阅读说明：本技术 树脂组合物、及粘接结构体的制造方法 (Resin composition and method for producing bonded structure ) 是由 新田步 田中亚树子 保井淳 于 2020-03-17 设计创作，主要内容包括：本发明涉及一种树脂组合物,其包含环氧树脂和潜在性固化剂,前述环氧树脂包含含有羟基并且水溶率为65％以上的脂肪族环氧树脂,前述潜在性固化剂具有45℃以上且120℃以下的反应开始温度。(The present invention relates to a resin composition comprising an epoxy resin and a latent curing agent, wherein the epoxy resin comprises an aliphatic epoxy resin containing a hydroxyl group and having a water solubility of 65% or more, and the latent curing agent has a reaction initiation temperature of 45 ℃ or more and 120 ℃ or less.)

1. A resin composition comprising an epoxy resin and a latent curing agent,

the epoxy resin contains an aliphatic epoxy resin containing a hydroxyl group and having a water solubility of 65% or more,

the latent curing agent has a reaction initiation temperature of 45 ℃ or higher and 120 ℃ or lower.

2. The resin composition according to claim 1, wherein the epoxy resin contains 5 to 90 mass% of the aliphatic epoxy resin.

3. The resin composition according to claim 1 or 2, wherein the latent curing agent is an amine compound.

4. The resin composition according to any one of claims 1 to 3, wherein the latent curing agent is contained in an amount of 15 to 40 parts by mass based on 100 parts by mass of the epoxy resin.

5. The resin composition according to any one of claims 1 to 4, which is applied to the surface of SPCC specified in JIS G3141, wherein another SPCC is superimposed on the applied surface, and after 2 sheets of SPCC are bonded by heating at 80 ℃ for 30 minutes, the resin composition is stretched at 5 mm/min in the longitudinal direction of the SPCC, and wherein the shear adhesion force at the time of peeling is 10MPa or more.

6. A method of manufacturing a bonded structure, comprising:

a step (1) of disposing a resin composition layer formed from the resin composition according to any one of claims 1 to 5 on a 1 st adherend;

a step (2) of bringing a 2 nd adherend into contact with the side of the 1 st adherend on which the resin composition layer is disposed; and

and (3) heating and curing the resin composition layer at 70 ℃ to 150 ℃.

7. The method of producing a bonded structure according to claim 6, wherein the resin composition layer is cured under any of the following conditions (1) to (5),

(1) heating at a temperature of 70 ℃ or higher and less than 80 ℃ for 30 to 120 minutes

(2) Heating at 80-90 deg.C for 20-100 min

(3) Heating at a temperature of 90 ℃ or higher and less than 100 ℃ for 10 to 60 minutes

(4) Heating at a temperature of 100 ℃ or higher and less than 120 ℃ for 10 to 40 minutes

(5) Heating at a temperature of 120 ℃ or higher and less than 150 ℃ for 5 to 30 minutes.

Technical Field

The present invention relates to a resin composition and a method for producing an adhesive structure.

Background

Conventionally, in the electronics industry, adhesives for a semi-structure are used for mechanically bonding many components in an electronic device.

When a component in an electronic device is bonded using a semi-structural adhesive, there is a problem that a high curing activation temperature may damage a fine member in the electronic device.

In view of the above problems, adhesives and adhesive tapes that can be cured at relatively low temperatures have been studied. For example, in patent document 1, curing at a low temperature can be achieved by including a latent curing agent activated at a low temperature in a curing agent layer provided in an epoxy adhesive tape.

Documents of the prior art

Patent document

Patent document 1: japanese Kokai publication Hei-2013-538271

Disclosure of Invention

Problems to be solved by the invention

The epoxy adhesive tape described in the above patent document can be cured at a low temperature, but the storage stability of the cured composition used in the curing agent layer is insufficient. Therefore, when the composition is stored for a long time after its production, the composition loses fluidity and is problematic in use.

Accordingly, an object of the present invention is to provide a resin composition having high storage stability, being curable at low temperature, and having high adhesive strength, and a method for producing an adhesive structure using the same.

Means for solving the problems

The present inventors have made extensive studies to solve the above problems. As a result, they have found that a resin composition having high storage stability, being curable at low temperatures, and high adhesive strength can be provided by using a latent curing agent having a specific reaction initiation temperature as a curing agent and using a specific epoxy resin, and have completed the present invention.

One embodiment of the present invention relates to a resin composition including an epoxy resin and a latent curing agent, the epoxy resin including an aliphatic epoxy resin containing a hydroxyl group and having a water solubility of 65% or more, the latent curing agent having a reaction start temperature of 45 ℃ or more and 120 ℃ or less.

In one embodiment of the present invention, the epoxy resin preferably contains 5 to 90% by mass of the aliphatic epoxy resin.

In one embodiment of the present invention, the latent curing agent contained in the resin composition is preferably an amine compound.

In one embodiment of the present invention, the resin composition preferably contains 15 to 40 parts by mass of the latent curing agent per 100 parts by mass of the epoxy resin.

In one embodiment of the present invention, the resin composition is preferably applied to the surface of SPCC defined in JIS G3141, and the shear adhesion when the resin composition is peeled off by being stretched at 5 mm/min in the longitudinal direction of the SPCC after 2 pieces of SPCC are bonded by superposing another SPCC on the applied surface and heating at 80 ℃ for 30 minutes.

In addition, an embodiment of the present invention relates to a method for manufacturing a bonded structure, including: a step (1) of disposing a resin composition layer formed from the resin composition on a 1 st adherend; a step (2) of bringing a 2 nd adherend into contact with the side of the 1 st adherend on which the resin composition layer is disposed; and (3) heating and curing the resin composition layer at 70 ℃ to 150 ℃.

In one embodiment of the present invention, in the method for producing an adhesive structure, the resin composition layer is preferably cured under any of the following heating conditions (1) to (5).

(1) Heating at a temperature of 70 ℃ or higher and less than 80 ℃ for 30 to 120 minutes

(2) Heating at 80-90 deg.C for 20-100 min

(3) Heating at a temperature of 90 ℃ or higher and less than 100 ℃ for 10 to 60 minutes

(4) Heating at a temperature of 100 ℃ or higher and less than 120 ℃ for 10 to 40 minutes

(5) Heating at 120-150 deg.C for 5-30 min

ADVANTAGEOUS EFFECTS OF INVENTION

According to the present invention, a resin composition having high storage stability, being curable at low temperatures, and having high adhesion can be provided. In addition, the composition can produce an adhesive structure in which adherends are firmly adhered to each other even after long-term storage.

Drawings

Fig. 1 is a view showing a state where a resin composition layer 1 is disposed on a 1 st adherend 2 in a method for producing an adhesive structure according to an embodiment of the present invention.

Fig. 2 is a view showing a bonded structure 10 obtained by disposing the resin composition layer 1 on the 1 st adherend 2, further disposing the 2 nd adherend 3 thereon, and then heating and curing the resin composition layer 1 in the method for producing a bonded structure according to an embodiment of the present invention.

Detailed Description

Hereinafter, embodiments of the present invention will be described in detail. The present invention is not limited to the embodiments described below.

In the present specification, "a to B" indicating a range means "a to B inclusive". In the present specification, "mass%" and "weight%" are used as the same meaning, and "parts by mass" and "parts by weight" are used as the same meaning.

In the present specification, the term "epoxy resin" refers to both "aliphatic epoxy resin" and "epoxy resin other than aliphatic epoxy resin" in the present invention.

[ resin composition ]

The resin composition according to one embodiment of the present invention is characterized by containing an epoxy resin and a latent curing agent, wherein the epoxy resin contains an aliphatic epoxy resin containing a hydroxyl group and having a water solubility of 65% or more, and the latent curing agent has a reaction initiation temperature of 45 ℃ or more and 120 ℃ or less.

The resin composition can be cured at a low temperature by using a latent curing agent having a reaction initiation temperature of 45 ℃ to 120 ℃ as a curing agent. Further, the resin composition contains an aliphatic epoxy resin containing a hydroxyl group and having a water solubility of 65% or more, and thus can have high storage stability and impart high adhesion during curing. That is, the resin composition of the present embodiment is useful as, for example, an adhesive composition for bonding adherends to each other.

The components contained in the resin composition will be described in detail below.

< epoxy resin >

The resin composition according to an embodiment of the present invention contains an epoxy resin.

It is important that the epoxy resin in the embodiment of the present invention contains an aliphatic epoxy resin containing a hydroxyl group and having a water solubility of 65% or more. This enables the resin composition to maintain its fluidity for a long period of time, and to improve its storage stability. This is presumably because the aliphatic epoxy resin contains a hydroxyl group and thus has a low compatibility with the curing agent. In addition, it is assumed that: the aliphatic epoxy resin has a water solubility of 65% or more, and thus, the compatibility with the curing agent is further lowered by the increase in the amount of hydroxyl groups, and no reaction occurs until heating. In addition, the soft skeleton of the aliphatic epoxy resin can improve the adhesive strength during curing. However, the present disclosure is not limited to these mechanisms.

The aliphatic epoxy resin containing a hydroxyl group has at least 1 hydroxyl group in one molecule. The kind thereof is not particularly limited, and examples thereof include glycerol diglycidyl ether, glycerol triglycidyl ether, glycerol polyglycidyl ether, polyglycerol polyglycidyl ether, sorbitol polyglycidyl ether, and cyclohexanedimethanol diglycidyl ether.

The aliphatic epoxy resin having a water solubility of 65% or more in the embodiment of the present invention may be any aliphatic epoxy resin selected from the above-mentioned hydroxyl group-containing aliphatic epoxy resins and having a water solubility of 65% or more.

The water solubility of the epoxy resin is a solubility when 10 parts by mass of a compound having 1 or more epoxy groups is dissolved in 90 parts by mass of water at room temperature, and is represented by the following formula.

Water solubility (%) - (1-insoluble component cyclic oxygen amount/total epoxy weight) × 100

The water solubility of the aliphatic epoxy resin is 65% or more, preferably 70% or more, and more preferably 80% or more.

The content of the aliphatic epoxy resin containing a hydroxyl group and having a water solubility of 65% or more is preferably 5 to 90% by mass based on the total amount of the epoxy resin. More preferably 10% by mass or more, and still more preferably 15% by mass or more. Further, it is preferably 80% by mass or less, more preferably 70% by mass or less. By setting the content of the aliphatic epoxy resin to the above range, higher storage stability and high adhesion force during curing can be obtained.

The epoxy resin in the embodiment of the present invention may contain an epoxy resin other than the above-described aliphatic epoxy resin. That is, examples thereof include aliphatic epoxy resins, alicyclic epoxy resins, aromatic epoxy resins, and the like, which do not contain a hydroxyl group.

The aliphatic epoxy resin having no hydroxyl group is not particularly limited, and examples thereof include neopentyl glycol diglycidyl ether, 1, 4-cyclohexane diglycidyl ether, 1, 3-cyclohexane diglycidyl ether, 1, 2-cyclohexane diglycidyl ether, hexahydrophthalic acid diglycidyl ester, hexahydroterephthalic acid diglycidyl ester, 1, 4-butane diol diglycidyl ether, and 1, 6-hexane diol diglycidyl ether. These may be used alone, or 2 or more of them may be used in combination.

The alicyclic epoxy resin is not particularly limited, and examples thereof include glycidyl ethers of alicyclic alcohols (particularly alicyclic polyols). More specifically, examples thereof include hydrogenated bisphenol a-type epoxy compounds, hydrogenated bisphenol F-type epoxy compounds, hydrogenated biphenol-type epoxy compounds, hydrogenated phenol novolac-type epoxy compounds, and hydrogenated cresol novolac-type epoxy compounds. These may be used alone, or 2 or more of them may be used in combination.

The aromatic epoxy resin is not particularly limited, and examples thereof include bisphenol a type epoxy compounds, bisphenol F type epoxy compounds, biphenol type epoxy compounds, phenol novolac type epoxy compounds, and cresol novolac type epoxy compounds. These may be used alone, or 2 or more of them may be used in combination.

From the viewpoint of curability, bisphenol epoxy compounds are preferred, and bisphenol a epoxy compounds and bisphenol F epoxy compounds are more preferred.

The epoxy resin in the embodiment of the present invention may be in any form of a liquid, a semisolid, and a solid at normal temperature.

The compounding ratio of the epoxy resin is, for example, 40 mass% or more, preferably 50 mass% or more, relative to the total amount of the resin composition. The content is, for example, 100 mass% or less, preferably 70 mass% or less. By setting the compounding ratio of the epoxy resin in the above range, a more convenient and strong adhesion can be achieved.

The resin composition according to an embodiment of the present invention may contain a resin other than an epoxy resin. Examples thereof include silicone compounds, polyhydric alcohol compounds such as polypropylene glycol, urethane resins, and acrylic resins.

< latent curing agent >

The resin composition according to an embodiment of the present invention contains a latent curing agent.

The latent curing agent is a curing agent which is solid at normal temperature (specifically, 25 ℃) and is activated at a predetermined temperature to be compatible with an epoxy resin to cure the epoxy resin. In particular, in the embodiment of the present invention, the latent curing agent starts to be activated at a temperature ranging from 45 ℃ to 120 ℃. That is, the latent curing agent has a reaction initiation temperature of 45 ℃ or higher and 120 ℃ or lower. When the reaction start temperature of the latent curing agent is in the above range, the reaction can be performed at a relatively low temperature during curing while preventing the initiation of curing during the preparation and storage of the resin composition.

The latent curing agent in the embodiment of the present invention has a reaction initiation temperature of 120 ℃ or lower, and more preferably 100 ℃ or lower. The reaction initiation temperature is 45 ℃ or higher, preferably 50 ℃ or higher.

The reaction start temperature of the latent curing agent in the embodiment of the present invention can be measured, for example, by the following method.

About 5mg of a resin composition prepared by mixing 20 parts by mass of a latent curing agent with 100 parts by mass of a bisphenol F type epoxy resin (JeR806, manufactured by Mitsubishi chemical corporation) was weighed out in a closed sample cell made of aluminum. Then, the Heat Flow (Heat Flow) behavior of the resin composition was obtained at a temperature rise rate of 2 ℃ per minute under a nitrogen atmosphere of 50 mL/minute by using a temperature control DSC (trade name "Q-2000", manufactured by TA Instruments Inc.). The heat generation starting temperature, which is the temperature at which the heat flow behavior at this time increases, is set as the reaction starting temperature of the latent curing agent.

The latent curing agent in the embodiment of the present invention is not particularly limited in its kind as long as it satisfies the above-mentioned activation temperature condition. Examples thereof include amine compounds, urea compounds, amide compounds, dihydrazide compounds, imidazole compounds, and imidazoline compounds.

Examples of the amine compound include ethylenediamine, propylenediamine, diethylenetriamine, triethylenetetramine, amine adducts thereof, m-phenylenediamine, diaminodiphenylmethane, and diaminodiphenylsulfone.

Examples of the urea-based compound include 3- (3, 4-dichlorophenyl) -1, 1-Dimethylurea (DCMU), N ' -phenyl-N, N-dimethylurea, and 1,1 ' - (methyl-m-phenylene) bis (3,3 ' -dimethylurea).

Among such urea compounds, 3- (3, 4-dichlorophenyl) -1, 1-Dimethylurea (DCMU) is preferably used.

Examples of the amide compound include polyamide.

Examples of the hydrazide-based compound include dihydrazides such as adipic acid dihydrazide.

Examples of the imidazole-based compound include methylimidazole, 2-ethyl-4-methylimidazole, ethylimidazole, isopropylimidazole, 2, 4-dimethylimidazole, phenylimidazole, undecylimidazole, heptadecylimidazole, and 2-phenyl-4-methylimidazole.

Examples of the imidazoline-based compound include methylimidazoline, 2-ethyl-4-methylimidazoline, ethylimidazoline, isopropylimidazoline, 2, 4-dimethylimidazoline, phenylimidazoline, undecylimidazoline, heptadecylimidazoline, and 2-phenyl-4-methylimidazoline.

Such latent curing agents may be used alone or in combination.

Among such latent curing agents, amine compounds are preferably used.

The compounding ratio of such a latent curing agent is, for example, 15 to 40 parts by mass, preferably 20 to 35 parts by mass, and more preferably 20 to 30 parts by mass, based on 100 parts by mass of the epoxy resin. By setting the range, the initiation of curing during storage can be prevented, and the reaction can be carried out at a relatively low temperature during curing.

< other ingredients >

For the purpose of adjusting the elastic modulus of the cured layer, etc., a filler such as silica, mica, and calcium carbonate may be added to the resin composition according to an embodiment of the present invention. The amount of the filler is not particularly limited, and is, for example, 1 part by mass or more, preferably 10 parts by mass or more, per 100 parts by mass of the resin composition. The amount is, for example, 100 parts by mass or less, preferably 80 parts by mass or less.

The resin composition according to an embodiment of the present invention preferably has a shear adhesion of 10MPa or more, which will be described later. That is, the shear adhesion force when applying the coating on the surface of SPCC defined in JIS G3141, superposing another SPCC on the coated surface, bonding 2 SPCCs by heating at 80 ℃ for 30 minutes, and then stretching and peeling the resulting product at 5 mm/min in the longitudinal direction of the SPCC is preferably 10MPa or more. The shear adhesion is more preferably 12MPa or more, and still more preferably 15MPa or more.

[ method for producing adhesive Structure ]

A method for manufacturing a bonded structure according to an embodiment of the present invention includes: a step (1) of disposing a resin composition layer formed of the resin composition of the embodiment of the present invention on a 1 st adherend; a step (2) of bringing a 2 nd adherend into contact with the side of the 1 st adherend on which the resin composition layer is disposed; and (3) heating and curing the resin composition layer at 70 ℃ to 150 ℃.

Hereinafter, each step will be explained.

< step (1) of disposing a resin composition layer formed from the resin composition of the embodiment of the present invention on the first adherend (1) >

As shown in fig. 1, in order to dispose the resin composition layer 1 formed of the resin composition on the 1 st adherend 2, for example, the resin composition 1 may be applied to the 1 st adherend 2 to form a coating film.

Here, the thickness of the coating film (the undried resin composition layer) formed from the resin composition is, for example, 50 μm or more, preferably 100 μm or more, and more preferably 200 μm or more. For example, the particle diameter is 2000 μm or less, preferably 1000 μm or less, and more preferably 700 μm or less. In particular, the thickness of the coating film is preferably 100 to 700 μm in order to achieve both good curability and high adhesiveness after curing.

The first adherend 2 is not particularly limited, and examples thereof include metal, glass, plastic, slate (slate), mortar, concrete, rubber, wood, leather, cloth, and paper. Preferred examples of the 1 st adherend 2 include slate, mortar, and concrete.

As described above, the resin composition layer 1 is disposed on the 1 st adherend 2 as shown in fig. 1.

< step (2) of bringing the 2 nd adherend into contact with the side of the 1 st adherend on which the resin composition layer is disposed >

In this step, the 2 nd adherend is brought into contact with the side of the resin composition layer disposed on the 1 st adherend in the step (1). The method of bringing the 2 nd adherend into contact with the side of the 1 st adherend on which the resin composition layer is disposed is not particularly limited, and any method can be employed.

The reaction temperature is, for example, normal temperature before and after the 2 nd adherend 3 is brought into contact with the side of the 1 st adherend 2 on which the resin composition layer 1 is disposed.

The 2 nd adherend 3 is not particularly limited, and the same adherend as that exemplified for the 1 st adherend 2 can be exemplified.

< step (3) of curing the resin composition layer by heating at 70 ℃ to 150 ℃ >

In this step, in the above step (2), after the 1 st adherend 2 and the 2 nd adherend 3 are arranged with the resin composition layer 1 interposed therebetween, the resin composition layer 1 is heated and cured, whereby the 1 st adherend 2 and the 2 nd adherend 3 are strongly adhered to each other, and the adhered structure 10 shown in fig. 2 is obtained.

The resin composition in the embodiment of the present invention contains a latent curing agent having a reaction start temperature of 45 ℃ or more and 120 ℃ or less, and therefore a resin composition layer formed from the composition can be cured at a relatively low temperature.

The temperature at which the resin composition layer is heated and cured is 70 ℃ to 150 ℃. Preferably 75 ℃ or higher, more preferably 80 ℃ or higher. Further, it is preferably 120 ℃ or lower, more preferably 100 ℃ or lower.

The reaction time varies depending on the temperature, and is, for example, 5 to 120 minutes, preferably 10 to 60 minutes, and more preferably 20 to 40 minutes.

Specifically, it is preferably cured under any of the following heating conditions (1) to (5).

(1) Heating at a temperature of 70 ℃ or higher and less than 80 ℃ for 30 to 120 minutes. More preferably, the heating is carried out for 40 to 100 minutes.

(2) Heating at 80-90 deg.C for 20-100 min. More preferably, the heating is carried out for 25 to 90 minutes.

(3) Heating at a temperature of 90 ℃ or higher and less than 100 ℃ for 10 to 60 minutes. More preferably, the heating is carried out for 15 to 45 minutes.

(4) Heating at a temperature of 100 ℃ or higher and less than 120 ℃ for 10 to 40 minutes. More preferably, the heating is carried out for 15 to 30 minutes.

(5) Heating at a temperature of 120 ℃ or higher and less than 150 ℃ for 5 to 30 minutes. More preferably, the heating is carried out for 10 to 20 minutes.

In the bonded structure produced in the above manner, the shear adhesion of the resin composition layer 1 is preferably 10MPa or more, more preferably 12MPa or more, and still more preferably 15MPa or more. When the shear adhesion of the resin composition layer 1 is 10MPa or more, the adhesion of the resin composition layer 1 is excellent, and the 1 st adherend 2 and the 2 nd adherend 3 can be easily and reliably adhered, and therefore, this is preferable.

The shear adhesion of the resin composition layer 1 was measured by the following method.

The resin composition was applied to the tip of SPCC (JIS G3141) having a width of 25mm, a length of 100mm and a thickness of 1.6 mm. The coated area was 25mm in width × 10mm in length, and the coated area was held by providing a spacer having a thickness of 0.5 mm. The other SPCC was overlapped, fixed with a jig, and then cured. The test piece thus obtained was stretched at 5 mm/min in the longitudinal direction by a tensile tester AG-X (manufactured by shimadzu corporation), and the test force at the time of peeling was measured. The shear adhesion was calculated by the following formula.

Shear adhesion (MPa) test force (N)/250mm²

Examples

Hereinafter, embodiments of the present invention will be described in detail with reference to examples.

(Water solubility)

The water solubility of the aliphatic epoxy resins used in examples and comparative examples was calculated as follows.

The water and the aliphatic epoxy resin were mixed at a weight ratio of 90/10, and after standing for a while, the insoluble matter was taken out and the weight was measured. The water solubility is calculated by the following equation.

Water solubility (%) - (1-insoluble component cyclic oxygen amount/total epoxy weight) × 100

(storage stability)

The resin compositions prepared in examples and comparative examples were evaluated for storage stability by the following methods. That is, the prepared resin composition was stored at room temperature for 2 weeks, and those having fluidity were evaluated as "good" and those having no fluidity were evaluated as "poor".

(shear adhesion)

The shear adhesion of the resin compositions prepared in examples and comparative examples was performed in the following manner.

The resin composition was applied to the tip of SPCC (JIS G3141) having a width of 25mm, a length of 100mm and a thickness of 1.6 mm. The coated area was 25mm in width × 10mm in length, and the coated area was held by providing a spacer having a thickness of 0.5 mm. The other SPCC was stacked, fixed by a jig, and cured under the curing conditions shown in table 1. The test piece thus obtained was stretched at 5 mm/min in the longitudinal direction by a tensile tester AG-X (manufactured by shimadzu corporation), and the test force at the time of peeling was measured. The shear adhesion was calculated by the following formula.

Shear adhesion (MPa) test force (N)/250mm²

(reaction initiation temperature of latent curing agent)

The reaction initiation temperature of the latent curing agent used in the examples and comparative examples was measured by the following method.

About 5mg of a resin composition prepared by mixing 20 parts by mass of a latent curing agent with 100 parts by mass of a bisphenol F type epoxy resin (JeR806, manufactured by Mitsubishi chemical corporation) was weighed out in a closed sample cell made of aluminum. Then, the heat flow behavior of the resin composition was obtained at a temperature rise rate of 2 ℃ per minute under a nitrogen atmosphere of 50 mL/minute by using a temperature control DSC (trade name "Q-2000", manufactured by TA Instruments Inc.). The heat generation starting temperature, which is the temperature at which the heat flow behavior at this time increases, is set as the reaction starting temperature of the latent curing agent.

[ preparation of resin composition ]

(example 1)

The resin composition of example 1 was prepared by mixing 70 parts by mass of a bisphenol F type epoxy resin (trade name "jER 806", manufactured by Mitsubishi chemical corporation), 30 parts by mass of a glycerin polyglycidyl ether having a hydroxyl group and a water solubility of 70% (trade name "SR-GLG", manufactured by Kazakun Kagaku K.K.) as an aliphatic epoxy resin, and 30 parts by mass of an amine compound (trade name "Fujicure FXR-1020", manufactured by T & K TOKA Co., Ltd.) as a latent curing agent. The reaction initiation temperature of the latent curing agent was 54 ℃ as measured by the above method.

(example 2)

The resin composition of example 2 was prepared in the same manner as the resin composition of example 1 except that a polyglycidyl ether having a hydroxyl group and a water solubility of 97% (trade name "SR-6 GL", manufactured by saka chemical industries, ltd.) was used as the aliphatic epoxy resin.

(example 3)

The resin composition of example 3 was prepared in the same manner as the resin composition of example 1 except that sorbitol polyglycidyl ether having a hydroxyl group and a water solubility of 94% (trade name "EX-614B", manufactured by Nagase ChemteX Corporation) was used as the aliphatic epoxy resin.

(example 4)

The resin composition of example 4 was prepared in the same manner as the resin composition of example 1 except that 30 parts by mass of a bisphenol F-type epoxy resin and 70 parts by mass of a polyglycerol polyglycidyl ether (trade name "SR-4 GL", manufactured by saka chemical industries, ltd.) having a hydroxyl group and a water solubility of 99% were used as an aliphatic epoxy resin.

(example 5)

The resin composition of example 5 was prepared in the same manner as in the preparation of the resin composition of example 4, except that the bisphenol F type epoxy resin was used in an amount of 50 parts by mass and the aliphatic epoxy resin was used in an amount of 50 parts by mass.

(example 6)

The resin composition of example 6 was prepared in the same manner as the resin composition of example 4 except that the bisphenol F type epoxy resin was 70 parts by mass, the aliphatic epoxy resin was 30 parts by mass, and the latent curing agent was 30 parts by mass of an amine compound (trade name "Fujicure FXR-1081", manufactured by T & K TOKA). The reaction initiation temperature of the latent curing agent was 48 ℃ as measured by the above method.

(example 7)

The resin composition of example 7 was prepared in the same manner as the resin composition of example 4, except that the bisphenol F type epoxy resin was 90 parts by mass and the aliphatic epoxy resin was 10 parts by mass.

(example 8)

The resin composition of example 8 was prepared in the same manner as in the preparation of the resin composition of example 4, except that 70 parts by mass of a bisphenol a-type epoxy resin (trade name "jER 828", manufactured by mitsubishi chemical corporation) was used instead of the bisphenol F-type epoxy resin and the aliphatic epoxy resin was used in an amount of 30 parts by mass.

(example 9)

The resin composition of example 9 was prepared in the same manner as the resin composition of example 4 except that the bisphenol F type epoxy resin was 70 parts by mass, the aliphatic epoxy resin was 30 parts by mass, and the latent curing agent was 20 parts by mass of an amine compound (trade name "Fujicure FXR-1081", manufactured by T & K TOKA).

(example 10)

The resin composition of example 10 was prepared in the same manner as the resin composition of example 9 except that 35 parts by mass of an amine compound (trade name: Fujicure FXR-1020;. manufactured by T & KTOKA) was used as the latent curing agent.

(example 11)

The resin composition of example 11 was prepared in the same manner as the resin composition of example 9, except that the latent curing agent was changed to 40 parts by mass.

Comparative example 1

The resin composition of comparative example 1 was prepared by mixing 100 parts by mass of a bisphenol A type epoxy resin (trade name "jER 828", manufactured by Mitsubishi chemical corporation) and 30 parts by mass of an amine compound (trade name "Fujicure FXR-1020", manufactured by T & KTOKA) as a latent curing agent.

Comparative example 2

A resin composition of comparative example 2 was prepared by mixing 70 parts by mass of a bisphenol F type epoxy resin (trade name "jER 806", manufactured by mitsubishi chemical corporation), 30 parts by mass of a polyglycerol polyglycidyl ether having a hydroxyl group and a water solubility of 99% (trade name "SR-4 GL", manufactured by sakazakii chemical industries co., ltd.) as an aliphatic epoxy resin, and 7 parts by mass of Dicyandiamide (DICY) as a curing agent. The reaction initiation temperature of the curing agent is 140 ℃ or higher as measured by the above method, and is not a latent curing agent of the present invention.

Comparative example 3

The resin composition of comparative example 3 was prepared in the same manner as the resin composition of comparative example 2 except that 30 parts by mass of trimethylolpropane polyglycidyl ether (trade name "SR-TMP", manufactured by sakazakikai chemical industries co., ltd.) having no hydroxyl group and a water solubility of 35% was used as the aliphatic epoxy resin and 30 parts by mass of an amine compound (trade name "Fujicure FXR-1020", manufactured by T & KTOKA) was used as the latent curing agent.

Comparative example 4

A resin composition of comparative example 4 was prepared in the same manner as in the preparation of the resin composition of comparative example 3 except that 30 parts by mass of diethylene glycol diglycidyl ether (trade name "EX-850", manufactured by Nagase ChemteX Corporation) having no hydroxyl group and a water solubility of 100% was used as the aliphatic epoxy resin.

[ Table 1]

TABLE 1

The resin compositions of examples 1 to 11 were confirmed to have high storage stability, to be cured at a low temperature of 70 to 145 ℃ and to have high adhesion.

On the other hand, the resin composition of comparative example 1 does not contain an aliphatic epoxy resin, and therefore, the shear adhesion during curing is low. In addition, the resin composition of comparative example 2 does not contain a latent curing agent having a reaction initiation temperature of 45 ℃ or more and 120 ℃ or less, and therefore cannot be cured under curing conditions of 80 ℃ for 30 minutes. The resin compositions of comparative examples 3 and 4 had low storage stability because the aliphatic epoxy resin contained no hydroxyl group.

It should be noted that the present application is based on japanese patent application published on 28/3/2019 (japanese patent application 2019-065066), the contents of which are incorporated herein by reference.

Description of the reference numerals

1 layer of a resin composition

2 st adherend

3 nd 2 nd adherend

10 bonded structure