Negative photosensitive resin composition

Abstract

To provide a photosensitive resin composition capable of obtaining a cured film having high visible light shielding properties even when a colorant such as carbon black is reduced.SOLUTION: There is provided a negative photosensitive resin composition comprising the following components (A) to (E): (A) a novolac type phenolic resin in which the molar ratio [(a1):(a2):(a3):(a4)] of the structural unit derived from m-cresol (a1), the structural unit derived from catechol (a2), the structural unit derived from benzaldehyde (a3) and the structural unit derived from salicylaldehyde (a4) is 1:0.25 to 4.0:0.25 to 4.0:0.25 to 4.0, (B) one or more resins selected from an ethylenically unsaturated group-containing polyimide, an ethylenically unsaturated group-containing polyimide precursor, an ethylenically unsaturated group-containing polybenzoxazole and an ethylenically unsaturated group-containing polybenzoxazole precursor, (C) a radical polymerizable compound, (D) a photopolymerization initiator, (D) an organic solvent.SELECTED DRAWING: None

Description

[Technical field]

[0001] The present invention relates to a negative photosensitive resin composition, a cured film, and a resist film. [Background technology]

[0002] Organic EL displays have been attracting attention as the next generation of flat panel displays. Organic EL displays are self-luminous display devices that utilize electroluminescence from organic compounds, and are capable of displaying images with a wide viewing angle and high response speed. They can also be made thinner and lighter. In recent years, as organic EL displays have become more highly precise, there has been a demand for further miniaturization of light-emitting elements.

[0003] In an organic EL display, the element emits light using the energy generated by the recombination of electrons injected from the cathode and holes injected from the anode. Therefore, if a substance that forms an energy level that inhibits the recombination of electrons and holes is present, the light-emitting efficiency of the light-emitting element decreases, and the life of the organic EL display decreases. On the other hand, in order to divide the pixels of the light-emitting element, an insulating layer called a pixel division layer is generally formed between the transparent electrode on the light extraction side and the metal electrode on the opposite side. Since this pixel division layer is formed in a position adjacent to the light-emitting element, degassing or outflow of ion components from the pixel division layer can be one of the factors that shorten the life of the organic EL display. For this reason, the pixel division layer is required to be heat-resistant and durable.

[0004] From the viewpoint of high heat resistance, a photosensitive resin composition using a polyimide resin or a polybenzoxazole resin is used as the material for the pixel division layer (for example, Patent Document 1). Since the pixel division layer is required to be black, the photosensitive resin composition contains about 20% of a colorant such as carbon black in the solid content. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] International Publication No. 2022 / 070946 Summary of the Invention [Problem to be solved by the invention]

[0006] In the production of fine patterns, the colorant blended in the photosensitive resin composition may become a residue during development. In addition, since carbon black has electrical conductivity, it is preferable to use a small amount of carbon black in order to improve the insulating properties of the cured film. With the increase in the resolution of organic EL displays, there is a demand for a photosensitive resin composition that has a high visible light shielding ability even when the amount of colorant added is reduced, in order to enable the production of finer pixel division layers without generating residues. An object of the present invention is to provide a photosensitive resin composition which gives a cured film having high visible light shielding ability even when the amount of colorant added is reduced. [Means for solving the problem]

[0007] Means for Solving the Problems The present inventors have conducted intensive research to solve the above problems and have found that a cured film obtained from a negative photosensitive resin composition using a combination of a novolac-type phenolic resin composition having a specific structural unit and at least one of an ethylenically unsaturated group-containing polyimide and an ethylenically unsaturated group-containing polybenzoxazole has high visible light-shielding properties even when the amount of colorant used is reduced, thereby completing the present invention.

[0008] That is, the present invention relates to a negative type photosensitive resin composition containing the following components (A) to (E): (A) A novolak-type phenolic resin in which the molar ratio [(a1):(a2):(a3):(a4)] of the structural unit (a1) derived from m-cresol, the structural unit (a2) derived from catechol, the structural unit (a3) ​​derived from benzaldehyde, and the structural unit (a4) derived from salicylaldehyde is 1:0.25-4.0:0.25-4.0:0.25-4.0. (B) one or more resins selected from the group consisting of ethylenically unsaturated group-containing polyimides, ethylenically unsaturated group-containing polyimide precursors, ethylenically unsaturated group-containing polybenzoxazoles, and ethylenically unsaturated group-containing polybenzoxazole precursors; (C) Radical polymerizable compound (D) Photopolymerization initiator (E) Organic solvent

[0009] The present invention further relates to a cured film obtained from the negative type photosensitive resin composition. The present invention further relates to a resist film obtained from the negative photosensitive resin composition. Effect of the Invention

[0010] According to the present invention, there is provided a photosensitive resin composition which gives a cured film having high visible light shielding ability even when the amount of colorant added is reduced. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The following describes an embodiment of the invention. In this specification, "x to y" represents a numerical range of "not less than x and not more than y." The upper and lower limit values ​​described in relation to the numerical ranges can be combined in any combination. In addition, any combination of two or more of the individual aspects of the present invention described below is also an aspect of the present invention.

[0012] [Negative-type photosensitive resin composition] A negative photosensitive resin composition according to one embodiment of the present invention contains the following components (A) to (E). (A) A novolak-type phenolic resin in which the molar ratio [(a1):(a2):(a3):(a4)] of the structural unit (a1) derived from m-cresol, the structural unit (a2) derived from catechol, the structural unit (a3) ​​derived from benzaldehyde, and the structural unit (a4) derived from salicylaldehyde is 1:0.25-4.0:0.25-4.0:0.25-4.0. (B) one or more resins selected from the group consisting of ethylenically unsaturated group-containing polyimides, ethylenically unsaturated group-containing polyimide precursors, ethylenically unsaturated group-containing polybenzoxazoles, and ethylenically unsaturated group-containing polybenzoxazole precursors; (C) Radical polymerizable compound (D) Photopolymerization initiator (E) Organic solvent

[0013] In this embodiment, by using the novolac type phenolic resin (A) above, a cured film having high visible light shielding properties can be obtained even if the amount of colorant added is reduced. In addition, by using the resins (A) and (B) above in combination, the compatibility of both resins is improved. This makes it possible to suppress the occurrence of film formation defects (scum). In addition, the negative photosensitive resin composition can be obtained, which has high alkali solubility in the non-exposed areas and can provide a resist film and a cured film having excellent elasticity. The components of the negative photosensitive resin composition will be described below.

[0014] Ingredient (A) The novolac phenolic resin which is component (A) has a molar ratio [(a1):(a2):(a3):(a4)] of the structural unit (a1) derived from m-cresol, the structural unit (a2) derived from catechol, the structural unit (a3) ​​derived from benzaldehyde, and the structural unit (a4) derived from salicylaldehyde, of 1:0.25-4.0:0.25-4.0:0.25-4.0.

[0015] In this embodiment, the novolac phenolic resin of component (A) contains the structural unit (a2) derived from catechol, thereby improving the visible light shielding property of the cured film. Therefore, the amount of colorant used can be reduced. The visible light shielding property of the cured film can be adjusted by the molar ratio of the structural unit (a2). The molar ratio [(a1):(a2):(a3):(a4)] is preferably 1:0.3-3.5:0.8-3.0:0.5-2.0 from the viewpoint of obtaining a cured film that has high sensitivity, excellent compatibility with resins, and visible light shielding properties.

[0016] In one embodiment, the molar ratio [(a1)+(a2):(a3)+(a4)] of the sum [(a1)+(a2)] of the structural unit (a1) derived from m-cresol and the structural unit (a2) derived from catechol to the sum [(a3)+(a4)] of the structural unit (a3) ​​derived from benzaldehyde and the structural unit (a4) derived from salicylaldehyde in the component (A) is 1:0.8-1.2, preferably 1:0.9-1.1. This makes it easier to adjust the weight average molecular weight of the component (A) to a suitable range. In addition, when the negative type photosensitive resin composition of this embodiment is made into a photosensitive film, the alkali solubility (sensitivity) can be increased.

[0017] In one embodiment, the molar ratio [(a2) / ((a1)+(a2))] of the structural unit (a2) to the sum [(a1)+(a2)] of the structural unit (a1) derived from m-cresol and the structural unit (a2) derived from catechol in the component (A) is 0.01 to 0.8. The structural unit (a1) and the structural unit (a2) are both derived from a compound having a hydroxyl group. By increasing the molar ratio of the structural unit (a2), the visible light shielding property of the cured film can be improved. On the other hand, the alkali solubility can be adjusted by the molar ratio of the structural unit (a1). From the viewpoint of achieving both alkali solubility and visible light shielding property, the molar ratio [(a2) / ((a1)+(a2))] is preferably 0.1 to 0.7, more preferably 0.3 to 0.6.

[0018] In one embodiment, the molar ratio [(a3) / ((a3)+(a4))] of the structural unit (a3) ​​to the sum [(a3)+(a4)] of the structural unit (a3) ​​derived from benzaldehyde and the structural unit (a4) derived from salicylaldehyde in the component (A) is 0.2 to 0.8. Both the structural unit (a3) ​​and the structural unit (a4) are derived from a compound having an aldehyde group. The molar ratio [(a3) / ((a3)+(a4))] can be suitably adjusted to adjust the alkali solubility. The molar ratio [(a3) / ((a3)+(a4))] is preferably 0.3 to 0.7.

[0019] Component (A) may contain structural units other than the above structural units (a1) to (a4). Examples of structural units other than the above structural units (a1) to (a4) include structural units derived from phenols other than m-cresol and catechol, and aldehydes other than benzaldehyde and salicylaldehyde.

[0020] Examples of the phenols include phenol, o-cresol, p-cresol, 2,3-xylenol, 2,5-xylenol, 3,4-xylenol, 3,5-xylenol, 2,3,5-trimethylphenol, and 3,4,5-trimethylphenol.

[0021] Examples of the aldehydes include formalin, paraformaldehyde, acetaldehyde, chloroacetaldehyde, 4-hydroxybenzaldehyde, and 3-hydroxybenzaldehyde.

[0022] From the viewpoint of obtaining a resist film and a cured film that have high sensitivity, excellent compatibility with resins, and visible light-shielding properties, the total content of the structural units (a1), (a2), (a3), and (a4) in component (A) is preferably 30 mass % or more, more preferably 50 mass % or more, and even more preferably 90 mass % or more. The total content of the structural units (a1), (a2), (a3) ​​and (a4) may be substantially 100% by mass, which means that structural units other than the structural units (a1), (a2), (a3) ​​and (a4) are inevitably contained.

[0023] The weight average molecular weight of the novolac phenolic resin, which is component (A), is preferably 1,000 or more, more preferably 1,500 or more. It is also preferably 7,000 or less, more preferably 6,000 or less, and even more preferably 5,000 or less. A weight average molecular weight of 1,000 or more is preferable because of high heat resistance. On the other hand, a weight average molecular weight of 7,000 or less is preferable because of high sensitivity. In this specification, the weight average molecular weight is measured according to the conditions described in the examples.

[0024] Component (A) is obtained by polycondensing m-cresol, catechol, benzaldehyde, and salicylaldehyde in an organic solvent in a molar ratio (m-cresol:catechol:benzaldehyde:salicylaldehyde) range of 1:0.25-4.0:0.25-4.0:0.25-4.0 using an acid catalyst.

[0025] The molar ratio of m-cresol, catechol, benzaldehyde, and salicylaldehyde (m-cresol:catechol:benzaldehyde:salicylaldehyde) is preferably in the range of 1:0.3-3.5:0.8-3.0:0.5-2.0 from the viewpoint of obtaining a resist film and a cured film that have excellent resin compatibility and visible light-shielding properties in addition to high sensitivity.

[0026] In one embodiment, the molar ratio of the sum of m-cresol and catechol to the sum of benzaldehyde and salicylaldehyde ((m-cresol+catechol):(benzaldehyde+salicylaldehyde)) is 1:0.8 to 1.2. The molar ratio of catechol to the total of m-cresol and catechol (catechol / (m-cresol+catechol)) is 0.01 to 0.8. The molar ratio of salicylaldehyde to the total of salicylaldehyde and benzaldehyde (salicylaldehyde / (salicylaldehyde+benzaldehyde)) is 0.2 to 0.8.

[0027] When m-cresol, catechol, benzaldehyde, and salicylaldehyde are polycondensed in an organic solvent to obtain a novolak-type phenolic resin as component (A), as described above, phenols and aldehydes other than m-cresol, catechol, benzaldehyde, and salicylaldehyde may be contained in the organic solvent.

[0028] From the viewpoint of obtaining a resist film and a cured film that have excellent resin compatibility and visible light-shielding properties in addition to high sensitivity, the proportion of the total mass of m-cresol, catechol, benzaldehyde, and salicylaldehyde to the total mass of all starting materials that can become structural units constituting component (A) in the organic solvent is preferably 30 mass % or more, more preferably 50 mass % or more, and even more preferably substantially 100 mass %.

[0029] Examples of organic solvents used in producing component (A) include methanol, ethanol, 1-propanol, 2-propanol, butanol, hexanol, ethylene glycol, ethylene glycol monomethyl ether, propylene glycol monomethyl ether, methyl ethyl ketone, methyl isobutyl ketone, toluene, and the like. Among these, one or more selected from ethanol, 1-propanol, and 2-propanol are preferred, and ethanol is more preferred.

[0030] From the viewpoint of uniformity of the reaction, the amount of the organic solvent used is preferably 20 parts by mass or more, more preferably 50 parts by mass or more, relative to 100 parts by mass of the raw material for deriving the structural unit constituting component (A), and is preferably 500 parts by mass or less, more preferably 300 parts by mass or less.

[0031] Examples of the acid catalyst used in producing component (A) include inorganic acids such as hydrochloric acid, sulfuric acid, phosphoric acid, boric acid, etc., and organic acids such as oxalic acid, acetic acid, paratoluenesulfonic acid, etc. Among these, inorganic acids and paratoluenesulfonic acid are preferred in order to further promote the reaction, and paratoluenesulfonic acid is more preferred. The amount of the acid catalyst to be added is not particularly limited, but is preferably 5 parts by mass or more, more preferably 20 parts by mass or more, relative to 100 parts by mass of the raw material for deriving the structural unit constituting component (A), and is preferably 150 parts by mass or less, more preferably 100 parts by mass or less.

[0032] The reaction temperature during polycondensation of the raw material of component (A) is preferably 30° C. or higher, more preferably 40° C. or higher, in order to promote the reaction and efficiently increase the molecular weight, and is preferably 100° C. or lower, more preferably 80° C. or lower. The reaction time is preferably 4 hours or more, more preferably 12 hours or more, and is preferably 32 hours or less, more preferably 24 hours or less.

[0033] ·Component (B) Component (B) is one or more resins selected from ethylenically unsaturated group-containing polyimide, ethylenically unsaturated group-containing polyimide precursor, ethylenically unsaturated group-containing polybenzoxazole, and ethylenically unsaturated group-containing polybenzoxazole precursor. Component (B) is a polyimide, a polyimide precursor, a polybenzoxazole, or a polybenzoxazole precursor to which an ethylenically unsaturated group has been introduced. Component (B) can be any resin that has been used in conventional photosensitive resin compositions.

[0034] <Polyimide and polyimide precursor> Examples of the polyimide precursor include those obtained by reacting a tetracarboxylic acid, a corresponding tetracarboxylic dianhydride, or a tetracarboxylic diester dichloride, etc., with a diamine, a corresponding diisocyanate compound, or a trimethylsilylated diamine, etc., and have a tetracarboxylic acid and / or a derivative residue thereof and a diamine and / or a derivative residue thereof. Examples of the polyimide precursor include polyamic acid, polyamic acid ester, polyamic acid amide, and polyisoimide.

[0035] Examples of polyimides include those obtained by dehydrating and ring-closing the above-mentioned polyamic acid, polyamic acid ester, polyamic acid amide, or polyisoimide through heating or a reaction using an acid, a base, or the like, and have a residue of a tetracarboxylic acid and / or a derivative thereof, and a residue of a diamine and / or a derivative thereof. The tetracarboxylic dianhydride used in the synthesis of the polyimide is preferably pyromellitic anhydride from the viewpoint of heat resistance.The diamine used in the synthesis of the polyimide is preferably 4,4-diaminodiphenyl ether from the viewpoint of heat resistance.

[0036] The unsaturated group-containing polyimide and the unsaturated group-containing polyimide precursor used in the present invention have the above-mentioned polyimide or polyimide precursor and an ethylenically unsaturated group as a radical polymerizable group. By having an ethylenically unsaturated group, the sensitivity during exposure can be improved. The unsaturated group-containing polyimide and the unsaturated group-containing polyimide precursor are preferably obtained by reacting a part of the phenolic hydroxyl group and / or carboxyl group of the polyimide and the polyimide precursor with a compound having an ethylenically unsaturated group described later. The above reaction makes it possible to introduce an ethylenically unsaturated group into the resin.

[0037] <Polybenzoxazole and polybenzoxazole precursor> The polybenzoxazole precursor may be, for example, a product obtained by reacting a dicarboxylic acid, a corresponding dicarboxylic acid dichloride or a dicarboxylic acid active diester, etc., with a bisaminophenol compound, etc., as a diamine, and has a dicarboxylic acid and / or a derivative residue thereof and a bisaminophenol compound and / or a derivative residue thereof. The polybenzoxazole precursor may be, for example, a polyhydroxyamide.

[0038] Examples of polybenzoxazoles include those obtained by dehydrating and ring-closing a dicarboxylic acid and a bisaminophenol compound as a diamine through a reaction using polyphosphoric acid, and those obtained by dehydrating and ring-closing the above-mentioned polyhydroxyamide through heating or a reaction using phosphoric anhydride, a base, a carbodiimide compound, or the like, and have a dicarboxylic acid and / or a derivative residue thereof and a bisaminophenol compound and / or a derivative residue thereof. The bisaminophenol used in the synthesis of polybenzoxazole is preferably 3,3-hydroxybenzidine from the viewpoint of heat resistance.The dicarboxylic acid used in the synthesis of polybenzoxazole is preferably 4,4-biphenyldicarboxylic acid from the viewpoint of heat resistance.

[0039] The ethylenically unsaturated group-containing polybenzoxazole and ethylenically unsaturated group-containing polybenzoxazole precursor used in the present invention have an ethylenically unsaturated group as a radical polymerizable group. By having an ethylenically unsaturated group, the sensitivity during exposure can be improved. The ethylenically unsaturated group-containing polybenzoxazole and ethylenically unsaturated group-containing polybenzoxazole precursor are preferably obtained by reacting a part of the phenolic hydroxyl group and / or carboxyl group of the polybenzoxazole and polybenzoxazole precursor with a compound having an ethylenically unsaturated group described below. The above reaction makes it possible to introduce an ethylenically unsaturated group into the resin.

[0040] <Compound having an ethylenically unsaturated group> Examples of compounds having an ethylenically unsaturated group include isocyanate compounds, isothiocyanate compounds, epoxy compounds, aldehyde compounds, thioaldehyde compounds, ketone compounds, thioketone compounds, acetate compounds, carboxylic acid chlorides, carboxylic acid anhydrides, carboxylic acid active ester compounds, carboxylic acid compounds, alkyl halide compounds, alkyl azide compounds, alkyl triflate compounds, alkyl mesylate compounds, alkyl tosylate compounds, and alkyl cyanide compounds.

[0041] <Method for synthesizing polyimide, polybenzoxazole, polyimide precursor, or polybenzoxazole precursor> Polyimide, polyimide precursor, polybenzoxazole or polybenzoxazole precursor can be synthesized by a known method. For example, a specific method is to first dissolve diamines or bisaminophenol compounds in a reaction solvent, and gradually add substantially equimolar amounts of carboxylic acid anhydrides to this solution. Using a mechanical stirrer, the mixed solution is stirred at a temperature of preferably 0 to 200°C, more preferably 40 to 150°C, preferably for 0.5 to 50 hours, more preferably 2 to 24 hours. When a terminal blocking agent is used, after adding the carboxylic acid anhydrides, the mixture is stirred at a predetermined temperature for a predetermined time, and then the terminal blocking agent is gradually added and stirred.

[0042] The reaction solvent used in the polymerization reaction may be a polar solvent that can dissolve the diamines or bisaminophenol compounds and carboxylic anhydrides that are raw materials. Examples of the reaction solvent include amides such as N,N-dimethylformamide, N,N-dimethylacetamide, or N-methyl-2-pyrrolidone, cyclic esters such as γ-butyrolactone, γ-valerolactone, δ-valerolactone, γ-caprolactone, ε-caprolactone, or α-methyl-γ-butyrolactone, carbonates such as ethylene carbonate or propylene carbonate, glycols such as triethylene glycol, phenols such as m-cresol or p-cresol, or other solvents such as acetophenone, 1,3-dimethyl-2-imidazolidinone, sulfolane, and dimethyl sulfoxide. The amount of the reaction solvent is preferably from 100 to 1,900 parts by mass, and more preferably from 150 to 950 parts by mass, based on 100 parts by mass of the total of the diamines or bisaminophenol compounds and the carboxylic acid anhydrides.

[0043] It is preferable that one or more selected from polyimide, polybenzoxazole, polyimide precursor, and polybenzoxazole precursor are precipitated in a poor solvent for one or more selected from polyimide, polybenzoxazole, polyimide precursor, and polybenzoxazole precursor, such as methanol or water, after the polymerization reaction is completed, and then washed and dried. By carrying out the reprecipitation treatment, low molecular weight components and the like can be removed, and the mechanical properties (elastic modulus) of the cured film are significantly improved.

[0044] <Method for synthesizing ethylenically unsaturated group-containing polyimide, ethylenically unsaturated group-containing polyimide precursor, ethylenically unsaturated group-containing polybenzoxazole, or ethylenically unsaturated group-containing polybenzoxazole precursor> The ethylenically unsaturated group-containing polyimide, the ethylenically unsaturated group-containing polyimide precursor, the ethylenically unsaturated group-containing polybenzoxazole, or the ethylenically unsaturated group-containing polybenzoxazole precursor can be synthesized by a known method. As conditions for the reaction of further introducing an ethylenically unsaturated group into polyimide, polybenzoxazole, polyimide precursor, or polybenzoxazole precursor, it is preferable to sufficiently replace the atmosphere in a reaction vessel with nitrogen under air or by bubbling, degassing under reduced pressure, or the like, and then add polyimide, polyimide precursor, polybenzoxazole, or polybenzoxazole precursor and a compound having an ethylenically unsaturated group in a reaction solvent and react for 30 to 500 minutes at 20 to 110° C. Furthermore, a polymerization inhibitor such as a phenol compound, an acid catalyst, or a base catalyst may be used as necessary.

[0045] Regarding component (B), for specific descriptions of polyimide, polyimide precursor, polybenzoxazole, polybenzoxazole precursor, ethylenically unsaturated group-containing polyimide, ethylenically unsaturated group-containing polyimide precursor, ethylenically unsaturated group-containing polybenzoxazole, and ethylenically unsaturated group-containing polybenzoxazole precursor, the contents of

[0074] to

[0210] in WO 2017 / 159876 may be referred to as appropriate.

[0046] The weight average molecular weight of component (B) is preferably 5,000 or more, more preferably 10,000 or more. Also, it is preferably 50,000 or less, more preferably 40,000 or less. If the weight average molecular weight is 5,000 or more, it is preferred because it has high heat resistance. On the other hand, if the weight average molecular weight is 50,000 or less, it is preferred from the viewpoint of solvent solubility.

[0047] The amount of component (B) is preferably 10 parts by mass or more, more preferably 20 parts by mass or more, relative to 100 parts by mass of component (A), since good sensitivity and a cured film with excellent visible light shielding properties can be obtained. Also, the amount is preferably 2,000 parts by mass or less, more preferably 1,000 parts by mass or less, relative to 100 parts by mass of component (A).

[0048] ·Component (C) Component (C) is a radical polymerizable compound. The radical polymerizable compound refers to a compound having multiple ethylenically unsaturated groups in the molecule. By including the radical polymerizable compound, the curing of the exposed area is promoted, and the sensitivity during exposure can be improved. In addition, the crosslink density after thermal curing is improved, and the hardness (elastic modulus) of the cured film can be improved.

[0049] The radical polymerizable compound is not particularly limited, and any known radical polymerizable compound can be used, but a compound having a (meth)acrylic group, which is easily subjected to radical polymerization, is preferred. From the viewpoint of improving the sensitivity during exposure and the hardness of the cured film, a compound having two or more (meth)acrylic groups in the molecule is more preferred.

[0050] Examples of the radical polymerizable compound include diethylene glycol di(meth)acrylate, triethylene glycol di(meth)acrylate, tetraethylene glycol di(meth)acrylate, propylene glycol di(meth)acrylate, trimethylolpropane di(meth)acrylate, trimethylolpropane tri(meth)acrylate, ethoxylated trimethylolpropane di(meth)acrylate, ethoxylated trimethylolpropane tri(meth)acrylate, ditri ... diolpropane tetra(meth)acrylate, 1,3-butanediol di(meth)acrylate, neopentyl glycol di(meth)acrylate, 1,4-butanediol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, 1,9-nonanediol di(meth)acrylate, 1,10-decanediol di(meth)acrylate, dimethylol-tricyclodecane di(meth)acrylate, ethoxylated glycerin tri(meth)acrylate, pentaerythritol tri(meth)acrylate, pentaerythritol tetra(meth)acrylate (Meth)acrylate, ethoxylated pentaerythritol tri(meth)acrylate, ethoxylated pentaerythritol tetra(meth)acrylate, dipentaerythritol penta(meth)acrylate, dipentaerythritol hexa(meth)acrylate, tripentaerythritol hepta(meth)acrylate, tripentaerythritol octa(meth)acrylate, tetrapentaerythritol nona(meth)acrylate, tetrapentaerythritol deca(meth)acrylate, pentapentaerythritol undeca(meth)acrylate acrylate, pentaerythritol dodeca(meth)acrylate, ethoxylated bisphenol A di(meth)acrylate, 2,2-bis[4-(3-(meth)acryloxy-2-hydroxypropoxy)phenyl]propane, 1,3,5-tris((meth)acryloxyethyl)isocyanuric acid, 1,3-bis((meth)acryloxyethyl)isocyanuric acid, 9,9-bis[4-(2-(meth)acryloxyethoxy)phenyl]fluorene, 9,9-bis[4-(3-(meth)acryloxypropoxy)phenyl]fluorene or 9,9-bis(4-(meth)acryloxyphenyl)fluorene or an acid-modified product thereof, an ethylene oxide-modified product thereof, or a propylene oxide-modified product thereof.

[0051] The amount of the radical polymerizable compound is preferably 1 part by mass or more, more preferably 10 parts by mass or more, even more preferably 30 parts by mass or more, and particularly preferably 50 parts by mass or more, based on 100 parts by mass of component (A). On the other hand, the content of the radical polymerizable compound is preferably 500 parts by mass or less, more preferably 300 parts by mass or less, even more preferably 200 parts by mass or less, and particularly preferably 150 parts by mass or less. When the content is within the above range, the sensitivity during exposure can be improved.

[0052] The radically polymerizable compound as component (C) may be used either alone or in combination of two or more.

[0053] ·Component (D) Component (D) is a photopolymerization initiator. A photopolymerization initiator is a compound that generates radicals by bond cleavage and / or reaction upon exposure to light. By including a photopolymerization initiator, the exposed portion of the film of the negative photosensitive resin composition becomes insoluble in an alkaline developer, so that a negative pattern can be formed. In addition, curing of the exposed portion is promoted, and sensitivity can be improved.

[0054] The photopolymerization initiator is not particularly limited, and a known photopolymerization initiator can be used. Examples of the photopolymerization initiator include benzyl ketal-based photopolymerization initiators, α-hydroxyketone-based photopolymerization initiators, α-aminoketone-based photopolymerization initiators, acylphosphine oxide-based photopolymerization initiators, oxime ester-based photopolymerization initiators, acridine-based photopolymerization initiators, titanocene-based photopolymerization initiators, benzophenone-based photopolymerization initiators, acetophenone-based photopolymerization initiators, aromatic ketoester-based photopolymerization initiators, and benzoic acid ester-based photopolymerization initiators.

[0055] The photopolymerization initiator may be used alone or in combination of two or more kinds. The amount of the photopolymerization initiator is preferably 1 part by mass or more, more preferably 10 parts by mass or more, relative to 100 parts by mass of component (A), since good sensitivity and a desired pattern can be obtained. Also, the amount is preferably 50 parts by mass or less, more preferably 30 parts by mass or less.

[0056] ·Component (E) Examples of the organic solvent that is component (E) include polar aprotic solvents such as N-methyl-2-pyrrolidone, γ-butyrolactone, N,N-dimethylformamide, N,N-dimethylacetamide, and dimethylsulfoxide, ethers such as tetrahydrofuran, dioxane, propylene glycol monomethyl ether, and propylene glycol monoethyl ether, ketones such as acetone, methyl ethyl ketone, and diisobutyl ketone, esters such as ethyl acetate, butyl acetate, isobutyl acetate, propyl acetate, propylene glycol monomethyl ether acetate, and 3-methyl-3-methoxybutyl acetate, alcohols such as ethyl lactate, methyl lactate, diacetone alcohol, and 3-methyl-3-methoxybutanol, and aromatic hydrocarbons such as toluene and xylene. These solvents may be used alone or in combination of two or more.

[0057] The amount of component (E) in the negative photosensitive resin composition of the present embodiment is preferably an amount such that the solid content in the composition is 5% by mass or more, since the fluidity of the composition allows a uniform coating to be obtained by a coating method such as spin coating, and is preferably an amount such that the solid content in the composition is 65% by mass or less.

[0058] ·others In one embodiment, the negative photosensitive resin composition may contain various additives in addition to the above-mentioned components (A) to (E) within the range that does not impair the effects of the present invention. Examples of the additives include fillers, surfactants such as leveling agents, adhesion improvers, and dissolution promoters.

[0059] Since the cured film obtained from the negative type photosensitive resin composition of the present embodiment has a visible light shielding property, it is not necessary to add a separate colorant. However, when a higher visible light shielding property is required, the negative type photosensitive resin composition of the present embodiment may further contain a colorant. Examples of colorants include organic pigments such as benzofuranone-based black pigments, perylene-based black pigments, azo-based black pigments, anthraquinone-based black pigments, aniline-based black pigments, azomethine-based black pigments, carbon black, and graphite, and inorganic pigments such as oxides, composite oxides, sulfides, sulfates, nitrates, carbonates, nitrides, carbides, and oxynitrides of metals (alloys) such as silver-tin alloys, titanium, copper, iron, manganese, cobalt, chromium, nickel, zinc, calcium, and silver.

[0060] In one embodiment, the amount of the colorant is 0 to 30 parts by mass relative to 100 parts by mass of the solid content of the negative photosensitive resin composition. Since the negative photosensitive resin composition of this embodiment has a visible light shielding property, the amount of the colorant can be reduced more than in the past. The negative photosensitive resin composition may not contain a colorant, or may contain a colorant. When the negative photosensitive resin composition contains a colorant, the amount may be more than 0 parts by mass or 0.1 parts by mass or more relative to 100 parts by mass of the solid content of the negative photosensitive resin composition.

[0061] The negative type photosensitive resin composition of the present embodiment can be prepared by stirring and mixing the above-mentioned components (A) to (E) and, if necessary, various additives, in a conventional manner to prepare a homogeneous liquid. When solid materials such as fillers and pigments are blended into the composition, they are preferably dispersed and mixed using a dispersing device such as a dissolver, homogenizer, triple roll mill, etc. In addition, the composition can be filtered using a mesh filter, membrane filter, etc. to remove coarse particles and impurities.

[0062] The negative type photosensitive resin composition of the present embodiment can be suitably used for forming, for example, a negative type photoresist, an organic underlayer film, a thick film resist (bump formation resist), an interlayer insulating film, a liquid crystal alignment film, a heat resistance imparting agent, polyimide, a polybenzoxazole-based resist, or a pixel dividing layer in a display device such as an organic EL display.

[0063] [Hardened film / resist film] A cured film according to one embodiment of the present invention can be obtained by curing the above-mentioned negative type photosensitive resin composition according to the present invention. Specifically, the negative photosensitive resin composition of the present invention is applied onto an object to be subjected to photolithography, and then prebaked to obtain a film of the photosensitive resin composition (photosensitive film) from which the solvent has been removed.

[0064] Examples of the coating method include spin coating, roll coating, flow coating, dip coating, spray coating, doctor blade coating, etc. Pre-baking may be performed, for example, by heating at a temperature of 60° C. to 150° C. for a period of 30 seconds to 600 seconds.

[0065] By exposing the photosensitive film, the solubility of the exposed area in an alkaline developer is significantly reduced. Examples of light sources used for exposure include infrared light, visible light, ultraviolet light, far ultraviolet light, X-rays, and electron beams. Among these light sources, ultraviolet light is preferred, and g-rays (wavelength 436 nm) and i-rays (wavelength 365 nm) from a high-pressure mercury lamp are suitable. After exposure, the film is heated at about 100° C. to promote the crosslinking reaction between components (A), (B) and (C) through the catalytic reaction of the acid generated by the exposure.

[0066] The photosensitive film obtained from the negative photosensitive resin composition of the present invention has high alkali solubility, and therefore the difference in alkali solubility between the exposed area and the photosensitive film is large, which enables patterning with high resolution. Therefore, the photosensitive film can be suitably used as a resist film.

[0067] Examples of alkaline developers used for development after exposure include alkaline aqueous solutions of inorganic alkaline substances such as sodium hydroxide, potassium hydroxide, sodium carbonate, sodium silicate, sodium metasilicate, and aqueous ammonia; primary amines such as ethylamine and n-propylamine; secondary amines such as diethylamine and di-n-butylamine; tertiary amines such as triethylamine and methyldiethylamine; alcohol amines such as dimethylethanolamine and triethanolamine; quaternary ammonium salts such as tetramethylammonium hydroxide and tetraethylammonium hydroxide; and cyclic amines such as pyrrole and pyridine. The alkaline developer may be used by appropriately adding alcohol, a surfactant, etc., if necessary. The alkaline concentration of the alkaline developer is usually preferably in the range of 2 to 5% by mass, and a 2.38% by mass aqueous solution of tetramethylammonium hydroxide is generally used.

[0068] After development with an alkaline developer, a cured film in which the exposed areas are crosslinked can be obtained by heating at a low temperature, for example, from 150° C. to 200° C. The cured film of this embodiment has excellent visible light shielding properties. The cured film of the present embodiment can be used, for example, as a pixel dividing layer in a display device such as an organic EL display. EXAMPLES

[0069] The present invention will be described in more detail below with reference to specific examples. The weight average molecular weight (Mw) of the synthesized resin was measured under the following GPC measurement conditions. [GPC measurement conditions] Measurement equipment: Tosoh Corporation "HLC-8220 GPC" Column: Showa Denko K.K. "Shodex KF802": 8.0mmΦ×300mm +Showa Denko KF802: 8.0mmΦ×300mm +Showa Denko KF803: 8.0mmΦ×300mm +Showa Denko KF804: 8.0mmΦ×300mm Column temperature: 40℃ Detector: RI (differential refractometer) Data processing: Tosoh Corporation "GPC-8020 Model II Version 4.30" Developing solvent: Tetrahydrofuran Flow rate: 1.0mL / min Sample: 0.5% by mass of tetrahydrofuran solution (resin solid content equivalent) filtered through a microfilter Injection volume: 0.1mL Standard sample: monodisperse polystyrene as follows (Standard sample: monodisperse polystyrene) "A-500" manufactured by Tosoh Corporation "A-2500" manufactured by Tosoh Corporation "A-5000" manufactured by Tosoh Corporation "F-1" manufactured by Tosoh Corporation "F-2" manufactured by Tosoh Corporation "F-4" manufactured by Tosoh Corporation "F-10" manufactured by Tosoh Corporation "F-20" manufactured by Tosoh Corporation

[0070] [Component (A)] Synthesis Example 1 (Synthesis of Novolac-type Phenolic Resin (A-1)) In a 2000mL four-neck flask equipped with a cooling tube, 82g (0.76mol) of m-cresol, 84g (0.76mol), catechol, 103g (0.97mol), salicylaldehyde, 74g (0.61mol), and paratoluenesulfonic acid were charged and dissolved in 300g of ethanol as a reaction solvent. The mixture was then heated to 80°C using a mantle heater and stirred under reflux for 16 hours to react. After the reaction was completed, ethyl acetate and water were added and the mixture was washed five times by separation. The solvent was removed from the remaining resin solution under reduced pressure, and the mixture was dried in vacuum to obtain 279g of a pale red powder of novolac-type phenolic resin (A-1). The Mw of the novolak phenolic resin (A-1) obtained by GPC was 3,820.

[0071] Synthesis Example 2 (Synthesis of Novolac-type Phenolic Resin (A-2)) The same procedure as in Synthesis Example 1 was repeated except that the amounts of the starting materials used were 82 g (0.76 mol) of m-cresol, 84 g (0.76 mol) of catechol, 80 g (0.75 mol) of benzaldehyde, and 92 g (0.75 mol) of salicylaldehyde, to obtain 283 g of powder of novolak-type phenolic resin (A-2). The Mw of the novolak phenolic resin (A-2) obtained by GPC was 3,270.

[0072] Synthesis Example 3 (Synthesis of Novolac-type Phenolic Resin (A-3)) Except for changing the amounts of the starting materials to 82 g (0.76 mol) of m-cresol, 84 g (0.76 mol) of catechol, 117 g (1.10 mol) of benzaldehyde, and 58 g (0.47 mol) of salicylaldehyde, the same procedure as in Synthesis Example 1 was repeated to obtain 279 g of powder of novolac type phenolic resin (A-3). The Mw of the novolac type phenolic resin (A-3) was 3,620.

[0073] Synthesis Example 4 (Synthesis of Novolac-type Phenolic Resin (A-4)) The same procedure as in Synthesis Example 1 was repeated except that the amounts of the starting materials used were 82 g (0.76 mol) of m-cresol, 84 g (0.76 mol) of catechol, 67 g (0.63 mol) of benzaldehyde, and 115 g (0.94 mol) of salicylaldehyde, to obtain 286 g of powder of novolak-type phenolic resin (A-4). The Mw of the phenol novolak resin (A-4) obtained by GPC was 3,540.

[0074] Synthesis Example 5 (Synthesis of Novolac-type Phenolic Resin (A-5)) The same procedure as in Synthesis Example 1 was repeated except that the amounts of the starting materials used were 123 g (1.14 mol) of m-cresol, 42 g (0.38 mol) of catechol, 103 g (0.97 mol) of benzaldehyde, and 74 g (0.61 mol) of salicylaldehyde, to obtain 282 g of powder of novolak-type phenolic resin (A-5). The Mw of the phenol novolak resin (A-5) obtained by GPC was 3,210.

[0075] Synthesis Example 6 (Synthesis of Novolac-type Phenolic Resin (A-6)) The same procedure as in Synthesis Example 1 was repeated except that the amounts of the starting materials used were 41 g (0.38 mol) of m-cresol, 126 g (1.14 mol) of catechol, 103 g (0.97 mol) of benzaldehyde, and 74 g (0.61 mol) of salicylaldehyde, to obtain 281 g of powder of novolak-type phenolic resin (A-6). The Mw of the phenol novolak resin (A-6) obtained by GPC was 3,790.

[0076] Comparative Synthesis Example 1 (Synthesis of Novolac-type Phenolic Resin (A-7)) The same procedure as in Synthesis Example 1 was repeated except that the amounts of the starting materials charged were 164 g (1.52 mol) of m-cresol, 103 g (0.97 mol) of benzaldehyde, and 74 g (0.61 mol) of salicylaldehyde, to obtain 281 g of powder of novolak-type phenolic resin (A-7). The Mw of the novolak phenolic resin (A-7) obtained by GPC was 3,100.

[0077] [Component (B)] Synthesis Example 7 (Synthesis of ethylenically unsaturated group-containing polyimide precursor (B-1)) Under a dry nitrogen stream, 125 g (0.023 mol) of pyromellitic anhydride and 115 g (0.023 mol) of 4,4-diaminodiphenyl ether were dissolved in 1602 g of N-methyl-2-pyrrolidone in a 2000 mL four-neck flask equipped with a cooling tube, and the mixture was stirred at 100°C for 4 hours to react. After the reaction was completed, the solution was poured into 2000 g of water, and the precipitate of the polymer solid was collected by filtration. The polymer solid was dried in a vacuum dryer at 80°C for 72 hours to obtain a polymer solid powder. 32.8 g of the obtained solid powder was dissolved in 76.5 g of 3-methoxy-n-butyl acetate. After cooling this mixed solution to 0°C, a solution of 3.2 g of 2-methacryloxyethyl isocyanate dissolved in 3.2 g of 3-methoxy-n-butyl acetate was added dropwise. After the dropwise addition was completed, the mixture was stirred at 80°C for 1 hour to obtain an ethylenically unsaturated group-containing polymer solution. After the reaction was completed, the obtained solution was poured into 1000 g of water, and the precipitate of the ethylenically unsaturated group-containing polymer solid was collected by filtration. The precipitate of the polymer solid was collected by filtration. The ethylenically unsaturated group-containing polymer solid was dried in a vacuum dryer at 80°C for 72 hours to obtain a polymer powder of an ethylenically unsaturated group-containing polyimide precursor (B-1).

[0078] [Negative-type photosensitive resin composition] Example 1 A negative photosensitive resin composition (F-1) was obtained by dissolving 4.2 g of the phenol novolak resin (A-1) powder obtained in Synthesis Example 1 as component (A), 1.8 g of the polymer powder of the ethylenically unsaturated group-containing polyimide precursor (B-1) obtained in Synthesis Example 7 as component (B), 4.0 g of a radical polymerizable compound (dipentaerythritol hexaacrylate: manufactured by Nippon Kayaku Co., Ltd.) as component (C), and 0.9 g of a photopolymerization initiator (NCI-831: manufactured by ADEKA Corporation) as component (D) in 98 g of γ-butyrolactone as component (E).

[0079] Examples 2 to 6, Comparative Examples 1 and 2 In Examples 2 to 6 and Comparative Example 1, negative photosensitive resin compositions (F-2) to (F-7) were obtained in the same manner as in Example 1, except that phenol novolak resin (A-2) to (A-7) powders shown in Tables 1 and 2 were used as component (A). In Comparative Example 2, the phenol novolac resin (A-7) shown in Table 2 was used as the component (A), and 3.4 g of a benzofuran-based black pigment (BASF: Bk-S0100CF) and 1.3 g of a dispersant (BYK-167 DISPERBYK, BYK Japan Co., Ltd.) were dissolved in 140 g of γ-butyrolactone solvent (E). A negative photosensitive resin composition (F-8) was obtained in the same manner as in Example 1.

[0080] [evaluation] The negative photosensitive resin compositions prepared in the Examples and Comparative Examples were evaluated for resin compatibility, alkali solubility before exposure, visible light shielding ability, and elastic modulus of the cured film. (1) Evaluation of resin compatibility (film-forming ability) The negative photosensitive resin composition was applied to a silicon wafer having a diameter of 5 inches to a thickness of about 5 μm using a spin coater. The wafer was then prebaked at 120° C. for 180 seconds to obtain a wafer having a photosensitive film formed thereon. The photosensitive film formed on the wafer surface was observed using an optical microscope to evaluate the presence or absence of repellency and unevenness. Regarding the photosensitive film, those without repellency or unevenness were rated as having good resin compatibility (◯), and those with repellency or unevenness were rated as having insufficient resin compatibility (×). The evaluation results are shown in Tables 1 and 2.

[0081] (2) Alkaline solubility before exposure The negative photosensitive resin composition was applied to a silicon wafer having a diameter of 5 inches to a thickness of about 5 μm using a spin coater. The composition was then prebaked at 120° C. for 180 seconds to obtain a wafer having a photosensitive film formed thereon. The obtained wafer was immersed for 10 seconds in a vat filled with 250 mL of a developer (a 2.38 wt % aqueous solution of tetramethylammonium hydroxide (TMAH)). The wafer was removed from the vat and rinsed with pure water for 10 seconds, and the residue of the photosensitive film on the wafer was observed to evaluate the alkali solubility. The wafers without residue of the photosensitive film were evaluated as good (◯), and those with residue were evaluated as insufficient (×). The evaluation results are shown in Tables 1 and 2.

[0082] (3) Visible light shielding ability of the resin composition The negative photosensitive resin composition was diluted with γ-butyrolactone so that the solid content concentration of the composition became 1%, and the visible light shielding ability was evaluated using UV-vis (Shimadzu Corporation: SolidSpec-3700 DUV). The transmittance of 650 nm was evaluated as good (◯), and the transmittance of 10% or more was evaluated as insufficient (×). The evaluation results are shown in Tables 1 and 2.

[0083] (4) Elastic modulus of cured film The negative photosensitive resin composition was applied to a silicon wafer having a diameter of 5 inches to a thickness of about 5 μm using a spin coater. Then, the wafer was prebaked at 120° C. for 180 seconds to obtain a wafer on which a photosensitive film was formed. The obtained wafer was irradiated with 200 mJ of ghi line (g line: wavelength 436 nm, h line: wavelength 405 nm, i line: wavelength 365 nm) using a multilight manufactured by Ushio, and then pre-development baked (PEB) for 120 seconds on a hot plate at 130° C. Then, the wafer with the coating was heat-treated at 200° C. for 1 hour under inert. When the temperature of the heating device became 50° C. or less, the wafer was taken out and the film thickness was measured. The film hardness was measured by a nanoindentation method (ENT-2100: manufactured by Elionix Co., Ltd.). The indentation elastic modulus of 8 GPa or more was evaluated as good (◯), and the indentation elastic modulus of less than 8 GPa was evaluated as insufficient (×). The evaluation results are shown in Tables 1 and 2.

[0084] [Table 1]

[0085] [Table 2]

[0086] In Tables 1 and 2, (a1), (a2), (a3) ​​and (a4) respectively represent the structural unit (a1) derived from m-cresol, the structural unit (a2) derived from catechol, the structural unit (a3) ​​derived from benzaldehyde and the structural unit (a4) derived from salicylaldehyde in the phenol novolak resin, component (A).

[0087] From Tables 1 and 2, it is considered that the photosensitive film obtained from the negative photosensitive resin composition of the present invention has excellent compatibility, and therefore does not cause repellency or unevenness. It can also be confirmed that the composition has alkali solubility. It can also be confirmed that the composition has excellent visible light shielding properties without adding a black pigment.

Claims

1. A negative photosensitive resin composition comprising the following components (A) to (E): (A) A novolak-type phenolic resin in which the molar ratio [(a1):(a2):(a3):(a4)] of the structural unit (a1) derived from m-cresol, the structural unit (a2) derived from catechol, the structural unit (a3) ​​derived from benzaldehyde, and the structural unit (a4) derived from salicylaldehyde is 1:0.25-4.0:0.25-4.0:0.25-4.

0. (B) one or more resins selected from the group consisting of ethylenically unsaturated group-containing polyimides, ethylenically unsaturated group-containing polyimide precursors, ethylenically unsaturated group-containing polybenzoxazoles, and ethylenically unsaturated group-containing polybenzoxazole precursors; (C) Radically Polymerizable Compound (D) Photopolymerization initiator (E) Organic solvent

2. 2. The negative type photosensitive resin composition according to claim 1, wherein the component (A) is a novolak type phenolic resin obtained by polycondensing m-cresol, catechol, benzaldehyde, and salicylaldehyde in an organic solvent in a molar ratio of m-cresol:catechol:benzaldehyde:salicylaldehyde=1:0.25-4.0:0.25-4.0:0.25-4.0 using an acid catalyst.

3. 3. The negative type photosensitive resin composition according to claim 1, wherein a total content of the structural unit (a1) derived from m-cresol, the structural unit (a2) derived from catechol, the structural unit (a3) ​​derived from benzaldehyde, and the structural unit (a4) derived from salicylaldehyde in the component (A) is 30 mass% or more.

4. 3. The negative type photosensitive resin composition according to claim 1, wherein the weight average molecular weight of the component (A) is 1,000 or more and 7,000 or less.

5. 3. The negative type photosensitive resin composition according to claim 1, further comprising a colorant in an amount of 0 to 30 parts by mass per 100 parts by mass of the solid content of the negative type photosensitive resin composition.

6. A cured film obtained from the negative photosensitive resin composition according to claim 1 or 2.

7. A resist film obtained from the negative photosensitive resin composition according to claim 1 or 2.

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