JP5130501B2 - Latent curing agent - Google Patents

Description

  The present invention is a thermosetting composition containing an aluminum chelate-based latent curing agent, which is excellent in the latency and storage stability of the aluminum chelate-based latent curing agent in the composition, and has a sharp DSC exothermic peak. The present invention relates to a thermosetting composition.

  Thermosetting resin compositions such as epoxy resins are widely used as adhesive materials, molding materials, etc., but latent imidazole-based curing agents are used as one of the curing agents. Since this latent imidazole-based curing agent does not exhibit curing ability under normal storage conditions, the thermosetting epoxy resin composition is made into a one-pack type curing composition having good handleability and good storage stability. Widely used in As a typical example of such a latent imidazole curing agent, a microcapsule type in which the surface of an imidazole compound particle having the ability to cure an epoxy resin is coated with a cured epoxy resin is known.

  However, such a microcapsule-type latent imidazole-based curing agent has a relatively stable coating, both mechanically and thermally, so that it is heated to 180 ° C. or higher in order to initiate the curing reaction. It was necessary to press. For this reason, there has been a problem that it cannot cope with recent low-temperature curing type epoxy resin compositions.

  Therefore, without using a toxic co-catalyst such as antimony, as a latent curing agent that exhibits low-temperature fast curing properties, it generates protonic acid in cooperation with a silanol (silane coupling agent, etc.) that is a cocatalyst. Polyvinyl alcohol fine particles having hydroxyl groups that react with the aluminum chelating agent by the hybridization method on the surface of aluminum chelating agent particles (mother particles) capable of cationic ring-opening polymerization of cyclic ethers (epoxy compounds and oxetane compounds) ( A microcapsule-type aluminum chelate-based latent curing agent (Patent Document 1) formed by melting and adhering the child particles) to form a polyvinyl alcohol coating layer on the surface of the mother particles, and a functional group capable of reacting with the aluminum chelating agent Hive after electrostatically attaching non-fluororesin fine particles (child particles) The fluorine resin particles by melting integrated micro capsule obtained by forming a coating layer on the surface of the base particles the aluminum chelate-based latent curing agent (Patent Document 2) have been proposed by the die internalization process.

The details of the curing step of the aluminum chelate-based latent curing agent are described in paragraphs 0007 to 0010 of Patent Document 1 described above.
JP 2002-368047 A JP 2002-363255 A

  However, as described in Patent Documents 1 and 2, in the case of an aluminum chelate-based latent curing agent microencapsulated using a hybridization method, the child particles collide and melt with the mother particles, or electrostatic Because the microcapsule wall is formed by friction-melting the adhering child particles to each other, irregularities and unevenness are likely to occur on the surface, and stable curing characteristics cannot be obtained, and the curing conditions must be controlled. It was difficult. Moreover, since the polymerization start temperature with respect to the exothermic peak of DSC (differential thermal analysis) of the thermosetting epoxy resin composition which mix | blended such a hardening | curing agent was too low, it was hard to say that latency was sufficient. It has also been demanded to show a sharper exothermic peak.

  An object of the present invention is to solve the above-mentioned problems of the prior art, and an aluminum chelate-based latent curing capable of cationically curing a thermosetting compound at a relatively low temperature in a short time. It is intended to provide a thermosetting composition that can ensure sufficient potential and storage stability while containing an agent, and exhibits a sharp DSC exothermic peak.

  The present inventors reacted an aluminum chelating agent and a silsesquioxane-type oxetane derivative by heating in a non-aqueous solvent in the presence of a water-insoluble or poorly water-soluble cellulose ether, and formed an aluminum chelate as a precipitate. The above-mentioned object can be achieved by blending a trialkoxysilyl group-containing coupling agent having 2 or more carbon atoms of an alkoxy group into a thermosetting composition comprising a system latent curing agent and a thermosetting compound. The present invention was completed.

  That is, the present invention provides an aluminum chelate latent curing agent obtained by reacting an aluminum chelating agent with a silsesquioxane-type oxetane derivative in the presence of a water-insoluble or poorly water-soluble cellulose ether, A thermosetting composition containing an alkoxysilyl group-containing coupling agent and a thermosetting compound, wherein each alkoxy group of the trialkoxysilyl group-containing coupling agent has 2 or more carbon atoms A thermosetting composition is provided.

  The thermosetting composition of the present invention comprises an aluminum chelate latent curing agent made latent by reacting an aluminum chelating agent with a silsesquioxane type oxetane derivative in the presence of a water-insoluble or poorly water-soluble cellulose ether. contains. This aluminum chelate-based latent curing agent can be used in the same applications as conventional imidazole-based latent curing agents. Therefore, by using in combination with a silane coupling agent and a thermosetting compound, low temperature fast curing The thermosetting composition can be provided. By the way, since the oxetane ring of the silsesquioxane type oxetane derivative has higher nucleophilicity of ether oxygen than oxirane ring and has excellent cationic polymerizability, it undergoes ring-opening polymerization by the action of an aluminum chelating agent. In addition, some alkoxysilyl groups in the polymer may be hydrolyzed by a small amount of water in the polymerization system to generate silanol groups, or silanol groups are present in silsesquioxane type oxetane derivatives from the beginning. In some cases, these silanol groups interact with the aluminum chelating agent, and the aluminum chelating agent is combined and integrated with the polymer. Next, when the polymerization reaction is stopped and the temperature of the polymer solution is lowered, ethyl cellulose cannot be completely dissolved in the solution, and a microcapsule wall is formed around the polymer. Therefore, a non-aqueous type aluminum chelate curing agent is latent. Therefore, an aluminum chelating agent that is liquid at room temperature can also be used as a latent curing agent.

  Such a non-aqueous type aluminum chelate-based latent curing agent can cure thermosetting compounds such as epoxy resins and oxetane compounds at a relatively low temperature in a short time if the microcapsule wall is dissolved. Is possible. Moreover, since this aluminum chelate type | system | group latent hardening | curing agent can be manufactured in a non-aqueous solvent, it can avoid deactivating and can suppress the fall of hardening performance.

  Furthermore, the thermosetting composition of the present invention contains a trialkoxysilyl group-containing coupling agent in which each alkoxy group has 2 or more carbon atoms. A thermosetting composition containing such a coupling agent has a sharp DSC exothermic peak. Further, the heat generation start temperature is 70 ° C. or higher. In addition, the thermosetting composition containing a trialkoxysilyl group-containing coupling agent having an alkoxy group having 1 carbon atom (methoxy group) has an exotherm starting temperature of about 50 to 60 ° C., and has potential and storage stability. In many cases, the trialkoxysilyl group-containing coupling agent having an alkoxy group having 1 carbon atom contains a trialkoxysilyl group in which each alkoxy group has 2 or more carbon atoms. When a coupling agent is used in combination, the heat generation starting temperature of the thermosetting composition can be shifted to the high temperature side, and in many cases, the heat generation peak temperature can also be shifted to the high temperature side.

The present invention relates to an aluminum chelate latent curing agent obtained by reacting an aluminum chelating agent with a silsesquioxane type oxetane derivative in the presence of a water-insoluble or poorly water-soluble cellulose ether, and trialkoxysilyl. It is a thermosetting composition containing a group-containing coupling agent and a thermosetting compound.

The trialkoxysilyl group-containing coupling agent is used in combination with an aluminum chelating agent as described in paragraphs 0010 to 0014 of JP-A-2002-368047, for example, a thermosetting resin (for example, a thermosetting epoxy). Resin) has a function of initiating cationic polymerization. In addition, the trialkoxysilyl group-containing coupling agent caps a hydroxyl group that can remain an unstable and poisonous catalyst remaining in the water-insoluble or poorly water-soluble cellulose ether after the curing reaction, and also has a function of stabilizing the reaction system. It is thought to have. Each alkoxy group of such a trialkoxysilyl group-containing coupling agent has 2 or more carbon atoms, and a preferred trialkoxysilyl group includes a triethoxysilyl group. In addition, the trialkoxysilyl group-containing coupling agent is a group having reactivity in the molecule with respect to the functional group of the thermosetting resin, for example, vinyl group, styryl group, acryloyloxy group, methacryloyloxy group, epoxy group. , Amino group, mercapto group, oxetanyl group and the like. Of these, an epoxy group and an oxetanyl group are preferable. Therefore, preferred trialkoxysilyl group-containing coupling agents include epoxy-based trialkoxysilyl group-containing coupling agents having an epoxy group in the molecule and oxetane-based trialkoxysilyl group-containing coupling agents having an oxetanyl group.

  A particularly preferred oxetane-based trialkoxysilyl group-containing coupling agent is a compound represented by the formula (2).

A particularly preferred epoxy-based trialkoxysilyl group-containing coupling agent is a compound represented by the formula (3).

  When the content of the trialkoxysilyl group-containing coupling agent in the thermosetting composition of the present invention is too small, the curability is low, and when it is too large, the resin properties (eg, storage stability) of the cured product of the composition are low. Therefore, the amount is preferably 1 to 1000 parts by weight, more preferably 50 to 500 parts by weight with respect to 100 parts by weight of the aluminum chelate-based latent curing agent.

  The thermosetting composition of the present invention contains a trialkoxysilyl group-containing coupling agent in which each alkoxy group has 2 or more carbon atoms. However, if necessary, other silane coupling agents may be used in combination. Good. Examples of such silane coupling agents include vinyltris (2-methoxyethoxy) silane, vinyltriethoxysilane, vinyltrimethoxysilane, 3-styryltrimethoxysilane, 3-methacryloxypropyltrimethoxysilane, and 3-acryloxy. Propyltrimethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropylmethyldiethoxysilane, N-2- (aminoethyl) -3-aminopropyltrimethoxysilane, N-2- (aminoethyl) ) -3-aminopropylmethyldimethoxysilane, 3-aminopropyltriethoxysilane, N-phenyl-3-aminopropyltrimethoxysilane, 3-mercaptopropyltrimethoxysilane, 3-chloropropyltrimethoxysilane, etc. It can be.

  The aluminum chelate-based latent curing agent, which is one component constituting the thermosetting composition of the present invention, is an aluminum chelating agent containing a silsesquioxane-type oxetane derivative and the presence of a water-insoluble or poorly water-soluble cellulose ether. It was made latent by reacting below. Since this latent curing agent uses an aluminum chelating agent capable of realizing a low temperature rapid curability, a good low temperature rapid curability is imparted to a thermosetting resin composition containing this latent curing agent. Can do. In addition, since the aluminum chelating agent is coated with ethyl cellulose, the storage stability of the thermosetting composition can be greatly improved even when this latent curing agent is blended into the thermosetting composition to form a one-part solution. Can do.

  This aluminum chelate-based latent curing agent is a microcapsule having a structure in which a core of a complex of a silsesquioxane oxetane derivative polymer and an aluminum chelating agent is covered with an ethyl cellulose shell. When such microcapsules aggregate, there may be a structure in which a plurality of cores are scattered in the ethylcellulose matrix. Here, the polymer of the silsesquioxane type oxetane derivative is dimer, oligomer or higher polymer depending on the charged amount of the aluminum chelating agent or silsesquioxane type oxetane derivative, reaction temperature conditions, etc. An oligomer having a polymerization degree of 10 to 100 is preferable in terms of particle size control.

  The shape of the aluminum chelate-based latent curing agent used in the present invention is preferably spherical, and the particle diameter is preferably 1 to 10 μm, more preferably 2 to 3 μm from the viewpoints of curability and dispersibility.

  In addition, the amount of the silsesquioxane type oxetane derivative used in the aluminum chelate-based latent curing agent relative to the aluminum chelating agent is too small, the encapsulation reaction is slow, and if it is too large, the curing agent is solidified. Preferably it is 0.1-500 weight part with respect to 100 weight part, More preferably, it is 1-500 weight part, Especially preferably, it is 10-500 weight part. Moreover, since the amount of water-insoluble or poorly water-soluble cellulose ether used relative to the total of the aluminum chelating agent and silsesquioxane type oxetane derivative is not too small, it will not become a powder, and if it is too much, the curability will decrease. Preferably it is 0.1-1000 weight part with respect to a total of 100 weight part, More preferably, it is 0.5-500 weight part, Especially preferably, it is 1-500 weight part.

  Examples of the aluminum chelating agent in the aluminum chelate-based latent curing agent include a complex compound in which three β-keto enolate anions are represented by formula (4) and coordinated to aluminum.

Here, R ¹ , R ² and R ³ are each independently an alkyl group or an alkoxyl group. Examples of the alkyl group include a methyl group and an ethyl group. Examples of the alkoxyl group include a methoxy group, an ethoxy group, and an oleyloxy group.

  Specific examples of the aluminum chelating agent represented by the formula (4) include aluminum ethyl acetoacetate diisopropylate (ALCH, Kawaken Fine Chemical Co.), aluminum trisethyl acetoacetate (ALCH-TR, Kawaken Fine Chemical Co.), Aluminum alkyl acetoacetate diisopropylate (Aluminum chelate M, Kawaken Fine Chemicals), aluminum bisethyl acetoacetate monoacetylacetonate (Aluminum chelate D, Kawaken Fine Chemicals), or aluminum trisacetylacetonate (Aluminum chelate A (W), Kawaken Fine Chemical Co., Ltd.).

  As the silsesquioxane type oxetane derivative in the aluminum chelate-based latent curing agent, a compound represented by the formula (1) (OX-) in which the silsesquioxane skeleton is substituted with at least one oxetanyl group having an oxetane ring. SQ-H, Toagosei Co., Ltd.) is preferably used. The compound of the formula (1) is usually a light yellow viscous liquid having a number average molecular weight of 1000 to 2000, dissolves in a general-purpose organic solvent, and can be easily mixed with epoxy resins and oxetanes. In addition to the silsesquioxane type oxetane derivative, other oxetane derivatives (for example, biphenyl type oxetane derivative; OXBP, Ube Industries, Ltd.) can be used in combination as long as the effects of the invention are not impaired.

  The silsesquioxane type oxetane derivative of the formula (1) is an oxetanylsilane compound (OXT-610, Toagosei Co., Ltd .: boiling point 125-128 ° C / 1 mmHg, viscosity 7-8 mPa · s (25 ° C). )) Alkoxysilyl group can be easily produced by condensation in the presence of alkali or acid / water. As described above, the compound of the formula (2) can be used as an oxetane trialkoxysilyl group-containing coupling agent.

  As the water-insoluble or poorly water-soluble cellulose ether used in the aluminum chelate-based latent curing agent, those having a solubility in purified water at 80 ° C. of 1.0 or less are preferable. If the solubility exceeds 1.0, it is difficult to dissolve in an organic solvent, such being undesirable. Examples of such water-insoluble or sparingly water-soluble cellulose ethers include ethyl cellulose and hydroxypropylmethyl cellulose. Among them, ethyl cellulose is preferable because it is easily available.

  An aluminum chelate-based latent curing agent is obtained by reacting an aluminum chelate with a silsesquioxane-type oxetane derivative by heating in a non-aqueous solvent in the presence of a water-insoluble or poorly water-soluble cellulose ether. Can be obtained as a precipitate, for example, by cooling to room temperature.

  As the non-aqueous solvent, a lower alkyl acetate such as ethyl acetate or an aromatic solvent such as toluene can be preferably used. The heating temperature varies depending on the type of solvent and the like, but is usually 50 to 200 ° C, preferably 80 to 200 ° C. The heating time is usually 1 to 3 hours, preferably 1 to 2 hours. The amount of the non-aqueous solvent used can be appropriately determined according to the solubility of the water-insoluble or poorly water-soluble cellulose ether.

  After cooling the reaction solution, the produced precipitate is filtered off, washed with a poor solvent such as hexane, and dried under reduced pressure to obtain the aluminum chelate-based latent curing agent of the present invention.

  In addition, the aluminum chelate type | system | group latent hardening | curing agent obtained as mentioned above is a microparticle with a primary particle diameter of 0.5-10 micrometers in a reaction system by stirring a reaction system using a homogenizer (for example, IKA company). However, when taken out of the reaction system, secondary particles having a size of 0.5 to 100 μm are likely to be obtained. When such an anisotropic conductive adhesive coating liquid using a relatively large latent curing agent that has been agglomerated is applied onto the substrate, the latent curing agent is caught in the application port of the coating apparatus, and the coating liquid is sufficiently applied. A linear pattern (coating stripe) may occur. The occurrence of such coating stripes is an obstacle to the realization of reliable anisotropic conductive connection. Therefore, for the relatively large secondary particles in which the aluminum chelate-based latent curing agent is aggregated, an operation of pulverizing into primary particles is required.

  When pulverizing, a hammer mill, a turbo mill, a roll mill, a jet mill or the like can be used. If a hammer mill, turbo mill or roll mill is used, the primary particles of the latent curing agent itself may be destroyed, and if a jet mill is used (see JP 2001-137690 A). However, since the apparatus becomes large, there is a problem that the pulverization cost increases.

  For this reason, the present inventors have conducted research with the intention of giving the aluminum chelate-based latent curing agent a property that hardly aggregates even when taken out from the reaction system. As a result, the aluminum chelating agent and the silsesquioxane type oxetane derivative are reacted by heating in a non-aqueous solvent in the presence of a water-insoluble or poorly water-soluble cellulose ether, and further reacted with an isocyanate compound. It was found that the aluminum chelate-based latent curing agent obtained by the above method hardly aggregates even when taken out from the reaction system, and can be pulverized into primary particles under extremely slow conditions (for example, conditions of sedimentation) even when aggregated. In particular, it has been found that when an isocyanate compound is reacted and then an epoxy compound or an oxetane compound is further reacted, aggregation is further suppressed.

  In addition, the present inventors, when reacting an aluminum chelating agent and a silsesquioxane type oxetane derivative by heating in a non-aqueous solvent in the presence of a water-insoluble or poorly water-soluble cellulose ether, In addition, an aluminum chelate-based latent curing agent obtained by reacting with an epoxy compound or an oxetane compound is very unlikely to agglomerate even when removed from the reaction system. It has been found that it can be pulverized into primary particles.

  Therefore, a preferred embodiment of the aluminum chelate latent curing agent used in the present invention is: (a) an aluminum chelate latent curing agent obtained by further reacting an isocyanate compound after the latentization; (b) an isocyanate compound. After the reaction, it is obtained by reacting an epoxy compound or oxetane compound together with an aluminum chelate latent curing agent obtained by reacting an epoxy compound or oxetane compound; and (c) an isocyanate compound.

  In addition, since it is considered that the isocyanate group of the isocyanate compound reacts with the hydroxyl group on the surface of the fine particle of the aluminum chelate-based latent curing agent, the reaction of the isocyanate compound is a treatment of the surface treatment of the aluminum chelate-based latent curing agent with the isocyanate compound. It is thought that it is equivalent to doing. Moreover, since it is thought that an epoxy compound and an oxetane compound do not react substantially with the isocyanate group of an isocyanate compound, it is thought that it is cationically polymerized with the aluminum chelate type | system | group latent hardening | curing agent, and is being fixed to the particle | grain surface.

  Here, the isocyanate compound is a polyfunctional isocyanate compound having two or more isocyanate groups in one molecule, and specific examples thereof include m-phenylene diisocyanate, p-phenylene diisocyanate, 2,4-tolylene diisocyanate, 2 , 6-tolylene diisocyanate, naphthalene-1,4-diisocyanate and the like. These can be used by diluting with an organic solvent such as toluene.

  If the amount of the isocyanate compound used is too small, the effect of reacting the isocyanate compound cannot be expected. If the amount is too large, the reactivity of the curing agent is lowered. Therefore, the amount is preferably 0.1 with respect to 100 parts by weight of the aluminum chelating agent. It is -200 weight part, More preferably, it is 0.1-100 weight part.

  The epoxy compound is a polyfunctional epoxy compound having two or more epoxy groups in one molecule. Specific examples thereof include a bis A type epoxy compound such as Epicoat 828 (manufactured by Japan Epoxy Resin Co., Ltd.), Epicoat 806 (Japan Epoxy). Bis F type epoxy compounds such as Resin Co., Ltd., naphthalene type epoxy compounds such as HP-4032 (Dainippon Ink Co., Ltd.), and alicyclic epoxy compounds such as CEL2021P (Daicel Chemical Industries, Ltd.). . Among these, from the viewpoint of high reactivity, alicyclic epoxy compounds can be preferably used.

  If the amount of the epoxy compound used is too small, the effect of reacting the epoxy compound cannot be expected. If the amount is too large, the reactivity of the curing agent is lowered. Therefore, the amount is preferably 0.1 with respect to 100 parts by weight of the aluminum chelating agent. ˜300 parts by weight, more preferably 0.1 to 200 parts by weight.

  The oxetane compound is a polyfunctional oxetane compound having two or more oxetanyl groups in one molecule, and specific examples thereof include xylylene type oxetane such as OXT-121 (manufactured by Toagosei Co., Ltd.), OX-SQ-H (Toagogi). Silsesquioxane oxetane such as OTC-221 (made by Toagosei Co., Ltd.), ether type oxetane such as OXT-221 (made by Toagosei Co., Ltd.), biphenyl oxetane such as etanacol OXBP (made by Ube Industries), and PNOX-723 (made by Toagosei Co., Ltd.) And the like, and silicate type oxetanes such as OX-SC (manufactured by Toagosei Co., Ltd.). Among these, xylylene type oxetane, biphenyl type oxetane, and phenol novolac type oxetane can be preferably used from the viewpoint that the cured product has high heat resistance.

  If the amount of the oxetane compound used is too small, the effect of reacting the oxetane compound cannot be expected. If the amount is too large, the reactivity of the curing agent is lowered. Therefore, the amount is preferably 0.1 with respect to 100 parts by weight of the aluminum chelating agent. ˜300 parts by weight, more preferably 0.1 to 200 parts by weight.

  When the above isocyanate compound, epoxy compound, or oxetane compound is reacted, the aluminum chelating agent and the silsesquioxane type oxetane derivative are heated in a non-aqueous solvent in the presence of a water-insoluble or poorly water-soluble cellulose ether. The reaction can be carried out at the temperature at which the reaction was carried out.

  As explained above, by changing the type and amount of silsesquioxane oxetane derivative and water-insoluble or poorly water-soluble cellulose ether, the type and amount of aluminum chelating agent, reaction conditions, etc., the aluminum chelate system The curing characteristics of the latent curing agent can be controlled. For example, when the reaction temperature is lowered, the curing temperature can be lowered, and conversely, when the reaction temperature is raised, the curing temperature can be raised.

  If the content of the aluminum chelate-based latent curing agent in the thermosetting composition is too small, it will not be cured sufficiently, and if it is too large, the resin properties (for example, flexibility) of the cured product will decrease. The amount is preferably 1 to 30 parts by weight, more preferably 1 to 20 parts by weight with respect to 100 parts by weight of the thermosetting compound.

  The thermosetting compound that is one of the essential components constituting the thermosetting composition of the present invention includes a thermosetting epoxy resin or compound, a thermosetting urea resin, a thermosetting melamine resin, and a thermosetting phenol resin. An oxetane compound or the like can be used. Among these, in consideration of a good adhesive strength after curing, a thermosetting epoxy resin or compound and an oxetane compound can be preferably used.

  Such a thermosetting epoxy resin or compound may be liquid or solid, and preferably has an epoxy equivalent of usually about 100 to 4000 and having two or more epoxy groups in the molecule. For example, a bisphenol A type epoxy compound, a phenol novolak type epoxy compound, a cresol novolak type epoxy compound, an ester type epoxy compound, an alicyclic epoxy compound, or the like can be preferably used. These compounds include monomers and oligomers. Among these, from the viewpoint of high reactivity, an alicyclic epoxy compound such as CEL2021P (manufactured by Daicel Chemical Industries) can be preferably used.

  The oxetane compound may be liquid or solid, and preferably has two or more oxetanyl groups in the molecule. For example, OXT-121, OXT-221, and OX-SQ-H (manufactured by Toagosei Co., Ltd.) can be preferably used. These compounds include monomers and oligomers. Among these, OXT-221, OX-SQ-H, and the like can be preferably used because of low reactivity and low ionic impurity concentration.

  The thermosetting composition of the present invention comprises an aluminum chelate-based latent curing agent, a trialkoxysilyl group-containing coupling agent, a thermosetting compound, and other additives that are added as necessary in a uniform manner according to a conventional method. Can be produced by mixing and stirring.

  The thus obtained thermosetting composition of the present invention is excellent in storage stability even though it is a single agent type because the aluminum chelate-based latent curing agent is latent. In addition, the latent curing agent can cooperate with the trialkoxysilyl group-containing coupling agent to cationically polymerize the thermosetting compound by low-temperature rapid curing. In addition, the thermosetting composition of the present invention is anisotropic by further blending conductive particles such as known nickel particles for anisotropic conductive connection, known film forming resins such as phenoxy resin, and the like. It can be used as a conductive conductive composition. If formed into a film, it can also be used as an anisotropic conductive film. The kind of conductive particles, the particle size, the blending amount, the kind of film forming component, the blending amount, the film thickness, and the like can be the same as those of a known anisotropic conductive paste or anisotropic conductive film. Typical examples of anisotropic conductive paste or film are aluminum chelate-based latent curing agent 8-12 parts by weight, phenoxy resin 50-80 parts by weight, alicyclic epoxy compound 20-50 parts by weight, epoxy-modified polyolefin. 5 to 30 parts by weight, 1 to 20 parts by weight of a silane coupling agent, and 1 to 20 parts by weight of conductive particles. In addition, a solvent, a monomer for dilution, etc. can be suitably mix | blended as needed. Such an anisotropic conductive paste or anisotropic conductive film enables a low-temperature short-time connection of about 5 seconds at 150 ° C., a low conduction resistance, and a good adhesive strength.

  Hereinafter, the present invention will be specifically described by way of examples.

Reference Example 1 (Preparation of aluminum chelate-based latent curing agent)
In a three-necked flask made of Teflon (registered trademark) equipped with a condenser tube, 159.7 g of kerosene, 10 g of a 10% ethyl acetate solution of ethyl cellulose, an aluminum chelating agent (aluminum ethyl acetoacetate diisopropylate; ALCH, Kawaken Fine Chemical Co., Ltd.) ) Of 66% toluene solution and 21.2 g of 66% toluene solution of silsesquioxane type oxetane derivative (OX-SQ-H, Toagosei Co., Ltd.), heated with a mantle heater, and the temperature of the reaction solution When the temperature reached 120 ° C., the heating was stopped and the mixture was cooled to room temperature using an ice bath. As a result, a precipitate was formed. Next, the reaction solution is filtered to collect the precipitate. The precipitate is washed three times with heptane, dried under reduced pressure, and 10.0 g (yield 50%) of a white solid as an aluminum chelate-based latent curing agent. Got.

Examples 1-5 and Comparative Examples 1-2
Oxetane derivative (DOX (bis {[1-ethyl (3-oxetanyl)] methyl} ether), Toagosei Co., Ltd.) 3.3 g, latent curing agent 0.2 g of Reference Example 1, and silane coupling agent of Table 1 A thermosetting composition was obtained by uniformly mixing 0.8 g using a stirrer.

  The obtained thermosetting composition is subjected to thermal analysis using a differential thermal analysis (DSC) apparatus (DSC-60, manufactured by Shimadzu Corporation), and the heat generation start temperature (° C), the heat generation peak temperature (° C), the total The calorific value (J / g) was measured. The obtained results are shown in Table 1.

  As can be seen from the results of Examples 1 to 5 and Comparative Examples 1 and 2 in Table 1, when encapsulated with ethyl cellulose, the silane coupling agent having a triethoxysilyl group can be provided with potential to the aluminum chelate curing agent. Since the heat generation start temperature can be shifted to the high temperature side, the potential of the aluminum chelate curing agent and the storage stability of the thermosetting composition containing it can be improved. Moreover, the exothermic peak of the thermosetting composition could be sharpened.

  The thermosetting composition of the present invention ensures sufficient latency and storage stability while containing an aluminum chelate-based latent curing agent that can be cured by cationic polymerization at relatively low temperatures in a short time. In addition, it shows a sharp DSC exothermic peak. Therefore, it is useful as an adhesive material for electronic materials that can be cured at low temperature.

Claims (6)

An aluminum chelate latent curing agent made latent by reacting an aluminum chelating agent with a silsesquioxane type oxetane derivative in the presence of a water-insoluble or poorly water-soluble cellulose ether, and a trialkoxysilyl group-containing coupling In a thermosetting composition containing an agent and a thermosetting compound ,
The aluminum chelating agent is aluminum ethyl acetoacetate diisopropylate,
The silsesquioxane type oxetane derivative has the formula (1)

Containing oxetanylsilsesquioxane represented by
The water-insoluble or poorly water-soluble cellulose ether is ethyl cellulose,
The trialkoxysilyl group-containing coupling agent is a mixture of 3-glycidoxypropyltrimethoxysilane and 3-ethyl [(triethoxysilylpropoxy) methyl] oxetane, 3-glycidoxypropyltrimethoxysilane and 3- A mixture of glycidoxypropyltriethoxysilane, or 2- (3,4-epoxycyclohexyl) ethyltrimethoxysilane and 3-ethyl [(triethoxysilylpropoxy) methyl] oxetane, and
The aluminum chelate-based latent curing agent is 0.1 to 500 parts by weight of the silsesquioxane type oxetane derivative with respect to 100 parts by weight of the aluminum chelate agent, and a total of 100 weights of the aluminum chelate agent and the silsesquioxane type oxetane derivative. A thermosetting composition characterized by comprising 0.1 to 1000 parts by weight of water-insoluble or poorly water-soluble cellulose ether with respect to parts . The content of tri-alkoxysilyl group-containing coupling agent in the thermosetting composition, to aluminum chelate-based latent curing agent to 100 parts by weight, the heat-curable composition of claim 1 Symbol placement is 1-1000 parts by weight . The content of tri-alkoxysilyl group-containing coupling agent in the thermosetting composition, to aluminum chelate-based latent curing agent to 100 parts by weight, the heat-curable composition of claim 1 Symbol mounting 50 to 500 parts by weight . The thermosetting composition according to any one of claims 1 to 3 , wherein the thermosetting compound is a thermosetting epoxy resin, a thermosetting urea resin, a thermosetting melamine resin, or a thermosetting phenol resin. The thermosetting composition according to any one of claims 1 to 3 , wherein the thermosetting compound is an alicyclic epoxy compound or an oxetane compound. The thermosetting composition according to any one of claims 1 to 5 , wherein the aluminum chelate-based latent curing agent has a coating layer made of water-insoluble or poorly water-soluble cellulose ether.