Thermosetting composition and cured product thereof, photo-meltable composition, and structural body production method

Abstract

To provide a thermosetting composition which can be melted by light irradiation and is capable of forming a cured product (photo-meltable composition) where a resin component generated through melting under light irradiation can be removed with an aqueous solvent.SOLUTION: A thermosetting composition is disclosed that contains a polythiol compound having a disulfide bond, a cyclic ether compound having a polyether chain and two or more cyclic ether groups, a curing accelerator, and a photoradical generator.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present disclosure relates to a thermosetting composition and a cured product thereof, a photofusible composition, and a method for producing a structure. [Background technology]

[0002] Photo-meltable compositions that can be melted by irradiation with light are used in a variety of applications. For example, Patent Document 1 discloses an image-forming apparatus that includes a recording member having a photo-meltable resin layer made of a photo-meltable composition. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 11-190883 Summary of the Invention [Problem to be solved by the invention]

[0004] In conventional photo-meltable compositions, an organic solvent is required to remove the resin component generated by melting upon irradiation with light. However, from the viewpoint of the environment, safety, substrate damage, etc., it is required that the resin component generated by melting upon irradiation with light can be removed with an aqueous solvent. By having such properties, the photo-meltable composition can be expected to be used in a wider range of applications.

[0005] Therefore, a main object of the present disclosure is to provide a thermosetting composition that can be melted by light irradiation and can form a cured product (photo-meltable composition) from which the resin component produced by melting by light irradiation can be removed with an aqueous solvent. [Means for solving the problem]

[0006] One aspect of the present disclosure relates to a thermosetting composition. The thermosetting composition contains a polythiol compound having a disulfide bond, a cyclic ether compound having a polyether chain and two or more cyclic ether groups, a curing accelerator, and a photoradical generator. This thermosetting composition can form a cured product (photofusible composition) that can be melted by light irradiation and from which the resin component produced by melting by light irradiation can be removed with an aqueous solvent.

[0007] Although the reason for this effect is not entirely clear, the present inventors believe it to be as follows. First, by heating the thermosetting composition, the polythiol compound and the cyclic ether compound react to produce a cured thermosetting composition having disulfide bonds. Next, by irradiating the resulting cured product with light, the photoradical generator cleaves the disulfide bonds (-SS-) in the irradiated areas, potentially promoting molecular weight reduction. This reduction in molecular weight reduces the modulus of elasticity in the irradiated areas, potentially causing the cured product to melt and become liquid (liquid). It is believed that the resin component produced by melting upon light irradiation has many polyether chains or hydroxyl groups (derived from cyclic ether groups) and tends to exhibit hydrophilicity, making it possible to remove it with an aqueous solvent.

[0008] The thermosetting composition may contain, as the cyclic ether compound, a compound having two cyclic ether groups and a compound having three or more cyclic ether groups, since this can further shorten the curing time and further improve the photo-meltability and water solubility.

[0009] The cyclic ether group may be an oxirane group from the viewpoints of reactivity and availability.

[0010] Another aspect of the present disclosure relates to a cured product of a thermosetting composition. The cured product of the thermosetting composition may be a photo-meltable composition. The cured product of such a thermosetting composition can be melted by light irradiation, and the resin component produced by melting by light irradiation can be removed with an aqueous solvent.

[0011] Another aspect of the present disclosure relates to a photo-meltable composition. The photo-meltable composition contains a reaction product of a polythiol compound having a disulfide bond and a cyclic ether compound having a polyether chain and two or more cyclic ether groups, and a photo-radical generator. This photo-meltable composition can be melted by light irradiation, and the resin component produced by melting by light irradiation can be removed with an aqueous solvent.

[0012] Another aspect of the present disclosure relates to a method for producing a structure, comprising the steps of: irradiating at least a portion of a first structure made of a cured product of the thermosetting composition or the photo-fusible composition with light; and developing the light-irradiated first structure with an aqueous solvent to obtain a second structure.

[0013] The present disclosure provides a thermosetting composition according to any one of [1] to [3], a cured product of the thermosetting composition according to [4], a photo-meltable composition according to [5], and a method for producing a structure according to [6]. [1] A thermosetting composition comprising a polythiol compound having a disulfide bond, a cyclic ether compound having a polyether chain and two or more cyclic ether groups, a curing accelerator, and a photoradical generator. [2] The thermosetting composition according to [1], wherein the cyclic ether compound contains a compound having two cyclic ether groups and a compound having three or more cyclic ether groups. [3] The thermosetting composition according to [1] or [2], wherein the cyclic ether group is an oxirane group. [4] A cured product of the thermosetting composition according to any one of [1] to [3]. [5] A photomeltable composition comprising a reaction product of a polythiol compound having a disulfide bond and a cyclic ether compound having a polyether chain and two or more cyclic ether groups, and a photoradical generator. [6] A method for manufacturing a structure, comprising the steps of: irradiating light onto at least a portion of a first structure made of a cured product of the thermosetting composition described in [4] or the photo-meltable composition described in [5]; and developing the light-irradiated first structure with an aqueous solvent to obtain a second structure. [Effects of the Invention]

[0014] According to the present disclosure, there is provided a thermosetting composition that can be melted by light irradiation and that can form a cured product (photo-meltable composition) from which the resin component produced by melting by light irradiation can be removed with an aqueous solvent. Also, according to the present disclosure, there is provided a cured product of the thermosetting composition and a photo-meltable composition that can be melted by light irradiation and that can form the resin component produced by melting by light irradiation can be removed with an aqueous solvent. Furthermore, according to the present disclosure, there is provided a method for producing a structure using the photo-meltable composition. DETAILED DESCRIPTION OF THE INVENTION

[0015] Hereinafter, embodiments of the present disclosure will be described in detail, but the present disclosure is not limited to the following embodiments.

[0016] In this specification, the term "process" includes not only an independent process but also a process that cannot be clearly distinguished from other processes as long as the intended effect of the process is achieved. Furthermore, a numerical range indicated using "to" indicates a range that includes the numerical values ​​before and after "to" as the minimum and maximum values, respectively.

[0017] In this specification, the content of each component in a composition means the total amount of the components in the composition when the composition contains multiple substances corresponding to the component, unless otherwise specified. Furthermore, unless otherwise specified, the exemplified materials may be used singly or in combination of two or more.

[0018] Furthermore, in the numerical ranges described in stages in this specification, the upper or lower limit of a certain numerical range may be replaced with the upper or lower limit of another numerical range. Furthermore, in the numerical ranges described in this specification, the upper or lower limit of the numerical range may be replaced with a value shown in the examples. "A or B" may include either A or B, or may include both.

[0019] The thermosetting composition of one embodiment contains a polythiol compound having a disulfide bond (hereinafter sometimes referred to as "component (A)"), a cyclic ether compound having a polyether chain and two or more cyclic ether groups (hereinafter sometimes referred to as "component (B)"), a curing accelerator (hereinafter sometimes referred to as "component (C)"), and a photoradical generator (hereinafter sometimes referred to as "component (D)").

[0020] Component (A): Polythiol compound having a disulfide bond Component (A) is a compound having a disulfide bond (-SS-) and two or more thiol groups (-SH). Component (A) may be, for example, a dithiol compound, which is a compound having two thiol groups (-SH). Component (A) may be a high-molecular-weight component of a polymer or oligomer. A compound having two thiol groups (-SH) can be considered to be a compound consisting of two thiol groups and a group (first linking group) that contains a disulfide bond and links the two thiol groups.

[0021] The molecular weight or number average molecular weight of component (A) may be, for example, 100 to 10,000,000, 200 to 3,000,000, 300 to 1,000,000, 400 to 10,000, or 500 to 5,000. The number average molecular weight is a polystyrene-equivalent value obtained by gel permeation chromatography (GPC) using a calibration curve based on standard polystyrene.

[0022] Component (A) has one or more (two or more) disulfide bonds in the molecule. The number of disulfide bonds in component (A) may be, for example, 1 to 1,000, or 4 to 50.

[0023] Component (A) may be a compound (e.g., a polymer or oligomer) having a linear or branched molecular chain and terminal groups, with disulfide bonds in the molecular chain. In this case, the terminal groups in component (A) may be thiol groups. When component (A) is such a compound, it tends to be easier to form a cured product with excellent photomelt properties. The molecular chain in component (A) may contain a disulfide bond and a polyether chain, or may consist of a disulfide bond and a polyether chain.

[0024] The component (A) is, for example, a compound represented by the formula (1): HS-(XSS) n1 The compound (A) may be a compound represented by -X-SH (compound (1)). In the formula, X represents a polyether chain. Multiple Xs may be the same or different. n1 represents an integer of 1 or greater. n1 may be, for example, 1 or greater, or 4 or greater, or 1000 or less. When component (A) is a compound represented by formula (1), -(XSS) n1 The group represented by -X- is the first linking group. The compound obtained by chain extension of compound (1) may be, for example, a Michael adduct of compound (1) or a thiourethanized product of compound (1).

[0025] The polyether chain as X may be, for example, a polyoxyalkylene chain. 1 -OX 2 -OX 3 X may be a group represented by the formula -. 1 ~X 3 may each independently be an alkylene group, and may be an alkylene group having 1 to 2 carbon atoms (for example, a methylene group or an ethylene group). Examples of the polyether chain represented by X include -CH2CH2-O-CH2-O-CH2CH2-.

[0026] Commercially available examples of component (A) include the Thiokol LP series (dithiols with disulfide bonds, manufactured by Toray Fine Chemicals Co., Ltd.). Component (A) can also be obtained by converting the reactive functional group of a compound having a terminal reactive functional group (e.g., a carboxyl group or a hydroxyl group) and a disulfide bond to a thiol group. Examples of compounds having a terminal reactive functional group and a disulfide bond include 3,3'-dithiodipropionic acid (manufactured by Tokyo Chemical Industry Co., Ltd.), dithiodiethanol, and cystamine.

[0027] The content of component (A) may be 15% by mass or more, 25% by mass or more, or 35% by mass or more, and may be 80% by mass or less, 70% by mass or less, or 60% by mass or less, based on the total amount of the thermosetting composition.

[0028] Component (B): a cyclic ether compound having a polyether chain and two or more cyclic ether groups Component (B) is a compound having a polyether chain and two or more cyclic ether groups. When the thermosetting composition contains component (B), the resin component produced by melting upon irradiation with light has many polyether chains or hydroxyl groups (derived from the cyclic ether groups) and tends to be hydrophilic, making it possible to remove the resin component with an aqueous solvent. Component (B) may be a high-molecular-weight component of a polymer or oligomer.

[0029] The cyclic ether group of component (B) may be a group obtained by removing one hydrogen atom from a cyclic ether compound. Specific examples of the cyclic ether group of component (B) include an oxirane group (oxiranyl group, epoxy group), an oxetane group (oxetanyl group), a tetrahydrofuryl group, and a tetrahydropyranyl group. Among these, the cyclic ether group may be an oxirane group from the viewpoints of reactivity and availability. That is, component (B) may be an oxirane compound (epoxy compound) having a polyether chain and two or more oxirane groups (oxiranyl group, epoxy group). In this specification, the cyclic ether group includes a group having a cyclic ether structure (a structure containing a cyclic ether group). For example, the oxirane group includes a group having an oxirane structure (a structure containing an oxirane group (oxiranyl group, epoxy group)), such as a glycidyl group, a glycidyl ether group, or an epoxycyclohexyl group.

[0030] The molecular weight or number average molecular weight of component (B) may be, for example, 100 to 1,000,000, 100 to 500,000, 100 to 10,000, 150 to 5,000, or 200 to 2,000. The number average molecular weight is a polystyrene-equivalent value obtained by gel permeation chromatography (GPC) using a calibration curve based on standard polystyrene.

[0031] When the cyclic ether group of component (B) is an oxirane group (oxiranyl group, epoxy group), the epoxy equivalent of component (B) may be 50 to 2000 g / eq, 80 to 1500 g / eq, or 100 to 1000 g / eq.

[0032] The component (B) may be a compound having two cyclic ether groups (hereinafter sometimes referred to as component (B1)) or a compound having three or more cyclic ether groups (hereinafter sometimes referred to as component (B2)). The component (B1) can be considered a compound consisting of two cyclic ether groups and a group (second linking group) containing a polyether chain that connects the two cyclic ether groups. The component (B2) may be a compound of the component (B1) that has one or more cyclic ether groups as a side chain or substituent of the second linking group. The component (B) may contain both the components (B1) and (B2) because this can shorten the curing time and improve the photomeltability and water solubility.

[0033] The component (B1) may be a compound (e.g., a polymer or oligomer) having a linear molecular chain and terminal groups, with a polyether chain in the molecular chain. In this case, the terminal group in the component (B1) may be a cyclic ether group. When the component (B) is the component (B1), the resin component produced by melting upon irradiation with light tends to be easier to remove with an aqueous solvent. The polyether chain as the molecular chain may have a substituent such as a hydroxyl group or an alkyl group which may have a hydroxyl group. The molecular chain in the component (B1) may contain a polyether chain or may consist of a polyether chain.

[0034] The component (B1) is, for example, a compound represented by the formula (2): Z-(Y) n2 In the formula, Y represents a polyether chain, and Z represents a cyclic ether group. Multiple Zs may be the same or different. n2 represents an integer of 1 or more. n2 may be, for example, 1 or more, or 2 or more, or may be 1000 or less. When the component (B1) is a compound represented by formula (2), -(Y) n2 The group represented by - is the second linking group.

[0035] The polyether chain represented by Y may be, for example, a polyoxyalkylene chain. 1 -OY 2 -OY3 Y may be a group represented by the formula -. 1 ~Y 3 may each independently be an alkylene group, and may be an alkylene group having 1 to 3 carbon atoms (for example, a methylene group, an ethylene group, or a propylene group). Examples of the polyether chain represented by Y include -CH2CH2-O-CH2-CH2-O-CH2CH2-.

[0036] Commercially available products of the component (B1) include, for example, the Denacol EX series (EX-850, EX-851, EX-821, EX-830, EX-832, EX-841, EX-861, EX-920, manufactured by Nagase ChemteX Corporation).

[0037] The component (B2) can be a compound that has one or more cyclic ether groups as side chains of the second linking group (polyether chain as Y) in the component (B1).

[0038] Commercially available products of the component (B2) include, for example, the Denacol EX series (EX-614B, EX-313, EX-512, EX-521, manufactured by Nagase ChemteX Corporation).

[0039] The content of the component (B) (the sum of the components (B1) and (B2)) may be 15% by mass or more, 25% by mass or more, or 35% by mass or more, and may be 80% by mass or less, 70% by mass or less, or 60% by mass or less, based on the total amount of the thermosetting composition.

[0040] The mass ratio of the content of component (B2) to the content of component (B) (the sum of components (B1) and (B2)) (the content (mass) of component (B2) / the content (mass) of components (B) (the sum of components (B1) and (B2))) may be 0.01 to 0.40. A mass ratio of 0.01 or more tends to further shorten the curing time of the thermosetting composition, while a mass ratio of 0.40 or less tends to further improve the photomeltability and water solubility. The mass ratio may be 0.02 or more or 0.03 or more, or may be 0.35 or less, 0.30 or less, 0.25 or less, 0.20 or less, 0.15 or less, 0.10 or less, or 0.05 or less.

[0041] The equivalent ratio of the cyclic ether groups of component (B) to the thiol groups of component (A) (cyclic ether groups of component (B) / thiol groups of component (A)) may be, for example, 0.5 to 2.5. When this equivalent ratio is 0.5 or more, the water solubility of the thermosetting composition tends to be further improved, and when this equivalent ratio is 2.5 or less, the photomeltability tends to be further improved. This equivalent ratio may be 0.8 or more, 1.0 or more, 1.2 or more, or 1.5 or more, or may be 2.2 or less, or 2.0 or less.

[0042] Component (C): Curing accelerator Component (C) is a component that accelerates the (curing) reaction of components (A) and (B) and includes a component that functions as a catalyst for the curing reaction (catalytic curing agent). Examples of component (C) include amine compounds, imidazole derivatives, quaternary ammonium salts, organometallic salts, and phosphorus compounds.

[0043] Examples of the amine compound include dicyandiamide, trimethylamine, triethylamine, tripropylamine, tributylamine, tri-n-octylamine, dimethylethylamine, dimethylpropylamine, dimethylbutylamine, dimethyl-n-octylamine, 1,4-diazabicyclo[2.2.2]octane, 1,8-diazabicyclo[5.4.0]undec-7-ene, benzyldimethylamine, 4-methyl-N,N-dimethylbenzylamine, 2,4,6-tris(dimethylaminomethyl)phenol, and 4-dimethylaminopyridine.

[0044] Examples of the imidazole derivatives include 1-(1-cyanomethyl)-2-ethyl-4-methyl-1H-imidazole, 2-ethyl-4-methylimidazole, 2-methylimidazole, 2-phenylimidazole, 1-cyanoethyl-2-phenylimidazole, 2-phenyl-4,5-dihydroxymethylimidazole, 2-phenyl-4-methyl-5-hydroxymethylimidazole, 2,4,5-triphenylimidazole, 1-benzyl-2-imidazole, 1,2-dimethylimidazole, and 1-benzyl-2-phenylimidazole.

[0045] Examples of quaternary ammonium salts include tetramethylammonium chloride, tetraethylammonium chloride, tetrabutylammonium chloride, benzyltrimethylammonium chloride, benzyltriethylammonium chloride, benzyltributylammonium chloride, tetramethylammonium bromide, tetraethylammonium bromide, tetrabutylammonium bromide, benzyltrimethylammonium bromide, benzyltriethylammonium bromide, tetramethylammonium iodide, tetraethylammonium iodide, tetrabutylammonium iodide, and benzyltributylammonium iodide.

[0046] Examples of the organic metal salt include zinc(II) bis(2,4-pentanedionato), zinc octylate, zinc naphthenate, cobalt naphthenate, copper naphthenate, iron acetylacetonate, nickel octylate, and manganese octylate.

[0047] Examples of the phosphorus compound include tetraphenylphosphonium tetra-p-tolylborate, tetraphenylphosphonium tetraphenylborate, triphenylphosphine, tri-p-tolylphosphine, tris(4-chlorophenyl)phosphine, tris(4-methoxyphenyl)phosphine, tris(2,6-dimethoxyphenyl)phosphine, triphenylphosphinetriphenylborane, tetraphenylphosphonium dicyanamide, and tetraphenylphosphonium tetra(4-methylphenyl)borate.

[0048] The content of component (C) may be 0.01 mass% or more, 0.1 mass% or more, or 0.5 mass% or more, and may be 10 mass% or less, 5 mass% or less, or 2 mass% or less, based on the total amount of the thermosetting composition.

[0049] Component (D): Photoradical generator Component (D) is a component that generates radicals upon light irradiation in the cured product of the thermosetting composition. Examples of component (D) include hydrogen abstraction-type photoradical polymerization initiators that generate radicals by abstracting hydrogen from other molecules upon light irradiation, and intramolecular cleavage-type photoradical polymerization initiators that photocleave themselves upon light irradiation to generate two radicals. Component (D) may be an intramolecular cleavage-type photoradical polymerization initiator because the (photofusion) reaction easily proceeds.

[0050] Examples of hydrogen abstraction type photoradical generators include hexaarylbisimidazole (HABI) compounds, benzophenone compounds, thioxanthone compounds, fluorenone compounds, and α-diketone compounds.

[0051] HABI compounds include 2,2'-bis(o-chlorophenyl)-4,4',5,5'-tetraphenylbiimidazole (e.g., 2,2'-bis(2-chlorophenyl)-4,4',5,5'-tetraphenyl-1,2'-biimidazole), 2,2'-bis(o-bromophenyl)-4,4',5,5'-tetraphenylbiimidazole, 2,2'-bis(o,p-dichlorophenyl)-4,4',5,5'-tetraphenylbiimidazole, and 2,2'-bis(o-chlorophenyl)-4,4',5,5'-tetra(m-methoxyphenyl)biimidazole, 2,2'-bis(o,o'-dichlorophenyl)-4,4',5,5'-tetraphenylbiimidazole, 2,2'-bis(o-nitrophenyl)-4,4',5,5'-tetraphenylbiimidazole, and 2,2'-bis(o-methylphenyl)-4,4',5,5'-tetraphenylbiimidazole.

[0052] Examples of the benzophenone compound include 4,4'-bis(dimethylamino)benzophenone and 4,4'-bis(diethylamino)benzophenone.

[0053] Thioxanthone compounds include thioxanthone, 2-isopropylthioxanthone, 2-dodecylthioxanthone, 2-cyclohexylthioxanthone, 2,4-diethylthioxanthone, 2,4-dimethylthioxanthone, 1-phenoxythioxanthone, 1-methoxycarbonylthioxanthone, 2-ethoxycarbonylthioxanthone, 3-(2-methoxyethoxycarbonyl)-thioxanthone, 4-butoxycarbonylthioxanthone, 3-butoxycarbonyl-7-methylthioxanthone, 3,4-di-[2-(2-methoxyethoxy)-ethoxycarbonyl]-thioxanthone, 2-chlorothioxanthone, and 1-ethoxycarbonyl 1-ethoxycarbonyl-3-chlorothioxanthone, 1-chloro-4-n-propoxythioxanthone, 2-methyl-6-dimethoxymethyl-thioxanthone, 2-methyl-6-(1,1-dimethoxybenzyl)-thioxanthone, 6-ethoxycarbonyl-2-methoxy-thioxanthone, 6-ethoxycarbonyl-2-methylthioxanthone, 1-ethoxycarbonyl-3-(1-methyl-1-morpholinoethyl)-thioxanthone, 2-morpholinomethylthioxanthone, 2-methyl-6-morpholinomethylthioxanthone, thioxanthone-2-carboxylic acid polyethylene glycol ester, and the like.

[0054] Examples of fluorenone compounds include 9-fluorenone, 3,4-benzo-9-fluorenone, 2-dimethylamino-9-fluorenone, 2-methoxy-9-fluorenone, 2-chloro-9-fluorenone, 2,7-dichloro-9-fluorenone, 2-bromo-9-fluorenone, 2,7-dibromo-9-fluorenone, 2-nitro-9-fluorenone, and 2-acetoxy-9-fluorenone.

[0055] Examples of α-diketone compounds include benzil (a compound also known as diphenylethanedione or dibenzoyl).

[0056] Examples of the intramolecular cleavage-type photoradical generator include benzyl ketal-based photoradical generators, α-aminoalkylphenone-based photoradical generators, α-hydroxyalkylphenone-based photoradical generators, α-hydroxyacetophenone-based photoradical generators, and acylphosphine oxide-based photoradical generators.

[0057] Examples of benzyl ketal photoradical generators include 2,2-dimethoxy-1,2-diphenylethan-1-one (Omnirad651).

[0058] Examples of α-aminoalkylphenone photoradical generators include 2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)-butanone-1 (Omnirad369), 2-methyl-1-[4-(methylthio)phenyl]-2-morpholinopropan-1-one (Omnirad907), and 2-dimethylamino-2-(4-methyl-benzyl)-1-(4-morpholin-4-yl-phenyl)-butan-1-one (Omnirad379EG).

[0059] Examples of the α-hydroxyalkylphenone-based photoradical generator include 1-hydroxy-cyclohexyl-phenyl-ketone (Omnirad184).

[0060] Examples of α-hydroxyacetophenone-based photoradical generators include 2-hydroxy-1-{4-[4-(2-hydroxy-2-methyl-propionyl)-benzyl]-phenyl}-2-methyl-propan-1-one (Omnirad127) and 2-hydroxy-2-methyl-1-phenyl-propan-1-one (Omnirad1173).

[0061] Examples of the acylphosphine oxide photoradical generator include 2,4,6-trimethylbenzoyl-diphenyl-phosphine oxide (OmniradTPO 3 H), bis(2,4,6-trimethylbenzoyl)-phenylphosphine oxide (Omnirad819), and the like.

[0062] The content of component (D) may be 1 mass % or more, 5 mass % or more, or 10 mass % or more, and may be 30 mass % or less, 20 mass % or less, or 15 mass % or less, based on the total amount of the thermosetting composition.

[0063] The thermosetting composition may further contain other components in addition to components (A), (B), (C), and (D). Examples of other components include tackifiers (e.g., plasticizers, tackifiers), adhesion improvers (e.g., antioxidants, leuco dyes, sensitizers, and coupling agents), polymerization inhibitors, light stabilizers, antifoaming agents, fillers, chain transfer agents, thixotropy-imparting agents, flame retardants, mold release agents, surfactants, lubricants, and antistatic agents. Known additives can be used. The content of these other components may be 0 to 95 mass%, 0.01 to 50 mass%, or 0.1 to 10 mass%, based on the total amount of the thermosetting composition.

[0064] The thermosetting composition may be diluted with a solvent and used as a varnish. Examples of the solvent include aromatic hydrocarbons such as toluene, xylene, mesitylene, cumene, and p-cymene; aliphatic hydrocarbons such as hexane and heptane; cyclic alkanes such as methylcyclohexane; cyclic ethers such as tetrahydrofuran and 1,4-dioxane; ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, and 4-hydroxy-4-methyl-2-pentanone; esters such as methyl acetate, ethyl acetate, butyl acetate, methyl lactate, ethyl lactate, and γ-butyrolactone; carbonates such as ethylene carbonate and propylene carbonate; and amides such as N,N-dimethylformamide, N,N-dimethylacetamide, and N-methyl-2-pyrrolidone (NMP). The solid content in the varnish, that is, the total content other than the solvent in the varnish, may be 10 to 95 mass %, or 15 to 70 mass %, or 20 to 50 mass %, based on the total amount of the varnish.

[0065] The thermosetting composition can be prepared, for example, by a method comprising a step of mixing or kneading components (A), (B), (C), and (D), as well as other components added as needed. Mixing and kneading can be carried out using an appropriate combination of dispersing machines such as a conventional mixer, a mortar and pestle mixer, a three-roll mill, a ball mill, or a bead mill.

[0066] The thermosetting composition can be heated to form a cured product of the thermosetting composition. Heating the thermosetting composition causes a (curing) reaction between component (A) and component (B) (e.g., a compound having a glycidyl ether group as a cyclic ether group). During this reaction, component (C) can promote the reaction. The reaction product of components (A) and (B) can be, for example, a compound (polymer) containing a structure represented by the following formula: On the other hand, component (D) is less involved in the (curing) reaction, and the cured product can contain component (D) and the reaction product of components (A) and (B).

[0067] [ka]

[0068] In the formula, X represents a first linking group, and Y represents a second linking group. m represents an integer of 1 or greater. m may be, for example, 50 or greater, 100 or greater, 500 or greater, or 1000 or greater. * represents a bond.

[0069] The heating temperature of the thermosetting composition may be, for example, 0 to 200° C., 30 to 150° C., or 60 to 100° C. The heating time of the thermosetting composition may be, for example, 0.1 to 168 hours, and may be 72 hours or less, 24 hours or less, 12 hours or less, 6 hours or less, 4 hours or less, 3 hours or less, or 2 hours or less.

[0070] The cured product of the thermosetting composition can be formed into various shapes. For example, a cured product formed into a membrane (film) shape can be used as a film. A cured product formed into a block shape can be used as a block. The method for forming a membrane (film) or block-shaped cured product is not particularly limited, and known methods can be applied.

[0071] The cured product of the thermosetting composition has the property of melting when irradiated with light. The light used for light irradiation may be, for example, light containing light with a wavelength of 365 nm. By irradiating with such light, the cured product can be melted. The exposure dose of light irradiation is, for example, 1000 mJ / cm. 2 In this specification, the exposure dose is defined as the illuminance (mW / cm 2 ) and the irradiation time (seconds). Light irradiation may be performed directly on the object to be irradiated, or may be performed through glass or the like. The light source used for light irradiation is not particularly limited, and examples include LED lamps, mercury lamps (low pressure, high pressure, ultra-high pressure, etc.), metal halide lamps, excimer lamps, xenon lamps, etc. Among these, the light source used for light irradiation may be an LED lamp, mercury lamp, or metal halide lamp.

[0072] When a cured product of the thermosetting composition is irradiated with light, the component (D) in the cured product cleaves the disulfide bond (-SS-) in the reaction product of the components (A) and (B). This reduces the molecular weight of the reaction product of the components (A) and (B) and can result in a liquid (liquid state). Because the cured product of the thermosetting composition melts upon irradiation with light, it can also be called a photomeltable composition. The photomeltable composition can contain the reaction product of the components (A) and (B) and the component (D).

[0073] The resin component generated by melting a cured product of the thermosetting composition (photo-meltable composition) upon irradiation with light has many polyether chains or hydroxyl groups and tends to exhibit hydrophilicity, making it possible to remove the resin component with an aqueous solvent. Examples of aqueous solvents include water and mixed solvents of water and hydrophilic organic solvents. In mixed solvents of water and hydrophilic organic solvents, the proportion of water can be, for example, 80% by mass or more. The aqueous solvent may contain, for example, a pH adjuster.

[0074] Examples of water include tap water, natural water, purified water, distilled water, ion-exchanged water, pure water, and ultrapure water (such as Milli-Q water). Milli-Q water refers to ultrapure water obtained using a Milli-Q water production system manufactured by Merck Millipore (Merck). Since water has reduced impurities, it may be purified water, distilled water, ion-exchanged water, pure water, or ultrapure water.

[0075] Examples of hydrophilic organic solvents include alcohols such as methanol, ethanol, 2-propanol, and 1,2-propanediol; and glycol ethers such as ethylene glycol monomethyl ether, propylene glycol monomethyl ether, ethyl cellosolve, propylene glycol monopropyl ether, propylene glycol monoisopropyl ether, butyl cellosolve, ethylene glycol monoisobutyl ether, propylene glycol monobutyl ether, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, and dipropylene glycol monomethyl ether.

[0076] Examples of pH adjusters include inorganic acids, inorganic bases, organic acids, and organic bases. Examples of inorganic acids include nitric acid, sulfuric acid, hydrochloric acid, phosphoric acid, and boric acid. Examples of inorganic bases include sodium hydroxide, potassium hydroxide, and calcium hydroxide. Examples of organic acids include formic acid, acetic acid, propionic acid, butyric acid, acrylic acid, benzoic acid, and picolinic acid. Examples of organic bases include primary amines, secondary amines, tertiary amines, tetramethylammonium hydroxide, tetraethylammonium hydroxide, and imidazole-based compounds.

[0077] The thermosetting composition of the present embodiment can be used for applications such as temporary fixing adhesives, medical adhesives, easily dismantled adhesives, materials for reflow sheets, photoresist materials (photoresists that can be developed without alkali), and materials for 3D printers.

[0078] A method for producing a structure in one embodiment includes the steps of irradiating light onto at least a portion of a first structure made of the cured product of the thermosetting composition or the photo-meltable composition, and developing the light-irradiated first structure with an aqueous solvent to obtain a second structure. The method for producing a structure is a method for producing a second structure. The second structure is a structure in which the cured product of the thermosetting composition or the photo-meltable composition in the light-irradiated portion (part) of the first structure has been removed, and can be a structure having a recess of a desired shape.

[0079] The first structure is a cured product of the thermosetting composition or the photo-meltable composition formed into various shapes. The first structure may have a shape such as a membrane (film) or a block, and may be a film, a block, or the like. The method for forming the first structure is not particularly limited, and known methods can be applied.

[0080] The type of light when irradiating the first structure with light, the exposure dose of light irradiation, the light irradiation, the light source used for light irradiation, and the like may be the same as those described above.

[0081] In the case of a cured product of a thermosetting composition or a photo-meltable composition, the portions irradiated with light are removed with an aqueous solvent by development, and the portions not irradiated with light remain, similar to a positive photoresist, so that recesses of a desired shape can be formed. When irradiating the first structure with light, for example, a photomask or the like can be used to selectively irradiate predetermined portions (recess formation portions).

[0082] The irradiated first structure is developed with an aqueous solvent to obtain a second structure in which the cured product of the thermosetting composition or the photo-meltable composition in the irradiated portion (part) of the first structure has been removed. The aqueous solvent may be the same as that described above.

[0083] The second structure may be a film, a block, etc. having a recess of a desired shape. Specific examples of the second structure include a semiconductor resist pattern, a culture substrate, etc. [Example]

[0084] The present disclosure will be described in more detail below with reference to examples, although the present disclosure is not limited to these examples.

[0085] The following compounds were prepared. (A) Component: (A-1) Thiokol LP-3 (dithiol compound, manufactured by Toray Fine Chemicals Co., Ltd.) (B) Ingredients: (B1) Ingredients: (B1-1) Denacol EX-841 (oxirane compound, number of oxirane groups: 2, manufactured by Nagase ChemteX Corporation, epoxy equivalent: 372 g / eq) (B2) Ingredients: (B2-1) Denacol EX-512 (oxirane compound, number of oxirane groups: 4, manufactured by Nagase ChemteX Corporation, epoxy equivalent: 168 g / eq) (C) Ingredients: (C-1) DMP-30 (2,4,6-tris(dimethylaminomethyl)phenol) (D) Ingredients: (D-1) Omnirad651 (2,2-dimethoxy-1,2-diphenylethan-1-one (manufactured by IGM Resins BV)

[0086] (Examples 1 to 4 and Comparative Example 1) [Preparation of Thermosetting Composition] Component (A) and component (D) were added to a 35 mL ointment bottle in the amounts (unit: parts by mass) of the components shown in Table 1, and mixed for 90 seconds at 2000 rpm using a planetary mixer (Thinky Corporation, product name: Awatori Rentaro ARE-310) and then heated for 15 minutes at 90° C. After cooling, component (B) and component (C) were added, and the mixture was stirred for 90 seconds at 2000 rpm using the planetary mixer to obtain the thermosetting compositions of Examples 1 to 4 and Comparative Example 1.

[0087] [Cureability test] The prepared thermosetting composition was placed in a 90°C thermostatic bath (manufactured by Espec Corporation, product name: STH-120), and the surface of the thermosetting composition was lightly poked with a spatula every hour. The curing time was defined as one hour from when the thermosetting composition no longer adhered to the spatula, and the curability of the thermosetting composition was evaluated. The results are shown in Table 1.

[0088] [Film production] The prepared thermosetting composition was poured into a mold formed by sandwiching a 0.5 mm thick silicone spacer between a release-treated polyethylene terephthalate film (release PET, manufactured by Nakamoto Pax Co., Ltd., product name: NS-38+A-500, thickness 70 μm) and a glass plate. The mold into which the thermosetting composition had been poured was placed in a thermostatic chamber at 90°C and heated for the curing time determined in the above curing test (curing time listed in Table 1), yielding a film consisting of a cured product of the thermosetting composition.

[0089] [Photolysis test] The film prepared above was illuminated with an LED (main wavelength: 365 nm, illuminance: 1000 mW / cm 2) was used to irradiate the sample with light so as to obtain the exposure dose shown in Table 1. After irradiation, the release PET was peeled off, and the presence or absence of liquefaction of the irradiated area was confirmed by visual observation and palpation with a spatula. The case where the irradiated area was entirely liquid and no solid matter was present was evaluated as "A," and the case where the irradiated area was mostly liquid but some solid matter remained was evaluated as "B." In Comparative Example 1, the irradiated area did not liquefy and remained solid. The results are shown in Table 1.

[0090] [Water solubility after photolysis] 0.05g of the liquid portion (resin component) from the area irradiated with light in the photomelting test was weighed out and placed in a sample bottle, and 5g of pure water was added and gently shaken to mix. If the resin component dissolved in the pure water and was clear and transparent, it was rated as "A", and if it was slightly cloudy, it was rated as "B". The results are shown in Table 1.

[0091] [Table 1]

[0092] As shown in Table 1, the thermosetting compositions of Examples 1 to 4 exhibited photomeltability and excellent water solubility of the resin component. From the above, it was confirmed that the thermosetting compositions of the present disclosure can be melted by light irradiation and can form a cured product (photomeltable composition) from which the resin component produced by melting by light irradiation can be removed with an aqueous solvent.

Claims

1. A polythiol compound having a disulfide bond; A cyclic ether compound having a polyether chain and two or more cyclic ether groups; A curing accelerator; A photoradical generator; A thermosetting composition comprising:

2. The thermosetting composition according to claim 1 , wherein the cyclic ether compound comprises a compound having two cyclic ether groups and a compound having three or more cyclic ether groups.

3. The thermosetting composition of claim 1 , wherein the cyclic ether group is an oxirane group.

4. A cured product of the thermosetting composition according to any one of claims 1 to 3.

5. a reaction product of a polythiol compound having a disulfide bond and a cyclic ether compound having a polyether chain and two or more cyclic ether groups; A photoradical generator; A photomeltable composition comprising:

6. A step of irradiating light to at least a part of a first structure made of the cured product according to claim 4; developing the light-irradiated first structure with an aqueous solvent to obtain a second structure; A method for manufacturing a structure comprising:

7. A step of irradiating at least a part of a first structure made of the photo-meltable composition according to claim 5 with light; developing the light-irradiated first structure with an aqueous solvent to obtain a second structure; A method for manufacturing a structure comprising:

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