KR102654734B1 - Curable composition, cured film, display device, and method for forming the cured film - Google Patents

Abstract

(Problem) The object of the present invention is to provide a curable composition that can form a cured film with high hardness and excellent solvent resistance, even if it is a film obtained by a curing and baking process at 200°C or lower, while improving storage stability and radiation sensitivity. will be.
(Means for solving the problem) The invention made to solve the above problems is a curable composition containing [A] a compound having a polymerizable group, [B] a photosensitizer, and [C] a heat-activated delayed fluorescent compound.

Description

Curable composition, cured film, display element, and method of forming the cured film {CURABLE COMPOSITION, CURED FILM, DISPLAY DEVICE, AND METHOD FOR FORMING THE CURED FILM}

The present invention relates to a curable composition, a display element, and a method of forming a cured film.

Display elements such as liquid crystal display elements, organic electroluminescence elements (organic EL elements), and electronic paper elements include protective films to prevent deterioration or damage to electronic components, including touch panels, and wiring arranged in layers. Cured films such as an interlayer insulating film to maintain insulation between layers and a planarization film to increase the aperture ratio are formed. To form such a cured film, a radiation-sensitive curable composition is used. For example, a coating film of the curable composition is formed on a substrate, exposed through a photomask with a predetermined pattern, developed with a developer, and unnecessary portions are removed. , After that, a cured film is obtained by heating (post-baking).

The curable composition is required to have a viscosity that does not increase excessively even when stored for a long period of time (storage stability) and to have good radiation sensitivity. In addition, the cured film obtained from the curable composition is required to have high hardness and excellent resistance to solvents used in the post-cured film formation process (solvent resistance).

Additionally, in forming such a cured film, from the curing and firing process of usually 200°C or higher, curing is performed at 200°C or lower from the viewpoint of reducing environmental load, responding to plastic substrates, and preventing thermal deterioration of dyes or organic luminescent materials with insufficient heat resistance. The firing process is being reviewed (Japanese Patent Publication No. 2017-126068, Japanese Patent Publication No. 2011-257537).

However, with the curable composition described in the above publication, it was difficult to form a cured film with high hardness and excellent solvent resistance even in a low-temperature baking process while improving storage stability and radiation sensitivity.

Japanese Patent Publication No. 2017-126068 Japanese Patent Publication No. 2011-257537

The present invention was made based on the above-mentioned circumstances, and its purpose is to form a cured film with high hardness and excellent solvent resistance, even if it is a film obtained by a curing and baking process at 200° C. or lower, while improving storage stability and radiation sensitivity. The object is to provide a curable composition that can be used, a cured film obtained from the curable composition, a display element using the cured film, and a method of forming the cured film.

The present inventors conducted intensive studies to solve the above problems. As a result, it was discovered that the above problems could be solved by a curable composition having the following structure, and the present invention was completed.

The invention made to solve the above problem is,

(1) A curable composition containing [A] a compound having a polymerizable group, [B] a photosensitizer, and [C] a heat-activated delayed fluorescent compound.

(2) A curable composition in which the [C] heat-activated delayed fluorescent compound is a compound represented by the following formula (1) or (2).

(In Formula (1) and Formula (2), at least one of R ¹ to R ⁷ is a hydrogen atom, an alkyl group having 1 to 12 carbon atoms, a phenyl group, a tolyl group, a naphthyl group, a cyano group, or the following formula (X) It represents the group that appears as .)

(In formula (X), R ²¹ to R ²⁸ each independently represent a hydrogen atom or a substituent. However, at least one of <A> and <B> is satisfied.

<A> R ²⁵ and R ²⁶ are combined into one to form a single bond.

<B> R ²⁷ and R ²⁸ are combined to form a substituted or unsubstituted benzene ring.)

(3) The above formula (X) is substituted or unsubstituted 9-carbazolyl group, 3,6-di(t-butyl)-9-carbazolyl group, substituted or unsubstituted 1,2,3 It is a curable composition characterized in that it represents a 4-tetrahydro-9-carbazolyl group, a substituted or unsubstituted 1-indolyl group, or a substituted or unsubstituted diarylamino group.

(4) A curable composition in which the polymerizable group of the compound having the [A] polymerizable group is at least one selected from an epoxy group, a vinyl group, and a (meth)acryloyl group.

(5) Additionally, it is a curable composition containing [D] binder resin.

(6) The photosensitive agent [B] is a curable composition selected from acid generators, base generators, and radical polymerization initiators.

(7) Additionally, the photosensitive agent [B] is a curable composition in which the photosensitive agent is a radical polymerization initiator containing a condensed ring.

(8) A curable composition in which the content ratio of [C] thermally activated delayed fluorescent compound to the total content of [B] photosensitizer is in the range of 0.01 to 5.

(9) A method of forming a cured film including the following steps.

A process of forming a coating film of the curable composition on a substrate, exposing the coating film to light or heating it at 80°C or higher and 150°C or lower.

(10) A cured film obtained by the above cured film formation method.

(11) A display element having the above cured film.

The curable composition of the present invention can form a cured film with high hardness and excellent solvent resistance, even if it is a film obtained by a curing and baking process at 200°C or lower, while improving storage stability and radiation sensitivity.

(Form for carrying out the invention)

Hereinafter, embodiments of the present invention will be described in detail, but are not limited thereto.

<Curable composition>

The curable composition of the present invention is characterized as being a curable composition containing [A] a compound having a polymerizable group, [B] a photosensitizer, and [C] a heat-activated delayed fluorescent compound.

The curable composition improves storage stability and radiation sensitivity by containing [A] a compound having a polymerizable group, [B] a photosensitive agent, and [C] a heat-activated delayed fluorescent compound, while the cured film formed by the low-temperature firing process has hardness. It becomes possible to form a cured film that is high and has excellent solvent resistance.

Thermally Activated Delayed Fluorescence (also known as TADF) refers to a phenomenon of emitting light through conversion from a triplet exciton to a singlet exciton, which does not normally occur, and is activated by heat, and is more effective than ordinary fluorescent materials. It exhibits a long fluorescence lifetime. It is attracting attention as a next-generation organic EL emitting material that can improve light conversion efficiency. In the present invention, it was discovered that by using the compound that generates TADF in combination with a photosensitive agent having a similar structure, the curing reaction proceeds in the temperature range where TADF is generated to form a cured film.

In the formation of a normal cured film, a coating film is formed with a curable composition, and through exposure, [B] a photosensitive agent is sensitized to generate a polymerization initiator species, and [A] a crosslinking reaction of a compound having a polymerizable group is initiated to form a cured film. . Additionally, in a normal curing process, the formed cross-linked structure is heated to 200°C or higher to make it a stronger cross-linked structure. Usually, a cured film is formed by light curing or thermal curing.

However, in the present invention, the curing reaction is performed using the TADF effect instead of the above high temperature heating and baking process of 200°C or higher. Photoresistants with similar singlet excited state energy orders, such that the TADF effect occurs at a temperature higher than room temperature (50 to 100°C), are used in combination.

It is believed that electron transfer occurs from the material in which the TADF effect occurs to the photosensitive agent, and the photosensitive agent is excited to generate polymerization initiator species, and the curing reaction proceeds again due to the generation of the polymerization initiator species. Accordingly, it is assumed that a cured film can be formed without a high temperature process by using the [C] thermally activated delayed fluorescent compound.

First, we invent a compound having an [A] polymerizable group contained in the curable composition of the present invention.

<[A] Compound having a polymerizable group>

The compound having the [A] polymerizable group of the present invention is a compound having one or more polymerizable groups per molecule, and the polymerizable group is at least one selected from an epoxy group, a vinyl group, and a (meth)acryloyl group. [A] The compound having a polymerizable group may be a monomeric compound or a polymer.

[A] The polymerizable group of the monomer compound of the compound having a polymerizable group is preferably a polymerizable compound having a (meth)acryloyl group or a vinyl group from the viewpoint of radical polymerization. By including these compounds, it is possible to increase the hardness of the cured film obtained and improve the adhesion of the cured film to the substrate.

Specific examples of such compounds include the compounds shown below.

For example, monofunctional, difunctional, or trifunctional or more (meth)acrylic acid esters are preferred because the strength of the cured film formed through polymerization is improved. Additionally, it is also possible to use compounds having a vinyl group such as vinyl sulfide derivatives, (meth)acrylate derivatives, vinyl sulfoxide derivatives, or vinyl sulfone derivatives. These compounds are preferable because they improve sensitivity and maintain good storage stability of the curable composition.

Examples of the monofunctional (meth)acrylic acid ester include 2-hydroxyethyl (meth)acrylate, diethylene glycol monoethyl ether (meth)acrylate, (2-(meth)acryloyloxyethyl)( 2-hydroxypropyl)phthalate, ω-carboxypolycaprolactone mono(meth)acrylate, etc. are mentioned. Examples of these commercially available products include, by brand name, Aronics (registered trademark) M-101, M-111, M-114, and M-5300 (manufactured by Toagosei Co., Ltd.); KAYARAD (registered trademark) TC-110S, TC-120S (above, manufactured by Nippon Kayaku Co., Ltd.); Viscot 158, Copper 2311 (above, manufactured by Osaka Yuki Chemical Industry Co., Ltd.), etc. can be mentioned.

Examples of the bifunctional (meth)acrylic acid ester include ethylene glycol di(meth)acrylate, propylene glycol di(meth)acrylate, diethylene glycol di(meth)acrylate, and tetraethylene glycol di(meth)acrylate. 1,6-hexanediol di(meth)acrylate, 1,9-nonanediol di(meth)acrylate, and fluorene diacrylate. As these commercially available products, their brand names include, for example, Aronics (registered trademark) M-210, M-240, M-6200 (manufactured by Toagose Co., Ltd.), KAYARAD (registered trademark) HDDA, and HX-220, Copper R-604 (above, manufactured by Nippon Kayaku Co., Ltd.), Viscot 260, Copper 312, Copper 335HP (above, manufactured by Osaka Yuki Chemical Industry Co., Ltd.), Light Acrylate 1,9- NDA (manufactured by Kyoei Shaka Chemical Co., Ltd.), OGSOL (EA-0200 manufactured by Osaka Gas Chemical Co., Ltd.), etc.

Examples of the trifunctional or higher (meth)acrylic acid ester include trimethylolpropane tri(meth)acrylate, pentaerythritol tri(meth)acrylate, pentaerythritol tetra(meth)acrylate, and dipentaerythritol penta. (meth)acrylate, dipentaerythritol hexa(meth)acrylate;

A mixture of dipentaerythritol penta(meth)acrylate and dipentaerythritol hexa(meth)acrylate;

Ethylene oxide modified dipentaerythritol hexa(meth)acrylate, tri(2-(meth)acryloyloxyethyl)phosphate, succinic acid modified pentaerythritol tri(meth)acrylate, succinic acid modified dipentaerythritol penta(meth) ) Acrylate, tripentaerythritol hepta (meth)acrylate, tripentaerythritol octa (meth)acrylate, mixture of isocyanuric acid EO-modified diacrylate and isocyanuric acid EO-modified triacrylate;

It is obtained by reacting a compound having a straight-chain alkylene group and an alicyclic structure and having two or more isocyanate groups with a compound having one or more hydroxyl groups in the molecule and also having three, four or five (meth)acryloyloxy groups. Polyfunctional urethane acrylate-based compounds, etc. can be mentioned.

Commercially available products of the above-mentioned trifunctional or higher (meth)acrylic acid esters include, for example, Aronics (registered trademark) M-309, M-400, M-405, M-450, and M-7100 under brand names. , M-8030, M-8060, TO-1450 (manufactured by Toagosei Co., Ltd.), KAYARAD (registered trademark) TMPTA, DPHA, DPCA-20, DPCA-30, DPCA-60. , DPCA-120, DPEA-12 (manufactured by Nippon Kayaku Co., Ltd.), Viscote 295, 300, 360, GPT, 3PA, 400 (manufactured by Osaka Yuki Kagaku Kogyo Co., Ltd.) ), or commercially available products containing polyfunctional urethane acrylate-based compounds, such as New Frontier (registered trademark) R-1150 (manufactured by Dai-ichigogyo Seiyaku Co., Ltd.), KAYARAD (registered trademark) DPHA-40H (Nippon Kaya) (manufactured by Ku Co., Ltd.), etc. can be mentioned.

Among these, in particular, ω-carboxypolycaprolactone monoacrylate, 1,9-nonanediol dimethacrylate, trimethylolpropane triacrylate, pentaerythritol triacrylate, pentaerythritol tetraacrylate, and dipentaerythate. Ritol pentaacrylate, dipentaerythritol hexaacrylate;

A mixture of dipentaerythritol pentaacrylate and dipentaerythritol hexaacrylate;

A mixture of tripentaerythritol hepta(meth)acrylate and tripentaerythritol octa(meth)acrylate;

Commercially available products containing ethylene oxide-modified dipentaerythritol hexaacrylate, polyfunctional urethane acrylate-based compounds, succinic acid-modified pentaerythritol triacrylate, and succinic acid-modified dipentaerythritol pentaacrylate are preferable.

Compounds having a vinyl group include styrene, vinylnaphthalene, 1,3-divinylnaphthalene, 1,4-divinylnaphthalene, 1,5-divinylnaphthalene, 1,6-divinylnaphthalene, and 1,7-divinylnaphthalene. , 2,3-divinylnaphthalene, 2,6-divinylnaphthalene, 2,7-divinylnaphthalene, 1,2,4-trivinylnaphthalene, 1,2,6-trivinylnaphthalene, 1,3,6 -Trivinylnaphthalene, 1,3-divinyl-6-methoxy-naphthalene, 1,3-divinyl-6-methyl-naphthalene, 1,3-divinyl-6-chloro-naphthalene, 1,2-di Examples include vinyl-6-ethoxy-naphthalene, 1-vinyl-5-methoxy-naphthalene, 1-vinylnaphthalene, and 2-vinylnaphthalene.

It is also possible to use compounds having a vinyl group such as vinyl sulfide derivatives, (meth)acrylate derivatives, vinyl sulfoxide derivatives, or vinyl sulfone derivatives. Specific examples of such compounds include vinyl sulfide, phenylvinyl sulfoxide, divinyl sulfoxide, divinyl sulfone, phenylvinyl sulfone, and bis(vinylsulfonyl)methane.

The above monomer compounds can be used individually or in mixture of two or more types. The usage ratio of the monomer compound in the curable composition of the present invention is not particularly limited as the lower limit of the monomer compound, but is, for example, 50% by mass in terms of solid content, and 60% by mass is preferable. On the other hand, as this upper limit, 99 mass% is preferable and 95 mass% is more preferable.

When the compound having an [A] polymerizable group is a polymer, a polymer having a structural unit having a (meth)acryloyloxy group in the polymer can be used (hereinafter also referred to as [a] polymer). This polymer can be used in combination with a monomer compound, and in this case, the polymer can also be used as a binder resin.

The structural unit having a (meth)acryloyloxy group is, for example, a method of reacting (meth)acrylic acid with an epoxy group in a polymer, a method of reacting a (meth)acrylic acid ester having an epoxy group with a carboxyl group in a polymer, and a hydroxyl group in a polymer. It can be formed by reacting a (meth)acrylic acid ester having an isocyanate group, reacting (meth)acrylic acid with an acid anhydride moiety in a polymer, etc.

The [a] polymer is obtained, for example, by copolymerizing the (a1) compound that imparts a carboxyl group-containing structural unit with a compound that imparts other structural units in the presence of a polymerization initiator in a solvent. It can be manufactured by reacting a carboxyl group-containing structural unit with the compound (a2), which gives a (meth)acryloyl group-containing structural unit.

[(a1) Compound]

Examples of the compound (a1) include unsaturated monocarboxylic acid, unsaturated dicarboxylic acid, anhydride of unsaturated dicarboxylic acid, and mono[(meth)acryloyloxyalkyl]ester of polyhydric carboxylic acid. Examples of unsaturated monocarboxylic acids include acrylic acid, methacrylic acid, and crotonic acid. Examples of unsaturated dicarboxylic acids include maleic acid, fumaric acid, citraconic acid, mesaconic acid, and itaconic acid. Examples of anhydrides of unsaturated dicarboxylic acids include anhydrides of the compounds exemplified as dicarboxylic acids above. Examples of mono[(meth)acryloyloxyalkyl] esters of polyvalent carboxylic acids include mono[2-(meth)acryloyloxyethyl] succinic acid and mono[2-(meth)acryloyloxyethyl phthalate]. 〕 etc. can be mentioned.

Among these (a1) compounds, acrylic acid, methacrylic acid, and maleic anhydride are preferable, and acrylic acid, methacrylic acid, and maleic anhydride are more preferable due to copolymerization reactivity, solubility in aqueous alkaline solutions, and ease of availability. These (a1) compounds may be used individually, or two or more types may be mixed and used.

The proportion of the compound (a1) used is preferably 5% by mass to 30% by mass, and more preferably 10% by mass to 25% by mass, based on the total amount of monomers constituting the polymer [a]. By setting the usage ratio of the compound (a1) to 5% by mass to 30% by mass, the solubility of the polymer in an aqueous alkaline solution can be optimized.

(meth)acrylic acid ester having an epoxy group is an epoxy group-containing unsaturated compound, and examples of the epoxy group include oxiranyl group (1,2-epoxy structure) or oxetanyl group (1,3-epoxy structure). Specifically, glycidyl (meth)acrylate, 3-(meth)acryloyloxymethyl-3-ethyloxetane, 3,4-epoxycyclohexylmethyl (meth)acrylate, 3,4-epoxytricyclo [5.2.1.0 ^2,6 ] decyl (meth)acrylate, tris (4-hydroxyphenyl) ethane triglycidyl ether, etc.

The polymer of this embodiment can be manufactured by a known method, for example, Japanese Patent Application Laid-Open No. 2003-222717, Japanese Patent Application Laid-Open No. 2006-259680, International Publication No. 07/029871 Pamphlet, Japanese Patent Application Laid-Open. Patent Publication No. 5-19467, Japanese Unexamined Patent Publication No. 6-230212, Japanese Unexamined Patent Publication No. 7-207211, Japanese Unexamined Patent Publication No. 09-325494, Japanese Unexamined Patent Publication No. 11-140144, Japanese Patent Application Laid-open It can be synthesized by the method disclosed in Patent Publication No. 2008-181095, etc.

[a] The structural unit having a (meth)acryloyloxy group of the polymer is obtained by reacting a (meth)acrylic acid ester having an epoxy group with a carboxyl group in the copolymer, and the structural unit having a (meth)acrylic group after reaction is as follows. It appears as equation (3a).

In the formula (3a), R ³⁰ and R ³¹ each independently represent a hydrogen atom or a methyl group. a is an integer from 1 to 6. R ³² is a divalent group represented by the following formula (3a-1) or (3a-2).

In the above formula (3a-1), R ³³ is a hydrogen atom or a methyl group. In the above formulas (3a-1) and (3a-2), * represents a site that bonds to an oxygen atom. Regarding the structural unit represented by the above formula (3a), for example, when a copolymer having a carboxyl group is reacted with a compound such as glycidyl methacrylate or 2-methylglycidyl methacrylate, formula (3a) ), R ³² becomes formula (3a-1). On the other hand, when compounds such as 3,4-epoxycyclohexylmethyl methacrylate are reacted, R ³² in formula (3a) becomes formula (3a-2).

The weight average molecular weight (Mw) of the polymer [a] above is usually 1,000 to 100,000, preferably 3,000 to 50,000. Mw refers to the weight average molecular weight in terms of polystyrene measured by gel permeation chromatography (elution solvent: tetrahydrofuran).

[a] As the polymer, it is more preferable that a resin having an ethylenically unsaturated group and a carboxyl group is a resin having a structural moiety represented by the following formula (3b). By having an ethylenically unsaturated group and a carboxyl group, the polymerizability of the ethylenically unsaturated group and the alkali developability of the carboxyl group can be achieved at a high level, making it possible to achieve both sensitivity and developability at a high level.

(In formula (3b), R ⁴⁰ represents a divalent hydrocarbon group, and R ⁴¹ represents a hydrogen atom or a methyl group. * represents a bonding position.)

Specific examples of the resin having an ethylenically unsaturated group and a carboxyl group and having a structural moiety represented by the above formula (3b) are shown below.

As the resin having the structural portion represented by formula (3b), acid-modified epoxy (meth)acrylate resin is preferably used. Acid-modified, cresol novolak-type epoxy (meth)acrylate resin, phenol novolak-type epoxy (meth)acrylate resin, bisphenol A-type epoxy (meth)acrylate resin, bisphenol F-type epoxy (meth)acrylate resin, Biphenyl type epoxy (meth)acrylate resin and trisphenolmethane type epoxy (meth)acrylate resin can be mentioned.

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

The acid-modified cresol novolak-type epoxy (meth)acrylate resin has the rigid main chain skeleton of the cresol novolak-type epoxy resin, an ethylenically unsaturated group, and a carboxyl group, so that the film hardness is maintained despite curing and firing at low temperatures. It is possible to form a cured film that is excellent in solvent resistance and heat resistance.

In formula (3c), b and c each independently represent an integer of 1 to 30.

As specific examples of acid-modified cresol novolak-type epoxy (meth)acrylate resin, CCR-1171H, CCR-1291H, CCR-1307H, and CCR-1309H (manufactured by Nippon Kayaku Co., Ltd.) can be used.

[a] The acid value of the polymer is, for example, 10 to 300 mgKOH/g, preferably 30 to 270 mgKOH/g, and more preferably 50 to 250 mgKOH/g. The acid value represents the number of mg of KOH required to neutralize 1 g of solid content of the alkali-soluble resin.

[a] The weight average molecular weight (Mw) of the polymer is usually 1,000 to 100,000, preferably 3,000 to 50,000. Mw refers to the weight average molecular weight in terms of polystyrene measured by gel permeation chromatography (elution solvent: tetrahydrofuran).

A polymer having an epoxy group as a polymerizable group can also be used. This [a] polymer is obtained by using an epoxy group-containing unsaturated compound as a monomer and radically polymerizing it with other monomers such as methacrylic acid and acrylic acid as appropriate. Examples of the epoxy group-containing unsaturated compound include unsaturated compounds containing an oxiranyl group (1,2-epoxy structure), oxetanyl group (1,3-epoxy structure), etc.

Examples of the unsaturated compounds having the oxiranyl group include glycidyl acrylate, glycidyl methacrylate, 2-methylglycidyl methacrylate, 3,4-epoxybutyl acrylate, and 3,4-epoxy methacrylate. Butyl, 6,7-epoxyheptyl acrylate, 6,7-epoxyheptyl methacrylate, 6,7-epoxyheptyl α-ethylacrylate, 3,4-epoxycyclohexyl methacrylate, o-vinylbenzyl glycidyl ether , m-vinylbenzyl glycidyl ether, p-vinylbenzyl glycidyl ether, etc.

Examples of the unsaturated compound having the oxetanyl group include 3-(methacryloyloxymethyl)oxetane, 3-(methacryloyloxymethyl)-2-methyloxetane, and 3-(methacryloyl). Oxymethyl)-3-ethyloxetane, 3-(methacryloyloxymethyl)-2-phenyloxetane, 3-(2-methacryloyloxyethyl)oxetane, 3-(2-methacrylo 1-oxyethyl)-2-ethyloxetane, 3-(2-methacryloyloxyethyl)-3-ethyloxetane, 3-(2-methacryloyloxyethyl)-2-phenyloxetane, 3 -(2-methacryloyloxyethyl)-2,2-difluorooxetane and other methacrylic acid esters.

Among these unsaturated compounds containing an epoxy group, glycidyl methacrylate, 3,4-epoxycyclohexyl methacrylate, and 3-(methacryloyloxymethyl)-3-ethyloxetane are preferred from the viewpoint of polymerizability.

The content of [a] polymer in the curable composition is usually 30% by mass or more, preferably 40% by mass or more, based on 100% by mass of solid content of the composition, and the upper limit of the content of [a] polymer is 40% by mass or more. Of 100% by mass of solid content, it is usually 90% by mass, and in one embodiment, it is 70% by mass or 60% by mass.

By adopting this aspect, in addition to further improvement in brightness, alkali developability, storage stability of the composition, pattern shape, and chromaticity characteristics can be improved. In addition, solid content is all components other than the solvent.

<[B] photosensitizer>

The curable composition contains [B] photosensitizer. The radiation sensitivity of the curable composition can be further increased. [B] The photosensitizer may be used individually, or may be used in combination of two or more types.

[B] Examples of the photosensitizer include radiation-sensitive radical polymerization initiators, radiation-sensitive acid generators, radiation-sensitive base generators, and combinations thereof.

The radiation-sensitive radical polymerization initiator may, for example, carry out a radiation-induced curing reaction of the curable composition when the compound having the [A] polymerizable group has an ethylenically unsaturated group such as a (meth)acryloyl group or a vinyl group. It can be promoted.

The radiation-sensitive radical polymerization initiator has the activity to initiate the radical polymerization reaction of a compound having an [A] polymerizable group by exposure to radiation such as visible light, ultraviolet rays, deep ultraviolet rays, electron beams, and X-rays, for example. Compounds that can generate species, etc. may be mentioned.

Specific examples of the radiation-sensitive radical polymerization initiator include O-acyloxime compounds, α-aminoketone compounds, α-hydroxyketone compounds, and acylphosphine oxide compounds.

Examples of the O-acyloxime compound include 1-[9-ethyl-6-(2-methylbenzoyl)-9.H.-carbazol-3-yl]-ethane-1-one oxime-O-acetate. , 1-[9-ethyl-6-benzoyl-9.H.-carbazol-3-yl]-octan-1-oneoxime-O-acetate, 1-[9-ethyl-6-(2-methylbenzoyl )-9.H.-carbazol-3-yl]-ethane-1-oneoxime-O-benzoate, 1-[9-n-butyl-6-(2-ethylbenzoyl)-9.H.- Carbazol-3-yl]-ethan-1-oneoxime-O-benzoate, ethanone, 1-[9-ethyl-6-(2-methyl-4-tetrahydrofuranylbenzoyl)-9.H. -carbazol-3-yl]-,1-(O-acetyloxime), ethanone,1-[9-ethyl-6-(2-methyl-4-tetrahydropyranylbenzoyl)-9.H.- carbazol-3-yl]-,1-(O-acetyloxime), ethanone,1-[9-ethyl-6-(2-methyl-5-tetrahydrofuranylbenzoyl)-9.H.-car basol-3-yl]-,1-(O-acetyloxime), ethanone,1-[9-ethyl-6-{2-methyl-4-(2,2-dimethyl-1,3-dioxoranyl) )methoxybenzoyl}-9.H.-carbazol-3-yl]-,1-(O-acetyloxime), ethanone,1-[9-ethyl-6-(2-methyl-4-tetrahydro furanylmethoxybenzoyl)-9.H.-carbazol-3-yl]-,1-(O-acetyloxime), 1,2-octanedione,1-[4-(phenylthio)-,2-( O-benzoyl oxime)] and the like.

Examples of the α-aminoketone compound include 2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)-butan-1-one, 2-dimethylamino-2-(4-methylbenzyl) -1-(4-morpholin-4-yl-phenyl)-butan-1-one, 2-methyl-1-(4-methylthiophenyl)-2-morpholinopropan-1-one, etc. there is.

Examples of the α-hydroxyketone compound include 1-phenyl-2-hydroxy-2-methylpropan-1-one and 1-(4-i-propylphenyl)-2-hydroxy-2-methylpropane. -1-one, 4-(2-hydroxyethoxy)phenyl-(2-hydroxy-2-propyl)ketone, 1-hydroxycyclohexylphenylketone, etc. are mentioned.

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

As the radiation-sensitive radical polymerization initiator, a radical polymerization initiator containing a condensed ring is preferred from the viewpoint of strengthening the interaction with TADF and further promoting the curing reaction by radiation. Specific examples of condensed rings include naphthalene, anthracene, fluorene, indole, carbazole, and benzimidazole. Among these, a carbazolyl group derived from carbazole and a substituted or unsubstituted 1,2,3,4-tetrahydro-9-carbazolyl group are particularly preferred. As the radical polymerization initiator containing such a condensed ring, O-acyloxime compounds and α-aminoketone compounds are preferable, and 1-[9-ethyl-6-(2-methylbenzoyl)-9.H.-carbazole- 3-yl]-ethane-1-oneoxime-O-acetate is preferred.

When the curable composition contains a radiation-sensitive radical polymerization initiator, the lower limit of the content of the radiation-sensitive radical polymerization initiator is preferably 0.5 parts by mass, more preferably 1.0 parts by mass, per 100 parts by mass of the compound having the [A] polymerizable group. It is preferable, and 1.5 parts by mass is more preferable. Additionally, the upper limit of the content is preferably 20 parts by mass, more preferably 15 parts by mass, and even more preferably 10 parts by mass, relative to 100 parts by mass of the compound having the [A] polymerizable group. By setting the content within the above range, the curing reaction by radiation can be further promoted.

Specific examples of the above radiation-sensitive acid generator include, for example, iodonium salt-based radiation-sensitive acid generator, sulfonium salt-based radiation-sensitive acid generator, tetrahydrothiophenium salt-based radiation-sensitive acid generator, and imide. Examples include sulfonate-based radiation-sensitive acid generators, oxime sulfonate-based radiation-sensitive acid generators, and quinonediazide compounds.

Examples of the iodonium salt-based radiation sensitive acid generator include diphenyl iodonium trifluoromethane sulfonate, diphenyl iodonium pyrenesulfonate, diphenyl iodonium dodecylbenzenesulfonate, and diphenyl iodonium trifluoromethane sulfonate. Iodonium nonafluoro n-butanesulfonate, bis(4-t-butylphenyl)iodonium trifluoromethanesulfonate, bis(4-t-butylphenyl)iodonium dodecylbenzenesulfonate, etc. I can hear it.

Examples of the sulfonium salt-based radiation-sensitive acid generator include triphenylsulfonium trifluoromethane sulfonate, triphenylsulfonium hexafluoroantimonate, triphenylsulfonium naphthalenesulfonate, and triphenylsulfonium nona. Fluoro-n-butanesulfonate, (hydroxyphenyl)benzenemethylsulfoniumtoluenesulfonate, cyclohexylmethyl(2-oxocyclohexyl)sulfoniumtrifluoromethanesulfonate, dicyclohexyl(2-oxocyclohexyl) ) Sulfonium trifluoromethane sulfonate, dimethyl (2-oxocyclohexyl) sulfonium trifluoromethane sulfonate, triphenyl sulfonium camphorsulfonate, (4-hydroxyphenyl) benzylmethylsulfonium toluene sulfonate, 1-naphthyldimethylsulfonium trifluoromethane sulfonate, 1-naphthyldiethylsulfonium trifluoromethane sulfonate, 4-hydroxy-1-naphthyldimethylsulfonium trifluoromethane sulfonate, etc. there is.

Examples of the tetrahydrothiophenium salt-based radiation-sensitive acid generator include 4-hydroxy-1-naphthyltetrahydrothiophenium trifluoromethanesulfonate and 4-methoxy-1-naphthyltetrahydro. Thiophenium trifluoromethane sulfonate, 4-ethoxy-1-naphthyltetrahydrothiophenium trifluoromethane sulfonate, 4-methoxymethoxy-1-naphthyltetrahydrothiophenium trifluoro Methanesulfonate, 4-ethoxymethoxy-1-naphthyltetrahydrothiopheniumtrifluoromethane sulfonate, 4-(1-methoxyethoxy)-1-naphthyltetrahydrothiopheniumtrifluoro Methane sulfonate, 4-(2-methoxyethoxy)-1-naphthyltetrahydrothiophenium trifluoromethane sulfonate, etc. are mentioned.

Examples of the imide sulfonate-based radiation sensitive acid generator include trifluoromethylsulfonyloxybicyclo[2.2.1]hepto-5-enedicarboxyimide, succinimide trifluoromethylsulfonate, and phthalate. Imide trifluoromethyl sulfonate, N-hydroxynaphthalimide methane sulfonate, N-hydroxy-5-norbornene-2,3-dicarboxyimide propane sulfonate, etc. are mentioned.

Examples of the oxime sulfonate-based radiation sensitive acid generator include (5-propylsulfonyloxyimino-5H-thiophen-2-ylidene)-(2-methylphenyl)acetonitrile, (5-octylsulfonate) Ponyloxyimino-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, (5-octylsulfonyloxyimino)-(4-methoxyphenyl)acetonitrile, etc. I can hear it.

Examples of the quinonediazide compounds include 1,2-naphthoquinonediazide sulfonic acid ester of trihydroxybenzophenone, 1,2-naphthoquinonediazide sulfonic acid ester of tetrahydroxybenzophenone, and pentahydroxybenzo. 1,2-naphthoquinone diazide sulfonic acid ester of phenone, 1,2-naphthoquinone diazide sulfonic acid ester of hexahydroxybenzophenone, 1,2-naphthoquinone diazide sulfonic acid of (polyhydroxyphenyl)alkane. Ester, etc. can be mentioned.

Examples of the 1,2-naphthoquinone diazide sulfonic acid ester of trihydroxybenzophenone include 2,3,4-trihydroxybenzophenone-1,2-naphthoquinone diazide-4-sulfonic acid ester; 2,3,4-trihydroxybenzophenone-1,2-naphthoquinonediazide-5-sulfonic acid ester, 2,4,6-trihydroxybenzophenone-1,2-naphthoquinonediazide-4 -Sulfonic acid ester, 2,4,6-trihydroxybenzophenone-1,2-naphthoquinonediazide-5-sulfonic acid ester, etc. are mentioned.

Examples of the 1,2-naphthoquinonediazide sulfonic acid ester of tetrahydroxybenzophenone include 2,2',4,4'-tetrahydroxybenzophenone-1,2-naphthoquinonediazide-4. -Sulfonic acid ester, 2,2',4,4'-tetrahydroxybenzophenone-1,2-naphthoquinonediazide-5-sulfonic acid ester, 2,3,4,3'-tetrahydroxybenzophenone- 1,2-naphthoquinonediazide-4-sulfonic acid ester, 2,3,4,4'-tetrahydroxy-3'-methoxybenzophenone-1,2-naphthoquinonediazide-5-sulfonic acid ester etc. can be mentioned.

Examples of the 1,2-naphthoquinonediazide sulfonic acid ester of pentahydroxybenzophenone include 2,3,4,2',6'-pentahydroxybenzophenone-1,2-naphthoquinonediazide. -4-sulfonic acid ester, 2,3,4,2',6'-pentahydroxybenzophenone-1,2-naphthoquinonediazide-5-sulfonic acid ester, etc.

Examples of the 1,2-naphthoquinone diazide sulfonic acid ester of hexahydroxybenzophenone include 2,4,6,3',4',5'-hexahydroxybenzophenone-1,2-naphtho. Quinonediazide-4-sulfonic acid ester, 2,4,6,3',4',5'-hexahydroxybenzophenone-1,2-naphthoquinonediazide-5-sulfonic acid ester, 3,4,5 ,3',4',5'-hexahydroxybenzophenone-1,2-naphthoquinonediazide-4-sulfonic acid ester, etc.

Examples of the 1,2-naphthoquinonediazide sulfonic acid ester of the above-mentioned (polyhydroxyphenyl)alkane include bis(2,4-dihydroxyphenyl)methane-1,2-naphthoquinonediazide-4- Sulfonic acid ester, bis(2,4-dihydroxyphenyl)methane-1,2-naphthoquinonediazide-5-sulfonic acid ester, bis(p-hydroxyphenyl)methane-1,2-naphthoquinonediazide -4-sulfonic acid ester, etc. can be mentioned.

As the radiation-sensitive acid generator, oxime sulfonate-based radiation-sensitive acid generators and quinonediazide compounds are preferable, and (5-propylsulfonyloxyimino-5H-thiophen-2-ylidene)- (2-methylphenyl)acetonitrile and 1,1,1-tri(p-hydroxyphenyl)ethane-1,2-naphthoquinonediazide-5-sulfonic acid ester are more preferred.

Specific examples of radiation-sensitive base generators include,

4-(methylthiobenzoyl)-1-methyl-1-morpholinoethane, (4-morpholinobenzoyl)-1-benzyl-1-dimethylaminopropane, 2-benzyl-2-dimethylamino-1-( Radiation sensitive containing heterocyclic groups such as 4-morpholinophenyl)-butanone, N-(2-nitrobenzyloxycarbonyl)pyrrolidine, and 1-(anthraquinon-2-yl)ethylimidazole carboxylate base generator;

2-nitrobenzylcyclohexylcarbamate, [[(2,6-dinitrobenzyl)oxy]carbonyl]cyclohexylamine, bis[[(2-nitrobenzyl)oxy]carbonyl]hexane-1,6-diamine , triphenylmethanol, o-carbamoylhydroxylamide, o-carbamoyloxime, hexaamminecobalt(Ⅲ)tris(triphenylmethylborate), 1,2-dicyclohexyl-4,4,5,5 -Tetramethylbiguanidium n-butyltriphenylborate, etc., and from the viewpoint of further promoting the thiolation reaction of the [B] compound, 1,2-dicyclohexyl-4,4,5,5-tetra Methyl biguanidium n-butyltriphenylborate is preferred.

When the curable composition contains the [B] photosensitizer, the lower limit of the content of the [B] photosensitizer is preferably 0.5 parts by mass, more preferably 1.0 parts by mass, per 100 parts by mass of the compound having the [A] polymerizable group. Additionally, the upper limit of the content is preferably 30 parts by mass, more preferably 25 parts by mass, per 100 parts by mass of the compound having the [A] polymerizable group. By setting the content within the above range, the radiation sensitivity of the curable composition can be further increased.

<[C] Heat-activated delayed fluorescent compound>

Thermally Activated Delayed Fluorescence (also known as TADF) is a fluorescence that has the same spectrum as normal fluorescence and has a longer lifetime than normal fluorescence. Delayed fluorescence material refers to a material that emits such delayed fluorescence. The lifespan of the delayed fluorescence emitted by the delayed fluorescent material varies depending on the type of the delayed fluorescent material, for example, 1 μs or more, 5 μs or more, or 10 μs or more.

In the present invention, a delayed fluorescent material having these properties is selected and used as a light-emitting material. There are no particular restrictions on the mechanism of delayed fluorescence emission of the delayed fluorescent material used in the present invention. Delayed fluorescence includes fluorescence emitted by inverse intersystem crossing from the triplet excitation state to the singlet excitation state, and the inverse intersystem crossing at this time may be due to triplet-triplet annihilation or absorption of thermal energy. good night. Additionally, delayed fluorescence may involve Exiplex. Additionally, the delayed fluorescent material used in the present invention is preferably a heat-activated delayed fluorescent material that is activated by heat.

In the present invention, only a delayed fluorescent material may be used as the light emitting material, or a combination of a delayed fluorescent material and a light emitting material that does not emit delayed fluorescence may be used. Preferred is an embodiment that uses only delayed fluorescent materials. The delayed fluorescent material used as the light-emitting material of the present invention may be one type or a mixture of two or more types.

As a delayed fluorescent material that can be used in the present invention, preferred examples include compounds having a structure represented by the following general formula (1) or (2).

In general formulas (1) and (2), at least one of R ¹ to R ⁷ represents a cyano group. When any one is a cyano group, any of R ¹ to R ³ may be used. When any two are cyano groups, a combination of R ¹ and R ³ or a combination of R ² and R ⁴ can be used. When any three are cyano groups, a combination of R ¹ , R ³ , and R ⁴ can be exemplified.

In general formulas (1) and (2), at least one of R ¹ to R ⁷ represents a group represented by the following general formula (X). When two or more groups represent a group represented by general formula (X), they may be the same or different, but it is more preferable that they are the same.

In general formula (X), R ²¹ to R ²⁸ each independently represent a hydrogen atom or a substituent. However, at least one of <A> or <B> below must be met. It is more desirable if both conditions are met.

<A> R ²⁵ and R ²⁶ are combined into one to form a single bond.

<B> R ²⁷ and R ² 8 are combined to represent the atomic groups necessary to form a substituted or unsubstituted benzene ring.

The group represented by general formula ( It is preferable that it is a t-butyl)-9-carbazolyl group, a substituted or unsubstituted 1-indolyl group, or a substituted or unsubstituted diarylamino group. That is, in general formulas (1) and (2), any one of R ¹ to R ⁷ is a substituted or unsubstituted 9-carbazolyl group or a substituted or unsubstituted 1,2,3,4-tetra group. It is preferable that it is a hydro-9-carbazolyl group, a substituted or unsubstituted 1-indolyl group, or a substituted or unsubstituted diarylamino group. In general formula (1), any two or more of R ¹ to R ⁵ are a substituted or unsubstituted 9-carbazolyl group or a substituted or unsubstituted 1,2,3,4-tetrahydro-9-car More preferably, it is a bazolyl group, a substituted or unsubstituted 1-indolyl group, or a substituted or unsubstituted diarylamino group.

The group represented by general formula (X) is particularly preferably a substituted or unsubstituted 9-carbazolyl group or 3,6-di(t-butyl)-9-carbazolyl group.

Examples of R ²¹ to R ²⁸ in general formula (X) include a hydroxy group, a halogen atom, a cyano group, an alkyl group with 1 to 20 carbon atoms, an alkoxy group with 1 to 20 carbon atoms, an alkylthio group with 1 to 20 carbon atoms, Alkyl-substituted amino group with 1 to 20 carbon atoms, acyl group with 2 to 20 carbon atoms, aryl group with 6 to 40 carbon atoms, heteroaryl group with 3 to 40 carbon atoms, diarylamino group with 12 to 40 carbon atoms, substituted or Unsubstituted carbazolyl group, alkenyl group with 2 to 10 carbon atoms, alkynyl group with 2 to 10 carbon atoms, alkoxycarbonyl group with 2 to 10 carbon atoms, alkylsulfonyl group with 1 to 10 carbon atoms, haloalkyl group with 1 to 10 carbon atoms, Amide group, alkylamide group having 2 to 10 carbon atoms, trialkylsilyl group having 3 to 20 carbon atoms, trialkylsilylalkyl group having 4 to 20 carbon atoms, trialkylsilylalkenyl group having 5 to 20 carbon atoms, trialkyl having 5 to 20 carbon atoms Silylalkynyl group, nitro group, etc. are mentioned. Among these specific examples, those that can be further substituted by a substituent may be substituted. More preferable substituents include a halogen atom, a cyano group, a substituted or unsubstituted alkyl group with 1 to 20 carbon atoms, an alkoxy group with 1 to 20 carbon atoms, a substituted or unsubstituted aryl group with 6 to 40 carbon atoms, and a substituted or unsubstituted aryl group with 3 to 40 carbon atoms. Alternatively, it may be an unsubstituted heteroaryl group, a substituted or unsubstituted diarylamino group having 12 to 40 carbon atoms, or a substituted or unsubstituted carbazolyl group having 12 to 40 carbon atoms. More preferable substituents include a fluorine atom, a chlorine atom, a cyano group, a substituted or unsubstituted alkyl group with 1 to 10 carbon atoms, a substituted or unsubstituted alkoxy group with 1 to 10 carbon atoms, and a substituted or unsubstituted di group with 1 to 10 carbon atoms. These include an alkylamino group, a substituted or unsubstituted aryl group having 6 to 15 carbon atoms, and a substituted or unsubstituted heteroaryl group having 3 to 12 carbon atoms.

The alkyl group referred to in this specification may be linear, branched, or cyclic, and more preferably has 1 to 6 carbon atoms, and specific examples include methyl group, ethyl group, propyl group, butyl group, t-butyl group, and pentyl group. , hexyl group, and isopropyl group. The alkoxy group may be linear, branched, or cyclic, and more preferably has 1 to 6 carbon atoms, and specific examples include methoxy group, ethoxy group, propoxy group, butoxy group, t-butoxy group, and pentyloxy group. , hexyloxy group, and isopropoxy group. The two alkyl groups of the dialkylamino group may be the same or different from each other, but are preferably the same. The two alkyl groups of the dialkylamino group may each independently be linear, branched, or cyclic, and more preferably have 1 to 6 carbon atoms, and specific examples include methyl, ethyl, propyl, butyl, and pentyl groups. , hexyl group, and isopropyl group. The aryl group may be a single ring or a fused ring, and specific examples include a phenyl group and a naphthyl group. The heteroaryl group may be a single ring or a fused ring, and specific examples include pyridyl group, pyridyl group, pyrimidyl group, triazyl group, triazolyl group, and benzotriazolyl group. These heteroaryl groups may be groups bonded through a hetero atom or groups bonded through a carbon atom constituting the heteroaryl ring.

In general formulas (1) and (2), when any one of R ¹ to R ⁷ is a group represented by general formula (X), any of R ¹ to R ³ may be used. When any two are groups represented by general formula (X), a combination of R ¹ and R ³ or a combination of R ² and R ⁴ can be exemplified. In the case where any three are groups represented by general formula (X), a combination of R ¹ , R ³ , and R ⁴ can be exemplified.

It is preferable that one of the two ortho positions of the benzene ring to which the group represented by general formula (X) is bonded is a cyano group. Both sides of the two ortho positions may be cyano groups. Additionally, when two or more groups represented by the general formula (X) are bonded to the benzene ring, one of the two ortho positions of the benzene ring to which the group represented by the general formula ( It is desirable that the condition of anger is met.

In general formulas (1) and (2), at least one of R ¹ to R ⁷ represents a cyano group, and at least one of R ¹ to R ⁷ represents a group represented by the general formula (X), but the remainder R ¹ to R ⁷ may represent a hydrogen atom or a substituent.

Preferred substituents that R ¹ to R ⁷ may have include, for example, a hydroxy group, a halogen atom, an alkyl group with 1 to 20 carbon atoms, an alkoxy group with 1 to 20 carbon atoms, an alkylthio group with 1 to 20 carbon atoms, and a C 1 to 20 alkyl group. Alkyl-substituted amino group of 20, acyl group of 2 to 20 carbon atoms, aryl group of 6 to 40 carbon atoms, heteroaryl group of 3 to 40 carbon atoms, alkenyl group of 2 to 10 carbon atoms, alkynyl group of 2 to 10 carbon atoms, 2 to 2 carbon atoms. Alkoxycarbonyl group of 10, alkylsulfonyl group of 1 to 10 carbon atoms, amide group, alkylamide group of 2 to 10 carbon atoms, trialkylsilyl group of 3 to 20 carbon atoms, trialkylsilylalkyl group of 4 to 20 carbon atoms, 5 to 5 carbon atoms. Examples include a trialkylsilylalkenyl group of 20, a trialkylsilylalkynyl group of 5 to 20 carbon atoms, and a nitro group. Among these specific examples, those that can be further substituted by a substituent may be substituted. More preferable substituents include a hydroxy group, a halogen atom, a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, a substituted or unsubstituted alkoxy group having 1 to 20 carbon atoms, and a substituted or unsubstituted dialkylamino group having 1 to 20 carbon atoms. , a substituted or unsubstituted aryl group having 6 to 40 carbon atoms, and a substituted or unsubstituted heteroaryl group having 3 to 40 carbon atoms. More preferable substituents include hydroxy groups, fluorine atoms, chlorine atoms, substituted or unsubstituted alkyl groups with 1 to 10 carbon atoms, substituted or unsubstituted alkoxy groups with 1 to 10 carbon atoms, and substituted or unsubstituted groups with 1 to 10 carbon atoms. These include a dialkylamino group, a substituted or unsubstituted aryl group with 6 to 15 carbon atoms, and a substituted or unsubstituted heteroaryl group with 3 to 12 carbon atoms. Even more preferably, they are a hydroxy group, a fluorine atom, or a chlorine atom.

In general formulas (1) and (2), the number of hydrogen atoms among R ¹ to R ⁷ is preferably 3 or less, more preferably 2 or less, still more preferably 1 or less, and also preferably 0. .

Examples of preferred specific compounds include compounds represented by the following formulas (4), (5), (6), and (7). In formula (7), tBU represents a t-butyl group.

In the curable composition, the content of [C] thermally activated delayed fluorescent compound is in the range of 0.01 to 5, more preferably 0.05 to 1, relative to the total content of [B] photosensitizer. By being within this range, a cured film with excellent solvent resistance can be formed while increasing the radiation sensitivity of cured film formation.

The curable composition may contain a solvent in addition to the above components. When the curable composition contains a solvent, applicability improves. The solvent is not particularly limited as long as it can dissolve or disperse each of the above components, but examples include solvents used when synthesizing the above-mentioned [a] polymer. In addition, the solvent may be used individually, or may be used in combination of two or more types.

[Other ingredients]

The curable composition may contain other components such as other polymers and additives within the range that does not impair the purpose of the present invention. Other components include, for example, surfactants, fillers such as inorganic particles, antioxidants, ultraviolet absorbers, and polymers such as polyimide. The content of these additives can be appropriately selected within a range that does not impair the purpose of the present invention.

The curable composition can be prepared by an appropriate method, for example, by mixing the [A] compound having a polymerizable group, the [B] compound, and optional components as needed in a solvent. The lower limit of the concentration of solid content in the composition when mixing is preferably 5% by mass and more preferably 10% by mass. Additionally, the upper limit of the concentration is preferably 50% by mass, and more preferably 40% by mass. By setting the solid content concentration within the above range, applicability can be improved. In addition, in this specification, “solid content” refers to the remaining content obtained by drying the sample on a hot plate at 175°C for 1 hour and removing volatile substances.

<Curated film>

The cured film is obtained from the curable composition. Examples of the cured film include a protective film, an interlayer insulating film, and a planarizing film. Since the cured film is obtained from the curable composition, it has high hardness and excellent solvent resistance. The method of forming the cured film is not particularly limited, but it is preferable to apply the method of forming the cured film described later.

<Display element>

The display element has the cured film. In other words, the cured film can be suitably used in a display element. Examples of the display element include liquid crystal display elements, organic EL elements, and electronic paper elements. Since the display element has a cured film that has high hardness and excellent solvent resistance, the yield can be increased and durability can be improved, for example.

<Method of forming cured film>

The method of forming the cured film includes a step of forming a coating film with the curable composition (hereinafter, also referred to as “coating film formation step”), and a step of irradiating (exposure) radiation to at least a portion of the coating film (hereinafter, “radiation irradiation step”). ), a process of developing the irradiated coating film (hereinafter, also referred to as a “development process”), and a process of heating the developed coating film (hereinafter, also referred to as a “heating process”). In addition, the method of forming the cured film may include, as an optional process, a step of heating the irradiated coating film between the radiation irradiation step and the development step (hereinafter also referred to as the “PEB step”).

According to the method for forming the cured film, since the curable composition described above is used, a cured film with high hardness and excellent solvent resistance can be easily and efficiently formed. Hereinafter, each process will be described.

[Coat film formation process]

In this process, the curable composition is applied to the surface on which the cured film is to be formed, such as the surface of the substrate, and then the coated surface is preferably heated (prebaked) to remove the solvent and the like to form the coated film. Examples of the material of the substrate include glass, quartz, silicon, and resin. Specific examples of the resin include polyethylene terephthalate, polyethylene naphthalate, polybutylene terephthalate, polyethersulfone, polycarbonate, polyimide, addition polymer of cyclic olefin, ring-opening polymer of cyclic olefin, and hydrogenated products thereof. I can hear it.

The application method of the curable composition is not particularly limited, and appropriate methods such as spraying, roll coating, spin coating, slit die coating, and bar coating can be employed. Among these coating methods, spin coating and slit die coating methods are particularly preferable. The conditions for prebaking are different depending on the type and mixing ratio of each component, but for example, a heating time of 1 minute or more and 10 minutes or less at a temperature of 70°C or more and 130°C or less can be used.

[Irradiation process]

In this process, radiation is irradiated to a portion of the coating film formed in the coating film forming process. Normally, when irradiating radiation to a part of a coating film, it is irradiated through a photomask with a predetermined pattern. As the radiation, for example, visible rays, ultraviolet rays, deep ultraviolet rays, electron beams, X-rays, etc. can be used. Among these radiations, radiation whose wavelength is in the range of 190 nm to 450 nm is preferable, and radiation containing ultraviolet rays of 365 nm is more preferable.

The lower limit of the exposure amount in this process is preferably 10 mJ/cm2, as the intensity at a wavelength of 365 nm of radiation measured with an illuminance meter (OAI: “OAI model356” from Optical Associates Inc.), and 20 mJ/cm2. ㎠ is more preferable. Additionally, the upper limit of the exposure amount, as measured by the illuminance meter, is preferably 2,000 mJ/cm 2 and more preferably 1,000 mJ/cm 2 .

[Development process]

In this process, a predetermined pattern is formed by developing the coating film after irradiation with a developer solution. As the developer, an alkaline developer is preferable. As an alkaline developer, for example, an alkaline aqueous solution in which at least one type of alkaline compound such as sodium hydroxide, potassium hydroxide, sodium carbonate, sodium silicate, sodium metasilicate, ammonia, tetramethylammonium hydroxide, and tetraethylammonium hydroxide is dissolved. etc. can be mentioned. Additionally, an appropriate amount of a water-soluble organic solvent such as methanol or ethanol or a surfactant may be added to the alkaline developer.

As a developing method, for example, an appropriate method such as the puddle method, dipping method, shaking immersion method, or spray method can be adopted. The development time varies depending on the composition of the curable composition, but is, for example, 10 seconds or more and 180 seconds or less. Following this development treatment, a desired pattern can be formed by, for example, performing running water cleaning for a treatment time of 30 seconds or more and 90 seconds or less, and then air drying with, for example, compressed air or compressed nitrogen.

[Heating process]

In this process, the developed and patterned coating film is heated (post-baked) using a heating device such as a hot plate or oven to obtain a cured film having a desired pattern. As a lower limit of the heating temperature, 80°C is preferable, 120°C is more preferable, and 150°C is still more preferable. The heating time varies depending on the type of heating device, but for example, when heating on a hot plate, it can be 5 minutes or more and 30 minutes or less, and when heating in an oven, it can be 10 minutes or more and 90 minutes or less. In addition, heating may be performed in air or in an inert gas atmosphere such as nitrogen or argon. Additionally, it is also possible to use a step baking method in which two or more heating processes are performed. The average thickness of the cured film formed in this way is, for example, 0.1 μm or more and 10 μm or less. The order of exposure or heating processes may be different.

[Example]

Examples are given below to illustrate the present invention in more detail, but the present invention is not limited to the following examples.

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

Mw and Mn were measured by gel permeation chromatography (GPC) under the following conditions. Additionally, molecular weight distribution (Mw/Mn) was calculated from the obtained Mw and Mn.

Device: Showa Denko’s “GPC-101”

Column: Showa Denko's “GPC-KF-801,” “GPC-KF-802,” “GPC-KF-803,” and “GPC-KF-804.”

Mobile phase: tetrahydrofuran

Column temperature: 40℃

Flow rate: 1.0mL/min

Sample concentration: 1.0 mass%

Sample injection volume: 100μL

Detector: Differential refractometer

Standard material: monodisperse polystyrene

[ ^1H -NMR analysis]

¹ For H-NMR analysis, a nuclear magnetic resonance device (“ECX400P” manufactured by Nippon Electronics Co., Ltd.) was used.

<Synthesis of polymer>

[Synthesis Example 1] Synthesis of polymer (A-1)

11 parts by mass of 2,2'-azobis(2,4-dimethylvaleronitrile) and 300 parts by mass of propylene glycol monomethyl ether were placed in a flask equipped with a cooling pipe and a stirrer. Next, 75 parts by mass of methacrylic acid and 25 parts by mass of benzyl methacrylate were added, and after purging with nitrogen, the temperature of the solution was raised to 70°C with slow stirring, and this temperature was maintained for 5 hours to polymerize. After that, the solution temperature was set to 100°C, stirred for 1 hour, and then returned to room temperature. Next, 50 parts by mass of glycidyl methacrylate and 2 parts by mass of tetrabutylammonium bromide were added, the temperature of the solution was raised to 90°C, and this temperature was maintained for 9 hours to cause reaction. Accordingly, a polymer solution containing polymer (A-1) having a methacryloyl group in the side chain was obtained. The solid content concentration of this polymer solution was 23.0% by mass, the Mw of polymer (A-1) was 11,000, and the molecular weight distribution (Mw/Mn) was 2.0.

[Synthesis Example 2] Synthesis of polymer (A-2)

Into a flask equipped with a cooling pipe and a stirrer, add 200 parts by mass of cresol novolak-type epoxy resin "E OCN-1020" (manufactured by Nippon Kayaku, epoxy equivalent 200) and 245 parts by mass of propylene glycol monomethyl ether acetate, and stir to 110°C. It was heated and dissolved uniformly. Subsequently, 76 parts by mass (1.07 mole parts) of acrylic acid, 2 parts by mass of triphenylphosphine, and 0.2 parts by mass of p-methoxyphenol were added and reacted at 110°C for 10 hours. An additional 91 parts by mass (0.60 mole part) of tetrahydrophthalic anhydride was added to the reaction product, the reaction was further performed at 90°C for 5 hours, and after cooling, propylene glycol monomethyl ether acetate was added to adjust the solid content to form carboxyl groups and acryloyl groups. A propylene glycol monomethyl ether acetate solution of polymer (A-2) (Mn: 2,200) was obtained (solid content: 25% by mass).

[Synthesis Example 3] Synthesis of polymer (A-6)

7 parts by mass of 2,2'-azobis(2,4-dimethylvaleronitrile) and 200 parts by mass of diethylene glycol ethylmethyl ether were placed in a flask equipped with a cooling pipe and a stirrer. Subsequently, 16 parts by mass of methacrylic acid, 16 parts by mass of tricyclo[5.2.1.0 ^2,6 ]decan-8-yl methacrylate, 38 parts by mass of methyl methacrylate, 10 parts by mass of styrene, glycidyl methacrylate. 20 parts by mass were added, purged with nitrogen, the temperature of the solution was raised to 70°C while slowly stirred, and this temperature was maintained for 4 hours for polymerization to obtain a solution containing polymer (A-6) (solid concentration = 34.4 mass%, Mw = 8,000, Mw/Mn = 2.3).

<Preparation of curable composition, formation of cured film, and evaluation of physical properties>

Each component used in the preparation of each curable composition is shown below.

[[A] ingredient]

A-1: Polymer (A-1)

A-2: Polymer (A-2)

A-3: Fluorene-based diacrylate (“OGSOL EA-0200” from Osaka Gas Chemical Co., Ltd.)

A-4: Tris(4-hydroxyphenyl)ethane triglycidyl ether

A-5: Dipentaerythritol hexaacrylate (“KAYARAD DPHA” from Nippon Kayaku Co., Ltd.)

A-6: Polymer (A-6)

[B]

[Radiation-sensitive radical polymerization initiator]

B1-1: 1-[9-ethyl-6-(2-methylbenzoyl)-9.H.-carbazol-3-yl]-ethane-1-one oxime-O-acetate (“IRGACURE OX02” from BASF) )

B1-2: Bis(2,4,6-trimethylbenzoyl)-phenylphosphine oxide (brand name “Irgacure 819”, manufactured by BASF)

B1-3: 10 parts by mass of 2,2'-bis(2,4-dichlorophenyl)-4,4',5,5'-tetraphenylbiimidazole, 4,4'-bis(dimethylamino)benzophenone A mixture of 10 parts by mass and 5 parts by mass of 2-mercaptobenzothiazole

[Radiation-sensitive acid generator]

B2-1: (5-propylsulfonyloxyimino-5H-thiophen-2-ylidene)-(2-methylphenyl)acetonitrile (“IRGACURE PAG 103” from BASF)

[Radiation-sensitive base generator]

B3-1: 1,2-dicyclohexyl-4,4,5,5-tetramethylbiguanidium n-butyltriphenylborate (“WPBG-300” manufactured by Wako Pure Chemical Industries, Ltd.)

[[C] component]

C-1: Compound (4)

C-2: Compound (5)

C-3: Compound (6)

C-4: Compound (7)

[Example 1]

Polymer (A-1) as component [A] is mixed with propylene glycol monodimethyl ether acetate (PGMEA) (100 parts by mass in terms of solid content), 10 parts by mass of (B1-1) as component [B], and 10 parts by mass as component [C]. 2 parts by mass of (C-1) was added, 0.1 parts by mass of SH 190 (manufactured by Toray Dow Corning Silicone) was added as a surfactant, mixed and stirred, and then filtered using a 0.2 ㎛ filter to prepare a curable composition. did.

[Examples 2 to 9 and Comparative Examples 1 to 2]

Each curable composition was prepared in the same manner as in Example 1, except that the types and mixing amounts of each compounding component were as described in Table 1 below. In addition, “-” in Table 1 indicates that the corresponding component was not used.

Each obtained curable composition was evaluated according to the following method. The evaluation results are shown in Table 1.

[Storage stability]

Evaluation of storage stability was performed by measuring the time until the viscosity of the curable composition when stored at 25°C reaches 10 times the viscosity immediately after preparation. The viscosity was measured using an “ELD type viscometer” manufactured by Tokyo Keiki Co., Ltd. under the conditions of 25°C and a rotation speed of 20 rpm. The longer the time it takes to reach 10 times the viscosity immediately after preparation, the better the storage stability. For example, if it is 800 hours or more, the storage stability can be evaluated as good. The results are shown in Table 1.

[Hardness]

The hardness was evaluated with a pencil hardness meter based on JIS K 5600-5-4 (1999) for the cured film formed from the curable composition by the following formation method. Hardness can be evaluated as good if it is H or higher. The results are shown in Table 1.

(Method of forming cured film)

After applying the curable composition on an alkali-free glass substrate with a spinner, it was prebaked for 3 minutes on a hot plate at 90°C to form a coating film with an average thickness of 3 μm. The obtained coating film was exposed to radiation containing each wavelength of 365 nm, 405 nm, and 436 nm using a high-pressure mercury lamp without passing through a photomask at an integrated irradiation dose of 300 mJ/cm2. Next, it was heated at 150°C in an oven for 30 minutes to obtain a cured film.

[Solvent resistance]

Solvent resistance was evaluated by measuring the change rate of the average thickness of the cured film formed from the curable composition before and after immersion in acetone according to the following method. Formation of the cured film was performed in the same manner as evaluation of hardness. The results are shown in Table 1.

(Method of measuring change rate of average thickness)

The average thickness (T1) of the cured film after formation and the average thickness (T2) after immersion in acetone for 20 minutes were measured, respectively, and the rate of change was calculated using the following equation. Additionally, when the change rate of average thickness is 5% or less, solvent resistance can be evaluated as good.

Average thickness change rate (%) = {(T1-T2)/T1} × 100

[Radiation sensitivity]

Radiation sensitivity was evaluated for the cured film formed from the curable composition by the exposure amount when the hardness was H, which was measured using a pencil hardness meter in the same manner as the hardness evaluation described above. The cured film was formed in the same manner as the hardness evaluation described above, except that the exposure amount was arbitrarily changed. Additionally, if the radiation sensitivity is 100 mJ/cm2 or less, it can be evaluated as good. The results are shown in Table 1.

“-” in the table indicates that it was not added.

As described above, the curable composition of the present invention, as shown in the results in Table 1, is a curable composition containing [A] a compound having a polymerizable group, [B] a photosensitizer, and [C] a heat-activated delayed fluorescent compound. , it was shown that a cured film with high hardness and excellent solvent resistance can be formed, even if it is a film obtained by a curing and baking process at 200°C or lower, while improving storage stability and radiation sensitivity.

Claims (11)

[A] Compound having a polymerizable group,
[B] photosensitizer,
[C] A curable composition containing a heat-activated delayed fluorescence compound,
The [B] photosensitizer,
1-[9-ethyl-6-(2-methylbenzoyl)-9.H.-carbazol-3-yl]-ethane-1-oneoxime-O-acetate,
1-[9-ethyl-6-benzoyl-9.H.-carbazol-3-yl]-octane-1-oneoxime-O-acetate,
1-[9-ethyl-6-(2-methylbenzoyl)-9.H.-carbazol-3-yl]-ethane-1-oneoxime-O-benzoate,
1-[9-n-butyl-6-(2-ethylbenzoyl)-9.H.-carbazol-3-yl]-ethane-1-oneoxime-O-benzoate,
Ethanone, 1-[9-ethyl-6-(2-methyl-4-tetrahydrofuranylbenzoyl)-9.H.-carbazol-3-yl]-,1-(O-acetyloxime),
Ethanone, 1-[9-ethyl-6-(2-methyl-4-tetrahydropyranylbenzoyl)-9.H.-carbazol-3-yl]-,1-(O-acetyloxime),
Ethanone, 1-[9-ethyl-6-(2-methyl-5-tetrahydrofuranylbenzoyl)-9.H.-carbazol-3-yl]-,1-(O-acetyloxime),
Ethanone, 1-[9-ethyl-6-{2-methyl-4-(2,2-dimethyl-1,3-dioxoranyl)methoxybenzoyl}-9.H.-carbazol-3-yl ]-,1-(O-acetyloxime),
Ethanone, 1-[9-ethyl-6-(2-methyl-4-tetrahydrofuranylmethoxybenzoyl)-9.H.-carbazol-3-yl]-,1-(O-acetyloxime)
It is a radical polymerization initiator containing a condensed ring selected from the group,
A curable composition wherein the [C] thermally activated delayed fluorescent compound is a compound represented by the following formula (1) or (2):

(In Formula (1) and Formula (2), at least one of R ¹ to R ⁷ is a hydrogen atom, an alkyl group having 1 to 12 carbon atoms, a phenyl group, a tolyl group, a naphthyl group, a cyano group, or the following formula (X) (represents a group represented by );

(In formula (X), R ²¹ to R ²⁸ each independently represent a hydrogen atom or a substituent; provided that at least one of <A> or <B> is satisfied:
<A> R ²⁵ and R ²⁶ combine into one to form a single bond
<B> R ²⁷ and R ²⁸ are combined to form a substituted or unsubstituted benzene ring). According to paragraph 1,
The above formula ( A curable composition characterized by representing a tetrahydro-9-carbazolyl group, a substituted or unsubstituted 1-indolyl group, or a substituted or unsubstituted diarylamino group. According to paragraph 1,
A curable composition wherein the polymerizable group of the compound having the [A] polymerizable group is at least one selected from an epoxy group, a vinyl group, and a (meth)acryloyl group. According to paragraph 1,
Additionally, [D] a curable composition comprising a binder resin. According to paragraph 1,
[B] A curable composition in which the content ratio of [C] thermally activated delayed fluorescent compound to the total content of photosensitizer is in the range of 0.01 to 5. Method for forming a cured film comprising the following steps:
(1) A process of forming a coating film of the curable composition according to any one of claims 1 to 5 on a substrate;
(2) A process of exposing the coating film to light or a process of heating it at 80°C or higher and 150°C or lower. A cured film obtained by the method for forming a cured film according to claim 6. A display element having the cured film according to claim 7. delete delete delete