JP2008007585A - (meth)acrylic composition, (meth)acrylic curable composition using the same and adhesive, and method for producing microcapsule - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a (meth)acrylic adhesive having ultra high-speed sticking properties. <P>SOLUTION: A (meth)acrylic composition in the form of a microcapsule contains a (meth)acrylic monomer and a reducing agent, wherein the (meth)acrylic monomer contains a (meth)acrylic monomer having two or more vinyl groups. A (meth)acrylic curable composition and a (meth)acrylic adhesive each comprises the (meth)acrylic composition, a polymerization initiator, and optionally a (meth)acrylic monomer. The (meth)acrylic composition is provided by a method for producing a microcapsule, the method comprising the steps of adding a water-soluble polymerization initiator to water and further adding a (meth)acrylic monomer and a reducing agent with stirring, wherein the (meth)acrylic monomer contains a (meth)acrylic monomer having two or more vinyl groups. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

The present invention is excellent in adhesiveness and curability, and is a (meth) acrylic adhesive suitably used for various applications such as metal, paper, cloth, and concrete structures, and a microencapsulated (meth) acrylic used therefor The present invention relates to a system composition, a (meth) acrylic curable composition, and a method for producing the microcapsules.

Conventionally, (meth) acrylic resins are widely used in the fields of molding materials, paints, adhesives and the like because of their good durability and environmental friendliness.

(Meth) acrylic adhesives are polymerized and cured using an organic peroxide as a polymerization initiator for acrylic monomers and oligomers and a curing agent that decomposes the organic peroxide to generate radicals. By doing so, adhesion is performed.

The combination of the organic peroxide and the curing agent is called a curing initiator system, but the two-part acrylic adhesive is a composition containing (A) an organic peroxide. It is an acrylic adhesive in which a curing initiator system component is separated into two components (A) and (B) comprising a product and a composition containing (B) a curing agent. In this case, the two agents (A) and (B) are mixed immediately before use and applied to the adherend to perform adhesion.

As for the organic oxide used in (A), cumene hydroperoxide (hereinafter abbreviated as CHP) and diisopropylbenzene hydroperoxide having a long half-life at room temperature are generally used from the viewpoint of storage stability. So-called curing agents that decompose and cure organic peroxides are also disclosed in Patent Document 1, Patent Document 2, Patent Document 3, and Patent Document 4.
Japanese Patent Publication No. 52-018478. British patent 715382. U.S. Pat. No. 3,591,438. U.S. Pat. No. 3,625,930.

The curing agent used in (B) can be broadly classified into ethylene thiourea derivatives and metal soaps. Ethylene thiourea derivatives have excellent adhesion to metal surfaces, and are characterized by cohesive failure when, for example, iron / iron peeling. Have. However, it has a strong anaerobic property (property of being susceptible to polymerization inhibition by atmospheric oxygen) and has a drawback that it does not adhere to a concrete surface or cardboard having numerous pores.

On the other hand, metal soaps, especially soaps such as cobalt, vanadium, and manganese, exhibit a so-called dryer effect that cures with oxygen, and hydroperoxides such as cumene hydroperoxide and methyl ethyl ketone peroxide decompose at room temperature to produce radicals. It is known as a material for forming a redox system that generates water (see Patent Document 5). Furthermore, Patent Document 6 and Patent Document 7 disclose ultrafast curing redox systems.
Japanese Patent Publication No. 55-002205. Japanese Patent Publication No. 51-017966. Japanese Patent Publication No. 52-024516.

However, it is preferable from the viewpoint of productivity and convenience that it can be cured and bonded at an extremely high speed. However, in the case of a two-component adhesive, since the curing starts during mixing of the two agents, the essence that adhesion failure occurs. Have some disadvantages.

As a method for avoiding this, Patent Document 8 discloses an adhesive containing N, N-dimethyl-P-toluidine that decomposes benzoyl peroxide by microencapsulating a core solution obtained by dissolving benzoyl peroxide in a solvent with gelatin or the like. A one-part adhesive dispersed in an agent mixture is disclosed, but benzoyl peroxide has an inherent disadvantage that the half-temperature of spontaneous decomposition is low and the effective amount decreases during storage, and benzoyl peroxide Since the dissolved solvent remains in the adhesive, it is essentially a solvent-containing adhesive and has drawbacks such as solvent bleeding.
Japanese Patent Publication No. 53-5894.

Note that the solvent or plasticizer is selected for the organic peroxide that constitutes the core liquid because there is a disadvantage that monomers containing a high concentration of organic peroxide cannot be stably present. This is because even if the cumene hydroperoxide is high, if the concentration in the monomer is increased to about 10% by mass or more, the preservability is remarkably lowered and the gelation occurs in a short period of time.

The present invention provides an ultra-high-speed adhesive (meth) acrylic adhesive while eliminating the disadvantages of the prior art as described above while maintaining the excellent properties of the (meth) acrylic adhesive. It was made for the purpose.

As a result of various investigations aimed at improving the prior art, the present invention has a simple operation of adding a water-soluble polymerization initiator to water and further adding a (meth) acrylic monomer and a reducing agent under stirring ( The (meth) acrylic monomer and the reducing agent can be contained in the microcapsule, and the (meth) acrylic curable composition and the adhesive using the microencapsulated (meth) acrylic composition are: (Meth) acrylic curable composition that can control the start of curing by breaking the microcapsule with a simple external force, and can also have an ultrafast solidification property by selecting an appropriate curing initiator system, The inventors have found that an adhesive can be obtained, and have arrived at the present invention.

That is, the present invention is as follows.
(1) A microcapsule-like (meth) acrylic composition containing a (meth) acrylic monomer and a reducing agent, wherein the (meth) acrylic monomer has two or more vinyl groups (meta ) A (meth) acrylic composition comprising an acrylic monomer.
(2) The (meth) acrylic monomer in the microcapsule contains (meth) acrylic acid ester having two or more vinyl groups in the (meth) acrylic monomer in an amount of 20% by mass or more. The (meth) acrylic composition according to (1).
(3) The (meth) acrylic acid ester having two or more vinyl groups is 2.2-BIS [4- (methacryloxyethoxy) phenyl] propane (1) or (2) ( (Meth) acrylic composition.
(4) The (meth) acrylic composition according to any one of (1) to (3), wherein the reducing agent in the microcapsule is vanadyl acetylacetonate or vanadium acetylacetonate.
(5) The (meth) acrylic composition according to any one of (1) to (4), wherein the diameter of the microcapsule containing the (meth) acrylic monomer and the reducing agent is 100 μm or more and 10 mm or less. object.
(6) The (meth) acrylic composition according to any one of (1) to (6), wherein the thickness of the shell of the microcapsule containing the (meth) acrylic monomer and the reducing agent is 5 to 100 μm object.
(7) The (meth) acrylic composition according to any one of (1) to (6) is further blended with a polymerization initiator and, if necessary, a (meth) acrylic monomer. (Meth) acrylic curable composition.
(8) The (meth) acrylic curable composition according to (7), wherein the polymerization initiator is contained in a microcapsule different from the microcapsule containing the (meth) acrylic monomer and the reducing agent. object.
(9) The (meth) acrylic curable composition according to (7) or (8), wherein the polymerization initiator is cumene hydroperoxide.
(10) The (meth) acrylic curable composition according to any one of (1) to (6) is further blended with a polymerization initiator and, if necessary, a (meth) acrylic monomer. A (meth) acrylic adhesive.
(11) It is characterized by further blending a (meth) acrylic curable composition according to any one of (1) to (6) with a polymerization initiator and, if necessary, a (meth) acrylic monomer. Two-component (meth) acrylic adhesive.
(12) The (meth) acrylic polymer according to (10) or (11), wherein the polymerization initiator is contained in a microcapsule different from the microcapsule containing the (meth) acrylic monomer and the reducing agent. Adhesives.
(13) The (meth) acrylic curable composition according to any one of (10) to (12), wherein the polymerization initiator is cumene hydroperoxide.
(14) A water-soluble polymerization initiator is added to water, and under stirring, a (meth) acrylic monomer and a reducing agent are added, and the (meth) acrylic monomer has two or more vinyl groups. The manufacturing method of the microcapsule characterized by including the (meth) acrylic acid ester.
(15) The method for producing microcapsules according to (14), wherein a dispersant is added to water in advance.
(16) The method for producing a microcapsule according to (15), wherein the dispersant is gelatin.
(17) The method for producing a microcapsule according to any one of (14) to (16), wherein the water-soluble polymerization initiator is cumene hydroperoxide and the reducing agent is vanadyl acetylacetonate or vanadium acetylacetonate.
(18) The method for producing a microcapsule according to any one of (14) to (17), wherein the (meth) acrylic monomer is 2.2-BIS [4- (methacryloxyethoxy) phenyl] propane.

Since the (meth) acrylic composition of the present invention is microencapsulated and the surface of the microcapsule is a cured product of the (meth) acrylic composition, the surface of the microcapsule is a (meth) acrylic composition. The polymerization does not start even when in contact with the polymerization initiator, but when the microcapsules are destroyed by external force under such conditions, the polymerization of the (meth) acrylic composition starts and cures quickly. Since this can be used, an ultrafast adhesive (meth) acrylic adhesive can be easily and stably provided.

Since the (meth) acrylic curable composition of the present invention uses the microencapsulated (meth) acrylic composition, curing is started by applying a slight external force during bonding while being excellent in storage stability. However, it has the characteristic of solidifying rapidly. The (meth) acrylic adhesive of the present invention can be easily and stably provided using the (meth) acrylic curable composition. Further, in the (meth) acrylic composition of the present invention, a polymerization initiator (which may contain a (meth) acrylic monomer or oligomer if necessary) is contained in another type of microcapsule different from the microcapsule. If it is allowed to be used, a (meth) acrylic curable composition and an adhesive that are excellent in powder workability as a whole can be provided, and the (meth) acrylic composition of the present invention can be provided as a (meth) acrylic composition. (A) liquid dispersed in a monomer or oligomer (hereinafter, simply referred to as “(meth) acrylic monomer”) is prepared, and (B) liquid containing at least a polymerization initiator is prepared. It can be used as a mold adhesive, and in this case as well, excellent adhesion workability can be ensured.

The method for producing a microcapsule according to the present invention is characterized in that a water-soluble polymerization initiator is added to water, and a (meth) acrylic monomer and a reducing agent are added with stirring. Can be provided stably.

The present invention is a (meth) acrylic composition characterized in that a (meth) acrylic monomer and a reducing agent are incorporated in a microcapsule, and is water-soluble in water, which can produce the microcapsule. And a (meth) acrylic monomer and a reducing agent are further added under stirring. Hereinafter, the latter invention will be described by taking the former invention as an example.

The microcapsule production method of the present invention uses cumene hydroperoxide, which is an organic peroxide having a slight water solubility in water containing a protective colloid for preventing coalescence of generated microcapsule particles. (Meth) acrylic having two or more vinyl groups that are highly lipophilic and solidify without being dissolved or swollen in the monomer while the medium is stirred while adding a small amount of the polymerization initiator. Adds a reducing agent such as vanadyl acetylacetonate that decomposes the polymerization initiator such as cumene hydroperoxide dissolved in the medium in the medium at a very high speed, but generates radicals with high water solubility in the system monomer The core liquid (microcapsule internal liquid) is rapidly added while stirring the medium. Cumene hydroperoxide vanadyl acetylacetonate and medium out in response to instantaneously generate a radical, is intended to form the microcapsules to produce a polymer film on the particle surface.

Examples of the protective colloid used as the medium of the microcapsule of the present invention include many synthetic and natural products such as gelatin polyvinyl alcohol and sodium alginate. Gelatin is a preferred material based on the results of investigation by the present inventors. They may be used by mixing with other protective colloid materials. When gelatin is used, an aqueous solution of 0.5% by mass or more and 15% by mass or less is preferable. If the abnormality is 0.5% by mass, no dispersion failure occurs, and if it is 15% by mass or less, the viscosity is not too high. 2-7 mass% is a more preferable range in the said range.

Furthermore, examples of the organic peroxide that is a water-soluble polymerization initiator that acts as a microcapsule film forming agent include cumene hydroperoxide and methyl ethyl ketone peroxide, but cumene that hardly decomposes at room temperature. Hydroperoxide is most preferable from the viewpoint of workability. The blending amount is preferably 0.01 parts by weight or more and 0.5 parts by weight or less per 100 parts by weight of the core liquid. However, the amount of decomposition of the polymerization initiator and the amount of undecomposed polymerization initiator are reduced to reduce the washing load. From a viewpoint, 0.02 mass part-0.06 mass part is still more preferable.

Examples of the reducing agent used in the core liquid of the present invention include vanadyl acetoacetonate and the like, but since a solid powder is included, a (meth) acrylic monomer is used to make a liquid. Used as a solvent. In the present invention, since water is used as a solvent during the production of the microcapsules, a highly lipophilic monomer is used as the (meth) acrylic monomer, such as methyl (meth) acrylate, ethyl (meth) acrylate, Propyl (meth) acrylate, butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, isooctyl (meth) acrylate, isooctyl (meth) acrylate, isodecyl (meth) acrylate, lauryl (meth) acrylate, stearyl (meth) acrylate , Phenyl (meth) acrylate, cyclohexyl (meth) acrylate, dicyclopentanyl (meth) acrylate, dicyclopentenyl (meth) acrylate, isobornyl (meth) acrylate, methoxylated cycloto En (meth) acrylate, dicyclopentenyloxyethyl (meth) acrylate, tri (meth) acrylate, epoxy (meth) acrylate, 2.2-BIS [4- (methacryloxyethoxy) phenyl] propanes, styrene, α-methyl Examples thereof include styrene and divinylbenzene. It is desirable to use a mixture of two or more of these for the purpose of adjusting the physical properties of the microcapsules.

The (meth) acrylic monomer (hereinafter simply referred to as “monomer”) used in the core liquid of the present invention must contain a (meth) acrylic acid ester having two or more vinyl groups. This is because a polymer of (meth) acrylic acid ester having two or more vinyl groups is cross-linked and hardly dissolved in the core liquid, thereby further ensuring microencapsulation. Since the monofunctional monomer alone dissolves in the core liquid and cannot form a film, the amount of the monofunctional monomer is limited to less than 80 parts by mass in 100 parts by mass of the monomer used in the core liquid. That is, in the present invention, the (meth) acrylic monomer used in the core liquid preferably contains 20% by mass or more of (meth) acrylic acid ester having two or more vinyl groups.
The higher the blending ratio, the harder the microcapsules.

Examples of the (meth) acrylic acid ester (meth) acrylic monomer having two or more vinyl groups include 2.2-BIS [4- (methacryloxyethoxy) phenyl] propane (NK ester BPE manufactured by Shin-Nakamura Chemical Co., Ltd.). −100) is preferred. However, since the substance has a high viscosity, it is preferable to add, for example, dicyclopentenyloxyethyl methacrylate (R57 and Haas M57T) as a diluent or an agent for improving the properties of the cured product.

Further, a reducing agent is added to the core liquid, and vanadyl acetylacetonate or vanadium acetylacetonate having a fast curing action is preferably selected. Since vanadium acetylacetonate is an expensive material, vanadyl acetylacetonate is preferably used. The amount is preferably 2 parts by mass or more and 20 parts by mass or less with respect to 100 parts by mass of the monomer in the core liquid. Fast curing of an adhesive containing microcapsules at 2 parts by mass or more can be expected sufficiently, and if it is 20 parts by mass or less, the viscosity of the core liquid is not too high. 5-10 mass parts is still more preferable.

In the method for producing microcapsules of the present invention, microcapsules can be obtained after a few minutes just by putting the core solution into the stirring aqueous medium, and no special condition setting is required. For example, in the method of forming a urea resin film disclosed in Japanese Patent Publication No. 46-030282, vanadyl acetylacetonate flows out into the medium water for the purpose of raising the temperature or aging for a long time. As a result, the concentration of vanadyl acetylacetonate in most microcapsule particles becomes extremely low, and the same result is exhibited by coacervation from a general high-temperature gelatin aqueous solution. As described above, there is no need to set special conditions, and the microcapsules are formed in a short time, so that there is a feature that microcapsules containing a high concentration of reducing agent can be obtained.

As above and below, according to the production method of the present invention, the (meth) acrylic composition according to the present invention can be obtained.

The (meth) acrylic composition according to the present invention can be made into microcapsules having various properties by appropriately selecting the conditions of the production method.

First, the size of the microcapsules and the thickness of the shell of the (meth) acrylic composition of the present invention are mainly the monomer and reducing agent type and concentration in the core liquid, and the concentration of the polymerization initiator when microencapsulated. The size is controlled by stirring conditions and the like, and the size (showing the outer diameter, meaning the number average diameter) is 100 μm or more and 10 mm or less, and the shell thickness is 5 to 100 μm. As the properties of the microcapsules, the size and the thickness of the shell are selected according to the application. For example, the diameter is preferably larger for the use of the anchor material, preferably 1 mm to 5 mm, the use of the adhesive is preferably 100 μm to 1 mm, and the shell thickness is 50 μm to 100 μm for the use of the anchor material. 5 to 50 μm is preferable.

The present invention is a (meth) acrylic curable composition comprising the above (meth) acrylic composition, further comprising a polymerization initiator and, if necessary, a (meth) acrylic monomer. A (meth) acrylic adhesive. When the microcapsule is destroyed by external force, the (meth) acrylic monomer present inside the microcapsule, the polymerization initiator containing the reducing agent outside the microcapsule (if necessary, the (meth) acrylic monomer is also present (Meth) acrylic adhesive having a characteristic that the polymerization reaction is initiated and rapidly cured, the pot life is long, and the initial high-speed adhesiveness is excellent.

In particular, when cumene hydroperoxide is used as the polymerization initiator, it is possible to exhibit the property of ultra-high speed curing in combination with the selection of vanadyl acetylacetonate or vanadium acetylacetonate as the reducing agent in the microcapsules. In addition, the composition is divided into two as appropriate to form a two-part type, each of which is applied to two surfaces to be bonded, and the microcapsules are destroyed by an external force that joins the surfaces together to cure the curing reaction. Can be started and bonded.

In the present invention, when the polymerization initiator is selected in a form in which the polymerization initiator is contained in a microcapsule different from the above-described microcapsule containing the (meth) acrylic monomer and the reducing agent, A (meth) acrylic curable composition and an adhesive can be obtained.

Hereinafter, the present invention will be described in more detail based on examples. Various physical properties are based on the following measurement methods.

Adhesive strength <br/> Adhesive specimen: Iron (SPCC manufactured by Test Piece)
Surface treatment: after degreasing acetone, 150 mesh gold sand sandblasting Surface treatment: 150 mesh gold sand sandblasting iron / iron tensile shear strength: JIS K-6855

Fixing time One end of a 25.4 mm x 100 mm iron test piece with a smooth surface was joined at a lap length of 12.7 mm in an atmosphere of 23C, and the time was taken until it stopped moving by finger touch after adhesion.

(Example 1)
<Manufacture of microcapsules>
(Preparation of aqueous gelatin solution)
In a 1000 ml beaker, 50 g of gelatin (gelatin powder manufactured by Kanto Chemical Co., Inc.) was put into 950 g of ion-exchanged water, stirred at 70 ° C. to obtain an aqueous solution, and allowed to cool to room temperature.

(Preparation of 1% cumene hydroperoxide solution)
1 g of cumene hydroperoxide (Nippon Yushi Co., Ltd. Park Mill H80) was weighed, and ion exchange water was added to make 100 g.

(Adjustment of core solution)
In a 50 ml beaker, 25 g of 2.2-BIS [4- (methacryloxyethoxy) phenyl] propane (NK Nakamura Chemical Co., Ltd. NK ester BPE-100) (hereinafter abbreviated as BPE-100) and dicyclopentenyloxyethyl 25 g of methacrylate (QM-57T manufactured by Rohm and Haas) was taken, and then 5 g of vanadyl acetylacetonate (Vanadyl acetoacetonate 50D manufactured by Shinsei Chemical Industry Co., Ltd.) was added and mixed.

(Synthesis of microcapsules)
In a 200 ml tall beaker, 100 g of the 5% gelatin aqueous solution was charged, and 2 ml of the 1% cumene hydroperoxide aqueous solution was charged with a syringe. Subsequently, it stirred with the speed | rate of about 500 rpm with the anchor type stirrer. The temperature at this time was 23 ° C. While stirring, all 55 g of the core solution at the same temperature was added. After 1 minute, the stirring speed is reduced to 300 rpm, and after 5 minutes, stirring is stopped, 100 ml of tap water is added, suction filtration is performed with an aspirator, microcapsules are recovered, and further, washing with tap water is performed twice and filtration. did. The paper was then made into a dry box and the product was air dried overnight.

As a result of measuring the particle diameter of the microcapsule under a microscope, it was spherical with an average diameter of 360 μm. Furthermore, after crushing between two glass plates, washing and drying with acetone, and measuring the thickness of the capsule wall with a microscope, it was about 30 μm.

(Example 2)
With respect to the core liquid of Example 1, BPE-100 was changed to 8.5 g and dicyclopentenyloxyethyl methacrylate (abbreviated as QM-57T) 41.5 g under the same conditions as in Example 1. Capsules were synthesized. As a result, although the size of the microcapsules and the thickness of the shell were almost the same as those of the example, a soft microcapsule having a flexible shape whose height was deformed to about 1/3 when pressed was obtained.

Example 3
Regarding the core liquid of Example 2, microcapsules were synthesized under the same conditions as Example 2 except that BPE-100 alone was changed to 50 g. As a result, the size of the microcapsules and the thickness of the shell were almost the same as those of the example, but a hard microcapsule was obtained that breaks down and releases the core liquid when pressed.

Example 4
As a result of raising the temperature of the medium liquid and the core liquid to 40 ° C. under the conditions of Example 1, the average particle size of the maiko capsules was 300 μm, and the microcapsule film thickness was 13 μm.

(Example 5)
2-hydroxyethyl methacrylate (Kyoei Chemical Co., Ltd. light ester HO) 20 g, dicyclopentenyloxyethyl methacrylate (Rohm and Haas QM-57T) 40 g, 1,2-polybutadiene urethane modified dimethacrylate 40 g of TE-2000) and 1 g of paraffin wax (Nippon Seiki Co., Ltd.) were mixed, heated to 70 ° C. with stirring and mixing to dissolve the paraffin wax, and then ultrafine silica powder (AS-380 manufactured by Nippon Aerosil Co., Ltd.). ) 3 g was added, mixed and dispersed, and then cooled to 25 ° C. Next, 2 g of cumene hydroperoxide (Nippon Yushi Co., Ltd., Park Mill H80) and 0.25 g of phosphate ester neutralized product (Phosmer MH manufactured by Unichemical Co., Ltd.) were added and stirred to obtain a cumene hydroperoxide-containing main agent. It was. Next, 10 parts of the microcapsules obtained in Example 1 were blended to obtain a one-component adhesive.

(Measurement of adhesion and adhesive strength)
About 0.5 g of adhesive was applied between two sandblasted iron test pieces, and the test pieces were stacked and pressed by hand and rubbed together three times. Similarly, after joining with a 12.7 mm lap, the shear strength was measured after standing overnight, and showed an adhesive strength of 21.6 MPa.

(Example 6) (Production of agent A)
20 g of 2-hydroxyethyl methacrylate, 40 g of dicyclopentenyloxyethyl methacrylate, 40 g of 1,2-polybutadiene urethane modified dimethacrylate, and 1 g of paraffin wax were added and heated to 70 ° C. with stirring and mixing to dissolve the paraffin wax. After that, 3 g of ultrafine silica powder was added, mixed and dispersed, and then cooled to 25 ° C. Next, 0.3 g of phosphoric acid ester neutralizing solution and 2 g of cumene hydroperoxide were added and mixed by stirring to obtain agent A.

(Manufacture of B agent)
20 g of 2-hydroxyethyl methacrylate, 40 g of dicyclopentenyloxyethyl methacrylate, 40 g of 1,2-polybutadiene urethane modified dimethacrylate and 1 g of paraffin wax are blended and heated to 70 ° C. with stirring and mixing to dissolve the paraffin wax. Then, 3 g of ultrafine silica powder was added and mixed and dispersed, and then 0.27 g of 2-ethylimidazole (Curesol 2EZ manufactured by Shikoku Kasei Co., Ltd.) was added and mixed with stirring. Next, 2 g of cobalt octylate (Octolife Co8 manufactured by Shinto Fine Chemical Co., Ltd .: cobalt content = 8 mass%) is added, and after stirring and mixing, 0.3 g of phosphoric acid ester neutralizing solution is added and stirred and mixed. And after cooling to 25 degreeC, 4 parts of microcapsules of Example 1 were thrown in and mixed, and B agent was obtained.

(Test specimen creation and evaluation results)
Two steel plate test pieces having a width of 25 mm and a length of 300 mm were prepared, and the agent A and the agent B were applied in a strip shape on one test piece after being mixed through a static mixer. Then, when the other test piece was joined and pressed to crush the microcapsule, it was fixed after about 20 seconds. Moreover, there was no clogging of the static mixer left for 20 minutes.

(Comparative Example 1)
A 10% by weight gelatin aqueous solution was put into a 100 ml Separa flask, and the pH was adjusted to 9 with a 10% sodium carbonate solution while heating and stirring at 70 ° C. Next, 1 g of vanadyl acetoacetonate was added to and mixed with 20 g of BPE-100 as a core solution, and charged. Next, PH = 5 with acetic acid, 20 g of 10% sodium sulfate was added and coacervated, and cooled with ice water to an internal temperature of 15 ° C. However, the green and green powders indicating the presence of vanadyl acetoacetonate are found only in some places in the gelatin sphere, and the medium water shows a strong blue-green color, indicating that vanadyl acetoacetonate has flowed out. It was. Next, the gelatin spheres were hardened by heating to 50 ° C. with addition of formalin. However, it did not become monocytes, but a block body was obtained. Only traces of vanadyl acetoacetonate were observed inside the sphere.

(Comparative Example 2)
In place of the core liquid BPE-100 of Example 3, the whole amount was implemented with trimethylolpropane trimethacrylate (Light Ester TMP, manufactured by Yushi Co., Ltd.). As a result, particles having an average particle diameter of 300 μm were formed, And no microcapsules were formed.

(Comparative Example 3)
As a result of carrying out in the same manner as in Example 1 with 2 hydroxypropyl methacrylate (Light Ester HOP manufactured by Yushi Co., Ltd.) instead of the core liquid QM57T in Example 1, particles having an average particle diameter of 380 μm were formed. It was cured and did not form microcapsules. In addition, the amount of vanadyl acetoacetonate efflux into the medium liquid was large.

Since the (meth) acrylic composition of the present invention is microencapsulated and the surface of the microcapsule is a cured product of the (meth) acrylic composition, the surface of the microcapsule is a (meth) acrylic composition. The polymerization does not start even when in contact with the polymerization initiator, but when the microcapsules are destroyed by external force under such conditions, the polymerization of the (meth) acrylic composition starts and cures quickly. Since it can be used, an ultrafast adhesive (meth) acrylic adhesive can be provided easily and stably by using this, and it is extremely useful industrially.

Since the (meth) acrylic curable composition and the adhesive of the present invention have a long pot life, and are excellent in initial curing characteristics that start curing by external pressure and rapidly cure, for example, glass tube containers and cylindrical shapes It can be used in various fields such as film bags, and as an anchor material for fixing metal bars to many wall materials such as structures, building walls, and wood.

The microcapsule production method of the present invention provides a microcapsule-like (meth) acrylic composition containing a (meth) acrylic monomer and a reducing agent without setting special conditions in a very short time. It is extremely useful in industry.

Claims (18)

A microcapsule-like (meth) acrylic composition containing a (meth) acrylic monomer and a reducing agent, wherein the (meth) acrylic monomer has two or more vinyl groups. A (meth) acrylic composition comprising a monomer. The (meth) acrylic monomer in the microcapsule contains (meth) acrylic acid ester having two or more vinyl groups in the (meth) acrylic monomer in an amount of 20% by mass or more. 1. The (meth) acrylic composition according to 1. The (meth) acrylic acid ester having two or more vinyl groups is 2.2-BIS [4- (methacryloxyethoxy) phenyl] propane. ) Acrylic composition. The (meth) acrylic composition according to any one of claims 1 to 3, wherein the reducing agent in the microcapsule is vanadyl acetylacetonate or vanadium acetylacetonate. The (meth) acrylic composition according to any one of claims 1 to 4, wherein the diameter of the microcapsule containing the (meth) acrylic monomer and the reducing agent is 100 µm or more and 10 mm or less. . The (meth) acrylic composition according to any one of claims 1 to 6, wherein the thickness of the shell of the microcapsule containing the (meth) acrylic monomer and the reducing agent is 5 to 100 µm. . The (meth) acrylic composition according to any one of claims 1 to 6 is further blended with a polymerization initiator and, if necessary, a (meth) acrylic monomer ( (Meth) acrylic curable composition. The (meth) acrylic curable composition according to claim 7, wherein the polymerization initiator is contained in a microcapsule different from the microcapsule containing the (meth) acrylic monomer and the reducing agent. The (meth) acrylic curable composition according to claim 7 or 8, wherein the polymerization initiator is cumene hydroperoxide. The (meth) acrylic curable composition according to any one of claims 1 to 6, further comprising a polymerization initiator and, if necessary, a (meth) acrylic monomer. (Meth) acrylic adhesive. The (meth) acrylic curable composition according to any one of claims 1 to 6, further comprising a polymerization initiator and, if necessary, a (meth) acrylic monomer. Two-component (meth) acrylic adhesive. The (meth) acrylic polymer according to claim 10 or 11, wherein the polymerization initiator is contained in a microcapsule different from the microcapsule containing the (meth) acrylic monomer and the reducing agent. adhesive. The (meth) acrylic curable composition according to any one of claims 10 to 12, wherein the polymerization initiator is cumene hydroperoxide. A water-soluble polymerization initiator is added to water, and further, with stirring, a (meth) acrylic monomer and a reducing agent are added, and the (meth) acrylic monomer has two or more vinyl groups (meth). The manufacturing method of the microcapsule characterized by containing acrylic ester. The method for producing microcapsules according to claim 14, wherein a dispersant is added in advance to water. The method for producing microcapsules according to claim 15, wherein the dispersing agent is gelatin. The method for producing microcapsules according to any one of claims 14 to 16, wherein the water-soluble polymerization initiator is cumene hydroperoxide and the reducing agent is vanadyl acetylacetonate or vanadium acetylacetonate. The method for producing a microcapsule according to any one of claims 14 to 17, wherein the (meth) acrylic monomer is 2.2-BIS [4- (methacryloxyethoxy) phenyl] propane.