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EP-4737506-A1 - CURED FILM AND ORGANIC EL DISPLAY DEVICE

EP4737506A1EP 4737506 A1EP4737506 A1EP 4737506A1EP-4737506-A1

Abstract

The present invention relates to a cured film having excellent long-term reliability and suppressing a decrease in luminance during high-temperature continuous operation in particular when used for an organic EL display device. The cured film of the present invention contains a polyimide and/or a polybenzoxazole. The molar ratio F (fluorine atom)/C (carbon atom) of a fluorine atom to a carbon atom obtained when a cross section of the cured film is measured with an electron probe microanalyzer is 0 or more and 0.05 or less.

Inventors

  • KOMORI, Yusuke
  • SAEKI, AKINORI
  • NISHIYAMA, MASAHITO

Assignees

  • Toray Industries, Inc.

Dates

Publication Date
20260506
Application Date
20240621

Claims (17)

  1. A cured film comprising a polyimide and/or a polybenzoxazole, wherein a molar ratio F (fluorine atom)/C (carbon atom) of a fluorine atom to a carbon atom obtained when a cross section of the cured film is measured with an electron probe microanalyzer is 0 or more and 0.05 or less.
  2. The cured film according to claim 1, further comprising one or more compounds selected from the group consisting of a carboxylic acid having an indene structure, a carboxylic acid ester having an indene structure, a sulfonic acid having an indene structure, and a sulfonic acid aryl ester having an indene structure.
  3. The cured film according to claim 1 or 2, further comprising polyhydroxystyrene and/or a polyhydroxystyrene/polystyrene copolymer.
  4. The cured film according to claim 1 or 2, further comprising an aromatic hydrocarbon compound having at least three phenolic hydroxyl groups in one aromatic ring.
  5. The cured film according to claim 1 or 2, further comprising β-alkoxypropionamide.
  6. The cured film according to claim 1 or 2, further comprising one or more sulfonic acids selected from the group consisting of compounds represented by any of the formulas (3) to (5) or sulfonate ions derived from one or more sulfonic acids selected from the group consisting of compounds represented by any of the formulas (3) to (5): wherein in the formula (3), R 5 each independently represents a hydrogen atom or a monovalent organic group having 1 to 10 carbon atoms, and n represents an integer of 1 to 5; and in the formula (4), R 6 represents a monovalent organic group having 1 to 10 carbon atoms.
  7. The cured film according to claim 1 or 2, wherein the polyimide and/or the polybenzoxazole has repeating units each composed of an acid component and an amine component, and when the acid component and the amine component in all the repeating units are each 100 mol%, the total of the acid component having a fluorene structure and the amine component having a fluorene structure is 0 mol% or more and 50 mol% or less with respect to 200 mol% of the total of the acid component and the amine component.
  8. The cured film according to claim 1 or 2, wherein the polyimide and/or the polybenzoxazole has a residue represented by the formula (6): wherein in the formula (6), X 1 each independently represents a direct bond, a divalent group represented by the formula (7) or a divalent group represented by the formula (8), X 2 represents a divalent group represented by the formula (9) or the formula (10), R 8 each independently represents an alkyl group having 1 to 4 carbon atoms or a hydroxyl group, and d each independently represents an integer of 0 to 4; in the formulas (7) and (8), R 9 each independently represents an alkyl group having 1 to 4 carbon atoms or a hydroxyl group, e each independently represents an integer of 0 to 4, * represents * in the formula (6), ** represents a bonding point bonded to an aromatic ring; in the formulas (9) and (10), R 11 each independently represents an alkyl group having 1 to 4 carbon atoms, R 12 and R 13 each independently represent a hydrocarbon group having 1 to 10 carbon atoms or a hydrogen atom, * represents a bonding point bonded to an aromatic ring, f each independently represents an integer of 1 to 4, g represents 1 or 2, provided that R 12 and R 13 represent different substituents.
  9. The cured film according to claim 1 or 2, wherein the polyimide and/or the polybenzoxazole has repeating units each composed of an acid component and an amine component, and when the acid component and the amine component in all the repeating units are each 100 mol%, the total of the acid component having an alicyclic structure and the amine component having an alicyclic structure is 0 mol% or more and 40 mol% or less with respect to 200 mol% of the total of the acid component and the amine component.
  10. The cured film according to claim 1 or 2, wherein the polyimide and/or the polybenzoxazole contains a repeating unit having a fluorine atom directly bonded to an sp2 carbon.
  11. The cured film according to claim 10, wherein the polyimide and/or the polybenzoxazole has repeating units each composed of an acid component and an amine component, and when the acid component and the amine component in all the repeating units are each 100 mol%, the total of the acid component having a fluorine atom directly bonded to the sp2 carbon and the amine component having a fluorine atom directly bonded to the sp2 carbon is 5 mol% or more and 100 mol% or less with respect to 200 mol% of the total of the acid component and the amine component.
  12. The cured film according to claim 1 or 2, wherein a molar ratio Si (silicon atom)/C (carbon atom) of a silicon atom to a carbon atom obtained when a cross section of the cured film is measured with an electron probe microanalyzer is 0.001 or more and 0.005 or less.
  13. The cured film according to claim 1 or 2, wherein the cured film has a transmittance of light at a wavelength of 450 nm per film thickness of 2.0 µm of 30% or less.
  14. The cured film according to claim 1 or 2, wherein the cured film has an OD value of 0.5 to 1.5 in visible light per film thickness of 1 um.
  15. An organic EL display device comprising the cured film according to claim 1 or 2.
  16. The organic EL display device according to claim 15, further comprising a color filter having a black matrix.
  17. An electronic component comprising the cured film according to claim 1 or 2.

Description

TECHNICAL FIELD The present invention relates to a cured film and an organic EL display device using the cured film. BACKGROUND ART Many products that use organic electroluminescence (hereinafter, "organic EL") display devices have been developed in display devices including thin displays, such as smartphones, tablet PCs, and televisions. In general, an organic EL display device has a drive circuit, a planarization layer, a first electrode, a pixel division layer, an organic EL layer, and a second electrode on a substrate. The organic EL display device can emit light when a voltage is applied or an electric current is passed between the first electrode and the second electrode facing each other. As materials for a planarization layer and materials for a pixel division layer among the above-described components, cured films of photosensitive resin compositions are generally used that can be patterned by UV irradiation. Meanwhile, the demand for high reliability of organic EL display devices has become severer year by year, and materials for a planarization layer and materials for a pixel division layer are also required to have a material that does not undergo a decrease in luminance and pixel shrinkage even after a reliability test under acceleration conditions such as high temperature, high humidity, light irradiation, and a continuous operation. Pixel shrinkage is a phenomenon that the decrease in luminance occurs from edges of each pixel or lighting failure occurs. The cured films of conventionally proposed positive-type photosensitive resin compositions include a cured film using a composition obtained by mixing a naphthoquinonediazide sulfonic acid ester compound as a photosensitive component with an alkali-soluble resin, the cured film using a polyimide precursor as a resin before curing (see, for example, Patent Document 1), and a polybenzoxazole precursor (see, for example, Patent Document 2). PRIOR ART DOCUMENTS PATENT DOCUMENTS Patent Document 1: Japanese Patent Laid-open Publication No. 2002-91343Patent Document 2: Japanese Patent Laid-open Publication No. 2002-116715Patent Document 3: International Publication No. 2016-047483 SUMMARY OF THE INVENTION PROBLEMS TO BE SOLVED BY THE INVENTION However, it is difficult to say that the materials proposed in the above-mentioned Patent Documents have sufficient performance from the viewpoint of long-term reliability. Meanwhile, as materials for a pixel division layer of an organic EL display device, there has also been proposed a positive-type photosensitive resin composition having long-term reliability enhanced by setting a sulfur concentration in a cured film within a certain range (see, for example, Patent Document 3). However, the cured film formed of the resin composition described in Patent Document 3 has improved long-term reliability against light irradiation, but it cannot be said that the cured film sufficiently suppresses a decrease in luminance during high-temperature continuous operation. In view of the above problems, an object of the present invention is to provide a cured film having excellent long-term reliability, and suppressing a decrease in luminance during high-temperature continuous operation in particular when used for an organic EL display device. SOLUTIONS TO THE PROBLEMS In order to solve the above-mentioned problems, a cured film of the present invention has the following configuration. [1] A cured film containing a polyimide and/or a polybenzoxazole, wherein a molar ratio F (fluorine atom)/C (carbon atom) of a fluorine atom to a carbon atom obtained when a cross section of the cured film is measured with an electron probe microanalyzer is 0 or more and 0.05 or less.[2] The cured film according to [1], further containing one or more compounds selected from the group consisting of a carboxylic acid having an indene structure, a carboxylic acid ester having an indene structure, a sulfonic acid having an indene structure, and a sulfonic acid aryl ester having an indene structure.[3] The cured film according to [1] or [2], further containing polyhydroxystyrene and/or a polyhydroxystyrene/polystyrene copolymer.[4] The cured film according to any one of [1] to [3], further containing an aromatic hydrocarbon compound having at least three phenolic hydroxyl groups in one aromatic ring.[5] The cured film according to any one of [1] to [4], further containing β-alkoxypropionamide.[6] The cured film according to [1] to [5], further containing one or more sulfonic acids selected from the group consisting of compounds represented by any of the formulas (3) to (5) or sulfonate ions derived from one or more sulfonic acids selected from the group consisting of compounds represented by any of the formulas (3) to (5): wherein in the formula (3), R5 each independently represents a hydrogen atom or a monovalent organic group having 1 to 10 carbon atoms, and n represents an integer of 1 to 5; andin the formula (4), R6 represents a monovalent or