JP5192178B2 - Curable composition - Google Patents

Description

The present invention relates to an acrylic curable composition and a room temperature curable acrylic adhesive composition. Specifically, a (meth) acrylic acid ester containing a curing accelerator that accelerates polymerization of a monomer by reacting a microcapsule encapsulating an organic peroxide as a curing initiator with the organic peroxide. The present invention relates to an acrylic curable composition added to a base composition.

Conventionally, a two-component type acrylic adhesive is known as a room temperature curing type acrylic adhesive composition. As a typical example, a second generation acrylic adhesive (SGA) is known.

SGA is classified into two types depending on the form of the two agents used. One is called one main agent, one auxiliary agent type (primer type). A curing initiator is added to the main agent mainly composed of an acrylic monomer, and this is used as one main agent, and a curing accelerator is dissolved or dispersed in a solvent or the like. Use the solution as a primer. The other is a two main agent type in which an acrylic monomer and a curing initiator are added to one of the two agents, and an acrylic monomer and a curing accelerator are added to the other.

Among these, although the two main agent type SGA is a two agent type, it does not require accurate measurement due to its high reaction propagation property, and is excellent in workability. In addition, oil surface adhesion is possible, and the balance of shear bond strength, peel bond strength, and impact bond strength is excellent. In addition, it is widely used because the cured portion is well cured.

However, the two-component type requires a process of mixing the two components, and when used in an automated line, a mixer is used. However, if continuous coating is interrupted, it will harden and the mixer part must be replaced. . Moreover, since it is a two-component type, the adhesive tank, the tube for pressurizing the adhesive tank with air, and the tube for transporting the adhesive composition are doubled as compared with the one-component type, which is complicated. Therefore, there is a need for a one-component adhesive composition that does not require a mixer and that facilitates equipment.

There is a heat-curing type as a one-component adhesive composition, but a heating line is required at the time of manufacturing, heating power, space for the heating device, curing time after bonding is a two-component acrylic adhesive Take more time.

There is also a photo-curing type as a one-component type adhesive composition, but the adherend that does not transmit light cannot be cured to the deep part even if the adhesive is exposed to the outside, even if it is irradiated with light. Will be limited.

In the curable composition containing a capsule, a curing initiator or a curing accelerator is encapsulated in the capsule, and the (meth) acrylic containing a curing accelerator or a curing initiator that reacts with the capsule encapsulation liquid. It is added to the base mainly composed of a monomer. When this curable composition is applied to an adherend and compressed between the adherends, the capsule is broken and the inclusion is released, so that the curing initiator and the curing accelerator react in the base. Bonding adherends.

The curable composition containing this capsule does not require the heat required for the heat-curing type, the light source required for the photo-curing type, and the power of the light source. Furthermore, as a limitation of the adherend, in the heat curing type, the adherend must be a material that can withstand heat for thermosetting, and in the photocuring type, the adherend is a material that transmits light for photocuring. This curable composition is not subject to such restrictions.

Curing initiators and curing accelerators that cannot be added due to poor storage stability with ordinary two-part acrylic adhesives, or even in amounts of curing accelerators, are kept in a stable state by wrapping them in a capsule film. Therefore, it is possible to add a large amount of a curing initiator and a curing accelerator, and it is possible to control a wide range of curing speed, and to design a curable composition that is cured in a shorter time than ordinary SGA and has good storage stability. be able to.

Furthermore, with a two-part acrylic adhesive, curing proceeds when mixed and applied, so that the original performance cannot be obtained unless adhesion is performed within a limited time. Since it does not harden | cure until it destroys, even if it apply | coats a capsule containing type curable composition to a to-be-adhered body, it can be left standing for a long time.

By using this capsule-containing type curable composition having a fast curing time in the production line, production of the joined body can be shortened, or the cost can be greatly reduced by simplifying the curing process.

Also, when there is a possibility of being exposed to high temperatures for a long period of time, such as when exporting to overseas, the conventional two-component acrylic curable composition will react, the viscosity will increase, the physical properties will be disturbed, and there will be a problem in quality. Although it was easy to occur, the capsule-containing curable composition can withstand long-term transportation.

From the above circumstances, specific capsule type one-component acrylic adhesives are proposed in Patent Documents 1 and 2 shown below. However, the capsule-type one-part acrylic adhesive has a slow curing speed, has not yet led to cost reduction and productivity improvement, and is applied when the adherends are large-sized ones. The microcapsules are smaller than the gaps between the bodies, and there is a problem that curing does not proceed satisfactorily. In addition, high durability in terms of moisture resistance, heat resistance, impact resistance, low stress, high toughness, etc. There remains a problem that physical properties are insufficient for use in a product group that requires properties and the like.
JP-A-1-146975 Japanese Patent No. 3412469

There is a product group in which high durability and the like are required as an application location of the curable composition. Such a product group is required to have moisture resistance, heat resistance, impact resistance, low stress, and high toughness. Further, there is a demand for faster curing than conventional acrylic curable compositions for increasing the production speed of production lines. In addition, high storage stability for overseas exports, etc. With the two-component type from application to bonding, assembly must be done in a short time of a few minutes, so when assembling by extending the time from application to bonding High convenience is also required.

In response to the above industrial requirements, the present invention has the same level of adhesiveness as conventional structural adhesives in terms of properties such as moisture resistance, heat resistance, impact resistance, low stress, and high toughness. Moreover, even if a gap is formed between the adherends, it is an object of the present invention to provide a curable composition that can be sufficiently bonded if the size of the gap is about 100 μm or less. It is another object of the present invention to provide a curable composition having a fast curability higher than that of a conventional acrylic curable composition.

As a result of various investigations, the present inventor has (b) a curing accelerator that reacts with one or more types of (a) an organic peroxide and reacts with the organic peroxide to promote polymerization of the monomer, and (c) a simple substance. The above-mentioned problem can be solved by adopting a structure comprising a functional (meth) acrylate and (d) a polyfunctional (meth) acrylate, wherein the (a) organic peroxide is encapsulated in a microcapsule. And the present invention has been achieved.

That is, the present invention includes one or more (a) organic peroxides, (b) a curing accelerator that reacts with the organic peroxide and accelerates the polymerization of the monomer, and (c-1) a carboxyl group. (C) monofunctional (meth) acrylate containing (meth) acrylate and / or (meth) acrylic acid and (c-2) (meth) acrylate containing alicyclic hydrocarbon, and (d) ) A curable composition comprising a polyfunctional (meth) acrylate, wherein the (a) organic peroxide is encapsulated in a microcapsule, (a), (A) 0.1 to 40 parts by mass, (c) with respect to 100 parts by mass of the total amount of (c), (d), (e) used as needed, and (f) used as needed -1) 0.5-50 mass parts, (c-2) 5-80 mass parts, (d) 0. It is a curable composition characterized by being -70 parts by mass, and the microcapsule contains 2 to 50% by mass of the wall membrane part with respect to 100% by mass of the whole microcapsule. A curable composition characterized in that it further comprises (e) an elastomer, and further comprises (f) a core-shell graft polymer or (g) an inorganic filler. The curable composition, wherein the microcapsules have a particle size of 180 μm or more, and the fixing time is 5 seconds to 5 minutes. , A B-type viscometer, a No. 6 rotor, the curable composition characterized by having a viscosity at 25 ° C. of 500 mPa · s or more and 60000 mPa · s or less; The curable composition is characterized by containing a plasticizer, and (c-1) (meth) acrylate and / or (meth) acrylic acid containing a carboxyl group is (meth) acrylic acid, 2- The (meth) acryloyloxyethyl succinic acid is a curable composition that is one or more of the group consisting of (meth) acryloyloxyethyl succinic acid, and (c-2) a (meth) acrylate containing an alicyclic hydrocarbon is dicyclopentanyl. (D) a polyfunctional (meth) acrylate that is one or more of the group consisting of (meth) acrylate, dicyclopentenyloxyethyl (meth) acrylate, and isobornyl (meth) acrylate. Is a curable composition comprising polyethylene oxide (10 mol) modified bisphenol A dimethacrylate, and a phosphate compound, The curable composition comprising a combination inhibitor, paraffins, and a rust inhibitor, and a joined body characterized by using the curable composition, and the adherend is a sheet metal The bonded body is characterized in that the adherend is an electrical component, the bonded body is characterized in that the electrical component is a motor, and the curable composition. It is a pressure sensitive adhesive characterized by consisting of a thing.

By making the curable composition of the present invention into a microcapsule type one-component type, the two-component type requires the mixing process, mixing ratio control, and work so that it is necessary to assemble after application to the adherend before curing. Work and conditions that are not good will disappear. The microcapsule-type one-component curable composition does not require time management from application to adhesion, and can be bonded by simply compressing or rubbing the adherends together. As described above, it has the characteristics that it can be manufactured with sufficient time and hardly requires special jigs, tools and devices when bonding.
In addition, changing the composition when used in an automatic line leads to cost reductions due to convenience and rapid curing, and the resulting cured product has high heat resistance, moisture resistance, and impact resistance adhesive strength, It is characterized by low residual stress on the body, high toughness, and good heat shock properties.

(A) Organic peroxides include cumene hydroperoxide, paramentane hydroperoxide, tertiary butyl hydroperoxide, diisopropylbenzene dihydroperoxide, methyl ethyl ketone peroxide, benzoyl peroxide and tertiary butyl peroxybenzoate And one or more of these can be used. Among these, cumene hydroperoxide and benzoyl peroxide are preferable in terms of reactivity.

(A) The amount of the microcapsules encapsulating the organic peroxide is 0.1% with respect to 100 parts by mass of the total amount of (a), (c), (d), (e), and (f). -40 mass parts is preferable and 0.2-30 mass parts is more preferable.

By encapsulating the substance in the microcapsule so that the substance that reacts with the organic peroxide does not come into contact with the organic peroxide, a large amount of the organic peroxide can be contained in the curable composition. Substances that break down microcapsules and react with organic peroxides can be brought into contact with a large amount of organic peroxides at a time, resulting in a faster curing time and a dramatic increase in storage stability. It becomes possible.

In the conventional known technology, the curable composition may be deteriorated due to long-term storage by long-term transportation, exposure to high temperature, and the like, leading to a decrease in physical properties. In the present invention, when the plasticizer is used as a diluent for the organic peroxide in the inclusion of the microcapsule, the effect of further preventing the deactivation of the microcapsule can be obtained.

Examples of plasticizers include di-2-ethylhexyl phthalate, dibutyl phthalate, diisooctyl phthalate, dibutyl phthalate, diisononyl phthalate, dicapryl phthalate, diisodecyl phthalate and other phthalates, di-2-ethylhexyl adipate, diisononyl adipate, Adipic acid esters such as diisobutyl adipate and diisodecyl adipate, sebacic acid esters such as di-2-ethylhexyl sebacate, azelaic acid esters such as dioctyl acrylate, tricresyl phosphate (TCP), tri-2-ethylhexyl phosphate, etc. Phosphate esters, citrate esters such as tri-2-ethylhexyl citrate and acetylbityl cylate, glycerol diacetate mono Aseechiru glyceride such Ureto, epoxidized soybean oil, and epoxidized glyceride of epoxidized linseed oil and the like. In addition, some compounds having at least one polymerizable double bond at the terminal or side chain of the molecule exemplified above may be used as a plasticizer for a curable composition. In addition, when a plasticizer having a specific gravity close to that of the base of the curable composition excluding the microcapsules is used as the diluent, it becomes possible to prevent the microcapsules from being settled and floated.

Examples of the material for forming the wall film of the microcapsule contained in the curable composition of the present invention include gelatin, aldehyde resin, acrylic resin, epoxy resin, and urea resin. Examples of the aldehyde resin include urea-formaldehyde resin and melamine. -A formaldehyde resin etc. are mentioned, Moreover, a polyurea, a polyurethane resin, etc. are mentioned as a urea resin. Moreover, microcapsules can be obtained by techniques such as interfacial polymerization, in-situ, insolubilized precipitation, coacervation, tumbling granulation and the like.

In the curable composition of the present invention, the contained microcapsules are compressed and broken by an external force or the like, and the inclusion liquid containing the organic peroxide is released, thereby curing other than the components included in the microcapsules. It can react with the base of the sexual composition to allow curing to proceed. That is, the curable composition provides a pressure-sensitive curable composition and a pressure-sensitive adhesive that are cured by receiving a compressive force such as an external force.

In the present invention, the wall membrane part of the microcapsule is preferably 2 to 50% by mass, and more preferably 4 to 10% by mass when the entire microcapsule including the encapsulated liquid is 100% by mass.

In addition, in the present invention, for example, in the case where a gap is formed on the joining surface of two adherends as in the case of sheet metal joining such as a steel plate having a large area, the particle size of the microcapsules is increased, By changing the material, thickness, and amount, the destruction rate is improved by compressing the microcapsules.

When the microcapsule particle size is Y (μm) and the gap between adherends where the microcapsules are broken is X (μm), the relationship between X and Y is measured and calculated to ensure that the gap It is possible to design a cracked particle size distribution. According to the results of the study by the present inventor, in the case of a microcapsule having a gelatin coating of 3 to 10% with respect to the radius of the microcapsule, when there is a gap of 100 μm between the adherends, the microcapsule particle size of 180 μm It is preferable to design a particle size distribution. In the case of a general application in which the gap is difficult to occur, the particle size of the microcapsule is preferably 0.01 mm to 10.0 mm, and more preferably 0.05 to 1.0 mm.

The microcapsule type 1-component acrylic curable composition is compressed between 0.25 MPa and 5-6 seconds between the joined bodies after application, or by sliding 5 strokes 5 mm while compressing at 0.063 MPa. Is destroyed, the encapsulated organic peroxide is released, reacts with the curing accelerator, and curing proceeds.

The (b) curing accelerator can be used as long as it is a curing accelerator that reacts with the organic peroxide (a) to generate radicals, and may be a known one. Typical curing accelerators include, for example, tertiary amines, thiourea derivatives and transition metal salts.

Examples of the tertiary amine include triethylamine, tripropylamine, tributylamine, N, N-dimethylparatoluidine, N, N-dimethylaniline, and the like. Examples of thiourea derivatives include 2-mercaptobenzimidazole, methylthiourea, dibutylthiourea, tetramethylthiourea, and ethylenethiourea. Examples of transition metal salts include cobalt octylate, cobalt naphthenate, copper naphthenate, and vanadyl acetylacetonate.

The amount of the curing accelerator used is preferably 0.05 to 15 parts by mass with respect to 100 parts by mass of the total amount of (a), (c), (d), (e), and (f). 3-5 mass parts is more preferable. If it is 0.05 parts by mass or more, a sufficiently high curing rate can be obtained, and if it is 15 parts by mass or less, an unreacted curing accelerator remains, and there is no possibility that the adhesiveness is lowered.

(C) Monofunctional (meth) acrylates include methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, isooctyl (meth) acrylate, Isodecyl (meth) acrylate, lauryl (meth) acrylate, stearyl (meth) acrylate, phenyl (meth) acrylate, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate 4-hydroxybutyl (meth) acrylate, tetrahydrofurfuryl (meth) acrylate, 2-hydroxy-3-phenoxypropyl (meth) acrylate, glycidyl (meth) acrylate, cap Lactone modified tetrahydrofurfuryl (meth) acrylate, 3-chloro-2-hydroxypropyl (meth) acrylate, N, N-dimethylaminoethyl (meth) acrylate, N, N-diethylaminoethyl (meth) acrylate, t-butylamino Ethyl (meth) acrylate, ethoxycarbonylmethyl (meth) acrylate, phenol ethylene oxide modified acrylate, phenol (ethylene oxide 2 mol modified) acrylate, phenol (ethylene oxide 4 mol modified) acrylate, paracumylphenol ethylene oxide modified acrylate, nonylphenol ethylene Oxide modified acrylate, nonylphenol (ethylene oxide 4 mol modified) acrylate, nonylphenol (ethylene oxide) 8 mol modified) acrylate, nonylphenol (2.5 mol modified propylene oxide) acrylate, 2-ethylhexyl carbitol acrylate, trifluoroethyl (meth) acrylate, β- (meth) acryloyloxyethyl hydrogen succinate, ω-carboxy -Polycaprolactone mono (meth) acrylate, n- (meth) acryloyloxyalkylhexahydrophthalimide, etc. (c-1) (meth) acrylate and / or (meth) acrylic acid ( ) containing a carboxyl group described later ( Hereinafter, (c-1) (meth) acrylate containing a carboxyl group may be generically named) , (c-2) (meth) acrylate containing an alicyclic hydrocarbon described later can be mentioned, One or more of these can be used.

In the present invention, (c) monofunctional (meth) acrylate, which will be described later, (c-1) (meth) acrylate containing a carboxyl group, and (c-2) (meth) containing an alicyclic hydrocarbon. When both the acrylate and acrylate are contained, the curing time of the curable composition of the present invention can be drastically shortened, which is effective for mass production on the production line of the joined body.

(C-1) As a (meth) acrylate containing a carboxyl group, acrylic acid, methacrylic acid, maleic acid, fumaric acid, ω-carboxy-polycaprolactone mono (meth) acrylate, monohydroxyethyl (meth) acrylate phthalate , (Meth) acrylic acid dimer, β- (meth) acryloyloxyethyl hydrogen succinate, 2-acryloyloxyethyl succinic acid, 2-methacryloyloxyethyl succinic acid and the like.

(C-1) The (meth) acrylate containing a carboxyl group is 0.5 to 100 parts by mass with respect to a total amount of 100 parts by mass of (a), (c), (d), (e), and (f). 50 mass parts is preferable and 1-25 mass parts is more preferable. In the present invention, since the carboxyl group-containing (meth) acrylate is added, the fixing time of the curable composition can be adjusted to a short time such as 5 seconds to 5 minutes. .

The curable composition is required to have moisture resistance, heat resistance, and low stress depending on the use state of the joined body. In the present invention, by containing (meth) acrylate containing a bulky alicyclic hydrocarbon in the curable composition, the moisture resistance, heat resistance, and low stress of the cured product of the curable composition. Can be improved.

(C-2) Examples of (meth) acrylates containing alicyclic hydrocarbons include cyclohexyl (meth) acrylate, dicyclopentanyl (meth) acrylate, dicyclopentenyl (meth) acrylate, dicyclopentenyloxyethyl ( Examples include meth) acrylate, isobornyl (meth) acrylate, and methoxylated cyclodecatriene (meth) acrylate.

(C-2) The (meth) acrylate containing the alicyclic hydrocarbon is 5 with respect to 100 parts by mass of the total amount of (a), (c), (d), (e), and (f). -80 mass parts is preferable, and 10-60 mass parts is more preferable.

In the present invention, the heat resistance and impact adhesive strength are improved by using (d) a polyfunctional (meth) acrylate. In particular, when a bifunctional (meth) acrylate having a molecular weight of 400 or more is used, impact adhesive strength is increased, and low stress and high toughness can be achieved.

(D) The polyfunctional (meth) acrylate is a polyfunctional (meth) acrylate oligomer or polymer in which two or more terminal or side chains of the oligomer or polymer are (meth) acroylated, or two or more (meth) acryloyl. Monomers having groups can be used. For example, as the polyfunctional (meth) acrylate oligomer or polymer, 1,2-polybutadiene-terminated urethane (meth) acrylate (for example, “TE-2000”, “TEA-1000” manufactured by Nippon Soda Co., Ltd.), the hydrogenated product ( For example, “TEAI-1000” manufactured by Nippon Soda Co., Ltd.), 1,4-polybutadiene-terminated urethane (meth) acrylate (for example, “BAC-45” manufactured by Osaka Organic Chemical Co., Ltd.), polyisoprene-terminated (meth) acrylate, polyester-based urethane (Meth) acrylate, polyether urethane (meth) acrylate, polyester (meth) acrylate, bis-A type epoxy (meth) acrylate (for example, “Biscoat # 540” manufactured by Osaka Organic Chemical Co., Ltd., “Biscoat VR manufactured by Showa Polymer Co., Ltd.) -77 ").

As bifunctional (meth) acrylate monomers, 1,3-butylene glycol di (meth) acrylate, 1,4-butanediol di (meth) acrylate, 1,6-hexadiol di (meth) acrylate, 1,9-nonane Diol di (meth) acrylate, neopentyl glycol di (meth) acrylate, dicyclopentanyl di (meth) acrylate, 2-ethyl-2-butyl-propanediol (meth) acrylate, neopentyl glycol modified trimethylolpropane di ( (Meth) acrylate, stearic acid-modified pentaerythritol diacrylate, polyethylene glycol-modified bisphenol A di (meth) acrylate, polypropylene glycol-modified bisphenol A di (meth) acrylate, polypropylene glycol di ( ) Acrylate, 2,2-bis (4- (meth) acryloxydiethoxyphenyl) propane, 2,2-bis (4- (meth) acryloxypropoxyphenyl) propane, 2,2-bis (4- ( (Meth) acryloxytetraethoxyphenyl) propane and the like, and trifunctional (meth) acrylate monomers include trimethylolpropane tri (meth) acrylate, tris [(meth) acryloxyethyl] isocyanurate, As tetrafunctional or higher (meth) acrylate monomers, dimethylolpropane tetra (meth) acrylate, pentaerythritol tetra (meth) acrylate, pentaerythritol ethoxytetra (meth) acrylate, dipentaerystol penta (meth) acrylate, dipenta Elisto Include Ruhekisa (meth) acrylate

(D) Polyfunctional (meth) acrylate is 0.5-70 mass parts with respect to 100 mass parts of total amounts of (a), (c), (d), (e), and (f). It is preferable to contain, and it is more preferable that 2-50 mass parts is contained.

In the present invention, by balancing the contents of (a) to (d), the curing rate of the curable composition is increased, and moisture resistance, heat resistance, impact adhesion strength, low stress, It becomes possible to improve toughness in a well-balanced manner.

In addition, when a part of the joined body is a relatively soft material, stress is applied due to shrinkage during curing, thermal expansion of the cured product, and shrinkage due to cooling, and the possibility of destroying the adherend or the strength of adhesion due to stress. There is a risk of lowering. Moreover, there is a possibility of causing brittle fracture due to expansion and contraction on the low temperature side. In the present invention, (e) by adding an elastomer, the elastomer and the resin component are graft-polymerized, the elastic modulus of the entire resin is lowered, and the extensibility is increased, so that the curable composition is bonded to the bonded body. It is possible to reduce such stress or increase toughness.

(E) As the elastomer, acrylonitrile-butadiene-methacrylic acid copolymer, acrylonitrile-butadiene-methyl methacrylate copolymer, acrylonitrile-styrene-butadiene copolymer, acrylonitrile-butadiene rubber, linear polyurethane, styrene-butadiene Various synthetic rubbers such as rubber, chloroprene rubber and butadiene rubber, natural rubber, styrene thermoplastic elastomer such as styrene-polybutadiene-styrene synthetic rubber, olefinic thermoplastic elastomer such as polyethylene-EPDM synthetic rubber, and caprolactone type, Urethane thermoplastic elastomer such as adipate type and PTMG type, polyester such as polybutylene terephthalate-polytetramethylene glycol multiblock polymer Thermoplastic elastomers, nylon - polyol block copolymer or nylon - polyester block copolymer and polyamide-based thermoplastic elastomer, 1,2-polybutadiene-based thermoplastic elastomers, and include vinyl chloride based thermoplastic elastomer. These elastomer components may be used alone or in combination of two or more if the compatibility is good.

(E) The elastomer is preferably less than 40 parts by mass and more preferably less than 30 parts by mass with respect to 100 parts by mass of the total amount of (a), (c), (d), (e), and (f). .

In the prior art, in order to improve the storage stability of the curable composition, the microcapsules are prevented from settling and floating and separated, and the curable composition is added to the production line of the joined body. When used, it is necessary to reduce dripping from a nozzle for applying a curable composition, and to reduce application failure due to stringing. In the present invention, in order to solve the above-mentioned problems, (f) a core-shell graft polymer or (g) an inorganic filler is added to impart structural viscosity and thixotropic properties to the curable composition. It can simultaneously improve sedimentation, floating separation, dripping from nozzles in production lines, and poor coating due to stringing.

(F) Examples of the core-shell graft polymer include butadiene-styrene-methyl methacrylate copolymer (MBS), butadiene-styrene-acrylonitrile-methyl methacrylate copolymer (MBS), silicone acrylic composite rubber, acrylic rubber, and the like. (F) About the compounding quantity of a core-shell graft polymer, it is 17 mass parts or less with respect to 100 mass parts of total amounts of (a), (c), (d), (e), and (f). 15 parts by mass or less is more preferable.

(G) Powdered silicon oxide such as “Aerosil # 380” manufactured by Nippon Aerosil Co., Ltd. C. A mixture of magnesium oxide and silicon oxide such as “Calidria” manufactured by C Company, or aluminum hydroxide such as “Hydrite” manufactured by Showa Denko KK can be used alone or as a mixture. (G) About the compounding quantity of an inorganic filler, it is preferable that it is 6 mass parts or less with respect to 100 mass parts of total amounts of (a), (c), (d), (e), and (f). 0.5 parts by mass or less is more preferable.

Viscosity of the curable composition of the present invention by changing the amount of (e) elastomer, (f) core-shell graft polymer or (g) inorganic filler (B-type viscometer, No6 rotor, viscosity at 25 ° C.) Can be adjusted to 500 mPa · s or more and 60000 mPa · s or less. The curable composition within the above numerical range can prevent the microcapsules from settling, floating and separating, and when applied to the production line of the joined body, the liquid spills from the nozzle that applies the curable composition. In addition, application failure due to stringing can be prevented.

Moreover, when applying to the joining containing a metal, the adhesive property can be improved dramatically and it is preferable to apply to the joining containing a metal to the curable composition of this invention.

The curable composition of the present invention further comprises (meth) acryloyloxyethyl acid phosphate, dibutyl 2- (meth) acryloyloxyethyl acid phosphate, dioctyl 2- (meth) acryloyloxyethyl phosphate, diphenyl 2- (meth). ) Phosphoric acid ester having vinyl group or (meth) acrylic group such as acryloyloxyethyl phosphate, (meth) acryloyloxyethyl polyethylene glycol acid phosphate, (meth) acryloyloxyethyl acid phosphate monoethanolamine halfsalt By using together, the adhesiveness to a metal surface can further be improved.

Various physical properties of the curable composition of the present invention can be adjusted by adding a polymerizable vinyl monomer other than the polymerizable (meth) acrylic acid derivative.

Polymerizable vinyl monomers other than polymerizable (meth) acrylic acid derivatives include styrene, α-alkylstyrene, divinylbenzene, vinyl ether, divinyl ether, N-vinylpyrrolidone, 2-vinylpyridine, vinyl acetate and vinyl propionate. And vinyl esters.

Furthermore, in the curable composition of the present invention, a polymerizable substance other than the polymerizable vinyl monomer can be used in combination to adjust the physical properties of the curable composition. Examples of such polymerizable substances include maleic acid having a polymerizable unsaturated bond, maleic anhydride, fumaric acid, itaconic acid, polycarboxylic acids such as itaconic anhydride and citraconic acid, and monocarboxylic acids such as crotonic acid and isocrotonic acid. Examples thereof include acids and polymerizable olefinic hydrocarbons having 6 or more carbon atoms. These 1 type (s) or 2 or more types can be used.

The curable composition of this invention can add the compound comprised from organic substance and silicon. Thereby, durability and adhesion to an adherend can be improved. As shown in Formula 1, it is an organosilicon compound having two or more types of functional groups having different reactivity in the molecule.
(Formula _1); X 3 Si-Y
X: Hydrolyzable group; CH ₃ O—, C ₂ H ₅ O—, CH ₃ OC ₂ H ₄ O—, Cl—
Y: Organic functional group; vinyl group, epoxy group, amino group, mercapto group, methacryl group

The hydrolyzable group represented by X in Formula 1 is hydrolyzed by water in the aqueous solution, air in the air, water adsorbed on the inorganic surface, or the like to generate a highly reactive silanol group (SiOH). This silanol group can be adsorbed or chemically bonded to an inorganic material such as glass, silica, or metal, thereby further improving the initial adhesiveness of the curable composition of the present invention. The hydrolyzable group represented by X is preferably a methoxy group or an ethoxy group from the viewpoint of stability and ease of handling. Y in Formula 1 may be anything as long as it is an organic functional group capable of binding to various organic synthetic resins, but representative examples include vinyl, epoxy, methacryl, amino, mercapto groups and the like.

The curable composition of the present invention can use a small amount of a polymerization inhibitor and an antioxidant for improving the heat stability and improving the storage stability. For example, polymerization inhibitors and antioxidants include methyl hydroquinone, hydroquinone, 2,2-methylene-bis (4-methyl-6-tertiary butyl phenol), catechol, hydroquinone monomethyl ether, mono tertiary butyl hydroquinone, 2,5 -Ditertiary butyl hydroquinone, p-benzoquinone, 2,5-diphenyl-p-benzoquinone, 2,5-ditertiary butyl-p-benzoquinone, picric acid, citric acid, lactic acid, tartaric acid, malic acid, glycolic acid, methyl lactate , Ethyl lactate, ethyl glycolate, hydroxyacetone, dihydroxyacetone, acetoin, benzoin, phenothiazine, tertiary butylcatechol, 2-butyl-4-hydroxyanisole, p-methoxyphenol, 1,3 - trimethyl-2,4,6-tris (3,5-di -tert- butyl-4-hydroxybenzyl) benzene and 2,6-di-tert-butyl--p- cresol.

The amount of the polymerization inhibitor and the antioxidant used is 0.001 to 3 parts by mass with respect to 100 parts by mass of the total amount of (a), (c), (d), (e), and (f). Preferably, 0.01-2 mass parts is more preferable. Storage stability is ensured at 0.001 part by mass or more, good adhesiveness is obtained at 3 parts by mass or less, and it does not become uncured.

Furthermore, the curable composition of the present invention can use various paraffins in order to quickly cure the portion in contact with air. Examples of paraffins include paraffin, microcrystalline wax, carnauba wax, beeswax, lanolin, whale wax, ceresin and candelilla wax. Of these, paraffin is preferred. The melting point of paraffins is preferably 40 ° C to 100 ° C.

Furthermore, when the adherend to be bonded using the curable composition of the present invention is a metal, a rust inhibitor can be added to prevent rust. Examples are the vaporizable rust inhibitors benzotriazole, tolyltriazole, dicyclohexylammonium nitrite, dicyclohexylammonium salicylate, monoethanolamine benzoate, dicyclohexylammonium benzoate, diisopropylammonium benzoate, diisopropylammonium nitrite, cyclohexylamine carbamate, nitronaphthaleneammonium nitrite Examples include light, cyclohexylamine benzoate, dicyclohexylammonium cyclohexanecarboxylate, cyclohexylamine cyclohexanecarboxylate, dicyclohexylammonium acrylate, and cyclohexylamine acrylate.

In addition to these, known substances such as plasticizers, fillers, rust preventive pigments, and colorants may be used as desired.

In the present invention, the adherend can be joined by a cured body of the curable composition to produce a joined body. The various materials of the adherend are not limited, such as paper, wood, ceramic, glass, ceramics, rubber, plastic, mortar, concrete, or metal, but when the adherend is a metal, it exhibits a better adhesive effect. .

The curable composition of the present invention can be used as an electric component, and examples of the electric component include a motor, a transformer, and a speaker.

The curable composition of the present invention can also be used for a structure using a casing or a sheet metal.

The curable composition containing microcapsules does not require the heat required for the heat-curing type, the light source required for the photo-curing type, and the power of the light source. Furthermore, as a limitation of the adherend, in the heat curing type, the adherend must be a material that can withstand heat for thermosetting, and in the photocuring type, the adherend is a material that transmits light for photocuring. This curable composition is not subject to such restrictions.

Curing initiators and curing accelerators can be stabilized by wrapping them with a microcapsule film, even if a two-part acrylic adhesive cannot be added due to poor storage stability or even a large amount of curing accelerators. It is possible to add a large amount of curing initiator and curing accelerator, and it is possible to control the curing speed over a wide range, and it is possible to cure in a shorter time than ordinary SGA and has better storage stability. Compositions can be designed.

Also, when there is a possibility of being exposed to high temperatures for a long period of time, such as when exporting to overseas, the conventional two-component acrylic curable composition will react, the viscosity will increase, the physical properties will be disturbed, and there will be a problem in quality. Although it was easy to occur, the microcapsule-containing curable composition can withstand long-term transportation.

Furthermore, with a two-component acrylic adhesive, curing proceeds when mixed and applied, so that the original performance cannot be obtained unless the adhesion is carried out within a limited time. However, the microcapsule-containing curable composition is microscopic. Since it does not harden | cure until a capsule is destroyed, even if it applies a microcapsule containing type curable composition to a to-be-adhered body, it can be left standing for a long time.

By using this microcapsule-containing curable composition with a fast curing time in the production line, production of the joined body can be shortened or cost can be greatly reduced by simplifying the curing process.

Hereinafter, the present invention will be described in more detail based on examples. The unit of the amount used of each substance is shown in parts by mass.

[Examples 1 to 19 and Comparative Examples 2 to 3 ]
In Example 1, when the total amount of blended substances was 126.2 parts by mass, microcapsules (gelatin film 15% by mass, Parkmill H80 (Nippon Yushi Co., Ltd., cumene hydroperoxide 80%) 30% by mass, Cresyl phosphate (manufactured by Daihachi Chemical Industry Co., Ltd.) 55% by mass, particle size 180 μm or more, average particle size 300 μm) 10 parts by mass, vanadyl acetylacetonate (manufactured by Shinsei Chemical Co., Ltd.) 0.5 parts by mass, methacrylic acid (Mitsubishi) 15 parts by mass of Gas Chemical Co., Ltd., 45 parts by mass of dicyclopentenyloxyethyl methacrylate (QM-657, manufactured by Rohm and Haas), polyethylene oxide (10 mol) modified bisphenol A dimethacrylate (manufactured by Shin-Nakamura Chemical Co., BPE500) 25 Parts by mass, 5 parts by mass of NBR (manufactured by JSR, N260S), MBS (Kureha Chemical) Manufactured by Kogyo Co., Ltd., BTA712) 15 parts by mass, Aerosil (Japan Aerosil Co., Ltd., R-974) 0.5 part by mass, polyethylene oxide (2 mol) modified bisphenol A dimethacrylate (Shin Nakamura Chemical Co., BPE100) 3 parts by mass, 3 parts by mass of trimethylolpropane trimethacrylate (manufactured by Mitsubishi Rayon Co., Ltd., acrylic ester TMP), 1.5 parts by mass of (2 hydroxyethyl) methacrylic acid phosphate (Johoku Chemical Co., Ltd., JPA514), paraffin wax (manufactured by Nippon Seiwa Co., Ltd.) 0.5 parts by mass, 0.2 parts by mass of phenothiazine (Seiko Chemical Co., Ltd.), and 2 parts by mass of benzotriazole (Seiko Chemical Co., Ltd.). Hereinafter, the raw materials of the types shown in Tables 1 to 4 are mixed with the compositions shown in Tables 1 to 4 to adjust the curable composition, and for the obtained curable composition, tensile shear bond strength, fixing time measurement, Impact bond strength measurement, stress confirmation test, storage stability test, stability of bases other than microcapsules of curable compositions, storage stability test, microcapsule settling, stability of flotation separation, moisture resistance test, heat resistance A sex test was performed. Various physical properties were measured as follows. These results are shown in Tables 1-4. Table 5 shows the microcapsules used in Examples and Comparative Examples.

[Tensile shear bond strength]
In accordance with JIS K-6850, the adhesive composition was applied to one side of a test piece (100 mm × 25 mm × 1.6 mm, SPCC-D sandblasting), and the other test piece (100 mm × 25 mm × 1.6 mm, SPCC- D sandblasting), and the overlapped portion is pressed and pressed for 5 to 6 seconds with a load of 7 kgf with a push-pull gauge (manufactured by KOMURA, “model 1S”). This was cured at room temperature for 24 hours, and this was used as a sample for measuring the tensile shear bond strength. The tensile shear bond strength (unit: MPa) was measured under conditions of a tensile speed of 10 mm / min in an environment of a temperature of 23 ° C. and a humidity of 50%.

[Fixing time]
Apply an adhesive composition on one side of one test piece (100 mm × 25 mm × 1.6 mm, SPCC-D sandblasting) in accordance with JIS K-6850 under an environment of temperature 23 ° C. and humidity 50%. The test piece (100 mm × 25 mm × 1.6 mm, SPCC-D sand blast treatment) was overlapped, and the overlapped part was pressed with a push-pull gauge (“model 1S” manufactured by KOMURA) at a load of 7 kgf for 5 to 6 seconds. A sample for bonding and fixing time measurement was obtained. The fixing time of the sample is a time required to develop an adhesive strength of 0.125 MPa or more with a push-pull gauge (“MODEL 1S” manufactured by KOMURA) immediately after pressing in an environment of a temperature of 23 ° C. and a humidity of 50%. It was.

[Shock adhesive strength]
The adhesive composition was applied to one side of one test piece (44 mm × 25 mm × 19 mm, sandblasted iron) in accordance with JIS K-6855 under an environment of temperature 23 ° C. and humidity 50%, and then the other test A piece (25 mm × 25 mm × 9 mm, sandblasted iron) is piled up, rotated and rotated 90 ° to the left and right while being compressed at 0.063 MPa, pasted together, and cured for 24 hours in the same atmosphere as a measurement sample did. The impact adhesive strength was measured with an impact tester in an environment of a temperature of 23 ° C. and a humidity of 50%.

[Curing state confirmation test at 100 μm gap]
The adhesive composition is applied to one side of a test piece (100 mm × 25 mm × 1.6 mm, SPCC-D sandblasting), and two 100 μm steel wires are placed thereon. A 100 μm-thick PET film is placed on this, and the other test piece (100 mm × 25 mm × 1.6 mm, SPCC) is overlaid, and the overlapped portion is pushed with a push-pull gauge (“model 1S” manufactured by KOMURA). Clip it in a state of being pressed and stacked for 5-6 seconds with a load of 7 kgf. And it cured at room temperature for 24 hours, peeled off the PET film, and confirmed the hardening state of the adhesive agent.

[Residual stress confirmation test]
In the residual stress confirmation test, the curable composition of the present invention is liquefied and mixed to bond a cured product having a size of 25 mm × 95 mm × 2 mm in the middle of SPCC (200 mm × 25 mm × 0.3 mm). Residual stress is confirmed to the extent that this specimen is warped. In addition, the heat shock test is performed for 10 cycles at −45 ° C. for 1 hour to 120 ° C. for 1 hour, and the state is confirmed.

[Storage stability test / Stability of bases other than microcapsules of curable composition]
100 cc of the curable composition is exposed to 70 ° C. for 7 hours in a polyethylene container, and after stirring again, it is confirmed whether there is a difference in physical properties before exposure in fixing time and shearing adhesive strength.

[Storage stability test / Settling of microcapsules, stability of floating separation]
Expose 2.5 kg of the curable composition in a polyethylene container having a height of about 20 cm for 8 weeks at 40 ° C. to obtain a curable composition 1 cm below the liquid level of the curable composition and a curable composition 1 cm above the bottom. The sample was taken with a dropper, and it was confirmed whether the shear bond strength and the fixing time changed before and after the exposure.

[Moisture resistance test]
Cold rolled steel sheet (JIS G 3141) 100 mm x 25 mm x 1.6 mm and cold rolled steel sheet (JIS G 3141) 100 mm x 25 mm x 1.6 mm with a bonding area of 25 mm x 12.5 mm and a compression load of 7 kgf for 5 to 6 seconds Compress and bond. The test piece is evaluated by performing a compression shear test at 10 mm / min. The exposure is 80 ° C. and 95% for 1000 hours, and the compression shear adhesive strength is confirmed before and after the exposure.

[Heat resistance test]
Cold rolled steel sheet (JIS G 3141) 100 mm x 25 mm x 1.6 mm and cold rolled steel sheet (JIS G 3141) 100 mm x 25 mm x 1.6 mm with a bonding area of 25 mm x 12.5 mm and a compression load of 7 kgf for 5 to 6 seconds Compress and bond. This is exposed to 180 ° C. for 250 hours, and subjected to a shear test at 10 mm / min before and after the exposure, and evaluated.

The curable composition, adhesive, cured product, and bonded product of the present invention have the above-described characteristics, and are suitable for, for example, assembling applications such as a housing, a structure using a sheet metal, a motor, a transformer, and a speaker. It is extremely useful in industry.

Claims (17)

(B) a curing accelerator that reacts with one or more organic peroxides (a) and the organic peroxide to accelerate the polymerization of the monomer, and (c-1) a (meth) acrylate containing a carboxyl group And / or (c) monofunctional (meth) acrylate containing (meth) acrylic acid and (c-2) (meth) acrylate containing alicyclic hydrocarbon, and (d) polyfunctional (meta) ) A curable composition comprising acrylate, wherein (a) the organic peroxide is encapsulated in a microcapsule, and (a), (c), (d ), (A) 0.1 to 40 parts by mass, (c-1) 0.5 to 100 parts by mass of the total amount of (e) used as necessary and (f) used as necessary. -50 mass parts, (c-2) 5-80 mass parts, (d) 0.5-70 mass parts Curable composition characterized Rukoto. The curable composition according to claim 1, wherein the microcapsule contains 2 to 50% by mass of a wall film part with respect to 100% by mass of the entire microcapsule. Furthermore, (e) elastomer contains, The curable composition of Claim 1 or Claim 2 characterized by the above-mentioned. The curable composition according to any one of claims 1 to 3, further comprising (f) a core-shell graft polymer or (g) an inorganic filler. The curable composition according to any one of claims 1 to 4, wherein the microcapsules have a particle size of 180 µm or more . Fixing time is 5 second-5 minutes, The curable composition as described in any one of Claim 1 thru | or 5 characterized by the above-mentioned. The curable composition according to any one of claims 1 to 6, wherein a B-type viscometer, a No. 6 rotor, and a viscosity at 25 ° C are 500 mPa · s or more and 60000 mPa · s or less. Furthermore, the microcapsule contains a plasticizer, The curable composition according to claim 1 or 2. (C-1) One or more members selected from the group consisting of (meth) acrylate and / or (meth) acrylic acid containing a carboxyl group consisting of (meth) acrylic acid and 2- (meth) acryloyloxyethyl succinic acid the curable composition according to any one of a claims 1乃optimum 8. (C-2) (meth) acrylate containing alicyclic hydrocarbon is selected from the group consisting of dicyclopentanyl (meth) acrylate, dicyclopentenyloxyethyl (meth) acrylate, and isobornyl (meth) acrylate the curable composition according to at least one of any one of claims 1乃optimum 9. (D) a polyfunctional (meth) acrylate, curable composition according to any one of claims 1乃optimum 10 comprising a polyethylene oxide (10 mol) modified bisphenol A dimethacrylate. Furthermore, phosphoric acid ester compound, a polymerization inhibitor, paraffins, curable composition according to any one of claims 1乃optimum 11 comprising a corrosion inhibitor. A joined body comprising the curable composition according to any one of claims 1 to 12. The joined body according to claim 13, wherein the adherend is a sheet metal. The joined body according to claim 13, wherein the adherend is an electrical component. The joined body according to claim 15, wherein the electrical component is a motor. A pressure-sensitive adhesive comprising the curable composition according to any one of claims 1 to 12.