TWI811288B - One-component resin composition - Google Patents

Abstract

An object of the present invention is to provide a liquid resin composition that has better adhesion with respect to stresses in both the shearing direction and the peeling direction. The solution is to use a one-pack resin composition containing an epoxy resin, a bifunctional ester-free thiol, and a trifunctional or higher-functional ester-free thiol.

Description

One-component resin composition

The present invention relates to a one-component resin composition.

Thermosetting resin compositions using epoxy resin are used in coatings, electrical and electronic insulating materials, adhesives, etc. due to their excellent mechanical properties, electrical properties, thermal properties, chemical resistance, and bonding strength. Wide range of uses. As such resin compositions, two-component resin compositions and one-component resin compositions have been developed. The two-liquid resin composition is made by mixing epoxy resin and hardener to harden the epoxy resin during use. On the other hand, a one-component resin composition is made by mixing epoxy resin and a hardener in advance, and then hardening them with heat or the like during use. In recent years, in the field of sealing semiconductor components, one-component resin composition systems have played an important role in protecting electronic components, achieving high density of circuits, and improving connection reliability. Especially in order to improve productivity and workability, the requirements for hardening at low temperatures and in a short time are getting higher and higher. Furthermore, as the miniaturization of electronic components progresses, various devices become mobile and wearable, and electronic devices are used in various environments more frequently than ever before. Therefore, resin compositions are required to have higher reliability than ever before in terms of drop impact resistance and high temperature and high humidity resistance.

Regarding the above, for example, Patent Documents 1 and 2 describe low-temperature rapid-curing one-pack epoxy resin compositions with excellent moisture resistance, which describe the use of a thiol compound having a specific structure as a hardener for the epoxy resin. [Prior technical literature] [Patent Document]

[Patent Document 1] International Publication No. 2015/060440 [Patent Document 2] International Publication No. 2015/060439

[Problem to be solved by the invention]

In order for the bonded portion formed of the resin composition to have sufficient resistance to impact when dropped, it was determined that the bonded portion must exhibit sufficient bonding force against stress in either the shearing direction or the peeling direction. However, in general, in order to exhibit high shear adhesion, it is effective to increase the elastic modulus of the resin composition, but in this case, the peel adhesion strength will be significantly reduced. In addition, generally speaking, in order to exhibit high peel adhesion strength, it is effective to reduce the elastic modulus of the resin composition. However, in this case, the shear adhesion strength will be greatly reduced. Therefore, it is difficult to obtain a resin composition having excellent adhesion in both cases. In addition, as a method to improve peel adhesion, Patent Document 2 proposes a method of adding an epoxy resin with a soft skeleton. However, epoxy resins with a soft skeleton generally have low reactivity and poor low-temperature rapid hardening properties. problem. Therefore, an object of the present invention is to provide a liquid resin composition that is excellent in low-temperature rapid hardening properties, has better adhesion with respect to stresses in both the shearing direction and the peeling direction, and is also excellent in moisture resistance. [Means to solve the problem]

In order to solve the above problems, the present invention includes the following matters: [1] A one-pack resin composition containing the following components A, B and C: A: Epoxy resin B: A thiol compound with two thiol groups in the molecule and no ester skeleton C: A thiol compound with more than 3 thiol groups in the molecule and no ester skeleton. [2] The liquid resin composition of [1] above, which further contains the following component D: D: Latent hardening accelerator. [3] The liquid resin composition according to one of the above [1] or [2], wherein the B component and the C component do not have a hydroxyl group. [4] The liquid resin composition according to any one of [1] to [3] above, wherein the component C has a ring skeleton in the molecule. [5] The liquid resin composition according to any one of [1] to [4] above, wherein the component B does not have a ring skeleton in the molecule. [6] The liquid resin composition according to any one of the above [1] to [5], wherein the molecular weight of the component B is in the range of 130 to 1,000. [7] The liquid resin composition according to any one of [1] to [6] above, wherein when the total number of thiol groups of the component B and the component C is 1, the thiol group of the component C The ratio of the bases (the total number of thiol groups of the aforementioned component C/(the total number of thiol groups of the aforementioned component B + the total number of thiol groups of the aforementioned component C)) is 0.1 to 0.9. [8] An adhesive containing a liquid resin composition according to any one of the above [1] to [7]. [9] The adhesive as mentioned in [8] is used to connect neodymium magnets as adherends. [10] A sealing material containing a liquid resin composition according to any one of [1] to [7] above. [11] A cured product obtained by thermally curing the liquid resin composition according to any one of the above [1] to [7]. [12] An electronic component including the hardened material of [11] above. [13] A motor containing neodymium magnets, which includes an adherend and a hardened object as described in [11] for bonding the adherend. [14] An electronic component including a motor containing neodymium magnets, and containing the hardened material as described in [11]. [Effects of the invention]

According to the present invention, it is possible to provide a liquid resin composition that is excellent in low-temperature rapid hardening, has better adhesion with respect to stress in both the shearing direction and the peeling direction, and has moisture resistance.

[Form of carrying out the invention]

A liquid resin composition according to one embodiment of the present invention contains (component A) an epoxy resin, (component B) a thiol compound having two thiol groups in the molecule and not containing an ester skeleton, and (component C) molecules. Thiol compounds with more than 3 thiol groups and no ester skeleton. Hereinafter, "thiol compounds having two thiol groups in the molecule and not containing an ester skeleton" are hereby described as "bifunctional ester-free thiols"; "thiol compounds having more than three thiol groups in the molecule and not containing Thiol compounds with an ester skeleton are described as "polyfunctional ester-free thiols". According to the inventor's knowledge, by using a bifunctional ester-free thiol and a polyfunctional ester-free thiol in combination, a liquid resin composition having excellent adhesion in both the shearing direction and the peeling direction can be obtained. In addition, moisture resistance can be significantly improved by using an ester-free thiol compound as a thiol compound that is a hardener.

In addition, the "one-component" resin composition in the present invention refers to a composition in which a hardener and an epoxy resin are mixed in advance and has the property of being cured by heating.

[Component A: Epoxy resin] The epoxy resin is not particularly limited as long as it has at least one epoxy group in the molecule. It is preferable to use an epoxy resin having an average of 2 or more epoxy groups per molecule. Examples of the epoxy resin include polyphenols such as bisphenol A, bisphenol F, bisphenol AD, catechol, and resorcin, or polyhydric alcohols such as glycerol or polyethylene glycol, and polyols obtained by reacting with epichlorohydrin. Glycidyl ether; Glycidyl ether ester obtained from the reaction of hydroxy acids such as p-hydroxybenzoic acid and β-hydroxynaphthoic acid with epichlorohydrin; Polycarboxylic acids such as phthalic acid and terephthalic acid and epichlorohydrin Polypropylene oxide obtained from the reaction; and epoxidized novolac resin, epoxidized cresol varnish resin, epoxidized polyolefin, cycloaliphatic epoxy resin, other urethane modified epoxy resin, etc., but It is not limited to this.

As the epoxy resin, among these, from the viewpoint of maintaining high heat resistance and low moisture permeability, bisphenol A type epoxy resin, bisphenol F type epoxy resin, novolak type epoxy resin, and biphenyl are preferred. Aralkane type epoxy resin, phenol aralkyl type epoxy resin, aromatic glycidylamine type epoxy resin, epoxy resin with dicyclopentadiene structure, etc., preferably bisphenol A type epoxy resin and bisphenol A type epoxy resin. Phenol F type epoxy resin, and preferably bisphenol A type epoxy resin.

The epoxy equivalent of the epoxy resin is, for example, 50 to 500 g/eq, preferably 100 to 300, more preferably 150 to 200 g/eq. The epoxy equivalent here refers to the mass of epoxy resin per unit of epoxy, and can be measured in accordance with JIS K 7236 (2009).

The epoxy resin may be in liquid or solid form, and both liquid resin and solid resin may be used. The terms "liquid" and "solid" mentioned here refer to the state of epoxy resin at room temperature. From the viewpoint of coatability, processability, and adhesiveness, it is preferable that at least 10% by weight or more of the entire epoxy resin used is liquid. Specific examples of the liquid epoxy resin include liquid bisphenol A-type epoxy resin ("jER828EL" manufactured by Mitsubishi Chemical Corporation, "jER827" manufactured by Mitsubishi Chemical Corporation), liquid bisphenol F-type epoxy resin (Mitsubishi Chemical Corporation "jER827") "jER807" manufactured by the company), naphthalene type bifunctional epoxy resin ("HP4032", "HP4032D" manufactured by DIC Corporation), liquid bisphenol A type epoxy resin/bisphenol F type epoxy resin (Nippon Steel & Sumitomo Metal Co., Ltd. "ZXl059" manufactured by Chemical Corporation), epoxy resin with hydrogenated structure ("jERYX8000" manufactured by Mitsubishi Chemical Corporation). Among them, "jER828EL" manufactured by Mitsubishi Chemical Corporation and "jER807" manufactured by Mitsubishi Chemical Corporation, which are highly heat-resistant and have low viscosity, are preferred. Specific examples of solid epoxy resins include naphthalene-type tetrafunctional epoxy resin ("HP4700" manufactured by DIC Corporation) and dicyclopentadiene-type polyfunctional epoxy resin ("HP7200" manufactured by DIC Corporation). ), naphthol-type epoxy resin ("ESN-475V" manufactured by Nippon Steel & Sumitomo Metal Chemical Co., Ltd.), epoxy resin with butadiene structure ("PB-3600" manufactured by Taishiro Chemical Industry Co., Ltd.), Epoxy resins with biphenyl structure ("NC3000H" and "NC3000L" manufactured by Nippon Kayaku Co., Ltd., "jERYX4000" manufactured by Mitsubishi Chemical Corporation), etc.

When the mass of the entire resin composition is 100 mass %, the content of the epoxy resin of component A is, for example, preferably 5 mass % or more, more preferably 10 mass % or more, still more preferably 20 mass % or more, and more preferably Preferably, it is 30 mass% or more, more preferably, it is 40 mass% or more, and especially preferably, it is 45 mass% or more. Moreover, it is preferably 95 mass% or less, more preferably 90 mass% or less, still more preferably 85 mass% or less, still more preferably 80 mass% or less, still more preferably 75 mass% or less, and particularly preferably 70 mass%. %the following.

[Component B: Bifunctional ester-free thiol] The bifunctional ester-free thiol of component B is a compound with two thiol groups in the skeleton and no ester bond. In addition, the ester bond referred to in the present invention refers to the bond represented by "-C(=O)O-".

From the viewpoint of suppressing odor, the molecular weight of the bifunctional ester-free thiol is preferably 130 or more, more preferably 140 or more, still more preferably 150 or more, most preferably 160 or more. In addition, the molecular weight of the bifunctional ester-free thiol is, for example, 1000 or less, preferably 500 or less, more preferably 300 or less, and still more preferably 230 or less, from the viewpoint of obtaining good rapid hardening properties. In addition, the molecular weight of the bifunctional ester-free thiol can be in a range selected arbitrarily from the above upper and lower limits, for example, 130 to 1000, preferably 140 or more and 500 or less, more preferably 150 or more and 300 or less, most preferably 160 or more Below 230.

Preferably, the bifunctional ester-free thiol does not have a hydroxyl group in the molecule. When there are no hydroxyl groups in the molecule, it is often easier to obtain a good service life, and it is easier to balance the lifespan and rapid hardening of the resin composition.

Preferably, the bifunctional ester-free thiol does not have a ring skeleton in the molecule. When there is no ring skeleton, the skeleton is softer and a resin composition with better peel strength can be obtained.

Preferred bifunctional ester-free thiols include compounds represented by the following formula 1. In addition, in Formula 1, R ₁ represents a linear or branched divalent hydrocarbon group having 3 to 16 carbon atoms, preferably 4 to 12 carbon atoms. The hydrocarbon group may contain one or more divalent groups represented by the following (1a) to (1c). R ₁ is preferably a straight-chain hydrocarbon group, or a straight-chain hydrocarbon group containing one or more divalent groups represented by (1a) below. Specific examples of the bifunctional ester-free thiol represented by the above formula 1 include 1,4-butanedithiol, 1,6-hexanedithiol, 1,8-octanedithiol, and 1, 10-decanedithiol and 3,6-dioxa-1,8-octanedithiol and bis-2-mercaptoethyl sulfide, etc., preferably 1,8-octanedithiol and 1,10 - Decacedithiol and 3,6-dioxa-1,8-octanedithiol.

The content of the bifunctional ester-free thiol (component B) in the resin composition is not particularly limited and can be adjusted depending on the type of epoxy resin or polyfunctional ester-free thiol. For example, when the content of (A component) epoxy resin is 100 parts by mass, the content of (B component) bifunctional ester-free thiol is preferably 0.1 to 100 parts by mass, more preferably 1 to 60 parts by mass. More preferably, it is 10 to 40 parts by mass.

[Component C: Polyfunctional ester-free thiol] The polyfunctional ester-free thiol of component C is not particularly limited as long as it is a compound having three or more thiol groups (that is, trifunctional or more) in the skeleton and not having an ester bond.

Preferably, the polyfunctional ester-free thiol has 3 to 6 functions, and more preferably, it is a 3 to 4-functional ester-free thiol.

Preferably, the polyfunctional ester-free thiol does not have hydroxyl groups in the molecule. When there are no hydroxyl groups in the molecule, it is often easier to obtain a good service life, and it is easier to balance the lifespan and rapid hardening of the resin composition.

Preferred polyfunctional ester-free thiols are compounds with a cyclic skeleton. The ring skeleton can be any one of an alicyclic skeleton, an aromatic ring skeleton, a heteroaromatic ring skeleton, and a heterocyclic skeleton, and is preferably an aromatic ring skeleton, a heteroaromatic ring skeleton, or a heterocyclic skeleton, and is more preferably a heterocyclic skeleton. When it has a ring frame, the shear bonding force can be improved. Examples of such compounds having a heterocyclic skeleton include monocyclic or bicyclic compounds having a 5- to 8-membered ring containing at least one nitrogen atom as a ring atom. More specifically, the compound having a heterocyclic skeleton includes a compound containing an isocyanuric acid ring skeleton or a glycoluril skeleton.

For example, preferred polyfunctional ester-free thiols include compounds represented by the following formula 2: In the above formula 2, R ₂ , R ₃ and R ₄ each independently represent a carbon number of 1 to 6, preferably a linear or branched chain divalent hydrocarbon group with a carbon number of 1 to 5. The hydrocarbon group may further contain one or more divalent groups represented by the following (2a) to (2c). Specific examples of the polyfunctional ester-free thiol represented by the above formula 2 include ginseng(3-mercaptopropyl)isocyanurate.

Alternatively, as other preferred polyfunctional ester-free thiols, compounds represented by the following formula 3 can be cited: In the above formula 3, R ₅ , R ₆ , R ₇ and R ₈ each independently represent a carbon number of 1 to 6, preferably a linear or branched chain divalent hydrocarbon group with a carbon number of 1 to 4. The hydrocarbon group may further contain one or more divalent groups represented by the following (3a) to (3c). Specific examples of the polyfunctional ester-free thiol represented by the above formula 3 include 1,3,4,6-4(2-mercaptoethyl) glycoluril and the like.

The content of the polyfunctional ester-free thiol (component C) in the resin composition is not particularly limited and can be adjusted depending on the type of epoxy resin or bifunctional ester-free thiol. For example, when the content of (A component) epoxy resin is 100 parts by mass, the content of (C component) polyfunctional ester-free thiol is preferably 0.1 to 100 parts by mass, more preferably 1 to 60 parts by mass. More preferably, it is 10 to 50 parts by mass. When the total number of thiol groups of component B and component C contained in the composition is set to 1, the ratio of the number of thiol groups of component C (total number of thiol groups of component C/(total number of thiol groups of component B + The total number of thiol groups of component C) is, for example, 0.1 to 0.9, preferably 0.2 to 0.8, more preferably 0.3 to 0.7. The number of thiol groups here refers to the value obtained by dividing the mass parts of thiol contained in the composition by the thiol group equivalent (mass parts of thiol/thiol group equivalent). In addition, when the composition contains a plurality of thiols belonging to B component or C component, it means the total value obtained by dividing the mass parts of each thiol by the equivalent weight of each thiol group. In addition, the thiol group equivalent means a value indicating the mass of the thiol compound per thiol, and is a value obtained by dividing the molecular weight of the thiol compound by the number of thiol groups contained in one molecule of the compound.

Furthermore, in the resin composition of this embodiment, the ratio of "the total number of thiol groups of component B and component C" to "the number of epoxy groups of component A" (total number of thiol groups of component C and component B/component A The total number of epoxy groups) is preferably 0.2~2.0, more preferably 0.6~1.2. The number of epoxy groups here refers to the value obtained by dividing the mass parts of the epoxy resin contained in the composition by the epoxy group equivalent (mass parts of epoxy groups/epoxy group equivalent). In addition, when the composition contains multiple epoxy resins of component A, it represents the total value obtained by dividing the mass parts of each epoxy resin by the equivalent weight of each epoxy group.

[D component: latent hardening accelerator] Preferably, the resin composition of this embodiment contains a latent hardening accelerator. Latent hardening accelerator refers to an additive that does not contribute to the hardening of epoxy resin at room temperature (20°C ± 15°C (JISZ8703)) but has the function of accelerating the hardening of epoxy resin when heated.

It is preferable to use a solid dispersion type latent hardening accelerator as the latent hardening accelerator. A solid dispersion type latent hardening accelerator refers to a compound that is a solid insoluble in epoxy resin at room temperature, becomes soluble by heating, and functions as a hardening accelerator for epoxy resin. Examples of the solid dispersion type latent hardening accelerator include, but are not limited to, imidazole compounds that are solid at room temperature and solid dispersion type amine adduct-based latent hardening accelerators. Among these, a solid dispersion type amine adduct-based latent hardening accelerator is preferred.

Examples of the imidazole compounds that are solid at room temperature include 2-heptadecanylimidazole, 2-phenyl-4,5-dihydroxymethylimidazole, 2-undecylimidazole, and 2-phenyl-4- Methyl-5-hydroxymethylimidazole, 2-phenyl-4-benzyl-5-hydroxymethylimidazole, 2,4-diamino-6-(2-methylimidazolyl-(1))- Ethyl-S-triazine, 2,4-diamino-6-(2'-methylimidazolyl-(1)')-ethyl-S-triazine. Cyanuric acid adduct, 2-methylimidazole, 2-phenylimidazole, 2-phenyl-4-methylimidazole, 1-cyanoethyl-2-phenylimidazole, 1-cyanoethyl -2-methylimidazole-trimellitate, 1-cyanoethyl-2-phenylimidazole-trimellitate, N-(2-methylimidazolyl-1-ethyl)-urea, N,N'-(2-methylimidazolyl-(1)-ethyl)-adipamide and the like, but are not limited to these.

Examples of solid dispersed amine adduct latent hardening accelerators include reaction products of amine compounds and epoxy compounds (amine-epoxy adduct systems), reactions of amine compounds and isocyanate compounds or urea compounds. Products (urea type adduct system), etc.

Epoxy compounds used as one of the raw materials for manufacturing the solid dispersion type amine adduct-based latent hardening accelerator (amine-epoxy adduct system) include, for example, bisphenol A, bisphenol F, and catechu. Polyoxypropylene ether obtained by reacting polyphenols such as phenol and resorcin, or polyhydric alcohols such as glycerin or polyethylene glycol and epichlorohydrin; hydroxy acids such as p-hydroxybenzoic acid and β-hydroxynaphthoic acid and epichlorohydrin. Glycidyl ether ester obtained by the reaction of chlorohydrin; polyglycidyl ether obtained by the reaction of polycarboxylic acids such as phthalic acid and terephthalic acid with epichlorohydrin; 4,4'-diaminodiphenylmethane Or glycidylamine compounds obtained by the reaction of meta-aminophenol and epichlorohydrin; and polyfunctional epoxy compounds such as epoxidized novolak varnish resin, epoxidized cresol varnish resin, epoxidized polyolefin, or butyl glycidyl ether , phenyl glycidyl ether, glycidyl methacrylate and other monofunctional epoxy compounds, but are not limited to these.

The amine compound used as a raw material for manufacturing the solid dispersion type amine adduct latent hardening accelerator must have at least one active hydrogen in the molecule that can add to the epoxy group, and at least 1 active hydrogen in the molecule. More than one functional group selected from primary amine group, secondary amine group and tertiary amine group may be used. Examples of such amine compounds include diethylenetriamine, triethylenetetramine, n-propylamine, 2-hydroxyethylaminopropylamine, cyclohexylamine, and 4,4'-diamino-dicyclohexylmethane. Aliphatic amines such as 4,4'-diaminodiphenylmethane, 2-methylaniline and other aromatic amine compounds; 2-ethyl-4-methylimidazole, 2-ethyl-4- Heterocyclic compounds containing nitrogen atoms such as methyl imidazoline, 2,4-dimethyl imidazoline, piperidine, piperazine, etc., but are not limited to these.

Among them, compounds having a tertiary amine group in the molecule are raw materials that can provide latent hardening accelerators with excellent hardening accelerating ability. Examples of such compounds include dimethylaminopropylamine, dimethylaminopropylamine, Amine compounds such as ethylaminopropylamine, di-n-propylaminopropylamine, dibutylaminopropylamine, dimethylaminoethylamine, diethylaminoethylamine, N-methylpiperazine; such as 2- Methylimidazole, 2-ethylimidazole, 2-ethyl-4-methylimidazole, 2-phenylimidazole and other imidazole compounds have primary or secondary amines with a tertiary amine group in the molecule; 2-dimethyl Aminoethanol, 1-methyl-2-dimethylaminoethanol, 1-phenoxymethyl-2-dimethylaminoethanol, 2-diethylaminoethanol, 1-butoxymethyl Hydroxyl-2-dimethylaminoethanol, 1-(2-hydroxy-3-phenoxypropyl)-2-methylimidazole, 1-(2-hydroxy-3-phenoxypropyl)-2 -Ethyl-4-methylimidazole, 1-(2-hydroxy-3-butoxypropyl)-2-methylimidazole, 1-(2-hydroxy-3-butoxypropyl)-2- Ethyl-4-methylimidazole, 1-(2-hydroxy-3-phenoxypropyl)-2-phenylimidazoline, 1-(2-hydroxy-3-butoxypropyl)-2- Methyl imidazoline, 2-(dimethylaminomethyl)phenol, 2,4,6-gins(dimethylaminomethyl)phenol, N-β-hydroxyethylmorphine, 2-dimethylimidazole Methylaminoethanethiol, 2-mercaptopyridine, 2-benzimidazole, 2-mercaptobenzimidazole, 2-mercaptobenzothiazole, 4-mercaptopyridine, N,N-dimethylaminobenzoic acid, N,N-dimethylglycine, nicotinic acid, isonicotinic acid, 2-picolinic acid, N,N-dimethylglycine hydrazine, N,N-dimethylpropionic acid hydrazine, Nicotinic acid hydrazides, isonicotinic acid hydrazides, etc. have alcohols, phenols, thiols, carboxylic acids and hydrazides with tertiary amine groups in their molecules.

When the aforementioned epoxy compound and amine compound are subjected to an addition reaction to produce a latent hardening accelerator, an active hydrogen compound having two or more active hydrogens in the molecule may be further added. Examples of such active hydrogen compounds include polyphenols such as bisphenol A, bisphenol F, bisphenol S, hydroquinone, catechol, resorcinol, gallic acid, novolac resin, and trimethylolpropane. Polyols such as adipic acid, phthalic acid and other polybasic acids, 1,2-dimercaptoethane, 2-mercaptoethanol, 1-mercapto-3-phenoxy-2-propanol, thioglycolic acid, o- Aminobenzoic acid, lactic acid, etc., but are not limited to these.

Examples of the isocyanate compound used as a raw material for producing the solid dispersion type amine adduct-based latent hardening accelerator include monofunctional isocyanate compounds such as n-butyl isocyanate, isopropyl isocyanate, phenyl isocyanate, and benzyl isocyanate. ;Hexamethylene diisocyanate, tomylene diisocyanate, 1,5-naphthalene diisocyanate, diphenylmethane-4,4'-diisocyanate, isophorone diisocyanate, stubble diisocyanate, p-ethyl diisocyanate Polyfunctional isocyanate compounds such as phenyl diisocyanate, 1,3,6-hexamethylene triisocyanate, and bicycloheptane triisocyanate; and polyfunctional isocyanate compounds obtained from the reaction of these polyfunctional isocyanate compounds and active hydrogen compounds. Compounds with terminal isocyanate groups, etc. Examples of such compounds containing terminal isocyanate groups include addition compounds with terminal isocyanate groups obtained by the reaction of tolylene diisocyanate and trimethylolpropane, and addition compounds obtained from the reaction of tolylene diisocyanate and neopentyl tetracycline. Addition compounds having terminal isocyanate groups obtained by the reaction of alcohols, etc., but are not limited to these.

Examples of the urea compound used as a raw material for producing the solid dispersion type amine adduct-based latent hardening accelerator include urea, thiourea, etc., but are not limited thereto.

The solid dispersion type latent hardening accelerator can be prepared by, for example, suitably mixing the above-mentioned raw materials, reacting them at a temperature of 200°C starting from room temperature, cooling and solidifying, and then pulverizing them; or, by mixing methyl ethyl ketone, dioxane, and tetrahydrofuran After reacting in a solvent and removing the solvent, the solid component can be easily obtained by pulverizing it.

Typical examples of commercially available solid dispersion type latent hardening accelerators include "Ajicure PN-23" (manufactured by Ajinomoto Precision Technology Co., Ltd.) as an amine-epoxy adduct system (amine adduct system). Trade name), "Ajicure PN-H" (trade name manufactured by Ajinomoto Precision Technology Co., Ltd.), "NOVACURE HX-3742" (trade name manufactured by Asahi Kasei Co., Ltd.), "NOVACURE HX-3721" (trade name manufactured by Asahi Kasei Co., Ltd.), etc. ; Also, examples of urea-type adduct systems include "FUJICURE FXR-1020" (trade name manufactured by Fuji Chemical Corporation), "FUJICURE FXR-1030" (trade name manufactured by Fuji Chemical Corporation), but are not limited to these. .

When the content of (A component) epoxy resin is 100 parts by mass, the content of (D component) latent hardening accelerator is preferably 0.1 to 100 parts by mass, more preferably 1 to 60 parts by mass, and still more preferably 5 ~30 parts by mass.

[Ingredient E: Stabilizer] In order to achieve further excellent storage stability, the resin composition of this embodiment preferably contains a compound selected from the group consisting of borate compounds, titanate compounds, aluminate compounds, zirconate compounds, isocyanate compounds, carboxylic acids, acid anhydrides, and mercapto groups. One or more stabilizers for organic acids (component E).

Examples of the borate compound include trimethyl borate, triethyl borate, tri-n-propyl borate, triisopropyl borate, tri-n-butyl borate, tripentyl borate, triallyl borate, and boric acid. Trihexyl borate, tricyclohexyl borate, trioctyl borate, trinonyl borate, tridecyl borate, tridecyl borate, trihexadecand borate, trioctadecyl borate, ginseng (2- Ethylhexyloxy)borane, bis(1,4,7,10-tetraoxadecyl)(1,4,7,10,13-pentaoxatetradecyl)(1,4,7 -Triox undecanyl)borane, tribenzyl borate, triphenyl borate, tri-o-crephyl borate, tri-m-creyl borate, triethanolamine borate, etc.

Examples of the titanate compound include tetraethyl titanate, tetrapropyl titanate, tetraisopropyl titanate, tetrabutyl titanate, and tetraoctyl titanate.

Examples of the aluminate ester compound include triethyl aluminate, tripropyl aluminate, triisopropyl aluminate, tributyl aluminate, trioctyl aluminate, and the like.

Examples of the zirconate compound include tetraethyl zirconate, tetrapropyl zirconate, tetraisopropyl zirconate, and tetrabutyl zirconate.

Examples of the isocyanate compound include n-butyl isocyanate, isopropyl isocyanate, 2-chloroethyl isocyanate, phenyl isocyanate, p-chlorophenyl isocyanate, benzyl isocyanate, hexamethylene diisocyanate, and 2-ethyl isocyanate. Phenyl isocyanate, 2,6-dimethylphenyl isocyanate, 2,4-methylphenylene diisocyanate, methylphenylene diisocyanate, 2,6-methylphenylene diisocyanate, 1,5-naphthalene diisocyanate Isocyanate, diphenylmethane-4,4'-diisocyanate, toluidine diisocyanate, isophorone diisocyanate, styrene diisocyanate, p-phenylene diisocyanate, bicycloheptane triisocyanate, etc.

Examples of the carboxylic acid include saturated aliphatic monobasic acids such as formic acid, acetic acid, propionic acid, butyric acid, caproic acid, and capric acid, unsaturated aliphatic monobasic acids such as acrylic acid, methacrylic acid, and crotonic acid, and monochloroacetic acid. Halogenated fatty acids such as dichloroacetic acid, monovalent hydroxy acids such as glycolic acid and lactic acid, aliphatic aldehydes and keto acids such as glyoxylic acid and gluconic acid, aliphatic polybasic acids such as oxalic acid, malonic acid, succinic acid and maleic acid, Aromatic monobasic acids such as benzoic acid, halogenated benzoic acid, toluic acid, phenylacetic acid, cinnamic acid, and mandelic acid, and aromatic polybasic acids such as phthalic acid and benzenetricarboxylic acid.

Examples of the acid anhydride include succinic anhydride, dodecynyl succinic anhydride, maleic anhydride, an adduct of methylcyclopentadiene and maleic anhydride, hexahydrophthalic anhydride, and methyltetrahydrophthalic anhydride. Fatty acid polybasic acid anhydrides such as dicarboxylic anhydride; aromatic polybasic acid anhydrides such as phthalic anhydride, trimellitic anhydride, and pyromelite anhydride.

Examples of the aforementioned mercapto organic acids include mercapto aliphatic monocarboxylic acids such as thioglycolic acid, mercaptopropionic acid, mercaptobutyric acid, mercaptosuccinic acid, and dimercaptosuccinic acid; mercapto groups obtained by the esterification reaction of hydroxy organic acids and mercapto organic acids Aliphatic monocarboxylic acids; mercaptoaromatic monocarboxylic acids such as mercaptobenzoic acid, etc.

As the E component, among these, from the viewpoint of versatility, high safety, and improved storage stability, a borate ester compound is preferred, and triethyl borate, tri-n-propyl borate, and triisoborate are more preferred. Propyl ester, tri-n-butyl borate, and more preferably triethyl borate. The content of component E is not particularly limited as long as it can improve the storage stability of the resin; when the content of the epoxy resin of component A is set to 100 parts by mass, the content of component E is preferably 0.001 to 50 parts by mass, more preferably 0.05~30 parts by mass, more preferably 0.1~10 parts by mass.

As a method of blending component E into the resin composition, in addition to blending components A to D at the same time, the latent hardening accelerator of component D can also be mixed with component E in advance. The mixing method at this time can be carried out by contacting the two in a solvent such as methyl ethyl ketone or toluene, in a liquid epoxy resin, or in the absence of a solvent.

(F ingredient: other ingredients) In the liquid resin composition of this embodiment, fillers commonly used in the field of the present invention (such as fumed silica), diluents, solvents, pigments, flexibility-imparting agents, coupling agents, and antioxidants may also be added as needed. Various additives such as oxidizing agent, thixotropic agent, dispersant, etc.

There is no particular difficulty in preparing the liquid resin composition of this embodiment using the above-described components A to C and optional components D to F as raw materials, and it can be carried out by following a conventionally known method. For example, a one-liquid resin composition can be prepared by mixing each component with a mixer such as a Henschel mixer.

In addition, there is no particular difficulty in hardening the obtained liquid resin composition, and it can also be carried out according to a conventionally known method. For example, the obtained one-liquid resin composition can be hardened by heating at a temperature above room temperature. The heating system can be at a temperature of, for example, 70 to 150°C, preferably 75 to 120°C, more preferably 80 to 100°C, for, for example, 1 to 60 minutes, preferably 3 to 30 minutes, more preferably 5 to 15 minutes. minutes is more appropriate. In particular, as long as it is cured by heating at 80 or 100° C. for 10 minutes or less, it can be judged to have moderate low-temperature rapid curing properties.

This embodiment also includes a resin cured product obtained by heating the one-liquid resin composition and a functional product containing the resin cured product. Examples of functional products include adhesives, casting agents, sealants, sealants, fiber-reinforced resins, coating agents, and paints. Furthermore, this hardened epoxy resin can be used, for example, as an adhesive for bonding magnets and casings of neodymium-containing magnet motors or for electronic parts equipped with neodymium-containing magnet motors. Generally speaking, magnets are often demagnetized by heat. Since the resin composition of the present invention can reduce the heating pressure during bonding to a low temperature of 80° C. or less, it is suitable for use in bonding neodymium magnets and other components, and in electronic parts equipped with neodymium magnets, it is suitable for use in components other than neodymium magnets. The purpose of joining components to each other, and the purpose of joining electronic parts after loading neodymium magnet parts, etc. In addition, since neodymium magnets have the property of shrinking when heated and expanding when cooled, internal stress is generated during bonding unlike the linear expansion of other members used as adherends. Therefore, it is easy to cause peeling at the bonding interface due to impact such as dropping. In this regard, the resin composition of the present invention has high adhesive strength against stress in both the shearing direction and the peeling direction, and is less likely to peel off, making it suitable for bonding neodymium magnets.

In addition, since the above-mentioned (B component) bifunctional ester-free thiol and (C component) polyfunctional ester-free thiol can cure the epoxy resin (A component), these mixtures can be used as cured epoxy resins. Agent use. That is, the hardener for epoxy resin of this embodiment contains the above-mentioned (B component) bifunctional ester-free thiol and (C component) polyfunctional ester-free thiol. [Example]

Hereinafter, the present invention will be described in more detail based on examples, but the present invention is not limited to the following examples.

[Preparation of one-component resin composition] Each component was mixed with the blending composition shown in Table 1 and Table 2 to prepare the resin compositions of Examples 1 to 7 and Comparative Examples 1 to 7. In addition, in Table 1 and Table 2, the blending amount of each component means parts by mass. Furthermore, in each of the examples and comparative examples, the ratio of the number of epoxy groups to the number of thiol groups in the resin composition is approximately 1:1. Specifically, the amounts of materials shown in Table 1 and Table 2 are measured in special plastic containers. Thereafter, a rotation/revolution vacuum mixer THINKY MIXER (made by THINKY Co., Ltd.; ARE-250) was used to thoroughly mix the mixture at 2000 rpm at room temperature, and further perform degassing for 1 minute to obtain the target resin composition.

Additionally, details of the materials used are as follows: [Epoxy resin] jER828EL: Made by Mitsubishi Chemical Corporation, bisphenol A type (BPA type) epoxy resin, epoxy equivalent 186g/eq, jER807: Made by Mitsubishi Chemical Corporation, bisphenol F type (BPF type) epoxy resin, epoxy equivalent 165g/eq,

[2-functional ester-free thiol] 1,8-octanedithiol: manufactured by Tokyo Chemical Industry Co., Ltd., total equivalent weight of thiol groups 89g/eq, molecular weight 178

1,10-Dedecanedithiol: Made by Tokyo Chemical Industry Co., Ltd., total thiol group equivalent weight 103g/eq molecular weight 206

3,6-dioxa-1,8-octanedithiol: manufactured by Tokyo Chemical Industry Co., Ltd., total thiol group equivalent weight 91g/eq molecular weight 182

[2-functional ester-containing thiol] EGTP: Made by Yodo Chemical Co., Ltd., ethylene glycol disulfide propionate, total thiol group equivalent weight 124g/eq

[Polyfunctional ester-free thiol] TMPIC: Made by Ajinomoto Precision Technology Co., Ltd., (3-mercaptopropyl)isocyanurate, total thiol group equivalent weight 117g/eq

TS-G: Made by Shikoku Kasei Co., Ltd., 1,3,4,6-(2-mercaptoethyl) glycoluril, total thiol group equivalent weight 103g/eq

[Polyfunctional ester-containing thiol] TMTP: Made by Yodo Chemical Co., Ltd., trimethylolpropane (3-mercaptopropionate), total thiol group equivalent 140g/eq [Latent hardening accelerator] PN-23: Made by Ajinomoto Precision Technology Co., Ltd., amine epoxy adduct hardener [Stabilizer] TEB: Made by Tokyo Chemical Industry Co., Ltd., triethyl borate [filler] AEROSIL200: Made by Japan AEROSIL Company, fumed silica

[Evaluation of low temperature rapid hardening properties] For each Example and each Comparative Example, the low-temperature rapid hardening property was evaluated by measuring the gelation time (gelling time) in accordance with JISC6521. Specifically, first, a hot plate gelation tester (GT-D: manufactured by Nisshin Scientific Co., Ltd.) was used to measure the time during which the resin compositions of each example and comparative example did not string together at 80°C. More specifically, about 0.5 g of the sample (resin composition) was placed on a hot plate gelation testing machine. Starting from the time when it reaches 80°C (80°C gelation time), the resin composition is repeatedly contacted with a scraper with a tip width of 5mm so that the resin composition is limited to a diameter of 25mm on the heating plate. Circular motion (1 rotation per second). Lift the resin composition vertically 30 mm from the heating plate, take the time when the filament breaks as the end point, and measure the time from the starting point to the end point as the time before gelation. In addition, the scraper is not lifted up when the viscosity of the resin is low. After the viscosity gradually increases, the scraper is lifted vertically up about 30mm from the heating plate at any time, and this up and down movement is repeated until the filament breaks. Repeat the measurement twice and use the average value as the result. The shorter the gelation time, the better the low-temperature rapid hardening properties.

[Evaluation of initial bonding strength] (i) Initial tensile shear bonding strength Prepare two test pieces of mild steel plates (JISG3141, SPCC), and wipe away the oil with a cloth moistened with acetone. Furthermore, the surface of the joint surface of the mild steel plate was ground with an endless endless belt #120. The resin composition is evenly applied to the polished surface of the mild steel plate to a thickness of approximately 1 mm. Use two clamps to attach the two test pieces and clamp them so that the coated surfaces overlap by about 12mm. At this time, the exuded resin composition should be wiped off immediately with a wipe. The test pieces were evenly arranged in the oven and heated and hardened at 80° C. for 60 minutes to bond them. For the same resin, prepare 2 test pieces for each. The obtained test pieces were measured for tensile shear bonding strength in accordance with JIS-K-6850 using a TENSILON universal testing machine (UTM-5T manufactured by TOYO BALDWIN) (measurement environment: temperature 25°C/humidity 60%, tensile speed: 5 mm /min). Based on the maximum load (N) at which the test piece is destroyed, the bonding area (mm ² ) is measured, and the tensile shear bonding strength A is calculated from the following formula. (Formula): Tensile shear bonding strength A (N/mm ² ) = maximum load (N)/bonding area (mm ² )

(ii) Initial peel adhesion strength Wipe the test piece of the steel plate (25mm×150mm×0.4mm) with a cloth moistened with acetone to remove the oil. Furthermore, the surface of the bonding surface of the steel plate was ground with an endless endless belt #120. The resin composition is evenly applied to the polished surface of the steel plate with a thickness of approximately 20 to 30 μm. Stack another piece of steel plate and clamp it with 4 clamps. At this time, the exuded resin composition should be removed immediately. The test pieces were evenly arranged in the oven and heated and hardened at 80° C. for 60 minutes to bond them. For the same resin composition, two test pieces were prepared for each test piece. The obtained test piece was measured for tensile strength in accordance with JIS-K-6854-3 using a TENSILON universal testing machine (RTM-500 manufactured by ORIENTEC) (measurement environment: temperature 25°C/humidity 60%, tensile speed: 50mm/ min). Based on the average peel load (N), the peel adhesion strength A per width 25 mm was calculated.

[Evaluation of Moisture Resistance] (i) Tensile-shear bonding strength Two test pieces were prepared separately using the same procedure as the evaluation of the initial tensile-shear bonding strength. After placing it in a pressure cooker tester set at 121°C and 100%RH saturated conditions for 24 hours, the obtained test piece was tested in accordance with JIS- K-6850 measures tensile shear bonding strength (measurement environment: temperature 25°C/humidity 60%, tensile speed: 5mm/min). Based on the maximum load (N) at which the test piece was destroyed, the bonding area (mm ² ) was measured, and the tensile shear bonding strength B was calculated in the same manner as the evaluation of the adhesion. Tensile shear bonding strength B (N/mm ² ) = maximum load (N)/bonding area (mm ² )

[Tensile shear strength retention rate] In order to evaluate the influence of humidity on the bonding strength, the strength retention rate was calculated. The strength retention rate is calculated as follows from the values of the tensile shear bonding strength A and the tensile shear bonding strength B. [Strength retention rate]=[Tensile shear bonding strength B]/[Tensile shear bonding strength A]×100 In addition, the larger the value of the strength retention rate, the higher the resistance of the test piece to high humidity.

[Peel adhesion strength] Two test pieces were prepared separately for each test piece prepared in the same procedure as for the evaluation of initial peel adhesion strength. Each test piece was placed in a pressure cooker testing machine set at 121°C and 100% RH saturated conditions for 24 hours. The obtained test pieces were tested in accordance with JIS-K- 6854-3 measures tensile strength (measurement environment: temperature 25°C/humidity 60%, tensile speed: 50mm/min). Based on the average peel load (N), the peel adhesion strength B per width 25 mm was calculated.

[Peel adhesion strength retention rate] In order to evaluate the influence of humidity on peeling bonding strength, the strength retention rate was calculated. The strength retention rate is calculated as follows from the values of the above-mentioned peeling bonding strength A and peeling bonding strength B. [Strength retention rate]=[Peel adhesion strength B]/[Peel adhesion strength A]×100 The larger the value of the strength retention rate, the higher the resistance of the test piece to high humidity. [Storage stability] For each of Examples 1 to 7, approximately 5 g of the resin composition was sealed in a plastic container and placed in a constant temperature room with a temperature of 25° C. and a humidity of 60% for 24 hours, and then was opened and the fluidity was confirmed. As a result, all Examples 1 to 7 can be stirred using a spatula. That is, the resin compositions of Examples 1 to 7 were all confirmed to have excellent storage stability.

[Inspection of assessment results] The results of each of the above evaluations are shown in Table 1 and Table 2. It can be seen that the resin compositions of Examples 1 to 7 show better shear adhesive strength, peel adhesive strength, moisture resistance, and low-temperature rapid hardening properties than the resin compositions of Comparative Examples.

Specifically, when Examples 1 to 5 are compared with Comparative Example 1, the initial peel adhesion strength of Comparative Example 1 is 6 (1N/25mm), and that of Examples 1 to 5 is 15 (1N/25mm) or more. That is, compared with the case of using only polyfunctional ester-free thiol as the hardener (Comparative Example 1), it was found that bifunctional ester-free thiol and polyfunctional ester-free thiol were used in combination (Examples 1 to 5). Significantly improves initial peel adhesion strength. In addition, when Example 6, which has a different type of polyfunctional ester-free thiol from Examples 1 to 5, is compared with the corresponding Comparative Example 2, the same trend can be seen.

In addition, when Examples 2, 4, and 5 are compared with Comparative Examples 3 to 5 respectively, the initial tensile shear bonding strength A of each comparative example is significantly lower than that of each example. That is, compared with the case of using only a bifunctional ester-free thiol as the hardener (Comparative Examples 3 to 5), it was found that the initial tensile shear bonding strength can be improved by using a bifunctional and a polyfunctional ester-free thiol in combination. .

Next, when Examples 1 to 7 are compared with Comparative Examples 6 and 7, each Example clearly shows high moisture resistance. That is, it was found that moisture resistance can be significantly improved by using ester-free thiol as the hardener instead of ester-containing thiol.

In addition, the gelation time of Examples 1 to 7 was within 3 minutes, and they had good low-temperature rapid hardening properties.

Claims (14)

A one-liquid resin composition (containing one liquid of 2,4,6-trimercapto-s-triazine or 2-di-n-butylamino-4,6-dimercapto-s-triazine type resin composition), which contains the following components A, B and C: A: epoxy resin B: thiol compound with 2 thiol groups in the molecule and no ester skeleton C: 3 thiol groups in the molecule Thiol compounds with more than one thiol group and no ester skeleton. The liquid resin composition of claim 1 further contains the following D component: D: latent hardening accelerator. A liquid resin composition according to claim 1 or 2, wherein the component B and the component C do not have a hydroxyl group. A liquid resin composition according to claim 1 or 2, wherein the component C has a ring skeleton in the molecule. A liquid resin composition according to claim 1 or 2, wherein the component B does not have a ring skeleton in the molecule. A liquid resin composition according to claim 1 or 2, wherein the molecular weight of the component B is in the range of 130 to 1000. The liquid resin composition of claim 1 or 2, wherein when the total number of thiol groups of the aforementioned B component and the aforementioned C component is 1, the proportion of the thiol group number of the aforementioned C component (the aforementioned C component The total number of thiol groups/(the total number of thiol groups of the aforementioned component B + the total number of thiol groups of the aforementioned component C)) is 0.1 to 0.9. An adhesive comprising a liquid resin composition according to any one of claims 1 to 7. For example, the adhesive of claim 8 is used to connect neodymium magnets as adherends. A sealing material comprising a liquid resin composition according to any one of claims 1 to 7. A hardened product obtained by thermally hardening the liquid resin composition according to any one of claims 1 to 7. An electronic component including the hardened material according to claim 11. A motor containing neodymium magnets, which includes an adherend and a hardened object as claimed in claim 11 for bonding the adherend. An electronic component including a motor containing neodymium magnets and including the hardened material according to claim 11.