WO2019181851A1

WO2019181851A1 - Adhesive set and method for producing structure

Info

Publication number: WO2019181851A1
Application number: PCT/JP2019/011178
Authority: WO
Inventors: 亜季子川口; 藤本　大輔
Original assignee: 日立化成株式会社
Priority date: 2018-03-19
Filing date: 2019-03-18
Publication date: 2019-09-26
Also published as: JPWO2019181851A1; WO2019180791A1

Abstract

One embodiment of the present invention provides an adhesive set equipped with a first liquid containing a polymerization initiator and a second liquid containing a reducing agent, wherein the first and/or second liquids also contain a monomer having an ethylenically unsaturated group, and the first and/or second liquids also contain a (meth)acrylic elastomer having a weight average molecular weight of at least 250,000.

Description

Adhesive set and structure manufacturing method

The present invention relates to an adhesive set and a method of manufacturing a structure using the same.

Conventionally, (meth) acrylic adhesives have been used in various fields including the automobile field. Among them, a first liquid and a second liquid are provided, and by mixing them, the temperature is about room temperature (for example, 30 ° C.). ) Has been studied in various ways (so-called room temperature curable two-component adhesives). A rubber component such as polybutadiene may be added to such a two-pack type (meth) acrylic adhesive as disclosed in Patent Document 1, for example.

JP-A-5-098216

By the way, in the automobile field, replacement of steel with a lighter material such as aluminum, carbon fiber reinforced plastic (CFRP), etc., is being studied in order to reduce the weight of the automobile. In this case, adherends made of different materials (for example, a steel plate and an aluminum plate, a steel plate and a CFRP plate, etc.) need to be bonded to each other, but this is done using a conventional room temperature curable two-part adhesive. Even if such adherends are bonded together, sufficient adhesiveness cannot always be obtained.

Therefore, the present invention has been made in view of the above circumstances, an adhesive set capable of curing at room temperature, which has excellent adhesion to an adherend formed of different materials, and the adhesive. It aims at providing the manufacturing method of the structure using a set.

One aspect of the present invention includes a first liquid containing a polymerization initiator and a second liquid containing a reducing agent, and at least one of the first liquid and the second liquid has a monomer having an ethylenically unsaturated group. And at least one of the first liquid and the second liquid relates to an adhesive set containing a (meth) acryl elastomer having a weight average molecular weight of 250,000 or more.

The above-mentioned adhesive set is an adhesive set that can be cured at room temperature and has excellent adhesion even to an adherend formed of different kinds of materials. For this reason, by arranging the two liquids included in the adhesive set between the adherends, curing at room temperature, that is, adhesion between the adherends at room temperature is possible, and the adherends are different materials. Even if it is formed with, excellent adhesiveness is exhibited.

In one aspect, the glass transition temperature of the (meth) acryl elastomer may be 80 ° C. or less.

In one aspect, the (meth) acryl elastomer may have a weight average molecular weight of 300,000 or more, or 400,000 or more.

Another aspect of the present invention includes a step of bonding adherends to each other using the adhesive set, wherein the first liquid and the second liquid are disposed between the adherends in the step. It relates to a manufacturing method.

According to the above manufacturing method, adherends can be bonded to each other at room temperature, and a structure in which adherends formed of different materials are suitably bonded to each other can be obtained.

ADVANTAGE OF THE INVENTION According to this invention, the manufacturing method of the structure using the adhesive set which has the adhesiveness which was excellent also to the to-be-adhered body formed from a different material, and which can be cured at room temperature, and the said adhesive set is provided. Provided.

Hereinafter, embodiments of the present invention will be described. However, the present invention is not limited to the following embodiments. In addition, in this specification, (meth) acryl means acryl and methacryl corresponding to it.

(Adhesive set)
The adhesive set according to the present embodiment is an adhesive set (also referred to as a two-component adhesive) including a first liquid containing a polymerization initiator and a second liquid containing a reducing agent. At least one of the first liquid and the second liquid contains a monomer having an ethylenically unsaturated group (hereinafter also referred to as “component (A)”), and at least one of the first liquid and the second liquid is a (meth) acryl elastomer. (Hereinafter also referred to as “component (B)”). The adhesive set according to the present embodiment is an adhesive set that can be cured at room temperature and has excellent adhesion to an adherend formed of different materials. The reason why such an effect is obtained is not necessarily clear, but (meth) acryl elastomer is excellent in compatibility with a monomer having an ethylenically unsaturated group, so this adhesive cures quickly even at room temperature, It is considered that the adherend (hereinafter also referred to as “different kind of adherend”) formed of the above material is excellent in adhesiveness.

From the viewpoint of excellent affinity when mixing the first liquid and the second liquid, making it possible to increase the degree of mixing, and suppressing variation in characteristics, in one embodiment, the first liquid includes (A) component, (B) A component and a polymerization initiator are contained, and the 2nd liquid contains (A) component, (B) component, and a reducing agent.

In another embodiment, the first liquid contains the component (A), the component (B) and the polymerization initiator, and the second liquid contains the reducing agent (the components (A) and (B). Not contained). In another embodiment, the first liquid contains a polymerization initiator (not containing (A) component and (B) component), and the second liquid contains (A) component, (B) component and reducing agent. Containing. In another embodiment, the first liquid contains the component (A) and the polymerization initiator (does not contain the component (B)), and the second liquid contains the component (B) and the reducing agent (( A) does not contain a component). In another embodiment, the first liquid contains the component (B) and the polymerization initiator (not containing the component (A)), and the second liquid contains the component (A) and the reducing agent (( B) Contains no component).

In another embodiment, the first liquid contains the component (A), the component (B) and the polymerization initiator, and the second liquid contains the component (A) and the reducing agent (the component (B). Not contained). In another embodiment, the first liquid contains the component (A), the component (B) and the polymerization initiator, and the second liquid contains the component (B) and the reducing agent (the component (A). Not contained). In another embodiment, the first liquid contains the component (A) and the polymerization initiator (does not contain the component (B)), and the second liquid contains the component (A), the component (B), and the reducing agent. Containing. In another embodiment, the first liquid contains the component (B) and the polymerization initiator (not containing the component (A)), and the second liquid contains the component (A), the component (B), and the reducing agent. Containing.

((A) component: monomer having an ethylenically unsaturated group)
The component (A) has an ethylenically unsaturated group (CH ₂ ═CR—, R represents a hydrogen atom or a methyl group). In addition to the ethylenically unsaturated group, the component (A) may contain a carboxyl group, an ester group, an amide group, a cyano group, a phosphoric acid group, a phosphonic acid group, a triazine ring, a thiol group, and the like. Component (A) is a monofunctional monomer having one ethylenically unsaturated group, a bifunctional monomer having two ethylenically unsaturated groups, or a trifunctional or higher polyfunctional monomer having three or more ethylenically unsaturated groups. Any of these may be used.

The component (A) preferably contains a (meth) acryl monomer having at least one (meth) acryloyl group from the viewpoint of excellent dispersibility in the (meth) acryl elastomer. The component (A) may contain acrylonitrile and the like.

(Meth) acrylic monomer may be, for example, (meth) acrylic acid, alkyl (meth) acrylate, or the like. The number of carbon atoms of the alkyl group in the alkyl (meth) acrylate may be, for example, 1 to 18, 1 to 12, or 1 to 8. The alkyl group may be linear, branched or cyclic. The alkyl (meth) acrylate may be, for example, methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, butyl (meth) acrylate, dicyclopentanyl (meth) acrylate, and the like (meth) From the viewpoint of further excellent dispersibility in the acrylic elastomer, methyl methacrylate is preferable.

(Meth) acrylic monomer may contain a phosphate group. Examples of such (meth) acrylic monomers include acid phosphooxyethyl (meth) acrylate, acid phosphooxypropyl (meth) acrylate, acid phosphooxypolyoxyethylene glycol mono (meth) acrylate, and acid phosphooxypolyoxypropylene. Examples include glycol mono (meth) acrylate, 2,2′-di (meth) acryloyloxydiethyl phosphate, EO (ethylene oxide) -modified di (meth) acrylate, and phosphoric acid-modified epoxy (meth) acrylate. The (meth) acrylic monomer may be, for example, a (meth) acrylic monomer having a triazine ring such as isocyanuric acid-modified (meth) acrylate. The (meth) acryl monomer may be, for example, a (meth) acryl monomer having an amino group such as acrylamide.

(Meth) acrylic monomer may contain two or more (meth) acryloyl groups. Examples of such (meth) acrylic monomers include bifunctional monomers such as diethylene glycol di (meth) acrylate and 1,6-hexanediol di (meth) acrylate, trimethylolpropane triacrylate, pentaerythritol tri (meth) ) Trifunctional monomers such as acrylate, or tetrafunctional monomers such as ditrimethylolpropane tetra (meth) acrylate. The (meth) acryl monomer may be a (meth) acrylate containing 5 or more (meth) acryloyl groups.

These (A) components can be used singly or in combination of two or more. When the component (A) is contained in both the first liquid and the second liquid, the component (A) contained in the first liquid and the component (A) contained in the second liquid may be the same as each other. They may be different and are preferably the same as each other.

The total amount of the component (A) in the first liquid and the second liquid may be, for example, 5 parts by mass or more with respect to 100 parts by mass of the total amount of the component (A) and the component (B). From a viewpoint, Preferably it is 10 mass parts or more, More preferably, it is 20 mass parts or more. The total amount of the content may be, for example, 99 parts by mass or less with respect to 100 parts by mass of the total amount of the component (A) and the component (B).

((B) component: (meth) acrylic elastomer)
A (meth) acryl elastomer is an elastomer containing a structural unit represented by the following formula (1).

In the formula, R ¹ represents a hydrogen atom or a methyl group, and R ² represents a hydrogen atom or a monovalent organic group.

The organic group represented by R ² may be, for example, a hydrocarbon group. The hydrocarbon group may be a chain or a ring. The chain hydrocarbon group may be linear or branched. These hydrocarbon groups may have, for example, 1 to 20, 1 to 15, or 1 to 10 carbon atoms. The hydrocarbon group may be an alkyl group, an alkenyl group, an alkynyl group, an aryl group, a cycloalkyl group, or the like.

Examples of the alkyl group include methyl group, ethyl group, propyl group, butyl group, pentyl group, hexyl group, heptyl group, octyl group, nonyl group, decyl group and the like. Examples of the alkenyl group include a vinyl group, a propenyl group, and a butenyl group. Examples of the alkynyl group include ethynyl group, propargyl group, butynyl group, pentynyl group, hexynyl group and the like. As an aryl group, a phenyl group, a toluyl group, a naphthyl group etc. are mentioned, for example. Examples of the cycloalkyl group include a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, a cyclopentadienyl group, a cyclohexyl group, a cycloheptyl group, a cyclooctyl group, a cyclononyl group, a cyclodecyl group, and a dicyclopentanyl group. .

The organic group represented by R ² may have a substituent other than a hydrocarbon group. As the substituent, an optimum substituent can be selected from the viewpoint of adhesiveness according to the type of material used for the adherend. The substituent may be, for example, a glycidyl group, a carboxyl group, a phosphate group, a sulfo group, a phosphonic acid group, a hydroxyl group, a nitro group, a cyano group, an amino group, an alkoxy group, an acyloxy group, etc., and is formed of a metal. From the viewpoint of excellent adhesion to an adherend, a glycidyl group, a hydroxyl group, a phosphoric acid group, a phosphonic acid group, a nitro group, a cyano group, an amino group, and the like are preferable.

The (meth) acryl elastomer may further contain a structural unit represented by the following formula (2) (a structural unit derived from acrylonitrile) in addition to the structural unit represented by the formula (1).

The (meth) acryl elastomer may further contain a structural unit (structural unit derived from acrylamide) represented by the following formula (3) in addition to the structural unit represented by the formula (1).

(Meth) acrylic elastomer contains one or more of the above-mentioned structural units so as to have rubber elasticity, and preferably contains two or more of the above-mentioned structural units. The (meth) acryl elastomer may contain only one type or two or more types of the structural units described above as the structural unit. In other words, the (meth) acrylic elastomer may be an elastomer that does not contain a structural unit other than the structural units described above (for example, a structural unit derived from an olefin such as ethylene, propylene, and butadiene).

In one embodiment, the (meth) acryl elastomer may be composed of two or more structural units represented by the formula (1). In this case, the (meth) acryl elastomer is represented by the formula (1), and the organic group represented by R ² is represented by the formula (1) and one or more structural units of a hydrocarbon group. The organic group represented by R ² may consist of one or more structural units having a glycidyl group or a hydroxyl group.

In another embodiment, the (meth) acryl elastomer may be composed of a structural unit represented by the formula (1) and a structural unit represented by the formula (2). In this case, the (meth) acryl elastomer may contain two or more kinds of structural units as the structural unit represented by the formula (1). The organic group represented by the formula (1) and represented by R ² 1 type or 2 types or more of structural units in which is a hydrocarbon group, and 1 type or 2 types or more of structural units represented by the formula (1), wherein the organic group represented by R ² has a glycidyl group or a hydroxyl group And may be included.

The content of the structural unit represented by the formula (1) may be 1% by mass or more, 20% by mass or more, or 50% by mass or more based on the total amount of structural units of the (meth) acryl elastomer.

The content of the structural unit represented by the formula (1) and the organic group represented by R ² is a hydrocarbon group is 1% by mass or more and 20% by mass based on the total amount of the structural unit of the (meth) acryl elastomer. It may be 30% by mass or more, or 99% by mass or less or 95% by mass or less.

The content of the structural unit represented by the formula (1) and the organic group represented by R ² having a substituent other than the hydrocarbon group is 1% by mass or more based on the total amount of the structural unit of the (meth) acryl elastomer. Or it may be 2 mass% or more, and may be 60 mass% or less, 50 mass% or less, or 40 mass% or less.

The content of the structural unit represented by the formula (2) may be 60% by mass or less, 50% by mass or less, or 40% by mass or less based on the total amount of the structural unit of the (meth) acryl elastomer.

The elastic modulus of the (meth) acryl elastomer is preferably 3000 MPa or less, 2000 MPa or less, or 1500 MPa or less from the viewpoint of excellent suppression of warpage when different types of adherends are joined. The elastic modulus of the (meth) acryl elastomer is calculated from the initial slope of the stress-strain curve by conducting a tensile test. The tensile test is performed using an autograph (“AGS-X” manufactured by Shimadzu Corporation) with a test piece cut into 5 mm × 0.5 mm (distance between chucks: 20 mm, tensile speed: 5 mm / min).

The glass transition temperature (Tg) of the (meth) acryl elastomer is preferably 130 ° C. or lower, 100 ° C. or lower, 80 ° C. or lower, 70 ° C. or lower, 60 ° C. or lower, from the viewpoint of further excellent adhesion to different types of adherends. 50 ° C or lower, 40 ° C or lower, 30 ° C or lower, 20 ° C or lower, 0 ° C or lower, or -10 ° C or lower. The glass transition temperature (Tg) of the (meth) acryl elastomer may be, for example, −50 ° C. or higher. The (meth) acryl elastomer may have two or more glass transition temperatures (Tg). In this case, it is preferable that at least one of the two or more glass transition temperatures (Tg) is in the above range, and it is more preferable that all of the two or more glass transition temperatures (Tg) are in the above range. .

The glass transition temperature (Tg) of the (meth) acryl elastomer means an intermediate glass transition temperature value by differential scanning calorimetry using a differential scanning calorimeter (for example, “Thermo Plus 2” manufactured by Rigaku Corporation). Specifically, the glass transition temperature (Tg) of the (meth) acryl elastomer is measured in the measurement temperature range: −50 to 300 ° C., and the temperature rise rate is 10 ° C./min. And means the midpoint glass transition temperature calculated by a method based on JIS K7121: 1987.

The weight average molecular weight (Mw) of the (meth) acryl elastomer is 250,000 or more, preferably 300,000 or more, more preferably 400,000 or more, 500,000 or more, 600,000 or more, or 700,000 or more. Also good. The weight average molecular weight (Mw) of the (meth) acryl elastomer may be 1 million or less, for example. The greater the weight average molecular weight (Mw) of the (meth) acryl elastomer, the better the elongation, strength and rupture energy of the cured product of the mixture of the first liquid and the second liquid, and the adhesion (stress) between different types of adherends. There is a tendency to be excellent in relaxation.

The weight average molecular weight (Mw) of the (meth) acryl elastomer means a value determined by using a gel permeation chromatography (GPC) method under the following conditions and determining polystyrene as a standard substance.
Measuring instrument: HLC-8320GPC (product name, manufactured by Tosoh Corporation)
・ Analytical column: TSKgel SuperMultipore HZ-H (3 units) (product name, manufactured by Tosoh Corporation)
Guard column: TSK guard column SuperMP (HZ) -H (product name, manufactured by Tosoh Corporation)
・ Eluent: THF
・ Measurement temperature: 25 ℃

(Meth) acrylic elastomer can be used alone or in combination of two or more. When the (meth) acryl elastomer is contained in both the first liquid and the second liquid, the (meth) acryl elastomer contained in the first liquid and the (meth) acryl elastomer contained in the second liquid are the same as each other. They may be different or different, and are preferably the same as each other.

The total amount of the component (B) in the first liquid and the second liquid may be, for example, 5 parts by mass or more with respect to 100 parts by mass of the total amount of the component (A) and the component (B). From a viewpoint, Preferably it is 10 mass parts or more, More preferably, it is 20 mass parts or more. The total amount of the content is, for example, 99 parts by mass or less with respect to 100 parts by mass of the total amount of the component (A) and the component (B).

(Polymerization initiator)
The polymerization initiator may be a radical polymerization initiator, for example. The radical polymerization initiator may be, for example, an organic peroxide or an azo compound. The organic peroxide may be, for example, hydroperoxide, peroxydicarbonate, peroxyester, peroxyketal, dialkyl peroxide, diacyl peroxide, and the like. The azo compound may be AIBN (2,2′-azobisisobutyronitrile), V-65 (azobisdimethylvaleronitrile) or the like. A polymerization initiator can be used individually by 1 type or in combination of 2 or more types.

Examples of hydroperoxide include diisopropylbenzene hydroperoxide and cumene hydroperoxide.

Peroxydicarbonates include di-n-propyl peroxydicarbonate, diisopropyl peroxydicarbonate, bis (4-tert-butylcyclohexyl) peroxydicarbonate, di-2-ethoxymethoxyperoxydicarbonate, di- (2-Ethylhexylperoxy) dicarbonate, dimethoxybutylperoxydicarbonate, di (3-methyl-3methoxybutylperoxy) dicarbonate and the like.

Peroxyesters include cumyl peroxyneodecanoate, 1,1,3,3-tetramethylbutylperoxyneodecanoate, 1-cyclohexyl-1-methylethylperoxyneodecanoate, t -Hexylperoxyneodecanoate, t-butylperoxypivalate, 1,1,3,3-tetramethylbutylperoxy-2-ethylhexanoate, 2,5-dimethyl-2,5-di ( 2-ethylhexanoylperoxy) hexane, 1-cyclohexyl-1-methylethylperoxy-2-ethylhexanate, t-hexylperoxy-2-ethylhexanoate, t-butylperoxy-2 -Ethylhexanoate, t-butylperoxyisobutyrate, 1,1-bis (t-butylperoxy) cyclohexane t-butylperoxy-3,5,5-trimethylhexanoate, t-butylperoxylaurate, 2,5-dimethyl-2,5-di (m-toluoylperoxy) hexane, t-hexyl Examples include peroxybenzoate and t-butyl peroxyacetate.

Peroxyketals include 1,1-bis (t-hexylperoxy) -3,3,5-trimethylcyclohexane, 1,1-bis (t-hexylperoxy) cyclohexane, 1,1- Bis (t-butylperoxy) -3,3,5-trimethylcyclohexane, 1,1-bis (t-butylperoxy) cyclododecane, 2,2-bis (t-butylperoxy) decane, etc. Can be mentioned.

Dialkyl peroxides include α, α'-bis (t-butylperoxy) diisopropylbenzene, dicumyl peroxide, 2,5-dimethyl-2,5-di (t-butylperoxy) hexane, t- Examples thereof include butyl cumyl peroxide.

Diacyl peroxides include isobutyl peroxide, 2,4-dichlorobenzoyl peroxide, 3,5,5-trimethylhexanoyl peroxide, octanoyl peroxide, lauroyl peroxide, stearoyl peroxide, succinic peroxide , Benzoylperoxytoluene, benzoyl peroxide and the like.

The radical polymerization initiator is preferably a peroxide, more preferably a hydroperoxide, and still more preferably cumene hydroperoxide from the viewpoint of storage stability.

The content of the polymerization initiator in the first liquid is, for example, 0.1 parts by mass or more with respect to 100 parts by mass of the total amount of the components (A) and (B) contained in the first liquid and the second liquid. It may be 20 parts by mass or less.

(Reducing agent)
The reducing agent may be, for example, a tertiary amine, a thiourea derivative, a transition metal salt, or the like. Examples of the tertiary amine include triethylamine, tripropylamine, tributylamine, N, N-dimethylparatoluidine and the like. Examples of the thiourea derivative include 2-mercaptobenzimidazole, methylthiourea, dibutylthiourea, tetramethylthiourea, ethylenethiourea and the like. Examples of transition metal salts include cobalt naphthenate, copper naphthenate, and vanadyl acetylacetonate. A reducing agent can be used individually by 1 type or in combination of 2 or more types.

The reducing agent is preferably a thiourea derivative or a transition metal salt from the viewpoint of curing speed. The thiourea derivative may be, for example, ethylene thiourea. From the same viewpoint, the transition metal salt is preferably vanadyl acetylacetonate.

The content of the reducing agent in the second liquid is, for example, 0.01 parts by mass or more with respect to 100 parts by mass of the total amount of the component (A) and the component (B) contained in the first liquid and the second liquid. The said content is 10 mass parts or less with respect to 100 mass parts of total amounts of (A) component and (B) component contained in a 1st liquid and a 2nd liquid, for example.

The adhesive set may contain other components other than the component (A), the component (B), the polymerization initiator, and the reducing agent. The other components may be contained in one or both of the first liquid and the second liquid, and may be contained in a third liquid different from the first liquid and the second liquid.

Other components may be polymerization inhibitors for the purpose of improving storage stability. Examples of the polymerization inhibitor include hydroquinone, methyl hydroquinone, hydroquinone monomethyl ether, catechol, pyrogallol, and phenothiazine.

Other components may be paraffins for the purpose of preventing polymerization inhibition by oxygen. Examples of paraffins include paraffin wax, microcrystalline wax, carnauba wax, beeswax, lanolin, whale wax, ceresin, and candelilla wax.

The other components may be fillers for the purpose of preventing dripping, imparting thixotropy, and improving adhesive strength. Examples of the shape of the filler include a fibrous filler and a spherical filler.

Examples of the filler component include metal fillers such as silver powder, gold powder, copper powder, and nickel powder, alumina, aluminum hydroxide, magnesium hydroxide, calcium carbonate, magnesium carbonate, calcium silicate, magnesium silicate, calcium oxide, and oxidation. Examples thereof include magnesium, aluminum oxide, aluminum nitride, crystalline silica, amorphous silica, boron nitride, titania, glass, iron oxide, inorganic fillers such as ceramics, and organic fillers such as carbon and rubber fillers.

(Manufacturing method of structure using adhesive set)
The manufacturing method of the structure using the adhesive set according to the present embodiment includes a step (adhesion step) of bonding adherends to each other using the above-described adhesive set.

In the bonding step, the first liquid and the second liquid are disposed between the adherends. The adherend is formed of, for example, metal such as steel, iron, copper, tin, aluminum, and stainless steel, resin, carbon fiber reinforced plastic (CFRP), and the like. The two adherends to be bonded may be made of the same kind of material, or may be made of different kinds of materials. Since the adhesive set used in this manufacturing method is excellent in adhesiveness to different types of adherends, even if one adherend and the other adherend are formed of different materials from each other, Thus, a structure in which adherends are suitably bonded to each other is obtained.

In the bonding step, specifically, for example, one adherend and another adherend are arranged with a predetermined gap therebetween, and the first liquid and the second liquid are placed in the gap using a device such as a mixing nozzle. Inject two liquids. In the bonding step, the first liquid and the second liquid may be mixed substantially simultaneously with the injection between the adherends, or the first liquid and the second liquid may be mixed immediately before the injection between the adherends. Good. When the first liquid and the second liquid are mixed with each other, the mixture is cured and the adherends are bonded to each other.

Since the adhesive set used in this manufacturing method can be cured at room temperature, the temperature at which the bonding step is performed may be, for example, 100 ° C. or lower, 80 ° C. or lower, or 50 ° C. or lower, and may be 5 ° C. or higher, 10 It may be higher than or equal to 20 ° C. The bonding step may be performed while changing the temperature stepwise. For example, after the bonding is performed at a temperature of 50 ° C. or lower, after-curing may be performed at a temperature of 100 ° C. or lower.

The structure obtained by the above manufacturing method is provided with one adherend, another adherend, and an adhesion part that adheres the one adherend and the other adherend. The adhesion part is a cured product of a mixture of liquids (for example, a mixture of the first liquid and the second liquid) constituting the above-described adhesive set.

Hereinafter, the present invention will be described more specifically with reference to examples, but the present invention is not limited to the examples.

(Synthesis Example 1A)
A 0.5 L flask equipped with a stirrer, a thermometer, a nitrogen gas inlet tube, a discharge tube, and a heating jacket was used as a reactor, and nitrogen was allowed to flow through the flask at 150 mL / min. As monomers, butyl acrylate (BA) 20 g, dicyclopentanyl acrylate (manufactured by Hitachi Chemical Co., Ltd., FA-513AS) 25.8 g, butyl methacrylate (BMA) 31.1 g, glycidyl methacrylate (GMA) 4.5 g, and 2 -18.6 g of ethylhexyl methacrylate (2EHMA) were mixed. In these monomers, 0.4 g of lauroyl peroxide as an initiator, 0.004 g of n-octyl mercaptan as a chain transfer agent, and 0.1 g of L-ascorbic acid as an antioxidant were dissolved to prepare a monomer mixture. 200 g of water and 1.7 g of polyvinyl alcohol (PVA) as a dispersion aid were added to the monomer mixture to obtain a dispersion. A dispersion liquid in which nitrogen was bubbled to reduce dissolved oxygen to 1 ppm or less was supplied into the flask, and then stirred and heated at a temperature in the flask of 60 ° C. and a stirring speed of 22 rotations / minute, and polymerized for 6 hours. Next, the temperature was raised to 90 ° C., the reaction was further continued for 2 hours, and after cooling, washing with water, dehydration and drying were performed to obtain a (meth) acryl elastomer (hereinafter referred to as (meth) acryl elastomer 1A).

<Measurement of weight average molecular weight>
About the obtained (meth) acryl elastomer, the weight average molecular weight (Mw) which uses polystyrene as a standard material was measured on condition of the following using the gel permeation chromatography (GPC) method. The obtained results are shown in Table 1.
Measuring instrument: HLC-8320GPC (product name, manufactured by Tosoh Corporation)
・ Analytical column: TSKgel SuperMultipore HZ-H (3 units) (product name, manufactured by Tosoh Corporation)
Guard column: TSK guard column SuperMP (HZ) -H (product name, manufactured by Tosoh Corporation)
・ Eluent: THF
・ Measurement temperature: 25 ℃

<Measurement of glass transition temperature (Tg)>
About the obtained (meth) acryl elastomer, the glass transition temperature (Tg) was measured using the differential scanning calorimeter (Rigaku Corporation make, "Thermo Plus 2"). The temperature range was −50 to 300 ° C., the rate of temperature increase was 10 ° C./min, and measurement was performed in a nitrogen atmosphere. The midpoint glass transition temperature was calculated by a method based on JIS K7121: 1987. The obtained results are shown in Table 1.

(Synthesis Example 1B)
Except having been changed to 0.6 g lauroyl peroxide as an initiator, it was synthesized under the same conditions as in Synthesis Example 1A, includes the same structural unit as (meth) acrylic elastomer 1A, and has Mw and Tg shown in Table 1 ( A (meth) acrylic elastomer (hereinafter referred to as (meth) acrylic elastomer 1B) was obtained.

(Synthesis Example 1C)
Except having been changed to 0.75 g of lauroyl peroxide as an initiator, it was synthesized under the same conditions as in Synthesis Example 1A, includes the same structural unit as (meth) acrylic elastomer 1A, and has Mw and Tg shown in Table 1 ( A (meth) acrylic elastomer (hereinafter referred to as (meth) acrylic elastomer 1C) was obtained.

(Synthesis Example 2A)
Instead of the monomer used in Synthesis Example 1A, synthesis was performed under the same conditions as in Synthesis Example 1A except that BA 69.5 g, acrylonitrile (AN) 28 g, and GMA 2.5 g were used. A (meth) acrylic elastomer (hereinafter referred to as (meth) acrylic elastomer 2A) was obtained.

(Synthesis Example 2B)
Except having been changed to 0.6 g lauroyl peroxide as an initiator, it was synthesized under the same conditions as in Synthesis Example 2A, includes the same structural unit as (meth) acrylic elastomer 2A, and has Mw and Tg shown in Table 1 ( A (meth) acrylic elastomer (hereinafter referred to as (meth) acrylic elastomer 2B) was obtained.

(Synthesis Example 2C)
Except having been changed to 0.75 g of lauroyl peroxide as an initiator, it was synthesized under the same conditions as in Synthesis Example 2A, includes the same structural unit as (meth) acrylic elastomer 2A, and has Mw and Tg shown in Table 1 ( A (meth) acrylic elastomer (hereinafter referred to as (meth) acrylic elastomer 2C) was obtained.

(Synthesis Example 3)
Instead of the monomer used in Synthesis Example 1, 10 g of BA, dicyclopentanyl acrylate (manufactured by Hitachi Chemical Co., Ltd., FA-513AS) 25.8 g, MMA 21.1 g, BMA 20 g, GMA 4.5 g, 2EHMA 18.6 g were used. Except for the above, synthesis was performed under the same conditions as in Synthesis Example 1A to obtain a (meth) acryl elastomer (hereinafter referred to as (meth) acryl elastomer 3).

(Synthesis Example 4)
The same structural unit as (meth) acrylic elastomer 1A was synthesized under the same conditions as in Synthesis Example 1A, except that the initiator was changed to 0.75 g of lauroyl peroxide and the temperature in the flask was changed to 65 ° C. A (meth) acryl elastomer (hereinafter referred to as (meth) acryl elastomer 4) having Mw and Tg shown in Table 1 was obtained.

(Examples 1 to 9)
(Meth) acrylic monomer, (Meth) acrylic elastomer 1A to 1C, 2A to 2C or 3, and a polymerization initiator were mixed in the amounts shown in Table 1 to obtain a first liquid. Further, (meth) acrylic monomer, (meth) acrylic elastomer 1A-1C, 2A-2C or 3, and a reducing agent were mixed in the blending amounts shown in Table 1 to obtain a second liquid. Details of each component used are shown below.
(Meth) acrylic monomer: methyl methacrylate polymerization initiator: cumene hydroperoxide reducing agent 1: ethylenethiourea reducing agent 2: vanadyl acetylacetonate

(Comparative Examples 1 to 4)
Instead of each (meth) acrylic elastomer used in the examples, polymethyl methacrylate (PMMA1, Tg: 105 ° C., Mw: 350,000), polymethyl methacrylate (PMMA2, Tg: 105 ° C., Mw: 500,000), butadiene Example 1 except that the blending amount shown in Table 1 was changed using a polymer (TH-21 (Denka Co., Ltd., trade name), Tg: 83 ° C.) or (meth) acryl elastomer 4 Thus, a first liquid and a second liquid were obtained.

<Evaluation of adhesive>
The adhesives obtained in Examples and Comparative Examples were evaluated for room temperature curability and adhesion between different types of adherends according to the following methods. The obtained results are shown in Table 1.

<Preparation of evaluation sample>
A 0.2 mm spacer was placed between an aluminum plate having a size of 5 mm × 100 mm and a thickness of 0.5 mm and a cold-rolled steel plate so that the thickness of the adhesive was 0.2 mm. In this state, the first liquid and the second liquid were mixed between the aluminum plate and the cold-rolled steel plate while mixing using a mixing nozzle (manufactured by Tomita Engineering Co., Ltd.) to produce an evaluation sample 1.

Evaluation sample 2 in the same manner as evaluation sample 1 except that a CFRP plate having a size of 5 mm × 100 mm and a thickness of 2 mm was used instead of the aluminum plate having a size of 5 mm × 100 mm and a thickness of 0.5 mm. Was made.

(Room temperature curing)
After the evaluation samples 1 and 2 were cured at room temperature (25 ° C.) for 1 day, the plate was peeled off, and it was visually confirmed whether or not the adhesive was cured. A case where the adhesive was cured in both evaluation samples 1 and 2 was evaluated as A, and a case where the adhesive was not cured in at least one of the evaluation samples 1 and 2 was evaluated as B.

(Adhesiveness between different types of adherends)
Evaluation samples 1 and 2 were heated at 170 ° C. for 20 minutes, then allowed to cool at room temperature (30 ° C.), and the presence or absence of warpage or peeling was visually confirmed. Of those that did not warp or peel over 5 mm, those with a warp of 1 mm or less were evaluated as A +, those with a warp of greater than 1 mm and less than 3 mm were evaluated as A, and those with a warp of 3 mm or more were evaluated as A-. . Moreover, the thing with the curvature or peeling of 5 mm or more was evaluated as B. The warpage was measured by measuring the distance between the other end and the base in a state where one end of the evaluation sample was fixed on a base parallel to the ground.

Claims

A first liquid containing a polymerization initiator and a second liquid containing a reducing agent;
At least one of the first liquid and the second liquid further contains a monomer having an ethylenically unsaturated group,
At least one of the first liquid and the second liquid is an adhesive set further containing a (meth) acryl elastomer having a weight average molecular weight of 250,000 or more.
The adhesive set according to claim 1, wherein the glass transition temperature of the (meth) acryl elastomer is 80 ° C or lower.
The adhesive set according to claim 1 or 2, wherein the (meth) acryl elastomer has a weight average molecular weight of 300,000 or more.
The adhesive set according to any one of claims 1 to 3, wherein the (meth) acryl elastomer has a weight average molecular weight of 400,000 or more.
A step of bonding adherends to each other using the adhesive set according to any one of claims 1 to 4,
In the step, the structure is manufactured by arranging the first liquid and the second liquid between the adherends.
The method for manufacturing a structure according to claim 5, wherein the adherends are made of different materials.