JP2000303051A - Adhesive composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a two-package ordinary-temperature curable adhesive composition which has a long pot life even in a high-temperature atmosphere and can be cured into a product excellent in mechanical strengths and bonding strength by using a base such as an epoxy resin having at least two functional groups in the molecule and a curing agent being an aliphatic amine having specified structures at molecular terminals and in a molecular chain. SOLUTION: This composition comprises a base mainly consisting of a compound having at least two functional groups capable of forming bonds by the action of active hydrogen in the molecule and a curing agent mainly consisting of a compound having functional groups represented by formula I at molecular terminals and having a skeleton represented by formula II in the molecular chain comprising a polyoxyalkylene. The curing agent may be the one mainly consisting of a compound having a skeleton represented by formula II in the molecular chain comprising a polyoxyalkylene. The compound having at least two functional groups capable of forming bonds by the action of active hydrogen in the molecule is desirably an epoxy resin.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a two-part mixture type cold-setting adhesive composition.

[0002]

2. Description of the Related Art Conventionally, a two-part mixture type room temperature curable adhesive composition comprising a main component mainly composed of a compound having a functional group capable of forming a bond by active hydrogen in a molecule and a curing agent thereof, for example, BACKGROUND ART Two-component type cold-setting epoxy resin-based adhesive compositions and urethane resin-based adhesive compositions are widely used as industrial or general adhesives.

[0003] However, in order to improve the workability in a high-temperature atmosphere such as in the summer, such a two-part mixture type cold-setting adhesive composition is generally used.
When the pot life after mixing the main agent and the curing agent is increased, there is a problem that the adhesive strength and mechanical strength of the cured product are reduced.

As a two-pack type epoxy resin-based adhesive composition, for example, Japanese Patent Application Laid-Open No. 53-73300 discloses
"Active hydrogen containing a polyepoxy compound having an average of more than one epoxy group per molecule and a hydroxyl-containing diamine represented by a specific chemical structural formula, and bonded to a nitrogen or oxygen atom in the hydroxyl-containing diamine Curable mixtures wherein the atom is present in 0.5 to 1.5 equivalents per equivalent of epoxy group "are disclosed.

However, the epoxy resin-based adhesive composition disclosed in the above publication is mainly based on the premise of heat curing, as shown in the examples, and is a two-part mixed type room temperature curable adhesive. It does not correspond to the above-mentioned problems of the agent composition.

[0006]

SUMMARY OF THE INVENTION In order to solve the above-mentioned conventional problems, the present invention has a pot life after mixing a main agent and a curing agent even in a high temperature atmosphere such as in summer. It is an object of the present invention to provide a two-part mixture type room temperature curable adhesive composition which is long and excellent in workability and exhibits various physical properties such as excellent mechanical strength and adhesive strength after curing.

[0007]

The adhesive composition according to the invention described in claim 1 (hereinafter referred to as "first invention")
A main agent mainly composed of a compound having two or more functional groups capable of forming a bond by active hydrogen in the molecule, and a polyoxyalkylene having a functional group represented by the following formula (1) at the molecular terminal and And a curing agent mainly containing a compound having a skeleton represented by the following formula (2) in the molecular main chain.

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The invention according to claim 2 (hereinafter referred to as “second
The adhesive composition according to the first aspect of the present invention is the adhesive composition according to the first aspect, wherein the curing agent has a functional group represented by the following general formula (3) at a molecular terminal, It is a curing agent mainly containing a compound having a skeleton represented by the above formula (2) in a molecular main chain composed of alkylene.

Embedded image (Wherein, R ¹ represents hydrogen or an alkyl group, and n represents a positive integer)

The first invention and the second invention (hereinafter referred to as "the present invention")
The main component of the adhesive composition according to the present invention contains, as a main component, a compound having two or more functional groups capable of forming a bond by active hydrogen in the molecule.

The compound having two or more functional groups capable of forming a bond with active hydrogen in the molecule is not particularly limited, but, for example, a compound having two or more epoxy groups in the molecule.
For example, an epoxy resin such as an epoxy oligomer having two or more isocyanate groups, or a urethane resin such as a urethane prepolymer having two or more isocyanate groups in a molecule, and the like are preferably used. Is more preferably used.

The compound having two or more functional groups capable of forming a bond by active hydrogen in the molecule may be used alone or in combination of two or more.

In the present invention, the epoxy resin more preferably used is not particularly limited.
For example, bisphenol A-type epoxy resin, bisphenol F-type epoxy resin, bisphenol AF-type epoxy resin, bisphenol AD-type epoxy resin, and other bisphenol-type epoxy resin obtained by reacting bisphenol A, bisphenol F, bisphenol AF, bisphenol AD, etc. with epichlorohydrin. Epoxy resin and its hydrogenated product; phenol novolak type epoxy resin; glycidylamine type epoxy resin; glycidyl ether type epoxy resin; glycidyl ester type epoxy resin; urethane modified epoxy resin having urethane bond; epoxidation of metaxylenediamine, hydantoin, etc. Nitrogen-containing epoxy resin; rubber-modified epoxy resin containing polybutadiene rubber (BR), acrylonitrile-butadiene copolymer rubber (NBR), etc. Resins and the like, but are preferably used, inter alia balance of performance and cost are better bisphenol A type epoxy resin is more preferably used.

The above epoxy resins may be used alone or in combination of two or more.

The above-mentioned bisphenol A type epoxy resin has various properties from liquid to semi-solid or solid at room temperature depending on the molecular weight. In the present invention, bisphenol A type epoxy resin which is liquid at room temperature is used. An epoxy resin alone may be used, or a bisphenol A type epoxy resin that is liquid at room temperature and a bisphenol A type epoxy resin that is semi-solid or solid at room temperature may be used in combination.

The combination ratio of the bisphenol A type epoxy resin which is liquid at room temperature and the semi-solid or solid bisphenol A type epoxy resin at room temperature is not particularly limited, but it is not limited by weight. It is preferable that the solid or solid bisphenol A epoxy resin / the liquid bisphenol A epoxy resin at room temperature ≦ 1.

If the bisphenol A type epoxy resin which is semi-solid or solid at normal temperature / the bisphenol A type epoxy resin which is liquid at normal temperature (weight ratio) exceeds 1, the viscosity of the obtained adhesive composition becomes too high. In some cases, the curing speed becomes too slow, and the workability is reduced, and the adhesive strength and mechanical strength of the cured product are reduced.

Specific examples of the above-mentioned bisphenol A type epoxy resin are not particularly limited, but for example, trade names “Epicoat 806, 807, 815, 82”
7, 828, 834, 1001, etc. "(Epicoat) series (all manufactured by Yuka Shell Epoxy Co., Ltd.), and" Epomix "under the trade name" Epomix R139, R140, etc. "
Series (all manufactured by Mitsui Petrochemical Industries, Ltd.) and the "Araldite" series (all manufactured by Nippon Ciba Geigy) under the trade name of "Araldite GY-250, GY-260, etc." are preferably used.

The bisphenol A type epoxy resin is
They may be used alone or in combination of two or more.

The main component of the adhesive composition according to the present invention includes:
If necessary, a reactive diluent, an adhesion-imparting agent, and the like may be added as long as the achievement of the object of the present invention is not hindered.

The reactive diluent is not particularly limited, and examples thereof include epoxy group-containing compounds such as butyl glycidyl ether, phenyl glycidyl ether, allyl glycidyl ether and 1,6-hexanediol diglycidyl ether. And it is preferably used.

The reactive diluents may be used alone or in combination of two or more.

The above-mentioned adhesiveness-imparting agent is not particularly limited, and examples thereof include various coupling agents such as a silane coupling agent, a titanium coupling agent, and an aluminum coupling agent. Among them, a silane coupling agent having a good balance between performance and cost is more preferably used.

The above-mentioned adhesiveness-imparting agents may be used alone or in combination of two or more.

The silane coupling agent is not particularly restricted but includes, for example, epoxysilanes such as γ-glycidoxypropyltrimethoxysilane and γ-glycidoxypropyltriethoxysilane; γ-mercapto Mercaptosilanes such as propyltrimethoxysilane and γ-mercaptopropyltriethoxysilane; γ
Aminosilanes such as-(2-aminoethyl) aminopropyltrimethoxysilane and γ-aminopropyltriethoxysilane; and the like, which is preferably used. Among them, active hydrogen is contained in the molecule used as a main component of the main agent. Epoxysilanes which are excellent in storage stability of a mixture with a compound having two or more functional groups capable of forming a bond by the use of epoxysilanes are more preferably used.

The above silane coupling agents may be used alone or in combination of two or more.

The curing agent for the adhesive composition according to the first invention has a functional group represented by the following formula (1) at a molecular terminal:
In addition, a compound having a skeleton represented by the following formula (2) is contained as a main component in a molecular main chain composed of polyoxyalkylene.

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The above compounds contained as a main component in the curing agent of the adhesive composition according to the first invention may be used alone or in combination of two or more.

Further, the curing agent of the adhesive composition according to the second invention has a functional group represented by the following general formula (3) at the molecular terminal and has a molecular main chain composed of polyoxyalkylene. A compound having a skeleton represented by the above formula (2) is contained as a main component.

Embedded image (Wherein, R ¹ represents hydrogen or an alkyl group, and n represents a positive integer)

The above compounds contained as a main component in the curing agent of the adhesive composition according to the second invention may be used alone or in combination of two or more.

Specific examples of the above compound contained as a main component in the curing agent of the adhesive composition according to the first or second invention are not particularly limited.
Aliphatic amines such as "Ditoclar D-677" (trade name, manufactured by Daito Sangyo Co., Ltd.) are mentioned, and are preferably used.

The above aliphatic amines may be used alone or in combination of two or more.

By using a compound having a specific structure (aliphatic amine) such as “Ditoclar D-677” as a main component of the curing agent, the composition can be used even in a high temperature atmosphere such as in summer. It is possible to obtain an adhesive composition exhibiting various physical properties such as excellent mechanical strength and adhesive strength after curing, since the pot life is long after mixing the main agent and the curing agent, and the workability is excellent. .

In the curing agent of the adhesive composition according to the present invention, if necessary, a curing agent other than the above-mentioned compound having a specific structure (aliphatic amine) may be used as long as the object of the present invention is not hindered. A functional compound, a curing accelerator or an adhesion-imparting agent may be added.

The compound functioning as a curing agent other than the compound having a specific structure (aliphatic amine) is not particularly limited, and examples thereof include a heterocyclic diamine, an aromatic amine, a polyamidoamine, and an aliphatic amine. Thioether and the like are mentioned, and are preferably used.

Compounds that function as curing agents other than the compound having a specific structure (aliphatic amine) may be used alone or in combination of two or more.

Examples of the curing accelerator include, but are not particularly limited to, tris (dimethylaminomethyl) phenol, benzyldimethylamine, m-xylylenedi (dimethylamine), N, N'-dimethylpiperazine, Tertiary amines such as N-methylpyrrolidine and N-methylhydroxypiperidine; m-xylylenediamine and its modified products, isophoronediamine and its modified products, N-aminoethylpiperazine and its modified products,
Diaminoethane and its modified products, diethylenetriamine and its modified products, polyoxypropylene polyamines and polyamines such as its modified products; polyaminoamine (polyaminoimidazoline) and its modified products, etc., which are preferably used. Tertiary amines having a good balance between cost and cost are more preferably used.
Tris (dimethylaminomethyl) among the primary amines
Phenol is particularly preferably used.

The curing accelerators may be used alone or in combination of two or more.

Further, the adhesiveness-imparting agent is not particularly limited. For example, the same silane coupling agent, titanium coupling agent, aluminum coupling agent and the like as those which can be added to the main component are used. Various coupling agents are mentioned and are preferably used. Among them, a silane coupling agent having a good balance between performance and cost is more preferably used.

The above-mentioned adhesiveness-imparting agents may be used alone or in combination of two or more.

The silane coupling agent is not particularly restricted but includes, for example, the above-mentioned aminosilanes, mercaptosilanes, epoxysilanes and the like which can be added to the main ingredient. Among them, aminosilanes and mercaptosilanes, which are excellent in storage stability of a mixture with the compound having a specific structure (aliphatic amine) described above, are more preferably used.

The above silane coupling agents may be used alone or in combination of two or more.

The adhesive composition according to the present invention comprises:
Or, in the curing agent, an inorganic filler, a thixotropic agent (thixotropy-imparting agent), a curing speed regulator, a coloring agent, a reinforcing agent, and a thickening agent, if necessary, as long as the object of the present invention is not hindered. One of various additives such as softener, plasticizer, surfactant, stabilizer, antioxidant, ultraviolet absorber, flame retardant, defoamer, organic solvent, etc.
Seeds or two or more kinds may be added.

The inorganic filler contributes to the improvement of physical properties such as the cohesive strength of the cured product and the cost reduction of the adhesive composition. Specific examples thereof are not particularly limited. And various inorganic fillers such as calcium carbonate, clay, talc, silicon oxide, and titanium oxide, and are preferably used. Among them, calcium carbonate having a good balance between performance and cost is more preferably used.

The above-mentioned inorganic fillers may be used alone or in combination of two or more.

The thixotropic agent (thixotropy-imparting agent) imparts thixotropic properties to the adhesive composition, and contributes to improvement in workability at the time of mixing and application of the main agent and the curing agent and prevention of sagging. Although there are no particular limitations on the specific examples thereof, for example, anhydrous silica fine particles, bentonite, hydrogenated castor oil, fatty acid bisamide, and the like are preferably used.

The thixotropic agent (thixotropic agent) may be used alone or in combination of two or more.

The curing rate adjusting agent is added, for example, when it is desired to delay the curing rate to further extend the pot life after mixing the main ingredient and the curing agent. Specific examples thereof include: Although not particularly limited, for example, various carboxylic acids such as octylic acid may be mentioned, and are preferably used.

The curing speed regulators may be used alone or in combination of two or more.

The coloring agent is added when it is desired to color the main agent and the curing agent in different colors, for example, in order to easily determine whether or not the main agent and the curing agent are properly mixed. Specific examples thereof are not particularly limited, and examples thereof include ordinary pigments and dyes such as carbon black, titanium oxide, red iron oxide, phthalocyanine blue, and chrome green, and are preferably used.

The above colorants may be used alone or in combination of two or more. Further, the coloring agent may be added to the main agent and / or the curing agent as it is, or may be added to the main agent and / or the curing agent, for example, as a paste-like master batch.

The method for producing the main agent or the curing agent of the adhesive composition according to the present invention is not particularly limited. A predetermined amount of each component contained in the main agent or the curing agent is weighed, and the mixture is stirred by a mixer or a kneader. The desired main agent or curing agent can be obtained by uniformly stirring and mixing using a mixer.

The mixing ratio of the thus obtained main agent and the curing agent at the time of use is not particularly limited.
For example, if the compound contained as a main component in the main component and having two or more functional groups capable of forming a bond with active hydrogen in the molecule is an epoxy resin, the epoxy resin in the main component (the reactive dilution in the main component) If the agent is added,
100 parts by weight of the reactive diluent).
The amount of amine in the curing agent (including a compound having a curing function other than the compound having the specific structure (aliphatic amine) and a curing accelerator other than the compound having the specific structure (aliphatic amine) are also included in the curing agent). It is preferable that the ratio satisfies the range of ± 30% by weight of the added part calculated from the formula.

The amount of amine in the curing agent with respect to 100 parts by weight of the epoxy resin is determined by the above equation.
If it exceeds 30% by weight, various physical properties such as mechanical strength and adhesive strength of the cured product may be reduced.

The method of using the adhesive composition according to the present invention
It is not special, for example, a predetermined amount of the main agent and a predetermined amount of the curing agent are charged into a stirring mixer such as a mixer, and uniformly stirred and mixed. Then, using a known device, coating, pouring, and casting are performed. It may be applied to a desired use by a construction method such as impregnation.

After mixing the above-mentioned main agent and the curing agent,
Since the pot life is limited, it is preferable to use the pot as soon as possible within the pot life. In addition, since the usable time becomes shorter as the mixing amount of the main agent and the curing agent per time increases, it is preferable to set the mixing amount per time according to the working speed. Furthermore, air bubbles are apt to be mixed during mixing work and construction work, and as a result, various physical properties such as mechanical strength and adhesive strength of the cured product are likely to be reduced. It is preferred to take.

[0056]

The adhesive composition according to the present invention is used as a curing agent for a main component mainly composed of a compound such as an epoxy resin having two or more functional groups capable of forming a bond with active hydrogen in the molecule, at the molecular terminal. Since a curing agent mainly containing a compound such as an aliphatic amine having a functional group having a specific structure and a skeleton having a specific structure in a molecular main chain composed of polyoxyalkylene is used, for example, in summer Even under a high temperature atmosphere, the working life after mixing the main agent and the curing agent becomes longer, and therefore the workability is excellent,
And, after curing, it exerts various physical properties such as excellent mechanical strength and adhesive strength.

[0057]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be described in more detail with reference to examples, but the present invention is not limited to these examples. In the examples, “parts” means “parts by weight”.

(Example 1)

(1) Production of Adhesive Composition As shown in Table 1, 85 parts of bisphenol A type epoxy resin (trade name “Epicoat 828”, manufactured by Yuka Shell Epoxy Co., Ltd.) which is liquid at room temperature is reactive. 1, as diluent
15 parts of 6-hexanediol diglycidyl ether (trade name "SR-16H", manufactured by Sakamoto Pharmaceutical Co., Ltd.) was added, and the mixture was uniformly stirred and mixed with a mixer to obtain a main ingredient. As shown in Table 1, 50 parts of an aliphatic amine (trade name "Ditoclar D-677", manufactured by Daito Sangyo Co., Ltd.) was used as a curing agent as it was.

(2) Evaluation The performance (pot life, compressive strength) of the adhesive composition obtained above was evaluated by the following method. The results were as shown in Table 1. In addition, evaluation, unless otherwise specified,
The test was performed under an atmosphere of 20 ° C. and 65% RH.

Pot life: 100 parts of main agent and 50 curing agents
After uniformly stirring and mixing the parts, the temperature changing with time was measured to obtain a time-temperature curve (curing heat generation curve). In the obtained curve, the time when the exothermic temperature sharply rose was determined, and a period of 70% of this time was defined as a usable time (minute). However, when the exothermic temperature did not rise sharply, the pot life (min) was defined as 50% of the time when the maximum exothermic temperature was reached. The pass / fail judgment was made based on the carbon fiber reinforced CCA (Carbonfifi) shown in Table 2.
ber for Civil Application)
Conducted in accordance with the Council's "Epoxy resin specification value for impregnation bonding (for summer)".

Compressive strength: In accordance with JIS K-7208 "Plastic compression test method", 100 parts of the base material and 50 parts of the curing agent were uniformly stirred and mixed.
It was poured into a square frame of 5 mm × 43 ± 0.2 mm and cured at 20 ° C. for 7 days. Next, the mold was released, and the compression strength (MPa) of the cured product was measured. In addition, pass / fail judgment
The test was carried out in accordance with the “Standard value of epoxy resin for impregnation bonding (for summer)” of the above-mentioned CCA Council shown in Table 2.

Example 2 As shown in Table 1, 85 parts of bisphenol A type epoxy resin "Epicoat 828", 15 parts of reactive diluent "SR-16H" and thixotropic agent (thixotropy) A main agent was obtained in the same manner as in Example 1 except that 3 parts of anhydrous silica fine particles (trade name “Aerosil RY-200”, manufactured by Nippon Aerosil Co., Ltd.) was used as an imparting agent. Further, as shown in Table 1, as a curing agent, 50 parts of an aliphatic amine “Ditoclar D-677” was used as it was.

(Example 3) As shown in Table 1, 103 parts of the main agent obtained in Example 2 was used as the main agent. As shown in Table 1, 10 parts of a heterocyclic diamine (trade name “Epomate LX-3S”, manufactured by Yuka Shell Epoxy) was added to 40 parts of an aliphatic amine “Ditoclar D-677”, Stir and mix evenly with a mixer,
A curing agent for the adhesive composition was obtained.

(Comparative Example 1) As shown in Table 1, as the main ingredient, 103 parts of the main ingredient obtained in Example 2 was used as it was. As shown in Table 1, 33 parts of a heterocyclic diamine “Epomate LX-3S” was used as a curing agent as it was.

(Comparative Example 2) As shown in Table 1, 103 parts of the main agent obtained in Example 2 was used as it was as the main agent. Further, as shown in Table 1, as a curing agent, 60 parts of polyamidoamine (trade name “Tomide TXE-524”, manufactured by Fuji Kasei Kogyo Co., Ltd.) was used as it was.

(Comparative Example 3) As shown in Table 1, 103 parts of the main agent obtained in Example 2 was used as it was as the main agent. Further, as shown in Table 1, 20 parts of the heterocyclic diamine "Epomate LX-3S" and 20 parts of the polyamideamine "Tomide TXE-524" were uniformly stirred and mixed with a mixer to obtain a curing agent.

The performances (pot life, compressive strength) of the five types of adhesive compositions obtained in Examples 2 and 3 and Comparative Examples 1 to 3 were evaluated in the same manner as in Example 1. The results were as shown in Table 1.

[0069]

[Table 1]

[0070]

[Table 2]

As is clear from Table 1, the adhesive compositions of Examples 1 to 3 according to the present invention had a long pot life after mixing the main agent and the curing agent, and were excellent in workability. Also, after curing, it exhibited excellent compressive strength. The above pot life and compressive strength passed the "standard value of epoxy resin for impregnation bonding (for summer)" of the CCA Council shown in Table 2.

On the other hand, the adhesive composition of Comparative Example 1 in which a heterocyclic diamine was used as a curing agent without containing an aliphatic amine in the curing agent was excellent in compressive strength, The time was extremely short, and the test failed significantly with respect to the standard values of the CCA Council.

Further, the adhesive composition of Comparative Example 2 in which polyamidoamine was used as a curing agent as it was without containing an aliphatic amine in the curing agent had a long pot life but an extremely high compressive strength. Low, and largely failed the standard values of the CCA Council.

Further, the adhesive composition of Comparative Example 3 using the same amount of a curing agent consisting of a heterocyclic diamine and a polyamidoamine without containing an aliphatic amine in the curing agent was prepared by the above-mentioned CCA Council. The pot life barely passed the specified value, but the compressive strength failed.

[0075]

As described above, the adhesive composition according to the present invention has a long pot life after mixing the main agent and the curing agent, and is excellent in workability. Further, after curing, it exhibits excellent physical properties such as excellent mechanical strength such as compressive strength and adhesive strength. Therefore, for example, as stipulated in the CCA Council's “Epoxy resin specification value for impregnation bonding (for summer)”,
A two-component mixed room temperature curable for various industrial and general uses that requires a long pot life and excellent workability, and also needs to exhibit various physical properties such as excellent mechanical strength and adhesive strength after curing. It is suitably used as an adhesive.

Claims (2)

[Claims] 1. A main agent mainly comprising a compound having two or more functional groups capable of forming a bond by active hydrogen in a molecule,
A curing agent having, as a main component, a compound having a functional group represented by the following formula (1) at a molecular terminal and having a skeleton represented by the following formula (2) in a molecular main chain composed of polyoxyalkylene. An adhesive composition comprising: Embedded image Embedded image 2. A curing agent having the following general formula (3) at a molecular terminal:
And a curing agent mainly comprising a compound having a skeleton represented by the above formula (2) in a molecular main chain composed of polyoxyalkylene having a functional group represented by the following formula: Item 7. The adhesive composition according to Item 1. Embedded image (Wherein, R ¹ represents hydrogen or an alkyl group, and n represents a positive integer)