JP6983380B2 - One-component resin composition - Google Patents

Description

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

Thermosetting resin compositions using epoxy resins have excellent performance in terms of mechanical properties, electrical properties, thermal properties, chemical resistance, adhesive strength, etc. It has been used in a wide range of applications such as adhesives. As such a resin composition, a two-component resin composition and a one-component resin composition have been developed. In the two-component resin composition, the epoxy resin and the curing agent are mixed at the time of use, and the epoxy resin is cured. On the other hand, in the one-component resin composition, the epoxy resin and the curing agent are mixed in advance and are cured by heat or the like at the time of use.
In recent years, one-component resin compositions have played an important role in protecting electronic components in the field of encapsulation such as semiconductor devices, increasing the density of circuits, and improving the reliability of connections. In particular, there is an increasing demand for curing at low temperature in a short time for the purpose of improving productivity and workability. In addition, as the miniaturization of electronic components has progressed and various devices have become mobile and wearable, the number of situations in which electronic devices are used in more diverse environments than before is increasing. As a result, the resin composition is also required to have higher reliability than before in terms of drop impact resistance and high temperature and high humidity resistance.

In relation to the above, for example, Patent Documents 1 and 2 describe low-temperature fast-curing one-pack epoxy resin compositions having excellent moisture resistance, respectively, in which a thiol compound having a specific structure is used as an epoxy resin. It is described that it is used as a curing agent.

International Publication No. 2015/060440 International Publication No. 2015/06439

In order for the bonded portion of the resin composition to have sufficient resistance to impact when dropped, it is considered necessary to exhibit sufficient adhesive force against stress in both the shearing direction and the peeling direction. However, in general, it is effective to increase the elastic modulus of the resin composition in order to develop a high shear adhesive force, but in this case, the peel adhesive force is greatly reduced. On the other hand, in general, it is effective to lower the elastic modulus of the resin composition in order to develop a high peeling adhesive force, but in this case, the shear adhesive force is greatly reduced. Therefore, it has been difficult to obtain a resin composition having excellent adhesive strength between them.
Further, as a method for improving the peeling adhesive strength, Patent Document 2 proposes a method of adding an epoxy resin having a flexible skeleton. However, since an epoxy resin having a flexible skeleton generally has low reactivity, the speed is low. There is a problem that the curability is inferior.
Therefore, the subject of the present invention is a one-component resin which is excellent in low-temperature quick-curing property, has more excellent adhesive force against stresses in both the shear direction and the peeling direction, and is also excellent in moisture resistance. The purpose is to provide the composition.

In order to solve the above problems, the present invention includes the following matters.
[1] A one-component resin composition containing the following components A, B and C.
A: Epoxy resin B: Thiol compound having two thiol groups in the molecule and not containing an ester skeleton C: Thiol compound having three or more thiol groups in the molecule and not containing an ester skeleton [2] The one-component resin composition according to the above [1], further comprising the following D component.
D: Potential curing accelerator [3] The one-component resin composition according to the above [1] or [2], wherein the B component and the C component do not have a hydroxyl group.
[4] The one-component resin composition according to any one of [1] to [3] above, wherein the C component has a ring skeleton in the molecule.
[5] The one-component resin composition according to any one of the above [1] to [4], wherein the component B does not have a ring skeleton in the molecule.
[6] The one-component 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 1000.
[7] When the total number of thiol groups of the B component and the C component is 1, the ratio of the number of thiol groups of the C component (total number of thiol groups of the C component / (total number of thiol groups of the B component). + The one-component resin composition according to any one of [1] to [6] above, wherein the total number of thiol groups of the C component)) is 0.1 to 0.9.
[8] An adhesive containing the one-component resin composition according to any one of the above [1] to [7].
[9] The adhesive according to the above [8], which is used for adhering a neodymium magnet as an adherend.
[10] A sealing material containing the one-component resin composition according to any one of the above [1] to [7].
[11] A cured product obtained by thermally curing the one-component resin composition according to any one of the above [1] to [7].
[12] An electronic component containing the cured product according to the above [11].
[13] A neodymium magnet-containing motor including the adherend and the cured product according to the above [11] used for adhering the adherend.
[14] An electronic component including a neodymium magnet-containing motor, which comprises the cured product according to the above [11].

According to the present invention, there is provided a one-component resin composition which is excellent in low-temperature quick-curing property, has more excellent adhesive force against stresses in both the shearing direction and the peeling direction, and has moisture resistance. Will be done.

The one-component resin composition according to the embodiment of the present invention comprises (component A) an epoxy resin, (component B) a thiol compound having two thiol groups in a molecule and containing no ester skeleton, and (component C). ) Contains a thiol compound having three or more thiol groups in the molecule and not containing an ester skeleton. Hereinafter, "a thiol compound having two thiol groups in the molecule and not containing an ester skeleton" is referred to as "bifunctional ester-free thiol", and "a thiol compound having three or more thiol groups in the molecule and containing an ester skeleton" is included. "No thiol compound" is referred to as "polyfunctional ester-free thiol". According to the findings of the present inventor, by using a bifunctional ester-free thiol and a polyfunctional ester-free thiol in combination, a one-component resin composition having excellent adhesive strength in both the shearing direction and the peeling direction can be obtained. be able to. Further, by using an ester-free thiol compound as the thiol compound as a curing agent, the moisture resistance can be remarkably enhanced.

In the present invention, the "one-component" resin composition means a composition in which a curing agent and an epoxy resin are mixed in advance and has a property of being cured by applying heat.

[Component A: Epoxy resin]
The epoxy resin is not particularly limited as long as it has at least one epoxy group in the molecule. Preferably, as the epoxy resin, one having two or more epoxy groups per molecule on average is used.
Examples of the epoxy resin include polyglycidyl ethers obtained by reacting polyhydric phenols such as bisphenol A, bisphenol F, bisphenol AD, catechol, and resorcinol with polyhydric alcohols such as glycerin and polyethylene glycol with epichlorohydrin; A glycidyl ether ester obtained by reacting a hydroxycarboxylic acid such as p-hydroxybenzoic acid or β-hydroxynaphthoic acid with an epichlorohydrin; a polycarboxylic acid such as phthalic acid or terephthalic acid and an epichlorohydrin. Polyglycidyl ester obtained by reacting with each other; further, epoxidized phenol novolak resin, epoxidized cresol novolak resin, epoxidized polyolefin, cyclic aliphatic epoxy resin, other urethane-modified epoxy resin; and the like are limited to these. It's not something.

Among these, the epoxy resins include bisphenol A type epoxy resin, bisphenol F type epoxy resin, phenol novolac type epoxy resin, biphenyl aralkyl type epoxy resin, and phenol aralkyl type from the viewpoint of maintaining high heat resistance and low moisture permeability. Epoxy resins, aromatic glycidylamine type epoxy resins, epoxy resins having a dicyclopentadiene structure and the like are preferable, bisphenol A type epoxy resins and bisphenol F type epoxy resins are more preferable, and bisphenol A type epoxy resins are more preferable.

The epoxy equivalent of the epoxy resin is, for example, 50 to 500 g / eq, preferably 100 to 300, and more preferably 150 to 200 g / eq. Here, the epoxy equivalent is the mass of the epoxy resin per epoxy group, and can be measured according to JIS K 7236 (2009).

The epoxy resin may be liquid or solid, and both liquid resin and solid resin may be used. Here, "liquid" and "solid" are states of the epoxy resin at room temperature. From the viewpoint of coatability, processability, and adhesiveness, it is preferable that at least 10% by mass or more of the entire epoxy resin used is liquid. Specific examples of such liquid epoxy resin include liquid bisphenol A type epoxy resin (“jER828EL” manufactured by Mitsubishi Chemical Co., Ltd., “jER827” manufactured by Mitsubishi Chemical Co., Ltd.), liquid bisphenol F type epoxy resin (“jER807” manufactured by Mitsubishi Chemical Co., Ltd.), and naphthalene. Type bifunctional epoxy resin ("HP4032", "HP4032D" manufactured by DIC), liquid bisphenol A type epoxy resin / bisphenol F type epoxy resin ("ZXl059" manufactured by Nippon Steel & Sumitomo Metal Corporation), epoxy resin with hydrogenated structure ("ZXl059" manufactured by Nippon Steel & Sumitomo Metal Corporation). There is "jERYX8000" manufactured by Mitsubishi Chemical Co., Ltd.). Of these, "jER828EL" manufactured by Mitsubishi Chemical Corporation and "jER807" manufactured by Mitsubishi Chemical Corporation, which have high heat resistance and low viscosity, are preferable.
Specific examples of the solid epoxy resin include a naphthalene type tetrafunctional epoxy resin (“HP4700” manufactured by DIC Corporation), a dicyclopentadiene type polyfunctional epoxy resin (“HP7200” manufactured by DIC Corporation), and a naphthol type epoxy resin (Nippon Steel & Sumikin Chemical Co., Ltd.). "ESN-475V" manufactured by DIC Corporation), epoxy resin having a butadiene structure ("PB-3600" manufactured by DIC CORPORATION), epoxy resin having a biphenyl structure ("NC3000H", "NC3000L" manufactured by Nippon Kayaku Co., Ltd.) , "JERYX4000" manufactured by Mitsubishi Chemical Corporation) and the like.

When the total mass of the resin composition is 100% by mass, the content of the epoxy resin of the component A is, for example, preferably 5% by mass or more, more preferably 10% by mass or more, further preferably 20% by mass or more, and 30% by mass. Even more preferably, it is more preferably 40% by mass or more, particularly preferably 45% by mass or more, and particularly preferably 45% by mass or more. Further, 95% by mass or less is preferable, 90% by mass or less is more preferable, 85% by mass or less is further preferable, 80% by mass or less is further preferable, 75% by mass or less is particularly preferable, and 70% by mass or less is particularly preferable.

[B component: bifunctional ester-free thiol]
The bifunctional ester-free thiol, which is a component B, is a compound having two thiol groups in the skeleton and no ester bond.
In the present invention, the ester bond means a bond represented by "-C (= O) O-".

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, and most preferably 160 or more, from the viewpoint of suppressing odor.
The molecular weight of the bifunctional ester-free thiol is, for example, 1000 or less, preferably 500 or less, more preferably 300 or less, still more preferably 230 or less, from the viewpoint of obtaining good rapid curability.
The molecular weight of the bifunctional ester-free thiol may be in a range arbitrarily selected from the above upper limit and lower limit, for example, 130 to 1000, preferably 140 or more and 500 or less, more preferably 150 or more and 300 or less, and most preferably 160 or more and 230. It is as follows.

Preferably, the bifunctional ester-free thiol has no hydroxyl group in the molecule. When the hydroxyl group is not present in the molecule, it tends to be easy to obtain a good pot life, and it is easy to achieve both the life of the resin composition and the quick curability.

Preferably, the bifunctional ester-free thiol does not have a ring skeleton in the molecule. When it does not have a ring skeleton, the skeleton becomes flexible and a resin composition having better peel strength can be obtained.

上記式１で表される２官能エステルフリーチオールとして、具体的には、１，４−ブタンジチオール、１，６−ヘキサンジチオール、１，８−オクタンジチオール、及び１，１０−デカンジチオール及び３，６−ジオキサ−１，８−オクタンジチオール及びビス-2−メルカプトエチルスルフィド等が挙げられ、１，８-オクタンジチオール及び１，１０−デカンジチオール及び３，６−ジオキサ−１，８−オクタンジチオールが好ましい。 Suitable bifunctional ester-free thiols include compounds represented by the following formula 1.
(Equation 1): HS-R _1- SH
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 shown in the following (1a) to (1c). R ₁ is preferably a linear hydrocarbon group or a linear hydrocarbon group containing one or more divalent groups shown in (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-decandithiol and 3, Examples include 6-dioxa-1,8-octanedithiol and bis-2-mercaptoethyl sulfide, including 1,8-octanedithiol and 1,10-decandithiol and 3,6-dioxa-1,8-octanedithiol. preferable.

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

[C component: polyfunctional ester-free thiol]
The polyfunctional ester-free thiol as the C component is not particularly limited as long as it is a compound having three or more thiol groups in the skeleton (that is, three or more functional groups) and no ester bond.

Preferably, the polyfunctional ester-free thiol is a 3-6-functional, more preferably 3-4-functional ester-free thiol.

Preferably, the polyfunctional ester-free thiol has no hydroxyl group in the molecule. When the hydroxyl group is not present in the molecule, it tends to be easy to obtain a good pot life, and it is easy to achieve both the life of the resin composition and the quick curability.

Preferred polyfunctional ester-free thiols are compounds having a ring skeleton. The ring skeleton may be any of an alicyclic skeleton, an aromatic ring skeleton, a heteroaromatic ring skeleton, and a heterocyclic skeleton, but is preferably an aromatic ring skeleton, a heteroaromatic ring skeleton, and a heterocyclic skeleton, and more preferably a heterocyclic skeleton. Is. When having a ring skeleton, the shear adhesive force is improved. Examples of the compound having such a heterocyclic skeleton include monocyclic or bicyclic compounds containing at least one nitrogen atom as a ring atom having a 5- to 8-membered ring. More specifically, examples of the compound having a heterocyclic skeleton include compounds containing an isocyanul ring skeleton and a glycoluril skeleton.

上式２中、Ｒ₂、Ｒ₃及びＲ₄は、それぞれ独立に、炭素数１〜６、好ましくは炭素数１〜５の直鎖もしくは分岐鎖の２価の炭化水素基を示す。炭化水素基中にはさらに下記（２ａ）〜（２ｃ）に示す２価の基を１つ以上含んでいてもよい。

上記式２で表される多官能エステルフリーチオールとして、具体的には、トリス（３−メルカプトプロピル）イソシアヌレートが挙げられる。 For example, suitable 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 linear or branched divalent hydrocarbon group having 1 to 6 carbon atoms, preferably 1 to 5 carbon atoms. The hydrocarbon group may further contain one or more divalent groups shown in the following (2a) to (2c).

Specific examples of the polyfunctional ester-free thiol represented by the above formula 2 include tris (3-mercaptopropyl) isocyanurate.

上式３中、Ｒ₅、Ｒ₆及びＲ₇及びＲ₈は、それぞれ独立に、炭素数１〜６、好ましくは炭素数１〜４の直鎖もしくは分岐鎖の２価の炭化水素基を示す。炭化水素基中には下記（３ａ）〜（３ｃ）に示す２価の基を１つ以上含んでいても良い。

上記式３で表される多官能エステルフリーチオールとして、具体的には、１，３，４，６−テトラキス（２−メルカプトエチル）グリコールウリル等が挙げられる。 Alternatively, as another suitable polyfunctional ester-free thiol, a compound represented by the following formula 3 can be mentioned.

In the above formula 3, R ₅ , R ₆ and R ₇ and R ₈ each independently represent a linear or branched divalent hydrocarbon group having 1 to 6 carbon atoms, preferably 1 to 4 carbon atoms. .. The hydrocarbon group may contain one or more divalent groups shown in the following (3a) to (3c).

Specific examples of the polyfunctional ester-free thiol represented by the above formula 3 include 1,3,4,6-tetrakis (2-mercaptoethyl) glycoluril and the like.

The content of the (C component) polyfunctional ester-free thiol in the resin composition is not particularly limited, and can be adjusted according to the type of the epoxy resin, the bifunctional ester-free thiol, and the like.
For example, when the content of the (A component) epoxy resin is 100 parts by mass, the content of the (C component) polyfunctional ester-free thiol is preferably 0.1 to 100 parts by mass, preferably 1 to 60 parts by mass. It is more preferably 10 parts by mass, and even more preferably 10 to 50 parts by mass.
When the total number of thiol groups of component B and component C contained in the composition is 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 + C). The total number of thiol groups)) of the component is, for example, 0.1 to 0.9, preferably 0.2 to 0.8, and more preferably 0.3 to 0.7.
Here, the number of thiol groups indicates a value obtained by dividing the mass part of thiol contained in the composition by the thiol group equivalent (mass part of thiol / thiol group equivalent). When a plurality of types of thiols as B component and C component are contained in the composition, the total value obtained by dividing the mass part of each thiol by the respective thiol group equivalent is shown.
The thiol group equivalent is a value indicating the mass of the thiol compound per thiol group, 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. ..

Further, in the resin composition according to the present embodiment, the ratio of "total number of thiol groups of component B and component C" to "number of epoxy groups of component A" (total number of thiol groups of component C and component B / The total number of epoxy groups of the component A) is preferably 0.2 to 2.0, more preferably 0.6 to 1.2.
Here, the number of epoxy groups indicates a value obtained by dividing the mass part of the epoxy resin contained in the composition by the epoxy group equivalent (mass portion of epoxy group / epoxy group equivalent). When a plurality of types of epoxy resins of component A are contained in the composition, the total value obtained by dividing the mass part of each epoxy resin by the respective epoxy group equivalents is shown.

[D component: latent curing accelerator]
Preferably, the resin composition according to the present embodiment contains a latent curing accelerator. The latent curing accelerator is an additive that does not contribute to the curing of the epoxy resin at room temperature (20 ° C. ± 15 ° C. (JISZ8703)) and has a function of accelerating the curing of the epoxy resin during heating.

Preferably, a solid dispersion type latent curing accelerator is used as the latent curing accelerator. The solid-dispersed latent curing accelerator is a compound that is insoluble in an epoxy resin at room temperature, is solubilized by heating, and functions as a curing accelerator for the epoxy resin.
Examples of the solid-dispersed latent curing accelerator include, but are not limited to, an imidazole compound that is solid at room temperature and a solid-dispersed amine adduct-based latent curing accelerator. Of these, a solid-dispersed amine adduct-based latent curing accelerator is preferable.

Examples of the imidazole compound solid at room temperature include 2-heptadecylimidazole, 2-phenyl-4,5-dihydroxymethylimidazole, 2-undecylimidazole, 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 isocyanuric acid adduct, 2-methylimidazole, 2-phenylimidazole, 2-phenyl-4-methylimidazole, 1-cyanoethyl-2-phenylimidazole, 1-Cyanoethyl-2-methylimidazole-trimethylate, 1-cyanoethyl-2-phenylimidazole-trimeritate, N- (2-methylimidazolyl-1-ethyl) -urea, N, N'-(2-methylimidazole- (1) )-Ethyl) -aziboyldimide and the like, but are not limited thereto.

Examples of the solid-dispersed amine adduct-based latent curing accelerator are a reaction product of an amine compound and an epoxy compound (amine-epoxyadduct system), and a reaction product of an amine compound and an isocyanate compound or a urea compound (urea type). Adduct system) and the like.

Examples of the epoxy compound used as one of the raw materials for producing the solid-dispersed amine adduct-based latent curing accelerator (amine-epoxy adduct-based) include polyvalent phenols such as bisphenol A, bisphenol F, catechol, and resorcinol, or Polyglycidyl ether obtained by reacting a polyhydric alcohol such as glycerin or polyethylene glycol with epichlorohydrin; hydroxycarboxylic acid such as p-hydroxybenzoic acid, β-hydroxynaphthoic acid and epichlorohydrin. Glycidyl ether ester obtained by reaction; Polycarboxylic acid such as phthalic acid and terephthalic acid and polyglycidyl ester obtained by reacting with epichlorohydrin; with 4,4'-diaminodiphenylmethane, m-aminophenol and the like. Glycidylamine compounds obtained by reacting with epichlorohydrin; further, polyfunctional epoxy compounds such as epoxidized phenol novolak resin, epoxidized cresol novolak resin, and epoxidized polyolefin, butyl glycidyl ether, phenyl glycidyl ether, and glycidyl methacrylate. Monofunctional epoxy compounds such as; etc .; but are not limited thereto.

The amine compound used as a raw material for producing the solid-dispersed amine adduct-based latent curing accelerator has at least one active hydrogen in the molecule capable of an addition reaction with an epoxy group, and has a primary amino group and a secondary amino group. Any one having at least one functional group selected from an amino group and a tertiary amino group in the molecule may be used. Examples of such amine compounds include aliphatic amines such as diethylenetriamine, triethylenetetramine, n-propylamine, 2-hydroxyethylaminopropylamine, cyclohexylamine, and 4,4'-diamino-dicyclohexylmethane; Aromatic amine compounds such as 4,4'-diaminodiphenylmethane, 2-methylaniline; nitrogen such as 2-ethyl-4-methylimidazole, 2-ethyl-4-methylimidazoline, 2,4-dimethylimidazolin, piperidine, piperazin and the like. Examples include, but are not limited to, heterocyclic compounds containing atoms;

Further, among these, a compound having a tertiary amino group in the molecule is a raw material for giving a latent curing accelerator having an excellent curing promoting ability, and examples of such a compound include, for example, dimethylamino. Amine compounds such as propylamine, diethylaminopropylamine, di-n-propylaminopropylamine, dibutylaminopropylamine, dimethylaminoethylamine, diethylaminoethylamine, N-methylpiperazine, 2-methylimidazole, 2-ethylimidazole, 2 -Primary or secondary amines with a tertiary amino group in the molecule, such as imidazole compounds such as ethyl-4-methylimidazole, 2-phenylimidazole; 2-dimethylaminoethanol, 1-methyl- 2-Dimethylaminoethanol, 1-phenoxymethyl-2-dimethylaminoethanol, 2-diethylaminoethanol, 1-butoxymethyl-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-phenylimidazolin, 1- (2-hydroxy-3-butoxypropyl) -2-methylimidazolin, 2 -(Dimethylaminomethyl) phenol, 2,4,6-tris (dimethylaminomethyl) phenol, N-β-hydroxyethylmorpholin, 2-dimethylaminoethanethiol, 2-mercaptopyridine, 2-benzoimidazole, 2-mercapto Benzoimidazole, 2-mercaptobenzothiazole, 4-mercaptopyridine, N, N-dimethylaminobenzoic acid, N, N-dimethylglycine, nicotinic acid, isonicotinic acid, picolinic acid, N, N-dimethylglycine hydrazide, N, Examples thereof include alcohols, phenols, thiols, carboxylic acids and hydrazides having a tertiary amino group in the molecule, such as N-dimethylpropionic acid hydrazide, nicotinic acid hydrazide, isonicotinic acid hydrazide and the like.

When the above-mentioned epoxy compound and amine compound are subjected to an addition reaction to produce a latent curing accelerator, an active hydrogen compound having two or more active hydrogens in the molecule can be further added. Examples of such active hydrogen compounds include polyhydric phenols such as bisphenol A, bisphenol F, bisphenol S, hydroquinone, catechol, resorcinol, pyrogallol, and phenol novolak resin, polyhydric alcohols such as trimethylolpropane, and adipic acid. , Polyvalent carboxylic acids such as phthalic acid, 1,2-dimercaptoethane, 2-mercaptoethanol, 1-mercapto-3-phenoxy-2-propanol, mercaptoacetic acid, anthranyl acid, lactic acid and the like. Not limited.

Examples of the isocyanate compound used as a raw material for producing the solid-dispersed amine adduct-based latent curing accelerator include monofunctional isocyanate compounds such as n-butyl isocyanate, isopropyl isocyanate, phenyl isocyanate, and benzyl isocyanate; hexamethylene diisocyanate and tolui. Polyfunctional isocyanates such as range isocyanate, 1,5-naphthalenediocyanate, diphenylmethane-4,4'-diisocyanate, isophorone diisocyanate, xylylene diisocyanate, paraphenylenedi isocyanate, 1,3,6-hexamethylenetriisocyanate, bicycloheptanetriisocyanate Compounds; Further, terminal isocyanate group-containing compounds obtained by reacting these polyfunctional isocyanate compounds with active hydrogen compounds; and the like can also be used. Examples of such a terminal isocyanate group-containing compound include an addition compound having a terminal isocyanate group obtained by reacting tolylene diisocyanate with trimethylolpropane, and a terminal isocyanate group obtained by reacting tolylene diisocyanate with pentaerythritol. Examples thereof include, but are not limited to, additional compounds having.

Further, examples of the urea compound used as a raw material for producing the solid-dispersed amine adduct-based latent curing accelerator include, but are not limited to, urea and thiourea.

The solid dispersion type latent curing accelerator may be, for example, appropriately mixed with the above-mentioned production raw materials, reacted at a temperature of room temperature to 200 ° C., cooled and solidified, and then pulverized, or methyl ethyl ketone, dioxane, tetrahydrofuran, etc. It can be easily obtained by reacting in the same solvent as above, removing the solvent, and then pulverizing the solid content.

As a typical example commercially available as a solid dispersion type latent curing accelerator, for example, as an amine-epoxyadduct system (amineadduct system), "Amicure PN-23" (trade name manufactured by Ajinomoto Fine-Techno Co., Ltd.). , "Amicure PN-H" (Ajinomoto Fine Techno Co., Ltd. product name), "Novacure HX-3742" (Asahi Kasei Co., Ltd. product name), "Novacure HX-3721" (Asahi Kasei Co., Ltd. product name), etc. , Urea-type adduct system includes "Fuji Cure FXR-1020" (trade name manufactured by Fuji Kasei Co., Ltd.), "Fuji Cure FXR-1030" (trade name manufactured by Fuji Kasei Co., Ltd.), etc. No.

When the content of the (A component) epoxy resin is 100 parts by mass, the content of the (D component) latent curing accelerator is preferably 0.1 to 100 parts by mass, preferably 1 to 60 parts by mass. More preferably, 5 to 30 parts by mass is further preferable.

[E component: stabilizer]
The resin composition according to the present embodiment further comprises a borate ester compound, a titanium acid ester compound, an aluminate compound, a zirconate compound, an isocyanate compound, a carboxylic acid, an acid anhydride and an acid anhydride in order to realize excellent storage stability. It is preferable to contain one or more stabilizers (component E) selected from mercapto organic acids.

Examples of the borate compound include trimethylborate, triethylborate, tri-n-propylborate, triisopropylborate, tri-n-butylborate, tripentylborate, triallylborate, trihexylborate, and tricyclohexylborate. Trioctylborate, Trinonylborate, Tridecylbolate, Tridodecylbolate, Trihexadecylbolate, Trioctadecylbolate, Tris (2-ethylhexyloxy) borate, Bis (1,4,7,10-tetraoxaundecyl) (1,4,7,10,13-pentaoxatetradecyl) (1,4,7-trioxaundecyl) borate, tribenzylborate, triphenylborate, tri-o-tolylborate, tri-m-trill Examples thereof include borate and triethanolamine borate.

Examples of the titanium acid ester compound include tetraethyl titanate, tetrapropyl titanate, tetraisoproprutitanate, tetrabutyl titanate, and tetraoctyl titanate.

Examples of the aluminate compound include triethylaluminate, tripropylaluminate, triisopropylaluminate, tributylaluminate, and trioctylaluminate.

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, 2-ethylphenyl isocyanate and 2,6-dimethylphenyl isocyanate. , 2,4-Toluene diisocyanate, toluylene diisocyanate, 2,6-toluene diisocyanate, 1,5-naphthalenedi isocyanate, diphenylmethane-4,4'-diisocyanate, trizine diisocyanate, isophorone diisocyanate, xylylene diisocyanate, paraphenylenedi isocyanate, bicyclo Examples thereof include heptane triisocyanate.

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 monochloro acid. Halogenized fatty acids such as acetic acid and dichloroacetic acid, monobasic oxy acids such as glycolic acid and lactic acid, aliphatic aldehyde acids such as glyoxal acid and grape acid, and ketone acids, oxalic acids, malonic acids, succinic acids and maleic acids. Examples thereof include aromatic monobasic acids such as aliphatic polybasic acid, benzoic acid, halogenated benzoic acid, toluic acid, phenylacetic acid, cinnamic acid and mandelic acid, and aromatic polybasic acids such as phthalic acid and trimesic acid. ..

Examples of the acid anhydride include succinic anhydride, dodecynyls succinic anhydride, maleic anhydride, adducts of methylcyclopentadiene and maleic anhydride, hexahydroanhydride, methyltetrahydrophthalic anhydride and the like. Examples thereof include aromatic polybasic acid anhydrides such as phthalic anhydride, trimellitic anhydride and pyrrolimellitic anhydride such as basic acid anhydride.

The mercapto organic acid is obtained by, for example, an esterification reaction between a mercapto aliphatic monocarboxylic acid such as mercaptoacetic acid, mercaptopropionic acid, mercaptobutyric acid, mercaptosuccinic acid, dimercaptosuccinic acid, and a hydroxyorganic acid. Examples thereof include mercapto aliphatic monocarboxylic acids such as mercapto aliphatic monocarboxylic acids and mercapto aromatic monocarboxylic acids such as mercapto benzoic acid.

Of these, the borate ester compound is preferable as the E component from the viewpoint of high versatility and safety and improvement of storage stability, and triethylborate, tri-n-propylborate, triisopropylborate, and tri-n. -Butyl borate is more preferred, and triethyl borate is even more preferred. The content of the E component is not particularly limited as long as the storage stability of the resin is enhanced, but when the content of the epoxy resin of the A component is 100 parts by mass, the content of the E component is 0.001 to 50 mass by mass. The amount is preferably 0.05 to 30 parts by mass, more preferably 0.1 to 10 parts by mass.

As a method of blending the E component into the resin composition, in addition to blending the A component to the D component at the same time, it is also possible to mix the latent curing accelerator of the D component and the E component in advance. The mixing method at this time can be carried out in a solvent such as methyl ethyl ketone toluene, in a liquid epoxy resin, or by contacting the two in a solvent-free manner.

(F component: other components)
The one-component resin composition of the present embodiment may contain, if necessary, a filler (for example, fumed silica), a diluent, a solvent, a pigment, a flexibility-imparting agent, which are commonly used in the field of the present invention. Various additives such as a coupling agent, an antioxidant, a thixotropic property-imparting agent, and a dispersant can be added.

There is no particular difficulty in preparing the one-component resin composition according to the present embodiment by using the components A to C described above and the components D to F which are optional components as raw materials, and there is no particular difficulty, and a conventionally known method is used. It can be done according to. For example, each component can be mixed with a mixer such as a Henschel mixer to prepare a one-component resin composition.

Further, there is no particular difficulty in curing the obtained one-component resin composition, and this can also be performed according to a conventionally known method. For example, it can be cured by heating the obtained one-component resin composition at a temperature of room temperature or higher. The heating is carried out, for example, at a temperature of 70 to 150 ° C., preferably 75 to 120 ° C., more preferably 80 to 100 ° C., for example, 1 to 60 minutes, preferably 3 to 30 minutes, more preferably 5 to 15 minutes. It is appropriate to do it for a minute. In particular, if it is cured by heating at 80 or 100 ° C. for 10 minutes or less, it can be determined that it has an appropriate low-temperature rapid curing property.

The present embodiment also includes a cured resin obtained by heating the above-mentioned one-component resin composition, and also includes a functional product containing the cured resin. Examples of the functional product include an adhesive, a casting agent, a sealing agent, a sealing agent, a fiber-reinforced resin, a coating agent, a paint and the like.
Further, this cured epoxy resin can be used, for example, as an adhesive between a magnet and a housing in a neodymium magnet-containing motor, or as an adhesive for an electronic component equipped with a neodymium magnet-containing motor. Generally, magnets are greatly demagnetized by heat. Since the resin composition of the present invention can suppress heating at the time of bonding to a low temperature of 80 ° C. or lower, it is used for bonding neodymium magnets and other members, and in electronic parts equipped with neodymium magnets, configurations other than neodymium magnets. It is suitable for applications in which members are bonded to each other, and in the process of bonding electronic components after mounting neodymium magnet-containing components. In addition, since neodymium magnets have the property of contracting when heated and expanding when cooled, the linear expansion differs from that of other members used as adherends, and internal stress is generated during bonding. For this reason, peeling at the adhesive interface is likely to occur as a result of an impact such as dropping. In this regard, the resin composition of the present invention has a high adhesive force in both the shearing direction and the peeling direction, so that peeling is unlikely to occur, and the resin composition is particularly suitable for bonding neodymium magnets.

Further, since the above-mentioned (B component) bifunctional ester-free thiol and (C component) polyfunctional ester-free thiol can cure the epoxy resin (A component), a mixture thereof is used as a curing agent for the epoxy resin. can do. That is, the curing agent for epoxy resin according to the present embodiment contains the above-mentioned (B component) bifunctional ester-free thiol and (C component) polyfunctional ester-free thiol.

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 compounding composition shown in Table 1 and Table 2, and the resin compositions according to Examples 1 to 7 and Comparative Examples 1 to 7 were prepared. In Tables 1 and 2, the blending amount of each component means parts by mass. Further, in each Example and Comparative Example, 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 Tables 1 and 2 were weighed in a dedicated plastic container. Then, using a rotating / revolving vacuum mixer Awatori Rentaro (manufactured by Shinky Co., Ltd .; ARE-250), the mixture was sufficiently mixed at room temperature at 2000 rpm and defoamed for another 1 minute to obtain the desired resin composition.

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

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

1,10-decanedithiol: manufactured by Tokyo Chemical Industry Co., Ltd., total equivalent of thiol groups 103 g / eq molecular weight 206

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

[Bifunctional ester-containing thiol]
EGTP: Manufactured by Yodo Chemical Co., Ltd., ethylene glycol bisthiopropionate, thiol group total equivalent 124 g / eq

[Polyfunctional ester-free thiol]
TMPI C: Ajinomoto Fine Techno Co., Ltd., Tris (3-mercaptopropyl) isocyanurate, total equivalent of thiol group 117 g / eq

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

[Tholiol containing polyfunctional ester]
TMTP: Trimethylolpropanetris (3-mercaptopropionate, thiol group total equivalent 140 g / eq) manufactured by Yodo Kagaku Co., Ltd.
[Latent Curing Accelerator]
PN-23: Ajinomoto Fine Techno Co., Ltd., amine epoxy adduct-based curing agent [stabilizer]
TEB: Triethyl borate [filler] manufactured by Tokyo Kasei Co., Ltd.
AEROSIL200: Fumed Silica, manufactured by Aerosil Japan Co., Ltd.

[Evaluation of low temperature fast curing]
For each Example and each Comparative Example, the low temperature fast curing property was evaluated by measuring the gel time (gelation time) according to JISC6521. Specifically, first, a hot plate type gelation tester (GT-D: manufactured by Nissin Kagaku Co., Ltd.) was used to measure the time during which the resin compositions of each Example and Comparative Example stopped drawing threads at 80 ° C. .. More specifically, about 0.5 g of a sample (resin composition) was placed on a hot plate gelling tester. Starting from the time when the temperature reaches 80 ° C. (80 ° C. gel time), the contact circular motion with a spatula having a tip width of 5 mm with respect to the resin composition so that the resin composition fits within the range of 25 mm in diameter on the hot plate. Was repeated (1 rotation per second). The measurement was performed by regarding the time from the start point to the end point as the time until gelation, with the time when the resin composition was lifted 30 mm vertically from the hot plate and the thread-like material was cut off. The spatula was not lifted while the viscosity of the resin was low, and when the viscosity increased, it was occasionally lifted vertically from the hot plate by about 30 mm, and this vertical movement was repeated until the thread-like material was cut. The measurement was repeated twice and the average value was used as the result. It can be said that the shorter the gel time, the better the low-temperature quick-curing property.

[Evaluation of initial adhesive strength]
(I) Initial tensile shear adhesive strength Two test pieces of mild steel plate (JISG3141, SPCC) were prepared, and the oil was wiped off with a waste cloth moistened with acetone. Further, the surface of the adhesive surface of the mild steel plate was polished with an endless belt # 120. The resin composition was uniformly applied to the polished surface of the mild steel plate to a thickness of about 1 mm. The two test pieces were bonded together with two clips and pressed so that the coated surfaces overlapped at about 12 mm. At this time, the exuded resin composition was immediately wiped off with a waste cloth. The test pieces were evenly arranged in an oven, heat-cured at 80 ° C. for 60 minutes, and adhered. Two test pieces were prepared for the same resin. The obtained test piece was measured for tensile shear adhesion strength using a Tensilon universal tester (UTM-5T manufactured by TOYO BALDWIN) in accordance with JIS-K-6850 (measurement environment; temperature 25 ° C / humidity). 60%, pulling speed; 5 mm / min). ^{The adhesive area (mm 2} ) was measured based on the maximum load (N) at which the test piece was broken, and the tensile shear adhesive strength A was calculated from the following formula.
(Equation): Tension shear adhesion strength A (N / mm ² ) = maximum load (N) / adhesion area (mm ² )

(Ii) Initial peeling adhesive strength A test piece of a steel sheet (25 mm × 150 mm × 0.4 mm) was wiped with a waste cloth moistened with acetone, and the oil content was wiped off. Further, the surface of the adhesive surface of the steel sheet was polished with an endless belt # 120. The resin composition was uniformly applied to the polished surface of the steel sheet to a thickness of about 20 to 30 μm. Another steel plate was overlapped and bonded with four clips and pressed. At this time, the exuded resin composition was immediately wiped off. The test pieces were evenly arranged in an oven and heat-cured at 80 ° C. for 60 minutes to adhere. Two test pieces were prepared for each of the same resin composition. The tensile strength of the obtained test piece was measured according to JIS-K-6854-3 with a Tensilon universal tester (RTM-500, manufactured by Orientec) (measurement environment; temperature 25 ° C / humidity 60%, tensile). Speed; 50 mm / min). Based on the average peeling load (N), the peeling adhesive strength A per 25 mm width was calculated.

[Evaluation of moisture resistance]
(I) Tension Shear Adhesive Strength Two separately prepared test pieces were prepared in the same procedure as the evaluation of the initial tensile shear adhesive strength. After leaving the test piece in a pressure cooker tester set to 121 ° C. and 100% RH saturation for 24 hours, the obtained test piece was subjected to an adhesion test using a Tensilon universal tester (UTM-5T manufactured by TOYO BALDWIN). Similarly, the tensile shear adhesive strength was measured according to JIS-K-6850 (measurement environment; temperature 25 ° C./humidity 60%, tensile speed; 5 mm / min). ^{The adhesive area (mm 2} ) was measured based on the maximum load (N) at which the test piece was broken, and the tensile shear adhesive strength B was calculated in the same manner as the evaluation of the adhesiveness.
Tension Shear Adhesive Strength B (N / mm ² ) = Maximum Load (N) / Adhesive Area (mm ² )

[Tension shear adhesion strength retention rate]
In order to evaluate the effect of humidity on the adhesive strength, the strength retention rate was calculated. The strength retention rate was calculated as follows from the values of the tensile shear adhesive strength A and the tensile shear adhesive strength B.
[Strength retention rate] = [Tension shear adhesion strength B] / [Tension shear adhesion strength A] x 100
It can be said that the larger the value of the strength retention rate, the more resistant the test piece to high humidity.

[Peeling adhesive strength]
Two test pieces prepared separately in the same procedure as the evaluation of the initial peeling adhesive strength were prepared. Each test piece was left in a pressure cooker tester set at 121 ° C. and 100% RH saturation for 24 hours, and then the obtained test piece was used in a Tensilon universal tester (RTM-500, manufactured by Orientec). , JIS-K-6854-3, the tensile strength was measured (measurement environment; temperature 25 ° C./humidity 60%, tensile speed; 50 mm / min). Based on the average peeling load (N), the peeling adhesive strength B per 25 mm width was calculated.

[Peeling adhesive strength retention rate]
In order to evaluate the effect of humidity on the peel-off adhesive strength, the strength retention rate was calculated. The strength retention rate was calculated as follows from the values of the peel-off adhesive strength A and the peel-off adhesive strength B.
[Strength retention rate] = [Peeling adhesive strength B] / [Peeling adhesive strength A] x 100
It can be said that the larger the value of the strength retention rate, the more resistant the test piece to high humidity.
[Storage stability]
For each of Examples 1 to 7, about 5 g of the resin composition was sealed in a plastic container, left in a constant temperature room at a temperature of 25 ° C. and a humidity of 60% for 24 hours, and then opened to check the fluidity.
As a result, in any of Examples 1 to 7, it was possible to stir using a spatula. That is, it was confirmed that all of the resin compositions according to Examples 1 to 7 had excellent storage stability.

[Discussion of evaluation results]
The results of each of the above evaluations are shown in Tables 1 and 2. It was found that the resin compositions of Examples 1 to 7 exhibited better shear adhesive strength, peel adhesive strength, moisture resistance, and low-temperature quick-curing property than the resin compositions of Comparative Examples.

Specifically, when Examples 1 to 5 and Comparative Example 1 are compared, the initial peeling adhesive strength was 6 (1N / 25 mm) in Comparative Example 1, whereas it was 15 (1N) in Examples 1 to 5. / 25mm) or more. That is, as compared with the case where only the polyfunctional ester-free thiol was used as the curing agent (Comparative Example 1), by using the bifunctional ester-free thiol and the polyfunctional ester-free thiol together (Examples 1 to 5), the initial stage was achieved. It was found that the peel-off adhesive strength was significantly increased. A similar tendency was observed when Example 6 in which the type of polyfunctional ester-free thiol was different from that in Examples 1 to 5 was compared with the corresponding Comparative Example 2.

Further, when Examples 2, 4 and 5 were compared with Comparative Examples 3 to 5, respectively, the initial tensile shear adhesive strength A of each Comparative Example was significantly lower than that of each Example. That is, the initial tensile shear adhesive strength can be improved by using the bifunctional and polyfunctional ester-free thiols together as compared with the case where only the bifunctional ester-free thiol is used as the curing agent (Comparative Examples 3 to 5). understood.

Next, when Examples 1 to 7 were compared with Comparative Examples 6 and 7, each Example showed significantly higher moisture resistance. That is, it was found that the moisture resistance was remarkably enhanced by using the ester-free thiol as the curing agent instead of the ester-containing thiol.

In addition, all of Examples 1 to 7 had a gel time of 3 minutes or less and had good low-temperature quick-curing properties.

Claims (14)

Component A: Epoxy resin,
Component B: A thiol compound having two thiol groups in the molecule and not containing an ester skeleton, and component C: a thiol compound having three or more thiol groups in the molecule and not containing an ester skeleton.
A one-component resin composition in which the component B does not have a ring skeleton in the molecule. The one-component resin composition according to claim 1, wherein the content of the B component is 10 to 40 parts by mass with respect to 100 parts by mass of the A component. The one-component resin composition according to claim 1 or 2 , further comprising the following component D.
Ingredient D: Latent curing accelerator The one-component resin composition according to any one of claims 1 to 3, wherein the component B and the component C do not have a hydroxyl group. The one-component resin composition according to any one of claims 1 to 4 , wherein the C component has a ring skeleton in the molecule. The one-component resin composition according to any one of claims 1 to 5 , wherein the molecular weight of the component B is in the range of 130 to 1000. When the total number of thiol groups of the B component and the C component is 1, the ratio of the number of thiol groups of the C component (total number of thiol groups of the C component / (total number of thiol groups of the B component +). The one-component resin composition according to any one of claims 1 to 6 , wherein the total number of thiol groups of the C component)) is 0.1 to 0.9. The one-component resin composition according to any one of claims 1 to 7 , which is used as an adhesive. The one-component resin composition according to claim 8 , which is used for adhering a neodymium magnet as an adherend. A sealing material containing the one-component resin composition according to any one of claims 1 to 7. A cured product obtained by thermally curing the one-component resin composition according to any one of claims 1 to 9. An electronic component comprising the cured product according to claim 11. A neodymium magnet-containing motor comprising an adherend and the cured product according to claim 11 used for adhering the adherend. An electronic component including a neodymium magnet-containing motor, which comprises the cured product according to claim 11.