TWI840326B - Method of forming pattern for partition - Google Patents

Abstract

A method of forming a pattern for a partition of a display device in which a color-specified luminous body is embedded in at least a part of a subpixel, the method including: a step (A) in which a black resist is patterned on a transparent substrate; a step (B) in which a positive resist composition having a thermosetting ability is coated on the transparent substrate having the black resist patterned thereon to form a resist film; a step (C) in which the resist film is exposed from the transparent substrate side; and a step (D) in which the exposed resist film is developed to form a resist pattern.

Description

Method for forming pattern for partition wall

The present invention relates to a method for forming a pattern for partitions between display elements in which a color-differentiated light-emitting body is embedded in at least a portion of a sub-pixel. This application claims priority based on U.S. Provisional Application No. 62/459,066 filed in the United States on February 15, 2017, and the contents of which are incorporated herein.

The display element of a liquid crystal display is a structure in which a liquid crystal layer is sandwiched between two substrates facing each other. Then, a color filter with pixels (pixels) composed of red (R), green (G), blue (B) and other colors is formed on the inner side of one of the substrates. In order to make the light and dark contrast of the image obvious, a black matrix is usually formed in the display element to divide the pixels (sub-pixels) of the R, G, and B colors.

Generally speaking, color filters are formed by lithography. Specifically, a black photosensitive composition is first applied to the substrate, exposed, and developed to form a black matrix and partition walls. After that, each R, G, and B photosensitive composition is repeatedly applied, exposed, and developed to form a pattern of each color at a specific position to manufacture a color filter.

Patent document 1 discloses a method of providing a light shielding wall between sub-pixels of an organic EL display. [Prior Art Document] [Patent Document]

[Patent Document 1] Japanese Patent Application Publication No. 2004-335224

[The problem that the invention is trying to solve]

As in the method of patent document 1, since a light shielding wall is arranged on the black matrix, there will be a problem of alignment accuracy with the black matrix pattern. 　　In order to solve the problem of alignment accuracy with the black matrix pattern, it is also conceivable to make the light shielding wall itself also constitute the black matrix. However, in the case of such a structure, if the light shielding wall becomes higher, the transparency to ultraviolet rays will also become lower. Therefore, when the black matrix pattern is formed, there will be a problem that the lithography technology becomes unsuitable. 　　The present invention is completed in view of the above situation, and its purpose is to provide a method for forming a pattern for partition walls with good alignment accuracy with the black matrix pattern in a display element in which a color light-emitting body is embedded in at least a part of the sub-pixel. [Means for solving the problem]

One aspect of the present invention is a method for forming a partition wall pattern, which is a method for forming a partition wall pattern of a display element in which a color light emitting body is embedded in at least a portion of a sub-pixel, comprising a step (A) of patterning a black resist on a transparent substrate, a step (B) of coating a positive resist composition having heat curing ability on the transparent substrate on which the black resist is patterned to form a resist film, a step (C) of exposing the resist film from the transparent substrate side, and a step (D) of developing the exposed resist film to form a resist pattern. [Effects of the invention]

According to the present invention, a method for forming a partition wall pattern with good alignment accuracy with a black matrix pattern can be provided in a display device having a color luminous body embedded in at least a portion of a sub-pixel.

In this specification and the scope of the patent application of the present invention, the term "aliphatic" is the opposite concept to aromatic, and is defined as a group, compound, etc. that does not have aromatic properties. "Alkyl", unless otherwise specified, refers to a monovalent saturated alkyl group including a linear, branched, or cyclic shape. The same applies to the alkyl group in the alkoxy group. "Alkylene", unless otherwise specified, refers to a divalent saturated alkyl group including a linear, branched, or cyclic shape. "Halogenated alkyl" is a group in which a part or all of the hydrogen atoms of an alkyl group are substituted by a halogen atom. Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom. The term "constituent unit" refers to a monomer unit (monomer unit) constituting a high molecular compound (resin, polymer, copolymer). The phrase "may have a substituent group" includes both the case where a hydrogen atom (-H) is substituted with a monovalent group and the case where a methylene group (-CH ₂ -) is substituted with a divalent group. "Exposure" is a general concept including irradiation with radiation. "(Meth)acrylate" means either or both of acrylate and methacrylate.

The following is a detailed description of various embodiments of the present invention. However, the present invention is not limited to the following embodiments and can be implemented with appropriate modifications within the scope of the purpose of the present invention.

[Method for forming a pattern for partition walls] The method for forming a pattern for partition walls of the present embodiment is a method for forming a pattern for partition walls of a display element having a color-specific light-emitting body embedded in at least a portion of a sub-pixel, comprising a step (A) of patterning a black resist on a transparent substrate, a step (B) of coating a positive type resist composition having heat curing ability on the transparent substrate on which the black resist has been patterned, a step (C) of exposing the resist film from the transparent substrate side, and a step (D) of developing the exposed resist film to form a resist pattern. As the color-specific light-emitting body, compound phosphors, quantum dot phosphors, etc., which have been used in color filters of display elements in the past, etc., can be cited. Among them, from the perspective of narrowing the luminescence range of each color of fluorescence or increasing the purity of red (R), it is better to use quantum dot phosphors as color-specific luminescent bodies.

<Step (A)> In step (A), a black resist is patterned on a transparent substrate 1 (FIG. 1(a) to (c)). The method of patterning the black resist is not particularly limited, and a conventionally known method can be used. For example, the black resist is applied to the transparent substrate using a contact transfer coating device such as a roller coater, a reverse coater, or a rod coater, or a non-contact coating device such as a rotator (rotary coating device) or a curtain-type flat coating device. Then, the applied black resist is dried to form a coating film 2. There is no particular limitation on the drying method, for example, (1) drying for 60 seconds to 120 seconds at 80°C to 120°C, preferably 90°C to 100°C, on a heating plate, (2) leaving it at room temperature for several hours to several days, (3) removing the solvent by placing it in a warm air heater or an infrared heater for several tens of minutes to several hours, any of which can be used. Next, active energy rays such as ultraviolet rays and excimer laser light are irradiated on this coating ² through a mask to perform partial exposure. Although the amount of energy irradiated varies depending on the composition of the black resist, it is preferably in the range of, for example, 30 mJ/ ^cm2 to 2000 mJ/cm2. Next, the exposed film is developed with a developer to form a pattern into the desired shape. There is no particular limitation on the developing method, and for example, an immersion method, a spraying method, etc. can be used. As the developer, there can be listed organic developers such as ethanolamine, diethanolamine, triethanolamine, or aqueous solutions of sodium hydroxide, potassium hydroxide, sodium carbonate, ammonia, quaternary ammonium salts, etc. Then, the developed pattern is post-baked at a temperature of 200~250°C. Through the above, the black resist can be patterned in a specific shape on the transparent substrate. The thickness of the patterned black resist (black matrix 2a) on the transparent substrate can generally be set to a range of 0.5μm~5μm, preferably 1μm~3μm, and more preferably 1μm~2μm. In particular, from the viewpoint of improving the resolution of the black matrix pattern, the thickness of the black matrix is preferably 3 μm or less.

(Transparent substrate) As a transparent substrate, there is no particular limitation as long as it is a light-transmitting substrate, but a general glass substrate can be used.

(Black Resist) There is no particular limitation on the black resist, and conventionally known ones can be used. For example, photosensitive resin compositions containing black pigments and resin components can be cited. As black pigments, inorganic pigments such as carbon black, titanium black, metal oxides, complex oxides, metal sulfides, metal lead sulfates or metal carbonates of copper, iron, manganese, cobalt, chromium, nickel, zinc, calcium, silver, etc. can be cited. Among these black pigments, it is more preferable to use carbon black or titanium black having high light-shielding properties. As carbon black, known carbon blacks such as channel black, furnace black, thermal cracking carbon black, and lamp black can be used. In addition, in order to improve the dispersibility in the black composition, it is more preferable to use resin-coated carbon black. As the resin component, there can be listed polyimide resins such as epoxy resins, acrylic epoxy resins, acrylic resins, silicone polymer resins, polyimide resins, silicone-containing polyimide resins, polyimide silicone resins, and maleimide resins.

The black resist may be a positive photosensitive composition or a negative photosensitive composition. 　　When the black resist is a positive photosensitive composition, the black resist preferably contains an alkali-soluble resin, a photosensitive agent and a black pigment. 　　When the black resist is a negative photosensitive resin composition, the black resist preferably contains a photopolymerizable compound, a photopolymerization initiator and a black pigment.

<Step (B)> In step (B), a positive type resist composition having heat curing ability is applied on the aforementioned transparent substrate on which the aforementioned black resist has been patterned to form a resist film 3 (FIG. 1(d)). For example, the positive type resist composition having heat curing ability is applied by a rotator, a rotary coater, a roller coater, a spray coater, a slit coater, etc., and dried to form a resist film. As the above-mentioned drying method, for example, a method of drying at a temperature of 80 to 120°C for 120 to 500 seconds by a heating plate can be cited. There is no particular limitation on the film thickness of the above-mentioned resist film 3, but it is preferably 6μm~50μm, more preferably 6μm~20μm, and even more preferably 6μm~10μm.

(Positive type resist composition having thermal curing ability) As the positive type resist composition having thermal curing ability, there is no particular limitation, but for example, a positive type resist composition containing an alkali-soluble resin (A) and a photosensitive agent (B) can be cited.

[Alkali-soluble resin (A)] As the alkali-soluble resin, any resin having an alkali-soluble group that is soluble in an alkali can be used. As the alkali-soluble resin (A) (hereinafter, also described as "copolymer (A)"), for example, an acrylic resin can be suitably used. As the acrylic resin, it is preferred that it contains a constituent unit (A1) represented by the general formula (a-1) or a unit (A3) containing an alicyclic epoxy group.

[Constituent unit (A1)] 　　Constituent unit (A1) is represented by the following general formula (a-1).

[In the above general formula, R represents a hydrogen atom or an alkyl group having 1 to 5 carbon atoms, and Ra ⁰¹ represents a hydrogen atom or an organic group having a hydroxyl group].

In the general formula (a-1), R represents a hydrogen atom or an alkyl group having 1 to 5 carbon atoms. As the alkyl group having 1 to 5 carbon atoms, a linear or branched alkyl group having 1 to 5 carbon atoms is preferred, and specifically, methyl, ethyl, propyl, isopropyl, n-butyl, isobutyl, tert-butyl, pentyl, isopentyl, neopentyl, etc. can be listed. In the general formula (a-1), Ra ⁰¹ represents a hydrogen atom or an organic group having a hydroxyl group. Here, the organic group includes, for example, a branched, linear, or cyclic alkyl group, an aryl group which may have a substituent, a heteroaryl group which may have a substituent, an aralkyl group which may have a substituent, or a heteroaralkyl group which may have a substituent. Ra ⁰¹ has at least one hydroxyl group in its structure. The carbon number of the organic group is preferably 1 to 20, more preferably 6 to 12. A larger carbon number is better in terms of storage stability, while a smaller carbon number is better in terms of resolution.

In addition, when Ra ⁰¹ as the constituent unit (A1) is a hydrogen atom, that is, selecting methacrylic acid or acrylic acid is also effective in improving the alkali developability of the copolymer. However, from the perspective of storage stability, it is preferred to use the above-mentioned organic group having a hydroxyl group as the constituent unit (A1).

As a preferred example of the constituent unit (A1), there can be mentioned a constituent unit represented by the following general formula (a-1-1).

[In the above general formula, R represents a hydrogen atom or an alkyl group having 1 to 5 carbon atoms, Ya ⁰¹ represents a single bond or an alkylene group having 1 to 5 carbon atoms, Ra ⁰⁰¹ represents an alkyl group having 1 to 5 carbon atoms, a represents an integer of 1 to 5, b represents an integer of 0 or 1 to 4, and a+b is 5 or less. In addition, when Ra ⁰⁰¹ is 2 or more, these Ra ⁰⁰¹ may be different from each other or the same].

In the general formula (a-1-1), R represents a hydrogen atom or an alkyl group having 1 to 5 carbon atoms, which is the same as described above. In the general formula (a-1-1), R is preferably a methyl group. In addition, Ya ⁰¹ represents a single bond or a linear or branched alkylene group having 1 to 5 carbon atoms. Specifically, methylene, ethylene, propenyl, isopropenyl, n-butenyl, isobutenyl, tert-butenyl, pentenyl, isopentenyl, neopentenyl, etc. can be listed. Among them, a single bond, a methylene group, and an ethylene group are preferred. Ya ⁰¹ is preferably a single bond because it can improve the alkali solubility and further improve the heat resistance when used as an interlayer insulating film.

Here, a represents an integer of 1 to 5, but from the viewpoint of ease of production, a is preferably 1. Furthermore, the bonding position of the hydroxyl group on the benzene ring is preferably bonded to the 4th position, with the carbon atom bonded to Ya ⁰¹ as the reference (the 1st position).

Furthermore, Ra ⁰⁰¹ is a linear or branched alkyl group having 1 to 5 carbon atoms. Specifically, methyl, ethyl, propyl, isopropyl, n-butyl, isobutyl, tert-butyl, pentyl, isopentyl, neopentyl, etc. are exemplified. Among them, methyl or ethyl is preferred from the viewpoint of easy production. Here, b represents 0 or an integer of 1 to 4, but from the viewpoint of easy production, b is preferably 0.

More specifically, as the constituent unit (A1), there can be mentioned o-hydroxyphenyl (meth)acrylate, m-hydroxyphenyl (meth)acrylate, p-hydroxyphenyl (meth)acrylate, o-hydroxybenzyl (meth)acrylate, m-hydroxybenzyl (meth)acrylate, p-hydroxybenzyl (meth)acrylate, o-hydroxyphenylethyl (meth)acrylate, m-hydroxyphenylethyl (meth)acrylate, p-hydroxyphenylethyl (meth)acrylate, etc., preferably p-hydroxyphenyl (meth)acrylate or p-hydroxybenzyl (meth)acrylate, and particularly preferably p-hydroxyphenyl (meth)acrylate.

The content of the aforementioned constituent unit (A1) in the copolymer is preferably 10 to 70 mol %, more preferably 15 to 60 mol %, and most preferably 20 to 50 mol %.

[Units containing alicyclic epoxy groups (A3)] In addition, the units containing alicyclic epoxy groups (A3) are not particularly limited as long as they have an alicyclic epoxy group in their structure and are constituent units derived from a compound having an ethylenic double bond. The carbon number of the alicyclic group of the alicyclic epoxy group is preferably about 5 to 10.

Specific examples of the alicyclic epoxy group-containing unit (A3) include units derived from alicyclic epoxy group-containing polymerizable unsaturated compounds represented by the following general formulae (1) to (31).

In the formula, R ⁴ represents a hydrogen atom or a methyl group, R ⁵ represents a divalent alkyl group having 1 to 8 carbon atoms, R ⁶ represents a divalent alkyl group having 1 to 20 carbon atoms, R ⁴ , R ⁵ and R ⁶ may be the same or different, and w represents an integer of 0 to 10.

Among these, those represented by general formulas (1) to (6), (14), (16), (18), (21), (23) to (25), and (30) are preferred. More preferred are general formulas (1) to (6).

In the copolymer, the content of the alicyclic epoxy group-containing unit (A3) is preferably 5 to 40 mol%, more preferably 10 to 30 mol%, and most preferably 15 to 25 mol%.

[Constituent unit (A2)] In addition, the above-mentioned copolymer preferably has a constituent unit (A2) represented by the general formula (a-2).

[R represents a hydrogen atom or an alkyl group having 1 to 5 carbon atoms, and Rb represents a alkyl group].

In the aforementioned general formula (a-2), R represents a hydrogen atom or an alkyl group having 1 to 5 carbon atoms, which is the same as described above. As the alkyl group of Rb, for example, a branched, linear, or cyclic alkyl group, an aryl group which may have a substituent, or an aralkyl group which may have a substituent, can be listed. The carbon number of the aforementioned alkyl group is preferably 1 to 20. In addition, as a branched or linear alkyl group, a carbon number of 1 to 12 is preferred, and 1 to 6 is optimal. As a cyclic alkyl group, a carbon number of 6 to 20 is preferred, and 6 to 12 is optimal. As an aryl group which may have a substituent, or an aralkyl group which may have a substituent, a carbon number of 6 to 20 is preferred, and 6 to 12 is optimal.

Specific examples of the constituent unit (A2) include linear or branched alkyl acrylates such as methacrylate, ethyl acrylate, propyl acrylate, isopropyl acrylate, butyl acrylate, pentyl acrylate, ethylhexyl acrylate, octyl acrylate, t-octyl acrylate, etc.; alicyclic alkyl acrylates such as cyclohexyl acrylate, dicyclopentyl acrylate, 2-methylcyclohexyl acrylate, isoborneol acrylate, etc.; benzyl acrylate, aryl acrylate (e.g., phenyl acrylate), etc.

Alternatively, there can be listed those derived from linear or branched alkyl methacrylates such as methyl methacrylate, ethyl methacrylate, propyl methacrylate, isopropyl methacrylate, n-butyl methacrylate, sec-butyl methacrylate, t-butyl methacrylate, pentyl methacrylate, hexyl methacrylate, octyl methacrylate, etc.; alicyclic alkyl methacrylates such as cyclohexyl methacrylate, dicyclopentyl methacrylate, 2-methylcyclohexyl methacrylate, isoborneol methacrylate, etc.; benzyl methacrylate, aryl methacrylate (for example, phenyl methacrylate, toluene methacrylate, naphthyl methacrylate, etc.), etc.

By introducing the above-mentioned constituent unit (A2) into the copolymer, the dissolution rate of the copolymer can be adjusted. The constituent unit (A2) is preferably derived from a monomer having an alicyclic group.

In the copolymer (A), the content of the constituent unit (A2) is preferably 5 to 50 mol %.

[Constituent unit (A4)] In addition, within the scope not violating the purpose of the present invention, the above-mentioned copolymer (A) may contain a constituent unit (A4) other than the constituent units (A1) to (A3). There is no particular limitation if this constituent unit is a constituent unit derived from a compound having an ethylenic double bond. As such a constituent unit, for example, constituent units selected from acrylamides, methacrylamides, allyl compounds, vinyl ethers, vinyl esters, and styrenes can be cited.

Specific examples of the acrylamides include acrylamide, N-alkyl acrylamide (preferably the alkyl group has 1 to 10 carbon atoms, and examples thereof include methyl, ethyl, propyl, butyl, t-butyl, heptyl, octyl, cyclohexyl, hydroxyethyl, benzyl, etc.), N-aryl acrylamide (as the aryl group, examples include phenyl, tolyl, nitrophenyl, naphthyl, hydroxyphenyl, etc.), N,N-dialkyl acrylamide (preferably the alkyl group has 1 to 10 carbon atoms), N,N-aryl acrylamide (as the aryl group, examples include phenyl), N-methyl-N-phenyl acrylamide, N-hydroxyethyl-N-methyl acrylamide, and N-2-acetamidoethyl-N-acetyl acrylamide.

Specific examples of the methacrylamides include methacrylamide, N-alkyl methacrylamide (the alkyl group is preferably a group having 1 to 10 carbon atoms, such as methyl, ethyl, t-butyl, ethylhexyl, hydroxyethyl, and cyclohexyl), N-aryl methacrylamide (the aryl group is phenyl), N,N-dialkyl methacrylamide (the alkyl group is ethyl, propyl, and butyl), N,N-diaryl methacrylamide (the aryl group is phenyl), N-hydroxyethyl-N-methyl methacrylamide, N-methyl-N-phenyl methacrylamide, and N-ethyl-N-phenyl methacrylamide.

Specific examples of the allyl compound include allyl esters (e.g., allyl acetate, allyl caproate, allyl octanoate, allyl laurate, allyl laurate, allyl stearate, allyl benzoate, allyl acetoacetate, allyl lactate, etc.), allyl hydroxyethyl ether, and the like.

Specific examples of the vinyl ethers include alkyl vinyl ethers (e.g., hexyl vinyl ether, octyl vinyl ether, decyl vinyl ether, ethylhexyl vinyl ether, methoxyethyl vinyl ether, ethoxyethyl vinyl ether, chloroethyl vinyl ether, 1-methyl-2,2-dimethylpropyl vinyl ether, 2-ethylbutyl vinyl ether, hydroxyethyl vinyl ether, diethylene glycol vinyl ether, dimethylaminoethyl vinyl ether, diethylaminoethyl vinyl ether, butylaminoethyl vinyl ether, benzyl vinyl ether, tetrahydrofurfuryl vinyl ether, etc.), and vinyl aryl ethers (e.g., vinyl phenyl ether, vinyl toluene ether, vinyl chlorophenyl ether, vinyl-2,4-dichlorophenyl ether, vinyl naphthyl ether, vinyl anthracenyl ether, etc.).

Specific examples of the vinyl esters include vinyl butyrate, vinyl isobutyrate, vinyl pivalate, vinyl diethyl acetate, vinyl valerate, vinyl hexanoate, vinyl chloroacetate, vinyl dichloroacetate, vinyl methoxyacetate, vinyl butoxyacetate, vinyl phenylacetate, vinyl acetic acid ester, vinyl lactate, vinyl-β-phenylbutyrate, vinyl benzoate, vinyl salicylate, vinyl chlorobenzoate, vinyl tetrachlorobenzoate, and vinyl naphthoate.

Specific examples of styrenes include styrene, alkyl styrenes (e.g., methyl styrene, dimethyl styrene, trimethyl styrene, ethyl styrene, diethyl styrene, isopropyl styrene, butyl styrene, hexyl styrene, cyclohexyl styrene, decyl styrene, benzyl styrene, chloromethyl styrene, trifluoromethyl styrene, ethoxymethyl styrene, acetyloxymethyl styrene, etc.), alkoxy styrenes (e.g., methoxy styrene, 4-methoxy-3-methyl styrene, dimethoxy styrene, etc.), halogen styrenes (e.g., chloro styrene, dichloro styrene, trichloro styrene, tetrachloro styrene, pentachloro styrene, bromostyrene, dibromostyrene, iodo styrene, fluoro styrene, trifluoro styrene, 2-bromo-4-trifluoromethyl styrene, 4-fluoro-3-trifluoromethyl styrene, etc.), and acrylonitrile, methacrylonitrile, etc.

In the present embodiment, the copolymer (A) is preferably composed of the aforementioned constituent units (A1), (A2) and (A3). The mass average molecular weight (Mw: measured value converted to polystyrene by gel permeation chromatography (GPC)) of the above copolymer (A) is preferably 2000~50000, more preferably 5000~30000. By setting the molecular weight to 2000 or more, a film can be easily formed. In addition, by setting the molecular weight to 50000 or less, appropriate alkali solubility can be obtained.

The above copolymer can be produced by known free radical polymerization, that is, by dissolving a polymerizable monomer from which the above-mentioned constituent units (A1) to (A3) and a known free radical polymerization initiator in a polymerization solvent, followed by heating and stirring.

In addition, the alkali-soluble resin (A) may contain one or more other copolymers in addition to the copolymers containing the above-mentioned constituent units (A1) to (A3). The amount of the copolymer is preferably 0 to 50 parts by mass, more preferably 0 to 30 parts by mass, relative to 100 parts by mass of the above-mentioned copolymer (A). The mass average molecular weight (Mw: measured value converted to polystyrene by gel permeation chromatography (GPC)) of the copolymer is preferably 2,000 to 50,000, more preferably 5,000 to 30,000.

[Photosensitive agent (B)] The photosensitive agent (B) of this embodiment is not particularly limited as long as it is a compound that can be used as a photosensitive component. However, a preferred example is a compound containing a quinonediazide group.

Specific examples of the quinonediazide group-containing compound include complete or partial esterification products of a phenol compound (also referred to as a phenolic hydroxyl group-containing compound) and a naphthoquinonediazide sulfonic acid compound.

Specific examples of the phenolic compounds include polyhydroxybenzophenones such as 2,3,4-trihydroxybenzophenone and 2,3,4,4′-tetrahydroxybenzophenone; tris(4-hydroxyphenyl)methane, bis(4-hydroxy-3-methylphenyl)-2-hydroxyphenylmethane, bis(4-hydroxy-2,3,5-trimethylphenyl)-2-hydroxyphenylmethane, bis(4-hydroxy-3,5-dimethylphenyl)-4 -Hydroxyphenylmethane, bis(4-hydroxy-3,5-dimethylphenyl)-3-hydroxyphenylmethane, bis(4-hydroxy-3,5-dimethylphenyl)-2-hydroxyphenylmethane, bis(4-hydroxy-2,5-dimethylphenyl)-4-hydroxyphenylmethane, bis(4-hydroxy-2,5-dimethylphenyl)-3-hydroxyphenylmethane, bis(4-hydroxy-2,5-dimethylphenyl)-2-hydroxyphenylmethane , bis(4-hydroxy-3,5-dimethylphenyl)-3,4-dihydroxyphenylmethane, bis(4-hydroxy-2,5-dimethylphenyl)-3,4-dihydroxyphenylmethane, bis(4-hydroxy-2,5-dimethylphenyl)-2,4-dihydroxyphenylmethane, bis(4-hydroxyphenyl)-3-methoxy-4-hydroxyphenylmethane, bis(5-cyclohexyl-4-hydroxy-2-methylphenyl)-4-hydroxybenzene triphenol type compounds such as bis(5-cyclohexyl-4-hydroxy-2-methylphenyl)-3-hydroxyphenylmethane, bis(5-cyclohexyl-4-hydroxy-2-methylphenyl)-2-hydroxyphenylmethane, bis(5-cyclohexyl-4-hydroxy-2-methylphenyl)-3,4-dihydroxyphenylmethane, and 4,4'-[(3,4-dihydroxyphenyl)methylene]bis(2-cyclohexyl-5-methylphenol);

Linear trinuclear phenolic compounds such as 2,4-bis(3,5-dimethyl-4-hydroxybenzyl)-5-hydroxyphenol and 2,6-bis(2,5-dimethyl-4-hydroxybenzyl)-4-methylphenol; 1,1-bis[3-(2-hydroxy-5-methylbenzyl)-4-hydroxy-5-cyclohexylphenyl]isopropane, bis[2,5-dimethyl-3-(4-hydroxy-5-methylbenzyl)-4-hydroxyphenyl]methane, bis[2,5-dimethyl bis[3-(3,5-dimethyl-4-hydroxybenzyl)-4-hydroxy-5-methylphenyl]methane, bis[3-(3,5-dimethyl-4-hydroxybenzyl)-4-hydroxy-5-ethylphenyl]methane, bis[3-(3,5-diethyl-4-hydroxybenzyl)-4-hydroxy-5-methylphenyl]methane, bis[3-(3,5-diethyl-4-hydroxybenzyl)-4-hydroxy-5-methylphenyl]methane, bis[3-(3,5-diethyl-4-hydroxybenzyl)-4-hydroxy-5-methylphenyl]methane, -4-hydroxy-5-ethylphenyl]methane, bis[2-hydroxy-3-(3,5-dimethyl-4-hydroxybenzyl)-5-methylphenyl]methane, bis[2-hydroxy-3-(2-hydroxy-5-methylbenzyl)-5-methylphenyl]methane, bis[4-hydroxy-3-(2-hydroxy-5-methylbenzyl)-5-methylphenyl]methane, bis[2,5-dimethyl-3-(2-hydroxy-5-methylbenzyl)-4-hydroxyphenyl]methane ]methane and the like; linear tetranuclear phenol compounds such as 2,4-bis[2-hydroxy-3-(4-hydroxybenzyl)-5-methylbenzyl]-6-cyclohexylphenol, 2,4-bis[4-hydroxy-3-(4-hydroxybenzyl)-5-methylbenzyl]-6-cyclohexylphenol, 2,6-bis[2,5-dimethyl-3-(2-hydroxy-5-methylbenzyl)-4-hydroxybenzyl]-4-methylphenol and the like linear pentanuclear phenol compounds and the like linear polyphenol compounds;

Bis(2,3,-trihydroxyphenyl)methane, Bis(2,4-dihydroxyphenyl)methane, 2,3,4-trihydroxyphenyl-4′-hydroxyphenylmethane, 2-(2,3,4-trihydroxyphenyl)-2-(2′,3′,4′-trihydroxyphenyl)propane, 2-(2,4-dihydroxyphenyl)-2-(2′,4′-dihydroxyphenyl)propane, 2-(4-hydroxyphenyl)-2-(4′-hydroxyphenyl)propane, 2-(3-fluoro-4-hydroxyphenyl)-2-(3′-fluoro-4′-hydroxyphenyl)propane, 2-(2,4-dihydroxyphenyl)-2-(4′-hydroxyphenyl) Bisphenol compounds such as propane, 2-(2,3,4-trihydroxyphenyl)-2-(4′-hydroxyphenyl)propane, and 2-(2,3,4-trihydroxyphenyl)-2-(4′-hydroxy-3′,5′-dimethylphenyl)propane; polynuclear branched compounds such as 1-[1-(4-hydroxyphenyl)isopropyl]-4-[1,1-bis(4-hydroxyphenyl)ethyl]benzene and 1-[1-(3-methyl-4-hydroxyphenyl)isopropyl]-4-[1,1-bis(3-methyl-4-hydroxyphenyl)ethyl]benzene; condensed phenol compounds such as 1,1-bis(4-hydroxyphenyl)cyclohexane, etc. These compounds may be used alone or in combination of two or more.

Examples of the naphthoquinonediazidesulfonic acid compound include naphthoquinone-1,2-diazide-5-sulfonic acid and naphthoquinone-1,2-diazide-4-sulfonic acid.

Other compounds containing quinone diazide groups include core-substituted derivatives of o-benzoquinone diazide, o-naphthoquinone diazide, o-anthraquinone diazide or o-naphthoquinone diazide sulfonates. Furthermore, products of the reaction of o-quinone diazide sulfonyl chloride with compounds having hydroxyl or amino groups (e.g., phenol, p-methoxyphenol, dimethylphenol, hydroquinone, bisphenol A, naphthol, pyrocatechol, pyrogallol, pyrogallol monomethyl ether, pyrogallol-1,3-dimethyl ether, gallic acid, gallic acid esterified or etherified with a portion of hydroxyl groups remaining, aniline, p-aminodiphenylamine, etc.) can also be used. These can also be used alone or in combination of two or more.

Such quinonediazolyl-containing compounds can be prepared, for example, by condensing a triphenol-type compound with naphthoquinone-1,2-diazolyl-5-sulfonyl chloride or naphthoquinone-1,2-diazolyl-4-sulfonyl chloride in a suitable solvent such as dioxane in the presence of a base such as triethanolamine, alkali carbonate, or bicarbonate, to produce the compound by complete or partial esterification.

Furthermore, as the above-mentioned component (B), it is preferred to use a non-benzophenone-based quinone diazide group-containing compound, and it is preferred to use a multi-nuclear branched compound. Moreover, the gram absorption coefficient of the phenolic hydroxyl group-containing compound at a wavelength of 350nm is preferably 1 or less. Thereby, a higher sensitivity can be obtained in the photosensitive resin composition.

As such component (B), a compound containing a quinone diazide group is preferred, and naphthoquinone diazide sulfonate is particularly preferred. Among them, naphthoquinone diazide sulfonate of 4,4'-[(3,4-dihydroxyphenyl)methylene]bis(2-cyclohexyl-5-methylphenol), 1-[1-(4-hydroxyphenyl)isopropyl]-4-[1,1-bis(4-hydroxyphenyl)ethyl]benzene and the like can be suitably used.

The content of component (B) is preferably 10-40% by mass, more preferably 15-30% by mass, relative to the total solid content. By making the content of component (B) 10% by mass or more, the resolution can be improved. In addition, the film of the pattern after pattern formation can be reduced. In addition, by making the content of component (B) 40% by mass or less, appropriate sensitivity or transmittance can be given.

[Organic solvent (S)] The positive resist composition of this embodiment preferably contains an organic solvent (S) in order to improve coating properties and adjust viscosity.

As the (S) component, there can be listed benzene, toluene, xylene, methyl ethyl ketone, acetone, methyl isobutyl ketone, cyclohexanone, methanol, ethanol, propanol, butanol, hexanol, cyclohexanol, ethylene glycol, diethylene glycol, glycerol, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, propylene glycol methyl ether (PGME), propylene glycol monoethyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, 3-methoxybutyl acetate (MA), 3-methoxybutanol (BM), 3-methyl-3-methoxybutyl acetate, propylene glycol methyl ether acetate (PGMEA), propylene glycol methyl ether propionate, propylene glycol monoethyl ether propionate, methyl carbonate, ethyl carbonate, propyl carbonate, butyl carbonate, or a mixture thereof. Among them, PGME, PGMEA, MA, a mixed solvent of PGME and PGMEA, a mixed solvent of MA and BM, etc. are preferably used.

The amount of the organic solvent (S) used is not particularly limited, but the concentration that can be applied to the substrate, etc., can be appropriately selected and set according to the coating thickness. Specifically, the solid content concentration of the photosensitive resin composition is 10-50 mass%, and preferably in the range of 15-35 mass%.

[Optional component] (black pigment) 　　In this embodiment, the positive resist composition preferably contains a black pigment in order to improve the light absorption of the partition wall. 　　As the black pigment, the same black pigment as the above-mentioned black resist can be cited. 　　When using the black pigment, the content of the black pigment is preferably 1% to 10% relative to the non-volatile component. 　　By having the content of the black pigment within the above-mentioned range, the light absorption of the partition wall can be sufficiently improved.

(Yellow pigment) 　　In this embodiment, the positive resist composition may also contain a yellow pigment in order to prevent the decrease in color purity caused by the mixing of sub-pixels other than blue (B). 　　As yellow pigments, there can be listed C.I. Pigment Yellow 1 (hereinafter, all are the same as "C.I. Pigment Yellow", so only the number is recorded), 3, 11, 12, 13, 14, 15, 16, 17, 20, 24, 31, 53, 55, 60, 61, 65, 71, 73, 74, 81, 83, 86, 93, 95, 97, 98, 99, 100, 101, 1 04, 106, 108, 109, 110, 113, 114, 116, 117, 119, 120, 125, 126, 127, 128, 129, 137, 138, 139, 147, 148, 150, 151, 152, 153, 154, 155, 156, 166, 167, 168, 175, 180, 185, etc. 　　When yellow pigment is used, the content of yellow pigment is preferably 1% to 10% relative to the non-volatile component. 　　By making the content of yellow pigment within the above range, the reduction of color purity caused by mixing of sub-pixels other than blue (B) can be fully prevented.

(Inorganic Particles) In the present embodiment, the positive resist composition may contain inorganic particles in order to impart light scattering properties to the partition walls. Examples of the inorganic particles include glass, ceramics (coriolis, etc.), and metals. Specifically, glass powders such as lead borosilicate glass _, zinc borosilicate _{glass ,} and bismuth borosilicate glass of the PbO- _SiO2 series, _PbO - _B2O3 - _SiO2 series, ZnO- _SiO2 series, ZnO-B2O3- _SiO2 series, _BiO -SiO2 series, and BiO- _B2O3 - _SiO2 series, or oxides of Na, K, Mg, Ca, Ba, Ti, Zr, and Al such as cobalt oxide, iron oxide, chromium oxide, nickel oxide, copper oxide, manganese oxide, neodymium oxide, vanadium oxide, tipaque yellow, cadmium oxide, ruthenium oxide, silicon dioxide, magnesium oxide, and spinel, ZnO: Zn, _Zn3 ( _PO4 ) ₂ : Mn, _{Y2 19} ：Mn、CaAl 12 O _{19 ：Mn、YBO 3 ：Tb、BaMgAl 14 O 23 ： Mn 、 LuBO 3 ： Tb} 、GdBO _： Tb、ScBO ₃ ：Tb、Sr6 Si ₃ O _{3 Cl 4 ：} Mn、BaAl ₁₂ O ₁₉ ： _Mn 、SrAl ₁₃ O ₁₉ ： _{Mn、YBO 3 ：Tb、BaMgAl 14 O 23 ： Mn 、 LuBO 3 ：} Tb、GdBO _： Tb、ScBO _{3 ：} Tb、Sr6 Si ₃ O ₃ Cl ₄ ：Eu, ZnS：(Cu, Al), ZnS：Ag, Y ₂ O ₂ S：Eu, ZnS：Zn, (Y, Cd)BO ₃ ：Eu, BaMgAl ₁₂ O ₂₃ ：Eu and other fluorescent powders, metal powders such as iron, nickel, palladium, tungsten, copper, aluminum, silver, gold, platinum and the like. Among them, silicon dioxide and titanium dioxide (TiO ₂ ) are preferred. The average particle size of the inorganic particles is preferably 0.1μm~1μm, more preferably 0.2~0.5μm. When the average particle size of the inorganic particles is within the above range, sufficient light scattering can be given to the partition wall. When inorganic particles are used, the content of the inorganic particles is preferably 2-20% by weight, more preferably 5-10% by weight, relative to 100 parts by weight of the alkali-soluble resin (A). When the content of the inorganic particles is within the above range, sufficient light scattering properties can be imparted to the partition wall while maintaining the lithography performance.

[Urethane oligomer (U)] In the present embodiment, the positive type resist composition may contain a urethane oligomer (U) having two or more polymerizable functional groups. As the urethane oligomer (U), it is preferably a (meth)acrylate compound having a urethane bond, and more preferably a urethane (meth)acrylate having a functional group number of 3 or more. The so-called urethane (meth)acrylate having a functional group number of 3 or more refers to a urethane (meth)acrylate having a urethane bond (-NH-CO-O-) and three or more (meth)acryloyloxy groups in the molecule. The functional group number of the urethane (meth)acrylate is preferably 3 or more, more preferably 3 to 10, still more preferably 3 to 5, particularly preferably 3 or 4, and most preferably 3 (i.e., a urethane (meth)acrylate having a functional group number of 3). When using the urethane oligomer (U), the content of the urethane oligomer (U) is relative to 100 mass % of the alkali-soluble resin (A), preferably 5 mass % or more, more preferably 10-60 mass %, and even more preferably 20-50 mass %. [(F) component] In the present embodiment, in order to give the resist film water-repellent property, the positive resist composition may contain a fluorine additive (hereinafter also referred to as "(F) component"). If the resist film has water-repellent property, it can prevent the ink from mixing into other sub-pixels when forming a color filter by inkjet method. As the (F) component, for example, fluorine-containing polymer compounds described in Japanese Patent Publication No. 2010-002870, Japanese Patent Publication No. 2010-032994, Japanese Patent Publication No. 2010-277043, Japanese Patent Publication No. 2011-13569, and Japanese Patent Publication No. 2011-128226 can be used.

In addition, as other optional components of the positive resist composition of this embodiment, various additives such as reaction accelerators, silane coupling agents, surfactants, thermal acid generators, bridgers, sensitizers, and defoaming agents can be listed.

<Step (C)> In step (C), the resist film 3 is exposed from the transparent substrate 1 side (FIG. 1(e)). By exposing from the transparent substrate 1 side, the black matrix 2a acts as a mask, and only the area between the resist film 3 and the transparent substrate 1 where the black matrix 2a is not formed is exposed, so that the alkali-soluble area 3a can be formed. The exposure is performed, for example, by irradiating the resist film 3 with active energy rays such as ultraviolet rays, excimer laser light, etc. from the transparent substrate 1 side. As the light source of the active energy ray, there can be listed, for example, low-pressure mercury lamp, high-pressure mercury lamp, ultra-high-pressure mercury lamp, chemical lamp, excimer laser generator, UV laser with triple YAG and double semiconductor laser wave, etc. Although the amount of energy ray irradiated varies depending on the composition of the positive resist composition, it can be, for example, 30 to 2000 mJ/ ^cm2 .

<Step (D)> In step (D), the above-mentioned exposed resist film 3 is developed to form a resist pattern. By developing, the alkali-soluble area 3a is removed, and a resist pattern 3b (partition wall pattern 3b) is formed on the black matrix 2a. As the developer used in the alkali development, there can be listed organic alkali aqueous solutions such as tetramethylammonium hydroxide (TMAH) aqueous solution, or inorganic alkali aqueous solutions such as sodium hydroxide, potassium hydroxide, sodium metasilicate, sodium phosphate, etc.

＜Optional Step＞ ＜Step (E)＞ 　　The method for forming a pattern for partitions in this embodiment may further include a step (E) of thermally curing the aforementioned resist pattern 3b. 　　The heating of the aforementioned resist pattern is performed, for example, at a temperature condition below 300°C, preferably at 90~250°C. In this embodiment, it is easy to cure at a lower temperature condition, preferably at a temperature below 220°C. 　　From the viewpoint of maintaining the verticality of the resist pattern, the thermal curing of step (E) is preferably performed in two or more stages. When thermal curing is performed in two or more stages, it is preferably to increase the thermal curing temperature in each stage. For example, after heating at 90~150℃ for 20~40 minutes, you can heat at 180~300℃ for 50~70 minutes.

<Step (C1)> The method for forming a pattern for partitions in this embodiment may include a step (C1) of performing a heat treatment (post-exposure heat treatment) between step (C) and step (D) as needed.

In the present embodiment, a positive resist composition having heat curing ability is coated on the black matrix pattern and exposed from the transparent substrate side. Therefore, the black matrix pattern acts as a mask, and a resist pattern (partition wall) with good alignment accuracy with the black matrix pattern can be formed. 　　Furthermore, the method for forming a partition wall pattern of the present embodiment is particularly useful for forming a partition wall pattern of a display element embedded with a quantum dot phosphor. 　　When using a quantum dot phosphor, dissolution resistance to organic liquids is required. In the present embodiment, since a positive resist composition having heat curing ability is used, the partition wall pattern formed has excellent dissolution resistance to organic liquids. 　　Furthermore, according to the present embodiment, a partition wall pattern with a shape with high perpendicularity to the transparent substrate can be formed. [Example]

The present invention is further described in detail below through examples, but the present invention is not limited to these examples.

(Example 1) <Adjustment of the inhibitor> 　　40 parts by weight of 4-hydroxyphenyl methacrylate, 40 parts by weight of methyl methacrylate and 20 parts by weight of 3,4-epoxyhexylmethyl methacrylate are mixed and free radical polymerization is carried out in an organic solvent (PGMEA) to obtain polymer A. 　　Resistant A is obtained by adding 200 parts by weight of PGMEA and PGME as a solvent to 75 parts by weight of the solid component of the polymer solution obtained above and 25 parts by weight of the product (esterification rate 80%) obtained by reacting naphthoquinone diazide-5-sulfonic acid ester in 4,4'-[(3,4-dihydroxyphenyl)methylene]bis(2-cyclohexyl-5-methylphenol) and 200 parts by weight of PGMEA and PGME in a ratio of PGMEA/PGME=60/40 to obtain 25 parts by weight of the product (esterification rate 80%).

<Formation of Pattern> A black resist (product name: CFPR BK-461; manufactured by Tokyo Ohka Industry) was applied to a glass substrate by spin coating to a film thickness of 2.0 μm, and then baked at 100°C for 2 minutes. The substrate was exposed to light of 150 mJ/ ^cm2 from an ultra-high pressure mercury lamp through a photomask, developed with a 0.04% KOH aqueous solution, washed with water, and thermally cured to obtain a substrate having a light shielding layer (black matrix pattern) formed using black photoresist. Resist A was applied to the surface on which this light shielding layer was formed by spin coating to a thickness of 10 μm, and ultraviolet light obtained from a high pressure mercury lamp was irradiated from the substrate surface at 1000 mJ/ ^cm2 . After that, the substrate was developed twice for 1 minute using a 2.38% TMAH aqueous solution, and then thermally cured by three-stage baking using a hot plate at (1) 100°C for 30 minutes, (2) 120°C for 30 minutes, and (3) 200°C for 60 minutes. As a result, the resist A was resolved to a pattern size of 5 μm in a highly vertical shape. In addition, the resist pattern was formed with good alignment accuracy with the black matrix pattern. The patterned substrate was immersed in PGMEA for 1 minute, but no change in the resist shape was observed.

(Example 2) <Adjustment of Resistors> In the Resistors A prepared in Example 1, 100 parts by weight of the non-volatile components of Resistors A, 100 parts by weight of silica particles (particle size 300 nm), and 100 parts by weight of PGME were mixed, and the mixture was stirred with a planetary stirrer to obtain Resistors B.

<Formation of Pattern> Resist B was applied on the substrate patterned with the same black resist as in Example 1, and exposure, development, and thermal curing were performed at 700 mJ/ ^cm2 . As a result, resist B was resolved to a minimum size of 8 μm. In addition, the resist pattern was formed with good alignment accuracy with the black matrix pattern.

(Comparative Example 1) A positive type resist (product name: PMER P-7130; manufactured by Tokyo Ohka Co., Ltd.) was applied by spin coating to a thickness of 2.0 μm on a substrate patterned with the same black resist as in Example 1, and ultraviolet light obtained by a high-pressure mercury lamp was irradiated from the substrate surface at 300 mJ/ ^cm2 , and developed by TMAH 2.38% aqueous solution. After the patterned substrate was immersed in PGMEA for 1 minute, the resist was completely peeled off.

(Comparative Example 2) A high-concentration product (solid content concentration of 35%) of a positive resist (product name: PMER P-7130; manufactured by Tokyo Ohka Industry) was applied to a substrate having a patterned black resist as in Example 1 by spin coating with a thickness of 10 μm, and irradiated with ultraviolet light obtained from a high-pressure mercury lamp from the side of the substrate at 1000 mJ/ ^cm2 , and developed with a 2.38% TMAH aqueous solution. Then, three-stage baking was performed on a hot plate at (1) 100°C for 30 minutes, (2) 120°C for 30 minutes, and (3) 200°C for 60 minutes as thermal curing. As a result, the resist shape became a lens shape with a strong cone angle from the substrate interface. Furthermore, when the patterned substrate was immersed in PGMEA for 1 minute, it was confirmed that the resist film thickness was reduced.

(Comparative Example 3) Resist B prepared in Example 2 is applied on a substrate patterned with the same black resist as in Example 1. Resist B is a mask patterned with a black resist, and is exposed from the side of Resist B (opposite to the substrate surface) at 700 mJ/ ^cm2 , and developed for 1 minute using a 2.38% TMAH aqueous solution. Thereafter, development and thermal curing are performed in the same manner as in Example 1. As a result, the largest pattern of 100 μm in size in the mask cannot be resolved. When Resist B is exposed again, although an attempt is made to align the underlying black resist pattern and mask, since Resist B is a strong white, it is difficult to align the position with the black resist pattern and mask.

1‧‧‧Transparent substrate 2‧‧‧Coating film 2a‧‧‧Black matrix 3‧‧‧Resist film 3a‧‧‧Alkali-soluble area 3b‧‧‧Resist pattern (partition wall pattern)

FIG. 1 is a schematic diagram showing a step-by-step process for explaining one embodiment of a method for forming a partition wall pattern.

Claims (5)

A method for forming a partition wall pattern is a method for forming a partition wall pattern of a display element in which a color light emitting body is embedded in at least a portion of a sub-pixel, comprising the steps of patterning a black resist on a transparent substrate (A), applying a positive type resist composition having heat curing ability on the transparent substrate on which the black resist is patterned to form a resist film (B), and using the black resist as a mask, only the resist film is separated from the transparent substrate on the opposite side of the transparent substrate on which the black resist pattern is formed. The method further comprises the steps of: exposing the region between the transparent substrates where the black matrix is not formed to light; and developing the exposed resist film and removing the exposed portion of the resist film to form a resist pattern on the black matrix; wherein the positive resist composition comprises an alkali-soluble resin (A) and a photosensitive agent (B); the alkali-soluble resin (A) comprises at least one selected from the group consisting of a constituent unit (A1) represented by the following general formula (a-1) and a unit (A3) containing an alicyclic epoxy group.

[In the above general formula, R represents a hydrogen atom or an alkyl group having 1 to 5 carbon atoms, and Ra ⁰¹ represents a hydrogen atom or an organic group having a hydroxyl group]. The method for forming a pattern for a partition wall as described in claim 1 further comprises a step (E) of thermally curing the aforementioned resist pattern. The method for forming a pattern for a partition wall as described in claim 1, wherein the color-differentiated light-emitting body is a quantum dot phosphor. A method for forming a pattern for a partition wall as described in claim 1, wherein the film thickness of the resist film is greater than 6 μm. A method for forming a pattern for a partition wall as described in any one of claim 1 to claim 4, wherein the positive type resist composition further contains inorganic particles with an average particle size of 0.1 to 1 μm.