JPWO2015133040A1 - Heat curable adhesive composition and heat curable adhesive sheet - Google Patents

Abstract

Containing acrylic rubber (A), at least one crosslinking agent (B) selected from the group consisting of an isocyanate crosslinking agent, a blocked isocyanate crosslinking agent and an amine crosslinking agent, and a ferromagnetic material (C), Preferably, the thermosetting adhesive composition contains 150 to 600 parts by mass of the ferromagnetic material (C) with respect to 100 parts by mass of the acrylic rubber (A). Such a heat-curable adhesive composition exhibits a temporary fixing force due to magnetic force in the initial stage, exhibits adhesiveness after heat-curing, has a large shearing force, and is excellent in heat resistance.

Description

  The present invention relates to a heat curable adhesive composition and a heat curable adhesive sheet that can be temporarily fixed and bonded to a ferromagnetic material, a method for producing a joined body using the same, a heat curable adhesive elastic body, and elasticity. The present invention relates to a method for manufacturing a body-attached member.

  Conventionally, an adhesive sheet has been used to join a member such as a reinforcing material to a steel plate such as an automobile door. If this adhesive sheet has a large adhesive force in the initial stage of bonding, even if it is difficult to re-apply or when it is possible to re-apply when the member is misaligned with the steel sheet, the adhesive sheet There is a problem that the adhesive remains on the surface of the steel plate. Therefore, there is a demand for an adhesive sheet with good workability that can be temporarily fixed without being affected by adhesive strength in the initial stage of bonding, and can be firmly bonded thereafter.

  Therefore, an adhesive sheet made of an adhesive composition containing acrylic rubber and magnetic powder may be used. However, the adhesive sheet using acrylic rubber in this way has a low shearing force, and there arises a problem that the bonded members are displaced with time.

  On the other hand, Patent Document 1 proposes an adhesive sheet using an adhesive composition containing a hot melt adhesive and a ferromagnetic material. In order to use such an adhesive sheet, the adhesive sheet is interposed between one member made of a ferromagnetic material and another member made of a ferromagnetic material, and both members are temporarily fixed and then heated. Thus, the two members are bonded to each other.

International Publication WO2009 / 119885

  In the above-mentioned adhesive sheet, the shearing force is kept high by using a hot melt adhesive. However, when the adhesive member is placed at a high temperature, the hot melt adhesive softens again and loses its adhesive force, which causes a problem of low heat resistance.

  The present invention has been made in view of such a situation, and shows a temporary fixing force by a magnetic force in the initial stage, exhibits adhesiveness after heat curing, has a large shearing force, and has excellent heat resistance. It is an object of the present invention to provide a curable adhesive composition, a heat curable adhesive sheet, and a method for producing a joined body using the same. Moreover, this invention aims at providing the manufacturing method of the thermosetting adhesive elastic body which uses the said thermosetting adhesive composition, and a member with an elastic body.

  In order to achieve the above object, first, the present invention provides at least one crosslinking agent (A) selected from the group consisting of an acrylic rubber (A), an isocyanate crosslinking agent, a blocked isocyanate crosslinking agent, and an amine crosslinking agent ( A heat-curable adhesive composition comprising B) and a ferromagnetic material (C) is provided (Invention 1).

  The heat curable adhesive composition according to the invention (Invention 1) has an initial stage (before heat curing) due to the magnetic force of the ferromagnetic material (C) and, in some cases, the fine adhesive force of the acrylic rubber (A). It shows a good temporary fixing force to an adherend made of a ferromagnetic material. In addition, since the heat-curable adhesive composition before heat-curing is excellent in flexibility, even if the adherend has a three-dimensional curved surface, it is excellent in the three-dimensional curved surface if formed into a sheet shape. Follow. On the other hand, the heat-curable adhesive composition exhibits adhesiveness after heat-curing, and the acrylic rubber (A) that is sufficiently (completely) crosslinked and cured by the crosslinking agent (B) has a large shearing force and is good. It becomes an adhesive having high elasticity. In addition, an adhesive formed by heat-curing the above-mentioned heat-curable adhesive composition is excellent in heat resistance because it does not soften or melt even when reheated. Hard to occur.

  In the said invention (invention 1), it is preferable that content of the said ferromagnetic material (C) is 150-600 mass parts with respect to 100 mass parts of said acrylic rubber (A) (invention 2).

  In the said invention (invention 1 and 2), it is preferable that the said ferromagnetic material (C) is strontium ferrite (invention 3).

  In the said invention (invention 1-3), the said acrylic rubber (A) is a copolymer containing the structural unit derived from the monomer which has the structural unit derived from the (meth) acrylic-acid alkylester, and a reactive functional group. (Invention 4)

  In the said invention (invention 1-4), it is preferable that the said acrylic rubber (A) exists in the uncrosslinked state or the semi-crosslinked state by the said crosslinking agent (B) (invention 5).

  Secondly, the present invention provides a heat curable adhesive sheet obtained by molding the heat curable adhesive composition (Invention 1 to 5) into a sheet (Invention 6).

  In the said invention (invention 6), it is preferable that the bending resistance measured by the Gurley method is 10 to 2000 N when formed into a 1 mm thick sheet (invention 7).

  Third, the present invention temporarily fixes a first member made of a ferromagnetic material and a second member made of a ferromagnetic material through the heat-curable adhesive sheet (Inventions 6 and 7), Heating the thermosetting adhesive sheet to develop the adhesive force of the thermosetting adhesive composition, and joining the first member and the second member to produce a joined body A method is provided (Invention 8).

  4th this invention forms the adhesive agent part which consists of the said thermosetting type adhesive composition (invention 1-5) in a 1st member, The said 1st member through the said adhesive agent part, Temporarily fixing the second member made of a ferromagnetic material, and then heating the adhesive portion to develop the adhesive force of the thermosetting adhesive composition, and the first member and the second member Provided is a method for producing a joined body characterized by joining members (Invention 9).

  Fifthly, the present invention provides a thermosetting adhesive elastic body formed by molding the thermosetting adhesive composition (Inventions 1 to 5) (Invention 10).

  Sixth, the present invention relates to the heat curable adhesive elastic body (invention 10) temporarily fixed to a member made of a ferromagnetic material, and then the heat curable adhesive elastic body is heated. Provided is a method for producing a member with an elastic body, wherein the adhesive force of the adhesive composition is expressed, and the heat-curable adhesive elastic body is bonded to the member to form a member with an elastic body (Invention) 11).

  The heat curable adhesive composition and the heat curable adhesive sheet according to the present invention exhibit a temporary fixing force due to magnetic force in the initial stage, exhibit adhesiveness after heat curing, have a large shearing force, and are excellent in heat resistance. . Moreover, according to the manufacturing method of the joined body which concerns on this invention, while being able to perform adhesion | attachment operation | work with the outstanding workability | operativity, the shearing force is large and the joined body excellent in heat resistance can be obtained.

Hereinafter, embodiments of the present invention will be described.
[Heat-curing adhesive composition]
The heat curable adhesive composition according to the present embodiment (hereinafter sometimes referred to as “heat curable adhesive composition T”) includes an acrylic rubber (A), an isocyanate-based crosslinking agent, and a blocked isocyanate-based crosslinking agent. And at least one cross-linking agent (B) selected from the group consisting of amine-based cross-linking agents and a ferromagnetic material (C).

  In this heat curable adhesive composition T, the acrylic rubber (A) may be in an uncrosslinked state, or may be in a partially crosslinked state partially crosslinked by the crosslinking agent (B). From the viewpoint of flexibility and handleability of the thermosetting adhesive composition T, the acrylic rubber (A) is preferably in a semi-crosslinked state. The “semi-crosslinked state” refers to a state in which the crosslinking reaction has progressed to some extent but has not yet reached complete crosslinking.

  In the initial stage (before heat curing), the heat curable adhesive composition T containing the above components has a magnetic force due to the ferromagnetic material (C) and, in some cases, a small adhesive force due to the acrylic rubber (A). Good temporary fixing force is exhibited for adherends made of ferromagnetic materials. Moreover, since the heat-curable adhesive composition T before heat-curing is excellent in flexibility, it is excellent in the three-dimensional curved surface even if the adherend has a three-dimensional curved surface if formed into a sheet shape. Follow. On the other hand, the heat curable adhesive composition T exhibits adhesiveness after heat curing, and the acrylic rubber (A) that is sufficiently (completely) crosslinked and cured by the crosslinking agent (B) has a large shearing force. It becomes an adhesive having good elasticity. In addition, the adhesive obtained by heat-curing the above-mentioned heat-curable adhesive composition T does not soften or melt even when reheated, so it has excellent heat resistance. Is unlikely to occur.

(1) Acrylic rubber (A)
The acrylic rubber in this specification is a homopolymer composed of structural units derived from (meth) acrylic acid esters, a copolymer composed of structural units derived from (meth) acrylic acid esters, and (meth) acrylic acid esters. It is a copolymer of a structural unit derived from a structural unit derived from a polymerizable monomer other than (meth) acrylic acid ester, or a mixture thereof, and refers to a material having mechanical properties as a rubbery elastic body. This acrylic rubber usually has little or no adhesion. In this specification, (meth) acrylic acid ester means both acrylic acid ester and methacrylic acid ester. The same applies to other similar terms.

  The acrylic rubber (A) is in an uncrosslinked state or a semi-crosslinked state before heat-curing and exhibits excellent flexibility, and after heat-curing, the crosslinking agent (B) is sufficient (completely). It is cross-linked and cured, and exhibits great shearing force and good elasticity in addition to adhesive strength.

  The acrylic rubber (A) is preferably a copolymer containing a structural unit derived from a (meth) acrylic acid alkyl ester and a structural unit derived from a monomer having a reactive functional group (reactive functional group-containing monomer). . By including a structural unit derived from (meth) acrylic acid alkyl ester, desired elasticity and / or adhesiveness (slightly adhesiveness) can be expressed. Moreover, by including the structural unit derived from the reactive functional group-containing monomer, the reactive functional group becomes a crosslinking point with the crosslinking agent (B), and the acrylic rubber (A) is crosslinked by the crosslinking agent (B). Is done.

  The (meth) acrylic acid alkyl ester is preferably a (meth) acrylic acid alkyl ester having 1 to 20 carbon atoms in the alkyl group. Examples of the (meth) acrylic acid alkyl ester having 1 to 20 carbon atoms in the alkyl group include, for example, methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, and (meth) acrylic acid n-. Butyl, n-pentyl (meth) acrylate, n-hexyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, isooctyl (meth) acrylate, n-decyl (meth) acrylate, (meth) acrylic acid Examples include n-dodecyl, myristyl (meth) acrylate, palmityl (meth) acrylate, stearyl (meth) acrylate, and the like. Among them, in order to make elasticity and slight adhesiveness more desirable, (meth) acrylic acid esters having 1 to 8, particularly 2 to 4 carbon atoms in the alkyl group are preferable, and ethyl (meth) acrylate and (meth) Particularly preferred is n-butyl acrylate. In addition, these may be used independently and may be used in combination of 2 or more type.

  The acrylic rubber (A) preferably contains 50 to 99.9% by mass of structural units derived from (meth) acrylic acid alkyl esters, particularly preferably 60 to 99% by mass, and more preferably 92 to 98% by mass. % Is preferable.

  As a kind of the reactive functional group of the reactive functional group-containing monomer, any reactive functional group may be used as long as it can react with the isocyanate crosslinking agent, the blocked isocyanate crosslinking agent or the amine crosslinking agent as the crosslinking agent (B). A carboxyl group, a hydroxyl group, an epoxy group, a halogen, etc. are mentioned, A carboxyl group and a hydroxyl group with high reactivity with a crosslinking agent (B) are especially preferable, and a carboxyl group is more preferable.

  Examples of the monomer having a carboxyl group (carboxyl group-containing monomer) include ethylenically unsaturated carboxylic acids such as acrylic acid, methacrylic acid, crotonic acid, maleic acid, itaconic acid, and citraconic acid. Among these, acrylic acid or methacrylic acid excellent in reactivity with the crosslinking agent (B) is preferable, and acrylic acid is particularly preferable.

  Examples of the monomer having a hydroxyl group (hydroxyl group-containing monomer) include, for example, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate, and (meth) acrylic acid 2. -(Meth) acrylic acid hydroxyalkyl esters such as hydroxybutyl, 3-hydroxybutyl (meth) acrylate and 4-hydroxybutyl (meth) acrylate. Among these, 2-hydroxyethyl (meth) acrylate having excellent reactivity with the crosslinking agent is preferable, and 2-hydroxyethyl acrylate is particularly preferable.

  The said reactive functional group containing monomer may be used independently, and may be used in combination of 2 or more type.

  The acrylic rubber (A) preferably contains 0.1 to 10% by mass, particularly preferably 1 to 5% by mass, more preferably 2 to 4% by mass, of the structural unit derived from the reactive functional group-containing monomer. It is preferable to include. When the content of the structural unit derived from the reactive functional group-containing monomer is 0.1% by mass or more, the above-described effect due to crosslinking is favorably obtained. Moreover, the elasticity of the adhesive agent obtained by heat curing can be favorably maintained as the content of the structural unit derived from the reactive functional group-containing monomer is 10% by mass or less.

  The acrylic rubber (A) is composed of other monomers, for example, (meth) acrylic acid alkoxyalkyl esters such as methoxyethyl (meth) acrylate and ethoxyethyl (meth) acrylate, and non-crosslinkable acrylamides such as acrylamide and methacrylamide. (Meth) acrylic acid ester having a non-crosslinkable tertiary amino group such as N, N-dimethylaminoethyl (meth) acrylate and N, N-dimethylaminopropyl (meth) acrylate, (meth) acrylic acid Derived from (meth) acrylic acid ester having an aliphatic ring such as cyclohexyl, (meth) acrylic acid ester having an aromatic ring such as benzyl (meth) acrylate, phenyl (meth) acrylate, vinyl acetate, styrene, etc. A structural unit may be included. Among the other monomers, an alkoxyalkyl (meth) acrylate is preferable, and methoxyethyl (meth) acrylate is particularly preferable.

  When the acrylic rubber (A) contains a structural unit derived from an alkoxyalkyl ester of (meth) acrylic acid, the content is preferably 1 to 49.9% by mass, particularly 5 to 40% by mass. It is preferable that it is 10-35 mass%.

  A random copolymer may be sufficient as the superposition | polymerization aspect of an acrylic rubber (A), and a block copolymer may be sufficient as it.

  The mass average molecular weight (Mw) of the acrylic rubber (A) is preferably 500,000 to 2,500,000, particularly preferably 800,000 to 2,000,000, and more preferably 1,000,000 to 1,500,000. The molecular weight distribution (Mw / Mn; Mn is the number average molecular weight) of the acrylic rubber (A) is preferably 1.0 to 10, and more preferably 1.0 to 4.0. In addition, the mass average molecular weight (Mw) and the number average molecular weight (Mn) in this specification are values in terms of standard polystyrene measured by a gel permeation chromatography (GPC) method.

  When the mass average molecular weight of the acrylic rubber (A) is 500,000 or more, tackiness of the resulting heat-curable adhesive composition T before curing is suppressed, and when the mass average molecular weight is 2.5 million or less, The tack of the heat-curable adhesive composition T before being cured can be easily peeled off by hand. Therefore, when the mass average molecular weight of the acrylic rubber (A) is within the above range, an adhesive force suitable for temporary fixing can be obtained.

  In the heat curable adhesive composition T according to the present embodiment, the acrylic rubber (A) may be used alone or in combination of two or more.

(2) Crosslinking agent (B)
The crosslinking agent (B) is at least one selected from the group consisting of an isocyanate crosslinking agent, a blocked isocyanate crosslinking agent, and an amine crosslinking agent. According to these cross-linking agents, the acrylic rubber (A) can be well cross-linked and desired physical properties can be obtained. Further, the degree of crosslinking of the acrylic rubber (A) can be easily controlled by the degree of heating.

  The isocyanate-based crosslinking agent usually contains a polyisocyanate compound. Examples of the polyisocyanate compound include aromatic polyisocyanates such as tolylene diisocyanate, diphenylmethane diisocyanate and xylylene diisocyanate, aliphatic polyisocyanates such as hexamethylene diisocyanate, alicyclic polyisocyanates such as isophorone diisocyanate and hydrogenated diphenylmethane diisocyanate, and the like. , And their biuret bodies, isocyanurate bodies, and adduct bodies that are a reaction product with low molecular active hydrogen-containing compounds such as ethylene glycol, propylene glycol, neopentyl glycol, trimethylolpropane, and castor oil. Among these, trimethylolpropane-modified aromatic polyisocyanate, especially trimethylolpropane-modified tolylene diisocyanate and trimethylolpropane-modified xylylene diisocyanate, and trimethylolpropane-modified aliphatic polyisocyanate, especially trimethylolpropane-modified hexamethylene diisocyanate Is preferred.

  The blocked isocyanate-based crosslinking agent usually contains a blocked isocyanate compound having two or more isocyanate groups in one molecule, and these isocyanate groups are blocked by a protective group. Examples of protective groups include alkoxy groups, phenoxy groups, active methylene compound residues, mercaptan compound residues, acid amide compound residues, amino groups, imidazole compound residues, imino groups, oxime compound residues, And lactam compound residues.

  The protecting group is a group derived from a blocking agent, and a blocked isocyanate compound can be obtained by treating the isocyanate group of polyisocyanate by a known blocking method using the blocking agent.

  Examples of the blocking agent include alcohol compounds such as methanol, ethanol, propanol, butanol, methyl cellosolve, butyl cellosolve, phenyl cellosolve, methyl carbitol, benzyl alcohol, cyclohexanol, and furfuryl alcohol; phenol, cresol, xylenol, p Phenol compounds such as ethylphenol, o-isopropylphenol, p-tert-butylphenol, p-tert-octylphenol, nonylphenol, α-naphthol, β-naphthol, p-nitrophenol, p-chlorophenol; dimethyl malonate; Active methylene compounds such as diethyl malonate, acetylacetone and ethyl acetoacetate; butyl mercaptan, dodecyl mercaptan, thiophenol, etc. Mercaptan compounds; acid amide compounds such as acetanilide, acetanisidide, acetylamide and benzamide; amine compounds such as diphenylamine, aniline and carbazole; imidazole compounds such as imidazole, 2-ethylimidazole and 2-ethyl-4-methylimidazole Pyrazole compounds such as pyrazole, 3-methylpyrazole, 3,5-dimethylpyrazole; imine compounds such as ethyleneimine; oxime compounds such as formaldoxime, acetoaldoxime, methylethylketoxime, cyclohexanone oxime; ε-caprolactam And lactam compounds such as δ-valerolactam and β-propiolactam. Among these, pyrazole compounds, particularly 3,5-dimethylpyrazole, are preferably used.

  When a blocked isocyanate-based crosslinking agent is used, the protecting group is removed from the isocyanate group by heating at about 80 ° C. or higher, and the reaction between the isocyanate group and the reactive functional group of the acrylic rubber (A) starts, thereby causing crosslinking. Start / Proceed.

  The amine-based crosslinking agent usually contains a polyamine. Examples of the polyamine include aliphatic polyamines (for example, triethylenetetramine, tetraethylenepentamine, ethylenediamine, N, N-dicinnamylidene-1,6-hexanediamine, trimethylenediamine, hexamethylenediamine carbamate, ethanolamine, 3,9- Bis (3-aminopropyl) -2,4,8,10-tetraoxa-2-spiro [5.5] undecane etc.) and their salts; aromatic polyamines (eg diaminodiphenylmethane, xylylenediamine, phenylenediamine, diamino) Diphenylsulfone and the like), among which hexamethylenediamine carbamate is preferred.

  When using an isocyanate type crosslinking agent as a crosslinking agent (B), it is preferable that content of an isocyanate type crosslinking agent is 0.01-20 mass parts with respect to 100 mass parts of acrylic rubber (A), especially 0. 0.05 to 10 parts by mass, more preferably 1 to 5 parts by mass. When a blocked isocyanate crosslinking agent is used as the crosslinking agent (B), the content of the blocked isocyanate crosslinking agent is preferably 0.01 to 20 parts by mass with respect to 100 parts by mass of the acrylic rubber (A). In particular, it is preferably 0.05 to 12 parts by mass, and more preferably 0.2 to 8 parts by mass. When an amine-based crosslinking agent is used as the crosslinking agent (B), the content of the amine-based crosslinking agent is preferably 0.01 to 5 parts by mass with respect to 100 parts by mass of the acrylic rubber (A), particularly 0. The amount is preferably 0.05 to 3 parts by mass, and more preferably 0.1 to 1 part by mass. When the content of each cross-linking agent is within the above range, the degree of cross-linking of the acrylic rubber (A) becomes preferable, and a large shear force and good elasticity are effectively exhibited.

(3) Ferromagnetic material (C)
The ferromagnetic material (C) used in the heat-curable adhesive composition T according to the present embodiment is a substance that can have spontaneous magnetization without an external magnetic field, and includes a ferrimagnetic material. Specific examples of the ferromagnet (C) include metals such as iron, nickel, and cobalt, alloys thereof (for example, stainless steel) or oxides, strontium ferrite, barium ferrite, manganese zinc ferrite, nickel zinc ferrite, Examples thereof include magnetic materials such as ferritic materials such as copper zinc ferrite, rare earth materials such as alnico materials such as aluminum-nickel-cobalt alloys, and rare earth-transition metal materials (eg, SmCo materials, SmFeN materials, NbFeB materials). Among these, from the viewpoint that it is easy to finely control the initial magnetism, a ferrite type is preferable, and strontium ferrite is particularly preferable.

  The ferromagnetic material (C) is preferably a powder (hereinafter referred to as “magnetic powder”). The average particle size of the magnetic powder is preferably 0.5 to 20 μm, particularly preferably 0.5 to 15 μm, and more preferably 1 to 5 μm. In addition, the average particle diameter of magnetic powder can be measured by the Coulter counter method, for example.

  The content of the ferromagnetic material (C) (magnetic powder) in the heat curable adhesive composition T according to this embodiment is preferably 5 to 60% by volume, particularly 10 to 50% by volume. It is preferable that it is 20 to 45 volume%. When the content of the ferromagnetic material (C) is 5% by volume or more, the temporary fixing force to the ferromagnetic material is exhibited by the magnetic force of the ferromagnetic material (C) before heat-curing. The shearing force of the adhesive to be obtained becomes sufficiently large. On the other hand, when the content of the ferromagnetic material (C) is 60% by volume or less, it is possible to suppress the effects of other components, particularly the flexibility.

  Moreover, content of the ferromagnetic material (C) in the thermosetting adhesive composition T according to the present embodiment is 150 to 600 parts by mass with respect to 100 parts by mass of the acrylic rubber (A) in terms of solid content. It is preferable that it is preferably 170 to 500 parts by mass, and more preferably 190 to 400 parts by mass. When the content of the ferromagnetic material (C) is 150 parts by mass or more, a temporary fixing force to the ferromagnetic material is exhibited by the magnetic force of the ferromagnetic material (C) before heat-curing. The shearing force of the adhesive to be obtained becomes sufficiently large. On the other hand, when the content of the ferromagnetic material (C) is 600 parts by mass or less, the flexibility becomes good and a sufficient shearing force can be maintained.

(4) Other components The thermosetting adhesive composition T according to the present embodiment includes, for example, an anti-aging agent, a foaming agent, a tackifier, an antioxidant, a filler, and a dispersant in addition to the above components. You may contain 1 or more types suitably.

  Examples of the antioxidant include amine-ketone antioxidants such as 2,2,4-trimethyl-1,2-dihydroquinoline polymer; 4,4-bis (α, α-dimethylbenzyl) diphenylamine, N , N′-di-2-naphthyl-p-phenylenediamine and other aromatic secondary amine antioxidants; benzimidazoles such as 2-mercaptobenzimidazole zinc salt and 2-mercaptomethylbenzimidazole zinc salt Anti-aging agents; dithiocarbamate-based anti-aging agents such as nickel dibutyldithiocarbamate; and phosphite-based anti-aging agents such as tris (nonylphenyl) phosphate. The anti-aging agent may be composed of one kind or two or more kinds.

(5) Manufacturing method of heat curable adhesive composition To manufacture the heat curable adhesive composition T according to this embodiment, acrylic rubber (A), crosslinking agent (B), ferromagnetic material (C). , And if necessary, other ingredients may be blended and mixed. When an isocyanate crosslinking agent and / or an amine crosslinking agent is used as the crosslinking agent (B), the acrylic rubber (A) is brought into a semi-crosslinked state by heating the mixture at about 40 to 80 ° C. for 1 to 20 minutes. be able to.

  As described above, the ferromagnetic material (C) mixed in the heat-curable adhesive composition T may be magnetized or may not be magnetized yet. In the latter case, after mixing, after the heat-curable adhesive composition T is obtained, it may be magnetized (magnetized). Magnetization can be performed by a known method, for example, using a commercially available magnetization / demagnetization power supply device or the like.

(6) Effects and uses of heat curable adhesive composition As described above, the heat curable adhesive composition T according to the present embodiment has a magnetic force and, in some cases, at an initial stage (before heat curing). Excellent temporary fixing force for ferromagnetic materials due to minute adhesion. Moreover, since the heat-curable adhesive composition T before heat-curing is excellent in flexibility, it is excellent in the three-dimensional curved surface even if the adherend has a three-dimensional curved surface if formed into a sheet shape. Follow. And the adhesive formed by heat-curing the thermosetting adhesive composition T exhibits a high shearing force and exhibits a large shearing force and good elasticity. Further, since the adhesive does not soften or melt even when reheated, the adhesive is excellent in heat resistance, and further, there is no change in thickness due to magnetic lines of force.

  The thermosetting adhesive composition T according to this embodiment can be used to join two or more members (adhered bodies) at least one of which is made of a ferromagnetic material. Examples of the member made of a material exhibiting ferromagnetism include a member made of a material containing iron, cobalt, nickel and the like. Moreover, since the heat-curable adhesive composition T according to the present embodiment has high heat resistance after curing, it is suitably used for a portion that becomes high temperature. Concretely, automotive parts such as automobile doors and body steel plates, hole-sealing plates of the steel plates, car body reinforcement parts, especially in the vicinity of heat generating parts such as engines and exhaust pipes; in structures such as buildings Steel frame part: It is suitably used in metal parts such as precision equipment and electronic equipment, particularly in the vicinity of heat generating parts in such equipment.

  The thermosetting adhesive composition T according to the present embodiment can be formed into a predetermined shape necessary for joining the members as described above. Specific examples of the shape include various shapes such as a polygon such as a triangle, a rectangle, a pentagon, a hexagon, and an octagon, a circle such as a circle and an ellipse, and a ring shape obtained by removing the central portion of these shapes. Examples of the sheet-like body (corresponding to the heat-curable adhesive sheet of the present invention), a plate-like body, a block-like body, a columnar body, and a rod-like body.

  The heating temperature when the adherend is bonded with the thermosetting adhesive composition T according to the present embodiment is preferably a temperature at which the acrylic rubber (A) is sufficiently (completely) crosslinked. Is preferably 110 to 220 ° C, particularly preferably 130 to 200 ° C. The heating time is preferably 10 to 60 minutes, particularly preferably 20 to 50 minutes. By heating at such temperature and time, the thermosetting adhesive composition T according to the present embodiment is cured and exhibits high adhesive force and shearing force, thereby firmly bonding the adherend.

[Thermosetting adhesive sheet]
The thermosetting adhesive sheet according to the present embodiment is obtained by molding the thermosetting adhesive composition T into a sheet shape. The thickness of the heat-curable adhesive sheet depends on its use, but is usually preferably 0.1 to 5 mm, particularly preferably 0.2 to 3 mm, and more preferably 0.3 to 2 mm. It is preferable that

  Although the manufacturing method of the thermosetting type adhesive sheet which concerns on this embodiment is not specifically limited, By hot-pressing the said thermosetting type adhesive composition T, it can manufacture preferably. The temperature of the hot press needs to be a temperature at which the acrylic rubber (A) remains in an uncrosslinked state or a semi-crosslinked state, and is specifically preferably 40 to 80 ° C., particularly 50 It is preferable that it is -70 degreeC. The hot pressing time is preferably 1 to 20 minutes, particularly preferably 5 to 15 minutes.

  When hot-pressing as described above, it is preferable to sandwich the thermosetting adhesive composition T between two release sheets so that the release sheets are laminated on both sides of the obtained thermosetting adhesive sheet. The release sheet may be a release sheet subjected to double-sided release treatment, or may be a release sheet subjected to single-sided release treatment. The release sheet is used so that the release treatment surface is on the thermosetting adhesive sheet side.

  Examples of the release sheet include polyethylene terephthalate resin, polybutylene terephthalate resin, polyester resin film such as polyethylene naphthalate resin, plastic film such as polypropylene resin and polyolefin resin film such as polyethylene resin, glassine paper, coated paper, For example, a laminate paper obtained by laminating a thermoplastic resin such as polyethylene on a paper base material such as high-quality paper or the like, and a release agent such as a silicone resin are applied. Although there is no restriction | limiting in particular in the thickness of this peeling sheet, Usually, it is preferable that it is 20-200 micrometers.

  The thermosetting adhesive sheet according to this embodiment preferably has a surface magnetic force at room temperature of 1 mT or more, particularly preferably 3 to 100 mT, and more preferably 5 to 70 mT. Here, the surface magnetic force in this specification means the surface magnetic force measured with a gauss meter at a distance of 1 cm from the surface of the thermosetting adhesive sheet having a thickness of 1 mm. When the surface magnetic force is 1 mT or more, it can be sufficiently temporarily fixed to a member made of a ferromagnetic material. Further, when the surface magnetic force is 100 mT or less, even if the temporarily fixed position is deviated from the predetermined position, the position can be easily repositioned.

  In addition, since the thermosetting adhesive sheet according to the present embodiment exhibits excellent flexibility before heat curing, even if the adherend has a three-dimensional curved surface, it follows the adherend. Can be securely bonded. This flexibility can be expressed by the following bending resistance.

  The thermosetting adhesive sheet according to this embodiment preferably has a bending resistance of 20 to 1000 mN, particularly preferably 30 to 800 mN, and more preferably 40 to 500 mN when the thickness is 1 mm. Is preferred. Here, the bending resistance in this specification refers to JIS L 1096 (1999) 8.20 using a bending resistance tester for a thermosetting adhesive sheet having a thickness of 1 mm, a length of 38 mm, and a width of 25 mm. This means the bending resistance measured according to the Gurley method. When the bending resistance is in the above range, it can be said that the flexibility and the handleability are excellent.

  On the other hand, the heat-curable adhesive sheet according to the present embodiment exhibits a high adhesive force after heat-curing, has a large shearing force, and is excellent in heat resistance because it does not soften or melt even when reheated. Furthermore, the thickness does not change due to the lines of magnetic force by not melting after heat curing.

The shear force of the thermosetting adhesive sheet according to this embodiment after being heat-bonded at 150 ° C. for 40 minutes is preferably 80 N / cm ² or more, particularly preferably 100 N / cm ² or more. It is preferable that it is 110-1000 N / cm < ² >. In addition, the shear force after heat-bonding at 180 ° C. for 30 minutes of the thermosetting adhesive sheet according to the present embodiment is preferably 80 N / cm ² or more, and particularly preferably 90 N / cm ² or more. Furthermore, it is preferable that it is 100-1000 N / cm < ² >.

  Here, in the present specification, the shearing force after heat bonding means that one surface of the thermosetting adhesive sheet is attached to a stainless steel plate (thickness 0.5 mm), and the other surface is another stainless steel plate (thickness). 0.5 mm), heated at 150 ° C. for 40 minutes or 180 ° C. for 30 minutes, returned to room temperature, and measured according to JIS K6850 (test speed 50 mm / min).

  The heat curable adhesive sheet according to the present embodiment contains the ferromagnetic material (C) while the acrylic rubber (A) is sufficiently (completely) crosslinked by the crosslinking agent (B) after the heat curing. Thus, a large shearing force can be achieved as described above. According to the thermosetting adhesive sheet having such a shearing force, it is possible to effectively prevent the adhered members from being displaced due to aging or the like.

  The thermosetting adhesive sheet according to the present embodiment can also be used for the same applications as the above-described thermosetting adhesive composition T.

[Method of manufacturing joined body]
Here, the manufacturing method of the joined body which concerns on one Embodiment of this invention is demonstrated.
The method for manufacturing a joined body according to the present embodiment is a method for producing a joined body by joining two or more adherends, at least one of which is made of a ferromagnetic material. First, two or more adherends are temporarily fixed using the above-described heat curable adhesive composition T or heat curable adhesive sheet, and then the heat curable adhesive composition T or heat curable adhesive is used. The sheet is heated to join the two or more adherends. More specifically, the following methods are exemplified.

  As a first example, a method will be described in which a first member made of a ferromagnetic material and a second member made of a ferromagnetic material are bonded to each other with the thermosetting adhesive sheet interposed therebetween. . First, a thermosetting adhesive sheet having the shape of the joint surface between the first member and the second member is prepared. The heat curable adhesive sheet is sandwiched between the joining surfaces of the two members, and the first member and the second member are temporarily fixed by the magnetic force (and adhesive force) of the heat curable adhesive sheet. Thereby, workability | operativity becomes a favorable thing. And after heating a thermosetting type adhesive sheet, it cools and the 1st member and the 2nd member are adhere | attached firmly, and a joined body is obtained. The shapes of the first member and the second member are not particularly limited.

  As a second example, a method for bonding a first member and a second member made of a ferromagnetic material to each other with a thermosetting adhesive composition T interposed therebetween will be described. First, an adhesive part made of the thermosetting adhesive composition T is formed on the first member. As a method for forming the adhesive part, the heat curable adhesive composition T may be applied to the first member, or the first member may be stacked on the heat curable adhesive composition T. Good. The first member may be a ferromagnetic material or may not be a ferromagnetic material.

  Next, the adhesive member formed on the first member is adsorbed to the second member by the magnetic force (and adhesive force) of the adhesive member, and the first member and the second member are temporarily fixed. . Thereby, workability | operativity becomes a favorable thing. And after heating the thermosetting type adhesive composition T, it cools and the 1st member and the 2nd member are adhere | attached firmly, and a joined body is obtained.

  The adhesive in the joined body obtained as described above has a large adhesive force and shearing force, and is excellent in heat resistance because it does not soften or melt even when reheated. Further, since the adhesive does not melt, the thickness change due to the magnetic field lines does not occur.

[Heat-curing adhesive elastic body]
The heat-curable adhesive composition T according to the present embodiment is used as a heat-curable adhesive elastic body that is bonded to a desired adherend other than the purpose of joining two or more members (adhesive bodies). can do. The heat curable adhesive elastic body according to the present embodiment is obtained by molding the heat curable adhesive composition T into a desired shape.

  Examples of the shape of the heat-curable adhesive elastic body include, for example, polygons such as triangles, quadrangles, pentagons, hexagons, and octagons, circles such as circles and ellipses, and rings obtained by removing the center of these shapes. Examples thereof include sheet-like bodies, plate-like bodies, block-like bodies, columnar bodies, and rod-like bodies having various shapes such as a shape.

  The molding method of the thermosetting adhesive composition T is not particularly limited, and examples thereof include a hot press method similar to the above-described manufacturing method of the thermosetting adhesive sheet, a T-die method, and the like. The heating temperature and heating time at that time are the same as in the method for producing the thermosetting adhesive sheet.

  A member made of a ferromagnetic material is preferable as the adherend to which the thermosetting adhesive elastic body is bonded. If the adherend is a member made of a ferromagnetic material, the heat-curable adhesive elastic body is temporarily fixed to the adherend by a magnetic force and then heated, whereby the heat-curable adhesive elastic body is bonded. Excellent workability. Thereby, a member with an elastic body is obtained. The heating temperature and heating time at that time are the same as those when the adherend is bonded with the above-described heat-curable adhesive composition T.

  The adherend is not particularly limited, and examples thereof include bodies and doors for automobiles, metal members for automobiles, steel frame portions and metal members in structures such as buildings, precision equipment, electronic equipment, and the like. Metal parts, metal members, and the like. That is, according to the thermosetting adhesive elastic body according to the present embodiment, a member with an elastic body can be obtained for the above members.

  The embodiment described above is described for facilitating understanding of the present invention, and is not described for limiting the present invention. Therefore, each element disclosed in the above embodiment is intended to include all design changes and equivalents belonging to the technical scope of the present invention.

  EXAMPLES Hereinafter, although an Example etc. demonstrate this invention further more concretely, the scope of the present invention is not limited to these Examples etc.

[Example 1]
As the acrylic rubber (A), n-butyl acrylate (BA), ethyl acrylate (EA), and acrylic acid (AA) were copolymerized at a mass ratio of 60: 37: 3. An acrylic rubber having a molecular weight distribution (Mw / Mn) of 2.70 was prepared.

  100 parts by mass of the above acrylic rubber (A) (in terms of solid content; the same applies hereinafter) and trimethylolpropane-modified hexamethylene diisocyanate (product name “Coronate HL”, manufactured by Nippon Polyurethane Industry Co., Ltd.) 2.4 as a crosslinking agent (B) Part by mass and 200 parts by mass (30.9% by volume) of strontium ferrite powder (average particle size 2 μm) as the ferromagnetic material (C) are mixed in a mixer (product name “30C150” manufactured by Toyo Seiki Seisakusho Co., Ltd.). The mixture was heated to 60 ° C. and mixed for 10 minutes to obtain a heat curable adhesive composition.

  On the other hand, as the release sheet, two release sheets (product name “SP-PET381130”, thickness: 38 μm, manufactured by Lintec Co., Ltd.) in which one side of the polyethylene terephthalate film was subjected to release treatment with a silicone release agent were prepared. Hot press so that the heat-curable adhesive composition obtained above is sandwiched between the two release sheets, and the release-treated surface of the release sheets is in contact with the heat-curable adhesive composition. Set to a machine (product name “SA-302” manufactured by Tester Sangyo Co., Ltd., heating temperature: 60 ° C., heating time 10 minutes) and formed into a sheet with a thickness of 1 mm by the hot press machine. Then, it magnetized using the metal mold | die in a magnetic field, and obtained the thermosetting type adhesive sheet by which the peeling sheet was laminated | stacked on both surfaces.

[Examples 2 to 9, Comparative Example 1]
A thermosetting adhesive sheet was produced in the same manner as in Example 1 except that the types and blending amounts of the components constituting the thermosetting adhesive composition were changed as shown in Table 1. In Example 6, as the acrylic rubber (A), n-butyl acrylate (BA), ethyl acrylate (EA), and acrylic acid (AA) were combined at a mass ratio of 47: 50: 3. Polymerized acrylic rubber (mass average molecular weight 1 million) was used. In Example 7, as acrylic rubber (A), n-butyl acrylate (BA), ethyl acrylate (EA), methoxyethyl acrylate (MEA), and acrylic acid (AA) : Acrylic rubber copolymerized at a mass ratio of 7: 33: 3 was used.

The details of the crosslinking agent (B) shown in Table 1 are as follows.
・ "HDI": Trimethylolpropane-modified hexamethylene diisocyanate (manufactured by Nippon Polyurethane Industry Co., Ltd., product name "Coronate HL")
"Block HDI": urethane-modified hexamethylene diisocyanate blocked with 3,5-dimethylpyrazole (product name "Duranate E402-B80B" manufactured by Asahi Kasei Chemicals)
"6-AHCA": Hexamethylenediamine carbamate (manufactured by DuPont Elastomers, product name "Diac No. 1")
"TDI": trimethylolpropane modified tolylene diisocyanate (product name "Coronate L", manufactured by Nippon Polyurethane Industry Co., Ltd.)
"XDI": trimethylolpropane-modified xylylene diisocyanate (manufactured by Soken Chemical Co., Ltd., product name "TD-75")

[Test Example 1] (Measurement of bending resistance before heating)
The thermosetting adhesive sheets obtained in the examples and comparative examples were cut into a length of 38 mm and a width of 25 mm, and the release sheets on both sides were peeled off. This was used as a measurement sample. For the measurement sample, using a bending resistance tester (manufactured by Toyo Seiki Co., Ltd., product name “Gurley type flexibility tester”), according to the Gurley method of JIS L 1096 (1999) 8.20.1, The bending resistance (mN) was measured. The results are shown in Table 2.

[Test Example 2] (Measurement of surface magnetic force before heating)
One release sheet was peeled from the heat curable adhesive sheets obtained in the examples and comparative examples, and a gauss meter (product name “Toyo Technica Co., Ltd., product name”) was separated from the exposed surface of the heat curable adhesive sheet by 1 cm. Surface magnetic force (mT) at room temperature was measured with a 5080 type handy Gauss meter "). The results are shown in Table 2.

[Test Example 3] (Measurement of shearing force after heating)
The thermosetting adhesive sheets obtained in Examples and Comparative Examples were cut into 1 cm × 1 cm squares. Then, peeling off the one of the release sheet was the thermosetting adhesive sheet was attached to a stainless steel plate (SUS430 (2B) # 280HL, thickness 0.5 mm) (adhesion area is ^{1 cm} 2). Next, the other release sheet is peeled off, the heat-curable adhesive sheet is attached to a separately prepared stainless steel plate (thickness 0.5 mm), and heated at 150 ° C. for 40 minutes or 180 ° C. for 30 minutes, Returned to. For the heat-cured adhesive in this way, a material testing machine (product name “5581” manufactured by Instron Co., Ltd.) is used. The shearing force (N / cm ² ) was measured by moving at / min. The results are shown in Table 2.

  As can be seen from Table 2, the heat-curable adhesive sheets obtained in the examples had low bending resistance before heating, excellent flexibility, and good surface magnetic force. Moreover, a large shearing force was exhibited after heat curing.

  The heat curable adhesive composition and the heat curable adhesive sheet according to the present invention are suitable for joining a certain member and a member made of a ferromagnetic material, or for joining members made of a ferromagnetic material to each other. Can be used. Moreover, the heat-curable adhesive elastic body according to the present invention can be suitably used for manufacturing a member with an elastic body formed by bonding an elastic body to a ferromagnetic material.

Claims (11)

Acrylic rubber (A),
At least one crosslinking agent (B) selected from the group consisting of an isocyanate crosslinking agent, a blocked isocyanate crosslinking agent and an amine crosslinking agent;
A thermosetting adhesive composition comprising a ferromagnetic material (C).   2. The heat-curable adhesive composition according to claim 1, wherein the content of the ferromagnetic material (C) is 150 to 600 parts by mass with respect to 100 parts by mass of the acrylic rubber (A).   The thermosetting adhesive composition according to claim 1 or 2, wherein the ferromagnetic material (C) is strontium ferrite.   The acrylic rubber (A) is a copolymer comprising a structural unit derived from a (meth) acrylic acid alkyl ester and a structural unit derived from a monomer having a reactive functional group. The heat-curable adhesive composition according to any one of the above.   The thermosetting adhesive composition according to any one of claims 1 to 4, wherein the acrylic rubber (A) is in an uncrosslinked state or in a semi-crosslinked state by the crosslinking agent (B).   The thermosetting type adhesive sheet formed by shape | molding the thermosetting type adhesive composition as described in any one of Claims 1-5 in a sheet form.   The thermosetting adhesive sheet according to claim 6, wherein when formed into a sheet having a thickness of 1 mm, the bending resistance measured by the Gurley method is 10 to 2000N. A first member made of a ferromagnetic material and a second member made of a ferromagnetic material are temporarily fixed through the thermosetting adhesive sheet according to claim 6 or 7,
Next, the thermosetting adhesive sheet is heated to develop the adhesive force of the thermosetting adhesive composition, and the first member and the second member are joined. Production method. Forming an adhesive part made of the thermosetting adhesive composition according to any one of claims 1 to 5 on a first member;
Temporarily fixing the first member and the second member made of a ferromagnetic material through the adhesive portion,
Next, the adhesive part is heated to develop the adhesive strength of the thermosetting adhesive composition, and the first member and the second member are joined together. .   The thermosetting adhesive elastic body formed by shape | molding the thermosetting adhesive composition as described in any one of Claims 1-5. The thermosetting adhesive elastic body according to claim 10 is temporarily fixed to a member made of a ferromagnetic material,
Next, the heat curable adhesive elastic body is heated to develop the adhesive force of the heat curable adhesive composition, the heat curable adhesive elastic body is adhered to the member, and a member with an elastic body is obtained. The manufacturing method of the member with an elastic body characterized by doing.