TWI782061B - Ink composition and method for producing the same, light conversion layer and color filter - Google Patents

Abstract

The present invention provides an ink composition with improved moisture stability, a manufacturing method thereof, and a light conversion layer and a color filter using the ink composition.

The present invention is an ink composition, a light conversion layer and a color filter with the light conversion layer. The above ink composition is characterized in that it contains luminescent nano crystal grains, a thermosetting resin and an organic solvent, and the organic solvent is The LogP value is not less than -1.0 and not more than 6.5; the light conversion layer has a plurality of pixel parts, and the plurality of pixel parts have a pixel part including a cured product of the ink composition.

Description

Ink composition and its manufacturing method, light conversion layer and color filter

The invention relates to an ink composition and its manufacturing method, a light conversion layer and a color filter.

The color filter pixel portion of a display such as a conventional liquid crystal display device, for example, uses a curable resist material containing red organic pigment particles or green organic pigment particles, an alkali-soluble resin and/or an acrylic monomer, and is exposed to light by light. Manufactured by etching.

In recent years, there is a strong demand for low power consumption of displays, and active research is being carried out on the formation of luminous nanocrystals such as quantum dots, quantum rods, and other inorganic phosphor particles instead of the above-mentioned red organic pigment particles or green organic pigment particles. Method of color filter pixel parts such as red pixel, green pixel, etc.

However, in the method of manufacturing a color filter using the photolithography method described above, according to the characteristics of the manufacturing method, there is a disadvantage that the resist material other than the pixel portion including the relatively expensive light-emitting nanocrystal particles becomes waste. Under such circumstances, in order to eliminate the above-mentioned waste of resist material, research has been started on forming a photoconverting substrate pixel portion by an inkjet method.

In such an ink composition, it is known to use various thermosetting resins as the thermosetting resins. As such thermosetting resins, there are many high-viscosity liquid or solid ones. In order to facilitate handling, use Most of them are dissolved or dispersed in organic solvents. There is no specific opinion on choosing an organic solvent that satisfies which characteristics and using it can reduce the defects of the light conversion layer composed of its cured product. The actual situation is: use any thermosetting resin and organic solvent separately and make them harden Then, a light conversion layer is formed, and various characteristic items of the light conversion layer are measured, and the presence or absence of defects is checked on the basis of trial and error.

For example, there is a problem that the quantum dot ink composed of luminescent nano crystal grains is degraded by the water in the air.

Patent Document 1 discloses a preparation containing a solvent saturated or supersaturated with an inert gas and a functional organic material, and discloses a preparation in which the total amount of oxygen and water is kept below a certain level.

However, this Patent Document 1 does not describe the use of a thermosetting resin.

And it does not show the actual measurement data of the water content, and it is not clear which degree of water content will have the degree of influence.

In addition, regarding the organic light-emitting materials for OLEDs, it is shown in the examples that there is an effect of the atmosphere, but regarding the quantum dots composed of luminescent nanocrystal grains, it is not revealed whether they will show specific technical effects. Regarding the quantum dots , it is not clear to what extent the technical effect will be. Moreover, the luminescent material for OLED shown in the embodiment has no wavelength conversion function, and cannot be transferred to a light conversion layer obtained by quantum dots.

Also, in the case of using a solvent that saturates or supersaturates the inert gas, the following problem arises: when using a pump to transport the coating liquid to the coating head or nozzle for coating, the flow path of the coating liquid Air bubbles are generated inside, air bubbles are mixed into the coating liquid, and the coated product becomes defective. Also, when used as an inkjet ink, there is a serious problem that air bubbles are generated in the printing head of an inkjet printer, resulting in ejection failure.

Patent Document 2 discloses a composition containing quantum dots that does not substantially contain water. However, the actual measurement data of the moisture content is not shown, and it is not clear what level of moisture content is effective.

Also, it does not describe the IJ method, nor does it describe the application of the light conversion layer to the color filter (CF) for LCD.

In the IJ method, ink is ejected from the nozzle of the printing head into the atmosphere, exposed to moisture in the air, and exposed to the atmosphere after printing. Since the CF substrate has a large area, setting the printing surface near the head or on the printing substrate as an inert gas environment without moisture has the problem of greatly increasing the equipment price and running cost. It is therefore desirable to have an ink that exhibits less performance degradation of the quantum dots even when the ink is exposed to atmospheric moisture.

Therefore, an ink with less degradation of quantum dots and less generation of air bubbles during liquid delivery or in the IJ head is sought.

Furthermore, Patent Document 3 discloses that oxygen is degassed by introducing an inert gas to remove dissolved oxygen, and that degassing is performed by reducing pressure. And it is disclosed that the luminescence of the oxygen-free quantum dot (QD) composition is not easily deteriorated.

However, when the IJ printing ink or ink cured film is exposed to the atmosphere, the QDs are exposed to moisture in the atmosphere. In such a case, deterioration cannot be suppressed by known methods, and a QD composition or a cured product thereof which is advantageous for IJ printing is desired.

Although Patent Documents 2 to 3 describe that acrylate monomers or oligomers can be used as photocurable compounds, the monomers used in the experiments are only dodecanediol di(meth)acrylate. Such as di(meth)acrylates containing long-chain alkylene radicals. These are not thermosetting resins.

[Prior Art Literature]

[Patent Document]

[Patent Document 1] Japanese Patent Application Publication No. 2016-501430

[Patent Document 2] US Laid-Open Patent 2014/0027673 specification

[Patent Document 3] WO2013/122820 Publication

An ink composition using luminescent nanocrystal particles, or a light conversion layer using the ink composition is unstable to moisture in the atmosphere, so stability must be improved.

The object of the present invention is to provide an ink composition with improved moisture stability, a method for producing the same, and a light conversion layer and a color filter using the ink composition.

The present invention provides inventions of the following embodiments respectively.

According to the ink composition of the following 1, since an organic solvent having a specific LogP value range is used as the organic solvent, no adverse events will occur in its cured product, for example, the stability in the atmosphere can be improved.

1. An ink composition, which contains luminescent nanocrystal grains, a thermosetting resin, and an organic solvent, and the LogP value of the organic solvent is -1.0 to 6.5.

2. An ink composition, which contains luminous nanocrystal grains, a thermosetting resin, and an organic solvent, and the LogP value of the organic solvent is -1.0 or more to 6.5 or less, based on Karl-Fischer moisture measurement The obtained moisture (H ₂ O) content rate is 90ppm or less.

3. An ink composition for inkjet, which contains luminescent nanocrystal grains, a thermosetting resin, and an organic solvent, and the LogP value of the above organic solvent is -1.0 or more to 6.5 or less, which is measured based on the card-fee moisture meter The moisture (H ₂ O) content is 90 ppm or less.

4. A method for producing the inkjet ink composition described in 3 above, which is a method for producing the above-mentioned ink composition, wherein the above-mentioned ink composition is depressurized to remove dissolved gas.

5. The inkjet ink composition according to the above 3, wherein the water (H ₂ O) content is 20 ppm or less.

6. The inkjet ink composition according to 3 or 5 above, wherein the thermosetting resin is alkali-insoluble.

7. The inkjet ink composition according to any one of 3, 5 or 6 above, which is capable of forming an alkali-insoluble coating film.

8. The inkjet ink composition as described in any one of 3, 5, 6 or 7 above, which has a surface tension of 20 to 40 mN/m.

9. The inkjet ink composition described in any one of 3, 5, 6, 7 or 8 above, which has a viscosity of 2~20mPa‧s.

10. The inkjet ink composition according to any one of 3, 5, 6, 7, 8 or 9 above, which further contains a solvent having a boiling point of 180°C or higher.

11. The inkjet ink composition according to any one of 3, 5, 6, 7, 8, 9 or 10 above, which is used for a color filter.

12. A light conversion layer comprising a cured product of the ink composition described in any one of 1 to 3 above.

13. A light conversion layer, wherein the light conversion layer composed of a cured product of the ink composition described in any one of 1 to 3 above is insoluble in alkali.

14. A light conversion layer comprising a plurality of pixel portions, and the plurality of pixel portions have: an inkjet ink composition comprising any one of the above-mentioned 3, 5, 6, 7, 8, 9 or 10. The pixel part of the hardened product.

15. The light conversion layer according to any one of the above 12 to 14, further comprising a light-shielding portion provided between the plurality of pixel portions, and the plurality of pixel portions have: a first pixel portion comprising the cured product and containing, as the above-mentioned luminescent nanocrystals, luminescent nanocrystals that absorb light of a wavelength in the range of 420 to 480 nm and emit light having a luminescence peak wavelength in the range of 605 to 665 nm; and the second pixel portion, which includes The cured product contains, as the above-mentioned luminescent nanocrystals, absorbing light having a wavelength in the range of 420 to 480 nm and emitting light having a wavelength of luminescence value in the range of 500 to 560 nm.

16. The light conversion layer according to any one of the above 12 to 15, wherein the plurality of pixel portions further have a third pixel portion, and the transmittance of the third pixel portion to light having a wavelength in the range of 420 to 480 nm more than 30%.

17. A color filter comprising the light conversion layer according to any one of 12 to 16 above.

The present invention provides an ink composition with improved stability in the atmosphere, a manufacturing method thereof, and a light conversion layer and a color filter using the ink composition.

10‧‧‧pixel part

10a‧‧‧1st pixel part

10b‧‧‧The second pixel part

10c‧‧‧The third pixel part

11a‧‧‧The first luminescent nanocrystal grain

11b‧‧‧The second luminous nanocrystal grain

12a‧‧‧First light-scattering particle

12b‧‧‧Second light scattering particles

13a‧‧‧The first hardening component

13b‧‧‧The second hardening component

13c‧‧‧The third hardening component

20‧‧‧shading part

30‧‧‧light conversion layer

40‧‧‧Substrate

100‧‧‧color filter

Fig. 1 is a schematic sectional view of a color filter according to an embodiment of the present invention.

Hereinafter, embodiments of the present invention will be described in detail.

<Ink Composition>

The ink composition of the embodiment is characterized in that it contains luminous nanocrystal particles, a thermosetting resin, and an organic solvent, and the LogP value of the organic solvent is -1.0 or more and 6.5 or less.

The ink composition of one embodiment is, for example, an ink composition for a color filter used for forming a pixel portion of a color filter by a method such as a photolithography method or an inkjet method.

The ink composition of one embodiment can be suitably used for forming color filter pixel portions by an inkjet method.

When using a conventional ink composition to form color filter pixel portions by, for example, an inkjet method, there is a problem of deterioration of the light conversion layer if exposed to moisture in the atmosphere.

On the other hand, according to the ink composition of this embodiment, such problems can be improved.

Hereinafter, an ink composition for a color filter (inkjet ink for a color filter) used in an inkjet method is taken as an example and described.

[Luminescent Nanoparticles]

Luminescent nanocrystals are nanometer-sized crystals that absorb excitation light and emit fluorescence or phosphorescence, for example, crystals with a maximum particle size of 100 nm or less measured by a transmission electron microscope or a scanning electron microscope.

Luminescent nanoparticles, for example, can emit light of a different wavelength (fluorescence or phosphorescence) from the absorbed wavelength by absorbing light of a specific wavelength. The luminescent nanocrystals can be red luminescent nanocrystals that emit light (red light) with a luminescence peak wavelength in the range of 605~665nm, or can emit light with a luminescence peak wavelength in the range of 500~560nm (Green light) green luminescent nanocrystal grains may also be blue luminescent nanocrystal grains emitting light (blue light) with a luminescence peak wavelength in the range of 420-480nm. In one embodiment, preferably, the ink composition includes at least one of the luminescent nanocrystals. In addition, the light absorbed by the luminescent nanocrystal grains can be, for example, light with a wavelength in the range of 400 nm to less than 500 nm (blue light), or light with a wavelength in the range of 200 nm to 400 nm (ultraviolet light). Furthermore, the luminescence peak wavelength of the luminescent nanocrystals can be confirmed, for example, in the fluorescence spectrum or phosphorescence spectrum measured by using an ultraviolet-visible spectrophotometer.

Red luminous nanocrystal grains are preferably below 665nm, below 663nm, below 660nm, below 658nm, below 655nm, below 653nm, below 651nm, below 650nm, below 647nm, below 645nm, below 643nm, below 640nm, below 637nm, It has a luminescence peak wavelength below 635nm, below 632nm, or below 630nm, and preferably has a luminescence peak wavelength above 628nm, above 625nm, above 623nm, above 620nm, above 615nm, above 610nm, above 607nm, or above 605nm. These upper limit values and lower limit values can be combined arbitrarily. In addition, in the following same description, the upper limit value and the lower limit value described individually can also be combined arbitrarily.

The green luminous nanocrystals preferably have a luminescence peak wavelength below 560nm, below 557nm, below 555nm, below 550nm, below 547nm, below 545nm, below 543nm, below 540nm, below 537nm, below 535nm, below 532nm or below 530nm , and preferably have a luminescence peak wavelength above 528 nm, above 525 nm, above 523 nm, above 520 nm, above 515 nm, above 510 nm, above 507 nm, above 505 nm, above 503 nm or above 500 nm.

The blue luminescent nanocrystal grains preferably have a luminescence peak below 480nm, below 477nm, below 475nm, below 470nm, below 467nm, below 465nm, below 463nm, below 460nm, below 457nm, below 455nm, below 452nm or below 450nm wavelength, and preferably has a luminescence peak wavelength above 450nm, above 445nm, above 440nm, above 435nm, above 430nm, above 428nm, above 425nm, above 422nm or above 420nm.

According to the solution of the Schrödinger wave equation of the Well-type potential model, the wavelength (luminous color) of the light emitted by the luminescent nanocrystal grains depends on the size of the luminescent nanocrystal grains (such as particle Diameter), also depends on the energy gap possessed by the luminescent nanocrystal grains. Therefore, the luminescent color can be selected by changing the constituent material and size of the luminescent nanocrystal grains used.

The luminescent nanocrystals may be luminescent nanoparticles comprising semiconductor materials (luminescent semiconductor nanoparticles). Examples of light-emitting semiconductor nanocrystal grains include quantum dots (hereinafter also referred to as "QD"), quantum rods, and the like. Among these, quantum dots are preferable from the viewpoint of being easy to control the emission spectrum, reducing production costs and improving mass productivity while ensuring reliability.

The luminescent semiconductor nanocrystal grains may only be composed of a core comprising the first semiconductor material, or may have a core comprising the first semiconductor material and at least one core comprising a second semiconductor material different from the first semiconductor material and covering the core. Part of the shell. In other words, the structure of the light-emitting semiconductor nanocrystal grains may be a structure consisting only of a core (core structure), or a structure consisting of a core and a shell (core/shell structure). In addition, in addition to the shell (first shell) comprising the second semiconductor material, the light-emitting semiconductor nanocrystal grain may further include a third semiconductor material different from the first and second semiconductor materials and cover at least a part of the core. shell (second shell). In other words, the structure of the light-emitting semiconductor nanocrystals may be a structure composed of a core, a first shell, and a second shell (core/shell/shell structure). Each of the core and the shell may be a mixed crystal including two or more semiconductor materials (for example, CdSe+CdS, CIS+ZnS, etc.).

The luminescent nanocrystal grain preferably comprises a compound selected from the group consisting of II-VI semiconductors, III-V semiconductors, I-III-VI semiconductors, IV semiconductors, and I-II-IV-VI semiconductors. At least one semiconductor material is used as the semiconductor material.

Specific semiconductor materials include CdS, CdSe, CdTe, ZnS, ZnSe, ZnTe, ZnO, HgS, HgSe, HgTe, CdSeS, CdSeTe, CdSTe, ZnSeS, ZnSeTe, ZnSTe, HgSeS, HgSeTe, HgSTe, CdZnS, CdZnSe, CdZnTe, CdHgS, CdHgSe, CdHgTe, HgZnS, HgZnSe, CdHgZnTe, CdZnSeS, CdZnSeTe, CdZnSTe, CdHgSeS, CdHgSeTe, CdHgSTe, HgZnSeS, HgZnSeTe, HgZnSTe; GaN, GaP, GaAs, AlGaSb, AlN, AlP, AlP InP, InAs, InSb, GaNP, GaNAs, GaNSb, GaPAs, GaPSb, AlNP, AlNAs, AlNSb, AlPAs, AlPSb, InNP, InNAs, InNSb, InPAs, InPSb, GaAlNP, GaAlNAs, GaAlNSb, GaAlPAs, GaAlPSb, GaInNP, GaInNAs, SnS, SnSe, SnTe, PbS, PbSe, PbTe, SnSeS, SnSeTe, SnSTe, PbSeS, PbSeTe, PbSTe, SnPbS, SnPbSe, SnPbTe, SnPbSSe, SnPbSeTe, SnPbSTe; Si, Ge, SiC, SiGe, AgInSe ₂ , CuGaSe ₂ , CuInS ₂ , CuGaS ₂ , CuInSe ₂ , AgInS ₂ , AgGaSe ₂ , AgGaS ₂ , C, Si, and Ge. Regarding the luminescent semiconductor nanocrystal grains, it is preferable to contain a compound selected from CdS, CdSe, CdTe, ZnS, ZnSe, ZnTe, ZnO, HgS, HgSe, HgTe, InP, InAs, InSb, GaP, GaAs, GaSb, AgInS ₂ , AgInSe ₂ , AgInTe ₂ , AgGaS ₂ , AgGaSe ₂ , AgGaTe ₂ , CuInS ₂ , CuInSe ₂ , CuInTe ₂ , CuGaS ₂ , CuGaSe ₂ , CuGaTe ₂ , Si, C, Ge, and Cu ₂ ZnSnS ₄ constitute at least one species.

As red luminescent semiconductor nanocrystal grains, for example, CdSe nanocrystal grains, CdSe rod-shaped nanocrystal grains, rod-shaped nanocrystal grains having a core-shell structure and the shell portion is Nanocrystalline grains of CdS with inner core of CdSe, rod-shaped nanocrystalline grains with core-shell structure and the shell of CdS with inner core of ZnSe nanocrystalline grains, with core-shell structure Nanocrystalline grains with the shell part being CdS and the inner core part being CdSe nanocrystalline grains, nanocrystalline grains having a core-shell structure and the shell part being CdS and the inner core part being ZnSe Rice crystal grains, CdSe and ZnS mixed crystal nano crystal grains, CdSe and ZnS mixed crystal rod shaped nano crystal grains, InP nano crystal grains, InP nano crystal grains, InP rod shaped Nanocrystalline grains, nanocrystalline grains of mixed crystals of CdSe and CdS, rod-like nanocrystalline grains of mixed crystals of CdSe and CdS, nanocrystalline grains of mixed crystals of ZnSe and CdS, mixed crystals of ZnSe and CdS Rod-shaped nanocrystal grains, etc.

Examples of green luminescent semiconductor nanocrystals include CdSe nanocrystals, CdSe rod-shaped nanocrystals, CdSe and ZnS mixed crystal nanocrystals, and CdSe and ZnS mixed crystals. Rod-shaped nanocrystal grains, etc.

Examples of blue luminescent semiconductor nanocrystal grains include: ZnSe nanocrystal grains, ZnSe rod-shaped nanocrystal grains, ZnS nanocrystal grains, ZnS rod-shaped nanocrystal grains, It is a nanocrystal grain with a core-shell structure and the shell part is ZnSe and the inner core is a nanocrystal grain of ZnS, and it is a rod-shaped nanocrystal with a core-shell structure and the shell part is ZnSe and the inner core is ZnS. The core part is ZnS nano-grains, CdS nano-grains, CdS rod-shaped nano-grains, etc. With respect to semiconductor nanocrystal grains, by changing the average grain diameter of the same chemical composition, the color that should be emitted from the grains can be changed to red or green. Also, as for the semiconductor nanocrystal grain itself, it is preferable to use one that has as little adverse effect on the human body as possible. When using semiconductor nanocrystal grains containing cadmium, selenium, etc. as luminescent nanocrystal grains, it is preferable to select semiconductor nanocrystal grains that do not contain the above-mentioned elements (cadmium, selenium, etc.) as much as possible to use alone, or It is used in combination with other luminous nanocrystal grains in such a way that the above elements are reduced as much as possible.

The shape of the luminescent nanocrystal grains is not particularly limited, and can be any geometric shape or any irregular shape. The shape of the luminescent nanocrystals can be, for example, spherical, ellipsoidal, pyramidal, disk-like, branch-like, net-like, rod-like, etc. However, as the luminescent nanocrystal grains, it is preferable to use particles with less directionality as a particle shape (for example, spherical, regular, etc.) in terms of further improving the uniformity and fluidity of the ink composition. Tetrahedral particles, etc.).

The average particle diameter (volume average diameter) of the luminescent nanocrystal grains may be 1nm or more and may be 1.5nm from the viewpoint of easily obtaining light emission at a desired wavelength, and from the viewpoint of excellent dispersibility and storage stability. or more, may be 2 nm or more. From the viewpoint of easily obtaining a desired emission wavelength, it may be 40 nm or less, 30 nm or less, or 20 nm or less. The average particle diameter (volume average diameter) of the luminescent nanocrystal grains can be obtained by measuring with a transmission electron microscope or a scanning electron microscope, and calculating the volume average diameter.

The luminescent nanocrystals preferably have organic ligands on their surfaces from the viewpoint of dispersion stability. The organic ligands, for example, can coordinately bond to the surface of the luminescent nanocrystals. In other words, the surface of luminescent nanocrystals can be passivated by organic ligands. In addition, the luminous nanocrystal particles may also have a polymer dispersant on the surface. In one embodiment, for example, the organic ligands can be removed from the above-mentioned luminescent nanocrystals with organic ligands, and the organic ligands can be exchanged with the polymer dispersant, so that the polymer dispersant can be bonded to the luminescent nanoparticles. The surface of rice grains. However, from the viewpoint of dispersion stability when used as an inkjet ink, it is preferable to add a polymer dispersant to the luminescent nanocrystal particles coordinated with an organic ligand.

Examples of organic ligands include: TOP (trioctylphosphine), TOPO (trioctylphosphine oxide), oleic acid, oleylamine, octylamine, trioctylamine, hexadecylamine, octanesulfur alcohol, dodecanethiol, hexylphosphonic acid (HPA), tetradecylphosphonic acid (TDPA), and octylphosphonic acid (OPA).

As the luminescent nanocrystal particles, those dispersed in an organic solvent in a colloidal state can be used. The surfaces of the luminescent nanocrystals dispersed in the organic solvent are preferably passivated by the above-mentioned organic ligands. Examples of organic solvents include cyclohexane, hexane, heptane, chloroform, toluene, octane, chlorobenzene, tetralin, diphenyl ether, propylene glycol monomethyl ether acetate, butyl carbitol ethyl alcohol, and acid esters, or mixtures thereof.

As the luminescent nanocrystal grains, commercially available ones can be used. Examples of commercially available luminescent nanocrystal grains include indium phosphide system zinc, D-dots, CuInS/ZnS from NN-Labs, InP/ZnS from Aldrich, and the like.

Regarding the content of the luminescent nanocrystal grains, from the point of view of a better light leakage reduction effect, based on the mass of the non-volatile components of the ink composition, it may be 5% by mass or more, or 10% by mass or more, It may be 15 mass % or more, 20 mass % or more, 30 mass % or more, or 40 mass % or more. Regarding the content of luminescent nanocrystal grains, from the viewpoint of excellent ejection stability, based on the mass of the non-volatile components of the ink composition, it may be 70% by mass or less, or 60% by mass or less. It is 55 mass % or less, and may be 50 mass % or less. In addition, in this specification, "the mass of the non-volatile component of an ink composition" means the mass obtained by subtracting the mass of an organic solvent from the total mass of an ink composition.

However, luminescent nanoparticles have higher reactivity due to surface atoms that can become coordination sites. Due to the higher reactivity and larger surface area than ordinary pigments, the luminous nanocrystalline particles are prone to agglomeration of particles. Since the luminescent nanocrystal grains emit light according to the effect of quantum size, the extinction phenomenon will occur when the particles are agglomerated, resulting in a decrease in fluorescence quantum yield, and a decrease in brightness and color reproducibility. On the other hand, in this embodiment, since the ink composition contains a polymer dispersant, the luminous nanocrystal particles are less likely to aggregate. Therefore, in this embodiment, the content of the luminescent nanocrystal grains can be set within the above-mentioned range.

[Light Scattering Particles]

The ink composition of one embodiment may contain light-scattering particles. In the case of forming a color filter pixel portion (hereinafter also simply referred to as a “pixel portion”) by using an ink composition having luminescent nanocrystals, there is a case where light from a light source is not absorbed by the luminescent nanocrystals And the case of leakage from the pixel part. Since such light leakage reduces the color reproducibility of the pixel portion, it is preferable to reduce the light leakage as much as possible when using the above-mentioned pixel portion as a light conversion layer. The above-mentioned light-scattering particles can be preferably used to prevent light leakage in the pixel portion. The light-scattering particles are, for example, optically inactive inorganic fine particles. The light-scattering particles can scatter the light from the light source irradiated onto the pixel portion of the color filter.

As the material constituting the light-scattering particles, for example, simple metals such as tungsten, zirconium, titanium, platinum, bismuth, rhodium, palladium, silver, tin, platinum, gold; silicon dioxide (silica), barium sulfate, carbonate Barium, calcium carbonate, talc, titanium oxide, clay, kaolin, barium sulfate, barium carbonate, calcium carbonate, aluminum white, titanium oxide, magnesium oxide, barium oxide, aluminum oxide, bismuth oxide, zirconium oxide, zinc oxide and other metal oxides ; Metal carbonates such as magnesium carbonate, barium carbonate, bismuth subcarbonate, calcium carbonate, etc.; Metal hydroxides such as aluminum hydroxide; Composite oxides such as barium zirconate, calcium zirconate, calcium titanate, barium titanate, strontium titanate, etc. , bismuth subnitrate and other metal salts. The light-scattering particles are preferably contained in the group consisting of titanium oxide, aluminum oxide, zirconium oxide, zinc oxide, calcium carbonate, barium sulfate, and silicon dioxide from the viewpoint of excellent light leakage reduction effect. At least one of them is more preferably at least one selected from the group consisting of titanium oxide, barium sulfate, and calcium carbonate.

The shape of the light-scattering particles may be spherical, filamentous, or indeterminate. However, as the light-scattering particles, in terms of further improving the uniformity, fluidity, and light-scattering properties of the ink composition, it is preferable to use particles with less directionality as a particle shape (for example, spherical , regular tetrahedral particles, etc.).

The average particle diameter (volume average diameter) of the light-scattering particles in the ink composition may be 0.05 μm or more, 0.2 μm or more, or 0.3 μm or more from the viewpoint of a better light leakage reduction effect. The average particle diameter (volume average diameter) of the light-scattering particles in the ink composition may be 1.0 μm or less, 0.6 μm or less, or 0.4 μm or less from the viewpoint of excellent discharge stability. The average particle size (volume average diameter) of the light scattering particles in the ink composition can be 0.05~1.0μm, 0.05~0.6μm, 0.05~0.4μm, 0.2~1.0μm, 0.2~0.6μm, 0.2~0.4μm , 0.3~1.0μm, 0.3~0.6μm, or 0.3~0.4μm. From the viewpoint of obtaining such an average particle diameter (volume average diameter) easily, the average particle diameter (volume average diameter) of the light-scattering particles used may be 50 nm or more and 1000 nm or less. The average particle diameter (volume average diameter) of the light-scattering particles can be obtained by measuring with a dynamic light scattering Nanotrac particle size distribution meter and calculating the volume average diameter. In addition, the average particle diameter (volume average diameter) of the light-scattering particles used can be obtained, for example, by measuring the particle diameter of each particle with a transmission electron microscope or a scanning electron microscope, and calculating the volume average path.

The content of the light-scattering particles may be 0.1% by mass or more, 1% by mass or more, or 1% by mass or more based on the mass of the non-volatile components of the ink composition from the viewpoint of better light leakage reduction effect. It may be 5 mass % or more, may be 7 mass % or more, may be 10 mass % or more, and may be 12 mass % or more. The content of the light-scattering particles may be 60% by mass or less based on the mass of the non-volatile components of the ink composition from the viewpoint of a better light leakage reduction effect and excellent ejection stability. 50% by mass or less, 40% by mass or less, 30% by mass or less, 25% by mass or less, 20% by mass or less, or 15% by mass or less. In this embodiment, since the ink composition contains a polymer dispersant, even when the content of the light-scattering particles is within the above range, the light-scattering particles can be well dispersed.

The mass ratio of the content of the light-scattering particles to the content of the luminescent nanocrystals (light-scattering particles/luminescent nanocrystals) is 0.1-5.0. The mass ratio (light-scattering particles/luminescent nanocrystal particles) may be 0.2 or more, or may be 0.5 or more from the viewpoint of a more excellent light leakage reduction effect. The mass ratio (light-scattering particles/luminescent nanocrystals) may be 2.0 or less or 1.5 or less from the standpoint of a better light leakage reduction effect and excellent continuous discharge performance during inkjet printing. The mass ratio (light-scattering particles/luminescent nanocrystals) can also be 0.1~2.0, 0.1~1.5, 0.2~5.0, 0.2~2.0, 0.2~1.5, 0.5~5.0, 0.5~2.0, or 0.5~1.5 . Furthermore, the reduction of light leakage by the light-scattering particles is considered to be due to the following mechanism. That is, it is considered that when there are no light-scattering particles, the backlight light passes through the pixel portion almost straight, and there is less chance of being absorbed by the luminescent nanocrystal particles. On the other hand, it is considered that if the light-scattering particles and the luminescent nanocrystal particles are present in the same pixel portion, the backlight light will be scattered omnidirectionally in the pixel portion, and the luminescent nanocrystal particles can receive the light. , so even if the same backlight is used, the amount of light absorbed in the pixel portion will increase. As a result, it is considered that light leakage can be prevented by using such a mechanism.

[Polymer dispersant]

The ink composition of one embodiment preferably contains a polymer dispersant. The polymer dispersant can uniformly disperse light-scattering particles in the ink.

In the present invention, the polymer dispersant is a polymer compound having a weight-average molecular weight of 750 or more and having a functional group having an affinity for light-scattering particles, and has a function of dispersing the light-scattering particles. The polymer dispersant is made to adsorb the polymer dispersant to the light-scattering particles through the functional group having affinity for the light-scattering particles, and the light-scattering particles are absorbed by the electrostatic repulsion and/or steric repulsion between the polymer dispersants Dispersed in the ink composition. The polymer dispersant is preferably bonded to the surface of the light-scattering particles and adsorbed on the light-scattering particles. Free in the composition.

Examples of the functional group having affinity for light-scattering particles include an acidic functional group, a basic functional group, and a nonionic functional group. Acidic functional groups have dissociative protons, which can be neutralized by bases such as amines and hydroxide ions, and basic functional groups can be neutralized by acids such as organic acids and inorganic acids.

As the acidic functional group, carboxyl group (-COOH), sulfo group (-SO ₃ H), sulfate group (-OSO ₃ H), phosphonic acid (phosphonic acid) group (-PO(OH) ₃ ), phosphoric acid group ( -OPO(OH) ₃ ), phosphinic acid group (-PO(OH)-), mercapto group (-SH).

、咪唑、三唑等含氮雜環基等。 As basic functional groups, primary, secondary and tertiary amine groups, ammonium groups, imine groups, and pyridine, pyrimidine, pyridine,

, imidazole, triazole and other nitrogen-containing heterocyclic groups, etc.

Examples of nonionic functional groups include: hydroxyl group, ether group, thioether group, sulfinyl group (-SO-), sulfonyl group (-SO ₂ -), carbonyl group, formyl group, ester group, carbonate group, amido group, carbamoyl group, urea group, thioamide group, thiourea group, sulfamoyl group, cyano group, alkenyl group, alkynyl group, phosphine oxide group, phosphine sulfide group.

From the point of view of the dispersion stability of light-scattering particles, the point of view that it is difficult to cause side effects of precipitation of luminescent nanocrystals, the point of view of the ease of synthesis of polymer dispersants, and the point of view of the stability of functional groups, as As the acidic functional group, carboxyl group, sulfo group, phosphonic acid group and phosphoric acid group can be preferably used, and as the basic functional group, amine group can be preferably used. Among them, a carboxyl group, a phosphonic acid group, and an amine group can be used more preferably, and an amine group is most preferably used.

Polymer dispersants with acidic functional groups have an acid value. The acid value of the polymer dispersant having an acidic functional group is preferably 1-150 mgKOH/g in terms of solid content. When the acid value is 1 or more, sufficient dispersibility of the light-scattering particles is easily obtained, and when the acid value is 150 or less, the storage stability of the pixel portion (cured product of the ink composition) is less likely to be lowered.

In addition, the polymer dispersant having a basic functional group has an amine value. The amine value of the polymer dispersant having a basic functional group is preferably 1 to 200 mgKOH/g in terms of solid content. When the amine value is 1 or more, sufficient dispersibility of the light-scattering particles is easily obtained, and when the amine value is 200 or less, the storage stability of the pixel portion (cured product of the ink composition) is less likely to be lowered.

The polymer dispersant can be a polymer (homopolymer) of a single monomer, or a copolymer (copolymer) of multiple monomers. Moreover, any one of a random copolymer, a block copolymer, or a graft copolymer may be sufficient as a polymer dispersing agent. Also, when the polymer dispersant is a graft copolymer, it may be a comb-shaped graft copolymer or a star-shaped graft copolymer. The polymer dispersant can be, for example, acrylic resin, polyester resin, polyurethane (polyurethane) resin, polyamide resin, polyether, phenol resin, polysiloxane resin, polyurea resin, amino resin, polyethyleneimine and poly Polyamine such as allylamine, epoxy resin, polyimide, etc.

Commercially available products can also be used as the above-mentioned polymer dispersant. As commercially available products, Ajisper PB series manufactured by Ajinomoto Fine-Techno Co., Ltd., DISPERBYK series manufactured by BYK Corporation, BYK-series, and Efka series manufactured by BASF Corporation can be used. Wait.

As commercially available products, for example, "DISPERBYK-130", "DISPERBYK-161", "DISPERBYK-162", "DISPERBYK-163", "DISPERBYK-164", "DISPERBYK-166" manufactured by BYK-Chemie, Inc. can be used. "DISPERBYK-167", "DISPERBYK-168", "DISPERBYK-170", "DISPERBYK-171", "DISPERBYK-174", "DISPERBYK-180", "DISPERBYK-182", "DISPERBYK-183", "DISPERBYK -184", "DISPERBYK-185", "DISPERBYK-2000", "DISPERBYK-2001", "DISPERBYK-2008", "DISPERBYK-2009", "DISPERBYK-2020", "DISPERBYK-2022", "DISPERBYK-2025 ”, “DISPERBYK-2050”, “DISPERBYK-2070”, “DISPERBYK-2096”, “DISPERBYK-2150”, “DISPERBYK-2155”, “DISPERBYK-2163”, “DISPERBYK-2164”, “BYK-LPN21116” and "BYK-LPN6919"; "EFKA4010", "EFKA4015", "EFKA4046", "EFKA4047", "EFKA4061", "EFKA4080", "EFKA4300", "EFKA4310", "EFKA4320", "EFKA4330" manufactured by BASF "EFKA4340", "EFKA4560", "EFKA4585", "EFKA5207", "EFKA1501", "EFKA1502", "EFKA1503" and "EFKAPX-4701"; "Solsperse 3000", "Solsperse 9000", "Solsperse 13240", "Solsperse 13650", "Solsperse 13940", "Solsperse 11200", "Solsperse 13940", "Solsperse 16000", "Solsperse 17000", "Solsperse 18000", "Solsperse 20000", "Solsperse 21000", "Solsperse twenty four 000", "Solsperse 26000", "Solsperse 27000", "Solsperse 28000", "Solsperse 32000", "Solsperse 32500", "Solsperse 32550", "Solsperse 32600", "Solsperse 33000", "Solsperse 34750", "Solsperse 35100”, “Solsperse 35200”, “Solsperse 36000”, “Solsperse 37500”, “Solsperse 38500”, “Solsperse 39000”, “Solsperse 41000”, “Solsperse 54000”, “Solsperse 71000” and “Solsperse 76500 to Fine”; - "Ajisper PB821", "Ajisper PB822", "Ajisper PB881", "PN411" and "PA111" manufactured by Techno Co., Ltd.; "TEGO Dispers650", "TEGO Dispers660C", "TEGO Dispers662C", " TEGO Dispers670", "TEGO Dispers685", "TEGO Dispers700", "TEGO Dispers710" and "TEGO Dispers760W"; "Disparlon DA-703-50", "DA-705" and "DA-725" manufactured by Kusumoto Chemicals, etc.

As a polymer dispersant, in addition to the above-mentioned commercial products, cationic monomers containing basic groups and/or anionic monomers with acidic groups, monomers with hydrophobic groups, and optionally It is obtained by copolymerizing other monomers (non-ionic monomers, monomers with hydrophilic groups, etc.). Details of cationic monomers, anionic monomers, monomers having a hydrophobic group, and other monomers include monomers described in paragraphs 0034 to 0036 of JP-A-2004-250502.

Also, for example, compounds obtained by reacting polyalkylene imines with polyester compounds described in JP-A-54-37082, JP-A-61-174939, etc., and The compound obtained by modifying the amino group of the side chain of polyallylamine by using polyester described in Japanese Patent Application Publication No. 9-169821, and the polyester macromonomer described in Japanese Patent Application Publication No. 9-171253 Graft polymers that are copolymerization components, polyester polyalcohol addition polyurethanes described in JP-A-60-166318, and the like.

The weight average molecular weight of the polymer dispersant may be 750 or more, 1000 or more, 2000 or more, or 2000 or more from the viewpoint of enabling good dispersion of light-scattering particles and further improving the effect of reducing light leakage. It can be more than 3000. With regard to the weight average molecular weight of the polymer dispersant, it is possible to disperse the light-scattering particles well, further enhance the effect of reducing light leakage, and set the viscosity of the inkjet ink to a viscosity suitable for ejection and stable ejection. From a viewpoint, it may be 100,000 or less, 50,000 or less, or 30,000 or less. In this specification, the weight average molecular weight is the weight average molecular weight in terms of polystyrene measured by GPC (Gel Permeation Chromatography, Gel Permeation Chromatography).

From the viewpoint of the dispersibility of the light-scattering particles, the content of the polymer dispersant may be 0.5 parts by mass or more, 2 parts by mass or more, or 5 parts by mass relative to 100 parts by mass of the light-scattering particles. parts by mass or more. The content of polymer dispersion may be 50 parts by mass or less or 30 parts by mass with respect to 100 parts by mass of light-scattering particles from the viewpoint of the moisture-heat stability of the pixel portion (cured product of the ink composition). It may be less than or equal to 10 parts by mass or less.

[thermosetting resin]

In this embodiment, a thermosetting resin is a resin that is crosslinked and cured by heat and functions as a binder in a cured product. A thermosetting resin has a curable group. Examples of curable groups include epoxy groups, oxetanyl groups, isocyanate groups, amine groups, carboxyl groups, and methylol groups. From the viewpoint of excellent heat resistance and storage stability of the cured product of the ink composition, and to From the viewpoint of excellent adhesion between a light-shielding part (such as a black matrix) and a base material, an epoxy group is preferable. The thermosetting resin may have one kind of curable group, or may have two or more kinds of curable groups.

Furthermore, in thermosetting resins, resins having photoradical polymerizability (polymerized by irradiation of light when used together with a photoradical polymerization initiator) and photocationically polymerizable resins are included. The (polymerization by light irradiation when used together with a photocationic polymerization initiator) resin.

Thermosetting resins can be polymers of a single monomer (homopolymers), or copolymers of multiple monomers (copolymers). Moreover, any one of a random copolymer, a block copolymer, or a graft copolymer may be sufficient as a thermosetting resin.

As the thermosetting resin, a compound having two or more thermosetting functional groups in one molecule can be used, and it is usually used in combination with a curing agent. In the case of using a thermosetting resin, a catalyst (hardening accelerator) capable of accelerating the thermosetting reaction may be further added. In other words, the ink composition may contain a thermosetting component including a thermosetting resin (and, if necessary, a curing agent and a curing accelerator). Moreover, in addition to these, it is also possible to further use a non-polymerizable polymer itself.

As a compound having two or more thermosetting functional groups in one molecule, for example, an epoxy resin having two or more epoxy groups in one molecule (hereinafter also referred to as "polyfunctional epoxy resin") can be used. "Epoxy resin" includes both monomeric epoxy resin and polymeric epoxy resin. Multifunctionality The number of epoxy groups in one molecule of the epoxy resin is preferably 2-50, more preferably 2-20. The epoxy group should just be a structure which has an oxirane ring structure, for example, a glycidyl group, an oxyethylene group, an epoxycyclohexyl group etc. are mentioned. As an epoxy resin, the well-known polyvalent epoxy resin hardenable with a carboxylic acid is mentioned. Such epoxy resins are widely disclosed, for example, in "Epoxy Resin Handbook" edited by Masaki Shinho, Nikkan Kogyo Shimbun (1987), and the like can be used.

Examples of thermosetting resins (including polyfunctional epoxy resins) having an epoxy group include polymers of monomers having an oxirane ring structure, monomers having an oxirane ring structure, and other monomers ( For example, copolymers of acrylic acid monomers). Examples of such monomers include various epoxy group-containing monomers such as glycidyl (meth)acrylate, β-methylglycidyl (meth)acrylate, glycidyl vinyl ether, and allyl glycidyl ether. Monomers; vinyl monomers containing (2-oxo-1,3-oxolane) groups such as (2-oxo-1,3-oxolane) methyl (meth)acrylate Class; 3,4-epoxycyclohexyl (meth)acrylate, 3,4-epoxycyclohexylmethyl (meth)acrylate, 3,4-epoxycyclohexylethyl (meth)acrylate, etc. Various vinyl monomers containing alicyclic epoxy groups, etc.

On the other hand, examples of ethylenically unsaturated double bond-containing monomers include various aromatic vinyl compounds such as styrene, α-methylstyrene, and vinyltoluene; methyl acrylate, ethyl acrylate, and the like; , butyl acrylate, cyclohexyl acrylate and other acrylates; methyl methacrylate, ethyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, tertiary butyl methacrylate Various methacrylates such as cyclohexyl methacrylate and benzyl methacrylate; various α-olefins such as ethylene, propylene, butene-1; vinyl chloride, vinylidene chloride and the like Various halogenated olefins (halogenated olefins) other than fluoroolefins; dimethyl fumarate, diethyl fumarate, dibutyl fumarate, dioctyl fumarate ester, dimethyl maleate, diethyl maleate, dibutyl maleate, dioctyl maleate, dimethyl itaconate, diethyl itaconate Diesters of various unsaturated dicarboxylic acids such as dibutyl itaconate and dioctyl itaconate and monohydric alcohols with 1 to 18 carbon atoms; vinyl acetate, vinyl propionate, butyric acid Vinyl ester, vinyl isobutyrate, vinyl caproate, vinyl caprylate, vinyl caprate, vinyl laurate, branched (branched) aliphatic vinyl carboxylate with 9 carbon atoms, carbon Various aliphatic carboxylic acid vinyl esters such as branched-chain aliphatic carboxylic acid vinyl esters having 10 atoms, branched-chain aliphatic carboxylic acid vinyl esters having 11 carbon atoms, and vinyl stearate.

As specific multifunctional epoxy resins, polyglycidyl methacrylate, methyl methacrylate-glycidyl methacrylate copolymer, benzyl methacrylate-glycidyl methacrylate copolymer, n-butyl methacrylate-glycidyl methacrylate copolymer, 2-hydroxyethyl methacrylate-glycidyl methacrylate copolymer, methacrylic acid (3-ethyl-3-oxocyclobutyl) Methyl ester-glycidyl methacrylate copolymer, styrene-glycidyl methacrylate copolymer, etc. In addition, as the thermosetting resin of the present embodiment, compounds described in paragraphs 0044 to 0066 of JP-A-2014-56248 can also be used.

Regarding the homopolymer or copolymer of monomers having an oxirane ring structure, it is preferably a two-dimensional (linear) copolymer from the viewpoint of ease of handling or manufacture. Obtained in the following manner: without solvent or in an organic solvent, with glycidyl (meth)acrylate as an essential component, and an aromatic vinyl compound or (meth)acrylic acid as a well-known and customary ethylenically unsaturated monomer that can be copolymerized (base) acrylate and other monomers containing one ethylenically unsaturated double bond, and optionally monomers containing two or more ethylenically unsaturated double bonds are polymerized together. By adjusting the combination ratio of glycidyl (meth)acrylate and other ethylenically unsaturated monomers, a copolymer with the required epoxy group content can also be obtained. Which monomer to choose for the ethylenic unsaturated monomer that can be copolymerized The unsaturated monomer can adjust the refractive index, glass transition temperature, flexibility, transparency, solubility in organic solvents, etc. of the copolymer depending on how much the average molecular weight of the whole is. The copolymerization ratio of monomers containing aromatic rings such as aromatic vinyl compounds will affect the refractive index of the resulting copolymer, and the alkyl chain length of (meth)acrylate will affect the flexibility of the resulting copolymer or the Adhesion of supports etc. is affected. Such a copolymer can also be easily obtained, for example, by using the above-mentioned glycidyl (meth)acrylate as an essential component in an organic solvent within the specific LogP value range of the present invention described below, and using known and commonly used Ethylenically unsaturated monomers that can be copolymerized are polymerized in such a way that the glycidyl group is not ring-opened until the desired molecular weight is achieved. Certainly, it can also be carried out in an organic solvent outside the specific LogP value range described below to prepare the above-mentioned copolymer by replacing the organic solvent described below with an organic solvent within the specific LogP value range described below.

Moreover, as a polyfunctional epoxy resin, for example, bisphenol A type epoxy resin, bisphenol F type epoxy resin, brominated bisphenol A type epoxy resin, bisphenol S type epoxy resin, diphenyl ether Type epoxy resin, hydroquinone type epoxy resin, naphthalene type epoxy resin, biphenyl type epoxy resin, fennel type epoxy resin, phenol novolak type epoxy resin, o-cresol novolak type epoxy resin , trihydroxyphenylmethane type epoxy resin, trifunctional epoxy resin, tetraphenol ethane type epoxy resin, dicyclopentadiene phenol type epoxy resin, hydrogenated bisphenol A type epoxy resin, bisphenol A nuclear polyol type epoxy resin, polypropylene glycol type epoxy resin, glycidyl ester type epoxy resin, glycidylamine type epoxy resin, glyoxal type epoxy resin, alicyclic epoxy resin, heterocyclic Type epoxy resin, etc.

More specifically, bisphenol A type epoxy resins such as trade name "Epikote 828" (manufactured by Japan Epoxy Resins Co., Ltd.), and bisphenol F type epoxy resins such as trade name "YDF-175S" (manufactured by Tohto Kasei Co., Ltd.) can be exemplified. Resin, product name "YDB-715" (manufactured by Tohto Kasei Co., Ltd.), etc. Brominated bisphenol A type epoxy resin, product name "EPICLON EXA1514" (manufactured by DIC Co., Ltd.) or other bisphenol S type epoxy resin, product name Hydroquinone-type epoxy resins such as "YDC-1312" (manufactured by Tohto Chemical Co., Ltd.), trade names "EPICLON EXA4032", "HP-4770", "HP-4700", "HP-5000" (DIC Co., Ltd. naphthalene-type epoxy resins such as "Epikote YX4000H" (manufactured by Japan Epoxy Resins Co., Ltd.), biphenyl-type epoxy resins such as "Epikote 157S70" (manufactured by Japan Epoxy Resins Co., Ltd.) Phenol novolak type epoxy resins such as epoxy resins, trade name "Epikote 154" (manufactured by Japan Epoxy Resins Co., Ltd.), trade name "YDPN-638" (manufactured by Tohto Kasei Co., Ltd.), trade name "YDCN-701" (manufactured by Tohto Chemical Co., Ltd.) Dicyclopentadiene phenol-type epoxy resins such as cresol novolak-type epoxy resins such as "EPICLON HP-7200" and "HP-7200H" (manufactured by DIC Co., Ltd.), trade names " Trifunctional epoxy resins such as Epikote 1032H60” (manufactured by Japan Epoxy Resins Co., Ltd.); trifunctional epoxy resins such as “Epikote 1031S” (manufactured by Japan Epoxy Resins Co., Ltd.) tetrafunctional epoxy resin such as tetraphenol ethane type epoxy resin (manufactured by Nagase Chemical Industry Co., Ltd.), trade name "DENACOL EX-411" (manufactured by Nagase Chemical Industry Co., Ltd.), trade name "ST-3000" (manufactured by Tohto Chemical Industry Co., Ltd.) Isohydrogenated bisphenol A type epoxy resin, glycidyl ester type epoxy resin such as trade name "Epikote 190P" (manufactured by Japan Epoxy Resins Co., Ltd.), glycidyl amine type such as trade name "YH-434" (manufactured by Tohto Kasei Co., Ltd.) Epoxy resins, glyoxal type epoxy resins such as trade name "YDG-414" (manufactured by Tohto Chemical Co., Ltd.), alicyclic polyfunctional epoxy compounds such as trade name "Epolead GT-401" (manufactured by Daicel Chemical Co., Ltd.), Heterocyclic epoxy resins such as triglycidyl isocyanate (TGIC), etc. Also, if necessary, a trade name "Neotohto E" (manufactured by Tohto Chemical Co., Ltd.) or the like may be mixed as an epoxy-reactive diluent.

In addition, as the polyfunctional epoxy resin, "FINEDIC A-247S", "FINEDIC A-254", "FINEDIC A-253", "FINEDIC A-229-30A", "FINEDIC A -261", "FINEDIC A249", "FINEDIC A-266", "FINEDIC A-241", "FINEDIC M-8020", "EPICLON N-740", "EPICLON N-770", "EPICLON N-865" ( product name), etc.

If a multifunctional epoxy resin with a relatively small molecular weight is used as a thermosetting resin, the epoxy group will be supplemented in the ink composition (inkjet ink), and the concentration of the reaction sites of the epoxy resin will become high, which can improve the exchange rate. joint density.

Among the polyfunctional epoxy resins, it is preferable to use an epoxy resin having four or more epoxy groups in one molecule (polyfunctional epoxy resin with four or more functions) from the viewpoint of increasing the crosslink density. In particular, when a thermosetting resin with a weight average molecular weight of 10,000 or less is used to improve the stability of ejection from the ejection head in the inkjet method, the strength and hardness of the pixel portion (cured product of the ink composition) tends to decrease Therefore, from the viewpoint of sufficiently increasing the crosslink density, it is preferable to blend a tetrafunctional or higher multifunctional epoxy resin into the ink composition (inkjet ink).

As a thermosetting resin with an epoxy group, it is easy to obtain a cured product that has the advantages of less coloring, better transparency, increased crosslink density, chemical resistance, and better flexibility. , The multiple copolymers of monomers with oxirane ring structure and other monomers are better than other multifunctional epoxy resins. The excellent optical characteristics and film physical properties of such a cured product are suitable, for example, for use in optical materials, especially in light conversion layers where long-term reliability is expected.

As the hardener and hardening accelerator used to harden the thermosetting resin, any of known and conventional ones that can be dissolved or dispersed in the above-mentioned organic solvents can be used, for example, 4-methylhexahydrophthalate Diformic anhydride, triethylenetetramine, diaminodiphenylmethane, phenol novolac resin, tris(dimethylaminomethyl)phenol, N,N-dimethylbenzylamine, 2-ethyl- 4-methylimidazole, triphenylphosphine, 3-phenyl-1,1-dimethylurea, etc.

Among them, it is preferable to use polymers such as phenol novolak resins that are liquid at room temperature or have excellent solubility in the above-mentioned organic solvents. It can be set to low viscosity, easy to harden and harden at a lower temperature and in a shorter time. Low-molecular hardener and hardening accelerator with less coloring.

The thermosetting resin may be alkali-insoluble from a viewpoint of being easy to obtain the color filter pixel part excellent in reliability. The thermosetting resin is alkali-insoluble, which means that the amount of the thermosetting resin dissolved in a 1 mass % potassium hydroxide aqueous solution at 25° C. is 30 mass % or less based on the total mass of the thermosetting resin. The above-mentioned dissolved amount of the thermosetting resin is preferably at most 10% by mass, more preferably at most 3% by mass.

Regarding the weight average molecular weight of the thermosetting resin, it is easy to obtain an appropriate viscosity as an inkjet ink, the curability of the ink composition becomes good, and the durability of the pixel portion (cured product of the ink composition) From the viewpoint of improvement of solvent property and abrasion resistance, it may be 750 or higher, 1000 or higher, or 2000 or higher. It may be 500,000 or less, 300,000 or less, or 200,000 or less from the viewpoint of setting it as an appropriate viscosity for inkjet ink. However, the molecular weight after crosslinking is not limited to this.

Regarding the content of the thermosetting resin, it is easy to obtain an appropriate viscosity as an inkjet ink, the curability of the ink composition becomes good, and the solvent resistance of the pixel portion (cured product of the ink composition) From the viewpoint of improving abrasion resistance, based on the mass of the non-volatile components of the ink composition, it may be 10% by mass or more, 15% by mass or more, or 20% by mass or more. Regarding the content of the thermosetting resin, from the point of view that the viscosity of the inkjet ink does not become too high and the thickness of the pixel portion does not become too thick for the light conversion function, the mass of the non-volatile components of the ink composition Based on this, it may be 90% by mass or less, 80% by mass or less, 70% by mass or less, 60% by mass or less, or 50% by mass or less.

[Organic solvents]

The organic solvent of the present invention is an organic solvent within the following specific LogP value range.

In the present invention, as the organic solvent contained in the ink composition, for example, ethylene glycol monobutyl ether acetate, diethylene glycol monobutyl ether acetate, diethylene glycol monoethyl ether acetate , diethylene glycol dibutyl ether, diethyl adipate, dibutyl oxalate, dimethyl malonate, diethyl malonate, dimethyl succinate, diethyl succinate, 1,4 -Butanediol diacetate, glycerin triacetate, etc.

The boiling point of the organic solvent is preferably 180° C. or higher from the viewpoint of the continuous discharge stability of the inkjet ink. In addition, since the solvent must be removed from the ink composition before the ink composition is cured during the formation of the pixel portion, the boiling point of the solvent is preferably 300° C. or lower from the viewpoint of easy removal of the solvent.

In the present invention, from the viewpoint of preparing the ink composition in a uniform manner, and from the viewpoint of improving the fluidity of the ink composition to form a color filter pixel portion (light conversion layer) with less unevenness, Preferably, an organic solvent is used.

[LogP value]

In the present invention, the biggest feature of the ink composition is the use of an organic solvent within a specific LogP value range. For example, an organic solvent within the specific LogP value range can be selected from the organic solvents exemplified above and used as an essential component. . By using the organic solvent in such a specific range of LogP value, in the present invention, the cured product of the ink composition can be made less likely to cause problems. In the present invention, the so-called LogP value represents the logarithmic value of the partition coefficient of the organic solvent in 1-octanol/water, using "Journal of Pharmaceutical Sciences, page 83, volume 84, No.1, 1995" (WILLIAM M. MEYLAN, PHILIP H.HOWARD) and calculated by the method described in. The LogP value is generally the value used in the relative evaluation of the hydrophilicity and hydrophobicity of organic compounds.

For example, it can be calculated|required as follows.

Furthermore, it is shown in the above-mentioned literature that the logarithmic value of the partition coefficient in 1-octanol/water can also be measured based on JIS Z 7260-117, and the value obtained by the above-mentioned calculation method shows the majority of the actual measurement results. very closely related.

In the ink composition of the present invention, especially in the inkjet ink composition, the LogP value of the organic solvent is not less than -1.0 and not more than 6.5. If necessary, it can also contain The LogP value is an organic solvent outside this range.

The LogP value of the organic solvent may be 5.0 or less, 4.0 or less, 3.0 or less, or 2.0 or less in order to suppress deterioration of the luminescent nanocrystal due to moisture. Also, from the viewpoint of suppressing the water absorption of the ink composition containing luminescent nanocrystals, it may be -0.5 or more, 0.0 or more, or 1.0 or more.

In the case of containing an organic solvent whose LogP value is outside the range of -1.0 or more to 6.5 or less of the above-mentioned range, the organic solvent suppresses deterioration of the luminescent nanocrystals due to oxygen or moisture in the atmosphere. It may be 30 mass % or less, 20 mass % or less, 10 mass % or less, 5 mass % or less, or 2 mass % or less in ink.

Since the ink composition of the present invention is a thermosetting ink composition using a thermosetting resin, for example, it is possible to suppress deterioration of luminous nanocrystal grains caused by photocuring.

The ink composition of this embodiment can be applied as the ink used in the manufacturing method of the known customary color filter, without wasteful consumption of materials such as relatively expensive luminescent nanocrystal grains, solvents, etc., and only used in necessary positions. It is preferable to prepare and use it suitably for the inkjet method rather than the photolithography method at the point which can form the color filter pixel part (light conversion layer).

The viscosity of the ink composition may be 2 mPa‧s or more, 5 mPa‧s or more, or 7 mPa‧s or more from the viewpoint of ejection stability during inkjet printing, for example. The viscosity of the ink composition may be less than 20mPa‧s, or less than 15mPa‧s, or less than 12mPa‧s. When the viscosity of the ink composition is above 2mPa‧s, the shape of the meniscus of the ink composition at the front end of the ink ejection hole of the ejection head is stable, so the ejection control of the ink composition (for example, the amount of ejection and the timing of ejection) control) made easy. On the other hand, when the viscosity is 20 mPa‧s or less, the ink composition can be smoothly ejected from the ink ejection holes. The viscosity of the ink composition can also be 2~20mPa‧s, 2~15mPa‧s, 2~12mPa‧s, 5~20mPa‧s, 5~15mPa‧s, 2~20mPa‧s, 7~15mPa‧s, 7~12mPa‧s, or 7~12mPa‧s. The viscosity of the ink composition is measured by, for example, an E-type viscometer.

The surface tension of the ink composition is preferably a surface tension suitable for an inkjet method, specifically, it is preferably in the range of 20-40 mN/m, more preferably 25-35 mN/m. By setting the surface tension within this range, the occurrence of flight bending can be suppressed. Furthermore, the so-called flight deflection means that when the ink composition is ejected from the ink ejection hole, the landing position of the ink composition deviates by more than 30 μm from the target position. When the surface tension is 40 mN/m or less, the shape of the meniscus at the front end of the ink discharge hole is stable, so the discharge control of the ink composition (for example, the control of the discharge amount and the discharge timing) becomes easy. On the other hand, when the surface tension is 20 mN/m or less, the occurrence of flight bending can be suppressed. That is, there is no possibility of insufficiently filling the pixel portion with the ink composition due to inaccurate landing on the formation area of the pixel portion to be landed, and the ink composition is not allowed to land on the pixel portion adjacent to the formation area of the pixel portion to be landed. Formation of regions (or pixel portions) degrades color reproducibility.

The ink composition may further contain components other than luminescent nanocrystal particles, light-scattering particles, thermosetting resin, polymer dispersant, and organic ligands within the range that does not hinder the effect of the present invention. As other components, a photopolymerizable compound, a polymerization initiator, a sensitizer, etc. are mentioned, for example.

[moisture content rate]

In the ink composition of the present invention, the moisture content of the ink composition can be measured by a card-fee moisture meter (for example, manufactured by Mitsubishi Chemical Co., Ltd., model CA-06, and the vaporization unit is manufactured by Mitsubishi Chemical Co., Ltd. VA-06) for determination. The moisture in the ink composition may be 90ppm or less, 50ppm or less, 20ppm or less, 9ppm or less, 4ppm or less, or 2ppm from the viewpoint of suppressing the deterioration of the luminous nanocrystals Below, it may be 1 ppm or less.

In the ink composition of the present invention, it is more preferable to use an organic solvent in a specific LogP value range from the viewpoint of being less likely to cause problems due to hardening and more effectively suppressing the deterioration of luminescent nanocrystals. Above, set it as the above-mentioned moisture content range. In the case of the ink composition for inkjet, the best technical effect can be expected by combining it with the ejection method.

In the present invention, the water content of ink composition raw materials such as ink composition or organic solvent can be controlled to the above-mentioned specific content value range by the following method. For example, the method of preparing an ink composition by adding molecular sieves to an organic solvent that has been dehydrated, or adding molecular sieves to a mixture of a thermosetting resin and an organic solvent, adding molecular sieves to an ink composition and filtering after dehydration. If necessary, the following filtering may not be performed.

The dehydration treatment time is not particularly limited. Since it takes time for molecular sieves to absorb water molecules contained in ink composition materials such as ink compositions or organic solvents, dehydration treatment can be carried out for more than 12 hours after adding molecular sieves, and for more than 24 hours after adding molecular sieves. Dehydration can be carried out after adding molecular sieves for more than 48 hours. At this time, it is preferable to perform the dehydration treatment under an inert gas environment in which moisture does not substantially exist, but it may be performed under an air environment. Furthermore, the molecular sieve used is preferably used to remove the adsorbed moisture by heating treatment before use, and the heating temperature can be above 200°C, above 250°C, above 300°C, or above 350°C above. From the viewpoint of removing adsorbed water molecules, it is also preferable to depressurize during heating, and it may be 0.1 mmHg or less, 0.01 mmHg or less, or 0.001 mmHg or less.

Solid materials such as light-scattering particles can absorb water molecules, so they can be dehydrated before use, and can be heated in the air, in an inert gas environment, or under reduced pressure to remove water.

Since water will dissolve in the liquid under the atmosphere, the ink composition can be prepared by dehydrating the ink composition raw materials separately, or the ink composition can be prepared without dehydrating the ink composition raw materials to form the ink composition to dehydrate. Alternatively, the ink composition may be prepared by dehydrating the ink composition raw materials, and the ink composition may be further dehydrated. By carrying out the dehydration operation more strictly, it is difficult to cause problems due to hardened products, and the deterioration of the luminous nanocrystals can be more reliably suppressed.

[Dissolved oxygen concentration]

In one embodiment, the dissolved oxygen concentration of the ink composition or organic solvent and other ink composition raw materials can be adjusted by exposing the ink or organic solvent to an inert gas flow such as nitrogen or argon, or blowing in an inert gas. reduce. For solid materials such as light-scattering particles, the incorporation of oxygen into the ink composition can also be suppressed by filling the container with a nitrogen gas flow and storing it under a nitrogen atmosphere.

The dissolved oxygen concentration is the value obtained by measuring the dissolved oxygen of the ink composition using an optical and solvent-resistant dissolved oxygen concentration meter. Specifically, for example, the dissolved oxygen concentration of the ink composition can be measured using the Visiferm of Hamilton. Furthermore, the concentration of dissolved oxygen can be reduced to be lower than the measurable lower limit of the device for measuring the concentration of dissolved oxygen, which is also an embodiment of the present invention.

[deoxidizer]

The ink composition of one embodiment only needs to contain a deoxidizer and the deoxidizer reacts with dissolved oxygen to reduce the oxygen concentration, for example, L-ascorbic acid, isoascorbic acid, gallic acid, and their salts, Triphenols, Galla ethyl ketone, etc.

Also, in the present invention, the content of the deoxidizer in the ink composition may be 0.01 mass % or more, 0.1 mass % or more, or 0.5 mass % in terms of suppressing the deterioration of the luminescent nanocrystals. Mass % or more, may be more than 1 mass %, may be 30 mass % or less, may be 20 mass % or less, may be 10 mass % or less, may be 5 mass % or less in order to avoid coloring of ink cured film .

As a method of removing dissolved gas from the ink composition, a method of removing dissolved gas including dissolved oxygen by introducing an inert gas such as nitrogen gas into the ink composition, or a method of depressurizing the ink composition is preferred. The reason is that it is easier.

Furthermore, by combining the above-mentioned method of removing dissolved gas including dissolved oxygen in the ink composition and the above-mentioned method of dehydrating the ink composition, an ink composition with a low concentration of dissolved gas and low water concentration can be prepared , it is more preferable from the viewpoint of more effectively suppressing defects of cured products or deterioration of luminous nanocrystals.

An embodiment of the ink composition for a color filter has been described above, but the ink composition of the above-mentioned embodiment may be used by, for example, a photolithography method in addition to the inkjet method. In this case, the ink composition contains an alkali-soluble resin in the form of a binder polymer.

When the ink composition is used in photography, first, the ink composition is coated on the substrate, and when the ink composition contains a solvent, the ink composition is dried to form a coating film. The coating film obtained in this manner is soluble in an alkaline developing solution, and can be patterned by treating with an alkaline developing solution. At this time, the alkaline developer is mostly an aqueous solution from the standpoint of ease of disposal of the developer waste. Therefore, the coating film of the ink composition is treated with an aqueous solution. On the other hand, when using an ink composition with luminescent nanocrystals (quantum dots, etc.), the luminescent nanocrystals are unstable to water, and luminescence (such as fluorescence) is impaired by moisture . Therefore, in this embodiment, an inkjet method that does not require treatment with an alkaline developer (aqueous solution) is preferable.

Also, even when the coating film of the ink composition is not treated with an alkaline developer, when the ink composition is alkali-soluble, the coating film of the ink composition easily absorbs moisture in the atmosphere, As time goes by, the luminescence (such as fluorescence) of luminescent nanoparticles (quantum dots, etc.) will also be damaged. From this point of view, in this embodiment, it is preferable that the coating film of the ink composition is alkali-insoluble. That is, the ink composition of this embodiment is preferably an ink composition capable of forming an alkali-insoluble coating film. Such an ink composition can be obtained by using an alkali-insoluble thermosetting resin as the thermosetting resin. The so-called coating film of the ink composition is alkali-insoluble, which means that the coating film of the ink composition at 25°C is based on the total amount of the coating film of the ink composition relative to the dissolved amount of 1% by mass of potassium hydroxide aqueous solution. The mass is based on 30% by mass or less. The above-mentioned dissolved amount of the coating film of the ink composition is preferably at most 10% by mass, more preferably at most 3% by mass. Furthermore, it can be confirmed that the ink composition is an ink composition capable of forming an alkali-insoluble coating film by applying the ink composition on the base material, in the case of including a solvent, at 80°C, Drying was carried out under the condition of 3 minutes, and the above-mentioned dissolved amount of the obtained coating film with a thickness of 1 μm was measured.

<Manufacturing method of ink composition>

Next, a method for manufacturing the ink composition of the above-mentioned embodiment will be described. A method for producing an ink composition includes, for example: a first step of preparing a dispersion of light-scattering particles containing light-scattering particles and a polymer dispersant; Rice grains are mixed. In this method, the dispersion of light-scattering particles may further contain a thermosetting resin and an organic solvent within a specific LogP value range as described above as essential components, and a thermosetting resin may be further mixed in the second step. According to this method, the light-scattering particles can be sufficiently dispersed. Therefore, an ink composition capable of reducing light leakage in the pixel portion can be easily obtained.

In the step of preparing the dispersion of light-scattering particles, the dispersion of light-scattering particles can be prepared by mixing the light-scattering particles, a polymer dispersant, and optionally a thermosetting resin and performing dispersion treatment. The mixing and dispersing treatment can be performed using a dispersing device such as a bead mill, a paint conditioner, or a planetary mixer. From the viewpoint of improving the dispersibility of the light-scattering particles and making it easy to adjust the average particle diameter of the light-scattering particles to a desired range, it is preferable to use a bead mill or a paint conditioner.

The manufacturing method of the ink composition may further include a step of preparing a dispersion of luminescent nanocrystals containing luminescent nanocrystals and a thermosetting resin before the second step. In this case, the dispersion of light-scattering particles and the dispersion of luminescent nanoparticles are mixed in the second step. According to this method, the luminescent nanocrystal particles can be sufficiently dispersed. Therefore, an ink composition capable of reducing light leakage in the pixel portion can be easily obtained. In the step of preparing the dispersion of luminescent nanocrystals, the same dispersion device as that of preparing the dispersion of light-scattering particles can be used for mixing and dispersing of the luminescent nanocrystals and the thermosetting resin .

The ink composition obtained in this manner can be prepared so as to have a specific water content as described above.

When the ink composition of this embodiment is used as an ink composition for an inkjet method, it is preferably applied to an inkjet recording device of a piezoelectric inkjet method by a mechanical ejection mechanism using a piezoelectric element. . Regarding the piezoelectric inkjet method, it is expected that the ink composition will not be exposed to high temperature instantaneously during ejection, and it will not easily cause deterioration of the luminescent nanocrystal grains, and it will be easier to obtain the pixel portion of the color filter (light conversion layer). General luminous properties.

<Light conversion layer and color filter>

Next, details of the light conversion layer and the color filter using the ink composition of the above embodiment will be described with reference to the drawings. In addition, in the following description, the same code|symbol is used for the same or equivalent element, and repeated description is abbreviate|omitted.

Fig. 1 is a schematic sectional view of a color filter according to an embodiment. As shown in FIG. 1 , the color filter 100 includes a substrate 40 and a light conversion layer 30 disposed on the substrate 40 . The light conversion layer 30 includes a plurality of pixel units 10 and a light shielding unit 20 .

The light conversion layer 30 has a first pixel portion 10 a , a second pixel portion 10 b , and a third pixel portion 10 c as pixel portions 10 . The first pixel portion 10a, the second pixel portion 10b, and the third pixel portion 10c are arranged in a lattice pattern so as to repeat in sequence. The light shielding portion 20 is disposed between adjacent pixel portions, that is, between the first pixel portion 10a and the second pixel portion 10b, between the second pixel portion 10b and the third pixel portion 10c, and between the third pixel portion 10c and the first pixel portion. between parts 10a. In other words, the adjacent pixel portions are separated from each other by the light shielding portion 20 .

The first pixel portion 10a and the second pixel portion 10b each include a cured product of the ink composition of the above-mentioned embodiment. The hardened product contains luminescent nanocrystal grains, light scattering particles, and hardened components. The curable component is a cured product of a thermosetting resin, specifically, a cured product obtained by crosslinking a thermosetting resin. That is, the first pixel portion 10a includes the first hardening component 13a, and the first light-emitting nanocrystal grains 11a and the first light-scattering particles 12a respectively dispersed in the first hardening component 13a. Similarly, the second pixel portion 10b includes a second hardening component 13b, and second light-emitting nanocrystal grains 11b and second light-scattering particles 12b respectively dispersed in the second hardening component 13b. In the first pixel portion 10a and the second pixel portion 10b, the first hardening component 13a and the second hardening component 13b may be the same or different, and the first light-scattering particle 12a and the second light-scattering particle 12b may be the same or different. different.

The first luminescent nanocrystal grains 11a are red luminescent nanocrystal grains that absorb light with a wavelength in the range of 420 to 480 nm and emit light with a peak wavelength in the range of 605 to 665 nm. That is, the first pixel portion 10a can be replaced with a red pixel portion for converting blue light into red light. Also, the second luminescent nanocrystal grains 11b are green luminescent nanocrystal grains that absorb light with a wavelength in the range of 420 to 480 nm and emit light with a peak wavelength in the range of 500 to 560 nm. That is, the second pixel portion 10b can be replaced with a green pixel portion for converting blue light into green light.

With regard to the content of the luminescent nanocrystal grains in the pixel portion including the cured product of the ink composition, from the viewpoint of a better light leakage reduction effect, based on the total mass of the cured product of the ink composition, it can be 5 Mass % or more may be 10 mass % or more, 15 mass % or more, 20 mass % or more, 30 mass % or more, or 40 mass % or more. The content of the luminescent nanocrystal grains may be 70% by mass or less, 60% by mass or less, or less than 60% by mass based on the total mass of the hardened ink composition from the viewpoint of excellent reliability of the pixel portion. It may be 55 mass % or less, and may be 50 mass % or less.

The content of the light-scattering particles in the pixel portion including the cured product of the ink composition may be 0.1% by mass based on the total mass of the cured product of the ink composition from the viewpoint of a better effect of reducing light leakage. Above, may be 1% by mass or more, may be 5% by mass or more, may be 7% by mass or more, may be 10% by mass or more, may be 12% by mass or more. The content of the light-scattering particles may be 60% by mass or less based on the total mass of the hardened ink composition from the viewpoint of a better light leakage reduction effect and excellent reliability of the pixel portion. 50% by mass or less, 40% by mass or less, 30% by mass or less, 25% by mass or less, 20% by mass or less, or 15% by mass or less. The content of light-scattering particles, based on the total mass of the hardened ink composition, can also be 0.1-60 mass%, 0.1-50 mass%, 0.1-40 mass%, 0.1-30 mass%, 0.1-25 Mass %, 0.1-20 mass %, 0.1-15 mass %, 1-60 mass %, 1-50 mass %, 1-40 mass %, 1-30 mass %, 1-25 mass %, 1-20 mass % , 1~15 mass%, 5~60 mass%, 5~50 mass%, 5~40 mass%, 5~30 mass%, 5~25 mass%, 5~20 mass%, 5~15 mass%, 7 ~60 mass%, 7~50 mass%, 7~40 mass%, 7~30 mass%, 7~25 mass%, 7~20 mass%, 7~15 mass%, 10~60 mass%, 10~50 mass% Mass%, 10~40mass%, 10~30mass%, 10~25mass%, 10~20mass%, 10~15mass%, 12~60mass%, 12~50mass%, 12~40mass% , 12~30 mass%, 12~25 mass%, 12~20 mass%, or 12~15 mass%.

The third pixel portion 10c has a transmittance of 30% or more for light having a wavelength in the range of 420 to 480 nm. Therefore, the third pixel unit 10 c functions as a blue pixel unit when a light source emitting light having a wavelength in the range of 420 to 480 nm is used. The third pixel portion 10c includes, for example, a cured product of a composition containing the above-mentioned thermosetting resin. The hardened product contains the third hardening component 13c. The third curable component 13c is a cured product of a thermosetting resin, specifically, a cured product obtained by crosslinking a thermosetting resin. That is, the third pixel portion 10c includes the third hardening component 13c. In the case where the third pixel portion 10c includes the above-mentioned cured product, the composition containing the thermosetting resin may further contain the above-mentioned ink composition as long as the transmittance of light with a wavelength in the range of 420 to 480 nm is 30% or more. Components other than thermosetting resins. Furthermore, the transmittance of the third pixel portion 10c can be measured by a microscopic spectroscopic device.

The thickness of the pixel portion (the first pixel portion 10a, the second pixel portion 10b, and the third pixel portion 10c) may be, for example, 1 μm or more, 2 μm or more, or 3 μm or more. The thickness of the pixel portion (the first pixel portion 10a, the second pixel portion 10b, and the third pixel portion 10c) may be, for example, 30 μm or less, 20 μm or less, or 15 μm or less.

The light shielding portion 20 is a so-called black matrix provided to separate adjacent pixel portions to prevent color mixing and light leakage from the light source. The material constituting the light-shielding portion 20 is not particularly limited. In addition to metals such as chromium, hardened resin compositions made of binder polymers containing light-shielding particles such as carbon particles, metal oxides, inorganic pigments, and organic pigments can also be used. things etc. As the binder polymer used here, polyimide resins, acrylic resins, epoxy resins, polyacrylamides, polyvinyl alcohols, gelatin, casein, cellulose, etc. may be used in combination. Resin, photosensitive resin, O/W latex type resin composition (for example, one formed by emulsifying reactive polysiloxane), etc. The thickness of the light shielding portion 20 may be, for example, not less than 0.5 μm and not more than 10 μm.

The substrate 40 is a transparent substrate with light transmission, for example, transparent glass substrates such as quartz glass, Pyrex (registered trademark) glass, and synthetic quartz plate, transparent flexible substrates such as transparent resin films, and optical resin films can be used. material etc. Among them, it is preferable to use a glass substrate composed of an alkali-free glass that does not contain an alkali component in the glass. Specifically, "7059 glass", "1737 glass", "Eagle 200" and "Eagle XG" manufactured by Corning, "AN100" manufactured by Asahi Glass, and "OA-10G" manufactured by Nippon Electric Glass are preferable. " and "OA-11". These are materials with a small thermal expansion rate, and are excellent in dimensional stability and workability in high-temperature heat treatment.

The color filter 100 provided with the above light conversion layer 30 is preferably used in the case of using a light source that emits light having a wavelength in the range of 420 to 480 nm.

The color filter 100 can be manufactured, for example, by forming the light-shielding portion 20 in a pattern on the base material 40, and then selectively disabling the ink composition (ink-jet ink) of the above-mentioned embodiment by an ink-jet method. The ink composition is adhered to the pixel portion formation area partitioned by the light-shielding portion 20 on the substrate 40, and the ink composition is cured by irradiation or heating of active energy rays.

The method of forming the light-shielding portion 20 includes forming a metal thin film such as chromium or a thin film of a resin composition containing light-shielding particles on one side of the substrate 40 in a plurality of regions that become boundaries between pixel portions, and patterning the thin film. method etc. The metal thin film can be formed, for example, by sputtering, vacuum evaporation, etc., and the thin film of the resin composition containing light-shielding particles can be formed, for example, by coating, printing, and the like. A photolithography method etc. are mentioned as a method of patterning.

Examples of the inkjet method include a Bubble Jet (registered trademark) method using an electrothermal transducer as an energy generating element, a piezoelectric inkjet method using a piezoelectric element, and the like.

When curing the ink composition by irradiation of active energy rays (such as ultraviolet rays), for example, mercury lamps, metal halide lamps, xenon lamps, LEDs, etc. can be used. The wavelength of the irradiated light may be, for example, not less than 200 nm and not more than 440 nm. The amount of exposure may be, for example, not less than 10 mJ/cm ² and not more than 4000 mJ/cm ² .

When curing the ink composition by heating, the heating temperature may be, for example, 110° C. or higher and 250° C. or lower. The heating time may be, for example, not less than 10 minutes and not more than 120 minutes.

As mentioned above, although one embodiment of a color filter, a light conversion layer, and the manufacturing method of these was demonstrated, this invention is not limited to the said embodiment.

For example, instead of the third pixel portion 10c, the light conversion layer may include a pixel portion (blue pixel portion) of a hardened product containing an ink composition containing blue light-emitting nanocrystal grains, or may include the pixel portion (blue pixel portion). pixel portion) and the third pixel portion 10c. In addition, the light conversion layer may include a pixel portion (for example, a yellow pixel portion) including a cured product of an ink composition containing nanocrystal grains emitting light of colors other than red, green, and blue. In these cases, each of the light-emitting nanocrystal grains contained in each pixel portion of the light conversion layer preferably has a maximum absorption wavelength in the same wavelength region.

In addition, at least a part of the pixel portion of the light conversion layer may be a cured product containing a composition containing a pigment other than luminescent nanocrystal particles.

In addition, the color filter may have an ink-repelling layer made of a material having ink-repelling properties and having a width narrower than that of the light-shielding portion on the pattern of the light-shielding portion. In addition, the ink-repelling layer may not be provided, and a layer containing a photocatalyst as a wettability variable layer may be formed in a full coating state in the region including the pixel portion formation region, and thereafter, the layer containing the photocatalyst may be irradiated through a photomask. Exposure to light selectively increases the ink affinity of the region where the pixel portion is formed. Titanium oxide etc. are mentioned as a photocatalyst.

Moreover, the color filter may be equipped with the ink receiving layer containing hydroxypropyl cellulose etc. between a base material and a pixel part.

Moreover, the color filter may be equipped with the protective layer on a pixel part. The protective layer is provided to flatten the color filter and prevent components contained in the pixel portion, or components contained in the pixel portion and the photocatalyst-containing layer from elution into the liquid crystal layer. As a material constituting the protective layer, known ones used as protective layers for color filters can be used.

In addition, the color filter and the light conversion layer can be manufactured by photolithography instead of inkjet to form the pixel portion. In this case, first, the ink composition is applied to the substrate in layers to form an ink composition layer. Next, the ink composition layer is patterned and exposed, and then developed using a developer. In this manner, a pixel portion composed of a hardened ink composition is formed. Since the developer is generally alkaline, an alkali-soluble polymer is used as the binder polymer. However, the inkjet method is superior to the photoetching method from the viewpoint of material usage efficiency. The reason is that in the photoetching method, more than 2/3 of the material should be removed in principle, and the material is wasted. Therefore, in this embodiment, it is preferable to use an inkjet ink and form the pixel portion by an inkjet method.

In addition, the pixel portion of the light conversion layer according to the present embodiment may further contain a pigment having substantially the same color as the light emission color of the luminescent nanocrystal particles in addition to the above-mentioned luminescent nanocrystal grains. For example, when using a pixel portion containing luminescent nanocrystal grains that absorb blue light and emit light as a pixel portion of a liquid crystal display element, blue light or quasi-white light with a peak at 450nm is used as the light from the light source. When the concentration of the luminescent nanocrystal grains in the pixel portion is insufficient, the light from the light source will pass through the light conversion layer when the liquid crystal display element is driven. The penetrating light (blue light, leakage light) from the light source and the light emitted by the luminescent nano crystal grains will mix colors. From the viewpoint of preventing the reduction in color reproducibility caused by such color mixing, a pigment may be contained in the pixel portion of the light conversion layer. In order to contain the pigment in the pixel portion, the ink composition may contain the pigment.

Also, one or both of the red pixel portion (R), green pixel portion (G), and blue pixel portion (B) in the light conversion layer of this embodiment may be set to contain a coloring material and not contain a light-emitting pixel. The pixel part of the nanocrystalline grain. As the coloring material usable here, a known coloring material can be used, for example, as a coloring material used for the red pixel part (R), a diketopyrrolopyrrole (diketopyrrolopyrrole) pigment and/or an anionic red organic dye can be mentioned. As the coloring material used in the green pixel portion (G), there may be selected from a mixture of a copper halide phthalocyanine pigment, a phthalocyanine green dye, a phthalocyanine blue dye, and an azo yellow organic dye. At least one of the group. Examples of the coloring material used in the blue pixel portion (B) include an ε-type copper phthalocyanine pigment and/or a cationic blue organic dye. Regarding the usage amount of these coloring materials, in the case of making it contained in the light conversion layer, it is preferable to use the total amount of the pixel portion (cured product of the ink composition) from the viewpoint of preventing the decrease of the transmittance. The mass is based on 1 to 5% by mass.

[Example]

Hereinafter, the present invention will be specifically described by way of examples. However, the present invention is not limited to the following examples.

The following operations of producing luminous nanocrystals and producing ink were carried out in a glove box filled with nitrogen, or in a flask with the atmosphere blocked and under nitrogen flow.

In addition, all the raw materials exemplified below were used by introducing nitrogen gas into the container beforehand to replace the atmosphere in the container with nitrogen gas. In addition, regarding the liquid material, nitrogen gas is introduced into the liquid to replace dissolved oxygen with nitrogen gas.

In addition, the following chloroform, ethanol, hexane, toluene, and 1,4-butanediol diacetate are used in advance using molecular sieves (basically use 3A, hexane, toluene, butanediol diacetate 4A) Those who have been dehydrated for more than 48 hours to make them dry.

Titanium oxide was heated at 120° C. under a reduced pressure of 1 mmHg for 2 hours and cooled in a nitrogen atmosphere before use.

[Manufacture of red luminous nanocrystals]

17.48 g of indium acetate, 25.0 g of trioctylphosphine oxide, and 35.98 g of lauric acid were added to a 1000 mL flask, while nitrogen gas was introduced and stirred at 160° C. for 40 minutes. Furthermore, it stirred at 250 degreeC for 20 minutes, and heated to 300 degreeC after that, and continued stirring. In a glove box, 4.0 g of tris(trimethylsilyl)phosphine was dissolved in 15.0 g of trioctylphosphine, and then filled into a glass syringe. This was poured into a flask kept at 300°C, and reacted at 250°C for 10 minutes. Furthermore, 7.5 g of tris(trimethylsilyl)phosphine was dissolved in 30.0 g of trioctylphosphine in a glove box, and 5 ml of the resulting mixture was added dropwise to the above reaction solution over 12 minutes, and then, 15 Every 5 mL was added to the reaction solution at minute intervals until used up.

In another three-necked flask, 5.595 g of indium acetate, 10.0 g of trioctylphosphine oxide, and 11.515 g of lauric acid were added, while nitrogen gas was introduced and stirred at 160°C for 40 minutes. Furthermore, it stirred at 250 degreeC for 20 minutes and heated to 300 degreeC, after that, the mixed solution cooled to 70 degreeC was added to the said reaction solution. In a glove box, 4.0 g of tris(trimethylsilyl)phosphine was dissolved in 15.0 g of trioctylphosphine, and 5 mL of the resulting mixture was added dropwise to the above reaction solution over 12 minutes, and then, over 15 minutes, Add to the reaction solution at intervals of 5 mL until used up. After maintaining stirring for 1 hour and cooling to room temperature, 100 mL of toluene and 400 mL of ethanol were added to aggregate the fine particles. Use a centrifuge to precipitate the microparticles, then discard the supernatant, and dissolve the precipitated microparticles in trioctylphosphine to obtain indium phosphide (InP) red luminous nanocrystal trioctylphosphine solution.

[Manufacture of green luminescent nanocrystals]

23.3 g of indium acetate, 40.0 g of trioctylphosphine oxide, and 48.0 g of lauric acid were added to a 1000 mL flask, while nitrogen gas was introduced and stirred at 160° C. for 40 minutes. Furthermore, it stirred at 250 degreeC for 20 minutes, and heated to 300 degreeC after that, and continued stirring. In a glove box, 10.0 g of tris(trimethylsilyl)phosphine was dissolved in 30.0 g of trioctylphosphine, and then filled into a glass syringe. This was poured into a flask kept at 300°C, and reacted at 250°C for 5 minutes. The flask was cooled to room temperature, and 100 mL of toluene and 400 mL of ethanol were added to aggregate the fine particles. Use a centrifuge to precipitate the microparticles, then discard the supernatant, and dissolve the precipitated microparticles in trioctylphosphine, thereby obtaining indium phosphide (InP) green luminous nanocrystal trioctylphosphine solution.

[Manufacturing of InP/ZnS core-shell nanocrystals]

In the trioctylphosphine solution of InP nanocrystals synthesized above, adjust to 3.6g of InP and 90g of trioctylphosphine, then put them into a 1000mL flask, and then add 90g of trioctylphosphine oxide, And lauric acid 30g. On the other hand, 42.9 mL of a 1 M hexane solution of diethylzinc, 92.49 g of a 9.09% by weight solution of trioctylphosphine of bis(trimethylsilyl)sulfide, and 162 g of trioctylphosphine were mixed in a glove box. , to make a stock solution. Replace the inside of the flask with a nitrogen atmosphere, then set the temperature of the flask to 180°C, and add 15mL of the above-mentioned stock solution when it reaches 80°C, and then continue to add 15mL every 10 minutes. (Flask temperature maintained at 180°C). After the last addition, the temperature was maintained for 10 minutes to complete the reaction. After the reaction, the solution was cooled to room temperature, and 500 mL of toluene and 2000 mL of ethanol were added to agglomerate the nanocrystals. The nanocrystals were precipitated using a centrifuge, and then the supernatant was discarded, and the precipitate was redissolved in chloroform so that the concentration of the nanocrystals in the solution became 20% by mass, thereby obtaining InP/ZnS cores Chloroform solution of shell nanocrystals.

[QD Ligand Exchange]

Referring to Japanese Patent Application Laid-Open No. 2002-121549, triethylene glycol monomethyl ether ester of 3-mercaptopropionic acid (triethylene glycol monomethyl ether mercaptopropionate) (TEGMEMP) was synthesized.

In a container filled with nitrogen, mix QD dispersion 1 (the above-mentioned InP/ZnS core-shell nanocrystals (red luminescence)) with 80 g of chloroform solution in which 8 g of the above-synthesized TEGMEMP is dissolved, and stir at 80°C for 2 hours to allow ligand exchange and cool to room temperature.

Thereafter, toluene/chloroform was evaporated while stirring at 40° C. under reduced pressure, and concentrated until the liquid volume became 100 mL. 4 times the weight of n-hexane was added to the dispersion to agglomerate the QDs, and the supernatant was removed by centrifugation and decantation. Add 50 g of toluene to the precipitate and redisperse it by ultrasonic wave. This washing operation was performed a total of 3 times to remove free ligand components remaining in the liquid. The decanted precipitate was vacuum-dried at room temperature for 2 hours to obtain 2 g of TEGMEMP-modified QD (QD-TEGMEMP) powder.

[Preparation of Titanium Oxide Dispersion]

In a container filled with nitrogen, 6 g of titanium oxide, 1.01 g of a polymer dispersant, and 1,4-butanediol diacetate were mixed so that the non-volatile content became 40%. Zirconia particles (diameter: 1.25 mm) were added to the blend in a nitrogen-filled container, and then the blend was dispersed by vibrating the nitrogen-filled closed container for 2 hours using a paint conditioner. Light-scattering particle dispersion 1 was thus obtained.

All the above-mentioned materials use nitrogen to replace dissolved oxygen with nitrogen.

[Example 1]

[Preparation of ink composition]

Mix the following (1), (2) and (3) evenly in a container filled with nitrogen, and then filter the mixture with a filter with a pore size of 5 μm in a glove box, and then introduce nitrogen into the ink Saturation with nitrogen.

Next, nitrogen gas was removed by reducing pressure, thereby obtaining an ink composition. Furthermore, the materials used are as follows.

[Light Scattering Particles]

‧Titanium oxide: MPT141 (manufactured by Ishihara Sangyo Co., Ltd.)

[Thermosetting resin]

‧Glycidyl-containing solid acrylic resin: "FINEDIC A-254"

(Manufactured by DIC Co., Ltd., epoxy equivalent 500)

[Polymer dispersant]

‧Polymer dispersant: BYK-2164

(Brand name manufactured by BYK, "DISPERBYK" is a registered trademark)

[Organic solvents]

‧1,4-Butanediol diacetate (manufactured by Daicel Co., Ltd.)

(1) Mix the organic solvent 1,4-butanediol diacetate in the QD-TEGMEMP prepared above to make 22.5g of QD dispersion with 30% non-volatile content

(2) Thermosetting resin: "FINEDIC A-254" (6.28g) manufactured by DIC Co., Ltd., hardener: 1-methylcyclohexane-4,5-dicarboxylic anhydride (1.05g), and Hardening accelerator: Dimethylbenzylamine (0.08g) dissolved in an organic solvent: 1,4-butanediol diacetate so that the non-volatile content becomes 30% Thermosetting resin solution 12.5g

(3) The above-mentioned light-scattering particle dispersion 1 7.5g

[Example 2]

[Preparation of ink composition]

Using QD dispersion 2 (the aforementioned InP/ZnS core-shell nanocrystals (green luminescence)) instead of QD dispersion 1, an ink composition was obtained in the same manner as in Example 1.

[Comparative example 1]

The ink composition sealed in nitrogen gas prepared in the same manner as in Example 1 using decylbenzene as an organic solvent was stirred in the air to obtain an ink composition. A rise in the dissolved oxygen concentration was confirmed.

[Production of light conversion filter]

The ink composition obtained above was coated on a glass substrate in the air with a spin coater so that the film thickness after drying became 3.5 μm. The coating film was heated to 180° C. in nitrogen gas to be cured, and a layer (light conversion layer) composed of a hardened ink composition was formed on a glass substrate. A light conversion filter was obtained through the above operations.

(3) Evaluation

Using the above-obtained ink composition and the above-obtained light conversion filter, evaluation was performed in the following procedure. The results are shown in Table 1.

[External Quantum Efficiency (EQE)]

Use the above-mentioned blue LED (peak emission wavelength: 450nm), connect the integrating sphere to the above-mentioned radiation spectrophotometer (trade name "MCPD-9800") manufactured by Otsuka Electronics Co., Ltd., and set the integrating sphere on the upper side of the blue LED. ball. Insert a substrate with a light conversion layer between the blue LED and the integrating sphere, turn on the blue LED, and measure the observed spectrum and the illuminance at each wavelength.

From the spectrum and illuminance measured by the above measuring device, the external quantum efficiency was calculated as follows. This value is a value indicating what percentage of light (photons) incident on the light conversion layer is radiated to the observer side as fluorescence. Therefore, if this value is large, it means that the light conversion layer is excellent, and it becomes an important evaluation index together with S(PL).

External quantum efficiency of red light-emitting light conversion layer = P(Red)/E(Blue)×100(%)

External quantum efficiency of green light-emitting light conversion layer=P(Green)/E(Blue)×100(%)

Here, E(Blue), P(Red), and P(Green) are represented as follows, respectively.

E(Blue): Indicates the total value of "illuminance x wavelength ÷ hc" in the wavelength range at the wavelength of 380~490nm. Furthermore, h represents Planck's constant, and c represents the speed of light. (which is a value equivalent to the number of photons observed)

P(Red): Indicates the total value of "illuminance × wavelength ÷ hc" in the wavelength range at the measurement wavelength of 490~590nm. (equivalent to the number of photons observed)

P(Green): Indicates the total value of "illuminance × wavelength ÷ hc" in the wavelength range at the measurement wavelength of 590~780nm. (equivalent to the number of photons observed)

Based on the above situation, calculate EQE, the EQE of embodiment 2 is set as 10, the EQE of the measured sample is evaluated as follows with relative value:

<Evaluation criteria>

Not up to 10 :D

10: C

More than 10 and less than 100: B

Over 100: A

[bubble evaluation]

Use the liquid delivery pump to transport the above ink, and visually observe the generation of air bubbles in the piping body.

[Moisture content evaluation]

The moisture content was measured with a Cal-Ferre moisture meter (manufactured by Mitsubishi Chemical Co., Ltd., model CA-06, and the vaporization unit was VA-06 produced by Mitsubishi Chemical Co., Ltd.).

[Example 3]

First, a substrate (BM substrate) having a light-shielding portion called a black matrix (BM) is produced in the following procedure. That is, a black resist ("CFPR BK" manufactured by TOKYO OHKA KOGYO Co., Ltd.) was applied on a glass substrate made of alkali-free glass ("OA-10G" manufactured by Nippon Electric Glass Co., Ltd.), and then a preliminary Baking, pattern exposure, development and post-baking, thereby forming a patterned light-shielding portion. Exposure was performed by irradiating the black resist with ultraviolet rays at an exposure dose of 250 mJ/cm ² . The pattern of the light-shielding portion is a pattern having an opening corresponding to a sub-pixel of 200 μm×600 μm, and has a line width of 20 μm and a thickness of 2.6 μm.

Then, the red luminescent ink composition obtained in Example 1 was inkjet printed on the opening on the BM substrate, and then irradiated with ultraviolet rays, and then heated at 150° C. for 30 minutes in a nitrogen atmosphere. Thereby, the ink composition is cured, and a pixel portion composed of a cured product of the ink composition is formed. The obtained pixel portion is a pixel portion that converts blue light into red light. The thickness of the pixel portion was 2.1 μm. Through the above operations, a patterned light conversion filter was obtained.

[Example 4]

A BM substrate was prepared in the same manner as in Example 3. Next, the red luminescent ink composition obtained in Example 1 and the green luminescent ink composition obtained in Example 2 were inkjet printed on the opening on the BM substrate, and then irradiated with ultraviolet rays, the same as in Example 3. to harden the ink composition. Thereby, the pixel part which converts blue light into red light, and the pixel part which converts blue light into green light are formed on a BM substrate. Through the above operations, a patterned light conversion filter having various types of pixel portions was obtained.

10‧‧‧pixel part

10a‧‧‧1st pixel part

10b‧‧‧The second pixel part

10c‧‧‧The third pixel part

11a‧‧‧The first luminescent nanocrystal grain

11b‧‧‧The second luminous nanocrystal grain

12a‧‧‧First light-scattering particle

12b‧‧‧Second light scattering particles

13a‧‧‧The first hardening component

13b‧‧‧The second hardening component

13c‧‧‧The third hardening component

20‧‧‧shading part

30‧‧‧light conversion layer

40‧‧‧Substrate

100‧‧‧color filter

Claims (16)

An ink composition, which contains luminescent nano crystal grains, a thermosetting resin, an organic solvent, and light-scattering particles, and the LogP value of the above-mentioned organic solvent is -1.0 to 6.5, and the volume average of the above-mentioned light-scattering particles The diameter is not less than 0.2 μm and not more than 1 μm. An ink composition, which contains luminescent nano crystal grains, a thermosetting resin, an organic solvent, and light-scattering particles, and the LogP value of the above-mentioned organic solvent is -1.0 to 6.5, based on Karl-Fischer (Karl-Fischer ) The moisture (H ₂ O) content rate measured by a moisture meter is 90 ppm or less, and the volume average diameter of the light-scattering particles is 0.2 μm or more and 1 μm or less. The ink composition according to claim 2, wherein the water (H ₂ O) content is 20 ppm or less. The ink composition according to claim 2 or 3, wherein the thermosetting resin is alkali-insoluble. The ink composition according to claim 2 or 3, which can form an alkali-insoluble coating film. The ink composition as described in Claim 2 or 3 has a surface tension of 20-40mN/m. The ink composition as described in Claim 2 or 3 has a viscosity of 2~20mPa‧s. The ink composition according to claim 2 or 3, further comprising a solvent having a boiling point of 180° C. or higher. The ink composition as described in claim 2 or 3, which is used for color filters. A method of manufacturing the ink composition described in claim 2, comprising depressurizing the ink composition to remove dissolved gas. A light conversion layer made of hardened ink composition as described in claim 1 or 2. A light conversion layer, wherein the light conversion layer made of the hardened ink composition according to claim 1 or 2 is alkali-insoluble. A light conversion layer comprising a plurality of pixel portions, and the plurality of pixel portions include: a cured product comprising the ink composition described in any one of claims 2, 4, 5, 6, 7, 8, or 9 pixel department. The light conversion layer according to claim 13, further comprising a light-shielding portion provided between the plurality of pixel portions, and the plurality of pixel portions include: a first pixel portion comprising the hardened material and absorbing 420-480nm The luminescent nanocrystal particles that emit light with a wavelength of light in the range of 605-665nm and have a peak wavelength of light in the range of 605-665nm are used as the above-mentioned luminescent nanocrystal particles; and the second pixel part, which includes the above-mentioned cured product and contains Luminescent nanocrystal grains that emit light with a wavelength in the range of 420 to 480 nm and have a peak wavelength of light in the range of 500 to 560 nm are used as the above-mentioned luminescent nanocrystal grains. The light conversion layer according to claim 13 or 14, wherein the plurality of pixel portions further have a third pixel portion, and the transmittance of the third pixel portion to light having a wavelength in the range of 420 to 480 nm is 30% or more . A color filter comprising the light conversion layer described in any one of Claims 11 to 15.

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