JPH05105862A - Two-pack adhesive - Google Patents

Abstract

PURPOSE:To provide a two-pack adhesive excellent in adhesion and storability and wide in the scope of applications. CONSTITUTION:A two-pack adhesive which is constituted of a liquid A comprising an epoxy resin, a latent curing agent and an org. peroxide and a liquid B comprising a monomer having at least one polymerizable ethylenically-unsatd. double bond per molecule, a polymer soluble in the above-mentioned monomer and a curing agent capable of curing the adhesive in the presence of the org. peroxide contained in the liquid A through polymn. thereof.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a two-part adhesive, and more particularly to a two-part structural adhesive having excellent adhesiveness and storability.

[0002]

2. Description of the Related Art Acrylic and epoxy adhesives are generally well known as two-component adhesives. The two-component acrylic adhesive consists mainly of (meth) acrylate, a polymer, and an elastomer. The redox catalyst oxidation system is separated into one solution and the reduction system is separated into the other solution. As a liquid, basically both liquids have almost the same physical properties. Polymerization is started by mixing or contacting the two liquids, and curing is started. Since this reaction is a radical reaction, it is not necessary to sufficiently mix the two liquids, and the polymerization can be initiated by simply bringing the adherends coated with each one liquid into contact with each other. In addition, a stable adhesive force can be obtained irrespective of a slight error in the compounding ratio.

Generally, by blending a polymer or an oligomer in a monomer, it is possible to adjust the viscosity, improve the adhesive strength, and impart flexibility. By changing the combination, the physical properties of the cured resin can be widely designed. The acrylic adhesive may be a one-component type. Anaerobic sealing agents are well known in the one-pack type. This is a mixture of the redox-based catalysts mentioned above in one liquid, and conditions such as contact with metal and blocking from air are required.

The advantages of acrylic adhesives are that they are easy to react, the curing agent cures sufficiently even if they are not completely mixed, and they adhere relatively well even if some oil is attached to the adhesive surface. , Can be mentioned. On the other hand, the base compound containing a peroxide has poor stability, and it is necessary to mix a polymerization-inhibiting stabilizer. There is also a drawback that the shrinkage at the time of curing increases as the proportion of the double bond-containing monomer increases.

On the other hand, epoxy-based two-component adhesives are mainly composed of a compound having an epoxy group in the molecule, an amine compound,
By mixing an acid anhydride as a curing agent, addition polymerization occurs and curing begins. In the one-pack type epoxy resin, the latent curing agent, which is pre-blended, is activated by heating and the addition polymerization is started. No need for mixing, but heating is required.

[0006] Epoxy cured products are widely used in various fields because of their excellent mechanical strength, chemical resistance and electrical properties. However, since it is inherently inferior in flexibility, it has low impact resistance, and depending on the standing conditions, it may crack or peel off from the adherend. In addition, if degreasing of a metal part or the like is not sufficient, the adhesive ability to the metal surface may not be exhibited, and the adhesive strength may be insufficient. Further, even if the two liquids are not sufficiently mixed, there is a drawback that the adhesive strength is insufficient and the curing is insufficient.

In recent years, structural adhesives have been used in a wide range of fields. Particularly in the automobile and aviation industries, structural members made of steel and aluminum have become thinner due to the progress of weight reduction.As a result, welding techniques that have been used in the past have problems such as deformation. ing. However, in these bonding steps, the time and cost for removing the press oil and rust preventive oil such as steel plates are very large, and the oil surface adhesiveness is an essential condition for omitting this work.

Epoxy adhesives are generally unsuitable as adhesives having the above-mentioned properties, and various improvements have been made so far (Japanese Patent Laid-Open No. 2-4558).
7, JP-A-63-186786). However, the method of adding a lipophilic elastomer or liquid rubber to the epoxy resin is
There is a possibility that chemical resistance and water resistance may be inferior, and it cannot be said that the performance of the epoxy resin is fully exhibited, and the oil surface adhesive strength is not as effective as that of the acrylic adhesive.

The object of the present invention is not only excellent in adhesiveness and storage stability but also capable of obtaining a wide variety of physical properties, which can be selectively used according to the required performance and the adherend, and in particular the adhesion to the oil surface of a metal or The purpose of the present invention is to provide a two-component adhesive that exhibits remarkable adhesive properties when bonding different materials such as metal and plastic.

[0010]

The two-component adhesive of the present invention comprises a combination of the following liquids A and B. [Liquid A] A liquid substance composed of an epoxy resin, a latent curing agent, and an organic peroxide. [Solution B] In the presence of a monomer having one or more polymerizable ethylenic double bonds in the molecule, a polymer soluble in this monomer, and an organic peroxide contained in Solution A. Liquid substance consisting of a curing agent that can be polymerized and cured.

By using the above combination, it becomes possible to make full use of the advantages of both the epoxy resin and the acrylic resin and to make up for the drawbacks. In the adhesive of the present invention, the liquid A is a heat-curable one-component epoxy resin containing a latent curing agent to which an organic peroxide is added. Solution B, which is represented by an acrylate resin containing a curing accelerator, initiates polymerization when it contacts solution A. The adherend in the set state is further completely cured and adhered by heating. By using this bonding method, the conventional problems are solved,
It becomes easy to adhere oily surfaces and different materials.

The epoxy resin used in the present invention is not particularly limited, for example, phenol novolac type epoxy resin, cresol novolac type epoxy resin,
Bisphenol A type epoxy resin, glycidyl ether type epoxy resin, glycidyl ester type epoxy resin,
Examples thereof include those having an epoxy group in one molecule such as glycidyl amine type epoxy resin, linear aliphatic epoxy resin, alicyclic epoxy resin, heterocyclic type epoxy resin and halogenated epoxy resin.

As the latent curing agent, acid anhydrides, tertiary amines and imidazoles are used. Examples of the acid anhydride system include succinic anhydride, phthalic anhydride, tetrahydrophthalic anhydride, methyltetrahydrophthalic anhydride, hexahydrophthalic anhydride, methylhexahydrophthalic anhydride, methylnadic acid anhydride, dodecenylsuccinic anhydride, and pyromellitic anhydride. Etc. 10 to 60 parts by weight of at least one of these is suitable for 100 parts by weight of the epoxy resin. As tertiary amines and imidazoles, benzylmethylamine, triethanolamine, dimethylaminomethylphenol, tris (dimethylaminomethyl) phenol, triethyltetramine, 3,9-bis (3-aminopropyl) -2,4,8, 10-tetraoxaspiro (5,5) undecane, etc., 1,2,3-benzotriazole, 5-methyltriazole, 2-phenylimidazole, 2-ethyl-4-methylimidazole, 2-methylimidazole, 2-ethylimidazole , 2,4-dimethylimidazole, 2-undecylimidazole, 2-heptadecylimidazole, 1-vinyl-2-methylimidazole, 2-phenyl-4,5-
Dihydroxymethylimidazole, 2-phenyl-4-
Methyl imidazole, 2-isopropyl imidazole,
1-Cyanomethyl-2-methylimidazole and the like can be mentioned. The appropriate amount of these used is 10 to 40 parts by weight per 100 parts by weight of the epoxy resin.

The organic peroxide forms a curing system for liquid B. Examples of such peroxides include cumene hydroperoxide, dicumyl peroxide, t-butylperoxybenzoate and the like. The peroxide is added in the range of 0.2 to 2% with respect to 100 parts by weight of the epoxy resin.

In contrast to solution A consisting of the above system, solution B contains a monomer having a polymerizable ethylenic double bond as a main component, and a polymer and elastomer soluble in these are compounded according to the required physical properties. However, it is a system in which a polymerization accelerator that accelerates the polymerization by the organic peroxide contained in the liquid A is added.
Specifically, as a monomer having an ethylenic double bond, methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, butyl (meth) acrylate, butyl (meth) acrylate, hydroxy (meth) Acrylate, hydroxypropyl (meth) acrylate, hydroxycyclopropyl (meth) acrylate, hydroxypropyl (meth) acrylate, polyethylene glycol mono (meth) acrylate, polypropylene glycol mono (meth) acrylate, methoxyethyl (meth) acrylate, ethoxyethyl ( (Meth) acrylate, 2-ethylhexyl (meth) acrylate, lauryl (meth) acrylate, ethylene glycol (meth) acrylate, tetraethylene glycol di (meth) ac , Polyethylene glycol di (meth) acrylate, trimethylolpropane tri (meth) acrylate, glycerin di (meth) acrylate.

Polymerization accelerators added to these include:
Diethyl-P-toluidine and diisopropanol-P-
Amine compounds such as toluidine, N, N-dimethylaniline, triethylamine, diethylenetriamine and triethylenetetramine, or products of condensation reaction of aldehyde compounds and amine compounds such as condensation products of butyraldehyde and butylamine, ascorbic acid, gallic acid Organic compounds such as reducing organic compounds such as acids, thiourea, thioureas such as ethylenethiourea, cobalt naphthenate, cobalt naphthenate, manganese naphthenate, iron and copper octaoctate, iron hexanoate, iron propionate, etc. can give. These are preferably added in an amount of about 0.05 to 3.0 with respect to the total amount.

As the polymer soluble in the monomer component, a chlorinated polyethylene chloroprene polymer, polyester polymer, vinyl chloride polymer, acrylonitrile polymer or fluoroelastomer is used, and as a reactive oligomer, terminal acrylic modified 1,2. -Acrylic-modified oligomers such as polybutadiene oligomer, terminal acrylic-modified urethane oligomer, terminal acrylic-modified polyester oligomer, and terminal vinyl-modified oligomer can be used. These are blended according to the required concentration and physical properties, but the blending amount is preferably about 5 to 30% with respect to the total amount. If it is too small, the viscosity will be low and workability will be poor, and if it is too large, the curing speed will decline. Polymerization is started at the time of contact with the liquid A, and the viscosity is 8 such that the adherend can hold it.
About 000 to 30,000 cp is desirable. Further, as a polymerization inhibitor for preventing gelation during storage in liquid A, for example, hydroquinone, P-benzoquinone, hydroquinone monomethyl ether, p-tert-butylcatechol, α-naphthol, pyrogallol, or the like as an adhesiveness-imparting agent. For example, it is possible to add a phosphoric acid ester or a silane coupling agent. Further, other additives such as a leveling agent, a defoaming agent, a dispersant and an anti-settling agent can be used.

Next, the present invention will be described based on Examples and Comparative Examples.

[0019]

【Example】

 Example: Solution A and solution B having the following compositions were prepared. 1. Liquid A Epicoat 807 (Okaka Shell Epoxy Co., Ltd.) 100 g Amicure MY24 (Ajinomoto Co., Inc.) 20 g Hugh Rex ZA-30 (silica filler: Tatsumori Co., Ltd.) 80 g Cumene hydroperoxide 3 g

2. Liquid B Hydroxyethyl methacrylate 100 g Pandex T-5201 (Dainippon Ink and Chemicals, Inc.) 30 g Ethylenethiourea 2.5 g

Comparative Example: 1. The following components were blended as a one-part epoxy resin for comparison. Epicoat 807 100g Amicure MY24 20g ZA-30 80g

2. Hydroxyethylmethacrylate 100 g, Pandex T-520130 g, and an adhesion promoter 1.5 g were blended as a two-component base type acrylic for comparison, and 2 parts of ethylenethiourea was added to this to prepare a solution I, and cumene hydroperoxide was added to 2 parts. Part II was used as solution II.

Oil surface adhesion test: Specimen: Dull steel plate (SPCC-SD) 1.6 × 25 ×
100 mm test method: Two degreased test pieces are bonded together with an adhesive so as to have an area of 2.5 cm ² , and the tensile shear adhesive strength after complete curing is measured. The value at this time is 100%. Next, engine oil is applied to one of the test pieces, and the adhesive force is measured in the same manner to compare the holding ratios. The results are shown in Table 1.

[0024]

[Table 1]

Adhesion test of different materials: Test piece: epoxy glass (1.0 × 25 × 150 m
m) Polyimide film (0.08 x 25 x 150 mm) Test method: Two materials are bonded together with an adhesive and the temperature is 120 ° C x
Complete cure in 30 minutes. Measure the adhesive force in the peeling direction at 180 ° C. The results are shown in Table 2.

[0026]

[Table 2]

[0027]

EFFECT OF THE INVENTION The two-component adhesive of the present invention exhibits excellent performance for oil surface adhesion and adhesion of different materials, and can be used in various ways by changing the composition of each of the two liquids according to the application and required characteristics. Is possible. Moreover, there is no need to newly synthesize the components constituting these or to obtain raw materials, and there is an advantage that the existing epoxy adhesive or acrylic adhesive can be used and can be designed with reference to the known performance. Have. Further, the bonding method of the present invention can be applied not only to fill the gap due to the difference in the material of the adherends and the difference in the surface condition but also to adhere the adherends having different conductivity and thermal expansion coefficient. It is a simple but effective method.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification code Office reference number FI technical display location C09J 163/00 JFP 8416-4J

Claims (4)

[Claims] 1. A two-component adhesive comprising a combination of the following liquids A and B. [Liquid A] A liquid substance composed of an epoxy resin, a latent curing agent, and an organic peroxide. [Solution B] In the presence of a monomer having one or more polymerizable ethylenic double bonds in the molecule, a polymer soluble in this monomer, and an organic peroxide contained in Solution A. Liquid substance consisting of a curing agent that can be polymerized and cured. 2. The two-component adhesive according to claim 1, wherein the polymer of the liquid B is a reactive oligomer having a monofunctional or polyfunctional polymerizable ethylenic double bond. 3. The two-component adhesive according to claim 1, wherein the monomer having a polymerizable ethylenic double bond is (meth) acrylate. 4. A bonding method, which comprises applying the liquid A to one adherend surface and the liquid B to the other adherend surface, adhering them to each other to polymerize and cure, and then subjecting to heat treatment.