Curable composition for organic el element, cured product for organic el element and method for producing same, organic el element, and polymer

Abstract

A curable composition for an organic EL element, the curable composition containing [A] a polymer containing a structural unit derived from a compound having an acidic group and [B] a photosensitive compound, the polymer [A] containing a structural unit (I) derived from an aromatic vinyl compound and a structural unit (II) derived from a maleimide compound, the compound having an acidic group being a compound having an aromatic vinyl group, and the compound having an aromatic vinyl group and a maleimide group being a compound having an aromatic vinyl group. The polymer [A] contains at least one compound selected from the group consisting of aromatic vinyl compounds and maleimide compounds, and the total proportion of the structural unit (I) and the structural unit (II) in the polymer [A] is 70 mol% or more with respect to all the structural units of the polymer [A].

Description

Technical Field

[0001] [Cross - Reference to Related Applications]

[0002] This application claims priority based on Japanese Patent Application No. 2022 - 180340 filed on November 10, 2022, and incorporates the entirety thereof by reference into this specification.

[0003] The present disclosure relates to a curable composition for an organic EL element, a cured product for an organic EL element, a method for manufacturing the same, an organic EL element, and a polymer. Background Art

[0004] An organic electroluminescence (EL) element (organic EL element) is a light - emitting element having a laminated structure including an anode, an organic light - emitting layer, and a cathode. Organic EL elements have been widely put to practical use in various applications such as display devices and lighting devices.

[0005] In an organic EL element, an insulating cured product such as a planarization film, a partition wall, or an interlayer insulating film is provided. In recent years, the following operation has been carried out: using a curable composition containing a polymer component and a photosensitive compound to form these cured products (for example, refer to Patent Document 1). Specifically, for a coating film formed from the curable composition, after irradiating with radiation through a mask having a pattern, a developing treatment is performed, and then a heat treatment is performed to thermally cure it, whereby a patterned cured film can be obtained.

[0006] Prior Art Documents

[0007] Patent Documents

[0008] Patent Document 1: Japanese Patent Laid - Open No. 2021 - 157173 Summary of the Invention

[0009] Problems to be Solved by the Invention

[0010] The organic light - emitting layer included in an organic EL element is liable to deteriorate due to contact with moisture or oxygen. For example, there are concerns such as the formation of a locally non - light - emitting region (dark spot) due to moisture infiltrating into the element during long - term driving, or a reduction in light - emitting characteristics due to contact with moisture or oxygen. Therefore, for the cured product provided in the organic EL element, it is required to be difficult for moisture to permeate (hereinafter, also referred to as "moisture - impermeability").

[0011] In addition, in recent years, in devices such as smartphones equipped with an organic EL display (organic light emitting diode, OLED), the application of flexible displays has been studied. The flexible display can be deformed into various shapes such as bending or folding by using a flexible substrate such as a resin film. Therefore, for the hard film used for the organic EL element included in the organic EL display, it is sometimes required to have bend resistance (hereinafter, also referred to as "flexural resistance") that can cope with the flexible display.

[0012] Furthermore, in recent years, in a mobile organic EL display, a technology of embedding a camera under the display (Under Display Camera: UDC technology) has been studied. Along with this, for the organic EL element, it is required to achieve a lower dielectric constant and a further multilayer wiring structure at the same time. In addition, in the manufacturing process of the element, a high-temperature treatment (for example, a heat treatment at 200 °C or higher) is sometimes performed on the hard film. Therefore, for the hard film applied in the organic EL element, excellent heat resistance is also required. In particular, with the increasing demand for higher definition / higher quality of organic EL display devices in recent years, there is a need for a hardenable composition for organic EL elements that can form a hardened product in the organic EL element, which has high sensitivity while maintaining high heat resistance and high transmittance, achieves a low dielectric constant, can improve water impermeability and flexural resistance well in balance, and has excellent element reliability.

[0013] The present disclosure has been made in view of the above problems, and its main object is to provide a hardenable composition for organic EL elements, which can form a hardened product having high sensitivity, low dielectric constant, high transmittance, excellent heat resistance, water impermeability and flexural resistance, and can obtain an organic EL element with high reliability.

[0014] Technical means for solving the problem

[0015] The present inventors focused on using a copolymer of an aromatic vinyl compound and a maleimide compound as a polymer component of the hardened product constituting the organic EL element, and found that the above problems can be solved by preparing a hardenable composition containing a specific polymer. That is, according to the present disclosure, the following hardenable composition for organic EL elements, hardened product for organic EL elements and its manufacturing method, organic EL element and polymer can be provided.

[0016] [1] A curable composition for an organic EL element, comprising [A] a polymer containing a structural unit derived from a compound having an acidic group and [B] a photosensitive compound, wherein the [A] polymer contains a structural unit (I) derived from an aromatic vinyl compound and a structural unit (II) derived from a maleimide compound, and as the compound having an acidic group, contains at least one selected from the group consisting of an aromatic vinyl compound and a maleimide compound. The total proportion of the structural unit (I) and the structural unit (II) in the [A] polymer is 70 mol% or more with respect to all the structural units of the [A] polymer.

[0017] [2] A method for producing a cured product for an organic EL element, comprising: a step of forming a coating film using the curable composition of [1]; a step of irradiating at least a part of the coating film with radiation; a step of developing the coating film after irradiation with radiation; and a step of heating the developed coating film.

[0018] [3] A cured product for an organic EL element, which is formed using the curable composition of [1].

[0019] [4] An organic EL element, comprising the cured product of [3].

[0020] [5] A polymer, comprising a structural unit derived from an aromatic vinyl compound and a structural unit derived from a maleimide compound, wherein the total proportion of the structural unit derived from an aromatic vinyl compound and the structural unit derived from a maleimide compound is 70 mol% or more with respect to all the structural units of the polymer. The polymer contains a structural unit derived from a compound having an acidic group and a structural unit derived from a compound having a crosslinkable functional group, and the compound having an acidic group and the compound having a crosslinkable functional group are at least one selected from the group consisting of an aromatic vinyl compound and a maleimide compound. The compound having an acidic group is at least one selected from the group consisting of a compound having a phenolic hydroxyl group, a compound having a group “* 1 -C(R 1 )(R 2 )-OH” (wherein R 1 and R 2 are each independently a cyano group or a fluoroalkyl group having 1 to 3 carbon atoms; “* 1 ” represents a bonding bond to an aromatic ring) and maleimide.

[0021] Effects of the Invention

[0022] The curable composition for an organic EL element according to the present disclosure can form a cured product having high sensitivity, low dielectric constant, high transmittance, and excellent heat resistance, water vapor barrier property, and bending resistance. In addition, the curable composition for an organic EL element according to the present disclosure can provide an organic EL element with high reliability. Detailed Description of Embodiments

[0023] Hereinafter, matters related to the embodiments will be described in detail. In addition, in this specification, a numerical range described using "~" means that the numerical values described before and after "~" are included as the lower limit value and the upper limit value. The term "structural unit" refers to a unit that mainly constitutes the main chain structure and includes at least two or more units in the main chain structure.

[0024] In this specification, the term "hydrocarbon group" includes a linear hydrocarbon group, an alicyclic hydrocarbon group, and an aromatic hydrocarbon group. The term "linear hydrocarbon group" refers to a straight-chain hydrocarbon group and a branched hydrocarbon group that do not contain a cyclic structure in the main chain and are composed only of a linear structure. Among them, the linear hydrocarbon group may be saturated or unsaturated. The term "alicyclic hydrocarbon group" refers to a hydrocarbon group that contains only an alicyclic hydrocarbon structure as the ring structure and does not contain an aromatic ring structure. Among them, the alicyclic hydrocarbon group does not need to be composed only of an alicyclic hydrocarbon structure and also includes a group having a linear structure in a part thereof. The term "aromatic hydrocarbon group" refers to a hydrocarbon group that contains an aromatic ring structure as the ring structure. Among them, the aromatic hydrocarbon group does not need to be composed only of an aromatic ring structure and may also include a linear structure or an alicyclic hydrocarbon structure in a part thereof. In addition, the ring structure of the alicyclic hydrocarbon group and the aromatic hydrocarbon group may also have a substituent containing a hydrocarbon structure. The term "cyclic hydrocarbon group" includes an alicyclic hydrocarbon group and an aromatic hydrocarbon group.

[0025] The expression "(substituted or unsubstituted) p-valent hydrocarbon group (where p is an integer of 1 or more)" includes a p-valent hydrocarbon group (i.e., an unsubstituted p-valent hydrocarbon group) and a group formed by removing p hydrogen atoms from the hydrocarbon structure part of a hydrocarbon group having a substituent. As an example of a (substituted or unsubstituted) p-valent hydrocarbon group, for example, an alkyl group or a fluoroalkyl group corresponds to the case where p = 1, and an alkylene group or a fluoroalkylene group corresponds to the case where p = 2. Among these, a fluoroalkyl group corresponds to a "substituted monovalent hydrocarbon group", and a fluoroalkylene group corresponds to a "substituted divalent hydrocarbon group". The same applies to other groups with "(substituted or unsubstituted)".

[0026] In this specification, the term "(meth)acrylic acid" includes "acrylic acid" and "methacrylic acid". The term "(meth)acryloyl" includes "acryloyl" and "methacryloyl". In this specification, oxiranyl and oxetanyl are also referred to as "epoxy group".

[0027] Curable Composition for Organic EL Element

[0028] The curable composition for an organic EL element of the present disclosure (hereinafter, also referred to as "the present composition") can be used to form an insulating cured product provided in the organic EL element. The present composition contains [A] a polymer containing a structural unit derived from a compound having an acidic group (hereinafter, also referred to as "[A] polymer") and [B] a photosensitive compound. Hereinafter, each component contained in the present composition and other components formulated as needed will be described in detail. In addition, regarding each component, unless otherwise specified, one kind can be used alone, or two or more kinds can be used in combination.

[0029] <[A] Polymer>

[0030] [A] The polymer is a copolymer containing a structural unit (I) derived from an aromatic vinyl compound and a structural unit (II) derived from a maleimide compound. In the [A] polymer, the total proportion of the structural unit (I) and the structural unit (II) is 70 mol% or more with respect to all the structural units of the [A] polymer. If the total proportion of the structural unit (I) and the structural unit (II) is less than 70 mol% with respect to all the structural units of the polymer, the heat resistance and water impermeability of the cured product obtained from the curable composition are insufficient, and the dielectric constant of the cured product tends to become too high. From the viewpoint of obtaining a cured product having excellent heat resistance and water impermeability and a sufficiently low dielectric constant, the total proportion of the structural unit (I) and the structural unit (II) in the [A] polymer is preferably 75 mol% or more, more preferably 80 mol% or more, further preferably 85 mol% or more, and still more preferably 90 mol% or more with respect to all the structural units of the [A] polymer.

[0031] In the [A] polymer, the aromatic vinyl compound and the maleimide compound may be arranged randomly or alternately. From the viewpoint of sufficiently obtaining the effects of reducing the dielectric constant, increasing the transmittance, improving the heat resistance and water impermeability of the cured product obtained from the present composition, and making the element reliability excellent, the molar ratio of the structural unit (I) to the structural unit (II) in the [A] polymer is preferably structural unit (I) / structural unit (II) = 60 / 40 to 40 / 60, more preferably 58 / 42 to 42 / 58, and further preferably 56 / 44 to 44 / 56.

[0032] In addition, the [A] polymer may also contain structural units (III) derived from monomers different from aromatic vinyl compounds and maleimide compounds (e.g., (meth)acrylic compounds, vinyl compounds, vinyl ether compounds, conjugated diene compounds, cycloolefins). The proportion of the structural units (III) in the [A] polymer is 30 mol% or less, preferably 25 mol% or less, more preferably 20 mol% or less, still more preferably 15 mol% or less, and even more preferably 10 mol% or less, relative to all the structural units of the [A] polymer.

[0033] (Structural units derived from compounds having an acidic group)

[0034] The [A] polymer contains structural units derived from compounds having an acidic group (hereinafter, also referred to as "structural units (A1)"). By the [A] polymer containing the structural units (A1), the solubility in an alkaline developer (alkali solubility) or the hardening reactivity can be improved. In addition, in the present specification, "alkali-soluble" means soluble in an alkaline aqueous solution such as a 2.38 mass% aqueous solution of tetramethylammonium hydroxide.

[0035] The structural units (A1) are not particularly limited as long as they have an acidic group. Preferred examples of the structural units (A1) include: structural units having a phenolic hydroxyl group, compounds having the group "* 1 -C(R 1 )(R 2 )-OH" (wherein R 1 and R 2 are each independently a cyano group or a fluoroalkyl group having 1 to 3 carbon atoms; "* 1 " represents a bonding bond to an aromatic ring; the same applies hereinafter), structural units having a carboxyl group, structural units having a sulfonic acid group, structural units having a sulfonamide group, structural units having a phosphonic acid group, structural units derived from maleimide, etc. In terms of being able to sufficiently achieve a low dielectric constant of the cured product, among these, the structural units (A1) are preferably structural units derived from at least one selected from the group consisting of compounds having a phenolic hydroxyl group, compounds having the group "* 1 -C(R 1 )(R 2 )-OH" and maleimide. In addition, in the present specification, the so-called "phenolic hydroxyl group" means a hydroxyl group directly bonded to an aromatic ring (e.g., benzene ring, naphthalene ring, anthracene ring, etc.).

[0036] [A] The polymer contains a structural unit derived from at least one selected from the group consisting of aromatic vinyl compounds and maleimide compounds (hereinafter, also referred to as "structural unit (A1-1)" as structural unit (A1)). Specific examples of the structural unit (A1-1) include structural units represented by the following formula (a-1), formula (a-2), or formula (a-3).

[0037] [Chemical 1]

[0038]

[0039] (In formula (a-1) to formula (a-3), R 3 , R 4 , R 6 , R 7 and R 8 are independently of each other a hydrogen atom, a methyl group, a hydroxymethyl group, a cyano group, or a trifluoromethyl group; R 5 is a substituted or unsubstituted (r1 + 1)-valent hydrocarbon group having 1 to 20 carbon atoms, or a (r1 + 1)-valent group containing -O-, -CO-, -COO-, -NH-, -CONH-, or -S- between carbon-carbon bonds in a substituted or unsubstituted hydrocarbon group having 2 to 20 carbon atoms; A 1 is a substituted or unsubstituted (r2 + 1)-valent aromatic ring group having 6 to 20 carbon atoms; X 1 and X 2 are independently of each other a phenolic hydroxyl group, the group "* 1 -C(R 1 )(R 2 )-OH", a carboxyl group, a sulfonic acid group, a sulfonamide group, or a phosphonic acid group; r1 and r2 are independently of each other 1 or 2)

[0040] In the formula (a-1) to formula (a-3), from the viewpoint of copolymerizability, R 3 , R 4 , R 6 , R 7 and R 8 are preferably a hydrogen atom or a methyl group.

[0041] When R 5 is a (r1 + 1)-valent hydrocarbon group, examples of the (r1 + 1)-valent hydrocarbon group include: a linear hydrocarbon group having 1 to 10 carbon atoms, an alicyclic hydrocarbon group having 3 to 20 carbon atoms, and an aromatic hydrocarbon group having 6 to 20 carbon atoms, etc.

[0042] As R 5The (r1 + 1)-valent chain hydrocarbon group having 1 to 10 carbon atoms represented includes a linear or branched saturated hydrocarbon group having 1 to 10 carbon atoms and a linear or branched unsaturated hydrocarbon group having 1 to 10 carbon atoms, etc. Among these, a linear or branched saturated hydrocarbon group having 1 to 10 carbon atoms is preferred.

[0043] As R 5 The (r1 + 1)-valent alicyclic hydrocarbon group having 3 to 20 carbon atoms represented includes a group formed by removing (r1 + 1) hydrogen atoms from a monocyclic saturated alicyclic hydrocarbon, a monocyclic unsaturated alicyclic hydrocarbon, or an alicyclic polycyclic hydrocarbon having 3 to 20 carbon atoms. Specific examples of these alicyclic hydrocarbons include, as the monocyclic saturated alicyclic hydrocarbon, cyclobutane, cyclopentane, cyclohexane, cycloheptane, cyclooctane, etc.; as the monocyclic unsaturated alicyclic hydrocarbon, cyclopentene, cyclohexene, cycloheptene, cyclooctene, cyclodecene, etc.; as the alicyclic polycyclic hydrocarbon, bicyclo[2.2.1]heptane (norbornane), bicyclo[2.2.2]octane, tricyclo[3.3.1.1 3,7 decane (adamantane), tetracyclo[6.2.1.1 3,6 .0 2,7 dodecane, etc.

[0044] As R 5 The (r1 + 1)-valent aromatic hydrocarbon group having 6 to 20 carbon atoms represented includes a group formed by removing (r1 + 1) hydrogen atoms from an aromatic ring such as benzene, naphthalene, anthracene, indene, and fluorene.

[0045] In terms of improving the heat resistance, flexural resistance, and water impermeability of the cured product obtained from this composition or in terms of being able to form crosslinking points by irradiation with radiation or heat application, among these, the group represented by R 5 is preferably a substituted or unsubstituted (r1 + 1)-valent aromatic hydrocarbon group having 6 to 20 carbon atoms, more preferably a (r1 + 1)-valent group having 6 to 20 carbon atoms (aromatic ring group) formed by removing (r1 + 1) hydrogen atoms from the ring portion of a substituted or unsubstituted aromatic hydrocarbon. Among them, the group represented by R 5 is preferably a group formed by removing (r1 + 1) hydrogen atoms from the ring portion of a substituted or unsubstituted benzene ring or naphthalene ring.

[0046] A 1 The aromatic ring group represented is a group formed by removing (r2 + 1) hydrogen atoms from the ring portion of a substituted or unsubstituted aromatic ring. The aromatic ring is preferably a benzene ring or a naphthalene ring, more preferably a benzene ring.

[0047] In the group represented by R 5 or A 1When the aromatic ring group represented has a substituent in the ring portion, examples of the substituent include: an alkyl group having 1 to 5 carbon atoms, an alkoxy group having 1 to 5 carbon atoms, an acyl group, a halogen atom (fluorine atom, chlorine atom, bromine atom, iodine atom, etc.), a hydroxyl group, a carboxyl group, a cyano group, a nitro group, etc.

[0048] X 1 and X 2 Preferably, it is a phenolic hydroxyl group, the group “* 1 -C(R 1 )(R 2 )-OH” or a carboxyl group. From the viewpoint of obtaining a cured product with a lower dielectric constant, it is more preferably a phenolic hydroxyl group or the group “* 1 -C(R 1 )(R 2 )-OH”.

[0049] As a further specific example of the structural unit (A1-1), the structural unit represented by the following formula can be cited.

[0050] [Chemical formula 2]

[0051]

[0052] (In the formula, R 41 , R 42 and R 43 are each independently a hydrogen atom, a methyl group, a hydroxymethyl group, a cyano group or a trifluoromethyl group)

[0053] [A] The polymer may also contain a structural unit (hereinafter, also referred to as “structural unit (A1-2)”) different from the structural unit (A1-1) as the structural unit (A1). As the monomer providing the structural unit (A1-2), there is no particular limitation as long as it is a compound having a polymerizable group capable of copolymerizing with the monomer providing the structural unit (A1-1) and an acidic group. As the monomer providing the structural unit (A1-2), for example, vinyl compounds and (meth)acrylic compounds can be cited.

[0054] Regarding specific examples of the monomer providing the structural unit (A1-2), as the monomer providing a structural unit having a carboxyl group, for example, unsaturated monocarboxylic acids such as (meth)acrylic acid, crotonic acid, 4-vinylbenzoic acid; unsaturated dicarboxylic acids such as maleic acid, fumaric acid, citraconic acid, mesaconic acid, itaconic acid; as the monomer providing a structural unit having a sulfonic acid group, for example, vinylsulfonic acid, (meth)allylsulfonic acid, (meth)acryloyloxyethylsulfonic acid, etc.; as the monomer providing a structural unit having a phenolic hydroxyl group, for example, (meth)acrylic acid phenyl ester, etc.

[0055] In terms of imparting good solubility in an alkaline developer, the content ratio of the structural unit (A1) in the [A] polymer is preferably 12 mol% or more, more preferably 15 mol% or more, and still more preferably 20 mol% or more, relative to all the structural units constituting the [A] polymer. On the other hand, if the content ratio of the structural unit (A1) is too high, the difference in solubility between the exposed part and the unexposed part in the alkaline developer becomes small, and it is difficult to obtain a good pattern shape. In terms of the above view, the content ratio of the structural unit (A1) is preferably 80 mol% or less, more preferably 75 mol% or less, and still more preferably 70 mol% or less, relative to all the structural units constituting the [A] polymer.

[0056] In terms of imparting good solubility in an alkaline developer to the polymer and further providing a curable composition that can form a cured product having heat resistance, a low dielectric constant, high transmittance, and water impermeability while maintaining high sensitivity, the content ratio of the structural unit (A1-1) in the [A] polymer is preferably 10 mol% or more, more preferably 15 mol% or more, and still more preferably 20 mol% or more, relative to all the structural units constituting the [A] polymer. In addition, the content ratio of the structural unit (A1-1) is preferably 80 mol% or less, more preferably 75 mol% or less, and still more preferably 70 mol% or less, relative to all the structural units constituting the [A] polymer.

[0057] When the [A] polymer contains the structural unit (A1-2), in terms of obtaining a cured product having heat resistance, a low dielectric constant, high transmittance, and water impermeability while maintaining the high sensitivity of the present composition, the content ratio of the structural unit (A1-2) is preferably 10 mol% or less, more preferably 5 mol% or less, still more preferably 1 mol% or less, and even more preferably 0.5 mol% or less, relative to all the structural units constituting the [A] polymer.

[0058] The [A] polymer may further contain a structural unit different from the structural unit (A1) (hereinafter, also referred to as "other structural unit"). Examples of the other structural unit include a structural unit having a crosslinkable functional group, a structural unit having an acid dissociable group, and the like.

[0059] (Structural unit having a crosslinkable functional group)

[0060] [A] The polymer preferably further contains a structural unit having a crosslinkable functional group (excluding the "structural unit (A1)"; hereinafter, also referred to as "structural unit (A2)"). By having a crosslinkable functional group in the [A] polymer, a cured product having more excellent heat resistance and flex resistance can be formed. In addition, in the present specification, a structural unit having a functional group that exhibits crosslinkability but dissociates by the action of an acid to generate an acidic group is classified as a "structural unit having an acid dissociable group" described later.

[0061] The crosslinkable functional group possessed by the structural unit (A2) is preferably a group that causes a crosslinking reaction by light or heat. Specific examples of the crosslinkable functional group include: a cyclic ether group, a cyclic thioether group, a carboxyl group, a cyclic carbonate group, an alcoholic hydroxyl group, an amino group, a protected amino group, a protected isocyanate group, a polymerizable unsaturated bond group, a hydroxyalkylamide group, etc. From the viewpoint of forming a crosslinked structure between or within the molecules of the [A] polymer and making the heat resistance and flex resistance of the cured product more excellent, among them, the crosslinkable functional group possessed by the structural unit (A2) is preferably at least one selected from the group consisting of an oxiranyl group, an oxetanyl group, a thiiranyl group, a hydroxyalkylamide group, a hydroxymethylphenyl group, an alkoxymethylphenyl group, a cyclic carbonate group, and a protected isocyanate group. From the viewpoint of balancing reactivity and storage stability, it is more preferably at least one selected from the group consisting of an oxiranyl group, an oxetanyl group, a hydroxyalkylamide group, a hydroxymethylphenyl group, an alkoxymethylphenyl group, and an alkoxysilyl group.

[0062] From the viewpoint of obtaining a cured product having excellent heat resistance, low water permeability, and low dielectric constant by sufficiently increasing the amounts of the structural unit (I) and the structural unit (II), the [A] polymer preferably contains a structural unit derived from a compound having a crosslinkable functional group (hereinafter, also referred to as "structural unit (A2-1)") as the structural unit (A2), and the compound having a crosslinkable functional group is at least one selected from the group consisting of an aromatic vinyl compound and a maleimide compound.

[0063] Specific examples of the structural unit (A2-1) include a structural unit represented by the following formula (b-1) or formula (b-2).

[0064] [Chemical formula 3]

[0065]

[0066] (In formula (b-1) and formula (b-2), R 13 , R 14 and R 16 are independently of each other a hydrogen atom, a methyl group, a hydroxymethyl group, a cyano group, or a trifluoromethyl group; R 15is a (r3 + 1)-valent hydrocarbon group having 1 to 20 carbon atoms which may be substituted or unsubstituted, or a (r3 + 1)-valent group containing -O-, -CO-, -COO-, -NH-, -CONH- or -S- between carbon-carbon bonds in a hydrocarbon group having 2 to 20 carbon atoms which may be substituted or unsubstituted; A 11 is a divalent aromatic ring group having 6 to 20 carbon atoms which may be substituted or unsubstituted; R 17 is a single bond, a (r4 + 1)-valent hydrocarbon group having 1 to 20 carbon atoms which may be substituted or unsubstituted, or a (r4 + 1)-valent group containing -O-, -CO-, -COO-, -NH-, -CONH- or -S- between carbon-carbon bonds in a hydrocarbon group having 2 to 20 carbon atoms which may be substituted or unsubstituted; X 11 and X 12 are each independently a crosslinkable functional group; r3 and r4 are each independently 1 or 2)

[0067] In the formulas (b-1) and (b-2), from the viewpoint of copolymerizability, R 13 , R 14 and R 16 are preferably a hydrogen atom or a methyl group.

[0068] As specific examples and preferred examples of R 15 , groups the same as those exemplified in the description of R 5 in the formula (a-1) can be cited.

[0069] As specific examples of R 17 , groups the same as those exemplified in the description of R 5 in the formula (a-1) can be cited. R 17 is preferably a single bond, a (r4 + 1)-valent linear hydrocarbon group having 1 to 20 carbon atoms which may be substituted or unsubstituted, or a (r4 + 1)-valent group containing -O-, -CO-, -COO-, -NH-, -CONH- or -S- between carbon-carbon bonds in a linear hydrocarbon group having 2 to 20 carbon atoms which may be substituted or unsubstituted.

[0070] As specific examples and preferred examples of A 11 , groups the same as those exemplified in the description of A 1 in the formula (a-2) can be cited.

[0071] As specific examples and preferred examples of X 11 and X 12 , groups the same as those exemplified as specific examples and preferred examples of the crosslinkable functional group above can be cited.

[0072] As further specific examples of the structural unit (A2-1), structural units represented by the following formulas can be cited.

[0073] [Chemical formula 4]

[0074]

[0075] (In the formula, R 61 , R 62 and R 63 are independently a hydrogen atom, a methyl group, a hydroxymethyl group, a cyano group, or a trifluoromethyl group)

[0076] [A] The polymer may also contain a structural unit (hereinafter, also referred to as "structural unit (A2-2)") different from the structural unit (A2-1) as the structural unit (A2). As the monomer that provides the structural unit (A2-2), if it is a compound having a polymerizable group and a crosslinkable functional group capable of copolymerizing with the monomers that provide the structural unit (A1) and the structural unit (A2-1), there is no particular limitation. For example, (meth)acrylic compounds, vinyl compounds, etc. can be cited. Specific examples of the monomer that provides the structural unit (A2-2) include: glycidyl (meth)acrylate, 3,4-epoxycyclohexyl (meth)acrylate, 3,4-epoxycyclohexylmethyl (meth)acrylate, 2-(3,4-epoxycyclohexyl)ethyl (meth)acrylate, 3,4-epoxytricyclo[5.2.1.0 2,6 decyl (meth)acrylate, (3-methyloxetane-3-yl)methyl (meth)acrylate, (3-ethyloxetane-3-yl) (meth)acrylate, (oxetane-3-yl)methyl (meth)acrylate, (3-ethyloxetane-3-yl)methyl (meth)acrylate, etc.

[0077] From the viewpoint of imparting good heat resistance and bending resistance to the cured product, the content ratio of the structural unit (A2) in the [A] polymer is preferably 5 mol% or more, more preferably 10 mol% or more, and still more preferably 15 mol% or more, relative to all the structural units constituting the [A] polymer. In addition, from the viewpoint of obtaining a good pattern shape, the content ratio of the structural unit (A2) is preferably 70 mol% or less, more preferably 65 mol% or less, and still more preferably 60 mol% or less, relative to all the structural units constituting the [A] polymer.

[0078] From the viewpoint of obtaining a cured product having good heat resistance and flexural resistance, and further obtaining a curable composition capable of obtaining a cured product having a low dielectric constant, a high transmittance, and water impermeability while maintaining high sensitivity, the content ratio of the structural unit (A2-1) in the [A] polymer is preferably 2 mol% or more, more preferably 7 mol% or more, and still more preferably 15 mol% or more, relative to all the structural units constituting the [A] polymer. In addition, the content ratio of the structural unit (A2-1) is preferably 70 mol% or less, more preferably 65 mol% or less, and still more preferably 60 mol% or less, relative to all the structural units constituting the [A] polymer.

[0079] When the [A] polymer contains the structural unit (A2-2), from the viewpoint of obtaining a cured product having good heat resistance, a low dielectric constant, a high transmittance, water impermeability, and flexural resistance while maintaining the high sensitivity of the present composition, the content ratio of the structural unit (A2-2) is preferably 30 mol% or less, more preferably 15 mol% or less, still more preferably 5 mol% or less, and even more preferably 1 mol% or less, relative to all the structural units constituting the [A] polymer.

[0080] (Structural unit having an acid dissociable group)

[0081] The acid dissociable group is a group that substitutes a hydrogen atom of an acidic group such as a carboxyl group, a phenolic hydroxyl group, an alcoholic hydroxyl group, a silanol group, or a sulfo group, and is a group that dissociates by the action of an acid. Since the [A] polymer has an acid dissociable group and a photoacid generator is used as the [B] photosensitive compound, the present composition can be made into a chemically amplified curable composition. That is, when a part of the curable composition is irradiated with radiation, in the exposed portion, due to the acid generated by the irradiation with radiation, the acid dissociable group dissociates to generate an acidic group. On the other hand, in the unexposed portion, the hydrogen atom of the acidic group is substituted by the acid dissociable group. Thereby, the solubility in the developer can be made different between the exposed portion and the unexposed portion. Subsequently, the exposed curable composition is developed, whereby a patterned cured product can be obtained.

[0082] As preferred specific examples of the structural unit having an acid dissociable group (hereinafter, also referred to as "structural unit (A3)"), there can be mentioned: a structural unit in which the acid dissociable group dissociates by the action of an acid to generate a carboxyl group (hereinafter, also referred to as "structural unit (A3-1)"), a structural unit in which the acid dissociable group dissociates by the action of an acid to generate a phenolic hydroxyl group (hereinafter, also referred to as "structural unit (A3-2)"), or a structural unit in which the acid dissociable group dissociates by the action of an acid to generate a hydroxyl group bonded to a silicon atom (hereinafter, also referred to as "structural unit (A3-3)").

[0083] ·Regarding the structural unit (A3-1)

[0084] As the structural unit (A3-1), protected structural units derived from unsaturated carboxylic acids can be cited. The unsaturated carboxylic acid used is not particularly limited, and examples thereof include: unsaturated monocarboxylic acids, unsaturated dicarboxylic acids, unsaturated acid anhydrides, unsaturated polycarboxylic acids, etc.

[0085] As the acid dissociable group contained in the structural unit (A3-1), for example, a tertiary carbon-containing hydrocarbon group, an acetal-based functional group, a tertiary alkyl carbonate group, and an alkyl-containing silyl group can be cited. Among these, from the viewpoint of being easily dissociated by an acid, a tertiary carbon-containing hydrocarbon group or an acetal-based functional group is preferred.

[0086] When the acid dissociable group is a tertiary carbon-containing hydrocarbon group, the structural unit (A3-1) preferably has a group represented by the following formula (X-1) as the protected carboxyl group.

[0087] [Chemical formula 5]

[0088]

[0089] (In formula (X-1), R 34 , R 35 and R 36 are as follows in (1) or (2); (1) R 34 , R 35 and R 36 are each independently an alkyl group having 1 to 12 carbon atoms or a monovalent alicyclic hydrocarbon group having 3 to 20 carbon atoms; (2) R 34 and R 35 represent an alicyclic hydrocarbon structure having 4 to 20 carbon atoms formed by combining with each other and together with the carbon atom to which R 34 and R 35 is bonded; R 36 is an alkyl group having 1 to 12 carbon atoms, an alkenyl group having 2 to 12 carbon atoms, or an aryl group having 6 to 20 carbon atoms; "*" represents a bonding bond)

[0090] When the acid dissociable group is an acetal-based functional group, the structural unit (A3-1) preferably has an acetal ester structure of a carboxylic acid as the protected carboxyl group, and specifically, preferably has a group represented by the following formula (X-2).

[0091] [Chemical formula 6]

[0092]

[0093] (In formula (X-2), R 31 , R 32 and R 33 are as follows in (1) or (2); (1) R 31is a hydrogen atom, an alkyl group having 1 to 12 carbon atoms, or a monovalent alicyclic hydrocarbon group having 3 to 20 carbon atoms; R 32 and R 33 are each independently an alkyl group having 1 to 12 carbon atoms, a monovalent alicyclic hydrocarbon group having 3 to 20 carbon atoms, or an aralkyl group having 7 to 20 carbon atoms; (2) R 31 is a hydrogen atom, an alkyl group having 1 to 12 carbon atoms, or a monovalent alicyclic hydrocarbon group having 3 to 20 carbon atoms; R 32 and R 33 represent a cyclic ether structure formed by combining with each other and together with the carbon atom to which R 32 and OR 33 are bonded; "*" represents a bonding bond)

[0094] R 31 、R 32 、R 33 、R 34 、R 35 and R 36 The alkyl group having 1 to 12 carbon atoms represented by may be linear or branched. The number of carbon atoms of the alkyl group is preferably 1 to 6, more preferably 1 to 4. Specifically, examples include: methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, etc.

[0095] As R 31 、R 32 、R 33 、R 34 、R 35 and R 36 The monovalent alicyclic hydrocarbon group having 3 to 20 carbon atoms represented by, for example, include: cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, norbornyl, isobornyl, adamantyl, etc. As R 32 and R 33 The aralkyl group having 7 to 20 carbon atoms represented by, examples include: phenylmethyl, phenylethyl, methylphenylmethyl, etc.

[0096] R 36 The alkenyl group having 2 to 12 carbon atoms represented by may be linear or branched. The number of carbon atoms of the alkenyl group is preferably 2 to 6, more preferably 2 to 4. Specifically, examples include: vinyl, 1-propenyl, 2-propenyl, 1-butenyl, etc.

[0097] As R 36 The aryl group having 6 to 20 carbon atoms represented by, examples include: phenyl, methylphenyl, ethylphenyl, dimethylphenyl, etc.

[0098] R 34 and R 35 The alicyclic hydrocarbon structure having 4 to 20 carbon atoms formed by combining with each other, for example, include: cyclobutane structure, cyclopentane structure, cyclohexane structure, cycloheptane structure, etc.

[0099] R 32 and R 33 The cyclic ether structure formed by combining them preferably has 5 or more ring members. Specifically, for example, a tetrahydrofuran ring structure, a tetrahydropyran ring structure, etc. can be mentioned.

[0100] As specific examples of the group represented by the formula (X-1), the following can be mentioned: tert-butoxycarbonyl, 1,1-dimethylpropyloxycarbonyl, 1-methyl-1-cyclopentyloxycarbonyl, 1-ethyl-1-cyclopentyloxycarbonyl, 1-methyl-1-cyclohexyloxycarbonyl, 1-ethyl-1-cyclohexyloxycarbonyl, etc.

[0101] Regarding "-C(R 31 )(R 32 )(OR 33 )" in the formula (X-2) being easily dissociated by the action of an acid, R 31 is preferably a hydrogen atom, a methyl group or an ethyl group, and more preferably a hydrogen atom.

[0102] As specific examples of the group represented by the formula (X-2), the following can be mentioned: 1-methoxyethoxycarbonyl, 1-ethoxyethoxycarbonyl, 1-propoxyethoxycarbonyl, 1-butoxyethoxycarbonyl, 1-cyclohexyloxyethoxycarbonyl, 2-tetrahydrofuranyloxycarbonyl, 2-tetrahydropyranyloxycarbonyl, 1-phenylmethoxyethoxycarbonyl, etc.

[0103] · Regarding the structural unit (A3-2)

[0104] The acid dissociable group possessed by the structural unit (A3-2) is not particularly limited as long as it detaches by the action of an acid to generate a phenolic hydroxyl group. From the viewpoints of the sensitivity, pattern shape, storage stability, etc. of this composition, the acid dissociable group possessed by the structural unit (A3-2) is preferably an acetal-based functional group, a tertiary alkyl group or an alkyl-containing silyl group.

[0105] As the acetal-based functional group that can be used in the structural unit (A3-2), the same groups as the acid dissociable groups that can be used in the structural unit (A3-1) can be mentioned. Among them, preferably a phenolic hydroxyl group protected by a group represented by "-O-C(R 31 )(R 32 )(OR 33 )" (wherein R 31 , R 32 and R 33 have the same meanings as in the formula (X-2)). In the above case, the protected phenolic hydroxyl group contained in the structural unit (A3-2) can be represented by the following formula (Z-1).

[0106] [Chemical formula 7]

[0107]

[0108] (In formula (Z-1), Ar 1 is a substituted or unsubstituted arylene group; R 31 , R 32 and R 33 have the same meanings as in formula (X-2); "*" represents a bonding bond)

[0109] As a preferred specific example of the group represented by "-C(R 31 )(R 32 )(OR 33 )" contained in the structural unit (A3-2), 1-alkoxyalkyl and 1-arylalkoxyalkyl can be cited. Specifically, for example, 1-ethoxyethyl, 1-methoxyethyl, 1-butoxyethyl, 1-isobutoxyethyl, 1-(2-ethylhexyloxy)ethyl, 1-propoxyethyl, 1-cyclohexyloxyethyl, 1-(2-cyclohexylethoxy)ethyl, 1-benzyloxyethyl, etc. can be cited.

[0110] As a specific example of a tertiary alkyl group, tert-butyl, 1,1-dimethylpropyl, etc. can be cited.

[0111] As a specific example of a silyl group containing an alkyl group, trimethylsilyl, triethylsilyl, triisopropylsilyl, tert-butyldimethylsilyl, tert-butyldiphenylsilyl, etc. can be cited.

[0112] ·Regarding the structural unit (A3-3)

[0113] The structural unit (A3-3) has a functional group that detaches by the action of an acid to generate a silanol group (Si-OH). Specifically, the structural unit (A3-3) preferably has a group "-Si(Y 1 )(Y 2 )(Y 3 )" (wherein Y 1 , Y 2 and Y 3 are each independently a hydrogen atom, a halogen atom, a hydroxyl group, an alkoxy group having 1 to 6 carbon atoms, an alkyl group having 1 to 10 carbon atoms or a phenyl group, and one or more of Y 1 , Y 2 and Y 3 are alkoxy groups having 1 to 6 carbon atoms).

[0114] Here, the alkoxy group represented by Y 1 to Y 3 preferably has 1 to 3 carbon atoms, more preferably a methoxy group or an ethoxy group. The alkyl group represented by Y 1 to Y 3 preferably is a methyl group, an ethyl group or a propyl group. Y 1~Y 3 One of the groups represented is an alkoxy group having 1 to 6 carbon atoms. The remaining groups are preferably a hydroxyl group, an alkoxy group having 1 to 6 carbon atoms, an alkyl group having 1 to 10 carbon atoms, or a phenyl group, more preferably a hydroxyl group, an alkoxy group having 1 to 3 carbon atoms, or an alkyl group having 1 to 3 carbon atoms, and still more preferably an alkoxy group having 1 to 3 carbon atoms or an alkyl group having 1 to 3 carbon atoms.

[0115] The group “-Si(Y 1 )(Y 2 )(Y 3 )” is preferably bonded to a benzene ring, a naphthalene ring, or an alkyl chain. Specifically, the structural unit (A3-3) preferably has at least one selected from the group consisting of the groups represented by the following formula (3-1), the group represented by the following formula (3-2), and the group represented by the following formula (3-3).

[0116] [Chemical formula 8]

[0117]

[0118] (In formula (3-1), formula (3-2), and formula (3-3), X 21 and X 22 are each independently a halogen atom, a hydroxyl group, an alkyl group having 1 to 6 carbon atoms, or an alkoxy group having 1 to 6 carbon atoms; n1 is an integer from 0 to 4; n2 is an integer from 0 to 6; wherein, when n1 is 2 or more, the plurality of X 21 are the same or different from each other; when n2 is 2 or more, the plurality of X 22 are the same or different from each other; R 50 is an alkanediyl group; Y 1 , Y 2 , and Y 3 have the same meaning as described above; “*” represents a bonding bond)

[0119] In terms of further improving the heat resistance and flexural resistance of the cured product obtained from this composition, in the above formula (3-1) to formula (3-3), the structural unit (A3-3) preferably has at least one selected from the group consisting of the group represented by the above formula (3-1) and the group represented by the above formula (3-2).

[0120] From the viewpoint of sufficiently increasing the introduction amounts of the structural unit (I) and the structural unit (II) to thereby obtain a cured product having excellent heat resistance, low water permeability, and a sufficiently low dielectric constant, the structural unit (A3) is preferably a structural unit derived from at least one selected from the group consisting of an aromatic vinyl compound and a maleimide compound. Specific examples of the structural unit (A3) include structural units represented by the following formulae, etc.

[0121] [Chemical formula 9]

[0122]

[0123] (In the formula, R 51 , R 52 and R 53 are each independently a hydrogen atom, a methyl group, a hydroxymethyl group, a cyano group or a trifluoromethyl group)

[0124] When a photoacid generator is used as the [B] photosensitive compound, the [A] polymer preferably contains a structural unit (A3). In such a case, the content ratio of the structural unit (A3) in the [A] polymer is preferably 5 mol% or more, more preferably 10 mol% or more, and still more preferably 15 mol% or more, relative to all the structural units constituting the [A] polymer. In addition, the content ratio of the structural unit (A3) is preferably 60 mol% or less, more preferably 55 mol% or less, and still more preferably 50 mol% or less, relative to all the structural units constituting the [A] polymer. By setting the content ratio of the structural unit (A3) within the above range, when a photoacid generator is used as the [B] photosensitive compound, high sensitivity of the present composition can be achieved and the coating film shows better resolution, which is preferable in this regard.

[0125] As monomers providing other structural units, in addition to the above, for example, there can be mentioned: (meth)acrylic acid alkyl esters, (meth)acrylates having an alicyclic structure, (meth)acrylates having an aromatic ring structure, vinyl compounds having a heterocyclic structure, vinyl ether compounds, conjugated diene compounds, nitrogen-containing vinyl compounds, unsaturated dicarboxylic acid dialkyl ester compounds, cycloolefins, etc., or compounds different from the structural units (A1) to (A3) as aromatic vinyl compounds or N-substituted maleimide compounds.

[0126] Regarding specific examples of the monomers, as (meth)acrylic acid alkyl esters, there can be mentioned methyl (meth)acrylate, ethyl (meth)acrylate, n-propyl (meth)acrylate, isopropyl (meth)acrylate, butyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, lauryl (meth)acrylate, stearyl (meth)acrylate, etc.;

[0127] As (meth)acrylates having an alicyclic structure, there can be mentioned cyclohexyl (meth)acrylate, 2-methylcyclohexyl (meth)acrylate, tricyclo[5.2.1.0 2,6 decane-8-yl (meth)acrylate, tricyclo[5.2.1.0 2,5 decane-8-yloxyethyl (meth)acrylate, isobornyl (meth)acrylate, α-methylene-γ-butyrolactone, etc.;

[0128] Examples of the (meth)acrylate having an aromatic ring structure include phenyl (meth)acrylate, benzyl (meth)acrylate, etc.;

[0129] Examples of the vinyl compound having a heterocyclic structure include tetrahydrofurfuryl (meth)acrylate, tetrahydropyranyl (meth)acrylate, 5-ethyl-1,3-dioxan-5-ylmethyl (meth)acrylate, 5-methyl-1,3-dioxan-5-ylmethyl (meth)acrylate, (2-methyl-2-ethyl-1,3-dioxolan-4-yl)methyl (meth)acrylate, 2-(meth)acryloyloxymethyl-1,4,6-trioxaspiro[4,6]undecane, (γ-butyrolactone-2-yl) (meth)acrylate, glycerol carbonate (meth)acrylate, (γ-lactam-2-yl) (meth)acrylate, N-(meth)acryloyloxyethyl hexahydrophthalimide, 2-vinyl-2-oxazoline, isopropenyl oxazoline, N-vinyl-2-pyrrolidone, itaconimide, etc.;

[0130] Examples of the vinyl ether compound include ethyl vinyl ether, butyl vinyl ether, vinyl glycidyl ether, 2-(glycidyloxy)ethyl vinyl ether, 4-(glycidyloxy)butyl vinyl ether, etc.;

[0131] Examples of the conjugated diene compound include 1,3-butadiene, isoprene, etc.;

[0132] Examples of the nitrogen-containing vinyl compound include (meth)acrylonitrile, (meth)acrylamide, etc.;

[0133] Examples of the unsaturated dicarboxylic acid dialkyl ester compound include diethyl itaconate, etc.;

[0134] Examples of the cycloolefin include cyclopentene, cyclohexene, cyclobutene, norbornene, etc. In addition, as the monomer providing other structural units, in addition to the above, monomers such as vinyl chloride, vinylidene chloride, vinyl acetate, etc. can also be cited.

[0135] In addition, regarding compounds different from structural units (A1) to (A3) that are aromatic vinyl compounds or N-substituted maleimide compounds, examples of aromatic vinyl compounds include styrene, 2-methylstyrene, 3-methylstyrene, 4-methylstyrene, α-methylstyrene, 2,4-dimethylstyrene, 2,4-diisopropylstyrene, 5-tert-butyl-2-methylstyrene, divinylbenzene, trivinylbenzene, tert-butoxystyrene, vinylbenzyldimethylamine, (4-vinylbenzyl)dimethylaminoethyl ether, N,N-dimethylaminoethylstyrene, N,N-dimethylaminomethylstyrene, 2-ethylstyrene, 3-ethylstyrene, 4-ethylstyrene, 2-tert-butylstyrene, 3-tert-butylstyrene, 4-tert-butylstyrene, diphenylethylene, vinylnaphthalene, vinylpyridine, etc.;

[0136] Examples of N-substituted maleimide compounds include N-cyclohexylmaleimide, N-cyclopentylmaleimide, N-(2-methylcyclohexyl)maleimide, N-(4-methylcyclohexyl)maleimide, N-(4-ethylcyclohexyl)maleimide, N-(2,6-dimethylcyclohexyl)maleimide, N-norbornenylmaleimide, N-tricyclodecylmaleimide, N-adamantylmaleimide, N-phenylmaleimide, N-(2-methylphenyl)maleimide, N-(4-methylphenyl)maleimide, N-(4-ethylphenyl)maleimide, N-(2,6-dimethylphenyl)maleimide, N-benzylmaleimide, N-naphthylmaleimide, N-methylmaleimide, N-ethylmaleimide, N-n-propylmaleimide, N-isopropylmaleimide, N-n-butylmaleimide, N-isobutylmaleimide, N-sec-butylmaleimide, N-tert-butylmaleimide, N-n-pentylmaleimide, N-n-hexylmaleimide, N-n-heptylmaleimide, N-n-octylmaleimide, N-laurylmaleimide, N-stearylmaleimide, N-2-ethylhexylmaleimide, etc.

[0137] From the viewpoint of further improving the effects of improving water impermeability, heat resistance, and flexural resistance in the cured product, among them, the N-substituted maleimide compound is preferably a compound having a cyclic structure in the substituted part, and more preferably a compound having a benzene ring or a cyclohexane ring.

[0138] When the [A] polymer contains structural units other than structural units (A2) and (A3) as other structural units, the content ratio of the structural units is preferably 70 mol% or less, more preferably 60 mol% or less, based on all the structural units of the [A] polymer.

[0139] (Synthesis of [A] polymer)

[0140] [A] polymer can be produced, for example, by using monomers capable of introducing the respective structural units in an appropriate solvent in the presence of a polymerization initiator or the like according to a known method such as radical polymerization. Examples of the polymerization initiator include azo compounds or organic peroxides. Examples of the azo compound include 2,2'-azobis(isobutyronitrile), 2,2'-azobis(2,4-dimethylvaleronitrile), dimethyl 2,2'-azobis(isobutyrate), etc. Examples of the organic peroxide include benzoyl peroxide, di-tert-butyl peroxide, etc. The use ratio of the polymerization initiator is preferably 0.01 to 30 parts by mass with respect to 100 parts by mass of the total amount of the monomers used in the reaction. Examples of the polymerization solvent include alcohols, ethers, ketones, esters, hydrocarbons, etc. The amount of the polymerization solvent used is preferably such that the total amount of the monomers used in the reaction becomes 0.1% by mass to 60% by mass with respect to the total amount of the reaction solution.

[0141] In the polymerization, the reaction temperature is usually 30°C to 180°C. The reaction time can be set according to the type of the polymerization initiator and the monomer or the reaction temperature. The reaction time is usually 0.5 hour to 10 hours. The polymer obtained by the polymerization reaction can be directly used for the preparation of this composition in a state dissolved in the reaction solution, or can be used for the preparation of this composition after separation from the reaction solution. Separation of the polymer can be carried out, for example, by the following known separation methods: a method of injecting the reaction solution into a large amount of a poor solvent and drying the precipitate thus obtained under reduced pressure; a method of subjecting the reaction solution to vacuum distillation using an evaporator to remove it, etc.

[0142] Regarding the [A] polymer, the weight average molecular weight (Mw) in terms of polystyrene obtained by gel permeation chromatography (GPC) is preferably 3,000 or more. If Mw is 3,000 or more, a cured product having sufficiently high heat resistance, flexural resistance, and chemical resistance and showing good developability can be obtained, and in this regard, it is preferable. The Mw of the [A] polymer is more preferably 5,000 or more, and further preferably 6,000 or more. In addition, from the viewpoint of good film-forming properties, the Mw of the [A] polymer is preferably 150,000 or less, more preferably 100,000 or less, and further preferably 80,000 or less.

[0143] Regarding the [A] polymer, the molecular weight distribution (Mw / Mn) represented by the ratio of the weight average molecular weight (Mw) to the number average molecular weight (Mn) is preferably 5.0 or less, more preferably 4.0 or less, and further preferably 3.0 or less.

[0144] <[B] Photosensitive Compound>

[0145] As the photosensitive compound, any component that changes the solubility of the present composition upon irradiation with radiation can be used. Examples thereof include quinonediazide compounds, photoacid generators, photopolymerization initiators, and the like. Among these, quinonediazide compounds or photoacid generators can be preferably used. Here, in the present specification, the "quinonediazide compound" is a substance that changes to indenecarboxylic acid upon irradiation with radiation, and the "photoacid generator" is a substance that generates an acid upon irradiation with radiation and causes the acid dissociable group possessed by the components in the composition to be detached.

[0146] (Quinonediazide compound)

[0147] As the quinonediazide compound, condensates of phenolic compounds or alcoholic compounds (hereinafter also referred to as "parent nuclei") and o-naphthoquinonediazide compounds can be cited. Among these, the quinonediazide compound used is preferably a condensate of a compound having a phenolic hydroxyl group as the parent nucleus and an o-naphthoquinonediazide compound. Specific examples of the parent nucleus include, for example, the compounds described in paragraphs 0065 to 0070 of Japanese Patent Laid-Open No. 2014-186300. The o-naphthoquinonediazide compound is preferably 1,2-naphthoquinonediazide sulfonyl halide.

[0148] As the quinonediazide compound, condensates of phenolic compounds or alcoholic compounds as the parent nucleus and 1,2-naphthoquinonediazide sulfonyl halide can be preferably used, and condensates of phenolic compounds and 1,2-naphthoquinonediazide sulfonyl halide can be more preferably used.

[0149] Specific examples of the quinonediazide compound include ester compounds of phenolic hydroxyl group-containing compounds selected from 4,4'-dihydroxydiphenylmethane, 2,3,4,2',4'-pentahydroxybenzophenone, 2,3,4,4'-tetrahydroxybenzophenone, tris(p-hydroxyphenyl)methane, 1,1,1-tris(p-hydroxyphenyl)methane, 1,1,1-tris(p-hydroxyphenyl)ethane, 1,1-bis(4-hydroxyphenyl)-1-phenylethane, 1,3-bis[1-(4-hydroxyphenyl)-1-methylethyl]benzene, 1,4-bis[1-(4-hydroxyphenyl)-1-methylethyl]benzene, 4,6-bis[1-(4-hydroxyphenyl)-1-methylethyl]-1,3-dihydroxybenzene, and 4,4'-[1-[4-[1-[4-hydroxyphenyl]-1-methylethyl]phenyl]ethylidene]bisphenol, and 1,2-naphthoquinonediazide-4-sulfonyl chloride or 1,2-naphthoquinonediazide-5-sulfonyl chloride.

[0150] In the condensation reaction for obtaining the condensate, regarding the ratio of the mother nucleus to 1,2-naphthoquinone diazide sulfonyl halide, it is preferable to set the amount of 1,2-naphthoquinone diazide sulfonyl halide used to an amount equivalent to 30 mol% to 85 mol% relative to the number of OH groups in the mother nucleus, and more preferably to an amount equivalent to 50 mol% to 70 mol%. In addition, the condensation reaction can be carried out according to a known method.

[0151] When using a quinone diazide compound as a photosensitive compound, relative to 100 parts by mass of the [A] polymer contained in the present composition, the content ratio of the quinone diazide compound in the present composition is preferably set to 2 parts by mass or more, more preferably set to 5 parts by mass or more, and still more preferably set to 10 parts by mass or more. In addition, relative to 100 parts by mass of the [A] polymer contained in the present composition, the content ratio of the quinone diazide compound is preferably set to 60 parts by mass or less, more preferably set to 50 parts by mass or less, and still more preferably set to 40 parts by mass or less.

[0152] If the content ratio of the quinone diazide compound is set to 2 parts by mass or more, acid is sufficiently generated by irradiation with actinic rays, and the difference in solubility between the exposed portion and the unexposed portion with respect to the developer can be sufficiently increased. Thereby, good patterning can be carried out. In addition, the amount of acid participating in the reaction with the polymer component can be increased, and the heat resistance or bending resistance of the cured product obtained using the present composition can be sufficiently ensured. On the other hand, if the content ratio of the quinone diazide compound is set to 60 parts by mass or less, the amount of unreacted quinone diazide compound can be sufficiently reduced, and the reduction in developability and transparency due to the remaining quinone diazide compound can be suppressed, which is preferable in this regard.

[0153] (Photoacid generator)

[0154] As the photoacid generator, a compound that generates acid in response to actinic rays having a wavelength of 300 nm or more (preferably 300 nm to 450 nm) can be preferably used. When using a photoacid generator that does not directly respond to actinic rays having a wavelength of 300 nm or more, acid can also be generated in response to actinic rays having a wavelength of 300 nm or more by using a sensitizer in combination.

[0155] As the photoacid generator, a compound that generates an acid having an acid dissociation constant (pKa) of 4 or less can be preferably used. The acid dissociation constant of the acid generated by the photoacid generator is more preferably 3 or less, and still more preferably 2 or less.

[0156] Specific examples of the photoacid generator include, for example, oxime sulfonate compounds, onium salts (sulfonium salts, iodonium salts, quaternary ammonium salts, etc.), sulfimide compounds, halogen-containing compounds, diazomethane compounds, sulfone compounds, sulfonate compounds, carboxylate compounds, and the like.

[0157] Specific examples of each of the oxime sulfonate compound, onium salt, sulfimide compound, halogen-containing compound, diazomethane compound, sulfone compound, sulfonate compound, and carboxylate compound include: the compounds described in paragraphs 0034 to 0038 of Japanese Patent Laid-Open No. 2012-252343, the compounds described in paragraphs 0078 to 0106 of Japanese Patent Laid-Open No. 2014-157252, the compounds described in International Publication No. 2016 / 124493, etc. As the photoacid generator, at least one selected from the group consisting of an oxime sulfonate compound, onium salt, sulfimide compound, halogen-containing compound, sulfone compound, and sulfonate compound is preferably used among these.

[0158] Regarding specific examples of these compounds, as the oxime sulfonate compound, examples include: (5-propylsulfonyloxyimino-5H-thiophen-2-ylidene)-(2-methylphenyl)acetonitrile, (5-octylsulfonyloxyimino-5H-thiophen-2-ylidene)-(2-methylphenyl)acetonitrile, (camphorsulfonyloxyimino-5H-thiophen-2-ylidene)-(2-methylphenyl)acetonitrile, (5-p-toluenesulfonyloxyimino-5H-thiophen-2-ylidene)-(2-methylphenyl)acetonitrile, {2-[2-(4-methylphenylsulfonyloxyimino)]-2,3-dihydrothiophen-3-ylidene}-2-(2-methylphenyl)acetonitrile, 2-(octylsulfonyloxyimino)-2-(4-methoxyphenyl)acetonitrile, the compounds described in International Publication No. 2016 / 124493, etc. As commercially available products of the oxime sulfonate compound, examples include Irgacure PAG121 manufactured by BASF Corporation.

[0159] Specific examples of the sulfimide 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)diphenylmaleimide, (4-methylphenylsulfonyloxy)diphenylmaleimide, 1,8-naphthalenedicarboximide trifluoromethanesulfonate (naphthalenedicarboximide triflate).

[0160] Specific examples of the onium salts include diphenyliodonium trifluoromethanesulfonate, diphenyliodonium nonafluoro-n-butanesulfonate, diphenyliodonium dodecylbenzenesulfonate, diphenyliodonium 10-camphorsulfonate, diphenyliodonium naphthalenesulfonate, triphenylsulfonium trifluoromethanesulfonate, triphenylsulfonium nonafluoro-n-butanesulfonate, triphenylsulfonium dodecylbenzenesulfonate, triphenylsulfonium naphthalenesulfonate, triphenylsulfonium 10-camphorsulfonate, triphenylsulfonium hexafluoroantimonate, 2-oxocyclohexyl dicyclohexylsulfonium trifluoromethanesulfonate, 1-naphthyldiethylsulfonium trifluoromethanesulfonate, 1-(4-benzyloxy)tetrahydrothiophenium trifluoromethanesulfonate, 1-(naphthylacetylmethyl)tetrahydrothiophenium trifluoromethanesulfonate, 4,7-di-n-butoxy-1-naphthyltetrahydrothiophenium trifluoromethanesulfonate, etc.

[0161] Specific examples of the halogen-containing compounds include phenylbis(trichloromethyl)-s-triazine, 4-methoxyphenylbis(trichloromethyl)-s-triazine, 1-naphthylbis(trichloromethyl)-s-triazine, etc. Specific examples of the sulfone compounds include 4-trityl methyl sulfone, mesityl benzoyl methyl sulfone, bis(phenylsulfonyl)methane, etc. Specific examples of the sulfonate compounds include benzoin tosylate, tris(trifluoromethanesulfonate) of pyrogallol, nitrobenzyl-9,10-diethoxyanthracene-2-sulfonate, trifluoromethylsulfonylbicyclo[2,2,1]hept-5-ene-2,3-dicarboximide, N-hydroxysuccinimide trifluoromethanesulfonate, 1,8-naphthalenedicarboximide trifluoromethanesulfonate, etc.

[0162] When a photoacid generator is used as the photosensitive compound, the content ratio of the photoacid generator in the present composition is preferably 0.5 parts by mass or more, more preferably 1 part by mass or more, relative to 100 parts by mass of the [A] polymer contained in the present composition. Further, the content ratio of the photoacid generator is preferably 35 parts by mass or less, more preferably 30 parts by mass or less, relative to 100 parts by mass of the [A] polymer contained in the present composition. If the content ratio of the photoacid generator is 0.5 parts by mass or more, acid is sufficiently generated in the exposed portion by irradiation with radiation, and the difference in solubility between the exposed portion and the unexposed portion with respect to the alkaline solution can be sufficiently increased. Thereby, good patterning can be performed. In addition, the amount of acid participating in the reaction with the [A] polymer can be increased, and the heat resistance or bend resistance of the obtained cured product can be sufficiently ensured. On the other hand, by setting the content ratio of the photoacid generator to 35 parts by mass or less, the amount of unreacted photoacid generator can be sufficiently reduced after exposure, and the reduction in developability due to the remaining photoacid generator can be suppressed.

[0163] <Other Components>

[0164] The composition may also contain components different from the [A] polymer and the [B] photosensitive compound (hereinafter also referred to as "other components"). Examples of the other components include a [C] compound having two or more crosslinkable functional groups (excluding the [A] polymer; hereinafter also simply referred to as "[C] compound"), a [D] adhesion promoter, an [E] surfactant, an [F] organic solvent, and the like.

[0165] ([C] compound)

[0166] [C] compound is a component that forms a crosslinked structure between or within the molecules of the [A] polymer by light or heat or forms a bond between [C] compounds themselves. With respect to this composition, by including the structural unit (A1) and the structural unit (A2) together in the [A] polymer or by preparing a curable composition containing the [A] polymer and the [C] compound, the heat resistance or flex resistance of the cured product obtained by using this composition can be further improved, and in this regard, it is preferable.

[0167] Examples of the crosslinkable functional groups possessed by the [C] compound include a cyclic ether group, a cyclic thioether group, a carboxyl group, a cyclic carbonate group, an alcoholic hydroxyl group, an amino group, a protected amino group, a protected isocyanate group, a polymerizable unsaturated bond group, a hydroxyalkylamide group, an oxazoline group, an alkoxymethylphenyl group, and the like. From the viewpoint of reacting with the [A] polymer to form a crosslinked structure between or within the molecules of the [A] polymer and making the cured product excellent in heat resistance and flex resistance, the crosslinkable functional group is preferably at least one selected from the group consisting of an oxiranyl group, an oxetanyl group, a thiiranyl group, a hydroxyalkylamide group, a hydroxymethylphenyl group, an alkoxymethylphenyl group, a cyclic carbonate group, and a protected isocyanate group, and more preferably at least one selected from the group consisting of an oxiranyl group, an oxetanyl group, a hydroxyalkylamide group, a hydroxymethylphenyl group, and an alkoxymethylphenyl group.

[0168] From the viewpoint of sufficiently obtaining the effect of improving the heat resistance or flex resistance of the cured product and suppressing film shrinkage, the number of crosslinkable functional groups possessed by the [C] compound in one molecule is preferably 2 to 10, and more preferably 3 to 8.

[0169] Specific examples of the [C] compound include, as compounds having an epoxy group, for example: ethylene glycol diglycidyl ether, polyethylene glycol diglycidyl ether, propylene glycol diglycidyl ether, tripropylene glycol diglycidyl ether, triglycidyl isocyanurate, glycerol polyglycidyl ether, pentaerythritol tetraglycidyl ether, 1,4-cyclohexanedimethanol diglycidyl ether, N,N',N',N''-tetraglycidylglycoluril, 1,6-hexanediol diglycidyl ether, trimethylolpropane triglycidyl ether, 2,2-dibromoneopentyl glycol diglycidyl ether, N,N,N',N'-tetraglycidyl-m-xylylenediamine, 1,3-bis(N,N-diglycidylaminomethyl)cyclohexane, N,N,N',N'-tetraglycidyl-4,4'-diaminodiphenylmethane, N,N-diglycidyl-benzylamine, N,N-diglycidyl-aminomethylcyclohexane, N,N-diglycidyl-cyclohexylamine, the epoxidation reaction product of 2,2'-diallylbisphenol A diallyl ether based on hydrogen peroxide, etc.;

[0170] As compounds having a cyclic carbonate group, there can be cited compounds in which the epoxy group of the above-exemplified compounds having an epoxy group is protected (for example, N,N,N',N'-tetrakis[(2-oxo-1,3-dioxolan-4-yl)ethyl]-4,4'-diaminodiphenylmethane);

[0171] As compounds having a thiiranyl group, there can be cited compounds in which the above-exemplified epoxy group is replaced with a thiiranyl group;

[0172] As compounds having a hydroxyalkylamide group, for example, there can be cited compounds represented by the following formulas (c-1) to (c-7), etc.;

[0173] As compounds having one or both of a hydroxymethylphenyl and an alkoxymethylphenyl, for example, there can be cited 2,2-bis(4-hydroxymethylphenyl)propane, 2,2-bis(2,3,4-trihydroxymethylphenyl)propane, compounds represented by the following formulas (c-8) to (c-16), etc.;

[0174] As compounds having a protected isocyanate group, for example, there can be cited compounds in which the isocyanate group in toluene diisocyanate, xylylene diisocyanate, chlorophenylene diisocyanate, hexamethylene diisocyanate, tetramethylene diisocyanate, isophorone diisocyanate or diphenylmethane diisocyanate is protected, etc.

[0175] [Chemical formula 10]

[0176]

[0177] When the composition contains the [C] compound, the content ratio of the [C] compound is preferably 1 part by mass or more, more preferably 2 parts by mass or more, and still more preferably 5 parts by mass or more, based on 100 parts by mass of the [A] polymer contained in the composition. In addition, the content ratio of the [C] compound is preferably 40 parts by mass or less, more preferably 30 parts by mass or less, based on 100 parts by mass of the [A] polymer contained in the composition.

[0178] ([D] Adhesion promoter)

[0179] The adhesion promoter is a component that improves the adhesion between the cured product formed using the composition and the substrate. As the adhesion promoter, a functional silane coupling agent having a reactive functional group can be preferably used. Examples of the reactive functional group possessed by the functional silane coupling agent include: carboxyl group, (meth)acryloyl group, epoxy group, vinyl group, isocyanate group, etc.

[0180] Specific examples of the functional coupling agent include, for example: trimethoxysilylbenzoic acid, γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropyltriethoxysilane, 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, 3-(meth)acryloxypropyltrimethoxysilane, 3-(meth)acryloxypropyltriethoxysilane, vinyltriacetoxysilane, vinyltrimethoxysilane, 3-isocyanatopropyltriethoxysilane, etc.

[0181] When the composition contains the adhesion promoter, the content ratio of the adhesion promoter is preferably 0.01 part by mass to 30 parts by mass, more preferably 0.1 part by mass to 20 parts by mass, based on 100 parts by mass of the [A] polymer contained in the composition.

[0182] ([E] Surfactant)

[0183] The surfactant can be used to improve the coatability of the composition (wetting spreadability or reduction of coating unevenness). Examples of the surfactant include: fluorine-based surfactants, silicone-based surfactants, nonionic surfactants. As the surfactant, it can be arbitrarily selected and used from known surfactants such as these commercially available products.

[0184] When the surfactant is formulated into the composition, the content of the surfactant is preferably 0.01 part by mass to 1.5 parts by mass, more preferably 0.02 part by mass to 1.2 parts by mass, and still more preferably 0.05 part by mass to 1.0 part by mass, based on 100 parts by mass of the [A] polymer contained in the composition.

[0185] ([F] Solvent)

[0186] This composition is preferably a liquid composition obtained by dissolving or dispersing a [A] polymer, a [B] photosensitive compound, and optionally formulated components in a solvent. As the solvent used, an organic solvent that dissolves each component formulated in this composition and does not react with each component is preferred.

[0187] Specific examples of the solvent include, for example: alcohols such as methanol, ethanol, isopropanol, 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, and ethyl 3-ethoxypropionate; ethers such as ethylene glycol monobutyl ether, propylene glycol monomethyl ether, ethylene glycol monomethyl ether, ethylene glycol ethyl methyl ether, dimethylene glycol dimethyl ether, diethylene glycol dimethyl ether, and diethylene glycol ethyl methyl ether; amides such as dimethylformamide, N,N-dimethylacetamide, and N-methylpyrrolidone; ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone, and cyclohexanone; and aromatic hydrocarbons such as benzene, toluene, xylene, and ethylbenzene.

[0188] Among these, the solvent preferably contains at least one selected from the group consisting of ethers and esters, and more preferably contains at least one selected from the group consisting of ethylene glycol alkyl ether acetates, diethylene glycols, propylene glycol monoalkyl ethers, and propylene glycol monoalkyl ether acetates.

[0189] With respect to 100 parts by mass of the total components of this composition, the content of the solvent in this composition (in the case of containing two or more solvents, it is the total amount thereof) is preferably 50 parts by mass to 95 parts by mass, and more preferably 60 parts by mass to 90 parts by mass.

[0190] As other components, in addition to the above, known additives such as an acid diffusion control agent, a sensitizer, an antioxidant, a thermal radical generator, a thermal acid generator, an ultraviolet absorber, a thickener, a development accelerator, an acid proliferator, a plasticizer, an anti-precipitation agent, a polymerization inhibitor, and a chain transfer agent can also be contained. The formulation ratios of these components can be appropriately selected according to each component within the range that does not impair the effects of the present disclosure.

[0191] The solid component concentration of the present composition (the proportion of the total mass of the components other than the solvent in the curable composition relative to the total mass of the curable composition) can be appropriately selected in consideration of viscosity, volatility, etc. The solid component concentration of the present composition is preferably in the range of 5% by mass to 60% by mass. When the solid component concentration is 5% by mass or more, the film thickness of the coating film can be sufficiently ensured when the present composition is coated on a substrate. In addition, when the solid component concentration is 60% by mass or less, the film thickness of the coating film does not become too large, and furthermore, the viscosity of the present composition can be moderately increased, and good coatability can be ensured. The solid component concentration of the present composition is more preferably 10% by mass to 55% by mass, and still more preferably 12% by mass to 50% by mass.

[0192] <Hardened Product for Organic EL Element and Method for Manufacturing the Same>

[0193] The hardened product of the present disclosure can be formed from the present composition prepared as described above. According to the present composition, a pattern film having high radiation sensitivity, high transmittance, low dielectric constant, and excellent heat resistance, water impermeability, and bend resistance can be formed. The thus obtained present composition can be preferably used as a composition for forming a hardened product of an organic EL element, and in particular, can be preferably used as a composition for forming a planarization film, a partition wall, or an interlayer insulating film in an organic EL element.

[0194] When manufacturing a hardened product using the present composition, it can be either positive development for removing the irradiated portion of the radiation or negative development for removing the non-irradiated portion of the radiation. The present composition can be particularly preferably used for forming a positive hardened product. The hardened product of the present disclosure can be manufactured, for example, by a method including the following steps 1 to 4 using the present composition.

[0195] (Step 1) A step of forming a coating film using the present composition.

[0196] (Step 2) A step of irradiating at least a part of the coating film with radiation.

[0197] (Step 3) A step of developing the coating film after irradiation with radiation.

[0198] (Step 4) A step of heating the developed coating film.

[0199] Hereinafter, each step will be described in detail.

[0200] [Step 1: Coating Film Formation Step]

[0201] In Step 1, the present composition is coated on a substrate. As the substrate, for example, a glass substrate, a silicon substrate, or a resin substrate can be used. For the surface of the substrate on which the coating film is to be formed, a metal thin film corresponding to the use can be formed, or various surface treatments such as hexamethyl disilazane (HMDS) treatment can be performed.

[0202] As the coating method of the present composition, for example, spray coating, roll coating, spin coating, slot die coating, bar coating, inkjet printing, etc. can be mentioned. Among these, it is preferably carried out by spin coating, slot die coating, or bar coating.

[0203] In Step 1, for the present composition coated on the substrate, it is preferably heat-treated (pre-baked) to remove the solvent in the present composition and form a coating film on the substrate. As the pre-baking conditions, they also vary depending on the types and content ratios of the respective components in the present composition, for example, 60°C to 130°C and 0.5 minutes to 10 minutes. The film thickness of the formed coating film (i.e., the film thickness after pre-baking) is preferably 0.1 μm to 12 μm. For the present composition coated on the substrate, reduced-pressure drying (vacuum dry, VCD) can also be performed before pre-baking.

[0204] [Step 2: Irradiation Step]

[0205] In Step 2, at least a part of the coating film containing the present composition formed in Step 1 is irradiated with radiation. At this time, by irradiating the coating film through a mask having a predetermined pattern, a hardened product having a pattern can be formed. As the radiation, for example, ultraviolet rays, far ultraviolet rays, visible light, X-rays, charged particle beams such as electron beams, etc. can be mentioned. Among these, ultraviolet rays are preferred, for example, g-rays (wavelength 436 nm), i-rays (wavelength 365 nm). As the exposure dose of the radiation, it is preferably 0.1 J / m 2 ~20,000 J / m 2 .

[0206] [Step 3: Development Step]

[0207] In Step 3, the coating film irradiated with radiation in Step 2 is developed. As the developer, an aqueous solution of an alkali (basic compound) can be mentioned. As the alkali, for example, sodium hydroxide, tetramethylammonium hydroxide, and the alkalis exemplified in paragraph 0127 of Japanese Patent Laid-Open No. 2016-145913 can be mentioned. From the viewpoint of obtaining appropriate developability, the alkali concentration of the alkaline aqueous solution is preferably 0.1% by mass to 5% by mass.

[0208] As the development method, suitable methods such as the liquid covering method, dipping method, shaking dipping method, spraying method, etc. can be cited. The development time also varies depending on the composition of the composition, for example, it is 30 seconds to 120 seconds. In addition, it is preferable to perform a rinsing treatment on the patterned coating film with running water cleaning after the development step.

[0209] [Process 4: Thermal curing process]

[0210] In Process 4, a treatment of heating the developed coating film in Process 3 (post-baking) is performed. Post-baking can be carried out, for example, using a heating device such as an oven or a hot plate. Regarding the post-baking conditions, the heating temperature is, for example, 120°C to 260°C. For example, in the case of performing a heating treatment on a hot plate, the heating time is 5 minutes to 40 minutes, and in the case of performing a heating treatment in an oven, the heating time is 10 minutes to 80 minutes. Through the above heating treatment, a curing reaction is carried out, and a cured product having a target pattern can be formed on the substrate. The shape of the pattern possessed by the cured product is not particularly limited, and examples thereof include a line and space pattern, a dot pattern, a hole pattern, and a lattice pattern.

[0211] The cured product obtained from this composition can also be used as a dry etching resist. In the case of using the cured product as a dry etching resist, as the etching treatment, dry etching treatments such as ashing, plasma etching, and ozone etching can be employed.

[0212] <Organic EL element>

[0213] The organic EL element of the present disclosure includes a cured product formed using this composition. The type of the cured product is not particularly limited, and examples thereof include a planarization film, a partition wall, or an interlayer insulating film included in the organic EL element. In terms of obtaining a cured product showing excellent bend resistance according to this composition, among these, this composition is particularly preferably a composition for forming a planarization film of an organic EL element, that is, a composition for forming a planarization film which is an insulating layer covering the step difference of a thin film transistor (TFT) circuit or wiring formed on a substrate.

[0214] The cured product formed using this composition has excellent water impermeability and bend resistance, and thus can be preferably used as an organic EL element for a flexible display. As the flexible display, examples include: a foldable display that can be folded, a bendable display that can be folded back or bent, a rollable display that can be wound, etc. Among these, the cured product formed using this composition is particularly preferably a cured product provided in an organic EL element for a bendable display, and particularly preferably a planarization film for a bendable organic EL display.

[0215] According to the present disclosure described in detail above, the following means can be provided.

[0216] 〔Means 1〕A curable composition for an organic EL element, comprising [A] a polymer containing a structural unit derived from a compound having an acidic group and [B] a photosensitive compound. The [A] polymer contains a structural unit (I) derived from an aromatic vinyl compound and a structural unit (II) derived from a maleimide compound. As the compound having an acidic group, it contains at least one selected from the group consisting of an aromatic vinyl compound and a maleimide compound. With respect to all the structural units of the [A] polymer, the total proportion of the structural unit (I) and the structural unit (II) in the [A] polymer is 70 mol% or more.

[0217] 〔Means 2〕The curable composition for an organic EL element according to 〔Means 1〕, wherein the molar ratio of the structural unit (I) to the structural unit (II) in the [A] polymer is structural unit (I) / structural unit (II) = 60 / 40 to 40 / 60.

[0218] 〔Means 3〕The curable composition for an organic EL element according to 〔Means 1〕 or 〔Means 2〕, wherein the [A] polymer has a crosslinkable functional group.

[0219] 〔Means 4〕The curable composition for an organic EL element according to 〔Means 3〕, wherein the crosslinkable functional group is at least one selected from the group consisting of an oxiranyl group, an oxetanyl group, an episulfide group, a hydroxyalkylamide group, a hydroxymethylphenyl group, an alkoxymethylphenyl group, a cyclic carbonate group, and a protected isocyanate group.

[0220] 〔Means 5〕The curable composition for an organic EL element according to 〔Means 3〕 or 〔Means 4〕, wherein the [A] polymer further contains a structural unit derived from a compound having a crosslinkable functional group, and the compound having a crosslinkable functional group is at least one selected from the group consisting of an aromatic vinyl compound and a maleimide compound.

[0221] 〔Means 6〕The curable composition for an organic EL element according to any one of 〔Means 1〕 to 〔Means 5〕, which further contains [C] a compound having two or more crosslinkable functional groups (wherein the [A] polymer is excluded).

[0222] 〔Means 7〕The curable composition for an organic EL element according to 〔Means 6〕, wherein the [C] compound has two or more selected from the group consisting of an oxiranyl group, an oxetanyl group, an episulfide group, a hydroxyalkylamide group, a hydroxymethylphenyl group, an alkoxymethylphenyl group, a cyclic carbonate group, and a protected isocyanate group.

[0223] [Means 8] The curable composition for an organic EL element according to any one of [Means 1] to [Means 7], wherein the [B] photosensitive compound is a quinone diazide compound.

[0224] [Means 9] The curable composition for an organic EL element according to [Means 1] to [Means 7], wherein the [B] photosensitive compound is a photoacid generator.

[0225] [Means 10] The curable composition for an organic EL element according to any one of [Means 1] to [Means 9], wherein the compound having an acidic group is selected from the group consisting of a compound having a phenolic hydroxyl group, a compound having a group “* 1 -C(R 1 )(R 2 )-OH” (wherein R 1 and R 2 are each independently a cyano group or a fluoroalkyl group having 1 to 3 carbon atoms; “* 1 ” represents a bonding bond to an aromatic ring), and maleimide.

[0226] [Means 11] A method for manufacturing a cured product for an organic EL element, comprising: a step of forming a coating film using the curable composition according to any one of [Means 1] to [Means 10]; a step of irradiating at least a part of the coating film with radiation; a step of developing the coating film after irradiation with radiation; and a step of heating the developed coating film.

[0227] [Means 12] A cured product for an organic EL element, which is formed using the curable composition according to any one of [Means 1] to [Means 10].

[0228] [Means 13] The cured product for an organic EL element according to [Means 12], which is a planarization film, a partition wall, or an interlayer insulating film.

[0229] [Means 14] An organic EL element, comprising the cured product according to [Means 12].

[0230] [Means 15] A polymer comprising a structural unit derived from an aromatic vinyl compound and a structural unit derived from a maleimide compound, wherein the total proportion of the structural unit derived from the aromatic vinyl compound and the structural unit derived from the maleimide compound is 70 mol% or more relative to all the structural units of the polymer. The polymer comprises a structural unit derived from a compound having an acidic group and a structural unit derived from a compound having a crosslinkable functional group, and the compound having an acidic group and the compound having a crosslinkable functional group are at least one selected from the group consisting of an aromatic vinyl compound and a maleimide compound. The compound having an acidic group is at least one selected from the group consisting of a compound having a phenolic hydroxyl group, a compound having a group "* 1 -C(R 1 )(R 2 )-OH" (wherein R 1 and R 2 are each independently a cyano group or a fluoroalkyl group having 1 to 3 carbon atoms; "* 1 " represents a bonding bond to an aromatic ring) and maleimide.

[0231] In addition, the polymer of [Means 15] is preferably a polymer component of a curable composition for forming a cured product (preferably a planarization film, an interlayer insulating film, or a partition wall) for an organic EL element. That is, the polymer of [Means 15] is a preferred embodiment of the [A] polymer contained in the curable composition for an organic EL element of the present disclosure. The specific structure and manufacturing method of the polymer are as described above.

[0232] Examples

[0233] Hereinafter, the present disclosure will be specifically described by way of examples, but the present disclosure is not limited to these examples. In addition, unless otherwise specified, "parts" and "%" in the examples and comparative examples are based on mass.

[0234] [Weight average molecular weight (Mw) and molecular weight distribution (Mw / Mn)]

[0235] The Mw and Mn of the polymer synthesized in the following synthesis examples were measured by gel permeation chromatography (GPC) using the following apparatus and conditions. The molecular weight distribution (Mw / Mn) was calculated from the measured Mw and Mn.

[0236] · Apparatus: GPC-101 manufactured by Showa Denko K.K.

[0237] · GPC column: A column formed by combining GPC-KF-801, GPC-KF-802, GPC-KF-803, and GPC-KF-804 manufactured by Shimadzu GLC K.K.

[0238] · Mobile phase: Tetrahydrofuran (in the case of styrene / maleimide resin) or N,N-dimethylformamide solution containing lithium bromide and phosphoric acid (in the case of polyimide)

[0239] · Column temperature: 40 °C

[0240] · Flow rate: 1.0 mL / min

[0241] · Sample concentration: 1.0 mass%

[0242] · Sample injection volume: 100 μL

[0243] · Detector: Differential refractometer

[0244] · Standard substance: Monodisperse polystyrene

[0245] [Monomer]

[0246] The abbreviations of the monomers used in the synthesis of the polymer are as described below.

[0247] 《Monomer with acidic group (aromatic vinyl compound, maleimide compound): M1》

[0248] MI-1 to MI-3, OL-1 to OL-3: Compounds represented by the following formulas (MI-1) to (MI-3), (OL-1) to (OL-3) respectively

[0249] [Chemical formula 11]

[0250]

[0251] 《Monomer with crosslinkable functional group (aromatic vinyl compound, maleimide compound): M2》

[0252] MI-4, OL-4 to OL-7: Compounds represented by the following formulas (MI-4), (OL-4) to (OL-7) respectively

[0253] [Chemical formula 12]

[0254]

[0255] 《Monomer with acid dissociable group (aromatic vinyl compound, maleimide compound): M3》

[0256] MI-5, MI-6, OL-8: Compounds represented by the following formulas (MI-5), (MI-6), (OL-8) respectively

[0257] [Chemical formula 13]

[0258]

[0259] "Other Monomers"

[0260] MMA: Methyl methacrylate (methyl methacrylate, MMA)

[0261] MAA: Methacrylic acid (methacrylic acid, MAA)

[0262] GMA: Glycidyl methacrylate (glycidyl methacrylate, GMA)

[0263] MI-7 to MI-10, OL-9 to OL-13: Compounds represented by the following formulas (MI-7) to (MI-10), formulas (OL-9) to (OL-13), respectively

[0264] [Chemical Formula 14]

[0265]

[0266] 1. Synthesis of Polymer

[0267] [Synthesis Example 1] Synthesis of Polymer P-1 (Styrene / Maleimide Resin)

[0268] Under nitrogen, 50 mol parts of maleimide as a polymerization monomer, 50 mol parts of styrene, 5 parts by mass of 2,2'-azobis(2,4-dimethylvaleronitrile) as a radical polymerization initiator, and N-methyl-2-pyrrolidone (N-methyl-2-pyrrolidone, NMP) as a solvent were added to a 100 mL two-necked flask to make it 20% by mass, and polymerized at 70 °C for 6 hours. After polymerization, the solid component obtained by reprecipitation in an aqueous methanol solution was filtered and vacuum dried at room temperature for 8 hours to obtain Polymer P-1 (styrene / maleimide resin). The Mw of the obtained Polymer P-1 was 41,300, and the molecular weight distribution (Mw / Mn) was 2.52.

[0269] [Synthesis Examples 2 to 18, 20, 21] Synthesis of Polymers P-2 to P-18, 20, 21 (Styrene / Maleimide Resins)

[0270] The types and amounts of the monomers used in the polymerization were changed as described in Table 1. Other than that, the polymerization was carried out in the same manner as in Synthesis Example 1 to obtain polymers P-2 to P-18, P-20, and P-21, respectively. In addition, in Table 1, the values in parentheses represent the amounts (unit: mol%) of the respective monomers used in each polymerization relative to the total amount of the monomers. The values in the "Total amount T(S / M)" column represent the total amount (unit: mol%) of the aromatic vinyl compound and the maleimide compound among all the monomers used in the synthesis of the polymer.

[0271]

[0272] [Synthesis Example 19] Synthesis of Polymer P-19 (Polyimide)

[0273] 100 mol parts of 2,2-bis(3-amino-4-hydroxyphenyl)hexafluoropropane was dissolved in N-methyl-2-pyrrolidone (NMP), and 100 mol parts of 4,4'-oxydiphthalic anhydride was added thereto, followed by reacting at 40°C for 8 hours to obtain a polyamic acid solution containing 20% by mass of polyamic acid.

[0274] Subsequently, NMP was added to the obtained polyamic acid solution to adjust the concentration of the polyamic acid to 10% by mass, pyridine and acetic anhydride were added thereto, and a dehydration ring-closure reaction was carried out at 90°C for 4 hours. After the dehydration ring-closure reaction, the solvent in the system was replaced with fresh NMP to obtain a polyimide solution containing 15% by mass of polyimide with an imidization rate of about 70%. The obtained polyimide solution was added to methanol, and the precipitated solid was washed with an aqueous methanol solution, and the obtained solid was dried to obtain polymer P-19 (polyimide). The Mw of the obtained polymer P-19 was 32,000, and the molecular weight distribution (Mw / Mn) was 2.21.

[0275] 2. Preparation and Evaluation of the Curable Composition

[0276] [Example 1]

[0277] (1) Preparation of Curable Composition R-1

[0278] 100 parts by mass of polymer P-1 as a resin, 20 parts by mass of a quinone diazide compound (condensate of 4,4'-[1-[4-[1-(4-hydroxyphenyl)-1-methylethyl]phenyl]ethylidene]bisphenol (1.0 mol) and 1,2-naphthoquinone diazide-5-sulfonyl chloride (2.0 mol)) as a photosensitive compound, 5 parts by mass of an adhesion promoter (γ-glycidoxypropyltrimethoxysilane), and 0.5 parts by mass of a surfactant (“FTX-218”, manufactured by NEOS Co., Ltd.) were mixed. Further, a mixed solution of γ-butyrolactone and diethylene glycol ethyl methyl ether (γ-butyrolactone:diethylene glycol ethyl methyl ether = 50:50 (mass ratio)) as a solvent was added so that the solid content concentration became 20% by mass, and then filtration was performed using a membrane filter with a pore size of 0.2 μm, whereby a curable composition R-1 was prepared.

[0279] (2) Evaluation of sensitivity (radiation sensitivity)

[0280] After applying the curable composition R-1 on a silicon substrate that had been subjected to HMDS treatment at 60°C for 60 seconds using a spinner, pre-baking was performed on a hot plate at 90°C for 2 minutes to form a coating film with a film thickness of 3.0 μm. For the said coating film, using an exposure machine “MPA-600FA” manufactured by Canon Inc., a predetermined amount of ultraviolet rays was irradiated through a pattern mask having a line-and-space pattern with a width of 10 μm. Subsequently, after performing a development treatment for 60 seconds at 25°C using a developer (2.38 mass% aqueous solution of tetramethylammonium hydroxide), rinsing was performed with ultrapure water for 1 minute. The minimum exposure amount capable of forming a line-and-space pattern with a width of 10 μm was measured, and when the measured value was less than 1000 J / m 2 it was designated as “excellent (◎)”, when it was 1000 J / m 2 or more and less than 2000 J / m 2 it was designated as “good (○)”, when a line-and-space pattern with a width of 10 μm was obtained but the minimum exposure amount was 2000 J / m 2 or more it was designated as “passable (△)”, and when a line-and-space pattern with a width of 10 μm could not be obtained it was designated as “non-passable (×)”, and the sensitivity was evaluated. As a result, in the said example, the evaluation was “good (○)”.

[0281] (3) Evaluation of transmittance (light transmittance)

[0282] After applying the curable composition R-1 on a glass substrate using a spinner, pre-baking was performed on a hot plate at 90°C for 2 minutes to form a coating film with a film thickness of 3.0 μm. Subsequently, the entire surface of the substrate was irradiated with 3000 J / m using a proximity exposure machine (“MA-1200” (ghi-ray mixture) manufactured by Canon Inc.) 2After exposure to light, in a clean oven purged with nitrogen, the glass substrate was heated at 250 °C for 60 minutes to form a hardened film. The transmittance of the formed hardened film was measured using an ultraviolet-visible spectrophotometer ("V-630" manufactured by JASCO Corporation). When the transmittance of light with a wavelength of 380 nm was 70% or more, it was rated as "good (○)"; when it was 50% or more and less than 70%, it was rated as "acceptable (△)"; when it was less than 50%, it was rated as "unacceptable (×)". The transmittance was evaluated. As a result, in the said example, it was rated as "good (○)".

[0283] (4) Evaluation of heat resistance

[0284] After applying the curable composition R-1 on a silicon substrate using a spinner, it was pre-baked on a hot plate at 90 °C for 2 minutes to form a coating film with a film thickness of 3.0 μm. Subsequently, using a proximity exposure machine ("MA-1200" (ghi-ray mixture) manufactured by Canon Inc.), the entire surface of the substrate was irradiated with 3000 J / m 2 of light. Then, in a clean oven purged with nitrogen, the silicon substrate was heated at 250 °C for 60 minutes to form a hardened film. Using a differential thermal / thermogravimetric simultaneous measurement device ("TG / DTA220U" manufactured by Hitachi High-Tech Science Corporation), the 1% thermogravimetric reduction temperature of the formed hardened film was measured in air. When the 1% weight reduction temperature was 300 °C or higher, it was rated as "good (○)"; when it was 250 °C or higher and less than 300 °C, it was rated as "acceptable (△)"; when it was less than 250 °C, it was rated as "unacceptable (×)". The heat resistance was evaluated. As a result, in the said example, it was rated as "good (○)".

[0285] (5) Evaluation of dielectric constant (measurement of relative dielectric constant)

[0286] After applying the curable composition R-1 on a SUS304 substrate whose surface was smoothed by polishing with a sisal polishing wheel (hemp polishing wheel), the reaching pressure was set to 100 Pa, and the solvent was removed from the curable composition R-1 on the substrate under vacuum. Then, it was pre-baked at 90 °C for 2 minutes to form a coating film with an average film thickness of 3.0 μm. Subsequently, using a proximity exposure machine ("MA-1200" (ghi-ray mixture) manufactured by Canon Inc.), the entire surface of the substrate was irradiated with 3000 J / m 2 of light. Then, it was heated at 250 °C for 60 minutes in a clean oven purged with nitrogen to form a hardened film (insulating film) on the substrate. On the said insulating film, a Pt / Pd electrode pattern was formed by evaporation to fabricate a sample for dielectric constant measurement.

[0287] Using the prepared sample for measuring the dielectric constant, and using an inductance-capacitance-resistance meter (LCR meter) (HP16451B electrodes and HP4284A Precision LCR meter manufactured by Hewlett Packard Japan, Ltd.), the relative dielectric constant was measured by the capacitance-voltage (CV) method at a frequency of 10 kHz. When the relative dielectric constant is 3.0 or less, it is rated as "excellent (◎)"; when it exceeds 3.0 and is 3.2 or less, it is rated as "good (○)"; when it exceeds 3.2 and is 3.5 or less, it is rated as "acceptable (△)"; when it exceeds 3.5, it is rated as "unacceptable (×)". The dielectric constant was evaluated. As a result, in the said embodiment, it was rated as "excellent (◎)".

[0288] (6) Evaluation of water impermeability

[0289] On a polyimide film with a thickness of 25 μm, the curable composition R-1 was coated by spin coating to a film thickness of 10 μm, and pre-baked at 80 °C for 1.5 minutes. Subsequently, the entire surface of the substrate was irradiated with light of 3000 J / m 2 using a proximity exposure machine ("MA-1200" (ghi-ray mixture) manufactured by Canon Inc.), and then heated at 250 °C for 60 minutes to form a cured film on the polyimide film. The laminated film of the polyimide film and the cured film was placed at the opening of an aluminum cup containing 15 g of distilled water with the surface of the cured film facing inward, and covered in such a way as to seal the opening of the aluminum cup with the laminated film. It was placed in a constant temperature bath at 50 °C, and the weight reduction of the cup after 150 hours was measured, and the water permeability per unit area was calculated. When the value of the weight reduction is 500 g / cm 2 or less, it is rated as "good (○)"; when it exceeds 500 g / cm 2 and is 700 g / cm 2 or less, it is rated as "acceptable (△)"; when it exceeds 700 g / cm 2 , it is rated as "unacceptable (×)". The water permeability was evaluated. When the value is 500 g / cm 2 or less, it can be said that the water permeability is sufficiently low. As a result, in the said embodiment, it was rated as "good (○)".

[0290] (7) Evaluation of flex resistance (flexural resistance)

[0291] After applying the curable composition R-1 on a polyimide film substrate using a spin coater, the pressure is set to 100 Pa, and the solvent is removed from the curable composition R-1 on the substrate under vacuum. Then, it is pre-baked at 90 °C for 2 minutes to form a coating film with an average film thickness of 3.0 μm. Subsequently, after developing for 60 seconds at 25 °C using a developer (2.38 mass% aqueous solution of tetramethylammonium hydroxide), it is rinsed with ultrapure water for 1 minute. For the obtained coating film, the entire surface of the substrate is irradiated with light of 3000 J / m 2 using a proximity exposure machine ("MA-1200" (ghi-ray mixture) manufactured by Canon Inc.), and then heated at 250 °C for 1 hour in a clean oven purged with nitrogen, thereby forming a cured film on the substrate.

[0292] The obtained substrate with the cured film is cut into a size of 50 mm in length × 50 mm in width. Next, with the surface on which the cured film is formed facing inward, the substrates with the cured film are held in a bent state for 10 minutes with the cured films in contact with each other. Ten minutes after bending, the bent substrate with the cured film is opened, and the bent portion of the surface of the cured film is observed using an optical microscope, and the flex resistance (bend resistance) is evaluated based on the appearance change. Regarding the evaluation criteria, the case where there are no cracks in the cured film is set as "good (○)", the case where a part of the cured film has cracks is set as "acceptable (△)", and the case where the entire cured film has cracks is set as "unacceptable (×)". As a result, the evaluation in the said example is "acceptable (△)".

[0293] (8) Element evaluation

[0294] <Fabrication of organic EL element substrate>

[0295] After applying the prepared composition on a glass substrate ("OA-10" manufactured by Nippon Electric Glass Co., Ltd.) on which indium tin oxide (ITO) transparent electrodes are formed in an array using a spinner, it is pre-baked on a hot plate at 90 °C for 2 minutes to form a coating film with a film thickness of 3.0 μm. For the said coating film, using an exposure machine "MPA-600FA" manufactured by Canon Inc., a predetermined amount of ultraviolet light is irradiated through a pattern mask having a contact hole pattern with a pitch of 10 μm. Subsequently, after developing for 60 seconds at 25 °C using a developer (2.38 mass% aqueous solution of tetramethylammonium hydroxide), it is rinsed with ultrapure water for 1 minute. At this time, the minimum exposure amount capable of forming a 10-μm contact hole pattern is measured. Then, the entire surface of the substrate is irradiated with light of 3000 J / m 2After exposure to light, it is heated at 250 °C for 1 hour in a clean oven purged with nitrogen, thereby forming a hardened film with contact holes (also referred to as "patterned hardened resin layer") on the glass substrate.

[0296] For the glass substrate with the patterned hardened resin layer, a metal mask that separates a predetermined pattern is used to form an Al film with a thickness of 100 nm on the patterned hardened resin layer by direct current (DC) sputtering using an Al target. An ITO film with a thickness of 20 nm is formed on the Al film by radio frequency (RF) sputtering using an ITO target. Thus, an anode layer including the Al film and the ITO film is formed.

[0297] A coating film is formed on the anode layer using a resist material ("Optomer NN803" manufactured by JSR), and a series of processes including i-ray (wavelength 365 nm) irradiation, development, running water cleaning, air drying, and heat treatment are performed to form a pixel defining layer having a part of the anode layer as an opening area.

[0298] The substrate on which the anode and the pixel defining layer are formed is moved to a vacuum deposition chamber. After evacuating the deposition chamber to 1E-4 Pa, on the substrate, using a vapor deposition mask with a predetermined pattern and by resistance heating vapor deposition method, molybdenum oxide (MoOx) having hole injection properties is deposited under the condition of a deposition rate of 0.004 nm / sec to 0.005 nm / sec to form a hole injection layer with a thickness of 1 nm.

[0299] On the hole injection layer, using a vapor deposition mask with a predetermined pattern and by resistance heating vapor deposition method, 4,4'-bis[N-(1-naphthyl)-N-phenyl amino]biphenyl (α-NPD) having hole transport properties is deposited under the same evacuation conditions as the hole injection layer to form a hole transport layer with a thickness of 35 nm. The deposition rate is under the condition of 0.2 nm / sec to 0.3 nm / sec.

[0300] On the hole transport layer, using a vapor deposition mask with a predetermined pattern and by resistance heating vapor deposition method, tris(8-hydroxyquinoline)aluminum, which is an alkylated complex and a green light emitting material, is deposited under the same film formation conditions as the hole transport layer to form a light emitting layer with a thickness of 35 nm. The deposition rate is under the condition of 0.5 nm / sec or less.

[0301] On the light emitting layer, using a vapor deposition mask with a predetermined pattern and by resistance heating vapor deposition method, lithium fluoride is deposited under the same evacuation conditions as the hole injection layer to form an electron injection layer with a thickness of 0.8 nm. The deposition rate is under the condition of 0.004 nm / sec or less.

[0302] Subsequently, on the electron injection layer, using an evaporation mask with a predetermined pattern and by resistance heating evaporation, Mg and Ag are simultaneously formed into a film under the same exhaust conditions as the hole injection layer to form a first cathode layer with a film thickness of 5 nm. The film formation rate is under the condition of 0.5 nm / sec or less.

[0303] Subsequently, the substrate is transferred to another film formation chamber (sputtering chamber), and on the first cathode layer, using a mask with a predetermined pattern, an ITO target is used and a second cathode layer with a film thickness of 100 nm is formed by RF sputtering.

[0304] An organic EL element is formed on the substrate in the above-described manner to obtain an organic EL element substrate.

[0305] <Thin film encapsulation of organic EL element>

[0306] On the obtained organic EL element, a thin film encapsulation layer is formed according to the following process.

[0307] The organic EL element substrate is transferred to a film formation chamber (sputtering chamber), and on the cathode layer, using a mask with a predetermined pattern, a SiNx target is used and an inorganic encapsulation layer (SiNx film) with a film thickness of 100 nm is formed by RF sputtering. Subsequently, the organic EL element substrate is transferred to a glove box replaced with N 2 A curable composition containing an epoxy compound, an oxetane compound, and a polymerization initiator is ejected in a predetermined pattern using a piezoelectric inkjet printer. Subsequently, using a 395 nm LED lamp (UniJet E110ZHD manufactured by USHIO Electric Inc.) with an exposure amount of 1000 mJ / cm 2 Irradiation is performed to cure the film-formed curable composition to form an organic encapsulation layer with a film thickness of 10 μm. The organic EL element substrate is transferred to a film formation chamber (sputtering chamber), and on the organic encapsulation layer, using a mask with a predetermined pattern, a SiNx target is used and an inorganic encapsulation layer (SiNx film) with a film thickness of 100 nm is formed by RF sputtering. An organic EL element substrate with an encapsulation layer is obtained in the above-described manner.

[0308] <Reliability evaluation of organic EL element>

[0309] For the obtained organic EL element substrate with a patterned cured resin layer, reliability evaluation is performed according to the following process. After storing the organic EL element substrate with a patterned cured resin layer in an oven set at 60 °C and 90% humidity for 300 hours, via an organic EL lighting fixture, a constant current source is used to apply a current of 20 mA / cm between the anode layer and the cathode layer of the organic EL element. 2The density circulation current causes the organic EL element to emit light. Next, a luminance meter is used to measure the luminance in the front direction of the organic EL element.

[0310] Regarding the lighting of the organic EL element and the measurement of the front luminance using a luminance meter, the organic EL element substrate with a patterned hardened resin layer and the reference organic EL element substrate without a formed patterned hardened resin layer are each carried out. It can be said that the fewer impurities generated from the patterned hardened resin layer or moisture passing through the patterned hardened resin layer, the smaller the influence of the impurities or moisture on the organic EL element, and the closer the front luminance of the organic EL element substrate with a sealing layer is to the front luminance of the reference organic EL element substrate. When the organic EL element substrate with a sealing layer emits light with a luminance of 80% or more relative to the front luminance of the reference organic EL element substrate, it is set as "good (○)". When it emits light with a luminance of 50% or more and less than 80%, it is set as "acceptable (△)". When it does not emit light normally, it is set as "unacceptable (×)", and the reliability of the organic EL element is evaluated. As a result, the evaluation in the said example is "good (○)".

[0311] [Examples 2 to 14, 18 to 21, Comparative Examples 1 to 6]

[0312] The composition of the formulation was changed as shown in Table 2. Except for this, curable compositions R-2 to R-14, R-18 to R-27 were prepared with the same solvent composition and solid content concentration as in Example 1. In addition, for Examples 2 to 14, 18 to 21 and Comparative Examples 1 to 6, the same types and amounts of adhesion aids and surfactants as in Example 1 were also formulated. For Examples 2 to 7, 11, 18 to 21 and Comparative Example 2, a crosslinking agent was formulated. In addition, using each curable composition, various evaluations were carried out in the same manner as in Example 1. The evaluation results are shown in Table 2. In addition, in Comparative Example 2 and Comparative Example 5, in the "(2) Evaluation of sensitivity (radiation sensitivity)", a line and space pattern with a width of 10 μm could not be obtained, so the subsequent evaluations were not carried out. Therefore, in Table 2, for evaluation items other than sensitivity, it is shown as "-".

[0313] [Examples 15 to 17]

[0314] The formulation was changed as shown in Table 2. Except for this, curable compositions R-15 to R-17 were prepared with the same solvent composition and solid component concentration as in Example 1. In addition, for Examples 15 to 17, the same type and amount of adhesion promoter and surfactant as in Example 1 were also formulated. For Example 16, a crosslinking agent was formulated. Additionally, using each curable composition, various evaluations were conducted in the same manner as in Example 1. Among them, when fabricating the patterned cured resin layer of the organic EL element substrate, in Examples 15 to 17, after development treatment and running water washing, the following treatment was not performed, that is, the entire surface of the substrate was irradiated with light of 3000 J / m 2 using a proximity exposure machine ("MA-1200" (ghi-ray mixture) manufactured by Canon Inc.), but instead, a treatment of heating in a nitrogen-purged clean oven at 250 °C for 1 hour was performed. The evaluation results are shown in Table 2. In addition, the unit of the values in Table 2 is parts by mass.

[0315]

[0316] In Table 2, the abbreviations of the compounds are as described below.

[0317] NQD: Quinone diazide compound (condensate of 4,4'-[1-[4-[1-(4-hydroxyphenyl)-1-methylethyl]phenyl]ethylidene]bisphenol (1.0 mol) and 1,2-naphthoquinone diazide-5-sulfonyl chloride (2.0 mol))

[0318] CAR: 4,7-Di-n-butoxy-1-naphthyltetrahydrothiophenium trifluoromethanesulfonate

[0319] Add-1 to Add-6: Compounds represented by the following formulas (Add-1) to (Add-6) respectively

[0320] [Chemical formula 15]

[0321]

[0322] As shown in Table 2, the sensitivity, transmittance, heat resistance, dielectric constant, water impermeability, flex resistance, and element reliability of the curable compositions of Examples 1 to 21 were all evaluated as "excellent", "good", or "acceptable", and various properties were improved with a well-balanced manner. Among these, in particular, in Examples 2 to 6, 8 to 10, 12 to 16, 20, and 21 where a crosslinkable functional group was introduced into the [A] polymer or any one of Add-1 to Add-5 was formulated as a crosslinking agent, the heat resistance and flex resistance were evaluated as good. Additionally, by including the use of a compound having a phenolic hydroxyl group, a group "* 1 -C(R 1 )(R 2)-OH” and one or more of maleimide as a monomer having an acidic group, a cured film having a lower dielectric constant can be obtained as compared with the case of using a compound having a carboxyl group (Example 8).

[0323] In contrast, in Comparative Examples 1 and 4 using a polymer in which the total proportion of structural unit (I) and structural unit (II) is less than 70 mol%, the heat resistance, dielectric constant, water impermeability, and device reliability are all "acceptable" or "unacceptable", and overall they are worse than those of Examples 1 to 21. In addition, in Comparative Example 3 using polyimide as the polymer component, the sensitivity, transmittance, and dielectric constant are not sufficient, and in Comparative Example 6 using a copolymer of a cycloolefin and a styrene compound, the evaluation of heat resistance, dielectric constant, and water impermeability is "acceptable", while the evaluation of bend resistance and device reliability is "unacceptable". Comparative Examples 2 and 5 are not photosensitive and cannot be used as photosensitive compositions.

Claims

1. A curable composition for an organic electroluminescent element, comprising: [A] A polymer containing a structural unit derived from a compound having an acidic group, and [B] A photosensitive compound, The [A] polymer contains a structural unit (I) derived from an aromatic vinyl compound and a structural unit (II) derived from a maleimide compound, As the compound having an acidic group, it contains at least one selected from the group consisting of an aromatic vinyl compound and a maleimide compound, With respect to all the structural units of the [A] polymer, the total proportion of the structural unit (I) and the structural unit (II) in the [A] polymer is 70 mol% or more.

2. The curable composition for an organic electroluminescent element according to claim 1, wherein, The molar ratio of the structural unit (I) to the structural unit (II) in the [A] polymer is structural unit (I) / structural unit (II) = 60 / 40 to 40 / 60.

3. The curable composition for an organic electroluminescent element according to claim 1, wherein, The [A] polymer has a crosslinkable functional group.

4. The curable composition for an organic electroluminescent element according to claim 3, wherein, The crosslinkable functional group is at least one selected from the group consisting of an oxiranyl group, an oxetanyl group, an episulfide group, a hydroxyalkylamide group, a hydroxymethylphenyl group, an alkoxymethylphenyl group, a cyclic carbonate group, and a protected isocyanate group.

5. The curable composition for an organic electroluminescent element according to claim 3, wherein, The [A] polymer further contains a structural unit derived from a compound having a crosslinkable functional group, and the compound having a crosslinkable functional group is at least one selected from the group consisting of an aromatic vinyl compound and a maleimide compound.

6. The curable composition for an organic electroluminescent element according to claim 1, which further contains [C] a compound having two or more crosslinkable functional groups ( wherein, excluding the [A] polymer).

7. The curable composition for an organic electroluminescent element according to claim 6, wherein, The [C] compound has two or more selected from the group consisting of an oxiranyl group, an oxetanyl group, an episulfide group, a hydroxyalkylamide group, a hydroxymethylphenyl group, an alkoxymethylphenyl group, a cyclic carbonate group, and a protected isocyanate group.

8. The curable composition for an organic electroluminescent element according to claim 1, wherein, The [B] photosensitive compound is a quinone diazide compound.

9. The curable composition for an organic electroluminescent element according to claim 1, wherein, The [B] photosensitive compound is a photoacid generator.

10. The curable composition for an organic electroluminescent element according to claim 1, wherein, The compound having an acidic group is selected from the group consisting of a compound having a phenolic hydroxyl group, a compound having a group "* 1 -C(R 1 )(R 2 )-OH" (wherein R 1 and R 2 are each independently a cyano group or a fluoroalkyl group having 1 to 3 carbon atoms; "* 1 " represents a bonding bond to an aromatic ring) and at least one selected from the group consisting of maleimide.

11. A method for manufacturing a cured product for an organic electroluminescent element, comprising: A step of forming a coating film using the curable composition according to any one of claims 1 to 10; A step of irradiating at least a part of the coating film with radiation; A step of developing the coating film after irradiation with radiation; and A step of heating the developed coating film.

12. A cured product for an organic electroluminescent element, which is formed using the curable composition according to any one of claims 1 to 10.

13. The cured product for an organic electroluminescent element according to claim 12, which is a planarization film, a partition wall, or an interlayer insulating film.

14. An organic electroluminescent element, comprising the cured product according to claim 12.

15. A polymer, comprising a structural unit derived from an aromatic vinyl compound and a structural unit derived from a maleimide compound, The total proportion of the structural unit derived from the aromatic vinyl compound and the structural unit derived from the maleimide compound is 70 mol% or more with respect to all the structural units of the polymer, The polymer comprises a structural unit derived from a compound having an acidic group and a structural unit derived from a compound having a crosslinkable functional group, and the compound having an acidic group and the compound having a crosslinkable functional group are at least one selected from the group consisting of an aromatic vinyl compound and a maleimide compound, The compound having an acidic group is selected from the group consisting of compounds having a phenolic hydroxyl group and compounds having the group "* 1 -C(R 1 )(R 2 )-OH"( wherein R 1 and R 2 each independently represents a cyano group or a fluoroalkyl group having 1 to 3 carbon atoms; "* 1 " represents a bond to the aromatic ring) and at least one selected from the group consisting of maleimide.

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