Optical film and method of manufacturing the same

• US 9,187,633 B2
• Filed: 05/02/2014
• Issued: 11/17/2015
• Est. Priority Date: 09/17/2007
• Status: Active Grant

• Current Assignee: LG Chem Limited (LG Corporation)
• Original Assignee: LG Chem Limited (LG Corporation)
• Inventors: Kang, Byoung-Il, Lee, Chan-Hong, Han, Chang-Hun
• Primary Examiner(s): Zemel, Irina S
• Assistant Examiner(s): LENIHAN, JEFFREY S
• Application Number:
  US14/268,467
• Publication Number:
  US 20140239523A1
• Time in Patent Office: 564 Days
• US Class Current: 1/1
• CPC Class Codes: B29D 11/00788 Producing optical films
• CPC Class Codes: C08J 2333/06 of esters containing only carbon, hydrogen, and oxygen, the oxygen atom being present only as part of the carboxyl radical
• CPC Class Codes: C08J 5/18 Manufacture of films or sheets
• CPC Class Codes: C08L 2666/24 Graft or block copolymers according to groups C08L51/00, C08L53/00 or C08L55/02; Derivatives thereof
• CPC Class Codes: C08L 33/14 of esters containing halogen, nitrogen, sulfur, or oxygen atoms in addition to the carboxy oxygen
• CPC Class Codes: C08L 37/00 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 heterocyclic ring containing oxygen of cyclic esters of polyfunctional acids C08L31/00; of cyclic anhydrides of unsaturated acids C08L35/00; Compositions of derivatives of such polymers
• CPC Class Codes: C08L 39/04 Homopolymers or copolymers of monomers containing heterocyclic rings having nitrogen as ring member
• CPC Class Codes: C08L 51/00 Compositions of graft polymers in which the grafted component is obtained by reactions only involving carbon-to-carbon unsaturated bonds for ABS polymers C08L55/02; Compositions of derivatives of such polymers
• CPC Class Codes: C08L 51/04 grafted on to rubbers
• 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 2201/50 Protective arrangements

Abstract

The present invention provides an optical film and a retardation film that each include an acryl resin, and 20 to 65 parts by weight of a graft copolymer including a conjugated diene rubber based on 100 parts by weight of the acryl resin, and an electronic device including the same.

Claims

1. A method of manufacturing an optical film, the method comprising:

a) preparing a resin composition that comprises a first acrylic resin, and 20 to 65 parts by weight of a graft copolymer comprising a conjugated diene rubber component based on 100 parts by weight of the first acrylic resin; and

b) forming a film having an in-plane retardation value and a thickness retardation value of 0 to 10 nm before stretching, and having an in-plane retardation value and a thickness retardation value of 80 to 200 nm after stretching, by using the resin composition;

wherein the first acrylic resin comprises one or more copolymers selected from the group consisting of a copolymer of an acrylic monomer, an aromatic vinyl monomer and an acid anhydride represented by Formula 2; and

a copolymer of an acrylic monomer, an aromatic vinyl monomer, an acrylonitrile monomer and an acid anhydride represented by Formula 2,

wherein the graft copolymer is a graft copolymer of a conjugated diene rubber and a second acrylic resin,

wherein the graft copolymer has a core-shell structure in which the conjugated diene rubber constitutes a core and the second acrylic resin constitutes a shell,

wherein a weight ratio of the conjugated diene rubber and the second acrylic resin is 10 to 50;

90 to 50,

2. The method of manufacturing an optical film as set forth in claim 1, wherein the optical film has a glass transition temperature of 110 to 130°

C., a heat deflection temperature (Vicat) of 110 to 140°

C., an MI (220°

C., 10 kg) of 2 to 6, a thermal expansion coefficient CTE (ppm/K, 40 to 90°

C.) of 50 to 120, a haze of 0.5 to 3%, and a transmittance of 88 to 93%.

3. The method of manufacturing an optical film as set forth in claim 1, wherein the conjugated diene rubber comprises one or more selected from the group consisting of an ethylene-propylene diene rubber and a butadiene rubber.

4. The method of manufacturing an optical film as set forth in claim 1, wherein the second acrylic resin comprises one or more selected from the group consisting of a homo or copolymer of an acryl monomer;

a copolymer of an acryl monomer and an aromatic vinyl monomer;

a copolymer of an acryl monomer, an aromatic vinyl monomer and an acrylonitrile monomer;

a copolymer of an acryl monomer, an aromatic vinyl monomer and an acid anhydride; and

a copolymer of an acryl monomer, an aromatic vinyl monomer, an acrylonitrile monomer and an acid anhydride.

5. A method of manufacturing a retardation film, the method comprising:

a) preparing a resin composition that comprises a first acrylic resin, and 20 to 65 parts by weight of a graft copolymer comprising a conjugated diene rubber component based on 100 parts by weight of the first acrylic resin;

b) forming a film having an in-plane retardation value and a thickness retardation value of 0 to 10 nm by using the resin composition; and

c) uniaxially or biaxially stretching the film to be a film having an in-plane retardation value and a thickness retardation value of 80 to 200 nm;

wherein the first acrylic resin comprises one or more copolymers selected from the group consisting of a copolymer of an acrylic monomer, an aromatic vinyl monomer and an acid anhydride represented by Formula 2; and

a copolymer of an acrylic monomer, an aromatic vinyl monomer, an acrylonitrile monomer and an acid anhydride represented by Formula 2,

wherein the graft copolymer is a graft copolymer of a conjugated diene rubber and a second acrylic resin,

wherein the graft copolymer has a core-shell structure in which the conjugated diene rubber constitutes a core and the second acrylic resin constitutes a shell,

wherein a weight ratio of the conjugated diene rubber and the second acrylic resin is 10 to 50;

90 to 50,