Two-component curing adhesive composition

Abstract

To provide a two-pack type curable adhesive composition capable of achieving both high fatigue durability and high damping properties.SOLUTION: There is provided a two-pack type curable adhesive composition which comprises a main ingredient (A) comprising an urethane prepolymer (a1) having an isocyanate group and a curing agent (B), wherein at least one of the main ingredient (A) and the curing agent (B) contains polymer fine particles (X) having an average particle diameter of 0.01 to 200 μm, the polymer fine particles (X) has a glass transition temperature of -40°C to +80°C, a content of the polymer fine particles (X) is 5 mass% or more in a total amount of the two-pack type curable adhesive composition. a cured object (P) obtained by curing the two-pack type curable adhesive composition has a loss tangent of 0.15 or more under conditions of a temperature range of -40°C to +80°C and a frequency of 100 Hz and in a tensile-shear fatigue test according to JIS K6864, the cured object (P) does not break under the conditions of a stress amplitude of 2.8 MPa and up to 107 times repetitions.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a two-component curing adhesive composition. [Background technology]

[0002] A two-component urethane adhesive composition has been disclosed in the past, with the aim of providing a two-component urethane adhesive composition that maintains the excellent curing speed of a two-component system and has good adhesion and heat resistance. The two-component urethane adhesive composition has a base component containing a urethane prepolymer (A) having an isocyanate group and a curing agent containing a compound (B) having two or more active hydrogen-containing groups per molecule, and at least one of the base component and the curing agent contains a compound (C) having an isocyanurate ring and fine particles (D) containing an organic substance and having an average particle size of 0.1 to 10 μm (Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2017-82118 Summary of the Invention [Problem to be solved by the invention]

[0004] In recent years, there has been a demand for adhesives to simultaneously improve their fatigue durability and damping properties in order to extend the service life and to suppress vibrations and the like. Under these circumstances, the present inventors prepared and evaluated a two-component curing adhesive composition with reference to the above patent documents, and found that it is extremely difficult to simultaneously improve the fatigue durability and damping properties of such a composition, because there is a trade-off between fatigue durability and damping properties.

[0005] Therefore, an object of the present invention is to provide a two-component curing adhesive composition that can achieve both high fatigue durability and high damping properties. [Means for solving the problem]

[0006] As a result of intensive research to solve the above-mentioned problems, the inventors discovered that the desired effects can be achieved by including specific polymer microparticles in at least one of the main agent containing a urethane prepolymer having isocyanate groups and the curing agent, and thus arrived at the present invention. The present invention is based on the above findings and solves the above problems by specifically providing the following configurations.

[0007] [1] A two-component curing adhesive composition comprising a main component (A) containing an isocyanate group-containing urethane prepolymer (a1) and a curing agent (B), At least one of the main agent (A) and the curing agent (B) contains polymer fine particles (X) having an average particle size of 0.01 to 200 μm, the glass transition temperature of the polymer microparticles (X) is in the range of -40°C to +80°C; the content of the polymer fine particles (X) is 5% by mass or more of the total amount of the two-component curing adhesive composition, the loss tangent of the cured product (P) obtained by curing the two-component curing adhesive composition is 0.15 or more under the conditions of a temperature range of −40° C. to +80° C. and a frequency of 100 Hz; The cured product (P) was tested for tensile shear fatigue properties in accordance with JIS K6864, and was found to have a stress amplitude of 2.8 MPa and a fatigue strength of 10 7 A two-component curing adhesive composition that does not break under repeated application conditions up to 100 times. [2] The two-component curing adhesive composition according to [1], wherein the cured product (P) has an elongation at break of 50% or more. [3] The two-component curing adhesive composition according to [1] or [2], wherein the curing agent (B) comprises a polyol compound (b1) and / or a polyamine compound (b2). [4] The two-component curing adhesive composition according to [3], wherein the polyol compound (b1) comprises at least one selected from the group consisting of polyoxyethylene polyol, polyoxypropylene polyol, polyoxyethylene polyoxypropylene polyol, polybutadiene polyol, polyisoprene polyol, polyacrylic polyol, and partially modified products of each of these. [5] The two-component curing adhesive composition according to any one of [1] to [4], wherein the polymer fine particles (X) comprise a polymer obtained by reacting a polyisocyanate compound (x1) with at least one compound (x2) selected from the group consisting of a polyol compound, a polyamine compound, and a latent polyamine compound. [6] The two-component curing adhesive composition according to any one of [1] to [5], wherein the polymer fine particles (X) comprise a polymer obtained by reacting a maleic anhydride-modified oligomer (x3) with at least one compound (x4) selected from the group consisting of a polyol compound, a polyamine compound, and a latent polyamine compound.

[0008] [7] the tensile modulus of elasticity of a cured product (M) obtained by curing the remainder of the two-component curing adhesive composition after removing the polymer fine particles (X) from the two-component curing adhesive composition is 5 MPa or more; The two-component curing adhesive composition according to any one of [1] to [6], wherein the polymer fine particles (X) have a minimum loss tangent of 0.05 or more, measured under conditions of a temperature range of −40° C. to +80° C. and a frequency of 100 Hz. [8] the urethane prepolymer (a1) is obtained by reacting a polyisocyanate compound (a2) with a polyol compound (a3) ​​in an equivalent ratio of an isocyanate group in the polyisocyanate compound (a2) to a hydroxyl group in the polyol compound (a3) ​​of 1.5 to 14; the curing agent (B) contains a polyol compound (b1) and a polyamine compound (b2), the equivalent ratio of the isocyanate group in the main component (A) to the active hydrogen-containing group in the curing agent (B) is 0.8 to 4; The two-component curing adhesive composition according to any one of [1] to [7], wherein the equivalent ratio of isocyanate groups in the main component (A) to amino groups in the polyamine compound (b2) is 1.2 to 6. [9] The two-component curing adhesive composition according to [8], wherein the polyol compound (a3) ​​comprises at least one selected from polyester polyol, polytetramethylene ether glycol, polycarbonate polyol, polycaprolactone polyol, and partially modified products of each of these.

[0009]

[10] a cured product (N) obtained by curing the remainder of the two-component curing adhesive composition excluding the polymer fine particles (X) has a minimum loss tangent of 0.05 or more, measured under conditions of a temperature range of −40° C. to +80° C. and a frequency of 100 Hz; The two-component curing adhesive composition according to any one of [1] to [6], wherein the polymer fine particles (X) have a tensile modulus of elasticity of 5 MPa or more.

[11] the urethane prepolymer (a1) is obtained by reacting a polyisocyanate compound (a2) with a polyol compound (a3) ​​in an equivalent ratio of an isocyanate group in the polyisocyanate compound (a2) to a hydroxyl group in the polyol compound (a3) ​​of 1.5 to 2.5; the curing agent (B) contains a polyol compound (b1) and a polyamine compound (b2), the equivalent ratio of the isocyanate group in the main component (A) to the active hydrogen-containing group in the curing agent (B) is 0.8 to 4; The two-component curing adhesive composition according to any one of [1] to [6] and

[10] , wherein the equivalent ratio of the isocyanate groups in the main component (A) to the amino groups in the polyamine compound (b2) is 1.5 to 8.0.

[12] The two-component curing adhesive composition according to

[11] , wherein the polyol compound (a3) ​​comprises at least one selected from polyoxypropylene glycol, polybutadiene polyol, polyisoprene polyol, polyacrylic polyol, and partially modified products of any of these.

[13] The two-component curing adhesive composition according to any one of [1] to

[12] , wherein the maximum value of the loss tangent of the cured product (P) measured under conditions of a temperature range of −40° C. to +80° C. and a frequency of 100 Hz is 0.3 or more.

[0010]

[14] The two-component curing adhesive composition according to any one of [1] to

[13] , wherein the polymer fine particles (X) are obtained by crosslinking a crosslinkable oligomer or a crosslinkable polymer in at least one medium selected from the group consisting of water, an organic solvent, an oligomer, and a polymer to form polymer fine particles. [Effects of the Invention]

[0011] The two-component curing adhesive composition of the present invention can achieve both high fatigue durability and high damping properties. [Brief explanation of the drawings]

[0012] [Figure 1] FIG. 1 is a schematic diagram showing an example of a cross section of a cured product (P) obtained by curing the two-component curing adhesive composition of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0013] The present invention will be described in detail below. In this specification, a numerical range expressed using "to" means a range that includes the numerical values ​​written before and after "to". In this specification, unless otherwise specified, each component may be used alone or in combination of two or more substances. When a component contains two or more substances, the content of the component means the total content of the two or more substances. In this specification, the fact that at least one of high fatigue durability and high damping property is superior may be referred to as the fact that the effect of the present invention is superior.

[0014] [Two-component curing adhesive composition] The two-component curing adhesive composition of the present invention (the composition of the present invention) is A two-component curing adhesive composition comprising a main component (A) containing an isocyanate group-containing urethane prepolymer (a1) and a curing agent (B), At least one of the main agent (A) and the curing agent (B) contains polymer fine particles (X) having an average particle size of 0.01 to 200 μm, the glass transition temperature of the polymer microparticles (X) is in the range of -40°C to +80°C; the content of the polymer fine particles (X) is 5% by mass or more of the total amount of the two-component curing adhesive composition, the loss tangent of the cured product (P) obtained by curing the two-component curing adhesive composition is 0.15 or more under the conditions of a temperature range of −40° C. to +80° C. and a frequency of 100 Hz; The cured product (P) was tested for tensile shear fatigue properties in accordance with JIS K6864, and was found to have a stress amplitude of 2.8 MPa and a fatigue strength of 10 7 This is a two-component curing adhesive composition that does not break even under conditions of repeated application up to 100 times. The composition of the present invention will be described in detail below.

[0015] The composition of the present invention is a two-component curing adhesive composition having a main component (A) containing a urethane prepolymer (a1) having an isocyanate group, and a curing agent (B).

[0016] <<Main ingredient (A)>> In the present invention, the main component (A) contains a urethane prepolymer (a1) having an isocyanate group.

[0017] <Urethane prepolymer (a1)> In the present invention, the urethane prepolymer (a1) has an isocyanate group, and preferably has a plurality of isocyanate groups per molecule.

[0018] From the viewpoint of achieving better effects of the present invention, the urethane prepolymer (a1) is preferably one obtained by reacting a polyisocyanate compound (a2) with a polyol compound (a3) ​​in such a manner that the equivalent ratio of the isocyanate groups in the polyisocyanate compound (a2) to the hydroxyl groups in the polyol compound (a3) ​​(isocyanate groups / hydroxyl groups) is 1.5 to 14.

[0019] The urethane prepolymer (a1) may further contain an unreacted polyisocyanate compound (a2).

[0020] (Polyisocyanate compound (a2)) The polyisocyanate compound (a2) is a compound having a plurality of isocyanate groups per molecule. The polyisocyanate compound (a2) is preferably an aromatic hydrocarbon compound having a plurality of isocyanate groups, more preferably diphenylmethane diisocyanate.

[0021] (Polyol compound (a3)) The polyol compound (a3) ​​is a compound having a plurality of hydroxyl groups per molecule. Examples of the polyol compound (a3) ​​include polyoxyalkylene polyols such as polytetramethylene ether glycol, polyoxyethylene polyol, polyoxypropylene polyol, and polyoxyethylene polyoxypropylene polyol; polycarbonate polyol; and polyisoprene polyol.

[0022] <<Hardening agent (B)>> In the present invention, the curing agent (B) is a concept corresponding to the main component (A) in a two-component curing adhesive composition, and refers to a general curing agent in the broad sense. The curing agent (B) usually contains a substantial curing agent (curing agent in the narrow sense) that can react with the urethane prepolymer (a1) contained in the main component (A).

[0023] The substantial curing agent (curing agent in the narrow sense) contained in the curing agent (B) includes a compound having a plurality of active hydrogen-containing groups. Examples of the active hydrogen-containing group include groups having active hydrogen, such as a hydroxyl group, an amino group, and an imino group.

[0024] From the viewpoint of achieving better effects of the present invention, the curing agent (B) preferably contains a polyol compound (b1) and / or a polyamine compound (b2) as a curing agent in the narrow sense, and more preferably contains a polyol compound (b1) and a polyamine compound (b2).

[0025] (Polyol compound (b1)) The polyol compound (b1) is a compound having a plurality of hydroxyl groups per molecule. From the viewpoint of achieving better effects of the present invention, it is preferable that the polyol compound (b1) contains at least one selected from the group consisting of polyoxyethylene polyol, polyoxypropylene polyol, polyoxyethylene polyoxypropylene polyol, polybutadiene polyol, polyisoprene polyol, polyacrylic polyol, and partially modified products of each of these. Examples of the modified polyol compound (b1) include compounds in which polyester chains are introduced in block form at the ends of the polyoxyethylene polyols exemplified above for the polyol compound (b1). The modified product with the polyester can have multiple hydroxy groups.

[0026] (Polyamine compound (b2)) The polyamine compound (b2) is a compound having a plurality of amino groups (NH2) per molecule. Examples of the polyamine compound (b2) include diethylmethylbenzenediamine (DETDA), 4,4'-methylenebis(2-chloroaniline), trimethylenebis(4-aminobenzoate), and dimethylthiotoluenediamine (DMTDA).

[0027] <<Polymer particles (X)>> In the present invention, at least one of the main agent (A) and the curing agent (B) contains polymer fine particles (X) having an average particle size of 0.01 to 200 μm.

[0028] At least one of the base agent (A) and the curing agent (B) may contain the polymer fine particles (X), and both the base agent (A) and the curing agent (B) may contain the polymer fine particles (X). From the viewpoint of achieving better effects of the present invention, it is preferred that at least the curing agent (B) contains the polymer fine particles (X).

[0029] <Average particle size of polymer particles (X)> In the present invention, the average particle size of the polymer fine particles (X) is 0.01 to 200 μm. The average particle size of the polymer fine particles (X) is preferably 0.1 μm to 100 μm, from the viewpoint of achieving better effects of the present invention.

[0030] (Method for measuring the average particle size of polymer particles (X)) In the present invention, the average particle size of polymer microparticles (X) means the average value of the diameters of 10 polymer microparticles (X) randomly selected from polymer microparticles (X) captured in a photograph at 2000x magnification using a scanning electron microscope (SEM).

[0031] <Glass transition temperature of polymer particles (X)> In the present invention, the glass transition temperature (Tg) of the polymer fine particles (X) is in the range of -40°C to +80°C. The Tg may be in the range of -40°C to +80°C. The Tg is preferably in the range of -35 to +55°C from the viewpoint of achieving better effects of the present invention. In the present invention, the glass transition temperature (Tg) of the polymer microparticles (X) is determined by measuring the peak (maximum) value of tanδ obtained by subjecting the cured product (corresponding to (H) described below) obtained by curing the above components (the cured product corresponds to (H) described below) to forced extensional vibration using dynamic mechanical analysis under conditions of a strain of 0.01%, a frequency of 100 Hz, and a heating rate of 5°C / min in a temperature range from -50°C to +120°C without using a medium described below when preparing the polymer microparticles (X), and leaving the remaining components under conditions of 23°C and 55% RH (relative humidity) for 7 days, and measuring the tanδ.

[0032] (Polymer skeleton constituting polymer particles (X)) The skeleton of the polymer constituting the polymer particles (X) is not particularly limited, but the skeleton preferably has a skeleton of polyurethane or conjugated diene rubber. The polyurethane skeleton is a polymer having a urethane bond and / or a urea bond (for example, polymer particles 1 to 3, 5, and 6 described below). The conjugated diene rubber skeleton may be any rubber as long as the monomers constituting the conjugated diene rubber contain at least a conjugated diene. Examples of conjugated diene rubbers include polybutadiene and polyisoprene (for example, polymer particles 4 and 7 described below).

[0033] (crosslinking) The polymer constituting the polymer particles (X) is preferably crosslinked, from the viewpoint of achieving better effects of the present invention. The crosslinking may be achieved by bonding the skeletons together via, for example, a urethane bond, a urea bond, an ester bond, or an amide bond. When the skeleton is polyurethane, it is preferable to crosslink it via a urethane bond or a urea bond. When the skeleton is a conjugated diene rubber, crosslinking is preferably carried out via an ester bond or an amide bond, and more preferably via an amide bond.

[0034] (Crosslinking points are urethane bonds and / or urea bonds) From the viewpoint of achieving superior effects of the present invention, one preferred embodiment of the polymer fine particles (X) is one that contains a polymer obtained by reacting a polyisocyanate compound (x1) with at least one compound (x2) selected from the group consisting of polyol compounds, polyamine compounds, and latent polyamine compounds (for example, polymer fine particles 1 to 3, 5, and 6 described below).

[0035] Polyisocyanate compound (x1) The polyisocyanate compound (x1) that can be used when producing the polymer microparticles (X) is a compound having a plurality of isocyanate groups. The polyisocyanate compound (x1) preferably contains a urethane prepolymer (for example, the urethane prepolymers used in producing the polymer microparticles 1 to 3, 5, and 6 described below). Examples of the urethane prepolymer include those similar to the urethane prepolymer (a1) described above. When the polyisocyanate compound (x1) contains a urethane prepolymer, it may further contain a polyisocyanate compound used in producing the urethane prepolymer. The polyisocyanate compound used in producing the urethane prepolymer may be an unreacted compound during the production, or may be added after the production.

[0036] ·Compound (x2) The compound (x2) that can be used when producing the polymer microparticles (X) preferably contains at least one selected from the group consisting of polyol compounds, polyamine compounds, and latent polyamine compounds (specifically, for example, in the case of polymer microparticles 1 to 3, 5, and 6 described later).

[0037] Polyol compounds In one preferred embodiment, the polyol compound as the compound (x2) has a molecular weight of 3,000 or less, from the viewpoint of more efficient production of the polymer fine particles (X). Examples of polyol compounds having a molecular weight of 3,000 or less include low molecular weight polyols such as butanediol, 1,6-hexanediol, 3-methyl-1,5-pentanediol, 1,9-nonanediol, glycerin, trimethylolpropane, and triethanolamine; polyisoprene polyol, polybutadiene polyol, polyacrylic polyol, and polycarbonate polyol (specifically, for example, in the case of polymer microparticles 1 to 3 described later). When the polyol compound as compound (x2) is a polymer polyol (for example, the above-mentioned polyisoprene polyol, etc.), the molecular weight of the polymer polyol can be a number average molecular weight.

[0038] Polyamine compounds The polyamine compound (x2) that can be used to produce the polymer microparticles (X) is a compound having multiple amino groups (NH2) per molecule. Examples of the polyamine compound include the polyamine compound (b2) used as the curing agent in the narrow sense (specifically, for example, in the case of the polymer microparticles 5 and 6 described below).

[0039] Latent polyamine compounds The latent polyamine compound (x2) that can be used in producing the polymer microparticles (X) is a compound having multiple latent amino groups. Examples of the latent amino groups include oxazolidine rings. Examples of the latent polyamine compound include oxazolidine compounds represented by the following formula (1): [ka] In formula (1), R 1 represents a hydrocarbon group, and R 2 represents a linking group having a valence of m+n, where m is an integer of 1 to 6, and n is an integer of 0 to 4.

[0040] In the above formula (1), R 1 represents a hydrocarbon group. Examples of the hydrocarbon group include an aliphatic hydrocarbon group (linear, branched, or cyclic), an aromatic hydrocarbon group, or a combination thereof. From the viewpoint of achieving better effects of the present invention, the hydrocarbon group is preferably an aliphatic hydrocarbon group, more preferably an aliphatic hydrocarbon group having 5 to 15 carbon atoms.

[0041] In formula (1), R 2 represents a linking group having a valence of m+n. Examples of the linking group include hydrocarbon groups. Examples of the hydrocarbon group include aliphatic hydrocarbon groups (linear, branched, or cyclic), aromatic hydrocarbon groups, or combinations thereof. The hydrocarbon group may have a heteroatom such as an oxygen atom, a nitrogen atom, or a sulfur atom. Examples of the linking group include aromatic aliphatic groups such as xylene.

[0042] In formula (1), m is an integer of 1 to 6. In particular, an integer of 2 to 3 is preferred in terms of curability and physical properties of the cured product. In formula (1), n ​​is an integer of 0 to 4. In particular, an integer of 0 to 1 is preferred in terms of curability.

[0043] The oxazolidine compound includes, for example, a compound represented by the following formula (IV). [ka]

[0044] (crosslinking points are ester bonds and / or amide bonds) In addition, from the viewpoint of achieving a more excellent effect of the present invention, one preferred embodiment of the polymer microparticles (X) is one that contains a polymer obtained by reacting a maleic anhydride-modified oligomer (x3) with at least one compound (x4) selected from the group consisting of polyol compounds, polyamine compounds, and latent polyamine compounds (specifically, for example, in the case of polymer microparticles 4 and 7 described later).

[0045] Maleic anhydride modified oligomer (x3) The maleic anhydride-modified oligomer (x3) that can be used to produce the polymer microparticles (X) is an oligomer having a maleic anhydride group. The skeleton of the maleic anhydride-modified oligomer (x3) can be, for example, a conjugated diene rubber. Examples of the conjugated diene rubber include polybutadiene and polyisoprene.

[0046] ·Compound (x4) The compound (x4) that can be used in producing the polymer fine particles (X) is the same as the compound (x2) described above. Because the compound (x4) has high reactivity with the maleic anhydride-modified oligomer (x3), it preferably contains at least one selected from the group consisting of polyamine compounds and latent polyamine compounds, and more preferably contains a latent polyamine compound.

[0047] <Content of polymer particles (X)> In the present invention, the content of the polymer fine particles (X) is 5% by mass or more based on the total amount of the composition of the present invention. The content of the polymer fine particles (X) is preferably 5 to 30 mass %, more preferably 10 to 20 mass %, of the total amount of the composition of the present invention, from the viewpoint of achieving better effects of the present invention. The content of the polymer fine particles (X) does not include the amount of a medium, which will be described later, that may be used when producing the polymer fine particles (X).

[0048] (Method for producing polymer microparticles (X)) Examples of methods for producing polymer microparticles (X) include a method in which a crosslinkable oligomer or a crosslinkable polymer (the crosslinkable oligomer or the crosslinkable polymer is the raw material for polymer microparticles (X)) is crosslinked in at least one medium selected from the group consisting of water, an organic solvent, an oligomer, and a polymer to form polymer microparticles.

[0049] Cross-linkable oligomer or cross-linkable polymer (raw material for polymer particles (X)) The crosslinkable oligomer as a raw material of the polymer fine particles (X), which can be used when producing the polymer fine particles (X), is an oligomer having crosslinkability. The crosslinkable polymer as a raw material of the polymer fine particles (X) is a polymer having crosslinkability (excluding the above-mentioned crosslinkable oligomers).

[0050] Examples of crosslinkable oligomers as raw materials for the polymer particles (X) include urethane prepolymers as polyisocyanate compounds (x1) (e.g., the urethane prepolymers used in the production of polymer particles 1-3, 5, and 6 described below). Specific examples of the urethane prepolymers include urethane prepolymer (a1). Examples of crosslinkable polymers used as raw materials for the polymer microparticles (X) include maleic anhydride-modified oligomers (x3), and specific examples thereof include maleic anhydride-modified polybutadiene (e.g., the maleic anhydride-modified polybutadiene used in the production of polymer microparticles 4 and 7 described below).

[0051] Crosslinking The crosslinking of the crosslinkable oligomer in the medium may be either a case where the crosslinkable oligomers crosslink with each other or a case where the crosslinkable oligomers crosslink via a crosslinking agent. The same applies to crosslinking of the crosslinkable polymer in the above medium. Examples of the crosslinking agent include the above-mentioned compound (x2) and compound (x4).

[0052] The polymer microparticles (X) can be produced by reacting a mixture containing a crosslinkable oligomer or crosslinkable polymer, the medium, and a crosslinking agent that can be used as needed, for example, under conditions of 20 to 40°C while stirring.

[0053] ·Medium The medium that can be used when producing the polymer fine particles (X) includes at least one selected from the group consisting of water, organic solvents, oligomers, and polymers. The medium can serve as a dispersion medium for dispersing the polymer fine particles (X) after the polymer fine particles (X) are produced. From the viewpoint of achieving superior effects of the present invention and efficiently producing polymer fine particles (X), the medium preferably contains an oligomer and / or a polymer, more preferably an oligomer. Examples of oligomers used as the medium include urethane prepolymers and polyoxyalkylene polyols. The medium used in producing the polymer microparticles (X) can be used to disperse the polymer microparticles (X) after production. Alternatively, after producing the polymer microparticles (X) in the presence of a medium, the medium containing the polymer microparticles (X) may be further reacted, and the polymer microparticles (X) may be dispersed in the reacted medium. In the present invention, the term "medium" refers to a medium used when producing the polymer microparticles (X), or a medium (dispersion medium) in which the polymer microparticles (X) are dispersed after production of the polymer microparticles (X). The medium is preferably liquid at room temperature (23°C).

[0054] Oligomers as carriers When the base component (A) contains polymer microparticles (X), the oligomer medium preferably contains a urethane prepolymer, from the viewpoint of achieving better effects of the present invention and efficiently producing the polymer microparticles (X). Examples of urethane prepolymers used as the medium include those similar to the urethane prepolymer (a1) described above. Furthermore, when the polyol compound (a3) ​​described above is used as the medium in producing the polymer microparticles (X), after the polymer microparticles (X) are formed, the polymer microparticles (X) are dispersed in the polyol compound (a3). Further, the polyisocyanate compound (a2) may be added to the medium to react the polyisocyanate compound (a2) with the polyol compound (a3) ​​to form the urethane prepolymer as the final medium. In the above case, the polymer microparticles (X) can be dispersed in the urethane prepolymer as the final medium. Furthermore, when the main component (A) contains a urethane prepolymer as a medium together with the polymer fine particles (X), a part or all of the urethane prepolymer (a1) contained in the main component (A) may be the urethane prepolymer as the medium. When the main component (A) contains a urethane prepolymer as a medium together with the polymer microparticles (X) and a portion of the urethane prepolymer (a1) is the urethane prepolymer as the medium, a separate urethane prepolymer may be added later to the mixture of the polymer microparticles (X) and the urethane prepolymer as the medium.

[0055] On the other hand, when the curing agent (B) contains polymer fine particles (X), the oligomer medium preferably contains a polyoxyalkylene polyol, more preferably a polyoxypropylene polyol and / or polytetramethylene glycol, from the viewpoint of achieving better effects of the present invention and enabling efficient production of polymer fine particles (X). The above-mentioned polyoxypropylene polyol regarding the oligomer medium includes the concept of polyoxyethylene polyoxypropylene polyol. In addition, when the curing agent (B) contains a polyoxyalkylene polyol as a medium together with the polymer fine particles (X), a part or all of the polyol compound (b1) that the curing agent (B) may contain may be the polyoxyalkylene polyol as the medium. In addition, when the curing agent (B) contains a polyoxyalkylene polyol as a medium together with the polymer fine particles (X), and a part of the polyol compound (b1) that the curing agent (B) may contain is the polyoxyalkylene polyol as the medium, the polyoxyalkylene polyol may be added separately to the mixture of the polymer fine particles (X) and the polyoxyalkylene polyol as the medium afterwards.

[0056] In the combination of the medium and the raw materials for the polymer microparticles (X) when producing the polymer microparticles (X), it is preferable that the oligomer or polymer used as the medium is a compound different from the above-mentioned crosslinkable oligomer and crosslinkable polymer and crosslinking agent (compound (x2) and compound (x4)) used as the raw materials for the polymer microparticles (X). When the base component (A) contains polymer microparticles (X) and the polymer microparticles (X) are accompanied by a medium, the medium used to produce the polymer microparticles (X) preferably contains an oligomer (polyoxyalkylene polyol) such as polytetramethylene glycol, from the viewpoint of excellent miscibility with the base component (A) and storage stability. The weight-average molecular weight of the oligomer is preferably less than 10,000. As described above, a polyisocyanate compound (a2) may be further added to the polyol compound (a3) ​​in which the polymer microparticles (X) are dispersed, and the polyisocyanate compound (a2) and the polyol compound (a3) ​​are reacted to form a urethane prepolymer as the final medium, and the urethane prepolymer may be used as the urethane prepolymer (a1). When the curing agent (B) contains polymer particles (X) and the polymer particles (X) are accompanied by a medium, the medium used in producing the polymer particles (X) preferably contains an oligomer (polyoxyalkylene polyol) such as polyoxypropylene diol, from the viewpoint of excellent miscibility with the curing agent (B) and storage stability. The weight-average molecular weight of the oligomer is preferably less than 10,000.

[0057] When the polymer fine particles (X) are accompanied by a medium, the amount of the medium is preferably 70 to 400 parts by mass, more preferably 100 to 400 parts by mass, per 100 parts by mass of the polymer fine particles (X), from the viewpoint of achieving better effects of the present invention and excellent storage stability.

[0058] <Loss tangent of the hardened material (P)> In the present invention, the loss tangent of the cured product (P) obtained by curing the composition of the present invention is 0.15 or more under conditions of a temperature range of -40°C to +80°C and a frequency of 100 Hz (hereinafter, these may be referred to as "under specific conditions"). In other words, the minimum value of the loss tangent of the cured product (P) measured under a frequency condition of 100 Hz is 0.15 or more in the temperature range of -40°C to +80°C. The present invention provides excellent damping properties when the loss tangent of the cured product (P) is 0.15 or more under the above-mentioned specific conditions. The higher the loss tangent of the cured product (P), the better the damping properties. The loss tangent (minimum value) of the cured product (P) in the temperature range of -40°C to +80°C is preferably 0.2 or more under the above-mentioned specific conditions, from the viewpoint of achieving better effects of the present invention.

[0059] The maximum value of the loss tangent of the cured product (P) measured under the above-mentioned specific conditions is not particularly limited, but from the viewpoint of achieving better effects of the present invention and maintaining excellent elongation at break, etc., it is preferably 0.3 or more.

[0060] <Tension-shear fatigue property test of cured material (P)> In the present invention, the cured product (P) obtained by curing the composition of the present invention has a fatigue strength of 100% at a stress amplitude of 2.8 MPa in a tensile shear fatigue property test in accordance with JIS K6864. 7 It will not break (it can withstand up to 1000 repetitions without breaking). In the present invention, the cured product (P) is subjected to the above-mentioned tensile shear fatigue property test at a stress amplitude of 2.8 MPa and a tensile shear fatigue property of 10 7 In the present invention, if the specimen does not break after the first cycle, it is judged that the specimen has excellent fatigue durability. 7 The tensile shear fatigue property test was carried out at cycles up to 1000 cycles, and the fatigue durability was evaluated as being better when the stress amplitude at which the cured product (P) first broke was greater than 2.8 MPa.

[0061] (Elongation at break of cured product (P)) The elongation at break of the cured product (P) obtained by curing the composition of the present invention is preferably 50% or more, more preferably 100 to 1000%, from the viewpoint of superior fatigue durability.

[0062] (Aspects of the cured product (P)) The cured product (P) obtained by curing the composition of the present invention can have the polymer fine particles (X) and a matrix remaining in the composition of the present invention excluding the polymer fine particles (X). The portion of the composition of the present invention excluding only the polymer fine particles (X) may be referred to as a "matrix" (hereinafter the same). In the present invention, when the polymer fine particles (X) are used as a mixture with the above-mentioned medium, the remainder of the composition of the present invention excluding the polymer fine particles (X) and the above-mentioned medium may be referred to as the "balance" (the same applies hereinafter).

[0063] The cured product (P) obtained by curing the composition of the present invention will be described below with reference to the accompanying drawings, although the present invention is not limited to the accompanying drawings. FIG. 1 is a schematic diagram showing an example of a cross section of a cured product (P) obtained by curing the two-component curing adhesive composition of the present invention. In FIG. 1, a cured product (P) 10 of the two-component curing adhesive composition of the present invention comprises polymer fine particles (X) 14 and a cured product 12 of the matrix remaining in the composition of the present invention without the polymer fine particles (X).

[0064] The present inventors have conceived the idea that the cured product (P) comprises polymer microparticles (X) and a matrix (the portion other than the polymer microparticles (X)), and that by imparting fatigue durability or damping property to both, it is possible to achieve both fatigue durability and damping property, which are in a trade-off relationship, in the cured product (P). That is, when the polymer fine particles (X) are mainly responsible for damping properties, the matrix is ​​mainly responsible for fatigue durability, and when the polymer fine particles (X) are mainly responsible for fatigue durability, the matrix is ​​mainly responsible for damping properties.

[0065] As described above, by having the polymer fine particles (X) and the matrix which have different functions, the composition of the present invention can achieve both high fatigue durability and high damping properties as a whole. In this specification, the case where the polymer microparticles (X) are mainly responsible for damping properties and the matrix is ​​mainly responsible for fatigue durability is sometimes referred to as "Method 1," and the case where the polymer microparticles (X) are mainly responsible for fatigue durability and the matrix is ​​mainly responsible for damping properties is sometimes referred to as "Method 2." As an embodiment of the cured product (P), Method 1 is preferred from the viewpoint of obtaining better effects of the present invention.

[0066] The present inventors have also found that it is preferable that the cured product (P) has a fatigue resistance portion having a tensile modulus of 5 MPa or more, and a damping property portion having a minimum loss tangent of 0.05 or more under the above-mentioned specific conditions. In the above case, the cured product of the portion having fatigue resistance has a loss tangent under the above-mentioned specific conditions, and the minimum value thereof is preferably less than 0.15.Furthermore, the cured product of the portion having damping properties usually has a tensile modulus of elasticity of less than 5 MPa.

[0067] In order to make the tensile modulus of the cured product of the portion of the cured product (P) that has fatigue resistance (the matrix or the remaining cured product in Method 1, or the polymer microparticles (X) in Method 2) 5 MPa or more, for example, the index when producing the urethane prepolymer (a1) in Method 1 must be 3.5 or more; the hydrocarbon group constituting the polyol compound (a3) ​​used when producing the urethane prepolymer (a1) in Method 1 or the urethane prepolymer that is the raw material for the polymer microparticles (X) in Method 2 must be linear (e.g., polyoxyethylene polyol, PTMG); or a compound having three or more active hydrogens must be used as a curing agent in the narrow sense in the curing agent (B) (however, it is preferable to use a larger amount of the above compound in the matrix in Method 1 than in Method 2).

[0068] The minimum value of the loss tangent of the cured product of the damping portion of the cured product (P) (the polymer microparticles (X) in Method 1, or the cured product of the matrix or the remainder in Method 2) under the above-mentioned specific conditions is preferably 0.05 or more, and more preferably 0.15 or more, from the viewpoint of achieving better effects of the present invention. In order to make the minimum loss tangent of the damping portion of the cured product (P) 0.05 or more (more preferably 0.15 or more) under the above-mentioned specific conditions, for example, the index when producing the urethane prepolymer (a1) in Method 2 is 3.0 or less; the hydrocarbon group constituting the polyol compound (a3) ​​used when producing the urethane prepolymer (a1) in Method 2 or the urethane prepolymer that is the raw material for the polymer microparticles (X) in Method 1 is branched (for example, polyoxypropylene polyol, polyisoprene polyol); or a compound having two or less active hydrogens is used as a curing agent in the strict sense in the curing agent (B) (however, it is preferable to use a smaller amount of the above compound in the matrix in Method 2 than in Method 1).

[0069] ·Method 1 When the polymer microparticles (X) are primarily responsible for damping properties and the matrix is ​​primarily responsible for fatigue durability in the cured product (P) of the composition of the present invention (Method 1), from the viewpoint of achieving superior effects of the present invention, it is preferable that the cured product (M) obtained by curing the matrix excluding the polymer microparticles (X) from the composition of the present invention (when the polymer microparticles (X) are accompanied by a medium, the portion of the composition of the present invention excluding the polymer microparticles (X) and the medium) has a tensile modulus of 5 MPa or more, and that the polymer microparticles (X) have a minimum loss tangent of 0.05 or more, measured under conditions of a temperature range of -40°C to +80°C and a frequency of 100 Hz.

[0070] Loss tangent of polymer particles (X) in Method 1 Minimum loss tangent In Method 1, from the viewpoint of achieving better effects of the present invention, the minimum value of the loss tangent of the polymer fine particles (X) is preferably 0.05 or more, more preferably 0.15 or more, and even more preferably 0.2 or more under the above-mentioned specific conditions.

[0071] Maximum loss tangent In Method 1, from the viewpoint of achieving better effects of the present invention, the maximum value of the loss tangent of the polymer fine particles (X) is preferably 0.3 or more, more preferably 0.5 or more, and even more preferably 0.8 or more under the above-mentioned specific conditions. In Method 1, the upper limit of the loss tangent of the polymer microparticles (X) under the above-mentioned specific conditions is not particularly limited, but from the viewpoint of achieving better effects of the present invention and maintaining excellent elongation at break, it is preferably 2.0 or less, and more preferably 1.5 or less.

[0072] Tensile modulus of polymer particles (X) in Method 1 In Method 1, the tensile modulus of the polymer fine particles (X) is preferably 0.5 to 50 MPa, from the viewpoint of achieving better effects of the present invention.

[0073] Example of polymer particles (X) in Method 1 The polymer fine particles (X) in Method 1 are not particularly limited, as long as they are, for example, a reaction product of a polyisocyanate compound (x1) or a maleic anhydride-modified oligomer (x3) with a compound (x2), and the minimum loss tangent of the reaction product is 0.05 or more under the above-mentioned specific conditions, and the glass transition temperature of the reaction product is −40° C. to +80° C. Examples of the urethane prepolymer as the polyisocyanate compound (x1) include a reaction product of an aromatic polyisocyanate such as MDI with at least one polyol selected from the group consisting of polyoxyalkylene polyols (e.g., polyoxypropylene polyols, polyoxyethylene polyols, polytetramethylene ether glycols), polycarbonate polyols, and polyisoprene polyols. The maleic anhydride-modified oligomer (x3) is the same as above. The maleic anhydride-modified oligomer (x3) preferably contains maleic anhydride-modified polybutadiene. The compound (x2) is the same as above. One preferred embodiment involves reacting the polyisocyanate compound (x1) with a polyol compound as the compound (x2) to form the polymer microparticles (X) of Method 1. The polyol compound preferably contains a low-molecular-weight polyol such as butanediol. Furthermore, when polymer microparticles (X) of Method 1 are formed by reacting a polyamine compound as compound (x2) with a polyisocyanate compound (x1), the molar index of the isocyanate groups in (x1) relative to the amino groups (NH groups) in the polyamine compound may be adjusted so that the minimum loss tangent of the resulting polymer microparticles (X) is 0.05 or more under the above-mentioned specific conditions and the glass transition temperature is −40°C to +80°C. When the polymer microparticles (X) of Method 1 are formed by reacting the maleic anhydride-modified oligomer (x3) with a latent polyamine as the compound (x2), the molar index of the maleic anhydride groups in (x3) relative to the amino groups (NH groups) in the latent polyamine compound may be adjusted so that the minimum loss tangent and the glass transition temperature of the resulting polymer microparticles (X) fall within the above-mentioned ranges.

[0074] Tensile modulus of cured product (M) obtained by Method 1 In Method 1, from the viewpoint of achieving a more excellent effect of the present invention, the tensile modulus of the cured product (M) obtained by curing the matrix obtained by excluding the polymer fine particles (X) from the composition of the present invention (or the remainder obtained by excluding the polymer fine particles (X) and the medium from the composition of the present invention) is preferably 5 MPa or more, more preferably 100 to 250 MPa.

[0075] Loss tangent of the cured product (M) in Method 1 In Method 1, the loss tangent of the cured product (M) is preferably within a range of 0.05 to 0.2, and more preferably within a range of 0.05 or more and less than 0.15, under the above-mentioned specific conditions, from the viewpoint of achieving better effects of the present invention.

[0076] Example of cured product (M) from Method 1 In Method 1, from the viewpoint of achieving a more excellent effect of the present invention and enabling the tensile modulus of elasticity of the cured product (M) to be 5 MPa or more, the urethane prepolymer (a1) is obtained by reacting a polyisocyanate compound (a2) with a polyol compound (a3) ​​in such a manner that the equivalent ratio (NCO / OH) of the isocyanate groups in the polyisocyanate compound (a2) to the hydroxyl groups in the polyol compound (a3) ​​is 1.5 to 14; the curing agent (B) contains a polyol compound (b1) and a polyamine compound (b2), the equivalent ratio of the isocyanate group in the main component (A) to the active hydrogen-containing group in the curing agent (B) is 0.8 to 4; The equivalent ratio of the isocyanate groups in the main component (A) to the amino groups in the polyamine compound (b2) is preferably 1.2-6. In the above, when the polymer fine particles (X) are accompanied by a polyol as a medium and the polymer fine particles (X) and the medium are added to the curing agent (B), the amount of active hydrogen-containing groups in the polyol as the medium is added to the amount of active hydrogen-containing groups in the curing agent (B) (the same applies below, and also in Method 2).

[0077] (Preferred embodiment of the cured product (M) obtained by Method 1) The equivalent ratio (NCO / OH) when producing the urethane prepolymer (a1) is preferably 3 to 14, more preferably 4 to 10, from the viewpoint of achieving better effects of the present invention. The equivalent ratio of the isocyanate groups in the main component (A) to the active hydrogen-containing groups in the curing agent (B) is preferably 0.5 to 4, from the viewpoint of achieving better effects of the present invention. The equivalent ratio of the isocyanate groups in the main component (A) to the amino groups in the polyamine compound (b2) is preferably 0.8 to 4, from the viewpoint of achieving better effects of the present invention.

[0078] In Method 1, the polyol compound (a3) ​​that can be used in producing the urethane prepolymer (a1) preferably contains at least one selected from polyester polyol, polytetramethylene ether glycol, polycarbonate polyol, polycaprolactone polyol, and partially modified products of each of these, from the viewpoint of achieving better effects of the present invention and enabling the cured product (M) to have a tensile modulus of elasticity of 5 MPa or more. The modification of the polyol compound (a3) ​​may be, for example, the introduction of a functional group such as a methyl group.

[0079] ·Method 2 In the cured product (P) of the composition of the present invention, when the polymer microparticles (X) are primarily responsible for fatigue durability and the matrix is ​​primarily responsible for damping properties (Method 2), from the viewpoint of achieving superior effects of the present invention, it is preferable that the cured product (N) obtained by curing the remainder of the composition of the present invention excluding the polymer microparticles (X) has a minimum loss tangent of 0.05 or more measured under conditions of a temperature range of -40°C to +80°C and a frequency of 100 Hz, and that the tensile modulus of the polymer microparticles (X) is 5 MPa or more.

[0080] Loss tangent of the cured product (N) in Method 2 Minimum loss tangent In Method 2, from the viewpoint of achieving a more excellent effect of the present invention, the minimum value of the loss tangent of the cured product (N) obtained by curing the matrix obtained by excluding the polymer fine particles (X) from the composition of the present invention (or the remainder obtained by excluding the polymer fine particles (X) and the medium from the composition of the present invention) under the above-mentioned specific conditions is preferably 0.05 or more, more preferably 0.1 or more, and even more preferably 0.2 or more.

[0081] Maximum loss tangent In Method 2, from the viewpoint of achieving better effects of the present invention, the maximum value of the loss tangent of the cured product (N) is preferably 0.3 or more, more preferably 0.5 or more, and even more preferably 0.6 or more under the above-mentioned specific conditions. In Method 2, the upper limit of the loss tangent of the cured product (N) under the above-mentioned specific conditions is not particularly limited, but from the viewpoint of achieving better effects of the present invention and maintaining excellent elongation at break, it is preferably 2.0 or less, and more preferably 1.0 or less. As mentioned above, when the polymer fine particles (X) are used as a mixture with the medium, the remainder is the composition of the present invention excluding the polymer fine particles (X) and the medium.

[0082] Tensile modulus of cured product (N) obtained by Method 2 In Method 2, the tensile modulus of the cured product (N) is preferably 0.5 to 50 MPa, from the viewpoint of achieving better effects of the present invention.

[0083] Tensile modulus of polymer particles (X) in Method 2 In Method 2, the tensile modulus of the polymer fine particles (X) is preferably 5 MPa or more, more preferably 70 to 300 MPa, and even more preferably 100 to 250 MPa, from the viewpoint of achieving better effects of the present invention.

[0084] ·· Loss tangent of polymer particles (X) in Method 2 In Method 2, the loss tangent of the polymer fine particles (X) is preferably within a range of 0.05 to 0.4, and more preferably within a range of 0.1 or more and less than 0.15, under the above-mentioned specific conditions, from the viewpoint of achieving better effects of the present invention.

[0085] Example of cured product (N) from Method 2 In Method 2, from the viewpoint of achieving a more excellent effect of the present invention and making the minimum value of the loss tangent of the cured product (N) 0.05 or more (more preferably 0.1 or more), the urethane prepolymer (a1) is obtained by reacting a polyisocyanate compound (a2) with a polyol compound (a3) ​​in an equivalent ratio of isocyanate groups in the polyisocyanate compound (a2) to hydroxyl groups in the polyol compound (a3) ​​of 1.5 to 2.5; the curing agent (B) contains a polyol compound (b1) and a polyamine compound (b2), the equivalent ratio of the isocyanate group in the main component (A) to the active hydrogen-containing group in the curing agent (B) is 0.8 to 4; The equivalent ratio of the isocyanate groups in the main component (A) to the amino groups in the polyamine compound (b2) is preferably 1.5 to 8.0.

[0086] (Preferred embodiment of cured product (N) in method 2) The equivalent ratio of the isocyanate groups in the main component (A) to the active hydrogen-containing groups in the curing agent (B) is preferably 0.5 to 4, from the viewpoint of achieving better effects of the present invention. The equivalent ratio of the isocyanate groups in the main component (A) to the amino groups in the polyamine compound (b2) is preferably 2 to 8, from the viewpoint of achieving better effects of the present invention.

[0087] In Method 2, the polyol compound (a3) ​​preferably contains at least one selected from polyoxypropylene glycol, polybutadiene polyol, polyisoprene polyol, polyacrylic polyol, and partially modified products of each of these. The modification of the polyol compound (a3) ​​may be, for example, the introduction of a functional group such as a methyl group.

[0088] (additives) The composition of the present invention may further contain additives. Examples of additives include fillers such as carbon black, calcium carbonate, and silica, plasticizers, and antioxidants. The type and content of the additives can be appropriately selected. It can be appropriately selected whether the main component (A) or the curing agent (B) contains each additive.

[0089] (Manufacturing method) The composition of the present invention can be produced, for example, by preparing a mixture of urethane prepolymer (a1) and additives that can be used as needed as a main component (A), and by preparing a mixture of a curing agent in the narrow sense and additives that can be used as needed as a curing agent (B), and adding polymer fine particles (X) to at least one of the main component (A) and the curing agent (B) during the preparation.

[0090] When polymer fine particles (X) are added to the main component (A), the polymer fine particles (X) are preferably a mixture with a urethane prepolymer (as a medium). The polymer fine particles (X) preferably have an isocyanate group.

[0091] When the polymer fine particles (X) are added to the curing agent (B), the polymer fine particles (X) are preferably a mixture with a polyoxyalkylene polyol such as polypropylene glycol (as a medium).

[0092] (How to use) The composition of the present invention can be prepared by mixing the main component (A) and the curing agent (B). (Application) The composition of the present invention can be used as an adhesive. Examples of substrates to which the composition of the present invention can be applied include metals, plastics, rubber, and glass. When a first substrate and a second substrate are bonded using the composition of the present invention, one or both of the first substrate and the second substrate is preferably a metal. The composition of the present invention can be used, for example, as an adhesive for automobiles or an adhesive for earthquake resistance. [Example]

[0093] The present invention will be specifically described below with reference to examples, but the present invention is not limited to these examples.

[0094] <<Synthesis of urethane prepolymer>> <Synthesis of urethane prepolymer 1> 100 g of polytetramethylene ether glycol (PTMG1000 (weight average molecular weight 1000, OH2 functionality), manufactured by Mitsubishi Chemical Corporation; the same applies below) and 100 g of 4,4'-diphenylmethane diisocyanate (index 4.0) were stirred and reacted at 80°C for 4 hours under a nitrogen atmosphere to synthesize urethane prepolymer 1. The index for producing the urethane prepolymer is the equivalent ratio (molar ratio) of NCO groups in the polyisocyanate compound (a2) to OH groups in the polyol compound (a3) ​​(the same applies hereinafter).

[0095] <Synthesis of urethane prepolymer 2> 100 g of polytetramethylene ether glycol and 150 g of 4,4'-diphenylmethane diisocyanate (index 6.0) were reacted with stirring at 80°C for 4 hours in a nitrogen atmosphere to synthesize urethane prepolymer 2.

[0096] <Synthesis of urethane prepolymer 3> 100 g of polycarbonate diol (Duranol T6001 (weight average molecular weight 1000), manufactured by Asahi Kasei Corporation, OH2 functionality) and 50 g of 4,4'-diphenylmethane diisocyanate (index 2.0) were stirred and reacted under a nitrogen atmosphere at 80°C for 4 hours to synthesize urethane prepolymer 3.

[0097] <Synthesis of urethane prepolymer 4> 100 g of polyoxypropylene glycol (Sannyx FA-921 (hydroxyl value 27.9 mg / KOHg), OH2 functionality, manufactured by Sanyo Chemical Industries, Ltd.) and 16 g of 4,4'-diphenylmethane diisocyanate (index 2.5) were reacted with stirring under a nitrogen atmosphere at 80°C for 4 hours to synthesize urethane prepolymer 4.

[0098] <Synthesis of urethane prepolymer 5> 100 g of polyisoprene polyol (Poly ip (number average molecular weight 2500, OH2 functionality), manufactured by Idemitsu Kosan Co., Ltd.) and 14 g of 4,4'-diphenylmethane diisocyanate (index 2.0) were stirred and reacted at 80°C for 4 hours under a nitrogen atmosphere to synthesize urethane prepolymer 5.

[0099] <<Synthesis of polymer particles (X)>> <Synthesis of polymer particle 1> 151 g of urethane prepolymer 3 and 5 g of 1,4-butanediol were stirred in 311 g of polyoxypropylene glycol (Sannyx GL-3000, manufactured by Sanyo Chemical Industries, Ltd., OH trifunctionality, hereinafter the same) as a medium under a nitrogen atmosphere at room temperature (23°C, hereinafter the same) for 3 hours to cause a crosslinking reaction, synthesizing polymer microparticles 1 dispersed in polyoxypropylene glycol. The index (molar ratio of NCO groups to OH groups) of the raw material was 0.52. The OH groups in this index are the sum of the OH groups in the medium and 1,4-butanediol (the same applies to the synthesis of polymer microparticles below). The crosslinks resulting from the crosslinking reaction have urethane bonds. The average particle size of the polymer microparticles 1 was 10 μm, and the concentration of the polymer microparticles 1 in the dispersion (total of the polymer microparticles 1 dispersed in polyoxypropylene glycol) was 56% by mass. The glass transition temperature of the polymer microparticles 1 was +40°C. Theoretically, the polymer microparticles 1 have hydroxyl groups as active hydrogen-containing groups. The medium (polyoxypropylene glycol) in the dispersion was liquid at 23°C.

[0100] <Synthesis of polymer particle 2> 119 g of urethane prepolymer 4 and 3 g of 1,4-butanediol were stirred in 183 g of polyoxypropylene glycol (Sanix GL-3000) as a medium for 3 hours at room temperature under a nitrogen atmosphere to cause a crosslinking reaction, synthesizing polymer microparticles 2 dispersed in polyoxypropylene glycol. The index (molar ratio of NCO groups to OH groups) of the raw materials was 0.32. The crosslinking points resulting from the crosslinking reaction contain urethane bonds. The average particle size of the polymer microparticles 2 was 2 μm, and the concentration of the polymer microparticles 2 in the dispersion was 46% by mass. The glass transition temperature of the polymer microparticles 2 was −30° C. Theoretically, the polymer microparticles 2 have hydroxyl groups as active hydrogen-containing groups. The medium (polyoxypropylene glycol) in the dispersion was liquid at 23° C.

[0101] <Synthesis of polymer particle 3> 125 g of urethane prepolymer 5 and 5 g of 1,4-butanediol were stirred in 260 g of polyoxypropylene glycol (Sannix GL-3000) as a medium for 3 hours at room temperature under a nitrogen atmosphere to cause a crosslinking reaction, synthesizing polymer microparticles 3 dispersed in polyoxypropylene glycol. The index (molar ratio of NCO groups to OH groups) of the raw materials was 0.34. The crosslinking points resulting from the crosslinking reaction contain urethane bonds. The polymer microparticles 3 had an average particle size of 5 μm, and the concentration of polymer microparticles 3 in the dispersion was 40% by mass. The glass transition temperature of polymer microparticles 3 was −20° C. Theoretically, polymer microparticles 3 have hydroxyl groups as active hydrogen-containing groups. The medium (polyoxypropylene glycol) in the dispersion was liquid at 23° C.

[0102] <Synthesis of polymer particle 4> In 80 g of polyoxypropylene glycol (Sannix GL-3000) as a medium, 40 g of maleic anhydride-modified polybutadiene (POLYVEST OC800S, Evonik) and 2 g of an oxazolidine compound having the following structure (3-(2-hydroxyethyl)-2-(1-methylbutyl)oxazolidine (5BO, Toyo Gosei) and xylylene diisocyanate (XDI) in a 2:1 molar ratio. Moisture in the air hydrolyzes the oxazolidine ring, producing a diamine with two amino groups (-NH2) derived from the hydrolysis. The same applies below.) were stirred at room temperature under atmospheric pressure for 3 hours to crosslink the compound, synthesizing polymer microparticles 4 dispersed in polyoxypropylene glycol. The molar ratio of maleic anhydride groups to NH2 groups in the raw materials was 1.0. The crosslinks resulting from the crosslinking reaction have amide bonds. The average particle size of the polymer microparticles 4 was 10 μm, and the concentration of the polymer microparticles 4 in the dispersion was 34% by mass. The glass transition temperature of the polymer microparticles 4 was −30° C. The medium (polyoxypropylene glycol) in the dispersion was liquid at 23° C.

[0103] [ka]

[0104] <Synthesis of polymer particle 5> 250 g of urethane prepolymer 2 and 80 g of DETDA (diethylmethylbenzenediamine) were stirred in 600 g of polyoxypropylene glycol (Sannix GL-3000) as a medium for 3 hours at room temperature under a nitrogen atmosphere to cause a crosslinking reaction, synthesizing polymer microparticles 5 dispersed in polyoxypropylene glycol. The index of the raw material [molar ratio of NCO groups to (OH + NH2 groups)] was 0.65. The crosslinking points resulting from the crosslinking reaction contain urethane bonds. The polymer fine particles 5 had an average particle size of 3 μm, a concentration of the polymer fine particles 5 in the dispersion of 40% by mass, and a glass transition temperature of −20° C. Theoretically, the polymer fine particles 5 have amino groups as active hydrogen-containing groups. In the polymer particles, the amino group as an active hydrogen-containing group refers to a group in which a hydrogen atom is bonded to a nitrogen atom, provided that the amino group does not include a urethane bond, a urea bond, or an amide bond (the same applies hereinafter). The medium (polyoxypropylene glycol) in the above dispersion was liquid at 23°C.

[0105] <Synthesis of polymer particle 6> Urethane prepolymer 2 (120 g) and 9 g of DETDA (diethylmethylbenzenediamine) were stirred in 150 g of polytetramethylene ether glycol (PTMG1000) as a medium under a nitrogen atmosphere at room temperature for 3 hours to allow for a crosslinking reaction (the raw material index [NCO group / (OH + NH2 group) molar ratio] was 0.2). The polytetramethylene ether glycol functioned as a medium for the reaction of urethane prepolymer 2 and DETDA. 150 g of 4,4'-diphenylmethane diisocyanate was added to the resulting mixture of urethane prepolymer 2 and DETDA and the polytetramethylene ether glycol. The mixture was stirred under a nitrogen atmosphere at 80°C for 4 hours to allow the reaction to proceed, ultimately synthesizing polymer microparticles 6 dispersed in the urethane prepolymer. The polymer fine particles 6 mainly contain a reaction product of the urethane prepolymer 2 and the DETDA as polymer fine particles. The crosslinked points formed by the reaction (crosslinking reaction) in the polymer fine particles 6 have a urea bond and / or a urethane bond. The polymer microparticles 6 were ultimately dispersed in a urethane prepolymer, and the final medium was primarily composed of a urethane prepolymer obtained by reacting the polytetramethylene ether glycol used in the crosslinking reaction with 150 g of 4,4'-diphenylmethane diisocyanate added after the crosslinking reaction. The final medium (urethane prepolymer) in the dispersion was liquid at 23°C. The polymer fine particles 6 had an average particle size of 8 μm, and the concentration of the polymer fine particles 6 in the dispersion was 28% by mass. The glass transition temperature of the polymer fine particles 6 was −20° C. Theoretically, the polymer fine particles 6 have isocyanate groups.

[0106] <Synthesis of polymer particles 7> In 292 g of polyoxypropylene glycol (Sanix GL-3000) as a medium, 100 g of maleic anhydride-modified polybutadiene (Ricon 130MA20, Mn 3600) and 46 g of the above oxazolidine compound were stirred and reacted at room temperature under atmospheric pressure for 3 hours to synthesize polymer microparticles 7 dispersed in polyoxypropylene glycol. The molar ratio of maleic anhydride groups to NH groups in the raw materials was 1.1. The crosslinking points resulting from the above crosslinking reaction have amide bonds. The average particle size of the polymer microparticles 7 was 10 μm, and the concentration of the polymer microparticles 7 in the dispersion was 33% by mass. The glass transition temperature of the polymer microparticles 7 was +10° C. The medium (polyoxypropylene glycol) in the dispersion was liquid at 23° C.

[0107] <<Production of Composition>> The main agent (A) was prepared by mixing the components in the compositions (parts by mass) shown in the main agent (A) columns of Tables 1 and 2 (hereinafter referred to as "each table") in the compositions shown in the tables with a stirrer under a nitrogen stream. The curing agents (B) of each example were also prepared in the same manner. In preparing the above base resin and curing agent, each of the polymer particles 1 to 7 was used in the form of a mixture with a medium. In the following tables, the columns for polymer particles 1 to 7 show the net amount of each polymer particle (amount excluding the medium). The content of polymer particles (X) in the total amount of the composition does not include the content of the medium that may be used in producing polymer particles (X). The "100 parts by mass" shown in the "Urethane prepolymer 1" column for the main component of Example 7 refers to 100 parts by mass of the urethane prepolymer used as a medium for dispersing the polymer microparticles 6 (39 parts by mass) after the production of the polymer microparticles 6. No urethane prepolymer was added to the main component of Example 7. The "Urethane prepolymer 1" column for Example 9 is the same as above. The "60 parts by mass" shown in the "Polyol 1" column for the curing agent (B) in Examples 1 to 6, 8, and 9 refers to the total amount of the medium accompanying the polymer fine particles (X) used in the curing agent (B) in each Example and the polyol 1 added later. The amount of polyol 1 added later in the curing agent (B) is as follows: (Amount of Polyol 1 added later in Curing Agent (B)) Example 1: 13 parts by weight Example 2: 1 part by weight Example 3: 0 parts by weight Example 4: 2 parts by weight Example 5: 0 parts by weight Example 6: 0 parts by weight Example 8: 13 parts by weight Example 9: 36 parts by weight

[0108] The main agent (A) and curing agent (B) of each example prepared as described above were mixed in a stirrer to produce a composition.

[0109] Equivalent ratio of isocyanate groups to active hydrogen-containing groups *1 The equivalent ratio of all isocyanate groups to all active hydrogen-containing groups (molar ratio of all isocyanate groups / total active hydrogen-containing groups) in the total amount of the mixture of the base agent (A) and the curing agent (B) (the composition of the present invention) is shown in the "Isocyanate group / active hydrogen-containing group equivalent ratio" column in each table. *1 " column. The amino group (a group in which a hydrogen atom is bonded to a nitrogen atom) that each polymer particle has as an active hydrogen-containing group does not include a urethane bond, a urea bond, or an amide bond (the same applies hereinafter). Furthermore, as described above, the molar ratio of maleic anhydride groups / NH groups when polymer fine particles 4 and 7 were produced was 1.0 or 1.1. Therefore, polymer fine particles 4 and 7 may theoretically have, as active hydrogen-containing groups, carboxylic acid anhydrides and / or amino groups derived from hydrolysis of oxazolidine rings. However, the carboxylic acid anhydrides and the amino groups that polymer fine particles 4 and 7 may have are determined based on the "isocyanate group / active hydrogen-containing group equivalent ratio." *1 "The equivalent ratio of isocyanate groups to amino groups" described later is not included in the "active hydrogen-containing groups" in "isocyanate groups / amino groups." *2 " and "Amino group / hydroxyl group equivalent ratio *3 The same applies to the "amino group" in ".

[0110] Isocyanate group / amino group equivalent ratio *2 The equivalent ratio of all isocyanate groups to all amino groups (molar ratio of all isocyanate groups / total amino groups) in the total amount of the mixture of base agent (A) and curing agent (B) (the composition of the present invention) is shown in the "Isocyanate group / amino group equivalent ratio" column in each table. *2 The total amino groups listed above include, for example, amino groups possessed by polyamines in each table.

[0111] Amino group / hydroxyl group equivalent ratio *3 The equivalent ratio of all amino groups to all hydroxyl groups (molar ratio of all amino groups / total hydroxyl groups) in the total amount of the mixture of the base agent (A) and the curing agent (B) (the composition of the present invention) is calculated by referring to the "Amino group / hydroxyl group equivalent ratio" in each table. *3 The total amino groups listed above include, for example, amino groups possessed by polyamines in each table.

[0112] <<Evaluation>> The compositions prepared as described above were subjected to the following evaluations, and the results are shown in the tables.

[0113] <Sample preparation> ·Cured product (P) As described above, each composition was left to stand for 7 days under conditions of 23°C and 55% RH (relative humidity) to cure, thereby obtaining a cured product (P) of the two-component curing adhesive composition (whole). Each of the cured products (P) obtained as described above was evaluated for tan δ, fatigue durability, and elongation at break, as described below.

[0114] ·Cured product (M), (N) The components in the column for base agent (A) in each example in the tables below were used in the compositions (parts by mass) shown in the tables and mixed in a stirrer under a nitrogen stream to prepare base agent (A). The curing agent (B) in each example was also prepared in the same manner. However, in preparing the base agent, polymer fine particles and the accompanying medium were not used. The same applies to curing agent (B). The above two-component curing adhesive compositions were mixed to prepare the remainder, excluding the polymer microparticles (X) and the accompanying medium. The remainder was cured by leaving it at 23°C and 55% RH (relative humidity) for 7 days, to obtain the cured product (M) or (N) of the remainder.

[0115] Polymer particles (X): Hardened material (H) In the synthesis of each of the polymer microparticles 1 to 7 described above, no medium is used, and the remaining components are left for 7 days under conditions of 23°C and 55% RH (relative humidity), and the cured product (H) obtained by curing the above components is treated as polymer microparticle (X).

[0116] <tanδ> For each of the cured products (P), (M), (N), and (H) obtained as described above, dynamic mechanical analysis was performed to measure tan δ by applying forced extensional vibration under conditions of a strain of 0.01%, a frequency of 100 Hz, and a temperature rise rate of 5°C / min in the temperature range from -40°C to +80°C.

[0117] The tan δ values ​​of the cured product (P) at -40°C, +20°C, and 80°C, as well as the minimum and maximum values ​​of tan δ in the temperature range from -40°C to +80°C, are shown in each table.

[0118] [Evaluation Criteria for Damping Properties in the Present Invention] In the present invention (the entire present invention including methods 1 and 2), damping property was evaluated based on whether tan δ of the cured product (P) was 0.15 or more in the temperature range from -40°C to +80°C. In other words, in the present invention, if the tan δ was 0.15 or more over the entire temperature range from -40°C to +80°C, the damping property was evaluated as excellent. The greater the minimum value of tan δ was 0.15, the better the damping property was evaluated to be. On the other hand, when the tan δ of the cured product (P) in the temperature range from −40° C. to +80° C. was less than 0.15 in at least a part of the temperature range, the damping property was evaluated as poor.

[0119] The minimum and maximum values ​​of tan δ for the cured products (M), (N), and (H) in the temperature range from -40°C to +80°C are shown in each table.

[0120] <Fatigue durability> Using each of the compositions obtained as described above, samples for evaluating fatigue durability were prepared under the following conditions, and a tensile shear fatigue property test in accordance with JIS K6864 was carried out under the condition of a stress amplitude of 2.8 MPa. -Type of substrate: Electroplated steel sheet Surface treatment method: The surface was wiped with a solvent and washed. Composition application method and curing conditions: Each composition obtained as described above was applied to the adherend using a cartridge gun. The composition was cured at 23°C, 55% RH, for 7 days. Average adhesive layer thickness: 30μm

[0121] [Evaluation Criteria for Fatigue Durability in the Present Invention] At least 10 at a stress amplitude of 3.6 MPa 7 When the sample did not break after the first cycle, it was evaluated as having the best fatigue durability and was designated as "AAA." At least 10 at a stress amplitude of 3.2 MPa 7 The sample did not break after 10 cycles at a stress amplitude of 3.6 MPa. 7If the sample broke within the first 10 cycles, it was evaluated as having excellent fatigue durability and was given the grade "AA." At least 10 at a stress amplitude of 2.8 MPa 7 The sample did not break after 10 cycles at a stress amplitude of 3.2 MPa. 7 If the sample broke within the first 10 cycles, it was evaluated as having slightly excellent fatigue durability, and this was indicated as "A." In the present invention (the entire present invention including methods 1 and 2), if the above evaluation is A or higher, the fatigue durability is deemed to be excellent. On the other hand, at a stress amplitude of 2.8 MPa, 7 If the sample broke during the first 100 cycles, it was evaluated as having poor fatigue durability and was marked with "B."

[0122] <Elongation at break, tensile modulus> Using each of the cured products obtained as described above, dumbbell-shaped No. 3 test pieces (thickness: 2 mm) were prepared. A tensile test was carried out on the cured product (P) using the above test piece in accordance with JIS K6251, where the elongation at break (elongation at break) was measured at a temperature of 20°C and a crosshead speed (tensile speed) of 200 mm / min, with benchmark lines for measuring elongation at break marked at 20 mm intervals. Furthermore, the tensile modulus of elasticity of the cured products (M), (N), and (H) was measured using the least squares method from all points between 0.1 and 1% strain.

[0123] (Evaluation criteria) Elongation at break of cured material (P) The elongation at break of the cured product (P) is preferably 50% or more, more preferably 100 to 1000%, from the viewpoint of achieving better fatigue resistance.

[0124] (Evaluation criteria for Method 1) Aspects of Method 1 were also evaluated according to the following criteria: Tensile modulus of cured material (M) and maximum and minimum tan δ values ​​of cured material (H) When the cured product (P) is obtained by method 1, the tensile modulus of the cured product (M) obtained by curing a matrix obtained by excluding the polymer fine particles (X) from the two-component curing adhesive composition (or the remainder obtained by excluding the polymer (X) and the medium from the two-component curing adhesive composition) is 5 MPa or more, and When the minimum loss tangent of the polymer microparticles (X) (i.e., the cured product (H)) is 0.05 or more under the above-mentioned specific conditions, it is evaluated that the fatigue durability and damping properties are better and that the fatigue durability and damping properties can be balanced at a higher level. The greater the tensile modulus of the cured product (M) is above 5 MPa, the better the fatigue durability is. The greater the minimum value of the loss tangent of the polymer fine particles (X) is from 0.05, the better the damping properties are.

[0125] (Evaluation criteria for Method 2) Aspects of Method 2 were also evaluated according to the following criteria: Minimum tanδ value of the cured material (N) and tensile modulus of the cured material (H) When the cured product (P) is obtained by Method 2, if the maximum value of the loss tangent of the cured product (N) obtained by curing the matrix obtained by excluding the polymer microparticles (X) from the two-component curing adhesive composition (or the remainder obtained by excluding the polymer (X) and the medium from the two-component curing adhesive composition) is 0.3 or more under the above-mentioned specific conditions, and if the tensile modulus of the polymer microparticles (X) (i.e., the cured product (H)) is 5 MPa or more, it was evaluated that the fatigue durability and damping properties are better and that a higher level of balance between fatigue durability and damping properties can be achieved. The greater the maximum value of the loss tangent of the cured product (N) is above 0.3, the better the damping properties are. The greater the tensile modulus of the cured product (P) is above 5 MPa, the better the fatigue durability is.

[0126] [Table 1]

[0127] [Table 2]

[0128] [Table 3]

[0129] [Table 4]

[0130] Details of each component shown in each table are as follows: <Main ingredient (A)> (urethane prepolymer) Urethane prepolymers 1, 2, and 4: Urethane prepolymers 1, 2, and 4 prepared as described above

[0131] (Polymer particles (X)) Polymer microparticles 6: Polymer microparticles 6 produced as described above

[0132] Carbon black: 200MP, manufactured by Shin-Nichika Carbon Co., Ltd. Calcium carbonate 1: Heavy calcium carbonate, Super S, manufactured by Maruo Calcium Co., Ltd. Plasticizer: Diisononyl phthalate, manufactured by J-Plus

[0133] <Curing agent (B)> (active hydrogen group-containing compound) Polyol 1: Polypropylene glycol, Sannix GL-3000, manufactured by Sanyo Chemical Industries, Ltd. OH 3 functional group When the polymer fine particles (X) with polyol as a medium were added to the curing agent (B), the polyol as a medium was added to the polyol 1.

[0134] (Polymer particles (X)) Polymer microparticles 1 to 5, 7: Polymer microparticles 1 to 5, 7 produced as described above

[0135] Comparative polymer microparticles 1: A mixture of comparative polymer microparticles 1 and polyoxypropylene glycol as a medium was prepared as follows. 15 parts by mass of polymethacrylic acid microparticles (product number: XX-2851Z, manufactured by Sekisui Chemical Co., Ltd., microparticle concentration: 100% by mass, average particle diameter of microparticles: 0.3 μm, glass transition temperature of microparticles: 100°C) as comparative polymer microparticles 1 and 100 parts by mass of polyoxypropylene glycol (Sanix GL-3000) as a medium were mixed and homogenized using a paint mill (S-43 / 4X11, manufactured by Inoue Seisakusho). The polymethacrylic acid microparticles do not have active hydrogen-containing groups.

[0136] Polyamine: Diethylmethylbenzenediamine, DETDA, manufactured by Mitsui Fine Chemicals

[0137] Calcium carbonate 2: Precipitated calcium carbonate, Kalfain 200, manufactured by Maruo Calcium Co., Ltd. Silica: Reolosil QS-102S, manufactured by Tokuyama Corporation

[0138] As is clear from the results shown in the tables, the composition of the present invention was able to achieve both high fatigue durability and high damping properties.

[0139] On the other hand, in Comparative Example 1, which did not contain polymer microparticles (X) for improving damping properties in the above-mentioned Method 1, the fatigue durability of the cured product obtained by curing the entire composition was excellent, but the minimum value of the loss tangent of the cured product was less than 0.15 in part of the temperature range of -40°C to +80°C, and the damping properties were poor. In addition, in Comparative Example 3, which did not contain polymer microparticles (X) but instead contained polymer microparticles with a Tg exceeding 80°C, the fatigue durability of the cured product obtained by curing the entire composition was excellent, but the minimum value of the loss tangent of the cured product was less than 0.15 in part of the temperature range from -40°C to +80°C, and the damping properties were poor.

[0140] In Comparative Example 2, which did not contain polymer microparticles (X) for improving fatigue durability in the above-mentioned Method 2, the damping properties of the cured product obtained by curing the entire composition were excellent, but the fatigue durability of the cured product was poor. Furthermore, in Comparative Example 4, which did not contain polymer fine particles (X) but instead contained polymer fine particles with a Tg of more than 80° C., the fatigue durability of the resulting cured product was poor. [Explanation of symbols]

[0141] 10 Cured product (P) 12 Hardened matrix 14 Polymer microparticles (X)

Claims

1. A two-component curing adhesive composition comprising a main component (A) containing a urethane prepolymer (a1) having an isocyanate group, and a curing agent (B), At least one of the base agent (A) and the curing agent (B) contains polymer fine particles (X) having an average particle size of 0.01 to 200 μm, the glass transition temperature of the polymer fine particles (X) is in the range of −40° C. to +80° C., the content of the polymer fine particles (X) is 5 mass% or more of the total amount of the two-component curing adhesive composition, the loss tangent of the cured product (P) obtained by curing the two-component curing adhesive composition is 0.15 or more under the conditions of a temperature range of −40° C. to +80° C. and a frequency of 100 Hz; The cured product (P) had a tensile shear fatigue property test conforming to JIS K6864 at a stress amplitude of 2.8 MPa and a tensile shear fatigue property test of 10 7 No breakage occurs under the conditions of up to 1000 cycles. A two-component curing adhesive composition that satisfies the following condition 1 and / or condition 2, and also satisfies the following condition 3 or condition 4: Condition 1 the tensile modulus of a cured product (M) obtained by curing the remainder of the two-component curing adhesive composition after removing the polymer fine particles (X) from the two-component curing adhesive composition is 5 MPa or more; The polymer fine particles (X) have a minimum loss tangent of 0.05 or more when measured under conditions of a temperature range of −40° C. to +80° C. and a frequency of 100 Hz. Condition 2 a cured product (N) obtained by curing the remainder of the two-component curing adhesive composition excluding the polymer fine particles (X) has a minimum loss tangent of 0.05 or more, measured under conditions of a temperature range of −40° C. to +80° C. and a frequency of 100 Hz; The polymer fine particles (X) have a tensile modulus of elasticity of 5 MPa or more. Condition 3 The polymer fine particles (X) contain a polymer obtained by reacting a polyisocyanate compound (x1) with at least one compound (x2) selected from the group consisting of a polyol compound, a polyamine compound, and a latent polyamine compound. Condition 4 The polymer fine particles (X) contain a polymer obtained by reacting a maleic anhydride-modified oligomer (x3) with at least one compound (x4) selected from the group consisting of polyol compounds, polyamine compounds, and latent polyamine compounds.

2. The two-component curing adhesive composition according to claim 1, wherein the cured product (P) has an elongation at break of 50% or more.

3. The two-component curing adhesive composition according to claim 1 or 2, wherein the curing agent (B) comprises a polyol compound (b1) and / or a polyamine compound (b2).

4. 4. The two-component curing adhesive composition according to claim 3, wherein the polyol compound (b1) comprises at least one selected from the group consisting of polyoxyethylene polyol, polyoxypropylene polyol, polyoxyethylene polyoxypropylene polyol, polybutadiene polyol, polyisoprene polyol, polyacrylic polyol, and partially modified products thereof.

5. If only condition 1 is satisfied, or if both condition 1 and condition 2 are satisfied, the urethane prepolymer (a1) is obtained by reacting a polyisocyanate compound (a2) with a polyol compound (a3) ​​in an equivalent ratio of an isocyanate group in the polyisocyanate compound (a2) to a hydroxyl group in the polyol compound (a3) ​​of 1.5 to 14; the curing agent (B) contains a polyol compound (b1) and a polyamine compound (b2), the equivalent ratio of the isocyanate group in the main component (A) to the active hydrogen-containing group in the curing agent (B) is 0.8 to 4; 5. The two-component curing adhesive composition according to claim 1, wherein an equivalent ratio of isocyanate groups in the main component (A) to amino groups in the polyamine compound (b2) is 1.2 to 6.

6. 6. The two-component curing adhesive composition according to claim 5, wherein the polyol compound (a3) ​​comprises at least one selected from polyester polyol, polytetramethylene ether glycol, polycarbonate polyol, polycaprolactone polyol, and partially modified products of any of these.

7. If only condition 2 is satisfied, the urethane prepolymer (a1) is obtained by reacting a polyisocyanate compound (a2) with a polyol compound (a3) ​​in an equivalent ratio of an isocyanate group in the polyisocyanate compound (a2) to a hydroxyl group in the polyol compound (a3) ​​of 1.5 to 2.5; the curing agent (B) contains a polyol compound (b1) and a polyamine compound (b2), the equivalent ratio of the isocyanate group in the main component (A) to the active hydrogen-containing group in the curing agent (B) is 0.8 to 4; 5. The two-component curing adhesive composition according to claim 1, wherein an equivalent ratio of isocyanate groups in the main component (A) to amino groups in the polyamine compound (b2) is 1.5 to 8.

0.

8. 8. The two-component curing adhesive composition according to claim 7, wherein the polyol compound (a3) ​​comprises at least one selected from polyoxypropylene glycol, polybutadiene polyol, polyisoprene polyol, polyacrylic polyol, and partially modified products of any of these.

9. 9. The two-component curing adhesive composition according to claim 1, wherein the maximum value of the loss tangent of the cured product (P) is 0.3 or more, as measured under conditions of a temperature range of −40° C. to +80° C. and a frequency of 100 Hz.

10. The two-component curing adhesive composition according to any one of claims 1 to 9, wherein the polymer fine particles (X) are formed by crosslinking a crosslinkable oligomer or a crosslinkable polymer in at least one medium selected from the group consisting of water, an organic solvent, an oligomer, and a polymer.

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