CN117075428A

CN117075428A - Negative photosensitive resin composition

Info

Publication number: CN117075428A
Application number: CN202310547262.9A
Authority: CN
Inventors: 长田裕仁; 伊部武史
Original assignee: DIC Corp
Current assignee: DIC Corp
Priority date: 2022-05-16
Filing date: 2023-05-16
Publication date: 2023-11-17
Also published as: KR20230160163A; TW202405084A; JP2023169106A

Abstract

The invention provides a negative photosensitive resin composition. Provided is a curable composition which has alkali solubility, can suppress occurrence of film formation failure, can be cured at a low temperature, and can give a cured film having excellent chemical resistance. A negative photosensitive resin composition comprising the following components (A) to (D). The molar ratio [ (a 1): (a 2): (a 3) ] of (a 1) structural unit derived from m-cresol, (a 2) structural unit derived from benzaldehyde and structural unit derived from salicylaldehyde to (a 3) is 1.0:0.4 to 0.8:0.3 to 0.6, and the ratio of (B) phenolic resin/(C) sensitizer/(D) solvent is 1 or more selected from the group consisting of polyimide having an ethylenically unsaturated group, polyimide precursor having an ethylenically unsaturated group, polybenzoxazole having an ethylenically unsaturated group and polybenzoxazole precursor having an ethylenically unsaturated group.

Description

Negative photosensitive resin composition

Technical Field

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

Background

As a new generation of flat panel displays, organic EL displays are attracting attention. The organic EL display is a self-luminous display device that emits light by an electric field generated by an organic compound, and can realize image display with a wide field of view and high response speed. In addition, the thickness and weight can be reduced. In recent years, with the high definition of organic EL displays, further miniaturization of light emitting elements has been demanded.

The organic EL display emits light using energy by which electrons injected from a cathode and holes injected from an anode are recombined. Therefore, if a substance that forms an energy level that inhibits recombination of electrons and holes is present, the light-emitting efficiency of the light-emitting element decreases, and the lifetime 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 dividing layer is generally formed between the transparent electrode on the light extraction side and the metal electrode on the opposite side. Since the pixel dividing layer is formed adjacent to the light emitting element, outgas from the pixel dividing layer and outflow of ion components may cause a reduction in the lifetime of the organic EL display. Therefore, heat resistance and durability are required for the pixel dividing layer.

From the viewpoint of high heat resistance, a positive photosensitive resin composition using polyimide or polybenzoxazole is used as a material of the pixel dividing layer (for example, patent document 1). However, since the pixel-dividing layer using the positive photosensitive resin composition contains a naphthoquinone diazide compound in the photosensitizer, outgas from the pixel-dividing layer occurs, which is one cause of a reduction in the lifetime of the organic EL display.

Therefore, a method of forming a pixel-dividing layer using a negative photosensitive resin composition that does not use naphthoquinone diazide has been studied (for example, patent document 2). However, the negative resist described in patent document 2 does not have sufficient alkali developability and low-temperature curability, and has problems such as generation of residues (scum) after development, sagging of the divided layer after heat treatment, and low solvent resistance.

As described above, with the high definition of organic EL displays, there is a demand for photosensitive resin compositions which can achieve finer pixel division layer drawing without generating residues, and which have low-temperature curability and chemical resistance.

Prior art literature

Patent literature

Patent document 1: U.S. patent application publication No. 2002/162998 specification

Patent document 2: international publication No. 2017/159876

Disclosure of Invention

Problems to be solved by the invention

The purpose of the present invention is to provide a curable composition which has alkali solubility, can suppress the occurrence of film formation failure, can be cured at a low temperature, and can give a cured film having excellent chemical resistance.

Solution for solving the problem

The present inventors have conducted intensive studies to solve the above problems, and as a result, found that: the present invention has been accomplished by the above-described findings, and it is an object of the present invention to provide a novolak type phenol resin composition having specific structural units, which has high alkali solubility in a non-exposed portion of a negative photosensitive resin composition obtained by using at least one selected from the group consisting of an ethylenically unsaturated group-containing polyimide and an ethylenically unsaturated group-containing polybenzoxazole, can be cured at a low temperature after development, and can provide a cured film having excellent chemical resistance.

Specifically, the present invention relates to a negative photosensitive resin composition containing the following components (a) to (D).

(A) A novolac type phenolic resin having a molar ratio [ (a 1): a 2): a 3) ] of the m-cresol-derived structural unit (a 1), the benzaldehyde-derived structural unit (a 2) and the salicylaldehyde-derived structural unit (a 3) of 1.0:0.4 to 0.8:0.3 to 0.6;

(B) More than 1 resin selected from the group consisting of 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 sensitizer;

(D) And (3) a solvent.

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

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

ADVANTAGEOUS EFFECTS OF INVENTION

According to the present invention, a curable composition having alkali solubility, capable of suppressing occurrence of film formation failure, capable of being cured at a low temperature, and capable of obtaining a cured film excellent in chemical resistance can be provided.

Drawings

FIG. 1 is a GPC chart of a novolak-type phenol resin obtained in Synthesis example 1.

FIG. 2 is a GPC chart of the novolak-type phenol resin obtained in Synthesis example 2.

FIG. 3 is a GPC chart of the novolak-type phenol resin obtained in Synthesis example 3.

FIG. 4 is a GPC chart of the novolak-type phenol resin obtained in Synthesis example 4.

FIG. 5 is a GPC chart of the novolak-type phenol resin obtained in production example 1.

Detailed Description

Hereinafter, modes for carrying out the invention will be described.

In the present specification, "x to y" means a numerical range of "x or more and y or less". The upper limit and the lower limit described in the numerical range may be arbitrarily combined.

The present invention is also a combination of 2 or more aspects of the present invention described below.

[ negative-type photosensitive resin composition ]

The negative photosensitive resin composition according to one embodiment of the present invention contains the following components (a) to (D).

(C) A sensitizer;

(D) And (3) a solvent.

In this embodiment, the novolak-type phenol resin of the above (a) and the resin of the above (B) are used in combination, whereby compatibility of both resins is improved. This can suppress occurrence of film formation failure. In addition, the resin composition which forms the non-exposed part has high alkali solubility, can be cured at a low temperature after development, and can obtain a cured film with excellent chemical resistance.

The constituent components of the negative photosensitive resin composition will be described below.

Component (A)

In the novolak-type phenol resin as the component (A), the molar ratio [ (a 1): a 2): a 3) ] of the structural unit (a 1) derived from m-cresol, the structural unit (a 2) derived from benzaldehyde and the structural unit (a 3) derived from salicylaldehyde is 1.0:0.4 to 0.8:0.3 to 0.6.

From the viewpoint of obtaining a cured film having chemical resistance by low-temperature curing on the basis of high sensitivity, the molar ratio [ (a 1): a 2): a 3) ] of the m-cresol-derived structural unit (a 1), the benzaldehyde-derived structural unit (a 2) and the salicylaldehyde-derived structural unit (a 3) possessed by the component (a) is preferably 1.0:0.5 to 0.7:0.3 to 0.5, more preferably 1.0:0.55 to 0.65:0.35 to 0.45.

Component (a) may contain structural units other than the structural unit (a 1) derived from m-cresol, the structural unit (a 2) derived from benzaldehyde, and the structural unit (a 3) derived from salicylaldehyde. Examples of the structural units other than (a 1) to (a 3) 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, and 3,4, 5-trimethylphenol.

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

From the viewpoint of obtaining a cured film having chemical resistance by low-temperature curing in addition to high sensitivity, the total content of the above-mentioned structural units (a 1), (a 2), and (a 3) in the component (a) is preferably 30 mass% or more, more preferably 50 mass% or more, and still more preferably 90 mass% or more.

The total content of the above-mentioned structural units (a 1), (a 2) and (a 3) may be substantially 100 mass%. The term "substantially 100 mass%" means: the case of containing structural units other than the above-mentioned structural units (a 1), (a 2) and (a 3) inevitably.

The weight average molecular weight of the novolak-type phenol resin as the component (a) is preferably 1000 or more, more preferably 1,500 or more. Further, it is preferably 7,000 or less, more preferably 6,000 or less, and still more preferably 5,000 or less. When the weight average molecular weight is 1000 or more, heat resistance is high, and thus it is preferable. On the other hand, if the weight average molecular weight is 7,000 or less, the sensitivity is high, so that it is preferable. In the present specification, the weight average molecular weight was measured under the conditions described in examples.

In the novolak type phenol resin as the component (a), the component having a molecular weight of less than 500 is preferably less than 3.0 mass% in terms of an area ratio in gel permeation chromatography measurement. By reducing the low molecular weight component having a molecular weight of less than 500 in the novolak type phenol resin, the alkali solubility can be further improved.

The lower limit of the component having a molecular weight of less than 500 in the novolac type phenolic resin is not particularly limited, and is, for example, 0.0 mass% or more, 0.1 mass% or more, or 0.3 mass% or more.

The proportion of the component having a molecular weight of less than 500 in the novolak type phenol resin was less than 3.0 mass% as determined by Gel Permeation Chromatography (GPC) measurement described in examples.

The component having a molecular weight of less than 500 in the novolak-type phenol resin is 3.0 mass%, and can be obtained by, for example, further reprecipitating the novolak-type phenol resin obtained by a production method described later. Specifically, after the novolak-type phenol resin is dissolved in a good solvent (for example, methyl isobutyl ketone), a poor solvent (for example, heptane) is further added, whereby the novolak-type phenol resin is reprecipitated. By performing this operation a plurality of times, the component having a molecular weight of less than 500 can be set to less than 3.0 mass%.

The component (A) is obtained by polycondensing m-cresol, benzaldehyde and salicylaldehyde in an organic solvent using an acid catalyst in a molar ratio (m-cresol: benzaldehyde: salicylaldehyde) in the range of 1.0:0.4 to 0.8:0.3 to 0.6.

From the viewpoint of obtaining a cured film having chemical resistance by low-temperature curing in addition to high sensitivity, the molar ratio of m-cresol, benzaldehyde and salicylaldehyde (m-cresol: benzaldehyde: salicylaldehyde) in the organic solvent is preferably in the range of 1.0:0.5 to 0.7:0.3 to 0.5, more preferably 1.0:0.55 to 0.65:0.35 to 0.45.

The molar ratio of benzaldehyde is preferably smaller than the molar ratio of salicylaldehyde. That is, benzaldehyde < salicylaldehyde (molar ratio) is preferably satisfied.

When the novolak-type phenol resin as the component (a) is obtained by polycondensing m-cresol, benzaldehyde and salicylaldehyde in an organic solvent, the organic solvent may contain phenols and aldehydes other than m-cresol, benzaldehyde and salicylaldehyde as described above.

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

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

The amount of the organic solvent used is preferably 20 parts by mass or more, more preferably 50 parts by mass or more, based on 100 parts by mass of the raw material for deriving the structural unit constituting the component (a), from the viewpoint of reaction uniformity. Further, the content is preferably 500 parts by mass or less, more preferably 300 parts by mass or less.

Examples of the acid catalyst used in the production of the component (a) include inorganic acids such as hydrochloric acid, sulfuric acid, phosphoric acid, and boric acid; organic acids such as oxalic acid, acetic acid and p-toluenesulfonic acid. Among these, inorganic acids and p-toluenesulfonic acid are preferable, and p-toluenesulfonic acid is more preferable, 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, based on 100 parts by mass of the raw material for deriving the structural unit constituting the component (a). Further, it is preferably 150 parts by mass or less, more preferably 100 parts by mass or less.

The reaction temperature at the time of polycondensation of the raw material of the component (a) is preferably 30 ℃ or higher, more preferably 40 ℃ or higher, from the viewpoint of promoting the reaction and efficiently increasing the molecular weight. The temperature is preferably 100℃or lower, more preferably 80℃or lower.

The reaction time is preferably 4 hours or more, more preferably 12 hours or more. Further, the time is preferably 32 hours or less, more preferably 24 hours or less.

Component (B)

The component (B) is at least 1 resin selected from the group consisting of 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. The component (B) is a component obtained by introducing an ethylenically unsaturated group into each of polyimide, a polyimide precursor, polybenzoxazole, and a polybenzoxazole precursor. The component (B) may be any component conventionally used in a photosensitive resin composition.

< polyimide and polyimide precursor >

Examples of the polyimide precursor include those obtained by reacting a diamine, a corresponding diisocyanate compound, or trimethylsilylated diamine with a tetracarboxylic acid, a corresponding tetracarboxylic dianhydride, or a tetracarboxylic acid diester diacid chloride, or the like, and those having a tetracarboxylic acid and/or derivative residue thereof and a diamine and/or derivative residue thereof. Examples of polyimide precursors include polyamic acids, polyamic acid esters, polyamic acid amides, and polyisoimides.

Examples of the polyimide include those obtained by dehydrating and ring-closing the polyamic acid, polyamic acid ester, polyamic acid amide or polyisoimide by heating or by a reaction using an acid or a base, etc., and those having a tetracarboxylic acid and/or its derivative residue and a diamine and/or its derivative residue.

From the viewpoint of heat resistance, the tetracarboxylic dianhydride used for synthesizing polyimide is preferably pyromellitic anhydride. From the viewpoint of heat resistance, the diamine used for synthesizing polyimide is preferably 4, 4-diaminodiphenyl ether.

The unsaturated group-containing polyimide and the unsaturated group-containing polyimide precursor used in the present invention have the above polyimide or polyimide precursor and have an ethylenically unsaturated group as a radical polymerizable group. By having an ethylenically unsaturated group, sensitivity at the time of exposure can be improved. The unsaturated group-containing polyimide and the unsaturated group-containing polyimide precursor are preferably obtained by reacting a part of phenolic hydroxyl groups and/or carboxyl groups of the polyimide and the polyimide precursor with a compound having an ethylenically unsaturated group, which will be described later. By the above reaction, an ethylenically unsaturated group can be introduced into the resin.

< polybenzoxazole and polybenzoxazole precursor >

Examples of the polybenzoxazole precursor include those obtained by reacting a dicarboxylic acid, a corresponding dicarboxylic acid diacid chloride, a dicarboxylic acid active diester, or the like with a diaminophenol compound or the like as a diamine, and having a dicarboxylic acid and/or a derivative residue thereof and a diaminophenol compound and/or a derivative residue thereof. As the polybenzoxazole precursor, for example, polyhydroxyamide is cited.

Examples of the polybenzoxazole include those obtained by dehydrating and ring-closing a dicarboxylic acid and a diaminophenol compound as a diamine by a reaction using polyphosphoric acid; the polyhydroxyamide is dehydrated and closed by heating or by a reaction using anhydrous phosphoric acid, a base, a carbodiimide compound or the like, and has a dicarboxylic acid and/or a derivative residue thereof and a bisaminophenol compound and/or a derivative residue thereof.

From the viewpoint of heat resistance, the bisaminophenol used for synthesizing polybenzoxazole is preferably 3, 3-dihydroxybenzidine. From the viewpoint of heat resistance, the dicarboxylic acid used for synthesizing polybenzoxazole is preferably 4,4' -biphenyldicarboxylic acid.

The polybenzoxazole containing an ethylenically unsaturated group and the polybenzoxazole precursor containing an ethylenically unsaturated group used in the present invention have an ethylenically unsaturated group as a radical polymerizable group. By having an ethylenically unsaturated group, sensitivity at the time of exposure can be improved. The polybenzoxazole containing an ethylenically unsaturated group and the polybenzoxazole precursor containing an ethylenically unsaturated group are preferably obtained by reacting a part of phenolic hydroxyl groups and/or carboxyl groups of the polybenzoxazole and the polybenzoxazole precursor with a compound having an ethylenically unsaturated group described later. By the above reaction, an ethylenically unsaturated group can be introduced into the resin.

< Compound having an ethylenically unsaturated group >

Examples of the compound 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, haloalkyl compounds, alkyl azide compounds, alkyl triflate compounds, alkyl mesylate compounds, alkyl tosylate compounds, or alkyl cyanide compounds.

< method for synthesizing polyimide, polybenzoxazole, polyimide precursor or polybenzoxazole precursor >

The polyimide, polyimide precursor, polybenzoxazole or polybenzoxazole precursor can be synthesized by a known method. As a specific method, for example, a diamine or a bisphenol compound is first dissolved in a reaction solvent, and a substantially equimolar amount of a carboxylic anhydride is gradually added to the solution. The mixed solution is preferably stirred at a temperature of 0 to 200 ℃, more preferably 40 to 150 ℃ for 0.5 to 50 hours, more preferably 2 to 24 hours, using a mechanical stirrer. When the blocking agent is used, the carboxylic acid anhydride is added and then stirred at a predetermined temperature for a predetermined time, and then the blocking agent is slowly added and stirred.

The reaction solvent used in the polymerization reaction is preferably a polar solvent as long as it can dissolve the diamine or the bisaminophenol compound and the carboxylic anhydride compound as raw materials. Examples of the reaction solvent include amides such as N, N-dimethylformamide, N-dimethylacetamide and N-methyl-2-pyrrolidone; cyclic esters such as gamma-butyrolactone, gamma-valerolactone, delta-valerolactone, gamma-caprolactone, epsilon-caprolactone, and alpha-methyl-gamma-butyrolactone; carbonates such as ethylene carbonate and propylene carbonate; glycols such as triethylene glycol; phenols or acetophenones such as m-cresol or p-cresol; other solvents such as 1, 3-dimethyl-2-imidazolidone, sulfolane, dimethyl sulfoxide, etc. The amount of the reaction solvent is preferably 100 to 1900 parts by mass, more preferably 150 to 950 parts by mass, based on 100 parts by mass of the total of the diamine or the bisaminophenol compound and the carboxylic anhydride.

The one or more selected from the group consisting of polyimide, polybenzoxazole, polyimide precursor and polybenzoxazole precursor is preferably obtained by precipitating one or more selected from the group consisting of polyimide, polybenzoxazole, polyimide precursor and polybenzoxazole precursor in a poor solvent such as methanol or water after completion of the polymerization reaction, and then washing and drying the resulting product. By performing the reprecipitation treatment, low molecular weight components and the like can be removed, and therefore, the mechanical properties of the cured film are greatly improved.

< 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 reaction conditions for further introducing an ethylenically unsaturated group into polyimide, polybenzoxazole, polyimide precursor or polybenzoxazole precursor, preferable are: for example, after the inside of the reaction vessel is sufficiently replaced with nitrogen gas by bubbling or degassing under reduced pressure, polyimide, a polyimide precursor, polybenzoxazole or a polybenzoxazole precursor is added to the reaction solvent, and a compound having an ethylenically unsaturated group is added thereto, and the mixture is reacted at 20 to 110 ℃ for 30 to 500 minutes. Further, a polymerization inhibitor such as a phenol compound, an acid catalyst or a base catalyst may be used as required.

In the component (B), specific descriptions of polyimide, polyimide precursor, polybenzoxazole precursor, polyimide containing an ethylenically unsaturated group, polyimide precursor containing an ethylenically unsaturated group, polybenzoxazole containing an ethylenically unsaturated group, and polybenzoxazole precursor containing an ethylenically unsaturated group can be appropriately referred to in the contents [0074] to [0210] of international publication No. 2017/159876.

The weight average molecular weight of the component (B) is preferably 5,000 or more, more preferably 10,000 or more. Further, it is preferably 50,000 or less, more preferably 40,000 or less. When the weight average molecular weight is 5,000 or more, it is preferable because it is highly heat-resistant. On the other hand, when the weight average molecular weight is 50,000 or less, it 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, per 100 parts by mass of component (a) in order to obtain a desired pattern with good sensitivity. Further, it is preferably 2,000 parts by mass or less, more preferably 1,000 parts by mass or less.

Component (C)

Component (C) is a sensitizer. The negative photosensitive resin composition of the present invention preferably contains 1 or more kinds selected from the group consisting of photoacid generators, photopolymerization initiators and radical polymerizable compounds as a photosensitizer.

[ photoacid generator ]

Photoacid generators refer to compounds that undergo bond cleavage upon exposure to light to generate an acid. By containing the photoacid generator, curing of the exposed portion is promoted, and sensitivity can be improved. The photoacid generator that can improve the chemical resistance of the cured film by improving the crosslink density after heat curing of the negative photosensitive resin composition is not particularly limited, and known photoacid generators can be used. Examples thereof include organic halogen compounds, sulfonates, onium salts, diazonium salts, and disulfone compounds.

Specific examples of the photoacid generator include the following.

Halogenated alkyl-containing s-triazine derivatives such as tris (trichloromethyl) s-triazine, tris (tribromomethyl) s-triazine, tris (dibromomethyl) s-triazine, 2, 4-bis (tribromomethyl) -6-p-methoxyphenyl s-triazine, and (2- [2- (5-methylfuran-2-yl) vinyl ] -4, 6-bis (trichloromethyl) s-triazine;

halogen-substituted alkane hydrocarbon compounds such as 1,2,3, 4-tetrabromobutane, 1, 2-tetrabromoethane, carbon tetrabromide and iodoform; halogen-substituted cycloalkane-based hydrocarbon compounds such as hexabromocyclohexane, hexachlorocyclohexane and hexabromocyclododecane;

halogenated alkyl-containing benzene derivatives such as bis (trichloromethyl) benzene and bis (tribromomethyl) benzene; halogenated alkyl group-containing sulfone compounds such as tribromomethylphenyl sulfone and trichloromethylphenyl sulfone; halogen-containing sulfolane compounds such as 2, 3-dibromosulfolane; halogenated alkyl group-containing isocyanurate compounds such as tris (2, 3-dibromopropyl) isocyanurate;

Sulfonium salts such as triphenylsulfonium chloride, diphenyl-4-methylphenylsulfonium trifluoromethane sulfonate, triphenylsulfonium methane sulfonate, triphenylsulfonium trifluoromethane sulfonate, triphenylsulfonium p-toluene sulfonate, triphenylsulfonium tetrafluoroborate, triphenylsulfonium hexafluoroarsenate, and triphenylsulfonium hexafluorophosphonate;

iodonium salts such as diphenyliodonium trifluoromethane sulfonate, diphenyliodonium p-toluene sulfonate, diphenyliodonium tetrafluoroborate, diphenyliodonium hexafluoroarsenate, diphenyliodonium hexafluorophosphonate, and the like;

sulfonate compounds such as methyl p-toluenesulfonate, ethyl p-toluenesulfonate, butyl p-toluenesulfonate, phenyl p-toluenesulfonate, 1,2, 3-tris (p-toluenesulfonyloxy) benzene, benzoin p-toluenesulfonate, methyl methanesulfonate, ethyl methanesulfonate, butyl methanesulfonate, 1,2, 3-tris (methanesulfonyloxy) benzene, phenyl methanesulfonate, benzoin methanesulfonate, methyl trifluoromethanesulfonate, ethyl trifluoromethanesulfonate, butyl trifluoromethanesulfonate, 1,2, 3-tris (trifluoromethanesulfonyloxy) benzene, phenyl trifluoromethanesulfonate, benzoin trifluoromethanesulfonate and the like; disulfone compounds such as diphenyl disulfone;

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, cyclohexylsulfonyl- (4-fluorophenylsulfonyl) diazomethane, cyclohexylsulfonyl-4-trifluoromethylsulfonyl-diazomethane, cyclopentylsulfonyl- (2-chlorophenyl sulfonyl) diazomethane, cyclopentylsulfonyl- (3-chlorophenyl sulfonyl) diazomethane, cyclopentylsulfonyl- (4-chlorophenyl sulfonyl) diazomethane, cyclohexylsulfonyl- (2-trifluoromethylphenyl sulfonyl) diazomethane, cyclohexylsulfonyl- (3-trifluoromethylphenyl sulfonyl) diazomethane, cyclohexylsulfonyl- (4-trifluoromethylphenyl sulfonyl) diazomethane, cyclopentylsulfonyl- (2-trifluoromethylphenyl sulfonyl) diazomethane, cyclopentylsulfonyl- (3-trifluoromethylphenyl sulfonyl) diazomethane, cyclohexylsulfonyl- (3-trifluoromethylsulfonyl) 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, bis (3-methoxyphenylsulfonyl) diazomethane, 4-trimethylphenylsulfonyl, 2, 4-triethylphenylsulfonyl, 4-trifluoromethanesulfonyl, sulfone diazide compounds such as 2, 4-dimethylphenylsulfonyl- (2, 4, 6-trimethylphenylsulfonyl) diazomethane, 2, 4-dimethylphenylsulfonyl- (2, 3, 4-trimethylphenylsulfonyl) diazomethane, phenylsulfonyl- (2-fluorophenylsulfonyl) diazomethane, phenylsulfonyl- (3-fluorophenylsulfonyl) diazomethane, and phenylsulfonyl- (4-fluorophenylsulfonyl) diazomethane;

O-nitrobenzyl ester compounds such as o-nitrobenzyl-p-toluenesulfonate;

sulfone hydrazide compounds such as N, N' -bis (phenylsulfonyl) hydrazide;

sulfonium cations such as triarylsulfonium and triarylalkyl sulfonium, and sulfonium salts such as fluoroalkane sulfonate, aromatic hydrocarbon sulfonate, and alkane sulfonate;

iodonium salts of iodonium cations such as diaryliodonium and sulfonates such as fluoroalkanesulfonate, arenesulfonate, and alkanesulfonate;

bis (alkylsulfonyl) diazomethane, bis (cycloalkylsulfonyl) diazomethane, bis (perfluoroalkylsulfonyl) diazomethane, bis (arylsulfonyl) diazomethane, bis (aralkylsulfonyl) diazomethane, and the like;

an N-sulfonyloxy imide compound formed by a combination of a dicarboxylic acid imide compound and a sulfonate such as a fluoroalkane sulfonate, an aromatic hydrocarbon sulfonate, an alkane sulfonate, or the like;

benzoin sulfonate compounds such as benzoin tosylate, benzoin mesylate, benzoin butane sulfonate, and the like;

polyhydroxy aromatic hydrocarbon sulfonate compounds obtained by substituting all hydroxyl groups of polyhydroxy aromatic hydrocarbon compounds with sulfonate such as fluoroalkanesulfonate, arenesulfonate, alkane sulfonate and the like;

Nitrobenzyl sulfonate compounds such as (poly) nitrobenzyl sulfonate of fluoroalkanesulfonic acid, (poly) nitrobenzyl sulfonate of aromatic hydrocarbon sulfonic acid and (poly) nitrobenzyl sulfonate of alkane sulfonic acid;

fluoroalkyl benzyl sulfonate compounds such as fluoroalkyl benzyl (poly) sulfonate, fluoroalkane benzyl (poly) sulfonate, and fluoroalkane benzyl (poly) sulfonate;

bis (arylsulfonyl) alkane compounds;

bis-O- (arylsulfonyl) - α -dialkylglyoxime, bis-O- (arylsulfonyl) - α -bicycloalkyl glyoxime, bis-O- (arylsulfonyl) - α -dialkylglyoxime, bis-O- (alkylsulfonyl) - α -bicycloalkyl glyoxime, bis-O- (alkylsulfonyl) - α -diarylhydrazine, bis-O- (fluorosulfonyl) - α -dialkylglyoxime, bis-O- (fluoroalkylsulfonyl) - α -bicycloalkyl glyoxime, and bis-O- (fluoroalkyl sulfonyl) -alpha-diaryl glyoxime, bis-O- (arylsulfonyl) -alpha-dialkyl dioxime, bis-O- (arylsulfonyl) -alpha-dicycloalkyl dioxime, bis-O- (arylsulfonyl) -alpha-diaryl dioxime, bis-O- (alkylsulfonyl) -alpha-dialkyl dioxime, bis-O- (alkylsulfonyl) -alpha-dicycloalkyl dioxime, bis-O- (alkylsulfonyl) -alpha-diaryl dioxime, bis-O- (fluoroalkyl sulfonyl) -alpha-dialkyl dioxime, oxime compounds such as bis-O- (fluoroalkyl sulfonyl) - α -dicycloalkyl dioxime, bis-O- (fluoroalkyl sulfonyl) - α -diaryl dioxime;

Modified oxime compounds such as arylsulfonyloxy iminoarylacetonitrile, alkylsulfonyloxy iminoarylacetonitrile, fluoroalkylsulfonyliminoarylacetonitrile, ((arylsulfonyl) oxyimino-thiophen-ylidene) arylacetonitrile, ((alkylsulfonyl) oxyimino-thiophen-ylidene) arylacetonitrile, ((fluoroalkylsulfonyl) oxyimino-thiophen-ylidene) arylacetonitrile, bis (arylsulfonyloxy) iminoarylene diacetonitrile, bis (alkylsulfonyloxy) iminoarylene diacetonitrile, bis (fluoroalkylsulfonyloxy iminoarylene diacetonitrile, arylfluoroalkyl-O- (alkylsulfonyl) oxime, arylfluoroalkyl-O- (arylsulfonyl) oxime, and arylfluoroalkyl-O- (fluoroalkyl sulfonyl) oxime.

The photoacid generator may be used alone in an amount of 1, or may be used in combination of 2 or more.

The blending amount of the photoacid generator is preferably 0.1 part by mass or more, more preferably 5 parts by mass or more per 100 parts by mass of the component (a) in view of obtaining a desired pattern with good sensitivity. The amount is preferably 20 parts by mass or less, more preferably 15 parts by mass or less.

[ photopolymerization initiator ]

Photopolymerization initiators are compounds which undergo bond cleavage and/or reaction by exposure to light to generate free radicals. By containing the photopolymerization initiator, the exposed portion of the film of the negative photosensitive resin composition is insoluble in the alkali developer, and thus a negative pattern can be formed. In addition, the curing of the exposed portion is promoted, and the sensitivity can be improved.

The photopolymerization initiator is not particularly limited, and a known photopolymerization initiator can be used. Examples of the photopolymerization initiator include benzil ketal photopolymerization initiator, α -hydroxyketone photopolymerization initiator, α -aminoketone photopolymerization initiator, acylphosphine oxide photopolymerization initiator, oxime ester photopolymerization initiator, acridine photopolymerization initiator, titanocene photopolymerization initiator, benzophenone photopolymerization initiator, acetophenone photopolymerization initiator, aromatic ketone ester photopolymerization initiator, and benzoate photopolymerization initiator.

The photopolymerization initiator may be used alone in an amount of 1 kind, or may be used in an amount of 2 or more kinds.

The amount of the photopolymerization initiator to be blended is preferably 0.1 part by mass or more, more preferably 5 parts by mass or more, per 100 parts by mass of the component (a) in view of obtaining a desired pattern with good sensitivity. The amount is preferably 20 parts by mass or less, more preferably 15 parts by mass or less.

[ radically polymerizable Compound ]

The radical polymerizable compound means a compound having a plurality of ethylenically unsaturated groups in the molecule. By containing the radical polymerizable compound, curing of the exposed portion is promoted, and sensitivity at the time of exposure can be improved. Further, the crosslinking density after heat curing is increased, and the hardness of the cured film can be increased.

The radical polymerizable compound is not particularly limited, and a known radical polymerizable compound can be used, and a compound having a (meth) acryloyl group which can be easily radical polymerized is preferable.

From the viewpoints of improving sensitivity at the time of exposure and improving hardness of a cured film, a compound having two or more (meth) acryloyl groups in a molecule is more preferable.

As the radical polymerizable compound, a radical polymerizable compound, examples thereof include diethylene glycol di (meth) acrylate, triethylene glycol di (meth) acrylate, tetraethylene glycol di (meth) acrylate, propylene glycol di (meth) acrylate, trimethylolpropane tri (meth) acrylate, ethoxylated trimethylolpropane di (meth) acrylate, ethoxylated trimethylolpropane tri (meth) acrylate, ditrimethylolpropane 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 glycerol tri (meth) acrylate, pentaerythritol tetra (meth) acrylate, ethoxylated pentaerythritol tri (meth) acrylate, dipentaerythritol di (meth) acrylate, dipentaerythritol, heptapentaerythritol (meth) acrylate, pentaerythritol (meth) acrylate, tripentaerythritol octa (meth) acrylate, tetrapentaerythritol nona (meth) acrylate, tetrapentaerythritol deca (meth) acrylate, pentapentapentaerythritol undec (meth) acrylate, pentapentaerythritol dodeca (meth) acrylate, ethoxylated bisphenol A di (meth) acrylate, 2-bis [4- (3- (meth) acryloyloxy-2-hydroxypropoxy) phenyl ] propane, 1,3, 5-tris ((meth) acryloyloxyethyl) isocyanurate, 1, 3-bis ((meth) acryloyloxyethyl) isocyanurate, 9-bis [4- (2- (meth) acryloyloxyethoxy) phenyl ] fluorene, 9-bis [4- (3- (meth) acryloyloxypropoxy) phenyl ] fluorene, or 9, 9-bis (4- (meth) acryloyloxyphenyl) fluorene, or an acid modification, ethylene oxide modification, or propylene oxide modification thereof.

The amount of the radical polymerizable compound to be blended is preferably 0.1 part by mass or more, more preferably 0.5 part by mass or more, still more preferably 1 part by mass or more, and particularly preferably 5 parts by mass or more, based on 100 parts by mass of the component (a). When the content is within the above range, the sensitivity at the time of exposure can be improved. On the other hand, the content of the radical polymerizable compound is preferably 50 parts by mass or less, more preferably 30 parts by mass or less, further preferably 25 parts by mass or less, and particularly preferably 20 parts by mass or less.

The sensitizer (C) may be used alone or in combination of two or more. For example, a photopolymerization initiator and a radical polymerizable compound may be simultaneously compounded.

Component (D)

The solvent of the component (D) may be a polar aprotic solvent such as N-methyl-2-pyrrolidone, gamma-butyrolactone, N-dimethylformamide, N-dimethylacetamide or 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, 3-methyl-3-methoxybutanol; aromatic hydrocarbons such as toluene and xylene. These solvents may be used alone in an amount of 1 kind, or may be used in combination of 2 or more kinds.

The amount of component (D) blended in the negative photosensitive resin composition of the present embodiment is preferably an amount of 5 mass% or more of the solid content concentration in the composition, from the viewpoints of fluidity of the composition and obtaining a uniform coating film by a coating method such as spin coating. The solid content concentration in the composition is preferably 65 mass% or less.

Others

In one embodiment, in addition to the components (a) to (D) described above, various additives may be blended in the negative photosensitive resin composition within a range that does not impair the effects of the present invention. Examples of the additive include a surfactant such as a filler, a pigment, and a leveling agent; adhesion improving agents, dissolution accelerators, and the like.

In one embodiment, an organic base compound for neutralizing an acid generated by a photoacid generator (component (C)) upon exposure may be included. By including the organic alkali compound in the negative photosensitive resin composition, the effect of preventing the dimensional change of the resist pattern due to the movement of the acid generated by the photoacid generator can be obtained.

Specific examples of the organic base compound include pyrimidine compounds such as pyrimidine, (poly) aminopyrimidine, (poly) hydroxypyrimidine, (poly) amino (poly) alkylpyrimidine, (poly) amino (poly) alkoxypyrimidine, (poly) hydroxy (poly) alkylpyrimidine, and (poly) hydroxy (poly) alkoxypyrimidine; pyridine compounds such as pyridine, (poly) alkylpyridine and dialkylaminopyridine; amine compounds having a hydroxyalkyl group, such as a polyalkanolamine, a tris (hydroxyalkyl) aminoalkyl, and a bis (hydroxyalkyl) iminotris (hydroxyalkyl) alkane; amino aryl compounds such as aminophenol, and the like.

The organic alkali compound may be used alone or in combination of 1 or more than 2.

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

The negative photosensitive resin composition of the present embodiment can be prepared by mixing the above components (a) to (D) and, if necessary, various additives by stirring by a usual method to prepare a uniform liquid.

When a solid material such as a filler or pigment is blended with the composition, it is preferable to disperse and mix the solid material with a dispersing device such as a dissolver, a homogenizer, or a three-roll mill. In order to remove coarse particles and impurities, the composition may be filtered using a mesh filter, a membrane filter, or the like.

[ cured film, resist film ]

The cured film according to one embodiment of the present invention is obtained by curing the negative photosensitive resin composition of the present invention.

Specifically, the negative photosensitive resin composition of the present invention is applied to an object to be subjected to photolithography, and prebaked to obtain a film (photosensitive film) of the photosensitive resin composition from which the solvent has been removed.

Examples of the coating method include spin coating, roll coating, flow coating, dip coating, spray coating, and blade coating. The pre-baking may be performed at a temperature of 60 ℃ or more and 150 ℃ or less for a time of 30 seconds or more and 600 seconds or less.

By exposing the photosensitive film, the solubility of the exposed portion with respect to the alkali developer is greatly reduced. Examples of the light source 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-rays (wavelength 436 nm) and i-rays (wavelength 365 nm) of a high-pressure mercury lamp are suitable.

After the exposure, a heat treatment is performed at about 100 ℃ in order to promote the crosslinking reaction with the component (a), the component (B) and the component (C) by the catalytic reaction of the acid generated by the exposure.

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

Examples of the alkali developer used for development after exposure include inorganic alkaline substances such as sodium hydroxide, potassium hydroxide, sodium carbonate, sodium silicate, sodium metasilicate, and ammonia water; 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; basic aqueous solutions such as cyclic amines including pyrrole and piperidine.

If necessary, an alcohol, a surfactant, or the like may be appropriately added to the alkali developer. The alkali concentration of the alkali developer is preferably in the range of 2 to 5 mass%, and an aqueous solution of 2.38 mass% tetramethylammonium hydroxide is usually used.

After development with an alkali developer, the cured film is heated at a low temperature of 150 ℃ or higher and 200 ℃ or lower, for example, to obtain a cured film having an exposed portion crosslinked. The cured film of the present embodiment is excellent in chemical resistance.

The cured film of the present embodiment can be used for a pixel dividing layer in a display device such as an organic EL display.

Examples

Hereinafter, the present invention will be described in more detail with reference to specific examples. The weight average molecular weight (Mw) of the synthesized resin was measured under the following GPC measurement conditions.

[ measurement conditions of GPC ]

Measurement device: HLC-8220GPC manufactured by Tosoh Corp "

Column: shodex KF802 manufactured by Showa electric company: 8.0mm phi x 300mm

"Shodex KF802" manufactured by Showa Denko Co., ltd. ":8.0mm phi x 300mm

"Shodex KF803" manufactured by Showa Denko Co., ltd. ":8.0mm phi x 300mm

"Shodex KF804" manufactured by Showa Denko Co., ltd. ":8.0mm phi x 300mm

Column temperature: 40 DEG C

A detector: RI (differential refractometer)

And (3) data processing: GPC-8020model II 4.30 version of Tosoh Co "

Developing solvent: tetrahydrofuran (THF)

Flow rate: 1.0 mL/min

Sample: the tetrahydrofuran solution was filtered through a microfilter to obtain a solution of 0.5 mass% in terms of resin solid content.

Injection amount: 0.1mL

Standard sample: the monodisperse polystyrene described below

(Standard sample: monodisperse polystyrene)

"A-500" manufactured by Tosoh Corp "

"A-2500" manufactured by Tosoh Corp "

"A-5000" manufactured by Tosoh corporation "

"F-1" manufactured by Tosoh Corp "

"F-2" manufactured by Tosoh Corp "

"F-4" manufactured by Tosoh Corp "

"F-10" manufactured by Tosoh Corp "

"F-20" manufactured by Tosoh Corp "

[ component (A) ]

Synthesis example 1 (Synthesis of novolak-type phenol resin (A-1))

To a four-necked flask having a capacity of 2000mL and provided with a condenser, 164g (1.52 mol) of m-cresol, 103g (0.97 mol) of benzaldehyde, 74g (0.61 mol) of salicylaldehyde and 8g of p-toluenesulfonic acid were charged and dissolved in 300g of ethanol as a reaction solvent. Thereafter, the mixture was heated to 80℃by a mantle heater and stirred at reflux for 16 hours to react. After the reaction, ethyl acetate and water were added, and washing was performed 5 times. After the solvent was distilled off from the remaining resin solution under reduced pressure, vacuum drying was performed to obtain 281g of powder of novolak-type phenol resin (A1) as pale red powder.

The Mw of the novolak-type phenol resin (A-1) was 3100. GPC chart of the novolak type phenol resin (A-1) is shown in FIG. 1.

Synthesis example 2 (Synthesis of novolak-type phenol resin (A-2))

The procedure of Synthesis example 1 was repeated except that the amounts of the starting materials added were changed to 164g (1.52 mol) of m-cresol, 80g (0.75 mol) of benzaldehyde and 92g (0.75 mol) of salicylaldehyde, and 280g of powder of novolak-type phenol resin (A-2) was obtained. The Mw of the novolak-type phenol resin (A-2) was 2370.

GPC chart of the novolak type phenol resin (A-2) is shown in FIG. 2.

Synthesis example 3 (Synthesis of novolak-type phenol resin (A-3))

The procedure of Synthesis example 1 was repeated except that the amounts of the starting materials were changed to 164g (1.52 mol) of m-cresol, 117g (1.10 mol) of benzaldehyde and 58g (0.47 mol) of salicylaldehyde, thereby obtaining 279g of powder of novolak-type phenol resin (A-3). The Mw of the novolak-type phenol resin (A-3) was 2700.

GPC patterns of the novolak-type phenol resin (A-3) are shown in FIG. 3.

Synthesis example 4 (Synthesis of novolak-type phenol resin (A-4))

The same procedures as in Synthesis example 1 were repeated except that the reaction solvent was changed to 250g of ethanol, 30g of 1-propanol and 15g of 2-propanol, to obtain 282g of powder of novolak-type phenol resin (A5). The Mw of the novolak-type phenol resin (A-4) was 3200.

GPC patterns of the novolak-type phenol resin (A-4) are shown in FIG. 5.

Comparative Synthesis example 1 (Synthesis of novolak-type phenol resin (A-5))

To a 2000mL three-necked flask equipped with a condenser was charged 70.29g (0.65 mol) of m-cresol, 37.85g (0.35 mol) of anisole as a reaction accelerator, and 0.62g (0.005 mol) of oxalic acid dihydrate under a dry nitrogen flow, and after dissolving them in 198.85g of methyl isobutyl ketone (MIBK), 243.49g (3.00 mol) of 37 mass% aqueous formaldehyde solution was added, and the mixture was heated to 95℃by a mantle heater and stirred for 5 hours while refluxing the reaction solution. Thereafter, the temperature was raised to 180℃to distill water and MIBK out of the system. Thereafter, the temperature was further raised to 195℃and the unreacted monomers were distilled off under reduced pressure of 150torr (2.0 kPa). The obtained resin solid was redissolved in MIBK, water was added thereto, and the mixture was subjected to 5-time liquid-separation washing. After MIBK was distilled off under reduced pressure at 60℃by an evaporator, vacuum drying was performed to obtain 212g of novolak-type phenol resin (A-5) as pale red powder. The Mw of the novolak-type phenol resin (A-5) was 5500.

Comparative Synthesis example 2 (Synthesis of novolak-type phenol resin (A-6))

Powder 284g of novolak-type phenol resin (A-6) was obtained in the same manner as in Synthesis example 1 except that the amount of the starting materials to be charged was changed to 164g (1.52 mol) of m-cresol, 39g (0.38 mol) of benzaldehyde and 137g (1.13 mol) of salicylaldehyde. The Mw of the novolak-type phenol resin (A-6) was 4700.

[ component (B) ]

Synthesis example 5 Synthesis of an ethylenically unsaturated group-containing polyimide precursor (B-1)

In a 2000mL four-necked flask equipped with a condenser, 125g (0.023 mol) of pyromellitic anhydride and 115g (0.023 mol) of 4, 4-diaminodiphenyl ether were dissolved in 1602g of N-methyl-2-pyrrolidone under a dry nitrogen flow, and the mixture was stirred at 100℃for 4 hours to react. After the reaction was completed, the solution was poured into 2000g of water, and the precipitate of polymer solids was collected by filtration. The polymer solids were dried in a vacuum dryer at 80 ℃ for 72 hours to give a polymer solids powder.

32.8g of the obtained solid powder was dissolved in 76.5g of 3-methoxy-n-butyl acetate. After cooling the mixed solution to 0 ℃, a solution of 3.2g of 2-methacryloyloxyethyl isocyanate dissolved in 3.2g of 3-methoxy n-butyl acetate was added dropwise. After the completion of the dropwise addition, stirring was carried out at 80℃for 1 hour to obtain a polymer solution containing an ethylenically unsaturated group. After the reaction was completed, the resulting solution was poured into 1000g of water, and the precipitate of the polymer solid containing an ethylenically unsaturated group was collected by filtration. The precipitate of polymer solids was collected by filtration. The polymer solid containing an ethylenically unsaturated group was dried in a vacuum dryer at 80℃for 72 hours to obtain a polymer powder of the polyimide precursor (B-1) containing an ethylenically unsaturated group.

[ negative-type photosensitive resin composition ]

Example 1

A negative photosensitive resin composition (F-1) was obtained by dissolving 4.2g of the phenol novolac resin (A-1) powder obtained in Synthesis example 1 as component (A), 1.8g of the polymer (B-1) powder containing an ethylenically unsaturated group as a polyimide precursor obtained in Synthesis example 6 as component (B), and 4.0g of the radical polymerizable compound solution (dipentaerythritol hexaacrylate: manufactured by Japanese chemical Co., ltd.) and 0.9g of the photopolymerization initiator solution (NCI-831: manufactured by ADEKA Co., ltd.) as component (C) in 98g of gamma-butyrolactone as component (D).

Examples 2 to 4 and comparative examples 1 to 3

Negative photosensitive resin compositions (F-2) to (F-6) were obtained in the same manner as in example 1 except that the powders of phenol novolac resins (A-2) to (A-6) shown in Table 1 were used as the component (A) in examples 2 to 4 and comparative examples 1 and 2.

A negative photosensitive resin composition (F-7) was obtained in the same manner as in example 1 except that the phenol novolac resin shown in Table 1 was not contained as the component (A) in comparative example 3.

[ evaluation ]

The negative photosensitive resin compositions prepared in examples and comparative examples were used to evaluate alkali solubility before exposure, chemical resistance of a cured film, and hardness of the cured film.

(1) Evaluation of film Forming Property (resin compatibility)

The negative photosensitive resin composition was applied to a silicon wafer having a diameter of 5 inches so that the thickness became about 5 μm using a spin coater, and then pre-baked at 120℃for 180 seconds, to obtain a wafer having a photosensitive film formed thereon. The photosensitive film formed on the wafer surface was observed with an optical microscope, and rejection and unevenness at the time of film formation were evaluated.

The photosensitive film was considered to have good compatibility ((good)) when no rejection or unevenness occurred, and insufficient compatibility (x) when rejection or unevenness occurred. The evaluation results are shown in table 1.

(2) Alkali solubility before exposure

The negative photosensitive resin composition was applied to a silicon wafer having a diameter of 5 inches so that the thickness became about 5 μm using a spin coater, and then pre-baked at 120℃for 180 seconds, to obtain a wafer having a photosensitive film (resist film) formed thereon. The wafer was immersed in a 250mL tank containing a developer solution (2.38 wt% aqueous tetramethylammonium hydroxide (TMAH)) for 10 seconds. The wafer taken out of the tub was subjected to a rinsing treatment with pure water for 10 seconds, and residues of the photosensitive film on the wafer were observed, whereby the alkali solubility was evaluated. The case where there is no residue at all was regarded as excellent, the case where there is almost no residue was regarded as excellent, and the case where there is residue was regarded as insufficient (x). The evaluation results are shown in table 1.

(3) Chemical resistance of cured films

The negative photosensitive resin composition was applied to a silicon wafer having a diameter of 5 inches so that the thickness became about 10 μm using a spin coater, and then pre-baked at 120℃for 180 seconds, to obtain a wafer having a photosensitive film formed thereon. Next, 200mJ of ghi rays were irradiated to the photosensitive film with Multilight manufactured by USHIO corporation. After the irradiation, the cured film was formed by heating on a hot plate at 130℃for 120 seconds and further heating at 200℃for 1 hour under a nitrogen atmosphere.

After the heating, the wafer was taken out when the temperature in the heating device became 50 ℃ or lower, and the film thickness was measured.

Wafer 3 was then aliquoted and immersed in acetone, N-methylpyrrolidone (NMP) and 2.38 wt% TMAH, respectively, for 15 minutes. The wafer taken out from each solvent was rinsed with pure water, and the film thickness was measured again.

The chemical resistance was evaluated based on the rate of change of the film thickness before and after immersion in the solvent. When the change rate was less than 2%, the change rate was good, and when it was not less than 2%, the change rate was insufficient (poor). The evaluation results are shown in table 1.

(4) Hardness of cured film

After a cured film was obtained in the same manner as in (2), the wafer was taken out when the temperature of the heating device became 50 ℃ or lower, and the film thickness was measured. Film hardness was measured by nanoindentation (ENT-2100: manufactured by ELIONIX Co.). The press-fit elastic modulus was set to be 8GPa or more, and the press-fit elastic modulus was set to be less than 8GPa (no), and the press-fit elastic modulus was set to be insufficient (x). The evaluation results are shown in table 1.

TABLE 1

In Table 1, the molar ratio "(a 1)/(a 2)/(a 3)" of the structural unit of the component (A) is the molar ratio of the structural unit (a 1) derived from m-cresol, the structural unit (a 2) derived from benzaldehyde and the structural unit (a 3) derived from salicylaldehyde.

From the results in table 1, it can be confirmed that: the negative photosensitive resin composition of the invention has no occurrence of film formation failure and excellent compatibility. It can be additionally confirmed that: the resist film obtained from the negative photosensitive resin composition of the present invention has alkali solubility. Further, it can be confirmed that: although the cured film is cured at a low temperature of 200 ℃, chemical resistance is excellent and hardness is also high.

Preparation example 1 (preparation of novolak-type phenol resin (a-1))

As a result of evaluating the content of the low molecular component having a weight average molecular weight of less than 500 in the novolak type phenol resin (A-1) obtained in Synthesis example 1 by GPC, the content was 3.9% by mass in terms of GPC area ratio.

200g of this novolak type phenol resin (A-1) was sufficiently dissolved in 300g of methyl isobutyl ketone in a 2000ml beaker, and 300g of heptane was added thereto to precipitate a resin component. The low molecular components are removed by removing the supernatant. After repeating this operation 3 times, the precipitated resin component was dissolved in 300g of methyl isobutyl ketone again to recover the resin component, and after the solvent was distilled off under reduced pressure, the resultant was dried under vacuum to obtain 153g of a low molecular weight component-removed phenol novolac resin powder (a-1) as pale red powder.

The weight average molecular weight (Mw) of the phenol novolak resin (a-1) was 2,750, and the content of the low molecular component having a weight average molecular weight of less than 500 was 0.7% in terms of GPC area ratio. GPC patterns of the phenol novolac resin (a-1) are shown in FIG. 5.

Preparation example 2 (preparation of novolak-type phenol resin (a-2))

As a result of evaluating the content of the low molecular component having a weight average molecular weight of 500 or less in the novolak type phenol resin (A-2) obtained in Synthesis example 2 by GPC, the content was 3.7% by mass in terms of GPC area ratio.

The novolak type phenol resin (A-2) was subjected to removal of low molecular components in the same manner as in production example 1, to obtain 156g of a novolak type phenol resin powder (a-2).

The weight average molecular weight (Mw) of the phenol novolak resin (a-2) was 2,840, and the content of the low molecular component having a weight average molecular weight of less than 500 was 0.6% in terms of GPC area ratio.

Preparation example 3 (preparation of novolak-type phenol resin (a-3))

As a result of evaluating the content of the low molecular component having a weight average molecular weight of less than 500 in the novolak type phenol resin (A-3) obtained in Synthesis example 3 by GPC, the content was 3.2% by mass in terms of GPC area ratio.

The novolak type phenol resin (A-3) was subjected to removal of low molecular components in the same manner as in production example 1, to obtain 151g of phenol novolak resin powder (a-3).

The weight average molecular weight (Mw) of the phenol novolak resin (a-3) was 3,130, and the content of the low molecular component having a weight average molecular weight of less than 500 was 0.7% in terms of GPC area ratio.

Preparation example 4 (preparation of novolak-type phenol resin (a-4))

As a result of evaluating the content of the low molecular component having a weight average molecular weight of less than 500 in the novolak type phenol resin (A-4) obtained in Synthesis example 4 by GPC, the ratio of GPC area was 4.1% by mass.

The low molecular weight component of this novolak resin (A-4) was removed in the same manner as in production example 1 to obtain 152g of a novolak resin powder (a-4).

The weight average molecular weight (Mw) of the phenol novolak resin (a-4) was 2,780, and the content of the low molecular component having a weight average molecular weight of less than 500 was 0.8% in terms of GPC area ratio.

[ negative-type photosensitive resin composition ]

Example 5

A negative photosensitive resin composition (f-1) was obtained by dissolving 4.2g of the phenol novolac resin (a-1) powder obtained in preparation example 1 as component (A), 1.8g of the polymer (B-1) powder containing an ethylenically unsaturated group as a polyimide precursor obtained in Synthesis example 6 as component (B), and 4.0g of the radical polymerizable compound solution (dipentaerythritol hexaacrylate: manufactured by Japanese chemical Co., ltd.) and 0.9g of the photopolymerization initiator solution (NCI-831: manufactured by ADEKA Co., ltd.) as component (C) in 98g of gamma-butyrolactone as component (D).

Examples 6 to 8 and reference examples 1 to 2

In examples 6 to 8 and reference examples 1 and 2, negative photosensitive resin compositions (f-2) to (f-6) were obtained in the same manner as in example 1 except that the phenol novolac resins (a-2) to (a-4), (a-1) and (a-6) powders shown in table 2 were used as the component (a).

The negative photosensitive resin compositions obtained were evaluated in the same manner as in examples 1 to 4 and comparative examples 1 to 3. The results are shown in Table 2.

TABLE 2

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Claims

1. A negative photosensitive resin composition comprising the following components (A) to (D),

(C) A sensitizer;

(D) And (3) a solvent.

2. The negative photosensitive resin composition according to claim 1, wherein the component (a) is a novolac type phenol resin obtained by polycondensing m-cresol, benzaldehyde and salicylaldehyde in an organic solvent with an acid catalyst in a molar ratio of m-cresol, benzaldehyde, salicylaldehyde=1.0:0.4 to 0.8:0.3 to 0.6.

3. The negative-type photosensitive resin composition according to claim 1 or 2, wherein the total content of the m-cresol-derived structural unit (a 1), benzaldehyde-derived structural unit (a 2) and salicylaldehyde-derived structural unit (a 3) in the component (a) is 30 mass% or more.

4. The negative-type 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-type photosensitive resin composition according to any one of claims 1 to 4, wherein the component (a) having a molecular weight of less than 500 is less than 3.0 mass% in terms of an area ratio in a gel permeation chromatography measurement.

6. The negative-working photosensitive resin composition according to any one of claims 1 to 5, wherein the component (C) is 1 or more selected from the group consisting of photoacid generators, photopolymerization initiators and radical polymerizable compounds.

7. A cured film obtained from the negative photosensitive resin composition according to any one of claims 1 to 6.

8. A resist film obtained from the negative photosensitive resin composition according to any one of claims 1 to 6.