JP2020184010A - Radiation-sensitive composition, insulation film for display device, display device, method of forming insulation film for display device, and silsesquioxane - Google Patents

Abstract

To provide a radiation-sensitive composition that gives a cured film that has sufficient lithography performance and has sufficient etching chemical solution resistance and oxygen ashing resistance even by heating at a relatively low temperature (for example, 120°C or lower), an insulation film for a display device and a display device obtained by using the radiation-sensitive composition, a method of forming an insulation film for a display device using the radiation-sensitive composition, and silsesquioxane suitable as a component of the radiation-sensitive composition.SOLUTION: A radiation-sensitive composition contains silsesquioxane having a first structural unit represented by formula (1) and a second structural unit represented by formula (2), a radiation-sensitive radical polymerization initiator, and an organic solvent. In formula (1), X is a monovalent organic group having an unsaturated double bond.SELECTED DRAWING: Figure 1

Description

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.

As one of the light emitting devices being developed in recent years, an organic electroluminescence (EL) device having a laminated structure including an anode layer, an organic light emitting layer and a cathode layer is known. As a display device having an organic EL element, an organic EL device with a touch panel provided with a touch panel on the front surface of the device is known (see Patent Document 1).

An organic EL device with a touch panel is manufactured by, for example, attaching a touch panel to a substrate on which an organic EL element is formed via an adhesive layer or an adhesive layer. A touch panel is usually manufactured by providing a touch panel member such as a sensor electrode on a support substrate for a touch panel.

JP-A-2015-161806

As described above, when the touch panel is attached to the substrate on which the organic EL element is formed via the adhesive layer or the adhesive layer, the thickness of the entire organic EL device with the touch panel becomes large. In the case of a device having a large thickness, damage or functional deterioration is likely to occur when the device is bent. Further, in various display devices, thinning itself is desired. Therefore, it is considered that the thickness of the entire display device such as the organic EL device with a touch panel can be reduced by providing the touch panel directly on the substrate on which the organic EL element is formed by a method such as lithography or etching. .. However, in the conventional method using a material containing a polyfunctional (meth) acrylate or the like as a curable component, the insulating film for forming the touch panel is cured by heating at a temperature of more than 100 ° C, preferably more than 120 ° C. is required. When the insulating layer is formed on the substrate on which the organic EL element is formed, there is a disadvantage that the organic light emitting layer is deteriorated by heating above 100 ° C., particularly above 120 ° C. On the other hand, when the insulating film is formed by heating at 120 ° C. or lower, particularly 100 ° C. or lower using a conventional material, the obtained insulating film cannot withstand the etching chemical solution for wiring formation and oxygen ashing. It tends to be difficult to fabricate a touch panel structure. Not only in the insulating film for organic EL devices with a touch panel, but also in various applications such as insulating films for other display devices, a cured film having sufficient etching chemical resistance and oxygen ashing resistance can be obtained even by heating at a relatively low temperature. The development of a radiation-sensitive composition is desired.

The present invention has been made based on the above circumstances, has sufficient lithography performance, and has sufficient etching chemical resistance and oxygen ashing resistance even when heated at a relatively low temperature (for example, 120 ° C. or lower). A radiation-sensitive composition capable of obtaining a cured film, an insulating film for a display device and a display device obtained by using the radiation-sensitive composition, and a method for forming an insulating film for a display device using the radiation-sensitive composition. In addition, it is an object of the present invention to provide silsesquioxane suitable as a component of the radiation-sensitive composition.

（式（１）中、Ｘは、不飽和二重結合を有する１価の有機基である。
式（２）中、Ｙは、カルボキシ基、カルボン酸無水物基、フェノール性水酸基又はこれらの組み合わせを有する１価の有機基である。） The invention made to solve the above problems is a 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 composition containing a radioactive radical polymerization initiator and an organic solvent.

(In formula (1), X is a monovalent organic group having an unsaturated double bond.
In the formula (2), Y is a monovalent organic group having a carboxy group, a carboxylic acid anhydride group, a phenolic hydroxyl group or a combination thereof. )

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

Yet another invention made to solve the above problems is a display device having an insulating film for the display device.

Yet another invention made to solve the above problems is a step of directly or indirectly forming a coating film on a substrate, a step of irradiating at least a part of the coating film with radiation, and a step of developing the coating film. This is a method for forming an insulating film for a display device, which comprises a step of heating the coating film in this order and forms the coating film with the radiation-sensitive composition.

（式（１ａ）及び式（２ａ）中、Ｒ^１は、それぞれ独立して、水素原子又はメチル基である。Ｒ^２は、それぞれ独立して、炭素数２〜１０のアルカンジイル基である。Ｒ^３は、２価の有機基である。） Yet another invention made to solve the above problems is a silsesquioki having a first structural unit represented by the following formula (1a) and a second structural unit represented by the following formula (2a). Sun.

(In the formulas (1a) and (2a), R ¹ is an independent hydrogen atom or a methyl group, and R ² is an alkanediyl group having 2 to 10 carbon atoms, respectively. R ³ is a divalent organic group.)

According to the present invention, the above-mentioned radiation-sensitive composition, which has sufficient lithography performance and can obtain a cured film having sufficient etching chemical solution resistance and oxygen ashing resistance even by heating at a relatively low temperature. An insulating film for a display device and a display device obtained by using an object, a method for forming an insulating film for a display device using the radiation-sensitive composition, and silsesquioxane suitable as a component of the radiation-sensitive composition. Can be provided.

FIG. 1 is a cross-sectional view schematically showing an organic EL device with a touch panel according to an embodiment of the present invention.

<Radiation-sensitive composition>
The radiation-sensitive composition according to one embodiment of the present invention contains (A) silsesquioxane, (B) a radiation-sensitive radical polymerization initiator, and (C) an organic solvent. The radiation-sensitive composition preferably further contains one or both of (D) a polymerizable compound and (E) an alkali-soluble resin. Hereinafter, each component and the like will be described in detail.

((A) Silsesquioxane)
(A) silsesquioxane has a first structural unit represented by the following formula (1) (hereinafter, also referred to as “structural unit (1)”) and a second structural unit represented by the following formula (2). It has a structural unit (hereinafter, also referred to as “structural unit (2)”). Sufficient lithography because the radiation-sensitive composition contains (A) silsesquioxane having a structural unit (1) having an unsaturated double bond and a structural unit (2) having a specific acidic group. A cured film having high performance and having sufficient etching chemical solution resistance and oxygen ashing resistance can be obtained even by heating at a relatively low temperature such as 120 ° C. or lower or 100 ° C. or lower. Further, conventionally, when a siloxane-based material forms a thick film of, for example, 2 μm or more, cracks are likely to occur. On the other hand, according to the radiation-sensitive composition using (A) silsesquioxane, the occurrence of cracks is reduced even when a thick cured film is formed.

In addition, silsesquioxane is a structural unit usually obtained by hydrolyzing and condensing a trifunctional silane, which is represented by-(RSiO _1.5 )-(R is a monovalent organic group). It is a polymer having. (A) Silsesquioxane may have any structure such as a cage-type structure, a ladder-type structure, and a random structure, but as will be described later, it may have a cage-type structure or a ladder-type structure. preferable. As the (A) silsesquioxane, one kind or two or more kinds can be used.

(Structural unit (1))

In formula (1), X is a monovalent organic group having an unsaturated double bond. The organic group means a group containing a carbon atom.

As the group represented by X, a group having a carbon-carbon double bond is preferable, a group having a vinyl group or a (meth) acryloyl group is more preferable, and a group having a (meth) acryloyl group is preferable. It is even more preferable that the group has an acryloyl group. The lower limit of the number of carbon atoms of X may be 2, but 4 is preferable, and 6 is more preferable. Further, as the upper limit of the number of carbon atoms, 20 is preferable, and 10 is more preferable.

The above X is composed of a (meth) acryloyloxy group (CH ₂ = CR ¹ COO−: R ¹ is a hydrogen atom or a methyl group) and a divalent hydrocarbon group bonded to this (meth) acryloyloxy group. Groups are preferred. Specifically, the X is more preferably a group represented by the following formula (3).

In formula (3), R ¹ is a hydrogen atom or a methyl group. R ² is an alkanediyl group having 2 to 10 carbon atoms. * Indicates the binding site.

A hydrogen atom is preferable as R ¹ in the above formula (3). As R ² in the above formula (3), a group represented by − (CH ₂ ) _n − (n is an integer of 2 to 10) is preferable. As the carbon number of R ^{2 in} the above formula (3) and the lower limit of the above n, 3 is preferable. As the number of carbon atoms of R ^{2 in} the above formula (3) and the upper limit of the above n, 8 is preferable, 6 is more preferable, and 4 is more preferable.

(Structural unit (2))

In the formula (2), Y is a monovalent organic group having a carboxy group, a carboxylic acid anhydride group, a phenolic hydroxyl group or a combination thereof.

As the group represented by Y, a carboxy group or a group having a phenolic hydroxyl group is preferable, and a group having a carboxy group is more preferable. The lower limit of the number of carbon atoms in Y may be 2, but 4 is preferable, and 8 is more preferable. Further, as the upper limit of the number of carbon atoms, 30 is preferable, and 20 is more preferable.

As the Y, a group represented by the following formula (4a), formula (4b) or formula (4c) is preferable. Among these, the group represented by the formula (4a) or the formula (4b) is preferable, and the group represented by the formula (4a) is more preferable.

In formulas (4a) to (4c), R ¹ is independently a hydrogen atom or a methyl group. Each of R ² is an alkanediyl group having 2 to 10 carbon atoms independently. R ³ is a divalent organic group. R ⁴ is a single bond or 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 of 1-12. * Indicates the binding site.

A hydrogen atom is preferable as R ¹ in the above formulas (4a) and (4b). As R ² in the above formulas (4a) and (4b), a group represented by − (CH ₂ ) _n − (n is an integer of 2 to 10) is preferable. As the carbon number of R ^{2 in} the formulas (4a) and (4b) and the lower limit of n, 3 is preferable. As the carbon number of R ^{2 in} the formulas (4a) and (4b) and the upper limit of n, 8 is preferable, 6 is more preferable, and 4 is more preferable.

Examples of the divalent organic group represented by R ³ and R ⁴ include a divalent hetero atom contained in the carbon-carbon relationship of the divalent hydrocarbon group or the divalent hydrocarbon group or at the terminal on the bond side. Examples thereof include a group containing a group (h), a group in which a part or all of the hydrogen atoms of the above-mentioned hydrocarbon group and group (h) are replaced with a monovalent heteroatom-containing group, and the like.

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

Examples of the divalent chain hydrocarbon group include an alkandyl group such as a methanediyl group, an ethanediyl group, an n-propanediyl group, an i-propanediyl group, an n-butanjiyl group, an i-butandyl group and a sec-butandyl group;
Arkendiyl groups such as ethendyl groups, propendyl groups, butendyl groups;
Examples thereof include an alkyndiyl group such as an ethyndiyl group, a propindiyl group and a butindiyl group.

Examples of the divalent alicyclic hydrocarbon group include a monocyclic cycloalkandyl group such as a cyclopropanediyl group, a cyclobutandyl group, a cyclopentanediyl group, and a cyclohexanediyl group;
Monocyclic cycloalkenediyl groups such as cyclopropenediyl group, cyclobutendyl group, cyclopentendyl group, cyclohexenediyl group;
Polycyclic cycloalkanediyl group such as norbornanediyl group, adamantandiyl group, tricyclodecanediyl group, tetracyclododecanediyl group;
Examples thereof include a polycyclic cycloalkenediyl group such as a norbornene diyl group, a tricyclodecenediyl group, and a tetracyclododecenediyl group.

Examples of the divalent aromatic hydrocarbon group include an arenediyl group such as a benzenediyl group, a toluenediyl group, and a naphthalenediyl group;
Examples thereof include arenediylalkandyl groups such as benzenediylmethanediyl group and naphthalenediylmethanediyl group.

Examples of the divalent hetero atom-containing group, for example -O -, - CO -, - CO-O -, - S -, - CS -, - SO 2 -, - NR'-, 2 or more of these Examples include a group that combines the above. R'is a hydrogen atom or a monovalent hydrocarbon group having 1 to 10 carbon atoms.

Examples of the monovalent heteroatom-containing group include halogen atoms such as fluorine atom, chlorine atom, bromine atom and iodine atom, hydroxy group, carboxy group, cyano group, amino group and sulfanyl group (-SH).

The number of carbon atoms of the divalent organic group represented by R ³ and R ⁴ is not particularly limited, and the lower limit may be 1. On the other hand, the upper limit of the number of carbon atoms may be, for example, 20 or 10.

As the ^{_{R 3, - (CH 2)}} m1 - (. M1 is an integer from 1 to 6) the group represented by the formula. The upper limit of m1 is preferably 4 and more preferably 2. It is also preferable that R ³ is a group in which one of the hydrogen atoms of the group represented by − (CH ₂ ) _m1 − is substituted with a carboxy group.

Examples of the ^{_{R 4, - (CH 2)}} m2 - (. M2 is an integer from 1 to 6) group and a single bond are preferred are represented by a single bond is more preferable.

As the Z, a sulfur atom (S) is preferable.

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

(A) 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 silsesquioxane is preferably 10 mol%, more preferably 20 mol%. , 40 mol% is even more preferred, and 60 mol% is even more preferred. On the other hand, as the upper limit of this content, 90 mol% is preferable, and 80 mol% is more preferable. By setting the content of the structural unit (1) to the above lower limit or more, the curability in heating at a low temperature can be further enhanced. On the other hand, by setting the content of the structural unit (2) to be equal to or less than the above upper limit, a sufficient amount of the structural unit (2) can be present and the lithography performance can be improved. That is, it is sufficient to set the content of the structural unit (1) in the total content of the structural unit (1) and the structural unit (2) in (A) silsesquioxane to be equal to or greater than the above lower limit and equal to or less than the above upper limit. It is possible to further enhance the effect of the present invention that a cured film having sufficient etching chemical solution resistance and oxygen ashing resistance can be obtained by lithography performance and heating at 100 ° C. or lower.

(A) Silsesquioxane may have a structural unit other than the structural unit (1) and the structural unit (2). Examples of other structural units include structural units having a silanol group (-SiOH), structural units represented by-(RaSiO _1.5 )-(Ra is a monovalent hydrocarbon group), and the like. However, the content of the silanol group with respect to the total content of the structural unit (1) and the structural unit (2) in (A) silsesquioxane is preferably less than 0.3 in terms of molar ratio, and less than 0.25. Is more preferable. When the molar ratio is small, the degree of condensation is high and the tendency to have a cage-type structure or a ladder-type structure becomes strong. When the molar ratio is less than 0.3, the number of silanol groups is small, so that the storage stability is excellent, and even when forming a thick film, it has more sufficient lithography performance, more sufficient etching chemical resistance and oxygen ashing. A hardened film having resistance can be obtained. The lower limit of the molar ratio is not particularly limited and may be 0, but may be 0.01 or 0.05.

For the same reason, the content of silanol groups relative to the content of all structural units represented by (A) silsesquioxane- (RSiO _1.5 )-(R is a monovalent organic group) The molar ratio is preferably less than 0.3, more preferably less than 0.25. The lower limit of the molar ratio is not particularly limited and may be 0, but may be 0.01 or 0.05.

The total content α of the structural unit (1) and the structural unit (2) in the total structural unit of (A) silsesquioxane is preferably 60 mol% or more, more preferably 70 mol% or more in terms of molar ratio. Further, (A) of the structural unit (1) and the structural unit (2) in the total structural unit represented by- (RSiO _1.5 )-(R is a monovalent organic group) possessed by silsesquioxane. The total content β 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 unit (1) and the structural unit (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%, respectively, but may be 99 mol% or 90 mol%.

The lower limit of the weight average molecular weight of (A) silsesquioxane is preferably 1,000, more preferably 2,000, even more preferably 3,000, and even 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, and even more preferably 6,000.

The lower limit of the content of (A) silsesquioxane in the total solid content of the radiation-sensitive composition is preferably 10% by mass, preferably 20% by mass, and even more preferably 30% by mass. On the other hand, as the upper limit of this content, 80% by mass is preferable, 70% by mass is more preferable, 60% by mass is further preferable, and 50% by mass is more preferable. The total solid content means all components other than the solvent such as (C) organic solvent. The lower limit of the content of (A) silsesquioxane in the total resin content of the radiation-sensitive composition is preferably 20% by mass, preferably 40% by mass, and even more preferably 60% by mass. On the other hand, the upper limit of this content may be 100% by mass, but 90% by mass is preferable, and 80% by mass is more preferable. The total resin content refers to (A) silsesquioxane, (E) alkali-soluble resin and other resins. By setting the content of (A) silsesquioxane in the above range, the ratio with other components is optimized, and the effect of the present invention can be further enhanced.

(A) Silsesquioxane can be synthesized, for example, by the following synthetic method (i) or synthetic method (ii). Of these, the synthetic method (i) is preferable.

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

In the above scheme (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 are synonymous with X and Y in the formula (1). R ^{3, R 4} and Z have the same meanings as ^R 3, ^{R 4} and Z in the formula (4a) and formula (4b).

By hydrolyzing and condensing trialkoxysilane represented by the formula (TASX) as a starting material in the presence of a base, silsesquioxane represented by the formula (S) can be obtained. Subsequently, (A) silsesquioxane can be obtained by subjecting this silsesquioxane to an addition reaction with a compound represented by the formula (SH).

Examples of the trialkoxysilane represented by the formula (TASX) include acryloxipropyltrimethoxysilane, methacrylatetrioxypropyltrimethoxysilane, acryloxipropyltriethoxysilane, methacrylate, propyltriethoxysilane, and acryloxyoctyltrimethoxysilane. Preference is given to methacryloxyoctyltrimethoxysilane, acryloxyoctylriethoxysilane, methacryloxyoctylriethoxysilane, 4-vinylphenyltrimethoxysilane, and 4-vinylphenyltriethoxysilane. Among these, acryloxypropyltrimethoxysilane and methaloxypropyltrimethoxysilane are more preferable.

Examples of the base used in the hydrolysis condensation reaction include trimethylamine, triethylamine, tripropylamine, imidazole, diazabicycloundecene, pyridine, morpholine, piperidine, piperidine, sodium hydroxide, potassium hydroxide and the like. , Triethylamine is preferred.

Examples of the method for adding the compound represented by the formula (SH) include a Michael addition reaction and an enthiol reaction, but the Michael addition reaction is preferable. Examples of the compound represented by the formula (SH) include a monovalent thiol compound and a monovalent amine compound, but a monovalent thiol compound is preferable. Specific examples thereof include compounds represented by the following formulas (SH-1) to (SH-3), and among them, compounds represented by the following formulas (SH-1) are preferable.

Examples of the base used in the Michael addition reaction include trimethylamine, triethylamine, tripropylamine, imidazole, diazabicycloundecene, pyridine, morpholine, piperazine, piperidine, sodium hydroxide, potassium hydroxide and the like. preferable.

According to the synthesis method (i), for example, the above formula (1) X is represented by the above formula (3), and the Y in the above formula (2) is represented by the above formula (4a) or the above formula (4b). Sesquioxane can be effectively obtained. Specifically, silsesquioxane represented by the formula (M-1-1) can be obtained by the following scheme.

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

In the above scheme (M-2), R ⁸ and R ⁹ are independently alkyl groups having 1 to 6 carbon atoms. X and Y are synonymous with X and Y in equations (1) and (2). m and n are natural numbers.

(A) silsesquioxane is obtained by hydrolyzing and condensing the trialkoxysilane represented by the formula (TASX) and the trialkoxysilane represented by the formula (TASY) in the presence of a base as starting materials. Can be done.

Examples of the trialkoxysilane represented by the formula (TASX) include compounds similar to those exemplified in the synthetic method (i). Examples of the trialkoxysilane represented by the formula (TASY) include compounds represented by the following formula (TASY-1).

In the formula (TASY-1), j is an integer of 1-12. R ¹⁰ is a methyl group or an ethyl group. As the lower limit of j, 2 is preferable, and 3 is more preferable. On the other hand, as the upper limit of j, 8 is preferable, and 4 is more preferable. A methyl group is preferable as R ¹⁰ .

((B) Radiation-sensitive radical polymerization initiator)
The (B) radiation-sensitive radical polymerization initiator has an activity capable of initiating the radical polymerization reaction of (A) silsesquioxane by exposure to radiation such as visible light, ultraviolet rays, far ultraviolet rays, electron beams, and X-rays. Examples include compounds capable of generating seeds. (B) The radiation-sensitive radical polymerization initiator may be used alone or in combination of two or more.

Specific examples of the (B) radiation-sensitive radical polymerization initiator include, for example, an O-acyloxime compound, an α-aminoketone compound, an α-hydroxyketone compound, an acylphosphine oxide compound and the like.

Examples of the O-acyloxime compound include 1- [9-ethyl-6- (2-methylbenzoyl) -9. H. -Carbazole-3-yl] -ethane-1-one oxime-O-acetate, 1- [9-ethyl-6-benzoyl-9. H. -Carbazole-3-yl] -octane-1-one oxime-O-acetate, 1- [9-ethyl-6- (2-methylbenzoyl) -9. H. -Carbazole-3-yl] -ethane-1-one oxime-O-benzoate, 1- [9-n-butyl-6- (2-ethylbenzoyl) -9. H. -Carbazole-3-yl] -ethane-1-one oxime-O-benzoate, ethaneone, 1- [9-ethyl-6- (2-methyl-4-tetrahydrofuranylbenzoyl) -9. H. -Carbazole-3-yl]-, 1- (O-acetyloxime), etanone, 1- [9-ethyl-6- (2-methyl-4-tetrahydropyranylbenzoyl) -9. H. -Carbazole-3-yl]-, 1- (O-acetyloxime), etanone, 1- [9-ethyl-6- (2-methyl-5-tetrahydrofuranylbenzoyl) -9. H. -Carbazole-3-yl]-, 1- (O-acetyloxime), etanone, 1- [9-ethyl-6- {2-methyl-4- (2,2-dimethyl-1,3-dioxolanyl) methoxy Benzoyl} -9. H. -Carbazole-3-yl]-, 1- (O-acetyloxime), etanone, 1- [9-ethyl-6- (2-methyl-4-tetrahydrofuranylmethoxybenzoyl) -9. H. -Carbazole-3-yl]-, 1- (O-acetyloxime), 1,2-octanedione, 1- [4- (phenylthio)-, 2- (O-benzoyloxime)] and the like.

Examples of the α-aminoketone compound include 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) -butane-1-one and 2-dimethylamino-2- (4-methylbenzyl) -1- (4). -Morpholine-4-yl-phenyl) -butane-1-one, 2-methyl-1- (4-methylthiophenyl) -2-morpholinopropane-1-one, 2- (dimethylamino) -1- (4-) Examples thereof include morpholinophenyl) -2-benzyl-1-butanone, 1- [4- (2-hydroxyethylsulfanyl) phenyl] -2-methyl-2- (4-morpholino) propan-1-one.

Examples of the α-hydroxyketone compound include 1-phenyl-2-hydroxy-2-methylpropan-1-one, 1- (4-i-propylphenyl) -2-hydroxy-2-methylpropan-1-one, and the like. Examples thereof include 4- (2-hydroxyethoxy) phenyl- (2-hydroxy-2-propyl) ketone and 1-hydroxycyclohexylphenyl ketone.

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

(B) As the radiation-sensitive radical polymerization initiator, an O-acyloxime compound, an α-aminoketone compound and an acylphosphine oxide compound are preferable, and an O-acyloxime compound and an α- are preferable from the viewpoint of further promoting the curing reaction by radiation. Aminoketone compounds are more preferred, and O-acyloxime compounds are even more preferred.

The lower limit of the content of the (B) radiation-sensitive radical polymerization initiator in the radiation-sensitive composition is preferably 5 parts by mass and more preferably 10 parts by mass with respect to 100 parts by mass of (A) silsesquioxane. Preferably, 15 parts by mass is even more preferable, 20 parts by mass is even more preferable, and 30 parts by mass is even more preferable. On the other hand, as the upper limit of this content, 150 parts by mass is preferable, 100 parts by mass is more preferable, 70 parts by mass is further preferable, 60 parts by mass is more preferable, and 50 parts by mass is more preferable. (B) By setting the content of the radiation-sensitive radical polymerization initiator to the above lower limit or more and the above upper limit or less, more sufficient lithography performance and curability can be exhibited.

((C) Organic solvent)
The organic solvent (C) is not particularly limited, and examples thereof include an alcohol solvent, an ether solvent, an ester solvent, and a ketone solvent. The organic solvent (C) may be used alone or in combination of two or more.

Examples of alcohol-based solvents include methanol, ethanol, isopropyl alcohol, 1-butanol, 2-butanol, isobutyl alcohol, t-butyl alcohol, 1-hexanol, 1-octanol, 1-nonanol, 1-dodecanol, 1-methoxy- Alcohols such as 2-propanol and diacetone alcohol;
Aromatic alcohols such as benzyl alcohol can be mentioned.

Examples of the ether solvent include ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monopropyl ether, and ethylene glycol monoalkyl ether such as ethylene glycol monobutyl ether;
Propylene glycol monoalkyl ethers such as propylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol monopropyl ether, propylene glycol monobutyl ether;
Diethylene glycol monoalkyl ethers such as diethylene glycol monomethyl ether and diethylene glycol monoethyl ether;
Diethylene glycol dialkyl ethers such as diethylene glycol dimethyl ether and diethylene glycol ethyl methyl ether;
Examples thereof include dipropylene glycol monoalkyl ethers such as dipropylene glycol monomethyl ether, dipropylene glycol monoethyl ether, dipropylene glycol monopropyl ether and dipropylene glycol monobutyl ether.

Examples of the ester solvent include carboxylic acid esters such as ethyl acetate, i-propyl acetate, n-butyl acetate, amyl acetate, ethyl lactate, methyl 3-methoxypropionate, and ethyl 3-ethoxypropionate;
Polyhydric alcohol carboxylate solvent such as propylene glycol diacetate;
Examples thereof include polyhydric alcohol partially ether carboxylate-based solvents such as propylene glycol monomethyl ether acetate and propylene glycol monoethyl ether acetate.

Examples of the ketone solvent include acetone, methyl ethyl ketone, diethyl ketone, methyl isobutyl ketone, methyl amyl ketone, diisobutyl ketone, cyclopentanone, cyclohexanone, cycloheptanone and the like.

Among these, an ether solvent and an ester solvent are preferable, an ester solvent is more preferable, and a polyhydric alcohol partial ether carboxylate solvent is further preferable. Among the ether solvent and the ester solvent, 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 preferable.

The content of the organic solvent (C) in the radiation-sensitive composition is not particularly limited, but it is preferably prepared so that the solid content concentration is within the following range. The lower limit of the solid content concentration in the radiation-sensitive composition is preferably 5% by mass, more preferably 10% by mass, and even more 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 even more preferably 40% by mass.

((D) Polymerizable compound)
When the radiation-sensitive composition contains the (D) polymerizable compound, the resistance to the etching chemical solution and the resistance to oxygen ashing of the obtained cured film can be further enhanced. The polymerizable compound (D) is a compound having a plurality of polymerizable groups. However, (A) silsesquioxane is not included in (D) the polymerizable compound. The polymerizable compound (D) is preferably a monomer, that is, a non-polymer.

Examples of the polymerizable group contained in the (D) polymerizable compound include (meth) acryloyl group, vinyl group, N-alkoxymethylamino group, oxylanyl group (epoxy group), oxetanyl group and N-alkoxymethylamino group. The (meth) acryloyl group and the N-alkoxymethylamino group are preferable, and the (meth) acryloyl group is more preferable. (D) The lower limit of the number of polymerizable groups contained in the polymerizable compound is 2. On the other hand, the upper limit is not particularly limited, and may be, for example, 20, preferably 12, and more preferably 8. As the (D) polymerizable compound, a compound having a plurality of (meth) acryloyl groups and a compound having a plurality of N-alkoxymethylamino groups are preferable, and a compound having a plurality of (meth) acryloyl groups is more preferable.

Examples of the compound having a plurality of (meth) acryloyl groups include a reaction product of an aliphatic polyhydroxy compound and (meth) acrylic acid [polyfunctional (meth) acrylate], caprolactone-modified polyfunctional (meth) acrylate, and alkylene. Oxide-modified polyfunctional (meth) acrylate, reaction product of (meth) acrylate having a hydroxyl group and polyfunctional isocyanate [polyfunctional urethane (meth) acrylate], reaction of (meth) acrylate having a hydroxyl group and acid anhydride Examples thereof include products [polyfunctional (meth) acrylate having a carboxy group] and the like. Among these, a reaction product of an aliphatic polyhydroxy compound and (meth) acrylic acid [polyfunctional (meth) acrylate] is preferable. Specific examples of the aliphatic polyhydroxy compound, the (meth) acrylate having a hydroxyl group, the polyfunctional isocyanate and the acid anhydride include the compounds described in paragraph [0065] of JP-A-2015-232964, which are modified with caprolactone. Examples of the polyfunctional (meth) acrylate and the alkylene oxide-modified polyfunctional (meth) acrylate include the compounds described in paragraph [0066] of the same publication.

Specific examples of the compound having a plurality of (meth) acryloyl groups include, for example, trimethylpropantri (meth) acrylate, pentaerythritol tri (meth) acrylate, pentaerythritol tetra (meth) acrylate, and dipentaerythritol penta (meth) acrylate. , Dipentaerythritol hexa (meth) acrylate, succinic acid-modified pentaerythritol tri (meth) acrylate, tri (meth) acrylate 2-hydroxyethane-1,1,1-triyltrismethylene, trisocyanurate (2-( Meta) acryloyloxyethyl), trimethylolpropane polypropylene glycol tri (meth) acrylate and the like.

Examples of the compound having a plurality of N-alkoxymethylamino groups include compounds having a melamine structure, a benzoguanamine structure or a urea structure. Specific examples of these include the compounds described in paragraph [0067] of Japanese Patent Application Laid-Open No. 2015-232964.

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, and 200 parts by mass with respect to 100 parts by mass of (A) silsesquioxane. Parts are even more preferable, and 220 parts by mass is even more preferable. By setting the content of the polymerizable compound (D) to the above lower limit or higher, the resistance to the etching chemical solution and the resistance to oxygen ashing of the obtained cured film can be further enhanced. On the other hand, as the upper limit of this content, 1,000 parts by mass is preferable, 600 parts by mass is more preferable, 400 parts by mass is further preferable, 300 parts by mass is more preferable, and 260 parts by mass is even more preferable. By setting the content of the (D) polymerizable compound to the above upper limit or less, the lithography performance can be further improved.

((E) Alkali-soluble resin)
When the radiation-sensitive composition contains (E) an alkali-soluble resin, it can exhibit good developability with an alkali developing solution, and can further enhance the etching chemical resistance and oxygen ashing resistance of the obtained cured film. The alkali-soluble resin (E) is usually a resin having an acidic group such as a carboxy group or a phenolic hydroxyl group, and a resin having a carboxy group is preferable.

The alkali-soluble resin (E) preferably has a (meth) acryloyl group, a group containing an unsaturated double bond such as vinyl, and the like. When the alkali-soluble resin (E) has a group containing an unsaturated double bond, the developability and the physical properties of the cured film can be further improved. As such an alkali-soluble resin, an acid-modified epoxy (meth) acrylate resin is preferable, and for example, an acid-modified cresol novolac type epoxy (meth) acrylate resin, a phenol novolac type epoxy (meth) acrylate resin, and the like, respectively. Examples thereof include 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. Examples of the (E) alkali-soluble resin include acid-modified cardo-based resins having a (meth) acryloyl group and a carboxy group.

The alkali-soluble resin (E) preferably has a side chain represented by the following formula (5), and in this case, further preferably has an aromatic ring in the main chain. Among them, as the alkali-soluble resin (E), a resin having a side chain represented by the following formula (5) and having a phenolic novolak main chain is more preferable. Phenolic novolaks include not only novolaks synthesized using phenols, but all novolaks synthesized using compounds belonging to phenols such as cresol. The resin having a side chain represented by the following formula (5) and having a phenol-based novolak main chain is an acid-modified cresol novolac type epoxy (meth) acrylate resin or an acid-modified phenol novolac type epoxy (meth). This is an example of an acrylate resin or the like. Such an alkali-soluble resin (E) has sufficient lithographic performance by having a rigid main chain skeleton and a side chain containing an ethylenically unsaturated group and a carboxy group, and can be heated at a relatively low temperature. The effect of the present invention that a cured film having sufficient etching chemical resistance and oxygen ashing resistance can be obtained can be further enhanced. In addition, as the alkali-soluble resin having a side chain represented by the following formula (5) and having an aromatic ring as the main chain, a cardo-based resin or the like that has undergone a predetermined acid modification can be used.

Wherein (5), ^{R 5} is a hydrogen atom or a methyl group. R ⁶ and R ⁷ are independently divalent organic groups. * Represents the binding site with the main chain.

As the ^{R 5,} a hydrogen atom is preferable.

Examples of the divalent organic group represented by R ⁶ and R ⁷ include those similar to those exemplified as the divalent organic group represented by R ³ and the like. The number of carbon atoms of the divalent organic group represented by R ⁶ and R ⁷ is not particularly limited, and the lower limit may be 1. On the other hand, the upper limit of the number of carbon atoms may be, for example, 20 or 10.

As the R ^6, preferably a divalent hydrocarbon group, a divalent chain hydrocarbon group and a divalent alicyclic hydrocarbon group is more preferable. As the ^{R _7,} -CH 2 -O- *, etc., divalent group the main chain side end an oxygen atom (-O-) is bonded hydrocarbon radicals are preferred.

Examples of the acid-modified cresol novolac type epoxy (meth) acrylate resin include a polymer represented by the following formula (6). The acid-modified cresol novolac type epoxy (meth) acrylate resin is prepared by, for example, phthalic anhydride, 1, 2,, with an epoxy (meth) acrylate resin obtained by reacting a cresol novolac type epoxy resin with (meth) acrylic acid. It is obtained by reacting an acid anhydride such as 3,6-tetrahydrophthalic anhydride.

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

Among the alkali-soluble resins having a side chain represented by the above formula (5) and having an aromatic ring as the main chain, the commercially available resin having a phenolic novolak main chain is an acid-modified cresol novolac type epoxy. Examples thereof include "CCR-1358H" and "CCR-1316H" (manufactured by Nippon Kayaku Co., Ltd.), which are (meth) acrylate resins. In addition, as a commercially available alkali-soluble resin having a side chain represented by the above formula (5) and having an aromatic ring as a main chain, an acid-modified cardo-based resin "WR-301" (ADEKA Corporation). ) Etc. can be mentioned.

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. On the other hand, the upper limit of this 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.

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

The lower limit of the content of the (E) alkali-soluble resin in the radiation-sensitive composition is preferably 10 parts by mass, more preferably 15 parts by mass, and 25 parts by mass with respect to 100 parts by mass of (A) silsesquioxane. Parts are even more preferable, and 30 parts by mass is even more preferable. On the other hand, the upper limit of this content is preferably 150 parts by mass, more preferably 100 parts by mass, further preferably 70 parts by mass, and even more preferably 50 parts by mass. By setting the content of the alkali-soluble resin (E) to the above lower limit or more and the above upper limit or less, more sufficient lithography performance and curability can be exhibited.

(Other ingredients)
The radiation-sensitive composition is other than the above-mentioned (A) silsesquioxane, (B) radiation-sensitive radical polymerization initiator, (C) organic solvent, (D) polymerizable compound, and (E) alkali-soluble resin. Other components can be further contained. Examples of such other components include a curing agent, a curing accelerator, an adhesion aid, an antioxidant, a surfactant and the like. However, other than (A) silsesquioxane, (B) radiation-sensitive radical polymerization initiator, (C) organic solvent, (D) polymerizable compound and (E) alkali-soluble resin in the radiation-sensitive composition. The content ratio of the other components may be preferably 10% by mass or less, and more preferably 1% by mass or less.

(Curing temperature)
As described above, the radiation-sensitive composition can obtain a cured film having sufficient etching chemical solution resistance and oxygen ashing resistance even by heating at a relatively low temperature. The radiation-sensitive composition is preferably a composition that can be cured by heating in a temperature range of 60 ° C. or higher and 120 ° C. or lower, and is a composition that can be cured by heating in a temperature range of 60 ° C. or higher and 100 ° C. or lower. It is more preferable to have.

(Method for preparing radiation-sensitive composition)
The radiation-sensitive composition can be prepared by mixing each component in a predetermined ratio and dissolving it in (C) an organic solvent. The prepared composition is preferably filtered with, for example, a filter having a pore size of about 0.2 μm.

<Insulating film for display devices>
The insulating film for a display device according to an embodiment of the present invention is a cured film formed from the radiation-sensitive composition. The insulating film for the display device may be a patterned film. Since the insulating film for the display device is formed of a radiation-sensitive composition capable of obtaining a cured film having sufficient etching chemical resistance and oxygen ashing resistance even by heating at a relatively low temperature, the yield is high and durability is high. It is also excellent in sex.

The insulating film for a display device is suitable as an interlayer insulating film, and may also be used as a flattening film, a spacer, a protective film, or the like. The insulating film for a display device can be used for a display device including a liquid crystal display element (liquid crystal display device), a display device including an organic EL element (organic EL device), and a display device such as electronic paper. Further, as will be described later, the insulating film for the display device is suitable as an interlayer insulating film for a touch panel in a display device with a touch panel such as an organic EL device with a touch panel.

Even when the insulating film for the display device is relatively thick, cracks are unlikely to occur. Therefore, the insulating film for the display device can be thickened. The lower limit of the average thickness of the insulating film for the display device may be, for example, 0.1 μm, but is preferably 0.5 μm, more preferably 1 μm, and even more preferably 2 μm. On the other hand, the upper limit of this average thickness is, for example, 10 μm, 6 μm, or 4 μm.

<Display device>
The display device according to the embodiment of the present invention has an insulating film for the display device. Examples of the display device include a liquid crystal display device, an organic EL device, electronic paper, and the like. Among these, the display device according to the embodiment of the present invention is preferably an organic EL device.

The organic EL device includes an organic EL element. The organic EL element usually has a laminated structure including an anode layer, an organic light emitting layer, and a cathode layer. The organic EL device preferably has a touch panel laminated on a substrate having an organic EL element. It is preferable that the insulating film for a display device according to the embodiment of the present invention is used for at least a part of the insulating film in the touch panel. In particular, it is preferable that the insulating film for a display device according to one embodiment of the present invention is used as the insulating film of the touch panel that is laminated on the substrate having the organic EL element without the intervention of an adhesive layer or an adhesive layer. By doing so, the touch panel can be directly laminated on the substrate on which the organic EL element is formed, so that the organic EL device with the touch panel can be made thinner. Further, since the radiation-sensitive composition can obtain a cured film having sufficient etching chemical resistance and oxygen ashing resistance even by heating at a relatively low temperature, deterioration of the organic EL element in the manufacturing process can be suppressed. It is possible to increase the yield. Further, since the deterioration of the organic EL element in the manufacturing process can be suppressed by forming the insulating film by heating at a relatively low temperature using the radiation-sensitive composition in this way, the organic EL device with a touch panel The radiation-sensitive composition can be particularly preferably used for forming an insulating film in various organic EL devices including organic EL devices other than the above.

FIG. 1 shows a form of an organic EL device with a touch panel. The organic EL device 10 with a touch panel of FIG. 1 includes an organic EL display board 20 and a touch panel 30. The organic EL display substrate 20 has a structure in which a support 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 laminated in this order. At least the anode layer 22, the organic light emitting layer 23, and the cathode layer 24 constitute an organic EL element. As the organic light emitting layer 23, for example, 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 laminated in this order from the anode layer 22 side is adopted. Can be done.

The touch panel 30 is of a capacitance type in which the first sensor electrode 31, the interlayer insulating film 33, and the second sensor electrode 32 are laminated in this order. The touch panel 30 has a first sensor electrode 31, a second sensor electrode 32 arranged to face the first sensor electrode 31, an interlayer insulating film 33, and a transparent substrate 34 arranged on the outermost surface. In the present 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 and the second sensor electrode 32, and is formed from the radiation-sensitive composition. The touch panel is not limited to such a capacitance type touch panel.

<Method of forming an insulating film for display devices>
The method for forming an insulating film for a display device according to an embodiment of the present invention is a step of directly or indirectly forming a coating film on a substrate (hereinafter, also referred to as a “coating film forming step”), or at least the above coating film. A step of partially irradiating (exposing) radiation (hereinafter, also referred to as "radiation irradiation step"), a step of developing the coating film (hereinafter, also referred to as "development step"), and heating the coating film. The steps (hereinafter, also referred to as “heating steps”) are provided in this order, and the coating film is formed by the radiation-sensitive composition according to the embodiment of the present invention. The forming method may include, as an optional step, a step of heating the coating film (hereinafter, also referred to as “PEB step”) between the irradiation step and the developing step.

According to the forming method, since the above-mentioned radiation-sensitive composition is used, an insulating film that can be patterned into a good shape and has sufficient etching chemical resistance and oxygen ashing resistance even by heating at a relatively low temperature. Can be obtained. Further, even if the substrate on which the coating film is formed contains an organic EL element, deterioration of the organic EL element can be suppressed by performing the heating step at a relatively low temperature. Hereinafter, each step will be described.

(Coating film forming process)
In this step, after the radiation-sensitive composition is applied directly on the substrate or through another layer, the coated surface is preferably heated (prebaked) to remove the organic solvent and the like to form a coating film. To do. Examples of the material of the substrate include glass, quartz, silicon, resin and the like. Specific examples of the above resin include polyethylene terephthalate, polyethylene naphthalate, polybutylene terephthalate, polyether sulfone, polycarbonate, polyimide, addition polymers of cyclic olefins, ring-opening polymers of cyclic olefins, and hydrogenated products thereof. Be done.

The substrate may include an organic EL element or the like. Further, the substrate may be provided with electrodes, wiring, etc. on the coated surface. As such a substrate, the organic EL display substrate 20 in FIG. 1 described above on which the first sensor electrode 31 is formed can be exemplified.

The coating method of the radiation-sensitive composition is not particularly limited, and for example, an appropriate method such as a spray method, a roll coating method, a rotary coating method (spin coating method), a slit die coating method, or a bar coating method shall be adopted. Can be done. Among these coating methods, the spin coating method and the slit die coating method are particularly preferable. The pre-baking conditions vary depending on the type of each component, the mixing ratio, and the like, but for example, the heating time may be 1 minute or more and 10 minutes or less at a temperature of 60 ° C. or higher and 120 ° C. or lower, more preferably 100 ° C. or lower.

(Irradiation process)
In this step, at least a part of the coating film formed in the coating film forming step is irradiated with radiation. Usually, when irradiating a part of the coating film with radiation, it is irradiated through a photomask having a predetermined pattern. As the radiation, for example, visible light, ultraviolet rays, far ultraviolet rays, electron beams, X-rays and the like can be used. Among these radiations, radiation having a wavelength in the range of 190 nm or more and 450 nm or less is preferable, and radiation containing ultraviolet rays having a wavelength of 365 nm is more preferable.

As the lower limit of the exposure dose in this step is a value measured by a ( "OAI Model356" of OAI Optical Associates Inc. Co.) luminometer intensity at a wavelength 365nm radiation, preferably ^{10mJ / cm 2, 50mJ / cm} 2 is More preferred. The upper limit of the exposure amount is preferably 2,000 mJ / cm ^{2 and} more preferably 1,000 mJ / cm ² as a value measured by the illuminometer.

(PEB process)
When the PEB step is provided, the PEB conditions vary depending on the type of each component, the mixing ratio, etc., but for example, a heating time of 1 minute or more and 10 minutes or less at a temperature of 60 ° C. or higher and 120 ° C. or lower, more preferably 100 ° C. or lower. And it is sufficient.

(Development process)
In this step, a predetermined pattern is formed by developing the coating film after irradiation with a developing solution. An alkaline developer is preferable as the developer. The alkaline developing solution is alkaline in which at least one alkaline compound such as sodium hydroxide, potassium hydroxide, sodium carbonate, sodium silicate, sodium metasilicate, ammonia, tetramethylammonium hydroxide, or tetraethylammonium hydroxide is dissolved. Examples include aqueous solution. Further, an appropriate amount of a water-soluble organic solvent such as methanol or ethanol or a surfactant may be added to the alkaline developer.

As the developing method, for example, an appropriate method such as a liquid filling method, a dipping method, a rocking dipping method, or a spraying method can be adopted. The developing time varies depending on the composition of the radiation-sensitive composition, but is, for example, 10 seconds or more and 180 seconds or less. A desired pattern can be formed by, for example, washing with running water for a treatment time of 30 seconds or more and 90 seconds or less after such a development treatment, and then air-drying with compressed air or compressed nitrogen, for example.

(Heating process)
In this step, the developed and patterned coating film is heated (post-baked) using a heating device such as a hot plate or an oven to obtain an insulating film for a display device having a desired pattern. The coating film may be irradiated with radiation such as ultraviolet rays between the developing step and the heating step. The exposure amount at this time may be, for example, 100 mJ / cm ² or more 2,000 mJ / cm ² or less. The lower limit of the heating temperature is preferably 60 ° C. and may be 80 ° C. By setting the heating temperature to the above lower limit or higher, a sufficiently cured insulating film can be obtained. On the other hand, the upper limit of the heating temperature is preferably 120 ° C., more preferably 100 ° C. By setting the heating temperature to the above lower limit or higher, for example, a sufficiently cured insulating film can be obtained while suppressing deterioration of the organic EL element provided on the substrate. Further, by setting the heating temperature to the above upper limit or less, it is possible to suppress the generation of excessive stress such as sudden film shrinkage, so that the generation of cracks can be suppressed. As described above, in the heating step, it is preferable to perform heating in a temperature range of 60 ° C. or higher and 120 ° C. or lower. The heating time varies depending on the type of heating equipment, but for example, it may be 5 minutes or more and 30 minutes or less when heating on a hot plate, and 10 minutes or more and 90 minutes or less when heating in an oven. The heating may be performed in air or in an atmosphere of an inert gas such as nitrogen or argon. It is also possible to use a step baking method in which the heating steps are performed two or more times.

(Other processes)
In the case of manufacturing a touch panel or the like having the insulating film for the display device, in order to form further electrodes, wiring and the like (for example, the second sensor electrode 32 in the touch panel 30 of FIG. 1) after forming the insulating film for the display device. Other steps such as are performed. Examples of such a step include an electrode forming step, a wiring forming step, an etching step, an ashing step, and the like. A known method such as printing or vapor deposition can be adopted for forming the electrodes and wiring. Etching can be performed using a known etching chemical solution such as an amine solution. Ashing can be performed by a known ashing method such as oxygen ashing. When manufacturing a touch panel or the like, the formation of an insulating film, the formation of electrodes, wiring, and the like may be performed a plurality of times.

<Silsesquioxane>
The silsesquioxane according to an embodiment of the present invention has a first structural unit represented by the following formula (1a) and a second structural unit represented by the following formula (2a). Is.

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

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

Hereinafter, the present invention will be specifically described based on examples, but the present invention is not limited to these examples.

[Weight average molecular weight (Mw)]
Mw was measured by gel permeation chromatography (GPC) under the following conditions.
Equipment: Showa Denko's "GPC-101"
Column: Showa Denko's "GPC-KF-801", "GPC-KF-802", "GPC-KF-803" and "GPC-KF-804" connected Mobile phase: tetrahydrofuran Column temperature: 40 ° C.
Flow velocity: 1.0 mL / min Sample concentration: 1.0 mass%
Sample injection volume: 100 μL
Detector: Differential Refractometer Standard Material: Monodisperse Polystyrene

The compounds used in the synthesis are shown below.
・ Silsesquioxane (AC-SQ)
"AC-SQ TA-100" from Toagosei Co., Ltd .: Silsesquioxane having the following structural units

・ Silsesquioxane (MAC-SQ)
"MAC-SQ TM-100" of Toagosei Co., Ltd .: Silsesquioxane having the following structural units

-Compound (SH-1) to compound (SH-3) and compound (SH'-1)

-Silane compounds (TAS-1) to (TAS-3)

[Synthesis Example 1] Synthesis of silsesquioxane (A-1) using synthetic method (i) (Michael addition reaction) Silsesquioxane (AC) was placed in a 200 mL three-necked flask equipped with a thermometer and a nitrogen introduction tube. -SQ) 15 g (100 mol% in terms of (meth) acryloyl group), acetonitrile 15 g, and compound (SH-1) 4.8 g (25 mol%) were added, and then 9.2 g (50 mol%) of triethylamine was slowly added. The reaction was carried out at 50 ° C. for 2 hours. When the GPC was confirmed at this point, the weight average molecular weight was 4400, and the compound (SH-1) was 0.1% or less, so that it was confirmed that the Michael addition proceeded quantitatively. After completion of the reaction, the mixture was transferred to a separating funnel, 100 mL of ethyl acetate was added, and the mixture was washed once with 100 mL of 1 M hydrochloric acid water and three times with 50 mL of water. Next, 40 g of propylene glycol monomethyl ether acetate (PGMEA) was added and concentrated to a liquid volume of 40 g, and then 40 g of PGMEA was added again for concentration. Then, 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.

The obtained silsesquioxane (A-1) was reprecipitated with hexane and then dried, dissolved in dimethyl sulfoxide-d6, and ¹ H-NMR was measured. As a result, δ12.2 ppm (broad) and 6.3 ppm ( s, 0.75H), 6.1ppm (s, 0.75H), 5.9ppm (s, 0.75H), 4.0ppm (d, 2H), 2.5-2.7ppm (m, 2H) , 1.6 ppm (m, 2H), 0.6 ppm (m, 2H). From this, it can be seen that the compound (SH-1) can be quantitatively Michael-added. From this, it can be seen that the compound (SH-1) can be quantitatively Michael-added. Further, when Si-NMR of silsesquioxane (A-1) was measured, it was found that the T2 component (component having a silanol group) was -55-58 ppm and the T3 component (component having no silanol group) was -65-. Multiple peaks were observed at -70 ppm. In the present synthesis example 1, the component having no silanol group corresponds to either the structural unit (1) or the structural unit (2) in the above embodiment. The silanol group content (SiOH content ratio) with respect to the total content of the structural unit (1) and the structural unit (2) in silsesquioxane (A-1) determined from the strength of the T2 component and the T3 component is , The molar ratio was 0.2. From these facts, it is inferred that the obtained silsesquioxane (A-1) has a highly condensed cage-type structure as a main structure. Further, the structural unit (1) to which the compound (SH-1) was not added and the compound (SH-1) were added to the obtained silsesquioxane (A-1) based on the amount of the raw material used and the like. The molar ratio to structural unit (2) is estimated to be 75:25.

[Synthesis Examples 2-5, 7] Synthesis of silsesquioxane (A-2) to (A-5), (A-7) Table 1 shows the types and amounts of compounds used in the synthesis, and the reaction time. Silsesquioxane (A-2) to (A-5) and (A-7) were obtained in the same manner as in Synthesis Example 1 except as shown. The weight average molecular weight, NMR and SiOH content ratios of each of the obtained silsesquioxane were measured in the same manner as in Synthesis Example 1. The measurement results are shown in Table 1. Also in these synthesis, the content ratio (mol%) of the structural unit (2) added by the compound in the obtained silsesquioxane is the amount of the compound used in the Michael addition reaction with respect to the (meth) acryloyl group. It is estimated that the molar ratio (mol%) was reached.

[Synthesis Example 6] Synthesis of silsesquioxane (A-6) 15 g of silsesquioxane (AC-SQ) (100 mol in terms of (meth) acryloyl group) in a 200 mL three-necked flask equipped with a thermometer and a nitrogen introduction tube. %), 15 g of methanol, and 5.7 g (50 mol%) of compound (SH-3) were added, and then 9.2 g (100 mol%) of triethylamine was slowly added, and the mixture was reacted at room temperature for 2 hours. After completion of the reaction, the mixture was transferred to a separating funnel, 100 mL of ethyl acetate was added, and the mixture was washed once with 100 mL of 1 M hydrochloric acid water and three times with 50 mL of water. Next, 40 g of PGMEA was added and concentrated to a liquid volume of 40 g, and then 40 g of PGMEA was added again and concentrated. Then, 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 ratios of the obtained silsesquioxane were measured in the same manner as in Synthesis Example 1. The measurement results are shown in Table 1.

[Synthesis Example 8] Synthesis of acryloyl group-containing silsesquioxane (A-8) (synthesis of acryloyl group-containing silsesquioxane)
To a 500 mL separable flask equipped with a stirrer, a thermometer, a nitrogen introduction tube and a reflux tube, 100 g of silane compound (TAS-1), 100 g of methyl isobutyl ketone, 10 g of triethylamine, and 80 g of water were added, and the mixture was vigorously stirred at 60 g for 8 hours. did. After completion of the reaction, water was removed with a separating funnel, and solvent substitution was performed twice with PGMEA to obtain a PGMEA solution of silsesquioxane (S-1) having an acryloyl group (weight average molecular weight 4100, solid content concentration). Was 50%) 150 g was obtained.

(Michael reaction)
5. 50 g of silsesquioxane (S-1) (100 mol% in terms of (meth) acryloyl group), 50 g of tetrahydrofuran, and compound (SH-1) in a 300 mL three-necked flask equipped with a thermometer and a nitrogen introduction tube. After adding 3 g (50 mol%), 10.1 g (100 mol%) of triethylamine was slowly added, and the mixture was reacted at 50 ° C. for 24 hours. After completion of the reaction, the mixture was transferred to a separating funnel, 150 mL of ethyl acetate was added, and the mixture was washed once with 150 mL of 1 M hydrochloric acid water and three times with 75 mL of water. Next, 60 g of PGMEA was added and concentrated to a liquid volume of 60 g, and then 60 g of PGMEA was added again and concentrated. Then, the solid content concentration was adjusted to 50% with PGMEA to obtain a solution of silsesquioxane (A-8). Table 1 shows the weight average molecular weight and the results of NMR. The weight average molecular weight, NMR and SiOH content ratios of the obtained silsesquioxane were measured in the same manner as in Synthesis Example 1. The measurement results are shown in Table 1.

[Comparative Synthesis Example 1]
(Synthesis of linear polysiloxane with acryloyl group)
In a 500 mL separable flask equipped with a stirrer, thermometer, nitrogen introduction tube and reflux tube, 23.4 g of silane compound (TAS-2), 211 g of 1-methoxy-2-propanol, 1.8 g of water and 0. 12 g was added and the mixture was stirred at 60 ° C. for 4 hours. After completion of the reaction, 211 g of 1-methoxy-2-propanol was added and concentrated to 160 g, 211 g of 1-methoxy-2-propanol was added again and concentrated to 150 g, and 1-methoxy-2-propanol was added to concentrate the solid content. A solution of polysiloxane (RS-1) having an acryloyl group having a concentration of 10% was obtained. When Si-NMR of polysiloxane (RS-1) was measured, multiple peaks were observed at -55-58 ppm as the T2 component and -65-70 ppm as the T3 component. The silanol group content (SiOH content ratio) with respect to the total content of the structural unit (1) and the structural unit (2) in the polysiloxane (RS-1) determined from the strength of the T2 component and the T3 component is a molar ratio. It was 1.1. It can be inferred that polysiloxane (RS-1) has a structure containing many linear structures.

(Michael reaction)
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 introduction tube, Gelation occurred when 5.1 g (50 mol%) of triethylamine was slowly added and the temperature was raised to 50 ° C.

[Synthesis Example 9] Synthesis of silsesquioxane (A-9) using the synthesis method (ii) A silane compound (TAS-) was placed in a 500 mL separable flask equipped with a stirrer, a thermometer, a nitrogen introduction tube and a reflux tube. 2) 47.2 g, 52.8 g of silane compound (TAS-3), 100 g of methyl isobutyl ketone, 10 g of triethylamine, and 80 g of water were added, and the mixture was vigorously stirred at 60 g for 2 hours. After completion of the reaction, water was removed with a separating funnel and solvent substitution was performed twice with PGMEA to obtain a PGMEA solution of silsesquioxane (A-9) (weight average molecular weight 3600, solid content concentration 50%). There was) 140g was obtained.

The components used in the preparation of the radiation-sensitive compositions of Examples and Comparative Examples are shown.
(A) Silsesquioxane, etc. (A-1) to (A-9)
Silsesquioxane (A-1) to (A-9) synthesized in Synthesis Examples 1 to 9 above.
・ (RS-1)
Polysiloxane (RS-1) synthesized in Comparative Synthesis Example 1 above
・ (RS-2)
Linear polysiloxane (Shin-Etsu Chemical's "KR-513")

(B) Radiation-sensitive radical polymerization initiator (B-1): Oxime-based photoradical polymerization initiator ("NCI-930" from ADEKA Corporation
(B-2): BASF Japan Ltd. "Irgacure (registered trademark) Oxe01"
(B-3): Phenylbis (2,4,6-trimethylbenzoyl) phosphine oxide- (B-4): 2- (dimethylamino) -1- (4-morpholinophenyl) -2-benzyl-1- Butanone (B-5): 1- [4- (2-hydroxyethylsulfanyl) phenyl] -2-methyl-2- (4-morpholino) propan-1-one

(D) Polymerizable compound · (D-1): 2-hydroxyethanetriacrylate-1,1,1-triyltrismethylene · (D-2): pentaerythritol tetraacrylate · (D-3): di Pentaerythritol hexaacrylate (D-4): Tris isocyanurate (2-acryloyloxyethyl)
(D-5): Trimethylolpropane Polypropylene Glycol Triacrylate

(E) Alkali-soluble resin (E-1): "CCR-1358H" from Nippon Kayaku Co., Ltd.
Cresol novolac type epoxy acrylate resin modified with acid anhydride (alkali-soluble resin having a side chain represented by the above formula (5) and having a phenolic novolac main chain)
・ (E-2): “CCR-1316H” from Nippon Kayaku Co., Ltd.
Cresol novolac type epoxy acrylate resin modified with acid anhydride (alkali-soluble resin having a side chain represented by the above formula (5) and having a phenolic novolac main chain)
(E-3): ADEKA's "WR-301"
Acid anhydride-modified cardo resin (alkali-soluble resin having a side chain represented by the above formula (5) and having an aromatic ring as the main chain)

[Preparation Example 1] Preparation of Radiation Sensitive Composition (C-1) (A) 200 parts by mass of PGMEA solution containing (A-1) as silsesquioxane (100 parts by mass of (A-1) as resin solid content) (Parts), (B) 5 parts by mass of (B-1) as a radiation-sensitive radical polymerization initiator, and 0.15 parts by mass of a surfactant (“DOWNSIL 8019 Adaptive” by Toray Dow Corning) were mixed. Next, the mixture was diluted with PGMEA so that the total solid content concentration was 30% by mass, and then filtered through a membrane filter having a pore size of 0.2 μm to prepare a radiation-sensitive composition (C-1).

[Preparation Examples 2-38, Comparative Preparation Examples 1-3] Preparation of Radiation Sensitive Compositions (C-2)-(C-38) and (R-1)-(R-3) Preparation Example 1 (A) -1) Preparation Examples 2-38 in the same manner as in Preparation Example 1 except that the types and amounts of each component shown in Table 2 were used instead of 100 parts by mass and (B-1) 30 parts by mass. And the radiation-sensitive compositions (C-2) to (C-38) and (R-1) to (R-3) of Comparative Preparation Examples 1 to 3 were prepared. Blanks in Table 2 indicate that the component is not used.

[Example 1]
(Formation of insulating film)
The radiation-sensitive composition (C-1) was spin-coated on a silicon substrate so as to have a film thickness of 2.0 μm. Then, it was prebaked at 85 ° C. for 2 minutes using a hot plate to form a coating film. For this coating film, a scanning method (illuminance = 500 mW, NA = 0.10, λ = ghi line, 120 mJ / cm ² ) was performed using "DSC-200" manufactured by SUSS via a 5 μm × 5 μm square hole pattern mask. The exposure was performed. Then, it was developed at 25 ° C. for 1 minute using an aqueous solution of tetramethylammonium hydroxide (concentration: 2.38%). Then, it was washed with running water and dried to form a pattern on the substrate. Next, using "TME-400PRJ" manufactured by TOPCON, irradiate ultraviolet rays of 600 mJ / cm ² with a ghee mixing line, and further heat in an oven at 85 ° C. for 60 minutes to obtain an insulating film having an average thickness of 2.0 μm. It was.

(Evaluation of lithography performance)
The presence or absence of residues in the holes of the insulating film (patterned thin film) obtained by the above method and the size of the bottom were observed using a scanning electron microscope (SEM) and evaluated according to the following criteria. The evaluation results are shown in Table 3.
A: No residue and bottom size is 3 μm or more B: No residue and bottom size is 2 μm or more and less than 3 μm C: No residue and bottom size is 1 μm or more and less than 2 μm D: Residue or no residue, And the bottom size is less than 1 μm

(Evaluation of etching chemical resistance)
The silicon substrate on which the insulating film was formed by the above method was immersed in an amine-based stripping solution (etching chemical solution) at 60 ° C. for 60 seconds. The evaluation was made according to the following criteria based on the film 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.
A: 97% or more and less than 103% B: 95% or more and less than 97%, or 103% or more and less than 105% C: Less than 95% or 105% or more D: The insulating film is peeled off.

(Evaluation of oxygen ashing resistance)
When forming the insulating film, the entire surface was exposed without using a 5 μm × 5 μm square hole pattern mass to form an insulating film having an average thickness of 2.0 μm. Thus on an insulating film formed on a silicon substrate, a predetermined condition _{(300W, 30s, O 2 30} (SCCM), 25 ℃) ashing under film remaining ratio ((the average film thickness / ash ashed The previous average film thickness) × 100%) was measured and evaluated according to the following criteria. The evaluation results are shown in Table 3.
A: 95% or more B: 93% or more and less than 95% C: 90% or more and less than 93% D: less than 90%

[Examples 2-42 and Comparative Examples 1-3]
An insulating film was formed and each evaluation was performed in the same manner as in Example 1 except that the types of radiation-sensitive compositions used and the heating temperature after development were as shown in Table 3. The evaluation results are shown in Table 3.

As shown in Table 3, Examples 1 to 42 have sufficient lithography performance (A to C), sufficient etching chemical resistance (A to C) even when heated to 120 ° C. or lower, and sufficient oxygen ashing. It can be seen that a cured film (insulating film) having resistance (A to C) can be formed.

The radiation-sensitive property of the present invention can be suitably used as a material for forming an insulating film or the like of a display device.

10 Organic EL device with touch panel 20 Organic EL display substrate 21 Support substrate 22 Anomotive layer 23 Organic light emitting layer 24 Cathode layer 25 Adhesive layer 26 Sealing substrate 30 Touch panel 31 First sensor electrode 32 Second sensor electrode 33 Interlayer insulating film 34 Transparent substrate

Claims (16)

A 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 composition containing a radiation-sensitive radical polymerization initiator and an organic solvent.

(In formula (1), X is a monovalent organic group having an unsaturated double bond.
In the formula (2), Y is a monovalent organic group having a carboxy group, a carboxylic acid anhydride group, a phenolic hydroxyl group or a combination thereof. ) The feeling according to claim 1, wherein the 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. Radiation composition. The radiation-sensitive radiation according to claim 1 or 2, wherein the content of the silanol group with respect to the total content of the first structural unit and the second structural unit in the silsesquioxane is less than 0.3 in terms of molar ratio. Sex composition. X in the above formula (1) is represented by the following formula (3).
The radiation-sensitive composition according to claim 1, claim 2 or claim 3, wherein Y in the above formula (2) is represented by the following formula (4a) or formula (4b).

(In formulas (3), (4a) and (4b), R ¹ is an independent hydrogen atom or a methyl group, and R ² is an alkane having 2 to 10 carbon atoms, respectively. The diyl group. R ³ is a divalent organic group. R ⁴ is a single bond or a divalent organic group. Z is a sulfur atom or −NR ^x −, respectively. R ^x is a hydrogen atom or an alkyl group having 1 to 3 carbon atoms.) * Indicates a bond site. ) The radiation-sensitive composition according to any one of claims 1 to 4, further comprising a polymerizable compound having a plurality of polymerizable groups. The radiation-sensitive composition according to any one of claims 1 to 5, further comprising an alkali-soluble resin having a side chain represented by the following formula (5) and having an aromatic ring as a main chain.

(In formula (5), R ⁵ is a hydrogen atom or a methyl group. R ⁶ and R ⁷ are independent divalent organic groups. * Indicates a bond site with the main chain. .) The radiation-sensitive composition according to claim 6, wherein the alkali-soluble resin has a phenolic novolak main chain. The radiation-sensitive composition according to any one of claims 1 to 7, which can be cured by heating in a temperature range of 60 ° C. or higher and 120 ° C. or lower. An insulating film for a display device formed from the radiation-sensitive composition according to any one of claims 1 to 8. A display device having the insulating film for the display device according to claim 9. The display device according to claim 10, which is an organic electroluminescence device. The display device according to claim 11, which is an organic electroluminescence device with a touch panel. The process of forming a coating film directly or indirectly on a substrate,
The step of irradiating at least a part of the coating film with radiation,
A display device comprising a step of developing the coating film and a step of heating the coating film in this order, and forming the coating film with the radiation-sensitive composition according to any one of claims 1 to 8. How to form an insulating film. The method for forming an insulating film for a display device according to claim 13, wherein the substrate includes an organic electroluminescence element. The method for forming an insulating film for a display device according to claim 13 or 14, wherein the heating is performed in a temperature range of 60 ° C. or higher and 120 ° C. or lower. A silsesquioxane having a first structural unit represented by the following formula (1a) and a second structural unit represented by the following formula (2a).

(In the formulas (1a) and (2a), R ¹ is an independent hydrogen atom or a methyl group, and R ² is an alkanediyl group having 2 to 10 carbon atoms, respectively. R ³ is a divalent organic group.)

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