JP2011085895A - Radiation-senstive resin composition for producing cured product as protection film, insulation film or spacer of display device, cured product and method of forming the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a radiation-senstive resin composition which excels in sensitivity, film thickness uniformity and resistance to light such as ultraviolet light, and has general demand characteristics such as resistance to rubbing and compression performance including recovery rate and flexibility, and can be used to form cured products as a protection film, an insulation film or a spacer of a display device; and to provide the cured products and a production method thereof. <P>SOLUTION: The radiation-senstive resin composition used for producing the cured products as the protection film, the insulation film or the spacer, includes: (A) a polymer having a carboxyl group; (B) a polymerizable unsaturated compound; (C) a radiation-senstive polymerization initiator; and (D) a thermosensitive dye. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a radiation-sensitive resin composition for forming a cured product as a protective film, insulating film or spacer for a display element, a cured product, and a method for forming the same.

  Conventionally, spacer particles such as glass beads and plastic beads are used in order to keep a constant distance (cell gap) between two substrates in a liquid crystal display device. Since the spacer particles are randomly distributed on a transparent substrate such as a glass substrate, there is a disadvantage that incident light is scattered and the contrast of the liquid crystal panel is lowered. Therefore, a method of forming a spacer in a region other than the pixel region using a radiation sensitive resin composition is employed (see Patent Document 1).

  As a structure of the liquid crystal display element, a spacer is arranged on a color filter formed on a substrate, a counter substrate is arranged thereon, and liquid crystal molecules are arranged in a cell gap. Therefore, in order to keep the cell gap constant in the entire region of the substrate, the spacer is required to have a high degree of film thickness uniformity. In particular, liquid crystal display elements in recent years are required to have high image quality and high-speed response, so that the demand for film thickness uniformity is increasing.

  On the other hand, in the color filter manufacturing process, an alignment film is usually formed after a spacer is formed on the color filter. Here, before the alignment film is printed, in order to make the film thickness uniform, the surface of the substrate on which the spacers and spacers are formed is irradiated with ultraviolet rays to perform surface modification. However, when the entire surface of the substrate is irradiated with ultraviolet rays, the oxidative decomposition of the ozone surface accelerates in certain parts, resulting in uneven height of the spacers, resulting in a cell gap defect and a liquid crystal panel display defect. Leads to. Therefore, the spacer is required to have excellent light resistance against ultraviolet rays in addition to film thickness uniformity.

  For the purpose of improving light resistance, attempts have been made to add a colorant or the like to the radiation-sensitive resin composition for forming the spacer (see Patent Document 2 and Patent Document 3). For example, Patent Document 4 discloses a technique for forming a black matrix by combining a heat-sensitive dye that is transparent at the time of exposure and colored after heating and a developer. However, the sensitivity as such a radiation sensitive resin composition and the performance of the spacer formed are not fully satisfactory.

  In view of such a situation, a protective film for a display element that has excellent film thickness uniformity and light resistance to ultraviolet rays, etc., and has general required characteristics such as rubbing resistance, compression performance (recovery rate and flexibility), There is a need for a radiation sensitive resin composition with excellent sensitivity that can form a cured product as an insulating film or spacer.

JP 2001-261761 A JP 2009-8755 A JP 2001-154206 A JP-A-10-170715

  The present invention has been made on the basis of the above circumstances, and its purpose is excellent in film thickness uniformity and light resistance to ultraviolet rays and the like, and is generally required characteristics such as rubbing resistance and compression performance (recovery). A radiation-sensitive resin composition excellent in sensitivity, a cured product, and a method for forming the same, capable of forming a cured product as a protective film, insulating film, or spacer for a display element. It is.

The invention made to solve the above problems is
A radiation-sensitive resin composition used for forming a cured product as a protective film, an insulating film or a spacer for a display element,
(A) a polymer having a carboxyl group,
(B) a polymerizable unsaturated compound,
A radiation-sensitive resin composition comprising (C) a radiation-sensitive polymerization initiator and (D) a thermal dye.

  The composition has such a specific component so that it has excellent film thickness uniformity and light resistance to ultraviolet rays, etc., and has generally required characteristics such as rubbing resistance and compression performance (recovery rate and flexibility). Can be formed. Further, the composition is excellent in sensitivity.

  (D) Thermal dye content is 0.5 mass% or more and 5 mass% with respect to the total amount of (A) polymer, (B) polymerizable unsaturated compound, (C) polymerization initiator and (D) thermal dye. % Or less is preferable. (D) By making the usage-amount of a thermal dye into the said specific range, hardened | cured materials, such as a spacer, can be formed with a small exposure amount, and still higher film thickness uniformity and light resistance can be achieved.

  (D) The thermal dye is preferably at least one selected from the group consisting of compounds represented by the following formulas (1) to (6).

（式（１）中、Ｒ^１〜Ｒ^４はそれぞれ独立して水素原子、炭素数１〜６のアルキル基、炭素数１〜６のアルコキシ基、炭素数３〜８のシクロアルキル基、フェニル基、ベンジル基、フェネチル基又はナフチル基である。但し、フェニル基、ベンジル基、フェネチル基及びナフチル基の水素原子の一部又は全部は、炭素数１〜６のアルキル基、炭素数１〜６のアルコキシ基、ハロゲン原子又はトリフルオロメチル基で置換されていてもよい。Ｒ^１及びＲ^２はモルホリノ基を形成してもよい。Ｒ^５及びＲ^６はそれぞれ独立して水素原子又は炭素数１〜６のアルキル基である。
式（２）中、Ｒ^１及びＲ^２は式（１）と同義である。Ｒ^７は水素原子、炭素数１〜６のアルキル基、炭素数１〜６のアルコキシ基又はハロゲン原子である。ｎは０〜４の整数である。但し、ｎが２以上の場合、複数のＲ^７は同一であっても異なっていてもよい。
式（３）中、Ｒ^１及びＲ^２は式（１）と同義である。Ｒ^８は水素原子、炭素数１〜６のアルキル基、炭素数１〜６のアルコキシ基、ハロゲン原子又はトリフルオロメチル基である。ｎは０〜４の整数である。但し、ｎが２以上の場合、複数のＲ^８は同一であっても異なっていてもよい。
式（４）中、Ｒ^１及びＲ^２は式（１）と同義である。Ｒ^１ａ、Ｒ^２ａ、Ｒ^１ｂ及びＲ^２ｂはそれぞれ独立して水素原子、炭素数１〜６のアルキル基、炭素数１〜６のアルコキシ基、炭素数３〜８のシクロアルキル基、フェニル基、ベンジル基、フェネチル基又はナフチル基である。但し、フェニル基、ベンジル基、フェネチル基及びナフチル基の水素原子の一部又は全部は、炭素数１〜６のアルキル基、炭素数１〜６のアルコキシ基、ハロゲン原子又はトリフルオロメチル基で置換されていてもよい。Ｒ^１ａ及びＲ^２ａ、並びにＲ^１ｂ及びＲ^２ｂはモルホリノ基を形成してもよい。
式（５）中、Ｒ^１、Ｒ^２、Ｒ^１ａ及びＲ^２ａは式（４）と同義である。Ｒ^７は式（２）と同義である。ｍは０〜５の整数である。ｍが２以上の場合、複数のＲ^７は同一であっても異なっていてもよい。
式（６）中、Ｒ^１、Ｒ^２、Ｒ^１ａ及びＲ^２ａは式（４）と同義である。Ｒ^９は炭素数１〜６のアルキル基、炭素数１〜６のアルコキシ基、炭素数３〜８のシクロアルキル基、フェニル基、ベンジル基、フェネチル基又はナフチル基である。但し、フェニル基、ベンジル基、フェネチル基及びナフチル基の水素原子の一部又は全部は、炭素数１〜６のアルキル基、炭素数１〜６のアルコキシ基、ハロゲン原子又はニトロ基で置換されていてもよい。）

(In Formula (1), R < ¹ > -R < ⁴ > is respectively independently a hydrogen atom, a C1-C6 alkyl group, a C1-C6 alkoxy group, a C3-C8 cycloalkyl group, and a phenyl group. , A benzyl group, a phenethyl group or a naphthyl group, provided that a part or all of the hydrogen atoms of the phenyl group, benzyl group, phenethyl group and naphthyl group are an alkyl group having 1 to 6 carbon atoms and an alkyl group having 1 to 6 carbon atoms. ^May be substituted with an alkoxy group, a halogen atom or a trifluoromethyl group, R ¹ and R ² may form a morpholino group, R ⁵ and R ⁶ each independently represent a hydrogen atom or a carbon number of 1 to 6 alkyl groups.
In formula (2), R ¹ and R ² have the same meaning as in formula (1). R ⁷ is a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, or a halogen atom. n is an integer of 0-4. However, when n is 2 or more, the plurality of R ⁷ may be the same or different.
In formula (3), R ¹ and R ² have the same meaning as in formula (1). R ⁸ is a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, a halogen atom, or a trifluoromethyl group. n is an integer of 0-4. However, when n is 2 or more, the plurality of R ⁸ may be the same or different.
In formula (4), R ¹ and R ² have the same meaning as in formula (1). R ^1a , R ^2a , R ^1b and R ^2b are each independently a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, a cycloalkyl group having 3 to 8 carbon atoms, a phenyl group, A benzyl group, a phenethyl group or a naphthyl group; However, some or all of the hydrogen atoms of the phenyl group, benzyl group, phenethyl group and naphthyl group are substituted with an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, a halogen atom or a trifluoromethyl group. May be. R ^1a and R ^2a , and R ^1b and R ^2b may form a morpholino group.
In formula (5), R ¹ , R ² , R ^1a and R ^2a have the same ^{meaning as} in formula (4). R ⁷ has the same meaning as in formula (2). m is an integer of 0-5. When m is 2 or more, the plurality of R ⁷ may be the same or different.
In formula (6), R ¹ , R ² , R ^1a and R ^2a have the same ^{meaning as} in formula (4). R ⁹ is an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, a cycloalkyl group having 3 to 8 carbon atoms, a phenyl group, a benzyl group, a phenethyl group, or a naphthyl group. However, some or all of the hydrogen atoms of the phenyl group, benzyl group, phenethyl group, and naphthyl group are substituted with an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, a halogen atom, or a nitro group. May be. )

  (A) It is preferable that a polymer further has an epoxy group or a (meth) acryloyl group. (A) Since the polymer has the above specific group, a cured product having more excellent light resistance can be formed.

  The composition preferably further contains (E) a thermosensitive acid generator (hereinafter sometimes referred to as “(E) acid generator”). (E) The acid generator is a compound that generates an acid by heating, and (D) it is possible to promote the opening of a lactone ring located at the center of the thermal dye. Coloring can be further promoted by adding such an acid generator (E).

  The present invention suitably includes a cured product as a protective film for a display element, an insulating film or a spacer formed from the composition.

A method for forming a cured product as a protective film for a display element, an insulating film or a spacer included in the present invention,
(1) A step of applying the composition onto a substrate to form a coating film,
(2) a step of exposing at least a part of the coating film;
(3) a step of developing the coated film after exposure; and (4) a step of heating the coated film after development.

  By the forming method having the above-described steps, a cured product as a protective film, insulating film or spacer for a display element that is excellent in various performances such as film thickness uniformity without causing minute unevenness of the coating film is obtained. .

  According to the present invention, the protective film for a display element has excellent film thickness uniformity, light resistance to ultraviolet rays, etc., and has generally required characteristics such as rubbing resistance and compression performance (recovery rate and flexibility). Further, it is possible to provide a radiation-sensitive resin composition, a cured product, and a method for forming the same, which are capable of forming a cured product as an insulating film or a spacer and are excellent in sensitivity.

<Radiation-sensitive resin composition for forming cured product as protective film, insulating film or spacer for display element>
The composition is a radiation-sensitive resin composition for forming a cured product as a protective film, insulating film or spacer for a display element, and comprises (A) a polymer, (B) a polymerizable unsaturated compound, (C) A polymerization initiator and (D) a thermal dye are contained. The composition may further contain (E) an acid generator as a suitable component. Furthermore, the said composition may contain another arbitrary component, unless the effect of invention is impaired. Hereinafter, each component will be described in detail.

<(A) Polymer>
(A) The polymer is an alkali-soluble resin having solubility in a developer, preferably an alkali developer, used in a development step described later. Such (A) polymer has at least one selected from the group consisting of a carboxyl group and a carboxylic anhydride group. Furthermore, it is more preferable that the (A) polymer further has an epoxy group or a (meth) acryloyl group.

  (A) As the polymer, (a1) at least one selected from the group consisting of an unsaturated carboxylic acid and an unsaturated carboxylic acid anhydride (hereinafter sometimes referred to as “(a1) compound”); a2) A copolymer with an unsaturated compound other than (a1) (hereinafter sometimes referred to as “(a2) compound”) is preferred.

(A) As a preferable example as a polymer,
[A1] a copolymer of a monomer (hereinafter, referred to as “(a2-1) compound”) having a compound (a1) and an unsaturated compound having at least one hydroxyl group in one molecule (hereinafter, referred to as “(a2-1) compound”) A polymer obtained by reacting an unsaturated isocyanate compound with (sometimes referred to as “(α) copolymer”) (hereinafter sometimes referred to as “[A1] polymer”);
[A2] a copolymer of a monomer (hereinafter referred to as “(a2-2) compound”) (hereinafter referred to as “(a2-2) compound”) and an unsaturated compound having an epoxy group (hereinafter referred to as “[A2] copolymer” Sometimes referred to as “union”);
[A3] From (a1) compound and (a1) compound, (a2-1) compound and unsaturated compound other than (a2-2) compound (hereinafter sometimes referred to as “(a2-3) compound”) And a monomer copolymer (hereinafter sometimes referred to as “[A3] copolymer”).

  In the production of the (α) copolymer, the (a2-3) compound is allowed to coexist, and the (α) copolymer is converted into a copolymer of the (a1) compound, the (a2-1) compound and the (a2-3) compound. It may be combined.

  In producing the [A2] copolymer, in addition to the (a1) compound and the (a2-2) compound, the (a2-3) compound is allowed to coexist, and the [A2] copolymer is converted to the (a1) compound, (a2 -2) It is good also as a copolymer of a compound and (a2-3) compound.

  Examples of (α) compounds, [A2] copolymers, and (A1) compounds used in the production of [A3] copolymers include monocarboxylic acids, dicarboxylic acids, dicarboxylic acid anhydrides, and the like. .

  Examples of the monocarboxylic acid include acrylic acid, methacrylic acid, crotonic acid, 2-acryloyloxyethyl succinic acid, 2-methacryloyloxyethyl succinic acid, 2-acryloyloxyethyl hexahydrophthalic acid, and 2-methacryloyloxyethyl hexahydro. Examples include phthalic acid.

  Examples of the dicarboxylic acid include maleic acid, fumaric acid, and citraconic acid. Examples of the anhydride of the dicarboxylic acid include maleic anhydride and fumaric anhydride.

  Among these, acrylic acid, methacrylic acid, 2-acryloyloxyethyl succinic acid, 2-methacryloyloxyethyl succinic acid, and maleic anhydride are from the viewpoint of copolymerization reactivity and solubility of the resulting copolymer in a developer. preferable.

  (A1) A compound can be used individually or in mixture of 2 or more types. In the (α) copolymer, [A2] copolymer and [A3] copolymer, the content of the structural unit derived from the compound (a1) is preferably 5 to 60% by mass, more preferably It is 7-50 mass%, Most preferably, it is 8-40 mass%. (A1) When the content rate of the structural unit derived from a compound is 5-60 mass%, the said composition by which characteristics, such as a radiation sensitivity, developability, and storage stability, were balanced by the higher level is obtained.

  (Α) As the compound (a2-1) used for the production of the copolymer, hydroxyalkyl ester of (meth) acrylic acid, dihydroxyalkyl ester of (meth) acrylic acid, (6-hydroxy of (meth) acrylic acid And hexanoyloxy) alkyl esters.

  Examples of the hydroxyalkyl ester of (meth) acrylic acid include (meth) acrylic acid 2-hydroxyethyl ester, (meth) acrylic acid 3-hydroxypropyl ester, (meth) acrylic acid 4-hydroxybutyl ester, and the like.

  Examples of dihydroxyalkyl esters of (meth) acrylic acid include (meth) acrylic acid 2,3-dihydroxypropyl ester, (meth) acrylic acid 1,3-dihydroxypropyl ester, and (meth) acrylic acid 3,4-dihydroxybutyl ester. Examples include esters.

  Examples of the (6-hydroxyhexanoyloxy) alkyl ester of (meth) acrylic acid include (meth) acrylic acid 2- (6-hydroxyhexanoyloxy) ethyl ester and (meth) acrylic acid 3- (6-hydroxyhexa). Noyloxy) propyl ester and the like.

  Among these, acrylic acid 2-hydroxyethyl ester, acrylic acid 3-hydroxypropyl ester, acrylic acid 4-hydroxybutyl ester, methacrylic acid 2-hydroxyethyl ester from the point of copolymerization reactivity and reactivity with isocyanate compounds Methacrylic acid 3-hydroxypropyl ester, methacrylic acid 4-hydroxybutyl ester, acrylic acid 2,3-dihydroxypropyl ester, methacrylic acid 2,3-dihydroxypropyl ester and (meth) acrylic acid (6-hydroxyhexanoyloxy) Alkyl esters are preferred. (Meth) acrylic acid (6-hydroxyhexanoyloxy) alkyl ester and methacrylic acid 2-hydroxyethyl ester are particularly preferable from the viewpoint of improving developability and improving compression performance of the resulting spacer and the like.

  Examples of commercially available products of a mixture of methacrylic acid 2- (6-hydroxyhexanoyloxy) ethyl ester and methacrylic acid 2-hydroxyethyl ester include PLACEL FM1D, FM2D (Daicel Chemical Industries, Ltd.) and the like.

  In the (α) copolymer, the compound (a2-1) can be used alone or in admixture of two or more. In the (α) copolymer, the content of the structural unit derived from the compound (a2-1) is preferably 1 to 50% by mass, more preferably 3 to 40% by mass, and particularly preferably 5 -30 mass%. When the content of the structural unit derived from the compound (a2-1) is 1 to 50% by mass, the stability of the copolymer obtained by the reaction with the unsaturated isocyanate compound becomes good, and the composition obtained as a result The storage stability of is improved.

  [A2] The epoxy group in the compound (a2-2) used for the production of the copolymer includes an oxiranyl group (having a 1,2-epoxy structure), an oxetanyl group (having a 1,3-epoxy structure), and the like. Can be mentioned.

  Examples of the unsaturated compound having an oxiranyl group include (meth) acrylic acid oxiranyl (cyclo) alkyl ester, α-alkylacrylic acid oxiranyl (cyclo) alkyl ester, and a glycidyl ether compound having an unsaturated bond.

  Examples of (meth) acrylic acid oxiranyl (cyclo) alkyl esters include glycidyl (meth) acrylate, 2-methylglycidyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate glycidyl ether, (meth) acrylic acid 3, Examples include 4-epoxybutyl, (meth) acrylic acid 6,7-epoxyheptyl, (meth) acrylic acid 3,4-epoxycyclohexyl, (meth) acrylic acid 3,4-epoxycyclohexylmethyl, and the like.

  Examples of the α-alkylacrylic acid oxiranyl (cyclo) alkyl ester include α-ethyl acrylate glycidyl, α-n-propyl acrylate glycidyl, α-n-butyl acrylate glycidyl, α-ethyl acrylate 6,7-epoxy. Examples include heptyl and α-ethyl acrylate 3,4-epoxycyclohexyl.

  Examples of the glycidyl ether compound having an unsaturated bond include o-vinylbenzyl glycidyl ether, m-vinylbenzyl glycidyl ether, and p-vinylbenzyl glycidyl ether.

  Examples of the unsaturated compound having an oxetanyl group include (meth) acrylic acid ester having an oxetanyl group.

  Examples of the (meth) acrylic acid ester having an oxetanyl group include 3- (meth) acryloyloxymethyl oxetane, 3- (meth) acryloyloxymethyl-3-ethyloxetane, and 3- (meth) acryloyloxymethyl-2-methyl. Oxetane, 3- (meth) acryloyloxyethyl-3-ethyloxetane, 2-ethyl-3- (meth) acryloyloxyethyloxetane, 3-methyl-3- (meth) acryloyloxymethyloxetane, 3-ethyl-3- (Meth) acryloyloxymethyloxetane and the like can be mentioned.

  Among these, glycidyl methacrylate, 2-methylglycidyl methacrylate, 3,4-epoxycyclohexyl methacrylate, 3,4-epoxycyclohexylmethyl methacrylate, 3-methyl-3-methacryloyloxymethyloxetane, 3-ethyl-3 -Methacryloyloxymethyloxetane is preferred from the viewpoint of polymerizability.

  [A2] In the production of the copolymer, the compound (a2-2) can be used alone or in admixture of two or more. In the [A2] copolymer, the content of the structural unit derived from the compound (a2-2) is preferably 0.5 to 70% by mass, more preferably 1 to 60% by mass, and particularly preferably. Is 3-50 mass%. (A2-2) When the content of the structural unit derived from the compound is 0.5 to 70% by mass, the heat resistance of the copolymer, the storage stability of the copolymer and the composition, and the compression of the resulting spacer, etc. The composition is obtained in which the performance is balanced at a higher level.

  Examples of the (A2-3) compound that can be used in the production of the [A3] copolymer or can be optionally used in the production of the (α) copolymer and the [A2] copolymer include (meth) acrylic acid, for example. Alkyl ester, (meth) acrylic acid cycloalkyl ester, (meth) acrylic acid aryl ester, (meth) acrylic acid aralkyl ester, unsaturated dicarboxylic acid dialkyl ester, oxygen-containing hetero 5-membered ring or oxygen-containing hetero 6-membered ring (Meth) acrylic acid ester, vinyl aromatic compound, conjugated diene compound and other unsaturated compounds.

  Examples of the (meth) acrylic acid alkyl ester include, for example, methyl (meth) acrylate, n-propyl (meth) acrylate, isopropyl (meth) acrylate, n-butyl (meth) acrylate, and (meth) acrylic sec. -Butyl, (meth) acrylic acid t-butyl etc. are mentioned.

Examples of the (meth) acrylic acid cycloalkyl ester include cyclohexyl (meth) acrylate, 2-methylcyclohexyl (meth) acrylate, and tricyclo [5.2.1.0 ^2,6 ] decane-8 (meth) acrylate. -Yl, (meth) acrylic acid 2- (tricyclo [5.2.1.0 ^2,6 ] decan-8-yloxy) ethyl, (meth) acrylic acid isobornyl, and the like.

  Examples of the (meth) acrylic acid aryl ester include phenyl (meth) acrylate.

  Examples of (meth) acrylic acid aralkyl esters include benzyl (meth) acrylate.

  Examples of the unsaturated dicarboxylic acid dialkyl ester include diethyl maleate and diethyl fumarate.

  Examples of the (meth) acrylic acid ester having an oxygen-containing hetero 5-membered ring or oxygen-containing hetero 6-membered ring include, for example, tetrahydrofuran-2-yl (meth) acrylate, tetrahydropyran-2-yl (meth) acrylate, (meta ) 2-methyltetrahydropyran-2-yl acrylate, tetrahydrofurfuryl (meth) acrylate, and the like.

  Examples of the vinyl aromatic compound include styrene, α-methylstyrene, p-methoxystyrene, and the like.

  Examples of the conjugated diene compound include 1,3-butadiene and isoprene.

  Examples of other unsaturated compounds include acrylonitrile, methacrylonitrile, acrylamide, and methacrylamide.

Among these, n-butyl methacrylate, benzyl methacrylate, tricyclo [5.2.1.0 ^2,6 ] decane-8-yl methacrylate, styrene, p-methoxystyrene, methacrylic acid from the viewpoint of copolymerization reactivity. Acid tetrahydrofuran-2-yl and 1,3-butadiene are preferred.

  In the production of the (α) copolymer, the [A2] copolymer, and the [A3] copolymer, the compound (a2-3) can be used alone or in admixture of two or more. In the (α) copolymer, [A2] copolymer and [A3] copolymer, the content of the structural unit derived from the compound (a2-3) is preferably 10 to 70% by mass, and more Preferably it is 20-50 mass%, Most preferably, it is 30-50 mass%. (A2-3) When the content of the structural unit of the compound is 10 to 70% by mass, the molecular weight of the copolymer can be easily controlled, and the developability and radiation sensitivity are balanced at a higher level. Is obtained.

  The (α) copolymer, [A2] copolymer and [A3] copolymer are preferably obtained by polymerizing a mixture of the above monomers in an appropriate solvent, preferably in the presence of a radical polymerization initiator. Can be manufactured. Examples of the solvent used for the polymerization include diethylene glycol alkyl ether, propylene glycol monoalkyl ether acetate, alkyl alkoxypropionate, and acetate. These solvents can be used alone or in admixture of two or more.

  Examples of the radical polymerization initiator include 2,2′-azobisisobutyronitrile, 2,2′-azobis- (2,4-dimethylvaleronitrile), 2,2′-azobis- (4-methoxy-). 2,4-dimethylvaleronitrile) and the like. These radical polymerization initiators can be used alone or in admixture of two or more.

  The weight average molecular weight (Mw) in terms of polystyrene measured by gel permeation chromatography (GPC) for the (α) copolymer, [A2] copolymer and [A3] copolymer is preferably 1,000-100. 2,000, more preferably 2,000 to 50,000. (Α) When the Mw of the copolymer, [A2] copolymer and [A3] copolymer is 1,000 to 100,000, the heat resistance, developability, radiation sensitivity, etc. are balanced at a higher level. The composition is obtained.

  [A1] The polymer can be obtained by reacting the (α) copolymer with an unsaturated isocyanate compound. The (α) copolymer obtained as described above may be used for the production of the polymer [A1] as it is in the polymerization reaction solution, or (α) after the copolymer is once separated from the solution [ A1] You may use for manufacture of a polymer.

  Examples of unsaturated isocyanate compounds include (meth) acrylic acid isocyanate alkyl groups. Examples of the (meth) acrylic acid isocyanate alkyl group include 2- (meth) acryloyloxyethyl isocyanate, 4- (meth) acryloyloxybutyl isocyanate, 2- (2-isocyanatoethoxy) ethyl (meth) acrylate, and the like. .

  Examples of commercially available products of 2-acryloyloxyethyl isocyanate include Karenz AOI (Showa Denko), and examples of commercially available 2-methacryloyloxyethyl isocyanate include Karenz MOI (Showa Denko) and 2- (2-isocyanatoethoxy) methacrylate. As a commercially available product of ethyl, Karenz MOI-EG (Showa Denko) can be mentioned.

  Among these unsaturated isocyanate compounds, 2-acryloyloxyethyl isocyanate, 2-methacryloyloxyethyl isocyanate, 4-methacryloyloxybutyl isocyanate, 2- (2 methacrylate) from the viewpoint of reactivity with the (α) copolymer. -Isocyanatoethoxy) ethyl is preferred.

  [A1] In the production of a polymer, unsaturated isocyanate compounds can be used alone or in admixture of two or more.

  The reaction between the (α) copolymer and the unsaturated isocyanate compound is carried out in the presence of a suitable catalyst, if necessary, and preferably in a solution of the (α) copolymer containing a polymerization inhibitor at room temperature or under heating. Therefore, it can be carried out by adding the unsaturated isocyanate compound while stirring. Examples of the catalyst include di-n-butyltin (IV) dilaurate. Examples of the polymerization inhibitor include p-methoxyphenol.

  [A1] The proportion of the unsaturated isocyanate compound used in producing the polymer is preferably 0.1 to 95 mol% with respect to the hydroxyl group derived from the compound (a2-1) in the (α) copolymer. More preferably, it is 1.0-80 mol%, Most preferably, it is 5.0-75 mol%. When the use ratio of the unsaturated isocyanate compound is 0.1 to 95 mol%, the reactivity with the (α) copolymer, the heat resistance and the elastic properties of the composition can be further improved.

  In the composition, the [A1] polymer, the [A2] copolymer, and the [A3] copolymer may be used alone, but the [A1] polymer and the [A2] copolymer may be used alone. Are preferably used in combination, or [A2] copolymer and [A3] copolymer are preferably used in combination. By using together the [A1] polymer and the [A2] copolymer, the storage stability of the obtained composition and the strength and heat resistance of the obtained spacer and the like can be further improved. When the [A1] polymer and the [A2] copolymer are used in combination, the use ratio of the [A1] polymer is preferably 0.5 to 50 parts by mass with respect to 100 parts by mass of the [A2] copolymer. More preferably, it is 1-40 mass parts, Most preferably, it is 3-30 mass parts. [A1] When the ratio of the polymer used is 0.5 to 50 parts by mass, the composition can be obtained that is balanced at a high level of heat stability such as the storage stability of the composition and the resulting spacer.

  On the other hand, the combined use of the [A2] copolymer and the [A3] copolymer provides the advantage that the storage stability of the composition is improved. When the [A2] copolymer and the [A3] copolymer are used in combination, the use ratio of the [A2] copolymer is preferably 10 to 150 parts by mass with respect to 100 parts by mass of the [A3] copolymer. More preferably, it is 20-130 mass parts, Most preferably, it is 30-100 mass parts.

<(B) polymerizable unsaturated compound>
The (B) polymerizable unsaturated compound contained in the composition is an unsaturated compound that is polymerized by irradiation with radiation in the presence of a polymerization initiator (C) described later. As such a polymerizable unsaturated monomer, for example, a monofunctional, bifunctional, or trifunctional or higher (meth) acrylic acid ester has good polymerizability, and the strength of the resulting spacer and the like is improved. Is also preferable.

  Examples of the monofunctional (meth) acrylic acid ester include 2-hydroxyethyl acrylate, 2-hydroxyethyl methacrylate, diethylene glycol monoethyl ether acrylate, diethylene glycol monoethyl ether methacrylate, (2-acryloyloxyethyl) (2-hydroxypropyl). Examples include phthalate, (2-methacryloyloxyethyl) (2-hydroxypropyl) phthalate, and ω-carboxypolycaprolactone monoacrylate.

As these commercial products, for example, Aronix M-101, M-111, M-114, M-5300 (above, Toagosei Co., Ltd.);
KAYARAD TC-110S, TC-120S (Nippon Kayaku Co., Ltd.);
Viscoat 158, 2311 (Osaka Organic Chemical Industry Co., Ltd.) and the like.

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

As these commercial products, for example, Aronix M-210, M-240, M-6200 (above, Toagosei Co., Ltd.);
KAYARAD HDDA, HX-220, R-604 (Nippon Kayaku Co., Ltd.);
Biscote 260, 312 and 335HP (Osaka Organic Chemical Co., Ltd.);
Examples include light acrylate 1,9-NDA (Kyoeisha Chemical Co., Ltd.).

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

Examples of commercially available tri- or higher functional (meth) acrylic acid esters include Aronix M-309, M-400, M-405, M-450, M-7100, M-8030, and M- 8060, TO-1450 (above, Toagosei Co., Ltd.);
KAYARAD TMPTA, DPHA, DPCA-20, DPCA-30, DPCA-60, DPCA-120, DPCA-12 (Nippon Kayaku Co., Ltd.);
Biscote 295, 300, 360, GPT, 3PA, 400 (Osaka Organic Chemical Co., Ltd.);
As a commercial item containing a polyfunctional urethane acrylate type compound, new frontier R-1150 (Daiichi Kogyo Seiyaku Co., Ltd.), KAYARAD DPHA-40H (Nippon Kayaku Co., Ltd.), etc. are mentioned.

  Among these, ω-carboxypolycaprolactone monoacrylate, 1,9-nonanediol dimethacrylate, trimethylolpropane triacrylate, pentaerythritol triacrylate, pentaerythritol tetraacrylate, dipentaerythritol pentaacrylate, dipentaerythritol hexaacrylate, Contains a mixture of dipentaerythritol pentaacrylate and dipentaerythritol hexaacrylate, ethylene oxide modified dipentaerythritol hexaacrylate, succinic acid modified pentaerythritol triacrylate, succinic acid modified dipentaerythritol pentaacrylate, polyfunctional urethane acrylate compound Commercial products are preferred.

  Said (B) polymerizable unsaturated compound can be used individually or in mixture of 2 or more types. The use ratio of the polymerizable unsaturated compound (B) in the composition is preferably 30 to 250 parts by mass, more preferably 50 to 200 parts by mass with respect to 100 parts by mass of the polymer (A). . (B) When the usage-amount of a polymerizable unsaturated compound is 30-250 mass parts, the sensitivity of the said composition, heat resistance, such as a spacer obtained, and elastic characteristics become more favorable.

<(C) Polymerization initiator>
The (C) polymerization initiator contained in the composition is a component that generates an active species capable of initiating polymerization of the polymerizable unsaturated compound (B) in response to radiation. Examples of such (C) polymerization initiators include O-acyloxime compounds, acetophenone compounds, biimidazole compounds, and benzophenone compounds.

  Examples of the O-acyloxime compound include etanone-1- [9-ethyl-6- (2-methylbenzoyl) -9H-carbazol-3-yl] -1- (O-acetyloxime), 1- [9 -Ethyl-6-benzoyl-9. H. -Carbazol-3-yl] -octane-1-one oxime-O-acetate, 1- [9-ethyl-6- (2-methylbenzoyl) -9. H. -Carbazol-3-yl] -ethane-1-one oxime-O-benzoate, 1- [9-n-butyl-6- (2-ethylbenzoyl) -9. H. -Carbazol-3-yl] -ethane-1-one oxime-O-benzoate, ethanone-1- [9-ethyl-6- (2-methyl-4-tetrahydrofuranylbenzoyl) -9. H. -Carbazol-3-yl] -1- (O-acetyloxime), ethanone-1- [9-ethyl-6- (2-methyl-4-tetrahydropyranylbenzoyl) -9. H. -Carbazol-3-yl] -1- (O-acetyloxime), ethanone-1- [9-ethyl-6- (2-methyl-5-tetrahydrofuranylbenzoyl) -9. H. -Carbazole-3-yl] -1- (O-acetyloxime), ethanone-1- [9-ethyl-6- {2-methyl-4- (2,2-dimethyl-1,3-dioxolanyl) methoxybenzoyl } -9. H. -Carbazol-3-yl] -1- (O-acetyloxime) and the like.

  Of these, ethanone-1- [9-ethyl-6- (2-methylbenzoyl) -9H-carbazol-3-yl] -1- (O-acetyloxime), ethanone-1- [9-ethyl-6 -(2-Methyl-4-tetrahydrofuranylmethoxybenzoyl) -9. H. -Carbazol-3-yl] -1- (O-acetyloxime) or ethanone-1- [9-ethyl-6- {2-methyl-4- (2,2-dimethyl-1,3-dioxolanyl) methoxybenzoyl } -9. H. -Carbazol-3-yl] -1- (O-acetyloxime) is preferred. These O-acyl oxime compounds can be used alone or in admixture of two or more.

  Examples of the acetophenone compound include an α-aminoketone compound and an α-hydroxyketone compound.

  Examples of the α-aminoketone compound include 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) -butan-1-one, 2-dimethylamino-2- (4-methylbenzyl) -1- (4 -Morpholin-4-yl-phenyl) -butan-1-one, 2-methyl-1- (4-methylthiophenyl) -2-morpholinopropan-1-one, and the like.

  Examples of the α-hydroxyketone compound include 1-phenyl-2-hydroxy-2-methylpropan-1-one, 1- (4-i-propylphenyl) -2-hydroxy-2-methylpropan-1-one, 4- (2-hydroxyethoxy) phenyl- (2-hydroxy-2-propyl) ketone, 1-hydroxycyclohexyl phenylketone and the like can be mentioned.

  Of these, α-aminoketone compounds are preferred, and 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) -butan-1-one or 2-dimethylamino-2- (4-methylbenzyl) -1- (4-Morpholin-4-yl-phenyl) -butan-1-one is more preferred.

  Examples of the biimidazole compound include 2,2′-bis (2-chlorophenyl) -4,4 ′, 5,5′-tetrakis (4-ethoxycarbonylphenyl) -1,2′-biimidazole, 2,2 '-Bis (2-chlorophenyl) -4,4', 5,5'-tetraphenyl-1,2'-biimidazole, 2,2'-bis (2,4-dichlorophenyl) -4,4 ', 5 , 5′-tetraphenyl-1,2′-biimidazole, 2,2′-bis (2,4,6-trichlorophenyl) -4,4 ′, 5,5′-tetraphenyl-1,2′- Biimidazole etc. are mentioned.

  Among these, 2,2′-bis (2-chlorophenyl) -4,4 ′, 5,5′-tetraphenyl-1,2′-biimidazole, 2,2′-bis (2,4-dichlorophenyl) -4,4 ', 5,5'-tetraphenyl-1,2'-biimidazole or 2,2'-bis (2,4,6-trichlorophenyl) -4,4', 5,5'-tetra Phenyl-1,2'-biimidazole is preferred, and 2,2'-bis (2,4-dichlorophenyl) -4,4 ', 5,5'-tetraphenyl-1,2'-biimidazole is more preferred.

  In the composition, when a biimidazole compound is used as the polymerization initiator (C), an aliphatic or aromatic compound having a dialkylamino group (hereinafter sometimes referred to as “amino sensitizer”) and a thiol compound At least one selected from can be added.

  The amino sensitizer is a compound having a function of sensitizing the radiation sensitivity of the biimidazole compound and increasing the generation efficiency of the imidazole radical, improving the sensitivity and resolution of the composition, and forming a spacer or protection It can be added for the purpose of further improving the adhesion of the film to the substrate.

  Examples of amino sensitizers include N-methyldiethanolamine, 4,4′-bis (dimethylamino) benzophenone, 4,4′-bis (diethylamino) benzophenone, ethyl p-dimethylaminobenzoate, p-dimethylaminobenzoate. Examples include acid i-amyl.

  Of these, 4,4'-bis (diethylamino) benzophenone is preferred. These amino sensitizers can be used alone or in admixture of two or more. The addition amount of the amino sensitizer is preferably 0.1 to 50 parts by mass, more preferably 1 to 20 parts by mass with respect to 100 parts by mass of the biimidazole compound. When the addition amount of the amino sensitizer is 0.1 to 50 parts by mass, the effect of improving sensitivity, resolution and adhesion can be obtained.

  The thiol compound is a compound having a function of donating a hydrogen radical to an imidazole radical and, as a result, generating a component having a sulfur radical. The ability to initiate polymerization of imidazole radicals generated by cleavage of a biimidazole compound upon irradiation with radiation is moderate and is not very high. If this is used as it is for the formation of spacers for liquid crystal display elements, spacers, etc. In some cases, the cross-sectional shape becomes an unfavorable shape with a reverse taper. However, by adding a thiol compound here, hydrogen radicals are donated from the thiol compound to the imidazole radical, so that the imidazole radical is converted to neutral imidazole and also has a higher sulfur initiation radical. As a result, the shape of the spacer or the like can be surely made a more preferable forward tapered shape.

Examples of the thiol compound include aromatic thiol compounds such as 2-mercaptobenzothiazole, 2-mercaptobenzoxazole, 2-mercaptobenzimidazole, 2-mercapto-5-methoxybenzothiazole, 2-mercapto-5-methoxybenzimidazole;
Aliphatic monothiol compounds such as 3-mercaptopropionic acid, methyl 3-mercaptopropionate, ethyl 3-mercaptopropionate, octyl 3-mercaptopropionate;
Bifunctional or higher aliphatic thiol compounds such as 3,6-dioxa-1,8-octanedithiol, pentaerythritol tetra (mercaptoacetate), pentaerythritol tetra (3-mercaptopropionate) and the like can be mentioned. Of these thiol compounds, 2-mercaptobenzothiazole is preferred.

  The addition amount of the thiol compound is preferably 0.1 to 50 parts by mass, more preferably 1 to 20 parts by mass with respect to 100 parts by mass of the biimidazole compound. When the addition amount of the thiol compound is 0.1 to 50 parts by mass, the adhesion to the substrate such as a spacer to be obtained is improved and the shape is improved.

  In the composition, when a biimidazole compound is used as the polymerization initiator (C), it is preferable to add both the amino sensitizer and the thiol compound.

  The use ratio of the (C) polymerization initiator in the present invention is preferably 1 to 60 parts by mass, more preferably 2 to 50 parts by mass, further preferably 100 parts by mass of the (A) polymer. Is 5-40 parts by mass. By using the polymerization initiator (C) in the range of 1 to 60 parts by mass, a spacer having high hardness and adhesion can be formed even in the case of a low exposure amount.

<(D) Thermal dye>
The (D) thermosensitive dye contained in the composition is a kind of thermosensitive dye compound, and the compound itself is colorless, but by contacting with an electron accepting substance with heating, a part of the structure changes, Colored by changing absorption wavelength. Examples of electron-accepting substances include phenolic compounds and organic acids, which are also called color developers. In the present invention, it is not necessary to add such a developer positively, and the (A) polymer containing a carboxyl group is colored by acting on the thermal dye. (D) The thermosensitive dye is preferably at least one selected from the group consisting of compounds represented by the above formulas (1) to (6).

In formula (1), R ^{1 to} R ⁴ are each independently a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, a cycloalkyl group having 3 to 8 carbon atoms, a phenyl group, A benzyl group, a phenethyl group or a naphthyl group; However, some or all of the hydrogen atoms of the phenyl group, benzyl group, phenethyl group and naphthyl group are substituted with an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, a halogen atom or a trifluoromethyl group. May be. R ¹ and R ² may form a morpholino group. R ⁵ and R ⁶ are each independently a hydrogen atom or an alkyl group having 1 to 6 carbon atoms.
In formula (2), R ¹ and R ² have the same meaning as in formula (1). R ⁷ is a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, or a halogen atom. n is an integer of 0-4. However, when n is 2 or more, the plurality of R ⁷ may be the same or different.
In formula (3), R ¹ and R ² have the same meaning as in formula (1). R ⁸ is a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, a halogen atom, or a trifluoromethyl group. n is an integer of 0-4. However, when n is 2 or more, the plurality of R ⁸ may be the same or different.
In formula (4), R ¹ and R ² have the same meaning as in formula (1). R ^1a , R ^2a , R ^1b and R ^2b are each independently a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, a cycloalkyl group having 3 to 8 carbon atoms, a phenyl group, A benzyl group, a phenethyl group or a naphthyl group; However, some or all of the hydrogen atoms of the phenyl group, benzyl group, phenethyl group and naphthyl group are substituted with an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, a halogen atom or a trifluoromethyl group. May be. R ^1a and R ^2a , and R ^1b and R ^2b may form a morpholino group.
In formula (5), R ¹ , R ² , R ^1a and R ^2a have the same ^{meaning as} in formula (4). R ⁷ has the same meaning as in formula (2). m is an integer of 0-5. When m is 2 or more, the plurality of R ⁷ may be the same or different.
In formula (6), R ¹ , R ² , R ^1a and R ^2a have the same ^{meaning as} in formula (4). R ⁹ is an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, a cycloalkyl group having 3 to 8 carbon atoms, a phenyl group, a benzyl group, a phenethyl group, or a naphthyl group. However, part or all of the hydrogen atoms of the phenyl group, benzyl group, phenethyl group and naphthyl group are substituted with an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, a halogen atom or a nitro group. May be. )

  As said C1-C6 alkyl group, a methyl group, an ethyl group, a propyl group, a butyl group etc. are mentioned, for example.

  As said C1-C6 alkoxy group, a methoxy group, an ethoxy group, a propoxy group etc. are mentioned, for example.

  Examples of the cycloalkyl group having 3 to 8 carbon atoms include a cyclohexyl group.

  Since the composition contains such a thermal dye (D), the transmittance of the coating film is high at the time of exposure after forming the coating film, so that it is possible to form a spacer pattern with high sensitivity and high resolution. In the subsequent heating step by post-baking after development, the spacer pattern is colored by the thermal dye. The light resistance in an ultraviolet region etc. improves because a spacer pattern contains a coloring substance.

  The thermal dye (D) represented by the above formula (1) is a compound having a fluorane skeleton, such as 2-N, N-dibenzylamino-6-diethylaminofluorane, 2-anilino-3-methyl-6- Diethylaminofluorane, 2-anilino-3-methyl-6- (N-ethyl-N-isopentylamino) fluorane, 2-anilino-3-methyl-6- (N-ethyl-N-tolylamino) fluorane, 2- Anilino-3-methyl-6-morpholinofluorane, 2-o-chloroanilino-6-diethylaminofluorane, 2-N-benzyl-N-methylamino-6- (N-ethyl-N-tolylamino) fluorane, 2- Anilino-3-methyl-6-N, N-di-n-pentylaminofluorane, 2-anilino-3-methyl-6-N, N-di-n-propiyl Aminofluorane, 2-anilino-3-methyl-6- (N-ethyl-N-tolylamino) fluorane, 2- (3-trifluoromethylanilino) -3-methyl-6-diethylaminofluorane, 2-anilino -3-methyl-6- (N-ethyl-N-3-ethoxypropylamino) fluorane and the like.

  Examples of the thermosensitive dye (D) represented by the above formula (2) include 1,3-dimethyl-6-diethylaminofluorane, 1,3-diethyl-6-diethylaminofluorane, 1,3-diethyl-6-di- Propylaminofluorane, 1,3-dibromo-6-diethylaminofluorane, 1-methyl-3-phenyl-6-diethylaminofluorane, 1-methyl-3-phenyl-6-diethylaminofluorane, 1-methyl-6 -Diethylaminofluorane, 1,2,3-trimethyl-6-diethylaminofluorane, 2-bromo-3-methyl-6-dibutylaminofluorane and the like.

  Examples of the thermal dye (D) represented by the above formula (3) include 6-dimethylamino-benzo [a] -fluorane, 6-diethylamino-benzo [a] -fluorane, 6-dimethylamino-2,3-dimethylbenzo [A] -fluorane, 6-dimethylamino-2,3-diethylbenzo [a] -fluorane, 6-dimethylamino-2-ethylbenzo [a] -fluorane, 6-dimethylamino-2-bromobenzo [a] -fluorane , 6-dimethylamino-2-methoxybenzo [a] -fluorane and the like.

  Examples of the thermal dye (D) represented by the above formula (4) include 3,3-bis (p-dimethylaminophenyl) -6-dimethylaminophthalide, 3,3-bis (p-diethylaminophenyl) -6- Diethylaminophthalide, 3,3-bis (p-diisopropylaminophenyl) -6-diisopropylaminophthalide, 3,3-bis (p-din-butylaminophenyl) -6-din-propylaminophthalide, etc. Is mentioned.

  Examples of the thermal dye (D) represented by the above formula (5) include 3,7-bis (dimethylamino) -10-benzoyl-phenothiazine, 3,7-bis (diethylamino) -10-benzoyl-phenothiazine, 3,7 -Bis (diisopropylamino) -10-benzoyl-phenothiazine, 3,7-bis (di-n-butylamino) -10-benzoyl-phenothiazine and the like.

  As the thermal dye (D) represented by the above formula (6), 3,6-bis (dimethylamino) fluorane-γ- (4′-nitro) -anilinolactam, 3,6-bis (diethylamino) fluorane- γ- (4′-nitro) -anilinolactam, 3,6-bis (diethylamino) fluorane-γ- (4′-phenyl) -anilinolactam, 3,6-bis (diethylamino) fluorane-γ- (4 And '-naphthyl) -anilinolactam.

  Among these (D) thermosensitive dyes, 2-anilino-3-methyl-6- (N-ethyl-N-isopentylamino) fluorane, 2-silane, from the viewpoint of colorability by heat sensitivity and solubility in the composition. N, N-dibenzylamino-6-diethylaminofluorane, 2-N-benzyl-N-methylamino-6- (N-ethyl-N-tolylamino) fluorane, 2-anilino-3-methyl-6- (N -Ethyl-N-tolylamino) fluorane, 1,3-dimethyl-6-diethylaminofluorane, 2-bromo-3-methyl-6-dibutylaminofluorane, 6-dimethylamino-benzo [a] -fluorane, 3, 3-bis (p-dimethylaminophenyl) -6-dimethylaminophthalide, 3,7-bis (dimethylamino) -10-benzoyl-phenothiazine, 3 3,6-Bis (diethylamino) fluoran-.gamma.-(4'-nitro) - anilino lactam is preferred.

(D) As a content rate of a thermal dye, 0.5 mass% or more 5 with respect to the total amount of (A) polymer, (B) polymerizable unsaturated compound, (C) polymerization initiator, and (D) thermal dye. % By mass or less is preferable, and 1% by mass or more and 3% by mass or less is more preferable. (D) When the content ratio of the thermosensitive dye is in the range of 0.5 to 5% by mass, the spacer can be formed with an exposure amount of 850 (J / m ² ) or less, and higher film thickness uniformity and light resistance. Can be achieved.

<(E) Acid generator>
The composition can contain (E) an acid generator as a suitable component. (E) The acid generator is a compound that generates an acid by heating, and (D) it is possible to promote the opening of a lactone ring located at the center of the thermal dye. Although it is possible to color the cured film without using (E) an acid generator, coloring can be promoted by adding (E) an acid generator. Note that (E) the acid generator does not release an acidic active substance at the time of pre-baking at a relatively low temperature (for example, 70 to 120 ° C.) in the coating film forming step of the composition, and is relatively high in the heating step after development ( For example, those having a property of releasing an acidic active substance during post-baking at 120 to 250 ° C. are preferable.

  Examples of the acid generator (E) include onium salts such as diphenyliodonium salt, triphenylsulfonium salt, sulfonium salt, benzothiazonium salt, ammonium salt, phosphonium salt, and tetrahydrothiophenium salt.

  Examples of the diphenyliodonium salt include diphenyliodonium tetrafluoroborate, diphenyliodonium hexafluorophosphonate, diphenyliodonium hexafluoroarsenate, diphenyliodonium trifluoromethanesulfonate, diphenyliodonium trifluoroacetate, diphenyliodonium-p-toluenesulfonate, diphenyliodonium Butyltris (2,6-difluorophenyl) borate, 4-methoxyphenylphenyliodonium tetrafluoroborate, bis (4-t-butylphenyl) iodonium tetrafluoroborate, bis (4-t-butylphenyl) iodonium hexafluoroarsenate Bis (4-t-butylphenyl) iodonium trifluorome Sulphonate, bis (4-t-butylphenyl) iodonium trifluoroacetate, bis (4-t-butylphenyl) iodonium-p-toluenesulfonate, bis (4-t-butylphenyl) iodonium camphorsulfonic acid, etc. .

  Examples of the triphenylsulfonium salt include triphenylsulfonium trifluoromethanesulfonate, triphenylsulfonium camphorsulfonic acid, triphenylsulfonium tetrafluoroborate, triphenylsulfonium trifluoroacetate, triphenylsulfonium-p-toluenesulfonate, triphenylsulfonium. And butyl tris (2,6-difluorophenyl) borate.

  Examples of the sulfonium salt include alkylsulfonium salts, benzylsulfonium salts, dibenzylsulfonium salts, substituted benzylsulfonium salts, and the like.

  Examples of the alkylsulfonium salt include 4-acetoxyphenyldimethylsulfonium hexafluoroantimonate, 4-acetoxyphenyldimethylsulfonium hexafluoroarsenate, dimethyl-4- (benzyloxycarbonyloxy) phenylsulfonium hexafluoroantimonate, dimethyl-4- (Benzoyloxy) phenylsulfonium hexafluoroantimonate, dimethyl-4- (benzoyloxy) phenylsulfonium hexafluoroarsenate, dimethyl-3-chloro-4-acetoxyphenylsulfonium hexafluoroantimonate and the like can be mentioned.

  Examples of benzylsulfonium salts include benzyl-4-hydroxyphenylmethylsulfonium hexafluoroantimonate, benzyl-4-hydroxyphenylmethylsulfonium hexafluorophosphate, 4-acetoxyphenylbenzylmethylsulfonium hexafluoroantimonate, and benzyl-4-methoxyphenylmethyl. Sulfonium hexafluoroantimonate, benzyl-2-methyl-4-hydroxyphenylmethylsulfonium hexafluoroantimonate, benzyl-3-chloro-4-hydroxyphenylmethylsulfonium hexafluoroarsenate, 4-methoxybenzyl-4-hydroxyphenylmethyl Examples include sulfonium hexafluorophosphate.

  Examples of the dibenzylsulfonium salt include dibenzyl-4-hydroxyphenylsulfonium hexafluoroantimonate, dibenzyl-4-hydroxyphenylsulfonium hexafluorophosphate, 4-acetoxyphenyl dibenzylsulfonium hexafluoroantimonate, and dibenzyl-4-methoxyphenylsulfonium. Hexafluoroantimonate, dibenzyl-3-chloro-4-hydroxyphenylsulfonium hexafluoroarsenate, dibenzyl-3-methyl-4-hydroxy-5-t-butylphenylsulfonium hexafluoroantimonate, benzyl-4-methoxybenzyl- 4-hydroxyphenylsulfonium hexafluorophosphate and the like

  Examples of substituted benzylsulfonium salts include p-chlorobenzyl-4-hydroxyphenylmethylsulfonium hexafluoroantimonate, p-nitrobenzyl-4-hydroxyphenylmethylsulfonium hexafluoroantimonate, and p-chlorobenzyl-4-hydroxyphenylmethyl. Sulfonium hexafluorophosphate, p-nitrobenzyl-3-methyl-4-hydroxyphenylmethylsulfonium hexafluoroantimonate, 3,5-dichlorobenzyl-4-hydroxyphenylmethylsulfonium hexafluoroantimonate, o-chlorobenzyl-3- And chloro-4-hydroxyphenylmethylsulfonium hexafluoroantimonate

  Examples of the benzothiazonium salt include 3-benzylbenzothiazonium hexafluoroantimonate, 3-benzylbenzothiazonium hexafluorophosphate, 3-benzylbenzothiazonium tetrafluoroborate, and 3- (p-methoxybenzyl). ) Benzothiazonium hexafluoroantimonate, 3-benzyl-2-methylthiobenzothiazonium hexafluoroantimonate, 3-benzyl-5-chlorobenzothiazonium hexafluoroantimonate, and the like.

  Examples of the tetrahydrothiophenium salt include 1- (4-n-butoxynaphthalen-1-yl) tetrahydrothiophenium trifluoromethanesulfonate, 1- (4-n-butoxynaphthalen-1-yl) tetrahydrothiophenium nona. Fluoro-n-butanesulfonate, 1- (4-n-butoxynaphthalen-1-yl) tetrahydrothiophenium-1,1,2,2-tetrafluoro-2- (norbornan-2-yl) ethanesulfonate, 1 -(4-n-Butoxynaphthalen-1-yl) tetrahydrothiophenium-2- (5-t-butoxycarbonyloxybicyclo [2.2.1] heptan-2-yl) -1,1,2,2 -Tetrafluoroethanesulfonate, 1- (4-n-butoxynaphthalen-1-yl) tetrahydride Thiophenium-2- (6-t-butoxycarbonyloxybicyclo [2.2.1] heptan-2-yl) -1,1,2,2-tetrafluoroethanesulfonate, 1- (4,7-dibutoxy-1 -Naphthalenyl) tetrahydrothiophenium trifluoromethanesulfonate and the like.

  Of these, triphenylsulfonium salt, sulfonium salt, benzothiazonium salt, and tetrahydrothiophenium salt are preferable from the viewpoint of promoting coloring of the cured film. Among them, triphenylsulfonium trifluoromethanesulfonate, triphenylsulfonium camphorsulfonic acid, 4-acetoxyphenyldimethylsulfonium hexafluoroarsenate, benzyl-4-hydroxyphenylmethylsulfonium hexafluoroantimonate, 4-acetoxyphenylbenzylmethylsulfonium hexafluoro Antimonate, dibenzyl-4-hydroxyphenylsulfonium hexafluoroantimonate, 4-acetoxyphenylbenzylmethylsulfonium hexafluoroantimonate, 3-benzylbenzothiazonium hexafluoroantimonate, benzyl-4-hydroxyphenylmethylsulfonium hexafluorophosphate , 1- (4,7-dibutoxy-1-naphtha Yl) tetrahydrothiophenium trifluoromethanesulfonate is preferred.

  (E) An acid generator may be used independently and may be used in mixture of 2 or more types. (E) As usage-amount of an acid generator, Preferably it is 0.1 mass part-10 mass parts with respect to 100 mass parts of (A) polymers, More preferably, they are 1 mass part-8 mass parts. (E) By making the usage-amount of an acid generator into 0.1 mass part-10 mass parts, the said composition provided with sufficient heat resistance, such as promotion of coloring of a cured film and the spacer formed, is obtained.

<Solvent>
The composition is preferably used in a solution state after being dissolved in a suitable solvent. Examples of the solvent include alcohol, glycol ether, ethylene glycol alkyl ether acetate, diethylene glycol monoalkyl ether, diethylene glycol dialkyl ether, dipropylene glycol dialkyl ether, propylene glycol monoalkyl ether, propylene glycol alkyl ether acetate, propylene glycol alkyl ether propionate. , Ketones, esters and the like.

Examples of the alcohol include benzyl alcohol;
Examples of glycol ethers include ethylene glycol monomethyl ether and ethylene glycol monoethyl ether;
Examples of the ethylene glycol alkyl ether acetate include ethylene glycol monobutyl ether acetate and diethylene glycol monoethyl ether acetate;
Examples of the diethylene glycol monoalkyl ether include diethylene glycol monomethyl ether and diethylene glycol monoethyl ether;
Examples of the diethylene glycol dialkyl ether include diethylene glycol dimethyl ether, diethylene glycol diethyl ether, diethylene glycol ethyl methyl ether and the like;
Examples of the dipropylene glycol dialkyl ether include dipropylene glycol dimethyl ether, dipropylene glycol diethyl ether, and dipropylene glycol ethyl methyl ether;
Examples of the propylene glycol monoalkyl ether include propylene glycol methyl ether, propylene glycol ethyl ether, propylene glycol propyl ether, and propylene glycol butyl ether;
Examples of the propylene glycol alkyl ether acetate include propylene glycol methyl ether acetate and propylene glycol ethyl ether acetate;
Examples of the propylene glycol alkyl ether propionate include propylene glycol methyl ether propionate, propylene glycol ethyl ether propionate, propylene glycol propyl ether propionate and the like;
Examples of the ketone include methyl ethyl ketone, cyclohexanone, 4-hydroxy-4-methyl-2-pentanone, and methyl isoamyl ketone;
Examples of the ester include ethyl acetate, butyl acetate, ethyl 2-hydroxypropionate, methyl 2-hydroxy-2-methylpropionate, ethyl 2-hydroxy-2-methylpropionate, butyl hydroxyacetate, methyl lactate, ethyl lactate, Propyl lactate, butyl lactate, ethyl 2-ethoxypropionate, propyl 2-ethoxypropionate, butyl 2-ethoxypropionate, methyl 2-butoxypropionate, ethyl 2-butoxypropionate, propyl 2-butoxypropionate, 2- Butyl propionate butyl, methyl 3-methoxypropionate, ethyl 3-methoxypropionate, propyl 3-methoxypropionate, butyl 3-methoxypropionate, methyl 3-ethoxypropionate, ethyl 3-ethoxypropionate 3-ethoxy propionate propyl, 3-ethoxy propionate butyl, 3-propoxy-propionic acid methyl, and the like, respectively.

  Among these, benzyl alcohol, diethylene glycol ethyl methyl ether, propylene glycol methyl ether acetate, propylene glycol ethyl ether acetate, diethylene glycol dimethyl ether, ethylene glycol monobutyl ether acetate, diethylene glycol monoethyl ether acetate, diethylene glycol diethyl ether, methyl 3-methoxypropionate, Ethyl 3-ethoxypropionate, cyclohexanone, dipropylene glycol dimethyl ether, propylene glycol methyl ether propionate are preferred.

  As content of a solvent, Preferably it is 60 mass%-95 mass% with respect to the whole quantity of the said composition, More preferably, it is 70 mass%-95 mass%. When the content of the solvent is 60% by mass to 95% by mass, the viscosity and solid concentration of the composition are balanced at a higher level, and the high-speed coating property is excellent.

<Other optional components>
The said composition can contain other arbitrary components, such as surfactant and a close_contact | adherence adjuvant, in the range which does not impair the effect of this invention.

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

  Examples of commercially available fluorosurfactants include BM-1000, BM-1100 (above, BM CHEMIE), MegaFuck F142D, F172, F173, F183, F178, F191, F191, F471, F476 (above, Dainippon Ink & Chemicals), FT-100, -110, -140A, -150, -250, -251, -300, -310, -400S , Fantient FTX-218, and -251 (above, Neos).

  Examples of the silicone surfactant include Toray Silicone DC3PA, DC7PA, SH11PA, SH21PA, SH28PA, SH29PA, SH30PA, SH-190, SH-193, SZ-6032, SF- 8428, DC-57, DC-190 (above, Toray Dow Corning Silicone). These surfactants can be used alone or in admixture of two or more.

  As usage-amount of surfactant, it is 0.1-5 mass parts with respect to 100 mass parts of (A) polymers, More preferably, it is 0.15-3 mass parts. When the amount of the surfactant used is 0.1 to 5 parts by mass, coating unevenness can be reduced.

<Adhesion aid>
The adhesion assistant is a component used for improving the adhesion between the formed spacer and the substrate. As the adhesion assistant, a functional silane coupling agent having a reactive functional group such as a carboxyl group, a methacryloyl group, a vinyl group, an isocyanate group, or an epoxy group is preferable. For example, trimethoxysilylbenzoic acid, γ-methacryloxypropyltri Examples include methoxysilane, vinyltriacetoxysilane, vinyltrimethoxysilane, γ-isocyanatopropyltriethoxysilane, γ-glycidoxypropyltrimethoxysilane, β- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, and the like. . These adhesion assistants can be used alone or in admixture of two or more.

  The amount of the adhesion aid used is preferably in the range of 1 to 20 parts by mass, more preferably 2 to 15 parts by mass with respect to 100 parts by mass of the polymer (A). When the use amount of the adhesion assistant is in the range of 1 to 20 parts by mass, the adhesion of the pattern can be improved without producing a development residue in the development process.

<Preparation of the composition>
The composition comprises the above-mentioned (A) polymer, (B) polymerizable unsaturated compound, (C) polymerization initiator, (D) thermal dye and a suitable (E) acid generator, as required. It is prepared by mixing arbitrary components uniformly in a predetermined ratio. The composition is preferably used in a solution state after being dissolved in a suitable solvent. Such a composition solution can be used after being filtered using a Millipore filter having a pore diameter of about 0.5 μm.

  When the composition is prepared as a solution, the solid concentration (components other than the solvent in the composition solution, that is, the above-mentioned (A) polymer, (B) polymerizable unsaturated compound, (C) polymerization initiator (D) The thermosensitive dye and other optional components are dissolved in a solvent, and the ratio of the total amount is set to an arbitrary concentration (for example, 5 to 50% by mass) depending on the purpose of use, a desired film thickness value, and the like. The more preferable solid content concentration varies depending on the method of forming the film on the substrate, and the solid content concentration when the spin coating method is employed as the coating method is preferably 20 to 50% by mass. The solid content concentration in the case of employing the slit coating method is more preferably 10 to 35% by mass, and particularly preferably 15 to 30% by mass. .

<Method for forming cured product>
The present invention suitably includes a cured product as a protective film for a display element, an insulating film or a spacer formed from the composition.
The method of forming a cured product as a protective film for display elements, an insulating film or a spacer is as follows:
(1) A step of applying the composition onto a substrate to form a coating film,
(2) a step of exposing at least a part of the coating film;
(3) a step of developing the coated film after exposure; and (4) a step of heating the coated film after development. Hereinafter, each process is explained in full detail.

[Step (1)]
A transparent conductive film is formed on one side of the transparent substrate, and a film of the composition is formed on the transparent conductive film. Examples of the transparent substrate include a glass substrate and a resin substrate. More specifically, examples include glass substrates such as soda lime glass and alkali-free glass; resin substrates made of plastics such as polyethylene terephthalate, polybutylene terephthalate, polyethersulfone, polycarbonate, and polyimide. As the transparent conductive film provided on one surface of the transparent substrate, for example, a NESA film (registered trademark of PPG, USA) made of tin oxide (SnO ₂ ), ITO made of indium oxide-tin oxide (In ₂ O ₃ —SnO ₂ ), or the like. Examples include membranes.

  In the case of forming a film by a coating method, the film can be formed by heating (pre-baking) the coating surface after applying the solution of the composition on the transparent conductive film. As a coating method of the composition solution, an appropriate method such as a spray method, a roll coating method, a spin coating method (spin coating method), a slit coating method, a bar coating method, an ink jet coating method, or the like can be adopted. A coating method is preferred. When the slit coating method is employed, the advantageous effects of the present invention can be maximized.

  After application, preferably pre-bake and post-bake are performed. The pre-bake and post-bake conditions should be appropriately set depending on the types of components contained in the composition, the use ratio, and the like. Pre-baking can be performed, for example, at 70 ° C. to 120 ° C. under conditions of, for example, about 1 minute to 10 minutes. The film thickness of the coating film to be formed is preferably 0.1 μm to 8 μm, more preferably 0.1 μm to 6 μm, and particularly preferably 0.1 μm to 5 μm.

[Step (2)]
Next, radiation is applied to at least a part of the formed coating film. At this time, examples of the method of irradiating only a part of the coating film include a method of irradiating through a photomask having a predetermined pattern. Examples of radiation used for irradiation include visible light, ultraviolet light, and far ultraviolet light. Of these, radiation having a wavelength in the range of 250 to 550 nm is preferable, and radiation including ultraviolet light having a wavelength of 365 nm is particularly preferable. Radiation irradiation amount (exposure amount) is preferably 100 to 5,000 J / m ² , preferably as a value obtained by measuring the intensity of irradiated radiation at a wavelength of 365 nm with an illuminometer (OAI model 356, Optical Associates Inc.). preferably from 200~3,000J / ^{m 2.} The composition has high radiation sensitivity compared to a conventionally known composition, and even when the radiation dose is 850 J / m ² or less, a desired film thickness, good shape, excellent adhesion and high A cured product as a protective film, insulating film or spacer for a display device having hardness is obtained.

[Step (3)]
Next, by developing the coating film after irradiation, unnecessary portions (non-exposed portions) are removed, and a desired pattern is formed. Examples of the developer used for development include aqueous solutions of inorganic alkaline compounds such as sodium hydroxide, potassium hydroxide and sodium carbonate, and organic alkaline compounds such as quaternary ammonium salts such as tetramethylammonium hydroxide and tetraethylammonium hydroxide. Can be used. An appropriate amount of at least one selected from the group consisting of a water-soluble organic solvent such as methanol and ethanol and a surfactant may be added to the aqueous solution of the alkaline compound.

  As a developing method, any of a liquid piling method, a dipping method, a shower method and the like may be used, and the developing time is preferably about 10 to 180 seconds. The development temperature may be room temperature. Subsequent to the development processing, for example, after washing with running water for 30 to 90 seconds, a desired pattern can be obtained by air drying with compressed air or compressed nitrogen.

[Step (4)]
Next, the obtained patterned coating film is heated by a suitable heating device such as a hot plate or an oven, for example, at 100 ° C. to 250 ° C., for example, on the hot plate for 5 minutes to 30 minutes, and in the oven for 25 minutes to 180 minutes. By doing so, a cured product having a desired pattern is obtained.

  By the formation method having the above steps, a cured product as a protective film, insulating film or spacer for a display element excellent in various properties such as film thickness uniformity is obtained without causing minute unevenness of the coating film. It is done.

  EXAMPLES The present invention will be specifically described below with reference to examples, but the present invention is not limited to these examples.

The weight average molecular weight (Mw) and number average molecular weight (Mn) of the polymer were measured by gel permeation chromatography (GPC) under the following conditions.
Measuring apparatus: GPC-101 (Showa Denko), separation column: GPC-KF-801, GPC-KF-802, GPC-KF-803, and GPC-KF-804 are combined Column temperature: 40 ° C.
Elution solvent: Tetrahydrofuran (Wako Pure Chemical Industries)
Flow rate: 1.0 mL / min Sample concentration: 1.0 mass%
Sample injection volume: 100 μL
Detector: Differential refractometer Standard material: Monodisperse polystyrene

  The solution viscosity of the composition was measured at 25 ° C. using an E-type viscometer manufactured by Tokyo Keiki Co., Ltd.

<(A) Synthesis of polymer>
[Synthesis Example 1]
In a flask equipped with a condenser and a stirrer, 6 parts by mass of 2,2′-azobis (2,4-dimethylvaleronitrile), 3 parts of pentaerythritol tetrakis (3-mercaptopropionate), methyl 3-methoxypropionate 250 parts by mass were charged, followed by 14 parts by mass of methacrylic acid, 40 parts by mass of glycidyl methacrylate, 6 parts by mass of styrene, and 35 parts by mass of tricyclo [5.2.1.0 ^2,6 ] decane-8-yl methacrylate. After charging and replacing with nitrogen, 5 parts by mass of 1,3-butadiene was further charged, the temperature of the solution was raised to 70 ° C. while gently stirring, and this temperature was maintained for 4 hours to polymerize. A copolymer solution having a partial concentration of 28.1% was obtained. This is designated as (A2-1) copolymer. Mw with the obtained (A2-1) copolymer was 10,500.

[Synthesis Example 2]
A flask equipped with a condenser and a stirrer was charged with 5 parts by mass of 2,2′-azobisisobutyronitrile and 250 parts by mass of propylene glycol monomethyl ether acetate, followed by 18 parts by mass of methacrylic acid and tricyclomethacrylate [5 .2.1.0 ^2,6 ] Decan-8-yl 25 parts by mass, styrene 5 parts by mass, methacrylic acid 2-hydroxyethyl ester 30 parts by mass, benzyl methacrylate 22 parts by mass, While gently stirring, the temperature of the solution was raised to 70 ° C., and this temperature was maintained for 5 hours for polymerization to obtain an (α-1) copolymer solution having a solid content concentration of 28.8%. Mw of the obtained (α-1) copolymer was 13,000.

Next, after adding 12 parts by mass of 3-methacryloyloxyethyl isocyanate (Karenz MOI, Showa Denko KK) and 0.1 part by mass of 4-methoxyphenol to the (α-1) solution, further at 40 ° C. for 1 hour, The reaction was allowed to stir at 60 ° C. for 2 hours. The progress of the reaction between the isocyanate group derived from 3-methacryloyloxyethyl isocyanate and the hydroxyl group of (α-1) was confirmed by IR (infrared absorption) spectrum. The IR spectrum of the reaction solution after reaction at 40 ° C. for 1 hour and further at 60 ° C. for 2 hours was measured, and the peak near 2270 cm ⁻¹ derived from the isocyanate group of 3-methacryloyloxyethyl isocyanate had decreased. It was confirmed that the reaction was progressing. A (A1-1) polymer solution having a solid content concentration of 31.0% was obtained. This is designated as (A1-1) polymer.

[Synthesis Example 3]
A flask equipped with a condenser and a stirrer was charged with 6 parts by mass of 2,2′-azobis (isobutyronitrile) and 250 parts by mass of methyl 3-methoxypropionate, followed by 14 parts by mass of methacrylic acid and tetrahydromethacrylate. After charging 20 parts by weight of furfuryl, 5 parts by weight of styrene and 56 parts by weight of benzyl methacrylate and replacing with nitrogen, further 5 parts by weight of 1,3-butadiene was added and the temperature of the solution was adjusted to 70 ° C. while gently stirring. And the temperature was maintained for 5 hours for polymerization to obtain a polymer solution (A) having a solid content concentration of 27.9%. This is designated as (A3-1) copolymer. Mw of the obtained (A3-1) copolymer was 11,400.

[Synthesis Example 4]
A flask equipped with a condenser and a stirrer was charged with 6 parts by mass of 2,2′-azobis (isobutyronitrile) and 250 parts by mass of methyl 3-methoxypropionate, followed by 5 parts by mass of styrene and 14 parts by mass of methacrylic acid. , 33 parts by mass of benzyl methacrylate, 23 parts by mass of n-butyl methacrylate, and 20 parts by mass of 3- (methacryloyloxymethyl) -3-ethyloxetane were substituted with nitrogen. A polymer solution having a solid content concentration of 27.9% by weight was prepared by charging a part by mass, raising the temperature of the solution to 80 ° C. while gently stirring, and maintaining this temperature for 4 hours to polymerize. Obtained. This is designated as (A2-2) copolymer. Mw of the obtained (A2-2) copolymer was 11,200.

<Preparation of the composition>
[Example 1]
(A) The amount of the solution of the (A2-1) copolymer obtained in Synthesis Example 1 as a polymer in terms of 100 parts by mass (solid content) in terms of (A2-1) copolymer, (B ) 150 parts by mass of a mixture of dipentaerythritol hexaacrylate and dipentaerythritol pentaacrylate (KAYARAD DPHA, Nippon Kayaku Co., Ltd.) as the polymerizable unsaturated compound, and (C) ethanone-1- [9-ethyl-6 as the polymerization initiator -(2-Methylbenzoyl) -9H-carbazol-3-yl] -1- (O-acetyloxime) (Ciba Specialty Chemicals, Irgacure OXE02), 2 parts by mass, 2- (4-methylbenzyl)- 2- (Dimethylamino) -1- (4-morpholinophenyl) -butan-1-one (Irgacure 379, Ciba Specialty Ke Mikals) 10 parts by weight, 2,2′-bis (2-chlorophenyl) -4,4 ′, 5,5′-tetraphenyl-1,2′-biimidazole, 2 parts by weight, 4,4′-bis ( 1 part by weight of diethylamino) benzophenone, (D) 3 parts by weight of 2-anilino-3-methyl-6- (N-ethyl-N-isopentylamino) aminofluorane as the thermal dye, and methyl 3-methoxypropionate as the solvent 500 Part by mass, 5 parts by mass of γ-glycidoxypropyltrimethoxysilane as adhesion assistant, 0.2 parts by mass of Fantent FTX-218 (Neos) as surface activity are added, and the solid content concentration is 23.5% by mass Then, the composition was prepared by filtering with a Millipore filter having a pore size of 0.5 μm. The viscosity of the composition after preparation was 4.0 (mPa · s).

[Examples 2 to 20 and Comparative Example 1]
A solution of the composition was prepared in the same manner as in Example 1 except that the types and amounts as shown in Table 1 were used as the components (A) to (E).

  Details of the abbreviations of the components (B) to (E) shown in Table 1 are as follows.

(B) Polymerizable unsaturated compound (B-1): Mixture of dipentaerythritol hexaacrylate and dipentaerythritol pentaacrylate (KAYARAD DPHA, Nippon Kayaku Co., Ltd.)
(B-2): Multifunctional acrylate compound (KAYARAD DPHA-40H, Nippon Kayaku Co., Ltd.)
(B-3): Succinic acid-modified dipentaerythritol pentaacrylate (B-4): ω-carboxypolycaprolactone monoacrylate (Aronix M-5300, Toagosei Co., Ltd.)

(C) Polymerization initiator (C-1): Ethanone, 1- [9-ethyl-6- (2-methylbenzoyl) -9H-carbazol-3-yl]-, 1- (O-acetyloxime) (Irgacure OXE02, Ciba Specialty Chemicals)
(C-2): 2- (4-methylbenzyl) -2- (dimethylamino) -1- (4-morpholinophenyl) -butan-1-one (Irgacure 379, Ciba Specialty Chemicals)
(C-3): 2,2′-bis (2-chlorophenyl) -4,4 ′, 5,5′-tetraphenyl-1,2′-biimidazole (C-4): 2-methyl-1- [4- (Methylthio) phenyl] -2-morpholinopropan-1-one (Irgacure 907, Ciba Specialty Chemicals)
(C-5): 4,4′-bis (diethylamino) benzophenone

(D) Thermal dye (D-1): 2-anilino-3-methyl-6- (N-ethyl-N-isopentylamino) fluorane (S-205, Yamada Chemical Co., Ltd.)
(D-2): 2-anilino-3-methyl-6- (N-ethyl-N-tolylamino) fluorane (ETAC, Yamada Chemical Co., Ltd.)
(D-3): 2-N, N-dibenzylamino-6-diethylaminofluorane (GREEN-DCF, Hodogaya Chemical Co., Ltd.)
(D-4): 2-N-benzyl-N-methylamino-6- (N-ethyl-N-tolylamino) fluorane (D-5): 1,3-dimethyl-6-diethylaminofluorane (Orange-DCF) , Hodogaya Chemical Co., Ltd.)
(D-6): 2-bromo-3-methyl-6-dibutylaminofluorane (Vermilion-DCF, Hodogaya Chemical Co., Ltd.)
(D-7): 6-dimethylamino-benzo [a] -fluorane (Red-DCF, Hodogaya Chemical Co., Ltd.)
(D-8): 3,3-bis (p-dimethylaminophenyl) -6-dimethylaminophthalide (CVL, Hodogaya Chemical Co., Ltd.)
(D-9): 3,7-bis (dimethylamino) -10-benzoyl-phenothiazine (BLMB, Hodogaya Chemical Co., Ltd.)
(D-10): 3,6-bis (diethylamino) fluorane-γ- (4′-nitro) -anilinolactam (Pink-DCF, Hodogaya Chemical Co., Ltd.)

(E) Acid generator (E-1): Triphenylsulfonium trifluoromethanesulfonate (E-2): Benzyl-4-hydroxyphenylmethylsulfonium hexafluorophosphate

<Evaluation>
The following evaluation was performed about the composition prepared in Examples 1-20 and the comparative example 1, and the hardened | cured material obtained from the composition. The results are shown in Table 1.

[Evaluation of uniformity of coating thickness (uniformity)]
The prepared composition solution was applied onto a 550 mm × 650 mm chromium-deposited glass using a slit die coater (TR632105-CL, Tokyo Ohka Kogyo Co., Ltd.). After drying under reduced pressure to 0.5 Torr, pre-baking on a hot plate at 100 ° C. for 2 minutes to form a coating film, and further exposing to ultraviolet rays at an exposure amount of 2,000 J / m ² , a chromium film-forming glass A film having a thickness of 4 μm from the upper surface of was formed. The film thickness of the coating film on the chromium film-forming glass was measured using a needle contact type measuring machine (KLA Tencor AS200). The uniformity was calculated from the film thickness at nine measurement points. The nine measurement points are (X [mm], Y [mm]), where (X [mm], Y [mm]) is (275, 20), (275, 30), (275, 60), (275, 100), (275, 325), (275, 550), (275, 590), (275, 620), (275, 630). The uniformity calculation formula is expressed by the following formula. In the following formula, FT (X, Y) max is the maximum value in the film thickness at 9 measurement points, FT (X, Y) min is the minimum value in the film thickness at 9 measurement points, and FT (X, Y) avg . Is an average value in the film thickness at nine measurement points. When the uniformity is 2% or less, it can be judged that the film thickness uniformity is good.
(Uniformity calculation formula)
Uniformity (%) = {FT (X, Y) max−FT (X, Y) min} × 100 / {2 × FT (X, Y) avg. }

[Evaluation of sensitivity]
The composition was applied onto a 95 mm × 95 mm non-alkali glass substrate using a spin coating method and then pre-baked on a hot plate at 90 ° C. for 3 minutes to form a film having a thickness of 3.5 μm. Next, the obtained coating film was exposed with an ultraviolet ray having an intensity at 365 nm of 250 W / m ² through a photomask in which a circular pattern having a diameter of 12 μm was formed as an opening, and the exposure time was varied. Thereafter, development was performed with a 0.05% aqueous solution of potassium hydroxide at 25 ° C. for 60 seconds, followed by washing with pure water for 1 minute, and further post-baking in an oven at 230 ° C. for 30 minutes to form a spacer. At this time, the sensitivity was defined as the minimum exposure amount at which the remaining film ratio after post-baking (film thickness after post-baking × 100 / film thickness after exposure) was 90% or more. When the exposure amount at this time is 850 J / m ² or less, it can be said that the sensitivity is good. The results are shown in Table 1.

[Evaluation of light resistance]
A spacer was formed on the substrate in the same manner as the sensitivity evaluation, except that the exposure amount was the exposure amount corresponding to the sensitivity determined in the sensitivity evaluation. The obtained spacer was irradiated with 500 kJ / m ² of UV light using a UV light irradiation apparatus (USHIO Corporation UVX-02516S1JS01, lamp; UVL-4001M3-N1), and the remaining film ratio before and after irradiation (after UV light irradiation) The film thickness x 100 / film thickness before UV light irradiation) was evaluated. It can be said that the remaining film ratio is 97% or more and the light resistance is excellent.

[Rubbing resistance evaluation]
A spacer was formed on the substrate in the same manner as the sensitivity evaluation, except that the exposure amount was the exposure amount corresponding to the sensitivity determined in the sensitivity evaluation. A liquid crystal aligning agent AL3046 (JSR) was applied on a substrate on which a spacer was formed by a printing machine for applying a liquid crystal aligning film, and then dried at 180 ° C. for 1 hour to form a coating film of a liquid crystal aligning agent having a thickness of 0.05 μm. Formed. Next, the coating film was rubbed with a rubbing machine having a roll wound with a polyamide cloth under the conditions of a roll rotation speed of 500 rpm and a stage moving speed of 1 cm / sec. At this time, the presence or absence of pattern shaving or peeling was confirmed, and rubbing resistance A was determined when pattern shaving or peeling was not confirmed, and rubbing resistance B was determined when pattern shaving or peeling was confirmed.

[Evaluation of compression performance]
In the same manner as the sensitivity evaluation, a circular residual pattern was formed on the substrate with an exposure amount at which the residual film ratio was 90% or more. This pattern was subjected to a compression test with a load of 40 mN using a 50 μm square planar indenter with a micro compression tester (Fischerscope H100C, Fisher Instruments), and the change in the amount of compressive displacement with respect to the load was measured. At this time, the recovery rate (%) was calculated from the displacement when the load of 40 mN and the displacement when the load of 40 mN was removed. At this time, when the recovery rate is 90% or more and the displacement at a load of 40 mN is 0.15 μm or more, it can be said that the spacer has a compression performance having a high recovery rate and flexibility.

From the results of Table 1, the composition is highly sensitive, and the spacer formed from the composition is excellent in film thickness uniformity and light resistance, and has general rubbing resistance and compression performance (recovery). Rate and flexibility).
I understood.

  The radiation-sensitive resin composition of the present invention is highly sensitive, and the cured product as a protective film, insulating film or spacer for a display element formed from the composition provides film thickness uniformity and light resistance to ultraviolet rays and the like. It has excellent rubbing resistance and compression performance (recovery rate and flexibility), which are general required characteristics.

Claims (7)

A radiation-sensitive resin composition used for forming a cured product as a protective film, an insulating film or a spacer for a display element,
(A) a polymer having a carboxyl group,
(B) a polymerizable unsaturated compound,
A radiation-sensitive resin composition comprising (C) a radiation-sensitive polymerization initiator and (D) a thermal dye.   (D) Thermal dye content is 0.5 mass% or more based on the total amount of (A) polymer, (B) polymerizable unsaturated compound, (C) radiation sensitive polymerization initiator, and (D) thermal dye. The radiation sensitive resin composition according to claim 1, which is 5% by mass or less. The radiation sensitive resin composition according to claim 1 or 2, wherein (D) the thermosensitive dye is at least one selected from the group consisting of compounds represented by the following formulas (1) to (6).

(In Formula (1), R < ¹ > -R < ⁴ > is respectively independently a hydrogen atom, a C1-C6 alkyl group, a C1-C6 alkoxy group, a C3-C8 cycloalkyl group, and a phenyl group. , A benzyl group, a phenethyl group or a naphthyl group, provided that a part or all of the hydrogen atoms of the phenyl group, benzyl group, phenethyl group and naphthyl group are an alkyl group having 1 to 6 carbon atoms and an alkyl group having 1 to 6 carbon atoms. ^May be substituted with an alkoxy group, a halogen atom or a trifluoromethyl group, R ¹ and R ² may form a morpholino group, R ⁵ and R ⁶ each independently represent a hydrogen atom or a carbon number of 1 to 6 alkyl groups.
In formula (2), R ¹ and R ² have the same meaning as in formula (1). R ⁷ is a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, or a halogen atom. n is an integer of 0-4. However, when n is 2 or more, the plurality of R ⁷ may be the same or different.
In formula (3), R ¹ and R ² have the same meaning as in formula (1). R ⁸ is a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, a halogen atom, or a trifluoromethyl group. n is an integer of 0-4. However, when n is 2 or more, the plurality of R ⁸ may be the same or different.
In formula (4), R ¹ and R ² have the same meaning as in formula (1). R ^1a , R ^2a , R ^1b and R ^2b are each independently a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, a cycloalkyl group having 3 to 8 carbon atoms, a phenyl group, A benzyl group, a phenethyl group or a naphthyl group; However, some or all of the hydrogen atoms of the phenyl group, benzyl group, phenethyl group and naphthyl group are substituted with an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, a halogen atom or a trifluoromethyl group. May be. R ^1a and R ^2a , and R ^1b and R ^2b may form a morpholino group.
In formula (5), R ¹ , R ² , R ^1a and R ^2a have the same ^{meaning as} in formula (4). R ⁷ has the same meaning as in formula (2). m is an integer of 0-5. When m is 2 or more, the plurality of R ⁷ may be the same or different.
In formula (6), R ¹ , R ² , R ^1a and R ^2a have the same ^{meaning as} in formula (4). R ⁹ is an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, a cycloalkyl group having 3 to 8 carbon atoms, a phenyl group, a benzyl group, a phenethyl group, or a naphthyl group. However, part or all of the hydrogen atoms of the phenyl group, benzyl group, phenethyl group and naphthyl group are substituted with an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, a halogen atom or a nitro group. May be. )   The radiation sensitive resin composition according to claim 1, wherein the polymer (A) further has an epoxy group or a (meth) acryloyl group.   (E) The radiation sensitive resin composition according to any one of claims 1 to 4, further comprising a heat sensitive acid generator.   Hardened | cured material as a protective film for display elements, an insulating film, or a spacer formed from the radiation sensitive resin composition of any one of Claims 1-5. (1) The process of apply | coating the radiation sensitive resin composition of any one of Claims 1-5 on a board | substrate, and forming a coating film,
(2) a step of exposing at least a part of the coating film;
(3) The process of developing the coating film after exposure, and (4) The cured | curing material formation method as a protective film for display elements, an insulating film, or a spacer which has the process of heating the coating film after image development.