Radiation-sensitive composition, insulating film for display device and method for forming the same, and display device

Abstract

The present invention provides a radiation-sensitive composition, an insulating film for a display device obtained using the radiation-sensitive composition, a display device, a method for forming an insulating film for a display device using the radiation-sensitive composition, and a silsesquioxane preferably used as a component of the radiation-sensitive composition. The radiation-sensitive composition has sufficient photolithographic performance and can produce a cured film having sufficient resistance to etching solutions and oxygen ashing resistance even by heating at relatively low temperatures, such as below 120°C. The radiation-sensitive composition of the present invention is a radiation-sensitive composition comprising a silsesquioxane having a first structural unit represented by the following formula (1), a radiation-sensitive radical polymerization initiator, and an organic solvent. In formula (1), X is a monovalent organic group having an unsaturated double bond. [Chemistry 1]

Description

Technical Field

[0001] The present invention relates to a radiation-sensitive composition, an insulating film for a display device, a display device, a method for forming an insulating film for a display device, and silsesquioxane. Background Art

[0002] As one of the light-emitting elements that has been developed in recent years, organic electroluminescence (EL) elements having a stacked structure including an anode layer, an organic light-emitting layer, and a cathode layer are known. As a display device having an organic EL element, an organic EL device with a touch screen having a touch screen provided on the front surface of the device is known (see Patent Document 1).

[0003] Organic EL devices with touch screens are manufactured by, for example, bonding a touch screen to a substrate on which organic EL elements are formed via an adhesive layer or a bonding layer. Touch screens are generally manufactured by providing touch screen components such as sensor electrodes on a touch screen support substrate.

[0004] [Prior art literature]

[0005] [Patent Document]

[0006] [Patent Document 1] Japanese Patent Application Laid-Open No. 2015-161806 Summary of the Invention

[0007] [Problems to be solved by the invention]

[0008] As described above, when the touch screen is attached to the substrate forming the organic EL element via an adhesive layer or a bonding layer, the overall thickness of the organic EL device with the touch screen becomes larger. In the case of a device with a large thickness, it is easy to be damaged or its function is reduced when it is bent. In addition, various display devices are expected to be thinner. Therefore, it is believed that by directly providing a touch screen on the substrate forming the organic EL element using methods such as photolithography and etching, the overall thickness of the display device such as the organic EL device with a touch screen can be reduced. However, in the existing method using a material containing a multifunctional (meth)acrylate as a curing component, it is necessary to heat at a temperature exceeding 100°C, preferably exceeding 120°C, when curing the insulating film for forming the touch screen. In the case of forming an insulating layer on the substrate forming the organic EL element, there is a disadvantage that the organic light-emitting layer deteriorates due to heating exceeding 100°C, especially exceeding 120°C. On the other hand, when using existing materials to form insulating films by heating at temperatures below 120°C, particularly below 100°C, the resulting insulating films are unable to withstand etching solutions or oxygen ashing used to form wiring, making it difficult to fabricate touchscreen structures. For various applications, including insulating films for organic EL devices with touchscreens, as well as other display devices, there is a desire to develop radiation-sensitive compositions that can produce cured films with sufficient resistance to etching solutions and oxygen ashing even when heated at relatively low temperatures.

[0009] The present invention has been made based on the above circumstances, and its object is to provide a radiation-sensitive composition, an insulating film for a display device obtained using the radiation-sensitive composition, a display device, a method for forming an insulating film for a display device using the radiation-sensitive composition, and a silsesquioxane which is preferably a component of the radiation-sensitive composition. The radiation-sensitive composition has sufficient lithographic performance and can produce a cured film having sufficient resistance to etching solutions and oxygen ashing resistance even by heating at relatively low temperatures (e.g., 120°C or lower).

[0010] [Technical means to solve the problem]

[0011] The invention devised to solve the above problems is a radiation-sensitive composition comprising a silsesquioxane having a first structural unit represented by the following formula (1), a radiation-sensitive radical polymerization initiator, and an organic solvent: In formula (1), X is a monovalent organic group having an unsaturated double bond.

[0012] [Chemistry 1]

[0013]

[0014] The radiation-sensitive composition according to the first invention, wherein the silsesquioxane further has a second structural unit represented by the following formula (2).

[0015] [Chemistry 2]

[0016]

[0017] (In formula (2), Y is a monovalent organic group having a carboxyl group, a carboxylic anhydride group, a phenolic hydroxyl group, or a combination thereof)

[0018] Another invention made to solve the above-mentioned problems is an insulating film for a display device, formed from the above-mentioned radiation-sensitive composition.

[0019] Another invention made to solve the above-mentioned problems is a display device including the above-mentioned insulating film for a display device.

[0020] Yet another invention devised to solve the above-mentioned problems is a method for forming an insulating film for a display device, comprising, in sequence: forming a coating film directly or indirectly on a substrate, irradiating at least a portion of the coating film with radiation, developing the coating film, and heating the coating film, wherein the coating film is formed using the radiation-sensitive composition.

[0021] Yet another invention made to solve the above-mentioned problems is a silsesquioxane having a first structural unit represented by the following formula (1a) and a second structural unit represented by the following formula (2a).

[0022] [Chemistry 3]

[0023]

[0024] (In formula (1a) and formula (2a), R 1 are independently a hydrogen atom or a methyl group. 2 Each of R is independently an alkanediyl group having 2 to 10 carbon atoms. 3 (divalent organic radical)

[0025] [Effects of the Invention]

[0026] According to the present invention, there are provided a radiation-sensitive composition having sufficient lithographic performance and capable of producing a cured film having sufficient resistance to etching solutions and oxygen ashing resistance even by heating at relatively low temperatures; an insulating film for a display device obtained using the radiation-sensitive composition; a display device; a method for forming an insulating film for a display device using the radiation-sensitive composition; and a silsesquioxane preferably used as a component of the radiation-sensitive composition. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 This is a cross-sectional view schematically showing an organic EL device with a touch panel according to one embodiment of the present invention.

[0028] [Explanation of Symbols]

[0029] 10: Organic EL device with touch screen

[0030] 20: Organic EL display substrate

[0031] 21: Support substrate

[0032] 22: Anode layer

[0033] 23: Organic light-emitting layer

[0034] 24: Cathode layer

[0035] 25: Next layer

[0036] 26: Sealing substrate

[0037] 30: Touch screen

[0038] 31: First sensor electrode

[0039] 32: Second sensor electrode

[0040] 33: Interlayer insulation film

[0041] 34: Transparent substrate. DETAILED DESCRIPTION

[0042] <Radiation-sensitive composition>

[0043] The radiation-sensitive composition according to one embodiment of the present invention comprises (A) a silsesquioxane, (B) a radiation-sensitive radical polymerization initiator, and (C) an organic solvent. The radiation-sensitive composition preferably further comprises one or both of (D) a polymerizable compound and (E) an alkali-soluble resin. Each component is described in detail below.

[0044] ((A) Silsesquioxane)

[0045] (A) silsesquioxane has a first structural unit represented by the following formula (1) (hereinafter also referred to as "structural unit (1)"), and further has a second structural unit represented by the following formula (2) (hereinafter also referred to as "structural unit (2)"). Since the radiation-sensitive composition contains (A) silsesquioxane, and the (A) silsesquioxane has a structural unit (1) containing an unsaturated double bond, and further has a structural unit (2) containing a specific acidic group, it has sufficient photolithographic performance, and even by heating at a relatively low temperature of 120°C or below, or 100°C or below, a cured film with sufficient etching solution resistance and oxygen ashing resistance can be obtained. In addition, conventional siloxane-based materials are prone to cracking when forming a thick film, for example, of 2μm or more. In contrast, according to the radiation-sensitive composition using (A) silsesquioxane, the generation of cracks is reduced even when a thick cured film is formed.

[0046] Furthermore, silsesquioxane is generally obtained by hydrolysis and condensation of trifunctional silane and has -(RSiO 1.5 )-(R is a monovalent organic group). The silsesquioxane (A) may have any structure, such as a cage structure, a ladder structure, or a random structure. However, as described below, a cage structure or a ladder structure is preferred. One or more types of silsesquioxane (A) may be used. Examples of such cage-structured silsesquioxanes include those represented by the following structural formula.

[0047] [Chemistry 4]

[0048]

[0049] (Structural unit (1))

[0050] [Chemistry 5]

[0051]

[0052] In formula (1), X is a monovalent organic group having an unsaturated double bond. The organic group refers to a group containing carbon atoms.

[0053] The group represented by X is preferably a group having a carbon-carbon double bond, more preferably a group having a vinyl group or a (meth)acryloyl group, further preferably a group having a (meth)acryloyl group, and further more preferably a group having an acryloyl group. The lower limit of the number of carbon atoms in X may be 2, but is preferably 4, and more preferably 6. The upper limit of the number of carbon atoms is preferably 20, and more preferably 10.

[0054] The X preferably contains a (meth)acryloyloxy group (CH2=CR 1 COO-:R 1is a hydrogen atom or a methyl group) and a divalent hydrocarbon group bonded to the (meth)acryloyloxy group. Specifically, the X is more preferably a group represented by the following formula (3).

[0055] [Chemistry 6]

[0056]

[0057] In formula (3), R 1 is a hydrogen atom or a methyl group. 2 It is an alkanediyl group having 2 to 10 carbon atoms. * indicates a bonding site.

[0058] As R in the formula (3) 1 , preferably a hydrogen atom. 2 , preferably -(CH2) n - (n is an integer from 2 to 10). 2 The number of carbon atoms in the formula (3) and the lower limit of n are preferably 3. 2 The number of carbon atoms and the upper limit of n are preferably 8, more preferably 6, and further preferably 4.

[0059] Furthermore, X may be an organic group containing a carboxyl group in addition to a (meth)acryloyloxy group. In such a case, for example, it can be introduced using the reaction formula shown below.

[0060] [Chemistry 7]

[0061]

[0062] (Structural unit (2))

[0063] [Chemistry 8]

[0064]

[0065] In formula (2), Y is a monovalent organic group having a carboxyl group, a carboxylic anhydride group, a phenolic hydroxyl group, or a combination thereof.

[0066] The group represented by Y is preferably a group having a carboxyl group or a phenolic hydroxyl group, and more preferably a group having a carboxyl group. The lower limit of the number of carbon atoms in Y may be 2, but is preferably 4, and more preferably 8. The upper limit of the number of carbon atoms is preferably 30, and more preferably 20.

[0067] Y is preferably a group represented by the following formula (4a), formula (4b) or formula (4c). Among these, a group represented by formula (4a) or formula (4b) is preferred, and a group represented by formula (4a) is more preferred.

[0068] [Chemistry 9]

[0069]

[0070] In formula (4a) to formula (4c), R 1 are independently a hydrogen atom or a methyl group. 2 Each of R is independently an alkanediyl group having 2 to 10 carbon atoms. 3 Is a divalent organic group. 4 is a single bond or a divalent organic group. Z is independently a sulfur atom or -NR x -. R x is a hydrogen atom or an alkyl group having 1 to 3 carbon atoms. j is an integer from 1 to 12. * indicates a bonding site.

[0071] As R in the formula (4a) and formula (4b) 1 , preferably a hydrogen atom. 2 , preferably -(CH2) n - (n is an integer from 2 to 10). As R in the above formula (4a) and formula (4b) 2 The number of carbon atoms in and the lower limit of n are preferably 3. As R in the formula (4a) and formula (4b) 2 The number of carbon atoms and the upper limit of n are preferably 8, more preferably 6, and even more preferably 4.

[0072] As the R 3 and R 4 Examples of the divalent organic group include a divalent hydrocarbon group, a group (h) containing a divalent heteroatom-containing group at the end of the carbon-carbon or bonding side of the divalent hydrocarbon group, and a group in which a part or all of the hydrogen atoms possessed by the hydrocarbon group and the group (h) are substituted with a monovalent heteroatom-containing group.

[0073] Examples of the divalent hydrocarbon group include a divalent chain hydrocarbon group, a divalent alicyclic hydrocarbon group, and a divalent aromatic hydrocarbon group.

[0074] Examples of the divalent chain hydrocarbon group include:

[0075] Alkanediyl groups such as methanediyl, ethanediyl, n-propanediyl, isopropanediyl, n-butanediyl, isobutanediyl, and sec-butanediyl;

[0076] Alkenediyl groups such as ethylenediyl, propylenediyl, and butenediyl;

[0077] Alkynediyl groups such as acetylenediyl, propynediyl, butynediyl, etc.

[0078] Examples of the divalent alicyclic hydrocarbon group include:

[0079] Monocyclic cycloalkanediyl groups such as cyclopropanediyl, cyclobutanediyl, cyclopentanediyl, and cyclohexanediyl;

[0080] Monocyclic cycloalkene diyl groups such as cyclopropene diyl, cyclobutene diyl, cyclopentene diyl, and cyclohexene diyl;

[0081] Polycyclic cycloalkanediyl groups such as norbornanediyl, adamantanediyl, tricyclodecanediyl, and tetracyclododecandiyl;

[0082] Polycyclic cycloalkene diyl groups such as norbornene diyl, tricyclodecenediyl, and tetracyclododecenediyl, etc.

[0083] Examples of the divalent aromatic hydrocarbon group include:

[0084] Aromatic diyl groups such as benzene diyl, toluene diyl, and naphthalene diyl;

[0085] Arene diyl alkane diyl such as benzyl methane diyl and naphthalene methane diyl.

[0086] Examples of divalent heteroatom-containing groups include -O-, -CO-, -CO-O-, -S-, -CS-, -SO2-, -NR'-, and combinations of two or more of these. R' is a hydrogen atom or a monovalent hydrocarbon group having 1 to 10 carbon atoms.

[0087] Examples of the monovalent heteroatom-containing group include halogen atoms such as a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom, a hydroxyl group, a carboxyl group, a cyano group, an amino group, and a mercapto group (—SH).

[0088] As the R 3 and R 4 The carbon number of the divalent organic group is not particularly limited, but the lower limit thereof may be 1. On the other hand, the upper limit thereof may be 20 or 10, for example.

[0089] As the R 3 , preferably -(CH2) m1 - (m1 is an integer from 1 to 6). The upper limit of m1 is preferably 4, more preferably 2. 3 Also preferably the -(CH2) m1 - is a group in which one of the hydrogen atoms in the group represented by is substituted with a carboxyl group.

[0090] As the R 4 , preferably -(CH2) m2 -(m2 is an integer of 1 to 6) and a single bond, and a single bond is more preferably a group represented by -.

[0091] The Z is preferably a sulfur atom (S).

[0092] The lower limit of j in the formula (4c) is preferably 2, and more preferably 3. On the other hand, the upper limit of j is preferably 8, and more preferably 4.

[0093] The lower limit of the content of the structural unit (1) in the total content of the structural unit (1) and the structural unit (2) in the silsesquioxane (A) is preferably 10 mol%, more preferably 20 mol%, further preferably 40 mol%, and further more preferably 60 mol%. On the other hand, the upper limit of the content is preferably 90 mol%, more preferably 80 mol%. By setting the content of the structural unit (1) to be greater than the lower limit, the curability during heating at low temperatures can be further improved. On the other hand, by setting the content of the structural unit (1) to be less than the upper limit, a sufficient amount of the structural unit (1) can be present, and the photolithography performance can be improved. That is, by setting the content of the structural unit (1) in the total content of the structural unit (1) and the structural unit (2) in the silsesquioxane (A) to be greater than the lower limit and less than the upper limit, the effect of the present invention, that is, sufficient photolithography performance, can be further improved, and a cured film having sufficient etching solution resistance and oxygen ashing resistance can be obtained even by heating at 100°C or less.

[0094] (A) Silsesquioxane may have other structural units in addition to the structural units (1) and (2). Examples of other structural units include structural units having a silanol group (-SiOH) or -(RSiO 1.5 )-(R is a monovalent hydrocarbon group) and the like. Among them, the content of the silanol group is preferably less than 0.9, more preferably less than 0.3, in terms of molar ratio relative to the total content of the structural unit (1) and the structural unit (2) in the (A) silsesquioxane. When the molar ratio is small, the degree of condensation is high, and the tendency to have a cage structure or a ladder structure is enhanced. When the molar ratio is less than 0.9, the silanol group is small, so the storage stability is excellent, and when a thick film is formed, it also has more sufficient photolithographic performance, and a cured film with more sufficient etching solution resistance and oxygen ashing resistance can be obtained. Furthermore, the lower limit of the molar ratio is not particularly limited, and it can be 0, 0.01, or 0.05.

[0095] For the same reason, the content of silanol groups is 100% relative to the -(RSiO) of (A) silsesquioxane. 1.5 The content of all structural units represented by )-(R is a monovalent organic group) is preferably less than 0.9, more preferably less than 0.3 in terms of molar ratio. The lower limit of the molar ratio is not particularly limited and may be 0, 0.01, or 0.05.

[0096] The total content α of the structural unit (1) and the structural unit (2) in all the structural units contained in the silsesquioxane (A) is preferably 60 mol% or more, more preferably 70 mol% or more. 1.5 The total content β of the structural units (1) and (2) in all structural units represented by )-(R is a monovalent organic group) is preferably 80 mol% or more, more preferably 90 mol% or more, in terms of molar ratio. By increasing the total content of the structural units (1) and (2), the effect of the present invention can be further enhanced. The upper limits of the total content α and the total content β are not particularly limited, and may be 100 mol%, 99 mol%, or 90 mol%, respectively.

[0097] The lower limit of the weight average molecular weight of the silsesquioxane (A) is preferably 1,000, more preferably 2,000, further preferably 3,000, further more preferably 4,000. On the other hand, the upper limit of the weight average molecular weight is preferably 20,000, more preferably 10,000, further preferably 6,000.

[0098] The lower limit of the content of (A) silsesquioxane in the total solid content of the radiation-sensitive composition is preferably 10% by mass, more preferably 20% by mass, and further preferably 30% by mass. On the other hand, the upper limit of the content is preferably 80% by mass, more preferably 70% by mass, further preferably 60% by mass, and further more preferably 50% by mass. Furthermore, the so-called total solid content refers to all components other than solvents such as (C) organic solvents. The lower limit of the content of (A) silsesquioxane in the total resin components of the radiation-sensitive composition is preferably 20% by mass, more preferably 40% by mass, and further preferably 60% by mass. On the other hand, the upper limit of the content can be 100% by mass, but is preferably 90% by mass, and further preferably 80% by mass. Furthermore, the so-called total resin components refer to (A) silsesquioxane, (E) alkali-soluble resin, and other resins. By setting the content of (A) silsesquioxane to the above range and optimizing the ratio with other components, the effect of the present invention can be further improved.

[0099] (A) Silsesquioxane can be synthesized, for example, by the following synthesis method (i) or synthesis method (ii). Among these, the synthesis method (i) is preferred.

[0100] (Synthesis method (i))

[0101] The scheme (M-1) of the synthesis method (i) is shown below.

[0102] [Chemistry 10]

[0103]

[0104] In the process (M-1), R 8 is an alkyl group having 1 to 6 carbon atoms. k, m, and n are natural numbers satisfying k=m+n. X and Y have the same meanings as X and Y in formula (1) and formula (2). 3 、R 4 and Z and R in formula (4a) and formula (4b) 3 、R 4 and Z have the same meaning.

[0105] A silsesquioxane represented by formula (S) is obtained by hydrolyzing and condensing a trialkoxysilane represented by formula (TASX) as a starting material in the presence of a base. Subsequently, the silsesquioxane represented by formula (SH) is subjected to an addition reaction to obtain silsesquioxane (A).

[0106] As the trialkoxysilane represented by formula (TASX), for example, preferably acryloyloxypropyl trimethoxysilane, methacryloyloxypropyl trimethoxysilane, acryloyloxypropyl triethoxysilane, methacryloyloxypropyl triethoxysilane, acryloyloxyoctyl trimethoxysilane, methacryloyloxyoctyl trimethoxysilane, acryloyloxyoctyl triethoxysilane, methacryloyloxyoctyl triethoxysilane, 4-vinylphenyl trimethoxysilane, and 4-vinylphenyl triethoxysilane. Among these, acryloyloxypropyl trimethoxysilane and methacryloyloxypropyl trimethoxysilane are more preferable.

[0107] Examples of the base used in the hydrolysis condensation reaction include trimethylamine, triethylamine, tripropylamine, imidazole, diazabicycloundecene, pyridine, morpholine, piperazine, piperidine, sodium hydroxide, potassium hydroxide, and the like, with triethylamine being preferred.

[0108] Examples of addition reaction methods for the compound represented by formula (SH) include Michael addition reaction and ethanethiol reaction, with Michael addition reaction being preferred. Examples of the compound represented by formula (SH) include monovalent thiol compounds and monovalent amine compounds, with monovalent thiol compounds being preferred. Specifically, examples include compounds represented by the following formulas (SH-1) to (SH-3), with the compound represented by the following formula (SH-1) being preferred.

[0109] [Chemistry 11]

[0110]

[0111] Examples of the base used in the Michael addition reaction include trimethylamine, triethylamine, tripropylamine, imidazole, diazabicycloundecene, pyridine, morpholine, piperazine, piperidine, sodium hydroxide, and potassium hydroxide, with triethylamine being preferred.

[0112] According to the synthesis method (i), for example, a silsesquioxane in which X in the formula (1) is represented by the formula (3) and Y in the formula (2) is represented by the formula (4a) or (4b) can be efficiently obtained. Specifically, a silsesquioxane represented by the formula (M-1-1) can be obtained by the following process.

[0113] [Chemistry 12]

[0114]

[0115] (Synthesis method (ii))

[0116] The scheme (M-2) of the synthesis method (ii) is shown below.

[0117] [Chemistry 13]

[0118]

[0119] In the process (M-2), R 8 and R 9 Each independently represents an alkyl group having 1 to 6 carbon atoms. X and Y have the same meanings as X and Y in formula (1) and formula (2). m and n are natural numbers.

[0120] (A) Silsesquioxane can be obtained by using a trialkoxysilane represented by the formula (TASX) and a trialkoxysilane represented by the formula (TASY) as starting materials and subjecting them to hydrolysis and condensation in the presence of a base.

[0121] Examples of the trialkoxysilane represented by formula (TASX) include the same compounds as those exemplified in the synthesis method (i). Examples of the trialkoxysilane represented by formula (TASY) include compounds represented by the following formula (TASY-1).

[0122] [Chemistry 14]

[0123]

[0124] In the formula (TASY-1), j is an integer of 1 to 12. 10 is a methyl group or an ethyl group. The lower limit of j is preferably 2, and more preferably 3. On the other hand, the upper limit of j is preferably 8, and more preferably 4. 10 , preferably methyl.

[0125] ((B) Radiation-sensitive linear radical polymerization initiator)

[0126] Examples of the radiation-sensitive radical polymerization initiator (B) include compounds that generate active species capable of initiating a radical polymerization reaction of the silsesquioxane (A) upon exposure to radiation such as visible light, ultraviolet light, extreme ultraviolet light, electron beams, and X-rays. The radiation-sensitive radical polymerization initiators (B) may be used alone or in combination of two or more.

[0127] Specific examples of the (B) radiation-sensitive radical polymerization initiator include O-acyl oxime compounds, α-amino ketone compounds, α-hydroxy ketone compounds, and acylphosphine oxide compounds.

[0128] Examples of the O-acyl oxime compound include 1-[9-ethyl-6-(2-methylbenzoyl)-9.H.-carbazol-3-yl]-ethane-1-one oxime-O-acetate, 1-[9-ethyl-6-benzoyl-9.H.-carbazol-3-yl]-octane-1-one oxime-O-acetate, and 1-[9-ethyl-6-(2-methylbenzoyl)-9.H.-carbazol-3-yl]-octane-1-one oxime-O-acetate. 3-yl]-ethane-1-one oxime-O-benzoate, 1-[9-n-butyl-6-(2-ethylbenzoyl)-9.H.-carbazol-3-yl]-ethane-1-one oxime-O-benzoate, ethyl ketone, 1-[9-ethyl-6-(2-methyl-4-tetrahydrofurylbenzoyl)-9.H.-carbazol-3-yl]-, 1-(O-acetyl oxime), ethyl ketone, 1-[9-ethyl-6-(2-methyl-4-tetrahydrofurylbenzoyl)-9.H.-carbazol-3-yl]- -6-(2-methyl-4-tetrahydropyranylbenzoyl)-9.H.-carbazol-3-yl]-, 1-(O-acetyl oxime), ethyl ketone, 1-[9-ethyl-6-(2-methyl-5-tetrahydrofuranylbenzoyl)-9.H.-carbazol-3-yl]-, 1-(O-acetyl oxime), ethyl ketone, 1-[9-ethyl-6-{2-methyl-4-(2,2-dimethyl-1,3 -dioxolyl)methoxybenzoyl}-9.H.-carbazol-3-yl]-, 1-(O-acetyl oxime), ethyl ketone, 1-[9-ethyl-6-(2-methyl-4-tetrahydrofuranylmethoxybenzoyl)-9.H.-carbazol-3-yl]-, 1-(O-acetyl oxime), 1,2-octanedione, 1-[4-(phenylthio)-, 2-(O-benzoyl oxime)], etc.

[0129] Examples of the α-aminoketone compound include 2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)-butan-1-one, 2-dimethylamino-2-(4-methylbenzyl)-1-(4-morpholin-4-yl-phenyl)-butan-1-one, 2-methyl-1-(4-methylthiophenyl)-2-morpholinopropan-1-one, 2-(dimethylamino)-1-(4-morpholinophenyl)-2-benzyl-1-butanone, and 1-[4-(2-hydroxyethylmercapto)phenyl]-2-methyl-2-(4-morpholino)propan-1-one.

[0130] Examples of the α-hydroxyketone compound include 1-phenyl-2-hydroxy-2-methylpropane-1-one, 1-(4-isopropylphenyl)-2-hydroxy-2-methylpropane-1-one, 4-(2-hydroxyethoxy)phenyl-(2-hydroxy-2-propyl)ketone, and 1-hydroxycyclohexylphenylketone.

[0131] Examples of the acylphosphine oxide compound include 2,4,6-trimethylbenzoyl-diphenyl-phosphine oxide and phenylbis(2,4,6-trimethylbenzoyl)phosphine oxide.

[0132] As the radiation-sensitive radical polymerization initiator (B), from the viewpoint of further promoting the curing reaction by radiation, O-acyl oxime compounds, α-amino ketone compounds, and acylphosphine oxide compounds are preferred, O-acyl oxime compounds and α-amino ketone compounds are more preferred, and O-acyl oxime compounds are still more preferred.

[0133] The lower limit of the amount of the radiation-sensitive radical polymerization initiator (B) in the radiation-sensitive composition is preferably 5 parts by mass, more preferably 10 parts by mass, even more preferably 15 parts by mass, even more preferably 20 parts by mass, and even more preferably 30 parts by mass, relative to 100 parts by mass of the silsesquioxane (A). On the other hand, the upper limit of the amount is preferably 150 parts by mass, more preferably 100 parts by mass, even more preferably 70 parts by mass, even more preferably 60 parts by mass, and even more preferably 50 parts by mass. By setting the amount of the radiation-sensitive radical polymerization initiator (B) above the lower limit and below the upper limit, more sufficient lithographic performance and curability can be achieved.

[0134] ((C)Organic solvent)

[0135] The organic solvent (C) is not particularly limited, and examples thereof include alcohol solvents, ether solvents, ester solvents, ketone solvents, etc. The organic solvent (C) may be used alone or in combination of two or more.

[0136] Examples of the alcoholic solvent include alkyl alcohols such as methanol, ethanol, isopropanol, 1-butanol, 2-butanol, isobutanol, tert-butanol, 1-hexanol, 1-octanol, 1-nonanol, 1-dodecanol, 1-methoxy-2-propanol, and diacetone alcohol;

[0137] Aromatic alcohols such as benzyl alcohol, etc.

[0138] Examples of the ether solvent include:

[0139] Ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monopropyl ether, ethylene glycol monobutyl ether and other ethylene glycol monoalkyl ethers;

[0140] Propylene glycol monoalkyl ethers such as propylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol monopropyl ether and propylene glycol monobutyl ether;

[0141] Diethylene glycol monoalkyl ethers such as diethylene glycol monomethyl ether and diethylene glycol monoethyl ether;

[0142] Diethylene glycol dialkyl ethers such as diethylene glycol dimethyl ether and diethylene glycol ethyl methyl ether;

[0143] Dipropylene glycol monoalkyl ethers such as dipropylene glycol monomethyl ether, dipropylene glycol monoethyl ether, dipropylene glycol monopropyl ether, and dipropylene glycol monobutyl ether.

[0144] Examples of the ester solvent include:

[0145] Carboxylic acid esters such as ethyl acetate, isopropyl acetate, n-butyl acetate, amyl acetate, ethyl lactate, methyl 3-methoxypropionate, and ethyl 3-ethoxypropionate;

[0146] Polyol carboxylate solvents such as propylene glycol diacetate;

[0147] Polyhydric alcohol partial ether carboxylate solvents such as propylene glycol monomethyl ether acetate and propylene glycol monoethyl ether acetate.

[0148] Examples of the ketone-based solvent include acetone, methyl ethyl ketone, diethyl ketone, methyl isobutyl ketone, methyl amyl ketone, diisobutyl ketone, cyclopentanone, cyclohexanone, and cycloheptanone.

[0149] Among these, ether solvents and ester solvents are preferred, ester solvents are more preferred, and polyol partial ether carboxylate solvents are further preferred. Among ether solvents and ester solvents, diethylene glycol dimethyl ether, diethylene glycol ethyl methyl ether, propylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol monomethyl ether acetate, and methyl 3-methoxypropionate are preferred.

[0150] The content of the organic solvent (C) in the radiation-sensitive composition is not particularly limited, but is preferably adjusted so that the solid content concentration falls within the following ranges. The lower limit of the solid content concentration in the radiation-sensitive composition is preferably 5% by mass, more preferably 10% by mass, and further preferably 20% by mass. On the other hand, the upper limit of the solid content concentration is preferably 60% by mass, more preferably 50% by mass, and further preferably 40% by mass.

[0151] ((D) Polymerizable compound)

[0152] When the radiation-sensitive composition includes a polymerizable compound (D), the resulting cured film can further improve its resistance to etching solutions and oxygen ashing. The polymerizable compound (D) is a compound having multiple polymerizable groups. The silsesquioxane (A) is not included in the polymerizable compound (D). The polymerizable compound (D) is preferably a monomer, i.e., a non-polymer.

[0153] Examples of the polymerizable group possessed by the polymerizable compound (D) include a (meth)acryloyl group, a vinyl group, an N-alkoxymethylamino group, an oxiranyl group (epoxy group), and an oxetane group. Preferred are a (meth)acryloyl group and an N-alkoxymethylamino group, and more preferably a (meth)acryloyl group. The lower limit of the number of polymerizable groups possessed by the polymerizable compound (D) is 2. On the other hand, the upper limit thereof is not particularly limited, and for example, it may be 20, preferably 12, and more preferably 8. Preferred polymerizable compounds (D) are compounds having multiple (meth)acryloyl groups and compounds having multiple N-alkoxymethylamino groups, and more preferably compounds having multiple (meth)acryloyl groups.

[0154] Examples of compounds having multiple (meth)acryloyl groups include reaction products of aliphatic polyhydroxy compounds and (meth)acrylic acid (polyfunctional (meth)acrylates), caprolactone-modified polyfunctional (meth)acrylates, alkylene oxide-modified polyfunctional (meth)acrylates, reaction products of (meth)acrylates having a hydroxyl group and polyfunctional isocyanates (polyfunctional urethane (meth)acrylates), and reaction products of (meth)acrylates having a hydroxyl group and an acid anhydride (polyfunctional (meth)acrylates having a carboxyl group). Among these, reaction products of aliphatic polyhydroxy compounds and (meth)acrylic acid (polyfunctional (meth)acrylates) are preferred. Specific examples of aliphatic polyhydroxy compounds, (meth)acrylates having a hydroxyl group, polyfunctional isocyanates, and acid anhydrides include the compounds described in paragraph

[0065] of JP-A-2015-232694. Examples of caprolactone-modified polyfunctional (meth)acrylates and alkylene oxide-modified polyfunctional (meth)acrylates include the compounds described in paragraph

[0066] of the aforementioned publication.

[0155] Specific examples of the compound having a plurality of (meth)acryloyl groups include trimethylolpropane tri(meth)acrylate, pentaerythritol tri(meth)acrylate, pentaerythritol tetra(meth)acrylate, dipentaerythritol penta(meth)acrylate, dipentaerythritol hexa(meth)acrylate, succinic acid-modified pentaerythritol tri(meth)acrylate, 2-hydroxyethane-1,1,1-triyltrimethylene tri(meth)acrylate, tris(2-(meth)acryloyloxyethyl) isocyanurate, and trimethylolpropane polypropylene glycol tri(meth)acrylate.

[0156] Examples of compounds having multiple N-alkoxymethylamino groups include compounds having a melamine structure, a benzoguanamine structure, or a urea structure. Specific examples thereof include the compounds described in paragraph

[0067] of JP-A-2015-232694.

[0157] The lower limit of the content of the (D) polymerizable compound in the radiation-sensitive composition is preferably 30 parts by mass, more preferably 100 parts by mass, further preferably 200 parts by mass, and further more preferably 220 parts by mass, relative to 100 parts by mass of the (A) silsesquioxane. By setting the content of the (D) polymerizable compound to be above the lower limit, the etching solution resistance and oxygen ashing resistance of the obtained cured film can be further improved. On the other hand, the upper limit of the content is preferably 1,000 parts by mass, more preferably 600 parts by mass, further preferably 400 parts by mass, further more preferably 300 parts by mass, and further more preferably 260 parts by mass. By setting the content of the (D) polymerizable compound to be below the upper limit, the photolithography performance can be further improved.

[0158] ((E) Alkali-soluble resin)

[0159] When the radiation-sensitive composition includes (E) an alkali-soluble resin, good developability with an alkaline developer can be achieved, and the resulting cured film can further improve its resistance to etching solutions and oxygen ashing. The (E) alkali-soluble resin is generally a resin having an acidic group such as a carboxyl group or a phenolic hydroxyl group, and is preferably a resin having a carboxyl group.

[0160] (E) alkali-soluble resin preferably has a group containing an unsaturated double bond such as a (meth)acryloyl group or a vinyl group. By having a group containing an unsaturated double bond in the (E) alkali-soluble resin, the developability and the physical properties of the cured film can be further improved. As such (E) alkali-soluble resin, an acid-modified epoxy (meth)acrylate resin is preferably used, and examples thereof include: acid-modified cresol novolac type epoxy (meth)acrylate resin, phenol novolac type epoxy (meth)acrylate resin, bisphenol A type epoxy (meth)acrylate resin, bisphenol F type epoxy (meth)acrylate resin, biphenyl type epoxy (meth)acrylate resin, and trisphenol methane type epoxy (meth)acrylate resin. In addition, as the (E) alkali-soluble resin, an acid-modified cardo-based resin having a (meth)acryloyl group and a carboxyl group can also be used.

[0161] (E) alkali-soluble resin is preferably a side chain represented by the following formula (5), and in the case described, it is preferably further provided with an aromatic ring in the main chain. Wherein, as (E) alkali-soluble resin, it is more preferably a resin having a side chain represented by the following formula (5) and a phenolic novolac main chain. The resin having a side chain represented by the following formula (5) and a phenolic novolac main chain is an example of an acid-modified cresol novolac type epoxy (meth) acrylate resin. This (E) alkali-soluble resin can further improve the effect of the present invention by simultaneously having a rigid main chain skeleton and a side chain comprising an ethylenically unsaturated group and a carboxyl group, i.e., having sufficient photolithographic performance, and even by relatively low temperature heating, a cured film with sufficient etching solution resistance and oxygen ashing resistance can be obtained. As a resin having an aromatic ring in the main chain, various acid-modified epoxy (meth) acrylate resins can be exemplified.

[0162] [Chemistry 15]

[0163]

[0164] In formula (5), R 5 is a hydrogen atom or a methyl group. 6 and R 7 Each is independently a divalent organic group. * indicates the bonding site to the main chain.

[0165] As the R 5 , preferably a hydrogen atom.

[0166] As the R 6 and R 7 The divalent organic group represented by can be exemplified by the above R 3 The same groups are exemplified as the divalent organic groups represented by the above. 6 and R 7 The carbon number of the divalent organic group is not particularly limited, but the lower limit thereof may be 1. On the other hand, the upper limit thereof may be 20 or 10, for example.

[0167] As the R 6 , preferably a divalent hydrocarbon group, more preferably a divalent chain hydrocarbon group and a divalent alicyclic hydrocarbon group. 7 , preferably a group having an oxygen atom (—O—) bonded to the terminal of the main chain side of a divalent hydrocarbon group such as —CH 2 —O—*.

[0168] Examples of acid-modified cresol novolac-type epoxy (meth)acrylate resins include polymers represented by the following formula (6). Acid-modified cresol novolac-type epoxy (meth)acrylate resins are obtained, for example, by reacting an acid anhydride such as phthalic anhydride or 1,2,3,6-tetrahydrophthalic anhydride with an epoxy (meth)acrylate resin obtained by reacting (meth)acrylic acid with a cresol novolac-type epoxy resin.

[0169] [Chemistry 16]

[0170]

[0171] In formula (6), p and q are each independently an integer of 1 to 30.

[0172] Commercially available acid-modified cresol novolac epoxy (meth)acrylate resins include CCR-1358H and CCR-1316H (manufactured by Nippon Kayaku Co., Ltd.). Commercially available cardo-based resins having (meth)acryloyl and carboxyl groups include WR-301 (manufactured by ADEKA Co., Ltd.).

[0173] The lower limit of the acid value of the alkali-soluble resin (E) is, for example, 10 mgKOH / g, preferably 20 mgKOH / g, and more preferably 40 mgKOH / g. Meanwhile, the upper limit of the acid value is, for example, 300 mgKOH / g, preferably 270 mgKOH / g, and more preferably 250 mgKOH / g. The acid value represents the number of mg of KOH required to neutralize 1 g of the solid content of the alkali-soluble resin.

[0174] The lower limit of the weight average molecular weight (Mw) of the (E) alkali-soluble resin is, for example, 1,000, or preferably 3,000. On the other hand, the upper limit thereof is, for example, 100,000, or preferably 50,000.

[0175] The lower limit of the content of the alkali-soluble resin (E) in the radiation-sensitive composition is preferably 10 parts by mass, more preferably 15 parts by mass, even more preferably 25 parts by mass, and even more preferably 30 parts by mass, relative to 100 parts by mass of the silsesquioxane (A). On the other hand, the upper limit of the content is preferably 150 parts by mass, more preferably 100 parts by mass, even more preferably 70 parts by mass, and even more preferably 50 parts by mass. By setting the content of the alkali-soluble resin (E) to be above the lower limit and below the upper limit, more sufficient lithographic performance and curability can be achieved.

[0176] (Other ingredients)

[0177] The radiation-sensitive composition may further contain other components in addition to the (A) silsesquioxane, (B) radiation-sensitive radical polymerization initiator, (C) organic solvent, (D) polymerizable compound, and (E) alkali-soluble resin. Examples of such other components include hardeners, hardening accelerators, adhesion promoters, antioxidants, and surfactants. The content of the other components in the radiation-sensitive composition, other than the (A) silsesquioxane, (B) radiation-sensitive radical polymerization initiator, (C) organic solvent, (D) polymerizable compound, and (E) alkali-soluble resin, may preferably be 10% by mass or less, and more preferably 1% by mass or less.

[0178] (hardening temperature)

[0179] As described above, the radiation-sensitive composition can provide a cured film having sufficient resistance to etching solutions and oxygen ashing even by heating at relatively low temperatures. The radiation-sensitive composition is preferably curable by heating at a temperature range of 60°C to 120°C, and more preferably curable by heating at a temperature range of 60°C to 100°C.

[0180] (Method for Preparing Radiation-Sensitive Composition)

[0181] The radiation-sensitive composition can be prepared by mixing the components at a predetermined ratio and dissolving the mixture in the organic solvent (C). The prepared composition is preferably filtered through a filter having a pore size of about 0.2 μm.

[0182] <Insulating films for display devices>

[0183] An insulating film for a display device according to one embodiment of the present invention is a cured film formed from the radiation-sensitive composition. The insulating film for a display device may be a patterned film. Because the insulating film for a display device is formed from a radiation-sensitive composition that provides a cured film with sufficient resistance to etching solutions and oxygen ashing even when heated at relatively low temperatures, it exhibits high yield and excellent durability.

[0184] The insulating film for a display device is preferably used as an interlayer insulating film, and can also be used as a planarization film, spacer, protective film, etc. The insulating film for a display device can be used in display devices including liquid crystal display elements (liquid crystal display devices), display devices including organic EL elements (organic EL devices), electronic paper, and other display devices. In addition, as described later, the insulating film for a display device is preferably used as an interlayer insulating film for a touch screen in a display device with a touch screen, such as an organic EL device with a touch screen.

[0185] The insulating film for display devices is less likely to crack even when relatively thick. Therefore, the insulating film for display devices can be thicker. The lower limit of the average thickness of the insulating film for display devices may be, for example, 0.1 μm, preferably 0.5 μm, more preferably 1 μm, and even more preferably 2 μm. On the other hand, the upper limit of the average thickness may be, for example, 10 μm, 6 μm, or 4 μm.

[0186] <Display device>

[0187] A display device according to one embodiment of the present invention includes the insulating film for a display device. Examples of the display device include liquid crystal display devices, organic EL devices, and electronic paper. Among these, the display device according to one embodiment of the present invention is preferably an organic EL device.

[0188] An organic EL device includes an organic EL element. An organic EL element generally has a laminated structure comprising an anode layer, an organic light-emitting layer, and a cathode layer. The organic EL device preferably comprises a touch screen laminated on a substrate having an organic EL element. Preferably, the insulating film for a display device according to one embodiment of the present invention is used as an insulating film for at least a portion of the touch screen. Particularly preferably, the insulating film for a display device according to one embodiment of the present invention is used as an insulating film for a touch screen laminated on a substrate having an organic EL element without an adhesive layer or a bonding layer. By proceeding in this manner, the touch screen can be directly laminated on the substrate forming the organic EL element, thereby achieving a thinner organic EL device with a touch screen. Furthermore, the radiation-sensitive composition can produce a cured film having sufficient resistance to etching solutions and oxygen ashing even by heating at relatively low temperatures, thereby suppressing degradation of the organic EL element during the manufacturing process and improving yield. Furthermore, since the degradation of the organic EL element during the manufacturing process can be suppressed by forming an insulating film using the radiation-sensitive composition by heating at a relatively low temperature, the radiation-sensitive composition can be particularly preferably used in forming insulating films in various organic EL devices including organic EL elements other than organic EL devices with touch panels.

[0189] Figure 1 This shows one form of an organic EL device with a touch screen. Figure 1The organic EL device with a touch screen 10 includes an organic EL display substrate 20 and a touch screen 30. The organic EL display substrate 20 has a structure in which a supporting substrate 21, an anode layer 22, an organic light-emitting layer 23, a cathode layer 24, an adhesive layer 25, and a sealing substrate 26 are stacked in this order. Furthermore, at least the anode layer 22, the organic light-emitting layer 23, and the cathode layer 24 constitute an organic EL element. The organic light-emitting layer 23 may, for example, have a structure in which a hole injection layer, a hole transport layer, an organic EL light-emitting layer, an electron transport layer, and an electron injection layer are stacked in this order from the anode layer 22 side.

[0190] The touch screen 30 is a capacitive touch screen in which a first sensor electrode 31, an interlayer insulating film 33, and a second sensor electrode 32 are stacked in this order. The touch screen 30 includes the first sensor electrode 31, the second sensor electrode 32 facing the first sensor electrode 31, the interlayer insulating film 33, and a transparent substrate 34 disposed on the outermost surface. In this embodiment, the first sensor electrode 31 is formed directly on the sealing substrate 26 of the organic EL display substrate 20. The interlayer insulating film 33 is a transparent insulating film that insulates the first sensor electrode 31 from the second sensor electrode 32 and is formed from the aforementioned radiation-sensitive composition. The touch screen is not limited to this capacitive touch screen.

[0191] <Method for forming an insulating film for a display device>

[0192] A method for forming an insulating film for a display device according to one embodiment of the present invention sequentially includes: forming a coating film directly or indirectly on a substrate (hereinafter also referred to as the "coating film forming step"), irradiating (exposing) at least a portion of the coating film with radiation (hereinafter also referred to as the "radiation irradiation step"), developing the coating film (hereinafter also referred to as the "development step"), and heating the coating film (hereinafter also referred to as the "heating step"). The coating film is formed from a radiation-sensitive composition according to one embodiment of the present invention. The forming method may also include, as an optional step, a step of heating the coating film between the radiation irradiation step and the development step (hereinafter also referred to as the "post-exposure bake (PEB) step").

[0193] According to the above-described formation method, the use of the radiation-sensitive composition enables patterning into a fine shape, and even through relatively low-temperature heating, an insulating film with sufficient resistance to etching solutions and oxygen ashing can be obtained. Furthermore, even if the substrate on which the coating film is formed includes an organic EL element, performing the heating step at a relatively low temperature can suppress degradation of the organic EL element. Each step is described below.

[0194] (Coating film forming step)

[0195] In this step, after applying the radiation-sensitive composition directly or via another layer onto the substrate, the coated surface is preferably heated (prebaked) to remove the organic solvent and other substances, thereby forming a coating film. Examples of materials for the substrate include glass, quartz, silicon, and resins. Specific examples of the resin include polyethylene terephthalate, polyethylene naphthalate, polybutylene terephthalate, polyethersulfone, polycarbonate, polyimide, cyclic olefin addition polymers, cyclic olefin ring-opening polymers, and hydrides thereof.

[0196] The substrate may include an organic EL element, etc. In addition, the substrate may also be a substrate having electrodes, wiring, etc. provided on the coating surface. As such a substrate, examples thereof include Figure 1 The organic EL display substrate 20 in FIG. 1 is a substrate on which the first sensor electrodes 31 are formed.

[0197] The method for applying the radiation-sensitive composition is not particularly limited, and suitable methods such as spraying, roll coating, spin coating, slot die coating, and bar coating can be employed. Of these coating methods, spin coating and slot die coating are particularly preferred. Prebaking conditions vary depending on the type and proportion of the components, but for example, a temperature of 60°C to 120°C, more preferably 100°C or less, and a heating time of 1 minute to 10 minutes are sufficient.

[0198] (Radiation irradiation process)

[0199] In this process, at least a portion of the coating film formed in the coating film forming process is irradiated with radiation. Usually, when irradiating a portion of the coating film with radiation, the radiation is performed through a photomask having a predetermined pattern. As the radiation, for example, visible light, ultraviolet light, far ultraviolet light, electron beam, X-ray, etc. can be used. Of these radiations, radiation having a wavelength of 190 nm or more and 450 nm or less is preferred, and radiation containing ultraviolet light of 365 nm is more preferred.

[0200] The lower limit of the exposure amount in this step is preferably 10 mJ / cm2, as measured by an illuminometer ("OAI model 356" manufactured by OAI Optical Associates Inc.) at a wavelength of 365 nm. 2 , more preferably 50 mJ / cm 2 The upper limit of the exposure dose is preferably 2,000 mJ / cm2 as measured by the illuminometer. 2 , more preferably 1,000 mJ / cm2 .

[0201] (PEB process)

[0202] When a PEB process is provided, the PEB conditions vary depending on the types and blending ratios of the components. For example, the temperature may be 60°C to 120°C, more preferably 100°C to below, and the heating time may be 1 minute to 10 minutes.

[0203] (Development Process)

[0204] In this step, the coating film after radiation exposure is developed using a developer to form a predetermined pattern. The developer is preferably an alkaline developer. Examples of alkaline developers include alkaline aqueous solutions containing at least one alkaline compound such as sodium hydroxide, potassium hydroxide, sodium carbonate, sodium silicate, sodium metasilicate, ammonia, tetramethylammonium hydroxide, and tetraethylammonium hydroxide. Furthermore, an appropriate amount of a water-soluble organic solvent such as methanol or ethanol or a surfactant may be added to the alkaline developer.

[0205] As a development method, suitable methods such as a coating method, an immersion method, a shaking immersion method, and a spray method can be employed. The development time varies depending on the composition of the radiation-sensitive composition, but is, for example, from 10 seconds to 180 seconds. Following this development treatment, the desired pattern can be formed by washing with running water for, for example, from 30 seconds to 90 seconds, followed by air drying using, for example, compressed air or compressed nitrogen.

[0206] (Heating process)

[0207] In this process, the developed and patterned coating film is heated (post-baked) using a heating device such as a hot plate or an oven, thereby obtaining an insulating film for a display device having a desired pattern. Furthermore, the coating film may be irradiated with radiation such as ultraviolet rays between the development process and the heating process. The exposure dose at this time may be, for example, 100 mJ / cm 2 Above and 2,000mJ / cm 2Below. The lower limit of the heating temperature is preferably 60°C, and may also be 80°C. By setting the heating temperature to above the lower limit, a sufficiently hardened insulating film can be obtained. On the other hand, the upper limit of the heating temperature is preferably 120°C, and more preferably 100°C. By setting the heating temperature to below the upper limit, for example, a sufficiently hardened insulating film can be obtained while suppressing the degradation of the organic EL element included in the substrate. In addition, by setting the heating temperature to below the upper limit, the generation of excessive stress such as rapid film shrinkage can be suppressed, thereby suppressing the generation of cracks. Thus, in the heating process, heating is preferably performed in a temperature range of 60°C to 120°C. The heating time varies depending on the type of heating machine. For example, when heating on a hot plate, it can be set to 5 minutes to 30 minutes, and when heating in an oven, it can be set to 10 minutes to 90 minutes. Furthermore, heating can be performed in air or in an inert gas environment such as nitrogen or argon. In addition, a step-by-step baking method in which two or more heating processes are performed can also be used.

[0208] (Other processes)

[0209] When manufacturing a touch panel or the like having the above-mentioned insulating film for a display device, after forming the insulating film for a display device, further electrodes, wirings, etc. (for example, Figure 1 Other processes such as forming the second sensor electrode 32 in the touch screen 30 are also performed. Examples of such processes include an electrode forming process, a wiring forming process, an etching process, and an ashing process. Electrodes or wiring can be formed using known methods such as printing or vapor deposition. Etching can be performed using known etching solutions such as amine solutions. Ashing can be performed using known ashing methods such as oxygen ashing. Furthermore, when manufacturing a touch screen, etc., the formation of an insulating film or the formation of electrodes, wiring, etc. can be performed multiple times.

[0210] <Silsesquioxane>

[0211] The silsesquioxane according to one embodiment of the present invention is a silsesquioxane having a first structural unit represented by the following formula (1a) and a second structural unit represented by the following formula (2a).

[0212] [Chemistry 17]

[0213]

[0214] In formula (1a) and formula (2a), R 1 are independently a hydrogen atom or a methyl group. 2 Each of R is independently an alkanediyl group having 2 to 10 carbon atoms. 3 It is a divalent organic group.

[0215] The silsesquioxane can be preferably used as a component of a radiation-sensitive composition for forming an insulating film for a display device. The silsesquioxane is a preferred embodiment of the silsesquioxane (A) in the radiation-sensitive composition according to one embodiment of the present invention. Therefore, the specific and preferred embodiments of the silsesquioxane are as described above for the embodiment of the silsesquioxane (A).

[0216] [Example]

[0217] Hereinafter, the present invention will be specifically described based on Examples, but the present invention is not limited to these Examples.

[0218] [Weight average molecular weight (Mw)]

[0219] Mw was measured by gel permeation chromatography (GPC) under the following conditions.

[0220] Device: Showa Denko's "GPC-101"

[0221] Tube string: Connected to Showa Denko's "GPC-KF-801", "GPC-KF-802", "GPC-KF-803" and "GPC-KF-804"

[0222] Mobile phase: tetrahydrofuran

[0223] Column temperature: 40°C

[0224] Flow rate: 1.0 mL / min

[0225] Sample concentration: 1.0 mass%

[0226] Sample injection volume: 100 μL

[0227] Detector: Differential refractometer

[0228] Standard material: monodisperse polystyrene

[0229] The compounds used in the synthesis are shown below.

[0230] Silsesquioxane (AC-SQ)

[0231] Toagosei's "AC-SQ TA-100": Silsesquioxane with the following structural units

[0232] [Chemistry 18]

[0233]

[0234] ·Silsesquioxane (MAC-SQ)

[0235] Toagosei Co., Ltd.'s "MAC-SQ TM-100": Silsesquioxane with the following structural units

[0236] [Chemistry 19]

[0237]

[0238] Compounds (SH-1) to (SH-5) and (SH'-1)

[0239] [Chemistry 20]

[0240]

[0241] Silane compounds (TAS-1) to (TAS-4)

[0242] [Chemistry 21]

[0243]

[0244] [Synthesis Example 1] Synthesis of Silsesquioxane (A-1) using Synthesis Method (i) (Michael Addition Reaction)

[0245] A 200 mL three-necked flask equipped with a thermometer and a nitrogen inlet was charged with 15 g of silsesquioxane (AC-SQ) (100 mol % based on (meth)acryloyl groups), 15 g of acetonitrile, and 4.8 g of compound (SH-1) (25 mol %). Then, 9.2 g of triethylamine (50 mol %) was slowly added, and the mixture was reacted at 50°C for 2 hours. GPC analysis revealed a weight-average molecular weight of 4400 and a concentration of compound (SH-1) of less than 0.1%, confirming that Michael addition had proceeded quantitatively. After the reaction was complete, the mixture was transferred to a separatory funnel, 100 mL of ethyl acetate was added, and the mixture was washed once with 100 mL of 1M hydrochloric acid and three times with 50 mL of water. Next, 40 g of propylene glycol monomethyl ether acetate (PGMEA) was added, and the mixture was concentrated to 40 g. Another 40 g of PGMEA was then added and the mixture was concentrated. Thereafter, the solid content concentration was adjusted to 50% with PGMEA to obtain a solution of silsesquioxane (A-1). The weight average molecular weight of the obtained silsesquioxane (A-1) was 4400.

[0246] The obtained silsesquioxane (A-1) was reprecipitated with hexane and dried, and the obtained product was dissolved in dimethyl sulfoxide-d6 and measured. 1H-NMR (nuclear magnetic resonance) results showed δ12.2 ppm (broad), 6.3 ppm (s, 0.75H), 6.1 ppm (s, 0.75H), 5.9 ppm (s, 0.75H), 4.0 ppm (d, 2H), 2.5 ppm to 2.7 ppm (m, 2H), 1.6 ppm (m, 2H), and 0.6 ppm (m, 2H). This indicates that compound (SH-1) undergoes quantitative Michael addition. Furthermore, Si-NMR measurements of silsesquioxane (A-1) revealed multiple peaks at -55 ppm to -58 ppm for the T2 component (a component having a silanol group), and at -65 ppm to -70 ppm for the T3 component (a component not having a silanol group). In this Synthesis Example 1, the component not having a silanol group corresponds to either the structural unit (1) or the structural unit (2) in the aforementioned embodiment. The molar ratio of the silanol group content (SiOH content ratio) relative to the total content of the structural unit (1) and the structural unit (2) in the silsesquioxane (A-1), calculated from the strengths of the T2 component and the T3 component, was 0.2. Based on this, it is inferred that the obtained silsesquioxane (A-1) has a highly condensed cage structure as its main structure. Furthermore, based on the amounts of raw materials used, etc., it is inferred that the molar ratio of the structural unit (1) of the unadded compound (SH-1) to the structural unit (2) of the added compound (SH-1) in the obtained silsesquioxane (A-1) is 75:25.

[0247] [Synthesis Examples 2 to 5, 7, 10, and 11] Synthesis of Silsesquioxane (A-2) to Silsesquioxane (A-5), and Silsesquioxane (A-7)

[0248] Silsesquioxanes (A-2) to (A-5) and (A-7) were obtained in the same manner as in Synthesis Example 1 except that the types and amounts of the compounds used for synthesis and the reaction time were set as shown in Table 1. The weight average molecular weight, NMR and SiOH content ratio of each silsesquioxane obtained were measured in the same manner as in Synthesis Example 1. The measurement results are shown in Table 1. In these syntheses, it is estimated that the content ratio (mol %) of the structural unit (2) to which the compound is added in the obtained silsesquioxane is the molar ratio (mol %) of the compound used in the Michael addition reaction relative to the amount of (meth)acryloyl group used.

[0249] [Chemistry 22]

[0250]

[0251] [Synthesis Example 6] Synthesis of Silsesquioxane (A-6)

[0252] In a 200mL three-necked flask equipped with a thermometer and a nitrogen inlet tube, 15g of silsesquioxane (AC-SQ) (100mol% in terms of (meth)acryloyl conversion), 15g of methanol, and 5.7g (50mol%) of compound (SH-3) were added, and then 9.2g (100mol%) of triethylamine was slowly added and reacted at room temperature for 2 hours. After the reaction was completed, it was transferred to a separatory funnel, 100mL of ethyl acetate was added, and it was washed once with 100mL of 1M hydrochloric acid water and 3 times with 50mL of water. Then, 40g of PGMEA was added and concentrated to a liquid volume of 40g, and then 40g of PGMEA was added again and concentrated. After that, the solid content concentration was adjusted to 50% with PGMEA to obtain a solution of silsesquioxane (A-6). The weight average molecular weight, NMR and SiOH content ratio of the obtained silsesquioxane were measured in the same manner as in Synthesis Example 1. The measurement results are shown in Table 1.

[0253] [Synthesis Example 8] Synthesis of Silsesquioxane (A-8) Having Acryloyl Group

[0254] (Synthesis of Acryloyl-Containing Silsesquioxane)

[0255] In a 500 mL separable flask equipped with a stirrer, a thermometer, a nitrogen inlet tube, and a reflux tube, 100 g of a silane compound (TAS-1), 100 g of methyl isobutyl ketone, 10 g of triethylamine, and 80 g of water were added and vigorously stirred at 60°C for 8 hours. After the reaction was completed, the water was removed using a separatory funnel, and the solvent was replaced twice with PGMEA to obtain 150 g of a PGMEA solution (weight average molecular weight 4100, solid content concentration 50%) of silsesquioxane (S-1) having an acryloyl group.

[0256] (Michael addition reaction)

[0257] In a 300mL three-necked flask equipped with a thermometer and a nitrogen inlet tube, 50g (100mol% in terms of (meth)acryloyl) of silsesquioxane (S-1), 50g of tetrahydrofuran, and 5.3g (50mol%) of compound (SH-1) were added, and then 10.1g (100mol%) of triethylamine was slowly added and reacted at 50°C for 24 hours. After the reaction was completed, it was transferred to a separatory funnel, 150mL of ethyl acetate was added, and it was washed once with 150mL of 1M hydrochloric acid water and three times with 75mL of water. Then, 60g of PGMEA was added and concentrated to a liquid volume of 60g, and then 60g of PGMEA was added again and concentrated. After that, the solid content concentration was adjusted to 50% with PGMEA to obtain a solution of silsesquioxane (A-8). The weight average molecular weight and NMR results are shown in Table 1. The weight average molecular weight, NMR, and SiOH content ratio of the obtained silsesquioxane were measured in the same manner as in Synthesis Example 1. The measurement results are shown in Table 1.

[0258] [Comparative Synthesis Example 1]

[0259] (Synthesis of linear polysiloxane having an acryloyl group)

[0260] A 500 mL separable flask equipped with a stirrer, thermometer, nitrogen inlet, and reflux line was charged with 23.4 g of a silane compound (TAS-2), 211 g of 1-methoxy-2-propanol, 1.8 g of water, and 0.12 g of phosphoric acid, and stirred at 60°C for 4 hours. After the reaction was completed, 211 g of 1-methoxy-2-propanol was added and the mixture was concentrated to 160 g. 211 g of 1-methoxy-2-propanol was added again and the mixture was concentrated to 150 g. 1-methoxy-2-propanol was then added to obtain a 10% solids concentration solution of polysiloxane (RS-1) having an acryloyl group. Si-NMR analysis of the polysiloxane (RS-1) revealed multiple peaks at -55 ppm to -58 ppm for the T2 component and -65 ppm to -70 ppm for the T3 component. The molar ratio of the silanol group content (SiOH content ratio) to the total content of structural units (1) and (2) in polysiloxane (RS-1), calculated from the strengths of components T2 and T3, was 1.1. This suggests that polysiloxane (RS-1) contains a large amount of linear structures.

[0261] (Michael addition reaction)

[0262] After adding 174 g (100 mol%) of polysiloxane (RS-1), 2.7 g (25 mol%) of compound (SH-1), and 174 g of tetrahydrofuran to a 500 mL three-necked flask equipped with a thermometer and a nitrogen inlet tube, 5.1 g (50 mol%) of triethylamine was slowly added, and gelation occurred when the temperature reached 50°C.

[0263] [Table 1]

[0264]

[0265] [Synthesis Example 9] Synthesis of Silsesquioxane (A-9) using Synthesis Method (ii)

[0266] In a 500 mL separable flask equipped with a stirrer, a thermometer, a nitrogen inlet tube, and a reflux tube, 47.2 g of the silane compound (TAS-2), 52.8 g of the silane compound (TAS-3), 100 g of methyl isobutyl ketone, 10 g of triethylamine, and 80 g of water were added and vigorously stirred at 60°C for 2 hours. After the reaction was completed, the water was removed using a separatory funnel, and the solvent was replaced twice with PGMEA to obtain 140 g of a PGMEA solution of silsesquioxane (A-9) (weight average molecular weight 3600, solids concentration 50%).

[0267] [Synthesis Example 12] Synthesis of Silsesquioxane (A-12) Having an Acryloyl Group (MAC034)

[0268] (Synthesis of Acryloyl-Containing Silsesquioxane)

[0269] In a 1000 mL separable flask equipped with a stirrer, a thermometer, a nitrogen inlet tube, and a reflux tube, 164 g of the silane compound (TAS-1), 62.4 g of (TAS-4), 226 g of ethanol, 10 g of triethylamine, and 60 g of water were added and vigorously stirred at 60°C for 2 hours. After the reaction was completed, the water was removed using a separatory funnel, and the solvent was replaced twice with PGMEA to obtain 267 g of a PGMEA solution (weight average molecular weight 8800, solid content 50%) of silsesquioxane (S-2) having an acryloyl group.

[0270] (Michael addition reaction)

[0271] After adding 267g (100mol% in terms of Si atom conversion) of silsesquioxane (S-2) and 15.9g (15mol%) of compound (SH-1) to a 1000mL three-necked flask equipped with a thermometer and a nitrogen inlet tube, 30.3g (30mol%) of triethylamine was slowly added and the mixture was reacted at 50°C for 2 hours. After the reaction was completed, it was transferred to a separatory funnel, 1000mL of ethyl acetate was added, and the mixture was washed once with 1000mL of 1M hydrochloric acid water and three times with 500mL of water. Next, 160g of PGMEA was added and concentrated to a liquid volume of 160g. Then, 160g of PGMEA was added again and concentrated. After that, the solid content concentration was adjusted to 50% with PGMEA to obtain a solution of silsesquioxane (A-12). The weight average molecular weight, NMR and SiOH content ratio of the obtained silsesquioxane were measured in the same manner as in Synthesis Example 1. The measurement results are shown in Table 1.

[0272] [Chemistry 23]

[0273]

[0274] The components used to prepare the radiation-sensitive compositions of Examples and Comparative Examples are shown.

[0275] (A) Silsesquioxane, etc.

[0276] (A-1) to (A-12)

[0277] Silsesquioxane (A-1) to silsesquioxane (A-12) synthesized in Synthesis Examples 1 to 9

[0278] (RS-1)

[0279] The polysiloxane (RS-1) synthesized in the comparative synthesis example 1

[0280] (RS-2)

[0281] Linear polysiloxane (Shin-Etsu Chemical's "KR-513")

[0282] (B) Radiation-sensitive linear radical polymerization initiator

[0283] (B-1): Oxime-based photoradical polymerization initiator ("NCI-930" manufactured by ADEKA)

[0284] (B-2): Irgacure (registered trademark) Oxe01 from BASF Japan

[0285] (B-3): Phenylbis(2,4,6-trimethylbenzoyl)phosphine oxide

[0286] (B-4): 2-(Dimethylamino)-1-(4-morpholinophenyl)-2-benzyl-1-butanone

[0287] (B-5): 1-[4-(2-hydroxyethylmercapto)phenyl]-2-methyl-2-(4-morpholinyl)propan-1-one

[0288] (D) Polymerizable compound

[0289] (D-1): 2-Hydroxyethane-1,1,1-triyltrimethylene triacrylate

[0290] (D-2): Pentaerythritol tetraacrylate

[0291] (D-3): Dipentaerythritol hexaacrylate

[0292] (D-4): Tris(2-acryloyloxyethyl) isocyanurate

[0293] (D-5): Trimethylolpropane polypropylene glycol triacrylate

[0294] (E) Alkali-soluble resin

[0295] (E-1): Nippon Kayaku Co., Ltd.'s "CCR-1358H"

[0296] Anhydride-modified cresol novolac-type epoxy acrylate resin (an alkali-soluble resin having a side chain represented by the formula (5) and an aromatic ring in the main chain)

[0297] (E-2): Nippon Kayaku Co., Ltd.'s "CCR-1316H"

[0298] Anhydride-modified cresol novolac-type epoxy acrylate resin (an alkali-soluble resin having a side chain represented by the formula (5) and an aromatic ring in the main chain)

[0299] (E-3): ADEKA's "WR-301"

[0300] Acid-modified cardo resin with acryloyl and carboxyl groups

[0301] [Preparation Example 1] Preparation of Radiation-Sensitive Composition (C-1)

[0302] 200 parts by mass of a PGMEA solution containing (A-1) as the silsesquioxane (A) (100 parts by mass of (A-1) based on the resin solid content), 5 parts by mass of (B-1) as the radiation-sensitive radical polymerization initiator (B), and 0.15 parts by mass of a surfactant (DOWSIL 8019 Additive, manufactured by Toray Dow Corning) were mixed. The mixture was then diluted with PGMEA to a total solids concentration of 30% by mass, and filtered through a membrane filter with a pore size of 0.2 μm to prepare a radiation-sensitive composition (C-1).

[0303] Preparation Examples 2 to 38, Comparative Preparation Examples 1 to 3] Preparation of Radiation-Sensitive Compositions (C-2) to (C-44) and Radiation-Sensitive Compositions (R-1) to (R-3)

[0304] Radiation-sensitive compositions (C-2) to (C-44) and radiation-sensitive compositions (R-1) to (R-3) of Preparation Examples 2 to 38 and Comparative Preparation Examples 1 to 3 were prepared in the same manner as Preparation Example 1, except that the types and amounts of the components listed in Table 2 were used instead of 100 parts by mass of (A-1) and 30 parts by mass of (B-1) in Preparation Example 1. Blank columns in Table 2 indicate that the component was not used.

[0305] [Table 2]

[0306]

[0307] *Converted to solid content

[0308] [Example 1]

[0309] (Formation of Insulating Film)

[0310] The radiation-sensitive composition (C-1) was spin-coated on a silicon substrate to a film thickness of 2.0 μm. The film was then pre-baked at 85°C for 2 minutes using a hot plate to form a coating. The coating was scanned using a SUSS "DSC-200" with a 5 μm x 5 μm square hole pattern mask (illuminance = 500 mW, NA = 0.10, λ = ghi ray, 120 mJ / cm 2 ) for exposure. Then, it was developed at 25°C for 1 minute using a tetramethylammonium hydroxide aqueous solution (concentration 2.38%). After that, it was washed with running water and dried to form a pattern on the substrate. Then, it was irradiated with GHI mixed radiation at 600mJ / cm using "TME-400PRJ" manufactured by TOPCON.2 The film was irradiated with ultraviolet rays and then heated in an oven at 85°C for 60 minutes to obtain an insulating film with an average thickness of 2.0 μm.

[0311] (Evaluation of Lithography Performance)

[0312] The presence of residue in the pores and the size of the bottoms of the insulating film (patterned thin film) obtained by the above method were observed using a scanning electron microscope (SEM) and evaluated according to the following criteria. The evaluation results are shown in Table 3.

[0313] A: No residue and the bottom size is 3μm or more

[0314] B: No residue and the bottom size is 2 μm or more and less than 3 μm

[0315] C: No residue and the bottom size is 1 μm or more and less than 2 μm

[0316] D: There is residue, or there is no residue and the size of the bottom is less than 1μm

[0317] (Evaluation of Etching Solution Resistance)

[0318] A silicon substrate having an insulating film formed thereon using the above method was immersed in an amine-based stripping solution (etching solution) at 60°C for 60 seconds. Evaluation was performed according to the following criteria, based on the thickness ratio of the insulating film before and after immersion ((film thickness after immersion / film thickness before immersion) × 100%). The evaluation results are shown in Table 3.

[0319] A: 97% or more and less than 103%

[0320] B: 95% or more and less than 97%, or 103% or more and less than 105%

[0321] C: less than 95% or more than 105%

[0322] D: Insulation film peeling

[0323] (Evaluation of oxygen ashing resistance)

[0324] When forming the insulating film, a full-surface exposure was performed without using a 5μm x 5μm square hole pattern mask, resulting in an insulating film with an average thickness of 2.0μm. The insulating film formed on the silicon substrate in this manner was ashed under specified conditions (300W, 30s, O2 30 (SCCM), 25°C). The residual film rate ((average film thickness after ashing / average film thickness before ashing) × 100%) was measured and evaluated according to the following criteria. The evaluation results are shown in Table 3.

[0325] A: More than 95%

[0326] B: 93% or more but less than 95%

[0327] C: 90% or more but less than 93%

[0328] D: less than 90%

[0329] [Example 2 to Example 42 and Comparative Examples 1 to 3]

[0330] An insulating film was formed and evaluated in the same manner as in Example 1 except that the type of radiation-sensitive composition used and the heating temperature after development were set as shown in Table 3. The evaluation results are shown in Table 3.

[0331] [Table 3]

[0332]

[0333] As shown in Table 3, Examples 1 to 42 have sufficient lithography performance (A to C), and can form cured films (insulating films) having sufficient etching solution resistance (A to C) and sufficient oxygen ashing resistance (A to C) even by heating at 120°C or below.

[0334] [Industrial Applicability]

[0335] The radiation-sensitive composition of the present invention can be preferably used as a material for forming an insulating film or the like of a display device.

Claims

1. A radiation-sensitive composition comprising: Silsesquioxane having a first structural unit represented by the following formula (1) and a second structural unit represented by the following formula (2); a radiation-sensitive linear radical polymerization initiator; and organic solvents, In formula (1), X is represented by the following formula (3): In formula (2), Y is represented by the following formula (4a) or formula (4b), In formula (3), formula (4a) and formula (4b), R 1 are independently a hydrogen atom or a methyl group; R 2 are each independently an alkanediyl group having 2 to 10 carbon atoms; R 3 is a divalent organic group; R 4 is a single bond or a divalent organic group; Z is each independently a sulfur atom; * represents a bonding site. 2 . The radiation-sensitive composition according to claim 1 , wherein a content of the first structural unit in the total content of the first structural unit and the second structural unit in the silsesquioxane is 10 mol % or more and 90 mol % or less. 3 . The radiation-sensitive composition according to claim 2 , wherein the content of the silanol groups in the silsesquioxane is less than 0.9 in terms of molar ratio. 4 . The radiation-sensitive composition according to claim 1 , further comprising a polymerizable compound having a plurality of polymerizable groups.

5. The radiation-sensitive composition according to any one of claims 1 to 3, further comprising an alkali-soluble resin having a side chain represented by the following formula (5) and an aromatic ring in the main chain, In formula (5), R 5 is a hydrogen atom or a methyl group; R 6 and R 7 are each independently a divalent organic group; * indicates the bonding site to the main chain. 6 . The radiation-sensitive composition according to claim 5 , wherein the alkali-soluble resin has a phenolic novolac backbone. 7 . The radiation-sensitive composition according to claim 1 , which is curable by heating in a temperature range of 60° C. to 120° C. 8 . An insulating film for a display device, formed from the radiation-sensitive composition according to claim 1 . 9 . A display device comprising the insulating film for a display device according to claim 8 . 10 . The display device according to claim 9 , which is an organic electroluminescent device. The display device according to claim 10 , which is an organic electroluminescent device with a touch screen.

12. A method for forming an insulating film for a display device, comprising: A process of forming a coating film directly or indirectly on a substrate; a step of irradiating at least a portion of the coating film with radiation; a step of developing the coating film; as well as The coating film is heated, and The coating film is formed using the radiation-sensitive composition according to any one of claims 1 to 7. 13 . The method for forming an insulating film for a display device according to claim 12 , wherein the substrate includes an organic electroluminescent element. 14 . The method for forming an insulating film for a display device according to claim 12 , wherein the heating is performed at a temperature in a range of 60° C. to 120° C.

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