Curing composition and method for producing the same

Abstract

To provide a curing agent that can be cured at a lower temperature than conventional agents and has significantly improved one-component storage stability, as well as a method for manufacturing the same and a curing composition. [Solution] A curing composition comprising a curing catalyst, a curing agent having an aliphatic cyclic polyolefin resin on the surface of the curing catalyst, and an epoxy resin, wherein the curing catalyst is either a polyurea porous particle holding an aluminum chelate compound or a water-insoluble catalyst powder having a solubility in water of 5% by mass or less, the water-insoluble catalyst powder is an amine adduct compound, the glass transition temperature of the aliphatic cyclic polyolefin resin is 80°C or higher, and the exothermic peak temperature PT1 of the curing composition in differential scanning calorimetry is 100°C or lower.

Description

[Technical Field]

[0001] The present invention relates to a curing composition and a method for producing the same. [Background technology]

[0002] Conventionally, aluminum chelate compounds have been used as curing catalysts that, when mixed with silanol compounds, generate cation species and can cure epoxy resins at room temperature. However, their lack of latent properties has made their practical application difficult.

[0003] To solve the aforementioned problems, the inventors have conducted extensive research and have proposed a curing catalyst that enables low-temperature, rapid curing of epoxy resin at a specific temperature and achieves one-component storage stability in epoxy resin by microencapsulating the aluminum chelate compound with a polyurea porous resin obtained by interfacial polymerization of a polyfunctional isocyanate compound (see, for example, Patent Documents 1 to 3). However, these proposals have a problem in that the aluminum chelate compound reacts with water and changes composition, so when it is encapsulated in water using interfacial polymerization of a polyfunctional isocyanate compound, it undergoes hydrolysis and the activity of the aluminum chelate compound decreases.

[0004] To solve the aforementioned problems, a method for producing an aluminum chelate-based latent curing agent has been proposed, for example, in which an aluminum chelate compound is added to a particulate curing agent prepared using an aluminum chelate compound, a silanol compound, and a polyfunctional isocyanate compound in an organic solvent, and then the surface is treated with an epoxyalkoxysilane coupling agent (see, for example, Patent Document 4). However, the polymerized film formed by the epoxyalkoxysilane coupling agent is a film formed by the polymerization of a monofunctional epoxy compound, and its one-component storage stability at room temperature, especially in polar solvent formulations, was not entirely satisfactory.

[0005] Also, there has been proposed a latent curing agent comprising porous particles made of a polyurea resin and holding an aluminum chelate and an aryl silanol compound, and having a film made of a cured product of an alicyclic epoxy resin on the surface of the porous particles (see, for example, Patent Document 5). This proposal aims to achieve both low-temperature curability and suppression of an increase in viscosity during storage of a thermosetting epoxy resin composition. However, since the film made of a cured product of an alicyclic epoxy resin contains a polar ester group in its structure, the one-component storage stability at room temperature, particularly in a system containing a polar solvent, has not been sufficiently satisfactory.

[0006] On the other hand, there has been proposed a water-soluble curing agent encapsulated capsule using a water-soluble curing agent as a core and having a water-soluble polymer in the inner layer of the shell and a hydrophobic polymer in the outer layer of the shell (see, for example, Patent Document 6). In Example 12 of this proposal, an aliphatic cyclic polyolefin resin is used as the polymer in the outer layer.

Prior Art Documents

Patent Documents

[0007]

Patent Document 1

Patent Document 2

Patent Document 3

Patent Document 4

Patent Document 5

Patent Document 6

Summary of the Invention

Problems to be Solved by the Invention

[0008] However, in the above-mentioned Patent Document 6, the materials that can be encapsulated are limited to water-soluble curing agents such as imidazole compounds, amine compounds, and phenolic compounds, and highly active curing catalysts that react with water and water-insoluble curing catalysts cannot be used. Furthermore, the invention described in Patent Document 6 uses a water-soluble curing agent in the core, and therefore a polymer is added to solidify the core, and the shell consists of an inner layer and an outer layer, which clearly differs in structure from the present invention. Moreover, the invention described in Patent Document 6 aims to rapidly advance the curing reaction during curing to form a cured product with few voids, which differs in its problem from the present invention, which aims to enable curing at a lower temperature than conventional methods and significantly improve the one-component storage stability.

[0009] The present invention aims to solve the aforementioned problems of the conventional method and achieve the following objectives. Specifically, the present invention aims to provide a curing agent that can be cured at a lower temperature than conventional methods and has significantly improved one-component storage stability, a method for producing the curing agent, and a curing composition containing the curing agent. [Means for solving the problem]

[0010] The means to solve the aforementioned problem are as follows: <1> The invention comprises a curing catalyst and an aliphatic cyclic polyolefin resin on the surface of the curing catalyst. The curing agent is characterized in that the curing catalyst is either a polyurea porous particle holding an aluminum chelate compound, or a water-insoluble catalyst powder having a solubility in water of 5% by mass or less. <2> The non-water-soluble catalyst powder contains a curable resin, <1> This is the hardening agent described in [the document]. <3> The volume-average particle diameter is 10 μm or less, <1> from <2> It is a hardening agent as described in any of the following. <4> The water-insoluble catalyst powder is an amine adduct compound. <1> from <3> It is a hardening agent as described in any of the following. <5> The amine adduct compound is either an imidazole adduct or an aliphatic amine adduct. <4> This is the hardening agent described in [the document]. <6> The glass transition temperature of the aliphatic cyclic polyolefin resin is 140°C or lower. <1> from <5> It is a hardening agent as described in any of the following. <7> The aliphatic cyclic polyolefin resin is at least one of a cycloolefin copolymer (COC) and a cycloolefin homopolymer (COP), <1> from <6> It is a hardening agent as described in any of the following. <8> The curing agent is characterized in that the amount of carbon atoms C1 (atomic %) of a first curing agent having an aliphatic cyclic polyolefin resin, measured by X-ray photoelectron spectroscopy (XPS), and the amount of carbon atoms C2 (atomic %) of a second curing agent obtained by removing the aliphatic cyclic polyolefin resin from the first curing agent, measured by XPS, satisfy the following equation: [(C1-C2) / C2] × 100 ≥ 1%. <9> The curing agent is characterized in that the exothermic onset temperature ST1 (°C) and exothermic peak temperature PT1 of a first curing composition containing an epoxy resin and an aliphatic cyclic polyolefin resin, as measured by differential scanning calorimetry (DSC), and the exothermic onset temperature ST2 (°C) and exothermic peak temperature PT2 (°C) of a second curing composition containing an epoxy resin and aliphatic cyclic polyolefin resin, as measured by DSC, satisfy the following equations: ST1-ST2≧4°C and PT1-PT2≦5°C. <10> The method for producing a curing agent is characterized by spray-drying a dispersion in which either polyurea porous particles holding an aluminum chelate compound or a water-insoluble catalyst powder having a solubility in water of 5% by mass or less is dispersed in an organic solvent containing an aliphatic cyclic polyolefin resin in an amount of 1% by mass or less. <11> The aforementioned <1> from <9> A hardening agent as described in any of the following, This is a curing composition characterized by containing epoxy resin. <12> The above is at least one selected from alicyclic epoxy resins, glycidyl ether type epoxy resins, glycidyl ester type epoxy resins, and solvent-containing epoxy resins obtained by dissolving these in a solvent. <11> This is the curing composition described in [reference]. <13> Furthermore, the above contains a silanol compound. <11> from <12> The curing composition is one of the following: [Effects of the Invention]

[0011] According to the present invention, it is possible to solve the aforementioned problems in the conventional method, achieve the aforementioned objectives, enable curing at lower temperatures than conventional methods, and provide a curing agent, a method for producing the curing agent, and a curing composition containing the curing agent, which have significantly improved one-component storage stability. [Brief explanation of the drawing]

[0012] [Figure 1] Figure 1 is a graph showing the volume-based particle size distribution for the curing agents of Example 1, Example 2, and Comparative Example 1. [Figure 2] Figure 2 is a chart showing the DSC measurement results for the curing agents of Example 1, Example 2, and Comparative Example 1. [Figure 3] Figure 3 is a graph showing the relationship between storage time and viscosity for the curing agents of Example 1, Example 2, and Comparative Example 1. [Figure 4] Figure 4 is a chart showing the DSC measurement results for the curing agent of Comparative Example 1 before and after the solvent resistance test. [Figure 5] Figure 5 is a chart showing the DSC measurement results for the curing agent of Comparative Example 2 before and after the solvent resistance test. [Figure 6] Figure 6 is a chart showing the DSC measurement results for the curing agent of Example 1 before and after the solvent resistance test. [Figure 7] Figure 7 is a chart showing the DSC measurement results for the curing agent of Example 2 before and after the solvent resistance test. [Figure 8]Figure 8 is an SEM image (5,000x magnification) of the curing agent of Comparative Example 1. [Figure 9] Figure 9 is an SEM image (5,000x magnification) of the curing agent from Example 1. [Figure 10] Figure 10 is an SEM image (5,000x magnification) of the curing agent from Example 2. [Figure 11] Figure 11 is a chart showing the DSC measurement results for the curing agents of Example 3 and Comparative Example 1. [Figure 12] Figure 12 is a graph showing the relationship between storage time and viscosity for the curing agents of Example 3 and Comparative Example 1. [Figure 13] Figure 13 is a graph showing the volume-based particle size distribution for the curing agents of Example 4 and Comparative Example 4. [Figure 14] Figure 14 is a chart showing the DSC measurement results for the curing agents of Example 4 and Comparative Example 4. [Figure 15] Figure 15 is a chart showing the DSC measurement results for the curing agents of Example 5 and Comparative Example 5. [Figure 16] Figure 16 is a graph showing the relationship between storage time and viscosity for the curing agents of Example 4 and Comparative Example 4. [Figure 17] Figure 17 is a graph showing the relationship between storage time and viscosity for the curing agents of Example 5 and Comparative Example 5. [Figure 18] Figure 18 is a chart showing the results of TG measurement for COC resin (APL6509T). [Figure 19] Figure 19 is a graph showing the correlation between COC resin concentration and TG (mg). [Modes for carrying out the invention]

[0013] (Hardening agent) The curing agent of the present invention comprises a curing catalyst and an aliphatic cyclic polyolefin resin on the surface of the curing catalyst, wherein the curing catalyst is either a polyurea porous particle that holds an aluminum chelate compound or a water-insoluble catalyst powder having a solubility in water of 5% by mass or less, and further contains other components as needed.

[0014] In the present invention, the curing catalyst has an aliphatic cyclic polyolefin resin on its surface. Having an aliphatic cyclic polyolefin resin is not particularly limited as long as an aliphatic cyclic polyolefin resin is present on the surface of the curing catalyst. It is preferable that a film of the aliphatic cyclic polyolefin resin is formed, but the aliphatic cyclic polyolefin resin may be retained on the surface by any interaction such as adhesion, coagulation, adsorption, or van der Waals bonding. If the aliphatic cyclic polyolefin resin forms a film on the surface of the curing catalyst, the film only needs to be formed on at least a portion of the surface of the curing catalyst, or it may be formed to cover the entire surface of the curing catalyst. Furthermore, the film may be formed as a continuous film, or at least a portion of it may be a discontinuous film.

[0015] One method for analyzing the presence of aliphatic cyclic polyolefin resin on the surface of the curing catalyst is to dissolve the aliphatic cyclic polyolefin resin of the curing catalyst with a solvent that selectively dissolves aliphatic cyclic polyolefin resin, and then analyze the aliphatic cyclic polyolefin resin in this solution using a thermogravimetric differential thermal analyzer (TG / DTA) or the like. Examples of solvents that selectively dissolve aliphatic cyclic polyolefin resin include cyclohexane and chlorobenzene.

[0016] In the present invention, the amount of carbon atoms C1 (atomic %) measured by X-ray photoelectron spectroscopy (XPS) of a first curing agent having an aliphatic cyclic polyolefin resin, and the amount of carbon atoms C2 (atomic %) measured by XPS of a second curing agent obtained by removing the aliphatic cyclic polyolefin resin from the first curing agent, satisfy the following equation, [(C1-C2) / C2]×100≧1%. By satisfying the following equation, [(C1-C2) / C2]×100≧1%, it is revealed that an aliphatic cyclic polyolefin resin is present on the surface of the curing catalyst, enabling curing at lower temperatures than conventional methods and significantly improving the one-component storage stability. A method for removing the aliphatic cyclic polyolefin resin from the first curing agent is, for example, to dissolve the aliphatic cyclic polyolefin resin of the curing catalyst with a solvent that selectively dissolves the aliphatic cyclic polyolefin resin (e.g., cyclohexane, chlorobenzene, etc.).

[0017] Furthermore, in the present invention, the exothermic onset temperature ST1 (°C) and exothermic peak temperature PT1 in differential scanning calorimetry (DSC) measurements of a first curing composition containing an epoxy resin and a first curing agent having an aliphatic cyclic polyolefin resin, and the exothermic onset temperature ST2 (°C) and exothermic peak temperature PT2 (°C) in DSC measurements of a second curing composition containing an epoxy resin and a second curing agent from which the aliphatic cyclic polyolefin resin has been removed, satisfy the following equations, ST1-ST2≧4°C and PT1-PT2≦5°C. This makes it possible to cure at a lower temperature than conventional methods, and significantly improves the one-component storage stability. A method for removing the aliphatic cyclic polyolefin resin from the first curing agent is, for example, to dissolve the aliphatic cyclic polyolefin resin of the curing catalyst with a solvent that selectively dissolves the aliphatic cyclic polyolefin resin (e.g., cyclohexane, chlorobenzene, etc.).

[0018] <Curing catalyst> The curing catalyst is either a porous polyurea particle holding an aluminum chelate compound, or a non-water-soluble catalyst powder having a solubility in water of 5% by mass or less.

[0019] <<Polyurea porous particles that hold aluminum chelate compounds>> The porous particles are composed of polyurea resin. The porous particles hold an aluminum chelate compound. The porous particles, for example, hold the aluminum chelate compound within their pores. In other words, the aluminum chelate compound is incorporated into and held in the fine pores present in the porous particle matrix composed of polyurea resin.

[0020] -Polyurea resin- The aforementioned polyurea resin is a resin that has urea bonds in it. The polyurea resin constituting the porous particles is obtained, for example, by polymerizing a polyfunctional isocyanate compound in an emulsion. Details will be described later. The polyurea resin may contain bonds derived from isocyanate groups other than urea bonds, such as urethane bonds. When urethane bonds are included, it may be referred to as polyurea-urethane resin.

[0021] -Aluminum chelate compounds- Examples of the aforementioned aluminum chelate compounds include complex compounds in which three β-ketoenolate anions are coordinated to aluminum, as represented by the following general formula (1). Here, the alkoxy group is not directly bonded to the aluminum. This is because if it were directly bonded, it would be easily hydrolyzed and unsuitable for emulsification treatment.

[0022] [ka]

[0023] In the above general formula (1), R 1 , R 2 and R 3 Each of these independently represents an alkyl group or an alkoxy group. Examples of the alkyl group include a methyl group and an ethyl group. Examples of the alkoxy group include a methoxy group, an ethoxy group, and an oleyloxy group.

[0024] Examples of complex compounds represented by the general formula (1) include aluminum tris(acetylacetonate), aluminum tris(ethylacetoacetate), aluminum monoacetylacetonate bis(ethylacetoacetate), and aluminum monoacetylacetonate bis(oleylacetoacetate). These may be used individually or in combination of two or more.

[0025] The aforementioned aluminum chelate compound undergoes exothermic decomposition upon contact with water, and is therefore insoluble in water. Consequently, the porous polyurea particles holding the aluminum chelate compound are water-reactive curing catalysts.

[0026] There are no particular restrictions on the content of the aluminum chelate compound in the porous particles, and it can be appropriately selected depending on the purpose.

[0027] There are no particular restrictions on the average pore diameter of the porous particles, and it can be appropriately selected depending on the purpose, but it is preferably 1 nm to 300 nm, and more preferably 5 nm to 150 nm.

[0028] There are no particular restrictions on the volume-average particle diameter of the porous particles, and they can be appropriately selected depending on the purpose, but a diameter of 10 μm or less is preferred, a diameter of 1 μm or more and 10 μm or less is more preferred, and a diameter of 1 μm or more and 5 μm or less is particularly preferred.

[0029] [Method for producing porous polyurea particles that retain aluminum chelate compounds] The method for producing the porous polyurea particles that hold the aluminum chelate compound includes a porous particle manufacturing step, and further includes other steps as necessary.

[0030] -Porous particle fabrication process- The porous particle manufacturing step includes at least an emulsification liquid manufacturing process and a polymerization process, preferably a high-impregnation process, and further, if necessary, other processes.

[0031] --Emulsification Process-- The emulsification preparation process is not particularly limited as long as it involves emulsifying a liquid obtained by mixing an aluminum chelate compound, a polyfunctional isocyanate compound, and preferably an organic solvent. It can be appropriately selected depending on the purpose, and can be carried out, for example, using a homogenizer.

[0032] Examples of the aluminum chelate compound include the aluminum chelate compound described in the description of the curing agent of the present invention.

[0033] There are no particular restrictions on the size of the oil droplets in the emulsified liquid, and they can be appropriately selected depending on the purpose, but a size of 0.5 μm to 100 μm is preferred.

[0034] --Polyfunctional isocyanate compounds-- The aforementioned polyfunctional isocyanate compound is a compound having two or more isocyanate groups, preferably three isocyanate groups, in one molecule. More preferred examples of such trifunctional isocyanate compounds include the TMP adduct of general formula (2) below, obtained by reacting 1 mole of trimethylolpropane with 3 moles of a diisocyanate compound; the isocyanurate of general formula (3) below, obtained by self-condensing 3 moles of a diisocyanate compound; and the biuret of general formula (4) below, obtained by condensing the remaining 1 mole of diisocyanate onto a diisocyanate urea obtained from 2 moles of the 3 moles of a diisocyanate compound.

[0035] [ka]

[0036] In the general formulas (2) to (4) above, substituent R is the portion of the diisocyanate compound from which the isocyanate group has been removed. Specific examples of such diisocyanate compounds include toluene 2,4-diisocyanate, toluene 2,6-diisocyanate, m-xylylene diisocyanate, hexamethylene diisocyanate, hexahydro-m-xylylene diisocyanate, isophorone diisocyanate, and methylenediphenyl-4,4'-diisocyanate. These may be used individually or in combination of two or more.

[0037] There are no particular restrictions on the mixing ratio of the aluminum chelate compound and the polyfunctional isocyanate compound, and it can be appropriately selected according to the purpose. However, if the amount of aluminum chelate is too small, the curability of the cationic curable compound to be cured will decrease, and if it is too large, the potential of the resulting curing agent will decrease. In this respect, it is preferable that the amount of aluminum chelate compound be 10 to 500 parts by mass, and more preferably 10 to 300 parts by mass, per 100 parts by mass of the polyfunctional isocyanate compound.

[0038] --Organic Solvents-- There are no particular restrictions on the organic solvent, and it can be appropriately selected depending on the purpose, but volatile organic solvents are preferred. The organic solvent is preferably a good solvent for the aluminum chelate compound and the polyfunctional isocyanate compound (preferably with a solubility of 0.1 g / ml (organic solvent) or more for each), substantially insoluble in water (solubility of water is 0.5 g / ml (organic solvent) or less), and has a boiling point of 100°C or less at atmospheric pressure. Specific examples of such volatile organic solvents include alcohols, acetate esters, and ketones. Among these, ethyl acetate is preferred due to its high polarity, low boiling point, and poor water solubility.

[0039] There are no particular restrictions on the amount of the aforementioned organic solvent used, and it can be appropriately selected depending on the purpose.

[0040] -Polymerization process- The polymerization treatment is not particularly limited as long as it is a treatment in which the polyfunctional isocyanate compound is polymerized in the emulsion to obtain porous particles, and can be appropriately selected according to the purpose.

[0041] The porous particles hold the aluminum chelate compound. In the polymerization treatment described above, some of the isocyanate groups of the polyfunctional isocyanate compound are hydrolyzed to form amino groups, and these amino groups react with the isocyanate groups of the polyfunctional isocyanate compound to form urea bonds, thereby obtaining a polyurea resin. Here, if the polyfunctional isocyanate compound has urethane bonds, the resulting polyurea resin also has urethane bonds, and in that respect, the produced polyurea resin can also be called a polyurea-urethane resin.

[0042] There are no particular restrictions on the polymerization time in the polymerization treatment, and it can be appropriately selected depending on the purpose, but it is preferably 1 hour or more and 30 hours or less, and more preferably 2 hours or more and 10 hours or less. There are no particular restrictions on the polymerization temperature in the polymerization treatment, and it can be appropriately selected depending on the purpose, but it is preferably 30°C to 90°C, and more preferably 50°C to 80°C. After polymerization, a high-impregnation treatment of the aluminum chelate compound can be performed to increase the amount of aluminum chelate compound retained in the porous particles.

[0043] -High-impregnation treatment- The high-impregnation treatment is not particularly limited as long as it is a treatment in which an aluminum chelate compound is additionally filled into the porous particles obtained by the polymerization treatment, and can be appropriately selected according to the purpose. For example, one method is to immerse the porous particles in a solution obtained by dissolving the aluminum chelate compound in an organic solvent, and then remove the organic solvent from the solution.

[0044] By performing the aforementioned high-impregnation treatment, the amount of aluminum chelate compound held in the porous particles increases. The porous particles to which the aluminum chelate compound has been added can be filtered, washed, and dried as needed, and then crushed into primary particles using a known crushing device.

[0045] The aluminum chelate compound additionally filled in the high-impregnation treatment may be the same as or different from the aluminum chelate compound blended into the emulsion. For example, since water is not used in the high-impregnation treatment, the aluminum chelate compound used in the high-impregnation treatment may be an aluminum chelate compound in which an alkoxy group is bonded to aluminum. Examples of such aluminum chelate compounds include diisopropoxyaluminum monooleyl acetate, monoisopropoxyaluminum bis(oleyl acetate), monoisopropoxyaluminum monooleate monoethyl acetate, diisopropoxyaluminum monolauryl acetate, diisopropoxyaluminum monostearyl acetate, diisopropoxyaluminum monoisostearyl acetate, and monoisopropoxyaluminum mono-N-lauroyl-β-aranate monolauryl acetate. These may be used individually or in combination of two or more.

[0046] The organic solvent is not particularly limited and can be appropriately selected depending on the purpose. Examples include the organic solvents exemplified in the description of the emulsification process. The same applies to preferred embodiments.

[0047] There are no particular limitations on the method for removing the organic solvent from the solution, and a suitable method can be selected depending on the purpose. Examples include heating the solution to a point above the boiling point of the organic solvent, or reducing the pressure of the solution.

[0048] There are no particular restrictions on the content of the aluminum chelate compound in the solution obtained by dissolving the aluminum chelate compound in the organic solvent, and it can be appropriately selected depending on the purpose, but it is preferably 10% by mass or more and 80% by mass or less, and more preferably 10% by mass or more and 50% by mass or less.

[0049] <<Water-insoluble catalyst powder>> The aforementioned non-water-soluble catalyst powder is sparingly soluble or insoluble in water, and its solubility in water is 5% by mass or less. The solubility of the non-water-soluble catalyst powder in water can be determined by adding 5 g of the non-water-soluble catalyst powder to 95 g of water at 25°C, stirring with a stirrer for 24 hours, and then measuring the liquid obtained by passing it through a filter with an average pore size of 0.1 μm using a thermogravimetric differential thermal analyzer (TG / DTA). The specific weight loss of the non-water-soluble catalyst powder in the high-temperature range of 200°C or higher can be measured.

[0050] The non-water-soluble catalyst powder preferably contains a curable resin. The curable resin preferably contains, for example, (meth)acrylic compounds and epoxy compounds.

[0051] Examples of the (meth)acrylic compounds include (meth)acrylic acid ester compounds obtained by reacting (meth)acrylic acid with a compound having a hydroxyl group, epoxy (meth)acrylates obtained by reacting (meth)acrylic acid with an epoxy compound, and urethane (meth)acrylates obtained by reacting an isocyanate compound with a (meth)acrylic acid derivative having a hydroxyl group. These may be used individually or in combination of two or more.

[0052] Examples of the epoxy compounds include bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol S type epoxy resin, 2,2'-diallylbisphenol A type epoxy resin, hydrogenated bisphenol type epoxy resin, propylene oxide-added bisphenol A type epoxy resin, resorcinol type epoxy resin, biphenyl type epoxy resin, sulfide type epoxy resin, diphenyl ether type epoxy resin, dicyclopentadiene type epoxy resin, naphthalene type epoxy resin, phenol novolac type epoxy resin, orthocresol novolac type epoxy resin, dicyclopentadiene novolac type epoxy resin, biphenyl novolac type epoxy resin, naphthalenephenol novolac type epoxy resin, glycidylamine type epoxy resin, alkyl polyol type epoxy resin, rubber-modified epoxy resin, and glycidyl ester compounds. These may be used individually or in combination of two or more types.

[0053] The non-water-soluble catalyst powder is in particulate form, and there are no particular restrictions on its volume-average particle size, which can be appropriately selected depending on the purpose. However, a particle size of 10 μm or less is preferred, a particle size of 1 μm to 10 μm is more preferred, and a particle size of 1 μm to 5 μm is particularly preferred.

[0054] The water-insoluble catalyst powder is preferably an amine adduct compound. Examples of the amine adduct compounds include adducts of imidazole compounds and epoxy compounds, and adducts of aliphatic amine compounds and epoxy compounds. Examples of commercially available amine adduct compounds include Amicure PN-23, Amicure PN-23J, Amicure PN-H, Amicure PN-31, Amicure PN-31J, Amicure PN-40, Amicure PN-40J, Amicure PN-50, Amicure PN-F, Amicure MY-24, and Amicure MY-H (all manufactured by Ajinomoto Fine Techno Co., Ltd.). Examples include P-0505 (manufactured by Shikoku Chemicals Co., Ltd.), P-200 (manufactured by Mitsubishi Chemical Corporation), Adeka Hardener EH-5001P, Adeka Hardener EH-5057PK, Adeka Hardener EH-5030S, Adeka Hardener EH-5011S (all manufactured by ADEKA Corporation), Fujicure FXR-1036, Fujicure FXR-1020, Fujicure FXR-1081 (manufactured by T&K TOKA Corporation). These can be used individually or in combination of two or more types.

[0055] <Aliphatic cyclic polyolefin resin> The aliphatic cyclic polyolefin resin refers to a polymer resin having an aliphatic cyclic olefin structure. Examples of the aliphatic cyclic polyolefin resin include (1) norbornene polymers, (2) polymers of monocyclic cyclic olefins, (3) polymers of cyclic conjugated dienes, (4) vinyl alicyclic hydrocarbon polymers, and hydrides of (1) to (4). In the present invention, preferred polymers are addition (co)polymer cyclic polyolefins containing at least one repeating unit represented by the following general formula (II), and, if necessary, further addition (co)polymer cyclic polyolefins containing at least one repeating unit represented by the following general formula (I). Ring-opening (co)polymers containing at least one cyclic repeating unit represented by the following general formulas (III) and (IV) can also be suitably used. Among these, it is preferable that at least one of cycloolefin copolymers (cycloolefin copolymer (COC resin), ethylene-norbornene copolymer) and cycloolefin homopolymers (cycloolefin polymer (COP resin)) is used.

[0056] [Chemical]

[0057] [Chemical]

[0058] [Chemical]

[0059] [Chemical]

[0060] However, in the general formulas (I) to (IV), m represents an integer from 0 to 10. R 1 ~R 7 represents a hydrogen atom or a hydrocarbon group having 1 to 10 carbon atoms. X 1 ~X 2 , and Y 1 are a hydrogen atom, a hydrocarbon group having 1 to 10 carbon atoms, a halogen atom, a hydrocarbon group having 1 to 10 carbon atoms substituted with a halogen atom, -(CH2) n COOR 8 , -(CH2) n OCOR 9 , -(CH2) n NCO, -(CH2) n NO2, -(CH2) n CN, -(CH2) n CONR 10 R 11 , -(CH2) n NR 10 R 11 , -(CH2) n OZ, -(CH2) n W, or X 1 and Y 1 or X 2 and Y 1 composed of (-CO)2O, (-CO)2NR 12 is shown. Here, R 8 ,R9 ,R 10 ,R 11 ,R 12 is a hydrogen atom, a hydrocarbon group having 1 to 20 carbon atoms, Z is a hydrocarbon group having 1 to 10 carbon atoms or a hydrocarbon group having 1 to 10 carbon atoms substituted with a halogen, and W is SiR 13 p D 3-p (R 13 -OCOR is a hydrocarbon group with 1 to 10 carbon atoms, D is a halogen atom, and -OCOR 14 OR 14 (where p represents an integer from 0 to 3). 14 represents a hydrogen atom or a hydrocarbon group having 1 to 10 carbon atoms, and n represents an integer from 0 to 10.

[0061] The norbornene-based polymer hydrides are synthesized by hydrogenation after addition polymerization or metathesis ring-opening polymerization of a polycyclic unsaturated compound, as disclosed in Japanese Patent Publication No. 1-240517, Japanese Patent Publication No. 7-196736, Japanese Patent Publication No. 60-26024, Japanese Patent Publication No. 62-19801, Japanese Patent Publication No. 2003-1159767, or Japanese Patent Publication No. 2004-309979, etc. In the norbornene polymer, R 5 ~R 7 X is preferably a hydrogen atom or -CH3. 2 The group is preferably a hydrogen atom, Cl, or -COOCH3, and other groups are selected as appropriate. The norbornene-based resin is commercially available from JSR Corporation under the trade name Arton, and from Zeon Corporation under the trade names Zeonor and Zeonex.

[0062] The norbornene-based addition (co)polymers are disclosed in Japanese Patent Publication No. 10-7732, Japanese Patent Publication No. 2002-504184, US Publication No. 2004229157A1, or WO2004 / 070463A1, etc. They are obtained by addition polymerization of norbornene-based polycyclic unsaturated compounds. Alternatively, norbornene-based polycyclic unsaturated compounds can also be added polymerized with conjugated dienes such as ethylene, propylene, butene, butadiene, and isoprene; unconjugated dienes such as ethylidene norbornene; and linear diene compounds such as acrylonitrile, acrylic acid, methacrylic acid, maleic anhydride, acrylic acid esters, methacrylic acid esters, maleimide, vinyl acetate, and vinyl chloride. The norbornene-based addition (co)polymer is commercially available from Mitsui Chemicals, Inc. under the trade name Apel. Additionally, pellets are commercially available from Polyplastics Corporation under the trade name TOPAS.

[0063] The glass transition temperature (Tg) of the aliphatic cyclic polyolefin resin is preferably 140°C or lower, more preferably 135°C or lower, and even more preferably 120°C or lower. By using a low-Tg aliphatic cyclic polyolefin resin with a glass transition temperature of 140°C or lower, the temperature responsiveness (based on the breakdown of hydrogen bonds) of the porous polyurea particles holding the aluminum chelate compound is not inhibited even when coated with the aliphatic cyclic polyolefin resin.

[0064] The amount of aliphatic cyclic polyolefin resin attached (coating) to the curing catalyst is not particularly limited as long as it enables curing at a lower temperature than conventional methods and significantly improves the one-component storage stability. It can be appropriately selected according to the purpose.

[0065] (Method of manufacturing the hardening agent) The present invention provides a method for producing a curing agent, in which a dispersion is obtained by spray-drying a dispersion in which either polyurea porous particles holding an aluminum chelate compound or a water-insoluble catalyst powder having a solubility in water of 5% by mass or less is dispersed in an organic solvent containing an aliphatic cyclic polyolefin resin in an amount of 1% by mass or less. The content of aliphatic cyclic polyolefin resin in the organic solvent is 1% by mass or less, preferably 0.5% by mass or less, and more preferably 0.1% by mass or less. The lower limit of the content is preferably 0.01% by mass or more. If the aliphatic cyclic polyolefin resin content in the organic solvent exceeds 1% by mass, problems such as stringing and the formation of coarse particles may occur during spray drying. The content of polyurea porous particles holding the aluminum chelate compound in the dispersion, or water-insoluble catalyst powder having a solubility in water of 5% by mass or less, is preferably 5% by mass or more and 30% by mass or less.

[0066] The organic solvents preferably include, for example, chlorine-based solvents such as dichloromethane and chloroform; and solvents selected from chain hydrocarbons having 3 to 12 carbon atoms, cyclic hydrocarbons having 3 to 12 carbon atoms, aromatic hydrocarbons having 6 to 12 carbon atoms, esters, ketones, and ethers. The esters, ketones, and ethers may have a cyclic structure. Examples of chain hydrocarbons having 3 to 12 carbon atoms include hexane, octane, isooctane, and decane. Examples of cyclic hydrocarbons having 3 to 12 carbon atoms include cyclopentane, cyclohexane, or derivatives thereof. Examples of aromatic hydrocarbons with 6 to 12 carbon atoms include benzene, toluene, and xylene. Examples of esters include ethyl formate, propyl formate, pentyl formate, methyl acetate, ethyl acetate, and pentyl acetate. Examples of ketones include acetone, methyl ethyl ketone, diethyl ketone, diisobutyl ketone, cyclopentanone, cyclohexanone, and methylcyclohexanone. Examples of ethers include diisopropyl ether, dimethoxymethane, dimethoxyethane, 1,4-dioxane, 1,3-dioxolane, tetrahydrofuran, anisole, and phenethole.

[0067] Spray drying is not particularly limited and can be carried out using known spray drying equipment. The resulting curing agent can be washed with an organic solvent as needed, roughly crushed, dried, and then crushed into primary particles using a known crushing device. There are no particular restrictions on the organic solvent used for the cleaning, and it can be appropriately selected depending on the purpose, but a non-polar solvent is preferred. Examples of the non-polar solvent include hydrocarbon solvents. Examples of the hydrocarbon solvent include toluene, xylene, and cyclohexane.

[0068] (Curing composition) The curing composition of the present invention contains the curing agent of the present invention and an epoxy resin, preferably contains a silanol compound, and may further contain other components as needed.

[0069] <Hardening agent> The curing agent contained in the curing composition is the curing agent of the present invention.

[0070] There are no particular restrictions on the content of the curing agent in the curing composition, and it can be appropriately selected depending on the purpose, but it is preferably 1 part by mass or more and 70 parts by mass or less, and more preferably 1 part by mass or more and 50 parts by mass or less, per 100 parts by mass of epoxy resin. If the content is less than 1 part by mass, the curability may decrease, and if it exceeds 70 parts by mass, the resin properties of the cured product (e.g., flexibility) may decrease.

[0071] <Epoxy resin> The epoxy resin is not particularly limited and can be appropriately selected depending on the purpose. Examples include alicyclic epoxy resins, glycidyl ether type epoxy resins, glycidyl ester type epoxy resins, or solvent-containing epoxy resins obtained by dissolving these in a solvent.

[0072] The alicyclic epoxy resin is not particularly limited and can be appropriately selected depending on the purpose. Examples include vinylcyclopentadiene dioxide, vinylcyclohexene mono or dioxide, dicyclopentadiene oxide, epoxy-[epoxy-oxaspiro C 8-15 Alkyl]-CycloC 5-12 Alkanes (e.g., 3,4-epoxy-1-[8,9-epoxy-2,4-dioxaspiro[5.5]undecane-3-yl]cyclohexane, etc.), 3,4-epoxycyclohexylmethyl-3',4'-epoxycyclohexanecarborate, epoxy C 5-12 Cycloalkyl C 1-3 Alkyl-epoxy C 5-12 Cycloalkane carboxylates (e.g., 4,5-epoxycyclooctylmethyl-4',5'-epoxycyclooctanecarboxylate, etc.), bis(C) 1-3 Alkyl-epoxy C 5-12 Cycloalkyl C 1-3 Examples include alkyl dicarboxylates (for example, bis(2-methyl-3,4-epoxycyclohexylmethyl) adipate). These may be used individually or in combination of two or more.

[0073] Furthermore, as an alicyclic epoxy resin, 3,4-epoxycyclohexylmethyl-3',4'-epoxycyclohexanecarboxylate (manufactured by Daicel Corporation, trade name: Celoxide #2021P, epoxy equivalent: 128-140) is preferably used because it is readily available as a commercially available product.

[0074] In addition, in the above examples, C 8-15 , C 5-12 , C 1-3The notation indicates that the number of carbon atoms is 8-15, 5-12, and 1-3, respectively, showing that there is a range in the structure of the compound.

[0075] The structural formula of an example of the alicyclic epoxy resin is shown below. [ka]

[0076] The glycidyl ether-type epoxy resin or glycidyl ester-type epoxy resin may be liquid or solid, and preferably has an epoxy equivalent of approximately 100 to 4,000 and contains two or more epoxy groups in its molecule. Examples include bisphenol A-type epoxy resin, bisphenol F-type epoxy resin, phenol novolac-type epoxy resin, cresol novolac-type epoxy resin, and phthalate ester-type epoxy resin. These may be used individually or in combination of two or more. Among these, bisphenol A-type epoxy resin is preferred in terms of resin properties. These epoxy resins also include monomers and oligomers.

[0077] <Silanol compounds> Examples of the silanol compounds include arylsilanol compounds. The aforementioned arylsilanol compound is represented, for example, by the following general formula (A).

[0078] [ka] However, in the general formula (A) above, m is 2 or 3, preferably 3, and the sum of m and n is 4. Ar is an aryl group which may have substituents. The arylsilanol compound represented by the general formula (A) is either a monool or a diol.

[0079] In the general formula (A) above, Ar is an aryl group which may have substituents. Examples of the aryl group include phenyl group, naphthyl group (e.g., 1-naphthyl group, 2-naphthyl group, etc.), anthracenyl group (e.g., 1-anthracenyl group, 2-anthracenyl group, 9-anthracenyl group, benz[a]-9-anthracenyl group, etc.), phenalyl group (e.g., 3-phenalyl group, 9-phenalyl group, etc.), pyrenyl group (e.g., 1-pyrenyl group, etc.), azlenyl group, fluorenyl group, biphenyl group (e.g., 2-biphenyl group, 3-biphenyl group, 4-biphenyl group, etc.), thienyl group, furyl group, pyrrolyl group, imidazolyl group, and pyridyl group. These may be used individually or in combination of two or more. Among these, the phenyl group is preferred from the viewpoint of availability and cost of acquisition. The m Ar groups may all be the same or different, but it is preferable that they be the same from the viewpoint of availability.

[0080] These aryl groups may have, for example, 1 to 3 substituents. Examples of the substituents include electron-withdrawing groups and electron-donating groups. Examples of the electron-withdrawing groups include halogen groups (e.g., chloro group, bromo group, etc.), trifluoromethyl group, nitro group, sulfo group, carboxyl group, alkoxycarbonyl group (e.g., methoxycarbonyl group, ethoxycarbonyl group, etc.), and formyl group. Examples of the electron-donating groups include alkyl groups (e.g., methyl group, ethyl group, propyl group, etc.), alkoxy groups (e.g., methoxy group, ethoxy group, etc.), hydroxyl groups, amino groups, monoalkylamino groups (e.g., monomethylamino group, etc.), and dialkylamino groups (e.g., dimethylamino group, etc.).

[0081] Specific examples of substituted phenyl groups include, for example, 2-methylphenyl group, 3-methylphenyl group, 4-methylphenyl group, 2,6-dimethylphenyl group, 3,5-dimethylphenyl group, 2,4-dimethylphenyl group, 2,3-dimethylphenyl group, 2,5-dimethylphenyl group, 3,4-dimethylphenyl group, 2,4,6-trimethylphenyl group, 2-ethylphenyl group, and 4-ethylphenyl group.

[0082] Furthermore, by using electron-withdrawing groups as substituents, the acidity of the hydroxyl group of the silanol group can be increased. By using electron-donating groups as substituents, the acidity of the hydroxyl group of the silanol group can be decreased. Therefore, the curing activity can be controlled by the substituents. Here, each of the m Ar atoms may have a different substituent, but it is preferable that the substituents be the same for all m Ar atoms due to ease of availability. Furthermore, some of the Ar atoms may have substituents while others do not.

[0083] Among these, triphenylsilanol and diphenylsilanediol are preferred, with triphenylsilanol being particularly preferred.

[0084] <Other ingredients> The aforementioned other components are not particularly limited and can be appropriately selected depending on the purpose. Examples include oxetane compounds, silane coupling agents, fillers, pigments, and antistatic agents.

[0085] <<Oxetane Compounds>> In the curing composition, the exothermic peak can be made sharper by using the oxetane compound in combination with the epoxy resin. Examples of the oxetane compounds include 3-ethyl-3-hydroxymethyloxetane, 1,4-bis{[(3-ethyl-3-oxetanyl)methoxy]methyl}benzene, 4,4'-bis[(3-ethyl-3-oxetanyl)methoxymethyl]biphenyl, 1,4-benzenedicarboxylate bis[(3-ethyl-3-oxetanyl)]methyl ester, 3-ethyl-3-(phenoxymethyl)oxetane, 3-ethyl-3-(2-ethylhexyloxymethyl)oxetane, di[1-ethyl(3-oxetanyl)]methyl ether, 3-ethyl-3-{[3-(triethoxysilyl)propoxy]methyl}oxetane, oxetanylsilsesquioxane, and phenol novolac oxetane. These may be used individually or in combination of two or more.

[0086] There are no particular restrictions on the content of the oxetane compound in the curing composition, and it can be appropriately selected depending on the purpose, but it is preferably 10 parts by mass or more and 100 parts by mass or less, and more preferably 20 parts by mass or more and 70 parts by mass or less, per 100 parts by mass of the epoxy resin.

[0087] <<Silane coupling agent>> As described in paragraphs

[0007] to

[0010] of Japanese Patent Publication No. 2002-212537, the silane coupling agent has the function of cooperating with an aluminum chelate compound to initiate cationic polymerization of the epoxy resin. Therefore, by using a small amount of such a silane coupling agent in combination, the effect of accelerating the curing of the epoxy resin can be obtained. Such a silane coupling agent has 1 to 3 lower alkoxy groups in its molecule, and may also have reactive groups in its molecule, such as a vinyl group, styryl group, acryloyloxy group, methacryloyloxy group, epoxy group, amino group, mercapto group, etc. Coupling agents having amino groups or mercapto groups can be used when the curing agent of the present invention is a cationic curing agent and the amino groups or mercapto groups do not substantially capture the generated cation species.

[0088] Examples of the silane coupling agent include vinyltris(β-methoxyethoxy)silane, vinyltriethoxysilane, vinyltrimethoxysilane, γ-styryltrimethoxysilane, γ-methacryloxypropyltrimethoxysilane, γ-acryloxypropyltrimethoxysilane, β-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropylmethyldiethoxysilane, N-β-(aminoethyl)-γ-aminopropyltrimethoxysilane, N-β-(aminoethyl)-γ-aminopropylmethyldimethoxysilane, γ-aminopropyltriethoxysilane, N-phenyl-γ-aminopropyltrimethoxysilane, γ-mercaptopropyltrimethoxysilane, and γ-chloropropyltrimethoxysilane. These may be used individually or in combination of two or more.

[0089] There are no particular restrictions on the content of the silane coupling agent in the curing composition, and it can be appropriately selected depending on the purpose, but it is preferably 1 to 300 parts by mass, and more preferably 1 to 100 parts by mass, per 100 parts by mass of the curing agent.

[0090] The curing composition of the present invention enables curing at lower temperatures than conventional compositions, significantly improves one-component storage stability, and offers high convenience, making it suitable for a wide range of applications in various fields. [Examples]

[0091] The following describes embodiments of the present invention, but the present invention is not limited in any way to these embodiments.

[0092] (Example 1) <Manufacturing of hardening agents> <<Porous particle fabrication process>> -Preparation of the aqueous phase- 800 parts by mass of distilled water, 0.05 parts by mass of surfactant (Newlex RT, manufactured by NOF Corporation), and 4 parts by mass of polyvinyl alcohol (PVA-205, manufactured by Kuraray Co., Ltd.) as a dispersant were placed in a 3-liter interfacial polymerization container equipped with a thermometer, and mixed uniformly to prepare the aqueous phase.

[0093] - Preparation of the oil phase - Next, an oil phase was prepared by dissolving 100 parts by mass of ethyl acetate in 100 parts by mass of a 24% by mass isopropanol solution of aluminum monoacetylacetonate bis(ethyl acetoacetate) (aluminum chelate D, manufactured by Kawaken Fine Chemicals Co., Ltd.), 70 parts by mass of a trimethylolpropane (1 mole) adduct of methylenediphenyl-4,4'-diisocyanate (3 moles) (polyfunctional isocyanate compound, D-109, manufactured by Mitsui Chemicals, Inc.), 30 parts by mass of divinylbenzene (manufactured by Merck KGaA) as a radical polymerizable compound, and a radical polymerization initiator (Perloyl L, manufactured by NOF Corporation) in an amount equivalent to 1% by mass of the radical polymerizable compound (0.3 parts by mass).

[0094] -Emulsification- The prepared oil phase was added to the previously prepared aqueous phase, mixed in a homogenizer (10,000 rpm / 5 min, T-50, manufactured by IKA Japan Co., Ltd.), and emulsified to obtain an emulsion.

[0095] -polymerization- The prepared emulsion was subjected to interfacial polymerization and radical polymerization at 80°C for 6 hours. After the reaction was complete, the polymerization reaction solution was allowed to cool to room temperature (25°C), the generated polymerization particles were filtered off, and the mixture was air-dried at room temperature (25°C) to obtain a lump-shaped curing agent. The obtained lump-shaped curing agent was crushed into primary particles using a crushing device (AO Jet Mill, manufactured by Seishin Corporation) to obtain a particulate curing agent.

[0096] -High-impregnation treatment of aluminum chelate compounds- 10.0 parts by mass of the obtained particulate curing agent was added to an aluminum chelate solution [a solution prepared by dissolving 12.5 parts by mass of an aluminum chelate compound (aluminum chelate D, manufactured by Kawaken Fine Chemical Co., Ltd.) and 25.0 parts by mass of another aluminum chelate compound (ALCH-TR, manufactured by Kawaken Fine Chemical Co., Ltd.) in 62.5 parts by mass of ethyl acetate], and the mixture was stirred at a stirring speed of 200 rpm at 80°C for 9 hours while volatilizing the ethyl acetate. After stirring, the curing agent was filtered and washed with cyclohexane to obtain a lump-shaped curing agent. The obtained lump-shaped curing agent was vacuum-dried at 30°C for 4 hours, and then crushed into primary particles using a crushing device (AO Jet Mill, manufactured by Seishin Corporation) to obtain 11 parts by mass of particulate curing agent (porous particles) highly impregnated with an aluminum chelate compound.

[0097] <Preparation of treatment solution for spray drying> APL6509T (COC resin, glass transition temperature: 80°C, manufactured by Mitsui Chemicals, Inc.) was dissolved in cyclohexane to a concentration of 0.1% by mass as an aliphatic cyclic polyolefin resin (hereinafter sometimes referred to as "APL6509T solution"). Subsequently, a particulate curing agent, which had been highly impregnated with the above aluminum chelate compound, was ultrasonically dispersed in the APL6509T solution at a concentration of 10% by mass to prepare a treatment solution for spray drying.

[0098] -Spray treatment- Using a spray drying apparatus (Mini Spray Dryer B-290, manufactured by Nippon Buchi Co., Ltd.), the treatment liquid for spray drying was spray-dried to obtain coarse-grained hardener. The inlet temperature of the hardener drying chamber was set to 45°C. The obtained coarse-grained hardener was crushed into primary particles using a crushing apparatus (AO Jet Mill, manufactured by Seishin Corporation) to obtain particulate hardener. Thus, the hardener of Example 1 was obtained.

[0099] (Example 2) In Example 1, the curing agent for Example 2 was obtained in the same manner as in Example 1, except that the concentration of APL6509T was changed to 0.01% by mass in the <Preparation of the treatment solution for spray drying> step.

[0100] (Comparative Example 1) The curing agent for Comparative Example 1 was obtained in the same manner as in Example 1, except that spray drying using an aliphatic cyclic polyolefin resin was not performed.

[0101] (Comparative Example 2) In Comparative Example 2, a curing agent consisting of porous particles surface-treated with a silane coupling agent was obtained in the same manner as in Example 1, except that 100 parts by mass of triphenylsilanol (manufactured by Tokyo Chemical Industry Co., Ltd.) was added in the <Preparation of the oil phase> and the silane coupling agent surface treatment shown below was performed instead of spray treatment.

[0102] -Silane coupling agent surface treatment- A silane coupling agent treatment solution was prepared by dissolving 240 parts by mass of epoxyalkoxysilane coupling agent (KBM-303, manufactured by Shin-Etsu Chemical Co., Ltd.) in 30 parts by mass of cyclohexane. 30 parts by mass of the particulate curing agent was added to 300 parts by mass of this treatment solution, and the silane coupling agent was surface-treated by stirring the mixture at 200 rpm at 30°C for 8 hours. After the treatment reaction was complete, the mixture was filtered and washed with cyclohexane to obtain a lump of curing agent. The obtained lump of curing agent was vacuum-dried at 30°C for 4 hours, and then crushed into primary particles using a crushing device (AO Jet Mill, manufactured by Seishin Corporation) to obtain the curing agent.

[0103] (Comparative Example 3) In Example 1, the curing agent for Comparative Example 3 was obtained in the same manner as in Example 1, except that 100 parts by mass of triphenylsilanol (manufactured by Tokyo Chemical Industry Co., Ltd.) was added in the <Preparation of the oil phase> and a coating treatment with a cured alicyclic epoxy resin, as shown below, was performed instead of spray treatment. The curing agent for Comparative Example 3 consisted of porous particles surface-treated with a cured alicyclic epoxy resin.

[0104] -Coating treatment with cured alicyclic epoxy resin- The 25 parts by mass of the particulate curing agent were put into 300 parts by mass of a solution [a solution in which 180 parts by mass of an alicyclic epoxy resin (CEL2021P, manufactured by Daicel Corporation) was dissolved in 120 parts by mass of cyclohexane], and stirred at 30°C for 20 hours at 200 rpm. During this stirring, the alicyclic epoxy resin polymerized and cured on the surface of the porous particles. As a result, a film composed of the cured product of the alicyclic epoxy resin was formed on the surface of the porous particles. After completion of the stirring, filtration was carried out, and washing with cyclohexane was performed to obtain a块状 curing agent. The obtained块状 curing agent was vacuum dried at 30°C for 4 hours, and then crushed into primary particles using a crushing device (A-O Jet Mill, manufactured by Seishin Enterprise Co., Ltd.) to obtain a curing agent.

[0105] <Particle size distribution> Regarding the curing agents of Examples 1 to 2 and Comparative Example 1, the volume-based particle size distribution was measured using MT3300EXII (laser diffraction / scattering method, manufactured by Microtrac·BEL Corporation). The results are shown in Table 1 and FIG. 1.

[0106]

Table 1

[0107] <DSC measurement> Next, DSC measurements were carried out on the curing agents of Comparative Example 1, Example 1, and Example 2 as follows. The results are shown in Table 2. Also, the DSC charts of Comparative Example 1, Example 1, and Example 2 are shown in FIG. 2.

[0108] ―Composition for DSC measurement - A composition prepared so that the mass ratio was EP828:triphenylsilanol:curing agent = 80:8:4 was used as a sample for DSC measurement. ·EP828 (bisphenol A type epoxy resin, manufactured by Mitsubishi Chemical Corporation) ·Triphenylsilanol (manufactured by Tokyo Chemical Industry Co., Ltd.) • Curing agent: Curing agent for Comparative Example 1, Example 1, and Example 2

[0109] -DSC measurement conditions- • Measuring device: DSC6200 (manufactured by Hitachi High-Tech Science Co., Ltd.) • Evaluation dose: 5mg • Heating rate: 10℃ / min

[0110] [Table 2]

[0111] As shown in Figure 2 and Table 2, the COC resin-treated products of Examples 1 and 2 all showed an exothermic onset temperature that was 10°C or more higher than that of the untreated product in Comparative Example 1. Furthermore, since Examples 1 and 2 used COC resin with a low glass transition temperature (Tg), the increase in the exothermic peak temperature compared to the untreated product in Comparative Example 1 was less than 3°C.

[0112] <1-liquid storage stability> Next, the one-component storage stability of the curing agents of Comparative Example 1, Example 1, and Example 2 was evaluated based on viscosity changes as follows. The results are shown in Table 3. Figure 3 shows the viscosity changes of Comparative Example 1, Example 1, and Example 2.

[0113] -Composition for storage stability measurement- A composition prepared with a mass ratio of CEL2021P:KBM-403:triphenylsilanol:curing agent = 100:0.5:7:2 was used as a sample for measuring storage stability. • CEL2021P (alicyclic epoxy resin, manufactured by Daicel Corporation) • KBM-403 (Silane coupling agent, manufactured by Shin-Etsu Chemical Co., Ltd.) • Triphenylsilanol (manufactured by Tokyo Chemical Industry Co., Ltd.) • Curing agent: Curing agent for Comparative Example 1, Example 1, and Example 2

[0114] -Conditions for storage stability- ·Storage temperature: 25℃ • Storage period: 48 hours • Viscosity measurement: SV-10 (Tuning fork vibration viscometer, manufactured by A&D Company, Limited) ·Viscosity measurement temperature: 20℃

[0115] [Table 3]

[0116] From the results in Table 3 and Figure 3, it was confirmed that the curing agents treated with COC resin in Examples 1 and 2 exhibited superior high latent properties in alicyclic epoxy resins with excellent cationic polymerization properties compared to the untreated product in Comparative Example 1. Furthermore, it was found that the viscosity ratio after 48 hours in Examples 1 and 2 was 2 times or less.

[0117] <Solvent resistance evaluation> Next, the solvent resistance of the curing agents of Comparative Example 1, Comparative Example 2, Comparative Example 3, Example 1, and Example 2 was evaluated as follows. The results are shown in Table 4. Figure 4 is a chart showing the DSC measurement results for the curing agent of Comparative Example 1. Figure 5 is a chart showing the DSC measurement results for the curing agent of Comparative Example 2. Figure 6 is a chart showing the DSC measurement results for the curing agent of Example 1. Figure 7 is a chart showing the DSC measurement results for the curing agent of Example 2.

[0118] —Composition for evaluating solvent resistance— A composition prepared with a mass ratio of YP solution:YX8000:triphenylsilanol:curing agent = 50:40:7:3 was used as the sample for solvent resistance evaluation. • YP70 (Phenoxy resin, manufactured by Nippon Steel Chemical & Material Co., Ltd.) • YP70 solution (YP70 was dissolved in propylene glycol monomethyl ether acetate at a concentration of 45% by mass) • YX8000 (Hydrogenated bisphenol A epoxy resin, manufactured by Mitsubishi Chemical Corporation) · Evaluation method: The formulated product immediately after formulation (0 hours) and the formulated product left standing at room temperature (25 °C) for 4 hours were applied onto a PET film with a bar coater to a thickness of 20 μm. Then, the product dried at 80 °C for 5 minutes was evaluated using DSC. · Curing agent: The curing agents of Comparative Example 1, Comparative Example 2, Comparative Example 3, Example 1, and Example 2

[0119] - DSC measurement conditions - · Measuring device: DSC6200 (manufactured by Hitachi High-Tech Science Corporation) · Evaluation quantity: 5 mg · Heating rate: 10 °C / min

[0120]

Table 4

[0121] From the results in Table 4 and Figures 4 to 7, it was confirmed that, compared with Comparative Example 1 (untreated product), Comparative Example 2 (surface treatment with a silane coupling agent), and Comparative Example 3 (coating treatment with a cured product of an alicyclic epoxy resin), Examples 1 and 2 showed no decrease in the total heat of exotherm by DSC after standing at room temperature for 4 hours and were excellent in solvent resistance.

[0122] <Surface elemental analysis by XPS> Next, surface elemental analysis by XPS was performed on the curing agents of Comparative Example 1, Example 1, and Example 2 under the following conditions. The results are shown in Table 5.

[0123] - XPS measurement conditions - As the measuring device, XPS (PHI 5000 Versa ProbeIII, manufactured by ULVAC-PHI, Inc.) was used. As the X-ray source, AlKα was used, and as the measurement conditions, a current value of 34 mA, an acceleration voltage value of 15 kV, and a scan rate of 1 eV were used.

[0124]

Table 5

[0125] <SEM (Scanning Electron Microscope) Observation> Next, SEM photographs taken with JSM-6510A (manufactured by JEOL Ltd.) are shown for the curing agents of Comparative Example 1, Example 1, and Example 2. FIG. 8 is a 5,000-fold SEM photograph of the curing agent of Comparative Example 1. FIG. 9 is a 5,000-fold SEM photograph of the curing agent of Example 1, and FIG. 10 is a 5,000-fold SEM photograph of the curing agent of Example 2.

[0126] From the SEM photographs in FIGS. 8 to 10, since Examples 1 and 2 were coating treatments with a low concentration of COC resin, no formation of coarse particles and deformation were observed compared to untreated Comparative Example 1.

[0127] (Example 3) In Example 1, except that the COC resin (APL6509T) was changed to a COP resin (ZNR1020, glass transition temperature Tg: 102°C, manufactured by Nippon Zeon Co., Ltd.) in <Preparation of Treatment Liquid for Spray Drying>, the curing agent of Example 3 was obtained in the same manner as in Example 1.

[0128] <DSC Measurement> Next, DSC measurement was performed on the curing agent of Example 3 in the same manner as in Example 1. The results are shown in Table 6. Also, the DSC charts of Comparative Example 1 and Example 3 are shown in FIG. 11.

[0129]

Table 6

[0130] The results in Table 6 and Figure 11 confirm a significant increase in the exothermic onset temperature even in the COP treatment. Although the increase in the exothermic peak temperature was greater compared to the COC treatment, it was less than 3°C, so it is consistent with claim 9 and there is no problem (PT1-PT2≦5°C).

[0131] <1-liquid storage stability> Next, the one-component storage stability of the curing agent in Example 3 was evaluated based on viscosity changes in the same manner as in Example 1. The results are shown in Table 7. The viscosity changes of Comparative Example 1 and Example 3 are shown in Figure 12.

[0132] [Table 7]

[0133] (Example 4) -Water-insoluble catalyst powder- In Example 4, the curing agent was obtained by treating with APL6509T at a concentration of 0.1% by mass, in the same manner as in Example 1, except that the particulate curing agent (porous particles) highly impregnated with an aluminum chelate compound was replaced with a water-insoluble catalyst powder: CureDuct P-0505 (imidazole adduct, manufactured by Shikoku Chemicals, Inc.).

[0134] (Example 5) -Water-insoluble catalyst powder- In Example 5, the curing agent was obtained by treating with APL6509T at a concentration of 0.1% by mass, in the same manner as in Example 1, except that the particulate curing agent (porous particles) highly impregnated with an aluminum chelate compound was replaced with a water-insoluble catalyst powder: Amicure MY-24 (aliphatic amine adduct, manufactured by Ajinomoto Fine Techno Co., Ltd.).

[0135] (Comparative Example 4) The curing agent for Comparative Example 4 was obtained in the same manner as in Example 4, except that spray drying using an aliphatic cyclic polyolefin resin was not performed.

[0136] (Comparative Example 5) In Comparative Example 5, a curing agent was obtained in the same manner as in Example 5, except that spray drying using an aliphatic cyclic polyolefin resin was not performed.

[0137] <Water solubility test> 5 g of Cureduct P-0505 (imidazole adduct, manufactured by Shikoku Kasei Co., Ltd.) or Amicure MY-24 (aliphatic amine adduct, manufactured by Ajinomoto Fine-Techno Co., Inc.) was added to 95 g of water at 25°C, and after stirring for 24 hours while stirring with a stirrer, when the liquid obtained through a filter with an average pore size of 0.1 μm was measured using a thermogravimetric differential thermal analyzer (TG / DTA), usually, in the high temperature region of 200°C or higher, 87.2% of P-0505 and 74.5% of MY-24 should have a weight decrease, but in either case, no weight decrease could be confirmed. Therefore, it was confirmed that Cureduct P-0505 and Amicure MY-24 do not dissolve in water (the solubility in water is 5 mass% or less).

[0138] Next, for the curing agents of Example 4 and Comparative Example 4 (untreated product), the volume-based particle size distribution was measured using MT3300EXII (laser diffraction / scattering method, manufactured by Microtrac Bell Corporation). The results are shown in Table 8 and Figure 13.

[0139]

Table 8

[0140] From the results of Table 8 and Figure 13, in Example 4, since the COC resin concentration in the treatment liquid was set to a low concentration of less than 1 mass%, no formation of coarse particles due to the COC resin coating treatment was observed.

[0141] <DSC measurement> Next, DSC measurements were performed on the curing agents of Comparative Example 4, Comparative Example 5, Example 4, and Example 5 as follows. The results are shown in Table 9. Also, the DSC charts of Comparative Example 4 and Example 4 are shown in Figure 14, and the DSC charts of Comparative Example 5 and Example 5 are shown in Figure 15.

[0142] -Composition for DSC measurement- A composition prepared with a mass ratio of EP828:curing agent = 72:8 was used as the sample for DSC measurement. • EP828 (Bisphenol A type epoxy resin, manufactured by Mitsubishi Chemical Corporation) • Curing agent: Curing agent for Comparative Example 4, Comparative Example 5, Example 4, and Example 5

[0143] -DSC measurement conditions- • Measuring device: DSC6200 (manufactured by Hitachi High-Tech Science Co., Ltd.) • Dosage: 5mg • Heating rate: 10℃ / min

[0144] [Table 9]

[0145] From the results in Table 9, Figure 14, and Figure 15, it can be seen that in Examples 4 and 5, the COC resin coating treatment increased the exothermic onset temperature compared to Comparative Examples 4 and 5 (which were untreated), but the increase in the peak exothermic temperature was less than +3°C.

[0146] <1-liquid storage stability> Next, the one-component storage stability of the curing agents for Comparative Example 4, Example 4, Comparative Example 5, and Example 5 was evaluated as follows. The results for Comparative Example 4 and Example 4 are shown in Table 10, and the results for Comparative Example 5 and Example 5 are shown in Table 11. The results for Comparative Example 4 and Example 4 are shown in Figure 16. The results for Comparative Example 5 and Example 5 are shown in Figure 17.

[0147] -Composition for storage stability measurement- A composition prepared with a mass ratio of EP828:curing agent = 72:8 was used as the sample for DSC measurement. • EP828 (Bisphenol A type epoxy resin, manufactured by Mitsubishi Chemical Corporation) • Curing agent: Curing agent of Comparative Example 4, Example 4, and Comparative Example 5, Example 5

[0148] -Storage stability conditions- ·Storage temperature: 30°C ·Storage period: 72 hours (Comparative Example 4 and Example 4), 168 hours (Comparative Example 5 and Example 5) ·Viscosity measurement: SV-10 (fork vibration type viscometer, manufactured by A&D Company, Limited) ·Viscosity measurement temperature: 20°C

[0149]

Table 10

[0150]

Table 11

[0151] From the results of Table 10, Table 11, Figure 16, and Figure 17, even under storage at 30°C, the viscosity magnification factor of Example 4 treated with COC resin after 72 hours was less than 1.2 times. Also, in Example 5, the viscosity magnification factor after 168 hours was less than 1.1 times.

[0152] <Surface elemental analysis by XPS> Next, surface elemental analysis by XPS was performed on the curing agents of Comparative Example 4, Comparative Example 5, Example 4, and Example 5 under the following conditions. The results are shown in Table 12.

[0153] -XPS measurement conditions- As the measurement apparatus, XPS (PHI 5000 Versa ProbeIII, manufactured by ULVAC-PHI, Inc.) was used. As the X-ray source, AlKα was used, and as the measurement conditions, a current value of 34 mA, an acceleration voltage value of 15 kV, and a scan speed of 1 eV were used.

[0154]

Table 12

[0155] <Method for Confirming the Presence of Aliphatic Cyclic Polyolefin Resin on the Surface of Curing Catalyst> The presence of aliphatic cyclic polyolefin resin on the surface of the curing catalyst was confirmed as follows.

[0156] First, for the COC resin (APL6509T, glass transition temperature Tg: 80°C, manufactured by Mitsui Chemicals, Inc.), TG was measured under the following conditions. The results are shown in Fig. 18.

[0157] -TG Measurement Conditions- ·TG / DTA6200 (manufactured by Hitachi High-Tech Science Corporation) ·Heating rate: 10°C / min ·Measured weight: 5 mg

[0158] From the results in Fig. 18, it was confirmed that the COC resin (APL6509T) decreased in weight by about 92% when heated from 400°C to 500°C. Subsequently, Fig. 19 shows the correlation graph of the COC resin concentration and TG (mg) measured by applying this method. The measurement was carried out using a solution of the COC resin dissolved in chlorobenzene. TG plotted the weight loss value in the range of 400°C to 500°C.

[0159] <Quantification of COC Content in COC-Treated Curing Catalyst Particles> Based on the correlation graph in Fig. 19 above, quantitative analysis of the COC resin content in Examples 1 and 2 was performed.

[0160] -Measurement Method- The COC resin-treated curing catalysts (Examples 1 and 2) were dispersed in chlorobenzene at a concentration of 25% by mass and stirred at 200 rpm for 7 days at room temperature to dissolve the COC resin. After removing the curing catalyst using a filter with an average pore size of 0.45 μm, the COC resin concentration in the recovered liquid was measured using TG / DTA, and the COC resin concentration in the measured liquid was calculated using the COC resin concentration-TG correlation graph. Subsequently, the COC resin ratio contained in the curing catalyst was calculated from the amount of treated curing catalyst and the volume of liquid. The results are shown in Table 13.

[0161] [Table 13] *In Table 13, TG (mg) indicates the weight loss between 400°C and 500°C. From the results in Table 13, the COC resin ratio of the curing catalyst in Example 1 was 0.26% by mass, and the COC resin ratio of the curing catalyst in Example 2 was 0.06% by mass. Therefore, it was confirmed that the COC resin coated the surface of the curing catalyst particles in a thin film state.

[0162] As described above, a curing agent obtained by coating the surface of a curing catalyst, which is either a porous polyurea particle holding an aluminum chelate compound or a non-water-soluble catalyst powder with a water solubility of 5% by mass or less, with an aliphatic cyclic polyolefin resin, allows for curing at lower temperatures than conventional methods. Furthermore, it has been found that incorporating this curing agent results in an epoxy resin composition with significantly improved one-component storage stability.

Claims

1. A curing catalyst, and a curing agent having an aliphatic cyclic polyolefin resin on the surface of the curing catalyst, Epoxy resin and A curing composition containing, The curing catalyst is either a porous polyurea particle holding an aluminum chelate compound, or a non-water-soluble catalyst powder having a solubility in water of 5% by mass or less. The water-insoluble catalyst powder is an amine adduct compound. A curing composition characterized in that the glass transition temperature of the aliphatic cyclic polyolefin resin is 80°C or higher, and the exothermic peak temperature PT1 of the curing composition in differential scanning calorimetry is 10°C or lower.

2. The curing composition according to claim 1, wherein the non-water-soluble catalyst powder comprises a curable resin.

3. The curing composition according to any one of claims 1 to 2, wherein the volume average particle diameter of the curing catalyst is 10 μm or less.

4. The curing composition according to any one of claims 1 to 3, wherein the amine adduct compound is either an imidazole adduct or an aliphatic amine adduct.

5. The curing composition according to any one of claims 1 to 4, wherein the aliphatic cyclic polyolefin resin is at least one of a cycloolefin copolymer (COC) and a cycloolefin homopolymer (COP).

6. The amount of carbon atoms in the curing agent, measured by X-ray photoelectron spectroscopy (XPS), is defined as C1 (atomic %). When the amount of carbon atoms in the curing agent obtained by removing the aliphatic cyclic polyolefin resin from the curing agent is measured by XPS and defined as C2 (atomic %), A curing composition according to any one of claims 1 to 5, satisfying the following formula: [(C1 - C2) / C2] × 100 ≥ 1%.

7. Let ST1 (°C) be the exothermic start temperature in the differential scanning calorimetry of the curing composition, and PT1 be the exothermic peak temperature. When the heating start temperature in differential scanning calorimetry for a curing composition containing a curing agent obtained by removing the aliphatic cyclic polyolefin resin from the curing agent is ST2 (°C) and the heating peak temperature is PT2 (°C), A curing composition according to any one of claims 1 to 6, satisfying the following equation: ST1 - ST2 ≥ 4°C, PT1 - PT2 ≤ 5°C.

8. The curing composition according to any one of claims 1 to 7, wherein the epoxy resin is at least one selected from alicyclic epoxy resins, glycidyl ether type epoxy resins, glycidyl ester type epoxy resins, and solvent-containing epoxy resins obtained by dissolving these in a solvent.

9. The curing composition according to any one of claims 1 to 8, further comprising a silanol compound.

10. A dispersion is prepared by spray-drying a dispersion in which a curing catalyst is dispersed in an organic solvent containing an aliphatic cyclic polyolefin resin in a content of 1% by mass or less, and either polyurea porous particles holding an aluminum chelate compound or a water-insoluble catalyst powder having a solubility in water of 5% by mass or less. The curing composition is obtained by mixing the curing catalyst having the aliphatic cyclic polyolefin resin on the surface after spray drying with the epoxy resin. Includes, The water-insoluble catalyst powder is an amine adduct compound. A method for producing a curing composition, characterized in that the glass transition temperature of the aliphatic cyclic polyolefin resin is 80°C or higher, and the exothermic peak temperature PT1 of the curing composition in differential scanning calorimetry is 10°C or lower.

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