 1 , wherein the bisphenol compound is represented by General Formula 11-2 below;

wherein R 3 and R 4 each represent hydrogen or a hydrocarbon group having a carbon number within a range from 1 to 15, and R 3 and R 4 may bind to form a single cyclic structure.

3. An optical film as defined in claim 1 , wherein:
the content of the bisphenol compound with respect to the total solid content of the photocurable composition is within a range from 1% by mass to 40% by mass.

4. An optical film as defined in claim 1 , wherein:
the substrate is a cellulose ester substrate.

5. An optical film as defined in claim 1 , wherein:
the optical film is employed as a polarizing plate protecting film.

6. A polarizing plate, comprising:
a polarizer; and
the optical film as defined in claim 5 provided on at least one surface of the polarizer.

7. A liquid crystal display device comprising:
a pair of polarizing plates; and
a liquid crystal cell clamped between the pair of polarizing plates;
at least one of the pair of polarizing plates being the polarizing plate defined in claim 6 .

8. A method for producing an optical film comprising a substrate and a hard coat layer provided on the substrate, comprising:
coating a photocurable composition including an epoxide represented by Chemical Formula I below, a bisphenol compound represented by General Formula II-1 below, and a cationic photopolymerization initiator on the substrate to form a coated film; and
forming the hard coat layer by irradiating light onto the coated film to cure the coated film:

and

wherein R 1 is hydrogen and R 2 is a methyl group, and X represents a divalent linking group formed by at least one species selected from among a single bond, a hydrocarbon group having a carbon number within a range from 1 to 15, an oxygen atom, a sulfur atom, and a sulfonyl group.

9. A method for producing an optical film as defined in claim 8 , wherein the bisphenol compound is represented by General Formula II-2 below;

wherein R 3 and R 4 each represent hydrogen or a hydrocarbon group having a carbon number within a range from 1 to 15, and R 3 and R 4 may bind to form a single cyclic structure.

10. A method for producing an optical film as defined in claim 8 , wherein:
the light which is irradiated onto the coated film is ultraviolet light.

11. A method for producing an optical film as defined in claim 8 , wherein:
the irradiation of light is performed in a state in which the substrate having the coated formed thereon is heated.

12. A method for producing an optical film as defined in claim 8 , wherein:
the hard coat layer is produced without applying heat after the light is irradiated.

Assignees

• Fujifilm Corp

Inventors

• Yasushita Chihiro

Classifications

• B32B23/08

  of synthetic resin · CPC title

• B32B7/12

  using interposed adhesives or interposed materials with bonding properties · CPC title

• B32B2307/42

  Polarizing, birefringent, filtering · CPC title

• Y10T428/10

  Cross-Sectional Technologies · mapped topic

• B32B2307/412

  Transparent · CPC title