WO-2026094721-A1 - INKJET INK COMPOSITION

Abstract

Provided is a technology capable of inhibiting the occurrence of defects that accompany formation of a layer composed of metal oxide nanoparticles, which an optical element has between a cathode and an anode, by an inkjet printing method. This inkjet ink composition comprises: metal oxide nanoparticles composed of a material selected from the group consisting of a hole injection material, a hole transport material, and an electron transport material; and a dispersion medium containing a glycol-based solvent and a non-alcohol-based solvent having 7-9 carbon atoms.

Inventors

• HIROTA, TETSUYA
• YAMAMOTO, KEISUKE

Assignees

• ＴＯＰＰＡＮホールディングス株式会社

Dates

Publication Date

20260507

Application Date

20251021

Priority Date

20241101

Claims (13)

1. Metal oxide nanoparticles made of a material selected from the group consisting of hole injection materials, hole transport materials, and electron transport materials, An inkjet ink composition comprising a glycol-based solvent and a dispersion medium containing a non-alcohol-based solvent having 7 to 9 carbon atoms.
2. The inkjet ink composition according to claim 1, wherein the ratio of the mass of the non-alcoholic solvent to the total mass of the glycol-based solvent and the non-alcoholic solvent is within the range of 5% to 35% by mass.
3. The inkjet ink composition according to claim 1 or 2, wherein the non-alcoholic solvent comprises one or more selected from the group consisting of 3-methoxybutyl acetate, diethylene glycol methyl ethyl ether, propylene glycol diacetate, dipropylene glycol dimethyl ether, and dipropylene glycol methyl ether acetate.
4. The inkjet ink composition according to any one of claims 1 to 3, wherein the glycol-based solvent is one or more selected from the group consisting of ethylene glycol, diethylene glycol, propylene glycol, triethylene glycol, and hexylene glycol.
5. An inkjet ink composition according to any one of claims 1 to 4, comprising the metal oxide nanoparticles in a concentration ranging from 0.05% to 20% by mass.
6. The inkjet ink composition according to any one of claims 1 to 5, wherein the metal oxide nanoparticles comprise one or more of several types of nanoparticles, each containing bismuth oxide, cobalt oxide, copper oxide, magnesium oxide, nickel oxide, zinc oxide, magnesium-doped zinc oxide, and titanium oxide.
7. The inkjet ink composition according to any one of claims 1 to 6, wherein the metal oxide nanoparticles comprise one or more nanoparticles containing nickel oxide, nanoparticles containing zinc oxide, and nanoparticles containing magnesium-doped zinc oxide.
8. The inkjet ink composition according to any one of claims 1 to 7, wherein the metal oxide nanoparticles have an average particle size in the range of 3 nm to 50 nm as determined by dynamic light scattering.
9. The ratio of the mass of the non-alcoholic solvent to the total mass of the glycol-based solvent and the non-alcoholic solvent is within the range of 5% to 35% by mass. The non-alcoholic solvent comprises one or more selected from the group consisting of 3-methoxybutyl acetate, diethylene glycol methyl ethyl ether, propylene glycol diacetate, dipropylene glycol dimethyl ether, and dipropylene glycol methyl ether acetate. The metal oxide nanoparticles are contained in a concentration ranging from 0.05% by mass to 20% by mass. The inkjet ink composition according to any one of claims 1, 4, 6, and 7, wherein the metal oxide nanoparticles have an average particle size in the range of 3 nm to 50 nm as determined by dynamic light scattering.
10. The inkjet ink composition according to any one of claims 1 to 9 is applied to a substrate by an inkjet printing method to form a coating film, A method for manufacturing a display device, comprising curing the aforementioned coating film to form a functional layer.
11. The manufacturing method according to claim 10, wherein the functional layer is one of a hole injection layer, a hole transport layer, and an electron transport layer.
12. A display device comprising one or more layers, each made from a cured product of an inkjet ink composition according to any one of claims 1 to 9.
13. The display device according to claim 12, wherein the one or more layers include any one of a hole injection layer, a hole transport layer, and an electron transport layer.

Description

Inkjet ink composition This disclosure relates to an inkjet ink composition. The layers contained between the anode and cathode in organic electroluminescent elements and quantum dot light-emitting diodes can sometimes be formed by inkjet printing. For example, Patent Document 1 describes forming an electron transport layer by inkjet printing. Furthermore, Patent Document 1 describes forming a hole injection layer, a hole transport layer, and an electron transport layer by inkjet printing. This disclosure aims to provide a technology that can reduce the likelihood of problems occurring when forming a layer of metal oxide nanoparticles between the cathode and anode of a light-emitting element using an inkjet printing method. According to one aspect of the present invention, an inkjet ink composition is provided comprising metal oxide nanoparticles made of a material selected from the group consisting of hole injection materials, hole transport materials, and electron transport materials, and a dispersion medium containing a glycol-based solvent and a non-alcohol-based solvent having a carbon atom number in the range of 7 to 9. According to another aspect of the present invention, an inkjet ink composition is provided in which the proportion of the non-alcoholic solvent to the total of the glycol-based solvent and the non-alcoholic solvent is within the range of 5% to 35% by mass. According to yet another aspect of the present invention, an inkjet ink composition is provided relating to any of the above aspects, wherein the non-alcoholic solvent comprises one or more selected from the group consisting of 3-methoxybutyl acetate, diethylene glycol methyl ethyl ether, propylene glycol diacetate, dipropylene glycol dimethyl ether, and dipropylene glycol methyl ether acetate. According to yet another aspect of the present invention, an inkjet ink composition is provided, wherein the glycol-based solvent is one or more selected from the group consisting of ethylene glycol, diethylene glycol, propylene glycol, triethylene glycol, and hexylene glycol. According to yet another aspect of the present invention, an inkjet ink composition relating to any of the above aspects is provided, comprising the metal oxide nanoparticles in a concentration ranging from 0.05% to 20% by mass. According to yet another aspect of the present invention, an inkjet ink composition is provided that comprises one or more nanoparticles of a plurality of types, each containing bismuth oxide, cobalt oxide, copper oxide, magnesium oxide, nickel oxide, zinc oxide, magnesium-doped zinc oxide, and titanium oxide, according to any of the above aspects. According to yet another aspect of the present invention, an inkjet ink composition is provided that comprises one or more nanoparticles containing nickel oxide, nanoparticles containing zinc oxide, and nanoparticles containing magnesium-doped zinc oxide, as described above. According to yet another aspect of the present invention, an inkjet ink composition is provided in which the metal oxide nanoparticles have an average particle size in the range of 3 nm to 50 nm as determined by dynamic light scattering, as described above. According to yet another aspect of the present invention, an inkjet ink composition is provided relating to any of the above aspects, wherein the ratio of the mass of the non-alcoholic solvent to the total mass of the glycol-based solvent is in the range of 5% to 35% by mass, the non-alcoholic solvent comprises one or more selected from the group consisting of 3-methoxybutyl acetate, diethylene glycol methyl ethyl ether, propylene glycol diacetate, dipropylene glycol dimethyl ether, and dipropylene glycol methyl ether acetate, and the metal oxide nanoparticles are contained in a concentration in the range of 0.05% to 20% by mass, and the average particle size of the metal oxide nanoparticles measured by dynamic light scattering is in the range of 3 nm to 50 nm. According to yet another aspect of the present invention, a method for manufacturing a display device is provided, comprising applying an inkjet ink composition according to any of the above aspects to a substrate by an inkjet printing method to form a coating film, and curing the coating film to form a functional layer. According to yet another aspect of the present invention, a manufacturing method is provided relating to the above aspect, wherein the functional layer is one of a hole injection layer, a hole transport layer, and an electron transport layer. According to yet another aspect of the present invention, a display device is provided comprising one or more layers, each made from a cured product of an inkjet ink composition according to any of the above aspects. According to yet another aspect of the present invention, a display device is provided in which the one or more layers include any one of a hole injection layer, a hole transport layer, and an electron transport layer. This disclosure provides a technol