JP7201024B2 - Negative photosensitive resin composition - Google Patents

Description

TECHNICAL FIELD The present invention relates to a negative photosensitive resin composition, a cured film, and a resist film.

Organic EL displays are attracting attention as next-generation flat panel displays. An organic EL display is a self-luminous display device that utilizes electroluminescence from an organic compound, and is capable of displaying images with a wide angle of view and high-speed response. In addition, thinning and weight reduction are possible. In recent years, as the definition of organic EL displays has increased, there has been a demand for further miniaturization of light-emitting elements.

An organic EL display emits light by using the recombination energy of electrons injected from a cathode and holes injected from an anode. Therefore, if there is a substance that forms an energy level that inhibits recombination of electrons and holes, the luminous efficiency of the light-emitting element is lowered, and the life of the organic EL display is shortened. On the other hand, in general, an insulating layer called a pixel dividing layer is formed between the transparent electrode on the light extraction side and the metal electrode on the opposite side in order to divide the pixels of the light emitting element. Since the pixel division layer is formed at a position adjacent to the light emitting element, outgassing from the pixel division layer and outflow of ion components can be a factor in shortening the life of the organic EL display. Therefore, the pixel division layer is required to have heat resistance and durability.

From the viewpoint of high heat resistance, a positive photosensitive resin composition using polyimide or polybenzoxazole is used as the material of the pixel dividing layer (for example, Patent Document 1). However, since the pixel division layer using the positive photosensitive resin composition contains a naphthoquinonediazide compound as a photosensitive agent, outgassing occurs from the pixel division layer, which reduces the life of the organic EL display. cause.
Therefore, a method for forming a pixel division layer using a negative photosensitive resin composition that does not use naphthoquinonediazide has been studied (for example, Patent Document 2). However, the negative resist described in Patent Document 2 does not provide sufficient alkali developability and low-temperature curability, and has problems of residue generation after development and sagging of the split layer after heat treatment.

A negative photosensitive resin composition using polyimide and having a phenolic hydroxyl group as a terminal group has also been studied (for example, Patent Document 3). However, in the negative photosensitive resin composition described in Patent Document 3, the methylol group of the cross-linking agent generated by the photoacid generator reacts with the phenolate ion derived from the phenolic hydroxyl group, resulting in low-temperature curability due to high cross-linking density. However, the generation of residues after development remains a problem in the fine pixel division layer drawing required in recent years.

A negative photosensitive resin composition that improves alkali solubility and suppresses residue generation by mixing a phenolic resin instead of a polyimide having a phenolic hydroxyl group is also being studied (for example, Patent Document 4). However, the phenolic resin used in Patent Document 4 does not have sufficient alkali solubility in the non-exposed areas. Further, in the curing step after development, when the film is cured at a low temperature of 200° C. or less, there is a problem that the film is insufficiently cured and has low resistance to solvents (chemicals).

As described above, there is a demand for a photosensitive resin composition capable of drawing a finer pixel division layer without generating a residue and having low-temperature curability and chemical resistance as the definition becomes higher.

U.S. Patent Application Publication No. 2002/162998 WO2017/159876 JP 2006-308765 A Japanese Patent Application Laid-Open No. 2005-250161

An object of the present invention is to provide a curable composition which has alkali solubility, can be cured at a low temperature, and provides a cured film having excellent chemical resistance.

The present inventors have made intensive studies to solve the above problems, and found that a negative photosensitive resin composition using a novolac-type phenolic resin composition having a specific structural unit has high alkali solubility in the non-exposed area. The present inventors have also found that low-temperature curing is possible after development and that a cured film having excellent chemical resistance can be obtained, thereby completing the present invention.

That is, the present invention relates to a negative photosensitive resin composition containing the following components (A) to (E).
(A) the molar ratio of the structural unit (a1) derived from m-cresol, the structural unit (a2) derived from benzaldehyde, and the structural unit (a3) derived from salicylaldehyde [(a1):(a2) : (a3)] is 1.0:0.3-0.8:0.3-0.8 novolac-type phenolic resin (B) polyimide, polybenzoxazole, polyimide precursor, and polybenzoxazole precursor one or more resins selected from the body (C) photoacid generator (D) cross-linking agent (E) solvent

The present invention further relates to a cured film obtained from the negative photosensitive resin composition.
The present invention further relates to a resist film obtained from the negative photosensitive resin composition.

According to the present invention, it is possible to provide a curable composition that has alkali solubility, can be cured at a low temperature, and gives a cured film having excellent chemical resistance.

1 is a GPC chart of the novolac-type phenolic resin obtained in Synthesis Example 1. FIG. 2 is a GPC chart of the novolac-type phenolic resin obtained in Synthesis Example 2. FIG. 2 is a GPC chart of the novolac-type phenolic resin obtained in Synthesis Example 3. FIG. 4 is a GPC chart of the novolac-type phenolic resin obtained in Synthesis Example 4. FIG. 2 is a GPC chart of the novolac-type phenolic resin obtained in Synthesis Example 5. FIG.

Modes for carrying out the invention will be described below.
In this specification, "x to y" represents a numerical range of "x or more and y or less". The upper and lower limits recited for numerical ranges can be arbitrarily combined.
Moreover, the form which combined two or more of the individual forms of this invention described below is also the form of this invention.

[Negative photosensitive resin composition]
A negative photosensitive resin composition according to one embodiment of the present invention contains the following components (A) to (E).
(A) the molar ratio of the structural unit (a1) derived from m-cresol, the structural unit (a2) derived from benzaldehyde, and the structural unit (a3) derived from salicylaldehyde [(a1):(a2) : (a3)] is 1.0:0.3-0.8:0.3-0.8 novolac-type phenolic resin (B) polyimide, polybenzoxazole, polyimide precursor, and polybenzoxazole precursor one or more resins selected from the body (C) photoacid generator (D) cross-linking agent (E) solvent

In the present embodiment, by using the novolak-type phenolic resin (A) above and using a combination of the resin (B) and the cross-linking agent (D), the alkali solubility of the non-exposed area is high. It becomes a resin composition which can be cured at a low temperature after development and which gives a cured film having excellent chemical resistance.
The constituent components of the negative photosensitive resin composition are described below.

・Component (A)
The novolac-type phenolic resin as component (A) contains the structural unit (a1) derived from m-cresol, the structural unit (a2) derived from benzaldehyde, and the structural unit (a3) derived from salicylaldehyde. The ratio [(a1):(a2):(a3)] is 1.0:0.3-0.8:0.3-0.8.

The molar ratio of the structural unit (a1) derived from m-cresol, the structural unit (a2) derived from benzaldehyde, and the structural unit (a3) derived from salicylaldehyde in component (A) [(a1): (a2):(a3)] is preferably 1.0:0.3 to 0.7:0.3 to 0.3 to 0.3 from the viewpoint of obtaining a cured film having chemical resistance at low temperature curing in addition to high sensitivity. 7, more preferably 1.0:0.4-0.7:0.4-0.7.

Component (A) contains structural units other than the structural unit (a1) derived from m-cresol, the structural unit (a2) derived from benzaldehyde, and the structural unit (a3) derived from salicylaldehyde. good too. Structural units other than (a1) to (a3) include structural units derived from phenols and aldehydes other than m-cresol, benzaldehyde, and salicylaldehyde.

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, 3 , 4,5-trimethylphenol and the like.

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

The total content of the structural units (a1), (a2) and (a3) in the component (A) is preferably 30 from the viewpoint of obtaining a cured film having high sensitivity and chemical resistance at low temperature curing. % by mass or more, more preferably 50% by mass or more, and still more preferably 90% by mass or more.
The total content of the structural units (a1), (a2) and (a3) may be substantially 100% by mass. Note that "substantially 100% by mass" means that structural units other than the structural units (a1), (a2) and (a3) are inevitably included.

The weight-average molecular weight of the novolac-type phenolic resin as component (A) is preferably 1,000 or more, more preferably 1,500 or more. Also, it is preferably 7,000 or less, more preferably 6,000 or less, and still more preferably 5,000 or less. A weight-average molecular weight of 1000 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 addition, in this specification, a weight average molecular weight is measured according to the conditions described in an Example.

Component (A) is m-cresol, benzaldehyde, and salicylaldehyde in an organic solvent at a molar ratio (m-cresol: benzaldehyde: salicylaldehyde) of 1.0:0.3 to 0.8:0.3. It is obtained by polycondensation using an acid catalyst within the range of 0.8.

The molar ratio of m-cresol, benzaldehyde, and salicylaldehyde (m-cresol: benzaldehyde: salicylaldehyde) in the organic solvent is preferable from the viewpoint of obtaining a cured film having chemical resistance at low temperature curing in addition to high sensitivity. is in the range of 1.0:0.3-0.7:0.3-0.7, more preferably 1.0:0.4-0.7:0.4-0.7.

Preferably, the molar ratio of benzaldehyde is lower than that of salicylaldehyde. That is, it is preferable to satisfy benzaldehyde < salicylaldehyde (molar ratio).

When polycondensing m-cresol, benzaldehyde, and salicylaldehyde in an organic solvent to obtain the component (A) novolac phenolic resin, as described above, phenols other than m-cresol, benzaldehyde, and salicylaldehyde and aldehydes may be contained in the organic solvent.

The ratio of the total mass of m-cresol, benzaldehyde, and salicylaldehyde to the total mass of all starting materials that can be structural units constituting component (A) in the organic solvent provides high sensitivity and low-temperature curing resistance. From the viewpoint of obtaining a cured film having chemical properties, it is preferably 30% by mass or more, more preferably 50% by mass or more, and still more preferably substantially 100% by mass.

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

From the viewpoint of reaction uniformity, the amount of the organic solvent used is preferably 20 parts by mass or more, more preferably 50 parts by mass, per 100 parts by mass of the starting material for deriving the structural unit constituting component (A). Part by mass or more. Also, it is preferably 500 parts by mass or less, more preferably 300 parts by mass or less.

Examples of acid catalysts used in the production of component (A) include inorganic acids such as hydrochloric acid, sulfuric acid, phosphoric acid and boric acid; and organic acids such as oxalic acid, acetic acid and p-toluenesulfonic acid. Among these, inorganic acids and p-toluenesulfonic acid are preferred, and p-toluenesulfonic acid is more preferred, in order to further promote the reaction.
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 starting material for deriving the structural unit constituting component (A). Also, it is preferably 150 parts by mass or less, more preferably 100 parts by mass or less.

The reaction temperature for the polycondensation of the raw material of component (A) is preferably 30° C. or higher, more preferably 40° C. or higher, because the reaction can be promoted and the molecular weight can be efficiently increased. Also, it is preferably 100° C. or lower, more preferably 80° C. or lower.
The reaction time is preferably 4 hours or longer, more preferably 12 hours or longer. Also, it is preferably 32 hours or less, more preferably 24 hours or less.

・Component (B)
Component (B) is one or more resins selected from polyimides, polybenzoxazoles, polyimide precursors, and polybenzoxazole precursors. As component (B), those conventionally used in photosensitive resin compositions can be used.
Specifically, the polyimide can be obtained, for example, by reacting a tetracarboxylic dianhydride and a diamine to obtain a polyamic acid, which is a polyimide precursor, and then dehydrating and ring-closing the polyamic acid by heat treatment.
The tetracarboxylic dianhydride used for polyimide synthesis is preferably pyromellitic anhydride from the viewpoint of heat resistance. From the viewpoint of heat resistance, the diamine used in polyimide synthesis is preferably 4,4-diaminodiphenyl ether.

Polybenzoxazole can be obtained, for example, by reacting bisaminophenol and dicarboxylic acid to obtain polyhydroxyamide, which is a polybenzoxazole precursor, and then dehydrating and ring-closing the polyhydroxyamide by heat treatment.
From the viewpoint of heat resistance, 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.

Examples of polyimide precursors include polyamic acid, polyamic acid ester, polyamic acid amide, and polyisoimide.
Examples of polybenzoxazole precursors include polyhydroxyamides and the like.

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. A weight-average molecular weight of 5,000 or more is preferable because of high heat resistance. On the other hand, a weight average molecular weight of 50,000 or less is preferable from the viewpoint of solvent solubility.

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 can be obtained and a desired pattern can be obtained. is. Also, it is preferably 2,000 parts by mass or less, more preferably 1,000 parts by mass or less.

・Component (C)
The photoacid generator that is component (C) is not particularly limited, and known photoacid generators can be used. Examples include organic halogen compounds, sulfonic acid esters, onium salts, diazonium salts, and disulfone compounds.

Specific examples of the photoacid generator include the following.
tris(trichloromethyl)-s-triazine, tris(tribromomethyl)-s-triazine, tris(dibromomethyl)-s-triazine, 2,4-bis(tribromomethyl)-6-p-methoxyphenyl-s - haloalkyl group-containing s-triazine derivatives such as triazine, (2-[2-(5-methylfuran-2-yl)ethenyl]-4,6-bis(trichloromethyl)-s-triazine);

Halogen-substituted paraffinic hydrocarbon compounds such as 1,2,3,4-tetrabromobutane, 1,1,2,2-tetrabromoethane, carbon tetrabromide, iodoform; hexabromocyclohexane, hexachlorocyclohexane, hexabromocyclohexane Halogen-substituted cycloparaffinic hydrocarbon compounds such as dodecane;

Haloalkyl group-containing benzene derivatives such as bis(trichloromethyl)benzene and bis(tribromomethyl)benzene; Haloalkyl group-containing sulfone compounds such as tribromomethylphenylsulfone and trichloromethylphenylsulfone; Halogen-containing compounds such as 2,3-dibromosulfolane sulfolane compounds; haloalkyl group-containing isocyanurate compounds such as tris(2,3-dibromopropyl) isocyanurate;

Triphenylsulfonium chloride, diphenyl-4-methylphenylsulfonium trifluoromethanesulfonate, triphenylsulfonium methanesulfonate, triphenylsulfonium trifluoromethanesulfonate, triphenylsulfonium p-toluenesulfonate, triphenylsulfonium tetrafluoroborate, triphenylsulfonium hexafluoroarsenate sulfonium salts such as triphenylsulfonium hexafluorophosphonate;

Iodonium salts such as diphenyliodonium trifluoromethanesulfonate, diphenyliodonium p-toluenesulfonate, diphenyliodonium tetrafluoroborate, diphenyliodonium hexafluoroarsenate, diphenyliodonium hexafluorophosphonate;

Methyl p-toluenesulfonate, Ethyl p-toluenesulfonate, Butyl p-toluenesulfonate, Phenyl p-toluenesulfonate, 1,2,3-Tris(p-toluenesulfonyloxy)benzene, Benzoin p-toluenesulfonate ester, methyl methanesulfonate, ethyl methanesulfonate, butyl methanesulfonate, 1,2,3-tris(methanesulfonyloxy)benzene, phenyl methanesulfonate, benzoin methanesulfonate, methyl trifluoromethanesulfonate, trifluoromethane Sulfonic acid ester compounds such as ethyl sulfonate, butyl trifluoromethanesulfonate, 1,2,3-tris(trifluoromethanesulfonyloxy)benzene, phenyl trifluoromethanesulfonate, and benzoin trifluoromethanesulfonate; disulfone compounds such as diphenyldisulfone ;

bis(phenylsulfonyl)diazomethane, bis(2,4-dimethylphenylsulfonyl)diazomethane, bis(cyclohexylsulfonyl)diazomethane, cyclohexylsulfonyl-(2-methoxyphenylsulfonyl)diazomethane, cyclohexylsulfonyl-(3-methoxyphenylsulfonyl)diazomethane, Cyclohexylsulfonyl-(4-methoxyphenylsulfonyl)diazomethane, Cyclopentylsulfonyl-(2-methoxyphenylsulfonyl)diazomethane, Cyclopentylsulfonyl-(3-methoxyphenylsulfonyl)diazomethane, Cyclopentylsulfonyl-(4-methoxyphenylsulfonyl)diazomethane, Cyclohexylsulfonyl -(2-fluorophenylsulfonyl) diazomethane, cyclohexylsulfonyl-(3-fluorophenylsulfonyl) diazomethane, cyclohexylsulfonyl-(4-fluorophenylsulfonyl) diazomethane, cyclopentylsulfonyl-(2-fluorophenylsulfonyl) diazomethane, cyclopentylsulfonyl-( 3-fluorophenylsulfonyl)diazomethane, cyclopentylsulfonyl-(4-fluorophenylsulfonyl)diazomethane, cyclohexylsulfonyl-(2-chlorophenylsulfonyl)diazomethane, cyclohexylsulfonyl-(3-chlorophenylsulfonyl)diazomethane, cyclohexylsulfonyl-(4-chlorophenylsulfonyl)diazomethane ) diazomethane, cyclopentylsulfonyl-(2-chlorophenylsulfonyl)diazomethane, cyclopentylsulfonyl-(3-chlorophenylsulfonyl)diazomethane, cyclopentylsulfonyl-(4-chlorophenylsulfonyl)diazomethane, cyclohexylsulfonyl-(2-trifluoromethylphenylsulfonyl)diazomethane, Cyclohexylsulfonyl-(3-trifluoromethylphenylsulfonyl)diazomethane, Cyclohexylsulfonyl-(4-trifluoromethylphenylsulfonyl)diazomethane, Cyclopentylsulfonyl-(2-trifluoromethylphenylsulfonyl)diazomethane, Cyclopentylsulfonyl-(3-trifluoro methylphenylsulfonyl)diazomethane, cyclopentylsulfonyl-(4-trifluoromethylphenylsulfonyl)diazomethane, cyclohexylsulfonyl-(2- trifluoromethoxyphenylsulfonyl)diazomethane, cyclohexylsulfonyl-(3-trifluoromethoxyphenylsulfonyl)diazomethane, cyclohexylsulfonyl-(4-trifluoromethoxyphenylsulfonyl)diazomethane, cyclopentylsulfonyl-(2-trifluoromethoxyphenylsulfonyl)diazomethane, cyclopentylsulfonyl-(3-trifluoromethoxyphenylsulfonyl)diazomethane, cyclopentylsulfonyl-(4-trifluoromethoxyphenylsulfonyl)diazomethane, cyclohexylsulfonyl-(2,4,6-trimethylphenylsulfonyl)diazomethane, cyclohexylsulfonyl-(2, 3,4-trimethylphenylsulfonyl)diazomethane, cyclohexylsulfonyl-(2,4,6-triethylphenylsulfonyl)diazomethane, cyclohexylsulfonyl-(2,3,4-triethylphenylsulfonyl)diazomethane, cyclopentylsulfonyl-(2,4, 6-trimethylphenylsulfonyl)diazomethane, cyclopentylsulfonyl-(2,3,4-trimethylphenylsulfonyl)diazomethane, cyclopentylsulfonyl-(2,4,6-triethylphenylsulfonyl)diazomethane, cyclopentylsulfonyl-(2,3,4- triethylphenylsulfonyl)diazomethane, phenylsulfonyl-(2-methoxyphenylsulfonyl)diazomethane, phenylsulfonyl-(3-methoxyphenylsulfonyl)diazomethane, phenylsulfonyl-(4-methoxyphenylsulfonyl)diazomethane, bis(2-methoxyphenylsulfonyl)diazomethane Diazomethane, bis(3-methoxyphenylsulfonyl)diazomethane, bis(4-methoxyphenylsulfonyl)diazomethane, phenylsulfonyl-(2,4,6-trimethylphenylsulfonyl)diazomethane, phenylsulfonyl-(2,3,4-trimethylphenyl sulfonyl)diazomethane, phenylsulfonyl-(2,4,6-triethylphenylsulfonyl)diazomethane, phenylsulfonyl-(2,3,4-triethylphenylsulfonyl)diazomethane, 2,4-dimethylphenylsulfonyl-(2,4,6 -trimethylphenylsulfonyl)diazomethane, 2,4-dimethylphenylsulfonyl-(2,3,4-trimethylphenylsulfonyl) sulfonediazide compounds such as diazomethane, phenylsulfonyl-(2-fluorophenylsulfonyl)diazomethane, phenylsulfonyl-(3-fluorophenylsulfonyl)diazomethane, phenylsulfonyl-(4-fluorophenylsulfonyl)diazomethane;

o-nitrobenzyl ester compounds such as o-nitrobenzyl-p-toluenesulfonate;
Sulfonehydrazide compounds such as N,N'-di(phenylsulfonyl)hydrazide;
sulfonium salts that are salts of sulfonium cations such as triarylsulfonium and trialkylsulfonium with sulfonates such as fluoroalkanesulfonates, arenesulfonates and alkanesulfonates;

iodonium salts that are salts of iodonium cations such as diaryliodonium and sulfonates such as fluoroalkanesulfonates, arenesulfonates, alkanesulfonates;
bissulfonyldiazomethane compounds such as bis(alkylsulfonyl)diazomethane, bis(cycloalkylsulfonyl)diazomethane, bis(perfluoroalkylsulfonyl)diazomethane, bis(arylsulfonyl)diazomethane, bis(aralkylsulfonyl)diazomethane;

N-sulfonyloxyimide compounds comprising a combination of a dicarboxylic acid imide compound and a sulfonate such as a fluoroalkanesulfonate, arenesulfonate, or alkanesulfonate;
benzoin sulfonate compounds such as benzoin tosylate, benzoin mesylate, benzoin butane sulfonate;
A polyhydroxyarene sulfonate compound in which all of the hydroxy groups of the polyhydroxyarene compound are substituted with sulfonates such as fluoroalkanesulfonates, arenesulfonates, and alkanesulfonates;

Nitrobenzylsulfonate compounds such as (poly)nitrobenzyl fluoroalkanesulfonate, (poly)nitrobenzyl arenesulfonate, and (poly)nitrobenzyl alkanesulfonate;
fluoroalkanebenzylsulfonate compounds such as (poly)fluoroalkanebenzyl fluoroalkanesulfonate, (poly)fluoroalkanebenzyl arenesulfonate, and (poly)fluoroalkanebenzyl alkanesulfonate;

bis(arylsulfonyl)alkane compounds;
Bis-O-(arylsulfonyl)-α-dialkylglyoxime, bis-O-(arylsulfonyl)-α-dicycloalkylglyoxime, bis-O-(arylsulfonyl)-α-diarylglyoxime, bis-O -(alkylsulfonyl)-α-dialkylglyoxime, bis-O-(alkylsulfonyl)-α-dicycloalkylglyoxime, bis-O-(alkylsulfonyl)-α-diarylglyoxime, bis-O-(fluoro alkylsulfonyl)-α-dialkylglyoxime, bis-O-(fluoroalkylsulfonyl)-α-dicycloalkylglyoxime, bis-O-(fluoroalkylsulfonyl)-α-diarylglyoxime, bis-O-(aryl sulfonyl)-α-dialkylnioxime, bis-O-(arylsulfonyl)-α-dicycloalkylnioxime, bis-O-(arylsulfonyl)-α-diarylnioxime, bis-O-(alkylsulfonyl)- α-dialkylnioxime, bis-O-(alkylsulfonyl)-α-dicycloalkylnioxime, bis-O-(alkylsulfonyl)-α-diarylnioxime, bis-O-(fluoroalkylsulfonyl)-α- Oxime compounds such as dialkylnioxime, bis-O-(fluoroalkylsulfonyl)-α-dicycloalkylnioxime, bis-O-(fluoroalkylsulfonyl)-α-diarylnioxime;

arylsulfonyloxyiminoarylacetonitrile, alkylsulfonyloxyiminoarylacetonitrile, fluoroalkylsulfonyloxyiminoarylacetonitrile, ((arylsulfonyl)oximino-thiophene-ylidene)arylacetonitrile, ((alkylsulfonyl)oximino-thiophene-ylidene)arylacetonitrile, ((fluoroalkylsulfonyl)oximino-thiophene-ylidene)arylacetonitrile, bis(arylsulfonyloxyimino)arylenediacetonitrile, bis(alkylsulfonyloxyimino)arylenediacetonitrile, bis(fluoroalkylsulfonyloxyimino)arylenediacetonitrile, aryl Modified oxime compounds such as fluoroalkanone-O-(alkylsulfonyl)oximes, arylfluoroalkanone-O-(arylsulfonyl)oximes, and arylfluoroalkanone-O-(fluoroalkylsulfonyl)oximes.

The photoacid generators may be used singly or in combination of two or more.
The amount of component (C) is preferably 0.1 part by mass or more, more preferably 0.1 part by mass or more, and more preferably 5 parts by mass or more. Also, it is preferably 20 parts by mass or less, more preferably 15 parts by mass or less.

・Component (D)
The cross-linking agent that is component (D) is not particularly limited, and known cross-linking agents can be used. Specific examples include compounds having two or more thermally crosslinkable groups such as alkoxymethyl groups, methylol groups, epoxy groups, and oxetanyl groups in the molecule.
More specifically, polyfunctional methylol compounds shown below can be mentioned.

The cross-linking agents may be used singly or in combination of two or more.
The amount of component (D) is preferably 1 part by mass or more, more preferably 3 parts by mass, relative to 100 parts by mass of component (A), since good sensitivity can be obtained and a desired pattern can be obtained. There are more than departments. Also, it is preferably 30 parts by mass or less, and more preferably 15 parts by mass or less.

・Component (E)
Solvents as component (E) include polar aprotic solvents such as N-methyl-2-pyrrolidone, γ-butyrolactone, N,N-dimethylformamide, N,N-dimethylacetamide, dimethylsulfoxide, tetrahydrofuran, and dioxane. Ethers such as propylene glycol monomethyl ether and propylene glycol monoethyl ether, ketones such as acetone, methyl ethyl ketone and diisobutyl ketone, ethyl acetate, butyl acetate, isobutyl acetate, propyl acetate, propylene glycol monomethyl ether acetate, 3-methyl-3 and esters such as -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 singly or in combination of two or more.

The amount of the component (E) in the negative photosensitive resin composition of the present embodiment is such that a uniform coating film can be obtained by a coating method such as spin coating, so that the fluidity of the composition is The solid content concentration is preferably 5% by mass or more. Also, the amount is preferably 65% by mass or less.

- Others In one embodiment, in addition to the components (A) to (E) described above, various additives may be added to the negative photosensitive resin composition within a range that does not impair the effects of the present invention. Additives include fillers, pigments, surfactants such as leveling agents, adhesion improvers, dissolution accelerators, and the like.

In one embodiment, an organic base compound may be included to neutralize the acid generated from the photoacid generator (component (C)) upon exposure. By including the organic base compound in the negative photosensitive resin composition, it is possible to obtain the effect of preventing the dimensional variation of the resist pattern due to the migration of the acid generated from the photoacid generator.

Specific examples of organic base compounds include pyrimidine, (poly)aminopyrimidine, (poly)hydroxypyrimidine, (poly)amino(poly)hydroxypyrimidine, (poly)amino(poly)alkylpyrimidine, (poly)amino(poly) Alkoxypyrimidine, (poly)hydroxy(poly)alkylpyrimidine, (poly)hydroxy(poly)alkoxypyrimidine and other pyrimidine compounds; pyridine, (poly)alkylpyridine, dialkylaminopyridine and other pyridine compounds; polyalkanolamine, tri(hydroxy hydroxyalkyl group-containing amine compounds such as alkyl)aminoalkanes and bis(hydroxyalkyl)iminotris(hydroxyalkyl)alkanes; and aminoaryl compounds such as aminophenols.
An organic base compound may be used individually by 1 type, and may use 2 or more types together.

The content of the organic base compound in the negative photosensitive resin composition is preferably 0.1 mol % or more, more preferably 1 mol % or more, relative to 1 mol of the photoacid generator. Also, it is preferably 100 mol % or less, more preferably 50 mol % or less.

The negative type photosensitive resin composition of the present embodiment can be obtained by mixing the components (A) to (E) described above and, if necessary, various additives by a normal method with stirring to form a uniform liquid. can be prepared.
When solid materials such as fillers and pigments are added to the composition, they are preferably dispersed and mixed using a dispersing device such as a dissolver, homogenizer, or three-roll mill. Moreover, in order to remove coarse particles and impurities, the composition can be filtered using a mesh filter, a membrane filter, or the like.

[Hardened film/resist film]
A cured film according to one embodiment of the present invention is obtained by curing the negative photosensitive resin composition of the present invention described above.
Specifically, the film (photosensitive film) of the photosensitive resin composition from which the solvent has been removed is formed by applying the negative photosensitive resin composition of the present invention onto an object to be photolithographed and pre-baking it. can get.

Examples of coating methods include spin coating, roll coating, flow coating, dip coating, spray coating, and doctor blade coating. Pre-baking may be carried out at a temperature of 60° C. to 150° C. for 30 seconds to 600 seconds, for example.

By exposing the photosensitive film to light, the solubility of the exposed area in an alkaline developer is greatly 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 preferable, and g-line (wavelength: 436 nm) and i-line (wavelength: 365 nm) of a high-pressure mercury lamp are suitable.
After exposure, heat treatment is performed at around 100° C. in order to promote the cross-linking reaction with component (A), component (B) and component (D) by catalytic reaction of acid generated by exposure.

Since the photosensitive film obtained from the negative type photosensitive resin composition of the present invention has high alkali solubility, the difference in alkali solubility from the exposed area is large, so patterning can be performed with high resolution. Therefore, it can be suitably used as a resist film.

Alkaline developers used for development after exposure include 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; ammonium salts; alkaline aqueous solutions of cyclic amines such as pyrrole and pyrridine;
An alcohol, a surfactant, or the like may be appropriately added to the alkali developer as necessary. The alkali concentration of the alkali 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.

After development with an alkaline developer, heating at a low temperature such as 150° C. or higher and 200° C. or lower yields a cured film in which the exposed portions are crosslinked. The cured film of this embodiment has excellent chemical resistance.
The cured film of this embodiment can be used, for example, as a pixel division layer in a display device such as an organic EL display.

The present invention will be described in more detail below with specific examples. The weight average molecular weight (Mw) of the synthesized resin was measured under the following GPC measurement conditions.
[Measurement conditions of GPC]
Measuring device: "HLC-8220 GPC" manufactured by Tosoh Corporation
Column: "Shodex KF802" manufactured by Showa Denko Co., Ltd.: 8.0 mm Φ × 300 mm
+ "Shodex KF802" manufactured by Showa Denko Co., Ltd.: 8.0 mm Φ × 300 mm
+ "Shodex KF803" manufactured by Showa Denko Co., Ltd.: 8.0 mm Φ × 300 mm
+ "Shodex KF804" manufactured by Showa Denko Co., Ltd.: 8.0 mm Φ × 300 mm
Column temperature: 40°C
Detector: RI (differential refractometer)
Data processing: "GPC-8020 model II version 4.30" manufactured by Tosoh Corporation
Developing solvent: Tetrahydrofuran Flow rate: 1.0 mL/min Sample: 0.5% by mass tetrahydrofuran solution in terms of resin solid content filtered through a microfilter Injection volume: 0.1 mL
Standard sample: the following monodisperse polystyrene (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

[(A) Novolac-type phenolic resin]
Synthesis Example 1 (Synthesis of novolac-type phenolic resin (A1))
164 g (1.52 mol) of m-cresol, 103 g (0.97 mol) of benzaldehyde, 74 g (0.61 mol) of salicylaldehyde, and 8 g of p-toluenesulfonic acid were charged into a four-necked flask with a capacity of 2000 mL equipped with a cooling tube, and the reaction was carried out. It was dissolved in 300 g of ethanol as a solvent. Then, the mixture was heated to 80° C. with a mantle heater and stirred under reflux for 16 hours to react. After the reaction, ethyl acetate and water were added to separate and wash five times. After distilling off the solvent from the remaining resin solution under reduced pressure, the residue was vacuum-dried to obtain 281 g of pale red novolac-type phenolic resin (A1) powder.
Mw of the novolak-type phenol resin (A1) was 3,100. A GPC chart of the novolac-type phenolic resin (A1) is shown in FIG.

Synthesis Example 2 (Synthesis of novolak-type phenolic resin (A2))
A novolak-type phenolic resin was prepared in the same manner as in Synthesis Example 1, except that the amounts of starting materials charged were m-cresol 164 g (1.52 mol), benzaldehyde 96 g (0.90 mol), and salicylaldehyde 74 g (0.6 mol). 280 g of powder (A2) was obtained. Mw of the novolac-type phenolic resin (A2) was 2,250.
A GPC chart of the novolac-type phenolic resin (A2) is shown in FIG.

Synthesis Example 3 (Synthesis of Novolak Phenolic Resin (A3))
A novolak-type phenolic resin was prepared in the same manner as in Synthesis Example 1, except that the amounts of starting materials charged were 164 g (1.52 mol) of m-cresol, 117 g (1.10 mol) of benzaldehyde, and 58 g (0.47 mol) of salicylaldehyde. 279 g of powder (A3) was obtained. Mw of the novolac-type phenolic resin (A3) was 2,700.
A GPC chart of the novolac-type phenolic resin (A3) is shown in FIG.

Synthesis Example 4 (Synthesis of Novolak Phenolic Resin (A4))
A novolac-type phenolic resin was prepared in the same manner as in Synthesis Example 1, except that the amounts of starting materials charged were 164 g (1.52 mol) of m-cresol, 67 g (0.63 mol) of benzaldehyde, and 115 g (0.94 mol) of salicylaldehyde. 282 g of powder (A4) was obtained. Mw of the novolac-type phenolic resin (A4) was 2,900.
A GPC chart of the novolac-type phenolic resin (A4) is shown in FIG.

Synthesis Example 5 (Synthesis of Novolak Phenolic Resin (A5))
A powder of 282 g of a novolak-type phenolic resin (A5) was obtained in the same manner as in Synthesis Example 1, except that 250 g of ethanol, 30 g of 1-propanol and 15 g of 2-propanol were used as the reaction solvent. Mw of the novolac-type phenolic resin (A5) was 3,200.
FIG. 5 shows a GPC chart of the novolak-type phenolic resin (A5).

Comparative Synthesis Example 1 (Synthesis of novolac-type phenolic resin (A6))
Under a stream of dry nitrogen, 140 g (1.30 mol) of m-cresol, 76 g (0.7 mol) of p-cresol, 151 g (1.86 mol of formaldehyde) of 37% by weight aqueous formaldehyde solution, 151 g of 37 wt% formaldehyde aqueous solution (1.86 mol of formaldehyde), and sulfur 1 g (0.01 mol) of acid dihydrate was charged and dissolved in 528 g of methyl isobutyl ketone (MIBK), and then stirred for 4 hours while refluxing the reaction solution with a mantle heater for reaction. After the reaction, water was added and liquid separation and washing were performed five times. After the methyl isobutyl ketone was distilled off under reduced pressure at 60° C. by an evaporator, the residue was dried in a vacuum to obtain 212 g of pale red powdery novolac type phenol resin (A6). Mw of the novolac-type phenolic resin (A6) was 3,500.

Comparative Synthesis Example 2 (Synthesis of novolak-type phenolic resin (A7))
A novolac-type phenolic resin ( A7) 211 g of powder was obtained. Mw of the novolak-type phenolic resin (A7) was 5,000.

[(B) polyimide precursor (B1)]
Synthesis example 6
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-necked flask equipped with a condenser tube. and stirred at 100° C. for 4 hours to react. After completion of the reaction, the solution was poured into 2000 g of water, and the polymer solid precipitate was collected by filtration. The polymer solid was dried in a vacuum dryer at 80° C. for 72 hours to obtain a polyimide precursor (B1) powder.

[Negative photosensitive resin composition]
Example 1
5 g of the phenol novolac resin (A1) powder obtained in Synthesis Example 1 as component (A), 2.5 g of the polyimide precursor polymer (B1) powder obtained in Synthesis Example 6 as component (B), and light as component (C). Acid generator solution (CPI-101A: manufactured by San-Apro Co., Ltd., 50% propylene carbonate solution) 1.0 g, cross-linking agent (2,6-bis(hydroxymethyl)-p-cresol: manufactured by Tokyo Chemical Industry Co., Ltd. as component (D) ) was dissolved in 74 g of γ-butyrolactone as the component (E) to obtain a negative photosensitive resin composition (F1).

Examples 2 to 5, Comparative Examples 1 and 2
Negative photosensitive resin compositions (F2) to (F7) were obtained in the same manner as in Example 1, except that the phenol novolac resin (A2) to (A7) powders shown in Table 1 were used as the component (A). .

[evaluation]
Using the negative photosensitive resin compositions prepared in Examples and Comparative Examples, the alkali solubility before exposure, the chemical resistance of the cured film, and the hardness of the cured film were evaluated.
(1) Alkali solubility before exposure A negative photosensitive resin composition was coated on a silicon wafer having a diameter of 5 inches using a spin coater so as to have a thickness of about 5 μm, and then prebaked at 120° C. for 180 seconds. , a wafer having a photosensitive film (resist film) formed thereon was obtained. The wafer was immersed for 10 seconds in a vat filled with 250 mL of developer (2.38 wt % tetramethylammonium hydroxide aqueous solution (TMAH)). The wafer removed from the vat was rinsed with pure water for 10 seconds, and the alkali solubility was evaluated by observing the residue of the photosensitive film on the wafer. Those with no residue were rated as good (O), and those with residues were rated as unsatisfactory (X). Table 1 shows the evaluation results.

(2) Chemical resistance of cured film A negative photosensitive resin composition was coated on a silicon wafer with a diameter of 5 inches using a spin coater so as to have a thickness of about 10 μm, and then prebaked at 120° C. for 180 seconds. , a wafer having a photosensitive film formed thereon was obtained. Next, the photosensitive film was irradiated with 200 mJ of ghi rays using a Ushio Multilight. After the irradiation, the film was heated on a hot plate at 130° C. for 120 seconds and further heated at 200° C. for 1 hour in a nitrogen atmosphere to obtain a cured film.
After the heating was completed, the wafer was taken out when the temperature in the heating device became 50° C. or less, and the film thickness was measured.
The wafer was then divided into three halves and each immersed in acetone, N-methylpyrrolidone (NMP) and 2.38 wt% TMAH for 15 minutes. After washing the wafer taken out from each solvent with pure water, the film thickness was measured again.
The chemical resistance was evaluated by the film thickness change rate before and after immersion in the solvent. A rate of change of less than 2% was rated as good (◯), and a rate of change of 2% or more was rated as unsatisfactory (x). Table 1 shows the evaluation results.

(3) Hardness of Cured Film After obtaining a cured film in the same manner as in (2) above, the wafer was taken out when the temperature of the heating device became 50° C. or less, and the film thickness was measured. Film hardness was measured by a nanoindentation method (ENT-2100: manufactured by Elionix Co., Ltd.). Those having an indentation modulus of elasticity of 8 GPa or more were evaluated as good (◯), and those having an indentation modulus of less than 8 GPa were evaluated as insufficient (×). Table 1 shows the evaluation results.

In Table 1, the molar ratio "(a1)/(a2)/(a3)" of the structural units of component (A) is the structural unit (a1) derived from m-cresol, the structural unit derived from benzaldehyde ( a2) and a structural unit (a3) derived from salicylaldehyde.
The molar ratio (m-Cr/p-Cr) is the molar ratio of structural units (m-Cr) derived from m-cresol and structural units (p-Cr) derived from p-cresol.

From the results in Table 1, it can be confirmed that the resist film obtained from the negative photosensitive resin composition of the present invention has alkali solubility. Moreover, although the cured film is cured at a low temperature of 200° C., it can be confirmed that it has excellent chemical resistance and high hardness.

Claims (7)

A negative photosensitive resin composition containing the following components (A) to (E).
(A) the molar ratio of the structural unit (a1) derived from m-cresol, the structural unit (a2) derived from benzaldehyde, and the structural unit (a3) derived from salicylaldehyde [(a1):(a2) : (a3)] is 1.0:0.3-0.8:0.3-0.8 novolac-type phenolic resin (B) polyimide, polybenzoxazole, polyimide precursor, and polybenzoxazole precursor (C) a photoacid generator that is one or more selected from organic halogen compounds, sulfonate esters, onium salts, diazonium salts and disulfone compounds (D) a cross-linking agent (E) solvent Component (A) is m-cresol, benzaldehyde, and salicylaldehyde in an organic solvent at a molar ratio of m-cresol: benzaldehyde: salicylaldehyde = 1.0:0.3 to 0.8:0.3. The negative photosensitive resin composition according to claim 1, which is a novolak-type phenolic resin obtained by polycondensation with an acid catalyst in the range of 0.8. The total content of the structural unit (a1) derived from m-cresol, the structural unit (a2) derived from benzaldehyde, and the structural unit (a3) derived from salicylaldehyde in the component (A) is 30. % by mass or more, the negative photosensitive resin composition according to claim 1 or 2. 4. The negative photosensitive resin composition according to any one of claims 1 to 3, wherein the component (A) has a weight average molecular weight of 1,000 or more and 7,000 or less. 5. The negative according to any one of claims 1 to 4, wherein said component (D) is a compound having two or more of one or more selected from alkoxymethyl groups, methylol groups, epoxy groups and oxetanyl groups in its molecule. type photosensitive resin composition. A cured film obtained from the negative photosensitive resin composition according to any one of claims 1 to 5 . A resist film obtained from the negative photosensitive resin composition according to any one of claims 1 to 5 .

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