JP2017171748A - Cured film, display element, material for forming cured film and method for forming cured film - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a cured film having low dielectric property and high heat resistant transparency and capable of enhancing display performance of a display element or the like, the display element having the cured film, a material for forming the cured film capable of forming the cured film and a method for forming the cured film.SOLUTION: There is provided a cured film formed from a material for forming the cured film containing a compound having a group represented by the following formula (1) or formula (2) and a carboxyl group in same or different molecule and having relative dielectric constant at 10 kHz of 2.5 to 3.0. In the formula (1), Ris a 3,4-epoxycyclohexyl group or the like and Ris a single bond or a bivalent hydrocarbon group. In the formula (2), Ris an oxiranyl group and Ris a trivalent hydrocarbon group having 2 or more carbon atoms.SELECTED DRAWING: None

Description

  The present invention relates to a cured film, a display element, a material for forming a cured film, and a method for forming a cured film.

  Generally, a cured film such as an interlayer insulating film, a spacer, a protective film, and a color filter coloring pattern is used for a display element such as a liquid crystal display element. The cured film such as the interlayer insulating film is required to have high hardness, low dielectric constant, high voltage holding ratio, and excellent heat-resistant transparency. As a material for forming such a cured film, a radiation-sensitive resin composition is widely used because the number of steps for forming a pattern is small and a high surface hardness is obtained.

  As a radiation-sensitive resin composition (cured film forming material) for forming a cured film, one containing a copolymer containing an epoxy group and a carboxy group is known (see JP-A-2001-354822). . This radiation-sensitive resin composition is configured such that a cured film having a high surface hardness can be obtained by a reaction between an epoxy group and a carboxy group. In this copolymer, glycidyl methacrylate or the like is used as a monomer that gives a structural unit having an epoxy group, and methacrylic acid or the like is used as a monomer that gives a structural unit having a carboxy group. However, a cured film obtained from such a material for forming a cured film does not have a sufficiently low dielectric constant. When the dielectric constant of the cured film is not low, the display performance of the display element is affected.

JP 2001-354822 A

  The present invention has been made based on the circumstances as described above, and the object thereof is a cured film having low dielectric properties and high heat-resistant transparency, which can enhance the display performance and the like of the display element, and this curing. It is providing the display element provided with a film | membrane, the cured film formation material which can form the said cured film, and the formation method of a cured film.

（式（１）中、Ｒ^１は、オキシラニル基、３，４−エポキシシクロヘキシル基、３，４−エポキシノルボルニル基、下記式（３−１）で表される基、又は下記式（３−２）で表される基である。Ｒ^２は、単結合又は２価の炭化水素基である。但し、Ｒ^１がオキシラニル基の場合、Ｒ^２は炭素数２以上の２価の炭化水素基である。
式（２）中、Ｒ^３は、オキシラニル基である。Ｒ^４は、炭素数２以上の３価の炭化水素基である。）

（式（３−１）及び（３−２）中、＊は結合部位を示す。） The invention made in order to solve the above-mentioned problem is a compound having a group represented by the following formula (1) or formula (2) and a carboxy group in the same or different molecule (hereinafter referred to as “[A] compound”). A cured film having a relative dielectric constant of 2.5 or more and 3.2 or less at 10 kHz.

(In the formula (1), R ¹ represents an oxiranyl group, a 3,4-epoxycyclohexyl group, a 3,4-epoxynorbornyl group, a group represented by the following formula (3-1), or the following formula (3 -2) R ² is a single bond or a divalent hydrocarbon group, provided that when R ¹ is an oxiranyl group, R ² is a divalent hydrocarbon having 2 or more carbon atoms. It is a group.
In formula (2), R ³ is an oxiranyl group. R ⁴ is a trivalent hydrocarbon group having 2 or more carbon atoms. )

(In formulas (3-1) and (3-2), * represents a binding site.)

  Another invention made to solve the above problems is a display element comprising the cured film.

（式（１）中、Ｒ^１は、オキシラニル基、３，４−エポキシシクロヘキシル基、３，４−エポキシノルボルニル基、下記式（３−１）で表される基、又は下記式（３−２）で表される基である。Ｒ^２は、単結合又は２価の炭化水素基である。但し、Ｒ^１がオキシラニル基の場合、Ｒ^２は炭素数２以上の２価の炭化水素基である。
式（２）中、Ｒ^３は、オキシラニル基である。Ｒ^４は、炭素数２以上の３価の炭化水素基である。）

（式（３−１）及び（３−２）中、＊は結合部位を示す。） Still another invention made in order to solve the above-mentioned problems contains a compound having a group represented by the following formula (1) or formula (2) and a carboxy group in the same or different molecule, and is cured. This is a cured film forming material having a relative dielectric constant of 2.5 or more and 3.2 or less at 10 kHz of the obtained cured film.

(In the formula (1), R ¹ represents an oxiranyl group, a 3,4-epoxycyclohexyl group, a 3,4-epoxynorbornyl group, a group represented by the following formula (3-1), or the following formula (3 -2) R ² is a single bond or a divalent hydrocarbon group, provided that when R ¹ is an oxiranyl group, R ² is a divalent hydrocarbon having 2 or more carbon atoms. It is a group.
In formula (2), R ³ is an oxiranyl group. R ⁴ is a trivalent hydrocarbon group having 2 or more carbon atoms. )

(In formulas (3-1) and (3-2), * represents a binding site.)

  Yet another invention made in order to solve the above problems is a method for forming a cured film comprising a step of forming a coating film on a substrate and a step of heating the coating film, wherein the coating film is cured. It is formed using a film forming material.

  The present invention relates to a cured film having low dielectric properties and high heat-resistant transparency and capable of improving the display performance of a display element, a display element including the cured film, and a cured film capable of forming the cured film. A forming material and a method for forming a cured film can be provided. Therefore, the present invention can be suitably used for a manufacturing process of an electronic device such as a flexible display.

<Curing film>
The cured film which concerns on one Embodiment of this invention is a cured film which is formed from the material for cured film containing [A] compound, and whose relative dielectric constant in 10 kHz is 2.5 or more and 3.0 or less. The cured film has a low relative dielectric constant and high heat resistant transparency. The cured film can also exhibit good chemical resistance and the like. Accordingly, the cured film includes, for example, an interlayer insulating film, a planarization film, a bank (partition) for defining a region for forming a light emitting layer, a spacer, a protective film, a color pattern for a color filter, etc. Can be used for Among these, it is preferable to be used as an interlayer insulating film that can particularly sufficiently enjoy the advantages of low dielectric properties and high heat-resistant transparency.

  The upper limit of the relative dielectric constant of the cured film is 3.0, preferably 2.9, more preferably 2.8, further preferably 2.7, and particularly preferably 2.6. When the relative dielectric constant of the cured film is so low, suitability as a cured film such as an interlayer insulating film is further increased. The relative permittivity is a value measured at a frequency of 10 kHz by the method described in the examples.

<Curing film forming material>
Below, the cured film formation material which is the formation material of the said cured film is explained in full detail. The cured film forming material contains the [A] compound, and the cured film obtained by curing has a relative dielectric constant of 2.5 or more and 3.0 or less at 10 kHz. The cured film forming material preferably contains [B] a photosensitizer. Furthermore, the cured film forming material can contain other optional components. However, the other optional components may not be contained.

In addition, formation of the cured film at the time of measuring the dielectric constant of the cured film formed from the said cured film formation material shall be performed in the following procedures. Using the cured film forming material, a coating film having an average thickness of 3 μm is formed on the substrate. This coating film is pre-baked on a hot plate at 90 ° C. for 2 minutes. Next, after irradiating the entire surface of the coating film with 300 mJ / cm ² of ultraviolet rays (mixed ghi rays), it is heated in an oven at 230 ° C. for 30 minutes to obtain a cured film.

  The cured film forming material can provide a cured film having low dielectric properties and high heat-resistant transparency. Moreover, the said cured film formation material can also obtain the cured film which is excellent in chemical resistance, and can also obtain the cured film which has a favorable taper shape. Furthermore, the cured film forming material can also have good radiation sensitivity. Hereinafter, each component of the cured film forming material will be described in detail.

<[A] Compound>
The compound [A] has a group represented by the following formula (1) or formula (2) (hereinafter also referred to as “specific epoxy-containing group”) and a carboxy group in the same or different molecules.

In formula (1), R ¹ is an oxiranyl group (3-membered cyclic ether group: epoxy group), 3,4-epoxycyclohexyl group, 3,4-epoxynorbornyl group, and the following formula (3-1) Or a group represented by the following formula (3-2). R ² is a single bond or a divalent hydrocarbon group. However, when R ¹ is an oxiranyl group, R ² is a divalent hydrocarbon group having 2 or more carbon atoms.

In formula (2), R ³ is an oxiranyl group. R ⁴ is a trivalent hydrocarbon group having 2 or more carbon atoms.

  In formulas (3-1) and (3-2), * indicates a binding site.

Examples of R ¹ include a 3,4-epoxycyclohexyl group, a 3,4-epoxynorbornyl group, a group represented by the above formula (3-1), and a group represented by the above formula (3-2). Is preferable, and a 3,4-epoxycyclohexyl group is more preferable.

Examples of the divalent hydrocarbon group represented by R ² include a divalent aliphatic hydrocarbon group and a divalent aromatic hydrocarbon group. Examples of the divalent aliphatic hydrocarbon group include a divalent chain hydrocarbon group and a divalent alicyclic hydrocarbon group.

Examples of the divalent chain hydrocarbon group include alkanediyl groups such as methanediyl group, ethanediyl group, propanediyl group, butanediyl group, pentanediyl group;
Alkenediyl groups such as ethenediyl group, propenediyl group, butenediyl group, pentenediyl group;
Examples thereof include alkynediyl groups such as ethynediyl group, propynediyl group, butynediyl group, and pentynediyl group.

Examples of the divalent alicyclic hydrocarbon group include cycloalkanediyl groups such as cyclopropanediyl group, cyclopentanediyl group, and cyclohexanediyl group;
Cycloalkenediyl groups such as cyclopropenediyl group, cyclopentenediyl group, cyclohexenediyl group;
And divalent bridged ring hydrocarbon groups such as a norbornanediyl group, an adamantanediyl group, and a norbornenediyl group.

  Examples of the divalent aromatic hydrocarbon group include a benzenediyl group, a naphthalenediyl group, and an anthracenediyl group.

R ² is preferably a divalent hydrocarbon group having 2 or more carbon atoms, more preferably a divalent hydrocarbon group having 2 to 10 carbon atoms, and further a divalent hydrocarbon group having 2 to 4 carbon atoms. preferable. In addition, as R ² , a divalent chain hydrocarbon group is preferable, an alkanediyl group is more preferable, and an ethane-1,2-diyl group is more preferable. In addition, as R ² , a single bond, a methanediyl group, and an ethane-1,2-diyl group may be preferable, and a single bond and a methanediyl group may be more preferable.

Examples of the trivalent hydrocarbon group having 2 or more carbon atoms represented by R ⁴ include a trivalent aliphatic hydrocarbon group having 2 or more carbon atoms and a trivalent aromatic hydrocarbon group having 2 or more carbon atoms. It is done. Examples of the trivalent aliphatic hydrocarbon group having 2 or more carbon atoms include a trivalent chain hydrocarbon group having 2 or more carbon atoms and a trivalent alicyclic hydrocarbon group having 2 or more carbon atoms. .

Specific examples of the trivalent hydrocarbon group include a group obtained by removing one hydrogen atom from the above-described specific groups of the divalent hydrocarbon group having 2 or more carbon atoms. it can. R ⁴ is preferably a trivalent hydrocarbon group having 2 to 10 carbon atoms, more preferably a trivalent alicyclic hydrocarbon group having 4 to 10 carbon atoms, and a cycloalkanetriyl having 4 to 10 carbon atoms. A group is more preferred, and a cyclohexanetriyl group is particularly preferred.

The specific epoxy-containing group is preferably a group represented by the above formula (1). Further, in the formula (1), R ¹ is a 3,4-epoxycyclohexyl group and R ² is an ethane-1,2-diyl group, that is, a 2- (3,4-epoxycyclohexyl) ethyl group. Is preferred.

  According to the cured film forming material, by containing the [A] compound, a cured film having a low dielectric constant and high heat-resistant transparency can be obtained. Although this reason is not certain, the following reasons are presumed as the reason why the dielectric property of the obtained cured film is lowered. A conventional copolymer containing a general epoxy group and carboxy group has a structural unit derived from glycidyl methacrylate (GMA) and the like and a structural unit derived from methacrylic acid (MA) and the like as described above. . When a material containing such a copolymer is cured, crosslinking occurs due to a reaction between an epoxy group and a carboxy group. At this time, as shown in the following scheme, a crosslinked structure is formed in which two carbonyloxy groups (—COO—) having high polarity and hydroxyl groups (—OH) therebetween are present relatively densely. For this reason, it is estimated that a large orientation polarization occurs and the dielectric constant increases.

  On the other hand, when the [A] compound having the specific epoxy-containing group is used, in the cross-linked structure generated by the cross-linking reaction, the closeness of polar groups (carbonyloxy group and hydroxyl group) is lowered and the orientation polarization is reduced. . Thereby, it is guessed that the dielectric constant of the obtained cured film falls.

  [A] The compound may be a mixture of the compound having the specific epoxy-containing group (epoxy component) and the compound having a carboxy group (carboxylic acid component), or the specific epoxy-containing group and the carboxy group. It may be the case where it consists of a compound (epoxy-carboxylic acid component) having both. [A] The compound may be a polymer or a compound other than a polymer.

  Examples of the compound having the specific epoxy-containing group (epoxy component) include a siloxane compound having the specific epoxy-containing group and a polymer (α) having the structural unit (I) including the specific epoxy-containing group. . [A] The compound preferably contains a siloxane compound having the specific epoxy-containing group. By using the siloxane compound having the specific epoxy-containing group, in addition to low dielectric properties in the cured film, heat-resistant transparency, chemical resistance, pattern formability, and the like can be improved.

  Examples of the compound having a carboxy group (carboxylic acid component) include a polymer (β) having a structural unit (II) containing a carboxy group. The compound having both the specific epoxy-containing group and the carboxy group (epoxy-carboxylic acid component) includes the structural unit (I) containing the specific epoxy-containing group and the structural unit (II) containing a carboxy group. And a polymer (γ) having the same. As described above, when the compound [A] includes the polymer having the structural unit (II) containing a carboxy group, various properties of the cured film and radiation sensitivity can be increased.

As a preferable form of the compound [A],
A mixture of a siloxane compound having a specific epoxy-containing group and a polymer (β) having a structural unit (II) containing a carboxy group;
A mixture of a polymer (α) having a structural unit (I) having a specific epoxy-containing group and a polymer (β) having a structural unit (II) containing a carboxy group; and a structural unit containing the specific epoxy-containing group Polymer (γ) having (I) and structural unit (II) containing carboxy group
Can be mentioned. Among these, a mixture of a siloxane compound having a specific epoxy-containing group and a polymer (β) having a structural unit (II) containing a carboxy group is more preferable.

<Siloxane compound: Epoxy component (1)>
A siloxane compound refers to a compound having a siloxane bond (—Si—O—Si—). Examples of the siloxane compound having the specific epoxy-containing group include polyorganosiloxane. By using a siloxane compound, the heat-resistant transparency of the obtained cured film can be further enhanced.

  The polyorganosiloxane having the specific epoxy-containing group is a silane compound having the specific epoxy-containing group (usually a group represented by the formula (1)), or a silane compound having the specific epoxy-containing group and another silane. The mixture with the compound can be obtained by hydrolysis or hydrolytic condensation, preferably in the presence of a suitable organic solvent, water and a catalyst.

(Structural unit (i))
The polyorganosiloxane having the specific epoxy-containing group is not particularly limited as long as it has the specific epoxy-containing group, preferably the group represented by the formula (1), but the structure represented by the following formula (4) It is preferable to have the unit (i).

In the formula (4), R ⁵ is a group represented by the above formula (1). This R ^5, that is, the preferred form of the group represented by the formula (1) is as described above, and is particularly preferably a 2- (3,4-epoxycyclohexyl) ethyl group.

  When the polyorganosiloxane has such a structural unit (i), the heat resistance and chemical resistance of the cured film can be improved.

  The structural unit (i) can be formed by using a trifunctional silane compound as the silane compound having the specific epoxy-containing group. Examples of the trifunctional silane compound having a specific epoxy-containing group include 2- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, 2- (3,4-epoxycyclohexyl) ethyltriethoxysilane, and 3,4-epoxycyclohexyl. Examples thereof include methyltrimethoxysilane, 3,4-epoxycyclohexylmethyltrimethoxysilane, 2-oxiranylethyltrimethoxysilane, and 3-oxiranylpropyltrimethoxysilane. Among these, a trifunctional silane compound having a 2- (3,4-epoxycyclohexyl) ethyl group is preferable. These silane compounds can be used individually by 1 type or in mixture of 2 or more types.

  As a minimum of the content rate of the above-mentioned structural unit (i) to all the structural units of the above-mentioned polyorganosiloxane, 50 mass% is preferred, 70 mass% is more preferred, 90 mass% is still more preferred, and 95 mass% is still more preferred. 99 mass% is still more preferable, and 100 mass% is especially preferable. On the other hand, the upper limit may be 100% by mass. By making the content rate of structural unit (i) into the said range, heat resistance, chemical-resistance, etc. can be improved more. The content of each structural unit in the polyorganosiloxane can be regarded as the same as the charged amount of the corresponding silane compound as a monomer.

When the polyorganosiloxane is composed only of the structural unit (i), that is, synthesized from only the trifunctional silane compound having the specific epoxy-containing group, a cage-type silsesquioxane compound is obtained. Can be formed. Examples of such a silsesquioxane compound include (SiO _3/2 R ⁵ ) ₈ (R ⁵ has the same meaning as in formula (4)).

(Structural unit (ii))
The polyorganosiloxane may have a structural unit (ii) other than the structural unit (i). As a silane compound which gives this structural unit (ii),
Tetrafunctional silane compounds such as tetramethoxysilane, tetraethoxysilane, tetrachlorosilane;
Methyltrimethoxysilane, methyltriethoxysilane, ethyltrimethoxysilane, ethyltriethoxysilane, 3- (meth) acryloxypropyltrimethoxysilane, 3- (meth) acryloxypropyltrimethoxysilane, 3-mercaptopropyltriethoxy Trifunctional silane compounds such as silane, vinyltrimethoxysilane and allyltrimethoxysilane;
Bifunctional silane compounds such as dimethyldimethoxysilane, dimethyldimethoxysilane, diethyldimethoxysilane, di3- (meth) acryloxypropyldimethoxysilane, and di-2- (3,4-epoxycyclohexyl) ethyldimethoxysilane. it can. These silane compounds can be used individually by 1 type or in mixture of 2 or more types.

  Among these, a tetrafunctional silane compound and a trifunctional silane compound are preferable. As the trifunctional silane compound, a silane compound having an alkyl group or a reactive group as a non-hydrolyzable group is preferable. Examples of the reactive group include a group having an unsaturated double bond such as a (meth) acryloxy group and a vinyl group, and a mercapto group.

  When the polyorganosiloxane has a structural unit (ii), the lower limit of the content of the structural unit (ii) with respect to all the structural units of the polyorganosiloxane is preferably 1% by mass, more preferably 5% by mass, 10 mass% is more preferable. On the other hand, the upper limit is preferably 30% by mass.

  The lower limit of the weight average molecular weight (Mw) in terms of polystyrene by GPC of the polyorganosiloxane is preferably 1,000, and more preferably 1,500. On the other hand, the upper limit is preferably 10,000, and more preferably 5,000.

  The polyorganosiloxane (silane compound) may be a cyclic siloxane compound. Examples of the cyclic siloxane compound include “X-40-2670” manufactured by Shin-Etsu Chemical Co., Ltd.

<Polymer (α) having structural unit (I): Epoxy component (2)>
The polymer (α) having the structural unit (I) is a homopolymerization of an unsaturated monomer that gives the structural unit (I), or an unsaturated monomer that gives the structural unit (I) and other structures. It can be obtained by copolymerization with an unsaturated monomer giving the unit (III). This polymerization or copolymerization can be obtained by a known method such as radical polymerization in the presence of a suitable solvent and a suitable polymerization initiator. By using such a polymer (α), it is possible to further improve the low dielectric property and high heat-resistant transparency of the obtained cured film.

(Structural unit (I))
The structural unit (I) is a structural unit having a specific epoxy-containing group represented by the formula (1) or (2).

The unsaturated monomer that gives the structural unit (I) is an unsaturated monomer having the specific epoxy-containing group. Examples of such unsaturated monomers include 3,4-epoxybutyl acrylate, 6,7-epoxyheptyl acrylate, 3,4-epoxycyclohexyl acrylate, 3,4-epoxycyclohexylmethyl acrylate, and 3,4-epoxy. Acrylic esters such as norboninyl acrylate, α-ethylacrylic acid-6,7-epoxyheptyl;
Methacrylic acid esters such as 3,4-epoxybutyl methacrylate, 6,7-epoxyheptyl methacrylate, 3,4-epoxycyclohexyl methacrylate, 3,4-epoxycyclohexylmethyl methacrylate, 3,4-epoxynorbornyl methacrylate;
And so on. The said unsaturated monomer can be used individually by 1 type or in mixture of 2 or more types.

  50 mass% is preferable, as for the minimum of the content rate of structural unit (I) with respect to all the structural units of a polymer ((alpha)), 70 mass% is more preferable, and 80 mass% is further more preferable. On the other hand, the upper limit may be 100% by mass, 99% by mass, or 95% by mass. In addition, the content rate of the structural unit in a polymer can be considered that it is the same as the preparation ratio of a corresponding unsaturated monomer (hereinafter, it is the same).

(Structural unit (III))
Examples of the unsaturated monomer that gives the structural unit (III) include methyl methacrylate, ethyl methacrylate, n-butyl methacrylate, sec-butyl methacrylate, t-butyl methacrylate, 2-ethylhexyl methacrylate, and methacrylic acid. Methacrylic acid chain alkyl esters such as isodecyl, n-lauryl methacrylate, tridecyl methacrylate, n-stearyl methacrylate;
Cyclohexyl methacrylate, 2-methylcyclohexyl methacrylate, tricyclo [5.2.1.0 ^2,6 ] decan-8-yl methacrylate, tricyclo [5.2.1.0 ^2,6 ] decane-8 methacrylate -Cyclic alkyl esters of methacrylic acid such as yloxyethyl, isobornyl methacrylate;
Methyl acrylate, ethyl acrylate, n-butyl acrylate, sec-butyl acrylate, t-butyl acrylate, 2-ethylhexyl acrylate, isodecyl acrylate, n-lauryl acrylate, tridecyl acrylate, n-acrylate Acrylic acid chain alkyl esters such as stearyl;
Cyclohexyl acrylate, 2-methylcyclohexyl acrylate, tricyclo [5.2.1.0 ^2,6 ] decan-8-yl acrylate, tricyclo [5.2.1.0 ^2,6 ] decane-acrylate Acrylic acid cyclic alkyl esters such as 8-yloxyethyl, isobornyl acrylate;
Methacrylic acid aryl esters such as phenyl methacrylate and benzyl methacrylate;
Acrylic acid aryl esters such as phenyl acrylate and benzyl acrylate;
Unsaturated dicarboxylic acid diesters such as diethyl maleate, diethyl fumarate, diethyl itaconate;
N-phenylmaleimide, N-cyclohexylmaleimide, N-benzylmaleimide, N- (4-hydroxyphenyl) maleimide, N- (4-hydroxybenzyl) maleimide, N-succinimidyl-3-maleimidobenzoate, N-succinimidyl-4- Maleimide compounds such as maleimide butyrate, N-succinimidyl-6-maleimidocaproate, N-succinimidyl-3-maleimide propionate, N- (9-acridinyl) maleimide;
Unsaturated aromatic compounds such as styrene, α-methylstyrene, m-methylstyrene, p-methylstyrene, vinyltoluene, p-methoxystyrene;
Conjugated dienes such as 1,3-butadiene, isoprene, 2,3-dimethyl-1,3-butadiene;
Unsaturated monomers containing a tetrahydrofuran skeleton such as tetrahydrofurfuryl methacrylate, 2-methacryloyloxy-propionic acid tetrahydrofurfuryl ester, 3- (meth) acryloyloxytetrahydrofuran-2-one;
Other examples include acrylonitrile, methacrylonitrile, vinyl chloride, vinylidene chloride, acrylamide, methacrylamide, and vinyl acetate. Among these, (meth) acrylic acid ester is preferable, and (meth) acrylic acid chain alkyl ester is more preferable. The said unsaturated monomer can be used individually by 1 type or in mixture of 2 or more types.

  When the polymer (α) has the structural unit (III), the lower limit of the content of the structural unit (III) with respect to all the structural units of the polymer (α) is preferably 1% by mass, and more preferably 5% by mass. On the other hand, the upper limit is preferably 20% by mass.

  The polymer (α) may be a polymer having a polyether structure. An example of such a polymer is a polymer having a structural unit represented by the following formula (5).

R ³ and R ⁴ in the above formula (5) have the same meaning as in the above formula (2). As such a polymer, commercially available products such as “EHPE3150” manufactured by Daicel Corporation can also be used.

  The lower limit of the weight average molecular weight (Mw) in terms of polystyrene by GPC of the polymer (α) is preferably 2,000, more preferably 5,000. On the other hand, the upper limit is preferably 20,000, and more preferably 15,000. By setting Mw to be equal to or higher than the above lower limit value, the film formability can be improved. On the other hand, by making Mw equal to or less than the above upper limit value, it is possible to prevent a decrease in developability.

<Other epoxy components>
Examples of the compound having the specific epoxy-containing group include siloxane compounds described above and compounds other than the polymer (α). Such compounds include 3 ', 4'-epoxycyclohexylmethyl 3,4-epoxycyclohexanecarboxylate, butanetetracarboxylic acid tetra (3,4-epoxycyclohexylmethyl) modified ε-caprolactone, 2- (3,4 -Epoxycyclohexyl) ethyltrimethoxysilane, 3,4-epoxycyclohexylmethyl (meth) acrylate and the like.

<Polymer (β) having carboxy group-containing structural unit (II): carboxylic acid component>
The polymer (β) having the structural unit (II) is a homopolymerization of an unsaturated monomer that gives the structural unit (II), or an unsaturated monomer that gives the structural unit (II) and other structures. It can be obtained by copolymerization with an unsaturated monomer giving the unit (III). This polymerization or copolymerization can be obtained by a known method such as radical polymerization in the presence of a suitable solvent and a suitable polymerization initiator.

(Structural unit (II))
The unsaturated monomer that gives the structural unit (II) is an unsaturated monomer having a carboxy group. Examples of such unsaturated monomers include unsaturated monocarboxylic acids such as acrylic acid, methacrylic acid, crotonic acid, and 4-vinylbenzoic acid;
Unsaturated dicarboxylic acids such as maleic acid, fumaric acid, citraconic acid, mesaconic acid, itaconic acid;
The anhydride of the said unsaturated dicarboxylic acid etc. are mentioned. The said unsaturated monomer can be used individually by 1 type or in mixture of 2 or more types.

  As a minimum of the content rate of structural unit (II) with respect to all the structural units of a polymer (beta), 5 mass% is preferable, 10 mass% is more preferable, and 15 mass% is further more preferable. On the other hand, this upper limit is preferably 50% by mass, more preferably 40% by mass, and even more preferably 30% by mass. By making the content rate of structural unit (II) into the said range, sclerosis | hardenability, developability, a sensitivity, low dielectric constant, etc. can be made favorable with sufficient balance.

(Structural unit (III)
The other structural unit (III) that the polymer (β) may have is the same as the structural unit (III) of the polymer (α).

  When the polymer (β) has the structural unit (III), the lower limit of the content of the structural unit (III) with respect to all the structural units of the polymer (β) is preferably 50% by mass, and more preferably 70% by mass. On the other hand, the upper limit is preferably 95% by mass, and more preferably 90% by mass.

  The lower limit of the weight average molecular weight (Mw) in terms of polystyrene by GPC of the polymer (β) is preferably 2,000, and more preferably 5,000. On the other hand, the upper limit is preferably 20,000, and more preferably 15,000. By setting Mw to be equal to or higher than the above lower limit value, the film formability can be improved. On the other hand, by making Mw equal to or less than the above upper limit value, it is possible to prevent a decrease in developability.

<Polymer (γ) having structural unit (I) and structural unit (II): epoxy-carboxylic acid component>
The polymer (γ) is a polymer having both the specific epoxy-containing group and the carboxy group in the same molecule. The polymer (γ) includes an unsaturated monomer that gives the structural unit (I) having the specific epoxy-containing group, an unsaturated monomer that gives the structural unit (II) having a carboxy group, and other if necessary. It can be obtained by copolymerization of an unsaturated monomer giving the structural unit (III). This copolymerization can be obtained by a known method such as radical polymerization in the presence of a suitable solvent and a suitable polymerization initiator.

  The unsaturated monomer units giving the structural units (I) to (III) are as described above as the structural units in the polymer (α) and the polymer (β).

  As a minimum of the content rate of structural unit (I) with respect to all the structural units of a polymer (gamma), 5 mass% is preferable, 10 mass% is preferable, and 15 mass% is more preferable. On the other hand, as an upper limit of the content rate of this structural unit (I), 50 mass% is preferable, 40 mass% is more preferable, and 30 mass% is further more preferable. Moreover, as a minimum of the content rate of structural unit (II) with respect to all the structural units of a polymer ((gamma)), 5 mass% is preferable, 10 mass% is preferable, and 15 mass% is more preferable. On the other hand, as an upper limit of the content rate of this structural unit (II), 50 mass% is preferable, 40 mass% is more preferable, 30 mass% is further more preferable. In the polymer (γ), the content (mass%) of the structural unit (I) is preferably higher than the content (mass%) of the structural unit (II).

  When the polymer (γ) has the structural unit (III), the lower limit of the content of the structural unit (III) with respect to all the structural units of the polymer (γ) is preferably 20% by mass, and more preferably 40% by mass. On the other hand, the upper limit is preferably 90% by mass, and more preferably 80% by mass.

  The lower limit of the weight average molecular weight (Mw) in terms of polystyrene by GPC of the polymer (γ) is preferably 2,000, and more preferably 5,000. On the other hand, the upper limit is preferably 20,000, and more preferably 15,000. By setting Mw to be equal to or higher than the above lower limit value, the film formability can be improved. On the other hand, by making Mw equal to or less than the above upper limit value, it is possible to prevent a decrease in developability.

<Content of [A] compound, etc.>
As a minimum of the content rate of the [A] polymer component in the total solid in the said cured film formation material, it can be set as 50 mass%, for example, and 70 mass% is preferable. On the other hand, as this upper limit, it can be 95 mass%, for example, and 90 mass% is preferable. [A] By making the content rate of a polymer component into the said range, a sensitivity, the hardness of the cured film obtained, etc. can be made more favorable.

  [A] When using the mixture of an epoxy component and a carboxylic acid component as a compound, as a minimum of content of the epoxy component with respect to 100 mass parts of carboxylic acid components, 30 mass parts is preferable, 50 mass parts is more preferable, 75 A mass part may be sufficient. On the other hand, as an upper limit of content of the epoxy component with respect to 100 mass parts of this carboxylic acid component, 200 mass parts is preferable, 150 mass parts is more preferable, and 75 mass parts may be sufficient.

  In addition, it is preferable that an [A] compound, ie, an epoxy component, a carboxylic acid component, and an epoxy-carboxylic acid component, is a compound which does not have a phenolic hydroxyl group substantially. Since the phenolic hydroxyl group is oxidized by heating or the like, the resulting cured film is likely to be colored. Therefore, by using a compound having substantially no phenolic hydroxyl group as the [A] compound, a cured film that is superior in heat-resistant transparency can be obtained.

<[B] Photosensitive agent>
[B] When a photosensitive agent (radiation-sensitive compound) is contained in the cured film forming material, the cured film forming material is positive or negative by irradiation with radiation (visible light, ultraviolet light, far ultraviolet light, etc.). A negative pattern can be formed. [B] Photosensitive agents include [B1] acid generators, [B2] polymerization initiators, [B3] base generators, [B1] acid generators, [B2] polymerization initiators, and these The combination of is preferable. These can be used individually by 1 type or in mixture of 2 or more types. [B] When [B1] acid generator or [B3] base generator is used as the photosensitive agent, the positive or negative pattern is formed by changing the solubility of the exposed portion in the developer. be able to. In addition, when the [B1] acid generator or the [B3] base generator functions as a curing catalyst and curing of the exposed part is promoted, a negative pattern can be formed. On the other hand, when the [B2] polymerization initiator is used as the [B] photosensitizer, the exposed portion is caused by reaction with a compound having a vinyl group or a (meth) acryloyl group ([C] cross-linking agent etc. described later). Is accelerated, and a negative pattern can be formed.

<[B1] Acid generator>
[B1] The acid generator (radiation sensitive acid generator) is a compound that generates an acid in response to radiation. [B1] Examples of the acid generator include oxime sulfonate compounds, onium salts, sulfonimide compounds, sulfonic acid ester compounds, quinone diazide compounds, halogen-containing compounds, diazomethane compounds, and carboxylic acid ester compounds. These [B1] acid generators may be used alone or in admixture of two or more.

  As the oxime sulfonate compound, a compound containing an oxime sulfonate group represented by the following formula (6) is preferable.

In the above formula (6), R ^a is an alkyl group having 1 to 12 carbon atoms, a fluoroalkyl group having 1 to 12 carbon atoms, an alicyclic hydrocarbon group having 4 to 12 carbon atoms, or an aryl having 6 to 20 carbon atoms. It is a group. Some or all of the hydrogen atoms of these alkyl groups, alicyclic hydrocarbon groups and aryl groups may be substituted with substituents.

  Specific examples of the oxime sulfonate compound include (5-propylsulfonyloxyimino-5H-thiophen-2-ylidene)-(2-methylphenyl) acetonitrile, (5-octylsulfonyloxyimino-5H-thiophen-2-yl). Ylidene)-(2-methylphenyl) acetonitrile, (camphorsulfonyloxyimino-5H-thiophen-2-ylidene)-(2-methylphenyl) acetonitrile, (5-p-toluenesulfonyloxyimino-5H-thiophene-2- Examples include ylidene)-(2-methylphenyl) acetonitrile, 2- (octylsulfonyloxyimino) -2- (4-methoxyphenyl) acetonitrile, and the like, which are commercially available.

  Examples of the onium salt include diphenyliodonium salt, triphenylsulfonium salt, sulfonium salt, benzothiazonium salt, tetrahydrothiophenium salt, and benzylsulfonium salt. As the onium salt, a tetrahydrothiophenium salt and a sulfonium salt are preferable.

  Examples of the sulfonimide compound include N- (trifluoromethylsulfonyloxy) succinimide, N- (camphorsulfonyloxy) succinimide, N- (4-methylphenylsulfonyloxy) succinimide, N- (2-trifluoromethylphenylsulfonyloxy). ) Succinimide, N- (4-fluorophenylsulfonyloxy) succinimide, N- (trifluoromethylsulfonyloxy) phthalimide, N- (camphorsulfonyloxy) phthalimide, N- (2-trifluoromethylphenylsulfonyloxy) phthalimide, N -(2-fluorophenylsulfonyloxy) phthalimide, N- (trifluoromethylsulfonyloxy) diphenylmaleimide, N- (camphorsulfonyloxy) diphenyl monomer Imides, 4-methylphenyl sulfonyloxy) diphenyl maleimide, trifluoromethanesulfonic acid 1,8-naphthalimide and the like.

  Examples of the sulfonic acid ester compound include haloalkyl sulfonic acid esters and the like, and N-hydroxynaphthalimide-trifluoromethanesulfonic acid ester is preferable.

  As the quinonediazide compound, for example, a condensate of a phenolic compound or an alcoholic compound (hereinafter also referred to as “mother nucleus”) and 1,2-naphthoquinonediazidesulfonic acid halide or 1,2-naphthoquinonediazidesulfonic acid amide is used. be able to.

  Examples of the mother nucleus include trihydroxybenzophenone, tetrahydroxybenzophenone, pentahydroxybenzophenone, hexahydroxybenzophenone, (polyhydroxyphenyl) alkane, and the like.

Specific examples of the mother nucleus include, for example, 2,3,4-trihydroxybenzophenone, 2,4,6-trihydroxybenzophenone and the like as trihydroxybenzophenone;
As tetrahydroxybenzophenone, 2,2 ′, 4,4′-tetrahydroxybenzophenone, 2,3,4,3′-tetrahydroxybenzophenone, 2,3,4,4′-tetrahydroxybenzophenone, 2,3,4 2,2'-tetrahydroxy-4'-methylbenzophenone, 2,3,4,4'-tetrahydroxy-3'-methoxybenzophenone, etc .;
As pentahydroxybenzophenone, 2,3,4,2 ′, 6′-pentahydroxybenzophenone and the like;
As hexahydroxybenzophenone, 2,4,6,3 ′, 4 ′, 5′-hexahydroxybenzophenone, 3,4,5,3 ′, 4 ′, 5′-hexahydroxybenzophenone, etc .;
As (polyhydroxyphenyl) alkane, bis (2,4-dihydroxyphenyl) methane, bis (p-hydroxyphenyl) methane, tris (p-hydroxyphenyl) methane, 1,1,1-tris (p-hydroxyphenyl) Ethane, bis (2,3,4-trihydroxyphenyl) methane, 2,2-bis (2,3,4-trihydroxyphenyl) propane, 1,1,3-tris (2,5-dimethyl-4- Hydroxyphenyl) -3-phenylpropane, 4,4 '-[1- [4- [1- [4-hydroxyphenyl] -1-methylethyl] phenyl] ethylidene] bisphenol, bis (2,5-dimethyl-4 -Hydroxyphenyl) -2-hydroxyphenylmethane, 3,3,3 ', 3'-tetramethyl-1,1'-spirobiindene-5,6 , 7,5 ′, 6 ′, 7′-hexanol, 2,2,4-trimethyl-7,2 ′, 4′-trihydroxyflavan and the like;
Can be mentioned.

  Examples of other mother nuclei include 2-methyl-2- (2,4-dihydroxyphenyl) -4- (4-hydroxyphenyl) -7-hydroxychroman, 1- [1- (3- {1- (4 -Hydroxyphenyl) -1-methylethyl} -4,6-dihydroxyphenyl) -1-methylethyl] -3- (1- (3- {1- (4-hydroxyphenyl) -1-methylethyl} -4 , 6-dihydroxyphenyl) -1-methylethyl) benzene, 4,6-bis {1- (4-hydroxyphenyl) -1-methylethyl} -1,3-dihydroxybenzene, and the like.

  Of these, 2,3,4,4′-tetrahydroxybenzophenone, 1,1,1-tris (p-hydroxyphenyl) ethane, and 4,4 ′-[1- [4- [1- [4-Hydroxyphenyl] -1-methylethyl] phenyl] ethylidene] bisphenol is preferred.

  As the 1,2-naphthoquinonediazidesulfonic acid halide, 1,2-naphthoquinonediazidesulfonic acid chloride is preferable, and 1,2-naphthoquinonediazide-4-sulfonic acid chloride and 1,2-naphthoquinonediazide-5-sulfonic acid chloride are preferable. More preferred is 1,2-naphthoquinonediazide-5-sulfonic acid chloride.

  As the 1,2-naphthoquinonediazide sulfonic acid amide, 2,3,4-triaminobenzophenone-1,2-naphthoquinonediazide-4-sulfonic acid amide is preferable.

  In the condensation reaction between a phenolic compound or an alcoholic compound (mother nucleus) and 1,2-naphthoquinone diazide sulfonic acid halide or 1,2-naphthoquinone diazide sulfonic acid amide, it is preferable for the number of OH groups in the mother nucleus. 1,2-naphthoquinone diazide sulfonic acid halide or 1,2-naphthoquinone diazide sulfonic acid amide corresponding to 30 mol% or more and 85 mol% or less is preferably used. In addition, the said condensation reaction can be implemented by a well-known method.

  [B1] The acid generator is preferably a quinonediazide compound when the cured film forming material is a positive type. On the other hand, when the cured film forming material is a negative type, an acid generator other than a quinonediazide compound is preferable, and an onium salt and a sulfonimide compound are more preferable. [B1] By using the acid generator as the above compound, the sensitivity and the like can be improved.

  [B1] The lower limit of the content of the acid generator is preferably 1 part by mass, more preferably 5 parts by mass, and still more preferably 10 parts by mass with respect to 100 parts by mass of the compound [A]. On the other hand, as this upper limit, 50 mass parts is preferable and 30 mass parts is more preferable. [B1] By setting the content of the acid generator within the above range, the sensitivity can be optimized, and a cured film having better characteristics can be formed.

<[B2] Polymerization initiator>
[B2] A polymerization initiator (radiation-sensitive radical polymerization initiator) is a compound capable of initiating polymerization by generating radicals in response to radiation. [B2] Examples of the polymerization initiator include O-acyloxime compounds, acetophenone compounds, biimidazole compounds, and the like. These compounds may be used alone or in combination of two or more.

  Examples of the O-acyloxime compound include 1,2-octanedione 1- [4- (phenylthio) -2- (O-benzoyloxime)], ethanone-1- [9-ethyl-6- (2-methylbenzoyl). ) -9H-carbazol-3-yl] -1- (O-acetyloxime), 1- (9-ethyl-6-benzoyl-9.H.-carbazol-3-yl) -octane-1-one oxime-O -Acetate, 1- [9-ethyl-6- (2-methylbenzoyl) -9. H. -Carbazol-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, ethanone-1- [9-ethyl-6- (2-methyl-4-tetrahydrofuranylbenzoyl) -9. H. -Carbazol-3-yl] -1- (O-acetyloxime), ethanone-1- [9-ethyl-6- (2-methyl-4-tetrahydropyranylbenzoyl) -9. H. -Carbazol-3-yl] -1- (O-acetyloxime), ethanone-1- [9-ethyl-6- (2-methyl-5-tetrahydrofuranylbenzoyl) -9. H. -Carbazole-3-yl] -1- (O-acetyloxime), ethanone-1- [9-ethyl-6- {2-methyl-4- (2,2-dimethyl-1,3-dioxolanyl) methoxybenzoyl } -9. H. -Carbazol-3-yl] -1- (O-acetyloxime) and the like.

  As commercially available O-acyloxime compounds, NCI-831, NCI-930 (above, manufactured by ADEKA Corporation), DFI-020, DFI-091 (above, manufactured by Daito Chemix Corporation), and the like can also be used. .

  Examples of acetophenone compounds include α-aminoketone compounds and α-hydroxyketone compounds.

  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, and the like.

  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, 4- (2-hydroxyethoxy) phenyl- (2-hydroxy-2-propyl) ketone, 1-hydroxycyclohexyl phenylketone and the like can be mentioned.

  As the acetophenone compound, an α-aminoketone compound is preferable, and 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) -butan-1-one, 2-dimethylamino-2- (4-methylbenzyl)- 1- (4-morpholin-4-yl-phenyl) -butan-1-one and 2-methyl-1- (4-methylthiophenyl) -2-morpholinopropan-1-one are more preferred.

  Examples of the biimidazole compound include 2,2′-bis (2-chlorophenyl) -4,4 ′, 5,5′-tetraphenyl-1,2′-biimidazole, 2,2′-bis (2,4 -Dichlorophenyl) -4,4 ', 5,5'-tetraphenyl-1,2'-biimidazole or 2,2'-bis (2,4,6-trichlorophenyl) -4,4', 5,5 Examples include '-tetraphenyl-1,2'-biimidazole. Among these, 2,2'-bis (2,4-dichlorophenyl) -4,4 ', 5,5'-tetraphenyl-1,2'-biimidazole is preferable.

  [B2] Among these, an O-acyloxime compound is preferable as the polymerization initiator.

  [B2] The polymerization initiators can be used alone or in admixture of two or more. [B2] The lower limit of the content of the polymerization initiator is preferably 1 part by mass, more preferably 3 parts by mass, and still more preferably 5 parts by mass with respect to 100 parts by mass of the [A] compound. On the other hand, as this upper limit, 20 mass parts is preferable and 10 mass parts is more preferable. [B2] By setting the content ratio of the polymerization initiator in the above range, good curability and the like can be exhibited.

<[B3] Base generator>
[B3] The base generator (radiation sensitive base generator) is a compound that generates a base in response to radiation. [C3] Examples of the base generator include [[(2,6-dinitrobenzyl) oxy] carbonyl] cyclohexylamine, 2-nitrobenzylcyclohexylcarbamate, N- (2-nitrobenzyloxycarbonyl) pyrrolidine, bis [[( 2-nitrobenzyl) oxy] carbonyl] hexane-1,6-diamine, triphenylmethanol, O-carbamoylhydroxyamide, O-carbamoyloxime, 4- (methylthiobenzoyl) -1-methyl-1-morpholinoethane, (4 -Morpholinobenzoyl) -1-benzyl-1-dimethylaminopropane, 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) -butanone, hexaamminecobalt (III) tris (triphenylmethylborate) and the like. Can be mentioned.

<Other ingredients>
The cured film forming material may further contain other components in addition to the above-described [A] compound and [B] photosensitive agent. Examples of such other components include [C] cross-linking agents, [D] adhesion assistants, [E] antioxidants, and [F] surfactants in addition to the solvents described below. In addition, the said cured film formation material may use said each component individually or in combination of 2 or more types.

<[C] Crosslinking agent>
[C] The crosslinking agent is usually a compound having a plurality of crosslinkable groups. However, the above [A] compound is not included in the [C] crosslinking agent. Examples of the crosslinkable group include a vinyl group, a (meth) acryloyl group, and a hydroxymethylphenyl group. Among these, a vinyl group and a (meth) acryloyl group are preferable. By using the [C] crosslinker having such a crosslinkable group in combination with the [B2] polymerization initiator, curing of the exposed area is promoted, and a negative pattern can be efficiently formed.

  [C] As a crosslinking agent, polyfunctional (meth) acrylic acid ester, such as bifunctional (meth) acrylic acid ester and (meth) acrylic acid ester more than trifunctional, can be illustrated.

  Examples of the bifunctional (meth) acrylic acid ester include ethylene glycol di (meth) acrylate, propylene glycol diacrylate, propylene glycol dimethacrylate, ethylene glycol dimethacrylate, diethylene glycol diacrylate, diethylene glycol dimethacrylate, tetraethylene glycol diacrylate, tetra Examples include ethylene glycol dimethacrylate, 1,6-hexanediol diacrylate, 1,6-hexanediol dimethacrylate, 1,9-nonanediol diacrylate, and 1,9-nonanediol dimethacrylate.

  Examples of the tri- or higher functional (meth) acrylic acid ester include trimethylolpropane triacrylate, trimethylolpropane trimethacrylate, pentaerythritol triacrylate, pentaerythritol trimethacrylate, pentaerythritol tetraacrylate, pentaerythritol tetramethacrylate, dipentaerythritol penta Acrylate, dipentaerythritol pentamethacrylate, dipentaerythritol hexaacrylate, a mixture of dipentaerythritol pentaacrylate and dipentaerythritol hexaacrylate, dipentaerythritol hexamethacrylate, ethylene oxide modified dipentaerythritol hexaacrylate, tri (2-acryloyloxy) Ethyl) Pho Fete, tri (2-methacryloyloxyethyl) phosphate, succinic acid modified pentaerythritol triacrylate, succinic acid modified dipentaerythritol pentaacrylate, linear alkylene group and alicyclic structure, and two or more Polyfunctional urethane acrylate obtained by reacting with a compound having an isocyanate group and one or more hydroxy groups in the molecule and having 3, 4, or 5 (meth) acryloyloxy groups System compounds and the like.

  [C] The crosslinking agent may be a polymer. Examples of such a polymer include a polymer containing a structural unit having a (meth) acryloyl group or a vinyl group.

  The content of the [C] crosslinking agent in the cured film forming material is not particularly limited, but the lower limit relative to 100 parts by mass of the [A] compound is preferably 10 parts by mass, and more preferably 20 parts by mass. On the other hand, as this upper limit, 100 mass parts is preferable and 50 mass parts is more preferable. By setting the content of the [C] crosslinking agent in the cured film forming material in the above range, various characteristics of the obtained cured film can be more effectively enhanced.

<[D] Adhesion aid>
[D] The adhesion aid is a component that improves the adhesion between the obtained cured film and the substrate. [D] As the adhesion assistant, a functional silane coupling agent having a reactive functional group such as a carboxy group, a methacryloyl group, a vinyl group, an isocyanate group, or an oxiranyl group is preferable. However, the [D] adhesion assistant does not include the [A] compound.

  Examples of the functional silane coupling agent include trimethoxysilylbenzoic acid, γ-methacryloxypropyltrimethoxysilane, vinyltriacetoxysilane, vinyltrimethoxysilane, γ-isocyanatopropyltriethoxysilane, and γ-glycidoxy. And propyltrimethoxysilane.

  [D] The content of the adhesion assistant is preferably 0.1 parts by mass or more and 5 parts by mass or less with respect to 100 parts by mass of the [A] compound.

<[E] Antioxidant>
[E] Antioxidant is a component capable of decomposing radicals generated by exposure or heating, or peroxide generated by oxidation, and preventing the bond breakage of polymer molecules. As a result, the obtained cured film is prevented from oxidative deterioration over time, and for example, changes in the film thickness of the cured film can be suppressed.

  [E] Examples of the antioxidant include a compound having a hindered phenol structure, a compound having a hindered amine structure, a compound having an alkyl phosphite structure, and a compound having a thioether structure. In these, as [E] antioxidant, the compound which has a hindered phenol structure is preferable.

<[F] Surfactant>
[F] Surfactant is a component that improves film-forming properties. [F] Surfactants include, for example, fluorine-based surfactants, silicone-based surfactants, and other surfactants.

  The fluorine-based surfactant is preferably a compound having a fluoroalkyl group and / or a fluoroalkylene group in at least one of the terminal, main chain and side chain, for example, 1,1,2,2-tetrafluoro-n. -Octyl (1,1,2,2-tetrafluoro-n-propyl) ether, 1,1,2,2-tetrafluoro-n-octyl (n-hexyl) ether, hexaethylene glycol di (1,1,2, 2,3,3-hexafluoro-n-pentyl) ether, octaethylene glycol di (1,1,2,2-tetrafluoro-n-butyl) ether, hexapropylene glycol di (1,1,2,2,3, 3-hexafluoro-n-pentyl) ether, octapropylene glycol di (1,1,2,2-tetrafluoro-n-butyl) ether Sodium perfluoro-n-dodecanesulfonate, 1,1,2,2,3,3-hexafluoro-n-decane, 1,1,2,2,8,8,9,9,10,10-decafluoro-n -Dodecane, sodium fluoroalkylbenzenesulfonate, sodium fluoroalkylphosphate, sodium fluoroalkylcarboxylate, diglycerin tetrakis (fluoroalkylpolyoxyethylene ether), fluoroalkylammonium iodide, fluoroalkylbetaine, other fluoroalkylpolyoxy Examples thereof include ethylene ether, perfluoroalkyl polyoxyethanol, perfluoroalkyl alkoxylate, and carboxylic acid fluoroalkyl ester.

  Examples of commercially available fluorosurfactants include BM-1000, BM-1100 (above, BM CHEMIE), MegaFuck F142D, F172, F173, F183, F178, F191, F191, F471, F476 (above, Dainippon Ink & Chemicals, Inc.), Florard FC-170C, -171, -430, -431 (above, Sumitomo 3M), Surflon S-112, -113, -131, -141, -145, -382, Surflon SC-101, -102, -103, -104, -105, and -106 (Asahi Glass Co., Ltd.), Ftop EF301, and 303, 352 (above, Shin-Akita Kasei Co., Ltd.), Aftergent FT-100, -110, -140A, -150, -250, 51, the same -300, the -310, the -400S, FTX-218, the -251 (or, Neos Co., Ltd.).

  Examples of commercially available silicone surfactants include Toresilicone DC3PA, DC7PA, SH11PA, SH21PA, SH28PA, SH29PA, SH30PA, SH-190, SH-193, SZ-6032, SF-8428, DC-57, DC-190 (above, Toray Dow Corning Silicone), TSF-4440, TSF-4300, TSF-4445, TSF-4446, TSF-4460, TSF-4442 ( As mentioned above, GE Toshiba Silicone), organosiloxane polymer KP341 (Shin-Etsu Chemical Co., Ltd.) and the like can be mentioned.

  Examples of the other surfactants include polyoxyethylene alkyl ethers such as polyoxyethylene lauryl ether, polyoxyethylene stearyl ether, and polyoxyethylene oleyl ether; polyoxyethylene-n-octylphenyl ether, polyoxyethylene-n -Polyoxyethylene aryl ethers such as nonylphenyl ether; Nonionic surfactants such as polyoxyethylene dialkyl esters such as polyoxyethylene dilaurate and polyoxyethylene distearate.

  Examples of other commercially available surfactants include (meth) acrylic acid copolymer polyflow No. 57, no. 95 (above, Kyoeisha Chemical Co., Ltd.).

<Method for preparing cured film forming material>
The cured film forming material can be prepared by mixing the [A] compound, [B] photosensitizer, and other components as required, in a predetermined ratio, and preferably dissolving in an appropriate [G] solvent. The prepared cured film forming material is preferably filtered with a filter having a pore diameter of about 0.2 μm, for example. As solid content concentration of the said cured film formation material, it can be 10 mass% or more and 50 mass% or less, for example.

<[G] solvent>
[G] As the solvent, a solvent that uniformly dissolves or disperses each component contained in the cured film forming material and does not react with each of the above components is used.

[G] Examples of the solvent include alcohols such as methanol, ethanol, isopropyl alcohol, butanol and octanol;
Esters such as ethyl acetate, butyl acetate, ethyl lactate, γ-butyrolactone, propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate, methyl 3-methoxypropionate, ethyl 3-ethoxypropionate;
Ethers such as ethylene glycol monobutyl ether, propylene glycol monomethyl ether, ethylene diglycol monomethyl ether, ethylene diglycol ethyl methyl ether;
Amides such as dimethylformamide, N, N-dimethylacetamide, N-methylpyrrolidone;
Ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone;
Aromatic hydrocarbons such as benzene, toluene, xylene, and ethylbenzene can be used. [G] The solvent may be used alone or in combination of two or more.

<Method for forming cured film>
A method for forming a cured film according to an embodiment of the present invention includes:
(1) A step of forming a coating film on a substrate (hereinafter, also referred to as “step (1)”),
(2) A step of irradiating a part of the coating film (hereinafter also referred to as “step (2)”),
(3) a step of developing the coating film irradiated with the radiation (hereinafter also referred to as “step (3)”), and (4) a step of heating the developed coating film (hereinafter referred to as “step (4)”). Is also called)
A cured film forming method comprising:
The coating film is formed using the cured film forming material. In addition, when forming the cured film which does not have a pattern, the said process (2) and process (3) can be abbreviate | omitted. That is, the forming method may include at least a step (1) of forming a coating film on a substrate and a step (4) of heating the coating film.

  According to the method of forming the cured film, a cured film having a low dielectric constant and excellent heat-resistant transparency and suitable as an interlayer insulating film or the like can be formed. Hereinafter, each process is explained in full detail.

[Step (1)]
In this step, a coating film is formed on the substrate using the cured film forming material. Specifically, a solution-like material for forming a cured film is applied to the surface of the substrate, and preferably a prebake is performed to remove the solvent and form a coating film. Examples of the substrate include a glass substrate, a silicon substrate, a plastic substrate, and a substrate on which various metal thin films are formed. Examples of the plastic substrate include a resin substrate made of plastic such as polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polyethersulfone, polycarbonate, polyimide, and the like.

  As a coating method, for example, an appropriate method such as a spray method, a roll coating method, a spin coating method (spin coating method), a slit die coating method, a bar coating method, or an ink jet method can be employed. Of these, spin coating, bar coating, and slit die coating are preferred as the coating method. The pre-baking conditions vary depending on the type of each component, the use ratio, and the like, but can be, for example, 60 ° C. or higher and 130 ° C. or lower and 30 seconds or longer and 10 minutes or shorter. The film thickness of the coating film to be formed is preferably 0.1 μm or more and 8 μm or less as a value after pre-baking.

[Step (2)]
In this step, a part of the coating film is irradiated with radiation. Specifically, the coating film formed in step (1) is irradiated with radiation through a mask having a predetermined pattern. Examples of the radiation used at this time include ultraviolet rays, far ultraviolet rays, X-rays, and charged particle beams.

Examples of the ultraviolet rays include g-line (wavelength 436 nm), i-line (wavelength 365 nm), and the like. Examples of the far ultraviolet light include KrF excimer laser light. Examples of X-rays include synchrotron radiation. Examples of the charged particle beam include an electron beam. Among these radiations, ultraviolet rays are preferable, and among the ultraviolet rays, radiation containing g-line, h-line and / or i-line is more preferable. The exposure dose of radiation is preferably 0.1 J / m ² or more and 20,000 J / m ² or less.

[Step (3)]
In this step, the coating film irradiated with the radiation is developed. Specifically, the coating film irradiated with radiation in the step (2) is developed with a developer to remove the radiation irradiated portion. Examples of the developer include sodium hydroxide, potassium hydroxide, sodium carbonate, sodium silicate, sodium metasilicate, ammonia, ethylamine, n-propylamine, diethylamine, diethylaminoethanol, di-n-propylamine, triethylamine, methyl Diethylamine, dimethylethanolamine, triethanolamine, tetramethylammonium hydroxide (TMAH), tetraethylammonium hydroxide, pyrrole, piperidine, 1,8-diazabicyclo [5,4,0] -7-undecene, 1,5-diazabicyclo Examples thereof include an aqueous solution of an alkali (basic compound) such as [4,3,0] -5-nonane. In addition, an aqueous solution obtained by adding an appropriate amount of a water-soluble organic solvent such as methanol or ethanol or a surfactant to the alkaline aqueous solution, or an alkaline aqueous solution containing a small amount of various organic solvents capable of dissolving the cured film forming material is used as a developer. It may be used.

As a developing method, for example, an appropriate method such as a liquid piling method, a dipping method, a rocking dipping method, or a shower method can be employed. The development time varies depending on the composition of the cured film forming material, but can be, for example, 30 seconds or longer and 120 seconds or shorter. After the development step, the patterned coating film is rinsed with running water, and then exposed to a whole surface with a high-pressure mercury lamp or the like (post-exposure) to remain in the coating film [B It is preferable to decompose the photosensitizer. The exposure amount in this post-exposure is preferably 2,000 J / m ² or more and 5,000 J / m ² or less.

[Step (4)]
In this step, the developed coating film is heated. Although it does not specifically limit as a heating method, For example, it can heat using heating apparatuses, such as oven and a hotplate. As heating temperature in this process, it can be set as 120 to 250 degreeC, for example. The heating time varies depending on the type of heating equipment, but for example, when heat treatment is performed on a hot plate, it is 5 minutes to 40 minutes, and when heat treatment is performed in an oven, it is 30 minutes to 80 minutes. be able to. In this manner, a desired cured film such as an interlayer insulating film can be formed on the substrate.

<Display element>
A display element according to an embodiment of the present invention includes the cured film. Examples of the display element include a liquid crystal display element and an organic EL display. In these display elements, the cured film is used as, for example, an interlayer insulating film that insulates between wirings, a spacer, a protective film, a color filter coloring pattern, or the like. Since the display element includes the cured film having low dielectric properties and high heat-resistant transparency, the display element is excellent in general characteristics required in practical aspects such as display performance.

  In the liquid crystal display element which is an example of the display element, for example, two TFT array substrates having a liquid crystal alignment film formed on the surface are arranged on the liquid crystal alignment film side through a sealant provided in the peripheral portion of the TFT array substrate. The liquid crystal is filled between these two TFT array substrates. The TFT array substrate has wirings arranged in layers, and the wirings are insulated by the cured film as an interlayer insulating film.

  EXAMPLES Hereinafter, although this invention is demonstrated concretely based on an Example, this invention is not limited to these Examples. The measuring method of each physical property value is shown below.

[Weight average molecular weight (Mw) and number average molecular weight (Mn)]
Mw and Mn were measured by gel permeation chromatography (GPC) under the following conditions. The molecular weight distribution (Mw / Mn) was calculated from the obtained Mw and Mn.
Equipment: GPC-101 from Showa Denko
GPC column: GPC-KF-801, GPC-KF-802, GPC-KF-803 and GPC-KF-804 manufactured by Shimadzu GL Corp. Combined mobile phase: Tetrahydrofuran Column temperature: 40 ° C.
Flow rate: 1.0 mL / min Sample concentration: 1.0 mass%
Sample injection volume: 100 μL
Detector: Differential refractometer Standard material: Monodisperse polystyrene

<Synthesis of [A] Compound>
[Synthesis Example 1] (Synthesis of polymer ( _AEP- 1))
A flask equipped with a reflux condenser, a dropping funnel, a thermometer, and a stirrer was charged with 100 parts by mass of 2- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, 500 parts by mass of methyl isobutyl ketone, and 10 parts by mass of triethylamine. Mixed with. Next, 100 parts by mass of deionized water was added dropwise from the dropping funnel over 30 minutes, and then the mixture was heated to 80 ° C. and reacted for 6 hours while stirring under reflux. After completion of the reaction, the organic layer is taken out and washed with a 0.2% by mass aqueous ammonium nitrate solution until the water after washing becomes neutral, and then the solvent and water are distilled off under reduced pressure, whereby a polyorgano having an epoxy group is obtained. siloxane _(a EP -1) was obtained as a viscous transparent liquid.

[Synthesis Examples 2-4, Comparative Synthesis Examples 1-2] (Synthesis of Polymers ( _AEP- 2) to ( _AEP- 4), ( _CAEP- 1) to ( _CAEP- 2))
Polyorganosiloxanes having epoxy groups ( _AEP- 2) to ( _AEP- 4) and ( _CAEP- 1) in the same manner as in Synthesis Example 1 except that the raw materials (silane compounds) are as shown in Table 1. ) And (CA _EP- 2) were obtained as viscous transparent liquids, respectively. Table 1 shows the polystyrene-reduced weight average molecular weight (Mw) of the obtained polyorganosiloxane.

In Table 1, the abbreviations of the silane compounds have the following meanings, and “-” in the table indicates that they are not contained.
ECHETMS: 2- (3,4-epoxycyclohexyl) ethyltrimethoxysilane GPTMS: 3-glycidoxypropyltrimethoxysilane MTMS: methyltrimethoxysilane TMOS: tetramethoxysilane APTMS: acryloxypropyltrimethoxysilane

[Synthesis Example 5] (Synthesis of polymer ( _AEP- 5))
A flask equipped with a condenser and a stirrer was charged with 7 parts by mass of 2,2′-azobis (2,4-dimethylvaleronitrile) and 200 parts by mass of propylene glycol monomethyl ether acetate. Subsequently, after 90 parts by mass of 3,4-epoxycyclohexylmethyl methacrylate and 10 parts by mass of methyl methacrylate were charged and purged with nitrogen, stirring was started gently. The temperature of the solution was raised to 80 ° C., and this temperature was maintained for 6 hours to obtain a polymer solution containing a polymer ( _AEP- 5). The polymer ( _AEP- 5) had a weight average molecular weight (Mw) in terms of polystyrene of 10,000.

[Synthesis Example 6, Comparative Synthesis Example 3] (Synthesis of Polymer ( _AEP- 6) and ( _CAEP- 3))
Based on the monomer compositions shown in Table 2, polymers were prepared in the same manner as in Synthesis Example 5. Table 2 shows the polystyrene equivalent weight average molecular weight (Mw) of the obtained polymer.

In Table 2, the abbreviations of the monomers have the following meanings, and “-” in the table indicates that they are not contained.
ECHMA: 3,4-epoxycyclohexylmethyl methacrylate ENMA: 3,4-epoxynorbornyl methacrylate GMA: glycidyl methacrylate MMA: methyl methacrylate

[Synthesis Example 7] (Synthesis of polymer (A _CA -1))
A flask equipped with a condenser and a stirrer was charged with 7 parts by mass of 2,2′-azobis (2,4-dimethylvaleronitrile) and 200 parts by mass of propylene glycol monomethyl ether acetate. Subsequently, 15 parts by weight of methacrylic acid and 85 parts by weight of methyl methacrylate were charged and purged with nitrogen, and then gently stirring was started. The temperature of the solution was raised to 70 ° C., and this temperature was maintained for 6 hours to obtain a polymer solution containing a polymer (A _CA -1). The polymer (A _CA -1) had a polystyrene equivalent weight average molecular weight (Mw) of 12,000.

[Synthesis Examples 8 to 14, Comparative Synthesis Examples 4 to 5] (Polymer (A _CA- 2) to Polymer (A _CA -4), (A _EP-CA -1) to (A _EP-CA -4) , (CA _CA- 1) to (CA _CA- 2) synthesis)
Polymers were prepared in the same manner as in Synthesis Example 7 based on the monomer compositions shown in Table 3, respectively. Table 3 shows the polystyrene equivalent weight average molecular weight (Mw) of the obtained polymer.

In Table 3, the abbreviations for the monomers have the following meanings, and “-” in the table indicates that they are not contained.
MA: methacrylic acid MMA: methyl methacrylate ST: styrene DCM: tricyclodecyl methacrylate DMI: dimethyl itaconate GMA: glycidyl methacrylate ECHMA: 3,4-epoxycyclohexylmethyl methacrylate ENMA: 3,4-epoxynorbornyl methacrylate

<Preparation of cured film forming material>
The components used for preparing the cured film forming materials of Examples and Comparative Examples are shown below.
[A] Compound (epoxy component)
A _EP -1~A _EP -6: synthesized polymer in Synthesis Example _{1~6 (A EP -1) ~ (} A EP -6)
CA _EP -1~CA _EP -3: polymers synthesized in Comparative Synthesis Example _{1~3 (CA EP -1) ~ (} CA EP -3)
a _EP- 1: a compound having a structure represented by the following formula (“X-40-2670” manufactured by Shin-Etsu Chemical Co., Ltd.)

a _EP- 2: a polymer having a structure represented by the following formula ("EHPE3150" manufactured by Daicel)

a _EP- 3: 3,4-epoxycyclohexylmethyl 3,4-epoxycyclohexanecarboxylate ("Celoxide 2021P" from Daicel)
ca _EP -1: phenol novolac type epoxy resin ("jER152" manufactured by Mitsubishi Chemical Corporation)
ca _EP- 2: bisphenol A type epoxy resin ("jER828" manufactured by Mitsubishi Chemical Corporation)

(Carboxylic acid component)
A _CA -1~A _CA -4: synthesized polymer in Synthesis Example _{7~10 (A CA -1) ~ (} A CA -4)
CA _CA- 1 to _{CA CA-} 2: Polymers synthesized in Comparative Synthesis Examples 4 to 5 (CA _CA- 1) to (CA _CA- 2)
ca _CA- 1: CIC acid (Shikoku Chemicals)

(Epoxy-carboxylic acid component)
AEP _{-CA-1 to} AEP _-CA- 4: Polymers synthesized in Synthesis Examples 11 to 14 (AEP _{-CA -} 1) to (AEP _-CA- 4)

[B] Photosensitizer B-1: 4,4 ′-[1- [4- [1- [4-hydroxyphenyl] -1-methylethyl] phenyl] ethylidene] bisphenol (1.0 mol) and 1,2 -Condensation product (acid generator) with naphthoquinonediazide-5-sulfonic acid chloride (2.0 mol)
B-2: Polymerization initiator (O-acyl oxime compound: “NCI-930” manufactured by ADEKA)

[C] Crosslinking agent C-1: Dipentaerythritol penta / hexaacrylate (“Aronix M-402” manufactured by Toagosei Co., Ltd.)

[D] Adhesion aid D-1: 3-glycidyloxypropyltrimethoxysilane

[G] Solvent G-1: Ethylene diglycol methyl ethyl ether (EDM)
G-2: Propylene glycol monomethyl ether acetate (PGMEA)

[Example 1]
Relative to the amount corresponding to the compound _(A EP -1) 100 parts by weight (solids), the compound _(A CA -1) 100 parts by weight, acid generator as a photosensitive agent (B-1) 30 parts by weight and the adhesive After mixing 3 parts by weight of auxiliary agent (D-1) and dissolving in solvent (G-1) so that the solid content concentration is 30% by mass, it is filtered through a membrane filter having a pore size of 0.2 μm and cured. A film-forming material (S-1) was prepared.

[Examples 2 to 40 and Comparative Examples 1 to 8]
Except having used each component of the kind shown in following Table 4, it operated similarly to Example 1, the cured film formation material (S-2)-(S-40) of Examples 2-40 and Comparative Examples 1-8. ), (CS-1) to (CS-8) were prepared.

[Example 41]
Relative to the amount corresponding to the compound _(A EP -1) 50 parts by weight (solids), the compound _(A CA -1) 100 parts by weight, the polymerization initiator as a photosensitive agent (B-2) 10 parts by weight, crosslinking 50 parts by mass of the agent (C-1) and 3 parts by mass of the adhesion assistant (D-1) were mixed and dissolved in the solvent (G-2) so that the solid content concentration was 30% by mass. A cured film forming material (S-41) was prepared by filtration through a 2 μm membrane filter.

[Examples 42 to 80 and Comparative Examples 9 to 16]
Except having used each component of the kind shown in following Table 5, it operated similarly to Example 41, and the cured film formation material (S-42)-(S-80) of Examples 42-80 and Comparative Examples 9-16 ), (CS-9) to (CS-16) were prepared.

<Positive evaluation>
Using the cured film forming materials of Examples 1 to 40 and Comparative Examples 1 to 8, radiation sensitivity, cured film dielectric constant, cured film heat-resistant transparency, cured film chemical resistance, and hole pattern taper Shape evaluation was performed. The evaluation results are shown in Table 6.

[Evaluation of radiation sensitivity]
A cured film forming material was applied on a silicon substrate using a spinner, and then prebaked on a hot plate at 90 ° C. for 2 minutes to form a coating film having a thickness of 3.0 μm. Subsequently, using an exposure machine (Canon's “MPA-600FA” (ghi line mixing)), the exposure dose was changed to the coating film through a mask having a 10 μm line and space pattern. Irradiated. Then, it developed by the piling method for 60 seconds at 23 degreeC with 2.38 mass% tetramethylammonium hydroxide aqueous solution. Next, running water was washed with ultrapure water for 1 minute and then dried to form a pattern. At this time, the exposure amount necessary for completely dissolving the 10 μm space pattern was examined. For the exposure, A: 100 mJ / cm less than ^2, B: 100 mJ / cm ² or more 150 mJ / cm less than ^2, C: 150 mJ / cm ² or more 200 mJ / cm less than ^2, and D: was evaluated as 200 mJ / cm ² or more .

[Fabrication of electrical property evaluation board]
Using a cured film forming material, each was coated on an ITO substrate, which is a glass substrate with an ITO film, with a spin coater to a film thickness of 3 μm, then pre-baked on a hot plate at 90 ° C. for 2 minutes to obtain an organic solvent. Etc. were evaporated to form each coating film. Next, as an electrode extraction site for measuring electrical characteristics, a part of the edge of the substrate coated with the cured film forming material was wiped with acetone to expose the underlying ITO. Using a proximity exposure machine (Canon's “MA-1200” (ghi line mixing)), the entire surface of the substrate was irradiated with 300 mJ / cm ² light, and then heated (post-baked) at 230 ° C. for 30 minutes in an oven. And an insulating film was formed on the ITO substrate.

[Evaluation of relative permittivity]
An Al (aluminum) electrode for measuring the capacitance is formed on a vacuum deposition apparatus (JEOL VACUUM) on the insulating film of each electrical property evaluation substrate produced by the method described in [Production of electrical property evaluation substrate]. It was prepared using EVAPROTOR JEE-420). Next, a lead wire for electrode connection is soldered to the ITO portion exposed in advance, and the lead wire and the Al electrode produced by the vacuum deposition apparatus are respectively positive terminals of an LCR meter (HEWRET PACKARD 4284A PRECISION LCR METER) The capacitance C of the insulating film was measured under the conditions of an applied voltage of 100 mV and a frequency of 10 kHz. Substituting the measured capacitance C value, Al electrode area S (m ² ), and cured film thickness d (m) into the following equation, the value of dielectric constant ε is obtained, and from this, the relative dielectric constant The rate was calculated.
Dielectric constant ε = capacitance C × cured film thickness d (m) ÷ electrode area S (m ² )
When the relative dielectric constant is 3.0 or less, the low dielectric constant is considered good.

[Evaluation of heat-resistant transparency of cured film]
The heat resistant transparency of the cured film was evaluated as the transmittance at 400 nm of the cured film. A cured film forming material was applied onto a glass substrate using a spinner, and then prebaked on a hot plate at 90 ° C. for 2 minutes to form a coating film having a thickness of 3.0 μm. Subsequently, the entire surface of the substrate was irradiated with 300 mJ / cm ² light using a proximity exposure machine (“MA-1200” manufactured by Canon Inc. (mixed with ghi line)), and then heated using an oven heated to 230 ° C. Baking for a minute to form a cured film. This film was baked for 30 minutes on a hot plate heated to 300 ° C. in a nitrogen-filled glove box. The transmittance of this film was measured at 25 ° C. using an ultraviolet-visible spectrophotometer (“V-670” manufactured by JASCO Corporation), and used as an index of transparency. In the case of A to C, the transmittance at 400 nm is A: transmittance 95% or more, B: transmittance 90% or more and less than 95%, C: transmittance 85% or more and less than 90%, D: transmittance 85% or less The heat-resistant transparency was good. In the case of A or B, it was evaluated that the heat-resistant transparency was particularly good.

[Evaluation of chemical resistance of cured film]
The chemical resistance of the cured film was evaluated as swelling due to the stripping solution. A cured film forming material was applied on a silicon substrate using a spinner, and then prebaked on a hot plate at 90 ° C. for 2 minutes to form a coating film having a thickness of 3.0 μm. Subsequently, the entire surface of the substrate was irradiated with 300 mJ / cm ² of light using a proximity exposure machine (“MA-1200” manufactured by Canon Inc. (ghi line mixing)), and then heated using an oven heated to 230 ° C. Baking for a minute to form a cured film. This film was immersed in an N-methylpyrrolidone solvent heated to 40 ° C. for 6 minutes, and the rate of change in film thickness (%) before and after immersion was obtained as an index of chemical resistance. The film thickness change rate is as follows: A: film thickness change rate of less than 5%, B: film thickness change rate of 5% or more and less than 10%, C: film thickness change rate of 10% or more and less than 15%, D: film thickness change rate of 15% In the case of A to C, the chemical resistance was good, and in the case of A or B, the chemical resistance was evaluated to be particularly good. The film thickness was measured at 25 ° C. using an optical interference type film thickness measuring device (Lambda Ace VM-1010).

[Taper shape evaluation]
A cured film forming material was applied on a silicon substrate using a spinner, and then prebaked on a hot plate at 90 ° C. for 2 minutes to form a coating film having a thickness of 3.0 μm. Subsequently, using an exposure machine (Canon's “MPA-600FA” (ghi line mixing)), the exposure amount obtained by the above-described sensitivity evaluation for the coating film through a mask having a 5 μm contact hole pattern. Irradiated. Then, it developed by the piling method for 60 seconds at 23 degreeC with 2.38 mass% tetramethylammonium hydroxide aqueous solution. Next, running water was washed with ultrapure water for 1 minute and then dried to form a pattern. This pattern was irradiated with 300 mJ / cm ² light on the entire surface of the substrate using a proximity exposure machine (Canon “MA-1200” (ghi line mixing)) and then heated to 230 ° C. using an oven. The cured film was formed by baking for 30 minutes. In order to observe the tapered shape of the contact hole pattern, the hole pattern was cut along with the substrate, and platinum was deposited on the pattern surface using a vacuum deposition apparatus, and then observed with a scanning electron microscope. At this time, the angle of the pattern at the contact point with the substrate is A: 65 degrees or more, B: less than 65 degrees 60 degrees or more, C: less than 60 degrees 50 degrees or more, D: less than 50 degrees, The taper shape was evaluated as particularly good.

As is clear from the results in Table 6, the cured films formed from the cured film forming materials of Examples 1 to 40 were excellent in low dielectric properties and heat-resistant transparency. It can be seen that such a cured film can improve the display performance of the display element. In particular, as seen in Examples 1-4, Examples 10-13, Examples 19-22, and Examples 28-31, the epoxy components ( _AEP- 1) to ( _AEP- 4) are included. The cured film forming material was excellent in radiation sensitivity, and the cured film formed from these cured film forming materials was excellent in low dielectric property, chemical resistance, heat-resistant transparency and tapered shape. On the other hand, it turned out that the cured film formation material of Comparative Examples 1-3 and Comparative Examples 5-7 is inferior to low dielectric constant. Further, from the results of Comparative Example 4 and Comparative Example 8, the cured film formed from the cured film forming material containing the epoxy component (ca _EP -1) is inferior in heat-resistant transparency, although it has good low dielectric properties. I understood. Incidentally, this is the epoxy component (ca EP _-1) is added to it does not have the specific epoxy-containing group, a phenolic hydroxyl group remaining in the epoxy component (ca EP _-1) is oxidized by heating or the like This is presumed to be a factor.

<Negative evaluation>
Using the cured film forming materials of Examples 41 to 80 and Comparative Examples 9 to 16, the dielectric constant of the cured film, the heat-resistant transparency of the cured film, and the chemical resistance of the cured film were evaluated by the above methods. . Moreover, taper shape evaluation of the hole pattern was implemented with the following method. Table 7 shows the evaluation results.

[Taper shape evaluation]
A cured film forming material was applied on a silicon substrate using a spinner, and then prebaked on a hot plate at 90 ° C. for 2 minutes to form a coating film having a thickness of 3.0 μm. Subsequently, the coating film was irradiated with 100 mJ / cm ² of radiation through a mask having a 5 μm contact hole pattern using an exposure machine (“MPA-600FA” manufactured by Canon Inc. (mixed with ghi line)). Then, it developed by the piling method for 60 seconds at 23 degreeC with 2.38 mass% tetramethylammonium hydroxide aqueous solution. Next, running water was washed with ultrapure water for 1 minute and then dried to form a pattern. This pattern was baked for 30 minutes using an oven heated to 230 ° C. to form a cured film. In order to observe the tapered shape of the contact hole pattern, the hole pattern was cut along with the substrate, and platinum was deposited on the pattern surface using a vacuum deposition apparatus, and then observed with a scanning electron microscope. At this time, the angle of the pattern at the contact point with the substrate is A: 65 degrees or more, B: less than 65 degrees 60 degrees or more, C: less than 60 degrees 50 degrees or more, D: less than 50 degrees, The taper shape was evaluated as particularly good.

As is clear from the results in Table 7, the cured films formed from the cured film forming materials of Examples 41 to 80 were excellent in low dielectric properties and heat-resistant transparency. It can be seen that such a cured film can improve the display performance of the display element. In particular, Example 41-44, Example 50-53, Example 59-62, as clearly seen the examples 68 to 71, an epoxy component _{(A EP -1) ~ (A} EP -4) The cured film formed from the cured film forming material was excellent in low dielectric property, chemical resistance, heat-resistant transparency and tapered shape. On the other hand, it turned out that the cured film formed from the material for cured film formation of Comparative Examples 9-11 and Comparative Examples 13-15 is inferior in low dielectric constant. Further, from the results of Comparative Examples 12 and 16, the cured film formed from the cured film forming material containing the epoxy component (ca _EP -1) has a low dielectric constant but is inferior in heat-resistant transparency. I understood.

  The present invention can be suitably used as a material for forming a cured film provided in a display element such as an interlayer insulating film.

Claims (10)

In the same or different molecules, formed from a cured film forming material containing a compound having a group represented by the following formula (1) or formula (2) and a carboxy group,
A cured film having a relative dielectric constant of 2.5 or more and 3.0 or less at 10 kHz.

(In the formula (1), R ¹ represents an oxiranyl group, a 3,4-epoxycyclohexyl group, a 3,4-epoxynorbornyl group, a group represented by the following formula (3-1), or the following formula (3 -2) R ² is a single bond or a divalent hydrocarbon group, provided that when R ¹ is an oxiranyl group, R ² is a divalent hydrocarbon having 2 or more carbon atoms. It is a group.
In formula (2), R ³ is an oxiranyl group. R ⁴ is a trivalent hydrocarbon group having 2 or more carbon atoms. )

(In formulas (3-1) and (3-2), * represents a binding site.)   The cured film of Claim 1 in which the said compound contains the polymer which has a structural unit containing a carboxy group.   The cured film according to claim 1, wherein the material for forming a cured film further contains a photosensitive agent.   The cured film of Claim 1, Claim 2, or Claim 3 in which the said compound contains the siloxane compound which has group represented by the said Formula (1). The cured film according to claim 4, wherein the siloxane compound has a structural unit represented by the following formula (4).

(In formula (4), R ⁵ is a group represented by the above formula (1).) The cured film according to claim 4 or 5, wherein R ¹ in the formula (1) is a 3,4-epoxycyclohexyl group, and R ² is an ethane-1,2-diyl group.   The cured film according to any one of claims 1 to 6, which is an interlayer insulating film.   A display element provided with the cured film of any one of Claims 1-7. In the same or different molecule, containing a compound having a group represented by the following formula (1) or formula (2) and a carboxy group,
A cured film-forming material having a relative dielectric constant of 2.5 or more and 3.0 or less at 10 kHz of a cured film obtained by curing.

(In the formula (1), R ¹ represents an oxiranyl group, a 3,4-epoxycyclohexyl group, a 3,4-epoxynorbornyl group, a group represented by the following formula (3-1), or the following formula (3 -2) R ² is a single bond or a divalent hydrocarbon group, provided that when R ¹ is an oxiranyl group, R ² is a divalent hydrocarbon having 2 or more carbon atoms. It is a group.
In formula (2), R ³ is an oxiranyl group. R ⁴ is a trivalent hydrocarbon group having 2 or more carbon atoms. )

(In formulas (3-1) and (3-2), * represents a binding site.) A method of forming a cured film comprising: forming a coating film on a substrate; and heating the coating film,
A method for forming a cured film, wherein the coating film is formed using the material for forming a cured film according to claim 9.