Resin composition, cured product, scintillator panel, and inductor

Abstract

Provided is a resin composition with which it is possible to form a pattern having a high aspect ratio. This resin composition contains (A) a resin, (B) an oxetane compound, and a photocation polymerization initiator, the (A) resin including a resin having an alkali-soluble group, and the (B) oxetane compound including a compound having four or more (B-1) oxetanyl groups.

Description

Resin composition, cured product, scintillator panel and inductor

[0001] The present invention relates to a resin composition, a cured product, a scintillator panel, and an inductor.

[0002] Digital radiation detection devices such as flat panel radiation detectors (FPDs) are used in the medical field and industrial applications such as structural inspection and baggage inspection. Indirect conversion FPDs use a scintillator panel to convert X-rays into visible light. The scintillator panel has a phosphor layer (scintillator layer) containing a phosphor such as gadolinium oxysulfide (GOS), which emits light when irradiated with X-rays. The scintillator panel converts the light emitted from the scintillator panel into an electrical signal using a sensor (photoelectric conversion layer) including a thin film transistor (TFT) or a charge-coupled device (CCD), thereby converting X-ray information into digital image information. However, scintillator panels have a problem in that the light emitted from the radioactive phosphor is scattered within the phosphor layer, reducing the sharpness of the resulting image.

[0003] Therefore, in order to reduce the effect of light scattering, a method of filling a space partitioned by partitions with a phosphor has been proposed.Furthermore, as a technology for solving the problem of brightness reduction caused by partitions, a scintillator panel has been proposed which includes a substrate, partitions formed on the substrate, and a scintillator layer partitioned by the partitions and containing a phosphor, in which the partitions contain one or more compounds (P) selected from the group consisting of polyimide, polyamide, polyamideimide, and polybenzoxazole (see, for example, Patent Document 1).

[0004] On the other hand, in industrial applications such as food and electronic components, continuous irradiation with high-energy X-rays during in-line inspection has tended to result in a decrease in brightness over time. In response to this, a scintillator panel has been proposed that has a substrate and a scintillator layer containing a phosphor, the scintillator layer including a binder resin having a π-conjugated structure composed of seven or more atoms, the glass transition point of the binder resin being 30 to 430°C, and the film thickness of the scintillator layer being 50 to 800 μm (see, for example, Patent Document 2).

[0005] International Publication No. 2021 / 200327 International Publication No. 2022 / 024860

[0006]

[0003] In particular, in industrial applications, a thicker phosphor layer and thinner barrier ribs are required to increase the amount of phosphor used in order to irradiate high-energy X-rays. Under these circumstances, barrier ribs with a higher aspect ratio are required. However, it has been difficult to form patterns such as barrier ribs with a high aspect ratio required under these circumstances with conventionally known resin compositions.

[0007] In view of the problems with the prior art, the present invention aims to provide a resin composition, a cured product, a scintillator panel, and an inductor that are capable of forming a pattern with a high aspect ratio.

[0008] A resin composition according to one aspect of the present invention that solves the above-described problems includes: (A) a resin; (B) an oxetane compound; and a photocationic polymerization initiator; the (A) resin includes a resin having an alkali-soluble group; and the (B) oxetane compound includes (B-1) a compound having four or more oxetanyl groups.

[0009] Furthermore, a cured product according to one aspect of the present invention that solves the above-mentioned problems is a cured product obtained by curing the above-mentioned resin composition.

[0010] Furthermore, a scintillator panel according to one aspect of the present invention that solves the above-described problems is a scintillator panel that includes a substrate, partition walls formed on the substrate, and phosphor layers in cells partitioned by the partition walls, wherein the partition walls are made of the cured product.

[0011] Furthermore, an inductor according to one aspect of the present invention that solves the above-mentioned problems includes an insulating film and a coil, and the insulating film is the above-mentioned cured product.

[0012] 1 is a cross-sectional view schematically illustrating a radiation detector member including a scintillator panel according to an embodiment of the present invention. 2 is an enlarged cross-sectional view schematically illustrating a substrate and a partition wall portion of the radiation detector member shown in FIG. 1. 3 is a cross-sectional view schematically illustrating the structure of an inductor according to an embodiment of the present invention.

[0013] A resin composition according to one embodiment of the present invention includes (A) a resin, (B) an oxetane compound, and a photocationic polymerization initiator. The (A) resin includes a resin having an alkali-soluble group. The (B) oxetane compound includes (B-1) a compound having four or more oxetanyl groups (hereinafter, sometimes abbreviated as "(B-1) oxetane compound").

[0014] The (A) resin has the effect of maintaining the shape of the resin composition and improving its processability. The (B) oxetane compound is cured by cationic polymerization. In particular, by selecting (B-1) a compound having four or more oxetanyl groups, which has excellent curability, from among various oxetane compounds, the resin composition can form a high-aspect ratio pattern with high resolution. The resin composition may contain, as the (B) oxetane compound, an oxetane compound having one to three oxetanyl groups in addition to the (B-1) oxetane compound.

[0015] The resin composition of this embodiment preferably further contains an epoxy compound (C). The resin composition also contains a cationic photopolymerization initiator. The epoxy compound (C) has the effect of improving adhesion to a substrate when the resin composition is formed on the substrate. By containing the cationic photopolymerization initiator, the resin composition exhibits negative photosensitivity in which, upon irradiation with light, the cationic photopolymerization initiator generates an acid, which polymerizes the oxetane compound (B), rendering the resin composition insoluble in a developer. Pattern formation using negative photosensitivity allows the formation of a pattern with excellent mechanical properties, since the exposed portions undergo photocrosslinking to form a pattern.

[0016] <(A) Resin> The resin may be an acrylic resin, a styrene-based resin, a phenolic resin, an epoxy resin, a polyester, a polyvinyl alcohol, a polyamide, a polyimide, a polyamideimide, a polybenzoxazole, or the like. The resin may contain two or more of these. Among these, the resin is preferably polyamide, polyimide, polyamideimide, or polybenzoxazole. By using these as the resin, the resin composition can improve the mechanical properties of the obtained cured product and form a pattern with a higher aspect ratio. The resin is more preferably polyimide or polybenzoxazole.

[0017] The weight average molecular weight of the (A) resin is preferably 1,000 or more, more preferably 2,000 or more. The weight average molecular weight of the resin is preferably 20,000 or less, more preferably 10,000 or less. By making the weight average molecular weight of the (A) resin 1,000 or more, the film-forming properties of the resin composition can be improved. On the other hand, by making the weight average molecular weight of the (A) resin 20,000 or less, the solubility of the resin composition during development can be improved. The weight average molecular weight of the (A) resin in this embodiment is measured by gel permeation chromatography (GPC) and calculated in terms of polystyrene.

[0018] From the viewpoint of cationic polymerization, it is preferable that the (A) resin is substantially free of basic functional groups such as amino groups that can inhibit cationic polymerization. By being substantially free of cationic polymerization inhibitor groups, the resin composition can enhance cationic polymerization properties and form patterns with higher aspect ratios. Here, "substantially free" specifically refers to a basic functional group equivalent weight of 1,000 g / eq or more.

[0019] The (A) resin contains a resin having an alkali-soluble group. This allows the resin composition to obtain appropriate solubility when developed with an alkaline developer, thereby enhancing the contrast between exposed and unexposed areas. Examples of the alkali-soluble group include a phenolic hydroxyl group, a carboxyl group, a silanol group, and a sulfo group. The (A) resin may contain two or more of these alkali-soluble groups. Among these, the alkali-soluble group is preferably a phenolic hydroxyl group. Examples of resins having a phenolic hydroxyl group include polyhydroxyphenyl acrylate, polyhydroxyphenyl methacrylate, polyparahydroxystyrene, and polyamides, polyimides, polyamideimides, and polybenzoxazoles having phenolic hydroxyl groups. The (A) resin may contain two or more of these resins having phenolic hydroxyl groups.

[0020] The polyamide, polyimide, polyamideimide, and polybenzoxazole having a phenolic hydroxyl group preferably have a diamine residue having a phenolic hydroxyl group. Examples of the diamine residue having a phenolic hydroxyl group include residues derived from aromatic diamines such as bis(3-amino-4-hydroxyphenyl)hexafluoropropane, bis(3-amino-4-hydroxyphenyl)sulfone, bis(3-amino-4-hydroxyphenyl)propane, bis(3-amino-4-hydroxyphenyl)methylene, bis(3-amino-4-hydroxyphenyl)ether, bis(3-amino-4-hydroxy)biphenyl, 2,2'-ditrifluoromethyl-5,5'-dihydroxyl-4,4'-diaminobiphenyl, bis(3-amino-4-hydroxyphenyl)fluorene, and 2,2'-bis(trifluoromethyl)-5,5'-dihydroxybenzidine, as well as compounds in which a portion of the hydrogen atoms of these aromatic rings or hydrocarbons are substituted with alkyl groups or fluoroalkyl groups having 1 to 10 carbon atoms, halogen atoms, or the like. The polyamide, polyimide, polyamideimide, and polybenzoxazole having a phenolic hydroxyl group may have two or more of these diamine residues having a phenolic hydroxyl group. The polyamide, polyimide, polyamideimide, and polybenzoxazole having an alkali-soluble group may further have a diamine residue not having a phenolic hydroxyl group.

[0021] The content of the (A) resin in the resin composition of this embodiment is preferably 15% by mass or more, more preferably 25% by mass or more, based on the solid content. Furthermore, the content of the (A) resin in the resin composition is preferably 70% by mass or less, more preferably 60% by mass or less, based on the solid content. By having the (A) resin content of 15% by mass or more, the mechanical properties and thermal properties of the cured product obtained by curing the resin composition can be improved. On the other hand, by having the (A) resin content of 70% by mass or less, the resin composition can suppress development residues during development.

[0022] <(B) Oxetane Compound> The resin composition of this embodiment contains a (B) oxetane compound. Examples of the (B) oxetane compound include 3-methyl-3-hydroxymethyloxetane, 3-ethyl-3-hydroxymethyloxetane, 2-ethylhexyl (3-ethyl-3-oxetanylmethyl) ether, 2-hydroxyethyl (3-ethyl-3-oxetanylmethyl) ether, 2-hydroxypropyl (3-ethyl-3-oxetanylmethyl) ether, 1,4-bis[(3-ethyl-3-oxetanylmethoxy)methyl]benzene, oxetanyl silsesquioxane, phenol novolac oxetane, and OXT-191 (trade name, manufactured by Toagosei Co., Ltd.). The resin composition may contain two or more of these (B) oxetane compounds. In this embodiment, compounds having an oxetanyl group are classified as (B) oxetane compounds, even if they are resins or compounds having an epoxy group.

[0023] The resin composition of this embodiment is characterized by containing (B-1) a compound having four or more oxetanyl groups. As described above, by selecting a (B-1) compound having four or more oxetanyl groups, which has excellent curability, as the (B) oxetane compound, the resin composition can form a pattern with a high aspect ratio. When a resin composition containing only a compound having fewer than four oxetanyl groups as the (B) oxetane compound forms a high pattern, the resolution and aspect ratio become insufficient. Examples of the (B-1) oxetane compound include oxetanyl silsesquioxane, phenol novolac oxetane, and OXT-191 (trade name, manufactured by Toagosei Co., Ltd.). The resin composition may contain two or more of these (B-1) oxetane compounds. The number of oxetanyl groups per molecule is preferably seven or more. This further improves the curability of the resin composition, allowing the formation of a pattern with a higher aspect ratio. On the other hand, the number of oxetanyl groups per molecule is preferably 20 or less. This allows the resin composition to suppress the occurrence of cracks during pattern processing. An example of an oxetane compound having 7 to 20 oxetanyl groups per molecule is OXT-191 (trade name, manufactured by Toagosei Co., Ltd.).

[0024] (B-1) The compound having four or more oxetanyl groups preferably has a structure represented by the following general formula (1):

[0025]

[0026] In the above general formula (1), R 1 represents an n-valent group having a siloxane bond. 2 represents a hydrogen atom or a monovalent organic group having 1 to 6 carbon atoms. n represents a number ranging from 4 to 30, preferably from 7 to 20.

[0027] R 1 R has a siloxane bond. The siloxane bond is hydrolyzed by an alkaline developer, and therefore, when developed with an alkaline developer, it has a suitable solubility, which can enhance the contrast between the exposed and unexposed areas. 1 The silicate and polysilicate are preferred.

[0028] R 2 The organic group constituting R is preferably an alkyl group such as a methyl group or an ethyl group. The alkyl group may be substituted with a halogen such as fluorine, and when it has a substituent, it is preferably a perfluoroalkyl group such as a trifluoromethyl group or a pentafluoroethyl group. 2 By containing a hydrogen atom or a monovalent organic group having 1 to 6 carbon atoms, the resin composition has excellent solubility in an alkaline developer, and developability can be improved.

[0029] An example of an oxetane compound having the structure represented by the general formula (1) is oxetanylsilsesquioxane, OXT-191 (trade name, manufactured by Toagosei Co., Ltd.).

[0030] The oxetane compound having the structure represented by the above general formula (1) more preferably has a structure represented by the following general formula (2).

[0031]

[0032] In the above general formula (2), R 2 represents R in general formula (1). 2m is the number of repetitions and is an integer of 1 or more.

[0033] In general formula (2), the resin composition has a silicate structure in which four oxygen atoms are bonded to silicon, thereby improving heat resistance. In addition, the resin composition has many siloxane bonds, which allows the resin composition to further enhance the contrast between exposed and unexposed areas by hydrolysis with an alkaline developer.

[0034] An example of an oxetane compound having the structure represented by the above general formula (2) is OXT-191 (trade name, manufactured by Toagosei Co., Ltd.).

[0035] The content of the (B-1) oxetane compound in the resin composition of this embodiment is preferably 30 parts by mass or more, and more preferably 50 parts by mass or more, per 100 parts by mass of the (A) resin. Furthermore, the content of the (B-1) oxetane compound is preferably 160 parts by mass or less, and more preferably 130 parts by mass or less, per 100 parts by mass of the (A) resin. By setting the content of the (B-1) oxetane compound to 30 parts by mass or more, the curability of the resin composition is further improved, and a pattern with a higher aspect ratio can be formed. On the other hand, by setting the content of the (B-1) oxetane compound to 160 parts by mass or less, the resin composition can improve the resolution during pattern processing.

[0036] <(C) Epoxy Compound> The resin composition of the present embodiment preferably further contains an epoxy compound (C). The epoxy compound (C) is, for example, an aromatic epoxy compound, an alicyclic epoxy compound, an aliphatic epoxy compound, or the like. The resin composition may contain two or more of these epoxy compounds (C).

[0037] The aromatic epoxy compound is, for example, a glycidyl ether of a monohydric or polyhydric phenol having at least one aromatic ring (phenol, bisphenol A, phenol novolak, or an alkylene oxide adduct thereof).

[0038] Alicyclic epoxy compounds are, for example, compounds obtained by epoxidizing a compound having at least one cyclohexene or cyclopentene ring with an oxidizing agent (e.g., 3,4-epoxycyclohexylmethyl-3,4-epoxycyclohexanecarboxylate).

[0039] Examples of aliphatic epoxy compounds include polyglycidyl ethers of aliphatic polyhydric alcohols or their alkylene oxide adducts (1,4-butanediol diglycidyl ether, 1,6-hexanediol diglycidyl ether, etc.), polyglycidyl esters of aliphatic polybasic acids (diglycidyl tetrahydrophthalate, etc.), and epoxidized long-chain unsaturated compounds (epoxidized soybean oil, epoxidized polybutadiene, etc.).

[0040] At least one of the (B) oxetane compound and the (C) epoxy compound preferably has a polyalkylene glycol chain. By having a highly flexible polyalkylene glycol chain, the resin composition can suppress the occurrence of cracks in the film or cured product after drying.

[0041] The number-average molecular weight of the compound having a polyalkylene glycol chain is preferably 300 to 4,000 from the viewpoint of compatibility with the resin (A). By setting the number-average molecular weight to 300 or more, the resin composition can further improve the compatibility between the resin (A) and the compound having a polyalkylene glycol chain, as well as flexibility, and can further suppress the occurrence of cracks. On the other hand, by setting the number-average molecular weight to 4,000 or less, the resin composition can appropriately suppress the epoxy / oxetane equivalent, further improve curability, and form patterns with higher aspect ratios. The chemical structure of the compound having a polyalkylene glycol chain can be analyzed using a combination of nuclear magnetic resonance (NMR), Fourier transform infrared spectroscopy (FT-IR), and high-performance liquid chromatography / mass spectrometry (HPLC / MS). The number-average molecular weight of the compound having a polyalkylene glycol chain can be measured by gel permeation chromatography (GPC).

[0042] From the viewpoint of hydrophilicity, the number of carbon atoms in the alkylene group in the repeating unit of the polyalkylene glycol chain is preferably 2 to 6, and more preferably 2. By setting the number of carbon atoms in the alkylene group within this range, the resin composition has excellent solubility in an alkaline developer and can improve developability.

[0043] Furthermore, the number of epoxy groups and oxetanyl groups in at least one of the (B) oxetane compound having a polyalkylene glycol chain or the (C) epoxy compound is preferably two or more. This further improves the curability of the resin composition, enabling the formation of patterns with higher aspect ratios. Examples of such (B) oxetane compounds include bis-[(3-ethyloxetan-3-yl)methoxy]polyethylene glycol, and examples of (C) epoxy compounds include polyethylene glycol diglycidyl ether and polypropylene glycol diglycidyl ether.

[0044] The (B) oxetane compound and the (C) epoxy compound are preferably water-soluble compounds from the viewpoint of solubility in an aqueous developer during development. Specifically, at least one of the (B) oxetane compound or the (C) epoxy compound is preferably a water-soluble compound that dissolves in 900 parts by mass of water at 20°C within 1 minute per 100 parts by mass of the compound. Specifically, at least one of the (B) oxetane compound or the (C) epoxy compound is preferably 3-methyl-3-hydroxymethyloxetane, 3-ethyl-3-hydroxymethyloxetane, glycerol polyglycidyl ether, polyglycerol polyglycidyl ether, ethylene glycol diglycidyl ether, polyethylene glycol diglycidyl ether, polypropylene glycol diglycidyl ether, phenol (EO) 5 glycidyl ether, lauryl alcohol (EO) 15 Glycidyl ethers and the like.

[0045] The total content of the (B) oxetane compound and the (C) epoxy compound in the resin composition of this embodiment is preferably 50 parts by mass or more, and more preferably 70 parts by mass or more, per 100 parts by mass of the (A) resin. Furthermore, the total content of the (B) oxetane compound and the (C) epoxy compound is preferably 170 parts by mass or less, and more preferably 140 parts by mass or less, per 100 parts by mass of the (A) resin. By making their total content 50 parts by mass or more, the resin composition can suppress the occurrence of cracks in the coating film. On the other hand, by making their total content 170 parts by mass or less, the resin composition can suppress the development of tackiness in the coating film.

[0046] <Cationic Photopolymerization Initiator> The cationic photopolymerization initiator generates an acid by exposure to light, causing cationic polymerization. Examples of the cationic photopolymerization initiator include aromatic iodonium salts, aromatic sulfonium salts, and aromatic borate salts. The resin composition may contain two or more of these cationic photopolymerization initiators. Among these, the photocationic polymerization initiator is preferably an aromatic sulfonium salt, such as diphenyl[(phenylsulfanyl)phenyl]sulfonium hexafluorophosphate, diphenyl[4-(phenylthio)phenyl]sulfonium hexafluoroantimonate(V), diphenyl[4-(phenylsulfanyl)phenyl]sulfonium trifluoride tris(pentafluoroethane-1-ide)phosphate, diphenyl[(phenylsulfanyl)phenyl]sulfonium tetrakis(pentafluorophenyl)borate, CPI-310B, CPI-310FG, CPI-410S, CPI-410B (trade names, all manufactured by San-Apro Ltd.), and the like.

[0047] The content of the cationic photopolymerization initiator in the resin composition of this embodiment is preferably 0.3 parts by mass or more per 100 parts by mass of the (A) resin. This further improves the curability of the resin composition, allowing the formation of a pattern with a higher aspect ratio. On the other hand, the content of the cationic photopolymerization initiator is preferably 10 parts by mass or less per 100 parts by mass of the (A) resin. This allows the stability of the resin composition to be improved.

[0048] <Other Components> The resin composition of this embodiment may contain, in addition to the (B) epoxy compound and the (C) oxetane compound, a cationically polymerizable compound other than these. Examples of the cationically polymerizable compound other than the (B) epoxy compound and the (C) oxetane compound include an ethylenically unsaturated compound, a bicycloorthoester, a spiroorthocarbonate, and a spiroorthoester. The resin composition may contain two or more of these cationically polymerizable compounds other than the (B) epoxy compound and the (C) oxetane compound.

[0049] Examples of ethylenically unsaturated compounds include aliphatic monovinyl ethers, aromatic monovinyl ethers, polyfunctional vinyl ethers, styrene, and cationically polymerizable nitrogen-containing monomers. Examples of aliphatic monovinyl ethers include methyl vinyl ether, ethyl vinyl ether, butyl vinyl ether, and cyclohexyl vinyl ether. Examples of aromatic monovinyl ethers include 2-phenoxyethyl vinyl ether, phenyl vinyl ether, and p-methoxyphenyl vinyl ether. Examples of polyfunctional vinyl ethers include butanediol-1,4-divinyl ether and triethylene glycol divinyl ether. Examples of styrenes include styrene, α-methylstyrene, p-methoxystyrene, and tert-butoxystyrene. Examples of cationically polymerizable nitrogen-containing monomers include N-vinylcarbazole and N-vinylpyrrolidone.

[0050] Examples of bicyclo orthoesters include 1-phenyl-4-ethyl-2,6,7-trioxabicyclo[2.2.2]octane, 1-ethyl-4-hydroxymethyl-2,6,7-trioxabicyclo-[2.2.2]octane, and the like.

[0051] Examples of spiro orthocarbonates include 1,5,7,11-tetraoxaspiro[5.5]undecane and 3,9-dibenzyl-1,5,7,11-tetraoxaspiro[5.5]undecane.

[0052] Examples of spiro orthoesters include 1,4,6-trioxaspiro[4.4]nonane, 2-methyl-1,4,6-trioxaspiro[4.4]nonane, and 1,4,6-trioxaspiro[4.5]decane.

[0053] The resin composition of this embodiment may further contain additives such as a sensitizer and a surfactant, inorganic particles, a solvent, etc., as necessary. The solvent is preferably one that dissolves the components constituting the resin composition. Examples of the solvent include ethers such as ethylene glycol monoethyl ether, propylene glycol monomethyl ether, propylene glycol monoethyl ether, ethylene glycol dimethyl ether, ethylene glycol diethyl ether, and ethylene glycol dibutyl ether; alcohols such as ethylene glycol monoethyl ether acetate, propylene glycol monomethyl ether acetate, propyl acetate, butyl acetate, isobutyl acetate, 3-methoxybutyl acetate, 3-methyl-3-methoxybutyl acetate, 3-methyl-2-butanol, 3-methyl-3-methoxybutanol, and diacetone alcohol; N,N-dimethylformamide, N,N-dimethylacetamide, dimethyl sulfoxide, and γ-butyrolactone. The resin composition may contain two or more of these solvents.

[0054] The resin composition of the present embodiment can be produced, for example, by adding (A) to (B) and, if necessary, (C) an epoxy compound, a solvent, and other additives, followed by stirring.

[0055] The resin composition of the present embodiment can be used by processing it into various shapes such as a varnish or a film.

[0056] <Cured Product> Next, a cured product according to one embodiment of the present invention will be described. The cured product according to this embodiment is a cured product obtained by curing the resin composition described above. The cured product according to this embodiment can be suitably used, for example, as a surface protection film for semiconductor elements and inductor devices, an interlayer insulating film, a partition wall for MEMS (microelectromechanical systems), a scintillator panel, and the like.

[0057] The method for producing a cured product of this embodiment is, for example, a method in which a resin composition coating film is irradiated (exposed) with actinic rays, and if necessary, developed to form a pattern, followed by heating to cure. Heat curing causes a thermal crosslinking reaction and, if a photocationic polymerization initiator is contained, a cationic polymerization reaction to proceed, thereby curing the resin composition. Actinic rays used for exposure include, for example, ultraviolet rays, visible rays, electron beams, and X-rays. The heating temperature is preferably 120°C to 300°C.

[0058] <Scintillator Panel> A scintillator panel according to one embodiment of the present invention has a substrate, partition walls formed on the substrate, and a phosphor layer in cells partitioned by the partition walls. The partition walls are made of the cured product according to the above-described embodiment. By using the resin composition according to the above-described embodiment, partition walls with a high aspect ratio can be easily formed in the scintillator panel. Furthermore, by having such partition walls, the scintillator panel can improve its brightness. Furthermore, because the partition walls have excellent surface smoothness, the scintillator panel can improve the light extraction efficiency of the phosphor and improve its brightness.

[0059] Hereinafter, the scintillator panel of the present embodiment will be described with reference to the drawings. Note that the drawings are schematic. Furthermore, the present embodiment is not limited to the embodiments described below.

[0060] FIG. 1 is a cross-sectional view schematically illustrating a radiation detector member including a scintillator panel according to this embodiment. The radiation detector member 1 includes a scintillator panel 2 and an output substrate 3. The scintillator panel 2 includes a substrate 4, partition walls 5, and phosphor layers 6 within cells defined by the partition walls 5. A metal reflective layer 11 is formed on the surface of the partition walls 5, and an organic protective layer 12 is provided on the surface of the metal reflective layer 11. The phosphor layer 6 contains phosphors 13 and a binder resin 14. The output substrate 3 includes an output layer 9 and a photoelectric conversion layer 8 having a photodiode, which are disposed in this order on a substrate 10. A barrier layer 7 may be provided on the photoelectric conversion layer 8. The light-emitting surface of the scintillator panel 2 and the photoelectric conversion layer 8 of the output substrate 3 are preferably bonded or adhered to each other via the barrier layer 7. Light emitted from the phosphor layer 6 reaches the photoelectric conversion layer 8, where it is photoelectrically converted and output. Each of these components is described below.

[0061] <Substrate> The material constituting the substrate is preferably a material having radiation transparency. The material constituting the substrate is, for example, one of the materials exemplified as the material constituting the substrate in International Publication No. 2021 / 200327. Among these, the material constituting the substrate is preferably a polymer material having high radiation transparency and high surface smoothness. The polymer material is preferably polyester such as polyethylene terephthalate or polyethylene naphthalate, polyamide, polyimide, or the like.

[0062] In the case of a substrate made of a polymer material, the thickness of the substrate is preferably 3.0 mm or less.

[0063] <Partitions> The partitions are provided to form at least partitioned spaces (cells). Therefore, in a scintillator panel, the size and pitch of the pixels of the photoelectric conversion elements arranged in a grid pattern can be matched with the size and pitch of the cells of the scintillator panel, so that each pixel of the photoelectric conversion elements can correspond to each cell of the scintillator panel. This allows for a highly sharp image to be obtained.

[0064] The partition walls are preferably made of the cured product of this embodiment. By providing partition walls made of the cured product of the resin composition of this embodiment, the scintillator panel can improve its brightness. The principle behind this is thought to be mainly as follows: By using the resin composition of the above-mentioned embodiment, the scintillator panel can easily form partition walls with a high aspect ratio. Therefore, the scintillator panel can increase the loading amount of phosphor in the phosphor layer and improve its brightness.

[0065] Fig. 2 is an enlarged cross-sectional view schematically showing the substrate and partition wall portion of the radiation detector component shown in Fig. 1. The partition wall 5 on the substrate 4 has a trapezoidal cross-sectional shape with a height L1, a bottom width L3, and a top width L4, spaced apart by a distance L2. The width of the partition wall at a position halfway along the height L1 is defined as a central width L5.

[0066] The height L1 of the partition walls is preferably 100 μm or more, and more preferably 200 μm or more. By setting L1 to 100 μm or more, the scintillator panel can increase the phosphor filling amount and further improve the brightness. On the other hand, the height L1 of the partition walls is preferably 3,000 μm or less, and more preferably 1,000 μm or less. By setting L1 to 3,000 μm or less, the scintillator panel can suppress absorption of emitted light by the phosphor itself and further improve the brightness.

[0067] The distance L2 between adjacent partition walls is preferably 40 μm or more and more preferably 1,000 μm or less. The bottom width L3 of the partition wall is preferably 3 μm or more and 150 μm or less. The top width L4 of the partition wall 5 is preferably 3 μm or more and 30 μm or less.

[0068] The aspect ratio (L1 / L5) of the partition wall height L1 to the partition wall central width L5 is preferably 5.0 or more. This allows the scintillator panel to have a larger phosphor filling amount, thereby further improving brightness. The aspect ratio (L1 / L5) is more preferably 12 or more, more preferably 14 or more, and even more preferably 15 or more. On the other hand, the aspect ratio (L1 / L5) is preferably 100 or less, and more preferably 50 or less. This allows the scintillator panel to have improved partition wall strength.

[0069] The partition wall height L1, the spacing L2 between adjacent partition walls, the bottom width L3, the top width L4, and the central width L5 can be measured by cutting a cross section perpendicular to the substrate or by observing a cross section exposed by a polishing device such as a cross-section polisher using a scanning electron microscope. Here, the width of the partition wall at the contact point between the partition wall and the substrate is defined as L3. The width of the partition wall at the top is defined as L4, and the width of the central portion at a position halfway down the height L1 is defined as L5. Each of the lengths L1 to L5 is calculated by averaging the measured values ​​for partition walls at three randomly selected locations.

[0070] The method for adjusting the aspect ratio (L1 / L5) to fall within the above-described range is preferably a method for forming partition walls from the resin composition of the present embodiment, and it is more preferable to adjust the components and contents of the resin composition to fall within the above-described preferred ranges.

[0071] <Metallic Reflective Layer> In the scintillator panel of this embodiment, the partition wall preferably has a reflective layer containing metal on its surface (hereinafter referred to as a "metallic reflective layer"). The metallic reflective layer may be provided on at least a portion of the partition wall. The metallic reflective layer has high reflectivity even when it is a thin film. Therefore, by providing a thin metallic reflective layer, the loading amount of the phosphor is less likely to decrease, and the brightness of the scintillator panel is further improved. Examples of metallic reflective layers include those exemplified as metallic reflective layers in WO 2019 / 181444.

[0072] <Protective Layer> The scintillator panel of this embodiment preferably has a protective layer on the surface of the metal reflective layer. Even when the metal reflective layer uses an alloy or the like that has poor resistance to discoloration in the atmosphere, the provision of the protective layer can reduce discoloration. This prevents a decrease in the reflectance of the metal reflective layer due to a reaction between the metal reflective layer and the phosphor layer, thereby further improving the brightness of the scintillator panel.

[0073] The protective layer may be either an inorganic protective layer or an organic protective layer, or may be a combination of an inorganic protective layer and an organic protective layer.

[0074] <Inorganic Protective Layer> The inorganic protective layer has low water vapor permeability and is therefore suitable as a protective layer. Examples of the inorganic protective layer include those exemplified as inorganic protective layers in WO 2019 / 181444.

[0075] <Organic protective layer> The organic protective layer is preferably formed from a polymer compound having excellent chemical durability, and preferably contains, for example, polysiloxane or amorphous fluororesin as a main component. The organic protective layer is, for example, one exemplified as an organic protective layer in WO 2019 / 181444. The polysiloxane or amorphous fluororesin is, for example, one exemplified as a material constituting the organic protective layer in WO 2021 / 200327.

[0076] <Phosphor Layer> The scintillator panel of this embodiment has a phosphor layer in each cell defined by partition walls.

[0077] The phosphor layer absorbs the energy of incident radiation such as X-rays and emits electromagnetic waves with wavelengths in the range of 300 nm to 800 nm, i.e., light in the range from ultraviolet light to infrared light, with a focus on visible light. The light emitted from the phosphor layer undergoes photoelectric conversion in the photoelectric conversion layer and is output as an electrical signal through the output layer. The phosphor layer preferably contains a phosphor and a binder resin.

[0078] <Phosphor> The phosphor is, for example, one exemplified as a phosphor in WO 2021 / 200327. From the viewpoint of high luminous efficiency, the phosphor is preferably a terbium-activated rare earth oxysulfide phosphor.

[0079] <Binder Resin> Examples of the binder resin include those exemplified as binder resins in WO 2021 / 200327.

[0080] The binder resin is preferably in contact with the protective layer. In this case, it is sufficient that the binder resin is in contact with at least a portion of the protective layer. This makes it difficult for the phosphor to fall out of the cell in the scintillator panel. Note that the binder resin may be filled in the cell with almost no voids, as shown in FIG. 1, or may be filled with voids.

[0081] As described above, the scintillator panel of this embodiment provides a high brightness image.

[0082] <Method for manufacturing scintillator panel> A method for manufacturing a scintillator panel according to one embodiment of the present invention preferably includes, for example, a partition wall forming step of forming partition walls on a substrate to separate cells, a reflective layer forming step of forming a metal reflective layer on the surface of the partition walls as needed, and a filling step of filling the cells separated by the partition walls with a phosphor. The partition walls contain the cured product of the above-described embodiment. Each step will be described below. In the following description, explanation of matters common to those described in the above-described embodiment of the scintillator panel will be omitted as appropriate.

[0083] <Partition Wall Forming Step> The partition wall forming step using the resin composition of this embodiment will be described. The resin composition of the embodiment described above is applied entirely or partially to the surface of a substrate to obtain a coating film. The resin composition can be applied, for example, by screen printing or by using a coater such as a bar coater, a roll coater, a die coater, or a blade coater. The thickness of the coating film can be adjusted by the number of applications, the mesh size of the screen, the viscosity of the resin composition, etc.

[0084] Next, a pattern is formed from the resin composition coating film formed by the above method. When the resin composition is photosensitive, the resin composition coating film is exposed to actinic radiation through a mask having a desired pattern. The actinic radiation used for exposure is, for example, ultraviolet light, visible light, electron beams, X-rays, etc. In this embodiment, it is preferable to use the i-ray (365 nm), h-ray (405 nm), and g-ray (436 nm) of a mercury lamp as the actinic radiation.

[0085] After exposure, the exposed area is removed with a developer. The developer is, for example, one exemplified as a developer in WO 2021 / 200327.

[0086] Development can be carried out by spraying the developer onto the coating surface, puddling the developer onto the coating surface, immersing the coating in the developer, or immersing the coating in the developer and applying ultrasonic waves, etc. The development conditions, such as the development time and the temperature of the developer in the development step, may be any conditions that allow the exposed area to be removed and a pattern to be formed.

[0087] After development, it is preferable to carry out a rinsing treatment with water. Alternatively, rinsing treatment may be carried out by adding alcohols such as ethanol and isopropyl alcohol, or esters such as ethyl lactate and propylene glycol monomethyl ether acetate to water.

[0088] If necessary, a baking treatment may be carried out before development. This may improve the resolution of the developed pattern and increase the tolerance for development conditions. The baking temperature is preferably in the range of 50 to 180°C, more preferably in the range of 60 to 120°C. The baking time is preferably from 5 seconds to several hours.

[0089] After pattern formation, unreacted cationic polymerizable compounds and cationic polymerization initiators remain in the coating film of the photosensitive resin composition. Therefore, these may thermally decompose and generate gas during the thermal crosslinking reaction described below. To avoid this, it is preferable to irradiate the entire surface of the resin composition coating film after pattern formation with the above-mentioned exposure light to generate acid from the cationic polymerization initiator. By doing so, the reaction of the unreacted cationic polymerizable compounds proceeds during the thermal crosslinking reaction, and the generation of gas due to thermal decomposition can be suppressed.

[0090] After development, the resin composition is cured by applying a temperature of 120°C to 300°C to promote a thermal crosslinking reaction, thereby obtaining partition walls. Crosslinking can improve heat resistance and chemical resistance. This heat treatment method can be selected by gradually increasing the temperature at a selected temperature, or by continuously increasing the temperature within a selected temperature range for 5 minutes to 5 hours.

[0091] In the method for producing a scintillator panel of this embodiment, the substrate used in forming the partition walls may be used as the substrate of the scintillator panel, or the partition walls may be peeled off from the substrate and then placed on the substrate. The partition walls may be peeled off from the substrate by any known method, such as providing a peel-off auxiliary layer between the substrate and the partition walls.

[0092] When a metal reflective layer, an inorganic protective layer, and / or an organic protective layer is provided on the surface of the partition wall, the method for forming these is, for example, the method exemplified as the formation process thereof in WO 2019 / 181444 and WO 2021 / 200327.

[0093] <Semiconductor element> The cured product of one embodiment of the present invention can be suitably used for a semiconductor element, particularly an inductor having an insulating film and a coil, and the cured product of this embodiment is used as an insulating film. The resin composition of the above embodiment can easily form a pattern with a high aspect ratio, so it is preferably used for an inductor, which is a semiconductor element having a cured product with a high aspect ratio.

[0094] 3 is a cross-sectional view showing a schematic configuration of an inductor according to this embodiment. The inductor 15 has a coil 17 and an insulating film 16 that maintains insulation between the coils 17, with resin layers 18 sandwiched between the top and bottom of a substrate 19. The inductor 15 further has a magnetic agent 21 sandwiched between insulating films 20, and is sealed with a molded resin 22.

[0095] The cured product of the above embodiment is preferably used for the insulating film 16. By using the cured product of the above embodiment as the insulating film 16, the inductor 15 can exhibit sufficient insulation even when the pattern width W of the insulating film 16 is small. Therefore, the cross-sectional area of ​​the wiring of the coil 17 of the inductor 15 can be increased, and the inductance can be increased.

[0096] The thickness T of the insulating film 16 is preferably 40 μm or more, and more preferably 80 μm or more, from the viewpoint of increasing the cross-sectional area of ​​the coil 17. On the other hand, the thickness T of the insulating film 16 is preferably 300 μm or less, and more preferably 200 μm or less, from the viewpoint of reducing the film stress.

[0097] The aspect ratio obtained by dividing the film thickness of the insulating film 16 by the pattern width is preferably 4 or more, and more preferably 8 or more, from the viewpoint of improving the wiring density of the coil 17. On the other hand, from the viewpoint of maintaining insulation properties, the aspect ratio of the insulating film 16 is preferably 30 or less, and more preferably 20 or less.

[0098] An embodiment of the present invention has been described above. The present invention is not particularly limited to the above embodiment. Note that the above embodiment mainly describes an invention having the following configuration.

[0099] (1) A resin composition comprising: (A) a resin, (B) an oxetane compound, and a photocationic polymerization initiator, wherein the (A) resin comprises a resin having an alkali-soluble group, and the (B) oxetane compound comprises (B-1) a compound having four or more oxetanyl groups. (2) The resin composition according to (1), wherein the (B-1) compound having four or more oxetanyl groups has a structure represented by the following general formula (1): (In the above general formula (1), R 1 represents an n-valent group having a siloxane bond. 2represents a hydrogen atom or a monovalent organic group having 1 to 6 carbon atoms. n represents a range of 4 to 30. (3) The resin composition according to (1) or (2), further comprising (C) an epoxy compound. (4) The resin composition according to any one of (1) to (3), wherein at least one of the (B) oxetane compound and the (C) epoxy compound has a polyalkylene glycol chain. (5) The resin composition according to (4), wherein the weight-average molecular weight of the polyalkylene glycol chain is 300 to 4,000. (6) The resin composition according to any one of (1) to (5), wherein the content of the (B-1) compound having 4 or more oxetanyl groups is 30 to 160 parts by mass per 100 parts by mass of the (A) resin. (7) A cured product obtained by curing the resin composition according to any one of (1) to (6). (8) A scintillator panel comprising a substrate, partition walls formed on the substrate, and phosphor layers in cells partitioned by the partition walls, the partition walls comprising the cured product according to (7). (9) The scintillator panel according to (8), wherein the partition walls have a height L1 of 100 μm or more. (10) The scintillator panel according to (8) or (9), wherein the aspect ratio (L1 / L5) of the partition wall height L1 to the partition wall central width L5 is 5.0 or more. (11) An inductor comprising an insulating film and a coil, the insulating film being the cured product according to (7).

[0100] The present invention will be described in more detail below with reference to Examples and Comparative Examples. The compounds used in the Examples and Comparative Examples were synthesized by the following methods.

[0101] Synthesis Example 1: Synthesis of Polyimide A-1 Under a dry nitrogen stream, 29.30 g (0.08 mol) of 2,2-bis(3-amino-4-hydroxyphenyl)hexafluoropropane (hereinafter abbreviated as "BAHF") (manufactured by Tokyo Chemical Industry Co., Ltd.) was added to 80 g of γ-butyrolactone (hereinafter abbreviated as "GBL") (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.), and the mixture was stirred and dissolved at 120°C. Next, 30.03 g (0.1 mol) of acid anhydride "RIKACID" (registered trademark) TDA-100 (hereinafter abbreviated as "TDA-100") (manufactured by New Japan Chemical Co., Ltd.) was added together with 20 g of GBL, and the mixture was stirred at 120°C for 1 hour, and then at 200°C for 4 hours to obtain a reaction solution. Next, the reaction solution was poured into 3 L of water, and a white precipitate was precipitated. The precipitate was collected by filtration, washed three times with water, and then dried in a vacuum dryer at 80°C for 5 hours to obtain polyimide A-1 having a weight average molecular weight of 4,000 and a basic functional group equivalent of 1,000 g / eq or more.

[0102] Synthesis Example 2: Synthesis of Polyimide A-2 Under a dry nitrogen stream, 32.96 g (0.09 mol) of BAHF was added to 80 g of GBL and dissolved by stirring at 120°C. Next, 30.03 g (0.1 mol) of TDA-100 was added together with 20 g of GBL, and the mixture was stirred at 120°C for 1 hour, and then at 200°C for 4 hours to obtain a reaction solution. Next, the reaction solution was poured into 3 L of water to precipitate a white precipitate. This precipitate was collected by filtration, washed three times with water, and then dried in a vacuum dryer at 80°C for 5 hours to obtain polyimide A-2 having a weight average molecular weight of 8,000 and a basic functional group equivalent of 1,000 g / eq or more.

[0103] Synthesis Example 3 Synthesis of Polyamideimide A-3 BAHF (18.3 g, 0.05 mol) (manufactured by Tokyo Chemical Industry Co., Ltd.) was dissolved in 100 mL of acetone (manufactured by Tokyo Chemical Industry Co., Ltd.) and propylene oxide (17.4 g, 0.3 mol) (manufactured by Fujifilm Wako Pure Chemical Industries Co., Ltd.), and the solution was cooled to −15°C. To this solution, a solution of 3-nitrobenzoyl chloride (20.4 g, 0.11 mol) (manufactured by Tokyo Chemical Industry Co., Ltd.) dissolved in 100 mL of acetone (manufactured by Tokyo Chemical Industry Co., Ltd.) was added dropwise. After completion of the addition, the mixture was stirred at −15°C for 4 hours to react, and then the temperature was returned to room temperature. The precipitated white solid was filtered off and dried in vacuo at 50°C.

[0104] 30 g of the obtained white solid was placed in a 300 mL stainless steel autoclave and dispersed in 250 mL of methyl cellosolve (Tokyo Chemical Industry Co., Ltd.), and 2 g of 5 mass % palladium on carbon was added. Hydrogen was introduced into the mixture using a balloon, and the mixture was stirred at room temperature to carry out a reduction reaction. After approximately 2 hours, it was confirmed that the balloon was no longer deflating, and stirring was stopped. After stirring was completed, the mixture was filtered to remove the palladium compound catalyst, and the mixture was concentrated using a rotary evaporator to obtain hydroxyl group-containing diamine compound (a).

[0105] Under a dry nitrogen stream, 31.4 g (0.08 mol) of a hydroxyl group-containing diamine compound (a) was added to 80 g of GBL (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) and stirred at 120 ° C. Next, 30.0 g (0.1 mol) of TDA-100 (manufactured by New Japan Chemical Co., Ltd.) was added together with 20 g of GBL, and the mixture was stirred at 120 ° C. for 1 hour, and then at 200 ° C. for 4 hours to obtain a reaction solution. Next, the reaction solution was poured into 3 L of water to precipitate a white precipitate. This precipitate was collected by filtration, washed three times with water, and then dried in a vacuum dryer at 80 ° C. for 5 hours to obtain polyamideimide A-3 having a weight average molecular weight of 5,000 and a basic functional group equivalent of 1,000 g / eq or more.

[0106] Synthesis Example 4 Synthesis of Oxetane Compound B-1a 90.0 g (0.01 mol) of novolak resin (number average molecular weight 900) (manufactured by Meiwa Chemical Industry Co., Ltd.) was dissolved in 100 mL of dimethyl sulfoxide (manufactured by FUJIFILM Wako Pure Chemical Industries, Ltd.). After nitrogen substitution, 60.0 g of a 49% by mass aqueous potassium hydroxide solution (manufactured by FUJIFILM Wako Pure Chemical Industries, Ltd.) was added and stirred at 90°C for 1 hour. Next, while stirring, 60.5 g (0.5 mol) of 3-(chloromethyl)-3-methyloxetane (manufactured by Tokyo Chemical Industry Co., Ltd.) was slowly added dropwise using a dropping funnel. The mixture was then stirred at 90°C for 5 hours to allow the reaction to proceed, and the reaction solution was then poured into 1 L of water to precipitate a white precipitate. The precipitate was collected by filtration, washed three times with water, and then dried in a vacuum dryer at 80°C for 5 hours to obtain an oxetane compound B-1 (a water-insoluble compound that does not satisfy the general formula (1), does not have a polyalkylene glycol chain, and has an average of nine oxetanyl groups per molecule).

[0107] Synthesis Example 5: Synthesis of Epoxy Compound C-5 20.0 g (0.005 mol) of polyethylene glycol (number average molecular weight 4,000) (manufactured by Tokyo Chemical Industry Co., Ltd.) and 13.4 g (0.15 mol) of epichlorohydrin (manufactured by Tokyo Chemical Industry Co., Ltd.) were dissolved in 200 mL of toluene (manufactured by Fujifilm Wako Pure Chemical Industries Co., Ltd.), and then 6.0 g (0.15 mol) of sodium hydroxide (manufactured by Fujifilm Wako Pure Chemical Industries Co., Ltd.) was added and the mixture was stirred at 50°C for 7 hours to allow the reaction to proceed. After cooling to room temperature, the reaction solution was washed three times with distilled water and once with saturated saline, and the organic layer was extracted. The solvent was removed using an evaporator, and the mixture was dried in a vacuum dryer at 80°C for 5 hours to obtain a bifunctional epoxy compound (C-5) (number average molecular weight 4,200) having a polyethylene glycol chain.

[0108] Other raw materials used in the examples and comparative examples are listed below.

[0109] (A) Resins A-4: "Marukalinker" (registered trademark) M (manufactured by Maruzen Petrochemical Co., Ltd.), a polyparahydroxystyrene resin having a weight average molecular weight of 4,000 and a basic functional group equivalent of 1,000 g / eq or more. A-5: a copolymer of methacrylic acid / methyl methacrylate / styrene (mass ratio) at 40 / 40 / 30, to which 0.4 equivalents of glycidyl methacrylate have been added in relation to the carboxyl groups, having a weight average molecular weight of 43,000 and an acid value of 100 mgKOH / g.

[0110] (B) Oxetane Compound B-1b: Oxetane compound having an average of six oxetanyl groups and represented by general formula (1), obtained by separating low molecular weight components of OXT-191 (manufactured by Toagosei Co., Ltd.) by GPC. 1 is polysilicate, R 2 is an ethyl group, and a water-insoluble compound having no polyalkylene glycol chain. B-1c: OXT-191 (manufactured by Toagosei Co., Ltd.), having an average of 12 oxetanyl groups and represented by the general formula (1), 1 is polysilicate, R 2 is an ethyl group, and has no polyalkylene glycol chain. B-1d: A water-insoluble compound having an average of 18 oxetanyl groups and represented by general formula (1), which is obtained by separating the polymer component of OXT-191 (manufactured by Toagosei Co., Ltd.) by GPC. 1is polysilicate, R 2 is an ethyl group, and is a water-insoluble compound having no polyalkylene glycol chain. B-2: OXIPA (manufactured by Ube Industries, Ltd.), a water-insoluble compound having no polyalkylene glycol chain.

[0111] (C) Epoxy Compounds C-1: "TEPIC" (registered trademark)-VL (manufactured by Nissan Chemical Industries, Ltd.), a trifunctional epoxy compound having no polyalkylene glycol chain, a water-insoluble compound. C-2: "DENACOL" (registered trademark) EX-171 (manufactured by Nagase ChemteX Corporation), a monofunctional epoxy compound having a polyethylene glycol chain, a number-average molecular weight of 770, a water-soluble compound. C-3: "DENACOL" EX-861 (manufactured by Nagase ChemteX Corporation), a bifunctional epoxy compound having a polyethylene glycol chain, a number-average molecular weight of 1,100, a water-soluble compound. C-4: "DENACOL" EX-850 (manufactured by Nagase ChemteX Corporation), a bifunctional epoxy compound having a polyethylene glycol chain, a number-average molecular weight of 220, a water-soluble compound. C-6: "DENACOL" (registered trademark) EX-931 (manufactured by Nagase ChemteX Corporation), a bifunctional epoxy compound having a polypropylene glycol chain, a number average molecular weight of 1,000, and a water-insoluble compound

[0112] (D) Photocationic polymerization initiator CPI-410S (manufactured by San-Apro Co., Ltd.), aromatic sulfonium salt

[0113] (Others) Photosensitive monomer M-1: trimethylolpropane triacrylate Photosensitive monomer M-2: tetrapropylene glycol dimethacrylate Photopolymerization initiator: 2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)butanone-1 (manufactured by BASF) Polymerization inhibitor: 1,6-hexanediol-bis[(3,5-di-t-butyl-4-hydroxyphenyl)propionate]) UV absorber solution: 0.3 mass% solution of Sudan IV (manufactured by Tokyo Ohka Kogyo Co., Ltd.) in γ-butyrolactone Viscosity adjuster: Flownon EC121 (manufactured by Kyoeisha Chemical Co., Ltd.) Low softening point glass powder: 27 mass% SiO2, 31 mass% BO3, 6 mass% ZnO, 7 mass% Li2O, 2 mass% MgO, 2 mass% CaO, 2 mass% BaO, 2 mass% Al2O 23% by mass, refractive index (ng) 1.56, glass softening temperature 588°C, thermal expansion coefficient 70 x 10 -7 (K -1 ), average particle size 2.3 μm

[0114] The water solubility of the (B) oxetane compound and the (C) epoxy compound was determined by adding 1.0 g of each compound to 9.0 g of water and stirring at 20°C for 1 minute, and visually observing whether or not there was any insoluble matter. Compounds in which no insoluble matter was observed were deemed to be water-soluble.

[0115] Next, the evaluation methods used in the examples and comparative examples will be described.

[0116] <Tackiness> In each example and comparative example, a finger was pressed against the surface of the dried varnish coating film produced in forming the partition walls, and the surface was evaluated according to the following evaluation criteria. (Evaluation criteria) A: No stickiness was observed. B: Slight stickiness was observed, but the resin composition did not adhere to the finger. C: Stickiness was observed, and the resin composition adhered to the finger.

[0117] <Crack Resistance> In each Example and Comparative Example, the varnish coating film prepared for forming the partition walls after drying, and the film after exposure and heating or after exposure were each visually observed, and the observation area was 100 cm 2The crack resistance was evaluated based on the total number of cracks generated in the test piece according to the following criteria: (Evaluation criteria) 4: No cracks were observed. 3: The number of cracks generated was 1 or more but less than 25. 2: The number of cracks generated was 25 or more but less than 100. 1: The number of cracks generated was 100 or more.

[0118] <Developability> In each example and comparative example, the developability was evaluated based on the time taken for the unexposed areas to completely dissolve during development, according to the following criteria. (Evaluation criteria) 4: The time taken for the unexposed areas to completely dissolve during development was less than 10 minutes. 3: The time taken for the unexposed areas to completely dissolve during development was 10 minutes or more but less than 20 minutes. 2: The time taken for the unexposed areas to completely dissolve during development was 20 minutes or more but less than 30 minutes. 1: The time taken for the unexposed areas to completely dissolve during development was 30 minutes or more.

[0119] <Adhesion> In each example and comparative example, the interface between the partition wall and the substrate was visually observed after completion of development, and the adhesion was evaluated according to the following criteria: (Evaluation criteria) A: No peeling was observed. B: Partial peeling was observed. C: Peeling was observed over the entire surface.

[0120] <Resolution> A cross section of the grid-shaped partition wall formed in each Example and Comparative Example was exposed by fracturing, and for each Example and Comparative Examples 1 and 2, a partition wall corresponding to the smallest opening where no blockage or residue was observed in the pattern was selected from among the partition walls corresponding to mask openings with line widths of 12 μm, 15 μm, and 20 μm, and for Comparative Example 3, three partition walls were selected at random from the formed partition walls. The central widths L5 were measured at a magnification of 200 times using a scanning electron microscope S2400 (manufactured by Hitachi, Ltd.), and an average value was calculated.

[0121] <Aspect Ratio> For the grid-shaped partition walls formed in each of the Examples and Comparative Examples, the partition walls at three locations where the central width L5 was measured in the evaluation of <Resolution> were similarly observed under magnification to measure the heights L1 and calculate an average value. The aspect ratio (L1 / L5) was calculated from this and the average value of the central widths L5 calculated in the evaluation of <Resolution>.

[0122] <Relative Brightness> A radiation detector was fabricated by aligning the scintillator panels obtained in each Example and Comparative Example at the center of the sensor surface of an X-ray detector PaxScan 2520V (manufactured by Varex) so that the cells corresponded one-to-one to the pixels of the sensor, and fixing the edges of the substrate with adhesive tape. X-rays from an X-ray emitter L9181-02 (manufactured by Hamamatsu Photonics K.K.) were irradiated onto this detector under conditions of a tube voltage of 50 kV and a distance between the X-ray tube and the detector of 30 cm, to obtain an image. In the obtained image, the average value of the digital values ​​of 256 x 256 pixels at the center of the light-emitting position of the scintillator panel was measured as brightness, and the value relative to the brightness of Comparative Example 2, which was set to 100, was calculated as the relative brightness.

[0123] Example 1 Preparation of Varnish 10 g of (A) polyimide A-1 obtained in Synthesis Example 1 as the resin, 12 g of (B) oxetane B-1a obtained in Synthesis Example 4 as the oxetane compound, and 0.10 g of CPI-410S as a photocationic polymerization initiator were weighed and dissolved in GBL. The amount of GBL added was adjusted so that the solids concentration was 60 mass %, with the components other than GBL being considered as solids. The mixture was then pressure-filtered using a filter with a retention particle size of 1 μm to obtain a photosensitive polyimide varnish.

[0124] <Formation of Partition Walls> A PET film measuring 125 mm in length, 125 mm in width, and 0.25 mm in thickness was used as a substrate. A photosensitive polyimide varnish was applied to the surface of the substrate using a die coater so that the thickness after thermal crosslinking and curing would be 350 μm, and the applied film was dried to obtain a photosensitive polyimide varnish coating.

[0125] Next, a coating of photosensitive polyimide varnish was applied to the substrate through a chrome mask having lattice-shaped openings with a pitch of 200 μm and line widths of 12 μm, 15 μm, and 20 μm, using an ultra-high pressure mercury lamp at 5000 mJ / cm 2The film was exposed to an exposure dose of 100°C for 90 minutes using a hot air oven. After exposure, post-exposure baking was performed using a hot air oven. The exposed and heated coating film was developed in a 0.5% by mass aqueous potassium hydroxide solution at 30°C, and the unexposed portions were removed to obtain a lattice pattern. The obtained lattice pattern was heated in air at 200°C for 60 minutes to be thermally crosslinked and cured, thereby forming lattice partition walls.

[0126] <Fabrication of Scintillator Panel> <Formation of Metal Reflective Layer and Inorganic Protective Layer> The formed grid-shaped partition walls were sputtered using a commercially available sputtering device with APC (manufactured by Furuya Metal Co., Ltd.), a silver alloy containing palladium and copper, as a sputtering target to form a metal reflective layer. Sputtering was performed by placing a glass plate near the partition wall substrate under conditions such that the metal thickness on the glass plate was 300 nm. After forming the metal reflective layer, SiN was formed as an inorganic protective layer in the same vacuum batch. The inorganic protective layer was formed under conditions such that the thickness on the glass substrate was 100 nm.

[0127] <Formation of Organic Protective Layer> A resin solution was prepared by mixing 1 part by mass of an amorphous fluorine-containing resin "CYTOP" (registered trademark) CTL-809M with 1 part by mass of a fluorine-based solvent CT-SOLV180 (manufactured by AGC Corporation). The obtained resin solution was vacuum-printed onto the partition walls on which the metal reflective layer and the inorganic protective layer had been formed, dried at 90°C for 1 hour, and further heated at 190°C for 1 hour to form an organic protective layer. The cross section of the partition wall was exposed using a triple ion milling apparatus EMTIC3X (manufactured by LEICA), and images were taken and measured using a field emission scanning electron microscope (FE-SEM) Merlin (manufactured by Zeiss). The thickness of the organic protective layer on the side surface at the center in the height direction of the partition wall was 1 μm.

[0128] <Phosphor> Commercially available GOS:Tb (Tb-doped gadolinium oxysulfide) phosphor powder was used as is. The average particle diameter D50 measured with a particle size distribution analyzer MT3300 (manufactured by Nikkiso Co., Ltd.) was 11 μm.

[0129] <Binder Resin of Phosphor Layer> The raw materials used to prepare the binder resin of the phosphor layer are as follows: Binder resin: ETHOCEL (registered trademark) 7cp (manufactured by The Dow Chemical Company) Solvent: benzyl alcohol (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.).

[0130] <Formation of phosphor layer> A phosphor paste was prepared by mixing 10 parts by mass of phosphor GOS:Tb (Tb-doped gadolinium oxysulfide) with 5 parts by mass of a 10% by mass binder resin solution prepared by dissolving binder resin "Ethocel" (registered trademark) 7cp (manufactured by The Dow Chemical Company) in benzyl alcohol (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.). The average particle diameter D50 of the phosphor measured using a particle size distribution analyzer MT3300 (manufactured by Nikkiso Co., Ltd.) was 11 μm.

[0131] The obtained phosphor paste was vacuum-printed onto a partition wall having a metal reflective layer, an inorganic protective layer, and an organic protective layer formed thereon so that the volume fraction of the phosphor was 65%, and then dried at 150°C for 15 minutes to form a phosphor layer, thereby obtaining a scintillator panel.

[0132] Examples 2 to 19, Comparative Examples 1 and 2 Partition walls and scintillator panels were produced in the same manner as in Example 1, except that the types and added amounts (parts by mass) of (A) resin, (B) oxetane compound, and (C) epoxy compound were changed as shown in Tables 1 and 2.

[0133] Comparative Example 3 4 parts by mass of photosensitive monomer M-1, 6 parts by mass of photosensitive monomer M-2, 24 parts by mass of photosensitive polymer, 6 parts by mass of photopolymerization initiator, 0.2 parts by mass of polymerization inhibitor, and 12.8 parts by mass of ultraviolet absorber solution were heated and dissolved in 38 parts by mass of GBL (manufactured by FUJIFILM Wako Pure Chemical Industries, Ltd.) at a temperature of 80°C to obtain a photosensitive resin composition.

[0134] 50 parts by mass of low-softening point glass powder was added to 50 parts by mass of the obtained photosensitive resin composition, and then the mixture was kneaded using a three-roller kneader to obtain a paste containing glass powder.

[0135] <Formation of Partition Walls> A soda glass plate measuring 125 mm in length, 125 mm in width, and 0.7 mm in thickness was used as a substrate. A glass powder-containing paste was applied to the surface of the substrate using a die coater so that the thickness after thermal crosslinking and curing would be 350 μm, and the applied film was dried to obtain a coating film of the glass powder-containing paste.

[0136] Next, a coating film of the glass powder-containing paste was formed through a chrome mask having a grid-like opening with a pitch of 200 μm and a line width of 10 μm, using an ultra-high pressure mercury lamp at 300 mJ / cm 2 The exposed coating film was developed in a 0.5% by mass aqueous solution of ethanolamine at 30°C to remove the unexposed portions, thereby obtaining a lattice-shaped pre-baking pattern. The obtained lattice-shaped pre-baking pattern was baked in air at 580°C for 15 minutes to form lattice-shaped partition walls composed mainly of glass.

[0137] A scintillator panel was produced in the same manner as in Example 1 using the obtained partition wall substrate.

[0138] The results of evaluation of each of the Examples and Comparative Examples by the above-mentioned methods are shown in Tables 1 and 2.

[0139]

[0140]

[0141] REFERENCE SIGNS LIST 1 Radiation detector member 2 Scintillator panel 3 Output substrate 4 Substrate 5 Partition wall 6 Phosphor layer 7 Diaphragm layer 8 Photoelectric conversion layer 9 Output layer 10 Substrate 11 Metal reflective layer 12 Organic protective layer 13 Phosphor 14 Binder resin 15 Inductor 16 Insulating film 17 Coil 18 Resin layer 19 Substrate 20 Insulating film 21 Magnetic material 22 Molding resin L1 Height of partition wall L2 Distance between adjacent partition walls L3 Bottom width of partition wall L4 Top width of partition wall L5 Middle width of partition wall T Film thickness of insulating film W Pattern width of insulating film

Claims

1. (A) A resin, (B) an oxetane compound, and a photocationic polymerization initiator, The aforementioned resin (A) includes a resin having an alkali-soluble group, The (B) oxetane compound includes (B-1) a compound having four or more oxetanyl groups, The compound having four or more oxetanyl groups (B-1) is a negative-type photosensitive resin composition having a structure represented by the following general formula (1). 【Chemistry 1】 (In the general formula (1) above, R1 represents an n-valent group having a siloxane bond. R2 represents a hydrogen atom or a monovalent organic group having 1 to 6 carbon atoms. n represents a range of 4 to 30.)

2. The negative-type photosensitive resin composition according to claim 1, further comprising (C) an epoxy compound.

3. The negative-type photosensitive resin composition according to claim 1 or 2, wherein at least one of the (B) oxetane compound or the (C) epoxy compound has a polyalkylene glycol chain.

4. The negative-type photosensitive resin composition according to claim 3, wherein the number-average molecular weight of the polyalkylene glycol chain is 300 to 4,000.

5. The negative-type photosensitive resin composition according to claim 1 or 2, wherein the content of the compound having four or more oxetanyl groups (B-1) is 30 to 160 parts by mass per 100 parts by mass of the resin (A).

6. A cured product obtained by curing the negative-type photosensitive resin composition according to claim 1 or 2.

7. The cell comprises a substrate, a partition wall formed on the substrate, and a phosphor layer within the cell partitioned by the partition wall. The partition wall is a scintillator panel made of the cured product described in claim 6.

8. The scintillator panel according to claim 7, wherein the height L1 of the partition wall is 100 μm or more.

9. The scintillator panel according to claim 7, wherein the aspect ratio (L1 / L5) of the height L1 of the partition wall to the width L5 of the middle part of the partition wall is 5.0 or more.

10. Having an insulating film and a coil, The insulating film is the cured product according to claim 6, in an inductor.

11. The negative-type photosensitive resin composition according to claim 1 or 2, wherein the alkali-soluble group comprises at least one of a phenolic hydroxyl group, a carboxyl group, a silanol group, or a sulfo group.

12. The negative-type photosensitive resin composition according to claim 1 or 2, wherein the compound having four or more (B-1) oxetanyl groups has a structure represented by the following general formula (2). 【Chemistry 2】 (In the above general formula (2), R2 represents a hydrogen atom or a monovalent organic group having 1 to 6 carbon atoms. m is the number of repetitions and represents an integer of 1 or more.)

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