TWI808953B - Ink composition, light conversion layer and color filter - Google Patents

Abstract

The ink composition of the present invention contains luminescent nano crystal particles, light scattering particles, and photopolymerizable compounds and/or thermosetting resins.

Description

Ink composition, light conversion layer and color filter

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

Conventionally, a color filter pixel portion in a display such as a liquid crystal display device uses, for example, a curable resist material containing red organic pigment particles or green organic pigment particles and an alkali-soluble resin and/or an acrylic monomer. Manufactured by photolithography.

In recent years, there has been a strong demand for low power consumption of displays, and the industry is actively researching the use of luminous nanocrystalline particles 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. A method of forming color filter pixel portions such as red pixels and green pixels.

In addition, in the above-mentioned method of manufacturing a color filter by photolithography, the characteristic of the manufacturing method is that there is a change in the resist material other than the pixel portion containing relatively expensive luminescent nanocrystal particles. The disadvantage of being wasted. Under such circumstances, in order to eliminate the waste of the above-mentioned resist material, research has been started on forming a photoconverting substrate pixel portion by an inkjet method (Patent Document 1).

[Prior Art Literature]

[Patent Document]

[Patent Document 1] International Publication No. 2008/001693

In the case of forming a color filter pixel portion (hereinafter also simply referred to as a “pixel portion”) by using an ink composition using luminescent nanocrystalline particles, there is a possibility that the light from the light source is not absorbed by the luminescent nanocrystalline particles. In the case of leakage from the pixel portion. Since such light leakage reduces the color reproducibility of the pixel portion, it must be reduced as much as possible.

Therefore, the object of the present invention is to provide an ink composition capable of reducing light leakage, and a light conversion layer and a color filter using the ink composition.

One aspect of the present invention relates to an ink composition containing luminescent nano crystal particles, light scattering particles, and photopolymerizable compounds and/or thermosetting resins. With the ink composition, light leakage in the pixel portion can be reduced.

The ink composition may further contain a polymer dispersant. The weight average molecular weight of the polymer dispersant can be above 1000.

When the ink composition contains a photopolymerizable compound, the photopolymerizable compound may be a photoradical polymerizable compound or a photocationically polymerizable compound. In addition, the photopolymerizable compound may be alkali-insoluble.

When the ink composition contains a thermosetting resin, the thermosetting resin may be insoluble in alkali.

The ink composition may be an ink composition capable of forming an alkali-insoluble coating film.

The average particle size of the light-scattering particles may be 0.05-1.0 μm, or 0.3-0.6 μm.

The light-scattering particles may contain at least one selected from the group consisting of titanium oxide, aluminum oxide, zirconium oxide, zinc oxide, calcium carbonate, barium sulfate, and silica.

The surface tension of the ink composition can be 20~40mN/m.

The viscosity of the ink composition can be 2~20mPa‧s.

The ink composition may further contain a solvent having a boiling point of 180° C. or higher.

The ink composition can be used for color filters.

The ink composition may be an ink composition used in an inkjet method (inkjet ink).

One aspect of the present invention relates to a light conversion layer having a plurality of pixel portions including a pixel portion containing a cured product of the above-mentioned ink composition. With the light conversion layer, light leakage in the pixel portion can be reduced.

The light conversion layer may further include a light-shielding portion provided between the plurality of pixel portions, and the plurality of pixel portions may include: a first pixel portion containing the above-mentioned cured product, and containing light that absorbs light having a wavelength in the range of 420 to 480 nm and emits it at Luminescent nanocrystalline particles having a light emission peak wavelength in the range of 605 to 665 nm as the luminescent nano crystal particles; and a second pixel portion containing the above-mentioned cured product and containing light absorbing light having a wavelength in the range of 420 to 480 nm Luminescent nano crystal particles that emit light with a luminous peak wavelength in the range of 500-560 nm are used as luminescent nano crystal particles.

The plurality of pixel portions may further have a third pixel portion having a transmittance of 30% or more with respect to light having a wavelength in the range of 420 to 480 nm.

One aspect of the present invention relates to a color filter provided with the above-mentioned light conversion layer. With the color filter, light leakage in the pixel portion can be reduced.

According to the present invention, an ink composition capable of reducing light leakage, and a light conversion layer and a color filter using the ink composition can be provided.

10‧‧‧pixel part

10a‧‧‧1st pixel part

10b‧‧‧The second pixel part

10c‧‧‧The third pixel part

11a‧‧‧The first luminous nanocrystalline particles

11b‧‧‧Second Luminescent Nanocrystalline Particles

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.

Embodiments of the present invention will be described in detail below.

<Ink Composition>

An ink composition according to one embodiment contains luminescent nano crystal particles, light scattering particles, and a photopolymerizable compound and/or a thermosetting resin. An ink composition according to one embodiment is an ink composition for a color filter, which is used, for example, to form 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 a color filter pixel portion by an inkjet method. In the case of forming the pixel portion of the color filter by an inkjet method using a conventional ink composition, it is difficult to reduce light leakage from the pixel portion. On the other hand, according to the ink composition of the embodiment, even in an inkjet system, a pixel portion having an excellent effect of reducing light leakage can be obtained.

Hereinafter, an ink composition for a color filter used in an inkjet method (inkjet ink for a color filter) will be described as an example.

[Luminescent Nanocrystalline Particles]

Luminescent nanocrystalline particles 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 nanocrystalline particles, for example, can emit light of a wavelength different from the absorbed wavelength (fluorescence or phosphorescence) by absorbing light of a specific wavelength. Luminescent nano crystal particles can be red luminescent nano crystal particles that emit light (red light) with a luminous peak wavelength in the range of 605~665nm, or can be emitted with a luminous peak wavelength in the range of 500~560nm Green luminescent nano crystal particles of light (green light) may also be blue luminescent nano crystal particles emitting light (blue light) having a peak wavelength of light emission in the range of 420-480nm. In this embodiment, it is preferable that the ink composition contains at least one of the luminescent nano crystal particles. In addition, the light absorbed by the luminescent nanocrystalline particles may 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 luminescent peak wavelength of the luminescent nanocrystalline particles can be confirmed, for example, in the fluorescence spectrum or phosphorescence spectrum measured by using an ultraviolet-visible spectrophotometer.

Red luminescent nano crystal particles 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 , 635nm or less, 632nm or less or 630nm or less has a peak emission wavelength, 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 similar description, the upper limit value and the lower limit value described individually may be combined arbitrarily.

Green luminescent nano crystal particles preferably have a luminescence peak 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 wavelength, and preferably has a luminescence peak wavelength above 528nm, above 525nm, above 523nm, above 520nm, above 515nm, above 510nm, above 507nm, above 505nm, above 503nm or above 500nm.

The blue luminescent nano crystal particles preferably have light emission 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 The peak wavelength is preferably above 450nm, above 445nm, above 440nm, above 435nm, above 430nm, above 428nm, above 425nm, above 422nm or above 420nm.

Regarding the wavelength (luminous color) of light emitted by luminescent nanocrystalline particles, according to the solution of the Schrodinger wave equation (Schrodinger wave Equation) of the square-well potential model, it depends on the luminescent nanocrystalline particles. The size of the crystalline particles (such as the particle diameter) also depends on the energy gap of the luminescent nanocrystalline particles. Therefore, the luminescent color can be selected by changing the constituent material and size of the luminescent nano crystal particles used.

The luminescent nanocrystalline particles may be luminescent nanocrystalline particles containing a semiconductor material (luminescent semiconductor nanocrystalline particles). Examples of the light-emitting semiconductor nanocrystal particles include quantum dots (hereinafter also referred to as "QD"), quantum rods, and the like. Among them, quantum dots are preferable from the viewpoint of being easy to control the emission spectrum, ensuring reliability, reducing production costs, and improving mass productivity.

The luminescent semiconductor nanocrystalline particles may consist of only a core containing the first semiconductor material, or may have a core containing the first semiconductor material, and at least one core containing 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 luminescent semiconductor nanocrystalline particles 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) containing the second semiconductor material, the light-emitting semiconductor nanocrystalline particles may further have 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 luminescent semiconductor nanocrystalline particles can also be a structure composed of a core, a first shell and a second shell (core/shell/shell structure). Each core and shell can be a mixed crystal containing two or more semiconductor materials (for example, CdSe+CdS, CIS+ZnS, etc.).

The luminescent nanocrystalline particles preferably contain 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, GaSb, AlN, AlP, AlAs, AlSb, InN , 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, Sn PbSeTe , 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. Luminescent semiconductor nanocrystalline particles are preferably those containing 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 , At least one of the group consisting of CuGaSe ₂ , CuGaTe ₂ , Si, C, Ge, and Cu ₂ ZnSnS ₄ .

Examples of red luminescent semiconductor nanocrystalline particles include CdSe nanocrystalline particles, CdSe rod-shaped nanocrystalline particles, and those having a core-shell structure in which the shell part is CdS and the inner core part is CdSe. Rod-shaped nanocrystalline particles, rod-shaped nanocrystalline particles having a core-shell structure and the shell part is CdS and the inner core is ZnSe, having a core-shell structure and the shell part is CdS and the inner core is Nanocrystalline particles of CdSe, nanocrystalline particles having a core-shell structure in which the shell part is CdS and the inner core is ZnSe, nanocrystalline particles of mixed crystals of CdSe and ZnS, rods of mixed crystals of CdSe and ZnS nanocrystalline particles of InP, nanocrystalline particles of InP, nanocrystalline particles of InP, rod-shaped nanocrystalline particles of InP, mixed crystals of CdSe and CdS, mixed crystals of CdSe and CdS Rod-shaped nano crystal particles, mixed crystal nano crystal particles of ZnSe and CdS, rod-shaped nano crystal particles of mixed crystal ZnSe and CdS, etc.

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

As blue luminescent semiconductor nanocrystal particles, for example, ZnSe nanocrystal particles, ZnSe rod-shaped nanocrystal particles, ZnS nanocrystal particles, ZnS rod-shaped nanocrystal particles, Nanocrystalline particles having a core-shell structure in which the shell is ZnSe and the inner core is ZnS, rod-shaped nanocrystalline particles having a core-shell structure in which the shell is ZnSe and the inner core is ZnS, CdS Nanocrystalline particles of CdS, rod-shaped nanocrystalline particles of CdS, etc. Under the same chemical composition, the semiconductor nanocrystalline particles can change the color that should be emitted by the particles to red or green by changing their own average particle diameter. In addition, it is preferable to use semiconductor nanocrystalline particles with as low adverse effects on the human body as possible. When using semiconductor nanocrystalline particles containing cadmium, selenium, etc. as luminescent nanocrystalline particles, it is preferable to select semiconductor nanocrystalline particles that do not contain the above-mentioned elements (cadmium, selenium, etc.) as much as possible and use them alone, or Combined with other luminous nano crystal particles to minimize the above elements.

The shape of the luminescent nanocrystalline particles is not particularly limited, and can be any geometric shape or any irregular shape. The shape of the luminescent nanocrystalline particles can be, for example, spherical, ellipsoidal, pyramidal, disc-like, branch-like, net-like, rod-like, etc. However, in terms of further improving the uniformity and fluidity of the ink composition, as the luminescent nano crystal particles, it is preferable to use particles with less directionality as the particle shape (for example, spherical, regular four-sided Particles in body shape, etc.).

The average particle diameter (volume average diameter) of the luminescent nanocrystalline particles may be 1 nm or more, or 1.5 nm or more from the viewpoint of easily obtaining light emission at a desired wavelength, as well as excellent dispersibility and storage stability. , can also be more than 2nm. 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 nanocrystalline particles can be obtained by measuring with a transmission electron microscope or a scanning electron microscope and calculating the volume average diameter.

From the viewpoint of dispersion stability, the luminescent nanocrystalline particles preferably have an organic ligand on their surface. The organic ligands, for example, can be coordinately bonded to the surface of the luminescent nano crystal particles. In other words, the surface of the luminescent nano crystal particles can be passivated by organic ligands. Also, when the ink composition further contains a polymer dispersant described below, the luminescent nanocrystalline particles may have a polymer dispersant on the surface thereof. In this embodiment, for example, the organic ligand can be removed from the above-mentioned luminous nano crystal particles having the organic ligand, and the organic ligand can be exchanged with the polymer dispersant, thereby making the polymer dispersant bond Bonded on the surface of luminous nano crystal particles. However, from the viewpoint of dispersion stability when used as an inkjet ink, it is preferable to add a polymer dispersant to the luminescent nano crystal particles in a state where an organic ligand is coordinated.

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

As the luminescent nanocrystalline particles, those dispersed in an organic solvent, a photopolymerizable compound, etc. in a colloidal state can be used. The surface of the luminescent nanocrystalline particles dispersed in the organic solvent is 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, and butyl carbitol acetate. esters, or mixtures thereof.

As the luminescent nano crystal particles, commercially available ones can be used. Examples of commercially available luminescent nanocrystalline particles include indium phosphide/zinc sulfide, D-dots, CuInS/ZnS from NN-Labs, InP/ZnS from Aldrich, and the like.

The content of the luminescent nanocrystalline particles may be 5% by mass or more, 10% by mass or more, or 10% by mass or more based on the mass of the non-volatile components of the ink composition from the viewpoint of a better light leakage reduction effect. It may be 15 mass % or more, may be 20 mass % or more, may be 30 mass % or more, and may be 40 mass % or more. The content of luminous nano crystal particles may be 70% by mass or less, 60% by mass or less, or 55% by mass based on the mass of the non-volatile components of the ink composition from the viewpoint of excellent ejection stability. It may be less than or equal to 50% by mass. Furthermore, in this specification, the so-called "mass of non-volatile components of the ink composition" refers to the mass obtained by removing the mass of the solvent from the total mass of the ink composition when the ink composition contains a solvent. When the ink composition does not contain a solvent, it refers to the total mass of the ink composition.

[Light Scattering Particles]

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.

Examples of materials constituting light-scattering particles include simple metals such as tungsten, zirconium, titanium, platinum, bismuth, rhodium, palladium, silver, tin, platinum, and gold; silicon dioxide, barium sulfate, barium carbonate, and 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, zirconia, zinc oxide and other metal oxides; magnesium carbonate, Barium carbonate, bismuth subcarbonate, calcium carbonate and other metal carbonates; aluminum hydroxide and other metal hydroxides; barium zirconate, calcium zirconate, calcium titanate, barium titanate, strontium titanate and other composite oxides, bismuth subnitrate and other metal salts. The light-scattering particles preferably contain at least one element selected from the group consisting of titanium oxide, aluminum oxide, zirconium oxide, zinc oxide, calcium carbonate, barium sulfate, and silicon dioxide from the viewpoint of a better light leakage reduction effect. One type, 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, in terms of further improving the uniformity, fluidity, and light-scattering properties of the ink composition, as the light-scattering particles, it is preferable to use particles with less directionality in particle shape (for example, spherical, Tetrahedral particles, etc.).

The average particle size (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 in the ink composition 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 by measuring the particle diameter of each particle with, for example, a transmission electron microscope or a scanning electron microscope, and calculating the volume average diameter.

The content of the light-scattering particles may be 0.1% by mass or more, 1% by mass or more, or 5% by mass based on the mass of the non-volatile components of the ink composition from the viewpoint of better light leakage reduction effect. The mass % or more may be 7 mass % or more, 10 mass % or more, or 12 mass % or more. The content of light-scattering particles may be 60% by mass or less, or 50% by mass, 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. % or less, 40 mass % or less, 30 mass % or less, 25 mass % or less, 20 mass % or less, or 15 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-mentioned 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 nanocrystal particles (light-scattering particles/luminescent nanocrystal particles) may be 0.1 or more from the viewpoint of a better effect of reducing light leakage, or It may be 0.2 or more, and may be 0.5 or more. The mass ratio (light-scattering particles/luminescent nanocrystalline particles) may be 5.0 or less, or 2.0 or less, from the viewpoint of better light leakage reduction effect and excellent continuous ejection performance during inkjet printing. 1.5 or less. Furthermore, it is considered that the reduction of light leakage by the light-scattering particles utilizes the following mechanism. That is, it is considered that when there are no light-scattering particles, the light from the backlight only goes straight through the pixel portion, and there is less chance of being absorbed by the luminescent nanocrystal particles. On the other hand, if the light-scattering particles and the luminescent nanocrystalline particles are present in the same pixel portion, the light from the backlight in the pixel portion is scattered omnidirectionally, and the luminescent nanocrystalline particles can receive the light from the backlight. Therefore, even if the same backlight is used, it is considered that the amount of light absorbed in the pixel portion increases. As a result, it is considered that light leakage can be prevented by such a mechanism.

[Photopolymerizable compound]

The photopolymerizable compound of this embodiment is a photoradically polymerizable compound or a photocationically polymerizable compound polymerized by irradiation with light, and may be a photopolymerizable monomer or oligomer. These can be used together with a photopolymerization initiator. A photoradical polymerizable compound can be used together with a photoradical polymerization initiator, and a photocationically polymerizable compound can be used together with a photocationic polymerization initiator. In other words, the ink composition may contain: a photopolymerizable component including a photopolymerizable compound and a photopolymerization initiator, or may include: a photoradical polymerizable component including a photoradical polymerizable compound and a photoradical polymerization initiator. The component may contain a photocationically polymerizable component including a photocationically polymerizable compound and a photocationically polymerizable initiator. A photoradical polymerizable compound and a photocationically polymerizable compound may be used together, a compound having photoradical polymerizability and photocationically polymerizable compound may be used, and a photoradically polymerizable initiator and a photocationically polymerizable initiator may be used together. A photopolymerizable compound may be used individually by 1 type, and may use 2 or more types together.

A (meth)acrylate compound is mentioned as a photoradical polymerizable compound. The (meth)acrylate compound can be a monofunctional (meth)acrylate with one (meth)acryl group, or a multifunctional (meth)acrylate with multiple (meth)acryl groups . From the viewpoint of excellent fluidity when made into ink, superior discharge stability, and the viewpoint of suppressing the decrease in smoothness caused by hardening shrinkage when manufacturing color filters, it is preferable to use monofunctional inks in combination. (Meth)acrylates and multifunctional (meth)acrylates. Furthermore, in this specification, the so-called (meth)acrylate means "acrylate" and its corresponding "methacrylate". The expression "(meth)acryl" is also the same.

Examples of monofunctional (meth)acrylates include: methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, butyl (meth)acrylate, (meth)acrylate Amyl acrylate, 2-ethylhexyl (meth)acrylate, Octyl (meth)acrylate, Nonyl (meth)acrylate, Lauryl (meth)acrylate, Hexadecyl (meth)acrylate Alkyl esters, octadecyl (meth)acrylate, cyclohexyl (meth)acrylate, methoxyethyl (meth)acrylate, butoxyethyl (meth)acrylate, (meth) Phenoxyethyl acrylate, nonylphenoxyethyl (meth)acrylate, glycidyl (meth)acrylate, dimethylaminoethyl (meth)acrylate, diethylamino (meth)acrylate Ethyl ester, isobornyl (meth)acrylate, dicyclopentyl (meth)acrylate, dicyclopentenyl (meth)acrylate, dicyclopentenyloxyethyl (meth)acrylate, (meth)acrylic acid 2 -Hydroxy-3-phenoxypropyl, Tetrahydrofurfuryl (meth)acrylate, 2-Hydroxyethyl (meth)acrylate, Benzyl (meth)acrylate, Phenylbenzyl (meth)acrylate, Mono(2-acryloxyethyl)succinate, N-[2-(acryloxy)ethyl]phthalimide, N-[2-(acryloxy)ethyl] Tetrahydrophthalimide, etc.

Multi-functional (meth)acrylates can be 2-functional (meth)acrylates, 3-functional (meth)acrylates, 4-functional (meth)acrylates, 5-functional (meth)acrylates, 6-functional (meth)acrylates, base) acrylate, etc., for example, two (meth)acrylates in which two hydroxyl groups of diol compounds are substituted with (meth)acryloxy groups, and two or three hydroxyl groups in triol compounds are substituted by ( Meth)acryloxy di- or tri(meth)acrylate, etc.

Specific examples of bifunctional (meth)acrylates include: 1,3-butanediol di(meth)acrylate, 1,4-butanediol di(meth)acrylate, 1,5- Pentylene glycol di(meth)acrylate, 3-methyl-1,5-pentanediol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, neopentyl glycol Di(meth)acrylate, 1,8-octanediol di(meth)acrylate, 1,9-nonanediol di(meth)acrylate, tricyclodecane dimethanol di(meth)acrylate ester, ethylene glycol di(meth)acrylate, polyethylene glycol di(meth)acrylate, propylene glycol di(meth)acrylate, dipropylene glycol di(meth)acrylate, tripropylene glycol di(meth)acrylate ) acrylate, polypropylene glycol di(meth)acrylate, neopentyl glycol hydroxypivalate diacrylate, 2 hydroxyl groups of tris(2-hydroxyethyl)isocyanurate are replaced by (methyl) Two hydroxyl groups of acryloxy di(meth)acrylate, diol obtained by adding more than 4 moles of ethylene oxide or propylene oxide to 1 mole of neopentyl glycol are substituted with (form Two hydroxyl groups of diols obtained by adding 2 moles of ethylene oxide or propylene oxide to 1 mole of bisphenol A are substituted with ( Two hydroxyl groups of di(meth)acrylate of meth)acryloxy group and triol obtained by adding 3 moles or more of ethylene oxide or propylene oxide to 1 mole of trimethylolpropane Two (meth)acrylic acid esters substituted with (meth)acryloyloxy groups, and two diols obtained by adding 4 moles or more of ethylene oxide or propylene oxide to 1 mole of bisphenol A The hydroxyl group is substituted with (meth)acryloxy di(meth)acrylate or the like.

Specific examples of trifunctional (meth)acrylates include: trimethylolpropane tri(meth)acrylate, glycerin triacrylate, neopentylthritol tri(meth)acrylate, p-trimethylolpropane Triols obtained by adding 1 mole of propane to 3 moles or more of ethylene oxide or propylene oxide have three hydroxyl groups substituted with (meth)acryloxy tri(meth)acrylate, etc.

As a specific example of tetrafunctional (meth)acrylate, neopentylthritol tetra(meth)acrylate is mentioned.

As a specific example of pentafunctional (meth)acrylate, dipenteoerythritol penta(meth)acrylate is mentioned.

As a specific example of the hexafunctional (meth)acrylate, dipenteoerythritol hexa(meth)acrylate is mentioned.

The polyfunctional (meth)acrylate can be poly(meth) in which multiple hydroxyl groups of diperythritol are substituted with (meth)acryloxy groups such as dipenteoerythritol hexa(meth)acrylate Acrylate.

The (meth)acrylate compound may be ethylene oxide modified phosphoric acid (meth)acrylate having a phosphoric acid group, ethylene oxide modified alkyl phosphoric acid (meth)acrylate, or the like.

As a photocationically polymerizable compound, an epoxy compound, an oxetane compound, a vinyl ether compound, etc. are mentioned.

Examples of the epoxy compound include: bisphenol A type epoxy compound, bisphenol F type epoxy compound, phenol novolac type epoxy compound, trimethylolpropane polyglycidyl ether, neopentyl glycol diglycidyl ether Aliphatic epoxy compounds such as; 1,2-epoxy-4-vinylcyclohexane, 1-methyl-4-(2-methyloxiranyl)-7-oxabicyclo[4.1. 0] alicyclic epoxy compounds such as heptane, etc.

As an epoxy compound, a commercial item can also be used. As a commercial item of an epoxy compound, "Celloxide 2000", "Celloxide 3000", and "Celloxide 4000" etc. by Daicel Chemical Industry Co., Ltd. can be used, for example.

Examples of cationic polymerizable oxetane compounds include: 2-ethylhexyl oxetane, 3-hydroxymethyl-3-methyloxetane, 3-hydroxymethyl-3- Ethyloxetane, 3-hydroxymethyl-3-propyloxetane, 3-hydroxymethyl-3-n-butyloxetane, 3-hydroxymethyl-3-benzene oxetane, 3-hydroxymethyl-3-benzyloxetane, 3-hydroxyethyl-3-methyloxetane, 3-hydroxyethyl-3-ethyloxy Hetidine, 3-Hydroxyethyl-3-propyloxetane, 3-Hydroxyethyl-3-phenyloxetane, 3-Hydroxypropyl-3-methyloxetane Butane, 3-hydroxypropyl-3-ethyloxetane, 3-hydroxypropyl-3-propyloxetane, 3-hydroxypropyl-3-phenyloxetane , 3-hydroxybutyl-3-methyloxetane, etc.

A commercial item can also be used as an oxetane compound. As commercially available oxetane compounds, for example, ARONE OXETANE series ("OXT-101", "OXT-212", "OXT-121", "OXT-221" etc. manufactured by Toagosei Co., Ltd. can be used) ); "Celloxide 2021", "Celloxide 2021A", "Celloxide 2021P", "Celloxide 2080", "Celloxide 2081", "Celloxide 2083", "Celloxide 2085", "EPOLEAD GT300" manufactured by Daicel Chemical Industry Co., Ltd. "EPOLEAD GT301", "EPOLEAD GT302", "EPOLEAD GT400", "EPOLEAD GT401" and "EPOLEAD GT403"; "Cyracure UVR-6105", "Cyracure UVR-6107", "Cyracure UVR" manufactured by Dow Chemical Japan Co., Ltd. -6110", "Cyracure UVR-6128", "ERL4289" and "ERL4299", etc. In addition, known oxetane compounds (for example, oxetane compounds described in JP 2009-40830 and the like) can also be used.

Examples of the vinyl ether compound include 2-hydroxyethyl vinyl ether, triethylene glycol vinyl monoether, tetraethylene glycol divinyl ether, trimethylolpropane trivinyl ether, and the like.

Moreover, as a photopolymerizable compound in this embodiment, the photopolymerizable compound described in paragraph 0042-0049 of Unexamined-Japanese-Patent No. 2013-182215 can also be used.

In the ink composition of this embodiment, when the hardenable component is composed of only the photopolymerizable compound or its main component, the durability (strength, heat resistance, etc.) of the cured product can be further improved. More preferably, as the above-mentioned photopolymerizable compound, a bifunctional or more polyfunctional photopolymerizable compound having two or more polymerizable functional groups in one molecule is used as an essential component.

The photopolymerizable compound may be alkali-insoluble from the viewpoint of easily obtaining a color filter pixel portion excellent in reliability. In this specification, the term that the photopolymerizable compound is alkali-insoluble means that the amount of the photopolymerizable compound dissolved in a 1% by mass potassium hydroxide aqueous solution at 25°C is 30% by mass or less based on the total mass of the photopolymerizable compound . The above-mentioned dissolved amount of the photopolymerizable compound is preferably at most 10% by mass, more preferably at most 3% by mass.

The content of the photopolymerizable compound makes it easier to obtain a suitable viscosity as an inkjet ink, the viewpoint that the curability of the ink composition becomes better, and the solvent resistance and abrasion resistance of the pixel portion (cured product of the ink composition) In terms of improvement, 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. The content of the photopolymerizable compound can be based on the mass of the non-volatile components of the ink composition from the viewpoint of easily obtaining a suitable viscosity as an inkjet ink, and from the viewpoint of obtaining better optical characteristics (light leakage). 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.

The photopolymerizable compound may have a cross-linking group from the viewpoint of excellent stability of the pixel portion (cured product of the ink composition) (for example, it can suppress deterioration over time, and it is excellent in high-temperature storage stability and wet-heat storage stability). . The cross-linking group is a functional group that reacts with other cross-linking groups by heat or active energy rays (for example, ultraviolet rays), for example, epoxy group, oxetanyl group, vinyl group, acryl group group, acryloxy group, vinyl ether group, etc.

[Photo-radical polymerization initiator]

As the photoradical polymerization initiator, a molecular cleavage type or a hydrogen abstraction type photoradical polymerization initiator is suitable.

、2-異丙基-9-氧硫

、2,4,6-三甲基苯甲醯基二苯基氧化膦、2-苄基-2-二甲胺基-1-(4-嗎啉基苯基)-丁烷-1-酮、雙(2,6-二甲氧基苯甲醯基)-2,4,4-三甲基戊基氧化膦、(2,4,6-三甲基苯甲醯基)乙氧基苯基氧化膦等。作為該等以外之分子裂解型之光自由基聚合起始劑，亦可併用1-羥基環己基苯基酮、安息香乙醚、苯偶醯二甲基縮酮、2-羥基-2-甲基-1-苯基丙烷-1-酮、1-(4-異丙基苯基)-2-羥基-2-甲基丙烷-1-酮及2-甲基-1-(4-甲硫基苯基)-2-嗎啉基丙烷-1-酮。 As molecular cracking photoradical polymerization initiators, can be suitably used: benzoin isobutyl ether, 2,4-diethyl-9-oxysulfur

, 2-isopropyl-9-oxosulfur

, 2,4,6-trimethylbenzoyldiphenylphosphine oxide, 2-benzyl-2-dimethylamino-1-(4-morpholinylphenyl)-butane-1-one , Bis(2,6-dimethoxybenzoyl)-2,4,4-trimethylpentylphosphine oxide, (2,4,6-trimethylbenzoyl)ethoxybenzene Phosphine oxide etc. As photoradical polymerization initiators other than these molecular cleavage types, 1-hydroxycyclohexyl phenyl ketone, benzoin ethyl ether, benzoyl dimethyl ketal, 2-hydroxy-2-methyl- 1-Phenylpropan-1-one, 1-(4-isopropylphenyl)-2-hydroxy-2-methylpropan-1-one and 2-methyl-1-(4-methylthiobenzene base)-2-morpholinopropan-1-one.

Examples of hydrogen abstraction-type photoradical polymerization initiators include: benzophenone, 4-phenylbenzophenone, isophthalphenone, 4-benzoyl-4' -Methyl-diphenyl sulfide, etc. A molecular cleavage type photoradical polymerization initiator and a hydrogen abstraction type photoradical polymerization initiator may also be used together.

[Photocationic polymerization initiator]

As photocationic polymerization initiators, for example, polyaryl percite salts such as triphenylperme hexafluoroantimonate and triphenylperme hexafluorophosphate; Phenyliodonium hexafluoroantimonate and other polyaryliodonium salts, etc.

A commercial item can also be used as a photocationic polymerization initiator. Examples of commercially available products include: acyl phosphine oxide compounds such as "CPI-100P" manufactured by San-Apro, such as "CPI-100P" manufactured by San-Apro, acyl phosphine oxide compounds such as "Lucirin TPO" manufactured by BASF Corporation, " Irgacure 907", "Irgacure 819", "Irgacute 379EG", "Irgacure 184" and "Irgacure PAG290", etc.

The content of the photopolymerization initiator may be not less than 0.1 part by mass, not less than 0.5 part by mass, or not less than 1 part by mass relative to 100 parts by mass of the photopolymerizable compound from the viewpoint of curability of the ink composition. above. The content of the photopolymerization initiator may be 40 parts by mass or less or 30 parts by mass relative to 100 parts by mass of the photopolymerizable compound from the viewpoint of the hydroxyl stability of the pixel portion (cured product of the ink composition). 20 parts by mass or less, or 20 parts by mass or less.

[thermosetting resin]

In this embodiment, the thermosetting resin is a resin that is crosslinked and cured by heat and functions as a binder in the 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 cured ink compositions, and An epoxy group is preferable from a viewpoint of being excellent in the adhesiveness of a light-shielding part (for example, a black matrix) and a base material. The thermosetting resin may have one type of curable group, or may have two or more types of curable group.

Furthermore, the thermosetting resin contains a resin having photoradical polymerizability (polymerized by light irradiation when used together with a photoradical polymerization initiator), and photocation polymerizable ( A resin that is polymerized by irradiation with light when used together with a photocationic polymerization initiator. When the ink composition contains a photoradical polymerizable thermosetting resin and a photoradical polymerization initiator, the photoradical polymerizable thermosetting resin is classified as a photoradical polymerizable compound ( photopolymerizable compounds). When the ink composition contains a photocationically polymerizable thermosetting resin and a photocationically polymerizable initiator, the photocationically polymerizable thermosetting resin is classified as a photocationically polymerizable compound (photopolymerizable compound) ).

The thermosetting resin can be a polymer (homopolymer) of a single monomer, or a copolymer (copolymer) of multiple monomers. Moreover, any of a random copolymer, a block copolymer, and 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. When using a thermosetting resin, you may further add the catalyst (curing accelerator) which can accelerate a thermosetting reaction. In other words, the ink composition may contain a thermosetting component containing 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 polymer which itself has no polymerization reactivity.

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 "multifunctional epoxy resin") can be used. "Epoxy resin" includes both monomeric epoxy resin and polymeric epoxy resin. The number of epoxy groups in one molecule of the multifunctional epoxy resin is preferably 2 to 50, more preferably 2 to 20. The epoxy group may have a structure having an oxirane ring structure, for example, glycidyl group, oxyethylene group, epoxycyclohexyl group and the like. As an epoxy resin, the well-known polyvalent epoxy resin hardenable with a carboxylic acid is mentioned. Such epoxy resins are widely disclosed in, for example, "Epoxy Resin Handbook" edited by Masaki Shinho, Nikkan Kogyo Shimbun (1987), etc., and these can be used.

Examples of thermosetting resins (including polyfunctional epoxy resins) having an epoxy group include polymers of monomers having an oxirane ring structure and combinations of monomers having an oxirane ring structure and other monomers. copolymer. 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-oxetanyl ) methyl ester-glycidyl methacrylate copolymer, styrene-glycidyl methacrylate, etc. Moreover, the compound described in paragraph 0044-0066 of Unexamined-Japanese-Patent No. 2014-56248 can also be used as a thermosetting resin of this embodiment.

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", and "HP-5000" (from DIC Co., Ltd. Naphthalene-type epoxy resins such as 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 novolac type epoxy resins such as epoxy resin, 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 novolac epoxy resins such as cresol novolak type epoxy resins, trade names "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 trade name “VG3101M80” (manufactured by Mitsui Chemicals Co., Ltd.), trade name “EPIKOTE 1031S” (manufactured by Japan Epoxy Resins tetrafunctional epoxy resin such as "DENACOL EX-411" (manufactured by Nagase ChemteX Co., Ltd.), trade name "ST-3000" (manufactured by Tohto Kasei Co., Ltd.), etc. Hydrogenated bisphenol A type epoxy resin, glycidyl ester type epoxy resin such as trade name "EPIKOTE 190P" (manufactured by Japan Epoxy Resins Co., Ltd.), glycidylamine type epoxy resin such as trade name "YH-434" (manufactured by Tohto Kasei Co., Ltd.) Oxygen resins, glyoxal type epoxy resins such as "YDG-414" (made by Tohto Kasei Co., Ltd.) and alicyclic polyfunctional epoxy compounds such as "EPOLEAD GT-401" (made by Daicel Chemical Co. Heterocyclic epoxy resins such as triglycidyl cyanate (TGIC), etc. Moreover, 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" (trade name), etc.

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

Even among polyfunctional epoxy resins, it is preferable to use an epoxy resin having 4 or more epoxy groups in one molecule (polyfunctional epoxy resin with 4 or more functions) from the viewpoint of increasing the crosslink density. Especially in the case of using a thermosetting resin with a weight average molecular weight of 10,000 or less in order to improve the stability of ejection through the ejection head in the inkjet method, the strength and hardness of the pixel portion (cured product of the ink composition) tend 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).

Examples of hardeners and hardening accelerators for hardening thermosetting resins include: 4-methylhexahydrophthalic anhydride, triethylenetetramine, diaminodiphenylmethane, phenol novolac Varnish resin, tris(dimethylaminomethyl)phenol, N,N-dimethylbenzylamine, 2-ethyl-4-methylimidazole, triphenylphosphine, 3-phenyl-1,1- Dimethylurea, etc.

The thermosetting resin may be alkali-insoluble from the viewpoint of easily obtaining a color filter pixel portion excellent in reliability. The term that the thermosetting resin is alkali-insoluble means that the amount of the thermosetting resin dissolved in a 1 mass % potassium hydroxide aqueous solution at 25° C. is 30% by 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.

The weight-average molecular weight of the thermosetting resin makes it easy to obtain a suitable viscosity for inkjet ink, the viewpoint that the curability of the ink composition becomes good, and the solvent resistance of the pixel portion (cured product of the ink composition) and From the viewpoint of improving abrasion resistance, it may be 750 or more, may be 1000 or more, and may be 2000 or more. 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 thereto.

The content of the thermosetting resin makes it easier to obtain a suitable viscosity for inkjet ink, the viewpoint that the curability of the ink composition becomes better, and the solvent resistance and abrasion resistance of the pixel portion (cured product of the ink composition) In terms of improvement, 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. The content of the thermosetting resin can be based on the mass of the non-volatile components of the ink composition from the viewpoint that the viscosity of the inkjet ink does not become too high and the thickness of the pixel portion is not too thick for the light conversion function. 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.

In this embodiment, the ink composition may contain at least one of a photopolymerizable compound and a thermosetting resin, or may contain both of a photopolymerizable compound and a thermosetting resin. When the ink composition contains a photopolymerizable compound, it may not contain a thermosetting resin. Moreover, when an ink composition contains a thermosetting resin, it does not need to contain a photopolymerizable compound. From the standpoint of storage stability of ink compositions containing luminescent nanocrystalline particles (such as quantum dots) and durability (moisture and heat stability, etc.) Among compounds and thermosetting resins, it is preferable to use thermosetting resins because of the storage stability of ink compositions containing luminescent nanocrystalline particles (such as quantum dots) and the ability to be less susceptible to heat caused by quantum dots. From the viewpoint of curing at low temperature due to deterioration, it is more preferable to use a photoradical polymerizable compound in order to form a pixel portion (cured product of the ink composition) without being hindered by oxygen in the curing process. It is preferable to use a photocationically polymerizable compound.

When the ink composition contains a photopolymerizable compound and a thermosetting resin, the total content of the photopolymerizable compound and the thermosetting resin makes it easy to obtain a suitable viscosity for inkjet ink, hardening of the ink composition From the point of view of better performance, and from the point of view of improving the solvent resistance and abrasion resistance of the pixel portion (cured product of the ink composition), it can be 3% by mass or more based on the mass of the non-volatile components of the ink composition. , may be 5% by mass or more, may be 10% by mass or more, may be 15% by mass or more, and may be 20% by mass or more. In addition, the total content of the photopolymerizable compound and the thermosetting resin is not too high in the viscosity of the inkjet ink, and the thickness of the pixel portion is not too thick for the light conversion function. The mass of non-volatile components may be 80% by mass or less, 60% by mass or less, or 50% by mass or less on the basis of the mass of the non-volatile content.

The ink composition of this embodiment can be used as an ink used in a known and commonly used color filter manufacturing method, and it will not consume relatively expensive materials such as luminous nano crystal particles, solvents, etc., only by using it on the required part Since the color filter pixel portion (light conversion layer) can be formed in a required amount, it is preferably prepared and used in a manner more suitable for the inkjet method than for the photolithography method. .

The viscosity of the ink composition may be 2 mPa·s or higher, 5 mPa·s or higher, or 7 mPa·s or higher 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 more than 2 mPa‧s, since the meniscus shape of the ink composition at the front end of the ink discharge hole of the ejection head is stable, it becomes easy to control the ejection of the ink composition (for example, to control the amount of ejection and the time of ejection). 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 can be measured, for example, by 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 deviation can be suppressed. Furthermore, the so-called flying deviation means that when the ink composition is ejected from the ink ejection hole, the spraying 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 it becomes easy to control the discharge of the ink composition (for example, control the discharge amount and discharge timing). On the other hand, when the surface tension is 20 mN/m or less, the occurrence of flight deviation can be suppressed. That is to say, there is no such situation that the ink composition is not sprayed accurately to the formation area of the pixel portion that should be sprayed, resulting in insufficient filling of the pixel portion, or the ink composition is sprayed to the formation area of the pixel portion that should be sprayed. Adjacent pixel portions form a region (or pixel portion) and color reproducibility decreases.

The ink composition may further contain luminescent nano crystal particles, light scattering particles, photopolymerizable compounds, thermosetting resins, polymerization initiators, and organic ligands within the range that does not hinder the effects of the present invention. Element. As other components, a polymer dispersant, a sensitizer, a solvent, etc. are mentioned, for example.

[Polymer dispersant]

In the present invention, the polymer dispersant is a polymer compound having a weight average molecular weight of 750 or more and a functional group having an affinity for light-scattering particles, and has a function of dispersing the light-scattering particles. The polymer dispersant is adsorbed to the light-scattering particles through the functional group having affinity for the light-scattering particles, and the light-scattering particles are dispersed in the ink composition by the electrostatic repulsion and/or steric repulsion between the polymer dispersants middle. The polymer dispersant is preferably combined with the surface of the light-scattering particles and adsorbed on the light-scattering particles, but it can also be combined with the surface of the luminescent nano crystal particles to adsorb on the luminescent nanoparticles, and can also be used in ink composition Free in things.

However, when a conventional ink composition is used to form a color filter pixel portion by an inkjet method, there is a problem with the stability of ejection from the inkjet nozzle due to aggregation of luminescent nanocrystal particles and light scattering particles. situation of reduction. Also, it is considered that by miniaturizing the luminescent nanocrystal particles and light-scattering particles, reducing the content of the luminescent nanocrystal particles and light-scattering particles, etc., the ejection stability will be improved, but in this case, the amount of light leakage The reduction effect tends to decrease, and it is difficult to balance sufficient ejection stability and light leakage reduction effect. On the other hand, according to the ink composition further containing a polymer dispersant, it is possible to further reduce light leakage while ensuring sufficient discharge stability. The reason for obtaining such an effect is not clear, but it is speculated that the reason is that aggregation of luminescent nano crystal particles and light-scattering particles (especially light-scattering particles) is significantly suppressed by the polymer dispersant.

Examples of the functional group having an 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.

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

、咪唑、三唑等含氮雜環基等。 Examples of basic functional groups include: 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 the side effect of precipitation of luminescent nano crystal particles, 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 these, it is more preferable to use a carboxyl group, a phosphonic acid group, and an amine group, and it is most preferable to use an amine group.

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 decrease.

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 decrease.

The polymer dispersant can be a polymer (homopolymer) of a single monomer, or a copolymer (copolymer) of multiple monomers. Also, the polymer dispersant may be any of a random copolymer, a block copolymer, or a graft copolymer. 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 resin, polyamide resin, polyether, phenolic resin, silicone resin, polyurea resin, amino resin, polyethylene Polyamines such as imine and polyallylamine, epoxy resin, polyimide, etc.

As the above-mentioned polymer dispersant, commercially available products can also be used. As commercially available products, AJISPER PB series manufactured by Ajinomoto Fine-Techno Co., Ltd., DISPERBYK series and BYK-series manufactured by BYK Corporation, 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 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 "EFKA PX-4701"; "SOLSPERSE 3000", "SOLSPERSE 9000" manufactured by Lubrizol, "SOLSPERSE 13240", "SOLSPERSE 13650", "SOLSPERSE 13940", "SOLSPERSE 11200", "SOLSPERSE 13940", "SOLSPERSE 16000", "SOLSPERSE 17000", "SOLSPERSE 18000", "SOLSPERSE 200" 00", "SOLSPERSE 21000", "SOLSPERSE 24000", "SOLSPERSE 26000", "SOLSPERSE 27000", "SOLSPERSE 28000", "SOLSPERSE 32000", "SOLSPERSE 32500", "SOLSPERSE 32550", "SOLSPERSE 32600", "SOLSPERSE 330" 00", "SOLSPERSE 34750", "SOLSPERSE 35100", "SOLSPERSE 35200", "SOLSPERSE 36000", "SOLSPERSE 37500", "SOLSPERSE 38500", "SOLSPERSE 39000", "SOLSPERSE 41000", "SOLSPERSE 54000", "SOLSPERSE 710 00" and "SOLSPERSE 76500"; "AJISPER PB821", "AJISPER PB822", "AJISPER PB881", "PN411" and "PA111" manufactured by Ajinomoto Fine-Techno Co., Ltd.; "TEGO Dispers650", "TEGO Dispers660C", "TEGO Dispers662C" manufactured by Evonik , "TEGO Dispers670", "TEGO Dispers685", "TEGO Dispers700", "TEGO Dispers710" and "TEGO Dispers760W"; "Disparlon DA-703-50", "DA-705" and "DA-725" manufactured by Kusumoto Kasei wait.

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 Other monomers (non-ionic monomers, monomers with hydrophilic groups, etc.) are synthesized by copolymerization. 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 polyalkyleneimines and polyester compounds described in JP-A-54-37082, JP-A-61-174939, etc., JP-A The compound prepared by modifying the amine group of the side chain of polyallylamine with polyester as described in Kaihei No. 9-169821, and the compound with polyester macromonomer as the copolymerization component described in Japanese Patent Application Laid-Open No. 9-171253 Graft polymers, polyester polyol-added polyurethanes described in JP-A-60-166318, and the like.

The weight average molecular weight of the polymer dispersant may be 750 or more, may be 1000 or more, may be 2000 or more, or may be 750 or more, may be 750 or more, may be 2000 or more, or It is more than 3000. The weight-average molecular weight of the polymer dispersant can 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 that can be ejected and is suitable for stable ejection. It may be 100,000 or less, 50,000 or less, or 30,000 or less. In the present 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).

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 from the viewpoint of the dispersibility of the light-scattering particles relative to 100 parts by mass of the light-scattering particles above. The content of the polymer dispersant may be 50 parts by mass or less, or 30 parts by mass or less, relative to 100 parts by mass of the light-scattering particles from the viewpoint of the moisture-heat stability of the pixel portion (cured product of the ink composition). , and may be 10 parts by mass or less.

[sensitizer]

As the sensitizer, amines that do not undergo an addition reaction with photopolymerizable compounds and thermosetting resins can be used. As the sensitizer, for example, trimethylamine, methyldimethanolamine, triethanolamine, p-diethylaminoacetophenone, p-dimethylaminobenzoic acid ethyl ester, p-dimethylaminobenzoic acid iso Amyl ester, N,N-dimethylbenzylamine, 4,4'-bis(diethylamino)benzophenone, etc.

[solvent]

Examples of the solvent include: ethylene glycol monobutyl ether acetate, diethylene glycol monobutyl ether acetate, diethylene glycol monoethyl ether acetate, diethylene glycol dibutyl ether, adipic acid di Ethyl Ester, Dibutyl Oxalate, Dimethyl Malonate, Diethyl Malonate, Dimethyl Succinate, Diethyl Succinate, 1,4-Butanediol Diacetate, Glyceryl Triacetate Esters etc.

The boiling point of the solvent is preferably 180° C. or higher from the viewpoint of the continuous discharge stability of the inkjet ink. Also, since the solvent needs to be removed from the ink composition before the ink composition is cured when forming 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 case of using a thermosetting resin instead of a photopolymerizable compound, from the point of view of preparing the ink composition in a uniform manner, and improving the fluidity of the ink composition, etc., to form a color with less unevenness From the viewpoint of the filter pixel portion (light conversion layer), it is preferable to use a solvent. On the other hand, in the case of using a photopolymerizable compound, light scattering particles and luminescent nano crystal particles can be dispersed in the photopolymerizable compound without a solvent. In this case, there is an advantage that the step of removing the solvent by drying is unnecessary when forming the pixel portion.

An embodiment of the ink composition for color filters has been described above, but the ink composition of the above embodiment can also 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 as a binder polymer.

In the case of using the ink composition by photolithography, first, when the ink composition is coated on the substrate and the ink composition contains a solvent, the ink composition is further dried to form a coating film. The coating film thus obtained is soluble in an alkaline developing solution, and is patterned by treating with an alkaline developing solution. At this time, the alkaline developer is mostly an aqueous solution from the standpoint of the ease of disposal of the developer waste. Therefore, the coating film of the ink composition is treated with the aqueous solution. On the other hand, in the case of an ink composition using luminescent nanocrystalline particles (quantum dots, etc.), the luminescent nanocrystalline particles are unstable to water, and the luminescence (such as fluorescence) will be damaged by water . Therefore, in this embodiment, an inkjet system 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, and the As time passes, the luminescence (such as fluorescence) of luminescent nanocrystalline particles (quantum dots, etc.) is gradually damaged. From this point of view, in this embodiment, the coating film of the ink composition is preferably 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 photopolymerizable compound and/or an alkali-insoluble thermosetting resin as the photopolymerizable compound and/or thermosetting resin. The so-called coating film of the ink composition is alkali-insoluble means that the coating film of the ink composition at 25°C is dissolved in a 1% by mass potassium hydroxide aqueous solution based on the total mass of the coating film of the ink composition. 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, the ink composition is an ink composition capable of forming an alkali-insoluble coating film, which can be measured at 80°C for 3 minutes in the presence of a solvent after coating the ink composition on the substrate. The above-mentioned dissolution amount of a coating film having a thickness of 1 μm obtained by drying was confirmed.

<Manufacturing method of ink composition>

Next, a method of manufacturing the ink composition of the above-mentioned embodiment will be described. The ink composition can be obtained, for example, by mixing and dispersing the constituent components of the ink composition described above. Hereinafter, as an example of a method of manufacturing an ink composition, a method of manufacturing an ink composition further containing a polymer dispersant will be described.

The 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; Step 2 of mixing. In this method, the dispersion of light-scattering particles may further contain a photopolymerizable compound and/or a thermosetting resin, and in the second step, a photopolymerizable compound and/or a thermosetting resin may be further mixed. By this method, the light-scattering particles can be sufficiently dispersed. Therefore, light leakage in the pixel portion can be reduced, and an ink composition excellent in ejection stability can be easily obtained.

In the step of preparing the dispersion of light-scattering particles, the light-scattering particles, polymer dispersant, and optionally a photopolymerizable compound and/or thermosetting resin may be mixed and dispersed. , to prepare a dispersion of light-scattering particles. Mixing and dispersing can be performed using dispersing devices such as bead mills, paint conditioners, and planetary mixers. From the viewpoint of improving the dispersibility of the light-scattering particles and making it easier 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 nano crystal particles containing luminescent nano crystal particles, photopolymerizable compound and/or thermosetting resin before the second step. In this case, in the second step, the dispersion of light-scattering particles and the dispersion of luminescent nanocrystal particles are mixed. By this method, the luminescent nano crystal particles can be sufficiently dispersed. Therefore, light leakage in the pixel portion can be reduced, and an ink composition excellent in ejection stability can be easily obtained. In the step of preparing the dispersion of luminescent nanocrystalline particles, the luminescent nanocrystalline particles, the photopolymerizable compound, and/or thermosetting can be performed using the same dispersion device as the step of preparing the dispersion of light-scattering particles. Mixing and dispersion treatment of permanent resin.

When using the ink composition of this embodiment as an ink composition for an inkjet method, it is preferably applied to an inkjet recording device of a piezoelectric inkjet method using a mechanical ejection mechanism using a piezoelectric element. In the piezoelectric inkjet method, there is no instant exposure of the ink composition to high temperature during ejection, the deterioration of the luminescent nano crystal particles is not easy to occur, and the pixel part (light conversion layer) of the color filter is also easier to obtain Luminous properties as expected.

<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 cross-sectional view of a color filter of 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 includes a first pixel portion 10 a , a second pixel portion 10 b , and a third pixel portion 10 c as the pixel portion 10 . The first pixel portion 10a, the second pixel portion 10b, and the third pixel portion 10c are arranged in a grid pattern so as to repeat in order. The light shielding portion 20 is provided 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. between the first pixel portion 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 contain a cured product of the ink composition of the above-mentioned embodiment. The cured product contains luminescent nano crystal particles, light scattering particles, and a hardening component. The curing component is a cured product of a photopolymerizable compound and/or a thermosetting resin, specifically, a cured product obtained by polymerization of a photopolymerizable compound and/or crosslinking of a thermosetting resin. That is, the first pixel portion 10a includes the first curable component 13a, and the first luminescent nano crystal particles 11a and the first light-scattering particles 12a respectively dispersed in the first curable component 13a. Similarly, the second pixel portion 10b includes a second curable component 13b, and second luminous nano crystal particles 11b and second light-scattering particles 12b respectively dispersed in the second curable 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 nanocrystalline particles 11a are red luminescent nanocrystalline particles that absorb light with a wavelength in the range of 420-480nm and emit light with a peak emission wavelength in the range of 605-665nm. That is, the first pixel portion 10 a can be said to be a red pixel portion for converting blue light into red light. Also, the second luminescent nano crystal particles 11b are green luminescent nano crystal particles that absorb light with a wavelength in the range of 420 to 480 nm and emit light with a peak emission wavelength in the range of 500 to 560 nm. That is, the second pixel portion 10b can be said to be a green pixel portion for converting blue light into green light.

The content of the luminescent nanocrystalline particles in the pixel portion containing the cured product of the ink composition may be 5% 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. The above may be 10% by mass or more, 15% by mass or more, 20% by mass or more, 30% by mass or more, or 40% by mass or more. The content of luminescent nanocrystalline particles may be 70% by mass or less, 60% by mass or less, based on the total mass of the hardened ink composition from the viewpoint of excellent reliability of the pixel portion. It is 55 mass % or less, and may be 50 mass % or less.

The content of the light-scattering particles in the pixel portion containing the cured product of the ink composition may be 0.1% by mass or more based on the total mass of the cured product of the ink composition from the viewpoint of a better light leakage reduction effect, It may be 1 mass % or more, 5 mass % or more, 7 mass % or more, 10 mass % or more, or 12 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 third pixel portion 10c has a transmittance of 30% or more for light having a wavelength in the range of 420-480nm. 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 the above-mentioned composition containing a photopolymerizable compound and/or a thermosetting resin. The hardened product contains the third hardening component 13c. The third curable component 13c is a cured product of a photopolymerizable compound and/or a thermosetting resin, specifically, a cured product obtained by polymerization of a photopolymerizable compound and/or crosslinking of a thermosetting resin. That is, the third pixel portion 10c contains the third hardening component 13c. When the third pixel portion 10c contains the above-mentioned cured product, the composition containing the photopolymerizable compound and/or the thermosetting resin should have a transmittance of 30% or more for light having a wavelength in the range of 420 to 480 nm. It may further contain components other than the photopolymerizable compound and thermosetting resin among the components contained in the ink composition described above. 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 for the purpose of separating adjacent pixel portions to prevent color mixture, and for preventing light leakage from a light source. The material constituting the light-shielding portion 20 is not particularly limited. In addition to metals such as chromium, hardened resin compositions containing light-shielding particles such as carbon particles, metal oxides, inorganic pigments, and organic pigments in the binder polymer can be used. . As the binder polymer used here, one or more kinds of polyimide resin, acrylic resin, epoxy resin, polyacrylamide, polyvinyl alcohol, gelatin, casein, cellulose, etc. can be used. Resin mixtures, photosensitive resins, O/W emulsion resin compositions (for example, those made 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 penetration, for example, transparent glass substrates such as quartz glass, Pyrex (registered trademark) glass, and synthetic quartz plates, transparent resin films, and transparent flexible substrates such as optical resin films can be used. wait. Among these, it is preferable to use a glass substrate made of alkali-free glass which does not contain an alkali component in glass. Specifically, "7059 glass", "1737 glass", "Eagle 200" and "Eagle XG" manufactured by Corning Corporation, "AN100" manufactured by Asahi Glass Co., Ltd., "OA-10G" manufactured by NEC Glass Co., Ltd., 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 including the above light conversion layer 30 can be suitably 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 substrate 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 surface side of the base material 40 in a region that becomes a boundary between a plurality of pixel portions, and forming the thin film of the light-shielding particle. A method of patterning a thin film, etc. Metal thin films can be formed, for example, by sputtering, vacuum evaporation, etc., and thin films of resin compositions containing light-shielding particles can be formed, for example, by methods such as coating and printing. 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 light to be irradiated 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 the color filter, the light conversion layer, and the manufacturing method of these was demonstrated, this invention is not limited to the said embodiment.

For example, the light conversion layer may further include: a pixel portion (blue pixel portion) comprising a cured product of an ink composition containing blue luminescent nanocrystalline particles instead of the third pixel portion 10c, or in addition to the third pixel portion 10c In addition, it further includes: a pixel portion (blue pixel portion) including a cured product of an ink composition containing blue luminous nano crystal particles. 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 nano crystal particles emitting light of colors other than red, green, and blue. In these cases, it is preferable that each light-emitting nanocrystalline particle contained in each pixel portion of the light conversion layer 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 nanocrystalline particles.

In addition, the color filter may have an ink-repellent layer made of a material having ink-repellent property 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 after the photocatalyst-containing layer is formed as a wettability variable layer in a full coating state in the region including the pixel portion formation region, the photocatalyst-containing layer is exposed to light through a photomask, On the other hand, the ink affinity of the region where the pixel portion is formed is selectively increased. Titanium oxide etc. are mentioned as a photocatalyst.

In addition, the color filter may include an ink receiving layer containing hydroxypropyl cellulose or the like between the substrate and the pixel portion.

In addition, the color filter may be provided with a protective layer on the pixel portion. The protective layer is provided to planarize the color filter and prevent components contained in the pixel portion, or components contained in the pixel portion and components contained in 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, in the manufacture of the color filter and the light conversion layer, the pixel portion can also be formed by the photolithography method instead of the inkjet method. In this case, first, the ink composition is applied to the substrate in a layered form to form an ink composition layer. Next, after exposing the ink composition layer in a pattern, it develops using a developer. In this way, a pixel portion composed of a hardened ink composition is formed. Since the developer is usually alkaline, an alkali-soluble polymer is used as the binder polymer. However, from the point of view of the use efficiency of materials, the inkjet method is superior to the photolithography method. The reason for this is that in principle, more than 2/3 of the material is removed in the photolithography method, and the material becomes wasteful. Therefore, in this embodiment, it is preferable to form the pixel portion by an inkjet method using inkjet ink.

Also, in the pixel portion of the light conversion layer of this embodiment, in addition to the above-mentioned luminescent nanocrystal particles, a pigment having a color substantially the same as the luminescent color of the luminescent nanocrystal particles may be further contained. For example, when a pixel portion containing luminescent nanocrystalline particles that absorb blue light and emit light is used as a pixel portion of a liquid crystal display element, blue light or quasi-white light with a peak at 450 nm is used as the light from the light source, but in When the concentration of the luminescent nano crystal particles 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 particles are mixed in color. 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 also contain the pigment.

In addition, 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 no luminescent nanocrystals. The pixel portion containing the color material as particles. As a color material usable here, a well-known color material can be used, For example, a diketopyrrolopyrrole pigment and/or an anionic red organic dye are mentioned as a color material used for a red pixel part (R). As the color material used in the green pixel portion (G), one selected from the group consisting of a copper halide phthalocyanine pigment, a phthalocyanine green dye, a phthalocyanine blue dye, and an azo yellow organic dye at least one. Examples of the color material used for the blue pixel portion (B) include an ε-type copper phthalocyanine pigment and/or a cationic blue organic dye. When the usage amount of these color materials is included in the light conversion layer, it is preferable to use the total mass of the pixel portion (cured product of the ink composition) as a reference in order to prevent the reduction of the transmittance. 1 to 5% by mass.

[Example]

Hereinafter, the present invention will be specifically described with reference to examples. However, the present invention is not limited to the following examples.

In Examples and Comparative Examples, the following materials were used.

[Luminescent Nanocrystalline Particles]

‧QD Dispersion 1: 776785

(Product number manufactured by SIGMA-ALDRICH, QD composition: InP/ZnS, QD luminescence peak wavelength λem: 650nm, QD content: 5mg/mL, toluene solution)

‧QD Dispersion 2: 776750

(Product number manufactured by SIGMA-ALDRICH, QD composition: InP/ZnS, QD luminescence peak wavelength λem: 530nm, QD content: 5mg/mL, toluene solution)

[Light Scattering Particles]

‧Titanium oxide 1: JR-806 (trade name manufactured by Tayca Co., Ltd., average particle size (volume average diameter): 300nm)

‧Titanium oxide 2: TTO-80 (trade name manufactured by Ishihara Sangyo Co., Ltd., average particle size (volume average diameter): 60nm)

[Photopolymerizable compound]

‧Alicyclic epoxy monomer: Celloxide 2000 (trade name manufactured by Daicel Co., Ltd., "Celloxide" is a registered trademark)

‧Oxetane monomer: ARONE OXETANE OXT-212 (trade name manufactured by Toa Gosei Co., Ltd., "ARONE OXETANE" is a registered trademark)

[Polymer dispersant]

‧Polymer dispersant: DISPERBYK-2155 (trade name manufactured by BYK, "DISPERBYK" is a registered trademark)

[polymerization initiator]

‧Photocationic polymerization initiator: CPI-100P (trade name manufactured by San-Apro Co., Ltd., "CPI" is a registered trademark)

<Preparation of QD/alicyclic epoxy monomer dispersion>

(preparation example 1)

After mixing the QD dispersion liquid 1 of 400mL and the alicyclic epoxy monomer of 8g, the toluene from the QD dispersion liquid was removed by an evaporator, thereby obtaining QD/alicyclic epoxy monomer dispersion 1 (QD content: 20% by mass).

(preparation example 2)

Except having used the QD dispersion liquid 2 instead of the QD dispersion liquid 1, it carried out similarly to the preparation example 1, and obtained the QD/alicyclic epoxy monomer dispersion 2 (content of QD: 20 mass %).

<Preparation of Light Scattering Particle Dispersion>

(preparation example 3)

1.29 g of titanium oxide 1, 0.13 g of polymer dispersant, and 1.81 g of oxetane monomer were blended. After adding zirconia beads (diameter: 5 mm) to the obtained blend, the blend was shaken for 2 hours using a paint conditioner to perform dispersion treatment of the blend. Light-scattering particle dispersion 1 was thus obtained.

(preparation example 4)

Light-scattering particle dispersion 2 was obtained in the same manner as in Preparation Example 3 except that titanium oxide 2 was used instead of titanium oxide 1 .

(preparation example 5)

By using a planetary mixer (manufactured by Thinky Corporation, trade name "ARE-310") to stir at 2000rpm for 5 minutes to carry out the dispersion treatment of the blend, in the same manner as in Preparation Example 3, the dispersion of light-scattering particles was obtained. Body 3.

(preparation example 6)

By using a planetary mixer (manufactured by Thinky Corporation, trade name "ARE-310"), the dispersion treatment of the blend was carried out by stirring at 2000 rpm for 5 minutes, and the light-scattering particle dispersion was obtained in the same manner as in Preparation Example 4. Body 4.

(preparation example 7)

1.31 g of titanium oxide 1 was blended with 1.83 g of oxetane monomer. After adding zirconia beads (diameter: 5 mm) to the obtained blend, the blend was shaken for 2 hours using a paint conditioner to perform dispersion treatment of the blend. Thereby, a light-scattering particle dispersion 5 was obtained.

(preparation example 8)

Light-scattering particle dispersion 6 was obtained in the same manner as in Preparation Example 7 except that titanium oxide 2 was used instead of titanium oxide 1 .

(Example 1)

(1) Preparation of ink composition (inkjet ink)

After mixing 6.47g of QD/alicyclic epoxy monomer dispersion 1, 3.23g of light-scattering particle dispersion 1, and 0.3g of photocationic polymerization initiator, by using a filter with a pore size of 5 μm The mixture was filtered to obtain an ink composition. The average particle diameter (volume average diameter MV) of the light-scattering particles in the ink composition was 0.35 μm. Furthermore, in this example, the average particle diameter (volume average diameter MV) of the light-scattering particles in the above-mentioned ink composition was obtained using a dynamic light-scattering Nanotrac particle size distribution meter (manufactured by Nikkiso Co., Ltd., trade name "Nanotrac") for measurement.

(2) Production of light conversion filter

The ink composition obtained in (1) above was coated on a glass substrate (slide glass) with a spin coater so that the film thickness after drying became 5 μm. After drying the obtained film, the dried film was irradiated with ultraviolet light at an exposure dose of 2000 mJ/cm ² . Thereby, the ink composition was cured, and a layer (light conversion layer) composed of a cured product of the ink composition was formed on the glass substrate. A light conversion filter is obtained through the above operations.

(3) Evaluation

Using the ink composition obtained in (1) above and the light conversion filter obtained in (2) above, light leakage evaluation and ejection stability evaluation were performed in the following procedures. The results are shown in Table 1.

[Light leakage evaluation]

A blue LED (peak emission wavelength: 450 nm) manufactured by CCS Co., Ltd. was used as a surface emission light source. The light conversion filter is arranged on the light source with the glass substrate side as the lower side. The integrating sphere was connected to an emission spectrophotometer (trade name "MCPD-9800") manufactured by Otsuka Electronics Co., Ltd., so that the integrating sphere was placed close to the light conversion filter provided on the blue LED. In this state, the blue LED was turned on, and the peak intensity (S) of the observed light with a wavelength of 450 nm was measured. Next, the glass substrate (slide glass) used in the production of the light conversion filter was placed on the light source instead of the light conversion filter, and the light with a wavelength of 450 nm was observed in the same manner as the above method to measure the Light peak intensity (R). The light leakage rate T (peak intensity ratio: S/R×100) of light having a wavelength of 450 nm was calculated, and evaluated according to the following criteria. The smaller the light leakage rate, the higher the color purity and the better.

A: T<20%

B: 20≦T≦50%

C: T>50%

[Evaluation of ejection stability]

Using an inkjet printer (manufactured by Fuji Film Dimatix, trade name "DMP-2831"), the ink composition was continuously ejected for 10 minutes. Furthermore, 16 nozzles are formed on the head of the inkjet printer for ejecting ink, and the usage amount of the ink composition ejected once by each nozzle is set at 10 pL. Discharge stability was evaluated according to the following criteria.

A: Continuous spraying (out of 16 nozzles, more than 10 nozzles can spray continuously)

B: Cannot spray continuously (out of 16 nozzles, the number of nozzles that can spray continuously is less than 9 nozzles)

C: unable to eject

(Example 2)

An ink composition was obtained in the same manner as in Example 1 except that the light-scattering particle dispersion 2 was used instead of the light-scattering particle dispersion 1 . The average particle diameter (volume average diameter MV) of the light-scattering particles in the ink composition was 0.52 μm. A light conversion filter was obtained in the same manner as in Example 1 except for using this ink composition. Using the obtained ink composition and light conversion filter, light leakage evaluation and discharge stability evaluation were performed in the same manner as in Example 1. The results are shown in Table 1.

(Example 3)

An ink composition was obtained in the same manner as in Example 1 except that QD/alicyclic epoxy monomer dispersion 2 was used instead of QD/alicyclic epoxy monomer dispersion 1. The average particle diameter (volume average diameter MV) of the light-scattering particles in the ink composition was 0.35 μm. A light conversion filter was obtained in the same manner as in Example 1 except for using this ink composition. Using the obtained ink composition and light conversion filter, light leakage evaluation and discharge stability evaluation were performed in the same manner as in Example 1. The results are shown in Table 1.

(Example 4)

An ink composition was obtained in the same manner as in Example 1 except that the light-scattering particle dispersion 3 was used instead of the light-scattering particle dispersion 1 . The average particle diameter (volume average diameter MV) of the light-scattering particles in the ink composition was 1.49 μm. A light conversion filter was obtained in the same manner as in Example 1 except for using this ink composition. Using the obtained ink composition and light conversion filter, light leakage evaluation and discharge stability evaluation were performed in the same manner as in Example 1. The results are shown in Table 1.

(Example 5)

An ink composition was obtained in the same manner as in Example 1 except that the light-scattering particle dispersion 4 was used instead of the light-scattering particle dispersion 1 . The average particle diameter (volume average diameter MV) of the light-scattering particles in the ink composition was 1.51 μm. A light conversion filter was obtained in the same manner as in Example 1 except for using this ink composition. Using the obtained ink composition and light conversion filter, light leakage evaluation and discharge stability evaluation were performed in the same manner as in Example 1. The results are shown in Table 1.

(Example 6)

Use 6.55g of QD/alicyclic epoxy monomer dispersion 1, use 3.14g of light-scattering particle dispersion 5 instead of light-scattering particle dispersion 1, and use 0.31g of photocationic polymerization initiator, except Otherwise, an ink composition was obtained in the same manner as in Example 1. The average particle diameter (volume average diameter MV) of the light-scattering particles in the ink composition was 1.46 μm. A light conversion filter was obtained in the same manner as in Example 1 except for using this ink composition. Using the obtained ink composition and light conversion filter, light leakage evaluation and discharge stability evaluation were performed in the same manner as in Example 1. The results are shown in Table 1.

(Example 7)

An ink composition was obtained in the same manner as in Example 6 except that the light-scattering particle dispersion 6 was used instead of the light-scattering particle dispersion 5 . The average particle diameter (volume average diameter MV) of the light-scattering particles in the ink composition was 1.32 μm. A light conversion filter was obtained in the same manner as in Example 1 except for using this ink composition. Using the obtained ink composition and light conversion filter, light leakage evaluation and discharge stability evaluation were performed in the same manner as in Example 1. The results are shown in Table 1.

(comparative example 1)

After mixing 7.54g of QD/alicyclic epoxy monomer dispersion 1, 2.11g of oxetane monomer, and 0.35g of photocationic polymerization initiator, by using a filter with a pore size of 5 μm The mixture was filtered to obtain an ink composition. A light conversion filter was obtained in the same manner as in Example 1 except for using this ink composition. Using the obtained ink composition and light conversion filter, light leakage evaluation and discharge stability evaluation were performed in the same manner as in Example 1. The results are shown in Table 1.

As shown in Table 1, when the ink composition of Comparative Example 1 that did not use light-scattering particles was used, significant light leakage was confirmed. Also, as shown in Table 1, in the ink compositions of Examples 1 and 2, which use a polymer dispersant and disperse light-scattering particles with a paint conditioner and have a particle size of less than 1.0 μm, the polymer dispersant is used but The ink compositions of Examples 4 and 5 with a particle size greater than 1.0 μm for dispersion using a planetary mixer, and Example 6 and Example 6 with a particle size greater than 1.0 μm in which light-scattering particles were dispersed by a paint conditioner without using a polymer dispersant Compared with the ink composition of 7, it was confirmed that excellent ejection stability was obtained.

(Embodiment 8)

First, a substrate (BM substrate) having a light-shielding portion called a black matrix (BM) is produced in the following procedure. That is, pattern exposure is performed after coating a black resist ("CFPR BK" manufactured by Tokyo Ohka Industry Co., Ltd.) on a glass substrate made of alkali-free glass ("OQ-10G" manufactured by NEC Glass Co., Ltd.) , development and baking to form a patterned light-shielding portion. Exposure was performed by irradiating the black resist with ultraviolet rays at an exposure amount of 200 mJ/cm ² . The pattern of the light-shielding portion is a pattern having an opening portion corresponding to a sub-pixel of 200 μm×600 μm, a line width of 20 μm, and a thickness of 2.6 μm.

Next, the ink composition obtained in Example 1 was inkjet-printed on the opening on the BM substrate, and then irradiated with ultraviolet rays. Then, it heated at 150 degreeC for 30 minutes in 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 light conversion filter with a pattern is obtained.

(Example 9)

A BM substrate was prepared in the same manner as in Example 8. Next, the ink composition obtained in Example 1 and the ink composition obtained in Example 3 were ink-jet printed on the opening on the BM substrate, and then irradiated with ultraviolet rays to harden the ink composition. Thereby, the pixel part which converts red light into blue 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 luminous nanocrystalline particles

11b‧‧‧Second Luminescent Nanocrystalline Particles

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 (8)

An ink composition for forming a light conversion layer used in an inkjet method, and containing luminescent nano crystal particles, light scattering particles, and a photopolymerizable compound and/or a thermosetting resin, and the above-mentioned The light-scattering particles contain at least one selected from the group consisting of titanium oxide, aluminum oxide, zirconia, zinc oxide, calcium carbonate, barium sulfate, and silicon dioxide, and the above-mentioned light-scattering particles in the ink composition are The average particle diameter is not less than 0.2 μm and not more than 1.0 μm, the content of the above-mentioned luminescent nano-crystal particles is 10 to 50% by mass based on the mass of the non-volatile components of the above-mentioned ink composition, and the content of the above-mentioned light-scattering particles , based on the mass of the non-volatile components of the above-mentioned ink composition, which is 1 to 20% by mass, and the mass ratio of the content of the above-mentioned light-scattering particles to the content of the above-mentioned luminous nano crystal particles is 2.0 or less. Such as the ink composition of item 1 of the scope of the patent application, which further contains a polymer dispersant. Such as the ink composition of claim 2, wherein the weight average molecular weight of the polymer dispersant is above 1000. For example, the ink composition of any one of items 1 to 3 in the scope of the patent application can form an alkali-insoluble coating film. For example, the ink composition of any one of items 1 to 3 in the scope of the patent application has a surface tension of 20~40mN/m. The ink composition according to any one of items 1 to 3 of the patent claims, which contains the above-mentioned photopolymerizable compound. The ink composition of any one of items 1 to 3 of the scope of application, which further contains a solvent with a boiling point of 180°C or higher. The ink composition according to any one of claims 1 to 3, wherein the mass ratio of the content of the light-scattering particles to the content of the luminous nano crystal particles is 0.1 or more.

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