Negative-type photosensitive resin composition

Abstract

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

Description

Technical Field

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

Background Art

[0002] As a next-generation flat panel display, an organic EL display has attracted attention. An organic EL display is a self-emitting display device that utilizes electroluminescence by an organic compound, and can display images with a wide viewing angle and high-speed response. In addition, it can be made thinner and lighter. In recent years, with the higher definition of organic EL displays, further miniaturization of light-emitting elements has been demanded.

[0003] An organic EL display emits light using the energy generated by the recombination of electrons injected from the cathode and holes injected from the anode. Therefore, if there is a substance that forms an energy level that inhibits the recombination of electrons and holes, the luminous efficiency of the light-emitting element decreases, and the lifespan of the organic EL display decreases. On the other hand, generally, in order to divide pixels of a light-emitting element, an insulating layer called a pixel division layer is formed between a transparent electrode on the light extraction side and a metal electrode on the opposite side. Since this pixel division layer is formed at a position adjacent to the light-emitting element, outgassing and leakage of ionic components from the pixel division layer can contribute to a decrease in the lifespan of the organic EL display. Therefore, the pixel division layer is required to have heat resistance and durability.

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

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

[0006] In the fabrication of fine patterns, colorants incorporated into the photosensitive resin composition can sometimes leave residue during development. Furthermore, since carbon black is conductive, it is preferable to use less of it to improve the insulating properties of the cured film. With the increasing resolution of organic EL displays, there is a need for a photosensitive resin composition that possesses high visible light shielding ability even with reduced colorant content, in order to fabricate finer pixel division layers without generating residue. The object of the present invention is to provide a photosensitive resin composition that yields a cured film with high visible light shielding ability even when the amount of colorant added is reduced. [Means for solving the problem]

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

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

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

[0010] According to the present invention, it is possible to provide a photosensitive resin composition that can obtain a cured film with high visible light shielding ability even when the amount of colorant added is reduced. [Modes for carrying out the invention]

[0011] The following describes embodiments for carrying out the invention. In this specification, "x~y" represents a numerical range of "greater than or equal to x and less than or equal to y". The upper and lower limits specified for the numerical range can be combined in any way. Furthermore, forms that combine two or more of the individual embodiments of the present invention described below are also embodiments of the present invention.

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

[0013] In this embodiment, by using the novolac-type phenolic resin described in (A) above, a cured film with high visible light shielding properties can be obtained even with a reduced amount of colorant added. Furthermore, by using resins (A) and (B) in combination, the compatibility of the two resins is improved. This suppresses the occurrence of film formation defects (scum). In addition, a negative-type photosensitive resin composition is obtained in which a resist film and a cured film with high alkali solubility in the non-exposed areas and excellent elastic modulus can be obtained. The following describes the components of the negative-type photosensitive resin composition.

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

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

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

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

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

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

[0020] Examples of the above 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.

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

[0022] From the viewpoint of obtaining a resist film and a cured film that are highly sensitive, excellent in resin compatibility, and have visible light shielding properties, the total content of the above structural units (a1), (a2), (a3), and (a4) in component (A) is preferably 30% 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 above structural units (a1), (a2), (a3), and (a4) may be substantially 100% by mass. Note that substantially 100% by mass means the case where structural units other than the above structural units (a1), (a2), (a3), and (a4) are inevitably included.

[0023] The weight average molecular weight of the novolak type phenol 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. When the weight average molecular weight is 1,000 or more, it is preferable because of high heat resistance. On the other hand, when the weight average molecular weight is 7,000 or less, it is preferable because of high sensitivity. In this specification, the weight average molecular weight is measured according to the conditions described in the examples.

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

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

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

[0027] When polycondensing m-cresol, catechol, benzaldehyde, and salicylaldehyde in an organic solvent to obtain component (A), a novolac-type phenol resin, other phenols and aldehydes besides m-cresol, catechol, benzaldehyde, and salicylaldehyde may be included in the organic solvent, as described above.

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

[0029] 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, methyl isobutyl ketone, and toluene. Among these, one or more selected from ethanol, 1-propanol, and 2-propanol are preferred, and ethanol is more preferred.

[0030] From the viewpoint of reaction uniformity, the amount of the above-mentioned organic solvent used is preferably 20 parts by mass or more, more preferably 50 parts by mass or more, per 100 parts by mass of the raw material for deriving the structural units constituting component (A). Furthermore, it is preferably 500 parts by mass or less, more preferably 300 parts by mass or less.

[0031] 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, as they promote the reaction more effectively. The amount of acid catalyst added is not particularly limited, but is preferably 5 parts by mass or more, more preferably 20 parts by mass or more, per 100 parts by mass of raw material for deriving the structural units constituting component (A). It is also preferably 150 parts by mass or less, more preferably 100 parts by mass or less.

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

[0033] ·Component (B) Component (B) is one or more resins selected from ethylenically unsaturated group-containing polyimide, ethylenically unsaturated group-containing polyimide precursor, ethylenically unsaturated group-containing polybenzoxazole, and ethylenically unsaturated group-containing polybenzoxazole precursor. Component (B) is obtained by introducing an ethylenically unsaturated group into each of the polyimide, polyimide precursor, polybenzoxazole, or polybenzoxazole precursor. Component (B) can be one that has been conventionally used in photosensitive resin compositions.

[0034] <Polyimides and polyimide precursors> Examples of polyimide precursors include those obtained by reacting a tetracarboxylic acid, a corresponding tetracarboxylic acid dianhydride, or a tetracarboxylic acid diester dichloride with a diamine, a corresponding diisocyanate compound, or a trimethylsilylated diamine, and having tetracarboxylic acid and / or its derivative residues and diamine and / or its derivative residues. Examples of polyimide precursors include polyamic acid, polyamic acid ester, polyamic acid amide, or polyisoimide.

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

[0036] The unsaturated group-containing polyimide and unsaturated group-containing polyimide precursor used in the present invention have an ethylenically unsaturated group as a radical polymerizable group, in addition to the above-mentioned polyimide or polyimide precursor. The presence of an ethylenically unsaturated group can improve sensitivity during exposure. Preferably, the unsaturated group-containing polyimide and unsaturated group-containing polyimide precursor are obtained by reacting some of the phenolic hydroxyl groups and / or carboxyl groups of the polyimide and polyimide precursor with a compound having an ethylenically unsaturated group, as described later. Through the above reaction, it becomes possible to introduce an ethylenically unsaturated group into the resin.

[0037] <Polybenzoxazoles and polybenzoxazole precursors> Examples of polybenzoxazole precursors include those obtained by reacting a dicarboxylic acid, a corresponding dicarboxylic acid dichloride, or a dicarboxylic acid active diester with a diamine such as a bisaminophenol compound, and having residues of a dicarboxylic acid and / or its derivative, and a bisaminophenol compound and / or its derivative. Examples of polybenzoxazole precursors include polyhydroxyamides.

[0038] Examples of polybenzoxazoles include those obtained by dehydrating and cyclizing a dicarboxylic acid and a bisaminophenol compound as a diamine using polyphosphate, or those obtained by dehydrating and cyclizing the above-mentioned polyhydroxyamide by heating or using anhydrous phosphoric acid, a base, or a carbodiimide compound, and have dicarboxylic acid and / or derivative residues and bisaminophenol compounds and / or derivative residues. The bisaminophenol used in the synthesis of polybenzoxazoles is preferably 3,3-hydroxybenzidine from the viewpoint of heat resistance. The dicarboxylic acid used in the synthesis of polybenzoxazoles is preferably 4,4-biphenyldicarboxylic acid from the viewpoint of heat resistance.

[0039] The ethylenically unsaturated group-containing polybenzoxazole and ethylenically unsaturated group-containing polybenzoxazole precursor used in the present invention have an ethylenically unsaturated group as a radical polymerizable group. The presence of an ethylenically unsaturated group improves sensitivity during exposure. Preferably, the ethylenically unsaturated group-containing polybenzoxazole and ethylenically unsaturated group-containing polybenzoxazole precursor are obtained by reacting some of the phenolic hydroxyl groups and / or carboxyl groups of the polybenzoxazole and polybenzoxazole precursor with a compound having an ethylenically unsaturated group, as described later. Through the above reaction, it becomes possible to introduce an ethylenically unsaturated group into the resin.

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

[0041] <Method for synthesizing polyimides, polybenzoxazoles, polyimide precursors, or polybenzoxazole precursors> Polyimides, polyimide precursors, polybenzoxazoles, or polybenzoxazole precursors can be synthesized by known methods. Specifically, for example, diamines or bisaminophenol compounds are first dissolved in a reaction solvent, and substantially equimolar amounts of carboxylic acid anhydrides are gradually added to this solution. The mixed solution is stirred using a mechanical stirrer at a temperature preferably 0 to 200°C, more preferably 40 to 150°C, for preferably 0.5 to 50 hours, more preferably 2 to 24 hours. If a terminal encapsulant is used, after adding the carboxylic acid anhydrides, the mixture is stirred at a predetermined temperature for a predetermined time, and then the terminal encapsulant is gradually added and stirred.

[0042] The reaction solvent used in the polymerization reaction should be capable of dissolving the starting materials, which are diamines or bisaminophenol compounds and carboxylic acid anhydrides, and a polar solvent is preferred. Examples of reaction solvents include amides such as N,N-dimethylformamide, N,N-dimethylacetamide, or N-methyl-2-pyrrolidone; cyclic esters such as γ-butyrolactone, γ-valerolactone, δ-valerolactone, γ-caprolactone, ε-caprolactone, or α-methyl-γ-butyrolactone; carbonates such as ethylene carbonate or propylene carbonate; glycols such as triethylene glycol; phenols such as m-cresol or p-cresol; or other solvents such as acetophenone, 1,3-dimethyl-2-imidazolidinone, sulfolane, and dimethyl sulfoxide. The amount of reaction solvent is preferably 100 to 1900 parts by mass, and more preferably 150 to 950 parts by mass, when the total amount of diamines or bisaminophenol compounds and carboxylic acid anhydrides is 100 parts by mass.

[0043] It is preferable that one or more selected from polyimide, polybenzoxazole, polyimide precursor, and polybenzoxazole precursor are precipitated in a poor solvent such as methanol or water after the polymerization reaction is complete, followed by washing and drying. By performing reprecipitation treatment, low molecular weight components can be removed, thereby significantly improving the mechanical properties (elastic modulus) of the cured film.

[0044] <Method for synthesizing ethylenically unsaturated group-containing polyimide, ethylenically unsaturated group-containing polyimide precursor, ethylenically unsaturated group-containing polybenzoxazole, or ethylenically unsaturated group-containing polybenzoxazole precursor> Polyimides containing ethylenically unsaturated groups, polyimide precursors containing ethylenically unsaturated groups, polybenzoxazoles containing ethylenically unsaturated groups, or polybenzoxazole precursors containing ethylenically unsaturated groups can be synthesized by known methods. For the reaction to introduce ethylenically unsaturated groups into polyimide, polybenzoxazole, polyimide precursor, or polybenzoxazole precursor, it is preferable to, for example, thoroughly purge the reaction vessel with nitrogen by air, bubbling, or degassing under reduced pressure, and then add the polyimide, polyimide precursor, polybenzoxazole, or polybenzoxazole precursor to the reaction solvent and react at 20 to 110°C for 30 to 500 minutes. Polymerization inhibitors such as phenolic compounds, acid catalysts, or base catalysts may also be used as needed.

[0045] For specific descriptions of polyimide, polyimide precursor, polybenzoxazole, polybenzoxazole precursor, ethylenically unsaturated group-containing polyimide, ethylenically unsaturated group-containing polyimide precursor, ethylenically unsaturated group-containing polybenzoxazole, and ethylenically unsaturated group-containing polybenzoxazole precursor in component (B), refer to sections

[0074] to

[0210] of International Publication No. 2017 / 159876 as appropriate.

[0046] The weight-average molecular weight of component (B) is preferably 5,000 or more, more preferably 10,000 or more. It is also preferably 50,000 or less, more preferably 40,000 or less. A weight-average molecular weight of 5,000 or more is preferable because it provides 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.

[0047] 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 cured film with good sensitivity and excellent visible light shielding properties. Furthermore, it is preferably 2,000 parts by mass or less, and more preferably 1,000 parts by mass or less.

[0048] ·Component (C) Component (C) is a radical polymerizable compound. A radical polymerizable compound is a compound that has multiple ethylenically unsaturated groups in its molecule. By including a radical polymerizable compound, the curing of the exposed area is accelerated, improving sensitivity during exposure. In addition, the crosslinking density after heat curing is improved, and the hardness (elastic modulus) of the cured film can be improved.

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

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

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

[0052] The radical polymerizable compound, which is component (C), may be used alone or in combination of two or more types.

[0053] ·Component (D) Component (D) is a photopolymerization initiator. A photopolymerization initiator is a compound that generates radicals by cleaving bonds and / or reacting upon exposure. By including a photopolymerization initiator, the exposed areas of the negative-type photosensitive resin composition film become insoluble in alkaline developer, thereby forming a negative-type pattern. Furthermore, the curing of the exposed areas is accelerated, improving sensitivity.

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

[0055] The photopolymerization initiator may be used alone, or two or more may be used in combination. The amount of photopolymerization initiator added is preferably 1 part by mass or more, more preferably 10 parts by mass or more, per 100 parts by mass of component (A), in order to obtain good sensitivity and the desired pattern. Furthermore, it is preferably 50 parts by mass or less, and more preferably 30 parts by mass or less.

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

[0057] The amount of component (E) in the negative-type photosensitive resin composition of this embodiment is such that the solid content concentration in the composition is preferably 5% by mass or more, in order to obtain a uniform coating film by a coating method such as spin coating, which ensures the fluidity of the composition. Furthermore, it is preferably 65% ​​by mass or less.

[0058] ·others In one embodiment, the negative-type photosensitive resin composition may contain various additives in addition to the components (A) to (E) described above, as long as they do not hinder the effects of the present invention. Examples of additives include fillers, surfactants such as leveling agents, adhesion improvers, dissolution accelerators, and the like.

[0059] The cured film obtained from the negative-type photosensitive resin composition of this embodiment has visible light shielding properties, so there is no need to add a coloring agent separately. However, if higher visible light shielding properties are required, the negative-type photosensitive resin composition of this embodiment may further contain a coloring agent. Examples of colorants include organic pigments such as benzofuranone-based black pigments, perylene-based black pigments, azo-based black pigments, anthraquinone-based black pigments, aniline-based black pigments, azomethine-based black pigments, carbon black, and graphite, as well as inorganic pigments such as oxides, complex oxides, sulfides, sulfates, nitrates, carbonates, nitrides, carbides, and oxynitrides of metals (alloys) such as silver-tin alloys, titanium, copper, iron, manganese, cobalt, chromium, nickel, zinc, calcium, and silver.

[0060] In one embodiment, the amount of colorant is 0 to 30 parts by mass per 100 parts by mass of solid content of the negative-type photosensitive resin composition. Since the negative-type photosensitive resin composition of this embodiment has visible light shielding properties, the amount of colorant can be reduced compared to conventional compositions. The negative-type photosensitive resin composition may or may not contain a colorant. If a colorant is included, the amount may be more than 0 parts by mass per 100 parts by mass of solid content of the negative-type photosensitive resin composition, or 0.1 parts by mass or more.

[0061] The negative-type photosensitive resin composition of this embodiment can be prepared by stirring and mixing the above-mentioned components (A) to (E), and various additives as needed, in a conventional manner to obtain a homogeneous liquid. When solid materials such as fillers and pigments are incorporated into the composition, it is preferable to disperse and mix them using a dispersion device such as a dissolver, homogenizer, or three-roll mill. Furthermore, the composition can be filtered using a mesh filter, membrane filter, or the like to remove coarse particles and impurities.

[0062] The negative-type photosensitive resin composition of this embodiment can be suitably used, for example, in negative-type photoresists, organic underlayer films, thick-film resists (bump-forming resists), interlayer insulating films, liquid crystal alignment films, heat-resistant agents, polyimides, polybenzoxazole-based resists, or for forming pixel division layers in display devices such as organic EL displays.

[0063] [Cured film / resist film] A cured film according to one embodiment of the present invention is obtained by curing the negative-type photosensitive resin composition of the present invention described above. Specifically, by applying the negative-type photosensitive resin composition of the present invention to an object to be photolithographed and pre-baking it, a film of the photosensitive resin composition (photosensitive film) from which the solvent has been removed is obtained.

[0064] Application methods include spin coating, roll coating, flow coating, dip coating, spray coating, and doctor blade coating. Pre-baking can be done by heating at a temperature of 60°C to 150°C for a time of 30 seconds to 600 seconds.

[0065] Exposure of a photosensitive film significantly reduces its solubility in alkaline developer. Examples of light sources used for exposure include infrared light, visible light, ultraviolet light, far ultraviolet light, X-rays, and electron beams. Among these light sources, ultraviolet light is preferred, and the g-line (wavelength 436 nm) and i-line (wavelength 365 nm) of a high-pressure mercury lamp are particularly suitable. After exposure, the sample is heat-treated at around 100°C to promote the crosslinking reaction between components (A), (B), and (C) through the catalytic reaction of the acid generated by exposure.

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

[0067] Examples of 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; quaternary ammonium salts such as tetramethylammonium hydroxide and tetraethylammonium hydroxide; and alkaline aqueous solutions of cyclic amines such as pyrrole and pyreridine. Alkaline developers may be used with alcohol, surfactants, etc., added as needed. The alkali concentration of the alkaline developer is usually preferably in the range of 2 to 5% by mass, and a 2.38% by mass aqueous solution of tetramethylammonium hydroxide is commonly used.

[0068] After development with an alkaline developer, a cured film with crosslinked exposed areas can be obtained by heating at a low temperature, for example, between 150°C and 200°C. The cured film of this embodiment has excellent visible light shielding properties. 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. [Examples]

[0069] The present invention will be explained in more detail below with specific examples. The weight-average molecular weight (Mw) of the synthesized resin was measured under the GPC measurement conditions described below. [GPC measurement conditions] Measurement device: Tosoh Corporation "HLC-8220 GPC" Column: Showa Denko Corporation "Shodex KF802": 8.0mm diameter × 300mm +Showa Denko Corporation "Shodex KF802": 8.0mm diameter × 300mm +Showa Denko Corporation "Shodex KF803": 8.0mm diameter × 300mm +Showa Denko Corporation "Shodex KF804": 8.0mm diameter x 300mm Column temperature: 40℃ Detector: RI (Differential Refractometer) Data processing: Tosoh Corporation's "GPC-8020 Model II Version 4.30" Developing solvent: tetrahydrofuran Flow rate: 1.0mL / min Sample: A tetrahydrofuran solution containing 0.5% by mass (based on resin solids content) filtered through a microfilter. Injection volume: 0.1mL Standard sample: Monodisperse polystyrene (see below) (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 Tosoh Corporation's "F-10" F-20 manufactured by Tosoh Corporation

[0070] [Ingredients (A)] Synthesis Example 1 (Synthesis of Novolac-type Phenolic Resin (A-1)) In a 2000 mL four-necked flask equipped with a condenser, 82 g (0.76 mol) of m-cresol, 84 g (0.76 mol) of catechol, 103 g (0.97 mol) of benzaldehyde, 74 g (0.61 mol) of salicylaldehyde, and 8 g of p-toluenesulfonic acid were charged and dissolved in 300 g of ethanol as the reaction solvent. The mixture was then heated to 80°C using a mantle heater and stirred under reflux for 16 hours. After the reaction was complete, ethyl acetate and water were added and the mixture was subjected to five separatory washes. After removing the solvent from the remaining resin solution under reduced pressure, the mixture was vacuum-dried to obtain 279 g of a pale red powder of novolac-type phenolic resin (A-1). The Mw of the novolac-type phenolic resin (A-1) obtained by the GPC method was 3,820.

[0071] Synthesis Example 2 (Synthesis of Novolac-type Phenolic Resin (A-2)) Except for using m-cresol 82g (0.76mol), catechol 84g (0.76mol), benzaldehyde 80g (0.75mol), and salicylaldehyde 92g (0.75mol) as starting materials, 283g of novolac-type phenolic resin (A-2) powder was obtained in the same manner as in Synthesis Example 1. The Mw of the novolac-type phenolic resin (A-2) obtained by the GPC method was 3,270.

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

[0073] Synthesis Example 4 (Synthesis of Novolac-type Phenolic Resin (A-4)) Except for using m-cresol 82 g (0.76 mol), catechol 84 g (0.76 mol), benzaldehyde 67 g (0.63 mol), and salicylaldehyde 115 g (0.94 mol) as starting materials, 286 g of novolac-type phenolic resin (A-4) powder was obtained in the same manner as in Synthesis Example 1. The Mw of the phenol novolac resin (A-4) obtained by the GPC method was 3,540.

[0074] Synthesis Example 5 (Synthesis of Novolac-type Phenolic Resin (A-5)) Except for using m-cresol 123g (1.14mol), catechol 42g (0.38mol), benzaldehyde 103g (0.97mol), and salicylaldehyde 74g (0.61mol) as starting materials, 282g of novolac-type phenolic resin (A-5) powder was obtained in the same manner as in Synthesis Example 1. The Mw of the phenol novolac resin (A-5) obtained by the GPC method was 3,210.

[0075] Synthesis Example 6 (Synthesis of Novolac-type Phenolic Resin (A-6)) Except for using m-cresol 41 g (0.38 mol), catechol 126 g (1.14 mol), benzaldehyde 103 g (0.97 mol), and salicylaldehyde 74 g (0.61 mol) as starting materials, 281 g of novolac-type phenolic resin (A-6) powder was obtained in the same manner as in Synthesis Example 1. The Mw of the phenol novolac resin (A-6) obtained by the GPC method was 3,790.

[0076] Comparative Synthesis Example 1 (Synthesis of Novolac-type Phenolic Resin (A-7)) Except for using 164 g (1.52 mol) of m-cresol, 103 g (0.97 mol) of benzaldehyde, and 74 g (0.61 mol) of salicylaldehyde as starting materials, 281 g of novolac-type phenolic resin (A-7) powder was obtained in the same manner as in Synthesis Example 1. The Mw of the novolac-type phenolic resin (A-7) obtained by the GPC method was 3,100.

[0077] [Component (B)] Synthesis Example 7 (Synthesis of ethylenically unsaturated group-containing polyimide precursor (B-1)) Under a stream of dry nitrogen, 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, and the mixture was stirred at 100 °C for 4 hours to allow the reaction to proceed. After the reaction was complete, the solution was added to 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 polymer solid powder. 32.8 g of the obtained solid powder was dissolved in 76.5 g of 3-methoxy-n-butyl acetate. After cooling this mixed solution to 0°C, a solution of 3.2 g of 3-methoxy-n-butyl acetate in which 3.2 g of 2-methacryloxyethyl isocyanate was added dropwise. After the addition was complete, the mixture was stirred at 80°C for 1 hour to obtain a polymer solution containing ethylenically unsaturated groups. After the reaction was complete, the obtained solution was added to 1000 g of water, and the precipitate of the ethylenically unsaturated group-containing polymer solid was collected by filtration. The polymer solid containing ethylenically unsaturated groups was dried in a vacuum dryer at 80°C for 72 hours to obtain a polymer powder of the ethylenically unsaturated group-containing polyimide precursor (B-1).

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

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

[0080] [evaluation] The negative-type photosensitive resin compositions prepared in the examples and comparative examples were used to evaluate resin compatibility, alkali solubility before exposure, visible light shielding properties, and the elastic modulus of the cured film. (1) Evaluation of resin compatibility (film-forming properties) A negative-type photosensitive resin composition was applied to a 5-inch diameter silicon wafer to a thickness of approximately 5 μm using a spin coater. The wafer was then pre-baked at 120°C for 180 seconds to obtain a wafer with a photosensitive film formed on it. The photosensitive film formed on the wafer surface was observed using an optical microscope to evaluate its repulsion and the presence or absence of unevenness. For the photosensitive film, those that showed no repulsion or unevenness were judged to have good resin compatibility (○), while those that showed repulsion or unevenness were judged to have insufficient resin compatibility (×). The evaluation results are shown in Tables 1 and 2.

[0081] (2) Alkaline solubility before exposure A negative-type photosensitive resin composition was applied to a 5-inch diameter silicon wafer to a thickness of approximately 5 μm using a spin coater. The wafer was then pre-baked at 120°C for 180 seconds to obtain a wafer with a photosensitive film. The obtained wafer was immersed for 10 seconds in a tray containing 250 mL of developer (2.38 wt% tetramethylammonium hydroxide aqueous solution (TMAH)). After removing the wafer from the tray, it was rinsed with pure water for 10 seconds, and its alkali solubility was evaluated by observing the residue of the photosensitive film on the wafer. Wafers with no residue were rated as good (○), and those with residue were rated as insufficient (×). The evaluation results are shown in Tables 1 and 2.

[0082] (3) Visible light shielding properties of the resin composition The negative-type photosensitive resin composition was diluted with γ-butyrolactone to a solid content concentration of 1%, and its visible light shielding performance was evaluated using UV-vis (Shimadzu Corporation: SolidSpec-3700 DUV). A transmittance of less than 10% at 650 nm was rated as good (○), and a transmittance of 10% or more was rated as insufficient (×). The evaluation results are shown in Tables 1 and 2.

[0083] (4) Elastic modulus of the cured film A negative-type photosensitive resin composition was applied to a 5-inch diameter silicon wafer to a thickness of approximately 5 μm using a spin coater. The wafer was then pre-baked at 120°C for 180 seconds to obtain a wafer with a photosensitive film. The resulting wafer was irradiated with 200 mJ of ghi lines (g-line: wavelength 436 nm, h-line: wavelength 405 nm, i-line: wavelength 365 nm) using a Ushio Multi-Light, followed by pre-development baking (PEB) on a 130°C hot plate for 120 seconds. The coated wafer was then heat-treated at 200°C for 1 hour under inert conditions. The wafer was removed when the heating device temperature dropped below 50°C, and the film thickness was measured. Film hardness was measured using the nanoindentation method (ENT-2100: manufactured by Elionix Corporation). A compressive modulus of 8 GPa or higher was considered good (○), and a value below 8 GPa was considered insufficient (×). The evaluation results are shown in Tables 1 and 2.

[0084] [Table 1]

[0085] [Table 2]

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

[0087] From Tables 1 and 2, it can be seen that the photosensitive film obtained from the negative-type photosensitive resin composition of the present invention exhibits excellent compatibility, thus preventing repelling and unevenness. Furthermore, it can be confirmed that it possesses alkali solubility. Additionally, it can be confirmed that it exhibits excellent visible light shielding properties even without the addition of black pigment.

Claims

1. A negative-type photosensitive resin composition containing the following components (A) to (E). (A) A novolac-type phenolic resin in which the molar ratio [(a1):(a2):(a3):(a4)] of structural units derived from m-cresol (a1), catechol (a2), benzaldehyde (a3), and salicylaldehyde (a4) is 1:0.25 to 4.0:0.25 to 4.0 (B) One or more resins selected from ethylenically unsaturated group-containing polyimides, ethylenically unsaturated group-containing polyimide precursors, ethylenically unsaturated group-containing polybenzoxazoles, and ethylenically unsaturated group-containing polybenzoxazole precursors. (C) Radical polymerizable compound (D) Photopolymerization initiator (E) Organic solvents

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

3. The negative-type photosensitive resin composition according to claim 1 or 2, wherein the weight-average molecular weight of component (A) is 1,000 or more and 7,000 or less.

4. The negative-type photosensitive resin composition according to claim 1 or 2, comprising 0 to 30 parts by mass of a coloring agent per 100 parts by mass of solid content of the negative-type photosensitive resin composition.

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

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

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