CN112391084A

CN112391084A - Ink composition

Info

Publication number: CN112391084A
Application number: CN201910758900.5A
Authority: CN
Inventors: 李雪; 张滔; 向超宇
Original assignee: TCL Research America Inc
Current assignee: TCL Corp; TCL Research America Inc
Priority date: 2019-08-16
Filing date: 2019-08-16
Publication date: 2021-02-23

Abstract

The invention belongs to the technical field of display, and particularly relates to an ink composition. The invention provides an ink composition, comprising: the nano-material comprises inorganic nano-materials and a first solvent, wherein the first solvent comprises a naphthalene organic solvent, a naphthalene ring of the naphthalene organic solvent contains a plurality of aliphatic groups, and the aliphatic groups of the aliphatic groups are respectively and independently selected from alkyl groups with the carbon atom number of more than 6 and/or cycloalkyl groups with the carbon atom number of more than 3; the naphthalene-based organic solvent has a naphthalene ring unsaturation degree of 7 or less. The naphthalene organic solvent has good compatibility with inorganic nano materials such as quantum dot materials, and can stably disperse the inorganic nano materials, so that the viscosity of the ink composition is moderate, the ink jet printing requirement is met, the ink film forming is promoted, and the film forming performance is good.

Description

Ink composition

Technical Field

The invention belongs to the technical field of display, and particularly relates to an ink composition.

Background

In recent years, Quantum Dot (QD) luminescent materials play a great role in the fields of Light Emitting Diode (LED) illumination, liquid crystal display and the like, and Quantum dots can replace traditional fluorescent powder, thereby effectively improving the color gamut of LED and liquid crystal display. Quantum Dot Light Emitting Diodes (QLEDs) using Quantum Dot Light Emitting materials as Light Emitting layers have a wide application prospect in the fields of solid state lighting, flat panel display, etc., and have received extensive attention from academic and industrial fields.

The solution processing characteristics of quantum dots enable quantum dot light emitting layers to be prepared by various methods such as spin coating, blade coating, spraying, ink-jet printing and the like. Compared with the former methods, the ink-jet printing technology can accurately deposit the quantum dot light-emitting material at a proper position according to the required dosage, so that the semiconductor material is uniformly deposited to form a thin film layer, the utilization rate of the material is very high, the production cost is reduced, the manufacturing process is simplified, mass production is easy to popularize, the cost is reduced, and the method is an effective method which is generally accepted at present and can solve the manufacturing problem of the large-size QLED screen.

At present, printing ink is mainly prepared by directly dispersing a quantum dot material in a solvent, the requirement on the solvent is high, the relative dispersion stability of the quantum dot material in the organic solvent is required, and the viscosity of the printing ink is required to meet the requirement of ink-jet printing, so that the printing ink can be stably discharged, stably spread, dried uniformly and formed into a film uniformly. The traditional method is to disperse the quantum dot material by using organic solvents such as toluene, chloroform and the like, and although the quantum dot material has good relative dispersion stability in the organic solvents, the obtained printing ink has the problems of low viscosity, poor film forming property and the like. In order to increase the viscosity of the printing ink, some technicians have tried to add a high-molecular polymer with a high viscosity, however, the printing ink has poor dispersion stability to the quantum dots, and the high-molecular polymer has insulating properties, which also reduces the charge transport capability of the quantum dot film.

Disclosure of Invention

The invention mainly aims to provide an ink composition, aiming at solving the problem that the existing ink cannot give consideration to both dispersion stability and proper viscosity.

In order to achieve the above object, the present invention provides an ink composition comprising: the nano-material comprises inorganic nano-materials and a first solvent, wherein the first solvent comprises a naphthalene organic solvent, a naphthalene ring of the naphthalene organic solvent contains a plurality of aliphatic groups, and the aliphatic groups of the aliphatic groups are respectively and independently selected from alkyl groups with the carbon atom number of more than 6 and/or cycloalkyl groups with the carbon atom number of more than 3;

the naphthalene-based organic solvent has a naphthalene ring unsaturation degree of 7 or less.

The solvent of the ink composition provided by the invention comprises a naphthalene organic solvent, a naphthalene ring of the naphthalene organic solvent contains a plurality of aliphatic groups, the aliphatic groups of the aliphatic groups are respectively and independently selected from alkyl with the carbon atom number of more than 6 and/or cycloalkyl with the carbon atom number of more than 3, and the naphthalene organic solvent has good compatibility with inorganic nano materials such as quantum dot materials and can stably disperse the inorganic nano materials, so that the viscosity of the ink composition is moderate, the ink composition meets the requirements of ink-jet printing, the film forming of the ink is promoted, and the film forming performance is good.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is further described in detail with reference to the following embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

In order to solve the problem that the existing printing ink cannot give consideration to both dispersion stability and viscosity, the applicant provides an ink composition, and the specific technical scheme is as follows:

an ink composition comprising: the nano-material comprises inorganic nano-materials and a first solvent, wherein the first solvent comprises a naphthalene organic solvent, a naphthalene ring of the naphthalene organic solvent contains a plurality of aliphatic groups, and the aliphatic groups of the aliphatic groups are respectively and independently selected from alkyl groups with the carbon atom number of more than 6 and/or cycloalkyl groups with the carbon atom number of more than 3;

The solvent of the ink composition provided by the embodiment of the invention comprises a naphthalene organic solvent, a naphthalene ring of the naphthalene organic solvent contains a plurality of aliphatic groups, the aliphatic groups of the aliphatic groups are respectively and independently selected from alkyl groups with the carbon atom number of more than 6 and/or cycloalkyl groups with the carbon atom number of more than 3, the naphthalene organic solvent has good compatibility with quantum dot materials, so that the quantum dot materials can be relatively dispersed and stabilized in the organic solvent, and the mixture viscosity of the naphthalene organic solvent and the quantum dot materials is moderate, thereby meeting the requirements of ink-jet printing, promoting the film formation of ink and having good film-forming performance.

Specifically, the naphthalene organic solvent is used as a solvent of the inorganic nano material and is a compound with two mutually fused six-membered rings. In the embodiment of the invention, the unsaturation degree of the naphthalene ring of the naphthalene organic solvent is less than 7, for example, 7, 6, 5, 4, 3 or 2, which has good compatibility with inorganic nano materials, especially quantum dot materials, so that the inorganic nano materials can be relatively dispersed and stabilized in the organic solvent, and the naphthalene organic solvent has little influence on the efficiency and the service life of the quantum dot materials, does not influence the charge transport capability of the light-emitting layer film, and can ensure the photoelectric performance of the light-emitting film. The mixture of the naphthalene organic solvent and the quantum dot material has moderate viscosity, meets the requirement of ink-jet printing, promotes the film formation of the ink and has good film forming performance.

In the embodiment of the present invention, the naphthalene ring of the naphthalene organic solvent contains a plurality of aliphatic groups, each of the aliphatic groups of the plurality of aliphatic groups is independently selected from an alkyl group having 6 or more carbon atoms and/or a cycloalkyl group having 3 or more carbon atoms, and the number of aliphatic groups is one or more. The naphthalene organic solvent has long alkane or cycloalkane chain segments, and is particularly suitable for quantum dot materials with most nonpolar chain segments as ligands, such as oil-soluble quantum dot materials, so that the quantum dot materials are dispersed more uniformly, and have higher surface tension, the ink is not easy to climb on the side face of a bank and spread more uniformly in the bank, the film forming property of the ink is improved, the charge transmission effect of a light-emitting layer film is ensured, and good photoelectric property is maintained. In the present specification, the aliphatic group refers to a group containing only two atoms of carbon and hydrogen, and generally refers to a radical remaining after a corresponding hydrocarbon loses one hydrogen atom (H), including but not limited to alkyl, cycloalkyl, alkenyl, alkynyl and the like, such as methyl, ethyl, propyl, isopropyl, methylene, vinyl, allyl, ethynyl and the like.

In the present embodiment, the aliphatic group is selected from an alkyl group having a carbon number of preferably 6 to 25 or a cycloalkyl group having a carbon number of preferably 3 to 25, more specifically, 8 to 16, 10 to 20, 7 to 15, 9 to 23, 17 to 24 or 13 to 19, and 5 to 20, 7 to 15, 9 to 23, 10 to 18, 13 to 19 or 17 to 21.

Preferably, the alkyl group is selected from methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, nonyl, decyl, undecyl, dodecyl or octadecyl, or an isomer of one selected from propyl, butyl, pentyl, hexyl, heptyl, octyl, nonyl, decyl, undecyl, dodecyl, octadecyl. In some embodiments, the alkyl group is selected from at least one of methyl, ethyl, propyl, isopropyl, isobutyl, sec-butyl, tert-butyl, pentyl, isopentyl, neopentyl, hexyl, and isohexyl.

Preferably, the cycloalkyl group is selected from cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl, cyclononyl, cyclodecyl, cycloundecyl or hexadecyl, or an isomer of one selected from cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl, cyclononyl, cyclodecyl, cycloundecyl, hexadecyl. In some embodiments, the cycloalkyl group is selected from at least one of cyclobutyl, cyclopentyl, and cyclohexyl.

Further, the aliphatic radical of the aliphatic radicals can be selected from substituted or unsubstituted aliphatic radicals. Preferably, in the substituted aliphatic group, the substituent is preferably one of hydroxyl, aryl, heteroaryl, nitro, cyano, amino, halogen, carboxyl, ester, carbonyl, alkenyl, alkynyl, alkoxy, aryloxy, heteroaryloxy, alkoxycarbonyl, perfluoroalkyl, perfluoroalkoxy, thioalkoxy, sulfonamido, amide, and silyl, and in some embodiments, the substituent is selected from aryl and heteroaryl. Wherein, the aryl is preferably phenyl, biphenyl, triphenyl, benzo, naphthyl, anthryl, peribenzo naphthyl, phenanthryl, fluorenyl, pyrenyl, chrysenyl, perylenyl and azulenyl; the heteroaryl group is preferably a dibenzothienyl, dibenzofuryl, furyl, thienyl, benzofuryl, benzothienyl, carbazolyl, pyrazolyl, imidazolyl, triazolyl, isoxazolyl, thiazolyl, oxadiazolyl, oxatriazolyl, dioxazolyl, thiadiazolyl, pyridyl, pyridazinyl, pyrimidinyl, pyrazinyl, triazinyl, oxazinyl, thiazinyl, oxadiazinyl, indolyl, benzimidazolyl, indazolyl, indolizinyl, benzoxazolyl, isoxazolyl, benzothiazolyl, quinolyl, isoquinolyl, o-diaza (hetero) naphthyl, quinazolinyl, quinoxalinyl, naphthyl, phthalidyl, pteridinyl, oxaanthracenyl, acridinyl, phenazinyl, phenothiazinyl, phenoxazinyl, dibenzoselenophenyl, benzoselenophenyl, benzofuropyridpyrazolyl, indocarbazolyl, pyridylindolyl, pyrrolydinoindolyl, diazidoindolyl, Furan bipyridyl, benzothiophene furopyridinyl, thienodipyridyl, benzoselenophenopyridinyl and selenophenedipyridinyl.

As an embodiment, the naphthalene-based organic solvent has the following structure:

wherein m is₁And m₂Sum of (1) and n₁And n₂The sum of (A) is not 0 at the same time;

R₁、R₂each independently selected from hydrogen, substituted or unsubstituted aliphatic radical, R₁And R₂Not simultaneously hydrogen, and the aliphatic group is selected from an alkyl group having 6 or more carbon atoms or a cycloalkyl group having 3 or more carbon atoms.

It can be understood that when m is₁、m₂、n₁And n₂When both are greater than 1, each R on the naphthalene ring₁The substituents being different, R₂The same is true. Meanwhile, two mutually fused six-membered rings of the naphthalene ring are not primary and secondary, and the substituent R on the naphthalene ring₁、R₂The substitution position of (A) is not limited to the specific position shown in the formula, R₁The substituent can simultaneously substitute two mutually fused six-membered rings of the naphthalene ring, or only one of the six-membered rings; r₂The substituent can also be simultaneously substituted on two mutually fused six-membered rings of the naphthalene ring or only one of the six-membered rings. At the same time, R₁The substitution position of the substituent being free ofR₂Influence of the substituents, R₂And R₁The substituents can be arranged on the same ring at the same time or on two mutually fused six-membered rings of the naphthalene ring independently of one another.

Further, said R₁Selected from alkyl groups having 6 to 25 carbon atoms; and/or, said R₂Is selected from cycloalkyl with 3-25 carbon atoms. In some embodiments, in the naphthalene organic solvent, R₁Preferably an alkyl group having 6 to 25 carbon atoms, R₂Is selected from cycloalkyl with 3-25 carbon atoms. In other embodiments, in the naphthalene organic solvent, R₁Preferably an alkyl group having 6 to 25 carbon atoms, R₂Is selected from H. In still other embodiments, in the naphthalene organic solvent, R₁Selected from H, R₂Cycloalkyl groups having 3 to 25 carbon atoms are preferred.

Preferably, the naphthalene-based organic solvent further includes a substituent on the naphthalene ring, wherein the substituent is selected from one of aryl, heteroaryl, nitro, cyano, amino, halogen, carboxyl, ester, carbonyl, alkoxy, aryloxy, heteroaryloxy, alkoxycarbonyl, perfluoroalkyl, perfluoroalkoxy, thioalkoxy, sulfonamido, amide and silyl.

In the embodiment of the invention, the boiling point of the naphthalene organic solvent is preferably 120-450 ℃, and the naphthalene organic solvent can be completely removed in the post-treatment process by selecting a heating or cooling and/or pressure reduction mode, so that the charge transmission of the luminescent layer film is ensured to be effective, the luminescent performance is exerted, and the problem of nozzle blockage caused by too fast volatilization of the solvent when the boiling point is too low can be avoided.

In the embodiment of the present invention, at least one of the naphthalene organic solvents, for example, a mixed solvent of two or more of the naphthalene organic solvents may be used as long as the boiling point of the mixed solvent satisfies 120 ℃ to 450 ℃, and the viscosity and surface tension of the mixed solvent satisfy the requirements of inkjet printing.

As a preferred embodiment, the naphthalene organic solvent is selected from one or more of the following compounds:

dodecyl naphthalene;

1-cyclopropylnaphthalene;

2-butyl-3-hexylnaphthalene;

1,2,3, 4-tetrahydro-7-butyl-1-hexylnaphthalene;

7-butyl-1-hexylnaphthalene;

1-hexylnaphthalene;

2, 3-dimethyl-5- (4-methylpentyl) naphthalene;

1- (1-methylenepentyl) -naphthalene;

1- (1-methyleneheptyl) -naphthalene;

decahydro-1, 4-dimethyl-5-octylnaphthalene;

1-undecylnaphthalene;

decahydro-2, 6-dimethyl-3-octylnaphthalene;

2, 6-dimethyl-3-octylnaphthalene;

1, 4-dimethyl-5-octylnaphthalene;

sec-octadecyl-naphthalene;

hexadecyl naphthalene;

octadecylnaphthalene;

2-dodecylnaphthalene;

1,2,3, 4-tetrahydro-1-methyl-4-octylnaphthalene;

2-nonyl naphthalene;

dinonyl naphthalene;

2-octadecylnaphthalene;

2-hexylnaphthalene;

1-decylnaphthalene;

2-cycloheptylnaphthalene.

In the present embodiment, the viscosity of the ink composition at 20 ℃ to 30 ℃ is preferably 0.5 to 60cPs, more preferably 1.0mpa.s to 15.0mpa.s, specifically 1,3, 5, 8, 10, 12, 15; the ink composition preferably has a surface tension of 20 to 80mN/m, specifically 25, 27, 30, 31, 35, 38, 40, 44, 45, 48, 50, 52, 55, 56, 60, 61, 65, 67, 70, 74, 75 at 20 ℃ to 30 ℃.

In the embodiment of the invention, the ink composition only contains the inorganic nano material and the naphthalene organic solvent, and after the ink composition is subjected to ink-jet printing to form a film, the naphthalene organic solvent is removed to form the quantum dot luminescent film. In some embodiments, the ink composition further comprises a second solvent and/or a functional assistant in addition to the naphthalene organic solvent, for further adjusting the dispersibility, viscosity, volatilization speed of the solvent, and charge transport property of the inorganic nanomaterial in the ink.

The second organic solvent includes, but is not limited to, one or more of chlorobenzene, o-dichlorobenzene, tetrahydrofuran, anisole, morpholine, toluene, o-xylene, m-xylene, p-xylene, n-hexane, dichloromethane, chloroform, 1, 4-dioxane, 1,2 dichloroethane, 1,1, 1-trichloroethane, 1,1,2, 2-tetrachloroethane, tetrahydronaphthalene, decalin, phenoxytoluene, dodecane, 1-methoxynaphthalene, 1-butylnaphthalene, o-dimethoxybenzene, 1-methylnaphthalene, 1, 2-dimethylnaphthalene, cyclohexylbenzene, 1,2, 4-trimethoxybenzene, phenylhexane, tetradecane, 1, 2-dimethylnaphthalene, 4-isopropylbiphenyl, 2-isopropylnaphthalene, 1-ethylnaphthalene, 1,2,3, 4-tetrahydronaphthalene, as long as the boiling point, viscosity and surface tension of the ink are within the above numerical ranges. In one embodiment, the second organic solvent is added in an amount of 50% by mass or more of the total solvent of the ink.

The auxiliaries include, but are not limited to, one or more of a charge transport agent, a viscosity modifier, and a dispersant, as long as the boiling point, viscosity, and surface tension of the ink are within the above numerical ranges. In one embodiment, the auxiliary agent accounts for 0.1-10% of the total weight of the solvent. In another embodiment, the charge transport agent can improve charge transport performance after the ink composition is prepared into a quantum dot material layer such as a quantum dot light emitting layer, so that charge transport is smoother and more effective, and the threshold voltage is reduced, so that electrons and holes can perform composite radiation luminescence, and the charge transport agent is preferably at least one of polycarbazole, polyfluorene, polyaniline, poly (p-phenylene vinylene), polyacetylene, poly (p-phenylene), polythiophene, polypyridine, polypyrrole and derivatives thereof. In a further embodiment, the viscosity modifier is used to ensure stable release of the ink from the nozzles of the inkjet printhead without clogging, while having good film forming properties, preferably at least one of a polyhydric alcohol, an alkyl glycol ether or trimethylolpropane, trimethylolethane, casein, carboxymethylcellulose. More specifically, the polyhydric alcohol is at least one of ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, dipropylene glycol, hexylene glycol, 1, 3-butylene glycol, 1, 4-butylene glycol, 1, 5-pentanediol, 2-butene-1, 4-diol, 2-methyl-2-pentanediol, 1,2, 6-hexanetriol, glycerol, polyethylene glycol, dipropylene glycol, and polyvinyl alcohol. The alkyl glycol ether is at least one of polyethylene glycol monobutyl ether, diethylene glycol monoethyl ether, dipropylene glycol monomethyl ether and propylene glycol n-propyl ether. In still another embodiment, the dispersant is used to ensure that the quantum dot material can be uniformly dispersed in the solvent and the dispersion system is stable, and is preferably an anionic surfactant, a cationic surfactant, a nonionic surfactant or an amphoteric surfactant. More specifically, the anionic surfactant includes, but is not limited to, at least one of carboxylate (e.g., ether carboxylate and sulfosuccinate), sulfate (e.g., sodium lauryl sulfate), sulfonate (e.g., dodecylbenzene sulfonate, alpha-olefin sulfonate, alkyl diphenyl ether disulfonate, fatty acid taurate, alkyl naphthalene sulfonate), phosphate (e.g., phosphate esters of alkyl and aryl alcohols), phosphonate, and amine oxide surfactants and anionic fluorinated surfactants. The cationic surfactant includes, but is not limited to, at least one of quaternary ammonium compounds, cationic amine oxides, ethoxylated fatty amines, and imidazoline surfactants. The nonionic surfactant includes, but is not limited to, at least one of linear or secondary alcohol ethoxylates, alkylphenol ethoxylates, fluorosurfactants, polyoxyethylene esters of fatty acids, polyoxyethylene ethers of fatty amines, polyoxyethylene block copolymers and propoxylated block copolymers, polyoxyethylene and propylsilicone-based surfactants, alkyl polyglycosides, and acetylene polyethylene oxide surfactants. The amphoteric surfactant includes, but is not limited to, at least one of trimethylamine ethylester, sultaine, and aminopropionate.

In a preferred embodiment, the inorganic nanomaterial is 0.01% to 40.0% and the naphthalene organic solvent is 1% to 90% of the total weight of the ink composition is 100%.

In some embodiments, the ink composition comprises the following components in percentage by weight, based on 100% of the total weight of the ink composition:

0.01 to 40.0 percent of inorganic nano material;

60.0% -99.9% of solvent;

wherein the naphthalene organic solvent accounts for 1-90% of the total weight of the solvent.

Further, the above inorganic nano-materials are used in an amount ranging from 0.01 to 20.0% by weight, preferably from 4 to 15% by weight, based on the total weight of the ink composition; the naphthalene organic solvent preferably accounts for 30-70% of all solvents.

In an embodiment of the invention, the inorganic nanomaterial comprises at least one of a quantum dot material, a perovskite nanoparticle material, a metal nanoparticle material and a metal oxide nanoparticle material.

Preferably, the inorganic nano-material is selected from quantum dot materials, including group IV quantum dot materials, group II-VI quantum dot materials, group II-V quantum dot materials, group III-VI quantum dot materials, group IV-VI quantum dot materials, group I-III-VI quantum dot materials, group II-IV-VI quantum dot materials, and group II-IV-V quantum dot materials.

In an embodiment, the quantum dot material is selected from at least one of CdSe, CdS, CdTe, ZnO, ZnSe, ZnS, ZnTe, HgS, HgSe, HgTe and CdZnSe.

In another embodiment, the quantum dot material is selected from at least one of InAs, InP, InN, GaN, InSb, InAsP, InGaAs, GaAs, GaP, GaSb, AlP, AlN, AlAs, AlSb, CdSeTe, and ZnCdSe.

In yet another embodiment, the particle size of the quantum dot material is 1-20 nm.

In still another embodiment, the quantum dot material is a homogeneous binary component single-core structure, a homogeneous multi-component alloy component single-core structure of a quantum dot, a gradient single-core structure of a multi-component alloy component of a quantum dot, a discrete core-shell structure of a binary component of a quantum dot, a discrete core-shell structure of a multi-component alloy component of a quantum dot, or a gradient core-shell structure of a multi-component alloy component of a quantum dot.

In the embodiment of the invention, the quantum dot material is preferably an oily quantum dot. The oily quantum dots can be well dispersed in the naphthalene organic solvent, so that the dispersion stability is ensured; meanwhile, the oil-soluble quantum dots are prepared in the oil phase at high temperature, the stability is high, and the ligand is the oil-soluble ligand, so that the water absorption of a device prepared from the quantum dot material is reduced, and the efficiency of the device can be maintained after long-term use. Further, the surface of the oily quantum dot has ligands, and the ligands include acid ligands, thiol ligands, amine ligands, (oxy) phosphine ligands, phospholipids, lecithin and polyvinyl pyridine. Still further, the acid ligand comprises one or more of decaacid, undecylenic acid, tetradecanoic acid, oleic acid, and stearic acid; the thiol ligand comprises one or more of octaalkylthiol, dodecylthiol and octadecylthiol; the amine ligand comprises one or more of oleylamine, octadecylamine and octamine; the (oxy) phosphine ligand comprises one or more of trioctylphosphine and trioctylphosphine.

Correspondingly, the embodiment of the invention also provides a preparation method of the ink composition, which comprises the following steps:

s01, providing the inorganic nano material and the naphthalene organic solvent according to the formula;

s02, mixing the inorganic nano material with the naphthalene organic solvent to uniformly disperse the inorganic nano material in the naphthalene organic solvent.

In one embodiment, in step S02, an appropriate amount of assistant and a second organic solvent are added to obtain an inorganic nanomaterial printing ink with appropriate viscosity and surface tension.

Preferably, the mixing is performed by stirring for 20-40 min.

When the luminescent layer is used, a proper ink-jet printer is selected to perform ink-jet printing on the inorganic nano material printing ink to coat the inorganic nano material printing ink on a substrate material, and then organic solvents such as alkyl substituted naphthalene alcohols and the like in the inorganic nano material luminescent layer film are removed under the action of heating, temperature reduction and/or vacuum pressure, so that other organic substances in the ink composition except the inorganic nano material are completely volatilized, and the quantum dot material luminescent layer film with the pixel dot matrix is formed.

Preferably, the heating mode comprises various modes, such as pulse heating or continuous heating, and the heating temperature is 60-180 ℃ and the time is 0-30 min. The temperature for cooling is 0-20 ℃; the vacuum degree of the reduced pressure vacuum is 1 × 10^-6And (3) the Torr is at normal pressure, so that the naphthalene organic solvent and other organic solvents in the light-emitting layer film can be completely volatilized, and the photoelectric property of the light-emitting layer film is not damaged.

Preferably, the inorganic nanomaterial light-emitting layer film is formed to a dry film thickness of 10 to 100nm, more preferably 20 to 50 nm.

In order that the details of the above-described practice and operation of the invention will be clearly understood by those skilled in the art, and the improved performance of an ink composition of the present invention in its examples, the practice of the invention is illustrated by the following examples.

Example 1

The embodiment provides a red quantum dot ink which comprises the following components in percentage by weight: 10% of quantum dot material, 10% of cycloethyl benzene and 80% of 2-butylnaphthalene; wherein, the quantum dot material is selected from oleylamine-stabilized red CdSe/ZnS, and the cycloethylbenzene and the 2-butylnaphthalene are organic solvents which are refined to have the purity of more than 99.9 percent through water removal and oxygen removal.

During preparation, a quantum dot material, cycloethyl benzene and 2-butylnaphthalene are sequentially added into a 500mL single-neck flask under the stirring state, and stirred for 30 min.

When in use, the red quantum dot ink is injected into an ink-jet printer and is printed into a red quantum dot layer with the resolution of 20 multiplied by 30 mu m and 200 multiplied by 200 ppi; then, the mixture was heated on a hot plate to 145 ℃ and evacuated at 1X 10^-4And volatilizing and drying for 30min under the condition of Torr to obtain the monochromatic quantum dot luminescent layer.

Example 2

The embodiment provides a green quantum dot ink which comprises the following components in percentage by weight: 10% of quantum dot material, 25% of tetradecane, 40% of decalin and 25% of 1-decylnaphthalene; the quantum dot material is selected from green CdZnSe/CdZnS with stable oleylamine, and the tetradecane, the decalin and the 1-decylnaphthalene are all organic solvents which are refined to have the purity of more than 99.9 percent through water removal and oxygen removal.

During preparation, a quantum dot material, tetradecane, decalin and 1-decylnaphthalene are sequentially added into a 500mL single-neck flask under the stirring state, and the mixture is stirred for 30 min.

When in use, the green quantum dot printing ink is injected into an ink-jet printer to be printed into a red quantum dot layer with the resolution of 20 multiplied by 30 mu m and 200 multiplied by 200 ppi; and then heating the mixture on a hot plate to 180 ℃, and volatilizing and drying the mixture for 30min under nitrogen flow to obtain the monochromatic quantum dot light-emitting layer.

Example 3

The embodiment provides a three-color quantum dot ink which comprises the following components in percentage by weight: 10% of quantum dot material, 40% of cyclohexylbenzene, 40% of o-xylene, 10% of 1,2,3, 4-tetrahydro-1-methyl-4-octylnaphthalene; the quantum dot material is selected from a mixture of oleylamine-stabilized blue CdS/CdZnS, green CdZnSe/CdZnS and red CdSe/ZnS, and the cyclohexylbenzene, the o-xylene and the 1,2,3, 4-tetrahydro-1-methyl-4-octylnaphthalene are all organic solvents which are refined to be more than 99.9 percent in purity by removing water and deoxidizing.

During preparation, a quantum dot material, cyclohexylbenzene, o-xylene and 1,2,3, 4-tetrahydro-1-methyl-4-octylnaphthalene are sequentially added into a 500mL single-neck flask under the stirring state, and stirred for 30 min.

When in use, the three-color quantum dot ink is injected into an ink-jet printer to be printed into blue, green and red side-by-side quantum dot layers with the resolution of 200X 200ppi and the color is 20X 30 mu m, the temperature is reduced to 15 ℃, and the vacuum is 1X 10^-5And volatilizing and drying for 30min under the Torr to obtain the tricolor quantum dot light-emitting layer.

The above description is only for the purpose of illustrating the preferred embodiments of the present invention and is not to be construed as limiting the invention, and any modifications, equivalents and improvements made within the spirit and principle of the present invention are intended to be included within the scope of the present invention.

Claims

1. An ink composition, comprising: the nano-material comprises inorganic nano-materials and a first solvent, wherein the first solvent comprises a naphthalene organic solvent, a naphthalene ring of the naphthalene organic solvent contains a plurality of aliphatic groups, and the aliphatic groups of the aliphatic groups are respectively and independently selected from alkyl groups with the carbon atom number of more than 6 and/or cycloalkyl groups with the carbon atom number of more than 3;

2. The ink composition according to claim 1, wherein the number of carbon atoms of the alkyl group is 6 to 25; and/or

The number of carbon atoms of the cycloalkyl is 3 to 25.

3. The ink composition of claim 1, wherein the alkyl group is selected from hexyl, heptyl, octyl, nonyl, decyl, undecyl, dodecyl, or octadecyl, or an isomer of one selected from propyl, butyl, pentyl, hexyl, heptyl, octyl, nonyl, decyl, undecyl, dodecyl, and octadecyl; and/or

The cycloalkyl group is selected from cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl, cyclononyl, cyclodecyl, cycloundecyl or hexadecyl, or an isomer of one selected from cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl, cyclononyl, cyclodecyl, cycloundecyl and hexadecyl.

4. The ink composition of claim 1, wherein the aliphatic group of the plurality of aliphatic groups is a substituted or unsubstituted aliphatic group; in the substituted aliphatic group, the substituent is at least one selected from the group consisting of a hydroxyl group, an aryl group, a heteroaryl group, a nitro group, a cyano group, an amino group, a halogen group, a carboxyl group, an ester group, a carbonyl group, an alkenyl group, an alkynyl group, an alkoxy group, an aryloxy group, a heteroaryloxy group, an alkoxycarbonyl group, a perfluoroalkyl group, a perfluoroalkoxy group, a thioalkoxy group, a sulfonamido group, an amide group, and a silyl group.

5. The ink composition as claimed in claim 1, wherein the naphthalene-based organic solvent further comprises other substituents on the naphthalene ring, the other substituents being selected from at least one of aryl, heteroaryl, nitro, cyano, amino, halogen, carboxyl, ester, carbonyl, alkoxy, aryloxy, heteroaryloxy, alkoxycarbonyl, perfluoroalkyl, perfluoroalkoxy, thioalkoxy, sulfonamido, amide and silyl groups.

6. The ink composition according to claim 1, wherein the naphthalene-based organic solvent has a boiling point of 120 ℃ to 450 ℃ or lower; and/or

The naphthalene organic solvent is selected from dodecyl naphthalene, 1-cyclopropyl naphthalene, 2-butyl-3-hexyl naphthalene, 1,2,3, 4-tetrahydro-7-butyl-1-hexyl naphthalene, 2, 3-dimethyl-5- (4-methyl amyl) naphthalene, 1- (1-methylene amyl) -naphthalene, 1- (1-methylene heptyl) -naphthalene, decahydro-1, 4-dimethyl-5-octyl naphthalene, 1-undecyl naphthalene, decahydro-2, 6-dimethyl-3-octyl naphthalene, 1, 4-dimethyl-5-octyl naphthalene, 2-methyl-3-octyl naphthalene, 2, 4-dimethyl-5-octyl naphthalene, 2-methyl-1, 4-methyl, Any one or more of sec-octadecyl-naphthalene, hexadecylnaphthalene, octadecylnaphthalene, 2-dodecylnaphthalene, 1,2,3, 4-tetrahydro-1-methyl-4-octylnaphthalene, 2-nonylnaphthalene, dinonylnaphthalene, 2-octadecylnaphthalene, 2-hexylnaphthalene, 1-decylnaphthalene, and 2-cycloheptylnaphthalene.

7. Ink composition according to any one of claims 1 to 6, characterized in that it further comprises a second solvent and/or an auxiliary agent; and/or

The viscosity of the ink composition at 20-30 ℃ is 0.5-60 cPs; and/or

The surface tension of the ink composition at 20-30 ℃ is 20-80 mN/m.

8. The ink composition as claimed in claim 7, wherein the inorganic nanomaterial is 0.01% to 40.0% and the naphthalene organic solvent is 1% to 90% of the balance, based on 100% of the total weight of the ink composition.

9. The ink composition of claim 7, wherein the auxiliary agent comprises one or more of a charge transport agent, a viscosity modifier, and a dispersant.

10. The ink composition of claim 9, wherein the charge transport agent is selected from at least one of polycarbazole, polyfluorene, polyaniline, poly-p-phenylenevinylene (p-phenylene vinylene), polyacetylene, poly-p-phenylene, polythiophene, polypyridine, polypyrrole, and derivatives thereof; and/or

The viscosity regulator is selected from at least one of polyhydric alcohol, alkyl glycol ether or trimethylolpropane, trimethylolethane, casein and carboxymethyl cellulose; and/or

The dispersing agent is selected from anionic surfactant, cationic surfactant, nonionic surfactant or amphoteric surfactant.

11. The ink composition of any one of claims 1 to 6, wherein the inorganic nanomaterials comprise at least one of quantum dot materials, perovskite nanoparticle materials, metal nanoparticle materials, and metal oxide nanoparticle materials.