JP2021116400A - Polymer composition, cured film, and organic el element - Google Patents

Abstract

To provide a polymer composition capable of giving a cured film which causes less outgassing and is excellent in heat resistance.SOLUTION: The polymer composition contains a polymer component (A), a reaction initiator (B), and a polyfunctional polymerizable compound (C). The polymer component (A) contains a structural unit (Uα) derived from at least one selected from the group consisting of an N-substituted maleimide compound having a monovalent cyclic hydrocarbon group and a (meth)acrylic compound having a monovalent cyclic hydrocarbon group. The structural unit (Uα) contains a structural unit (U1) derived from the N-substituted maleimide compound having a monovalent cyclic hydrocarbon group in an amount of 28 mass% or more based on the total amount of the structural unit (Uα) contained in the polymer component (A).SELECTED DRAWING: None

Description

The present invention relates to polymer compositions, cured films and organic EL devices.

The organic electroluminescence element (organic EL element) is a light emitting element having a laminated structure including an anode, an organic light emitting layer, and a cathode, and is being put into practical use in applications such as display devices and lighting devices. Various devices such as organic EL elements and liquid crystal display elements generally include an insulating cured film such as a flattening film, an interlayer insulating film, and a partition wall. As a material for forming a cured film, polyimide, a (meth) acrylic polymer, or the like is known (see, for example, Patent Document 1).

Patent Document 1 describes a resin having a structural unit derived from an acrylic compound and a structural unit containing a cyclic ether group, and the content of the structural unit derived from the acrylic compound is 30% by mass or more with respect to the total structural unit. , It is disclosed that a cured film is formed by a composition containing a reaction initiator and a polyfunctional polymerizable compound. According to the composition of Patent Document 1, it is described in Patent Document 1 that a cured film that generates less outgas can be formed.

JP-A-2018-399979

The outgas generated from the cured film is considered to affect the reliability of devices such as organic EL elements. In particular, organic EL devices are required to have higher definition, and it is necessary to reduce outgas generated from the cured film as much as possible. Further, in the device manufacturing process, the cured film may be subjected to a high temperature treatment (for example, a heat treatment at 200 ° C. or higher). Therefore, as a cured film applied to an organic EL element, it is required to reduce outgassing and to have excellent heat resistance.

The present invention has been made in view of the above problems, and an object of the present invention is to provide a polymer composition capable of obtaining a cured film having less outgassing and excellent heat resistance.

In order to solve the above problems, according to the present invention, the following polymer compositions, cured films and organic EL devices are provided.

[1] The polymer component (A), the reaction initiator (B), and the polyfunctional polymerizable compound (C) are contained, and the polymer component (A) contains a monovalent cyclic hydrocarbon group. The structural unit (Uα) comprises a structural unit (Uα) derived from at least one selected from the group consisting of an N-substituted maleimide compound having and a (meth) acrylic compound having a monovalent cyclic hydrocarbon group. A polymer composition containing 28% by mass or more of the structural unit (U1) derived from the N-substituted maleimide compound with respect to the total amount of the structural unit (Uα) contained in the polymer component (A).
[2] A cured film formed by using the polymer composition of the above [1].
[3] An organic EL device including the cured film of the above [2].

According to the polymer composition of the present invention containing the polymer component (A), outgas generation is small and curing is excellent in heat resistance (specifically, linear expansion coefficient and transparency after heat application). A film can be obtained. Such a polymer composition of the present invention is useful as a flattening film material, a partition wall material, and a bank material, and is particularly useful as a flattening film material, a partition wall material, and a bank material for an organic EL device.

The figure which shows the schematic structure of the organic EL element of the top emission type structure. The figure which shows the schematic structure of the organic EL element of the bottom emission type structure.

Hereinafter, matters related to the embodiment will be described in detail. In addition, in this specification, the numerical value range described by using "~" means that the numerical value described before and after "~" is included as the lower limit value and the upper limit value. The "structural unit" is a monomer unit that mainly constitutes the main chain structure, and means a unit that is contained in at least two or more in the main chain structure.

<Polymer composition>
The polymer composition of the present disclosure is for forming an insulating film, and is preferably used for forming an insulating film for an organic EL device. The polymer composition of the present disclosure contains a polymer component (A), a reaction initiator (B), and a polyfunctional polymerizable compound (C). Hereinafter, each component will be described in detail. Unless otherwise specified, each component may be used alone or in combination of two or more.

Here, the term "hydrocarbon group" as used herein means to include a chain hydrocarbon group, an alicyclic hydrocarbon group, and an aromatic hydrocarbon group. The "chain hydrocarbon group" means a linear hydrocarbon group and a branched hydrocarbon group which do not contain a cyclic structure in the main chain and are composed only of a chain structure. However, it may be saturated or unsaturated. The "alicyclic hydrocarbon group" means a hydrocarbon group containing only the alicyclic hydrocarbon structure as the ring structure and not containing the aromatic ring structure. However, it does not have to be composed only of the alicyclic hydrocarbon structure, and some of them have a chain structure. The "aromatic hydrocarbon group" means a hydrocarbon group containing an aromatic ring structure as a ring structure. However, it does not have to be composed of only an aromatic ring structure, and a chain structure or an alicyclic hydrocarbon structure may be included in a part thereof. The ring structure of the alicyclic hydrocarbon group and the aromatic hydrocarbon group may have a substituent composed of a hydrocarbon structure. "Cyclic hydrocarbon group" means to include an alicyclic hydrocarbon group and an aromatic hydrocarbon group.

[Polymer component (A)]
-Structural unit (U1)
The polymer component (A) contains a structural unit (U1) derived from an N-substituted maleimide compound having a monovalent cyclic hydrocarbon group (hereinafter, also referred to as “monomer A1”). The cyclic hydrocarbon group contained in the monomer A1 is preferably a monovalent alicyclic hydrocarbon group having a monocyclic ring, a crosslinked ring or a spiro ring, or a monovalent aromatic hydrocarbon group. Specific examples of the monovalent cyclic hydrocarbon group include alicyclic hydrocarbon groups such as cyclopentyl group, cyclohexyl group, cycloheptyl group, cyclooctyl group, methylcyclopentyl group, dimethylcyclopentyl group, ethylcyclopentyl group and cyclo. Examples thereof include a pentenyl group, a cycloheptenyl group, a norbornyl group, an adamantyl group, an isoboronyl group, a dicyclopentanyl group, a tricyclo [5.2.1.0 ^2,6 ] decanyl group, a spirobicyclopentanyl group and the like. Examples of the aromatic hydrocarbon group include a phenyl group, a methylphenyl group, a dimethylphenyl group, an ethylphenyl group, a benzyl group, a phenethyl group, a naphthyl group, an anthryl group and the like.

Among the above, the cyclic hydrocarbon group contained in the monomer A1 is a monocyclic ring or a bridging ring in that the resolution, developability and heat resistance of the coating film obtained by using the polymer composition can be further improved. It is preferably a monovalent alicyclic hydrocarbon group having a monovalent or a monovalent aromatic hydrocarbon group, and is a monovalent alicyclic hydrocarbon group having a monocyclic ring or a bridging ring. Is more preferable, and a monovalent alicyclic hydrocarbon group having a single ring is further preferable.

（式（１）中、Ｒ^１は、１価の環状炭化水素基である。Ｒ^２及びＲ^３は、それぞれ独立して、水素原子又は炭素数１〜５のアルキル基である。） Specifically, the structural unit (U1) is preferably a structural unit represented by the following formula (1).

(In the formula (1), R ¹ is a monovalent cyclic hydrocarbon group. R ² and R ³ are independently hydrogen atoms or alkyl groups having 1 to 5 carbon atoms.)

In the above formula (1), in R ¹ , the ring structure of the cyclic hydrocarbon group may be directly bonded to the nitrogen atom, or the ring structure may be bonded via a divalent linking group. Examples of the divalent linking group include an alkanediyl group such as a methylene group, an ethylene group and a 1,3-propanediyl group. Of these, R ¹ preferably has a ring structure of a cyclic hydrocarbon group directly bonded to a nitrogen atom in that a cured film having better heat resistance can be obtained, and is of an alicyclic hydrocarbon. An alicyclic hydrocarbon group whose structure is directly bonded to a nitrogen atom is more preferable. R ² and R ³ are preferably a hydrogen atom or a methyl group, and more preferably a hydrogen atom.

Specific examples of the monomer A1 include N-phenylmaleimide, N- (2-methylphenyl) maleimide, N- (4-methylphenyl) maleimide, and N- (4) as compounds having an aromatic hydrocarbon group. -Ethylphenyl) maleimide, N- (2,6-dimethylphenyl) maleimide, N-benzylmaleimide, N-naphthylmaleimide, etc .; as compounds having an alicyclic hydrocarbon group, for example, N-cyclohexylmaleimide, N-cyclopentyl Maleimide, N- (2-methylcyclohexyl) maleimide, N- (4-methylcyclohexyl) maleimide, N- (4-ethylcyclohexyl) maleimide, N- (2,6-dimethylcyclohexyl) maleimide, N-norbornyl maleimide , N-tricyclodecylmaleimide, N-adamantylmaleimide and the like, respectively. The monomer A1 is at least selected from the group consisting of N-cyclohexylmaleimide, N- (4-methylcyclohexyl) maleimide, N-phenylmaleimide and N- (4-methylphenyl) maleimide. One is preferable, and at least one of N-cyclohexylmaleimide and N-phenylmaleimide is more preferable.

In the polymer component (A), the content ratio of the structural unit (U1) is preferably more than 15% by mass and 35% by mass or less with respect to all the structural units constituting the polymer component (A). When the content ratio of the structural unit (U1) is more than 15% by mass, the heat resistance of the cured film obtained by using the polymer composition can be sufficiently increased, and for example, cracks occur when wiring is formed on the cured film. It is preferable in that the occurrence can be suppressed. On the other hand, when the content ratio of the structural unit (U1) is 35% by mass or less, the solubility of the polymer tends to be kept good. Further, when the content ratio of the structural unit (U1) is 35% by mass or less, the glass transition temperature of the polymer can be appropriately raised, and the reactivity as a negative body is maintained when a negative type cured film is formed. Developability can be improved by dripping. From the above viewpoint, the content ratio of the structural unit (U1) is more preferably 16% by mass or more, still more preferably 18% by mass or more, based on all the structural units constituting the polymer component (A). Particularly preferably, it is 20% by mass or more. The content ratio of the structural unit (U1) is more preferably 34% by mass or less, still more preferably 32% by mass or less, and particularly preferably 32% by mass or less, based on all the structural units constituting the polymer component (A). Is 30% by mass or less.

The main chain of the polymer constituting the polymer component (A) has a high degree of freedom in selecting a monomer and that a cured film exhibiting good heat resistance, chemical resistance, developability, etc. can be obtained. In that respect, it is preferable that the polymer is obtained by using a monomer having a polymerizable unsaturated carbon-carbon bond (hereinafter, also referred to as “unsaturated monomer”). Further, according to the polymer obtained by using the unsaturated monomer, the cost can be reduced as compared with the polyimide conventionally used as the insulating film material. Examples of the unsaturated monomer include (meth) acrylic compounds, styrene compounds, maleimide compounds, vinyl compounds and the like. Of these, the unsaturated monomer preferably contains at least a maleimide-based compound, and preferably contains a maleimide-based compound and a (meth) acrylic compound. In addition, in this specification, "(meth) acrylic" means to include "acrylic" and "methacryl". Further, "(meth) acrylic compound" means to include "acrylic compound" and "methacryl compound".

The polymer component (A) contains a structural unit (U1) as a structural unit having a cyclic hydrocarbon group in the side chain. A polymer having a cyclic hydrocarbon group in a side chain has moderately high hydrophobicity and can obtain a cured film having high developability, and is therefore suitable as an insulating film material (particularly for an organic EL device). In the polymer component (A), the structural unit having a cyclic hydrocarbon group in the side chain may be only the structural unit (U1), or may further contain a structural unit different from the structural unit (U1). ..

A structural unit having a cyclic hydrocarbon group in the side chain and different from the structural unit (U1) is a monovalent cyclic hydrocarbon in that a cured film having high transparency, resolution and developability can be obtained. A structural unit derived from a (meth) acrylic compound having a group (hereinafter, also referred to as “monomer A2”) is preferable. Among these, the monomer A2 is a monovalent cyclic hydrocarbon in that decomposition (depolymerization) of the polymer main chain due to heat or the like is unlikely to occur and outgas generation due to decomposition of the main chain can be reduced. It is preferably an acrylic compound having a group. That is, the polymer component (A) preferably contains a structural unit (U1) and a structural unit derived from an acrylic compound having a monovalent cyclic hydrocarbon group (hereinafter referred to as “structural unit (U2)”).

In the following, the structural unit derived from the monomer A1 and the structural unit derived from the monomer A2 are collectively referred to as a “structural unit (Uα)”. The "monovalent cyclic hydrocarbon group" of the structural unit (Uα) means a group having a hydrocarbon structure, and does not include a group having a heteroatom-containing group such as an epoxy group. In the monomer A2, the content ratio of the methacrylic compound having a monovalent cyclic hydrocarbon group is preferably 10% by mass or less, more preferably 5% by mass or less, and 1% by mass with respect to the total amount of the monomer A2. The following are more preferable, and it is particularly preferable that the following is substantially not contained.

（式（２）中、Ｒ^４は、１価の環状炭化水素基である。） -Structural unit (U2)
The structural unit (U2) is preferably a structural unit represented by the following formula (2).

(In the formula (2), ^{R 4} is a monovalent cyclic hydrocarbon group.)

In the above formula (2), R ⁴ may be cyclic structure having a cyclic hydrocarbon group directly bonded to the nitrogen atom, the ring structure is bonded via a divalent linking group (e.g. alkanediyl group) May be. Cyclic hydrocarbon group R ⁴ is the resolution of the film obtained by using the polymer composition, in terms of the developing property and transparency can be higher, it is preferable that the alicyclic hydrocarbon group.

Specific examples of the acrylic compound having a monovalent cyclic hydrocarbon group include, for example, phenyl acrylate, benzyl acrylate, phenethyl acrylate, 2-naphthyl acrylate and the like as a compound having an aromatic hydrocarbon group; an alicyclic hydrocarbon group. Examples of the compound having, for example, cyclopentyl acrylate, cyclohexyl acrylate, cyclooctyl acrylate, cyclohexenyl acrylate, norbornyl acrylate, adamantyl acrylate, tricyclo [5.2.1.0 ^2,6 ] decane-8-yl. Acrylate and the like can be mentioned respectively.

In the polymer component (A), the content ratio of the structural unit (U2) is preferably more than 0% by mass and less than 35% by mass with respect to the total amount of the structural units constituting the polymer component (A). It is preferable that the polymer component (A) contains the structural unit (U2) because a film having high resolution and developability can be obtained while suppressing the glass transition temperature Tg from becoming too high. Further, by setting the content ratio of the structural unit (U2) to less than 35% by mass, decomposition of the polymer side chain due to heat or the like is unlikely to occur, and the generation of outgas due to decomposition of the polymer side chain can be sufficiently reduced. preferable. From such a viewpoint, the content ratio of the structural unit (U2) is more preferably 1% by mass or more, still more preferably 5% by mass or more, based on all the structural units constituting the polymer component (A). Yes, particularly preferably 10% by mass or more. The content ratio of the structural unit (U2) is more preferably 33% by mass or less, still more preferably 32% by mass or less, and further preferably 32% by mass or less, based on all the structural units constituting the polymer component (A). It is preferably less than 30% by mass, more preferably 28% by mass or less, and particularly preferably 25% by mass or less.

In the polymer composition containing the polymer component (A), the reaction initiator (B), and the polyfunctional polymerizable compound (C), the structural unit (U1) and the structural unit (U2) in the polymer component (A) The content ratio of the structural unit (U1) is preferably more than 15% by mass and 35% by mass or less with respect to all the structural units constituting the polymer component (A), and the content ratio of each of the structural units (U1). The content ratio of U2) is more than 0% by mass and less than 35% by mass. Within such a range, the cured film obtained by using the polymer composition is preferable in that it exhibits various performances such as low outgassing property, heat resistance, radiation sensitivity, resolution and transparency in a well-balanced manner.

The content ratio of the structural unit (Uα) is preferably 16% by mass or more and less than 70% by mass with respect to all the structural units constituting the polymer component (A). The content ratio of the structural unit (Uα) is more preferably 17% by mass or more, still more preferably 23% by mass or more, and particularly preferably 30 with respect to all the structural units constituting the polymer component (A). It is mass% or more. The content ratio of the structural unit (Uα) is more preferably 67% by mass or less, still more preferably 65% by mass or less, particularly preferably, with respect to all the structural units constituting the polymer component (A). Is 60% by mass or less.

In the polymer component (A), the content ratio of the structural unit (U1) to the total amount of the structural unit (Uα) is particularly preferably 28% by mass or more. Here, according to the study by the present inventors, the main chain of a polymer containing a structural unit derived from a methacrylic compound having a monovalent cyclic hydrocarbon group is easily decomposed (depolymerized) by heat or the like, and the polymer is depolymerized. There is a concern that outgas will be generated due to the above and affect the performance of the element (for example, when applied to an organic EL element, the performance of the organic light emitting layer, etc.). Further, in a polymer containing a structural unit derived from an acrylic compound having a monovalent cyclic hydrocarbon group, the side chain is easily decomposed by heat or the like, and an alcohol component generated by the decomposition (for example, a structural unit derived from cyclohexyl acrylate). In this case, there is a concern that cyclohexanol) may affect the performance of the device. In particular, in recent years, further improvement in performance has been required in the field of organic EL devices, and in order to realize this, it is necessary to develop organic EL devices that can reduce the generation of outgas as much as possible even under more severe conditions.

In this regard, by setting the content ratio of the structural unit (U1) to the total amount of the structural unit (Uα) within the above range, the hydrophobicity of the polymer component (A) can be sufficiently increased by introducing the structural unit (Uα), while the hydrophobicity of the polymer component (A) can be sufficiently increased. The generation of outgas caused by the polymer component (A) can be sufficiently reduced. The content ratio of the structural unit (U1) to the total amount of the structural unit (Uα) is more preferably 28.5% by mass or more, still more preferably 30% by mass or more, from the viewpoint of minimizing the generation of outgas. Even more preferably, it is 35% by mass or more, and particularly preferably 40% by mass or more. Further, the content ratio of the structural unit (U1) with respect to the total amount of the structural unit (Uα) is more preferably 90% by mass or less, still more preferably 80% by mass or less, from the viewpoint of improving the resolution and developability. It is particularly preferably 70% by mass or less.

The polymer component (A) may further contain a structural unit (hereinafter, also referred to as “other structural unit”) different from the structural unit (Uα) in addition to the structural unit (Uα). Examples of other structural units include a structural unit having a cyclic ether group (hereinafter, also referred to as “structural unit (U3)”) and a structural unit having an acid group (hereinafter, also referred to as “structural unit (U4)”). ..

・ Structural unit (U3)
When the polymer component (A) contains the structural unit (U3), the resolution of the film obtained by using the polymer composition, the adhesion of the cured film, and the chemical resistance can be improved. Further, the cyclic ether group of the structural unit (U3) acts as a crosslinkable group, so that a cured film in which deterioration is suppressed over a long period of time can be formed. Examples of the cyclic ether group contained in the structural unit (U3) include a cyclic ether group having a 3- to 8-membered ring. Of these, the cyclic ether group is preferably an oxylanyl group or an oxetanyl group. In addition, in this specification, an oxyranyl group and an oxetanyl group are included and are also referred to as an "epoxy group".

（式（３）中、Ｒ^５はエポキシ基を有する１価の基であり、Ｒ^６は水素原子又は炭素数１〜５のアルキル基であり、Ｘ^１は単結合又は２価の連結基である。） The structural unit (U3) is preferably a structural unit derived from an unsaturated monomer having a cyclic ether group, and specifically, it is preferably a structural unit represented by the following formula (3).

In formula (3), R ⁵ is a monovalent group having an epoxy group, R ⁶ is a hydrogen atom or an alkyl group having 1 to 5 carbon atoms, and X ¹ is a single bond or a divalent linking group. be.)

In the above formula (3), the ^{R 5,} oxiranyl group, oxetanyl group, 3,4-epoxycyclohexyl group, 3,4-epoxytricyclo [5.2.1.0 ^2,6] decyl group, 3- Ethyloxetanyl groups and the like can be mentioned. Of these, from the viewpoint of high reactivity, R ⁵ is preferably a monovalent group having an oxiranyl group.
R ⁶ is preferably a hydrogen atom or a methyl group. Examples of the divalent linking group of X ¹ include an alkanediyl group such as a methylene group, an ethylene group and a 1,3-propanediyl group.

Specific examples of the monomer constituting the structural unit (U3) include glycidyl (meth) acrylate, 3,4-epoxycyclohexyl (meth) acrylate, 3,4-epoxycyclohexylmethyl (meth) acrylate, and 2-. (3,4-Epoxycyclohexyl) ethyl (meth) acrylate, 3,4-epoxytricyclo [5.2.1.0 ^2,6 ] decyl (meth) acrylate, (3-methyloxetane-3-yl) methyl (Meta) acrylate, (3-ethyloxetane-3-yl) (meth) acrylate, (oxetane-3-yl) methyl (meth) acrylate, (3-ethyloxetane-3-yl) methyl (meth) acrylate, etc. Can be mentioned.

In the polymer component (A), the content ratio of the structural unit (U3) is preferably 5% by mass or more, more preferably 10% by mass or more, and more preferably 15% by mass or more, based on all the structural units constituting the polymer component (A). More preferably by mass% or more. The content ratio of the structural unit (U3) is preferably 60% by mass or less, more preferably 55% by mass or less, still more preferably 50% by mass or less, based on all the structural units constituting the polymer component (A). .. By setting the content ratio of the structural unit (U3) in the above range, it is preferable in that the coating film exhibits better developability and the heat resistance and chemical resistance of the obtained cured film can be sufficiently increased. ..

-Structural unit (U4)
The polymer component (A) preferably contains a structural unit (U4). Since the polymer component (A) contains the structural unit (U4), the coating film made of the polymer composition is preferable in that it can exhibit good developability with respect to an alkaline developer. The structural unit (U4) is not particularly limited as long as it has an acid group, but is selected from the group consisting of a structural unit having a carboxy group, a structural unit having a sulfonic acid group, a structural unit having a phenolic hydroxyl group, and a maleimide unit. It is preferably at least one kind.

As a specific example of the monomer constituting the structural unit (U4), the monomer constituting the structural unit having a carboxy group is unsaturated, for example, (meth) acrylic acid, crotonic acid, 4-vinylbenzoic acid and the like. Monocarboxylic acid; unsaturated dicarboxylic acid such as maleic acid, fumaric acid, citraconic acid, mesaconic acid, itaconic acid; as a monomer constituting a structural unit having a sulfonic acid group, for example, vinyl sulfonic acid, (meth) allyl Sulfonic acid, styrene sulfonic acid, (meth) acrylic yloxyethyl sulfonic acid, etc .; Examples of the monomer constituting the structural unit having a phenolic hydroxyl group include 4-hydroxy-α-methylstyrene and the like. can. The "maleimide unit" refers to a monomer unit derived from maleimide.

The polymer component (A) is preferably alkali-soluble. Therefore, it is preferable that the structural unit (U4) is contained in the polymer component (A) so that the polymer component (A) is alkali-soluble. Specifically, in the polymer component (A), the content ratio of the structural unit (U4) is preferably 2% by mass or more with respect to all the structural units constituting the polymer component (A). It is more preferably mass% or more, and further preferably 5 mass% or more. The content ratio of the structural unit (U4) is preferably 40% by mass or less, more preferably 35% by mass or less, and more preferably 30% by mass or less, based on all the structural units constituting the polymer component (A). It is more preferably mass% or less. In addition, in this specification, "alkali soluble" means that it can be dissolved or swelled in an alkaline aqueous solution such as a tetramethylammonium hydroxide aqueous solution having a concentration of 2.38% by mass.

Other structural units include, for example, methyl (meth) acrylate, butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, n-lauryl (meth) acrylate, n-stearyl (meth) acrylate and the like. (Meta) acrylic acid alkyl ester compound; unsaturated dicarboxylic acid dialkyl ester compound such as diethyl itacone; styrene, α-methylstyrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, p-methoxystyrene, etc. Aromatic vinyl compounds; conjugated diene compounds such as 1,3-butadiene and isoprene; nitrogen-containing vinyl compounds such as (meth) acrylonitrile and (meth) acrylamide; methylmaleimide, ethylmaleimide, etc. other than monomeric A1 and maleimide Maleimide-based compounds; structural units derived from unsaturated monomers such as vinyl chloride, vinylidene chloride, and vinyl acetate can be mentioned. The content ratio of the structural units derived from these unsaturated monomers is preferably 30% by mass or less, more preferably 20% by mass or less, based on all the structural units constituting the polymer component (A).

The polymer component (A) may contain only one type of structural unit (U1), or may contain two or more types. The same applies to the structural unit (U2) to the structural unit (U4). The content ratio of each structural unit is usually equivalent to the ratio of the monomers used in the production of the polymer. The polymer component (A) may be composed of one kind of polymer or two or more kinds of polymers as long as it contains the structural unit (U1). For example, when the polymer component (A) contains a structural unit (U1), a structural unit (U3), and a structural unit (U4), the polymer component (A) is a structural unit (U1), a structural unit (U3). And the structural unit (U4) may be contained in the same polymer, or may be contained in different polymers. The polymer component (A) may contain a polymer having neither structural unit (U1) to structural unit (U4).

As the content form of the polymer component (A) in the polymer composition, for example, [1] a weight having a structural unit (U1), a structural unit (U2), a structural unit (U3), and a structural unit (U4). An embodiment containing a coalescence (hereinafter, also referred to as "polymer P"), [2] a polymer having a structural unit (U1), a structural unit (U3), and a structural unit (U4), and a structural unit (U2), a structure. An embodiment containing a polymer having a unit (U3) and a structural unit (U4), [3] a polymer having a structural unit (U1), a polymer having a structural unit (U2), and a structural unit (U3). Examples thereof include an embodiment containing a polymer having a structural unit (U4) and a polymer having a structural unit (U4). Of these, the above [1] is preferable in that the effects of the present invention can be obtained while reducing the number of constituent components of the polymer composition. The polymer P is preferably an alkali-soluble resin.

In the polymer component (A), the polystyrene-equivalent weight average molecular weight (Mw) by gel permeation chromatography (GPC) is preferably 2000 or more. When Mw is 2000 or more, it is preferable in that a cured film having sufficiently high heat resistance and chemical resistance and showing good developability can be obtained. Mw is more preferably 5000 or more, further preferably 8000 or more, and particularly preferably 10000 or more. Further, Mw is preferably 50,000 or less, more preferably 30,000 or less, and further preferably 25,000 or less from the viewpoint of improving the film forming property.

In the polymer component (A), the dispersity (Mw / Mn) represented by the ratio of the weight average molecular weight Mw to the number average molecular weight Mn is preferably 4.0 or less, more preferably 3.0 or less, and 2. 5 or less is more preferable. When the polymer component (A) is composed of two or more kinds of polymers, it is preferable that Mw and Mw / Mn of a mixture of two or more kinds of polymers satisfy the above range.

The content ratio of the polymer component (A) is preferably 10% by mass or more, more preferably 20% by mass or more, and more preferably 30% by mass, based on the total amount of solids contained in the polymer composition. The above is more preferable. The content ratio of the polymer component (A) is preferably 90% by mass or less, more preferably 85% by mass or less, and more preferably 80% by mass, based on the total amount of solids contained in the polymer composition. It is more preferably mass% or less. By setting the content ratio of the polymer component (A) in the above range, a cured film having sufficiently high heat resistance and chemical resistance and exhibiting good developability and transparency can be obtained.

As the polymer component (A), for example, an unsaturated monomer into which each of the above-mentioned structural units can be introduced is used, and a known method such as radical polymerization is used in a suitable solvent in the presence of a polymerization initiator or the like. Can be manufactured according to.

[Reaction initiator (B)]
The reaction initiator (B) is a component that generates active species such as radicals and cations by light, heat, or the like. This reaction initiator (B) is added to the polymer composition as a component for initiating the polymerization reaction of the polyfunctional polymerizable compound. Specific examples of the reaction initiator (B) include polymerization initiators such as radical polymerization initiators and cationic polymerization initiators.

The radical polymerization initiator is not particularly limited as long as it generates radicals by light irradiation, heating, or the like. Specific examples of the radical polymerization initiator include photoradical polymerization initiators such as oxime ester compounds, alkylphenone compounds, acylphosphine oxide compounds, biimidazole compounds, triazine compounds, benzoin compounds, and benzophenone compounds; peroxides and azo compounds. Examples thereof include thermal radical polymerization initiators such as. Among these, the radical polymerization initiator is preferably a photoradical polymerization initiator, and more preferably an oxime ester compound in that a fine pattern can be formed by exposure.

Examples of the oxime ester compound include O-acyl oxime compounds. Specific examples of the O-acyloxime compound include 1,2-octanedione, 1- [4- (phenylthio) -2- (O-benzoyloxime)], and ethanone-1- [9-ethyl-6- (2). -Methylbenzoyl) -9H-carbazole-3-yl] -1- (O-acetyloxime), 1- (9-ethyl-6-benzoyl-9.H.-carbazole-3-yl) -octane-1- Onoxime-O-acetate, 1- [9-ethyl-6- (2-methylbenzoyl) -9. H. -Carbazole-3-yl] -ethane-1-one oxime-O-benzoate, 1- [9-n-butyl-6- (2-ethylbenzoyl) -9. H. -Carbazole-3-yl] -ethane-1-one oxime-O-benzoate, ethane-1- [9-ethyl-6- (2-methyl-4-tetrahydrofuranylbenzoyl) -9. H. -Carbazole-3-yl] -1- (O-acetyloxime), Etanone-1- [9-ethyl-6- (2-methyl-4-tetrahydropyranylbenzoyl) -9. H. -Carbazole-3-yl] -1- (O-acetyloxime), ethanone-1- [9-ethyl-6- (2-methyl-5-tetrahydrofuranylbenzoyl) -9. H. -Carbazole-3-yl] -1- (O-acetyloxime), ethanone-1- [9-ethyl-6- {2-methyl-4- (2,2-dimethyl-1,3-dioxolanyl) methoxybenzoyl) } -9. H. -Carbazole-3-yl] -1- (O-acetyloxime) can be mentioned.

Examples of the oxime ester compound include NCI-831, NCI-930 (above, manufactured by ADEKA Corporation), DFI-020, DFI-091 (above, manufactured by Daito Chemics Co., Ltd.), Irgacure OXE01, OXE02, OXE03 (above). , BASF) and other commercially available products can also be used.

The cationic polymerization initiator is not particularly limited as long as it generates protonic acid or Lewis acid by light irradiation, heating, or the like. The cationic polymerization initiator is preferably a photocationic polymerization initiator in that a fine pattern can be formed by exposure, and examples thereof include an ionic photoacid generation type and a nonionic photoacid generation type polymerization initiator.

Examples of the ionic photoacid generation type photocationic polymerization initiator include onium salt compounds, halogen-containing compounds, sulfone compounds, sulfonic acid compounds, sulfonimide compounds, and diazomethane compounds. Examples of the onium salt compound include aromatic sulfonium salts, aromatic iodonium salts, aromatic diazonium salts, aromatic ammonium salts, and (2,4-cyclopentadiene-1-yl) [(1-methylethyl) benzene]-. Examples include Fe salt. Specific examples of the above-mentioned onium salt compound include aromatic sulfonium, aromatic iodonium, aromatic diazonium, aromatic ammonium, or (2,4-cyclopentadiene-1-yl) [(1-methylethyl) benzene) having a cation moiety. ] -Fe cation, the anion moiety is BF ^4- , PF ^6- , SbF ₆ , [BX ₄ ] ^- (where X is a phenyl group substituted with two or more fluorine or trifluoromethyl groups. ), Or ^{an onium salt composed of [PRf 6-} ] (where Rf is an alkyl fluorinated group).

Examples of the nonionic photoacid-generating photocationic polymerization initiator include nitrobenzyl ester, sulfonic acid derivative, phosphoric acid ester, phenolsulfonic acid ester, diazonaphthoquinone, and N-hydroxyimideshonate.

The content ratio of the reaction initiator (B) (when two or more kinds are contained, the total amount of the two or more kinds of reaction initiators (B)) is preferably based on 100 parts by mass of the polymer component (A). It is 1 part by mass or more, more preferably 3 parts by mass or more, and further preferably 5 parts by mass or more. The content ratio of the reaction initiator (B) is preferably 20 parts by mass or less, more preferably 18 parts by mass or less, and further preferably 15 parts by mass with respect to 100 parts by mass of the polymer component (A). It is less than a part. By setting the content ratio of the reaction initiator (B) to the above range, when the coating film formed by using the polymer composition is exposed, the influence of deterioration of the pattern forming ability due to uneven exposure can be minimized. Further, it is preferable in that the developability is exhibited more satisfactorily and a cured film having excellent curability and transparency can be formed.

[Polyfunctional polymerizable compound (C)]
The polyfunctional polymerizable compound (C) is a compound having two or more polymerizable groups. The polymerizable group is preferably a group containing a carbon-carbon unsaturated double bond, and examples thereof include a vinyl group and a (meth) acryloyl group. The number of polymerizable groups contained in the polyfunctional polymerizable compound (C) is preferably 2 to 10, and more preferably 2 to 6.

The polyfunctional polymerizable compound (C) is preferably a polyfunctional (meth) acrylate having two or more (meth) acryloyl groups in terms of high reactivity to light and heat. Specific examples of the polyfunctional (meth) acrylate include, for example, ethylene glycol di (meth) acrylate, polyethylene glycol di (meth) acrylate, 1,6-hexanediol di (meth) acrylate, and 1,9-nonanediol di ( Polyfunctional (meth) acrylic acid ester of alkylene glycol or polyalkylene glycol such as meta) acrylate; monocycloalkane dimethanol such as cyclohexanedimethanol di (meth) acrylate, tricyclodecanedimethanol di (meth) acrylate or Polycycloalkanedimethanol polyfunctional (meth) acrylic acid ester; trimethylolpropane poly (meth) acrylate, ditrimethylolpropane poly (meth) acrylate, pentaerythritol poly (meth) acrylate, dipentaerythritol poly (meth) acrylate, etc. Polyfunctional (meth) acrylic acid ester of trivalent or higher polyhydric alcohol; pentaerythritol AO-modified polyfunctional (meth) acrylate, trimethylpropan AO-modified polyfunctional (meth) acrylate, dipentaerythritol AO-modified polyfunctional ( AO-modified or succinic acid-modified polyfunctional (meth) acrylic acid esters such as meta) acrylate, succinic acid-modified pentaerythritol tri (meth) acrylate, and succinic acid-modified dipentaerythritol penta (meth) acrylate; Polyfunctional urethane (meth) acrylates such as (meth) acrylate, ε-caprolactone-modified tris- (2- (meth) acryloxyethyl) isocyanurate; tri (2- (meth) acryloyloxyethyl) phosphate can be mentioned. .. In addition, in this specification, "AO modification" means alkylene oxide modification such as ethylene oxide (EO) modification and propylene oxide (PO) modification.

The content ratio of the polyfunctional polymerizable compound (C) is preferably 20 parts by mass or more, more preferably 30 parts by mass or more, and further preferably 40 parts by mass or more with respect to 100 parts by mass of the polymer component (A). The content ratio of the polyfunctional polymerizable compound (C) is preferably 200 parts by mass or less, more preferably 150 parts by mass or less, still more preferably 100 parts by mass or less, based on 100 parts by mass of the polymer component (A). .. By setting the content ratio of the polyfunctional polymerizable compound (C) to 20 parts by mass or more, it is preferable in that the heat resistance and chemical resistance of the cured film obtained by using the polymer composition can be improved. Further, by setting the content ratio of the polyfunctional polymerizable compound (C) to 200 parts by mass or less, it is preferable in that sufficient developability can be ensured and exposure unevenness can be effectively reduced.

[Other ingredients]
The polymer composition of the present disclosure may further contain other components shown below in addition to the above-mentioned polymer component (A), reaction initiator (B) and polyfunctional polymerizable compound (C). ..

・ Adhesion aid (D)
The adhesion aid (D) is a component that improves the adhesion between the cured film obtained by using the polymer composition and the lower layer (for example, a substrate). The adhesion aid (D) is a silane coupling agent having a reactive functional group such as a carboxy group, a (meth) acryloyl group, a vinyl group, an isocyanate group, and an oxylanyl group (hereinafter, also referred to as “functional silane coupling agent”). ) Is preferable. Examples of the functional silane coupling agent include trimethoxysilyl benzoic acid, (meth) acryloxipropyltrimethoxysilane, vinyltriacetoxysilane, vinyltrimethoxysilane, γ-isocyanuspropyltriethoxysilane, and 3-glycidyloxypropyltri. Examples thereof include methoxysilane, 2- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, and 2-((meth) acryloxy) ethyl phosphate. The content ratio of the adhesion aid (D) is preferably 0.01 to 10 parts by mass, more preferably 0.1 to 5 parts by mass, and 0.5 to 4 parts by mass with respect to 100 parts by mass of the polymer component (A). Parts by mass are even more preferred.

-Polymerization inhibitor (E)
The polymerization inhibitor (E) is a component that enhances the storage stability of the polymer composition. Examples of the polymerization inhibitor (E) include sulfur, quinones (for example, benzoquinone), hydroquinones (for example, hydroquinone, 2,5-di-t-butylhydroquinone), polyoxy compounds (for example, p-methoxyphenol), and amine compounds. (For example, N, N-diethylhydroxyamine), nitrosamine compounds (for example, N-nitroso-N-phenylhydroxylamine aluminum) can be mentioned. The content ratio of the polymerization inhibitor (E) is preferably 0.01 to 0.5 parts by mass, more preferably 0.01 to 0.3 parts by mass, and 0, based on 100 parts by mass of the polymer component (A). 0.01 to 0.2 parts by mass is more preferable.

・ Solvent (F)
In the polymer composition of the present disclosure, the polymer component (A), the reaction initiator (B) and the polyfunctional polymerizable compound (C), and other components to be blended as necessary are preferably contained in a solvent. It is a dissolved or dispersed liquid composition. As the solvent (F) to be used, an organic solvent that dissolves each of the above components and does not react with each component is preferable.

Specific examples of the solvent (F) include alcohols such as methanol, ethanol, isopropanol, butanol, and octanol; ethyl acetate, butyl acetate, ethyl lactate, γ-butyrolactone, propylene glycol monomethyl ether acetate, and propylene glycol monoethyl ether. Esters such as acetate, methyl 3-methoxypropionate, ethyl 3-ethoxypropionate; ethers such as ethylene glycol monobutyl ether, propylene glycol monomethyl ether, ethylene diglycol monomethyl ether, ethylene diglycol ethyl methyl ether; dimethylformamide, Amidos such as N, N-dimethylacetamide and N-methylpyrrolidone; ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone and cyclohexanone; aromatic hydrocarbons such as benzene, toluene, xylene and ethyl benzene can be mentioned. Of these, the solvent (F) is preferably esters.

In addition to the above, the polymer composition of the present disclosure may contain, for example, an antioxidant, a surfactant, a chain transfer agent, or the like as other components. The blending ratio of these components is appropriately selected according to each component as long as the effects of the present disclosure are not impaired.

When the polymer composition is a liquid composition, its solid content concentration (the ratio of the total mass of components other than the solvent in the polymer composition to the total mass of the polymer composition) is viscous or volatile. It is appropriately selected in consideration of properties and the like, but is preferably in the range of 5 to 60% by mass. When the solid content concentration is 5% by mass or more, a sufficient film thickness of the coating film can be secured when the polymer composition is applied onto the substrate. Further, when the solid content concentration is 60% by mass or less, the film thickness of the coating film does not become excessive, the viscosity of the polymer composition can be appropriately increased, and good coatability can be ensured. The solid content concentration in the polymer composition is more preferably 10 to 55% by mass, still more preferably 15 to 50% by mass.

<Cured film and its manufacturing method>
The cured film of the present disclosure is formed by the polymer composition prepared as described above. According to the above-mentioned polymer composition, it is possible to obtain a cured film in which the generation of outgas is reduced and the heat resistance and transparency are excellent. Therefore, the cured film is useful as an insulating film for organic EL elements. Specifically, the cured film is a partition film that defines a flattening film that flattens surface irregularities due to a thin film transistor (TFT) or the like, an interlayer insulating film that insulates between wirings, and a region that forms a light emitting layer in an organic EL element. It can also be used as a protective film that protects banks, TFTs, etc., spacers, adhesive layers for color filters, and the like. This cured film is significant in that it can reduce costs as compared with a conventional organic EL device that uses a polyimide material as a material for, for example, a partition wall, a bank, or a flattening film. In the present specification, the "partition wall" refers to a member used for color coding such as a color filter or a color conversion layer using quantum dots, and the "bank" refers to a member for separating the light emitting layer.

By using a radiation-sensitive curable composition as the polymer composition in the production of the cured film, a negative cured film can be formed by irradiation with radiation such as ultraviolet rays, far ultraviolet rays, and visible light. The cured film can be produced, for example, by a method including the following steps 1 to 4.
(Step 1) A step of forming a coating film on a substrate using the polymer composition.
(Step 2) A step of exposing at least a part of the coating film.
(Step 3) A step of developing a coating film.
(Step 4) A step of heating the developed coating film.
Hereinafter, each step will be described in detail.

[Step 1: Film forming step]
In this step, the polymer composition is applied to the surface on which the film is formed (hereinafter, also referred to as “the surface to be filmed”), and preferably heat treatment (pre-baking) is performed to remove the solvent on the surface to be filmed. A coating film is formed on the surface. The material of the surface to be filmed is not particularly limited, and is appropriately selected depending on the intended use of the cured film. For example, in the case of a flattening film, the polymer composition is applied onto a substrate provided with a switching element such as a TFT to form a coating film. As the substrate, for example, a glass substrate or a resin substrate is used. In the case of partition wall and bank applications, the polymer composition is applied onto a flattening film on which electrodes are formed to form a coating film. As the electrode, for example, a metal, an alloy, or an inorganic conductive material (ITO or the like) is used.

Examples of the coating method of the polymer composition include a spray method, a roll coating method, a spin coating method, a slit die coating method, a bar coating method, and an inkjet method. Among these, it is preferable to carry out by a spin coating method, a slit die coating method or a bar coating method. The prebaking conditions vary depending on the type and content ratio of each component in the polymer composition, but are, for example, 0.5 to 10 minutes at 60 to 130 ° C. The film thickness of the coating film formed (that is, the film thickness after prebaking) is preferably 1.0 to 12.0 μm.

[Step 2: Exposure step]
In this step, at least a part of the coating film formed in the above step 1 is irradiated with radiation. At this time, a cured film having a pattern can be formed by irradiating the coating film with radiation through a mask having a predetermined pattern. Examples of radiation include charged particle beams such as ultraviolet rays, far ultraviolet rays, visible rays, X-rays, and electron beams. Among these, ultraviolet rays are preferable, and examples thereof include g-line (wavelength 436 nm) and i-line (wavelength 365 nm). The amount of radiation exposure is preferably 0.1 to 20,000 J / m ^2.

[Process 3: Development process]
In this step, the radiation-irradiated coating film is developed. Specifically, the coating film irradiated with radiation in step 2 is developed with a developing solution to perform negative-type development in which a non-irradiated portion of radiation is removed. Examples of the developing solution include an aqueous solution of an alkali (basic compound). Examples of the alkali include sodium hydroxide, tetramethylammonium hydroxide, and the alkali exemplified in paragraph [0127] of JP-A-2016-145913. The alkali concentration in the alkaline aqueous solution is preferably 0.1 to 5.0% by mass from the viewpoint of obtaining appropriate developability.

Examples of the developing method include an appropriate method such as a liquid filling method, a dipping method, a rocking dipping method, and a shower method. The development time varies depending on the type and content ratio of each component in, but is, for example, 30 to 120 seconds. After the developing step, it is preferable to rinse the patterned coating film by washing with running water.

[Step 4: Heating step]
In this step, a process (post-baking) of heating the developed coating film is performed. Post-baking can be performed using a heating device such as an oven or a hot plate. For post-baking conditions, the heating temperature is, for example, 120-250 ° C. The heating time is, for example, 5 to 40 minutes when the heat treatment is performed on a hot plate, and 10 to 80 minutes when the heat treatment is performed in the oven. As described above, a cured film having a desired pattern can be formed on the substrate.

Since the cured film obtained by the above step is formed by using the above polymer composition, it is possible to reduce the generation of outgas even under severe conditions. Specifically, the amount of outgas generated while the temperature is raised from room temperature to 230 ° C. at a heating rate of 10 ° C./min and then held at 230 ° C. for 15 minutes is preferably less than ^{100 ng / cm 2.} .. Outgas amount in the conditions, more preferably 80 ng / cm ² or less, more preferably 70 ng / cm ² or less, particularly preferably less than 50 ng / cm ^2. The details of the method for measuring the outgas amount follow the method described in Examples described later.

<Organic EL element>
The organic EL device of the present disclosure has a cured film formed by using the above polymer composition. Examples of the organic EL element include a display element and a lighting element. In the organic EL display element and the organic EL illumination element, the cured film is at least one selected from the group consisting of, for example, a flattening film, an interlayer insulating film, a partition wall, a bank, a spacer, a protective film, and an adhesive layer for a color filter. Can be used.

Specific aspects of the organic EL element will be described with reference to the drawings as appropriate. One embodiment of the organic EL element 10 is an organic EL element having a top emission type structure shown in FIG. The organic EL element 10 is an active matrix type having a plurality of pixels formed in a matrix. The organic EL element 10 includes a support substrate 11, a pair of electrodes including a pixel electrode 12 and a counter electrode 13, an organic light emitting layer 14, and a sealing substrate 15.

In the organic EL element 10 having a top emission type structure, the support substrate 11 is not particularly limited, but may be a transparent substrate made of, for example, a glass material such as non-alkali glass; a resin material such as polyethylene terephthalate, polyethylene naphthalate, or polyimide. can. A thin film transistor (TFT) 16 is formed on the support substrate 11 for each pixel. The TFT 16 may be a bottom gate type in which a gate insulating film and a semiconductor layer are sequentially provided on the gate electrode, or a top gate type in which the gate insulating film and the gate electrode are sequentially provided on the semiconductor layer.

A flattening film 17 is arranged on the support substrate 11. The flattening film 17 is an insulating film and is formed on the entire surface of the support substrate 11 so as to cover the TFT 16. By forming the flattening film 17 on the support substrate 11, the surface unevenness due to the TFT 16 is flattened. A pixel electrode 12 as an anode is formed on the flattening film 17.

The pixel electrode 12 is made of a conductive material. When the organic EL element 10 has a top emission type structure, the pixel electrode 12 is required to have light reflectivity. The conductive materials that make up the light-reflecting electrode are Al (aluminum), APC alloy (alloy of silver, palladium and copper), ARA alloy (alloy of silver, rubidium and gold), MoCr alloy (alloy of molybdenum and chromium). ), NiCr alloy (alloy of nickel and chromium), or a laminated film of these metals and an electrode having high light transmittance (for example, ITO (Indium Tin Oxide)) is preferable. The pixel electrode 12 is electrically connected to the TFT 16 via a through hole 18 formed in the flattening film 17.

The counter electrode 13 is arranged at a position facing the pixel electrode 12. The counter electrode 13 is formed of a conductive material and functions as a common electrode for each pixel. When the organic EL element 10 has a top emission type structure, the counter electrode 13 is required to have light transmission. As the conductive material constituting the light-transmitting electrode, ITO, IZO (Indium Zinc Oxide) or tin oxide is preferable.

The organic light emitting layer 14 is arranged between the pixel electrode 12 and the counter electrode 13. Specifically, a partition wall 19 projecting from the film surface is formed on the flattening film 17. The partition wall 19 is arranged so as to cover the outer peripheral portion of each pixel electrode 12, and partitions the plurality of pixel electrodes 12. A recess 21 is formed in the region surrounded by the partition wall 19, and the organic light emitting layer 14 is arranged on the pixel electrode 12 in each recess 21. The organic light emitting layer 14 is a layer containing an organic light emitting material that emits electroluminescence. The organic light emitting material may be a small molecule compound or a polymer. Further, the organic light emitting layer 14 may be composed of a plurality of thin film layers including at least one of a hole injection layer, a hole transport layer, an electron transport layer and an electron injection layer together with the light emitting layer.

In the organic EL element 10, at least one of the flattening film 17 and the partition wall 19 is formed by using the above-mentioned polymer composition. For example, when the flattening film 17 is formed by using a negative type radiation-sensitive polymer composition as the polymer composition, first, the polymer composition is applied to the surface of the support substrate 11 provided with the TFT 16 on the TFT 16 side. A coating film is formed on the support substrate 11 by applying and preferably prebaking. Next, the coating film is irradiated with radiation through a mask, if necessary, to cause a curing reaction of the polyfunctional polymerizable compound (C) in the exposed portion. After the exposure, the flattening film 17 can be formed by performing a developing process and a post-baking process.

The same applies to the case of forming the partition wall 19. First, a negative-type radiation-sensitive polymer composition is applied as the polymer composition to the electrode-forming surface of the flattening film 17 on which the pixel electrodes 12 are formed, and a coating film is preferably formed by prebaking. .. Next, the coating film is irradiated with radiation through a mask having a pattern corresponding to the shape of the partition wall 19. After that, the partition wall 19 and the recess 21 can be formed on the flattening film 17 having the pixel electrodes 12 by performing a developing process and a post-baking process. The organic light emitting layer 14 is formed in the recess 21 thus formed by, for example, an inkjet method. The counter electrode 13 and the passivation film 22 are laminated in this order on the forming surface of the organic light emitting layer 14 in the flattening film 17.

The sealing substrate 15 is arranged at a predetermined interval with respect to the arrangement surface so as to face the surface on which the organic light emitting layer 14 and the like are arranged on the support substrate 11. The sealing substrate 15 is formed of an insulating material having high light transmittance, and is made of, for example, a glass substrate such as a non-alkali glass substrate; a transparent resin substrate such as polyethylene terephthalate, polyethylene naphthalate, or polyimide. The outer peripheral end of the sealing substrate 15 is bonded to the supporting substrate 11 using a sealing agent. As a result, the sealing layer 23 is formed in the space surrounded by the support substrate 11, the sealing substrate 15, and the sealing agent.

The sealing layer 23 is, for example, an inert gas layer filled with nitrogen gas or the like, or a packed layer with an adhesive or the like. Further, a black matrix 24 and a color filter 25 are arranged on the surface of the sealing substrate 15 on the sealing layer 23 side. The white light emitted from the organic light emitting layer 14 of each pixel becomes the color light transmitted and selected by the color filter 25 and transmits through the sealing substrate 15.

Another embodiment of the organic EL element 10 is an organic EL element having a bottom emission type structure shown in FIG. In the following description of FIG. 2, the same points as those of FIG. 1 will be referred to the description of FIG. 1, and the differences from FIG. 1 will be mainly described.

In the organic EL element 10 shown in FIG. 2, a TFT 16 and a color filter 25 are provided on the support substrate 11. On the flattening film 17, a pair of electrodes composed of a pixel electrode 12 and a counter electrode 13 and an organic light emitting layer 14 arranged between the pair of electrodes are provided. When the organic EL element 10 has a bottom emission type structure, the support substrate 11 and the pixel electrode 12 are required to have light transmission, and the counter electrode 13 is required to have light reflection. Examples of the light-transmitting substrate material, the light-transmitting conductive material, and the light-reflecting conductive material include the materials exemplified in FIG. The white light emitted from the organic light emitting layer 14 of each pixel becomes the color light transmitted and selected by the color filter 25 and transmits through the support substrate 11.

Hereinafter, the present invention will be described in more detail based on Examples, but the present invention is not limited to these Examples. In the following examples and the like, unless otherwise specified, "parts" means "parts by mass". The weight average molecular weight (Mw), number average molecular weight (Mn) and dispersity (Mw / Mn) of the polymer were measured by the following methods.

[Measurement method of Mw, Mn and Mw / Mn]
The Mw and Mn of the polymer were measured by gel permeation chromatography (GPC method) under the following analytical conditions using Tosoh's GPC columns (2 G2000HXL, 1 G3000HXL, 1 G4000HXL). The degree of dispersion (Mw / Mn) was calculated from the measurement results of Mw and Mn.
(Analysis conditions)
Elution solvent: tetrahydrofuran Flow rate: 1.0 mL / min Sample concentration: 1.0% by mass
Sample injection volume: 100 μL
Column temperature: 40 ° C
Detector: Differential refractometer Standard material: Monodisperse polystyrene

<Synthesis of alkali-soluble resin>
[Synthesis Example 1]
A flask equipped with a cooling tube and a stirrer was charged with 10 parts of 2,2'-azobis- (2,4-dimethylvaleronitrile) and 200 parts of methyl 3-methoxypropionate. Subsequently, 10 parts of methacrylic acid, 35 parts of 3,4-epoxycyclohexylmethylmethacrylate, 25 parts of cyclohexyl acrylate, 25 parts of N-cyclohexylmaleimide, and 5 parts of methyl methacrylate were charged. After substituting with nitrogen, stirring was started gently. The temperature of the solution was raised to 75 ° C., and this temperature was maintained for 5 hours to obtain a solution containing an alkali-soluble resin (hereinafter referred to as “resin (A-1)”). The solid content concentration of the obtained resin solution was 34.2% by mass, the Mw of the resin (A-1) was 12,000, and the Mw / Mn was 2.0.

[Synthesis Examples 2-12]
A solution containing the resins (A-2) to (A-20) was obtained by operating in the same manner as in Synthesis Example 1 except that each component of the type and blending amount shown in Table 1 was used as the monomer. The results are shown in Table 1.

In Table 1, the abbreviations of the monomers are as follows.
(A1) N-Cyclohexyl maleimide (a2) N-phenylmaleimide (a3) Cyclohexyl acrylate (a4) Tricyclo [5.2.1.0 ^2,6 ] Decane-8-yl acrylate (a5) benzyl acrylate (A6) Fenyl acrylate (a7) 3,4-epoxycyclohexylmethylmethacrylate (a8) 3,4-epoxytricyclo [5.2.1.0 ^2,6 ] decylacrylate (a9) glycidyl methacrylate (a10) (3) -Ethyloxetane-3-yl) Methylmethacrylate (a11) Methacrylate (a12) 4-Hydroxy-α-methylstyrene (a13) Maleimide (a14) Methylmethacrylate (a15) styrene

<Preparation of radiation-sensitive resin composition>
[Example 1]
In a solution containing the resin (A-1), 4 parts of "NCI-930" (ADEKA) and "Irgacure" as a reaction initiator for an amount corresponding to 100 parts (solid content) of the resin (A-1). OXE01 "(BASF) 5 parts, polyfunctional polymerizable compound" KAYARAD DPHA "(Nippon Kayakusha) 50 parts, methacryloxypropyltrimethoxysilane (Toray Dow Corning's" XIAMETER (R) OFS-6030 SILANE 3 parts and 0.1 part of 2,5-di-t-butylhydroquinone (Wako Pure Chemical Industries, Ltd.) are mixed, and the obtained mixture is 3-methoxy so that the solid content concentration is 30% by mass. After dissolving in a mixed solvent of methyl propionate and propylene glycol monomethyl ether acetate (mass ratio 50:50), the resin composition (S-1) was prepared by filtering with a membrane filter having a pore size of 0.2 μm.

[Examples 2 to 19 and Comparative Examples 1 to 4]
The resin composition (S) was operated in the same manner as in Example 1 except that the alkali-soluble resin, the reaction initiator and the polyfunctional polymerizable compound were used in the same manner as in Example 1 except that the components of the types and blending amounts shown in Tables 2 and 3 were used. -2)-(S-19) and (CS-1)-(CS-3) were prepared. Further, in Comparative Example 4, a polyimide-containing photosensitive composition (“DL1000” manufactured by Toray Industries, Inc.) was used as the resin composition (CS-4).

The meanings of the symbols in Tables 2 and 3 are as follows.
-Alkali-soluble resin A-1 to A to 20: Resin synthesized in Synthesis Examples 1 to 20, respectively-Reaction initiator B-1: "NCI-930" manufactured by ADEKA Corporation
B-2: 1,2-octanedione, 1- [4- (phenylthio) -2- (O-benzoyloxime)] (BASF's "Irgacure OXE01")
-Polyfunctional polymerizable compound C-1: Mixture of dipentaerythritol hexaacrylate and dipentaerythritol pentaacrylate (Nippon Kayaku Co., Ltd. "KAYARAD DPHA")
C-2: 1,9-nonanediol diacrylate
(Kyoeisha Chemical Co., Ltd. "Light Acrylate 1,9ND-A")

<Evaluation>
An insulating film is formed using the resin compositions obtained in Examples and Comparative Examples, and low outgassing property, wiring property, negative radiation sensitivity, negative resolution property, development adhesion, light according to the method described below. Transparency and heat-resistant light transmissivity were evaluated. The evaluation results are shown in Tables 2 and 3.

[Low outgassing]
The resin compositions obtained in Examples and Comparative Examples were applied onto a silicon substrate using a spinner, and then prebaked on a hot plate at 90 ° C. for 2 minutes to form a coating film. Next, the coating film was exposed at an exposure amount of ^{200 J / m 2} using an exposure machine (“PLA-501F” manufactured by Canon Inc .: using an ultrahigh pressure mercury lamp). Next, a development treatment was carried out at 25 ° C. by a liquid filling method using an aqueous solution of tetramethylammonium hydroxide (developing solution) having a concentration of 2.38% by mass. The time of the developing process was 100 seconds. After the development treatment, the coating film was washed with running water for 1 minute with ultrapure water and dried. This silicon substrate was heated at 230 ° C. for 30 minutes in a clean oven to obtain an insulating film having a film thickness of 2.0 μm.
A silicon substrate with an insulating film was cut into 1 cm x 5 cm pieces, and the four cut silicon substrates were subjected to a silicon wafer analyzer device ("Heat Desorption Device JTD-505" by Nippon Analytical Industry Co., Ltd., and "Gas Chromatograph Mass Spectrometry" by Shimadzu Corporation. ^{Using a total GCMS-QP2010Plus ”), the amount of alcoholic outgas (ng / cm 2} ) when the temperature was raised to 230 ° C. at a heating rate of 10 ° C./min and held at the same temperature for 15 minutes was determined. The outgas amount was evaluated according to the following criteria.
(Evaluation criteria)
A: Less than 50 ng / cm ² B: 50 ng / cm ² or more and less than 100 ng / cm ² C: 100 ng / cm ² or more

[Wiring property]
The same operation as when the insulating film was formed in the "low outgassing" evaluation was performed to obtain a silicon substrate on which the insulating film having a film thickness of 4.0 μm was formed. ITO wiring (width 50 μm) was formed on this insulating film using a sputtering device (“SH-550-C12” manufactured by ULVAC: target), and annealing treatment was performed at 230 ° C. for 30 minutes. When measured using a surface unevenness meter α-step, the thickness of the ITO wiring was 1000 Å. The heat resistance of the insulating film (particularly the coefficient of linear expansion, which is referred to as "wiring property") was evaluated by visually confirming the presence or absence of cracks in the obtained ITO wiring board. The wiring property was evaluated according to the following criteria.
(Evaluation criteria)
A: No cracks B: Cracks

[Negative radiation sensitivity]
The resin compositions obtained in Examples and Comparative Examples were applied onto a glass substrate (“Corning 7059” by Corning Inc.) using a spinner, and then prebaked on a hot plate at 90 ° C. for 2 minutes to obtain a film thickness. A 4.0 μm coating film was formed. Next, using an exposure machine (Canon's "PLA-501F": using an ultra-high pressure mercury lamp), the amount of exposure was changed, and a coating film was applied through a pattern mask having a plurality of rectangular light-shielding portions (10 μm × 10 μm). Was exposed. Next, a development treatment was carried out at 25 ° C. by a liquid filling method using an aqueous solution of tetramethylammonium hydroxide (developing solution) having a concentration of 2.38% by mass. The time of the developing process was 100 seconds. After the development treatment, the coating film was washed with running water for 1 minute with ultrapure water and dried to form a pattern on a glass substrate. This glass substrate was heated at 230 ° C. for 30 minutes in a clean oven to obtain an insulating film having through holes.
The film thickness of the insulating film formed by using the resin compositions (S-1) to (S-19) and (CS-1) to (CS-3) is the residual film represented by the following mathematical formula (1). The exposure amount at which the rate (that is, the ratio at which the patterned thin film remains appropriately) is 85% or more was determined as the sensitivity, and the radiation sensitivity was evaluated according to the following criteria.
Residual film ratio (%) = (film thickness after development / film thickness before development) x 100 ... (1)
For the resin composition (CS-4), the same operation is performed except that a pattern mask having a rectangular transmissive portion (10 μm × 10 μm) is used, and the exposure amount at which through holes are formed by exposure through this pattern mask is determined. It was determined as the sensitivity, and the sensitivity was evaluated according to the following criteria.
(Evaluation criteria)
A: Less than 200J / m ² B: 200J / m ² or more and less than 400J / m ² C: 400J / m ² or more

[Negative resolution]
An insulating film having through holes was formed in the same manner as in the evaluation of "negative radiation sensitivity" except that the exposure amount was set to 200 J / m ^2. The resolution was evaluated by observing the minimum diameter of the through hole of this insulating film with an optical microscope. The resolution was evaluated according to the following criteria.
(Evaluation criteria)
A: The minimum diameter of the through hole is 10 μm or more B: The minimum diameter of the through hole is 8 μm or more and less than 10 μm C: The minimum diameter of the through hole is 5 μm or more and less than 8 μm

[Development adhesion]
Evaluation of radiation sensitivity except that a mask with a line-and-space ratio (L / S) of 1: 1 (space width of the same size as the line width of 5 to 40 μm) was used and the exposure amount was 200 J / m ^2. An insulating film was formed in the same manner as in the above. With respect to this insulating film, the minimum width of the line remaining without peeling after development was observed with an optical microscope, and the development adhesion was evaluated according to the following criteria.
(Evaluation criteria)
A: Minimum width is less than 10 μm B: Minimum width is 10 μm or more and less than 30 μm C: Minimum width is 30 μm or more

[Light transmission and heat-resistant light transmission]
The resin compositions obtained in Examples and Comparative Examples are applied onto a glass substrate (“Corning 7059” by Corning Inc.) using a spinner, and then prebaked on a hot plate at 90 ° C. for 2 minutes to form a coating film. Formed. Next, the coating film was exposed at ^{an exposure amount of 200 J / m 2} using an exposure machine (“PLA-501F” manufactured by Canon Inc .: using an ultrahigh pressure mercury lamp). Next, a development treatment was carried out at 25 ° C. by a liquid filling method using an aqueous solution of tetramethylammonium hydroxide (developing solution) having a concentration of 2.38% by mass. The time of the developing process was 100 seconds. Further, by heating in a clean oven at 230 ° C. for 30 minutes, a cured film A having a film thickness of 3.0 μm was obtained. The cured film A was further heated at 230 ° C. for 5 hours in a clean oven to obtain a cured film B.
For each glass substrate having a cured film, after the cured film A is formed and after the cured film B is formed, a spectrophotometer (“150-20 type double beam” manufactured by Hitachi, Ltd.) is used to have a wavelength in the range of 400 to 800 nm. The light transmittance (light transmittance) was measured, and the lowest value of the light transmittance in the wavelength range of 400 to 800 nm was evaluated. The measured value of the cured film A was defined as the "minimum light transmittance", and the measured value of the cured film B was defined as the "minimum heat resistant light transmittance". The minimum light transmittance and the minimum heat resistant light transmittance are shown in Tables 2 and 3.

As shown in Tables 2 and 3, the cured films of Examples 1 to 19 have a small amount of outgas, and are excellent in wiring property, radiation sensitivity, resolution, development adhesion, light transmission, and heat-resistant light transmission. rice field. On the other hand, the cured films of Comparative Examples 1 and 2 using the polymer in which the content ratio of the structural unit (U2) is 40% by mass and the content ratio of the structural unit (U1) is 15% by mass are radiation sensitivity. Although the resolution and development adhesion were good, the amount of outgassing was large and the wiring property was inferior to that of the example. The cured film of Comparative Example 3 using the polymer having no structural unit (U1) was inferior in wiring property, resolution property and development adhesion. The cured film of Comparative Example 4 containing polyimide as a resin had a small amount of outgas and good wiring properties, but was inferior in radiation sensitivity, resolution and development adhesion to those of Examples. Further, the cured film of Comparative Example 4 has low minimum light transmittance and minimum heat-resistant light transmittance of 80% and 60%, respectively, and is inferior in light transparency and heat-resistant light transmittance to those of Example. Was there.

From these results, according to the polymer composition of the present invention, there is little outgas, wiring property (low coefficient of thermal expansion), radiation sensitivity, resolution, development adhesion, light transmission and heat resistance light transmission (heat imparting). It was found that a cured film having excellent transparency) can be provided. Therefore, the cured film of the present invention is particularly suitable as a flattening film, an interlayer insulating film, a partition wall, a bank, etc. of an organic EL element.

10 ... Organic EL element, 11 ... Support substrate, 12 ... Pixel electrode, 13 ... Common electrode, 14 ... Organic light emitting layer, 15 ... Encapsulating substrate, 16 ... Thin film transistor (TFT), 17 ... Flattening film, 18 ... Through hole , 19 ... partition, 21 ... recess, 22 ... passion film, 23 ... sealing layer, 24 ... black matrix, 25 ... color filter.

Claims (14)

Polymer component (A) and
Reaction initiator (B) and
With the polyfunctional polymerizable compound (C),
Contains,
The polymer component (A) is derived from at least one selected from the group consisting of an N-substituted maleimide compound having a monovalent cyclic hydrocarbon group and a (meth) acrylic compound having a monovalent cyclic hydrocarbon group. Includes structural units (Uα)
The structural unit (Uα) contains 28% by mass or more of the structural unit (U1) derived from the N-substituted maleimide compound with respect to the total amount of the structural unit (Uα) contained in the polymer component (A). , Polymer composition. The polymer component (A) according to claim 1, wherein the polymer component (A) contains the structural unit (U1) in an amount of more than 15% by mass and 35% by mass or less with respect to all the structural units constituting the polymer component (A). Polymer composition. The polymer component (A) contains a structural unit (U2) derived from an acrylic compound having a monovalent cyclic hydrocarbon group in an amount of 0% by mass based on all the structural units constituting the polymer component (A). The polymer composition according to claim 1 or 2, which comprises more than 35% by mass. The polymer composition according to any one of claims 1 to 3, which is used for an organic EL device. The polymer composition according to any one of claims 1 to 4, wherein the polymer component (A) has a weight average molecular weight of 10,000 or more. The polymer composition according to any one of claims 1 to 5, wherein the polymer component (A) further contains a structural unit (U3) having a cyclic ether group. The polymer composition according to any one of claims 1 to 6, wherein the polymer component (A) is alkali-soluble. The polymer component (A) further comprises at least one structural unit selected from the group consisting of a structural unit having a carboxy group, a structural unit having a sulfonic acid group, a structural unit having a phenolic hydroxyl group, and a maleimide unit. The polymer composition according to any one of claims 1 to 7, which comprises. The monovalent cyclic hydrocarbon group contained in the N-substituted maleimide compound is a monovalent alicyclic hydrocarbon group having a monocyclic ring, a crosslinked ring or a spiro ring, or a monovalent aromatic hydrocarbon group. The polymer composition according to any one of claims 1 to 8. The polymer composition according to any one of claims 1 to 9, which is used for forming a flattening film, a partition wall or a bank. A cured film formed by using the polymer composition according to any one of claims 1 to 10. The cured film according to claim 11, wherein the amount of outgas generated during holding at 230 ° C. for 15 minutes after raising the temperature from room temperature to 230 ° C. at a heating rate of 10 ° C./min ^{is less than 100 ng / cm 2.} .. The cured film according to claim 11 or 12, which is for an organic EL display element or an organic EL lighting element. An organic EL device comprising the cured film according to any one of claims 11 to 13.

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