JP2010277069A - Radiation-sensitive resin composition, cured film and method for forming the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a radiation-sensitive resin composition which, even when a slit coating method is adopted, allows high-speed coating and enables to save a composition solution without generating unevenness comprising fine concavities and convexities on a coating film. <P>SOLUTION: The radiation-sensitive resin composition contains (A) an alkali-soluble resin, (B) a polymerizable unsaturated compound, (C) a radiation-sensitive polymerization initiator, and (D) a solvent represented by formula (1), wherein R<SP>1</SP>and R<SP>2</SP>are independently 4 or 5C linear or branched alkyl. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

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

  In a liquid crystal display element, spacer particles such as glass beads and plastic beads having a predetermined particle diameter have been conventionally used in order to keep a distance (cell gap) between two substrates constant. Since these spacer particles are randomly distributed on a transparent substrate such as a glass substrate, if the spacer particles are present in the pixel formation region, the spacer particles may be reflected, or the incident light may be subjected to a scattering action to cause a liquid crystal panel. There is a problem that the contrast of the image is lowered. In order to solve these problems, a method of forming a spacer in a region other than the pixel region by photolithography using a radiation-sensitive resin composition has been adopted (Patent Document 1).

  Such a liquid crystal display device has a structure in which a spacer is disposed on a color filter formed on a substrate, a counter substrate having a counter electrode is disposed thereon, and liquid crystal molecules are disposed in a cell gap. . Therefore, in order to keep the cell gap constant in the entire region of the substrate, a high degree of film thickness uniformity of the spacer is necessary. In particular, liquid crystal display elements in recent years are required to have higher image quality and higher tracking speed (high-speed response) than ever before. Yes.

  On the other hand, in the manufacture of liquid crystal display elements, the size of glass substrates is increasing from the viewpoint of improving productivity and supporting large screens. The glass substrate size is 300 mm × 400 mm first generation, 370 mm × 470 mm second generation, 620 mm × 750 mm third generation, 960 mm × 1,100 mm fourth generation, 1,100 mm × 1,300 mm first generation Five generations are becoming mainstream. In addition, the substrate size is further increased in the future, with the sixth generation of 1,500 mm × 1,850 mm, the seventh generation of 1,850 mm × 2,100 mm, and the eighth generation of 2,200 mm × 2,600 mm. .

  In the case of a small substrate size up to the second generation, the radiation sensitive resin composition solution is applied by a spin coating method, but this method requires a large amount of the radiation sensitive resin composition solution, and further requires a large substrate. It cannot be applied. In addition, when the substrate size is 960 mm × 1,100 mm or less, the coating is performed by the slit & spin method, but it is difficult to cope with the substrate size after the fifth generation.

  A so-called slit coating method in which a composition is ejected from a slit-shaped nozzle and applied to a substrate size of the fifth generation or later is applied (Patent Documents 2 and 3). This slit coating method has an advantage that the amount of the composition required for coating can be reduced as compared with the spin coating method, and contributes to cost reduction of liquid crystal display element manufacturing. However, in such a slit coating method, the substrate is vacuum-sucked, and a coating film is formed by sweeping the coating nozzle in a certain direction while supporting several points on the substrate with minute pins. Unevenness called “Stage vacuum suction unevenness” due to suction holes, Unevenness called “support pin unevenness” due to support pins, Unevenness called “vertical streak unevenness” appearing in a streak pattern in the sweep direction of the application nozzle, etc. May occur, which hinders the achievement of the above-described high flatness. Furthermore, from the viewpoint of further reducing the cost of manufacturing the liquid crystal display element, there is a strong demand for reducing the amount of liquid of the composition required for coating (liquid saving).

JP 2001-261761 A JP 2006-184841 A JP 2001-25645 A

  The present invention has been made based on the circumstances as described above, and its purpose is to generate unevenness consisting of minute irregularities on the coating film even when the slit coating method is adopted as the coating method. It is an object of the present invention to provide a radiation-sensitive resin composition that can be applied at high speed and can save liquid. A further object of the present invention is a rubbing resistance and a high recovery rate (a ratio of returning from a state after deformation to a state before deformation as a spacer or a protective film of a liquid crystal display element. State after deformation. A cured film having a particularly high degree of film thickness uniformity and a method for forming the same are provided, while maintaining the compression performance having both flexibility and flexibility. There is.

（式（１）中、Ｒ^１及びＲ^２は、それぞれ独立して、炭素数４又は５の直鎖状又は分岐状のアルキル基である。） The invention made to solve the above problems is
(A) an alkali-soluble resin,
(B) a polymerizable unsaturated compound,
A radiation-sensitive resin composition containing (C) a radiation-sensitive polymerization initiator, and (D) a solvent represented by the following formula (1).

(In Formula (1), R ¹ and R ² are each independently a linear or branched alkyl group having 4 or 5 carbon atoms.)

  The radiation-sensitive resin composition uses a specific solvent represented by the above formula (1) (hereinafter also referred to as “(D) solvent”) as a solvent for dissolving each component. Even if unevenness occurs, the viscosity is low enough to be able to equalize it spontaneously, and at the same time, (D) the solvent has an appropriate vapor pressure. As a result, even if the slit method is adopted as a coating method on a substrate or the like, it is possible to form a coating film with a uniform film thickness by high-speed coating while preventing uneven coating. In addition, the radiation-sensitive resin composition uses (A) an alkali-soluble resin and (B) a polymerizable unsaturated compound in combination, and these start with (C) a radiation-sensitive polymerization initiator at the time of exposure. In addition to the generally required rubbing resistance, the resulting cured film can exhibit compression performance having both flexibility against external stress and a high recovery rate.

R ¹ and R ² are preferably the same. By employing a solvent having symmetry in such a structure, the film thickness uniformity can be further improved.

  The radiation sensitive resin composition is (E-1) at least one solvent selected from the group consisting of diethylene glycol dialkyl ether solvents, propylene glycol alkyl ether acetate solvents, ketone solvents and fatty acid alkyl ester solvents ( Hereinafter, it is preferable to further contain “(E-1) solvent”). The combined use of (D) solvent and (E-1) solvent can highly balance the viscosity and vapor pressure required for high-speed coating properties and film thickness uniformity, and as a result, with film thickness uniformity. High-speed coating property can be further improved.

  (E-1) The solvent is selected from the group consisting of diethylene glycol ethyl methyl ether, diethylene glycol dimethyl ether, propylene glycol methyl ether acetate, propylene glycol ethyl ether acetate, cyclohexanone, methyl 3-methoxypropionate and ethyl 3-ethoxypropionate. It is preferable that there is at least one. (E-1) By specifically adopting the above-mentioned solvent as a solvent, it becomes easy to adjust the viscosity of the radiation-sensitive resin composition, and a coating film having no coating unevenness can be obtained even by high-speed coating.

  The radiation-sensitive resin composition is (E-2) alcohol solvent, glycol ether solvent, ethylene glycol alkyl ether acetate solvent instead of (E-1) solvent or together with (E-1) solvent. , At least one solvent selected from the group consisting of diethylene glycol monoalkyl ether solvents, dipropylene glycol dialkyl ether solvents, propylene glycol monoalkyl ether solvents and propylene glycol alkyl ether propionate solvents (hereinafter referred to as “( E-2) Solvent ”). Since the radiation sensitive resin composition contains (E-2) solvent, the viscosity and vapor pressure required for high-speed coating property and film thickness uniformity can be highly balanced. High-speed coating property can be further improved together with uniformity.

  (E-2) The solvent is at least one selected from the group consisting of benzyl alcohol, ethylene glycol monobutyl ether acetate, diethylene glycol monoethyl ether acetate, diethylene glycol diethyl ether, dipropylene glycol dimethyl ether and propylene glycol methyl ether propionate. Preferably there is. (E-2) By specifically adopting the above-mentioned solvent as a solvent, it becomes easy to adjust the viscosity of the radiation-sensitive resin composition as in the case of (E-1) solvent, and the coating film has no coating unevenness even by high-speed coating. Can be obtained.

  (D) It is preferable that content of a solvent is 5 mass% or more and 90 mass% or less with respect to the total amount of solvents. (D) By making content of a solvent into the said range, generation | occurrence | production of application | coating nonuniformity is prevented at a high level and film thickness uniformity can be improved more.

  The (A) alkali-soluble resin preferably has at least one group selected from the group consisting of an epoxy group and a (meth) acryloyl group. (A) By having such a group in the alkali-soluble resin, it is possible to give the cured film high rubbing resistance and high recovery rate while maintaining the flexibility of the obtained cured film.

  The radiation-sensitive resin composition preferably contains an O-acyloxime compound as the (C) radiation-sensitive polymerization initiator. By employing such a specific radiation-sensitive polymerization initiator, the radiation sensitivity of the radiation-sensitive resin composition can be improved, and a predetermined cured film can be efficiently produced.

  The radiation-sensitive resin composition can form a coating film by high-speed and uniform application even when the slit coating method is adopted, and the resulting cured film has a uniform film thickness, rubbing resistance, high recovery rate and flexibility. Since it is excellent in property, it can be suitably used for forming a cured film as a spacer or protective film of a liquid crystal display element.

  The cured film of the present invention can be suitably formed from the radiation-sensitive resin composition so as to exhibit flatness, rubbing resistance, recovery rate and flexibility at a high level.

The method for forming the cured film of the present invention is as follows.
(1) A step of coating the radiation-sensitive resin composition on 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.

  The cured film can be efficiently formed by the method for forming a cured film of the present invention.

  According to the radiation-sensitive resin composition of the present invention, even when the slit coating method is adopted as the coating method, high-speed coating is possible without generating unevenness consisting of minute irregularities in the coating film, Liquid saving can also be achieved. In addition, the cured film of the present invention is a particularly high film thickness while maintaining compression performance having both a rubbing resistance, a high recovery rate and flexibility, which have been conventionally required, as a spacer or a protective film of a liquid crystal display element. Uniformity can be exhibited.

  The radiation-sensitive resin composition of the present invention contains (A) an alkali-soluble resin, (B) a polymerizable unsaturated compound, (C) a radiation-sensitive polymerization initiator, and (D) a solvent, and a suitable solvent. (E-1) A solvent and / or (E-2) a solvent may be included, and an optional additive such as a surfactant may be further included. Hereinafter, each component will be described.

<(A) Alkali-soluble resin>
The (A) alkali-soluble resin contained in the radiation-sensitive resin composition of the present invention is particularly limited as long as it has solubility in a developer, preferably an alkali developer, used in a development step in the process of forming a cured film. It is not a thing. Such (A) alkali-soluble resin preferably has at least one group selected from the group consisting of a carboxyl group and a carboxylic anhydride group, and the resulting cured film has flexibility, rubbing resistance and recovery rate. In view of the above, it is preferable to have at least one group selected from the group consisting of an epoxy group and a (meth) acryloyl group.

  (A) The alkali-soluble resin is not particularly limited as long as it exhibits solubility in an alkali developer as described above, but (a1) at least one selected from the group consisting of an unsaturated carboxylic acid and an unsaturated carboxylic acid anhydride. A copolymer of a seed (hereinafter also referred to as “compound (a1)”) and an unsaturated compound other than (a2) and (a1) (hereinafter also referred to as “compound (a2)”) is preferable. By using such a monomer for the preparation of the component (A), it is possible to impart alkali solubility to the component (A), and also satisfy other required characteristics (A) an alkali-soluble resin. Can be provided.

As a preferable example of such (A) alkali-soluble resin,
(1) A monomer copolymer (hereinafter referred to as “copolymer”) containing compound (a1) and an unsaturated compound having at least one hydroxyl group in one molecule (hereinafter also referred to as “compound (a2-1)”). Polymer [α] ”) and a polymer obtained by reacting an unsaturated isocyanate compound (hereinafter also referred to as“ polymer [A] ”),
(2) a monomer copolymer (hereinafter referred to as “copolymer [β]”) containing compound (a1) and an unsaturated compound having an epoxy group (hereinafter also referred to as “compound (a2-2)”). Also called).
(3) The compound (a1) and an unsaturated compound other than the compound (a1), the compound (a2-1), and the compound (a2-2) (hereinafter also referred to as “compound (a2-3)”) are included. And a copolymer of monomers (hereinafter also referred to as “copolymer [γ]”).
In addition, the said radiation sensitive resin composition is a range which does not impair the effect of this invention, the copolymer of the monomer containing this compound (a1), a compound (a2-1), and a compound (a2-2), or this The polymer obtained by making a copolymer and unsaturated isocyanate react may be included.

  When the copolymer [α] is produced, the compound (a2-3) is allowed to coexist, and the copolymer [α] is mixed with the compound (a1), the compound (a2-1) and the compound (a2-3). When the copolymer [β] is produced, the compound (a2-3) is allowed to coexist in addition to the compound (a1) and the compound (a2-2), and the copolymer [β] is converted into the compound (β). It is good also as a copolymer of a1), a compound (a2-2), and a compound (a2-3).

  Examples of the compound (a1) used in producing the copolymer [α], the copolymer [β], and the copolymer [γ] include unsaturated monocarboxylic acids, unsaturated dicarboxylic acids, and unsaturated dicarboxylic acids. The anhydride of these can be mentioned.

Examples of the unsaturated monocarboxylic acid include acrylic acid, methacrylic acid, crotonic acid, 2-acryloyloxyethyl succinic acid, 2-methacryloyloxyethyl succinic acid, 2-acryloyloxyethyl hexahydrophthalic acid, and 2-methacryloyloxyethyl. Hexahydrophthalic acid, etc .;
Examples of the unsaturated dicarboxylic acid include maleic acid, fumaric acid, citraconic acid and the like;
Examples of the unsaturated dicarboxylic acid anhydride include the above-mentioned unsaturated dicarboxylic acid anhydrides.
Among these, acrylic acid, methacrylic acid, 2-acryloyloxyethyl succinic acid, 2-methacryloyloxyethyl succinic acid, or maleic anhydride is used from the viewpoint of copolymerization reactivity and solubility of the resulting copolymer in a developer. preferable. A compound (a1) can be used individually or in mixture of 2 or more types.

  In the copolymer [α], the copolymer [β], and the copolymer [γ], the content of the repeating unit derived from the compound (a1) is preferably a monomer charge ratio, preferably 5 to 60% by mass. More preferably, it is 7-50 mass%, Most preferably, it is 8-40 mass%. When the content of the repeating unit derived from the compound (a1) is in the above range, a radiation sensitive resin composition in which various properties such as radiation sensitivity, developability and storage stability are balanced at a higher level can be obtained.

  Examples of the compound (a2-1) used in the production of the copolymer [α] include hydroxyalkyl esters of (meth) acrylic acid, dihydroxyalkyl esters of (meth) acrylic acid, (6- Hydroxyhexanoyloxy) alkyl ester and the like.

Specific examples of the compound (a2-1) include
Examples of hydroxyalkyl esters of (meth) acrylic acid include (meth) acrylic acid 2-hydroxyethyl ester, (meth) acrylic acid 3-hydroxypropyl ester, (meth) acrylic acid 4-hydroxybutyl ester;
As the dihydroxyalkyl ester of (meth) acrylic acid, for example, (meth) acrylic acid 2,3-dihydroxypropyl ester, (meth) acrylic acid 1,3-dihydroxypropyl ester, (meth) acrylic acid 3,4-dihydroxybutyl ester Esters, etc .;
Examples of (6-hydroxyhexanoyloxy) alkyl esters of (meth) acrylic acid include (meth) acrylic acid 2- (6-hydroxyhexanoyloxy) ethyl ester, (meth) acrylic acid 3- (6-hydroxyhexanoyloxy) ) Propyl ester and the like.

  Among these compounds (a2-1), from the viewpoint of copolymerization reactivity and reactivity with an isocyanate compound, acrylic acid 2-hydroxyethyl ester, acrylic acid 3-hydroxypropyl ester, acrylic acid 4-hydroxybutyl ester, Methacrylic acid 2-hydroxyethyl ester, methacrylic acid 3-hydroxypropyl ester, methacrylic acid 4-hydroxybutyl ester, acrylic acid 2,3-dihydroxypropyl ester, methacrylic acid 2,3-dihydroxypropyl ester, the above (meth) acrylic Acid (6-hydroxyhexanoyloxy) alkyl esters are preferred.

  Among the compounds (a2-1), the (meth) acrylic acid (6-hydroxyhexanoyloxy) alkyl ester and methacrylic acid 2-hydroxyethyl ester are improved in developability and improved in compression performance of the obtained spacer. From the viewpoint of As commercial products of a mixture of methacrylic acid 2- (6-hydroxyhexanoyloxy) ethyl ester and methacrylic acid 2-hydroxyethyl ester, PLACEL FM1D, FM2D (trade name, manufactured by Daicel Chemical Industries, Ltd.), etc., respectively. Can be mentioned. In the copolymer [α], the compound (a2-1) as described above may be used alone or in admixture of two or more.

  The content of the repeating unit derived from the compound (a2-1) in the copolymer [α] is preferably 1 to 50% by mass, more preferably 3 to 40% by mass, based on the monomer charge ratio. Especially preferably, it is 5-30 mass%. When the content of the repeating unit derived from the compound (a2-1) is in the above range, the stability of the copolymer obtained by the reaction with the unsaturated isocyanate compound becomes good, and as a result, the resulting radiation-sensitive resin. The storage stability of the composition is improved.

  As an epoxy group in the compound (a2-2) used for the production of the copolymer [β], an oxiranyl group (having a 1,2-epoxy structure) and an oxetanyl group (having a 1,3-epoxy structure). Etc.

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

Specific examples of these include, for example, (meth) acrylic acid oxiranyl (cyclo) alkyl ester such as (meth) acrylic acid glycidyl, (meth) acrylic acid 2-methylglycidyl, 4-hydroxybutyl (meth) acrylate glycidyl ether, 3,4-epoxybutyl (meth) acrylate, 6,7-epoxyheptyl (meth) acrylate, 3,4-epoxycyclohexyl (meth) acrylate, 3,4-epoxycyclohexylmethyl (meth) acrylate, and the like;
Examples of α-alkylacrylic acid oxiranyl (cyclo) alkyl esters include α-ethyl acrylate glycidyl, α-n-propyl acrylate glycidyl, α-n-butyl acrylate glycidyl, α-ethyl acrylate 6,7-epoxyheptyl , Α-ethyl acrylate 3,4-epoxycyclohexyl and the like;
Examples of the glycidyl ether compound having an unsaturated bond include o-vinylbenzyl glycidyl ether, m-vinylbenzyl glycidyl ether, p-vinylbenzyl glycidyl ether and the like;
Examples of the (meth) acrylic acid ester having an oxetanyl group include 3-((meth) acryloyloxymethyl) oxetane, 3-((meth) acryloyloxymethyl) -3-ethyloxetane, and 3-((meth) acryloyloxy. Methyl) -2-methyloxetane, 3-((meth) acryloyloxyethyl) -3-ethyloxetane, 2-ethyl-3-((meth) acryloyloxyethyl) oxetane, 3-methyl-3- (meth) acryloyl Oxymethyloxetane, 2-((meth) acryloyloxymethyl) oxetane, 2-((meth) acryloyloxymethyl) -2-methyloxetane, 2-((meth) acryloyloxymethyl) -2-ethyloxetane, 2- ((Meth) acryloyloxymethyl) -2-phenyl Xetane, 2- (2- (meth) acryloyloxyethyl) oxetane, 2- (2- (meth) acryloyloxyethyl) -2-ethyloxetane, 2- (2- (meth) acryloyloxyethyl) -2-ethyl Examples thereof include acrylic acid esters such as oxetane and 2- (2- (meth) acryloyloxyethyl) -2-phenyloxetane.

  Among these, glycidyl methacrylate, 2-methylglycidyl methacrylate, 3,4-epoxycyclohexyl methacrylate, 3,4-epoxycyclohexylmethyl methacrylate, 3-methyl-3-methacryloyloxymethyloxetane or 3-ethyl- 3-Methacryloyloxymethyloxetane is preferred from the viewpoint of polymerizability. In the production of the copolymer [β], the compound (a2-2) can be used alone or in admixture of two or more.

  In the copolymer [β], the content of the repeating unit derived from the compound (a2-2) is preferably from 0.5 to 70% by mass, and more preferably from 1 to 60% by mass, based on the monomer charge ratio. %, Particularly preferably 3 to 50% by mass. When the content of the repeating unit derived from the compound (a2-2) is in the above range, the heat resistance of the copolymer, the storage stability of the copolymer and the radiation-sensitive resin composition, the spacer or protective film obtained A radiation sensitive resin composition in which the compression performance is balanced at a higher level is obtained.

  Examples of the compound (a2-3) that can be used in the production of the copolymer [γ] or can be optionally used in the production of the copolymer [α] and the copolymer [β] include, for example, (meth) Acrylic acid 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 having

Specific examples of these are:
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 sec- (meth) acrylic acid. Butyl, t-butyl (meth) acrylate, etc .;
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, isomethanyl (meth) acrylate, and the like;
Examples of (meth) acrylic acid aryl esters include phenyl (meth) acrylate and the like;
Examples of (meth) acrylic acid aralkyl esters include benzyl (meth) acrylate and the like;
Unsaturated dicarboxylic acid dialkyl esters such as diethyl maleate, diethyl fumarate and the like;
Examples of the (meth) acrylic acid ester having an oxygen-containing hetero 5-membered ring or an oxygen-containing hetero 6-membered ring include, for example, (meth) acrylic acid tetrahydrofuran-2-yl, (meth) acrylic acid tetrahydropyran-2-yl, (meth) 2-methyltetrahydropyran-2-yl acrylate, tetrahydrofurfuryl (meth) acrylate, etc .;
Examples of vinyl aromatic compounds 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, methacrylamide, and the like.

Among these compounds (a2-3), from the viewpoint of copolymerization reactivity, n-butyl methacrylate, benzyl methacrylate, tricyclo [5.2.1.0 ^2,6 ] decan-8-yl methacrylate, Styrene, p-methoxystyrene, tetrahydrofuran-2-yl methacrylate, 1,3-butadiene and the like are preferable. In the production of the copolymer [α], the copolymer [β] and the copolymer [γ], the compound (a2-3) can be used alone or in admixture of two or more.

  In the copolymer [α] and the copolymer [β], the content of the repeating unit derived from the compound (a2-3) is preferably 10 to 70% by mass, more preferably 20 in terms of monomer charge ratio. It is -50 mass%, Most preferably, it is 30-50 mass%. When the content of the repeating unit of the compound (a2-3) is in the above range, the molecular weight of the copolymer can be easily controlled, and the radiation-sensitive resin composition in which developability and radiation sensitivity are balanced at a higher level. Is obtained.

  The copolymer [α], the copolymer [β] and the copolymer [γ] are preferably a mixture of the above monomers in an appropriate solvent, preferably in the presence of a radical polymerization initiator. It can be produced by polymerization. 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.

  The radical polymerization initiator is not particularly limited, and for example, 2,2′-azobisisobutyronitrile, 2,2′-azobis- (2,4-dimethylvaleronitrile), 2,2 An azo compound such as' -azobis- (4-methoxy-2,4-dimethylvaleronitrile) can be mentioned. These radical polymerization initiators can be used alone or in admixture of two or more.

  The polystyrene-converted mass average molecular weight (hereinafter referred to as “Mw”) measured by gel permeation chromatography (GPC) for the copolymer [α], copolymer [β] and copolymer [γ] is preferred. Is from 2,000 to 100,000, more preferably from 5,000 to 50,000. When Mw of the copolymer [α], copolymer [β] and copolymer [γ] is 2,000 to 100,000, the heat resistance, developability, radiation sensitivity, etc. are balanced at a higher level. A radiation-sensitive resin composition is obtained.

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

  Examples of the unsaturated isocyanate compound include (meth) acrylic acid derivatives. Specific examples thereof include 2- (meth) acryloyloxyethyl isocyanate, 4- (meth) acryloyloxybutyl isocyanate, (meth ) 2- (2-isocyanatoethoxy) ethyl acrylate and the like. As these commercial products, Karenz AOI (manufactured by Showa Denko KK) as a commercial product of 2-acryloyloxyethyl isocyanate, Karenz MOI (manufactured by Showa Denko KK), methacryl As a commercial product of the acid 2- (2-isocyanatoethoxy) ethyl, Karenz MOI-EG (manufactured by Showa Denko KK) can be mentioned.

  Among these unsaturated isocyanate compounds, 2-acryloyloxyethyl isocyanate, 2-methacryloyloxyethyl isocyanate, 4-methacryloyloxybutyl isocyanate or 2- (2) methacrylic acid is preferable from the viewpoint of reactivity with the copolymer [α]. -Isocyanatoethoxy) ethyl is preferred. In the production of the polymer [A], the unsaturated isocyanate compound can be used alone or in admixture of two or more.

  The reaction between the copolymer [α] and the unsaturated isocyanate compound is carried out in the presence of a suitable catalyst, if necessary, preferably in a solution of the copolymer [α] 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; and examples of the polymerization inhibitor include p-methoxyphenol.

  The proportion of the unsaturated isocyanate compound used in the production of the polymer [A] is preferably 0.1 to 95 mol% with respect to the hydroxyl group derived from the compound (a2-1) in the copolymer [α]. 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 copolymer [α], the heat resistance and the elastic properties of the obtained spacer or protective film are further improved, which is preferable.

  In the radiation-sensitive resin composition of the present invention, the polymer [A], the copolymer [β] and the copolymer [γ] may be used alone, respectively, but the polymer [A] and It is preferable to use the copolymer [β] in combination, or to use the copolymer [β] and the copolymer [γ] in combination. Use of the polymer [A] and the copolymer [β] in combination is preferable because the storage stability of the resulting radiation-sensitive resin composition and the strength and heat resistance of the resulting spacer can be further improved. When the polymer [A] and the copolymer [β] are used in combination, the use ratio of the polymer [A] is preferably 10 to 100 parts by mass with respect to 100 parts by mass of the copolymer [β]. More preferably, it is 20-80 mass parts, Most preferably, it is 30-70 mass parts. When the use ratio of the polymer [A] is in the above range, the radiation-sensitive resin composition balanced between the storage stability of the radiation-sensitive resin composition and the heat resistance of the obtained spacer or protective film is high. can get.

  On the other hand, the combined use of the copolymer [β] and the copolymer [γ] is preferable because it provides the advantage of improving the storage stability of the radiation-sensitive composition. When the polymer [β] and the copolymer [γ] are used in combination, the proportion of the copolymer [β] used is preferably 10 to 150 parts by mass with respect to 100 parts by mass of the copolymer [γ]. Yes, more preferably 20 to 130 parts by mass, particularly preferably 30 to 100 parts by mass.

<(B) polymerizable unsaturated compound>
The (B) polymerizable unsaturated compound contained in the radiation-sensitive resin composition of the present invention is an unsaturated compound that is polymerized by irradiation with radiation in the presence of the (C) radiation-sensitive polymerization initiator described later. is there. Although it does not specifically limit as such a polymerizable unsaturated monomer, For example, the monofunctional, bifunctional, or trifunctional or more (meth) acrylic acid ester has favorable polymerizability, and is obtained. It is also preferable from the viewpoint of improving the strength of the spacer or protective film.

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 commercially available products, for example, Aronix M-101, M-111, M-114, M-5300 (above,
KAYARAD TC-110S, TC-120S (above, manufactured by Nippon Kayaku Co., Ltd.); Biscote 158, 2311 (above, made by Osaka Organic Chemical Industries, Ltd.), etc. Can do.

  Examples of the bifunctional (meth) acrylic acid ester include ethylene glycol diacrylate, propylene glycol diacrylate, ethylene glycol dimethacrylate, propylene 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, manufactured by Toagosei Co., Ltd.), KAYARAD HDDA, HX-220, R-604. (Nippon Kayaku Co., Ltd.), Biscote 260, 312 and 335HP (Osaka Organic Chemical Co., Ltd.), Light Acrylate 1,9-NDA (Kyoeisha Chemical Co., Ltd.) be able to.

  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, a compound having a linear alkylene group and an alicyclic structure and having two or more isocyanate groups, Examples thereof include polyfunctional urethane acrylate compounds obtained by reacting with a compound having one or more hydroxyl groups and having 3, 4, or 5 (meth) acryloyloxy groups.

As a commercial item of trifunctional or higher functional (meth) acrylic acid ester, for example, Aronix M-309, M-400, M-405, M-450, M-7100, M-8030 are trade names. M-8060, TO-1450 (manufactured by Toagosei Co., Ltd.), KAYARAD TMPTA, DPHA, DPCA-20, DPCA-30, DPCA-60, DPCA-120, DPEA- 12 (above, Nippon Kayaku Co., Ltd.), Biscoat 295, 300, 360, GPT, 3PA, 400 (above, Osaka Organic Chemical Co., Ltd.) and polyfunctional urethane acrylate compounds Examples of commercially available products that contain NOF include New Frontier R-1150 (Daiichi Kogyo Seiyaku Co., Ltd.), KAYARAD DPHA-40H (Nippon Kayaku Co., Ltd.), and the like. Door can be.

Among these, ω-carboxypolycaprolactone monoacrylate, 1,9-nonanediol dimethacrylate, trimethylolpropane triacrylate, pentaerythritol triacrylate, pentaerythritol tetraacrylate, dipentaerythritol pentaacrylate, dipentaerythritol hexaacrylate A commercially available product containing a mixture of dipentaerythritol pentaacrylate and dipentaerythritol hexaacrylate, ethylene oxide-modified dipentaerythritol hexaacrylate, succinic acid-modified pentaerythritol triacrylate, a polyfunctional urethane acrylate compound, or the like is preferable.
The (B) polymerizable unsaturated compounds as described above can be used alone or in admixture of two or more.

  The proportion of the (B) polymerizable unsaturated monomer used in the radiation sensitive resin composition of the present invention is preferably 50 to 300 parts by mass, more preferably 100 parts by mass of the (A) alkali-soluble resin. Is 80-250 parts by mass. (B) When the usage-amount of a polymerizable unsaturated monomer exists in the said range, the sensitivity of a radiation sensitive resin composition, the heat resistance of the spacer obtained, and an elastic characteristic become more favorable.

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

  Specific examples of the O-acyloxime compound include ethanone-1- [9-ethyl-6- (2-methylbenzoyl) -9. H. -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-tetrahydrofuranylmethoxybenzoyl) -9. H. -Carbazol-3-yl] -1- (O-acetyloxime), 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, preferable O-acyloxime compounds include ethanone-1- [9-ethyl-6- (2-methylbenzoyl) -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) or ethanone-1- [9-ethyl-6- {2-methyl-4- (2,2-dimethyl-1,3-dioxolanyl) methoxybenzoyl } -9. H. -Carbazol-3-yl] -1- (O-acetyloxime).
The radiation-sensitive resin composition preferably contains such an O-acyl oxime compound, and 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. Specific 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 can be mentioned. Specific examples of the α-hydroxyketone compound include 1-phenyl-2-hydroxy-2-methylpropan-1-one and 1- (4-i-propylphenyl) -2-hydroxy-2-methylpropane. Examples include -1-one, 4- (2-hydroxyethoxy) phenyl- (2-hydroxy-2-propyl) ketone, 1-hydroxycyclohexyl phenylketone, and the like.

  Of these acetophenone compounds, 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 particularly preferred.

  Specific examples of the biimidazole compound include, for example, 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 and the like.

  Among these biimidazole compounds, 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 '-Tetraphenyl-1,2'-biimidazole is preferred, especially 2,2'-bis (2,4-dichlorophenyl) -4,4', 5,5'-tetraphenyl-1,2'-biimidazole Is preferred.

  In the radiation-sensitive resin composition of the present invention, when a biimidazole compound is used as the (C) radiation-sensitive polymerization initiator, an aliphatic or aromatic compound having a dialkylamino group (hereinafter referred to as “amino-based sensitizer”). And at least one selected from thiol compounds.

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, and is formed by improving the sensitivity and resolution of the radiation sensitive resin composition. It can be added for the purpose of further improving the adhesion of the spacer or the protective film to the substrate. Examples of such amino sensitizers include N-methyldiethanolamine, 4,4′-bis (dimethylamino) benzophenone, 4,4′-bis (diethylamino) benzophenone, ethyl p-dimethylaminobenzoate, p-dimethylamino. Examples include i-amyl benzoate. Of these amino sensitizers,
In particular, 4,4′-bis (diethylamino) benzophenone is preferable. 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 in the above range, an 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 not very high. Therefore, when this is used as it is for forming a spacer of a liquid crystal display element, the cross section of the spacer There is a case where the shape becomes an undesirable shape of a reverse taper shape (reverse trapezoid shape). 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. Thus, the shape of the spacer can be surely made a more preferable forward tapered shape (trapezoidal shape). Examples of such thiol compounds include aromatic thiol compounds such as 2-mercaptobenzothiazole, 2-mercaptobenzoxazole, 2-mercaptobenzimidazole, 2-mercapto-5-methoxybenzothiazole, 2-mercapto-5-methoxybenzimidazole. Aliphatic thiol compounds such as 3-mercaptopropionic acid, methyl 3-mercaptopropionate, ethyl 3-mercaptopropionate and octyl 3-mercaptopropionate; 3,6-dioxa-1,8-octanedithiol, pentaerythritol Bifunctional or higher aliphatic thiol compounds such as tetra (mercaptoacetate) and pentaerythritol tetrakis (3-mercaptopropionate) can be exemplified. Among these thiol compounds, pentaerythritol tetrakis (3-mercaptopropionate) and 2-mercaptobenzothiazole are particularly preferable.

  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 in the above range, the adhesion of the resulting spacer to the substrate is improved and the shape is improved.

  In the radiation-sensitive resin composition of the present invention, when a biimidazole compound is used as the (C) radiation-sensitive polymerization initiator, it is preferable to add both the amino sensitizer and the thiol compound.

  As a use ratio of the (C) radiation sensitive polymerization initiator in the present invention, it is preferably 1 to 60 parts by mass, more preferably 2 to 50 parts by mass with respect to 100 parts by mass of the (A) alkali-soluble resin. Yes, more preferably 5 to 40 parts by mass. By using the (C) radiation-sensitive polymerization initiator in the above range, a spacer or protective film having high hardness and adhesion can be formed even in the case of a low exposure amount. (C) The radiation sensitive polymerization initiator may be used alone or in combination of two or more, and when used in combination of two or more, (C) if the total amount of the radiation sensitive polymerization initiator is in the above range. Good.

<(D) Solvent>
The radiation sensitive resin composition of this invention contains the (D) solvent shown by following formula (1). As a result, the radiation-sensitive resin composition has a viscosity that is low enough to spontaneously equalize coating unevenness even during coating film formation, and maintains film thickness uniformity. (D) The solvent can exhibit an appropriate vapor pressure, and as a result, even if the slit method is used as a coating method on a substrate or the like, while preventing coating unevenness A coating film with a uniform film thickness can be formed by high-speed coating.

(In Formula (1), R ¹ and R ² are each independently a linear or branched alkyl group having 4 or 5 carbon atoms.)

  Examples of the compound represented by the formula (1) include di (n-butyl) ether, di (isobutyl) ether, di (t-butyl) ether, (n-butyl) isobutylether, and n-butyl-t. -Butyl ether, isobutyl-t-butyl ether, di (n-amyl) ether, n-amyl-3-methylbutyl ether, n-amyl-2-methylbutyl ether, n-amyl-1-methylbutyl ether, n-amyl-2, 2-dimethylpropyl ether, n-amyl-1,2-dimethylpropyl ether, n-amyl-1,1-dimethylpropyl ether, di (3-methylbutyl) ether, 3-methylbutyl-2-methylbutyl ether, 3-methylbutyl -1-methylbutyl ether, 3-methylbutyl-2,2-dimethylpropyl ether 3-methylbutyl-1,2-dimethylpropyl ether, 3-methylbutyl-1,1-dimethylpropyl ether, di (2-methylbutyl) ether, 2-methylbutyl-1-methylbutyl ether, 2-methylbutyl-2,2 -Dimethylpropyl ether, 2-methylbutyl-1,2-dimethylpropyl ether, 2-methylbutyl-1,1-dimethylpropyl ether, di (1-methylbutyl) ether, 1-methylbutyl-2,2-dimethylpropyl ether, 1 -Methylbutyl-1,2-dimethylpropyl ether, 1-methylbutyl-1,1-dimethylpropyl ether, di (2,2-dimethylpropyl) ether, 2,2-dimethylpropyl-1,2-dimethylpropyl ether, di (1,2-Dimethylpropyl) ether 1,2-dimethylpropyl-1,1-dimethylpropyl ether, di (1,1-dimethylpropyl) ether, n-butyl-n-amyl ether, n-butyl-3-methylbutyl ether, n-butyl-2 -Methylbutyl ether, n-butyl-1-methylbutyl ether, n-butyl-2,2-dimethylpropyl ether, n-butyl-1,2-dimethylpropyl ether, n-butyl-1,1-dimethylpropyl ether, isobutyl N-amyl ether, isobutyl-3-methylbutyl ether, isobutyl-2-methylbutyl ether, isobutyl-1-methylbutyl ether, isobutyl-2,2-dimethylpropyl ether, isobutyl-1,2-dimethylpropyl ether, isobutyl-1 , 1-Dimethylpropyl ether T-butyl-n-amyl ether, t-butyl-3-methylbutyl ether, t-butyl-2-methylbutyl ether, t-butyl-1-methylbutyl ether, t-butyl-2,2-dimethylpropyl ether, Examples thereof include t-butyl-1,2-dimethylpropyl ether and t-butyl-1,1-dimethylpropyl ether.

  Among these, di (n-butyl) ether, di (isobutyl) ether, di (t-butyl) ether, n-butyl-isobutyl ether, n-butyl-t-butyl ether, Isobutyl-t-butyl ether, di (n-amyl) ether, n-amyl-isoamylether (n-amyl- (3-methylbutyl) ether), diisoamylether (di (3-methylbutyl) ether), di (t- It is preferred to use (amyl) ether (di (1,1-dimethylpropyl) ether).

  Although the content of the solvent (D) in the radiation sensitive resin composition is not limited, it is preferably 10 parts by mass or more and 800 parts by mass or less, and 200 parts by mass or more and 700 parts by mass with respect to 100 parts by mass of the (A) alkali-soluble resin. The following is more preferable, and 30 to 600 parts by mass is particularly preferable. (D) By making content of a solvent into the said range, the viscosity and solid content concentration of the said radiation sensitive resin composition can be made into an appropriate range, and high-speed coating property and favorable film thickness uniformity are demonstrated. However, a coating film can be formed without application unevenness.

  The content of the solvent (D) with respect to the total amount of solvent in the radiation sensitive resin composition is preferably 5% by mass to 90% by mass, more preferably 8% by mass to 80% by mass, and particularly preferably. Is 10% by mass to 60% by mass. (D) When the content of the solvent with respect to the total amount of solvent in the radiation-sensitive resin composition is in the above range, the viscosity and solid concentration of the radiation-sensitive resin composition are balanced at a higher level, and the film thickness is uniform. A coating film having excellent properties can be obtained.

<(E) Other solvents>
In the present invention, a solvent other than the solvent (D) (hereinafter also referred to as “(E) solvent”) can be used in combination with the solvent (D). Such (E) solvent is not particularly limited, but is selected from the group consisting of (E-1) diethylene glycol dialkyl ether solvents, propylene glycol alkyl ether acetate solvents, ketone solvents and fatty acid alkyl ester solvents. It is preferable to further contain at least one solvent.

Specific examples of the solvent (E-1) include, for example,
Examples of diethylene glycol dialkyl ether solvents include diethylene glycol dimethyl ether, diethylene glycol diethyl ether, and diethylene glycol ethyl methyl ether;
As propylene glycol alkyl ether acetate solvents, propylene glycol methyl ether acetate, propylene glycol ethyl ether acetate, etc .;
Examples of ketone solvents include methyl ethyl ketone, cyclohexanone, 4-hydroxy-4-methyl-2-pentanone, and methyl isoamyl ketone;
As fatty acid alkyl ester solvents, ethyl acetate, butyl acetate, ethyl 2-hydroxypropionate, methyl 2-hydroxy-2-methylpropionate, ethyl 2-hydroxy-2-methylpropionate, butyl hydroxyacetate, methyl lactate, lactic acid Ethyl, propyl lactate, butyl lactate, ethyl 2-ethoxypropionate, propyl 2-ethoxypropionate, butyl 2-ethoxypropionate, methyl 2-butoxypropionate, ethyl 2-butoxypropionate, propyl 2-butoxypropionate, Butyl 2-butoxypropionate, methyl 3-methoxypropionate, ethyl 3-methoxypropionate, propyl 3-methoxypropionate, butyl 3-methoxypropionate, methyl 3-ethoxypropionate, 3-ethoxypropionate Ethyl phosphate, 3-ethoxy propionate propyl, 3-ethoxy propionate butyl, 3-propoxy-propionic acid methyl can be mentioned.

  The solvent (E-1) is selected from the group consisting of diethylene glycol ethyl methyl ether, diethylene glycol dimethyl ether, propylene glycol methyl ether acetate, propylene glycol ethyl ether acetate, cyclohexanone, methyl 3-methoxypropionate and ethyl 3-ethoxypropionate. It is preferable that it is at least one kind.

  The radiation-sensitive resin composition is (E-2) an alcohol-based solvent (however, it does not have an ether group), glycol ether, instead of the (E-1) solvent or together with the (E-1) solvent. Solvent, ethylene glycol alkyl ether acetate solvent, diethylene glycol monoalkyl ether solvent, dipropylene glycol dialkyl ether solvent, propylene glycol monoalkyl ether solvent, and propylene glycol alkyl ether propionate solvent. It may further contain at least one solvent.

Specific examples of the solvent (E-2) include, for example,
Alcohol solvents such as benzyl alcohol;
Examples of glycol ether solvents include ethylene glycol monomethyl ether and ethylene glycol monoethyl ether;
Examples of ethylene glycol alkyl ether acetate solvents include ethylene glycol monobutyl ether acetate and diethylene glycol monoethyl ether acetate;
Examples of diethylene glycol monoalkyl ether solvents include diethylene glycol monomethyl ether and diethylene glycol monoethyl ether;
As a dipropylene glycol dialkyl ether solvent, dipropylene glycol dimethyl ether, dipropylene glycol diethyl ether, dipropylene glycol ethyl methyl ether, etc .;
As propylene glycol monoalkyl ether solvents, propylene glycol methyl ether, propylene glycol ethyl ether, propylene glycol propyl ether, propylene glycol butyl ether, etc .;
Examples of the propylene glycol alkyl ether propionate solvent include propylene glycol methyl ether propionate, propylene glycol ethyl ether propionate, and propylene glycol propyl ether propionate.

  Among these, the solvent (E-2) is selected from the group consisting of benzyl alcohol, ethylene glycol monobutyl ether acetate, diethylene glycol monoethyl ether acetate, diethylene glycol diethyl ether, dipropylene glycol dimethyl ether and propylene glycol methyl ether propionate. At least one of these is preferred.

  (E) The content of the solvent is preferably 10% by mass to 80% by mass, more preferably 15% by mass to 70% by mass with respect to the total amount of the solvent in the radiation-sensitive resin composition. Preferably it is 20 mass%-60 mass%. (E) When the content of the solvent with respect to the total amount of the solvent in the radiation-sensitive resin composition is within the above range, the viscosity and solid concentration of the radiation-sensitive resin composition are balanced at a higher level, together with film thickness uniformity. Furthermore, a radiation sensitive resin composition excellent in high-speed coating property can be obtained.

<Surfactant>
The radiation sensitive resin composition of the present invention preferably contains a surfactant. Preferred 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, and examples thereof include 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 fluoroalkylpolyesters Examples thereof include oxyethylene ether, perfluoroalkyl polyoxyethanol, perfluoroalkyl alkoxylate, and carboxylic acid fluoroalkyl ester.

Moreover, as a commercial item of the said fluorosurfactant, BM-1000, BM-1100 (above, the product made from BM CHEMIE), MegaFack F142D, F172, F173, F183, F178, F178, F191, for example F471, F476 (above, manufactured by Dainippon Ink & Chemicals, Inc.), FT-100, -110, -140A, -150, -250, -251, -300, -310, -400S, Fantient FTX-218, -251 (above, manufactured by Neos Co., Ltd.) and the like.

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

  These surfactants can be used alone or in admixture of two or more. The usage-amount of surfactant is 0.1-5 mass parts with respect to 100 mass parts of (A) alkali-soluble resin, More preferably, it is 0.15-3 mass parts. When the amount of the surfactant used is in the above range, coating film unevenness can be reduced.

<Other optional additives>
In the radiation sensitive resin composition of the present invention, optional additives other than those described above, for example, adhesion assistants, storage stabilizers, and the like can be blended as needed, as long as the effects of the present invention are not impaired.
The adhesion assistant is a component used for improving the adhesion between the formed spacer and the substrate.

As such an 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, and an epoxy group is preferable, and examples thereof include trimethoxysilylbenzoic acid. , Γ-methacryloxypropyltrimethoxysilane, vinyltriacetoxysilane, vinyltrimethoxysilane, γ-isocyanatopropyltriethoxysilane, γ-glycidoxypropyltrimethoxysilane, β- (3,4-epoxycyclohexyl) ethyl And trimethoxysilane.
These adhesion assistants can be used alone or in admixture of two or more. The amount of the adhesion assistant used is preferably in the range of 1 to 20 parts by mass, more preferably in the range of 2 to 15 parts by mass with respect to 100 parts by mass of the (A) alkali-soluble resin. When the amount of the adhesion assistant is in the above range, the adhesion of the pattern can be improved without causing a development residue in the development process.

Examples of the storage stabilizer include sulfur, quinones, hydroquinones, polyoxy compounds, amines, nitronitroso compounds, and more specifically, 4-methoxyphenol, N-nitroso-N-. Examples include phenylhydroxylamine aluminum.
These storage stabilizers can be used alone or in admixture of two or more.
The amount of the storage stabilizer used is preferably in the range of 0.01 to 10 parts by mass, more preferably in the range of 0.1 to 5 parts by mass with respect to 100 parts by mass of the (A) alkali-soluble resin. When the usage-amount of a storage stabilizer is the said range, the storage stability of a radiation sensitive resin composition will become favorable.

  The viscosity of the radiation-sensitive resin composition is controlled in a range necessary for high-speed coating property and film thickness uniformity due to the presence of the component (D). The viscosity of the radiation-sensitive resin composition is not limited as long as the effect of the present invention is obtained, but is preferably 2.2 mPa · s or more and 3.8 mPa · s or less, and preferably 2.3 mPa · s or more and 3.7 mPa · s or less. More preferably, it is 2.5 mPa · s or more and 3.5 mPa · s or less. By controlling the viscosity of the radiation-sensitive resin composition within the above range, it is possible to apply at high speed while suppressing uneven application, and the uniformity of the resulting cured film should also be good. Can do.

<Preparation of radiation-sensitive resin composition>
The radiation-sensitive resin composition of the present invention, together with the above-mentioned (A) alkali-soluble resin, (B) polymerizable unsaturated compound, (C) radiation-sensitive polymerization initiator, and (D) solvent, if necessary ( E) It is prepared by adding a solvent and uniformly mixing other components optionally added as described above in a predetermined ratio. This radiation-sensitive resin composition is preferably used in a solution state after being dissolved in an appropriate solvent. The composition solution thus prepared can be used after being filtered using a Millipore filter having a pore size of about 0.5 μm.

  When preparing the radiation-sensitive resin composition of the present invention in a solution state, the solid content concentration (components other than the solvent in the composition solution, that is, (A) alkali-soluble resin, (B) polymerizable unsaturated compound , (C) The ratio of the total amount of the radiation-sensitive polymerization initiator and other components optionally added) is an arbitrary concentration (for example, 5 to 50 mass) depending on the purpose of use and the desired film thickness value. %) Can be set. A more preferable solid content concentration varies depending on a method of forming a coating film on a substrate. When the spin coating method is adopted as the coating method, the solid content concentration is more preferably 20 to 50% by mass, and particularly preferably 30 to 40% by mass. The solid 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 film as spacer or protective film>
Next, a method of forming a cured film as a spacer or a protective film using the radiation sensitive resin composition of the present invention will be described.

The method for forming the cured film of the present invention is as follows.
(1) A step of coating the radiation-sensitive resin composition on a substrate to form a coating film,
(2) a step of exposing at least a part of the coating film;
(3) developing the coated film after exposure, and (4) heating the coated film after development.
Hereinafter, each of these steps will be described sequentially.

(1) The process of apply | coating the said radiation sensitive resin composition on a board | substrate, and forming a coating film A transparent conductive film is formed in the single side | surface of a transparent substrate, and the radiation sensitive resin of this invention is formed on this transparent conductive film. The composition is applied to form a coating film.
Examples of the transparent substrate used here include glass substrates and resin substrates. More specifically, glass substrates such as soda lime glass and non-alkali glass; polyethylene terephthalate, polybutylene terephthalate, and polyether. Examples thereof include a resin substrate made of a plastic such as sulfone, 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. A film etc. can be mentioned.

  When a coating film is formed by a coating method, the coating film is formed by heating (pre-baking) the coated surface after coating the solution of the radiation sensitive resin composition of the present invention on the transparent conductive film. Can do. 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, or an ink jet coating method can be adopted. Or the slit coating method is preferred. In particular, when the slit coating method is employed, the advantageous effects of the present invention can be maximized, which is preferable.

After application, preferably pre-baking and post-baking are performed. The pre-bake and post-bake conditions should be appropriately set depending on the types of components contained in the radiation-sensitive resin composition of the present invention, the usage ratio, and the like. Prebaking can be performed, for example, at 70 to 100 ° C. under conditions of, for example, about 1 to 10 minutes. Post-baking can be performed by an appropriate heating device such as a hot plate or a clean oven. The post-baking temperature is preferably 180 to 240 ° C, and more preferably 200 to 230 ° C. The post-bake time varies depending on the type of heating device used. When using a hot plate as a post-bake heating device, the post-bake time is preferably 10 to 60 minutes, more preferably 15 to 40 minutes. The post-bake time when using a clean oven is preferably 20 to 120 minutes, more preferably 30 to 90 minutes.

  The film thickness of the coating film thus formed is preferably 0.1 to 8 μm, more preferably 0.1 to 6 μm, and further preferably 0.1 to 5 μm.

(2) Step of exposing at least a part of the coating film Next, at least a part of the formed coating film is exposed to radiation and exposed. At this time, when irradiating only a part of the coating film, for example, a method of irradiating through a photomask having a predetermined pattern can be used. The formation method of the spacer or the protective film differs depending on the size of the opening of the photomask to be used. For example, if a photomask having a dot pattern mask of 5 μm to 30 μm is used, the spacer is formed. If a photomask having a square pattern with one side of 50 μm or more is used according to the pixel size, a protective film is formed.

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 , as a value obtained by measuring the intensity of irradiated radiation at a wavelength of 365 nm with an illuminometer (OAI model 356, manufactured by Optical Associates Inc.). preferably from 200~3,000J / ^{m 2.} The radiation-sensitive resin composition of the present invention has high radiation sensitivity as compared with conventionally known compositions, and a desired film thickness, good shape, even if the radiation dose is 800 J / m ² or less. A spacer or protective film having excellent adhesion and high hardness can be obtained.

(3) The process of developing the said coating film after exposure Next, by developing the coating film after exposure, an unnecessary part (non-exposed part) is removed and a predetermined pattern is formed.

  Examples of the developer used for development include inorganic alkaline compounds such as sodium hydroxide, potassium hydroxide and sodium carbonate; aqueous solutions of 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.

(4) Step of heating the coating film after development The pattern coating film obtained by development is then predetermined at a predetermined temperature, for example, 100 to 250 ° C., by a suitable heating device such as a hot plate or oven. A spacer having a desired pattern can be obtained by heating for a period of time, for example, 5 to 30 minutes on a hot plate and 30 to 180 minutes in an oven.

  By passing through the above steps, a cured film as a spacer or protective film for a liquid crystal display element excellent in various properties such as film thickness uniformity can be formed without unevenness consisting of minute irregularities on the coating film.

  EXAMPLES Synthesis examples and examples will be shown below to describe the present invention more specifically. However, the present invention is not limited to these synthesis examples and examples. Unless otherwise specified, “parts” and “%” in the examples are all based on mass unless otherwise specified.

In the following, the mass average molecular weight (Mw) and the number average molecular weight (Mn) of the polymer were measured by gel permeation chromatography (GPC) under the following conditions.
Measuring device: “HLC8220 system” manufactured by Tosoh Corporation
Separation column: Tosoh Co., Ltd., TSKgelGMHHR-N 4 connected in series Column temperature: 40 ° C
Elution solvent: Tetrahydrofuran (Wako Pure Chemical Industries, Ltd.)
Flow rate: 1.0 mL / min Sample concentration: 1.0% by mass
Sample injection amount: 100 μm
Detector: Differential refractometer Standard material: Monodisperse polystyrene

  The solution viscosity of the radiation sensitive resin composition was measured at 30 ° C. using an E-type viscometer manufactured by Tokyo Keiki Co., Ltd.

<(A) Synthesis of alkali-soluble resin>
[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 copolymer (β-1). Mw of the obtained copolymer (β-1) 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 methyl 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, The temperature of the solution was raised to 70 ° C. while gently stirring, and polymerization was carried out while maintaining this temperature for 5 hours to obtain a copolymer [α-1] solution having a solid concentration of 28.8%. With respect to the obtained copolymer [α-1], Mw was measured using GPC to be 13,000.

Next, 12 parts by mass of 3-methacryloyloxyethyl isocyanate (trade name Karenz MOI, manufactured by Showa Denko KK) and 0.1 part by mass of 4-methoxyphenol were added to the copolymer [α-1] solution. Thereafter, the reaction was carried out by stirring at 40 ° C. for 1 hour and further at 60 ° C. for 2 hours. Progress of the reaction of the isocyanate group derived from 3-methacryloyloxyethyl isocyanate and the hydroxyl group of the copolymer [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 2270c derived from the isocyanate group of 3-methacryloyloxyethyl isocyanate.
It was confirmed that the reaction was progressing because the peak in the vicinity of m ⁻¹ decreased. A polymer (A-1) solution having a solid content concentration of 31.0% was obtained. This is referred to as a polymer (A-1).

[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 polymerization was carried out while maintaining this temperature for 5 hours to obtain a copolymer solution having a solid content concentration of 27.9%. This is designated as copolymer (γ-1). Mw of the obtained copolymer (γ-1) 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 copolymer solution having a solid content concentration of 27.9% by mass was obtained by charging the mass part, raising the temperature of the solution to 80 ° C. while gently stirring, and maintaining the temperature for 4 hours for polymerization. . This is referred to as a copolymer (β-2). It was 11,200 when Mw was measured using GPC about the obtained copolymer ((beta) -2).

[Examples 1 to 21 and Comparative Examples 1 to 4]
(I) Preparation of radiation-sensitive resin composition (A) 100 mass in terms of the solution of copolymer (α-1) obtained in Synthesis Example 2 as an alkali-soluble resin in terms of copolymer (α-1). Part (solid content), (B) a mixture of dipentaerythritol hexaacrylate and dipentaerythritol pentaacrylate as a polymerizable unsaturated compound (trade name “KAYARAD DPHA”, Nippon Kayaku Co., Ltd.) 150 mass Part, (C) 2,2′-bis (2-chlorophenyl) -4,4 ′, 5,5′-tetraphenyl-1,2′-biimidazole as 5 parts by mass as a radiation sensitive polymerization initiator, 3 parts by weight of 4′-bis (diethylamino) benzophenone, 3 parts by weight of 2-mercaptobenzothiazole, 685 parts by weight of diisoamyl ether as a solvent, and γ-glycidoxy as an adhesion assistant 5 parts by mass of propyltrimethoxysilane, 0.2 part by mass of a fluorosurfactant (trade name “Factent FTX-218”, manufactured by Neos Co., Ltd.) as a surfactant are added, and the solid content concentration is 23.1 masses. %, And then filtered through a Millipore filter having a pore size of 0.5 μm to prepare a radiation sensitive resin composition. The viscosity of the radiation sensitive resin composition after preparation was 3.0 (mPa · s).
The radiation-sensitive resin composition prepared above was evaluated according to the following procedure. The results are shown in Table 1.

(1) Measurement of viscosity of composition solution The viscosity was measured at 25 ° C. using an E-type viscometer (trade name “VISCONIC ELD.R”, manufactured by Toki Sangyo Co., Ltd.). The results are shown in Table 1.

(2) Measurement of solid content concentration in composition solution After precisely weighing 0.3 g of the composition solution in an aluminum dish and adding about 1 g of diethylene glycol dimethyl ether, it was dried on a hot plate at 175 ° C. for 60 minutes, The solid content concentration was determined from the mass before and after drying. Here, since the amount of liquid used for one slit coating correlates with the solid content concentration, the amount of liquid used increases when the solid content concentration is low when the viscosity of the composition is adjusted to 3.0 mPa · s. . Therefore, when the solid content concentration when the viscosity of the composition is adjusted to 3.0 mPa · s is 23% or less, it can be determined that the amount of liquid used for one slit coating increases and liquid saving cannot be achieved. The results are shown in Table 1.

(3) Evaluation of Unevenness The prepared composition solution was applied onto a 550 mm × 650 mm chromium film-forming glass using a slit die coater (trade name “TR6322105-CL”, manufactured by 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 at an exposure amount of 2,000 J / m ² , the upper surface of the chromium film-forming glass A film having a thickness of 4 μm was formed. The surface of the film was illuminated with a sodium lamp, and the coated film surface was visually confirmed. Vertical stripe unevenness (one or more straight line unevenness in the direction of application or crossing it), haze unevenness (cloudy unevenness), pin mark unevenness (dotted unevenness on the substrate support pin) Is marked as x when clearly confirmed, △ when slightly confirmed, ◯ when hardly confirmed, ◎ when streak unevenness, haze unevenness, pin pin unevenness could not be confirmed. The results are shown in Table 1.

(4) Evaluation of film thickness uniformity (uniformity) The film thickness of the coating film on the chromium film-forming glass produced as described above was measured using a needle contact type measuring device (trade name “AS200”, manufactured by KLA-Tencor). It measured using. 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. The results are shown in Table 1.
(Uniformity calculation formula)
Uniformity (%) = {FT (X, Y) max−FT (X, Y) min} × 100 / {2 × FT (X, Y) avg. }

(5) Evaluation of high-speed coating property It apply | coated using the slit coater on the 550 mm x 650 mm non-alkali glass substrate. As coating conditions, the coating liquid was discharged from the nozzle so that the distance between the base and the nozzle (GAP) was 150 μm and the film thickness was 2.5 μm after exposure, and the moving speed of the nozzle was 120 mm / sec. -220 mm / sec. The maximum speed at which streaky unevenness due to liquid breakage does not occur was determined. At this time, 200 mm / sec. If streaky unevenness does not occur even at the above speed, it can be determined that high-speed application is possible. The results are shown in Table 1.

(6) Evaluation of sensitivity After applying a radiation-sensitive resin composition on a 95 mm × 95 mm non-alkali glass substrate using a spin coating method, pre-baking on a hot plate at 90 ° C. for 3 minutes to obtain a film thickness of 3. A 5 μm coating film was formed. 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 minimum exposure amount at which the remaining film ratio obtained by the following formula after post-baking was 90% or more was defined as sensitivity. It can be said that the sensitivity of the exposure amount at this time is 800 J / m ² or less. The results are shown in Table 1.
(Calculation formula for remaining film ratio)
Residual film ratio (%) = film thickness after post-baking (μm) × 100 / film thickness after exposure (μm)

(7) Evaluation of rubbing resistance A spacer is formed on the substrate in the same manner as in “(6) Evaluation of sensitivity” except that the exposure amount is the exposure amount corresponding to the sensitivity determined in “(6) Evaluation of sensitivity”. did. On the obtained substrate, a liquid crystal aligning agent (trade name “AL3046”, manufactured by JSR Co., Ltd.) was applied by a printing machine for applying a liquid crystal alignment film, dried at 180 ° C. for 1 hour, and a film thickness of 0.05 μm. A liquid crystal aligning agent coating was formed. Then, a rubbing machine having a roll around which a polyamide cloth is wound is applied to this coating film by a roll rotation speed of 500 rpm and a stage moving speed of 1 cm / sec. The rubbing process was performed under the conditions of At this time, the presence or absence of pattern scraping or peeling was confirmed. The results are shown in Table 1.

(8) Evaluation of compression performance In the same manner as in the above “(6) Evaluation of sensitivity”, 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 (trade name “Fischer Scope H100C”, manufactured by Fisher Instruments), and the change in the amount of compressive displacement relative 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. The results are shown in Table 1.

Each component used in the examples and comparative examples is as follows.
(B) Component B-1: Mixture of dipentaerythritol hexaacrylate and dipentaerythritol pentaacrylate (trade name “KAYARAD DPHA”, manufactured by Nippon Kayaku Co., Ltd.)
B-2: Multifunctional acrylate compound (trade name “KAYARAD DPHA-40H”, manufactured by Nippon Kayaku Co., Ltd.)
B-3: Succinic acid-modified pentaerythritol triacrylate B-4: ω-carboxypolycaprolactone monoacrylate (trade name “Aronix M-5300”, manufactured by Toagosei Co., Ltd.)
(C) Component C-1: Ethanone, 1- [9-ethyl-6- (2-methylbenzoyl) -9. H. -Carbazol-3-yl]-, 1- (O-acetyloxime) (trade name “Irgacure OXE02”, manufactured by Ciba Specialty Chemicals)
C-2: 2-dimethylamino-2- (4-methylbenzyl) -1- (4-morpholin-4-yl-phenyl) -butan-1-one (trade name “Irgacure 379”, Ciba Specialty (Chemicals)
C-3: 2,2′-bis (2-chlorophenyl) -4,4 ′, 5,5′-tetraphenyl-1,2′-biimidazole C-4: 4,4′-bis (diethylamino) benzophenone C-5: 2-mercaptobenzothiazole (D) component D-1: diisoamyl ether D-2: di (n-amyl) ether D-3: di (n-butyl) ether (E) component E-1- 1: methyl 3-methoxypropionate E-1-2: propylene glycol methyl ether acetate E-1-3: diethylene glycol ethyl methyl ether E-1-4: cyclohexanone E-2-1: dipropylene glycol dimethyl ether E-2- 2: benzyl alcohol E-2-3: ethylene glycol monobutyl ether acetate
E-2-4: Propylene glycol methyl ether propionate

Claims (12)

(A) an alkali-soluble resin,
(B) a polymerizable unsaturated compound,
A radiation-sensitive resin composition containing (C) a radiation-sensitive polymerization initiator, and (D) a solvent represented by the following formula (1).

(In Formula (1), R ¹ and R ² are each independently a linear or branched alkyl group having 4 or 5 carbon atoms.) The radiation sensitive resin composition according to claim ^1, wherein R ¹ and R ² are the same.   (E-1) The solvent further comprises at least one solvent selected from the group consisting of diethylene glycol dialkyl ether solvents, propylene glycol alkyl ether acetate solvents, ketone solvents and fatty acid alkyl ester solvents. 2. The radiation sensitive resin composition according to 2.   (E-1) The solvent is selected from the group consisting of diethylene glycol ethyl methyl ether, diethylene glycol dimethyl ether, propylene glycol methyl ether acetate, propylene glycol ethyl ether acetate, cyclohexanone, methyl 3-methoxypropionate and ethyl 3-ethoxypropionate. The radiation sensitive resin composition according to claim 3, which is at least one kind.   (E-2) Alcohol solvents, glycol ether solvents, ethylene glycol alkyl ether acetate solvents, diethylene glycol monoalkyl ether solvents, dipropylene glycol dialkyl ether solvents, propylene glycol monoalkyl ether solvents and propylene glycol alkyl ether solvents The radiation sensitive resin composition of any one of Claims 1-4 which further contains the at least 1 sort (s) of solvent selected from the group which consists of a pioneate-type solvent.   (E-2) The solvent is at least one selected from the group consisting of benzyl alcohol, ethylene glycol monobutyl ether acetate, diethylene glycol monoethyl ether acetate, diethylene glycol diethyl ether, dipropylene glycol dimethyl ether and propylene glycol methyl ether propionate. The radiation-sensitive resin composition according to claim 5.   The radiation-sensitive resin composition according to any one of claims 1 to 6, wherein (D) the content of the solvent is from 5% by mass to 90% by mass with respect to the total amount of the solvent.   The radiation-sensitive resin composition according to any one of claims 1 to 7, wherein the (A) alkali-soluble resin has at least one group selected from the group consisting of an epoxy group and a (meth) acryloyl group. object.   (C) The radiation sensitive resin composition of any one of the Claims 1-8 containing an O-acyl oxime compound as a radiation sensitive polymerization initiator.   The radiation sensitive resin composition of any one of Claim 1 to 9 used in order to form the cured film as a spacer or protective film of a liquid crystal display element.   A cured film formed from the radiation-sensitive resin composition according to claim 10. (1) The process of apply | coating the radiation sensitive resin composition of Claim 10 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 process of heating the coating film after image development The forming method of the cured film.