JP7047642B2 - Photosensitive composition for partition wall formation, partition wall and display element - Google Patents

Description

The present invention relates to a photosensitive composition for forming a display element, a cured film, and a display element.

In the field of display panels, a fine pattern made of resin is formed on a substrate for a display element protected by a bezel or the like (panel edge), and the pattern is given characteristics to be used for various purposes. ..

For example, in a light emitting diode element, the above technique is used as a partition wall for partitioning to prevent color mixing of light (Patent Document 1). Further, the use as a partition for suppressing color mixing is used for light emission of an organic electroluminescence element (hereinafter abbreviated as an organic EL element), a micro-sized light emitting diode element (hereinafter abbreviated as a micro LED element), or the like. With the miniaturization of parts, it has become a particularly required technology in recent years.

WO2016 / 052025

Although the above-mentioned Patent Document 1 describes a partition wall exhibiting excellent characteristics, there is room for improvement in the function of extracting light emitted from the light emitting portion and the formability of the partition wall. That is, it is considered that the partition wall described in Patent Document 1 suppresses the color mixing of light by reflecting the primary light and the like emitted from the LED chip by the white pigment contained in the partition wall. It is difficult to achieve both the reflection function and the formation of a fine partition wall pattern containing a white pigment, and this point is not described at all in Patent Document 1.

The present invention has been made in view of the above, and provides a photosensitive composition for forming a display element, which is suitable for forming a cured film having both a high light reflection function and a fine pattern shape. be.

The present inventors have studied diligently to solve the above problems. As a result, it was found that the composition having the following constitution is a suitable material for solving the above-mentioned problems, and the present invention was completed.

That is, an example of the embodiment of the present invention is a photosensitive for forming a display element containing (A) a white pigment, (B) an alkali-soluble resin, (C) a polymerizable compound, (D) a photopolymerization initiator, and (E) a solvent. A photosensitive composition for forming a display element, wherein the content of the white pigment (A) is 30 to 90% by mass when the total amount of the components excluding the solvent (E) is 100% by mass. Is.

Further, an example of the embodiment of the present invention is a display element which is an organic EL element or a micro LED element having a cured film formed by using the photosensitive composition for forming the display element and a partition wall, and the partition wall is the said. It is a display element that is a cured film.

According to the photosensitive composition for forming a display element of the present invention, a cured film having a fine pattern shape can be formed. Further, the formed cured film has a high light reflection function. Therefore, by using the cured film formed from the photosensitive composition for forming a display element as a partition wall, it can be suitably used for forming a display element such as a micro LED element or an organic EL element.

<Photosensitive composition for forming display elements>
The photosensitive composition for forming a display element (hereinafter, abbreviated as the present composition) according to an embodiment of the present invention includes (A) a white pigment, (B) an alkali-soluble resin, (C) a polymerizable compound, and (D). It contains a photopolymerization initiator and (E) solvent, and (A) white pigment is contained in an amount of 30 to 90% by mass when the total amount of the components excluding (E) solvent is 100% by mass.

According to this composition, since the white pigment (A) having a relatively high concentration is contained, a cured film having a high light reflection function can be formed. Further, by containing (B) an alkali-soluble resin, (C) a polymerizable compound, and (D) a photopolymerization initiator, a cured film having a fine pattern shape of a desired shape can be easily formed. This composition can be suitably used as a material for forming a fine constituent member for which light reflection performance is required in a display element, and particularly as a material for forming a partition wall of an organic EL element or a micro LED element.
Hereinafter, each component and the like will be described.

<(A) White pigment>
Examples of the white pigment include alumina, magnesium oxide, antimony oxide, titanium oxide, zirconium oxide, aluminum hydroxide, magnesium hydroxide, barium sulfate, magnesium carbonate, barium carbonate, calcium carbonate, lead sulfate, lead phosphate, and the like. Zinc phosphate, silicon dioxide, zinc oxide, tin oxide, strontium sulfide, strontium titanate, barium tungstate, lead metasilicate, talc, kaolin, clay, bismuth chloride, hollow silica particles, organic hollow particles, core shell particles, etc. You can choose from.

(A) The white pigment is at least one inorganic substance selected from the group consisting of alumina, magnesium oxide, antimony oxide, titanium oxide, zirconium oxide, aluminum hydroxide, magnesium hydroxide, barium sulfate, magnesium carbonate and barium carbonate. It is preferable to contain it, and it is particularly preferable to contain titanium oxide. Since the inorganic substance has a high refractive index, the reflection characteristics of the formed cured film can be improved. Among them, titanium oxide has a particularly high refractive index and is also preferable from the viewpoint of dispersion characteristics in a solvent.

The lower limit of the average particle size of the white pigment (A) is preferably 50 nm, preferably 100 nm, and more preferably 200 nm. On the other hand, the upper limit is preferably 700 nm, more preferably 500 nm, and even more preferably 400 nm. (A) When the average particle size of the white pigment is in the above range, good dispersibility, light scattering, and the like can be exhibited, and as a result, light reflectivity and light-shielding property can be enhanced.

The content of the white pigment (A) is 30 to 90% by mass, preferably 40 to 85% by mass, when the total amount of the components (E) excluding the solvent of the present composition is 100% by mass. It is more preferably 45 to 80% by mass. The upper limit of the content of the white pigment (A) may be even more preferably 75% by mass, 70% by mass, 65% by mass, or 60% by mass. (A) When the content of the white pigment is 30% by mass or more, the formed cured film can obtain high light reflection characteristics. On the other hand, when the content of the white pigment (A) is 90% by mass or less, it becomes easy to adjust other components for forming a fine pattern, and it becomes easy to form a fine pattern having a desired shape. ..

<(B) Alkali-soluble resin>
(B) The alkali-soluble resin is a resin that is soluble in an alkaline solvent and has alkali developability. The alkali-soluble resin (B) is not particularly limited as long as it is a resin having alkali developability. By containing (B) an alkali-soluble resin, the present composition can easily form a fine cured film having a desired pattern shape.

(B) The alkali-soluble resin preferably contains an acidic group. Examples of the acidic group include a carboxyl group, an acid anhydride group, a phenolic hydroxyl group and a sulfo group. Among the above, as the acidic group, at least one selected from the group consisting of a carboxyl group and a phenolic hydroxyl group is preferable, and a carboxyl group is more preferable. The alkali-soluble resin (B) is preferably a resin containing a structural unit having one or more acidic groups.

As the (B) alkali-soluble resin having a carboxyl group, in particular, a monomer having one or more carboxyl groups (hereinafter, abbreviated as “carboxyl group-containing monomer”) and another copolymerizable monomer A copolymer with (hereinafter, abbreviated as "copolymerizable monomer") is preferable.

Examples of the carboxyl group-containing monomer include unsaturated monocarboxylic acids such as (meth) acrylic acid, crotonic acid, α-chloracrylic acid, and cinnamic acid; maleic acid, maleic anhydride, fumaric acid, itaconic acid, and itacone anhydride. Unsaturated dicarboxylic acids such as acids, citraconic acid, anhydrous citraconic acid, mesaconic acid or their anhydrides; monosuccinic acid mono [2- (meth) acryloyloxyethyl], mono phthalate [2- (meth) acryloyloxyethyl ], A mono-[(meth) acryloyloxyalkyl] ester of a divalent or higher valent carboxylic acid; a polymer mono [(meth) polycaprolactone mono (meth) acrylate, which has carboxy groups and hydroxyl groups at both ends. Meta) acrylate and the like can be mentioned. The above-mentioned carboxyl group-containing monomer can be used alone or in combination of two or more.

As the carboxyl group-containing monomer, (meth) acrylic acid, succinic acid mono [2- (meth) acryloyloxyethyl], and ω-carboxypolycaprolactone mono (meth) acrylate are preferable, and (meth) acrylic acid is particularly preferable. Is preferable.

Examples of the monomer having a phenolic hydroxyl group and giving a structural unit include 4-vinylphenol, 4-isopropenylphenol, 4-hydroxyphenyl (meth) acrylate and the like.

The content of the structural unit having an acidic group in the (B) alkali-soluble resin is preferably 1 to 50% by mass, more preferably 3 to 40% by mass, still more preferably, with respect to 100% by mass of the (B) alkali-soluble resin. Is 5 to 30% by mass. By setting the content of the structural unit having an acidic group to 1% by mass or more, the solubility of the obtained present composition in an alkaline developer can be enhanced, while by setting it to 50% by mass or less, the alkaline developer can be improved. It is possible to prevent the solubility from becoming excessive, and to sufficiently sufficiently suppress the detachment from the substrate and the roughening of the film on the surface when developing with an alkaline developer.

Further, the alkali-soluble resin (B) preferably contains a Si (silicon) atom or an F (fluorine) atom, and particularly preferably contains an F atom. By including such an atom, the (B) alkali-soluble resin is imparted with liquid-repellent properties. As a result, it becomes easy to apply a composition for forming a color filter, a composition for forming a phosphor layer, or the like between the cured films formed by the present composition, and by using the cured film as a partition wall, it becomes highly effective. It becomes easy to form a display element having functionality.

When the alkali-soluble resin (B) contains an F atom, it is particularly preferable that the alkali-soluble resin contains a group represented by the following formula (1).

In formula (1), R ¹ and R ² are independently hydrogen atoms or fluorine atoms, A is an ester bond or an ether bond, and n is an integer of 1 to 10. When n is 2 or more, the plurality of R ^1s may be the same or different, and the plurality of R ^2s may be the same or different. * Represents the binding site.

Since the alkali-soluble resin (B) has a group represented by the above formula (1), the alkali-soluble resin (B) is imparted with appropriate liquid-repellent properties. As a result, as described above, it becomes easy to form a display element having high functionality.

As the lower limit of n in the above formula (1), 3 is preferable, and 5 is more preferable. As the upper limit of n, 8 may be preferable.

Here, as the group represented by the above formula (1), preferably, the group represented by the following formula (2) and the following formula (3) can be mentioned.

In equations (2) and (3), A is independently synonymous with the above equation (1), and in equation (2), x is an integer of 0 to 2 and y is an integer of 1 to 8. Yes, in equation (3), z is an integer of 1-5.

As the lower limit of x in the above formula (2), 1 is preferable, and 2 is more preferable. As the lower limit of y, 2 is preferable, and 4 is more preferable. As the upper limit of y, 6 may be preferable.

The A in the above formulas (1) to (3) is preferably an ester bond. The ester bond is a divalent group represented by —C (= O) O—, and its direction is not limited. However, it is preferable that the binding site (*) side is a carbonyl group (-C (= O)-).

(B) The alkali-soluble resin preferably contains a structural unit containing a Si atom or an F atom, and more preferably contains a structural unit containing an F atom. As the structural unit containing an F atom, a structural unit having a group represented by the above formula (1) is preferable. Examples of the monomer that gives a structural unit having a group represented by the above formula (1) include a monomer represented by the following formula (4).

In formula (4), R ³ is a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, or a fluorinated alkyl group having 1 to 4 carbon atoms. R ^f is a group represented by the above formula (1).

The R ³ in the above formula (4) is preferably a hydrogen atom or a methyl group.

Examples of the monomer that gives a structural unit containing a Si atom include (meth) acrylate having a silyl group such as trimethylsilyl (meth) acrylate and triethylsilyl (mare) acrylate.

The content of the structural unit containing Si atom or F atom in the (B) alkali-soluble resin is preferably 1 to 70% by mass with respect to 100% by mass of the (B) alkali-soluble resin. Within this range, it becomes easy to impart appropriate liquid repellent properties to the (B) alkali-soluble resin. The content of the structural unit containing Si atom or F atom is more preferably 3% by mass to 50% by mass, and further preferably 5% by mass to 45% by mass with respect to 100% by mass of the (B) alkali-soluble resin. It is mass%. If the content of the structural unit containing Si atom or F atom is within this range, in addition to the above effects, the developability of the present composition can be further enhanced. From the viewpoint of liquid repellency and the like, the lower limit of the content of the structural unit containing Si atom or F atom is preferably 10% by mass, more preferably 20% by mass.

Further, the alkali-soluble resin (B) preferably has a polymerizable group in order to improve sensitivity and the like, and more preferably has a structural unit containing a polymerizable group. As the polymerizable group, at least one selected from the group consisting of a (meth) acryloyl group, a vinyl group, an oxylanyl group and an oxetanyl group is preferable. (B) Since the alkali-soluble resin has the above-mentioned specific polymerizable group, the cured film formed by the present composition has high surface curability, excellent deep curability, and improved heat resistance.

Among the above polymerizable groups, an oxylanyl group and an oxetanyl group are preferable, and an oxylanyl group is more preferable. Examples of the monomer giving a structural unit containing a polymerizable group include glycidyl (meth) acrylate, 3- (meth) acryloyloxymethyl-3-ethyloxetane, 3,4-epoxycyclohexylmethyl (meth) acrylate, and 3, 4- ^{Epoxytricyclo} [5.2.1.02.6] decyl (meth) acrylate and the like can be mentioned.

The content of the structural unit having a polymerizable group in the (B) alkali-soluble resin is preferably 5% by mass to 60% by mass, more preferably 10% by mass or more, based on 100% by mass of the (B) alkali-soluble resin. It is 55% by mass, more preferably 20% by mass to 50% by mass.

Further, the alkali-soluble resin (B) may be a polymer containing a ring structure in order to improve heat resistance. The ring structure is preferably contained in the main chain of the (B) alkali-soluble resin. (B) The alkali-soluble resin preferably has a structural unit containing a ring structure, and more preferably has a structural unit containing a ring structure in the main chain. The number of ring members of this ring structure may be, for example, 3 to 12, but 5 to 8 is preferable.

Examples of the monomer giving a structural unit containing a ring structure include an N-substituted maleimide-based monomer, a dialkyl-2,2'-(oxydimethylene) diacrylate-based monomer, and an α- (unsaturated alkoxyalkyl) acrylate. , Tricyclodecanyl (meth) acrylate, dicyclopentenyl (meth) acrylate, styrene, vinylphenyl ether and the like. In addition, the above-mentioned monomers giving a structural unit having an oxylanyl group or an oxetanyl group can also be mentioned.

Among them, the copolymer introduced from at least one selected from the group consisting of N-substituted maleimide-based monomers, tricyclodecanyl (meth) acrylate, and dicyclopentenyl (meth) acrylate has high heat resistance. It is preferable from the viewpoint of having.

Among these monomers, the N-substituted maleimide-based monomer is preferable because a ring structure can be introduced into the main chain and better heat resistance can be exhibited. The N-substituted maleimide-based monomer is a compound in which a hydrogen atom bonded to a nitrogen atom in maleimide is substituted with a substituent. As the substituent, a hydrocarbon group is preferable, a hydrocarbon group having a ring structure is more preferable, and an aromatic hydrocarbon group is more preferable. Examples of the N-substituted maleimide-based monomer include N-phenylmaleimide, N-naphthylmaleimide, N-cyclohexylmaleimide, N-cyclooctylmaleimide, and N-methylmaleimide.

The content of the structural unit having a ring structure in the (B) alkali-soluble resin is preferably 5 to 80% by mass, more preferably 10 to 50% by mass, based on 100% by mass of the (B) alkali-soluble resin. In some cases, 15-30% by mass is even more preferred.

(B) The alkali-soluble resin can be easily obtained by polymerizing with one or more kinds of monomers such as the above-mentioned carboxyl group-containing monomer. Further, in the synthesis of the alkali-soluble resin (B), other monomers other than the above-mentioned monomers may be optionally used for the synthesis.

(B) The alkali-soluble resin may be used alone or in combination of two or more. (B) As a specific example of using two or more kinds of alkali-soluble resins, the use of an alkali-soluble resin having many structural units containing acidic groups and an alkali-soluble resin containing many Si atoms or F atoms in combination is used. Can be mentioned. As described above, by properly using two or more kinds of alkali-soluble resins according to their functionality, the present composition having excellent moldability of a display element can be obtained.

Further, (B) the polystyrene-equivalent weight average molecular weight (Mw) of the alkali-soluble resin is preferably 2,000 to 500,000, more preferably 3, in the value measured by the gel permeation chromatography (GPC) method. It is 000 to 100,000, more preferably 4,000 to 50,000.

When Mw is in the above range, (B) an alkali-soluble resin having excellent solubility in a solvent or a developing solution can be obtained, and (B) an alkali-soluble resin having sufficient mechanical properties can be obtained.

The content of the alkali-soluble resin (B) is preferably 10 to 150 parts by mass, more preferably 20 to 70 parts by mass, and further preferably 25 to 50 parts by mass with respect to 100 parts by mass of the total of the white pigment (A). Is.

<(C) Polymerizable compound>
(C) The polymerizable compound means a compound having two or more polymerizable groups. However, (B) alkali-soluble resin is excluded. Examples of the polymerizable group include an ethylenically unsaturated group, an oxylanyl group, an oxetanyl group, an N-alkoxymethylamino group and the like. As the polymerizable compound, a compound having two or more (meth) acryloyl groups or a compound having two or more N-alkoxymethylamino groups is preferable.

Specific examples of the compound having two or more (meth) acryloyl groups include a polyfunctional (meth) acrylate obtained by reacting an aliphatic polyhydroxy compound with a (meth) acrylic acid, and a caprolactone-modified polyfunctional (? Meta) acrylate, alkylene oxide-modified polyfunctional (meth) acrylate, polyfunctional urethane (meth) acrylate obtained by reacting (meth) acrylate having a hydroxyl group with polyfunctional isocyanate, and (meth) acrylate having a hydroxyl group. Examples thereof include polyfunctional (meth) acrylates having a carboxyl group obtained by reacting with an acid anhydride.

Here, examples of the aliphatic polyhydroxy compound include divalent aliphatic polyhydroxy compounds such as ethylene glycol, propylene glycol, polyethylene glycol and polypropylene glycol; and trivalent such as glycerin, trimethylolpropane, pentaerythritol and dipentaerythritol. The above aliphatic polyhydroxy compounds can be mentioned. Examples of the (meth) acrylate having a hydroxyl group include 2-hydroxyethyl (meth) acrylate, trimethylolpropane di (meth) acrylate, pentaerythritol tri (meth) acrylate, dipentaerythritol penta (meth) acrylate, and glycerol di. Methacrylate and the like can be mentioned. Examples of the polyfunctional isocyanate include tolylene diisocyanate, hexamethylene diisocyanate, diphenylmethylene diisocyanate, isophorone diisocyanate and the like. Examples of the acid anhydride include dibasic acid anhydrides such as succinic anhydride, maleic anhydride, glutaric acid anhydride, itaconic anhydride, phthalic anhydride, and hexahydrophthalic anhydride, pyromellitic anhydride, and biphenyltetracarboxylic acid dianhydride. Tetrabasic acid dianhydrides such as anhydrides and benzophenone tetracarboxylic acid dianhydrides can be mentioned.

Examples of the caprolactone-modified polyfunctional (meth) acrylate include the compounds described in paragraphs [0015] to [0018] of JP-A-11-44955. The alkylene oxide-modified polyfunctional (meth) acrylate includes at least one selected from bisphenol A di (meth) acrylate modified with at least one selected from ethylene oxide and propylene oxide, ethylene oxide and propylene oxide. Trimethylol propanetri (meth) acrylate modified with at least one selected from modified isocyanuric acid tri (meth) acrylate, ethylene oxide and propylene oxide, modified with at least one selected from ethylene oxide and propylene oxide. Pentaerythritol Tri (meth) acrylate modified with at least one selected from tri (meth) acrylate, ethylene oxide and propylene oxide Dipentaerythritol penta modified with at least one selected from pentaerythritol tetra (meth) acrylate, ethylene oxide and propylene oxide. Examples thereof include dipentaerythritol hexa (meth) acrylate modified with at least one selected from (meth) acrylate, ethylene oxide and propylene oxide.

Examples of the compound having two or more N-alkoxymethylamino groups include a compound having a melamine structure, a benzoguanamine structure, a urea structure, and the like. The melamine structure and the benzoguanamine structure refer to a chemical structure having one or more triazine rings or phenyl-substituted triazine rings as a basic skeleton, and are a concept including melamine, benzoguanamine or a condensate thereof. Specific examples of compounds having two or more N-alkoxymethylamino groups include N, N, N', N', N'', N''-hexa (alkoxymethyl) melamine, N, N, N'. , N'-tetra (alkoxymethyl) benzoguanamine, N, N, N', N'-tetra (alkoxymethyl) glycoluryl and the like.

Among the polymerizable compounds, polyfunctional (meth) acrylate obtained by reacting a trivalent or higher aliphatic polyhydroxy compound with (meth) acrylic acid, caprolactone-modified polyfunctional (meth) acrylate, and poly. Functional urethane (meth) acrylate, N, N, N', N', N'', N''-hexa (alkoxymethyl) melamine, and N, N, N', N'-tetra (alkoxymethyl) benzoguanamine preferable. Among the polyfunctional (meth) acrylates obtained by reacting a trivalent or higher aliphatic polyhydroxy compound with (meth) acrylic acid, trimethylolpropane triacrylate, pentaerythritol triacrylate, pentaerythritol tetraacrylate, and dipenta Elythritol pentaacrylate and dipentaerythritol hexaacrylate have high cured film strength, excellent surface smoothness of the cured film, and are less likely to cause background stains, film residues, etc. on the substrate and light-shielding layer of the unexposed portion. Especially preferable in terms of points.

The polymerizable compound (C) may contain a Si atom or an F atom, and particularly preferably contains an F atom. By including such an atom, the (C) polymerizable compound is imparted with liquid-repellent properties. As a result, it becomes easy to apply a composition for forming a color filter, a composition for forming a phosphor layer, or the like between the cured films formed by the present composition, and by using the cured film as a partition wall, it becomes highly effective. It becomes easy to form a display element having functionality.

Examples of the (C) polymerizable compound containing an F atom include a polyfunctional (meth) acrylate in which a part or all of the hydrogen atom of the hydrocarbon group is replaced with an F atom, and a polyfunctional alkyl group. (Meta) acrylate and the like can be mentioned. Examples of the (C) polymerizable compound containing a Si atom include polyfunctional (meth) acrylates having a structure such as a silyl group, polyalkylsiloxane, and silsesquioxane. In addition, a polysiloxane having a plurality of polymerizable groups such as an oxylanyl group and an oxetanyl group can also be used.

The content of the (C) polymerizable compound is usually 3 to 200 parts by mass, preferably 5 to 100 parts by mass, and more preferably 10 to 50 parts by mass with respect to 100 parts by mass of the total of the white pigment (A). .. The content of the (C) polymerizable compound is usually 20 to 300 parts by mass, preferably 30 to 250 parts by mass, and more preferably 50 to 200 parts by mass with respect to 100 parts by mass of the (B) alkali-soluble resin. be. With such an embodiment, it is possible to form a cured film having excellent heat resistance and chemical resistance.

<(D) Photopolymerization Initiator>
The (D) photopolymerization initiator is a compound that generates an active species capable of initiating the polymerization of the (C) polymerizable compound by exposure to radiation such as visible light, ultraviolet rays, far ultraviolet rays, electron beams, and X-rays. The photopolymerization initiator may be used alone or in admixture of two or more.

Examples of such (D) photopolymerization initiator include thioxanthone-based compounds, acetophenone-based compounds, biimidazole-based compounds, triazine-based compounds, O-acyloxime-based compounds, onium salt-based compounds, benzoin-based compounds, and benzophenone-based compounds. , Acylphosphine oxide-based compounds, titanosen-based compounds, α-diketone-based compounds, polynuclear quinone-based compounds, diazo-based compounds, imidesulfonate-based compounds, onium salt-based compounds and the like can be mentioned. Among them, at least one selected from O-acyloxime-based compounds, acetophenone-based compounds, acylphosphine oxide-based compounds and titanocene-based compounds is preferable.

Examples of the O-acyloxime compound include 1,2-octanedione, 1- [4- (phenylthio) phenyl]-, 2- (O-benzoyloxime), etanone, 1- [9-ethyl-6- ( 2-Methylbenzoyl) -9H-carbazole-3-yl]-, 1- (O-acetyloxime), etanone, 1- [9-ethyl-6- (2-methyl-4-tetrahydrofuranylmethoxybenzoyl) -9H -Carbazole-3-yl]-, 1- (O-acetyloxime), etanone, 1- [9-ethyl-6- {2-methyl-4- (2,2-dimethyl-1,3-dioxolanyl) methoxy) Benzoyl} -9H-carbazole-3-yl]-, 1- (O-acetyloxime), 1-octanone, 1- [4- [3- [4- [[2- (acetyloxy) ethyl] sulfonyl]- 2-Methylbenzoyl] -6- [1-[(acetyloxy) imino] ethyl] -9H-carbazole] -9-yl] phenyl, 1- (O-acetyloxime) and the like can be mentioned. Commercially available products of O-acyloxime compounds include NCI-831, NCI-930 (above, manufactured by ADEKA Corporation), DFI-020, DFI-091 (above, manufactured by Daito Chemix Co., Ltd.), IrgacureOXE-03, IrgacureOXE. -04 (above, manufactured by BASF) or the like can also be used.

Among these O-acyloxime compounds, etanone, 1- [9-ethyl-6- (2-methylbenzoyl) -9H-carbazole-3-yl]-, 1- (O-acetyloxime), 1- Octanone, 1- [4- [3- [4- [[2- (Acetyloxy) Ethyl] sulfonyl] -2-methylbenzoyl] -6- [1-[(Acetyloxy) imino] ethyl] -9H-carbazole ] -9-Il] phenyl, 1- (O-acetyloxime) is preferred.

As the acetophenone compound, an α-aminoalkylphenone compound is more preferable, for example, 2-methyl-1- [4- (methylthio) phenyl] -2-morpholinopropane-1-one, 2-benzyl-2-dimethylamino. Examples include -1- (4-morpholinophenyl) butane-1-one, 2- (4-methylbenzyl) -2- (dimethylamino) -1- (4-morpholinophenyl) butane-1-one, and the like. Can be done.

Among these acetophenone compounds, 2-methyl-1- [4- (methylthio) phenyl] -2-morpholinopropan-1-one and 2-benzyl-2-dimethylamino-1- (4-morpholino) Phenyl) butane-1-one is preferred.

Examples of the acylphosphine oxide-based compound include isobutyrylmethylphosphinic acid methyl ester, isobutyrylphenylphosphinic acid methyl ester, pivaloylphenylphosphinic acid methyl ester, 2-ethylhexanoylphenylphosphinic acid methyl ester, and pivaloyl. Phenylphosphinic acid isopropyl ester, p-toluylphenylphosphinic acid methyl ester, o-toluylphenylphosphinic acid methyl ester, 2,4-dimethylbenzoylphenylphosphinic acid methyl ester, pt-butylbenzoylphenylphosphinic acid isopropyl ester, acryloylphenyl Phosphinic acid methyl ester, isobutyryldiphenylphosphine oxide, 2-ethylhexanoyldiphenylphosphine oxide, o-toluyldiphenylphosphine oxide, pt-butylbenzoyldiphenylphosphine oxide, 3-pyridylcarbonyldiphenylphosphine oxide, acryloyl-diphenylphosphine Oxide, benzoyldiphenylphosphine oxide, pivaloylphenylphosphinic acid vinyl ester, adipoil bisdiphenylphosphine oxide, pivaloyldiphenylphosphine oxide, p-toluyldiphenylphosphine oxide, 4- (t-butyl) benzoyldiphenylphosphine oxide, tele Phtaloylbisdiphenylphosphine oxide, 2-methylbenzoyldiphenylphosphine oxide, versatoyldiphenylphosphine oxide, 2-methyl-2-ethylhexanoyldiphenylphosphine oxide, 1-methyl-cyclohexanoyldiphenylphosphine oxide, pivaloylphenylphosphine Monoacylphosphine oxides such as acid methyl ester, pivaloylphenylphosphinic acid isopropyl ester, 2,4,6-trimethylbenzoyldiphenylphosphine oxide; bis (2,6-dichlorobenzoyl) phenylphosphine oxide, bis (2,6-- Dichlorobenzoyl) -2,5-dimethylphenylphosphine oxide, bis (2,6-dichlorobenzoyl) -4-ethoxyphenylphosphine oxide, bis (2,6-dichlorobenzoyl) -4-propylphenylphosphine oxide, bis (2) , 6-Dichlorobenzoyl) -2-naphthylphosphine oxide, bis (2) , 6-Dichlorobenzoyl) -1-naphthylphosphinoxide, bis (2,6-dichlorobenzoyl) -4-chlorophenylphosphinoxide, bis (2,6-dichlorobenzoyl) -2,4-dimethoxyphenylphosphinoxide, bis ( 2,6-Dichlorobenzoyl) decylphosphinoxide, bis (2,6-dichlorobenzoyl) -4-octylphenylphosphine oxide, bis (2,4,6-trimethylbenzoyl) phenylphosphinoxide, bis (2,4,6) -Trimethylbenzoyl) -2,5-dimethylphenylphosphine oxide, bis (2,6-dichloro 3,4,5-trimethoxybenzoyl) -2,5-dimethylphenylphosphine oxide, bis (2,6-dichloro-3) , 4,5-Trimethoxybenzoyl) -4-ethoxyphenylphosphine oxide, bis (2-methyl-1-naphthoyl) -2,5-dimethylphenylphosphine oxide, bis (2-methyl-1-naphthoyl) -4- Ethoxyphenylphosphine oxide, bis (2-methyl-1-naphthoyl) -2-naphthylphosphine oxide, bis (2-methyl-1-naphthoyl) -4-propylphenylphosphine oxide, bis (2-methyl-1-naphthoyl) -2,5-dimethylphenylphosphine oxide, bis (2-methoxy-1-naphthoyl) -4-ethoxyphenylphosphine oxide, bis (2-chloro-1-naphthoyl) -2,5-dimethylphenylphosphine oxide, bis ( Bisacylphosphine oxides such as 2,6-dimethoxybenzoyl) -2,4,4-trimethylpentylphosphine oxide; and the like. In addition, the acylphosphine compounds described in JP-A-3-101686, JP-A-5-345790, and JP-A-6-298818 can also be used.

Among these acylphosphine oxide compounds, 2,4,6-trimethylbenzoyldiphenylphosphine oxide (for example, DarocurTPO manufactured by BASF) is preferable as the monoacylphosphine oxide, and bis (2,4) is the bisacylphosphine oxide. , 6-trimethylbenzoyl) phenylphosphine oxide (eg, BASF, Irgacure819), and bis (2,6-dimethoxybenzoyl) -2,4,4-trimethylpentylphenylphosphine oxide (eg, BASF, Irgacure1700) are preferred. , Bis (2,4,6-trimethylbenzoyl) phenylphosphine oxide is more preferred.

Examples of titanium-based photocompounds include bis (cyclopentadienyl) -Ti-di-chloride, bis (cyclopentadienyl) -Ti-bis-phenyl, and bis (cyclopentadienyl) -Ti-bis-2. 3,4,5,6-pentafluorophenyl, bis (cyclopentadienyl) -Ti-bis-2,3,5,6-tetrafluorophenyl, bis (cyclopentadienyl) -Ti-bis-2, 4,6-Trifluorophenyl, bis (cyclopentadienyl) -Ti-bis-2,6-difluorophenyl, bis (cyclopentadienyl) -Ti-bis-2,4-difluorophenyl, bis (methylcyclo) Pentadienyl) -Ti-bis-2,3,4,5,6-pentafluorophenyl, bis (methylcyclopentadienyl) -Ti-bis-2,3,5,6-tetrafluorophenyl, bis ( Methylcyclopentadienyl) -Ti-bis-2,6-difluorophenyl (eg, BASF, Irgacure727L), bis (cyclopentadienyl) -bis (2,6-difluoro-3- (pyri-1-yl)) ) Titanium) Titanium (for example, manufactured by BASF, Irgacure784), Bis (cyclopentadienyl) -bis (2,4,6-trifluoro-3- (pyri-1-yl) phenyl) Titanium bis (cyclopentadienyl) ) -Bis (2,4,6-trifluoro-3- (2-5-dimethylpyri-1-yl) phenyl) Titanium and other compounds can be mentioned.

Among these titanosen compounds, bis (cyclopentadienyl) -bis (2,6-difluoro-3- (pyri-1-yl) phenyl) titanium is preferable.

Examples of the (D) photopolymerization initiator other than the above include those exemplified in paragraphs [0079] to [0995] of JP-A-2010-134419.

Among them, the (D) photopolymerization initiator preferably contains at least one selected from O-acyloxime-based compounds, acylphosphine oxide-based compounds and titanocene-based compounds. When at least one selected from O-acyloxime-based compounds, acylphosphine oxide-based compounds and titanosen-based compounds is contained, the content ratio thereof shall be 90% by mass or more, particularly 96% by mass or more of the total photopolymerization initiator. Is preferable.

The content of the (D) photopolymerization initiator is usually 1 to 100 parts by mass, preferably 3 to 70 parts by mass, and more preferably 5 to 50 parts by mass with respect to 100 parts by mass of the (C) polymerizable compound. .. With such an embodiment, it is possible to form a cured film having excellent heat resistance, chemical resistance, curability and the like.

<(E) Solvent>
The present composition contains the above-mentioned components (A) to (D) and other components optionally added, but usually, a solvent (E) such as an organic solvent is blended as a liquid composition. Prepared.
As the solvent (E), as long as it disperses or dissolves the components (A) to (D) and other components constituting the present composition, does not react with these components, and has appropriate volatility. , Can be appropriately selected and used.

Examples of the organic solvent include ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol mono-n-propyl ether, ethylene glycol mono-n-butyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, and diethylene glycol mono-n-propyl ether. , Diethylene glycol mono-n-butyl ether, triethylene glycol monomethyl ether, triethylene glycol monoethyl ether, propylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol mono-n-propyl ether, propylene glycol mono-n-butyl ether, di (Poly) alkylene glycols such as propylene glycol monomethyl ether, dipropylene glycol monoethyl ether, dipropylene glycol mono-n-propyl ether, dipropylene glycol mono-n-butyl ether, tripropylene glycol monomethyl ether, tripropylene glycol monoethyl ether, etc. Monoalkyl ether; Lactate alkyl esters such as methyl lactate and ethyl lactate; (cyclo) alkyl alcohols such as methanol, ethanol, propanol, butanol, isopropanol, isobutanol, t-butanol, octanol, 2-ethylhexanol, cyclohexanol; Keto alcohols such as acetone alcohol; ethylene glycol monomethyl ether acetate, ethylene glycol monoethyl ether acetate, diethylene glycol monomethyl ether acetate, diethylene glycol monoethyl ether acetate, propylene glycol monomethyl ether acetate (hereinafter abbreviated as PGMEA), propylene glycol monoethyl ether acetate. , Dipropylene glycol monomethyl ether acetate, 3-methoxybutyl acetate, 3-methyl-3-methoxybutyl acetate and other (poly) alkylene glycol monoalkyl ether acetate; diethylene glycol dimethyl ether, diethylene glycol methyl ethyl ether, diethylene glycol diethyl ether, tetrahydrofuran and the like. Glycol ether; ketones such as methyl ethyl ketone, cyclohexanone, 2-heptanone, 3-heptanone; propylene glycol diacete , 1,3-butylene glycol diacetate, diacetates such as 1,6-hexanediol diacetate; methyl 3-methoxypropionate, ethyl 3-methoxypropionate, methyl 3-ethoxypropionate, 3-ethoxypropionic acid Alkoxycarboxylic acid esters such as ethyl, ethyl ethoxyacetate, 3-methyl-3-methoxybutyl propionate; ethyl acetate, n-propyl acetate, i-propyl acetate, n-butyl acetate, i-butyl acetate, n formic acid. -Amil, i-amyl acetate, n-butyl propionate, ethyl butyrate, n-propyl butyrate, i-propyl butyrate, n-butyl butyrate, methyl pyruvate, ethyl pyruvate, n-propyl pyruvate, methyl acetate, Fatty acid alkyl esters such as ethyl acetoacetate and ethyl 2-oxobutanoate; aromatic hydrocarbons such as toluene and xylene; amides such as N, N-dimethylformamide, N, N-dimethylacetamide, N-methylpyrrolidone, or lactam and the like. Can be mentioned.

Of these organic solvents, (poly) alkylene glycol monoalkyl ether, lactic acid alkyl ester, (poly) alkylene glycol monoalkyl ether acetate, glycol from the viewpoint of solubility, dispersibility of (A) white pigment, coatability, etc. Ether, ketone, diacetate, alkoxycarboxylic acid ester, fatty acid alkyl ester are preferable, and propylene glycol monomethyl ether, propylene glycol monoethyl ether, ethylene glycol monomethyl ether acetate, propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate, 3 -Methoxybutyl acetate, diethylene glycol dimethyl ether, diethylene glycol methyl ethyl ether, cyclohexanone, 2-heptanone, 3-heptanone, 1,3-butylene glycol diacetate, 1,6-hexanediol diacetate, ethyl lactate, ethyl 3-methoxypropionate , 3-ethoxysellpropionate, n-butyl acetate, i-butyl acetate, n-amyl formate, i-amyl acetate, n-butyl propionate, ethyl butyrate, i-propyl butyrate, n-butyl butyrate, ethyl pyruvate Etc. are preferable.

(E) In addition, an inorganic solvent such as water may be used as the solvent.

In this composition, the solvent (E) can be used alone or in combination of two or more. The content of the solvent (E) is not particularly limited, but the total concentration of all the components of the composition (E) excluding the solvent is preferably 5 to 70% by mass, preferably 10 to 60. An amount of mass% is more preferable. With such an embodiment, the present composition having good coatability and storage stability can be obtained.

<Dispersant>
The composition may further contain a dispersant. The dispersant is not particularly limited as long as it is a compound that satisfactorily disperses the (A) white pigment in the (E) solvent.

Known dispersants include, for example, urethane dispersants, polyethyleneimine dispersants, polyoxyethylene alkyl ether dispersants, polyoxyethylene alkyl phenyl ether dispersants, polyethylene glycol diester dispersants, and sorbitan fatty acid ester dispersants. Agents, polyester-based dispersants, (meth) acrylic-based dispersants, phosphate ester-based dispersants and the like can be mentioned. As commercially available products, for example, (meth) acrylic dispersants such as Disperbyk-2000, Disperbyk-2001, Disperbyk-182, Disperbyk-184, BYK-LPN6919, BYK-LPN21116 (all manufactured by Big Chemie (BYK)), Disperby. 161 Polyester immin-based dispersant such as 24000 (manufactured by Lubrizol Co., Ltd.), polyester-based dispersant such as Ajispar PB821, Ajispar PB822, Ajispar PB880, Ajispar PB881 (all manufactured by Ajinomoto Fine Techno Co., Ltd.), Disperbyk-110, Disperbyk BYK-LPN21324 (manufactured by Big Chemie (BYK)) can be used in addition to a phosphate ester-based dispersant such as −180.

Among them, as the dispersant, at least one selected from the group consisting of (meth) acrylic dispersants, phosphate ester dispersants, urethane dispersants and polyester dispersants is selected from the viewpoint of improving storage stability. Preferably, at least one selected from the group consisting of (meth) acrylic dispersants and phosphate ester dispersants is more preferable.

The dispersant preferably has an acid value of 30 to 200 mgKOH / g or an amine value of 10 to 200 mgKOH / g from the viewpoint of improving storage stability. (A) From the viewpoint of dispersibility of the white pigment, the acid value is more preferably 40 to 100 mgKOH / g, and the amine value is more preferably 20 to 180 mgKOH / g. Here, the "amine value" represents the number of mg of HCl and equivalent amount of KOH required to neutralize 1 g of solid content.

The dispersant can be used alone or in admixture of two or more. When two or more kinds are mixed and used, it is preferable to contain at least a (meth) acrylic dispersant, and the content ratio of the (meth) acrylic dispersant is preferably 50% by mass or more with respect to the entire dispersant. 70% by mass or more is more preferable. With such an embodiment, it becomes easy to obtain the present composition having further excellent storage stability.

The content of the dispersant is usually 0.5 to 50 parts by mass, preferably 2 to 30 parts by mass with respect to 100 parts by mass of the white pigment (A). With such an embodiment, the present composition having excellent storage stability can be formed.

The composition preferably contains (B) an alkali-soluble resin and a dispersant as components that serve as a binder. The total content of (B) the alkali-soluble resin and the dispersant is preferably 2 to 150 parts by mass, more preferably 10 to 70 parts by mass with respect to 100 parts by mass of the total of (A) white pigment.

<(F) Surfactant>
The composition may further contain (F) a surfactant. (F) By using a surfactant, the film-forming property of the present composition can be enhanced, and the surface smoothness of the obtained coating film can be improved. As a result, the film thickness uniformity of the obtained cured film can be further improved.

Further, the (F) surfactant may contain a Si atom or an F atom, and specifically, contains the compounds described in JP-A-2003-015278 and JP-A-2013-231869. It may be. By including such an atom, the (F) surfactant is imparted with liquid repellency. As a result, it becomes easy to apply a composition for forming a color filter, a composition for forming a phosphor layer, or the like between the cured films formed by the present composition, and by using the cured film as a partition wall, it becomes highly effective. It becomes easy to form a display element having functionality.

(F) When a surfactant is used, the content thereof in the present composition is preferably 20 parts by mass or less, more preferably 0.01 to 15 parts by mass with respect to 100 parts by mass of the (B) alkali-soluble resin. , More preferably 0.05 to 10 parts by mass. (F) By setting the content of the surfactant in the above range, the film thickness uniformity of the formed coating film can be further improved.

As described above, the present composition further contains (F) a surfactant and is selected from the group consisting of (B) an alkali-soluble resin, (C) a polymerizable compound and (F) a surfactant. The seed preferably contains a Si atom or an F atom.

<Additives>
The composition may also contain various additives, if desired. Examples of the additive include fillers such as glass and alumina; polymer compounds such as polyvinyl alcohol and poly (fluoroalkyl acrylate); vinyltrimethoxysilane, vinyltriethoxysilane, vinyltris (2-methoxyethoxy) silane. , N- (2-aminoethyl) -3-aminopropylmethyldimethoxysilane, N- (2-aminoethyl) -3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 3-glycidoxypropyltri Methoxysilane, 3-glycidoxypropylmethyldimethoxysilane, 2- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, 3-chloropropylmethyldimethoxysilane, 3-chloropropyltrimethoxysilane, 3-methacryloyloxypropyl Adhesion promoters such as silane coupling agents such as trimethoxysilane and 3-mercaptopropyltrimethoxysilane; 2,2-thiobis (4-methyl-6-t-butylphenol), 2,6-di-t-butylphenol, Pentaerythritol tetrakis [3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate], 3,9-bis [2- [3- (3-t-butyl-4-hydroxy-5-methyl) Phenyl) -propionyloxy] -1,1-dimethylethyl] -2,4,8,10-tetraoxa-spiro [5.5] undecane, thiodiethylenebis [3- (3,5-di-t-butyl-) 4-Hydroxyphenyl) propionate], antioxidants such as tris (2,4-di-t-butylphenyl) phosphite; 2- (3-t-butyl-5-methyl-2-hydroxyphenyl) -5 UV absorbers such as chlorobenzotriazole and alkoxybenzophenones; antiaggregating agents such as sodium polyacrylate; malonic acid, adipic acid, itaconic acid, citraconic acid, fumaric acid, mesaconic acid, 2-aminoethanol, 3-amino- Residue improver such as 1-propanol, 5-amino-1-pentanol, 3-amino-1,2-propanediol, 2-amino-1,3-propanediol, 4-amino-1,2-butanediol Developable improvers such as mono-succinic acid [2- (meth) acryloyloxyethyl], mono-phthalic acid [2- (meth) acryloyloxyethyl], ω-carboxypolycaprolactone mono (meth) acrylate, etc. be able to. The adhesion accelerator does not correspond to the (C) polymerizable compound.

Among the above additives, the content of the adhesion promoter such as a silane coupling agent is preferably 1 to 20 parts by mass, more preferably 3 to 15 parts by mass with respect to 100 parts by mass of the (B) alkali-soluble resin. .. The content of the antioxidant is preferably 0.1 to 10 parts by mass, more preferably 1 to 5 parts by mass with respect to 100 parts by mass of the (B) alkali-soluble resin. The total content of the additives (components (A) to (F) and components other than the dispersant) in the present composition is preferably 1 to 20 parts by mass with respect to 100 parts by mass of the (B) alkali-soluble resin. 5 to 15 parts by mass may be more preferable. By setting the content of the additive in the above range, the effect of adding the additive can be fully exhibited together with the effect of the present invention.

The present composition can be prepared by an appropriate method, for example, the components (A) to (D) are mixed with the solvent (E) and other components optionally added. Can be prepared by. Above all, (A) the white pigment is mixed and dispersed while being crushed in (E) in a solvent in the presence of a dispersant, and in some cases together with a part of (B) an alkali-soluble resin, using, for example, a bead mill or a roll mill. Then, (C) a polymerizable compound, (B) an alkali-soluble resin, (D) a photopolymerization initiator, (E) a solvent and other components are added to the white pigment dispersion. A method of preparing by mixing (hereinafter, also referred to as preparation method I) is preferable.

Further, (A) a white pigment and (A) a colorant different from the white pigment are added to (E) a solvent in the presence of a dispersant, and in some cases, together with a part of (B) an alkali-soluble resin, for example, a bead mill, a roll mill, or the like. To obtain a white pigment dispersion liquid, which is mixed and dispersed while being pulverized, and then, (C) a polymerizable compound and, if necessary, (B) an alkali-soluble resin, (D) are added to the white pigment dispersion liquid. It is also possible to adopt a method of preparing by adding a photopolymerization initiator, (E) a solvent and other components and mixing them (hereinafter, also referred to as preparation method II). The white pigment dispersion in Preparation Method II can undergo a step of simultaneously and uniformly dispersing (A) a white pigment and a colorant different from (A) a white pigment in a solvent (E). The white pigment dispersion in Preparation Method II contains at least (A) a white pigment and a colorant different from (A) the white pigment, (B) an alkali-soluble resin, and (E) a solvent, but (B) an alkali-soluble resin. The contents of (A) white pigment and (A) white pigment are 80 parts by mass or less, particularly 60 parts by mass or less, and even 45 parts by mass or less with respect to 100 parts by mass of the white pigment. Different colorants are uniformly dispersed, and a white pigment dispersion having excellent storage stability can be obtained. Preparation method II is useful when the colorant different from (A) the white pigment is a compound that is sparingly soluble or insoluble in (E) a solvent such as a pigment.

The preparation method II can also be carried out with reference to, for example, the methods described in JP-A-2001-108817, JP-A-2013-205832, and the like.

<Curing film, display element, and manufacturing method thereof>
The cured film according to the embodiment of the present invention contains (A) a white pigment, and (A) the white pigment is 30 to 90% by mass when the total solid content is 100% by mass. Specifically, the cured film according to one embodiment of the present invention can be formed by using the present composition. Further, the display element according to the embodiment of the present invention includes the cured film of the present invention as a partition wall. The partition wall provided in the display element may be referred to as a bank, a matrix, or the like.

Hereinafter, a method for forming a cured film used for a partition wall constituting a display element will be described. First, the liquid composition of the present composition is applied onto the surface of the substrate, and then prebaked to evaporate the solvent to form a coating film. Next, the coating film is exposed through a photomask and then developed with an alkaline developer to dissolve and remove the unexposed portion of the coating film. Then, by post-baking, a cured film is formed in a predetermined arrangement.

Examples of the substrate used for forming the cured film include glass, silicon, polycarbonate, polyester, aromatic polyamide, polyamideimide, and polyimide.

Further, if desired, these substrates may be subjected to appropriate pretreatment such as chemical treatment with a silane coupling agent or the like, plasma treatment, ion plating, sputtering, gas phase reaction method, vacuum deposition and the like.

When applying this composition to a substrate, an appropriate coating method such as a spray method, a roll coating method, a rotary coating method (spin coating method), a slit die coating method (slit coating method), or a bar coating method is adopted. However, it is particularly preferable to adopt a spin coating method or a slit die coating method.

Pre-baking is usually performed by a combination of vacuum drying and heat drying. Drying under reduced pressure is usually carried out until it reaches 50 to 200 Pa. The conditions for heating and drying are usually about 1 to 10 minutes at 70 to 110 ° C.

The coating thickness is usually 1 to 100 μm, preferably 2 to 30 μm, and more preferably 5 to 20 μm as the film thickness after drying.

Examples of the light source of radiation used for forming the cured film include lamp light sources such as xenon lamps, halogen lamps, tungsten lamps, high pressure mercury lamps, ultrahigh pressure mercury lamps, metal halide lamps, medium pressure mercury lamps, and low pressure mercury lamps, and argon ion lasers. , YAG laser, XeCl excimer laser, laser light source such as nitrogen laser and the like can be mentioned. An ultraviolet LED can also be used as the exposure light source. The wavelength is preferably radiation in the range of 190 to 450 nm.

When the cured film formed by the above method is used as a partition wall of a display element, a pigment or the like of a color filter forming composition or a phosphor layer forming composition for forming a color filter or a phosphor layer between the partition walls is used. Is preferably liquid-repellent from the viewpoint of facilitating application of the composition in which the above is dispersed in an organic solvent.

Here, the liquid repellency is defined by measuring the static contact angle of the surface of the cured film with respect to PGMEA using a contact angle meter (automatic contact angle meter CA-V150 manufactured by Kyowa Surface Chemistry Co., Ltd.). The determined result indicates that it is 5 ° or more, more preferably 15 ° or more, and further preferably 30 ° or more. On the other hand, the upper limit of the static contact angle is, for example, 90 °.

The exposure amount of radiation is generally preferably 10 to 10,000 J / m ² .

Examples of the alkaline developer include sodium carbonate, sodium hydrogen carbonate, sodium hydroxide, potassium hydroxide, tetramethylammonium hydroxide, choline, 1,8-diazabicyclo- [5.4.0] -7-undecene. , 1,5-diazabicyclo- [4.3.0] -5-nonen and the like are preferable.

An appropriate amount of a water-soluble organic solvent such as methanol or ethanol, a surfactant, or the like can be added to the alkaline developer. After alkaline development, it is usually washed with water.

As the developing method, a shower developing method, a spray developing method, a dip (immersion) developing method, a paddle (liquid filling) developing method and the like can be applied. The developing conditions are preferably 5 to 300 seconds at room temperature.

The post-baking conditions are usually about 10 to 90 minutes at 120 to 300 ° C. The present composition can form a cured film with less yellowing even when the post-bake temperature is 180 to 300 ° C., further 230 to 290 ° C., and further 250 to 280 ° C.

The film thickness of the cured film thus formed is usually 1 to 100 μm, preferably 2 to 30 μm, and more preferably 5 to 20 μm.

Further, the shape of the cured film can be a shape having a forward taper, a shape having a vertical taper, a shape having a reverse taper, a shape having a substantially circular shape, or the like. Here, the shape having a forward taper means a shape in which the cured film becomes smaller upward with respect to the substrate, and the shape having a vertical taper means a shape in which the cured film becomes substantially upward with respect to the substrate. It refers to a shape that is constant, and a shape that has a reverse taper refers to a shape in which the cured film increases upward with respect to the substrate. When the cured film has the above-mentioned taper shape, the taper angle is preferably 50 to 130 °, more preferably 60 to 120 °.

The cured film formed from the present composition has a high content of white pigment, and therefore has a low light transmittance. The lower limit of the optical density (OD) of the cured film is preferably 0.05 / μm, more preferably 0.1 / μm, and even more preferably 0.2 / μm. On the other hand, the upper limit of this optical density (OD) is preferably 5.0 / μm.

A transparent conductive film can be formed by sputtering or a protective film can be formed on the cured film thus obtained, if necessary. When this composition has little yellowing even after being heat-treated at 250 ° C. or higher at the time of forming a transparent electrode, it is useful from the viewpoint of reliability as a partition wall used for a display element.

Further, in recent years, due to the demand for high functionality of the display element, a color filter or a phosphor layer may be provided between the partition walls. For example, in an organic EL element or a micro LED element which is an example of a display element, a color filter or a phosphor layer is provided between partition walls. In the micro LED element, a micro LED is usually further arranged between the partition walls. Here, when a cured film having high liquid repellency, which is one embodiment of the present invention, is used as a partition wall of the display element, a composition for forming a color filter or a phosphor layer for forming a color filter, a phosphor layer, or the like is formed. As a result of facilitating the application of the composition for use between the partition walls, it is possible to easily manufacture a display element having high functionality.

The method of applying the composition for forming a color filter, the composition for forming a fluorescent substance layer, or the like between the partition walls having high liquid repellency can be performed by a known method. Specifically, the coating method using a brush or brush, the dipping method, the spray method, the roll coating method, the rotary coating method (spin coating method), the slit die coating method, the bar coating method, the flexographic printing, the offset printing, and the screen. Known methods such as a printing method, an inkjet printing method, and a dispensing method can be mentioned. Among these, the dipping method, the spray method, the spin coating method, the slit die coating method, the offset printing method, the screen printing method, the inkjet method and the dispense method are preferable, and the inkjet method is particularly preferable.

The inkjet method has extremely small defective ejection amount of the composition to be applied and has industrially excellent characteristics, but there is a possibility that ink droplets may land at a place other than a desired point. However, when the partition wall having high liquid repellency is used, ink droplets are unlikely to remain on the crown of the partition wall, and the applied ink droplets easily enter the inside of the partition wall, resulting in a good pattern of the coated material. Therefore, when the cured film having high liquid repellency, which is one embodiment of the present invention, is used for the partition wall of the display element, a composition for forming a color filter, a composition for forming a phosphor layer, or the like is applied by an inkjet method. By doing so, it is possible to suppress the adhesion of ink to the portion that does not need to be applied, and to form a desired pattern such as a color filter or a phosphor layer.

The display element using the cured film of the present invention as the partition wall of the display element has a high light extraction function due to high reflection characteristics and the ease of forming a functional layer between the partition walls. Such a display element is suitably used in an organic EL element or a micro LED element, in which miniaturization between partition walls is particularly required.

Hereinafter, the present invention will be described in more detail with reference to examples. However, the present invention is not limited to the following examples. In the following synthesis example, the charging ratio (mass ratio) of each monomer and the content ratio (mass ratio) of the structural unit corresponding to each monomer in the obtained resin are substantially different. Can be considered the same.

<Synthesis of alkali-soluble resin>
[Synthesis Example 1] (B-1) Synthesis of alkali-soluble resin After replacing the inside of the flask with nitrogen, 250 parts by mass of a PGMEA solution in which 8 parts by mass of 2,2'-azobis (2,4-dimethylvaleronitrile) is dissolved is added. I prepared it. Subsequently, 20 parts by mass of methacrylic acid (hereinafter abbreviated as MA) and 80 parts by mass of methyl methacrylate (hereinafter abbreviated as MMA) were charged as monomers, and then gentle stirring was started. The temperature of the solution was raised to 70 ° C. and this temperature was maintained for 5 hours. Then, the reaction product solution was added dropwise to a large amount of methanol to solidify the reaction product. After washing this coagulated product with water, it was redissolved in 200 g of tetrahydrofuran and coagulated again with a large amount of methanol to obtain a (B-1) alkali-soluble resin. The Mw of the obtained (B-1) alkali-soluble resin was 9,500.

[Synthesis Example 2] (B-2) Synthesis of alkali-soluble resin As a monomer, 10 parts by mass of 1H, 1H, 2H, 2H-tridecafluorooctyl methacrylate (hereinafter abbreviated as F-containing acrylate), 10 parts by mass of MA, (B-2) An alkali-soluble resin was synthesized in the same manner as in Synthesis Example 1 except that 80 parts by mass of MMA was used. The Mw of the obtained (B-2) alkali-soluble resin was 8,900.

[Synthesis Example 3] Synthesis of alkali-soluble resin (B-3) Alkali-soluble resin in the same manner as in Synthesis Example 1 except that 30 parts by mass of F-containing acrylate, 10 parts by mass of MA, and 60 parts by mass of MMA were used as monomers. Was synthesized. The Mw of the obtained (B-3) alkali-soluble resin was 8,200.

[Synthesis Example 4] (B-4) Synthesis of alkali-soluble resin As a monomer, 40 parts by mass of glycidyl methacrylate (hereinafter abbreviated as GMA), 20 parts by mass of MA, and 40 parts by mass of MMA are used as Synthesis Example 1. Similarly, (B-4) an alkali-soluble resin was synthesized. The Mw of the obtained (B-4) alkali-soluble resin was 9,800.

[Synthesis Example 5] (B-5) Synthesis of alkali-soluble resin As monomers, 40 parts by mass of GMA, 20 parts by mass of MA, 22 parts by mass of N-phenylmaleimide (hereinafter abbreviated as PMI), and styrene (hereinafter referred to as St). (Omitted) An alkali-soluble resin was synthesized in the same manner as in Synthesis Example 1 except that 18 parts by mass was used. The Mw of the obtained (B-5) alkali-soluble resin was 8,800.

[Synthesis Example 6] (B-6) Synthesis of alkali-soluble resin 30 parts by mass of F-containing acrylate, 35 parts by mass of GMA, 7 parts by mass of MA, and 28 parts by mass of MMA are used in the same manner as in Synthesis Example 1. (B-6) An alkali-soluble resin was synthesized. The Mw of the obtained (B-6) alkali-soluble resin was 7,800.

[Synthesis Example 7] (B-7) Synthesis of alkali-soluble resin As a monomer, 30 parts by mass of F-containing acrylate, 35 parts by mass of GMA, 7 parts by mass of MA, 16 parts by mass of PMI, and 4-isopropenylphenol (hereinafter referred to as Hs). (Omitted) An alkali-soluble resin was synthesized in the same manner as in Synthesis Example 1 except that 12 parts by mass was used. The Mw of the obtained (B-7) alkali-soluble resin was 8,100.

[Synthesis Example 8] (B-8) Synthesis of non-alkali soluble resin Similar to Synthesis Example 1 except that 60 parts by mass of GMA, 22 parts by mass of PMI, and 18 parts by mass of St were used as monomers (B-8). An alkali-soluble resin was synthesized. The Mw of the obtained (B-8) non-alkali soluble resin was 9,800.

<Evaluation of particle size distribution diameter>
The white pigment dispersion prepared below was diluted 10-fold with PGMEA, and the average particle size of (A) white pigment was determined using a particle size distribution meter (L-500 manufactured by HORIBA).

<Preparation of white pigment dispersion>
[Preparation Example 1]
C.I. whose surface was modified with alumina and siloxane. I. Pigment White 6: 1 (titanium oxide) by 90 parts by mass, BYK-LPN21116 (manufactured by Big Chemie (BYK), (meth) acrylic dispersant, amine value 29 mgKOH / g solid content concentration 40% by mass) 25 by mass A white pigment dispersion (A-1) was prepared by mixing and dispersing PGMEA as a dispersion medium by mass so that the solid content concentration was 50% by mass by a bead mill for 12 hours. The average particle size of the white pigment in the obtained (A-1) white pigment dispersion was 280 nm.

<Preparation and evaluation of curable composition>
[Example 1]
(A) 220 parts by mass of (A-1) white pigment dispersion as a dispersion containing a white pigment, (B-1) 100 parts by mass of an alkali-soluble resin as an alkali-soluble resin, and (C) KAYARAD as a polymerizable compound. 100 parts by mass of DPHA (mixture of dipentaerythritol hexaacrylate and dipentaerythritol pentaacrylate manufactured by Nippon Kayaku Co., Ltd.), (D) 10 parts by mass of NCI-930 (manufactured by ADEKA Co., Ltd.) as a photopolymerization initiator, (F) 0.5 parts by mass of F-554 (manufactured by DIC Co., Ltd.) as a surfactant, and 3-glycidoxypropyltrimethoxysilane (KBM-403 manufactured by Shin-Etsu Chemical Co., Ltd.) as an additive silane coupling agent (adhesion promoter). ) 7 parts by mass, pentaerythritol tetrakis [3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate (Irganox 1010 manufactured by BASF) as an antioxidant as an additive, and (E) solvent. PGMEA was mixed so as to have a solid content concentration of 50% by mass to prepare (S-1) a photosensitive composition for forming a display element.

<Creation of cured film for optical density (OD), reflectance, and liquid repellency evaluation>
(S-1) The photosensitive composition for forming a display element is applied onto a soda glass substrate using a spin coater, and then prebaked at 90 ° C. for 2 minutes on a hot plate to form a coating film having a film thickness of 12 μm. bottom. Then, using a high-pressure mercury lamp, the coating film was exposed to radiation containing wavelengths of 365 nm, 405 nm and 436 nm at an exposure amount of 200 J / m ² without using a photomask. Then, a 0.04% potassium hydroxide aqueous solution at 23 ° C. was discharged onto the coating film at a developing pressure of 1 kgf / cm ² (nozzle diameter 1 mm) to perform shower development, and then post-baked at 230 ° C. for 1 hour. A cured film having a thickness of 10 μm was formed on the substrate.

<Creation of cured film for pattern formability and heat resistance evaluation>
(S-1) The photosensitive composition for forming a display element is applied onto a soda glass substrate using a spin coater, and then prebaked at 90 ° C. for 2 minutes on a hot plate to form a coating film having a film thickness of 12 μm. bottom. Then, using a high-pressure mercury lamp and using a photomask of L / S = 10 μm / 30 μm, the coating film was exposed to radiation containing wavelengths of 365 nm, 405 nm and 436 nm at an exposure amount of 50 J / m ² . Then, a 0.04% potassium hydroxide aqueous solution at 23 ° C. was discharged onto the coating film at a developing pressure of 1 kgf / cm ² (nozzle diameter 1 mm) to perform shower development, and then post-baked at 230 ° C. for 1 hour. A cured film having a film thickness of 10 μm and an aspect ratio of 0.8 (thickness / line width) was formed on the substrate.

[Examples 2 to 13 and Comparative Examples 1 to 3]
Each composition was prepared in the same manner as in Example 1 except that the type and mixing amount of each component were as shown in Table 1. Further, a cured film was formed in the same manner as in the photosensitive composition for forming the (S-1) display element of Example 1.

<Evaluation>
[Optical concentration (OD)]
The optical density (OD) of the cured film for evaluation was measured using an optical densitometer (LCF1100A manufactured by Otsuka Electronics Co., Ltd.). "A +" when OD is 0.2 / μm or more and 5.0 / μm or less, “A” when 0.1 / μm or more and less than 0.2 / μm, 0.05 / μm or more and 0.1 / The case of less than μm was evaluated as “B”, and the case of less than 0.05 / μm was evaluated as “C”. The evaluation results are shown in Table 1.

[Reflectance]
Using a spectral reflectance measuring device (CM-700D manufactured by Konica Minolta), the reflectance (light reflectance) of the cured film for evaluation in the wavelength range of 340 to 700 nm was measured from the substrate side. When the reflectance is 60% or more, it is evaluated as "A +", when it is 40% or more and less than 60%, it is evaluated as "A", when it is 20% or more and less than 40%, it is evaluated as "B", and when it is less than 20%, it is evaluated as "C". bottom. The evaluation results are shown in Table 1.

[Pattern formability]
It was visually confirmed whether or not the unexposed portion of the cured film for evaluation was completely dissolved. When dissolution was confirmed, it was evaluated as "A", and when it was not confirmed, it was evaluated as "C". The evaluation results are shown in Table 1.

[Liquid repellent]
Using a contact angle meter (automatic contact angle meter CA-V150 manufactured by Kyowa Interface Science Co., Ltd.), the static contact angle of PGMEA on the cured film for evaluation was measured, and the liquid repellency was evaluated. "A +" when the contact angle is 30 ° or more and 90 ° or less, "A" when the contact angle is 15 ° or more and less than 30 °, "B" when the contact angle is 10 ° or more and less than 15, and "B" when the contact angle is 5 ° or more and less than 10. "B-", the case of less than 5 ° was evaluated as "C". The evaluation results are shown in Table 1.

[Heat resistance evaluation]
The cured film for evaluation was baked at 270 ° C. for 1 hour, and the shape change was visually confirmed. When the shape change was hardly confirmed, it was evaluated as "A", when the shape change was confirmed, it was evaluated as "B", and when the shape change was significantly confirmed, it was evaluated as "C". The evaluation results are shown in Table 1.

As shown in Table 1, when each of the compositions of Examples 1 to 13 was used, a cured film having high optical density (OD) and reflectance was obtained, and the pattern forming property was also good. That is, it can be seen that according to the compositions of Examples 1 to 12, a cured film having both a high light reflection function and a fine pattern shape can be formed.

The photosensitive composition for forming a display element can be used as a material for forming a constituent member of the display element, and can be particularly preferably used as a material for forming a partition wall of an organic EL element or a micro LED element.

Claims (12)

Used for forming the partition wall of a display element which is an organic EL element or a micro LED element having a partition wall.
(A) White pigment,
(B) Alkaline-soluble resin,
(C) Polymerizable compound,
A photosensitive composition for forming a partition wall containing (D) a photopolymerization initiator and (E) a solvent.
The content of the white pigment (A) is 30 to 90% by mass when the total amount of the components excluding the solvent (E) is 100% by mass .
A photosensitive composition for partition wall formation, wherein the contact angle of the surface of the cured film formed from the photosensitive composition for partition wall formation with respect to propylene glycol monomethyl ether acetate is 15 ° or more . (F) Further containing a surfactant,
The partition wall according to claim 1, wherein at least one selected from the group consisting of (B) an alkali-soluble resin, (C) a polymerizable compound, and (F) a surfactant contains a Si atom or an F atom. Photosensitive composition for formation. (B) The photosensitive composition for forming a partition wall according to claim 1 or 2, wherein the alkali-soluble resin contains Si atoms or F atoms. (B) The photosensitive composition for forming a partition wall according to claim 3, wherein the alkali-soluble resin contains a group represented by the following formula (1).

(In the formula (1), R ¹ and R ² are independently hydrogen atoms or fluorine atoms, A is an ester bond or an ether bond, and n is an integer of 1 to 10. n is 2 or more. In some cases, the plurality of R ^1s may be the same or different, and the plurality of R ^2s may be the same or different. * Represents the binding site.) (B) The alkali-soluble resin contains a structural unit having a group represented by the above formula (1).
The photosensitive composition for forming a partition wall according to claim 4, wherein the content of the structural unit is 1 to 70% by mass with respect to 100% by mass of the (B) alkali-soluble resin. The photosensitive composition for forming a partition wall according to any one of claims 1 to 5, wherein the alkali-soluble resin contains at least one selected from the group consisting of a carboxyl group and a phenolic hydroxyl group. thing. (B) The alkali-soluble resin comprises at least one selected from the group consisting of a (meth) acryloyl group, a vinyl group, an oxylanyl group and an oxetanyl group, according to any one of claims 1 to 6. The photosensitive composition for forming a partition wall according to the above. (B) The photosensitive composition for forming a partition wall according to any one of claims 1 to 7, wherein the alkali-soluble resin contains a ring structure. (A) The white pigment is at least one inorganic substance selected from the group consisting of alumina, magnesium oxide, antimony oxide, titanium oxide, zirconium oxide, aluminum hydroxide, magnesium hydroxide, barium sulfate, magnesium carbonate and barium carbonate. The photosensitive composition for forming a partition wall according to any one of claims 1 to 8, which comprises. A partition wall formed by using the photosensitive composition for forming a partition wall according to any one of claims 1 to 9. The partition wall according to claim 10, wherein the optical density (OD) is 0.2 to 5.0 / μm. A display element that is an organic EL element or a micro LED element having a partition wall.
The display element in which the partition wall is the partition wall according to claim 10 or 11 .