Composition

Abstract

To provide a composition that exhibits flexibility and adhesion.SOLUTION: The present invention provides a composition comprising: (1) a reactive compound containing an aromatic ring and a hydroxyl group, whose cured product exhibits a tensile elongation of 50% or more as measured in a 23°C atmosphere in accordance with JIS K 7161-2:2014; (2) a reactive compound other than (1); and (3) a polymerization initiator.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a composition, and more particularly to a composition that exhibits excellent flexibility, heat cycle resistance, and heat resistance, and also exhibits excellent adhesion to both metals and resins. [Background technology]

[0002] From the viewpoint of labor, resource, and energy saving, room temperature fast-curing adhesive compositions are used as adhesives that bond in a short time at room temperature. Known room temperature fast-curing adhesive compositions include two-part fast-curing epoxy adhesive compositions, anaerobic adhesive compositions, instant adhesive compositions, and second-generation acrylic adhesive compositions (SGA).

[0003] Two-part fast-curing epoxy adhesives are prepared by measuring and mixing the base agent and curing agent, applying the mixture to the adherend, and then curing via the reaction between the base agent and curing agent. Two-part fast-curing epoxy adhesives have typically been widely used as structural adhesives due to their high durability and high adhesive strength. However, conventional two-part fast-curing epoxy adhesives are hard and brittle, with significantly low flexibility. As a result, when used to bond different types of adherends, they are unable to alleviate the strain caused by the difference in linear expansion coefficients between the adherends, often resulting in problems such as peeling and cracking. Furthermore, improper curing can occur if the base agent and curing agent are not accurately measured to achieve the required mixing ratio.

[0004] Anaerobic adhesives are cured by pressing the adhesive composition between adherends to block air. However, if a portion of the adhesive composition protrudes from the adherends during pressure bonding, the protruding portion comes into contact with air, inhibiting the curing reaction and causing poor curing. Furthermore, if there is a large clearance between the adherends, sufficient pressure bonding cannot be achieved and air cannot be completely blocked, resulting in poor curing.

[0005] Instant adhesives are typically made primarily of cyanoacrylate and cure very quickly, making them easy to work with. However, the resulting cured product is brittle and has poor adhesive properties, making them unsuitable for structural applications that require durability.

[0006] SGAs consist of a first agent containing an organic peroxide and a second agent containing a reducing agent that decomposes the organic peroxide contained in the first agent and generates radicals. SGAs are generally of the two-part type, with both the first and second agents containing main ingredients such as polymerizable (meth)acrylic monomers and elastomers.

[0007] A feature of two-component SGAs is that they do not require accurate measurement of the two components, and even if the measurement or mixing is incomplete, they cure at room temperature in a few minutes to a few tens of minutes simply by contacting the two components, which makes them easy to work with. Furthermore, they have high tensile elongation and good cure even in overhanging areas, which is why they are widely used in fields ranging from electrical and electronic parts to civil engineering and construction. Various proposals have been made regarding such SGAs, as described in Patent Documents 1 to 5. [Prior art documents] [Patent documents]

[0008] [Patent Document 1] Japanese Patent Application Laid-Open No. 2000-109783 [Patent Document 2] Japanese Patent Application Publication No. 2017-031262 [Patent Document 3] Japanese Patent Application Laid-Open No. 2010-188651 [Patent Document 4] Japanese Patent Application Laid-Open No. 2002-105109 [Patent Document 5] Japanese Patent Application Laid-Open No. 2007-056232 Summary of the Invention [Problem to be solved by the invention]

[0009] When an adhesive is to be used in a harsh environment, adhesives that are not designed for this purpose will not be able to perform adequately. It is known to be particularly difficult to maintain adhesiveness in an environment where high and low temperatures are repeatedly experienced (also known as improving "heat cycle resistance"). In the technical field, heat cycle resistance and heat resistance are considered to be separate properties.

[0010] For example, conventional SGAs have been unable to achieve both flexibility and adhesion. For example, conventional SGAs have been unable to achieve both flexibility, heat cycle resistance, and heat resistance, while also exhibiting excellent adhesion to both metals and resins. For example, Patent Document 1 reports that the use of flexible (meth)acrylates or urethane prepolymers can provide high flexibility and reduce distortion caused by cure shrinkage stress on metal adherends. However, there is no mention of adhesion to resin adherends. Furthermore, there is no mention of heat cycle resistance or heat resistance.

[0011] Patent Document 2 reports a technology for improving the low-temperature properties of SGA by using a liquid elastomer. However, Patent Document 2 does not mention achieving both flexibility and adhesion. Patent Document 2 does not mention heat cycle resistance and heat resistance, nor does it mention tensile elongation.

[0012] Patent Document 3 reports that a composition with high stress relaxation properties can be provided by reacting a (meth)acrylate having a hydroxyl group with a polyisocyanate having an isocyanate group. However, the urethane bond formed by the reaction of a hydroxyl group with an isocyanate group is known to be hydrolyzed, which poses a problem in terms of durability. Furthermore, polyisocyanates having isocyanate groups are known to decompose when reacted with water, which poses a problem in storage stability.

[0013] Patent Document 4 reports a technique for improving the heat resistance of SGA by using zeolite. However, Patent Document 4 does not mention achieving both flexibility and adhesion.

[0014] Patent Document 5 describes the use of a specific (meth)acrylate as a technology for improving adhesion to resins. For example, resin materials commonly used as structural members, such as polycarbonate resin, ABS (acrylonitrile-butadiene-styrene) resin, phenolic resin, and epoxy resin, have an aromatic skeleton as a structural unit, and it is believed that the use of phenoxyethyl (meth)acrylate, which also has an aromatic skeleton, improves adhesion to adherends. However, (meth)acrylates with aromatic skeletons generally have a rigid structure, and the resulting cured products do not have high flexibility. In other words, the problem of a trade-off between resin adhesion and flexibility has not been solved. [Means for solving the problem]

[0015] In order to solve the above-mentioned problems, the present invention can provide the following.

[0016] Aspect 1. A composition comprising the following (1) to (3): (1) A reactive compound having an aromatic ring and a hydroxyl group, and a cured product of which has a tensile elongation of 50% or more as measured in an atmosphere at 23°C according to JIS K 7161-2:2014; (2) Reactive compounds other than the above component (1), (3) Polymerization initiator

[0017] Aspect 2. The composition of embodiment 1, wherein the (1) component comprises a bisphenol structural moiety.

[0018] Aspect 3. (1) The composition according to aspect 1 or 2, wherein the component contains four or more aromatic rings per molecule.

[0019] Aspect 4. (1) The composition according to any one of aspects 1 to 3, wherein the component contains five or fewer hydroxyl groups per molecule.

[0020] Aspect 5. Aspect 5. The composition according to any one of Aspects 1 to 4, wherein the content of component (1) is 0.1 parts by mass or more and 20 parts by mass or less, based on 100 parts by mass of the total of components (1) and (2).

[0021] Aspect 6. Aspect 6. The composition of any one of aspects 1 to 5, wherein the component (1) has a (meth)acryloyl group.

[0022] Aspect 7. Aspect 7. The composition of any one of aspects 1 to 6, wherein component (1) is a reaction product of a lactone-modified (meth)acrylate monomer, an acid anhydride, and an epoxy monomer.

[0023] Aspect 8. Aspect 8. The composition of any one of aspects 1 to 7, wherein component (2) has a (meth)acryloyl group.

[0024] Aspect 9. Aspect 9. The composition according to any one of aspects 1 to 8, wherein the weight average molecular weight Mw of component (1) measured by GPC is 1,000 or greater.

[0025] Aspect 10. The composition according to any one of aspects 1 to 9, further comprising (4) an elastomer.

[0026] Aspect 11. The composition according to any one of aspects 1 to 10, further comprising (5) a reducing agent.

[0027] Aspect 12. The composition according to any one of Aspects 1 to 11, which is a two-part composition, wherein the first part contains at least (3) a polymerization initiator, and the second part does not contain at least (3) a polymerization initiator.

[0028] Aspect 13. The composition according to any one of Aspects 1 to 11, which is a two-part composition, wherein the first part contains at least (3) a polymerization initiator, and the second part contains at least (5) a reducing agent.

[0029] Aspect 14. A curable composition comprising the composition according to any one of Aspects 1 to 13.

[0030] Aspect 15. An adhesive composition comprising the curable composition of embodiment 14.

[0031] Aspect 16. A bonded structure obtained by bonding adherends with the adhesive composition according to embodiment 15.

[0032] Aspect 17. A bonding method comprising applying the adhesive composition according to embodiment 15 to an adherend and bonding the adherend.

[0033] Aspect 18. A compound having one of the following structural formulas: [ka] R in the formula 1 and R 2 are each independently a hydrogen atom or a methyl group, and k, m, n, p, and q are each independently an integer of 0 or greater. [ka] R in the formula 1 and R 2 are each independently a hydrogen atom or a methyl group, and k, m, n, p, and q are each independently an integer of 0 or greater.

[0034] Aspect 19. 19. The compound of embodiment 18, wherein k is an integer of 1 or greater. [Effects of the Invention]

[0035] The composition provided by the embodiment of the present invention has the effect of exhibiting flexibility and adhesion. The composition provided by the embodiment of the present invention has the effect of exhibiting, for example, excellent flexibility, heat cycle resistance, and heat resistance, and also excellent adhesion to both metals and resins. DETAILED DESCRIPTION OF THE INVENTION

[0036] Hereinafter, embodiments of the present invention will be described in detail, but the present invention is not limited to these embodiments. In this specification, "parts" and "%" are based on mass unless otherwise specified. Numerical ranges in this specification include upper and lower limit values ​​unless otherwise specified. In this specification, the "amount used" and "content" of a component refer to the amount based on the entire composition unless otherwise specified. In this specification, "room temperature" refers to the temperature defined in JIS Z 8703:1983, i.e., 20±15°C.

[0037] In this specification, the term "monofunctional (meth)acrylate" refers to a (meth)acrylate having one (meth)acryloyl group, and the term "polyfunctional (meth)acrylate" refers to a (meth)acrylate having two or more (meth)acryloyl groups.

[0038] The curable composition (hereinafter also simply referred to as "composition") that can be provided by an embodiment of the present invention includes (1) a reactive compound having an aromatic ring and a hydroxyl group, and a cured product of which has a tensile elongation of 50% or more as measured in an atmosphere at 23°C according to JIS K 7161-2:2014 with reference to JIS K 7161-1:2014, (2) a reactive compound other than the above-mentioned (1), and (3) a polymerization initiator.

[0039] Component (1) is a novel component that provides the composition with high adhesion to resins and metals and high flexibility as a cured body. It has high reactivity, allowing it to copolymerize with other reactive compounds. Therefore, component (1) alone must have a high tensile elongation at room temperature when cured. While component (1) has a rigid structure due to the presence of aromatic rings, the presence of hydroxyl groups allows it to achieve not only a high tensile elongation but also excellent adhesion to both metals and resins.

[0040] Component (1) may be a reactive monomer or oligomer, and its reactive group is preferably a group having a carbon-carbon double bond, and from the viewpoint of obtaining high reactivity, it may have, for example, one or more (meth)acryloyl groups per molecule. Component (1) may preferably be a monofunctional (meth)acrylate, a polyfunctional (meth)acrylate, or a mixture thereof.

[0041] From the viewpoint of improving heat resistance, component (1) preferably contains a bisphenol structural moiety, and from the viewpoint of further improving heat resistance, it is more preferable that component (1) has four or more aromatic rings per molecule.

[0042] From the viewpoint of improving adhesiveness without affecting heat resistance, the number of hydroxyl groups contained in component (1) is preferably 5 or less per molecule.

[0043] The amount of component (1) used is preferably 0.1 to 20 parts by mass, more preferably 0.1 to less than 20 parts by mass, and most preferably 1 to 15 parts by mass, based on 100 parts by mass of the total of components (1) and (2). When component (1) is 0.1 part by mass or more, high adhesion to resins and metals and high flexibility of the cured product are improved. When component (1) is 20 parts by mass or less, compatibility is improved, making it easier to obtain a uniform resin composition.

[0044] The weight-average molecular weight Mw of component (1), as measured by GPC (gel permeation chromatography), is preferably 1,000 or more, more preferably 2,000 or more, and is preferably 10,000 or less, more preferably 5,000 or less.

[0045] Specific examples of component (1) include reaction products of lactone-modified (meth)acrylate monomers, acid anhydrides, and epoxy monomers. Examples of lactones used in such lactone-modified (meth)acrylate monomers include α-acetolactone, β-propiolactone, γ-butyrolactone, δ-valerolactone, and ε-caprolactone. Examples of lactone-modified (meth)acrylate monomers include products from the PLACCEL series manufactured by Daicel Corporation, such as polycaprolactone-modified hydroxyethyl (meth)acrylates under the trade names "PLACCEL FA1DDM" and "PLACCEL FA1." Other examples include products from the Petrochemicals Specialty Monomers series manufactured by BASF, such as Hydroxyethylcaprolactone Acrylate under the trade name "HECLA." Furthermore, in addition to commercially available products, lactone-modified (meth)acrylate monomers can also be synthesized from hydroxy(meth)acrylates and hydroxycarboxylic acids. A lactone-modified (meth)acrylate monomer can be obtained by dehydration condensation of 2-hydroxyethyl (meth)acrylate (for example, manufactured by Osaka Organic Chemical Industry Co., Ltd.) and 6-hydroxycaproic acid (for example, manufactured by Chemwill Asia Co., Ltd.).

[0046] The acid anhydride is preferably a carboxylic acid anhydride, and any of phthalic anhydride, benzoic anhydride, acetic anhydride, propionic anhydride, oxalic anhydride, succinic anhydride, maleic anhydride, 2,3-naphthalenedicarboxylic anhydride, etc. From the viewpoint of ease of reaction, cyclic carboxylic acid anhydrides are preferred.

[0047] The epoxy monomer may be any known raw material for epoxy resins, and preferably has an aromatic ring. An example of an epoxy monomer having an aromatic ring is a compound having a glycidyloxyphenyl group. An example of such a compound having a glycidyloxyphenyl group is bisphenol A diglycidyl ether having the following structural formula:

[0048] [ka] In the formula, n is an integer of 0 or more, and preferably an integer of 0-3.

[0049] Specific examples of component (1) include those having any of the following structural formulas: [ka] R in the formula 1 and R 2 are each independently a hydrogen atom or a methyl group. k, m, n, p, and q are each independently an integer of 0 or greater, preferably an integer of 1 or greater. Preferably, k is 1 or greater, m+n is 2 to 25, and p and q are 1 to 10, and more preferably, k is 1 to 3, m+n is 10 to 25, and p and q are 2 to 10. Furthermore, an asterisk in a formula indicates a point where the structural formula should normally be connected, and is used solely for space reasons.

[0050] [ka] R in the formula 1 and R 2 are each independently a hydrogen atom or a methyl group. k, m, n, p, and q are each independently an integer of 0 or greater, preferably an integer of 1 or greater. Preferably, k is 1 or greater, m+n is 2 to 25, and p and q are 1 to 10, and more preferably, k is 1 to 3, m+n is 10 to 25, and p and q are 2 to 10. As above, an asterisk in the formula indicates the point where the structural formula is originally connected.

[0051] In this specification, the elongation of a cured product of component (1) alone is measured as follows: 3.0 parts by mass of photoinitiator is added to 100 parts by mass of component (1) and stirred. The stirred mixture is poured onto a PET film and coated with a bar coater to a thickness of 0.1 mm. This is cured by irradiating it with ultraviolet light to obtain a cured product. Using this cured product, a tensile test is performed in a 23°C environment according to JIS K 7161-2:2014 to measure the tensile elongation. The tensile elongation is measured in %, which indicates the increase in length from the cured product before the test.

[0052] The elongation of a cured product of component (1) alone is 50% or more, preferably 70% or more, and more preferably 100% or more. The elongation of a cured product of component (1) alone is preferably 500% or less, more preferably 300% or less, and most preferably 200% or less.

[0053] The reactive compound of component (2) is defined as excluding component (1) and has the function of dissolving other components of the composition. Component (2) is preferably one or more monomers selected from (meth)acrylates and hydroxyalkyl (meth)acrylates having a hydrocarbon group. Such hydrocarbon groups are preferably unsubstituted or substituted hydrocarbon groups having 1 to 32 carbon atoms. The hydrocarbon groups may be linear, branched, or alicyclic aliphatic groups, aromatic groups, or combinations thereof. From the viewpoint of achieving sufficient solubility of other components, component (2) preferably contains one or more (meth)acrylates or hydroxyalkyl (meth)acrylates having an aliphatic group.

[0054] Component (2) may be a monofunctional (meth)acrylate, a polyfunctional (meth)acrylate, or a mixture thereof.

[0055] Examples of the component (2) that has a linear or branched aliphatic group and is monofunctional include methyl (meth)acrylate, ethyl (meth)acrylate, hexyl (meth)acrylate, octyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, nonyl (meth)acrylate, isononyl (meth)acrylate, decyl (meth)acrylate, isodecyl (meth)acrylate, stearyl (meth)acrylate, isostearyl (meth)acrylate, dodecyl (meth)acrylate, lauryl (meth)acrylate, and tridecyl (meth)acrylate. , alkyl (meth)acrylates such as tetradecyl (meth)acrylate, pentadecyl (meth)acrylate, hexadecyl (meth)acrylate, heptadecyl (meth)acrylate, octadecyl (meth)acrylate, nonadecyl (meth)acrylate, and eicodecyl (meth)acrylate; and hydroxyalkyl (meth)acrylates such as 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 2-hydroxybutyl (meth)acrylate, and 4-hydroxybutyl (meth)acrylate. Further examples of monofunctional (meth)acrylates include 2-hydroxyethyl (meth)acryloyl phosphate, 4-butylhydroxy(meth)acrylate, 2-(meth)acryloyloxyethyl-2-hydroxypropyl phthalate, glycerin mono(meth)acrylate, 2-hydroxy-3-(meth)acryloyloxypropyl (meth)acrylate, pentaerythritol mono(meth)acrylate, dipentaerythritol mono(meth)acrylate, and caprolactone-modified 2-hydroxyethyl (meth)acrylate.

[0056] Examples of alicyclic or aromatic monofunctional (meth)acrylates include adamantyl (meth)acrylate, dicyclopentenyl (meth)acrylate, isobornyl (meth)acrylate, dicyclopentenyloxyethyl (meth)acrylate, cyclohexyl (meth)acrylate, tetrahydrofurfuryl (meth)acrylate, phenoxyethyl (meth)acrylate, 1-(1-adamantyl)-1-methylethyl (meth)acrylate, benzyl (meth)acrylate, methylbenzyl (meth)acrylate, ethylbenzyl (meth)acrylate, propylbenzyl (meth)acrylate, methoxybenzyl (meth)acrylate, chlorobenzyl (meth)acrylate, etc. Among these, isobornyl (meth)acrylate is preferred because of its large effect.

[0057] Examples of polyfunctional (meth)acrylates include di(meth)acrylates, tri(meth)acrylates, and tetra(meth)acrylates having a linear, branched, or alicyclic aliphatic or aromatic group. Specific examples of such polyfunctional (meth)acrylates include ethylene glycol di(meth)acrylate, diethylene glycol di(meth)acrylate, triethylene glycol di(meth)acrylate, polyethylene glycol di(meth)acrylate, ethoxylated bisphenol A di(meth)acrylate, tricyclodecane dimethanol di(meth)acrylate, 1,10-decanediol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, Examples include 2,2-bis(4-(meth)acryloxyphenyl)propane, 2,2-bis(4-(meth)acryloxyethoxyphenyl)propane, 2,2-bis(4-(meth)acryloxydiethoxyphenyl)propane, 2,2-bis(4-(meth)acryloxypropoxyphenyl)propane, 2,2-bis(4-(meth)acryloxytetraethoxyphenyl)propane, and 2,2-bis(4-(meth)acryloxypolyethoxyphenyl)propane.

[0058] Among the (2) components, one or more members selected from the group consisting of (2-1) alkyl (meth)acrylate, (2-2) hydroxyalkyl (meth)acrylate, and (2-3) (meth)acrylate having a cyclic structure are preferred, and a combination of (2-1) alkyl (meth)acrylate, (2-2) hydroxyalkyl (meth)acrylate, and (2-3) (meth)acrylate having a cyclic structure is more preferred.

[0059] (2-3) Among the (meth)acrylates having a cyclic structure, monofunctional (meth)acrylates having an alicyclic aliphatic group or an aromatic group are preferred.

[0060] (2-1) As the alkyl(meth)acrylate, a (meth)acrylate having an aliphatic group is preferred. As the (meth)acrylate having an aliphatic group, a (meth)acrylate represented by the following general formula (A) is preferred. General formula (A) ZOR 1 (wherein Z represents a (meth)acryloyl group, and R 1 represents an alkyl group having 1 to 20 carbon atoms.

[0061] R in the above formula 1 The alkyl group is preferably an alkyl group having 1 to 20 carbon atoms, more preferably an alkyl group having 1 to 12 carbon atoms. When the number of carbon atoms is 20 or less, the surface curability is improved, stickiness is suppressed, and the curing speed can be improved.

[0062] Examples of such alkyl (meth)acrylates include methyl (meth)acrylate, ethyl (meth)acrylate, n-propyl (meth)acrylate, isopropyl (meth)acrylate, butyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, isooctyl (meth)acrylate, isodecyl (meth)acrylate, lauryl (meth)acrylate, and stearyl (meth)acrylate, and one or more of these can be used. Among these, methyl (meth)acrylate is preferred because of its greater effect.

[0063] (2-2) As the hydroxyalkyl (meth)acrylate, a (meth)acrylate represented by the general formula (B) is preferred. General formula (B) ZO-(R 2 O)sH (wherein Z represents a (meth)acryloyl group, and R 2 is -C2H4-, -C3H6-, -CH2CH(CH3)-, -C4H8- or -C6H 12 -, and s represents an integer of 1 to 10.

[0064] Examples of such hydroxyalkyl (meth)acrylates include 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, and hydroxybutyl (meth)acrylate, and one or more of these can be used. Among these, 2-hydroxyethyl (meth)acrylate and / or 2-hydroxypropyl (meth)acrylate are preferred, and 2-hydroxyethyl (meth)acrylate is more preferred, in terms of their greater effect.

[0065] When the (2) component contains a combination of (2-1) an alkyl (meth)acrylate, (2-2) a hydroxyalkyl (meth)acrylate, and (2-3) a (meth)acrylate having a cyclic structure, the content ratio thereof is preferably (2-1):(2-2):(2-3)=10-90:2-50:3-20, more preferably 30-70:10-50:3-20, and most preferably 40-60:20-40:5-20, per 100 parts by mass of the total of (2-1) an alkyl (meth)acrylate, (2-2) a hydroxyalkyl (meth)acrylate, and (2-3) a (meth)acrylate having a cyclic structure.

[0066] The amount of component (2) used is preferably 80 parts by mass or more and 99.9 parts by mass or less, more preferably more than 80 parts by mass or less and 99.9 parts by mass or less, and most preferably 85 parts by mass or more and 99 parts by mass or less, when the total of components (1) and (2) is 100 parts by mass. When component (2) is 80 parts by mass or more, the viscosity of the composition becomes appropriate, which is effective in enabling uniform production. Furthermore, when component (1) is included, both flexibility and heat resistance can be achieved, and sufficient high adhesion to resins and metals can be obtained.

[0067] (3) The polymerization initiator has the function of promoting the polymerization reaction.

[0068] The (3) polymerization initiator used in the present invention is preferably an organic peroxide. Examples of organic peroxides include cumene hydroperoxide, paramenthane hydroperoxide, tertiary butyl hydroperoxide, diisopropylbenzene dihydroperoxide, methyl ethyl ketone peroxide, benzoyl peroxide, and tertiary butyl peroxybenzoate. One or more of these can be used. Among these, cumene hydroperoxide is preferred in terms of reactivity and storage stability.

[0069] The amount of (3) polymerization initiator added is preferably 0.5 to 10 parts by mass, more preferably 1 to 7 parts by mass, per 100 parts by mass of the total of (1), (2), and optional (4) components. If it is 0.5 parts by mass or more, the curing speed becomes appropriate, and if it is 10 parts by mass or less, storage stability becomes appropriate.

[0070] Without wishing to be bound by any particular theory, it is believed that the synergistic effect of containing the above-mentioned components (1), (2), and (3), or the synergistic effect of containing the above-mentioned components (1) to (4), results in the resulting composition having sufficiently reduced internal stress after curing. Moreover, the composition also has excellent adhesion to adherends such as resins and metals, allowing it to adhere sufficiently against the internal stress, resulting in extremely excellent heat cycle resistance. Furthermore, the composition also enables bonding between dissimilar materials.

[0071] In some embodiments, the composition may be in a two-part form, and the first part preferably contains at least component (3), and the second part preferably does not contain component (3). In this case, the second part more preferably contains a reducing agent that decomposes component (3) and generates radicals.

[0072] (4) Elastomer is added to improve the toughness or viscosity of the composition. In this specification, "elastomer" refers to a polymeric substance that has rubber-like elasticity at room temperature, and is preferably one that can be dissolved or dispersed in components (1) and (2).

[0073] (4) Examples of elastomer components include (meth)acrylonitrile-butadiene-methacrylic acid copolymer, (meth)acrylonitrile-butadiene-methyl (meth)acrylate copolymer, methyl (meth)acrylate-butadiene-(meth)acrylonitrile-styrene copolymer, methyl (meth)acrylate-butadiene-styrene copolymer (MBS), (meth)acrylonitrile-styrene-butadiene copolymer, and various synthetic rubbers such as (meth)acrylonitrile-butadiene rubber (NBR), linear polyurethane, styrene-butadiene rubber, chloroprene rubber, and butadiene rubber, natural rubber, and styrene-polybutadiene. Examples of suitable elastomers include styrene-based thermoplastic elastomers such as polyethylene-styrene-based synthetic rubber, olefin-based thermoplastic elastomers such as polyethylene-EPDM synthetic rubber, urethane-based thermoplastic elastomers such as caprolactone-type, adipate-type, and PTMG-type, polyester-based thermoplastic elastomers such as polybutylene terephthalate-polytetramethylene glycol multiblock polymer, polyamide-based thermoplastic elastomers such as nylon-polyol block copolymer and nylon-polyester block copolymer, 1,2-polybutadiene-based thermoplastic elastomer, and vinyl chloride-based thermoplastic elastomer. These elastomer components can be used alone or in combination as long as they are compatible.

[0074] Also, polybutadiene or modified polybutadiene can be used.

[0075] Among these, in terms of solubility in compounds and adhesiveness, methyl(meth)acrylate-butadiene-styrene copolymer and / or (meth)acrylonitrile-butadiene rubber are preferred, and (meth)acrylonitrile-butadiene rubber is more preferred.

[0076] The amount of the elastomer component (4) added is preferably 5 to 35 parts by mass, more preferably 10 to 30 parts by mass, per 100 parts by mass of the total of the components (1) and (2). When the amount of the component (4) is 5 parts by mass or more, the viscosity and adhesiveness are improved, and when it is 35 parts by mass or less, the viscosity becomes appropriate and workability is improved.

[0077] (5) The reducing agent that generates radicals may be any known reducing agent that decomposes the component (3) and generates radicals. Examples of reducing agents include metal salts of organic acids, β-diketone chelates, aromatic amines and / or pyridine derivatives, tertiary alkylamines, and thiourea derivatives. Among these, thiourea derivatives are preferred. Examples of thiourea derivatives include 1-acetyl-2-thiourea, benzoylthiourea, N,N-diphenylthiourea, N,N-diethylthiourea, N,N-dibutylthiourea, and tetramethylthiourea. Among these, 1-acetyl-2-thiourea is preferred.

[0078] The amount of reducing agent (5) added is preferably 0.1 to 10 parts by mass, more preferably 0.3 to 5 parts by mass, per 100 parts by mass of the total of components (1), (2), and the optional component (4). If the amount is 0.1 part by mass or more, the curing rate becomes appropriate, and if the amount is 10 parts by mass or less, the storage stability becomes appropriate.

[0079] In some embodiments, a curable composition including the above-described composition can be provided. In some embodiments, an adhesive composition containing the above-described curable composition can be provided. In some embodiments, a bonded structure in which adherends (e.g., metals or resins) are bonded using the adhesive composition, as well as a bonding method therefor, can be provided.

[0080] In a preferred embodiment, the composition has a tensile strain (tensile elongation) of preferably 20% or more (i.e., excellent low-temperature flexibility) in a tensile test conducted in a −20°C atmosphere according to JIS K 7161-1:2014, and more preferably greater than 20%.

[0081] In a preferred embodiment, the composition preferably has a tensile shear adhesive strength of 1 MPa or more after 24 hours between resins, as measured by the method specified in JIS K 6850:1999, or preferably fails by cohesive failure. More preferably, the tensile shear adhesive strength may be 1 MPa or more and the failure by cohesive failure. The tensile shear adhesive strength may be greater than 1 MPa.

[0082] In a preferred embodiment, the composition preferably has a tensile shear adhesive strength of 10 MPa or more after 24 hours to metals, as measured by the method specified in JIS K 6850:1999, or preferably fails by cohesive failure. More preferably, the tensile shear adhesive strength may be 10 MPa or more and the failure by cohesive failure. The tensile shear adhesive strength may be greater than 10 MPa.

[0083] Cohesive failure is preferred as the failure state because there is adhesiveness at the interface between the composition and the adherend. Interfacial failure occurs when the adhesiveness at the interface between the composition and the adherend is weaker than cohesive failure.

[0084] In a preferred embodiment, the composition has a storage modulus at 120°C measured using a dynamic viscoelasticity measuring device at a temperature rise rate of 2°C / min, a temperature range of -50 to 150°C, a frequency of 1 Hz, and in tension mode, of preferably 2.0 MPa or more (i.e., excellent heat cycle resistance and heat resistance), and more preferably exceeding 2.0 MPa. [Example]

[0085] The present invention will be described in detail below with reference to examples. [Example]

[0086] As component (1), a compound having the following structural formula was synthesized according to the following procedure.

[0087] [ka] In the formula, k=1, m+n=17 , p=q=5, and R 1 and R 2 is a hydrogen atom is.

[0088] [Compound synthesis] A 300 ml four-neck glass flask equipped with a Liebig condenser, a thermometer, a silicon rubber stopper for nitrogen replacement, and a glass stopper was charged with 46 g of polycaprolactone-modified hydroxyethyl acrylate (unsaturated fatty acid hydroxyalkyl ester-modified ε-caprolactone, Plaxel FA1DDM, manufactured by Daicel Corporation, molecular weight: 230 g / mol) and 0.46 g of dibutylhydroxytoluene (reagent grade, manufactured by Tokyo Chemical Industry Co., Ltd., molecular weight: 220) as a polymerization inhibitor. The flask was then placed on a magnetic stirrer with an oil bath and stirred at 23 °C for 30 minutes (stirring speed: 300 rpm) until the dibutylhydroxytoluene was completely dissolved. The flask was then cooled to 0 °C and 0.98 g of sulfuric acid (Wako Grade 1, manufactured by Fujifilm Wako Pure Chemical Industries, Ltd., 98 g / mol) was added dropwise as an acid catalyst. To this solution, 14.6 g of adipic acid (reagent grade, manufactured by Tokyo Chemical Industry Co., Ltd., molecular weight: 146 g / mol) was added and the mixture was stirred (stirring speed: 300 rpm) at 75°C for 5 hours under a nitrogen stream to allow the esterification reaction to proceed. To this solution, 29.6 g of phthalic anhydride (reagent grade, manufactured by Tokyo Chemical Industry Co., Ltd., molecular weight: 148 g / mol), 34 g of 2,2-bis(4-glycidyloxyphenyl)propane (EXA-850CRP, manufactured by DIC Corporation, molecular weight: 340 g / mol), and 0.34 g of triphenylphosphine (Hokuko TPP, molecular weight: 262 g / mol) as a reaction catalyst were added. The mixture was stirred (300 rpm) at 80°C for 24 hours to allow the addition reaction to proceed. This yielded crude product A.

[0089] [Compound purification] The entire amount of crude product A obtained was placed in a 500 ml separatory funnel, and 126 ml of pure water was added. The mixture was shaken at room temperature for 3 minutes. The mixture was left to stand at room temperature for 3 hours, and after confirming that the contents had separated into two layers, the pure water layer was removed. This series of operations was repeated two more times, for a total of three times, to obtain a colorless, viscous liquid product A.

[0090] [Compound Identification] The obtained colorless viscous liquid product A was dissolved in deuterated chloroform (reagent grade, manufactured by Tokyo Chemical Industry Co., Ltd.) to prepare a 3% by mass solution, and then 1 H-nuclear magnetic resonance measurement ( 1 H-NMR was performed. 1 The H-NMR analytical data was as follows: 1 H-NMR (CDCl3, 500.13 MHz): δ=7.82~7.65, 7.59~7.47, 7.14~7.06, 6.84~6.75, 6.47~6.37, 6.18~6.08, 5.88~5.80, 4.6 1~4.43, 4.41~4.40, 4.38~4.34, 4.33~4.28, 4.07~4.03, 2.38~2.27, 1.79~1.72, 1.70~1.57 This result supported the structure shown in the structural formula above.

[0091] 10 mg of the resulting colorless viscous liquid product A was dissolved in 10 ml of tetrahydrofuran (stabilizer-free reagent grade, manufactured by Wako Pure Chemical Industries, Ltd.), filtered through a membrane filter (PTFE, 0.50 μm), and subjected to gel permeation chromatography (GPC) analysis under the following measurement conditions. Standard material: Shodex STANDARD (Type: SL-105, manufactured by Showa Denko) Column: KF-801 (300 mm x 8.0 mm ID, Showa Denko) Column temperature: 40℃ Mobile phase: Tetrahydrofuran (stabilizer-free reagent grade, manufactured by Wako Pure Chemical Industries, Ltd.) Flow rate: 1ml / min Detector: Differential refractive index detector The weight average molecular weight Mw obtained was 3,300.

[0092] To 100 parts by mass of the compound (1) obtained, 3.0 parts by mass of the photoinitiator "2,2-Dimethoxy-2-phenylacetophenone (reagent grade, manufactured by Tokyo Chemical Industry Co., Ltd.)" was added, and the mixture was placed in a designated plastic container and stirred at 2000 rpm for 3 minutes using a hybrid mixer "ARE-310 (manufactured by Thinky Corporation)". After stirring, the mixture was poured onto a PET film and coated to a thickness of 0.1 mm using a bar coater. This was then cured with an electrodeless discharge metal halide lamp-equipped UV curing device (manufactured by Fusion UV Systems Japan) using an integrated light dose of 3000 mJ / cm at a wavelength of 365 nm. 2 Photocuring was carried out under the conditions shown above to obtain a cured product of component (1) alone. This cured product was subjected to a tensile test in accordance with JIS K 7161-2:2014 using an Instron model 3365 universal testing machine (manufactured by Instron) at 23°C, and the tensile elongation was measured to be 113%. The tensile elongation is measured in %, indicating the increase in length from the cured product before the test.

[0093] The compound obtained as described above was used as component (1) and was blended with the materials shown in the table below to prepare various compositions. The amounts in the table are shown in parts by mass.

[0094] <Materials used> (2) The following commercially available products were used as components. Methyl methacrylate: Acryester M (Mitsubishi Chemical Holdings Corporation) 2-Hydroxyethyl methacrylate: HEMA (Nippon Shokubai Co., Ltd.) Isobornyl acrylate: Light Acrylate IB-XA (Kyoeisha Chemical)

[0095] The following elastomers were used: Acrylonitrile-butadiene rubber: Nipol DN401LL (manufactured by Nippon Zeon)

[0096] As the polymerization initiator, the following organic peroxide was used as it was. Cumene hydroperoxide: Percumyl H-80 (NOF Corporation)

[0097] As a reducing agent for generating radicals, 1-acetyl-2-thiourea (ATU) (manufactured by Sanuki Chemical Industry Co., Ltd.) was used as it was.

[0098] Furthermore, for comparative examples, the following components were used as control components for component (1): The tensile elongation of these cured products was also measured in the same manner as above, and the results are shown below. Phenoxyethyl methacrylate: Light Ester PO (Kyoeisha Chemical Co., Ltd.) Tensile elongation of the cured product alone: ​​1% Hydroxypropyl methacrylate: VISIOMER HPMA98 (manufactured by Evonik Performance Materials GmbH) Tensile elongation of the cured product alone: ​​2% Lauryl methacrylate: Light Ester L (Kyoeisha Chemical Co., Ltd.) Tensile elongation of the cured product alone: ​​51% Bisphenol A diglycidyl ether acrylic acid adduct: Viscoat #540 (Osaka Organic Chemical Industry Co., Ltd.) Tensile elongation of the cured product alone: ​​7% 4-Hydroxybutyl acrylate: 4HBA (Mitsubishi Chemical Holdings Corporation) Tensile elongation of the cured product alone: ​​53% Bisphenol A ethylene oxide 30 modified dimethacrylate: BPE-1300N (manufactured by Shin-Nakamura Chemical Co., Ltd.) Tensile elongation of the cured product alone: ​​16%

[0099] <Formulation> The above raw materials were weighed as shown in the table below and added to a 1 L stainless steel flask. A stainless steel stirring blade was placed in the flask, and the mixture was stirred at 200 rpm for 24 hours using a Three-One motor to obtain a uniform viscous liquid.

[0100] <Evaluation> The samples obtained as described above were evaluated based on the following measurement methods. In the evaluation, the first and second agents shown in Tables 1 and 2 were mixed at the same mass ratio until homogeneous and then used.

[0101] Low-temperature flexibility: Tested in a -20°C atmosphere in accordance with JIS K 7161-1:2014. Test specimens were prepared using cured specimens shaped like 1BA dumbbells as specified in Appendix A of JIS K 7161-1:2014. Tensile tests were performed using a universal testing machine, Instron model 3365 (manufactured by Instron), and the measured tensile strain was calculated in %.

[0102] Resin adhesion: Test pieces (manufactured by Test Piece Co., Ltd.) made of Teijin's polycarbonate resin "Panlite L1225" were used as test pieces, measuring 2.0 x 25 x 100 mm, without any pretreatment. Tensile shear adhesive strength tests were performed at standard conditions (23°C) in accordance with JIS K 6850:1999 using an Instron model 4467 universal testing machine (manufactured by Instron). The shear strength was measured in MPa when the test pieces were overlapped and bonded together.

[0103] Metal adhesion: Zinc-plated chromate steel plates (manufactured by Test Piece Co., Ltd.) measuring 1.6 x 25 x 100 mm were purchased as test pieces and used as they were without any pretreatment. Tensile shear adhesive strength tests were performed at standard conditions (23°C) in accordance with JIS K 6850:1999 using an Instron model 4467 universal testing machine (manufactured by Instron). The shear strength was measured in MPa when the test pieces were overlapped and bonded together.

[0104] Heat cycle resistance / heat resistance: Test specimens were prepared using rectangular cured specimens measuring 0.5 × 5 × 40 mm. The storage modulus at 120°C was calculated in MPa using a dynamic viscoelasticity measuring device (DMS7100, manufactured by SII Corporation) at a heating rate of 2°C / min, in the temperature range of -50 to 150°C, at a frequency of 1 Hz, and in tensile mode.

[0105] [Table 1]

[0106] [Table 2]

[0107] In Examples 1 to 3, which used as component (1) a reactive compound having an aromatic ring and a hydroxyl group and having a tensile elongation of 50% or more in the cured product measured in an atmosphere at 23°C according to JIS K 7161-2:2014, all showed excellent results in all evaluation items.

[0108] On the other hand, Comparative Example 1, which did not use component (1), exhibited poor low-temperature flexibility and resin adhesion. Conversely, Comparative Example 8, which used only component (1), also exhibited poor resin adhesion and metal adhesion. Furthermore, Comparative Examples 2 to 7, which used various control components, also exhibited poor performance in one or more of the following areas:

[0109] The composition provided by the embodiment of the present invention has the effect of exhibiting excellent flexibility, heat cycle resistance, and heat resistance, as well as excellent adhesion to both metals and resins.

[0110] Patent Document 4 reports a technology for improving the heat resistance of SGA by using zeolite. However, the required properties are becoming more sophisticated and diverse every year, and a balance of heat cycle resistance, heat resistance, and flexibility is required. Adding zeolite, an inorganic compound, to SGA generally reduces flexibility. In other words, the trade-off between heat cycle resistance, heat resistance, and flexibility has not been resolved. Specifically, with the conventional bisphenol A epoxy (meth)acrylate described in Patent Document 4, improving flexibility requires lengthening the heat-sensitive alkylene chain, which in turn sacrifices heat cycle resistance and heat resistance, and therefore has not been resolved.

[0111] The embodiments of the present invention can solve the above-mentioned problems.

Claims

1. A two-dose composition comprising the following (1) to (3) and (5): (1) A reactive compound which is a reaction product of a polycaprolactone-modified hydroxyethyl acrylate monomer, phthalic anhydride, and 2,2-bis(4-glycidyloxyphenyl)propane and is represented by the following structural formula, and which, when cured alone, has a tensile elongation of 50% or more as measured in an atmosphere at 23°C according to JIS K 7161-2:2014. (wherein k=1, m+n=17, p=q=5, and R 1 and R 2 are hydrogen atoms) (2) a monomer which is a combination of methyl methacrylate, 2-hydroxyethyl methacrylate, and isobornyl acrylate; (3) Polymerization initiator (5) Reducing agent The content of component (1) is 0.1 parts by mass or more and 20 parts by mass or less, based on 100 parts by mass of the total of components (1) and (2), A composition wherein the first agent contains at least (3) a polymerization initiator and does not contain (5) a reducing agent, and the second agent does not contain at least (3) a polymerization initiator and contains (5) a reducing agent.

2. 2. The composition according to claim 1, wherein the content of component (1) is 1 part by mass or more and 15 parts by mass or less, based on 100 parts by mass of the total of components (1) and (2).

3. 3. The composition according to claim 1, wherein the weight average molecular weight Mw of component (1) measured by GPC is 1,000 or more.

4. The composition according to any one of claims 1 to 3, further comprising 5 parts by mass or more and 35 parts by mass or less of an elastomer (4) based on 100 parts by mass of the total of the components (1) and (2).

5. A curable composition comprising the composition according to any one of claims 1 to 4.

6. An adhesive composition containing the curable composition of claim 5.

7. A bonded body obtained by bonding adherends with the adhesive composition according to claim 6.

8. A bonding method comprising applying the adhesive composition according to claim 6 to an adherend and bonding the adherend.

Images