Photosensitive composition, method for manufacturing substrate, and display device

Abstract

This photosensitive composition contains a polymerizable monomer (A), a photopolymerization initiator (B), a black pigment (C), and a compound (D) having a phosphate ester group. The concentration of the phosphate ester group in the total nonvolatile components of the photosensitive composition is 0.067–0.130 mmol / g.

Description

Photosensitive composition, method for manufacturing substrate, and display device

[0001] The present invention relates to a photosensitive composition, a method for manufacturing a substrate, and a display device. More specifically, the present invention relates to a photosensitive composition containing a black pigment, a method for manufacturing a substrate on which a cured pattern formed by the photosensitive composition is formed, and a display device having a pattern formed using the photosensitive composition.

[0002] Various studies have been conducted on photosensitive compositions capable of forming black patterns by photolithography. Photosensitive compositions containing black pigments are used, for example, to form black matrices in display devices and partition walls in light-emitting devices.

[0003] Patent Document 1 describes a method for producing a substrate with black resin partition walls, which has a substrate and black resin partition walls formed on the substrate and having an inverted tapered shape. This method includes a coating step of coating a black photosensitive resin composition onto the substrate to form a black photosensitive resin layer on the substrate having an OD value of 0.3 to 3.5, an exposure step of exposing the black photosensitive resin layer to actinic light, and a development step of developing and removing uncured portions of the black photosensitive resin layer for a development time 1.1 to 10 times the minimum development time.

[0004] Patent Document 2 describes a composition for forming partition walls, which contains a black pigment, an alkali-soluble resin, and a solvent, and in which the content of the black pigment is 0.1% by mass or more and 5.0% by mass or less with respect to all components excluding the solvent. According to the description in Patent Document 2, this composition for forming partition walls is used for producing a laminate for a display device, which includes a substrate, partition walls that divide one surface of the substrate into a plurality of regions, and a wavelength conversion layer provided in at least one of the plurality of regions, and in which the partition walls have a height of 5 to 30 μm and an optical density per μm of partition wall height of 0.2 to 0.7.

[0005] Patent Document 3 describes a photosensitive resin composition comprising at least titanium black, a photopolymerizable compound, resin A having an acid value of 70 mgKOH / g or more and 250 mgKOH / g or less, resin B having an acid value of 26 mgKOH / g or more and 65 mgKOH / g or less, a photopolymerization initiator, and a solvent.

[0006] It is also conceivable to form a privacy filter (a filter for preventing peeping of a display) using a photosensitive composition. A typical structure of a privacy filter is one in which a long, thin, plate-like black pattern (sometimes called a louver) is formed on a transparent optical film or a backlight. This black pattern makes it difficult to see the light from the display when viewed from an angle. In other words, it makes it difficult to peepe. Patent Document 4 describes a display device in which a privacy filter is incorporated.

[0007] JP 2010-237327 A JP 2019-179111 A JP 2009-244692 A U.S. Pat. No. 1,287,688

[0008] It may be more difficult to form a desired pattern using a photosensitive composition containing a black pigment by a photolithography process than using a photosensitive composition not containing a black pigment. For example, when forming a black pattern using a photosensitive composition containing a black pigment, the adhesion of the black pattern to the substrate may become a problem. For another example, when forming a black pattern using a photosensitive composition containing a black pigment, the cross-sectional shape of the pattern tends to be inversely tapered, making it difficult to obtain a pattern with good rectangularity. One of the causes of these problems is thought to be that during exposure in photolithography, the amount of light reaching the bottom of the black pattern is reduced due to the black pigment, which tends to result in insufficient photocuring reaction.

[0009] In view of the above circumstances, the present inventors have carried out investigations with the aim of providing a photosensitive composition that has good adhesion to a substrate and is capable of forming a black pattern with good rectangularity.

[0010] The present inventors have solved the above problems by newly producing the following photosensitive composition and the like.

[0011] 1. A photosensitive composition comprising a polymerizable monomer (A), a photopolymerization initiator (B), a black pigment (C), and a compound (D) having a phosphate ester group, wherein the concentration of the phosphate ester group in all non-volatile components of the photosensitive composition is 0.067 to 0.130 mmol / g. 2. The photosensitive composition according to 1., wherein the proportion of the compound (D) in all non-volatile components of the photosensitive composition is 2 to 10 mass %. 3. The photosensitive composition according to 1. or 2., wherein the compound (D) has a polymerizable group. 4. The photosensitive composition according to any one of 1. to 3., wherein the polymerizable monomer (A) comprises a compound having an ethylenic carbon-carbon double bond, and the photopolymerization initiator (B) comprises a photoradical polymerization initiator. 5. The photosensitive composition according to 1. to 4. 5. The photosensitive composition according to any one of 1. to 5., wherein the black coloring matter (C) comprises a pigment. 6. The photosensitive composition according to any one of 1. to 5., further comprising an alkali-soluble resin. 7. The photosensitive composition according to any one of 1. to 6., further comprising a chain transfer agent. 8. The photosensitive composition according to any one of 1. to 7., wherein the photosensitive composition is used for forming a black pattern having a height of 5 to 30 μm and an aspect ratio of 1 to 3. 9. The photosensitive composition according to 8., wherein the optical density of the black pattern is 0.5 to 7.0. 10. A photosensitive composition according to 1. to 9., wherein a photosensitive composition according to any one of 1. to 9. is formed on a substrate. 11. A method for manufacturing a substrate on which a black cured pattern is formed, the method comprising: a film-forming step of applying the photosensitive composition according to any one of items 1 to 9 to form a film; an exposure step of patternwise exposing the film; a development step of developing the exposed film; and a curing step of heating the developed film to obtain a black cured pattern. 12. A display device comprising a black cured pattern formed using the photosensitive composition according to any one of items 1 to 9.

[0012] By using the above photosensitive composition, it is possible to form a black pattern that has good adhesion to the substrate and good rectangularity.

[0013] FIG. 1 is a supplementary diagram for explaining a method for evaluating the rectangularity of black cured patterns obtained in Examples.

[0014] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. The drawings are for illustrative purposes only, and the present invention should not be interpreted as being limited by the drawings.

[0015] In this specification, the expression "X to Y" in the description of a numerical range means at least X and at most Y, unless otherwise specified. For example, "1 to 5 mass %" means "at least 1 mass % and at most 5 mass %." In this specification, "total non-volatile components" means all components other than the solvent in the photosensitive composition, unless otherwise specified.

[0016] In the description of groups (atomic groups) in this specification, when a notation does not specify whether the group is substituted or unsubstituted, it encompasses both those that have no substituents and those that have a substituent. For example, the term "alkyl group" encompasses not only alkyl groups that have no substituents (unsubstituted alkyl groups) but also alkyl groups that have a substituent (substituted alkyl groups). The term "(meth)acrylic" in this specification represents a concept that encompasses both acrylic and methacrylic. The same applies to similar notations such as "(meth)acrylate." In this specification, the term "organic group" refers to an atomic group obtained by removing one or more hydrogen atoms from an organic compound, unless otherwise specified. For example, a "monovalent organic group" refers to an atomic group obtained by removing one hydrogen atom from any organic compound.

[0017] <Photosensitive Composition> The photosensitive composition of this embodiment contains a polymerizable monomer (A), a photopolymerization initiator (B), a black pigment (C), and a compound (D) having a phosphate ester group. The concentration of the phosphate ester group in the total nonvolatile components of the photosensitive composition is 0.067 to 0.130 mmol / g.

[0018] Compounds (D) having a phosphate ester group are known to have the function of improving the adhesion of patterns and resin films to substrates. Some compounds (D) having a phosphate ester group are commercially available as "adhesion improvers." However, due to concerns that compounds (D) having a phosphate ester group may adversely affect performance other than adhesion, the amount of compounds (D) used to improve adhesion has traditionally been quite small. Furthermore, in the formation of conventional black patterns with relatively small aspect ratios, adhesion has often been sufficiently improved even with a small amount of compounds (D) having a phosphate ester group.

[0019] The present inventors attempted to make improvements that were not bound by conventional thinking in order to drastically improve the adhesion of a black pattern to a substrate. Specifically, despite concerns that performance other than adhesion might be impaired, they decided to use a compound (D) having a phosphate ester group in a fairly large amount, equivalent to a phosphate ester group concentration of at least 0.067 mmol / g in the total nonvolatile components of the photosensitive composition (compared to a conventional concentration of at most about 0.05 mmol / g). This enabled them to improve the adhesion of the black pattern to a substrate to a level beyond that of conventional methods.

[0020] There was concern that using a larger amount of the compound (D) having a phosphate ester group than conventionally would result in a deterioration in other properties besides adhesion. However, surprisingly, the deterioration in other properties was suppressed. Rather, it was found that using a relatively large amount of the compound (D) having a phosphate ester group can improve the rectangularity of the formed black pattern. Although the details of the mechanism by which the rectangularity can be improved are not clear, it is possible that the chemical structure or some specific properties of the compound (D) having a phosphate ester group, among the many adhesion improvers, are involved. Although this is merely speculation, for example, it is possible that the compound (D) having a phosphate ester group present at the bottom of the pattern does not have a particularly high affinity with an alkaline developer, thereby preventing the bottom of the pattern from being dissolved or gouged out during the development process for pattern formation. However, if the amount of the compound (D) having a phosphate ester group is too large, the pattern shape may become forward tapered rather than rectangular (i.e., the rectangularity may be deteriorated). Therefore, it is preferable that the amount of the compound (D) having a phosphate ester group is not too large. In consideration of this, in the photosensitive composition of this embodiment, the amount of the compound (D) having a phosphate ester group is 0.130 mmol / g or less in terms of the concentration of the phosphate ester group in all nonvolatile components.

[0021] The components that can be contained in the photosensitive composition of this embodiment and the properties of the photosensitive composition of this embodiment will be described next.

[0022] (Polymerizable Monomer (A)) The photosensitive composition of the present embodiment contains a polymerizable monomer (A). The polymerizable monomer (A) is not particularly limited as long as it is polymerized by active species generated from a photopolymerization initiator (B) described in detail later to form a high molecular weight monomer.

[0023] The polymerizable monomer (A) preferably contains a compound having an ethylenic carbon-carbon double bond. Hereinafter, the compound having an ethylenic carbon-carbon double bond as the polymerizable monomer (A) will be specifically described.

[0024] The term "ethylenic carbon-carbon double bond" generally refers to a carbon-carbon double bond that can undergo a polymerization reaction due to the action of a radical. Conjugation-stabilized double bonds such as the double bond of a benzene ring do not fall under the category of ethylenic carbon-carbon double bonds. From the viewpoint of improving reactivity, it is preferable that a compound having an ethylenic carbon-carbon double bond has an ethylenic carbon-carbon double bond at its terminal.

[0025] The polymerizable monomer (A), such as a compound having an ethylenic carbon-carbon double bond, may be monofunctional or polyfunctional. Specifically, the compound having an ethylenic carbon-carbon double bond may have only one ethylenic carbon-carbon double bond per molecule, or may have two or more (specifically, 2 to 8, more specifically, 2 to 6) ethylenic carbon-carbon double bonds per molecule. From the viewpoints of further improving sensitivity and improving the physical properties of a cured film, the polymerizable monomer (A) preferably contains a compound having two or more (specifically, 2 to 8, more specifically, 2 to 6) ethylenic carbon-carbon double bonds per molecule.

[0026] The polymerizable monomer (A) is preferably a (meth)acrylate compound, i.e., a compound having a (meth)acryloyl group as a structure containing an ethylenic carbon-carbon double bond. The compound having an ethylenic carbon-carbon double bond is more preferably a (meth)acrylate compound.

[0027] Specific examples of the polymerizable monomer (A), particularly the compound having an ethylenic carbon-carbon double bond, include the following: Of course, the polymerizable monomer (A) is not limited to these.

[0028] Polyol polyacrylates such as ethylene glycol di(meth)acrylate, trimethylolpropane tri(meth)acrylate, ditrimethylolpropane tetra(meth)acrylate, pentaerythritol tri(meth)acrylate, pentaerythritol tetra(meth)acrylate, dipentaerythritol penta(meth)acrylate, and dipentaerythritol hexa(meth)acrylate; epoxy acrylates such as di(meth)acrylate of bisphenol A diglycidyl ether and di(meth)acrylate of hexanediol diglycidyl ether; and urethane (meth)acrylates obtained by the reaction of polyisocyanate with a hydroxy group-containing (meth)acrylate such as hydroxyethyl (meth)acrylate.

[0029] The photosensitive composition may contain only one polymerizable monomer (A) or may contain two or more polymerizable monomers (A). The content of the polymerizable monomer (A) is usually 5 to 60 mass %, preferably 10 to 55 mass %, and more preferably 15 to 50 mass %, of the total nonvolatile components of the black photosensitive composition.

[0030] (Photopolymerization initiator (B)) The photosensitive composition of the present embodiment contains a photopolymerization initiator (B). The photopolymerization initiator (B) is not particularly limited as long as it generates a chemical species capable of polymerizing the polymerizable monomer (A) when irradiated with light.

[0031] The photopolymerization initiator (B) preferably contains a photoradical polymerization initiator. As the photoradical polymerization initiator, any initiator that generates radicals upon irradiation with light (typically ultraviolet light such as i-line) can be used without any particular limitation.

[0032] Specific examples of the photopolymerization initiator (B), particularly the photoradical polymerization initiator, include an intramolecular cleavage type in which an intramolecular bond is cleaved by absorption of electromagnetic waves or electron beams to generate radicals, and a hydrogen abstraction type in which radicals are generated by the combined use of a hydrogen donor such as a tertiary amine or ether. In this embodiment, any of these may be used. Of course, photopolymerization initiators (B) other than these may also be used.

[0033] Specific examples of the photopolymerization initiator (B) include photoradical polymerization initiators such as benzophenone-based, acetophenone-based, diketone-based, acylphosphine oxide-based, quinone-based, acyloin-based, and oxime ester-based initiators.

[0034] Specific examples of the benzophenone-based photoradical polymerization initiator include benzophenone, 4-hydroxybenzophenone, 2-benzoylbenzoic acid, 4-benzoylbenzoic acid, 4,4'-bis(dimethylamino)benzophenone, 4,4'-bis(diethylamino)benzophenone, etc. Among these, 2-benzoylbenzoic acid, 4-benzoylbenzoic acid, and 4,4'-bis(diethylamino)benzophenone are preferred.

[0035] Specific examples of the acetophenone-based photoradical polymerization initiator include acetophenone, 2-(4-toluenesulfonyloxy)-2-phenylacetophenone, p-dimethylaminoacetophenone, 2,2'-dimethoxy-2-phenylacetophenone, p-methoxyacetophenone, 2-methyl-[4-(methylthio)phenyl]-2-morpholino-1-propanone, 2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)-butan-1-one, etc. Among these, p-dimethylaminoacetophenone and p-methoxyacetophenone are preferred.

[0036] Specific examples of the diketone-based photoradical polymerization initiator include 4,4'-dimethoxybenzyl, methyl benzoylformate, 9,10-phenanthrenequinone, etc. Among these, 4,4'-dimethoxybenzyl and methyl benzoylformate are preferred.

[0037] Specific examples of the acylphosphine oxide-based photoradical polymerization initiator include bis(2,4,6-trimethylbenzoyl)-phenylphosphine oxide.

[0038] Specific examples of the quinone-based photoradical polymerization initiator include anthraquinone, 2-ethylanthraquinone, camphorquinone, 1,4-naphthoquinone, etc. Among these, camphorquinone and 1,4-naphthoquinone are preferred.

[0039] Specific examples of the acyloin-based photoradical polymerization initiator include benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, etc. Among these, benzoin and benzoin methyl ether are preferred.

[0040] Specific examples of the oxime ester-based photoradical polymerization initiator include 1-[4-(phenylthio)phenyl]-1,2-octadione-2-(o-benzoyloxime, 1-[9-ethyl-6-(2-methylbenzoyl)-9H-carbazol-3-yl]-ethanone-1-(o-acetyloxime)]. Preferred examples of the oxime ester-based photoradical polymerization initiator include those having a structure represented by the following general formula (8):

[0041]

[0042] In general formula (8), R １４ is a hydrogen atom or a monovalent organic group, R １５ and R １６ are each independently a monovalent organic group, and preferably are each independently an alkyl group or an aromatic hydrocarbon group.

[0043] R １４ The monovalent organic group can be an alkyl group. The alkyl group may be linear or branched. The alkyl group preferably has 1 to 16 carbon atoms, more preferably 1 to 10 carbon atoms. The alkyl group may have a substituent. Specific examples of the alkyl group include a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, a sec-butyl group, a tert-butyl group, a pentyl group, a hexyl group, and a 2-ethylhexyl group. Of these, a methyl group, an ethyl group, a propyl group, or an isopropyl group is preferred, and a methyl group or an ethyl group is more preferred.

[0044] R １５The alkyl group may be linear, branched, or cyclic. The number of carbon atoms in the alkyl group is preferably 1 to 16, and more preferably 1 to 10. The alkyl group may have a substituent. Specific examples of the alkyl group include a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, a sec-butyl group, a tert-butyl group, a pentyl group, a hexyl group, a 2-ethylhexyl group, a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, a cyclohexyl group, a cyclopentylmethyl group, a cyclopentylethyl group, a cyclohexylmethyl group, and a cyclohexylethyl group. Of these, a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, a cyclopentylmethyl group, and a cyclohexylmethyl group are preferred, and a hexyl group, a cyclopentylmethyl group, and a cyclohexylmethyl group are more preferred. R １５ The aromatic hydrocarbon group preferably has 6 to 14 carbon atoms. The aromatic hydrocarbon group may have a substituent. Specific examples of the aromatic hydrocarbon group include a phenyl group, a naphthyl group, and an anthryl group.

[0045] R １６ The alkyl group may be linear, branched, or cyclic. The number of carbon atoms in the alkyl group is preferably 1 to 16, and more preferably 1 to 10. The alkyl group may have a substituent. Specific examples of the alkyl group include a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, a sec-butyl group, a tert-butyl group, a pentyl group, a hexyl group, a 2-ethylhexyl group, a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, a cyclohexyl group, a cyclopentylmethyl group, a cyclopentylethyl group, a cyclohexylmethyl group, and a cyclohexylethyl group. Of these, a methyl group, an ethyl group, a propyl group, and an isopropyl group are preferred, and a methyl group and an ethyl group are more preferred. R １５ The aromatic hydrocarbon group preferably has 6 to 14 carbon atoms. The aromatic hydrocarbon group may have a substituent. Specific examples of the aromatic hydrocarbon group include a phenyl group, a naphthyl group, and an anthryl group. Of these, a phenyl group is preferred.

[0046] Commercially available photopolymerization initiators (B) may be used. Preferred commercially available products include Irgacure 127, Irgacure 184, Irgacure 369, Irgacure 651, Irgacure 819, Irgacure 907, Irgacure 2959, Irgacure OXE-01, Irgacure OXE-02, Irgacure OXE-03, Irgacure OXE-04, Darocur 1173, and Lucirin TPO, both manufactured by BASF, and TR-PBG-305, both manufactured by Tronly.

[0047] The photosensitive composition of this embodiment may contain only one photopolymerization initiator (B), or may contain two or more photopolymerization initiators (B). The content of the photopolymerization initiator (B) may be appropriately adjusted taking into consideration sufficient sensitivity and resolution. The content of the photopolymerization initiator (B) is typically 0.1 to 10 mass%, preferably 0.3 to 8 mass%, and more preferably 0.5 to 5 mass%, of the total nonvolatile components of the photosensitive composition. From another perspective, the amount of the photopolymerization initiator (B) relative to 100 mass parts of the polymerizable monomer (A) is typically 0.2 to 25 mass parts, preferably 0.5 to 20 mass parts, and more preferably 1 to 15 mass parts.

[0048] (Black Pigment (C)) The photosensitive composition of the present embodiment contains a black pigment (C). The black pigment (C) can be jet black, but depending on the application of the photosensitive composition, it does not have to be jet black and may have a slight tint when observed with the naked eye. The black pigment (C) may, for example, exhibit a black color that appears slightly grayish or a black color that is slightly bluish (black with a slight bluish tinge). The black pigment (C) may contain a pigment or may contain a dye. From the viewpoint of resistance to fading, the black pigment (C) preferably contains a pigment. The black pigment (C) may contain multiple pigments as necessary. The black pigment (C) may contain an organic compound or an inorganic compound. From the viewpoints of solubility or dispersibility in a solvent and compatibility with other components, the black pigment (C) preferably contains an organic pigment such as an organic pigment.

[0049] In one embodiment, the black coloring matter (C) preferably contains a black pigment, such as carbon black, titanium black, iron oxide, manganese oxide, or graphite.

[0050] In another embodiment, the black pigment (C) may be a pigment that is substantially black by combining multiple non-black pigments (e.g., colored pigments). In this case, the mixture of multiple non-black pigments is considered to be the black pigment (C). As an example, the black pigment (C) can be obtained by mixing a blue pigment, a purple pigment, and an orange pigment. As another example, it is possible to combine a blue pigment, a purple pigment, a green pigment, a red pigment, and an orange pigment to form the black pigment (C). In this case, it is preferable to use the red pigment and the orange pigment in smaller amounts than the blue pigment, the purple pigment, and the green pigment. As yet another example, it is also possible to use a black pigment (C) with adjusted and optimized light absorption, which is a combination of a black pigment such as carbon black or titanium black with a non-black pigment.

[0051] When a black pigment (C) is obtained by combining a plurality of non-black pigments, examples of non-black pigments that can be preferably used are shown below. Of course, there is no limitation on the use of non-black pigments other than these. Blue pigments: For example, C.I. Pigment Blue 15, 15:1, 15:2, 15:3, 15:4, 15:6, 16, 17, 60, 64, 65, 75, 79, 80, etc. Among these, C.I. Pigment Blue 60 is preferred from the viewpoint of dispersibility and light-blocking properties. Purple pigments: For example, C.I. Pigment Violet 1, 1:1, 2, 2:2, 3, 3:1, 3:3, 5, 5:1, 14, 15, 16, 19, 23, 25, 27, 29, 31, 32, 37, 39, 42, 44, 47, 49, 50, etc. Among these ... Preferred are C.I. Pigment Violet 23. Orange pigments: For example, C.I. Pigment Orange 1, 2, 5, 13, 16, 17, 19, 20, 21, 22, 23, 24, 34, 36, 38, 39, 43, 46, 48, 49, 61, 62, 64, 65, 67, 68, 69, 70, 71, 72, 73, 74, 75, 77, 78, 79, etc. Among these, C.I. Pigment Orange 43 is preferred from the viewpoint of dispersibility and light-shielding properties. Green pigments: For example, C.I. Pigment Green 1, 2, 4, 7, 8, 10, 13, 14, 15, 16, 17, 17 Black, 18, 19, 20, 21, 22, 23, 24, 26, 36, 38, 39, 41, 42, 45, 48, 50, 51, 55, 56, etc. Red pigments: For example, C.I. Pigment 5, 9, 10, 17, 48, 48:1, 48:2, 48:3, 48:4, 52:2, 119, 166, 177, 207, 209, 216, 224, 226, 242, 254, etc. Others: Perylene pigments, lactam pigments, azo pigments, phthalocyanine pigments, etc.

[0052] For many commercially available dyes, the absorption spectra are available in literature, or manufacturers and distributors have spectral data. Furthermore, when multiple dyes are mixed, the resulting light absorption spectrum is, in principle, a superposition of the light absorption spectra of each dye. Therefore, even without actually mixing two or more dyes, simulations or paper studies alone can adequately predict whether a dye mixture will essentially function as a black dye.

[0053] When the black pigment (C) itself is insoluble in a solvent (usually an organic solvent), it is preferable that the black pigment (C) has been subjected to a dispersion treatment. Dispersion can be achieved, for example, by treating the pigment, dispersant, and, if necessary, the solvent using a bead mill. The type of dispersant is not particularly limited. Examples of dispersants that can be used include dispersants available from BYK-Chemie. Furthermore, when a solvent-insoluble black pigment (C) is subjected to a dispersion treatment to produce a pigment dispersion in which the black pigment (C) is dispersed in a solvent (usually an organic solvent), an alkali-soluble resin may also be used. Since the solvent-insoluble black pigment (C) is difficult to remove with an alkaline developer and tends to remain as a development residue, the inclusion of an alkali-soluble resin in the pigment dispersion can be expected to reduce the development residue. The alkali-soluble resins described below can be preferably used as the alkali-soluble resin.

[0054] The proportion of the black pigment (C) in the total nonvolatile components of the photosensitive composition is preferably 5 to 15% by mass, more preferably 7 to 13% by mass. Using a relatively large amount of black pigment (C) can increase the blackness of the resulting pattern. Furthermore, by not using too much black pigment (C), the proportions of other components become relatively higher, making it easier to improve the balance of various performances such as photocurability and cured film properties. When the black pigment (C) is a black pigment dispersion, the proportion of the black pigment dispersion in the total nonvolatile components of the photosensitive composition is preferably within the above-mentioned range.

[0055] (Compound (D) Having a Phosphate Ester Group) The photosensitive composition of the present embodiment contains a compound (D) having a phosphate ester group. Hereinafter, the compound (D) having a phosphate ester group may be omitted and simply referred to as "compound (D)."

[0056] Phosphate esters are phosphoric acid (O=P(OH) ３ ) some or all of the three hydrogen atoms are replaced by organic groups. Based on this, in this embodiment, the term "phosphate ester group" refers to a partial structure represented by the following chemical formula (D1):

[0057]

[0058] In chemical formula (D1), the dashed lines represent bonds to other atoms or atomic groups, provided that at least one of the three bonds is a bond to an organic group rather than a hydrogen atom.

[0059] Compound (D) may have only one phosphate ester group per molecule, or may have two or more (specifically, 2 to 4) phosphate ester groups per molecule. From the viewpoint of ease of synthesis and availability, it is preferable to use compound (D) having only one phosphate ester group per molecule.

[0060] It is preferred that the compound (D) has a polymerizable group, i.e., a group that can be polymerized by the chemical species generated from the photopolymerization initiator (B).This makes it easier for the polymerization reaction (curing reaction) to proceed, particularly in the vicinity of the substrate where the compound (D) functions as an adhesion improver (the portion of the film or pattern that is close to the substrate), and is therefore thought to further improve adhesion.In addition, it is thought that the promotion of the polymerization reaction (curing reaction) in the vicinity of the substrate makes it difficult for the final pattern shape to be reverse tapered, and also improves rectangularity.

[0061] When compound (D) has a polymerizable group, the polymerizable group is preferably a group having an ethylenic carbon-carbon double bond, and more preferably a (meth)acryloyl group. When compound (D) has a polymerizable group, compound (D) may have only one polymerizable group per molecule, or compound (D) may have two or more (specifically, 2 to 4) polymerizable groups per molecule. When compound (D) has a polymerizable group, the concentration of the polymerizable group in compound (D) in the total non-volatile components of the photosensitive composition is preferably 0.10 to 0.20 mmol / g, more preferably 0.113 to 0.18 mmol / g. It is believed that optimizing this concentration will further improve adhesion and rectangularity of the pattern shape.

[0062] Compound (D) is typically a low molecular weight compound. The molecular weight of compound (D) is usually 1,000 or less, preferably 100 to 1,000, more preferably 150 to 900, and even more preferably 200 to 800.

[0063] The compound (D) is preferably a compound represented by the following general formula (D2).

[0064]

[0065] In general formula (D2), R represents a hydrogen atom or a methyl group, L represents a divalent linking group, and x+y=3, 0<x≦3, 0≦y<3.

[0066] Examples of the divalent linking group for L include an alkylene group, an alicyclic group, an aromatic group, an ether group, an ester group, a thioether group, a sulfide group, a carbonyl group, an amide group, and a group in which two or more of these are linked together. The alkylene group may be linear or branched, and preferably has 1 to 12 carbon atoms, more preferably 1 to 6 carbon atoms. The alicyclic group may be monocyclic or polycyclic, and preferably has 3 to 12 carbon atoms. The aromatic group preferably has 6 to 20 carbon atoms. With regard to x and y, preferably 0.5≦x≦2.5 and 0.5≦y≦2.5.

[0067] Examples of compounds preferred as compound (D) are shown below. These compounds, or materials containing these compounds as the main component, can be purchased from Nippon Kayaku Co., Ltd. or Kyoeisha Chemical Co., Ltd. In the examples below, in the formula of the first exemplified compound, a+b=3, 0<a≦3, and 0≦b<3. Preferably, 1≦a≦2 and 1≦b≦2.

[0068]

[0069]

[0070]

[0071] The photosensitive composition may contain only one compound (D) or may contain two or more compounds (D). Compound (D) may be, for example, a mixture of multiple compounds represented by the general formula (D2) above, each having a different x and y. As already mentioned, the concentration of phosphate ester groups in the total nonvolatile components of the photosensitive composition is 0.067 to 0.130 mmol / g. This concentration is preferably 0.070 to 0.125 mmol / g, more preferably 0.075 to 0.120 mmol / g, and even more preferably 0.076 to 0.120 mmol / g. The proportion of compound (D) in the total nonvolatile components of the photosensitive composition is preferably 2 to 9 mass%, more preferably 2.5 to 7.5 mass%, even more preferably 2.9 to 5.5 mass%, and particularly preferably 3.25 to 5.5 mass%.

[0072] (Alkali-Soluble Resin) The photosensitive composition of this embodiment preferably contains an alkali-soluble resin. By using an alkali-soluble resin, it tends to be easier to form a pattern of a desired shape, particularly when forming a black pattern using an alkali developer. The alkali-soluble resin typically has an alkali-soluble group. Examples of the alkali-soluble group include a carboxy group and a phenolic hydroxy group.

[0073] An example of an alkali-soluble resin is an alkali-soluble novolak resin, which can be obtained by condensing a phenol with an aldehyde in the presence of an acid catalyst. Specific examples of phenols include phenol, o-cresol, m-cresol, p-cresol, 2,3-dimethylphenol, 2,4-dimethylphenol, 2,5-dimethylphenol, 3,4-dimethylphenol, 3,5-dimethylphenol, 2,3,5-trimethylphenol, 3,4,5-trimethylphenol, resorcinol, 2-methylresorcinol, 4-ethylresorcinol, hydroquinone, methylhydroquinone, catechol, 4-methylcatechol, pyrogallol, phloroglucinol, thymol, isothymol, etc. These phenols may be used alone or in combination of two or more. Specific examples of aldehydes include formaldehyde, trioxane, paraformaldehyde, benzaldehyde, acetaldehyde, propylaldehyde, phenylacetaldehyde, α-phenylpropylaldehyde, β-phenylpropylaldehyde, o-hydroxybenzaldehyde, m-hydroxybenzaldehyde, p-hydroxybenzaldehyde, o-methylbenzaldehyde, m-methylbenzaldehyde, p-methylbenzaldehyde, nitrobenzaldehyde, furfural, glyoxal, glutaraldehyde, terephthalaldehyde, and isophthalaldehyde. Specific examples of acid catalysts include hydrochloric acid, nitric acid, sulfuric acid, phosphoric acid, phosphorous acid, formic acid, oxalic acid, acetic acid, methanesulfonic acid, diethylsulfuric acid, and p-toluenesulfonic acid. These acid catalysts may be used alone or in combination of two or more.

[0074] Examples of alkali-soluble resins include alkali-soluble epoxy resins and acid-modified epoxy (meth)acrylate resins derived from epoxy resins. The epoxy resins or acid-modified epoxy (meth)acrylate resins may have polymerizable substituents such as hydroxyl groups or (meth)acryloyl groups in their side chains. Examples of epoxy resins include bisphenol-type epoxy resins, and examples of acid-modified epoxy (meth)acrylate resins include those obtained by reacting bisphenol-type epoxy resins with (meth)acrylic acid. Specifically, examples of such resins include bisphenol-type epoxy resins or acid-modified epoxy (meth)acrylate resins having a structural unit represented by the following general formula (e):

[0075]

[0076] In general formula (e), two R's each independently represent a linear or branched alkyl group having 1 to 3 carbon atoms, a linear perfluoroalkyl group having 1 to 3 carbon atoms, or a hydrogen atom, and Z represents a monovalent organic group or a hydrogen atom, provided that in at least some of the structural units represented by general formula (e) in the alkali-soluble resin, Z is a monovalent organic group having a carboxy group.

[0077] When R is a linear alkyl group having 1 to 3 carbon atoms or a branched alkyl group having 3 carbon atoms, specific examples of R include a methyl group, an ethyl group, a propyl group, and an isopropyl group. Of these, a methyl group is preferred from the viewpoint of availability. Specific examples of linear perfluoroalkyl groups having 1 to 3 carbon atoms include a trifluoromethyl group, a pentafluoroethyl group, and a heptafluoropropyl group. Of these, a trifluoromethyl group is preferred from the viewpoint of availability. Each R may have the same structure or different structures.

[0078] When Z is a monovalent organic group, Z is preferably an alkyl group having 1 to 10 carbon atoms. This alkyl group having 1 to 10 carbon atoms may be linear, branched, or cyclic. At least one hydrogen atom in the monovalent organic group of Z may be substituted with a carboxy group or a hydroxy group. This increases alkali solubility.

[0079] The carboxyl group or hydroxyl group of the alkyl group having 1 to 10 carbon atoms represented by Z may be reacted with an esterifying agent. Examples of the esterifying agent include acid halides, acid anhydrides, and acids and condensing agents. When Z is a hydrogen atom, -O-Z may be reacted with an esterifying agent. Examples of the esterifying agent include the same esterifying agents as described above. Examples of acid anhydrides include acrylic anhydride, methacrylic anhydride, succinic anhydride, phthalic anhydride, and 1,2,3,4-tetrahydrophthalic anhydride. By reacting these acid anhydrides with a resin, it is possible to introduce an ethylenically unsaturated bond or a carboxyl group into the resin. The amount of carboxyl groups or hydroxyl groups in the alkali-soluble resin to be reacted with the acid anhydride may be appropriately adjusted taking into account the solubility in alkali required for the alkali-soluble resin.

[0080] Epoxy (meth)acrylate resins having a structural unit represented by general formula (e) are available from, for example, Nippon Kayaku Co., Ltd.

[0081] In addition, alkali-soluble epoxy resins or acid-modified epoxy (meth)acrylate resins other than those mentioned above can also be used. Specific examples include alkali-soluble novolac-type epoxy resins, biphenyl-type epoxy resins, and acid-modified epoxy (meth)acrylate resins derived from these epoxy resins. Commercially available acid-modified epoxy (meth)acrylates can also be used. Examples of commercially available acid-modified epoxy acrylates that can be used include those manufactured by Nippon Kayaku Co., Ltd. under the product names: CCR-1218H, CCR-1159H, CCR-1222H, CCR-1291H, CCR-1235, PCR-1050, TCR-1335H, UXE-3024, ZAR-1035, ZAR-2001H, ZFR-1185, and ZCR-1569H.

[0082] The alkali-soluble resin may have a polycyclic aromatic skeleton such as a fluorene skeleton. The use of such an alkali-soluble resin may improve the heat resistance and durability of the cured pattern. Specific examples of the acid-modified epoxy (meth)acrylate resin described above may include those having a polycyclic aromatic skeleton, or resins having a polycyclic aromatic skeleton may be selected from a different family of resins than the acid-modified epoxy (meth)acrylate resin. Incidentally, resins having a fluorene skeleton are sometimes referred to as "cardo resins." Like other alkali-soluble resins, alkali-soluble resins having a polycyclic aromatic skeleton such as a fluorene skeleton preferably have an alkali-soluble group such as a carboxy group or a hydroxy group.

[0083] The alkali-soluble resin may or may not have an ethylenic carbon-carbon double bond. It is believed that an alkali-soluble resin having an ethylenic carbon-carbon double bond forms a bond with the polymerizable monomer (A) during curing of the composition and is incorporated into the cured product. This is believed to contribute to improving the stability and heat resistance of the cured product. Just to be clear, an alkali-soluble resin having an ethylenic carbon-carbon double bond is not classified as the above-mentioned polymerizable monomer (A).

[0084] The weight-average molecular weight of the alkali-soluble resin is preferably 1,000 to 50,000 from the viewpoint of the developability and resolution of the photosensitive composition. The acid value of the alkali-soluble resin (the number of milligrams of potassium hydroxide required to neutralize 1 g of sample) can be an indicator of alkali solubility. In this embodiment, the acid value of the alkali-soluble resin is preferably 20 to 80, more preferably 30 to 70, and even more preferably 40 to 60. The acid values ​​of the alkali-soluble resins used in the examples described below are on this order.

[0085] When an alkali-soluble resin is used, only one alkali-soluble resin may be used, or two or more alkali-soluble resins may be used. When an alkali-soluble resin is used, the amount thereof is usually 10 to 70% by mass, preferably 15 to 60% by mass, and more preferably 20 to 55% by mass, of the total nonvolatile components of the photosensitive composition.

[0086] (Chain Transfer Agent) The photosensitive composition of this embodiment preferably contains a chain transfer agent. As is known in the field of polymer synthesis, a chain transfer agent is a component that receives a radical from a growing polymer chain in a radical polymerization system and generates a new radical. By using a chain transfer agent, the degree of polymerization can be adjusted, and the properties of the cured film can be adjusted in some cases.

[0087] Any known chain transfer agent can be used without any particular limitation. Preferably, the chain transfer agent contains a thiol compound. The thiol compound may have only one mercapto group per molecule, or may have two or more (specifically, 2 to 8) mercapto groups per molecule.

[0088] Specific examples of thiol compounds include those represented by the following general formula (b).

[0089]

[0090] In the general formula (b), R is a hydrogen atom, an alkyl group, or a cycloalkyl group, and X is —CO— or —CH ２-, L is an n-valent linking group, and n is an integer of 2 or more, preferably 2 to 8, more preferably 2 to 6. Multiple Rs may be the same or different from each other. Furthermore, multiple Xs may be the same or different from each other. However, from the viewpoint of ease of synthesis, it is preferable that multiple Rs are the same as each other, and it is preferable that multiple Xs are the same as each other.

[0091] The alkyl group for R may be linear or branched. The alkyl group preferably has 1 to 16 carbon atoms, more preferably 1 to 10 carbon atoms. Specific examples of the alkyl group include a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, a sec-butyl group, a tert-butyl group, a pentyl group, a hexyl group, and a 2-ethylhexyl group. Of these, a methyl group, an ethyl group, a propyl group, or an isopropyl group is preferred, and a methyl group or an ethyl group is more preferred.

[0092] Examples of L, which is an n-valent linking group, include a linear or branched alkylene chain (having, for example, 2 to 6 carbon atoms), a trimethylolpropane residue, -(CH ２ ) ｐ Examples include trivalent linking groups such as an isocyanuric ring having three - (p is 2 to 6), tetravalent or pentavalent linking groups such as a pentaerythritol residue, and hexavalent linking groups such as a dipentaerythritol residue.

[0093] Commercially available thiol compounds include, for example, the "Karends" series manufactured by Showa Denko K.K. The thiols in this series are secondary thiols. Other examples include PEMP, TMMP, DPMP, and TEMPIC manufactured by SC Organic Chemical Co., Ltd. These thiols are primary thiols.

[0094] The content of mercapto groups contained in the thiol compound is preferably 5 to 60% by mass, more preferably 7 to 50% by mass, and even more preferably 10 to 30% by mass, based on the molecular weight of the thiol compound.

[0095] When a chain transfer agent is used, only one chain transfer agent may be used, or two or more chain transfer agents may be used. When a chain transfer agent is used, the amount thereof is not particularly limited, but in one embodiment, it is, for example, 0.1 to 10 mass %, specifically 0.5 to 8 mass %, more specifically 1 to 5 mass %, of the total nonvolatile components of the black photosensitive composition. When a chain transfer agent is used, the amount thereof is, for example, 0.2 to 25 mass parts, specifically 1 to 20 mass parts, more specifically 2 to 15 mass parts, relative to 100 mass parts of the polymerizable monomer (A).

[0096] (Other Optional Components) The photosensitive composition of this embodiment may contain any optional components other than those described above. Examples of optional components include a dissolution inhibitor, a plasticizer, a stabilizer, a surfactant, a thickener, a leveling agent, an antifoaming agent, a compatibilizer, an adhesion improver other than compound (D), and an antioxidant. Furthermore, when the colored photosensitive composition of this embodiment is used to form a partition wall in a light-emitting element, it is preferable to use a liquid repellent. Known compounds such as fluorine-containing compounds can be used as the liquid repellent. Commercially available products can be used as these optional components.

[0097] (Solvent) The black photosensitive composition of this embodiment typically comprises the above-described components dissolved or dispersed in a solvent, which usually contains an organic solvent.

[0098] Usable solvents are not particularly limited. Specific examples include ketones, alcohols, polyhydric alcohols and their derivatives, ethers, esters, aromatic solvents, and fluorine-containing solvents. These may be used alone or in combination of two or more.

[0099] Examples of ketones include acetone, methyl ethyl ketone, cyclopentanone, cyclohexanone, methyl isoamyl ketone, methyl isobutyl ketone, methyl isopentyl ketone, and 2-heptanone.

[0100] Examples of alcohols include isopropanol, butanol, isobutanol, n-pentanol, isopentanol, tert-pentanol, 4-methyl-2-pentanol, 3-methyl-3-pentanol, 2,3-dimethyl-2-pentanol, n-hexanol, n-heptanol, 2-heptanol, n-octanol, n-decanol, s-amyl alcohol, t-amyl alcohol, isoamyl alcohol, 2-ethyl-1-butanol, lauryl alcohol, hexyldecanol, and oleyl alcohol.

[0101] Examples of polyhydric alcohols and derivatives thereof include ethylene glycol, ethylene glycol monoacetate, ethylene glycol dimethyl ether, diethylene glycol, diethylene glycol dimethyl ether, diethylene glycol monoacetate, propylene glycol, propylene glycol monoacetate, propylene glycol monomethyl ether (PGME), propylene glycol monoethyl ether, propylene glycol monopropyl ether, propylene glycol monobutyl ether, propylene glycol monomethyl ether acetate (PGMEA), monomethyl ether, monoethyl ether, monopropyl ether, monobutyl ether, and monophenyl ether of dipropylene glycol or dipropylene glycol monoacetate.

[0102] Examples of ethers include diethyl ether, diisopropyl ether, tetrahydrofuran, dioxane, and anisole.

[0103] Examples of esters include methyl lactate, ethyl lactate (EL), methyl acetate, ethyl acetate, butyl acetate, methyl pyruvate, ethyl pyruvate, methyl methoxypropionate, ethyl ethoxypropionate, and γ-butyrolactone.

[0104] Examples of aromatic solvents include xylene and toluene.

[0105] Examples of fluorine-based solvents include chlorofluorocarbons, chlorofluorocarbon substitutes, perfluoro compounds, and hexafluoroisopropyl alcohol.

[0106] In addition, for the purpose of improving the coating property, it is possible to use a turpentine-based petroleum naphtha solvent or a paraffin-based solvent, which is a high-boiling weak solvent.

[0107] Among these, the solvents include methyl ethyl ketone, cyclohexanone, methyl isoamyl ketone, 2-heptanone, ethylene glycol, ethylene glycol dimethyl ether, ethylene glycol monoacetate, diethylene glycol, diethylene glycol monoacetate, diethylene glycol dimethyl ether, propylene glycol, propylene glycol monoacetate, propylene glycol monomethyl ether (PGME), propylene glycol monomethyl ether acetate (PGMEA), dipropylene glycol, dipropylene glycol monoacetate Preferably, the solvent contains at least one selected from the group consisting of dipropylene glycol monoacetate monomethyl ether, dipropylene glycol monoacetate monoethyl ether, dipropylene glycol monoacetate monopropyl ether, dipropylene glycol monoacetate monobutyl ether, dipropylene glycol monoacetate monophenyl ether, 1,4-dioxane, methyl lactate, ethyl lactate, methyl acetate, ethyl acetate, butyl acetate, methyl methoxypropionate, ethyl ethoxypropionate, γ-butyrolactone, and hexafluoroisopropyl alcohol. Furthermore, the solvent preferably contains methyl ethyl ketone, propylene glycol monomethyl ether acetate (PGMEA), propylene glycol monomethyl ether (PGME), cyclohexanone, ethyl lactate, butyl acetate, or γ-butyrolactone.

[0108] When a solvent is used, only one solvent may be used, or two or more solvents may be used. When a solvent is used, the amount of solvent in the photosensitive composition is preferably used in an amount such that the total solids concentration becomes, for example, 5 to 85 mass %, specifically 10 to 70 mass %. By adjusting the amount of solvent, the thickness of the film to be formed can be adjusted. Within the above range, it is easy to obtain a film with a thickness suitable for the black matrix of a display device, the partition wall of a light-emitting element, the black pattern (louver) of a privacy filter, etc.

[0109] (Applications) As already mentioned, the black pattern formed using the photosensitive composition of this embodiment has good adhesion to the substrate and good rectangularity. Therefore, the photosensitive composition of this embodiment is preferably used for forming a black pattern having a high aspect ratio. Quantitatively speaking, the photosensitive composition of this embodiment is preferably used for forming a black pattern having a height of 5 to 30 μm and an aspect ratio of 1 to 3. Furthermore, the photosensitive composition of this embodiment is preferably used for forming a black pattern having a height of 5 to 25 μm and an aspect ratio of 1 to 2.5. The fact that a black pattern having a high aspect ratio can be formed using the photosensitive composition of this embodiment means that the photosensitive composition of this embodiment is preferably used for forming a black pattern in, for example, a privacy filter.

[0110] The optical density (OD value) of a black pattern formed using the photosensitive composition of this embodiment - preferably a pattern having the height and aspect ratio described above - is, for example, 0.5 to 7.0, preferably 0.5 to 5.0, more preferably 1.0 to 5.0, and even more preferably 2.0 to 4.5. In this embodiment, despite a relatively high optical density (OD value), a black pattern with a good cross-sectional shape can be obtained, and a substrate having such a black pattern can be produced. For specific methods for measuring the optical density (OD value), see the description in the Examples.

[0111] <Method for manufacturing a substrate having a black cured pattern formed thereon, and a display device having a black cured pattern> Using the photosensitive composition of the present embodiment, a substrate having a black cured pattern formed thereon can be manufactured by carrying out a series of steps including, for example, the following steps (1) to (4), which are preferably carried out in this order.

[0112] (1) A film-forming step of applying the above-described photosensitive composition to a substrate to form a film; (2) An exposure step of pattern-exposing the film formed in (1); (3) A development step of developing the film after exposure; and (4) A curing step of heating the developed film to obtain a black cured pattern.

[0113] Furthermore, a display device including a black cured pattern formed using the photosensitive composition of this embodiment can be manufactured. As one example, a display device including a black cured pattern manufactured by the above-described series of steps (1) to (4) as a black matrix, partition wall, or the like can be manufactured. As another example, a display device including a black cured pattern manufactured by the above-described series of steps (1) to (4) as a long, thin, plate-like black pattern in a privacy filter can be manufactured.

[0114] The above steps (1) to (4) and other associated steps will be described below.

[0115] [(1) Film Forming Step] In the film forming step, the photosensitive composition of the present embodiment is applied onto a substrate to form a film.

[0116] The type of substrate is not particularly limited. The substrate may be appropriately selected depending on the product to be manufactured. Examples of the type of substrate include silicon wafers, SiN substrates, metal substrates, glass substrates, substrates with ITO films, base materials containing metal oxides, and organic resin substrates (e.g., polyimide, polycarbonate, polyester). One or both sides of the substrate may or may not have a layer formed thereon.

[0117] The method for applying the photosensitive composition is not particularly limited. Known methods such as spin coating, bar coating, and curtain coating can be used. In some cases, an inkjet method can also be applied. When a solvent-containing photosensitive composition is used, it is preferable to dry the solvent by heating after applying the photosensitive composition. The heating temperature can be, for example, 50 to 150°C, preferably 50 to 100°C, more preferably 60 to 90°C, even more preferably 70 to 90°C, and particularly preferably 80 to 90°C. The heating time can be 60 to 200 seconds. The film thickness (dry thickness) of the film is usually 0.5 to 30 μm, preferably 1 to 25 μm.

[0118] [(2) Exposure Step] In the exposure step, the film obtained in the film-forming step is exposed to a pattern. Specifically, light generated from a light source of an exposure device is irradiated onto the film through a photomask. The light can be ultraviolet light, gamma rays, X-rays, etc. Due to the availability of light sources, ultraviolet light (particularly g-rays, i-rays, etc.) is mainly used as the light. The exposure dose is not particularly limited, but is usually 1 to 500 mJ / cm. ２ , preferably 10 to 400 mJ / cm ２ After the exposure and before the development step described below, a heat treatment may or may not be carried out.

[0119] [(3) Development Step] In the development step, the film after the exposure step is typically developed using a developer, which usually dissolves the unexposed areas in the film, thereby obtaining a pattern (partition wall).

[0120] An alkaline aqueous solution is preferably used as the developer. Specifically, an aqueous solution of tetramethylammonium hydroxide (TMAH), an aqueous solution of tetrabutylammonium hydroxide (TBAH), an aqueous solution of sodium hydroxide, an aqueous solution of potassium hydroxide, etc. can be used. As the developer, an aqueous solution of tetramethylammonium hydroxide (TMAH) is particularly preferred in view of its good developability and long track record of use in the field of photosensitive compositions. The concentration of the TMAH aqueous solution is preferably 0.1 to 5% by mass, more preferably 0.2 to 3% by mass. Incidentally, a developer containing an organic solvent as its main component may be used in some cases.

[0121] As the developing method, known methods can be used, such as a dipping method, a puddle method, a spray method, etc. The developing time (the time during which the developer is in contact with the film) is preferably from 10 seconds to 3 minutes, and more preferably from 30 seconds to 2 minutes.

[0122] After the development treatment, if necessary, a step of washing the pattern with deionized water etc. The washing time is preferably from 10 seconds to 3 minutes, more preferably from 30 seconds to 2 minutes.

[0123] [(4) Curing Step] In the curing step, the developed film is heated. This allows the remaining reactive groups in the pattern obtained in the developing step to react as much as possible, thereby curing the film. In the heating step, the developed film is heated, for example, at 50 to 250°C, preferably 50 to 230°C, more preferably 60 to 220°C, and even more preferably 70 to 200°C. The heating time is, for example, 10 minutes to 3 hours, preferably 15 minutes to 1 hour. By appropriately adjusting the heating temperature and time here, it is possible to improve the durability of the black cured pattern while suppressing damage caused by heat.

[0124] [Optional Steps After Heating Step] The substrate provided with the cured film obtained in the heating step can be subjected to any treatment. For example, UV ozone treatment or oxygen plasma treatment can be performed. This can remove unnecessary organic matter remaining on the substrate. In addition, any other steps can be performed, for example, to manufacture a display device.

[0125] Although the embodiments of the present invention have been described above, these are merely examples of the present invention, and various other configurations may be adopted. Furthermore, the present invention is not limited to the above-described embodiments, and modifications and improvements within the scope of achieving the object of the present invention are included in the present invention.

[0126] The embodiments of the present invention will be described in detail based on examples and comparative examples. It should be noted that the present invention is not limited to the examples. In the following, "PGMEA" is an abbreviation for propylene glycol monomethyl ether acetate.

[0127] <Preparation of Black Pigment Dispersion 1> A mixture was obtained by mixing the pigment, dispersant, alkali-soluble resin, and solvent shown in the table below in the mass ratio shown. This mixture was dispersed in a bead mill at 25°C for 12 hours using 0.5 mmφ zirconia beads. After the dispersion process was completed, the zirconia beads were removed by filtration. In this way, Black Pigment Dispersion 1 was prepared.

[0128]

[0129] <Preparation of Photosensitive Composition> First, the following materials were prepared. [Alkali-soluble resins] Alkali-soluble resin 1: "ZAR-2050H" manufactured by Nippon Kayaku Co., Ltd. (special BIS-A type epoxy acrylate, containing a structural unit represented by the general formula (e) shown above.) [Polymerizable monomers] Monomer 1: "DPHA" (dipentaerythritol hexaacrylate) manufactured by Nippon Kayaku Co., Ltd. [Photopolymerization initiator] Photoradical polymerization initiator 1: "Irgacure OXE-01" manufactured by BASF [Black pigment] Black pigment dispersion 1: black pigment dispersion prepared in <Preparation of black pigment dispersion 1> above [Chain transfer agent] Chain transfer agent 1: "Karenz-MTPE1" manufactured by Showa Denko K.K. [Compounds having a phosphate ester group] Phosphate ester compound 1: "KAYAMER PM-21" manufactured by Nippon Kayaku Co., Ltd. (hereinafter referred to as chemical structure, the average value of a is 1.5, and the average value of b is 1.5)

[0130]

[0131] The prepared materials and PGMEA were uniformly stirred and mixed to prepare a photosensitive composition. The mixing ratios of the materials were as shown in the table below. The amount of PGMEA used was such that the non-volatile component concentration of the composition was 65% by mass.

[0132] <Formation of Black Cured Pattern> This was carried out according to the following procedure. (1) A 10 cm square ITO (Indium-Tin Oxide) substrate was prepared. This was washed with ultrapure water and then with acetone. The substrate was then subjected to UV ozone treatment for 5 minutes using a UV ozone treatment device (manufactured by Sen Special Light Sources Co., Ltd., Model PL17-110). In this manner, an evaluation substrate was obtained. (2) The black photosensitive resin composition obtained in <Preparation of Photosensitive Composition> was applied to the evaluation substrate using a spin coater. The evaluation substrate was then placed on a hot plate and heated at 80°C for 150 seconds. In this manner, a resin film was obtained. The film thickness of the resin film (unexposed film) here is listed in Tables 2 to 5 below. Incidentally, the film thickness was adjusted by changing the rotation speed of the spin coater. Specifically, the following procedure was followed. - 800 rpm when forming a resin film with a thickness of 5 μm - 450 rpm when forming a resin film with a thickness of 10 μm - 250 rpm when forming a resin film with a thickness of 15 μm - 160 rpm when forming a resin film with a thickness of 20 μm - 110 rpm when forming a resin film with a thickness of 30 μm (3) Using a mask aligner (product of SUSS MicroTec Co., Ltd.), the resin film was irradiated with i-line (wavelength 365 nm) through a mask with a line and space pattern. The specific masks and exposure doses used were as follows: - For a resin film with a thickness of 5 μm: A mask with a line / space = 5 / 5 μm was used, and the light exposure dose was 250 mJ / cm ２ For a resin film with a thickness of 10 μm: a mask with a line / space of 8 / 8 μm was used, and the light irradiation dose was 280 mJ / cm ２ For a resin film with a thickness of 15 μm: a mask with a line / space of 10 / 10 μm was used, and the light irradiation dose was 300 mJ / cm ２ For a resin film with a thickness of 20 μm: a mask with a line / space of 10 / 10 μm was used, and the light irradiation dose was 300 mJ / cm ２For a resin film with a thickness of 30 μm: a mask with a line / space of 15 / 15 μm was used, and the light irradiation dose was 700 mJ / cm ２ (4) Spray development was performed for 40 seconds using a 0.4% by mass aqueous solution of tetramethylammonium hydroxide (TMAH). After development, the substrate was rinsed with pure water for 10 seconds. The remaining developer and / or rinse solution was then removed by N ２ The coating was removed by blowing. (5) The evaluation substrate was placed on a hot plate and heated at 200°C for 60 minutes. A black cured pattern was obtained on the evaluation substrate. The obtained black cured pattern included not only a line and space pattern resulting from light irradiation through a mask, but also a solid film that had been cured by light irradiation without a mask.

[0133] <Evaluation> The black cured pattern obtained in the above <Formation of black cured pattern> was evaluated as follows.

[0134] [Optical Density (OD Value)] The optical density (OD value) of the cured product portion of the black cured pattern was measured using a black and white transmission densitometer (Ihara Electronics Co., Ltd.: T5plus, wavelength range 400-700 nm). Measurements were performed at five arbitrary locations on the solid film portion of the cured product. The average of the five measured values ​​was then used as the optical density (OD value).

[0135] [Pattern Shape] The cross section of the pattern obtained in <Formation of Black Cured Pattern> was photographed with a scanning electron microscope. The height from the top surface of the substrate to the top of the pattern was evaluated as the pattern height, and the maximum value of the pattern width in the horizontal direction was evaluated as the line width. In addition, the angle α in Figure 1 on the pattern cross section was evaluated as an index of rectangularity. When α was 90° or close to 90°, it can be said that the rectangularity was good.

[0136] [Adhesion] An area of ​​approximately 10 mm x 10 mm in the pattern obtained in <Formation of black cured pattern> was observed using an optical microscope. The adhesion was evaluated according to the following criteria: - When peeling of the pattern was confirmed in less than 1% of the area: Excellent - When peeling of the pattern was confirmed in 1-5% of the area: Good - When peeling of the pattern was confirmed in more than 5% of the area: Poor

[0137] Tables 2 to 5 summarize various information, such as the composition of the photosensitive composition and evaluation results. Table 2 shows the composition and evaluation results for a film thickness of approximately 5 μm before exposure; Table 3 shows the composition and evaluation results for a film thickness of approximately 10 μm before exposure; Table 4 shows the composition and evaluation results for a film thickness of approximately 15 μm before exposure; Table 5 shows the composition and evaluation results for a film thickness of approximately 20 μm before exposure; and Table 6 shows the composition and evaluation results for a film thickness of approximately 30 μm before exposure. [Note] In Tables 2 to 6, the phosphate ester group concentration (mmol / g) in the total nonvolatile components and the polymerizable group concentration (mmol / g) of compound (D) in the total nonvolatile components were calculated based on the molecular weight of the phosphate ester compound 1 shown above, where a = b = 1.5. In the evaluation results, parentheses around the line width indicate that the pattern line width could not be accurately measured due to pattern collapse / peeling (poor pattern adhesion).

[0138]

[0139]

[0140]

[0141]

[0142]

[0143] As shown in Tables 2 to 6, by using the photosensitive compositions of the Examples which contained the compound (D) having a phosphate ester group and in which the concentration of the phosphate ester group in the total non-volatile components was 0.067 to 0.130 mmol / g, it was possible to form black patterns which had good adhesion to the substrate and good rectangularity.

[0144] In contrast, in the comparative example in which the concentration of phosphate ester groups in all nonvolatile components was less than 0.067 mmol / g, the adhesion of the black pattern to the substrate was poor.Furthermore, because the adhesion of the black pattern to the substrate was poor, the rectangularity of the pattern could not be evaluated.

[0145] In addition, in the comparative examples in which the concentration of phosphate ester groups in all nonvolatile components exceeded 0.130 mmol / g, the adhesion of the black pattern to the substrate was good, but the angle α was significantly smaller than 90°, and the rectangularity of the pattern deteriorated.

[0146] From the above, it can be understood that the inclusion of the compound (D) having a phosphate ester group and the concentration of the phosphate ester group in all nonvolatile components being 0.067 to 0.130 mmol / g is closely related to the "combination" of adhesiveness to the substrate and rectangularity of the black pattern.

[0147] A more detailed analysis of the results in Tables 2 to 5 reveals that when the concentration of phosphate ester groups in all nonvolatile components of the photosensitive composition is 0.075 to 0.120 mmol / g, more specifically 0.076 to 0.120 mmol / g, the adhesion is "excellent," and both adhesion to the substrate and rectangularity are highly compatible.

[0148] This application claims priority based on Japanese Patent Application No. 2023-185238, filed October 30, 2023, the disclosure of which is incorporated herein by reference in its entirety.

Claims

1. A photosensitive composition comprising a polymerizable monomer (A), a photopolymerization initiator (B), a black pigment (C), and a compound having a phosphate ester group (D), wherein the concentration of the phosphate ester group in the total non-volatile components of the photosensitive composition is 0.067 to 0.130 mmol / g.

2. The photosensitive composition according to claim 1, wherein the ratio of said compound (D) to the total non-volatile components of said photosensitive composition is 2 to 10 mass %.

3. The photosensitive composition according to claim 1 or 2, wherein the compound (D) has a polymerizable group.

4. The photosensitive composition according to claim 1 or 2, wherein the polymerizable monomer (A) contains a compound having an ethylenic carbon-carbon double bond, and the photopolymerization initiator (B) contains a photoradical polymerization initiator.

5. The photosensitive composition according to claim 1 or 2, wherein the black colorant (C) comprises a pigment.

6. The photosensitive composition according to claim 1 or 2, further comprising an alkali-soluble resin.

7. The photosensitive composition according to claim 1 or 2, further comprising a chain transfer agent.

8. The photosensitive composition according to claim 1 or 2, which is used to form a black pattern having a height of 5 to 30 μm and an aspect ratio of 1 to 3.

9. The photosensitive composition according to claim 8, wherein the optical density of the black pattern is 0.5 to 7.

0.

10. A method for producing a substrate having a black cured pattern formed thereon, comprising: a film-forming step of coating a substrate with the photosensitive composition according to claim 1 or 2 to form a film; an exposure step of patternwise exposing the film; a development step of developing the exposed film; and a curing step of heating the developed film to obtain a black cured pattern.

11. A display device comprising a black cured pattern formed using the photosensitive composition according to claim 1 or 2.

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