Alkali-soluble resin, alkali-soluble resin composition, and method for producing the same

Abstract

The purpose of the present invention is to provide: an alkali-soluble resin and an alkali-soluble resin composition, each of which is capable of forming a cured product that has excellent thermal coloring resistance and a high refractive index; and a production method by which these can be obtained efficiently. The present invention provides an alkali-soluble resin which has a structure represented by formula (1); and this alkali-soluble resin is characterized in that the content of an ammonium salt compound is 0.06% by mass or less relative to 100% by mass of the alkali-soluble resin. (In formula (1), R1, R2 and R3 may be the same or different and each represents a hydrogen atom or a hydrocarbon group having 1 to 6 carbon atoms; R4 represents a direct bond or a divalent organic group; R5, R6, R7 and R8 may be the same or different and each represents a hydrogen atom or Y, and at least one of the R5 to R8 moieties represents Y; Y represents a group represented by formula (2); R9 and R10 may be the same or different and each represents a substituent; W represents a divalent organic group; X represents a direct bond or a divalent organic group; l represents the number of the R9 moieties, the number being an integer of 0 to 4; m represents the number of the R10 moieties, the number being an integer of 0 to 4; in cases where there are a plurality of R9 moieties and a plurality of R10 moieties, the moieties may be the same as or different from each other, respectively; and n represents an integer of 1 or more.) (In formula (2), R11 represents an optionally substituted divalent organic group.)

Description

[Technical Field]

[0001] This invention relates to alkali-soluble resins and alkali-soluble resin compositions. More specifically, this invention relates to alkali-soluble resins, alkali-soluble resin compositions, and methods for producing the same, which can provide cured products with excellent heat-resistant coloring properties and a high refractive index. [Background technology]

[0002] Regarding photosensitive resin compositions containing alkali-soluble resins, various applications are being considered for various optical components and electrical / electronic equipment, such as color filters used in liquid crystal display devices and solid-state image sensors, inks, printing plates, printed circuit boards, semiconductor elements, photoresists, organic insulating films, and organic protective films. Resins and resin compositions with excellent properties required for each application are being developed.

[0003] In recent years, there has been a growing trend towards miniaturization, thinning, and energy efficiency in optical components, electrical and electronic equipment, and consequently, higher performance is required for the various components used. To meet these demands, research is being conducted on alkali-soluble resins and photosensitive resin compositions that serve as materials for various components.

[0004] To date, various photosensitive resin compositions containing alkali-soluble resins have been developed to meet diverse requirements. For example, Patent Document 1 describes an image-forming photosensitive resin composition containing an acid-modified vinyl ester obtained by synthesizing from an epoxy compound, a phenol compound, an unsaturated monobasic acid, and a polybasic acid anhydride, using a crystalline epoxy with a melting point of 90°C or higher as at least a portion of the epoxy compound, and a phenol compound having a bisphenol S skeleton as at least a portion of the phenol compound.

[0005] Furthermore, for example, Patent Document 2 discloses an acid-modified vinyl ester synthesized from a difunctional epoxy compound, a difunctional phenol compound, an unsaturated monomer having a functional group that can react with an unsaturated monobasic acid and / or a phenolic hydroxyl group, and a polybasic acid anhydride, and in which at least a part of the difunctional epoxy compound or difunctional phenol compound has a biphenyl skeleton, and an epoxy acrylate, and a photosensitive resin composition for image formation. [Prior art documents] [Patent Documents]

[0006] [Patent Document 1] Japanese Patent Publication No. 2008-250306 [Patent Document 2] Japanese Patent Publication No. 2008-250307 [Overview of the project] [Problems that the invention aims to solve]

[0007] However, while these alkali-soluble resins offer excellent alkali-developability, photocurability, and dimensional stability under temperature changes, and can produce cured products that do not exhibit brittleness, they have the problem of discoloration occurring during heat curing. Furthermore, conventional alkali-soluble resins have low refractive indices, and for optical applications requiring high refractive indices, resins with a high refractive index of around 1.60 are needed, but such demands have not yet been adequately met.

[0008] This invention has been made in view of the above-mentioned circumstances, and aims to provide an alkali-soluble resin, an alkali-soluble resin composition, and a method for efficiently obtaining these, which can provide a cured product with excellent heat resistance and a high refractive index. [Means for solving the problem]

[0009] The present inventors have conducted various studies on alkali-soluble resins and found that by having a specific structure and the content of the ammonium salt compound within a specific range, it is possible to provide a cured product with excellent heat-resistant coloring properties and a high refractive index, thus completing the present invention.

[0010] That is, the present invention is an alkali-soluble resin having a structure represented by the following formula (1), wherein the content of the ammonium salt compound in the alkali-soluble resin is 0.06% by mass or less based on 100% by mass of the alkali-soluble resin.

[0011]

Chemical formula

[0012] (In formula (1), R 1 , R 2 and R 3 each independently represent a hydrogen atom or a hydrocarbon group having 1 to 6 carbon atoms. R 4 represents a direct bond or a divalent organic group. R 5 , R 6 , R 7 [ and R 8 each independently represent a hydrogen atom or Y, and at least one of R 5 to R 8 is Y. The above Y is a group represented by the following formula (2). R 9 and R 10 each independently represent a substituent. W represents a divalent organic group. X represents a direct bond or a divalent organic group. l represents the number of R 9 and is an integer from 0 to 4. m represents the number of R 10 and is an integer from 0 to 4. When there are a plurality of R 9 and R 10 , they may be the same or different. n represents an integer of 1 or more.)

[0013] [

Chemical formula

[0014] The present invention also relates to an alkali-soluble resin composition characterized by comprising the above-mentioned alkali-soluble resin and an acid group-containing epoxy (meth)acrylate.

[0015] The present invention also relates to a method for producing an alkali-soluble resin, the method for producing the alkali-soluble resin comprising: (a-1) a step of reacting a bifunctional epoxy compound having a Cardner color number of less than 12 according to JIS K 0071-2 and a melting point of 90°C or higher with a bisphenol compound; (a-2) a step of reacting the reaction product obtained in step (a-1) with an unsaturated monobasic acid; and (a-3) a step of reacting the reaction product obtained in step (a-2) with a polybasic acid anhydride, wherein the alkali-soluble resin obtained by the above production method is characterized in that the content of the ammonium salt compound is 0.06% by mass or less with respect to 100% by mass of the alkali-soluble resin.

[0016] The present invention also relates to a method for producing an alkali-soluble resin composition, the method for producing the alkali-soluble resin composition comprising: (b-1) reacting a bifunctional epoxy compound having a Cardner color number of less than 12 according to JIS K 0071-2 and a melting point of 90°C or higher with a bisphenol compound; (b-2) adding an epoxy resin to the reaction product obtained in step (b-1); (b-3) reacting an unsaturated monobasic acid with the mixture obtained in step (b-2); and (b-4) reacting a polybasic acid anhydride with the reaction mixture obtained in step (b-3), wherein the alkali-soluble resin composition obtained by the above production method is characterized in that the content of an ammonium salt compound is 0.06% by mass or less with respect to 100% by mass of the alkali-soluble resin.

[0017] The epoxy resin mentioned above is preferably an aromatic epoxy resin.

[0018] The above aromatic epoxy resin is preferably a bisphenol A type epoxy resin. [Effects of the Invention]

[0019] The alkali-soluble resin and alkali-soluble resin composition of the present invention exhibit excellent heat resistance to coloring and can yield cured products with a high refractive index. The alkali-soluble resin and alkali-soluble resin composition of the present invention can be widely applied to various uses such as optical components, electrical and electronic components, and display devices. [Modes for carrying out the invention]

[0020] The present invention will be described in detail below. Furthermore, combinations of two or more of the individual preferred embodiments of the present invention described below are also preferred embodiments of the present invention. Furthermore, in this specification, "(meth)acrylate" means "acrylate and / or methacrylate," and "(meth)acrylic acid" means "acrylic acid and / or methacrylic acid."

[0021] 1. Alkali-soluble resins The alkali-soluble resin of the present invention is an alkali-soluble resin having a structure represented by the following formula (1), characterized in that the content of the ammonium salt compound is 0.06% by mass or less based on 100% by mass of the alkali-soluble resin.

[0022] [ka]

[0023] (In formula (1), R 1 , R 2 and R 3 R represents a hydrogen atom or a hydrocarbon group having 1 to 6 carbon atoms, either identical or different. 4 R represents a directly bonded or divalent organic group. 5 , R 6 , R 7 and R 8These represent, either identical or different, a hydrogen atom or Y, and R 5 ~R 8 At least one of them is Y. The above Y is a group represented by the following formula (2). R 9 and R 10 represents a substituent, either identical or different. W represents a divalent organic group. X represents a directly bonded or divalent organic group. l represents R 9 This represents the number of elements and is an integer between 0 and 4. m is R 10 This represents the number of elements and is an integer between 0 and 4. 9 and R 10 If there are multiple values, they may be the same or different. n represents an integer greater than or equal to 1.

[0024] [ka] (In formula (2), R 11 (This represents a divalent organic group that may have substituents.)

[0025] The alkali-soluble resin of the present invention can yield a cured product with excellent heat-resistant coloring because the ammonium salt compound content is below a predetermined range, resulting in a small nitrogen content that can cause discoloration during heat curing, thus suppressing discoloration during heat curing. Furthermore, the high refractive index of the alkali-soluble resin of the present invention is thought to be due to the presence of a rigid skeleton in the main chain, such as a biphenyl skeleton or a skeleton in which aromatic rings are linked by divalent organic groups, which allows for the formation of a dense cured film through π-π stacking action.

[0026] The alkali-soluble resin of the present invention has a structure represented by the above formula (1). In the above equation (1), R 1 , R 2 and R 3 These represent, either identical or different, a hydrogen atom or a hydrocarbon group having 1 to 6 carbon atoms. Examples of the above-mentioned hydrocarbon groups having 1 to 6 carbon atoms include linear or cyclic hydrocarbon groups having 1 to 6 carbon atoms, but linear hydrocarbon groups having 1 to 6 carbon atoms are preferred, and alkyl groups having 1 to 6 carbon atoms are more preferred. In particular, due to the good reactivity of the unsaturated double bond, R 1 , R 2 and R 3 R is preferably the same or different hydrogen atom or methyl group. 1 , R 2 is a hydrogen atom, and R 3 It is more preferable that the atom is a hydrogen atom or a methyl group.

[0027] In the above equation (1), R 4 This represents a direct bond or a divalent organic group. The above R 4 Examples of divalent organic groups represented by include optionally substituted divalent hydrocarbon groups, -O-, -CO-, -NH-, -S-, -SO-, -SO2-, or combinations thereof. Among these, groups consisting of optionally substituted divalent hydrocarbon groups, -O-, -CO-, or combinations thereof are preferred in terms of superior heat resistance to coloring, and groups consisting of combinations of divalent hydrocarbon groups, -O-, and -CO- are more preferred.

[0028] The above-mentioned divalent hydrocarbon group may be a saturated hydrocarbon group or an unsaturated hydrocarbon group, but a saturated hydrocarbon group is preferred because it has superior heat resistance to discoloration. Furthermore, the divalent hydrocarbon group may be in the form of a chain (linear, branched, or cyclic), but a chain is preferred in terms of superior dimensional stability.

[0029] Examples of the above-mentioned divalent hydrocarbon groups include divalent aliphatic hydrocarbon groups, alicyclic hydrocarbon groups, and aromatic hydrocarbon groups. Examples of divalent aliphatic hydrocarbon groups include alkylene groups such as methylene, ethylene, propylene, isopropylene, butylene, isobutylene, t-butylene, pentylene, neopentylene, hexamethylene, heptylene, octylene, 2-ethylhexylene, nonylene, decylene, undecylene, and dodecylene, as well as alkenylene groups such as vinylene, propenylene, isopropenylene, butenylene, butadienylene, pentenylene, hexenylene, and heptenylene.

[0030] Examples of divalent alicyclic hydrocarbon groups include cycloalkylene groups such as cyclopropylene, cyclobutylene, cyclopentylene, cyclohexylene, norbornylene, and adamantylene, as well as cycloalkylidene groups such as cyclopentylidene and cyclohexylidene.

[0031] Examples of divalent aromatic hydrocarbon groups include arylene groups such as phenylene, torylene, and naphthylene, as well as cinnamyridene and biphenylene groups.

[0032] In particular, the above-mentioned divalent hydrocarbon group is preferably a divalent aliphatic hydrocarbon group or a divalent alicyclic hydrocarbon group, more preferably a divalent aliphatic hydrocarbon group, and even more preferably an alkylene group.

[0033] The number of carbon atoms in the above-mentioned divalent hydrocarbon group is preferably 1 to 7, more preferably 1 to 5, and even more preferably 1 to 3, in terms of excellent dimensional stability.

[0034] The substituents that the above-mentioned divalent hydrocarbon group may have include carboxyl groups, hydroxyl groups, alkoxy groups, halogen atoms, and hydrocarbon groups having 1 to 7 carbon atoms.

[0035] The above R 4 A preferred specific example of a divalent organic group represented by -R a -COO-, -R a -OCO-R a -COO-, -R a -COO-R a -COO- (both R a represents a divalent organic group which may have substituents, either identical or different. ) and -R a -COO-(R a ) represents a divalent hydrocarbon group. ) is more preferable. The above R 4 Direct bonding is most preferable.

[0036] In the above equation (1), R 5 , R 6 , R 7 and R 8 These represent, either identical or different, a hydrogen atom or Y, and R 5 , R 6 , R 7 and R 8 At least one of them is Y. The above Y is the group represented by formula (2) above.

[0037] In equation (2) above, R 11 R is a divalent organic group which may have substituents. 11 Examples of divalent organic groups represented by the above include groups similar to the divalent organic groups described above. Among these, divalent hydrocarbon groups are preferred, divalent aliphatic hydrocarbon groups, alicyclic hydrocarbon groups, or aromatic hydrocarbon groups are more preferred, and divalent aliphatic hydrocarbon groups or alicyclic hydrocarbon groups are even more preferred.

[0038] The above R 11 The number of carbon atoms in the divalent organic group represented is preferably 1 to 20, more preferably 1 to 10, even more preferably 1 to 8, even more preferably 2 to 6, particularly preferably 2 or 6, and most preferably 6.

[0039] The above R 11 Examples of substituents that the divalent organic group represented by may have include carboxyl groups and hydrocarbon groups having 1 to 20 carbon atoms. Among these, carboxyl groups are preferred because they can improve alkali solubility.

[0040] In the above formula (1), W represents a divalent organic group. Examples of divalent organic groups represented by W include the divalent organic groups mentioned above, but among them, divalent hydrocarbon groups which may have substituents, -O-, or combinations thereof are preferred. The above-mentioned divalent hydrocarbon groups include the divalent hydrocarbon groups described above, with divalent aromatic hydrocarbon groups being preferred, and biphenylene groups being more preferred. Examples of substituents that the above-mentioned divalent hydrocarbon group may have include hydrocarbon groups having 1 to 10 carbon atoms, halogen atoms, cyano groups, and the like.

[0041] A preferred specific example of the divalent organic group represented by W above is the group represented by the following formula (3).

[0042] [ka]

[0043] (In the formula, R 12 and R 13 R represents a divalent hydrocarbon group, either identical or different. 14 and R 15 represents a substituent, which is either the same or different. a is R 14 b represents the number of elements and is an integer between 0 and 4. 15 (This represents the number of elements, and is an integer between 0 and 4.)

[0044] The above R 12 and R 13 The divalent hydrocarbon group represented by the above is preferred, among which a divalent aliphatic hydrocarbon group is preferred, a divalent saturated aliphatic hydrocarbon group having 1 to 3 carbon atoms is more preferred, and a methylene group is even more preferred.

[0045] The above R 14 and R 15 The substituent represented by is not particularly limited and can be any monovalent substituent, but hydrocarbon groups are preferred, hydrocarbon groups having 1 to 10 carbon atoms are more preferred, aliphatic hydrocarbon groups having 1 to 5 carbon atoms are even more preferred, saturated aliphatic hydrocarbon groups having 1 to 5 carbon atoms are even more preferred, and methyl groups are most preferred.

[0046] a is an integer between 0 and 4, preferably between 0 and 2, and more preferably 2. b is an integer between 0 and 4, preferably between 0 and 2, and more preferably 2.

[0047] In formula (1) above, X represents a direct bond or a divalent organic group. Examples of divalent organic groups represented by X include the divalent organic groups mentioned above, but among them, divalent hydrocarbon groups which may have substituents, -SO2-, or combinations thereof are preferred, divalent hydrocarbon groups which may have substituents and have 1 to 20 carbon atoms, or -SO2- are more preferred, divalent aliphatic hydrocarbon groups which have 1 to 10 carbon atoms, or -SO2- are even more preferred, divalent saturated aliphatic hydrocarbon groups which have 1 to 5 carbon atoms, or -SO2- are even more preferred, and -SO2- is the most preferred. The presence of an S atom can improve the refractive index.

[0048] The substituents mentioned above include those listed above, but halogen atoms such as fluorine atoms, chlorine atoms, and iodine atoms are particularly preferred. Furthermore, if the divalent hydrocarbon group has a ring structure, halogen atoms and alkyl groups are preferred as substituents.

[0049] In particular, X is preferably directly bonded, an alkylene group, or -SO2-, more preferably directly bonded, an alkylene group having 1 to 10 carbon atoms, or -SO2-, and even more preferably directly bonded or -SO2-. Furthermore, if n is 2 or greater, the multiple X values ​​may be the same or different.

[0050] In the above equation (1), R 9 and R 10 These represent substituents that are identical or different. The above R 9 or R 10 Examples of substituents represented by include any monovalent substituent, such as a carboxyl group, a hydroxyl group, an amino group, a hydrocarbon group having 1 to 20 carbon atoms, a halogen atom, or a group consisting of a combination thereof. Regardless of the substituent, the stacking interaction of the aromatic ring allows the alkali-soluble resin to form a dense cured product, resulting in a cured product with a high refractive index.

[0051] l is a substituent R 9 This represents the number of elements, and is an integer from 0 to 4, preferably from 0 to 2, more preferably 0 or 2, and even more preferably 0. m is substituent R 10 This represents the number of elements, and is an integer from 0 to 4, preferably from 0 to 2, more preferably 0 or 2, and even more preferably 0. R 9 and R 10 If there are multiple instances, they may be the same or different. n represents an integer greater than or equal to 1.

[0052] The alkali-soluble resin described above has an ammonium salt compound content of 0.06% by mass or less relative to 100% by mass of the alkali-soluble resin. When the ammonium salt compound content in the alkali-soluble resin is 0.06% by mass or less, a cured product with excellent heat-resistant coloring properties can be obtained. Conventionally, when synthesizing the alkali-soluble resin described above, ammonium salt compounds such as benzyltriethylammonium chloride were used as catalysts. The present invention has found that such ammonium salt compounds cause deterioration of the heat-resistant coloring properties of alkali-soluble resins, and has found that by reducing the amount of ammonium salt compounds contained in the alkali-soluble resin to a predetermined level or less, the heat-resistant coloring properties of the alkali-soluble resin can be dramatically improved. The content of the above ammonium salt compound is more preferably 0.03% by mass or less, even more preferably 0.01% by mass or less, and most preferably 0% by mass, based on 100% by mass of the alkali-soluble resin, in terms of superior heat resistance to coloring.

[0053] Examples of the ammonium salt compounds mentioned above include benzyltriethylammonium chloride, benzyltrimethylammonium chloride, tetra-n-butylammonium chloride, tetraethylammonium chloride, tetramethylammonium chloride, or quaternary ammonium salts such as their bromides.

[0054] The content of the above ammonium salt compound can be determined by quantitative analysis of ammonium ions by ion chromatography or by mass spectrometry. Alternatively, the mass of the ammonium salt compound used can be calculated by dividing it by the total mass of the monomer components constituting the alkali-soluble resin having the structure represented by formula (1) above.

[0055] The acid value of the alkali-soluble resin described above is preferably 30 to 150 mg KOH / g, more preferably 40 to 135 mg KOH / g, even more preferably 50 to 120 mg KOH / g, and most preferably 70 to 100 mg KOH / g. The above acid value is obtained by a neutralization titration method using potassium hydroxide (KOH) solution and represents the acid value per gram of resin solids.

[0056] The weight-average molecular weight of the alkali-soluble resin is preferably 400 to 30000. More preferably, the weight-average molecular weight of the alkali-soluble resin is 1000 to 10000, even more preferably 2000 to 5000, and even more preferably 2500 to 3500, as this results in a faster development speed. The above weight-average molecular weight is a value obtained by gel permeation chromatography (GPC). Specifically, it can be measured using polystyrene as the standard substance, tetrahydrofuran as the eluent, and GPC using an HLC-8220GPC (manufactured by Tosoh Corporation) and a TSKgel SuperHZM-M column (manufactured by Tosoh Corporation).

[0057] The double bond equivalent of the alkali-soluble resin is preferably 500 to 2000 g / equivalent. More preferably, the double bond equivalent is 530 to 1500 g / equivalent, even more preferably 550 to 1100 g / equivalent, and even more preferably 570 to 900 g / equivalent, in that curability can be improved. Here, "double bond" refers to a double bond that exhibits radical polymerization. That is, a double bond like the (meth)acryloyl group. Double bonds that are formed, for example, by adding tetrahydrophthalic anhydride to an OH group are not reactive and are therefore not included in the calculation of double bond equivalents.

[0058] The double bond equivalent mentioned above is the mass of solids in the polymer solution per mole of double bonds in the resin. The mass of solids in the polymer solution is the mass of monomeric components constituting the resin. The double bond equivalent can be determined by dividing the mass (g) of resin solids in the polymer solution by the amount (mol) of double bonds in the resin. It can also be measured using various analytical methods such as titration, elemental analysis, NMR, IR, or differential scanning calorimeter. For example, it may be calculated by measuring the number of ethylenic double bonds contained in 1g of resin in accordance with the iodine value test method described in JIS K 0070:1992.

[0059] 2. Method for producing alkali-soluble resin The method for producing the alkali-soluble resin described above is not particularly limited as long as it is a method that can produce an alkali-soluble resin having the structure described above, and can be appropriately selected from known polymerization methods. In particular, in terms of efficiently obtaining the alkali-soluble resin, the method for producing the alkali-soluble resin described above preferably includes the steps of: reacting a bifunctional epoxy compound having a Gardner color number of less than 12 according to JIS K 0071-2 and a melting point of 90°C or higher with a bisphenol compound (a-1); reacting the reactant obtained in step (a-1) with an unsaturated monobasic acid (a-2); and reacting the reactant obtained in step (a-2) with a polybasic acid anhydride (a-3). Each step will be described below.

[0060] Process (a-1) In the above manufacturing method, first, a bifunctional epoxy compound having a Gardner color number of less than 12 according to JIS K 0071-2 and a melting point of 90°C or higher is reacted with a bisphenol compound. In the reaction of step (a-1) described above, the epoxy group of the difunctional epoxy compound reacts with the phenolic hydroxyl group of the bisphenol compound to produce a compound in which the difunctional epoxy compound and the bisphenol compound are linked.

[0061] The bifunctional epoxy compound used in this reaction step preferably has a Gardner color number of less than 12 according to JIS K 0071-2 and a melting point of 90°C or higher. When the Gardner color number of the bifunctional epoxy compound is less than 12, the resulting alkali-soluble resin can provide a cured product with excellent heat resistance, flexibility, and refractive index. This is thought to be because using a predetermined Gardner raw material reduces oxidative degradation of the product by oxygen. The Gardner color number of the above-mentioned difunctional epoxy compound is more preferably less than 11, even more preferably less than 10, and most preferably less than 8, in that the heat resistance of the resulting alkali-soluble resin can be further improved. The melting point of the above-mentioned bifunctional epoxy compound is more preferably 95°C or higher, and even more preferably 100°C or higher, in terms of excellent heat resistance.

[0062] The above-mentioned bifunctional epoxy compound preferably has an epoxy equivalent weight of 150 to 300 g / equivalent, more preferably 160 to 250 g / equivalent, and even more preferably 170 to 200 g / equivalent. The epoxy equivalents mentioned above can be determined by a method in accordance with JIS K7236:2001, and specifically by the method described in the examples below.

[0063] The above-mentioned difunctional epoxy compound is not particularly limited as long as it is a compound having two epoxy groups that satisfies the Gardner color number and melting point described above, but preferably, a compound represented by the following formula (4) is mentioned.

[0064] [ka] (In the formula, W represents a divalent organic group.)

[0065] In formula (4) above, it is preferable that W is the same divalent organic group as W in formula (1) above.

[0066] The compound represented by formula (4) above may have a molecular weight distribution, and the weight-average molecular weight of the compound represented by formula (4) above is preferably 80 to 5000, more preferably 100 to 1000, and even more preferably 150 to 500. The weight-average molecular weight mentioned above is a value obtained by measurement using gel permeation chromatography (GPC).

[0067] For the synthesis of the compound represented by formula (4) above, known methods can be used, such as the method described in Japanese Patent Publication No. 2016-108562. Generally, it is synthesized by adding epichlorohydrin to a biphenol compound.

[0068] The above-mentioned bifunctional epoxy compounds can also be obtained commercially, for example, YL6121H, YX4000 (manufactured by Mitsubishi Chemical Corporation), and YDC-1312, YSLV-120TE (manufactured by Nippon Steel Chemical & Material Corporation). The above-mentioned difunctional epoxy compounds may be used individually or in combination of two or more.

[0069] The above-mentioned bisphenol compound is not particularly limited as long as it is a compound having two phenolic hydroxyl groups, but preferably, a compound represented by the following formula (5) is mentioned.

[0070] [Chemical formula]

[0071] (In the formula, X represents a direct bond or a divalent organic group. R 9 and R 10 represent substituents, which may be the same or different. l represents the number of R 9 and is an integer from 0 to 4. m represents the number of R 10 and is an integer from 0 to 4. When there are multiple R 9 and R 10 , they may be the same or different respectively.)

[0072] In the above formula (5), X, R 9 , and R 10 are preferably the same as X, R 9 , and R 10 in the above formula (1) respectively. Also, l and m in the above (5) are preferably the same as l and m in the above formula (1) respectively.

[0073] Specific examples of the above bisphenol compound include, for example, bisphenol A, bisphenol AP, bisphenol AF, bisphenol B, bisphenol BP, bisphenol C, bisphenol E, bisphenol F, bisphenol G, bisphenol M, bisphenol S, bisphenol TMC, bisphenol P, bisphenol PH, bisphenol Z, etc. Among them, bisphenol A, bisphenol F, and bisphenol S are preferred because they are relatively easy to obtain, and bisphenol S is more preferred. The above bisphenol compound may be used alone or in combination of two or more.

[0074] The reaction between the above bifunctional epoxy compound and the above bisphenol compound can be carried out by mixing these components in a solvent.

[0075] The mixing ratio of the above-mentioned difunctional epoxy compound and the above-mentioned bisphenol compound is preferably 10 to 60 parts by mass of the above-mentioned bisphenol compound per 100 parts by mass of the above-mentioned difunctional epoxy compound, more preferably 15 to 55 parts by mass, even more preferably 20 to 50 parts by mass, and most preferably 30 to 40 parts by mass of the above-mentioned bisphenol compound.

[0076] Examples of the above solvents include ethers such as tetrahydrofuran, dioxane, ethylene glycol dimethyl ether, and diethylene glycol dimethyl ether; ketones such as acetone and methyl ethyl ketone; esters such as ethyl acetate, butyl acetate, cellosolve acetate, carbitol acetate, (di)propylene glycol monomethyl ether acetate, and 3-methoxybutyl acetate; aromatic hydrocarbons such as toluene, xylene, and ethylbenzene; chloroform; dimethyl sulfoxide; and dimethyl carbonate. Among these, esters are preferred, and carbitol acetate and (di)propylene glycol monomethyl ether acetate are more preferred. These solvents may be used individually or in combination of two or more.

[0077] In the above reaction, it is preferable to use a reaction catalyst. Preferred reaction catalysts include compounds other than the ammonium salt compounds mentioned above, such as tertiary amines like trimethylamine, triethylamine, tributylamine, tripropylamine, and trihexylamine; tertiary phosphines like triphenylphosphine; quaternary phosphonium salts like benzyltriphenylphosphonium bromide; and chelate compounds. Among these, tertiary phosphines such as triphenylphosphine are preferred as reaction catalysts due to their excellent activity. Furthermore, using tertiary phosphines can improve the voltage retention of the resulting cured product. The above reaction catalysts may be used individually or in combination of two or more types. Since metal compounds are electrically conductive, they can degrade the electrical properties of the composition, and therefore, it is undesirable to use catalysts containing metal atoms.

[0078] The amount of the above reaction catalyst is not particularly limited, but is preferably 0.05 to 5 parts by mass, more preferably 0.07 to 1 part by mass, even more preferably 0.08 to 0.8 parts by mass, and most preferably 0.1 to 0.6 parts by mass, per 100 parts by mass of the above bifunctional epoxy compound.

[0079] The reaction temperature for the above reaction is not particularly limited, but is preferably 80 to 150°C, more preferably 85 to 145°C, and even more preferably 90 to 140°C. The reaction time is not particularly limited, but is preferably 2 to 10 hours, more preferably 3 to 9 hours, and even more preferably 4 to 8 hours.

[0080] The above reaction may be carried out in an atmospheric environment or in an inert gas atmosphere such as nitrogen or argon. Of these, an inert gas atmosphere is preferred in that it suppresses catalyst deactivation.

[0081] Process (a-2) In step (a-2), an unsaturated monobasic acid is reacted with the reactant obtained in step (a-1). In this reaction, the unsaturated monobasic acid reacts with the epoxy group of the difunctional epoxy compound, introducing a radically polymerizable unsaturated bond to the end of the reactant.

[0082] Examples of the above-mentioned unsaturated monobasic acids include monobasic acids having one carboxyl group and one or more radically polymerizable unsaturated bonds. Specific examples include acrylic acid, methacrylic acid, crotonic acid, cinnamic acid, β-acryloxypropionic acid, reaction products of hydroxyalkyl (meth)acrylates having one hydroxyl group and one (meth)acryloyl group with dibasic acid anhydrides, reaction products of polyfunctional (meth)acrylates having one hydroxyl group and two or more (meth)acryloyl groups with dibasic acid anhydrides, and caprolactone-modified products of these monobasic acids. In particular, due to the good reactivity of the unsaturated double bond, the above unsaturated monobasic acid is preferably a compound having a (meth)acryloyl group, such as acrylic acid or methacrylic acid, more preferably acrylic acid or methacrylic acid, and most preferably methacrylic acid. The above unsaturated monobasic acids may be used individually or in combination of two or more.

[0083] The amount of unsaturated monobasic acid added is preferably such that the acid group content of the unsaturated monobasic acid is 0.6 to 1.4 moles per mole of epoxy group in the reactant obtained in step (a-1), more preferably 0.7 to 1.3 moles, even more preferably 0.8 to 1.2 moles, and even more preferably 1.0 to 1.1 moles. If epoxy groups remain in the resin, the storage stability may deteriorate.

[0084] The above unsaturated monobasic acid may be added all at once, in installments, or sequentially, but sequential addition in installments is preferred because it can suppress side reactions.

[0085] In the reaction of step (a-2) described above, it is preferable to use an addition catalyst. Examples of the addition catalysts mentioned above include those used in step (a-1) above, such as tertiary amines such as trimethylamine, triethylamine, tributylamine, tripropylamine, and trihexylamine; tertiary phosphines such as triphenylphosphine; quaternary phosphonium salts such as benzyltriphenylphosphonium bromide; and chelate compounds. These may be used individually or in combination of two or more. Among these, tertiary phosphines such as triphenylphosphine are preferred as the addition catalyst. Furthermore, since metal compounds are electrically conductive, they may degrade the electrical properties of the composition, and therefore, it is undesirable to use catalysts containing metal atoms.

[0086] The amount of the above addition catalyst is not particularly limited, but is preferably 0.05 to 5 parts by mass, more preferably 0.1 to 4 parts by mass, even more preferably 0.2 to 3 parts by mass, and most preferably 0.5 to 2.5 parts by mass, per 100 parts by mass of the above bifunctional epoxy compound. Note that the amount of catalyst here refers to the total amount including the reaction catalyst if a reaction catalyst is used in step (a-1) above.

[0087] In the reactions of steps (a-1) and (a-2) described above, if the same catalyst is used as both the reaction catalyst and the addition catalyst, the total amount of catalyst used in the manufacturing process may be added all at once in step (a-1). However, it is preferable to add the catalyst in two separate amounts in steps (a-1) and (a-2). Adding the catalyst in two separate amounts helps to suppress the decrease in catalytic activity. In particular, when using tertiary phosphine as a catalyst, it is oxidized in the presence of oxygen, reducing its catalytic activity. Therefore, it is preferable to add the catalyst in two separate amounts to compensate for the deactivation. If a large amount of phosphine is used initially in anticipation of the deactivation, the oxide of the phosphine will have a yellowish tint, which may increase the discoloration of the resulting resin. When the catalyst is added in two separate steps (a-1) and (a-2) as described above, the catalyst addition ratio in each step is preferably 5 / 95 to 95 / 5, more preferably 10 / 90 to 90 / 10, even more preferably 15 / 85 to 85 / 15, and even more preferably 20 / 80 to 80 / 20, as catalyst addition amount in step (a-1) / catalyst addition amount in step (a-2).

[0088] Furthermore, in each of the above steps (a-1) and (a-2), the catalyst may be added all at once, in divided portions, or sequentially in small amounts. However, in order to suppress a decrease in catalytic activity, it is preferable to add the catalyst in divided portions or sequentially in small amounts.

[0089] Furthermore, a polymerization inhibitor may be used in the reaction of step (a-2) described above. By using a polymerization inhibitor, gelation can be suppressed. Polymerization inhibitors are not particularly limited and known ones can be used, for example, benzoquinone, hydroquinones (e.g., hydroquinone, methylhydroquinone, hydroquinone monomethyl ether, p-tert-butylhydroquinone, p-benzoquinone, etc.), phenols (e.g., 2,6-di-t-butyl-4-methylphenol, 6-t-butyl-2,4-dimethylphenol, 2,2'-methylenebis(4-methyl-6-t-butylphenol), etc.), catechols (e.g., p-tert-butylcatechol, etc.), amines (e.g., N,N-diethylhydroxylamine, etc.), 1,1-diphenyl-2-picrylhydrazyl, tri-p-nitrophenylmethyl, phenothiazine, piperidine 1-oxyls (e.g., 2,2,6,6-tetramethylpiperidine 1-oxyl, etc.), oxygen, etc. Among these, hydroquinones are preferred because they further improve the heat-resistant coloring properties of the alkali-soluble resin, and hydroquinone is even more preferred because it improves the flexibility of the cured product of the alkali-soluble resin. The polymerization inhibitors mentioned above may be used individually or in combination of two or more.

[0090] As for the reaction conditions in step (a-2) above, the reaction temperature is not particularly limited, but is preferably 80 to 140°C, more preferably 85 to 135°C, and even more preferably 90 to 130°C. The reaction time is not particularly limited, but is preferably 5 to 30 hours, more preferably 6 to 25 hours, and even more preferably 7 to 20 hours.

[0091] Process (a-3) In step (a-3) above, the reactant obtained in step (a-2) above is reacted with a polybasic acid anhydride. In the reaction of step (a-3) above, the polybasic acid anhydride is added to the hydroxyl group of the reactant obtained in step (a-2) above, and the acidic group of the carboxyl group is introduced into the reactant.

[0092] Examples of the polybasic acid anhydrides mentioned above include phthalic anhydride, succinic anhydride, octenyl succinic anhydride, pentadodecenyl succinic anhydride, maleic anhydride, tetrahydrophthalic anhydride, hexahydrophthalic anhydride, methyltetrahydrophthalic anhydride, 3,6-endomethylenetetrahydrophthalic anhydride, methylendomethylenetetrahydrophthalic anhydride, tetrabromophthalic anhydride, dibasic acid anhydrides such as the reaction product of 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide with itaconic anhydride or maleic anhydride; trimellitic anhydride; aliphatic or aromatic tetrabasic acid dianhydrides such as biphenyltetracarboxylic dianhydride, naphthalenetetracarboxylic dianhydride, diphenylethertetracarboxylic dianhydride, butanetetracarboxylic dianhydride, cyclopentanetetracarboxylic dianhydride, pyromellitic anhydride, and benzophenonetetracarboxylic dianhydride. Among these, tetrahydrophthalic anhydride is preferred. The above polybasic acid anhydrides may be used individually or in combination of two or more types.

[0093] The above polybasic acid anhydride is preferably added in an amount of 0.1 to 1.1 moles, more preferably 0.15 to 1 mole, even more preferably 0.2 to 0.9 moles, and most preferably 0.4 to 0.7 moles, relative to 1 mole of hydroxyl groups in the reactant obtained in step (a-2) above.

[0094] A catalyst may be used in the reaction of step (a-3) above, if necessary. Examples of catalysts that can be used include those similar to those described above.

[0095] As for the reaction conditions in step (a-3) above, the reaction temperature is not particularly limited, but is preferably 60 to 150°C, more preferably 70 to 135°C, and even more preferably 80 to 120°C. The reaction time is not particularly limited, but is preferably 1 to 10 hours, more preferably 2 to 9 hours, and even more preferably 3 to 8 hours.

[0096] The above-described method for producing alkali-soluble resin may include other steps in addition to the reaction step described above. Examples of these other steps include a maturation step, a neutralization step, a dilution step, a drying step, a concentration step, and a purification step. These steps can be carried out by known methods.

[0097] The alkali-soluble resin obtained by the above method for producing alkali-soluble resin preferably has an ammonium salt compound content of 0.06% by mass or less, more preferably 0.03% by mass or less, even more preferably 0.01% by mass or less, and most preferably 0% by mass, based on 100% by mass of the alkali-soluble resin.

[0098] The above manufacturing method allows for the efficient production of an alkali-soluble resin that exhibits excellent heat resistance and colorability, and can yield a cured product with a high refractive index. A method for producing an alkali-soluble resin, comprising the steps of (a-1) reacting a bifunctional epoxy compound having a Cardner color number of less than 12 according to JIS K 0071-2 and a melting point of 90°C or higher with a bisphenol compound, (a-2) reacting the reactant obtained in step (a-1) with an unsaturated monobasic acid, and (a-3) reacting the reactant obtained in step (a-2) with a polybasic acid anhydride, and wherein the alkali-soluble resin obtained by the above production method is characterized in that the content of the ammonium salt compound is 0.06% by mass or less per 100% by mass of the alkali-soluble resin, is also one of the present inventions.

[0099] 3. Alkali-soluble resin composition The present invention also relates to an alkali-soluble resin composition characterized by comprising the above-mentioned alkali-soluble resin and an acid group-containing epoxy (meth)acrylate. The alkali-soluble resin composition of the present invention contains the above-mentioned alkali-soluble resin, and therefore exhibits excellent heat-resistant coloring properties and can yield a cured product with a high refractive index. Furthermore, by including an acid group-containing epoxy (meth)acrylate, it is possible to improve developability and curability, and impart properties derived from the acid group-containing epoxy (meth)acrylate skeleton.

[0100] The above-mentioned acid group-containing epoxy (meth)acrylate is an esterified product of epoxy resin and (meth)acrylic acid, and is a compound containing an acid group. The epoxy resin described above is preferably bifunctional, more preferably 2 to 20 functional, even more preferably 2 to 10 functional, and most preferably bifunctional, in terms of improving the crosslinking density of the cured product.

[0101] The epoxy resin mentioned above is not particularly limited as long as it is a compound having an epoxy group, and examples include known aliphatic epoxy resins and aromatic epoxy resins. Among these, aromatic epoxy resins are preferred because they can form a dense cured film and improve electrical insulation. The epoxy resin may be one or more types.

[0102] Examples of the aromatic epoxy resins mentioned above include bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol S type epoxy resin, biphenyl type epoxy resin, tetramethylbiphenyl type epoxy resin, phenol novolac type epoxy resin, cresol novolac type epoxy resin, bisphenol A novolac type epoxy resin, triphenylmethane type epoxy resin, tetraphenylethane type epoxy resin, dicyclopentadiene-phenol addition reaction type epoxy resin, phenol aralkyl type epoxy resin, naphthol novolac type epoxy resin, naphthol aralkyl type epoxy resin, naphthol-phenol copolymer novolac type epoxy resin, naphthol-cresol copolymer novolac type epoxy resin, aromatic hydrocarbon formaldehyde resin modified phenol resin type epoxy resin, and biphenyl novolac type epoxy resin. Among these, bisphenol A type epoxy resin and cresol novolac type epoxy resin are preferred in terms of good electrical properties, and bisphenol A type epoxy resin is more preferred in terms of superior heat resistance to coloring and the ability to obtain cured products with a higher refractive index. These epoxy resins may have substituents such as halogen atoms, alkyl groups, alkylene groups, cycloalkylene groups, arylene groups, and cyano groups.

[0103] The epoxy resin may have a molecular weight distribution, and the weight-average molecular weight of the epoxy resin is preferably 100 to 30000, more preferably 150 to 2000, and even more preferably 300 to 1000. The weight-average molecular weight mentioned above is a value obtained by measurement using gel permeation chromatography (GPC).

[0104] The epoxy equivalent of the epoxy resin described above is preferably 150 to 5000 g / equivalent, more preferably 170 to 1000 g / equivalent, and even more preferably 200 to 300 g / equivalent, in terms of the excellent properties of the resulting cured product. The epoxy equivalents mentioned above can be determined by a method in accordance with JIS K7236:2001, and specifically by the method described in the examples below.

[0105] Examples of the acid groups mentioned above include carboxyl groups, phenolic hydroxyl groups, carboxylic acid anhydride groups, phosphoric acid groups, and sulfonic acid groups. Among these, carboxyl groups are preferred because they have good developability.

[0106] The above-mentioned acid group-containing epoxy (meth)acrylate may be an acid group-containing epoxy (meth)acrylate obtained by reacting an epoxy (meth)acrylate obtained by reacting the epoxy resin with (meth)acrylic acid with a polybasic acid anhydride, or an acid group-containing epoxy (meth)acrylate obtained by reacting the epoxy resin having the above-mentioned acid group with (meth)acrylic acid. However, in terms of superior efficiency in producing alkali-soluble resin compositions, it is preferable that the acid group-containing epoxy (meth)acrylate obtained by reacting an epoxy (meth)acrylate obtained by reacting the epoxy resin with (meth)acrylic acid with a polybasic acid anhydride be used.

[0107] By reacting the above epoxy resin with (meth)acrylic acid, the epoxy group opens its ring to generate a hydroxyl group, and a structure is formed in which a polybasic acid anhydride is attached to that hydroxyl group. Examples of the polybasic acid anhydrides mentioned above include those similar to those described above.

[0108] The acid value of the above acid group-containing epoxy (meth)acrylate is preferably 20 to 160 mg KOH / g, more preferably 30 to 150 mg KOH / g, even more preferably 40 to 140 mg KOH / g, and most preferably 70 to 100 mg KOH / g.

[0109] In the alkali-soluble resin composition described above, the content of the alkali-soluble resin is preferably 1 to 99% by mass, more preferably 5 to 95% by mass, even more preferably 10 to 90% by mass, and most preferably 20 to 40% by mass, based on 100% by mass of the total solid content of the alkali-soluble resin composition. In this invention, the total solid content refers to the total amount of components that form the cured product (excluding solvents and curing catalysts that volatilize during the formation of the cured product).

[0110] In the alkali-soluble resin composition described above, the content of the acid group-containing epoxy (meth)acrylate is preferably 0.1 to 90% by mass, more preferably 1 to 85% by mass, even more preferably 5 to 80% by mass, and most preferably 60 to 80% by mass, based on 100% by mass of the total solid content of the alkali-soluble resin composition.

[0111] In the alkali-soluble resin composition described above, the content ratio of the alkali-soluble resin to the acid group-containing epoxy (meth)acrylate is preferably 0.1 to 500 parts by mass, more preferably 10 to 400 parts by mass, and even more preferably 100 to 300 parts by mass of the acid group-containing epoxy (meth)acrylate per 100 parts by mass of the alkali-soluble resin.

[0112] The acid value of the above alkali-soluble resin composition is preferably 20 to 150 mg KOH / g, more preferably 30 to 135 mg KOH / g, even more preferably 40 to 120 mg KOH / g, and most preferably 70 to 100 mg KOH / g, in terms of good developability. The acid value of the above alkali-soluble resin composition can be determined by the same method as the double bond equivalent of the alkali-soluble resin described above.

[0113] The double bond equivalent of the above alkali-soluble resin composition is preferably 300 to 2000 g / equivalent. More preferably, the double bond equivalent is 330 to 1500 g / equivalent, even more preferably 360 to 1100 g / equivalent, and even more preferably 400 to 900 g / equivalent, in that curability can be improved. The double bond equivalent of the alkali-soluble resin composition described above can be determined by the same method as that used to determine the double bond equivalent of the alkali-soluble resin described above.

[0114] The alkali-soluble resin composition described above may optionally contain other components besides those mentioned above. Examples of these other components include solvents; colorants (pigments, dyes); dispersants; heat resistance improvers; leveling agents; developing aids; inorganic fine particles such as silica fine particles; coupling agents such as silane, aluminum, and titanium; thermosetting resins such as fillers, phenolic resins, and polyvinylphenols; polymerizable compounds; curing aids such as polyfunctional thiol compounds; plasticizers; polymerization initiators; polymerization inhibitors; ultraviolet absorbers; antioxidants; matting agents; defoamers; antistatic agents; slip agents; surface modifiers; thixotropes; thixotrope aids; quinone diazide compounds; polyvalent phenolic compounds; cationic polymerizable compounds; and thermoacid generators. These may be used individually or in combination of two or more. These other components can be appropriately selected from known components, and their amounts can also be appropriately set.

[0115] In particular, the alkali-soluble resin composition preferably further contains at least one selected from the group consisting of polymerizable compounds, polymerization initiators, and inorganic fine particles.

[0116] (polymerizable compound) The polymerizable compounds described above are low-molecular-weight compounds having polymerizable unsaturated bonds (also called polymerizable unsaturated groups) that can be polymerized by irradiation with free radicals, electromagnetic waves (e.g., infrared rays, ultraviolet rays, X-rays, etc.), electron beams, or other active energy rays. Examples include monofunctional compounds having one polymerizable unsaturated group in the molecule and polyfunctional compounds having two or more polymerizable unsaturated groups.

[0117] Examples of the monofunctional compounds mentioned above include N-substituted maleimide monomers; (meth)acrylic acid esters; (meth)acrylamides; unsaturated monocarboxylic acids; unsaturated polycarboxylic acids; unsaturated monocarboxylic acids in which the chain between the unsaturated group and the carboxyl group is extended; unsaturated acid anhydrides; aromatic vinyls; conjugated dienes; vinyl esters; vinyl ethers; N-vinyl compounds; unsaturated isocyanates; and so on. Monomers having active methylene groups or active methine groups can also be used.

[0118] Examples of the polyfunctional compounds mentioned above include the following compounds. Difunctional (meth)acrylate compounds such as ethylene glycol di(meth)acrylate, diethylene glycol di(meth)acrylate, polyethylene glycol di(meth)acrylate, propylene glycol di(meth)acrylate, butylene glycol di(meth)acrylate, hexanediol di(meth)acrylate, cyclohexanedimethanol di(meth)acrylate, bisphenol A alkylene oxide di(meth)acrylate, and bisphenol F alkylene oxide di(meth)acrylate;

[0119] Trimethylolpropane tri(meth)acrylate, ditrimethylolpropane tetra(meth)acrylate, glycerin tri(meth)acrylate, pentaerythritol tri(meth)acrylate, pentaerythritol tetra(meth)acrylate, dipentaerythritol penta(meth)acrylate, dipentaerythritol hexa(meth)acrylate, tripentaerythritol hepta(meth)acrylate, tripentaerythritol octa(meth)acrylate, ethylene oxide-added trimethylolpropane tri(meth)acrylate, ethylene oxide-added ditrimethylolpropane tetra(meth)acrylate, ethylene oxide-added pentaerythritol tetra(meth)acrylate, ethylene oxide-added dipentaerythritol hexa(meth)acrylate, propylene oxide-added trimethylolpropane Dimethylolpropane tetra(meth)acrylate, propylene oxide-added ditrimethylolpropane tetra(meth)acrylate, propylene oxide-added pentaerythritol tetra(meth)acrylate, propylene oxide-added dipentaerythritol hexa(meth)acrylate, ε-caprolactone-added trimethylolpropane tri(meth)acrylate, ε-caprolactone-added ditrimethylolpropane tetra(meth)acrylate, ε-caprolactone-added pentaerythritol tetra(meth)acrylate, ε-caprolactone-added dipentaerythritol hexa(meth)acrylate, dipentaerythritol pentaacrylate succinate modified, pentaerythritol triacrylate succinate modified, dipentaerythritol pentaacrylate phthalate modified, pentaerythritol triacrylate phthalate modified, the following formula:

[0120] [ka]

[0121] Polyfunctional (meth)acrylate compounds with three or more functions, such as modified dipentaerythritol hexaacrylate represented by [formula];

[0122] Polyfunctional vinyl ethers such as ethylene glycol divinyl ether, diethylene glycol divinyl ether, polyethylene glycol divinyl ether, propylene glycol divinyl ether, butylene glycol divinyl ether, hexanediol divinyl ether, bisphenol A alkylene oxide divinyl ether, bisphenol F alkylene oxide divinyl ether, trimethylolpropane trivinyl ether, ditrimethylolpropane tetravinyl ether, glycerin trivinyl ether, pentaerythritol tetravinyl ether, dipentaerythritol pentavinyl ether, dipentaerythritol hexanyl ether, ethylene oxide-added trimethylolpropane trivinyl ether, ethylene oxide-added ditrimethylolpropane tetravinyl ether, ethylene oxide-added pentaerythritol tetravinyl ether, and ethylene oxide-added dipentaerythritol hexanyl ether;

[0123] Vinyl ether group-containing (meth)acrylic acid esters such as (meth)acrylate 2-vinyloxyethyl, (meth)acrylate 3-vinyloxypropyl, (meth)acrylate 1-methyl-2-vinyloxyethyl, (meth)acrylate 2-vinyloxypropyl, (meth)acrylate 4-vinyloxybutyl, (meth)acrylate 4-vinyloxycyclohexyl, (meth)acrylate 5-vinyloxypentyl, (meth)acrylate 6-vinyloxyhexyl, (meth)acrylate 4-vinyloxymethylcyclohexylmethyl, (meth)acrylate p-vinyloxymethylphenylmethyl, (meth)acrylate 2-(vinyloxyethoxy)ethyl, (meth)acrylate 2-(vinyloxyethoxyethoxyethoxy)ethyl;

[0124] Polyfunctional allyl ethers such as ethylene glycol diallyl ether, diethylene glycol diallyl ether, polyethylene glycol diallyl ether, propylene glycol diallyl ether, butylene glycol diallyl ether, hexanediol diallyl ether, bisphenol A alkylene oxide diallyl ether, bisphenol F alkylene oxide diallyl ether, trimethylolpropane triallyl ether, ditrimethylolpropane tetraallyl ether, glycerin triallyl ether, pentaerythritol tetraallyl ether, dipentaerythritol pentaallyl ether, dipentaerythritol hexaallyl ether, ethylene oxide-added trimethylolpropane triallyl ether, ethylene oxide-added ditrimethylolpropane tetraallyl ether, ethylene oxide-added pentaerythritol tetraallyl ether, and ethylene oxide-added dipentaerythritol hexaallyl ether;

[0125] Allyl group-containing (meth)acrylic acid esters such as (meth)acrylate; polyfunctional (meth)acryloyl group-containing isocyanurates such as tri(acryloyloxyethyl)isocyanurate, tri(methacryloyloxyethyl)isocyanurate, alkylene oxide-added tri(acryloyloxyethyl)isocyanurate, alkylene oxide-added tri(methacryloyloxyethyl)isocyanurate; polyfunctional allyl group-containing isocyanurates such as triallyl isocyanurate; polyfunctional urethane (meth)acrylates obtained by the reaction of polyfunctional isocyanates such as tolylene diisocyanate, isophorone diisocyanate, xylylene diisocyanate with hydroxyl group-containing (meth)acrylic acid esters such as 2-hydroxyethyl (meth)acrylate and 2-hydroxypropyl (meth)acrylate; polyfunctional aromatic vinyls such as divinylbenzene; etc. These polymerizable compounds may be used individually or in combination of two or more.

[0126] Among the polymerizable compounds mentioned above, it is preferable to use a polyfunctional polymerizable compound from the viewpoint of further enhancing the curability of the curable resin composition. The number of functions in the polyfunctional polymerizable compound is preferably 3 or more, and more preferably 4 or more. Furthermore, the number of functions is preferably 10 or less, and more preferably 8 or less. The molecular weight of the polymerizable compound is not particularly limited, but from the viewpoint of handling, it is preferably 2000 or less.

[0127] Among the polyfunctional polymerizable compounds mentioned above, from the viewpoint of reactivity, economy, and availability, preferred are compounds having a (meth)acryloyl group, such as polyfunctional (meth)acrylate compounds, polyfunctional urethane (meth)acrylate compounds, and (meth)acryloyl group-containing isocyanurate compounds, and more preferably polyfunctional (meth)acrylate compounds. By including a compound having a (meth)acryloyl group, the curable resin composition becomes more photosensitive and curable, and a cured product with even higher hardness and transparency can be obtained. It is even more preferable to use a polyfunctional (meth)acrylate compound with three or more functions as the polyfunctional polymerizable compound.

[0128] The content of the polymerizable compound is preferably 0 to 500 parts by mass, more preferably 5 to 300 parts by mass, and even more preferably 10 to 100 parts by mass, per 100 parts by mass of the alkali-soluble resin (solids).

[0129] (Polymerization initiator) The polymerization initiators mentioned above preferably include photopolymerization initiators, and more preferably radical polymerizable photopolymerization initiators.

[0130] Specific examples of the above photopolymerization initiators include, for example, aminoketone compounds such as 2-methyl-1-[4-(methylthio)phenyl]-2-morpholinopropan-1-one ("IRGACURE 907", BASF), 2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)-butanone-1 ("IRGACURE 369", BASF), and 2-dimethylamino-2-(4-methyl-benzyl)-1-(4-morpholin-4-yl-phenyl)-butan-1-one ("IRGACURE 379", BASF); 2,2-dimethoxy-1,2-diphenylethane-1-one ("IRGACURE 651", BASF), and phenylglyoxylic acid methyl ester ("DAROCURE 651"). Benzyl ketal compounds such as "MBF" (manufactured by BASF); 1-hydroxy-cyclohexyl-phenyl-ketone ("IRGACURE184", manufactured by BASF), 2-hydroxy-2-methyl-1-phenyl-propan-1-one ("DAROCUR1173", manufactured by BASF), 1-[4-(2-hydroxyethoxy)-phenyl]-2-hydroxy-2-methyl-1-propan-1-one ("IRGACURE2959", manufactured by BASF), 2-hydroxy Hydroketone compounds such as -1-{4-[4-(2-hydroxy-2-methylpropionyl)-benzyl]-phenyl}-2-methylpropan-1-one ("IRGACURE 127", manufactured by BASF), [1-hydroxy-cyclohexyl-phenyl-ketone + benzophenone] ("IRGACURE 500", manufactured by BASF); and other alkylphenone compounds exemplified in paragraphs

[0084] to

[0086] of Japanese Patent Application Publication No. 2013-227485;1,2-Octanedione, 1-[4-(phenylthio)phenyl]-,2-(O-benzoyl oxime) ("OXE01", manufactured by BASF), Ethanone, 1-[9-ethyl-6-(2-methylbenzoyl)-9H-carbazole-3-yl]-,1-(O-acetyl oxime) ("OXE02", manufactured by BASF), 1,2-Octanedione, 1-[4-(phenylthio)-,2-,(O-benzoyl oxime)], Ethanone ("OXE03", manufactured by BASF), 1-[9-ethyl Examples include oxime ester compounds such as -6-(2-methylbenzoyl)-9H-carbazole-3-yl]-,1-(O-acetyloxime) ("OXE04", manufactured by BASF); benzophenone compounds; benzoin compounds; thioxanthone compounds; halomethylated triazine compounds; halomethylated oxadiazole compounds; biimidazole compounds; titanocene compounds; benzoic acid ester compounds; acridine compounds, etc.; phosphine oxide compounds; etc. Among these, aminoketone compounds and oxime ester compounds are preferred. The above photopolymerization initiators may be used individually or in combination of two or more.

[0131] The content of the polymerization initiator is preferably 0 to 20% by mass, more preferably 0.3 to 15% by mass, even more preferably 0.5 to 10% by mass, and still more preferably 1 to 10% by mass, based on 100% by mass of the total solid content of the alkali-soluble resin composition.

[0132] (Inorganic fine particles) Examples of the inorganic fine particles mentioned above include the inorganic particles described in Japanese Patent Publication No. 2018-119086. In particular, the inorganic fine particles are preferably metal particles or metal oxide particles, and more preferably metal oxide particles.

[0133] Examples of the above-mentioned inorganic fine particles include metal particles or metal oxide particles containing metal elements with high light transmittance and refractive index, such as atoms of Be, Mg, Ca, Sr, Ba, Sc, Y, La, Ce, Gd, Tb, Dy, Yb, Lu, Ti, Zr, Hf, Nb, Mo, W, Zn, B, Al, Si, Ge, Sn, Pb, Sb, Bi, Te, etc. In particular, the above-mentioned inorganic fine particles preferably contain at least one metal element selected from the group consisting of Ti, Al, Zr, Zn, Sn, Ce, Nb, and Si, in order to provide a cured product with a higher refractive index. Furthermore, it is more preferable to include Zr from the viewpoint of providing a cured film with a high relative permittivity, and it is more preferable to include Si from the viewpoint of providing a cured film with high hardness.

[0134] The above metal oxides may be oxides of a single metal, solid solutions of two or more oxides, or composite oxides. Examples of single metal oxides include aluminum oxide (Al2O3), titanium oxide (TiO2), zirconium oxide (ZrO2), indium oxide (In2O3), zinc oxide (ZnO), tin oxide (SnO2), lanthanum oxide (La2O3), yttrium oxide (Y2O3), cerium oxide (CeO2), magnesium oxide (MgO), silicon oxide (SiO2), and niobium oxide (Nb2O5). Examples of solid solutions of two or more oxides include ITO and ATO. Examples of composite oxides include barium titanate (BaTiO3), titanite (CaTiO3), and spinel (MgAl2O4).

[0135] In particular, the inorganic fine particles are preferably zirconium dioxide particles (ZrO2 particles) and / or silicon dioxide particles (SiO2 particles) because they can provide a hardened product with a high refractive index and high dielectric constant or high hardness.

[0136] The inorganic fine particles described above may be surface-modified or not, but surface-modified inorganic fine particles are preferable because they can improve dispersibility in the resin composition. Surface modification makes the surface of the inorganic fine particles lipophilic, preventing particle aggregation and enabling fine dispersion.

[0137] If the inorganic fine particles described above are surface-modified, the mass of the inorganic fine particles also includes the mass of the surface modifier. The organic compound (surface modifier) ​​that modifies the surface of the inorganic fine particles may be chemically bonded and / or coordinated, or it may adhere to the inorganic fine particles by hydrogen bonding or salt formation. The term "surface modification" above includes both states in which the organic group is chemically bonded and / or coordinated to the inorganic fine particles, etc., or physically attached.

[0138] Surface-modified inorganic nanoparticles (hereinafter also referred to as "coated inorganic nanoparticles") can be obtained by known methods such as mixing the inorganic nanoparticles and a surface modifier in a solvent, or by carrying out a hydrothermal reaction in the presence of water.

[0139] In the method of mixing the inorganic fine particles and the surface modifier in a solvent, the surface modifier used is not particularly limited as long as it is an organic compound that can make the surface of the inorganic fine particles lipophilic, thereby preventing particle aggregation and fine dispersion. Examples include organic acids, coupling agents, and surfactants. One or more of these may be used.

[0140] Preferred organic acids include carboxylic acids (compounds having a carboxyl group) with 5 or more carbon atoms. Specific examples include pentanoic acid, hexanoic acid, heptanoic acid, octanoic acid, nonanoic acid, 2-ethylhexanoic acid, 2-methylheptanoic acid, 4-methyloctanoic acid, salicylic acid, naphthenic acid, decanoic acid, undecylic acid, neodecanoic acid, lauric acid, tridecylic acid, myristic acid, pentadecylic acid, palmitic acid, heptadecylic acid, pivalic acid, 2,2-dimethylbutyric acid, 3,3-dimethylbutyric acid, 2,2-dimethylvaleric acid, 2,2-diethylbutyric acid, 3,3-diethylbutyric acid, and stearin. Examples include acids, half-esters of C3-9 aliphatic dicarboxylic acids such as pristanic acid, 2-acryloyloxyethylhexahydrophthalic acid, 2-methacryloyloxyethylhexahydrophthalic acid, acrylic acid, methacrylic acid, 2-acryloyloxyethyl succinic acid, and 2-methacryloyloxyethyl succinic acid with (meth)acryloyloxy C1-6 alkyl alcohols; and half-esters of C8-14 aromatic dicarboxylic acids such as 2-acryloyloxyethyl phthalic acid and 2-methacryloyloxyethyl phthalic acid with (meth)acryloyloxy C1-6 alkyl alcohols. The above organic acids may be used individually or in combination of two or more.

[0141] Examples of the coupling agent include compounds having organic groups that can bond with the inorganic fine particles and reactive functional groups that can make them lipophilic. Examples of the reactive functional groups include (meth)acryloyloxy groups, epoxy groups, amino groups, vinyl groups, thiol groups, acid anhydride groups, and phenol groups. By surface treatment with a compound having the reactive functional groups, the inorganic fine particles can have reactive functional groups such as (meth)acryloyloxy groups, epoxy groups, amino groups, vinyl groups, thiol groups, acid anhydride groups, and phenol groups on their surface, derived from the coupling agent. The coupling agent may be used alone or in combination of two or more types.

[0142] Examples of the coupling agents mentioned above include silane coupling agents, titanate-based coupling agents, and aluminate-based coupling agents.

[0143] Examples of the above silane coupling agents include (meth)acryloyloxy silane coupling agents such as 3-(meth)acryloyloxypropylmethyldimethoxysilane, 3-(meth)acryloyloxypropyltrimethoxysilane, 3-(meth)acryloyloxypropylmethyldiethoxysilane, and 3-(meth)acryloyloxypropyltriethoxysilane; diethoxy(glycidyloxypropyl)methylsilane, 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, 3-glycidoxypropyltrimethoxysilane, and 3-glycidoxypropylmethyldimethoxysilane. Examples include epoxy silane coupling agents such as ethoxysilane and 3-glycidoxypropyltriethoxysilane; and amino silane coupling agents such as N-2(aminoethyl)3-aminopropylmethyldimethoxysilane, N-2(aminoethyl)3-aminopropyltrimethoxysilane, N-2(aminoethyl)3-aminopropyltriethoxysilane, 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 3-triethoxysilyl-N-(1,3-dimethylbutylidene)propylamine, and N-phenyl-3-aminopropyltrimethoxysilane.

[0144] Examples of the titanate-based coupling agents mentioned above include isopropyltriisostearoyl titanate, isopropyldimethacrylateisostearoyl titanate, isopropyltri(dodecyl)benzenesulfonyl titanate, neopentyl(diallyl)oxytri(dioctyl)phosphate titanate, and neopentyl(diallyl)oxytrineododecanoyl titanate.

[0145] Examples of the aluminate-based coupling agents mentioned above include acetalkoxyaluminum diisopropylate.

[0146] Examples of the above-mentioned surfactants include ionic surfactants such as anionic surfactants, cationic surfactants, and amphoteric surfactants, or nonionic surfactants. One type of surfactant may be used, or two or more types may be used.

[0147] Examples of the above-mentioned anionic surfactants include fatty acid-based surfactants such as sodium oleate, sodium stearate, sodium laurate, potassium fatty acid, and sodium fatty acid ester sulfonate; phosphate-based surfactants such as alkyl phosphate, alkyl phosphate ester, and sodium alkyl phosphate ester; olefin-based surfactants such as sodium alpha-oleinsulfonate; alcohol-based surfactants such as sodium alkyl sulfate; and alkylbenzene-based surfactants.

[0148] Examples of the cationic surfactants mentioned above include alkylmethylammonium chloride, alkyldimethylammonium chloride, alkyltrimethylammonium chloride, and alkyldimethylbenzylammonium chloride.

[0149] Examples of the above-mentioned amphoteric surfactants include carboxylic acid-based surfactants such as alkylaminocarboxylates and phosphate ester-based surfactants such as phosphobetaines.

[0150] Examples of the nonionic surfactants mentioned above include fatty acid-based surfactants such as polyoxyethylene lanolin fatty acid esters and polyoxyethylene sorbitan fatty acid esters; polyoxyethylene alkylphenyl ethers; fatty acid alkanolamides; and phosphoric acid-based surfactants such as organic phosphate esters, alkyl phosphate esters, phosphate polyesters, and polyoxyalkylene alkyl ether phosphate esters.

[0151] The mixing of the inorganic fine particles and the surface modifier may be carried out in a solvent. When mixing the inorganic fine particles and the surface modifier in a solvent, the powdered inorganic fine particles may be added to a dispersion of the surface modifier and mixed, or the surface modifier may be added to a dispersion (slurry) of the inorganic fine particles and mixed, or each dispersion may be prepared separately and then mixed.

[0152] For example, when preparing a dispersion of zirconium oxide (ZrO2) particles, the amount of dispersion medium used is preferably an amount sufficient to adequately disperse the zirconium oxide particles. For every 100 parts by mass of zirconium oxide particles, the total amount of dispersion medium is preferably 20 parts by mass or more, more preferably 40 parts by mass or more, even more preferably 60 parts by mass or more, and also preferably 600 parts by mass or less, more preferably 550 parts by mass or less, and even more preferably 500 parts by mass or less.

[0153] The solvent used in the above-mentioned dispersion, as well as the solvent (dispersion medium) used during the above-mentioned mixing, are not particularly limited, but include, for example, water; alcohols such as methanol, ethanol, propanol, 2-propanol (IPA), butanol, diacetone alcohol, furfuryl alcohol, tetrahydrofurfuryl alcohol; esters such as methyl acetate, ethyl acetate, isopropyl acetate, propyl acetate, isobutyl acetate, butyl acetate, isopentyl acetate, pentyl acetate, 3-methoxybutyl acetate, 2-ethylbutyl acetate, cyclohexyl acetate, ethylene glycol monoacetate; glycosides such as ethylene glycol and hexylene glycol. Examples include ethers such as diethyl ether, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, ethylene glycol isopropyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, propylene glycol monomethyl ether, and propylene glycol monoethyl ether; ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone, butyl methyl ketone, cyclohexanone, methylcyclohexanone, dipropyl ketone, methyl pentyl ketone, and diisobutyl ketone; and toluene. These may be used individually or in combination of two or more.

[0154] The mixing ratio of the inorganic fine particles and the surface modifier is not particularly limited and can be appropriately determined by known methods. For example, when a (silane) coupling agent is used as the surface modifier, the amount of the (silane) coupling agent used is preferably 0.01 to 100 parts by mass, more preferably 1 to 70 parts by mass, and even more preferably 1 to 40 parts by mass, per 100 parts by mass of the inorganic fine particles.

[0155] The temperature at which the inorganic fine particles and the surface modifier are mixed in the solvent can be appropriately selected from known methods. Furthermore, after mixing, the reaction may be carried out by heating or other means as needed.

[0156] Furthermore, coated inorganic nanoparticles can also be obtained by a method that carries out a hydrothermal reaction in the presence of water. Examples of such methods that carry out a hydrothermal reaction in the presence of water include heating a compound that generates coated inorganic nanoparticles by a hydrothermal reaction in the presence of water.

[0157] Examples of compounds that generate coated inorganic nanoparticles by the above hydrothermal reaction include various coated inorganic nanoparticle precursors, such as hydroxides, chlorides, oxychlorides, sulfates, acetates, organic acid salts, and alkoxides of various metals, and may also be salts of various metals with carboxylic acids.

[0158] Specific examples of compounds that produce coated inorganic fine particles by the above hydrothermal reaction include, for example, zirconium-containing compounds such as zirconium hydroxide, zirconium chloride, zirconium oxychloride, zirconium oxyacetate, zirconium oxynitrate, zirconium sulfate, zirconium octanoate, zirconium 2-ethylhexanoate, zirconium oleate oxide, zirconium acetate, zirconium stearate oxide, zirconium laurate oxide, and tetrabutoxyzirconium, as well as other zirconium alkoxides. Examples of titanium-containing compounds include titanium hydroxide, titanium chloride, titanium oxychloride, titanium oxyacetate, titanium oxynitrate, titanium sulfate, titanium octanoate, titanium oleate oxide, titanium acetate, titanium stearate oxide, titanium laurate oxide, and tetrabutoxytitanium (e.g., tetra-n-butoxytitanium), as well as other titanium alkoxides. For example, when zirconium 2-ethylhexanoate is subjected to a hydrothermal reaction, zirconium oxide coated with 2-ethylhexanoic acid and / or a carboxylic acid derived from 2-ethylhexanoic acid can be obtained.

[0159] The reaction conditions in the above hydrothermal reaction, such as the amount of water used, reaction temperature, and reaction time, are not particularly limited and can be appropriately selected from known methods.

[0160] The coated inorganic fine particles obtained by the above hydrothermal reaction may be further treated with the surface modifiers (organic acids, coupling agents, surfactants) described above. A method for treating with the above surface treatment agents is the same as the method for surface modifying inorganic fine particles with the surface modifiers described above.

[0161] Coated inorganic nanoparticles have an affinity for organic solvents because their surface is modified with reactive functional groups. Therefore, they remain stably dispersed as nanoparticles in the various organic solvents mentioned above. Specifically, they can be handled as a highly transparent solution. Coated inorganic nanoparticles can usually be used as a dispersion in which the inorganic nanoparticles are dispersed in the surface modification solution used for surface modification, or they can be used as a powder after solvent removal by vacuum distillation.

[0162] In coated inorganic fine particles, the amount of surface modifier is preferably 0 to 50 parts by mass, more preferably 1 to 40 parts by mass, and even more preferably 2 to 30 parts by mass, per 100 parts by mass of inorganic fine particles. When the amount of surface modifier is within the above range, the refractive index of the alkali-soluble resin composition of the present invention can be increased, and hardness, dielectric constant, etc., can also be improved.

[0163] The shapes of the above-mentioned inorganic fine particles (including coated inorganic fine particles; the same applies hereinafter) include spherical, ellipsoidal, cubic, rectangular, pyramidal, needle-shaped, columnar, rod-shaped, cylindrical, flake-shaped, plate-shaped, and flaky shapes. Considering dispersibility in solvents, spherical and columnar shapes are preferred.

[0164] The crystallite diameter of the above inorganic fine particles is preferably 20 nm or less. When the crystallite diameter of the above inorganic fine particles is within the above range, the transparency of the curable resin composition containing the above inorganic fine particles can be improved. The crystallite diameter is more preferably 15 nm or less, and still more preferably 10 nm or less. The lower limit of the crystallite diameter is usually about 1 nm. That is, the crystallite diameter is preferably 1 to 20 nm, more preferably 1 to 15 nm, and still more preferably 1 to 10 nm. The crystallite diameter can be calculated by X-ray diffraction analysis.

[0165] The number-average primary particle diameter of the above inorganic fine particles is preferably less than 30 nm, and more preferably 25 nm or less. When the number-average primary particle diameter of the above inorganic fine particles is within the above range, the transparency of the resin composition containing the above inorganic fine particles can be improved. The number-average primary particle diameter is more preferably 20 nm or less, and still more preferably 15 nm or less. The lower limit of the number-average primary particle diameter is preferably more than 1 nm, more preferably 3 nm or more, and still more preferably 5 nm or more. That is, the number-average primary particle diameter is preferably more than 1 nm and less than 30 nm, more preferably 3 to 25 nm, and still more preferably 5 to 20 nm. Even more preferably, it is 5 to 15 nm. The number-average primary particle diameter can be determined by magnifying and observing the inorganic fine particles with a transmission electron microscope (TEM), a field emission transmission electron microscope (FE-TEM), a field emission scanning electron microscope (FE-SEM), etc., randomly selecting 100 particles, measuring the length in the major axis direction thereof, and obtaining the arithmetic mean.

[0166] The refractive index of the above inorganic fine particles is not particularly limited, but from the viewpoint of obtaining a high refractive index, it is preferably 1.70 to 2.70, and more preferably 1.90 to 2.70. The refractive index is the refractive index with respect to the NaD line (589 nm) and can be determined by the method described in the examples below.

[0167] The specific surface area of the above inorganic fine particles is preferably 10 to 400 m 2 / g, more preferably 20 to 200 m 2It is even more preferable that the amount be / g, and 30-150m 2 It is most preferable that the value be / g.

[0168] The content of the above inorganic fine particles is preferably 0 to 95% by mass, more preferably 5 to 90% by mass, even more preferably 10 to 80% by mass, and still more preferably 20 to 70% by mass, based on 100% by mass of the total solid content of the above alkali-soluble resin composition.

[0169] The above alkali-soluble resin composition may be produced by mixing the alkali-soluble resin and the acid group-containing epoxy (meth)acrylate by a known method. However, the composition containing the alkali-soluble resin and the acid group-containing epoxy (meth)acrylate can be efficiently produced by the following production method. A preferred method for producing the above alkali-soluble resin composition is described below.

[0170] 4. Method for producing alkali-soluble resin composition A preferred method for producing the alkali-soluble resin composition described above includes the steps of: reacting a bifunctional epoxy compound having a Cardner color number of less than 12 according to JIS K 0071-2 and a melting point of 90°C or higher with a bisphenol compound (b-1); adding an epoxy resin to the reaction product obtained in step (b-1) (b-2); reacting an unsaturated monobasic acid with the mixture obtained in step (b-2) (b-3); and reacting a polybasic acid anhydride with the reaction mixture obtained in step (b-3) (b-4).

[0171] Process (b-1) The above step (b-1) is the same as step (a-1) in "2. Method for producing alkali-soluble resin" described above.

[0172] Process (b-2) Step (b-2) is the step of adding epoxy resin to the reactant obtained in step (b-1). By adding the epoxy resin, properties derived from the epoxy resin skeleton can be imparted to the cured product of the resulting alkali-soluble resin composition. Preferably, the epoxy resins mentioned above as starting materials for the acid group-containing epoxy (meth)acrylate are used as the epoxy resins described above. The epoxy resins mentioned above may be used individually or in combination of two or more types.

[0173] The amount of epoxy resin added is preferably 1 to 1000 parts by mass, more preferably 100 to 500 parts by mass, and even more preferably 200 to 300 parts by mass, per 100 parts by mass of the bifunctional epoxy compound used in step (b-1).

[0174] Process (b-3) Step (b-3) is a step in which an unsaturated monobasic acid is reacted with the mixture obtained in step (b-2). In this reaction, the unsaturated monobasic acid reacts with the epoxy groups of the reactant obtained in step (b-1) in the mixture, and with the epoxy groups of the epoxy resin, thereby introducing radically polymerizable unsaturated bonds into the reactant and the epoxy resin. Therefore, the reaction in step (b-3) yields a mixture of a compound in which radically polymerizable unsaturated bonds have been introduced into the reactant obtained in step (b-1), and a compound in which radically polymerizable unsaturated bonds have been introduced into the epoxy resin.

[0175] Examples of the unsaturated monobasic acids mentioned above include those described in "2. Method for Producing Alkali-Soluble Resins" above.

[0176] In step (b-3) above, the unsaturated monobasic acid is preferably charged and reacted in such a way that the amount of acid groups in the unsaturated monobasic acid is 0.6 to 1.4 moles per mole of epoxy groups in the mixture obtained in step (b-2), more preferably 0.7 to 1.3 moles, even more preferably 0.8 to 1.2 moles, and most preferably 1.0 to 1.1 moles. If epoxy groups remain, the storage stability may deteriorate.

[0177] To reduce the acid concentration in the reaction system, it is preferable to add the above-mentioned unsaturated monobasic acid in several installments or in small amounts sequentially, rather than adding the total amount all at once. If the acid concentration in the reaction system becomes too high, a dehydration condensation reaction may occur with the hydroxyl groups produced as by-products by the reaction between the acid and epoxy, or thermal polymerization of the acids themselves may proceed.

[0178] In the reaction of step (b-3) described above, it is preferable to use a catalyst. Examples of the catalysts mentioned above include the catalysts described in "2. Method for Producing Alkali-Soluble Resins" above.

[0179] In the reaction of step (b-3) described above, the catalyst may be added all at once or in installments, but installments are preferred. By adding the catalyst in installments, it is possible to compensate for the deactivation of the catalyst and suppress the decrease in catalytic activity. If a large amount of phosphine or the like is used initially in anticipation of deactivation, the phosphine oxide will have a yellowish tint, which may increase the discoloration of the resulting resin. As for the method of dividing and adding the above, the same method as described in "2. Method for producing alkali-soluble resin" above can be mentioned.

[0180] A polymerization inhibitor may be used in the reaction of step (b-3) described above. Examples of polymerization inhibitors include those described in "2. Method for Producing Alkali-Soluble Resins" above.

[0181] The reaction conditions for step (b-3) described above are not particularly limited, but conditions similar to those for the reaction with an unsaturated monobasic acid in step (a-2) of "2. Method for producing alkali-soluble resin" described above are preferred.

[0182] Process (b-4) Step (b-4) is a step in which a polybasic acid anhydride is reacted with the reaction mixture obtained in step (b-3). In step (b-4), the polybasic acid anhydride is added to the hydroxyl group of the reaction mixture obtained in step (b-3), and the acid group of the carboxyl group is introduced.

[0183] Examples of the polybasic acid anhydrides mentioned above include those described in "2. Method for Producing Alkali-Soluble Resins" above.

[0184] In step (b-4) described above, the polybasic acid anhydride is preferably charged in an amount of 0.1 to 1.1 moles, more preferably 0.15 to 1 mole, even more preferably 0.2 to 0.9 moles, and most preferably 0.4 to 0.6 moles, relative to 1 mole of hydroxyl groups in the reaction mixture obtained in step (b-3) described above.

[0185] The reaction conditions for step (b-4) described above are not particularly limited, but conditions similar to those for the reaction with the polybasic acid anhydride in step (a-3) of "2. Method for producing alkali-soluble resin" described above are preferred.

[0186] The method for producing the alkali-soluble resin composition described above may include other steps in addition to the reaction step described above. Examples of these other steps include a maturation step, a neutralization step, a dilution step, a drying step, a concentration step, a purification step, and so on. These steps can be carried out by known methods.

[0187] The alkali-soluble resin composition obtained by the above manufacturing method has an ammonium salt compound content of 0.06% by mass or less relative to 100% by mass of the alkali-soluble resin represented by formula (1) above. Because the ammonium salt compound content is within the above range, a cured product with excellent heat resistance and colorability can be obtained. The alkali-soluble resin composition is more preferably composed of an ammonium salt compound content of 0.03% by mass or less, even more preferably 0.01% by mass or less, and most preferably 0% by mass, based on 100% by mass of the alkali-soluble resin.

[0188] A method for producing such an alkali-soluble resin composition, comprising the steps of (b-1) reacting a bifunctional epoxy compound having a Cardner color number of less than 12 according to JIS K 0071-2 and a melting point of 90°C or higher with a bisphenol compound; (b-2) adding an epoxy resin to the reaction product obtained in step (b-1); (b-3) reacting an unsaturated monobasic acid with the mixture obtained in step (b-2); and (b-4) reacting a polybasic acid anhydride with the reaction mixture obtained in step (b-3), wherein the alkali-soluble resin composition obtained by the above method has an ammonium salt compound content of 0.06% by mass or less per 100% by mass of the alkali-soluble resin, is also one of the present inventions.

[0189] (Curing method) The method for curing the alkali-soluble resin or alkali-soluble resin composition of the present invention to obtain a cured product is not particularly limited, and known methods may be used. For example, a method may be used in which the alkali-soluble resin composition is applied to a substrate or molded, and then cured by heating, irradiation with active energy rays such as ultraviolet light, or a combination thereof to obtain a cured product.

[0190] A preferred method for curing the alkali-soluble resin composition includes, for example, a step of applying the alkali-soluble resin composition to a substrate to form a coating film (1), a step of irradiating the formed coating film with light (2), a step of developing and removing the unirradiated portion (3), and a step of heating the light-irradiated coating film (4).

[0191] The above-mentioned substrate is not particularly limited and can be appropriately selected according to the purpose and application. Examples include substrates made of various materials such as glass plates and plastic plates.

[0192] In step (1) above, the method for applying the alkali-soluble resin composition to form a coating film is not particularly limited and can be carried out by known methods such as spin coating, slit coating, roll coating, and casting.

[0193] In the curing method described above, it is preferable to apply the alkali-soluble resin composition onto a substrate and then dry the coated material to form a coating film. The drying can be carried out by known methods, such as using a hot plate, IR oven, or convection oven. The drying conditions are appropriately selected according to the boiling point of the solvent components, the type of curing component, the film thickness, the performance of the dryer, etc., but it is generally preferable to dry at a temperature of 50 to 160°C for 10 to 300 seconds.

[0194] In step (2) above, the method of irradiating the formed coating with light is not particularly limited and can be carried out by known methods. Examples of light sources for the active light used for light irradiation include lamp light sources such as xenon lamps, halogen lamps, tungsten lamps, high-pressure mercury lamps, ultra-high-pressure mercury lamps, metal halide lamps, medium-pressure mercury lamps, low-pressure mercury lamps, carbon arcs, and fluorescent lamps, as well as laser light sources such as argon ion lasers, YAG lasers, excimer lasers, nitrogen lasers, helium-cadmium lasers, and semiconductor lasers.

[0195] When irradiating the above coating with light, the light irradiation may be performed via a photomask. As the photomask, it is preferable to use a mask with light-shielding sections formed according to the desired pattern.

[0196] In step (3) above, after the light irradiation step described above, the material is developed with a developer to remove the unirradiated areas. Due to the light irradiation, the irradiated areas harden, and the hardened material becomes insoluble or sparingly soluble in the developer. On the other hand, the unirradiated areas dissolve in the developer and are removed by the development process, resulting in a patterned hardened film. The development process can usually be carried out at a development temperature of 10 to 50°C using methods such as immersion development, spray development, brush development, or ultrasonic development.

[0197] The developer used in step (3) above is not particularly limited as long as it dissolves the alkali-soluble resin composition, but usually an organic solvent or an alkaline aqueous solution is used, and a mixture thereof may also be used. When an alkaline aqueous solution is used as the developer, it is preferable to wash with water after development. Examples of organic solvents and alkaline aqueous solutions include those similar to those described in Japanese Patent Application Publication No. 2015-157909.

[0198] In step (4) above, the developed coating film is heated to 260°C or lower. In the heating step after light irradiation (post-curing step) in step (4) above, the heating temperature is preferably 260°C or lower, and more preferably 200°C or lower. As for the lower limit of the heating temperature, it is preferably 70°C or higher, and more preferably 90°C or higher, in order to maintain curability.

[0199] The heating time in the above heating process is not particularly limited, but is preferably 5 to 60 minutes. The heating method is also not particularly limited and can be carried out using known heating equipment such as a hot plate, convection oven, or high-frequency heater.

[0200] When the cured product obtained by the above curing method is a cured film, its film thickness is preferably 0.1 to 50 μm, more preferably 0.5 to 40 μm, and even more preferably 1 to 30 μm, in order to fully exhibit its protective film properties. The above cured film showed b in the heat coloring resistance test. * The value is preferably 6.0 or less, and more preferably 5.5 or less. The above heat-resistant coloring test is an evaluation test of heat-resistant coloring performed according to the method described in the examples below.

[0201] 5.Applications The alkali-soluble resin and alkali-soluble resin composition of the present invention exhibit excellent heat-resistant coloring properties and can produce cured products with high refractive indices, making them suitable for applications requiring heat-resistant coloring properties and high refractive indices. Furthermore, the alkali-soluble resin and alkali-soluble resin composition of the present invention have a fast development speed and are suitable for applications requiring good developability. Moreover, the alkali-soluble resin and alkali-soluble resin composition of the present invention also have good voltage retention, making them suitable for applications requiring high voltage retention.

[0202] The alkali-soluble resins and alkali-soluble resin compositions of the present invention are, for example, used in magnetic recording materials, catalyst materials, ultraviolet absorbing materials, dental materials, contact lenses, intraocular lenses, high-refractive index lenses for eyeglasses, optical computing, optical memory media, anti-reflective coatings, conformal coatings, microlens arrays, automotive topcoats, paints, coating agents, hair cosmetics, gradient refractive index optical components and dynamic gradient refractive index components, nanoimprint materials, photocurable plastics, polymerizable compounds for hologram recording, glass surface coating materials, transparent coating materials for solar cells, plastic lenses, printing plates, and semiconductor light-emitting elements (light-emitting diodes, organic light-emitting diodes, laser diodes). It can be widely applied to various applications such as optical guides (both planar and "fiber" geometric shapes), semiconductor elements, light diffusion members, prism sheets, hard coat materials, optical wiring members, diffraction gratings, sealing materials for LEDs, pressure-sensitive adhesives, glass used in sensor elements such as CCD / CMOS and display elements such as displays, protective films used on the surface of films and sheets, photocurable resins (OCR) used for bonding image display members such as liquid crystals to plastic cover panels, reflective protective films used for transparent electrodes, index matching for preventing the visibility of ITO electrodes in touch panels, antiblocking layers, anti-reflective films for displays, and interlayer insulating films for semiconductors. In particular, the alkali-soluble resin and alkali-soluble resin composition of the present invention are suitable for use in microlens arrays and nanoimprint materials because the resin is flexible. Furthermore, the alkali-soluble resin and alkali-soluble resin composition of the present invention are particularly suitable as curable resins or resin compositions for optical materials, and can provide cured films with excellent transparency, substrate adhesion, and electrical properties, for example.

[0203] In this invention, "optical material" refers to a material used as a component of devices in the optical or electrical / electronic fields. For example, it refers to a material used in color filters, light extraction layers, black matrices, photospacers, black column spacers, photoresists, overcoats, planarization layers for TFTs, insulating films for TFTs, and surface coatings for optical lenses used in liquid crystal, organic EL, quantum dot, mini / micro LED display devices, solid-state image sensors, and touch panel display devices. The resin of this invention is suitable for use in applications where photolithography is applied due to its alkali solubility, and can become a cured film with high refractive index, high hardness, high transparency, and high dielectric constant. Therefore, the resin composition of this invention is most preferably a curable resin composition for color filters, light extraction layers, and color conversion layers for organic EL display devices. Various light sources can be used for the light extraction layer, such as LEDs, mini / micro LEDs, and quantum dots, but organic EL is preferred because it can be made flexible. A specific example of a light extraction layer for organic EL is the configuration described in Japanese Patent Application Publication No. 2021-34545. The alkali-soluble resin and alkali-soluble resin composition of the present invention can be suitably used as a highly refractive member that is photolithographic and highly transparent. [Examples]

[0204] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to these examples. Unless otherwise specified, "parts" means "parts by mass" and "%" means "percent mass".

[0205] The various evaluation methods used in this embodiment are as follows.

[0206] <Acid value> 0.5 g of the resin solution was accurately weighed and dissolved in a mixed solvent of 90 g of acetone and 10 g of water. The solution was then titrated using a 0.1 N KOH aqueous solution as the titrant. The titration was performed using an automatic titrator (product name: COM-555, manufactured by Hiranuma Sangyo Co., Ltd.). The acid value per gram of solid content (mgKOH / g) was determined from the acid value of the resin solution and the solid content of the resin solution. The solid content of the resin solution was determined by the following method: Approximately 1 g of the resin solution was weighed into an aluminum cup, and approximately 1 g of acetone was added to dissolve it. The solution was then air-dried at room temperature. After drying at 160°C for 1.5 hours using a hot-air dryer (product name: PHH-101, manufactured by ESPEC), the solution was allowed to cool in a desiccator, and its mass was measured. The solid content (mass %) of the resin solution was calculated from the mass loss.

[0207] <Double bond equivalent (g / equivalent)> The amount of double bonds in the resin solution was determined by dividing the mass (g) of the solid content of the resin solution by the amount (mol) of double bonds in the resin. The amount of double bonds was determined by dividing the mass of the polymerizable double-bonded compound used for introducing polymerizable double bonds by its molecular weight.

[0208] <Heat resistance coloring> The obtained resin solution was uniformly applied onto a 5cm square glass substrate (soda-lime glass AS-2K, manufactured by Toshin Riko Co., Ltd.) using a spin coater (Mikasa Corporation, 1H-D7). By drying the coated plate at 90°C for 3 minutes, a laminate with a coating film formed on the glass substrate was obtained. After removing the resin adhering to the edges of the glass substrate, the obtained laminate was heat-treated at 230°C for 30 minutes using a Perfect Oven constant temperature chamber (ESPEC Corporation), cooled to room temperature, and a laminate with a film thickness of 15 μm was obtained. The surface of the coating film of the obtained laminate was measured using a colorimeter ZE6000 (Nippon Denshoku Industries Co., Ltd.), and the b after the heating test was measured. * The value was obtained.

[0209] <Refractive index> The obtained resin solution was uniformly applied onto a glass substrate (Matsunami Slide Glass S9111, Matsunami Glass Industry Co., Ltd.) using a spin coater (Mikasa Corporation, 1H-D7). By drying the coated plate at 90°C for 3 minutes, a laminate with a coated film formed on the glass substrate was obtained. After removing the resin adhering to the edges of the glass substrate, the obtained laminate was heat-treated at 230°C for 30 minutes using a Perfect Oven constant temperature chamber (ESPEC Corporation), cooled to room temperature, and a laminate with a film thickness of 0.5 μm was obtained. The refractive index of the obtained laminate was determined by measuring the reflectance spectrum. Specifically, for reflectance measurement, a film coated on a substrate such as a slide glass was used as the sample to be measured, and the reflectance value at 589 nm was calculated by performing a reflectance simulation of the thin film based on Fresnel's equation from the reflectance due to thin film interference measured using the following apparatus. Equipment: Film thickness measurement system F-20 manufactured by Filmetrix Corporation Standard fiber stage SS-1 (spot diameter 1.5mm)

[0210] <Quantitative Epoxy Group Quantity> The measurement was performed according to the method compliant with JIS K7236:2001. Specifically, 0.5 g of the resin solution was accurately weighed into a beaker, 25 ml of chloroform, 75 ml of acetic acid, and 2 g of tetraethylammonium bromide were added and stirred to dissolve. The solution was then titrated with a 0.1 N perchloric acid-acetic acid standard solution using an automatic titrator (product name: COM-555, manufactured by Hiranuma Sangyo Co., Ltd.) to calculate the mass of the resin solution containing one equivalent of epoxy groups.

[0211] <Developability Test> A resin solution is applied to a 10cm square glass substrate by spin coating, followed by heat treatment (90°C, 3 minutes). Then, a UV aligner (manufactured by Dainippon Kaken Co., Ltd., product name "MA-1100") equipped with a 2.0kW ultra-high pressure mercury lamp is used to apply 60mJ / cm² of mercury to a photomask with a 30μm line-and-space opening 50μm from the coated film. 2The developability was evaluated by exposing the samples to an exposure level equivalent to 365nm illuminance, spraying a 0.05% potassium hydroxide aqueous solution using a spin developer to dissolve and remove the unexposed areas, and then developing the remaining exposed areas by washing them with pure water for 10 seconds. Specifically, the coated film developed via a photomask as described above was observed using a surface roughness meter (Ryoka Systems Co., Ltd., product name "VertScan2.0"), and the development time was defined as the time required to spray the 0.05% potassium hydroxide aqueous solution so that the unexposed areas would run off. The presence or absence of residue during the development time was also observed.

[0212] <Bending resistance evaluation> A resin solution was applied to a copper plate 0.5 mm thick to a thickness of 20-30 μm, dried in a hot air circulating drying oven at 80°C for 30 minutes, and then cooled to room temperature to obtain a coating. Next, an ultraviolet light exposure device was used to obtain a coating at 2 J / cm². 2 The material was cured by light irradiation. This was heated at 150°C for 1 hour to prepare a test substrate. Using this test substrate, the flexural resistance of the cured coating film at a mandrel diameter of Φ10 mm was evaluated using the cylindrical mandrel method.

[0213] <Measurement of Mass Loss Rate> Using a TG-DTA (thermogravimetric-differential thermal analysis) apparatus, coated zirconium oxide particles were heated from room temperature to 800°C at a rate of 10°C / min under an air atmosphere, and the mass loss rate of the particles was measured. This mass loss rate allows us to determine the proportion of carboxylate compounds and metal oxides coating the metal oxide particles.

[0214] (Synthesis Example 1) Synthesis of resin solution (A-1) In a container equipped with a stirrer, thermometer, reflux condenser, and gas inlet tube, 188 parts of 3,3',5,5'-tetramethyl-4,4'-bis(glycidyloxy)-1,1'-biphenyl (cas. 85954-11-6, epoxy equivalent 188 g / equivalent, Gardner color number 6), 62.6 parts of bisphenol S, 244.3 parts of propylene glycol monomethyl ether acetate, and 0.3 parts of triphenylphosphine as a reaction catalyst were added, and the mixture was reacted at 140°C for 6 hours. The completion of the reaction between the phenolic hydroxyl group and the epoxy group was confirmed by epoxy group determination. Next, 43.5 parts of methacrylic acid, 0.9 parts of triphenylphosphine as an esterification catalyst, and 0.4 parts of hydroquinone as a polymerization inhibitor were charged, and the mixture was reacted at 120°C for 20 hours. The acid value of the reactant was confirmed to be 1.9 mg KOH / g. Next, 88.1 parts of tetrahydrophthalic anhydride were added and the mixture was reacted at 110°C for 5 hours with stirring. As a result, a resin solution (A-1) containing 61% alkali-soluble resin in a propylene glycol monomethyl ether acetate solution was obtained. Table 1 shows the acid value and double bond equivalents of the obtained resin solution (A-1) on a solid content basis.

[0215] (Synthesis Example 2) Synthesis of resin solution (A-2) In a container equipped with a stirring device, a thermometer, a reflux condenser, and a gas inlet tube, 187 parts of 3,3’,5,5’-tetramethyl-4,4’-bis(glycidyloxy)-1,1’-biphenyl (cas.85954-11-6, epoxy equivalent 187 g / equivalent, Gardner color number 10), 62.6 parts of bisphenol S, 243.5 parts of propylene glycol monomethyl ether acetate, and 0.3 parts of triphenylphosphine as a reaction catalyst were added, and the reaction was carried out at 140 °C for 6 hours. The completion of the reaction between phenolic hydroxyl groups and epoxy groups was confirmed by epoxy group quantification. Next, 43.5 parts of methacrylic acid, 0.9 parts of triphenylphosphine as an esterification catalyst, and 0.4 parts of hydroquinone as a polymerization inhibitor were charged, and the reaction was carried out at 120 °C for 20 hours. It was confirmed that the acid value of the reaction product reached 1.8 mgKOH / g. Then, 87.8 parts of tetrahydrophthalic anhydride were charged, and the reaction was carried out at 110 °C for 5 hours with stirring. As a result, a resin solution (A-2) containing 61% of an alkali-soluble resin in propylene glycol monomethyl ether acetate solution was obtained. The acid value and double bond equivalent in terms of solid content of the obtained resin solution (A-2) are shown in Table 1. <(Synthesis Example 3) Synthesis of Resin Solution (A-3)

[0216] [[ID=__3]] (Synthesis Example 3) Synthesis of Resin Solution (A-3) In a container equipped with a stirring device, a thermometer, a reflux condenser, and a gas introduction tube, 94 parts of the same 3,3’,5,5’-tetramethyl-4,4’-bis(glycidyloxy)-1,1’-biphenyl (cas.85954-11-6) as used in Synthesis Example 1, 31.3 parts of bisphenol S, 202.3 parts of propylene glycol monomethyl ether acetate, and 0.5 part of triphenylphosphine as a reaction catalyst were added, and the mixture was reacted at 140 °C for 6 hours. After confirming the completion of the reaction between phenolic hydroxyl groups and epoxy groups by epoxy group quantification, 251.8 parts of bisphenol A type epoxy resin (trade name "jER834"; manufactured by Mitsubishi Chemical; epoxy equivalent 248 g / equivalent) and 202.3 parts of propylene glycol monomethyl ether acetate were added and dissolved to obtain a uniform solution. Next, the internal temperature was maintained at 110 °C, 0.75 part of triphenylphosphine as an esterification catalyst and 0.6 part of methylhydroquinone as a polymerization inhibitor were charged, and 110 parts of methacrylic acid was continuously dropped using a dropping pump for 2 hours. After the dropping was completed, 0.75 part of triphenylphosphine as an additional catalyst was added, and then the temperature was raised to 120 °C and reacted for 15 hours. It was confirmed that the acid value of the reaction product reached 2.1 mgKOH / g. Next, 145.9 parts of tetrahydrophthalic anhydride was added and reacted at 110 °C for 5 hours to obtain a resin solution (A-3) containing 61% in a propylene glycol monomethyl ether acetate solution, which was a mixture of an alkali-soluble resin and a carboxyl group-containing bisphenol A type epoxy acrylate. The acid value and double bond equivalent in terms of solid content of the obtained resin solution (A-3) are shown in Table 1.

[0217] (Synthesis Example 4) Synthesis of Resin Solution (A-4) In a container equipped with a stirrer, thermometer, reflux condenser, and gas inlet tube, 93 parts of 3,3',5,5'-tetramethyl-4,4'-bis(glycidyloxy)-1,1'-biphenyl (cas. 85954-11-6, epoxy equivalent 186 g / equivalent, Gardner color number 7), 31.3 parts of bisphenol S, 174.3 parts of propylene glycol monomethyl ether acetate, and 0.5 parts of triphenylphosphine as a reaction catalyst were added and reacted at 140°C for 6 hours. After confirming the completion of the reaction between the phenolic hydroxyl group and the epoxy group by epoxy group determination, 251.8 parts of the same bisphenol A type epoxy resin "jER834" used in Synthesis Example 3 and 174.3 parts of propylene glycol monomethyl ether acetate were added and dissolved to obtain a homogeneous solution. Next, 110 parts of methacrylic acid, 1.5 parts of triphenylphosphine as an esterification catalyst, and 0.5 parts of hydroquinone as a polymerization inhibitor were charged and reacted at 120°C for 20 hours, and it was confirmed that the acid value of the reactant was 2.2 mg KOH / g. Then, 59.1 parts of tetrahydrophthalic anhydride were added and reacted at 110°C for 5 hours to obtain a resin solution (A-4) containing 61% of an alkali-soluble resin and a carboxyl group-containing bisphenol A type epoxy acrylate mixture in a propylene glycol monomethyl ether acetate solution. The acid value and double bond equivalent of the obtained resin solution (A-4) on a solid content basis are shown in Table 1.

[0218] (Synthesis Example 5) Synthesis of resin solution (A-5) In a container equipped with a stirrer, thermometer, reflux condenser, and gas inlet tube, 75.2 parts of 3,3',5,5'-tetramethyl-4,4'-bis(glycidyloxy)-1,1'-biphenyl (cas.85954-11-6), 25 parts of bisphenol S, 135.5 parts of propylene glycol monomethyl ether acetate, and 0.3 parts of triphenylphosphine as a reaction catalyst were added. The mixture was reacted at 140°C for 6 hours, and the completion of the reaction between the phenolic hydroxyl group and the epoxy group was confirmed by epoxy group determination. Then, 131.4 parts of cresol novolac type epoxy resin (trade name "EOCN-104S"; manufactured by Nippon Kayaku; epoxy equivalent 219 g / equivalent) and 135.5 parts of propylene glycol monomethyl ether acetate were added and dissolved to obtain a homogeneous solution. Next, 69.6 parts of methacrylic acid, 0.9 parts of triphenylphosphine as an esterification catalyst, and 0.4 parts of methylhydroquinone as a polymerization inhibitor were charged and reacted at 120°C for 20 hours, and it was confirmed that the acid value of the reactant was 1.9 mg KOH / g. Then, 122.7 parts of tetrahydrophthalic anhydride were added and reacted at 110°C for 5 hours to obtain a resin solution (A-5) containing 61% of an alkali-soluble resin and a carboxyl group-containing novolac-type epoxy acrylate mixture in a propylene glycol monomethyl ether acetate solution. The acid value and double bond equivalent of the obtained resin solution (A-5) on a solid content basis are shown in Table 1.

[0219] (Synthesis Example 6) Synthesis of resin solution (A-6) In a container equipped with a stirrer, thermometer, reflux condenser, and gas inlet tube, 94 parts of 3,3',5,5'-tetramethyl-4,4'-bis(glycidyloxy)-1,1'-biphenyl (cas.85954-11-6), the same as used in Synthesis Example 1, 31.3 parts of bisphenol S, 202.3 parts of propylene glycol monomethyl ether acetate, and 0.5 parts of triphenylphosphine as a reaction catalyst were added. The mixture was reacted at 140°C for 6 hours, and the completion of the reaction between the phenolic hydroxyl group and the epoxy group was confirmed by epoxy group determination. Then, 251.8 parts of bisphenol A type epoxy resin (trade name "jER834"; manufactured by Mitsubishi Chemical Corporation; epoxy equivalent 248 g / equivalent) and 202.3 parts of propylene glycol monomethyl ether acetate were added and dissolved to obtain a homogeneous solution. Next, the internal temperature was maintained at 110°C, and 0.75 parts of triphenylphosphine as an esterification catalyst and 0.6 parts of hydroquinone as a polymerization inhibitor were charged. 110 parts of methacrylic acid were then added dropwise for 2 hours using a dropping pump. After the dropwise addition was complete, 0.75 parts of triphenylphosphine, an additional catalyst, was added, and the temperature was raised to 120°C for 15 hours to allow the reaction to proceed. The acid value of the reactant was confirmed to be 2.1 mg KOH / g. Next, 145.9 parts of tetrahydrophthalic anhydride were added and the reaction was carried out at 110°C for 5 hours to obtain a resin solution (A-6) containing 61% of an alkali-soluble resin and a carboxyl group-containing bisphenol A type epoxy acrylate mixture in a propylene glycol monomethyl ether acetate solution. The acid value and double bond equivalent of the obtained resin solution (A-6) on a solid content basis are shown in Table 1.

[0220] (Synthesis Example 7) Synthesis of resin solution (A-7) In a container equipped with a stirrer, thermometer, reflux condenser, and gas inlet tube, 248 parts of the same bisphenol A type epoxy resin "jER834" used in Synthesis Example 3, 87 parts of methacrylic acid, 278.3 parts of propylene glycol monomethyl ether acetate, 1 part of triphenylphosphine as an esterification catalyst, and 0.4 parts of hydroquinone as a polymerization inhibitor were charged. The mixture was reacted at 120°C for 20 hours, and it was confirmed that the acid value of the reactant was 1.8 mg KOH / g. Next, 100.3 parts of tetrahydrophthalic anhydride were added, and the mixture was reacted at 110°C for 5 hours to obtain a resin solution (A-7) containing 61% carboxyl group-containing bisphenol A type epoxy acrylate in the propylene glycol monomethyl ether acetate solution. The acid value and double bond equivalent of the obtained resin solution (A-7) on a solid content basis are shown in Table 1.

[0221] (Synthesis Example 8) Synthesis of Resin Solution (B-1) In a container equipped with a stirrer, thermometer, reflux condenser, and gas inlet tube, 94 parts of 3,3',5,5'-tetramethyl-4,4'-bis(glycidyloxy)-1,1'-biphenyl (cas.85954-11-6), 31.3 parts of bisphenol S, 202.3 parts of propylene glycol monomethyl ether acetate, and 0.5 parts of benzyltriethylammonium chloride as a reaction catalyst were added. The mixture was reacted at 140°C for 6 hours, and the completion of the reaction between the phenolic hydroxyl group and the epoxy group was confirmed by epoxy group determination. Then, 251.8 parts of the bisphenol A type epoxy resin "jER834," the same as used in Synthesis Example 3, and 202.3 parts of propylene glycol monomethyl ether acetate were added and dissolved to obtain a homogeneous solution. Next, 110 parts of methacrylic acid, 1.5 parts of triphenylphosphine as an esterification catalyst, and 0.6 parts of methylhydroquinone as a polymerization inhibitor were charged and reacted at 120°C for 20 hours, and it was confirmed that the acid value of the reactant was 2.5 mg KOH / g. Then, 145.9 parts of tetrahydrophthalic anhydride were added and reacted at 110°C for 5 hours to obtain a resin solution (B-1) containing a mixture of a comparative alkali-soluble resin and a carboxyl group-containing bisphenol A type epoxy acrylate at 61% in a propylene glycol monomethyl ether acetate solution. The acid value and double bond equivalent of the obtained resin solution (B-1) on a solid content basis are shown in Table 1.

[0222] (Synthesis Example 9) Synthesis of resin solution (B-2) In a container equipped with a stirrer, thermometer, reflux condenser, and gas inlet tube, 113 parts of the same bisphenol A type epoxy resin "jER834" used in Synthesis Example 3, 63.2 parts of a different bisphenol A type epoxy resin (product name "YD-901"; manufactured by Nippon Steel Chemical & Material; epoxy equivalent 464 g / equivalent), 51.5 parts of methacrylic acid, 189.1 parts of propylene glycol monomethyl ether acetate, 0.7 parts of triphenylphosphine as an esterification catalyst, and 0.3 parts of hydroquinone as a polymerization inhibitor were charged. The mixture was reacted at 120°C for 20 hours, and it was confirmed that the acid value of the reactant was 2.0 mg KOH / g. Next, 68.2 parts of tetrahydrophthalic anhydride were added, and the mixture was reacted at 110°C for 5 hours to obtain a resin solution (B-2) containing 61% carboxyl group-containing bisphenol A type epoxy acrylate in a propylene glycol monomethyl ether acetate solution. Table 1 shows the acid value and double bond equivalents of the obtained resin solution (B-2) on a solid content basis.

[0223] (Synthesis Example 10) Synthesis of resin solution (B-3) In a container equipped with a stirrer, thermometer, reflux condenser, and gas inlet tube, 94 parts of 3,3',5,5'-tetramethyl-4,4'-bis(glycidyloxy)-1,1'-biphenyl (cas. 85954-11-6, epoxy equivalent 188 g / equivalent, Gardner color number 13), 31.3 parts of bisphenol S, 202.3 parts of propylene glycol monomethyl ether acetate, and 0.5 parts of triphenylphosphine as a reaction catalyst were added and reacted at 140°C for 6 hours. After confirming the completion of the reaction between the phenolic hydroxyl group and the epoxy group by epoxy group determination, 251.8 parts of bisphenol A type epoxy resin (trade name "jER834"; manufactured by Mitsubishi Chemical; epoxy equivalent 248 g / equivalent) and 202.3 parts of propylene glycol monomethyl ether acetate were added and dissolved to obtain a homogeneous solution. Next, 110 parts of methacrylic acid, 1.5 parts of triphenylphosphine as an esterification catalyst, and 0.6 parts of methylhydroquinone as a polymerization inhibitor were charged and reacted at 120°C for 20 hours, and it was confirmed that the acid value of the reactant was 2.1 mg KOH / g. Then, 145.9 parts of tetrahydrophthalic anhydride were added and reacted at 110°C for 5 hours to obtain a resin solution (B-3) containing 61% of a mixture of alkali-soluble resin and carboxyl group-containing bisphenol A type epoxy acrylate in a propylene glycol monomethyl ether acetate solution. The acid value and double bond equivalent of the obtained resin solution (B-3) on a solid content basis are shown in Table 1. Resin solution (B-3) had a brownish tint compared to resin solution (A-3).

[0224] (Synthesis Example 11) Synthesis of resin solution (B-4) In a reaction vessel equipped with a thermometer, stirrer, gas inlet pipe, condenser pipe, and dropper inlet, 119.2 parts of propylene glycol monomethyl ether acetate and 50.7 parts of propylene glycol monomethyl ether were charged, the mixture was purged with nitrogen, and the temperature was raised to 90°C. On the other hand, a mixture of 55.0 parts benzyl methacrylate, 45.0 parts methacrylic acid, and 1.0 part t-butyl peroxy-2-ethylhexanoate was prepared in dropping tank (A) by stirring, and a mixture of 2.8 parts n-dodecyl mercaptan and 15.9 parts propylene glycol monomethyl ether acetate was prepared in dropping tank (B) by stirring. After the reaction vessel reached 90°C, polymerization was carried out by starting the addition of the solution from the dropping vessel over a period of 3 hours while maintaining the same temperature. After the addition was completed, the temperature was maintained at 90°C for 30 minutes, then the temperature was raised to 115°C and aged for 90 minutes. To the obtained base polymer solution, 41.3 parts of glycidyl methacrylate, 0.4 parts of triethylamine, and 0.2 parts of Antige W400 were added, and the temperature was raised to 115°C while bubbling with an oxygen / nitrogen mixed gas adjusted to an oxygen concentration of 7% at 20 ml / min, and the reaction was carried out for 8 hours. After that, it was cooled to room temperature to obtain a resin solution (B-4) containing alkali-soluble resin. The acid value and double bond equivalents of the obtained resin solution (B-4) on a solid content basis are shown in Table 2.

[0225] <Preparation of inorganic microparticles> Manufacturing Example 1 (Production of coated zirconium oxide nanoparticles coated with 2-ethylhexanoic acid and / or carboxylate derived from 2-ethylhexanoic acid (coated ZrO2 particles 1)) 782 g of zirconium 2-ethylhexanoate mineral spirit solution (44% by mass zirconium 2-ethylhexanoate, manufactured by Daiichi Kigenso Kagaku Kogyo Co., Ltd.) was mixed with pure water (268 g). The resulting mixture was placed in an autoclave equipped with a stirrer, and the atmosphere inside the autoclave was replaced with nitrogen gas. The mixture was then heated to 180°C and maintained at this temperature for 16 hours (autoclave pressure of 0.94 MPa) to allow the reaction to occur and produce zirconium oxide particles. Subsequently, the mixture was removed after the reaction, the precipitate accumulated at the bottom was filtered off and washed with acetone, and then dried. When the dried precipitate (100 g) was dispersed in toluene (800 mL), a cloudy solution was obtained. Next, as a purification step, the solution was filtered again using quantitative filter paper (Advantec Toyo Co., Ltd., No. 5C) to remove coarse particles from the precipitate. Furthermore, white zirconium oxide nanoparticles 1 (coated ZrO2 particles 1) were recovered by concentrating the filtrate under reduced pressure to remove toluene.

[0226] When the crystal structure of the obtained coated ZrO2 particles 1 was confirmed by XRD diffraction, diffraction lines belonging to tetragonal and monoclinic phases were detected. Based on the intensity of the diffraction lines, the ratio of tetragonal to monoclinic phases was 54 / 46, and the particle size (crystallite size) was 5 nm.

[0227] The average particle size (number-mean primary particle size) of coated ZrO2 particles 1, measured using an electron microscope (JEOL Ltd., FE-TEM JEM-2100F, magnification 600,000x), was 12 nm. Furthermore, analysis of the obtained coated ZrO2 particles 1 by infrared absorption spectroscopy revealed absorption originating from CH and absorption originating from COOH. These absorptions are thought to be due to 2-ethylhexanoic acid and / or carboxylates derived from 2-ethylhexanoic acid that coat the surface of coated ZrO2 particles 1. Furthermore, the mass loss rate of coated ZrO2 particles 1, measured according to the above <Measurement of Mass Loss Rate>, was 12% by mass. Therefore, it was found that 2-ethylhexanoic acid and / or carboxylate derived from 2-ethylhexanoic acid, which coats the surface of coated ZrO2 particles 1, account for 12% by mass of the entire coated ZrO2 particle 1.

[0228] Manufacturing Example 2 (Production of zirconium oxide nanoparticles coated with 2-ethylhexanoic acid and / or carboxylate derived from 2-ethylhexanoic acid and 2-acryloyloxyethyl succinate (coated ZrO2 particles 2)) The coated ZrO2 particles 1 (10 g) obtained in the above Production Example 1 and 2-acryloyloxyethyl succinate (1.5 g) were stirred and mixed in propylene glycol monomethyl ether acetate (12 g, hereinafter referred to as "PGMEA") until uniformly dispersed. Next, n-hexane (36 g) was added to agglomerate the dispersed particles and make the solution cloudy, and the agglomerated particles were separated from the cloudy liquid using filter paper. Subsequently, the separated agglomerated particles were added to n-hexane (36 g), stirred for 10 minutes, and the agglomerated particles were separated using filter paper. The resulting particles were vacuum-dried at room temperature to prepare zirconium oxide nanoparticles (coated ZrO2 particles 2) surface-treated with 2-ethylhexanoic acid and / or carboxylate derived from 2-ethylhexanoic acid and 2-acryloyloxyethyl succinate.

[0229] The obtained coated ZrO2 particles 2 were dispersed in deuterated chloroform to be used as the measurement sample. 1 Analysis was performed using 1H-NMR. The results showed that the molar ratio of carboxylate derived from 2-ethylhexanoic acid and / or 2-ethylhexanoic acid to 2-acryloyloxyethyl succinate was 24:76.

[0230] The mass loss rate of coated ZrO2 particles 2, measured according to the above <Measurement of Mass Loss Rate>, was 18% by mass. Therefore, it was found that 2-ethylhexanoic acid and / or carboxylate derived from 2-ethylhexanoic acid, and 2-acryloyloxyethyl succinate, which coat the coated zirconium oxide particles, account for 18% by mass of the total coated zirconium oxide particles.

[0231] A zirconia particle dispersion was obtained by mixing the coated ZrO2 particles 2 (7g) obtained above, methyl ethyl ketone (3g), and DISPER BYK-111 (manufactured by Big Chemie Japan, 0.14g) and uniformly stirring the mixture. The number-average primary particle diameter of the coated ZrO2 particles 2, as measured by electron microscopy, was 12 nm.

[0232] (Examples 1-8, Comparative Examples 1-4) The heat resistance to coloring and refractive index of the resin solutions obtained in Synthesis Examples 1 to 11 or the alkali-soluble resin compositions prepared by mixing them were evaluated by the above method with the formulations shown in Table 3. The results are shown in Table 3. Note that the values shown in Table 3 are resin solid contents.

[0233] (Examples 9 to 10, Comparative Example 5) Propylene glycol monomethyl ether acetate (PGMEA) was mixed with the resin solution, mill base (MB), dipentaerythritol hexaacrylate (DPHA), and photoinitiator (Irgacure 907, manufactured by BASF) having the formulations (solid content) shown in Table 4 so that the solid content of the composition became 20% to prepare an alkali-soluble resin composition. The developability of the obtained alkali-soluble resin composition was evaluated by the above method. The results are shown in Table 4. The mill base (MB) used was prepared by the following method. (Preparation of Mill Base) 12.9 parts of propylene glycol monomethyl ether acetate, 0.4 part of Disparon DA-7301 as a dispersant, 2.25 parts of C.I. Pigment Green 58 as a colorant, and 1.5 parts of C.I. Pigment Yellow 138 were mixed and dispersed for 3 hours with a paint shaker to obtain a mill base (MB).

[0234] (Examples 11 to 13, Comparative Example 6) Propylene glycol monomethyl ether acetate (PGMEA) was mixed with the resin solution, dipentaerythritol hexaacrylate (DPHA), and photoinitiator (Irgacure 907, manufactured by BASF) having the formulations (solid content) shown in Table 5 so that the solid content of the composition became 30% to prepare a resin composition. The flexural resistance of the obtained resin composition was evaluated by the above method. The results are shown in Table 5.

[0235] [Table 1]

[0236] [Table 2]

[0237] [Table 3]

[0238] [Table 4]

[0239] [Table 5]

[0240] Table 3 shows that the resin solutions of Examples 1-8 achieved both excellent heat resistance and a high refractive index. Furthermore, Examples 7 and 8, in which inorganic fine particles were added, demonstrated improved heat resistance and an even higher refractive index. As shown in the comparative examples, the resin containing resin solution (B-1) had extremely poor heat-resistant coloring properties because it contained an ammonium salt (Comparative Example 1). Resins that did not contain the skeleton of formula (1) above, such as resin solution (B-2), had a low refractive index (Comparative Example 2). Resins with a high number of Gardner colors in the raw materials, such as resin solution (B-3), had extremely poor heat-resistant coloring properties (Comparative Example 3). Furthermore, the resin in this example showed a high refractive index that is unattainable with acrylic resins such as resin solution (B-4).

[0241] Table 4 shows that the resin compositions using the resin solutions of the examples have the advantage of faster development speed and less residue compared to resin compositions using acrylic resins.

[0242] Table 5 shows that the resin composition using the resin solution of the example had better flexural resistance than the resin composition using the resin solution of the comparative example. This was thought to be because the resin using raw materials with a large number of Gardner colors was more susceptible to oxidative degradation and became brittle.

[0243] Furthermore, in a comparison between the examples, the resin compositions using resin solutions A-1 and A-7, which use hydroquinone as a polymerization inhibitor, exhibited better flexural resistance than the resin composition using resin solution A-3, which uses methylhydroquinone as a polymerization inhibitor. Unlike methylhydroquinone, hydroquinone present in the resin composition does not have substituents other than phenolic hydroxyl groups, and therefore is not sterically hindered. It is thought that each of the two phenolic hydroxyl groups interacts more easily with the resin skeleton. For this reason, it is thought to act more readily as a buffer between the resin skeletons, resulting in an advantage in improving flexibility.

[0244] Furthermore, although not shown in the table, the display devices containing color filters made using resin solutions (A-1) to (A-7) as materials showed good voltage retention, whereas when resin solution (B-1) was used, ionic compound leakage into the liquid crystal layer was observed, and the voltage retention rate deteriorated significantly.

Claims

1. A method for producing an alkali-soluble resin having a structure represented by the following formula (1), The method for producing the alkali-soluble resin is a step (a-1) of reacting a difunctional epoxy compound having a Cardner color number of less than 12 according to JIS K 0071-2 and a melting point of 90°C or higher with a bisphenol compound. The reaction product obtained in step (a-1) is reacted with an unsaturated monobasic acid in step (a-2), and The process includes step (a-3) of reacting the reaction product obtained in step (a-2) with a polybasic acid anhydride, The alkali-soluble resin obtained by this manufacturing method has an ammonium salt compound content of 0.06% by mass or less relative to 100% by mass of the alkali-soluble resin. The difunctional epoxy compound is a compound represented by the following formula (4): The bisphenol compound is a compound represented by the following formula (5). A method for producing an alkali-soluble resin, characterized by the above. 【Chemistry 1】 (In formula (1), R １ , R ２ and R ３ are the same or different and each represents a hydrogen atom or a hydrocarbon group having 1 to 6 carbon atoms. R ４ represents a direct bond or a divalent organic group. R ５ , R ６ , R ７ and R ８ are the same or different and each represents a hydrogen atom or Y, and at least one of R ５ to R ８ is Y. The Y is a group represented by the following formula (2). R ９ and R １０ are the same or different and each represents a substituent. W represents a divalent organic group. X represents -SO ２ -. l represents the number of R ９ and is an integer of 0 to 4. m represents the number of R １０ and is an integer of 0 to 4. When there are a plurality of R ９ and R １０ , they may be the same or different. n represents an integer of 1 or more. ) 【Chemistry 2】 (In formula (2), R １１ (This represents a divalent organic group that may have substituents.) 【Transformation 3】 (In formula (4), W represents a divalent organic group.) 【Chemistry 4】 (In equation (5), X is -SO ２ Represents -. R ９ and R １０ l represents a substituent, which is either the same or different. ９ This represents the number of elements and is an integer between 0 and 4. m is R １０ This represents the number of elements and is an integer between 0 and 4. ９ and R １０ If there are multiple instances, they may be the same or different.

2. A method for producing an alkali-soluble resin composition comprising an alkali-soluble resin represented by the following formula (1) and an acid group-containing epoxy (meth)acrylate, A method for producing the alkali-soluble resin composition is a step (b-1) of reacting a bifunctional epoxy compound having a Cardner color number of less than 12 according to JIS K 0071-2 and a melting point of 90°C or higher with a bisphenol compound. Step (b-2) involves adding epoxy resin to the reactant obtained in step (b-1). The mixture obtained in step (b-2) is reacted with an unsaturated monobasic acid in step (b-3), and The process includes step (b-4) of reacting the reaction mixture obtained in step (b-3) with a polybasic acid anhydride, The alkali-soluble resin composition obtained by this manufacturing method has an ammonium salt compound content of 0.06% by mass or less relative to 100% by mass of the alkali-soluble resin. The difunctional epoxy compound is a compound represented by the following formula (4): The bisphenol compound is a compound represented by the following formula (5). A method for producing an alkali-soluble resin composition characterized by the above. 【Transformation 5】 (In formula (1), R １ , R ２ and R ３ R represents a hydrogen atom or a hydrocarbon group having 1 to 6 carbon atoms, either identical or different. ４ R represents a directly bonded or divalent organic group. ５ , R ６ , R ７ and R ８ These represent, either identical or different, a hydrogen atom or Y, and R ５ ~R ８ At least one of them is Y. Y is a group represented by the following formula (2). R ９ and R １０ The same or different substituents are represented. W represents a divalent organic group. X represents -SO ２ It represents -. l is R ９ This represents the number of elements and is an integer between 0 and 4. m is R １０ This represents the number of elements and is an integer between 0 and 4. ９ and R １０ If there are multiple values, they may be the same or different. (n represents an integer greater than or equal to 1.) 【Transformation 6】 (In formula (2), R １１ (This represents a divalent organic group that may have substituents.) 【Transformation 7】 (In formula (4), W represents a divalent organic group.) 【Transformation 8】 (In equation (5), X is -SO ２ Represents -. R ９ and R １０ l represents a substituent, which is either the same or different. ９ This represents the number of elements and is an integer between 0 and 4. m is R １０ This represents the number of elements and is an integer between 0 and 4. ９ and R １０ If there are multiple instances, they may be the same or different.

3. The method for producing the alkali-soluble resin composition according to claim 2, characterized in that the epoxy resin is an aromatic epoxy resin.

4. The method for producing the alkali-soluble resin composition according to claim 3, characterized in that the aromatic epoxy resin is a bisphenol A type epoxy resin.

Images