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US-12619005-B2 - Optical film with improved optical properties, display apparatus comprising same, and manufacturing method therefor

US12619005B2US 12619005 B2US12619005 B2US 12619005B2US-12619005-B2

Abstract

The present invention provides an optical film comprising a polymer resin, which comprises a first repeating unit, a second repeating unit, a third repeating unit and a fourth repeating unit, wherein the optical index of the film is 1.0%/GU or more, the first repeating unit is an imide repeating unit derived from a first diamine-based compound and a dianhydride-based compound, the second repeating unit is an imide-repeating unit derived from a second diamine-based compound and a dianhydride-based compound, the third repeating unit is an amide-repeating unit derived from a first diamine-based compound and a dicarbonyl-based compound, the fourth repeating unit is an amide-repeating unit derived from a second diamine-based compound and a dicarbonyl-based compound, the first diamine-based compound is 2,2′-bis(trifluoromethyl)benzidine (TFDB), the second diamine-based compound includes an aromatic diamine-based compound, and the third repeating unit and the fourth repeating unit are included in a proportion of 80% or more with respect to the total number of the repeating units comprising the first to fourth repeating units.

Inventors

  • Doo Li CHOI
  • Hak-Gee JUNG

Assignees

  • KOLON INDUSTRIES, INC.

Dates

Publication Date
20260505
Application Date
20211224
Priority Date
20201231

Claims (12)

  1. 1 . An optical film comprising a polymer resin comprising a first repeating unit, a second repeating unit, a third repeating unit, and a fourth repeating unit, the optical film having an optical index, calculated using the following Formula 1, of 1.0%/GU or more: Optical ⁢ Index = Parallel ⁢ transmittance 20 ⁢ ° ⁢ Gloss - RSPEC [ Equation ⁢ 1 ] wherein a parallel transmittance of the optical film is obtained by measuring a parallel transmittance of a sample film having a size of 50 mm×50 mm three times using a haze meter and calculating an average of three measurement values, and 20° gloss and RSPEC of the optical film are measured by placing white paper under one side of a sample film having a size of 30 mm×100 mm and performing measurement on a surface of the optical film using a gloss meter, wherein the first repeating unit is an imide repeating unit derived from a first diamine-based compound and a dianhydride-based compound, the second repeating unit is an imide repeating unit derived from a second diamine-based compound and the dianhydride-based compound, the third repeating unit is an amide repeating unit derived from the first diamine-based compound and a dicarbonyl-based compound, and the fourth repeating unit is an amide repeating unit derived from the second diamine-based compound and the dicarbonyl-based compound, wherein the first diamine-based compound is 2,2′-bis(trifluoromethyl)benzidine (TFDB) and the second diamine-based compound comprises an aromatic diamine-based compound, and a sum of numbers of the third and fourth repeating units is 80% or more of a total number of repeating units including the first to fourth repeating units.
  2. 2 . The optical film according to claim 1 , wherein the second diamine-based compound comprises at least one selected from the group consisting of bis(3-aminophenyl)sulfone (3DDS), bis(4-aminophenyl)sulfone (4DDS), 2,2-bis(3-amino-4-methylphenyl)hexafluoropropane (AMH), 9,9-bis(4-aminophenyl)fluorene (FDA), 9,9-bis(3-fluoro-4-aminophenyl)fluorene (FFDA), m-phenylene diamine (mPDA), p-methylene dianiline (pMDA), m-methylene dianiline (mMDA), 1,3-bis(3-aminophenoxy)benzene (133APB), 1,3-bis(4-aminophenoxy)benzene (134APB), 1,4-bis(4-aminophenoxy)benzene (144APB), 2,2′-bis(3-aminophenyl)hexafluoropropane (33-6F), 2,2′-bis(4-aminophenyl)hexafluoropropane (44-6F), 2,2-bis(3-amino-4-hydroxy-phenyl)-hexafluoropropane (6FAP), 2,2-bis(4-(4-aminophenoxy)phenyl)hexafluoropropane (HFBAPP), bis(4-(4-aminophenoxy)phenyl)sulfone (BAPS), bis(4-(3-aminophenoxy)phenyl)sulfone (BAPSM), 2,2-bis(4-(4-aminophenoxy)phenyl propane (BAPP), 4,4-bis(4-aminophenoxy)biphenyl (BAPB), 3,3-diamino-4,4,-dihydroxydiphenylsulfone (DABS), 2,2,-bis(3-amino-4-hydroxyphenyl)propane (BAP), 4,4′-oxydianiline (4-ODA), and 3,3′-oxydianiline (3-ODA).
  3. 3 . The optical film according to claim 1 , wherein a ratio of a number of repeating units derived from the first diamine-based compound to a number of repeating units derived from the second diamine-based compound is 95:5 to 50:50.
  4. 4 . The optical film according to claim 1 , wherein the optical film has a yellowness index (Y.I.) of 3.0 or less based on a thickness of 50 μm.
  5. 5 . The optical film according to claim 1 , wherein the optical film has a light transmittance of 88.50% or more based on a thickness of 50 μm.
  6. 6 . The optical film according to claim 1 , wherein the optical film has a 20° gloss of 200 to 250 GU based on a thickness of 50 μm.
  7. 7 . The optical film according to claim 1 , wherein the optical film has an RSPEC of 140 to 190 GU based on a thickness of 50 μm.
  8. 8 . A display device comprising: a display panel; and the optical film according to claim 1 disposed on the display panel.
  9. 9 . A method for manufacturing an optical film, the method comprising: forming a first reaction solution using a first diamine-based compound, a second diamine-based compound, a dianhydride-based compound, and a dicarbonyl-based compound; adding a dehydrating agent and an imidization catalyst to the first reaction solution and allowing a reaction to occur therebetween to form a second reaction solution; treating the second reaction solution to prepare a polymer resin in a solid phase; dissolving the solid-phase polymer resin to prepare a polymer resin solution; and casting the polymer resin solution, wherein the first diamine-based compound is 2,2′-bis(trifluoromethyl)benzidine (TFDB) and the second diamine-based compound comprises an aromatic diamine-based compound, the dicarbonyl-based compound has a bulk density of 0.5 to 0.8 g/ml, and a content of the dicarbonyl-based compound is 80 parts by mole or more and a content of the dianhydride-based compound is 20 parts by mole or less with respect to 100 parts by mole of a total content of the first diamine-based compound and the second diamine-based compound.
  10. 10 . The method according to claim 9 , further comprising reducing the bulk density of the dicarbonyl-based compound before forming the first reaction solution.
  11. 11 . The method according to claim 9 , wherein the second diamine-based compound comprises at least one selected from the group consisting of bis(3-aminophenyl)sulfone (3DDS), bis(4-aminophenyl)sulfone (4DDS), 2,2-bis(3-amino-4-methylphenyl)hexafluoropropane (AMH), 9,9-bis(4-aminophenyl)fluorene (FDA), 9,9-bis(3-fluoro-4-aminophenyl)fluorene (FFDA), m-phenylene diamine (mPDA), p-methylene dianiline (pMDA), m-methylene dianiline (mMDA), 1,3-bis(3-aminophenoxy)benzene (133APB), 1,3-bis(4-aminophenoxy)benzene (134APB), 1,4-bis(4-aminophenoxy)benzene (144APB), 2,2′-bis(3-aminophenyl)hexafluoropropane (33-6F), 2,2′-bis(4-aminophenyl)hexafluoropropane (44-6F), 2,2-bis(3-amino-4-hydroxy-phenyl)-hexafluoropropane (6FAP), 2,2-bis(4-(4-aminophenoxy)phenyl)hexafluoropropane (HFBAPP), bis(4-(4-aminophenoxy)phenyl)sulfone (BAPS), bis(4-(3-minophenoxy)phenyl)sulfone (BAPSM), 2,2-bis(4-(4-aminophenoxy)phenyl propane (BAPP), 4,4-bis(4-aminophenoxy)biphenyl (BAPB), 3,3-diamino-4,4,-dihydroxydiphenylsulfone (DABS), 2,2,-bis(3-amino-4-hydroxyphenyl)propane (BAP), 4,4′-oxydianiline (4-ODA), and 3,3′-oxydianiline (3-ODA).
  12. 12 . The method according to claim 9 , wherein a content of the first diamine-based compound is 50 to 95 parts by mole and a content of the second diamine-based compound is 5 to 50 parts by mole with respect to 100 parts by mole of a total content of the first diamine-based compound and the second diamine-based compound.

Description

CROSS REFERENCE TO RELATED APPLICATION(S) This application is a National Stage of International Application No. PCT/KR2021/019822 filed Dec. 24, 2021, claiming priority based on Korean Patent Application No. 10-2020-0188965 filed Dec. 31, 2020 and Korean Patent Application No. 10-2021-0186266 filed Dec. 23, 2021, the disclosures of which are incorporated herein by reference in their entireties. TECHNICAL FIELD The present disclosure relates to an optical film having excellent optical properties, and more particularly to an optical film having a high optical index, a display device including the same, and a method for manufacturing the same. BACKGROUND ART Recently, the use of an optical film instead of glass as a cover window of a display device has been considered with the goal of reducing the thickness and weight of the display device and increasing the flexibility thereof. In order for the optical film to be usable as a cover window of a display device, the optical film needs to have excellent optical and mechanical properties. Therefore, it is necessary to develop a film that exhibits excellent optical properties as well as superior mechanical properties, such as insolubility, chemical resistance, heat resistance, radiation resistance, and good low-temperature characteristics. Among optical films, polyimide (PI)-based resins have excellent insolubility, chemical resistance, heat resistance, radiation resistance and low-temperature characteristics, and are used as automobile materials, aviation materials, spacecraft materials, insulating coatings, insulating films, protective films, and the like. Recently, polyamide-imide-based resins having amide repeating units added to polyimide-based resins have been developed, and films prepared using polyamide-imide-based resins have superior optical properties as well as excellent insolubility, chemical resistance, heat resistance, radiation resistance, and low-temperature characteristics. Such polyamide-imide-based resins may be prepared using a diamine-based compound, a dianhydride-based compound, and a dicarbonyl-based compound as monomers. However, for example, 2,2′-bis(trifluoromethyl)benzidine (TFDB) used as the diamine causes a problem in that, during polymerization of TFDB with a large amount of dicarbonyl-based compound, the dicarbonyl-based compound is gelled due to the rigid structure of TFDB, so the polymerization reaction is insufficient. Therefore, there is a need to develop a polyamide-imide-based resin having a high degree of polymerization even when a large amount of dicarbonyl is added. DISCLOSURE Technical Problem It is an aspect of the present disclosure to provide an optical film that contains a polymer resin having a high degree of polymerization even when a large amount of dicarbonyl is added. It is another aspect of the present disclosure to provide an optical film that exhibits excellent optical properties. It is another aspect of the present disclosure to provide a method for manufacturing an optical film that contains a polymer resin having a high degree of polymerization. Technical Solution In accordance with the present disclosure, the above and other objects can be accomplished by the provision of an optical film containing a polymer resin including a first repeating unit, a second repeating unit, a third repeating unit, and a fourth repeating unit, the optical film having an optical index, calculated using the following Formula 1, of 1.0%/GU or more: Optical⁢ Index=Parallel⁢ transmittance20⁢°⁢ Gloss-RSPEC[Equation⁢ 1]wherein a parallel transmittance of the film is obtained by measuring a parallel transmittance of a sample film having a size of 50 mm×50 mm three times using a haze meter (model name: HM-150, MURAKAMI Corporation) and calculating an average of three measurement values, and 20° gloss and RSPEC of the film are measured by placing white paper under one side of a sample film having a size of 30 mm×100 mm and performing measurement on a surface of the film using a gloss meter (Rhopoint Instruments, RHOPOINT IQ), wherein the first repeating unit is an imide repeating unit derived from a first diamine-based compound and a dianhydride-based compound, the second repeating unit is an imide repeating unit derived from a second diamine-based compound and the dianhydride-based compound, the third repeating unit is an amide repeating unit derived from the first diamine-based compound and a dicarbonyl-based compound, and the fourth repeating unit is an amide repeating unit derived from the second diamine-based compound and the dicarbonyl-based compound, wherein the first diamine-based compound is 2,2′-bis(trifluoromethyl)benzidine (TFDB) and the second diamine-based compound comprises an aromatic diamine-based compound, and a sum of numbers of the third and fourth repeating units is 80% or more of a total number of repeating units including the first to fourth repeating units. The second diamine-based compound may include at l