Adhesive compositions, adhesives for electronic components, and adhesives for portable electronic devices

Abstract

The adhesive composition of the present invention comprises: a moisture-curing resin (A) having at least one of a polycarbonate backbone and a polyester backbone, and having isocyanate groups and (meth)acrylic groups; and a moisture-curing resin (B) having isocyanate groups and not having (meth)acrylic groups.

Description

Technical Field

[0001] This invention relates to an adhesive composition, an adhesive for electronic components, and an adhesive for portable electronic devices. Prior Technology

[0002] Moisture-curing adhesives containing moisture-curing resins that harden upon contact with external moisture have been widely used in the past. For example, Patent Document 1 discloses a moisture-curing adhesive with an isocyanate-terminated prepolymer as its main component. This isocyanate-terminated prepolymer is obtained by reacting a polyol containing a polycarbonate diol with a specific structure and a polyisocyanate compound in a molar ratio of isocyanate group to hydroxyl group of 1.3 to 3.5. The moisture-curing adhesive shown in Patent Document 1 can be used in clothing applications. It has excellent resistance to sweat degradation and hydrolysis, and can improve softness. In particular, it shows excellent resistance to degradation of higher fatty acids, which are one of the components of sweat.

[0003] In recent years, the use of moisture-curing adhesives in various applications has been studied. For example, as disclosed in Patent Document 2, applications in electronic devices such as display devices or semiconductor chips are also being studied. [Previous Technical Documents] [Patent Literature]

[0004] Patent Document 1: Japanese Patent Application Publication No. 2003-313531 Patent Document 2: International Publication No. 2020 / 149377 Summary of the Invention

[0005] [The problem that the invention aims to solve]

[0006] Furthermore, in recent years, portable electronic devices such as smartphones and tablet computers have become increasingly widespread. Wearable devices are also gaining popularity as portable electronic devices. These devices, including smartphones and wearables, have prolonged contact with the skin. Therefore, adhesives used in these devices come into frequent contact with sebum, sweat, and even chemicals in cosmetics and sunscreens, sometimes requiring oil resistance. Furthermore, since portable electronic devices are often dropped during use, adhesives used in portable electronic devices generally require high impact resistance to prevent parts from falling off when dropped.

[0007] For example, as described in Patent Document 1, by using a polyol with a specific structure such as polycarbonate in the moisture-curing resin, a certain level of oil resistance can be ensured. However, in the case of conventional moisture-curing adhesives, it is difficult to ensure both oil resistance and high impact resistance.

[0008] Therefore, the objective of this invention is to obtain an adhesive composition that has moisture-curing properties while simultaneously possessing high oil resistance and high impact resistance. [Technical means to solve the problem]

[0009] Through dedicated research, the inventors discovered that the above-mentioned problems can be solved by using at least two moisture-curing resins with specific structures, thereby completing the following invention. That is, the present invention provides the following [1] to

[26] . [1] An adhesive composition comprising: a moisture-curing resin (A) having at least one of a polycarbonate backbone and a polyester backbone, and having isocyanate groups and (meth)acrylic groups; and Moisture-curing resin (B) has isocyanate groups and does not have (meth)acrylic groups. [2] The adhesive composition as described in [1] above, wherein the moisture-curing resin (B) has at least one of a polycarbonate backbone and a polyester backbone. [3] The adhesive composition as described in [1] or [2] above, wherein the moisture-curing resin (B) has a polycarbonate backbone. [4] The adhesive composition described in any of [1] to [3] above, wherein the moisture-curing resin (B) has isocyanate groups at both ends. [5] The adhesive composition described in any of [1] to [4] above, wherein the moisture-curing resin (A) has a polycarbonate backbone. [6] The adhesive composition described in any of [1] to [5] above, wherein the moisture-curing resin (A) has an aromatic isocyanate group. [7] The adhesive composition described in any of [1] to [6] above further contains a free radical polymerizable compound (C) that does not contain an isocyanate group. [8] The adhesive composition described in [7] above, wherein the free radical polymerizable compound (C) contains at least one of the following: free radical polymerizable compounds selected from the group consisting of free radical polymerizable compounds having an aromatic ring and free radical polymerizable compounds having an amide ring. [9] The adhesive composition described in [7] or [8] above, wherein the free radical polymerizable compound (C) contains a compound having a (meth)acrylic group.

[10] The adhesive composition described in any of [7] to [9] above, wherein the free radical polymerizable compound (C) contains: other free radical polymerizable compounds besides free radical polymerizable compounds having aromatic rings and free radical polymerizable compounds having amide rings.

[11] The adhesive composition described in

[10] above, wherein the other free radical polymerizable compound comprises at least one selected from the group consisting of aliphatic amine esters (meth)acrylates and (meth)acrylate compounds.

[12] The adhesive composition described in any of [7] to

[11] above, wherein the content of the free radical polymerizable compound (C) is 5 parts by mass or more and 50 parts by mass or less relative to 100 parts by mass of the moisture-curing resin and the free radical polymerizable compound.

[13] The adhesive composition described in any of [7] to

[12] above further contains a photopolymerization initiator.

[14] The adhesive composition described in any of [1] to

[13] above, wherein the moisture-curing resin (A) has an isocyanate group at one end and a (meth)acrylic group at the other end.

[15] The adhesive composition described in any of [1] to

[14] above, wherein the moisture-curing resin (A) is a moisture-curing amine ester resin (A1).

[16] The adhesive composition described in

[15] above, wherein the moisture-curing amine resin (A1) is obtained by reacting a polyol compound, a polyisocyanate compound, and a compound having a (meth)acrylic group.

[17] In any of the adhesive compositions described in [1] to

[16] above, the content of the moisture-curing resin (A) is 0.1 parts by mass or more and 30 parts by mass or less relative to 100 parts by mass of the moisture-curing resin and the free radical polymerizable compound.

[18] The adhesive composition described in any of [1] to

[17] above, wherein the moisture-curing resin (B) is a moisture-curing amine ester resin (B1).

[19] The adhesive composition described in

[18] above, wherein the moisture-curing amine resin (B1) is obtained by reacting a polyol compound with a polyisocyanate compound.

[20] The adhesive composition described in any of [1] to

[19] above, wherein the content of the moisture-curing resin (B) is 30 parts by mass or more and 99.9 parts by mass or less relative to 100 parts by mass of the total mass of the moisture-curing resin and the free radical polymerizable compound.

[21] The adhesive composition described in any of [1] to

[20] above further contains a filler.

[22] An adhesive for electronic components, which is composed of the adhesive composition described in any one of [1] to

[21] above.

[23] An adhesive for portable electronic devices, which is composed of the adhesive composition described in any one of [1] to

[21] above.

[24] A hardened body, which is a hardened body of the adhesive composition described in any one of [1] to

[21] above.

[25] Use of an adhesive composition described in any one of [1] to

[21] above for use in electronic components.

[26] Use of an adhesive composition described in any one of [1] to

[21] above for use in a portable electronic device. [Effects of the Invention]

[0010] According to the present invention, it is possible to obtain an adhesive composition with moisture-curing properties that simultaneously possesses high oil resistance and high impact resistance. Simple Explanation of the Diagram

[0011] [Figure 1] is a schematic diagram of the method for evaluating adhesion force. Figure 1(a) is a top view and Figure 1(b) is a side view. [Figure 2] is a schematic side view showing the evaluation method of impact resistance. Implementation

[0012] <Adhesive composition> The adhesive composition of the present invention contains a moisture-curing resin (A) and a moisture-curing resin (B). The following is a detailed description of each moisture-curing resin.

[0013] [Moisture-curing resin (A)] The moisture-curing resin (A) has at least one of a polycarbonate backbone and a polyester backbone, and has an isocyanate group and a (meth)acrylic group. The adhesive composition of the present invention, by combining a moisture-curing resin (A) having the above-described structure and a moisture-curing resin (B) having the following structure, can achieve both a certain degree of adhesion and high oil resistance and high impact resistance. Furthermore, the adhesive composition, by containing both moisture-curing resin (A) and moisture-curing resin (B), possesses moisture-curing properties and can be used as a moisture-curing adhesive. Furthermore, in this specification, "(meth)acryl" refers to acrylonitrile or methacryl, and so do other similar terms.

[0014] Moisture-curing resin (A) may have either a polycarbonate backbone or a polyester backbone in one molecule, or both in one molecule. Furthermore, moisture-curing resin (A) may also be used in combination with moisture-curing resins having a polycarbonate backbone and moisture-curing resins having a polyester backbone. As for the moisture-curing resin (A), from the viewpoint of flexibility, a moisture-curing resin with a polyester backbone can be used, and a moisture-curing resin with a polycarbonate backbone is preferred. By using a moisture-curing resin with a polycarbonate backbone, oil resistance is improved, and adhesion is easily maintained even after contact with oil. As for the moisture-curing resin (A), it is preferable to use the moisture-curing resin (A) having a polycarbonate backbone alone, but as mentioned above, it can also be used in combination with the moisture-curing resin (A) having a polyester backbone. When the moisture-curing resin (A) contains the moisture-curing resin (A) having a polycarbonate backbone, the content of the moisture-curing resin (A) having a polycarbonate backbone is preferably 50% by mass or more, more preferably 75% by mass or more and 100% by mass or less. As described below, the polycarbonate backbone and polyester backbone in the moisture-curing resin (A) are preferably derived from polyol compounds. Therefore, the polycarbonate backbone can be derived from polycarbonate polyols, and the polyester backbone can be derived from polyester polyols.

[0015] Furthermore, the moisture-curing resin (A) may have one or more isocyanate groups per molecule, preferably one isocyanate group per molecule. Also, the moisture-curing resin (A) may have either or both aliphatic and aromatic isocyanate groups, preferably aromatic isocyanate groups. The presence of aromatic isocyanate groups in the moisture-curing resin (A) improves its oil resistance, easily maintaining good adhesion even after contact with oils. The moisture-curing resin (A) preferably has isocyanate groups at the ends. Furthermore, aromatic isocyanate groups are isocyanate groups directly bonded to aromatic rings, while aliphatic isocyanate groups are isocyanate groups directly bonded to aliphatic carbon atoms.

[0016] Aromatic isocyanate groups are derived from the isocyanate groups of aromatic isocyanate compounds, details of which are described below. Aliphatic isocyanate groups are derived from the isocyanate groups of aliphatic isocyanate compounds, details of which are described below. The (meth)acrylic group in the moisture-curing resin (A) may be derived from compounds containing (meth)acrylic groups as described later. The moisture-curing resin (A) preferably has a (meth)acrylic group at its terminal. The (meth)acrylic group in the moisture-curing resin (A) can react via photocuring as described later, but photocuring is not always necessary. That is, the moisture-curing resin (A) can react with itself via photocuring, and can also react with the free radical polymerizable compound (C) described later, but a reaction is not always required. From the viewpoint of impact resistance, the moisture-curing resin (A) preferably has an isocyanate group at one end and a (meth)acrylic group at the other end. Furthermore, in this specification, "end" refers to the end of the main chain.

[0017] (Moisture-curing amine ester resin (A1)) The moisture-curing resin (A) is preferably a moisture-curing amine ester resin (A1). Therefore, the moisture-curing resin (A) preferably has amine ester bonds in addition to isocyanate groups and (meth)acrylic groups. By using a moisture-curing amine ester resin (A1) as the moisture-curing resin (A), oil resistance and other properties are easily improved. The following explanation focuses on the case where the moisture-curing resin (A) is a moisture-curing amine ester resin (A1).

[0018] The moisture-curing amine resin (A1) is preferably obtained by reacting a polyol compound, a polyisocyanate compound, and a compound having a (meth)acrylic group. The compound having a (meth)acrylic group may have either a hydroxyl group or an isocyanate group, but from the viewpoint that (meth)acrylic groups can be easily introduced into the resin (A1), it is preferred to have an isocyanate group. The reactions of the aforementioned polyol compounds, polyisocyanate compounds, and compounds having (meth)acrylic groups are generally carried out in the range of [NCO] / [OH] = 2.0 to 2.5, where the molar ratio of isocyanate group (NCO) to hydroxyl group (OH) in these compounds is [NCO] / [OH] = 2.0 to 2.5.

[0019] Moisture-curing amine resin (A1) can also be obtained by reacting a polyol compound with a polyisocyanate compound to obtain a reaction product, and then reacting it with a compound having isocyanate or hydroxyl groups and (meth)acrylic groups. Alternatively, it can be obtained by reacting a polyol compound with a compound having isocyanate or (meth)acrylic groups to obtain a reaction product, and then reacting it with a polyisocyanate compound. Furthermore, it can also be obtained by reacting a polyisocyanate compound with a compound having hydroxyl or (meth)acrylic groups to obtain a reaction product, and then reacting it with a polyol compound. Moreover, moisture-curing amine resin (A1) can also be obtained by simultaneously reacting a polyol compound, a polyisocyanate compound, and a compound having isocyanate or hydroxyl groups and (meth)acrylic groups. Furthermore, in the synthesis of the moisture-curing amine ester resin (A1), at least a portion of the moisture-curing amine ester resin (B1) described later can be synthesized simultaneously. Examples of such moisture-curing amine ester resins (B1) include amine ester resins having isocyanate groups at both ends. Moreover, in the synthesis of the moisture-curing amine ester resin (A1), amine esters (meth)acrylates having (meth)acrylic groups but not isocyanate groups can also be synthesized.

[0020] The polyol compound that serves as a raw material for moisture-curing amine ester resin (A1) has two or more hydroxyl groups in one molecule. Either polycarbonate polyol or polyester polyol can be used as the polyol compound.

[0021] As a polycarbonate polyol, polycarbonate diol is preferred. Specific examples of polycarbonate diols include compounds represented by the following formula (1).

[0022] In equation (1), R is a divalent hydrocarbon group with 4 to 16 carbon atoms, and n is an integer from 2 to 500. []

[0023] In formula (1), R is preferably an aliphatic saturated hydrocarbon group. Because R is an aliphatic saturated hydrocarbon group, heat resistance and flexibility are easily improved. Furthermore, it is less prone to yellowing due to heat degradation, and weather resistance is also improved. R composed of aliphatic saturated hydrocarbon groups can have a chain structure or a cyclic structure, but a chain structure is preferred. Moreover, the chain structure R can be either straight-chain or branched. The optimal value for n is 5~200, more preferably 10~150, and even more preferably 20~50. Furthermore, the R contained in the polycarbonate polyol constituting the moisture-curing amine ester resin (A1) may be a single type or two or more types. When two or more types are used together, it is preferable that at least a portion of them are chain-like aliphatic saturated hydrocarbon groups with six or more carbon atoms. It is also preferable that one molecule contains two or more types of R, and more preferably two or three types of R in one molecule. The chain-like aliphatic saturated hydrocarbon group with 6 or more carbon atoms is preferably 6 or more carbon atoms and 12 or less, more preferably 6 or more carbon atoms and 10 or less, and even more preferably 6 or more carbon atoms and 8 or less. Specific examples of R can be linear chains such as tetramethylene, pentenyl, hexamethylene, heptamethylene, octamethylene, nonamethylene, and decamethylene, or branched chains such as methylpentyl or methyloctamethylene. Multiple Rs in a molecule can be identical or different. Furthermore, from the viewpoint of achieving a fixed or higher elastic modulus, R preferably contains branched aliphatic saturated hydrocarbon groups; from the viewpoint of weather resistance, R preferably contains linear aliphatic saturated hydrocarbon groups. In polycarbonate polyols, both branched and linear Rs can be used. Furthermore, polycarbonate polyols can be used alone or in combination of two or more.

[0024] Examples of the aforementioned polyester polyols include: polyester polyols obtained by reacting a polycarboxylic acid with a polyol; and poly-ε-caprolactone polyols obtained by ring-opening polymerization of ε-caprolactone. Polyester diols are preferred as polyester polyols. []

[0025] Examples of polycarboxylic acids that can be used as raw materials for polyester polyols include: diaromatic carboxylic acids such as terephthalic acid, isophthalic acid, 1,5-naphthalenedicarboxylic acid, and 2,6-naphthalenedicarboxylic acid; dialiphatic carboxylic acids such as succinic acid, glutaric acid, adipic acid, pimelic acid, octanoic acid, azelaic acid, sebacic acid, decamethyldicarboxylic acid, and dodecamethyldicarboxylic acid; triaromatic carboxylic acids such as trimellitic acid, pyromellitic acid, pyromellitic tetracarboxylic acid, and naphthalenetricarboxylic acid; and triaromatic carboxylic acids such as cyclohexanetricarboxylic acid and hexanetricarboxylic acid. These polycarboxylic acids can be used alone or in combination of two or more. Polyols that can be used as raw materials for polyester polyols include, for example, ethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,4-butanediol, neopentyl glycol, 1,5-pentanediol, 1,6-hexanediol, diethylene glycol, cyclohexanediol, etc.

[0026] In moisture-curing amine ester resins (A1), a single polyol compound may be used alone, or two or more may be used in combination. Furthermore, in this invention, by using a polycarbonate polyol as the polyol compound that serves as the raw material for the moisture-curing amine resin (A1), a polycarbonate backbone is introduced into the moisture-curing amine resin (A1), thereby producing a moisture-curing amine resin (A1) having a polycarbonate backbone. Similarly, by using a polyester polyol as the polyol compound that serves as the raw material for the moisture-curing amine resin (A1), a polyester backbone is introduced into the moisture-curing amine resin (A1), thereby producing a moisture-curing amine resin (A1) having a polyester backbone.

[0027] Furthermore, the moisture-curing amine resin (A1) can also be produced by using both polycarbonate polyol and polyester polyol as raw materials, thereby introducing both polycarbonate and polyester backbones into the moisture-curing amine resin (A1). That is, the moisture-curing amine resin (A1) can also be a moisture-curing amine resin (A1) containing both a polycarbonate backbone and a polyester backbone in a single molecule. Moreover, in this specification, the term "moisture-curing amine resin (A1) having a polycarbonate backbone" also includes moisture-curing amine resin (A1) containing both a polycarbonate backbone and a polyester backbone. Other similar terms are used similarly.

[0028] The polyisocyanate compound that serves as a raw material for moisture-curing amine ester resin (A1) has two or more isocyanate groups in one molecule, preferably having two isocyanate groups. Examples of polyisocyanate compounds include aromatic polyisocyanate compounds and aliphatic polyisocyanate compounds. Examples of aromatic polyisocyanate compounds include: diphenylmethane diisocyanate, liquid modified diphenylmethane diisocyanate, toluene diisocyanate, and naphthalene-1,5-diisocyanate. Aromatic polyisocyanate compounds can also be polymerized forms of these aromatic polyisocyanate compounds, and can also be polymerized MDI, etc. Diphenylmethane diisocyanate is preferred as an aromatic polyisocyanate compound. Examples of aliphatic polyisocyanate compounds include: hexamethylene diisocyanate, trimethylhexamethylene diisocyanate, lysine diisocyanate, norbornene diisocyanate, trans-cyclohexane-1,4-diisocyanate, isophorone diisocyanate, hydrogenated phenyl dimethyl diisocyanate, hydrogenated diphenylmethane diisocyanate, cyclohexane diisocyanate, bis(isocyanatomethyl)cyclohexane, dicyclohexylmethane diisocyanate, etc. Aliphatic polyisocyanate compounds can also be polymerized forms of these aliphatic polyisocyanate compounds. Polyisocyanate compounds can be used alone or in combination of two or more.

[0029] In this invention, in the synthesis of the moisture-curing amine ester resin (A1), if an aromatic polyisocyanate compound is used, the moisture-curing resin (A) contains aromatic isocyanate groups; if an aliphatic polyisocyanate compound is used, the moisture-curing resin (A) contains aliphatic isocyanate groups. Therefore, as the polyisocyanate compound, an aromatic polyisocyanate compound is preferred.

[0030] As described above, compounds containing (meth)acrylic groups that serve as raw materials for moisture-curing amine resins (A1) may contain either an isocyanate group or a hydroxyl group, preferably compounds containing both an isocyanate group and a (meth)acrylic group. Examples of compounds containing both an isocyanate group and a (meth)acrylic group include, for example, the compounds represented by the following formula (2).

[0031] In formula (2), R1 represents hydrogen or methyl, and R2 represents a divalent saturated hydrocarbon group with 1 to 10 carbon atoms that may have an ether bond.

[0032] Examples of compounds having an isocyanate group and a (meth)acrylic group include 2-(meth)acrylic oxyethyl isocyanate and 2-(meth)acrylic oxyethoxyethyl isocyanate.

[0033] Compounds containing hydroxyl and (meth)acrylic groups that can be used as raw materials for moisture-curing amine ester resins (A1) include: 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 2-hydroxybutyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, and hydroxyalkyl (meth)acrylates. Furthermore, these compounds having hydroxyl and (meth)acrylic groups can be reacted with various diisocyanate compounds at a ratio such as isocyanate group / hydroxyl (molar ratio) = 2 to obtain compounds, etc. These compounds can also be used as raw materials for moisture-curing amine resins (A1) having (meth)acrylic groups.

[0034] The weight-average molecular weight of the moisture-curing resin (A) is not particularly limited, but is preferably 1,000 or more and 50,000 or less, more preferably 2,000 or more and 30,000 or less, and even more preferably 3,000 or more and 20,000 or less. If the weight-average molecular weight is above the lower limit mentioned above, the crosslinking density will not become too high during curing, and the flexibility after curing will easily increase. Furthermore, for example, it has a certain hardness in the semi-cured state after light curing and before moisture curing, which easily ensures excellent shape retention. Furthermore, by making the weight-average molecular weight below the upper limit mentioned above, the adhesive composition can easily have moderate fluidity before curing, for example, even at room temperature (e.g., 25°C), and the coatability becomes good. Furthermore, in this specification, the weight-average molecular weight is determined using gel permeation chromatography (GPC) and calculated by conversion to polystyrene. Shodex LF-804 (manufactured by Showa Denko Corporation) is an example of the column used for determining the weight-average molecular weight using GPC and polystyrene conversion. Tetrahydrofuran is an example of the solvent used in GPC.

[0035] The content of the moisture-curing resin (A) in the adhesive composition is, for example, 0.1 parts by mass or more and 30 parts by mass or less, relative to 100 parts by mass of the total mass of the moisture-curing resin and the free radical polymerizable compound. By ensuring that the content of component (A) is within the above-mentioned range, the adhesive composition exhibits good oil resistance and adhesion, and readily improves impact resistance. Based on these views, the content of the moisture-curing resin (A) is preferably 0.5 parts by mass or more and 25 parts by mass or less, more preferably 0.7 parts by mass or more and 15 parts by mass or less, and even more preferably 1 part by mass or more and 10 parts by mass or less. Furthermore, in this specification, when the free radical polymerizable compound (C) component is not present, the total amount of moisture-curing resin and free radical polymerizable compound refers to the total content of moisture-curing resin.

[0036] [Moisture-curing resin (B)] The moisture-curing resin (B) in this invention is a resin having isocyanate groups but not (meth)acrylic groups. By having the moisture-curing resin (B), the adhesive composition can be endowed with suitable adhesive properties.

[0037] The moisture-curing resin (B) preferably has at least one of a polycarbonate backbone and a polyester backbone. By having any of these backbones, the moisture-curing resin (B) can easily achieve both oil resistance and impact resistance. A moisture-curing resin (B) having at least one of a polycarbonate backbone and a polyester backbone may have either a polycarbonate backbone or a polyester backbone in one molecule, or both a polycarbonate backbone and a polyester backbone in one molecule. Furthermore, the moisture-curing resin (B) may also be used in combination with a moisture-curing resin having a polycarbonate backbone and a moisture-curing resin having a polyester backbone.

[0038] Furthermore, the moisture-curing resin (B) is preferably one with a polycarbonate backbone. By using a moisture-curing resin (B) with a polycarbonate backbone, the adhesive composition can more easily achieve both high oil resistance and high impact resistance. In particular, the oil resistance becomes excellent, easily ensuring high adhesion even after contact with oil. As for the moisture-curing resin (B), it is preferable to use the moisture-curing resin (B) having a polycarbonate backbone alone, but as mentioned above, it can also be used in combination with the moisture-curing resin (B) having a polyester backbone. When the moisture-curing resin (B) contains the moisture-curing resin (B) having a polycarbonate backbone, the content of the moisture-curing resin (B) having a polycarbonate backbone is preferably 50% by mass or more, more preferably 75% by mass or more and 100% by mass or less.

[0039] As described below, the polycarbonate backbone and polyester backbone in the moisture-curing resin (B) are preferably derived from polyol compounds. Therefore, the polycarbonate backbone can be derived from polycarbonate polyols, and the polyester backbone can be derived from polyester polyols.

[0040] Furthermore, the moisture-curing resin (B) may have one or more isocyanate groups per molecule, preferably two or more isocyanate groups per molecule, and more preferably two isocyanate groups. Also, the moisture-curing resin (B) may have any one or both of aliphatic isocyanate groups and aromatic isocyanate groups, preferably aromatic isocyanate groups. By having aromatic isocyanate groups, the moisture-curing resin (B) improves oil resistance, easily maintaining good adhesion even after contact with oils.

[0041] Aromatic isocyanate groups are derived from the isocyanate groups of aromatic isocyanate compounds, while aliphatic isocyanate groups are derived from the isocyanate groups of aliphatic isocyanate compounds. The moisture-curing resin (B) preferably has isocyanate groups at its ends, and more preferably has isocyanate groups at both ends. Because the moisture-curing resin (B) has isocyanate groups at both ends, it is easily converted to a higher molecular weight through moisture curing, thus ensuring higher adhesion. Furthermore, from the viewpoint of oil resistance, the moisture-curing resin (B) is further preferably equipped with aromatic isocyanate groups at both ends.

[0042] (Moisture-curing amine ester resin (B1)) Moisture-curing resin (B) is preferably moisture-curing amine ester resin (B1). Therefore, moisture-curing resin (B) preferably has amine ester bonds in addition to isocyanate groups. By using moisture-curing amine ester resin (B1) as moisture-curing resin (B), oil resistance and other properties are easily improved. The following explanation focuses on the case where moisture-curing resin (B) is moisture-curing amine ester resin (B1). Moisture-curing amine ester resin (B1) may have one isocyanate group or more than two isocyanate groups in one molecule, but as mentioned above, it is more preferably that isocyanate groups are present at both ends of the main chain.

[0043] Moisture-curing amine resin (B1) can be obtained by reacting a polyol compound with a polyisocyanate compound. The reaction between the polyol compound and the polyisocyanate compound is usually carried out in a molar ratio of [NCO] / [OH] = 2.0 to 2.5 for the isocyanate group (NCO) in the polyisocyanate compound and the hydroxyl group (OH) in the polyol compound.

[0044] As a polyol compound for use in moisture-curing urethane resin (B1), a known polyol compound commonly used in the manufacturing process of polyurethane can be used. From the viewpoint that it has both oil resistance and impact resistance, polyester polyol and polycarbonate polyol are preferred, among which polycarbonate polyol is particularly preferred. Furthermore, in this invention, by using a polycarbonate polyol as the polyol compound that serves as the raw material for the moisture-curing amine ester resin (B1), a polycarbonate backbone is introduced into the moisture-curing amine ester resin (B1), thereby producing a moisture-curing amine ester resin (B1) having a polycarbonate backbone. Alternatively, by using a polyester polyol as the polyol compound that serves as the raw material for the moisture-curing amine ester resin (B1), a polyester backbone is introduced into the moisture-curing amine ester resin (B1), thereby producing a moisture-curing amine ester resin (B1) having a polyester backbone. Furthermore, both a polycarbonate backbone and a polyester backbone can also be introduced into a single molecule.

[0045] Polycarbonate polyols and polyester polyols used as raw materials for moisture-curing amine resins (B1) can be the same as those listed as raw materials for moisture-curing amine resins (A1), and therefore the description is omitted.

[0046] The polyisocyanate compound used as a raw material for moisture-curing amine ester resin (B1) has two or more isocyanate groups in one molecule, preferably two isocyanate groups. Examples of polyisocyanate compounds include aromatic polyisocyanate compounds and aliphatic polyisocyanate compounds. As for aromatic or aliphatic polyisocyanate compounds, those listed as raw materials for moisture-curing amine ester resin (A1) can be used, and the description is the same, therefore, the description is omitted. Similar to moisture-curing amine ester resin (B1), aromatic polyisocyanate compounds are preferred as polyisocyanate compounds, among which diphenylmethane diisocyanate is particularly preferred.

[0047] As a moisture-curing resin (B), it can also be a resin that, in addition to having isocyanate groups, has an organosilicone group represented by the following formula (3).

[0048] In formula (3), R3 and R4 are independently hydrogen atoms, alkyl groups with 1 to 5 carbon atoms, or aryl groups, and each R3 and R4 may be the same or different. x represents an integer from 0 to 2.

[0049] In formula (3) above, when R3 and R4 are both aryl groups, examples of such aryl groups include phenyl, naphthyl, and 2-methylphenyl. In formula (3) above, from the viewpoint of exhibiting superior adhesion, x is preferably 1 or 2. Furthermore, the case where x is 0 in the above formula (3) refers to the silicon atom being bonded to 3 -OR 4 bonds and not to the atom or base represented by R 3. In the radical represented by formula (3), from the viewpoint of improving adhesion, R3 and R4 are preferably alkyl groups having 1 to 5 carbons, and more preferably either methyl or ethyl.

[0050] Regarding the moisture-curing resin (B), when it contains the aforementioned organosilicone groups, the moisture-curing resin (B) is preferably a moisture-curing amine ester resin (B1). Therefore, it is preferable that, in addition to isocyanate groups and organosilicone groups, it also has amine ester bonds. Furthermore, when the moisture-curing resin (B) contains the aforementioned organosilicone groups, it is preferable that each single end has both an organosilicone group and an isocyanate group.

[0051] The moisture-curing amine resin (B1) with organosilicon groups can be obtained by reacting a polyol compound with a polyisocyanate compound to obtain a compound having amine bonds and isocyanate groups, and a compound having reactive functional groups and groups represented by formula (3). Furthermore, the above-mentioned "reactive functional groups" refer to groups that can react with the above-mentioned compounds having amine bonds and isocyanate groups, preferably groups that can react with isocyanate groups.

[0052] Polyol compounds and polyisocyanate compounds are as described above. Examples of compounds having the reactive functional groups and those represented by formula (3) include: 3-mercaptopropyltrimethoxysilane, 3-mercaptopropyltriethoxysilane, 3-epoxypropoxypropyltrimethoxysilane, 3-epoxypropoxypropyltriethoxysilane, 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, 3-epoxypropoxypropylmethyldiethoxysilane, 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 3-(2-aminoethyl)aminopropyltrimethoxysilane, 3-(2-aminoethyl)aminopropyltriethoxysilane, 3-(2- Aminoethylaminopropylmethyldimethoxysilane, 3-(meth)propenyloxypropyltrimethoxysilane, 3-(meth)propenyloxypropyltriethoxysilane, 3-(meth)propenyloxypropylmethyldimethoxysilane, 3-(meth)propenyloxypropylmethyldiethoxysilane, vinyltrimethoxysilane, vinyltriethoxysilane, 3-isocyanate-propyltrimethoxysilane, 3-mercaptopropylmethyldimethoxysilane, 3-mercaptopropylmethyldiethoxysilane, 3-epoxypropoxypropylmethyldimethoxysilane, 3-epoxypropoxypropylmethyldiethoxysilane, etc. From a reactivity perspective, compounds having a thiol group as a reactive functional group are preferred.

[0053] The weight-average molecular weight of the moisture-curing resin (B) is not particularly limited, but it is preferably 1,000 or higher and 50,000 or lower. If the weight-average molecular weight is above the lower limit mentioned above, the crosslinking density will not become too high during curing, and the flexibility after curing will be easily increased. Furthermore, for example, having a certain hardness in the semi-cured state after light curing and before moisture curing makes it easy to ensure excellent shape retention. Moreover, by making the weight-average molecular weight below the upper limit mentioned above, the adhesive composition has moderate fluidity even at room temperature (e.g., 25°C) before curing, and the room temperature coatability becomes good. Based on these views, the weight average molecular weight of the moisture-curing resin (B) is preferably 2,000 or more and 30,000 or less, and even more preferably 3,000 or more and 20,000 or less.

[0054] The content of moisture-curing resin (B) in the adhesive composition is, for example, 30 parts by mass or more and 99.9 parts by mass or less per 100 parts by mass of the total mass of the moisture-curing resin and the free radical polymerizable compound. If the content is above the lower limit, it is easy to improve the adhesion and to impart appropriate moisture curing properties. Furthermore, if it is below the upper limit, it is easy to contain a certain amount of moisture-curing resin (A), and it is easy to achieve both oil resistance and impact resistance. Based on the above viewpoints and the viewpoint that it contains a certain amount or more of the following free radical polymerizable compound (C), the content of the moisture-curing resin (B) is preferably 45 parts by mass or more and 94 parts by mass or less, more preferably 50 parts by mass or more and 88 parts by mass or less, and even more preferably 53 parts by mass or more and 80 parts by mass or less.

[0055] The moisture-curing resin is preferably composed of the aforementioned moisture-curing resins (A) and (B), but without impairing the effects of the present invention, it may also contain moisture-curing resins other than those (A) and (B). The moisture-curing resin is a resin that can react with water present in the air or in the adhesive to cure, and may contain functional groups such as isocyanate groups and organosilicone groups. The content of moisture-curing resin other than the aforementioned moisture-curing resins (A) and (B) is not particularly limited. When the total amount of moisture-curing resin is set to 100 parts by mass, it can be, for example, less than 30 parts by mass or less than about 10 parts by mass.

[0056] [Free radical polymerizable compound (C)] The adhesive composition of the present invention preferably contains, in addition to the moisture-curing resins (A) and (B) described above, a free radical polymerizable compound (C). The free radical polymerizable compound (C) is a compound that does not contain isocyanate groups. In this invention, by using a free radical polymerizable compound (C), the adhesive composition is easily endowed with photocurability, making it a photo-moisture-curing type with excellent photocurability. Therefore, since the adhesive composition can impart a fixed adhesive force simply by light irradiation, a certain level of adhesive force can still be ensured in the semi-cured state after photocuring and before moisture curing. Furthermore, the semi-cured state after photocuring and before moisture curing has a certain level of hardness, easily ensuring excellent shape retention. If the adhesive composition has excellent shape retention, for example, when the adhesive composition is applied using a dispensing device, the applied adhesive composition can maintain a certain height after photocuring, thus ensuring a certain spacing between the bonded elements in the cured body formed by the adhesive composition. Furthermore, by using a free radical polymerizable compound (C) in addition to moisture-curing resins (A) and (B), the viscosity of the adhesive composition can be easily reduced. Therefore, the adhesive composition can easily maintain adequate fluidity at room temperature (e.g., 25°C) before curing, resulting in good coatability. Furthermore, the free radical polymerizable compound (C) may be a compound that does not have moisture-curing properties, and therefore may not contain the aforementioned organosilicone or other moisture-curing functional groups.

[0057] Free radical polymerizable compounds (C) possess free radical polymerizable functional groups in their molecules. Suitable free radical polymerizable functional groups are compounds with unsaturated double bonds, such as (meth)acrylyl, vinyl, styryl, allyl, etc. From the perspective of adhesion, among the aforementioned free radical polymerizable functional groups, (meth)acrylic acid group is preferable; that is, free radical polymerizable compound (C) is preferably a compound containing a (meth)acrylic acid group. Furthermore, hereinafter, compounds containing a (meth)acrylic acid group are also referred to as "(meth)acrylic acid compounds".

[0058] The free radical polymerizable compound (C) is preferably one of the following: a free radical polymerizable compound selected from the group consisting of free radical polymerizable compounds having an aromatic ring and free radical polymerizable compounds having an amide ring. These compounds are preferably monofunctional compounds having one free radical polymerizable functional group in the molecule, but may also be polyfunctional compounds having two or more free radical polymerizable functional groups.

[0059] As free radical polymerizable compounds with aromatic rings, examples include monofunctional (meth)acrylate compounds with aromatic rings. Specifically, examples include: benzyl (meth)acrylate, 2-phenylethyl (meth)acrylate, and other phenylalkyl (meth)acrylates; phenoxyethyl (meth)acrylate and other phenoxyalkyl (meth)acrylates. Furthermore, (meth)acrylates with multiple benzene rings, such as a benzene skeleton or a biphenyl skeleton, can also be included. Specifically, examples include: benzene-type (meth)acrylates, ethoxylated o-phenylphenol acrylate, etc. Alternatively, examples include: phenoxy diethylene glycol (meth) acrylate, phenoxy polyethylene glycol (meth) acrylate, nonylphenoxy diethylene glycol (meth) acrylate, nonylphenoxy polyethylene glycol (meth) acrylate, and other phenoxy polyoxyethylene (meth) acrylates. Of these, phenoxyalkyl (meth)acrylate is preferred, and phenoxyethyl (meth)acrylate is even more preferred. Furthermore, examples of free radical polymerizable compounds with amide rings include: (meth)acrylate compounds with amide rings such as N-(meth)propenylamideoxyethylhexahydrophthalamideimide; and vinyl compounds with amide rings such as N-vinylphthalamideimide, N-allylphthalamideimide, N-(3-buten-1-yl)phthalamideimide, and N-allyloxyphthalamideimide.

[0060] The adhesive composition improves oil resistance by containing at least one of a free radical polymerizable compound having an aromatic ring and a free radical polymerizable compound having an imine ring, and thus maintains adhesion better even after contact with oil. [] The free radical polymerizable compound (C) may contain one of the following: a free radical polymerizable compound having an aromatic ring, or a free radical polymerizable compound having a amide ring, or both. More preferably, the free radical polymerizable compound (C) contains at least a free radical polymerizable compound having an amide ring.

[0061] The free radical polymerizable compound (C) may be composed of at least one of free radical polymerizable compounds selected from those having an aromatic ring and those having an amide ring, and may also contain other free radical polymerizable compounds (referred to as "other free radical polymerizable compounds"). The content of compounds selected from the group consisting of free radical polymerizable compounds having aromatic rings and free radical polymerizable compounds having amide rings in the adhesive composition, relative to the total amount of the free radical polymerizable compound (C), is preferably 20% by mass or more, more preferably 25% by mass or more, further preferably 50% by mass or more, and further preferably 80% by mass or more. Furthermore, the above-mentioned content of these compounds is only required to be 100% by mass or less. By containing a greater amount of these compounds, the oil resistance of the adhesive composition is improved, and a higher adhesion is maintained even after contact with oil. []

[0062] Various aliphatic (meth)acrylate compounds can be listed as other free radical polymerizable compounds. Specifically, aliphatic amine esters (meth)acrylates and other (meth)acrylate compounds other than aliphatic amine esters (meth)acrylates can be used as other free radical polymerizable compounds. Furthermore, as mentioned above, aliphatic amine esters (meth)acrylates do not have residual isocyanate groups. Other free radical polymerizable compounds can be monofunctional or difunctional or multifunctional, but monofunctional is preferred. Also, regarding aliphatic amine esters (meth)acrylates, when monofunctional ones are used, they can also be used in combination with difunctional or multifunctional ones.

[0063] As described above, aliphatic amine esters (meth)acrylates are preferably monofunctional, for example, those formed by reacting an isocyanate compound with a (meth)acrylate derivative having a hydroxyl group. Examples of the above-mentioned (meth)acrylic acid derivatives containing hydroxyl groups include: mono(meth)acrylates of diols such as ethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,3-butanediol, 1,4-butanediol, and polyethylene glycol; or mono(meth)acrylates of triols such as trimethylolethane, trimethylolpropane, and glycerol.

[0064] Examples of isocyanate compounds used to obtain aliphatic amine esters (meth)acrylates include: alkane monoisocyanates such as butane isocyanate, hexane isocyanate, octane isocyanate, and decane isocyanate (the number of carbon atoms in the alkane is preferably around 3 to 12); and cyclic aliphatic monoisocyanates such as cyclopentane isocyanate, cyclohexane isocyanate, and isophorone monoisocyanate. Regarding monofunctional aliphatic amine esters (meth)acrylates, more specifically, it is preferable to obtain amine esters (meth)acrylates by reacting the above-mentioned monoisocyanate compound with a mono(meth)acrylate of a diol. Suitable specific examples include 1,2-ethylene glycol-1-acrylate-2-(N-butyl carbamate) and other 1,2-ethylene glycol-1-acrylate-2-(N-alkyl carbamate). Furthermore, examples of multifunctional aliphatic amine esters (meth)acrylates include reaction products obtained by reacting a polyol compound with a compound having isocyanate and (meth)acrylic groups. Specifically, examples include amine esters (meth)acrylates having (meth)acrylic groups at both ends. Moreover, details of the polyol compound and the compound having isocyanate and (meth)acrylic groups are as described in the description of the raw materials for moisture-curing amine ester resin (A1).

[0065] (Meth)acrylate compounds other than aliphatic amine esters (meth)acrylates can be monofunctional or polyfunctional, but are preferably monofunctional. Specifically, monofunctional compounds among (meth)acrylates include, for example: methyl methacrylate, ethyl methacrylate, propyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, tributyl methacrylate, n-octyl methacrylate, isooctyl methacrylate, 2-ethylhexyl methacrylate, isononyl methacrylate, isodecanyl methacrylate, lauryl methacrylate, isomyrmethyl methacrylate, stearyl methacrylate, and other alkyl methacrylates; cyclohexyl methacrylate, 4-tert-butylcyclohexyl methacrylate, 3,3,5-trimethylcyclohexyl methacrylate, isocamphenyl methacrylate, dicyclopentenyl methacrylate, and other (meth)acrylate compounds with alicyclic structures. Esters; hydroxyalkyl methacrylates such as 2-hydroxyethyl methacrylate, 2-hydroxypropyl methacrylate, 2-hydroxybutyl methacrylate, and 4-hydroxybutyl methacrylate; alkoxyalkyl methacrylates such as 2-methoxyethyl methacrylate, 2-ethoxyethyl methacrylate, and 2-butoxyethyl methacrylate; alkoxyethylene glycol (meth)acrylates such as methoxyethylene glycol (meth)acrylate and ethoxyethylene glycol (meth)acrylate; polyoxyethylene glycol (meth)acrylates such as methoxydiethylene glycol (meth)acrylate, methoxytriethylene glycol (meth)acrylate, methoxypolyethylene glycol (meth)acrylate, ethoxydiethylene glycol (meth)acrylate, ethoxytriethylene glycol (meth)acrylate, and ethoxypolyethylene glycol (meth)acrylate.

[0066] Furthermore, examples of monofunctional (meth)acrylate compounds include: tetrahydrofurfuryl methacrylate, alkyl methacrylate tetrahydrofurfuryl methacrylate, cyclic trimethylolpropane methyl acetal (meth)acrylate, 3-ethyl-3-oxetane butyl methyl methacrylate, and other (meth)acrylates with heterocyclic structures; 2,2,2-trifluoroethyl methacrylate, 2,2,3,3-tetrafluoropropyl methacrylate, 1H,1H,5H-octafluoropentyl methacrylate, dimethylaminoethyl methacrylate, diethylaminoethyl methacrylate, 2-(meth)acrylic acid acetoethyl succinate, 2-(meth)acrylic acid acetoethyl-2-hydroxypropyl phthalate, glycidyl methacrylate, and 2-(meth)acrylic acid acetoethyl phosphate, etc.

[0067] Examples of difunctional compounds in (meth)acrylates include: 1,3-butanediol di(meth)acrylate, 1,4-butanediol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, 1,9-nonanediol di(meth)acrylate, 1,10-decanediol di(meth)acrylate, 2-n-butyl-2-ethyl-1,3-propanediol di(meth)acrylate, ethylene glycol di(meth)acrylate, diethylene glycol di(meth)acrylate, tetraethylene glycol di(meth)acrylate, polyethylene glycol di(meth)acrylate, and di... Propylene glycol di(meth)acrylate, tripropylene glycol di(meth)acrylate, polypropylene glycol di(meth)acrylate, dimethyloldicyclopentadiene di(meth)acrylate, neopentyl glycol di(meth)acrylate, ethylene oxide modified isocyanurate di(meth)acrylate, 2-hydroxy-3-(meth)acrylic acid propyl acrylate, carbonate glycol di(meth)acrylate, polyether glycol di(meth)acrylate, polyester glycol di(meth)acrylate, polycaprolactone glycol di(meth)acrylate, polybutadiene glycol di(meth)acrylate, etc.

[0068] Furthermore, examples of (meth)acrylate compounds with three or more functionalities include: trimethylolpropane tri(meth)acrylate, ethylene oxide addition trimethylolpropane tri(meth)acrylate, propylene oxide addition trimethylolpropane tri(meth)acrylate, caprolactone-modified trimethylolpropane tri(meth)acrylate, neopentyltetrol tri(meth)acrylate, ethylene oxide addition isocyanurate tri(meth)acrylate, glycerol tri(meth)acrylate, propylene oxide addition glycerol tri(meth)acrylate, tri(meth)acryloxyethyl phosphate, di-trimethylolpropane tetra(meth)acrylate, neopentyltetrol tetra(meth)acrylate, dinepentyltetrol penta(meth)acrylate, dinepentyltetrol hexa(meth)acrylate, etc.

[0069] Other free radical polymerizable compounds besides those mentioned above may also be appropriately used. Examples of other free radical polymerizable compounds include: N,N-dimethyl(meth)acrylamide, N-(meth)acrylmorpholine, N-hydroxyethyl(meth)acrylamide, N,N-diethyl(meth)acrylamide, N-isopropyl(meth)acrylamide, N,N-dimethylaminopropyl(meth)acrylamide, and other (meth)acrylamide compounds; and vinyl compounds such as N-vinyl-2-pyrrolidone and N-vinyl-ε-caprolactam. Furthermore, epoxy (meth)acrylates may also be used as (meth)acrylate compounds.

[0070] As a free radical polymerizable compound other than free radical polymerizable compounds having aromatic rings and free radical polymerizable compounds having amide rings, it is preferably selected from at least one of the group consisting of aliphatic amine esters (meth)acrylates and (meth)acrylate compounds. More preferably, it is selected from at least one of the group consisting of aliphatic amine esters (meth)acrylates and (meth)acrylates having alicyclic structures. Other free radical polymerizable compounds may be used alone or in combination with two or more.

[0071] The content of the free radical polymerizable compound (C) is preferably 5 parts by mass or more and 50 parts by mass or less relative to 100 parts by mass of the combined weight of the moisture-curing resin and the free radical polymerizable compound. By setting the content of the free radical polymerizable compound (C) to the lower limit mentioned above, it is easier to impart appropriate photocurability to the adhesive composition, and it is also easier to ensure shape retention after photocuring and before moisture curing. Furthermore, it is easier to achieve good coatability of the adhesive composition. On the other hand, by setting it to the upper limit mentioned above, the amounts of the moisture-curing resins (A) and (B) can be kept at a certain level or more, which can impart appropriate moisture curability to the adhesive composition. Based on these views, the content of the free radical polymerizable compound (C) is more preferably 10 parts by mass or more and 45 parts by mass or less, and more preferably 15 parts by mass or more and 40 parts by mass or less. []

[0072] (Photopolymerization initiator) The adhesive composition of the present invention may further contain a photopolymerization initiator. By containing a photopolymerization initiator, the adhesive composition can be appropriately endowed with photocurability. When the adhesive composition contains a free radical polymerizable compound (C), a photopolymerization initiator is preferred. Examples of photopolymerization initiators include: benzophenone compounds, acetophenone compounds, phosphine oxide compounds, titanium dioxide compounds, oxime ester compounds, benzoin ether compounds, and 9-oxosulfuron-methyl compounds. wait. Commercially available photopolymerization initiators include, for example: IRGACURE184, IRGACURE369, IRGACURE379, IRGACURE651, IRGACURE784, IRGACURE819, IRGACURE907, IRGACURE2959, IRGACURE OXE01, Lucirin TPO (all manufactured by BASF); benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether (all manufactured by Tokyo Chemical Industry Co., Ltd.), etc.

[0073] The content of the photopolymerization initiator in the adhesive composition is preferably 0.01 parts by mass and 8 parts by mass or less, more preferably 0.1 parts by mass and 6 parts by mass or less, and even more preferably 0.4 parts by mass and 4 parts by mass or less, relative to 100 parts by mass of the adhesive composition. By keeping the content of the photopolymerization initiator within these ranges, the obtained adhesive composition exhibits excellent photocurability and storage stability. Furthermore, by being within the above ranges, the photoradical polymer compound (C) is appropriately cured, facilitating good adhesion.

[0074] (Moisture-induced hardening catalyst) The adhesive composition of the present invention may also contain a moisture-curing promoter that promotes the moisture-curing reaction of the moisture-curing resin. By using a moisture-curing promoter, the adhesive composition becomes more moisture-curing and thus more easily improves adhesion. As catalysts for promoting moisture hardening, amine compounds and metal-based catalysts can be specifically listed. Examples of amine compounds include: di(methylmorpholino)diethyl ether, 4-morpholinopropylmorpholine, 2,2'-dimorpholinodiethyl ether, and other compounds with a morpholine skeleton; bis(2-dimethylaminoethyl) ether, 1,2-bis(dimethylamino)ethane, and other amine compounds containing two dimethylamino groups; triethylamine, 1,4-diazabicyclo[2.2.2]octane, 2,6,7-trimethyl-1,4-diazabicyclo[2.2.2]octane, etc. Examples of metal-based catalysts include: tin compounds such as di-n-butyltin dilaurate, di-n-butyltin diacetate, and tin octoate; zinc compounds such as zinc octoate and zinc naphthenate; and other metal compounds such as zirconium tetraacetate, copper naphthenate, and cobalt naphthenate. The content of the moisture curing promoter in the adhesive composition is preferably 0.1 parts by mass and less than 10 parts by mass relative to 100 parts by mass of the adhesive composition, more preferably 0.2 parts by mass and less than 8 parts by mass, and even more preferably 0.3 parts by mass and less than 5 parts by mass.

[0075] (filler) The adhesive composition of the present invention may also contain a filler. By containing a filler, the adhesive composition of the present invention becomes one with suitable thixotropic properties, which facilitates good shape retention after coating. As a filler, only particulate fillers are required. The filler is preferably an inorganic filler, such as silica, talc, titanium dioxide, zinc oxide, and calcium carbonate. Among these, silica is preferred due to its superior ultraviolet transmittance. Furthermore, the filler may also undergo hydrophobic surface treatments such as silanization, alkylation, or epoxyation. One type of filler can be used alone, or two or more types can be used in combination. The content of the filler relative to 100 parts by weight of the adhesive composition is preferably 0.5 parts by weight or more and 30 parts by weight or less, more preferably 1 part by weight or more and 25 parts by weight or less, and even more preferably 2 parts by weight or more and 15 parts by weight or less.

[0076] In addition to the above-mentioned components, the adhesive composition of the present invention may also contain other additives, such as: silane coupling agents, titanate coupling agents, zirconate coupling agents, wax particles, ionic liquids, colorants, foaming particles, expanding particles, reactive diluents, antioxidants, free radical scavengers, etc. The adhesive composition may also be diluted with a solvent as needed. When the adhesive composition is diluted with a solvent, the amounts (parts by mass, percentage by mass) of the adhesive composition are based on the solids content, that is, the parts by mass and percentage by mass obtained after removing the solvent.

[0077] As a method for manufacturing the adhesive composition of the present invention, examples include using a mixer to mix moisture-curing resins (A) and (B), and optionally blended free radical polymerizable compound (C), photopolymerization initiator, moisture-curing accelerator, filler, coupling agent, and other additives. Examples of mixers include: homogenizers, homogenizing mixers, universal mixers, planetary mixers, kneaders, and three-roll mills.

[0078] <How to use> The adhesive composition of the present invention is cured and can be used in the form of a cured body. The adhesive composition of the present invention has at least moisture-curing properties. Therefore, regarding the adhesive composition, for example, the adhesive composition or a semi-cured adhesive composition can be disposed between two bonded objects, so that the two bonded objects are bonded by an adhesive composition (cured body) that is at least cured by moisture.

[0079] Furthermore, the adhesive composition of the present invention can exhibit photocurability, preferably by means of a free radical polymerizable compound (C) that exhibits good photocurability. That is, the adhesive composition is preferably used as a photo-moisture curing type. Therefore, the adhesive composition of the present invention is preferably photocured by light irradiation, for example, to a B-stage state (semi-cured state), and then further cured by moisture to achieve complete curing before use. Here, when an adhesive composition is disposed between adhesive substrates to bond them together, the adhesive composition can be applied to one substrate, and then photocured by light irradiation, for example, to a stage B state. Another adhesive substrate is then superimposed on the photocured adhesive composition, temporarily bonding the substrates together with a suitable adhesive force. Subsequently, the stage B adhesive composition is fully cured by the curing resin (A) through moisture curing, resulting in a bond between the substrates superimposed with the adhesive composition using a sufficient adhesive force.

[0080] The application of the adhesive composition to the substrate can be performed, for example, using a dispensing device, and is not particularly limited. Furthermore, the light used for photocuring is not particularly limited as long as it is light that cures one or both of the moisture-curing resin (A) and the free radical polymerizable compound (C), but ultraviolet light is preferred. Also, to completely cure the adhesive composition by means of moisture, it is sufficient to leave it in the atmosphere for a specified time.

[0081] The adhesive composition of the present invention can be used, for example, as an adhesive for electronic components. Furthermore, the adhesive composition of the present invention is preferably used as an adhesive for electronic devices, especially portable electronic devices. Moreover, electronic components or portable electronic devices using the adhesive composition of the present invention preferably have a cured form of the adhesive composition. There are no particular limitations on the substrate to which the adhesive composition is used, but it is preferably a component constituting a portable electronic device, and this component is preferably an electronic component. The material of the substrate can be any of metal, glass, plastic, etc. Furthermore, there are no particular limitations on the shape of the substrate, and examples include: film, sheet, plate, panel, tray, rod (rod-like) shape, box shape, shell shape, etc. Portable electronic devices are not particularly limited, but may include: mobile phones such as smartphones, digital cameras, wearable terminals, portable game consoles, tablet computers, laptop computers, action cameras, etc., among which smartphones and wearable terminals are preferred. Because the adhesive composition of this invention has good impact resistance and oil resistance, it is particularly suitable for portable electronic devices.

[0082] Electronic components typically have a substrate; therefore, electronic components using the adhesive composition of the present invention can have a cured form of the adhesive composition and a substrate. Various electronic circuits are typically disposed on the substrate. Similarly, portable electronic devices and other electronic devices using the adhesive composition of the present invention can also have a cured form of the adhesive composition of the present invention and a substrate.

[0083] In electronic components, for example, a substrate can be used as the bonded body, and the substrates can be bonded to each other via the adhesive composition of the present invention. The substrate can also be bonded to other components of an electronic device (e.g., housing) via the adhesive composition of the present invention. For example, in the internal components of electronic machines, the adhesive composition of the present invention can also be used to bond substrates to obtain an assembled part. The assembled part thus obtained has a first substrate, a second substrate, and the hardened body of the present invention, and at least a portion of the first substrate is bonded to at least a portion of the second substrate via the hardened body. [Example]

[0084] The invention will be described in more detail with reference to the embodiments, but the invention is not limited to these embodiments in any way.

[0085] In this embodiment, the adhesive composition is evaluated in the following manner. (Continuing force) As shown in Figure 1(a), a first substrate 11 with a diameter of 12 mm and a thickness of 5 mm and a circular hole 11A with a diameter of 12 mm is prepared; and a second substrate 12 with a diameter of 50 mm and a thickness of 5 mm is prepared. Both the first substrate 11 and the second substrate 12 are polycarbonate sheets. Using a dispensing applicator, adhesive composition 10 is applied to surround the hole 11A of the first substrate 11, forming a 20 mm × 20 mm border with a width of 1 mm ± 0.2 mm and a height of 0.25 mm ± 0.05 mm. Within one minute after coating, UV-LED (wavelength 365 nm) is used to irradiate with ultraviolet light at 1000 mJ / cm² to photocur the adhesive composition 10. Subsequently, the second substrate 12 is stacked on the first substrate 11 with the center positions of the first substrate 11 and the second substrate 12 aligned, using a 0.2 mm high gap material (not shown) and adhesive composition 10. A 2 kg weight is then placed on the second substrate 12 for 10 seconds to press the first substrate 11 and the second substrate 12 together via adhesive composition 10. Subsequently, the 2 kg weight was removed, and the mixture was left to stand at 25°C and 50% RH for 24 hours to allow the adhesive composition 10 to moisture harden, thus obtaining the test sample 13. After moisture hardening, the gap material was removed from the test sample 13. The obtained test sample 13 was arranged with the first substrate 11 on top and the second substrate 12 on the bottom. With the first substrate 11 supported by a stainless steel fixture, a rod-shaped member 14 with a diameter of 10 mm and a cross-sectional shape of a circle was inserted into the hole 11A. Then, as shown in FIG1(b), the second substrate 12 was pushed vertically downwards by the rod-shaped member 14 at a speed of 10 mm / min. The stress at which the second substrate 12 peeled off from the first substrate 11 was measured, and the measured stress was used as the adhesion force (adhesion force before oil contact). The adhesion force was evaluated according to the following evaluation criteria. AA: Adhesion force is above 4 MPa A: Adhesion force is 3 MPa or higher but less than 4 MPa B: The force did not reach 3 MPa.

[0086] (Adhesion after oil contact) Prepare the test sample in the same order as described above. Wrap the entire test sample in non-woven fabric (product name "Kimwipe", manufactured by NIPPON PAPER CRECIA) that has absorbed oleic acid, and seal it in a polyethylene bag. Curl the bag at 60°C and 90% RH for 2 days. After curing, wash the test sample with ethanol, and measure the adhesion in the same manner as above; this is the adhesion after oil contact. Evaluate the rate of decrease in adhesion after oil contact relative to the adhesion before oil contact according to the following evaluation criteria. AA: Adhesion reduction rate is below 30% A: Adhesion strength reduction rate greater than 30% but less than 50% B: Adhesion force reduction rate greater than 50% but less than 70% C: Adhesion strength reduction rate is greater than 70%.

[0087] (Impact resistance) As shown in Figure 2, the sample 13 for measurement is prepared in the same order as described above, and after being arranged with the first substrate 11 on the top and the second substrate 12 on the bottom, the first substrate 11 is supported by a stainless steel fixture. Furthermore, prepare a fixture 16 (material: stainless steel) having a flat plate portion 16B (20 mm × 20 mm, thickness 5 mm) and a rod-shaped portion 16A (diameter 10 mm, cylindrical) connected to the center of the flat plate portion 16B. Insert the rod-shaped portion 16A of the fixture 16 into the hole 11A of the first substrate 11 as shown in Figure 2, so that it stands in the center of the second substrate 12. In this state, a DuPont drop impact tester is used to repeatedly drop a 300 g spherical stainless steel weight 15 vertically downwards from a position 200 mm above the plate 16B to the center of the plate 16B. The number of times the weight is dropped until the second substrate 12 peels off due to the impact of the weight 15 is used as the durability test count. AA: Durability count is 50 or more. A: Durability count is 30 or more but less than 50. C: Durability count not reached 30 times []

[0088] (shape retention) Prepare the first and second substrates in the same order as when preparing the sample for measurement, and apply an adhesive composition to the first substrate to allow it to photocur. Subsequently, without using a gap material, the second substrate was stacked on top of the first substrate using an adhesive composition, with the centers of the first and second substrates aligned. A 100 g weight was then placed on the second substrate and held for 10 seconds to press the first and second substrates together using the adhesive composition. The weight was then removed. The thickness of the adhesive composition after the weight was removed was measured and evaluated according to the following evaluation criteria. A: The thickness of the adhesive composition is 0.1 mm or more. C: The thickness of the adhesive composition is less than 0.1 mm.

[0089] The moisture-curing resins used in the various embodiments and comparative examples were prepared according to the following synthesis examples. <<Moisture-curing resins (1)>> [Synthesis example 1] In a 500 mL separable flask, 100 parts by weight of polycarbonate diol (represented by formula (1); 90 mol% of R is 3-methylpentyl, 10 mol% is hexamethylene; manufactured by Kuraray Co., Ltd.; trade name "Kuraraypolyol C-1090") and 0.01 parts by weight of dibutyltin dilaurate were placed. The mixture was stirred for 60 minutes under vacuum (below 20 mmHg) and at 80°C. Then, under normal pressure, 30 parts by weight of 2-methacryloxyethyl isocyanate (manufactured by Showa Denko Co., Ltd.; trade name "Karenz MOI") were added to the obtained reaction product, and the mixture was stirred at 100°C for 3 hours to allow it to react, thereby obtaining a reaction product with a polycarbonate (PC) backbone and a single methacrylyl group at one end. 50 parts by weight of diphenylmethane diisocyanate (manufactured by Tosoh Corporation, trade name "MILLIONATE MT"), a polyisocyanate compound, were added to the obtained reaction product, and the mixture was stirred at 80°C for 3 hours to allow it to react, thereby obtaining a moisture-curing amine resin (1-1) with a polycarbonate (PC) backbone. In the moisture-curing amine resin (1-1), the proportion of moisture-curing amine resin (A1) with one end of methacrylic acid and the other end of isocyanate group is 80% by weight. Furthermore, the moisture-curing amine resin (1-1) also contains moisture-curing amine resin (B1) with two ends of isocyanate groups. The weight average molecular weight of the obtained moisture-curing amine resin (1-1) is 5000.

[0090] [Synthesis example 2] In a 500 mL separable flask, 100 parts by weight of a polyester polyol (a polyester polyol mainly composed of adipic acid, 1,6-hexanediol, and isophthalic acid; aromatic ring concentration 15% by mass; weight average molecular weight 1000) and 0.01 parts by weight of dibutyltin dilaurate were placed. The mixture was stirred for 1 hour under vacuum (below 20 mmHg) at 80°C. Then, under normal pressure, 30 parts by weight of 2-methacryloxyethyl isocyanate (manufactured by Showa Denko Co., Ltd., trade name "Karenz MOI") were added, and the mixture was stirred at 100°C for 3 hours to allow the reaction to proceed, thereby obtaining a reaction product with a polyester backbone and a single methacrylyl group at the end. 50 parts by mass of diphenylmethane diisocyanate (manufactured by Tosoh Corporation, trade name "MILLIONATE MT"), a polyisocyanate compound, were added to the obtained reaction product, and the mixture was reacted at 80°C for 3 hours to obtain a moisture-curing amine resin (1-2) with a polyester backbone. In the moisture-curing amine resin (1-2), the proportion of moisture-curing amine resin (A1) with one end of methacrylic acid and the other end of isocyanate group is 80% by mass. Furthermore, the moisture-curing amine resin (1-2) also contains moisture-curing amine resin (B1) with two ends of isocyanate groups. The weight-average molecular weight of the obtained moisture-curing amine resin (1-2) is 3000.

[0091] <<Moisture-curing resins (2)>> [Synthesis example 3] In a 500 mL separable flask, 100 parts by weight of polycarbonate diol (represented by formula (1); 90 mol% of R is 3-methylpentyl, 10 mol% is hexamethylene; manufactured by Kuraray Co., Ltd.; trade name "Kuraraypolyol C-1090") and 0.01 parts by weight of dibutyltin dilaurate were placed. The mixture was stirred for 30 minutes under vacuum (below 20 mmHg) and at 100°C. Then, the pressure was reduced to atmospheric pressure, and 50 parts by weight of diphenylmethane diisocyanate (manufactured by Tosoh Co., Ltd.; trade name "MILLIONATE MT"), a polyisocyanate compound, were added. The mixture was stirred at 80°C for 3 hours to allow it to react, thereby obtaining a moisture-curing amine resin (2-1) with a polycarbonate (PC) backbone and isocyanate groups at both ends. The weight average molecular weight of the obtained moisture-curing amine resin (2-1) was 6000.

[0092] [Synthesis example 4] In a 500 mL separable flask, 100 parts by weight of a polyester polyol (a polyester polyol mainly composed of adipic acid, 1,6-hexanediol, and isophthalic acid; aromatic ring concentration 15% by mass; weight average molecular weight 1000) and 0.01 parts by weight of dibutyltin dilaurate were placed. The mixture was stirred for 30 minutes under vacuum (below 20 mmHg) at 100°C. Then, under normal pressure, 52.5 parts by weight of diphenylmethane diisocyanate (manufactured by Tosoh Corporation, trade name "MILLIONATE MT") was added, and the mixture was stirred at 80°C for 3 hours to allow reaction, thereby obtaining a moisture-curing amine resin (2-2) with a polyester backbone and isocyanate groups at both ends. The obtained moisture-curing amine resin (2-2) had a weight average molecular weight of 1500. []

[0093] The components other than the moisture-curing amine ester resin used in each embodiment and comparative example are described below. (Free radical polymeric compounds) Acrylates containing a nitroimidene ring: Manufactured by Dong-A Synthetic Co., Ltd., trade name "M-140", N-acryloxyethyl hexahydrophthalimide, monofunctional Acrylates containing aromatic rings: Manufactured by Kyoeisha Chemical Co., Ltd., trade name "Light acrylate PO-A", phenoxyethyl acrylate, monofunctional. Aliphatic acrylates: Manufactured by DAICEL-ALLNEX, trade name "IBOA-B", isoborneol acrylate, monofunctional Filler: Trimethylsilane-treated silicon dioxide, manufactured by Aerosil Corporation of Japan, trade name "R812", primary particle size 7 nm Photopolymerization initiator: 2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)-butanone-1, manufactured by BASF, trade name "IRGACURE 369" Other additives: free radical scavengers, antioxidants, and moisture-curing catalysts.

[0094] [Examples 1-6, Comparative Examples 1-3] According to the mixing ratios recorded in Table 1, each material was stirred at 50°C using a planetary stirring device (Thinky Corporation, "Defoaming Stirring Taro"), and then uniformly mixed at 50°C using a ceramic three-roll mill to obtain the adhesive compositions of Examples 1-6 and Comparative Examples 1-3.

[0095] [Table 1] Example Comparative example 1 2 3 4 5 6 1 2 3 Combination (parts by weight) Moisture hardening Resin (1) Moisture-curing amine ester resin (1-1) 20 20 5 5 10 Moisture-curing amine resins (1-2) 20 Moisture hardening Resin (2) Moisture-curing amine ester resin (2-1) 70 50 50 60 70 90 55 Moisture-curing amine resin (2-2) 70 90 free radical polymeric compounds Acrylates containing amide ring 10 10 10 Acrylates containing aromatic rings 25 Aliphatic acrylates 25 20 25 filler 5 5 5 5 5 5 5 5 5 Photopolymerization initiator 1 1 1 1 Other additives 5 5 4 4 4 5 5 5 4 total 100 100 100 100 100 100 100 100 100 Parts by mass relative to the total of 100 parts by mass of moisture-curing resin and free radical polymerizable compound Moisture-curing resin (A) 17.8 17.8 4.4 4.4 8.9 17.8 0.0 0.0 0.0 Moisture-curing resin (B) 82.2 82.2 56.7 56.7 68.9 82.2 100.0 100.0 61.1 Free radical polymerizable compounds (C) 0.0 0.0 38.9 38.9 22.2 0.0 0.0 0.0 38.9 evaluate Then force MPa 6.0 5.2 3.9 3.8 3.3 5.2 8.2 6.4 3.4 evaluate AA AA A A A AA AA AA A Adhesion after oil contact (adhesion reduction rate) % 38 68 31 20 56 45 31 69 51 evaluate A B A AA B A A B B Impact resistance (Durability cycles) frequency 45 39 111 120 102 46 28 25 twenty two evaluate A A AA AA AA A C C C Shape retention (Thickness of the components) mm 0.05 0.03 2.5 2.4 2.5 0.08 0.03 0.05 2.3 evaluate C C A A A C C C A

[0096] As shown in Table 1, in each embodiment, the adhesive composition improves impact resistance and oil resistance by containing moisture-curing resin (A) and moisture-curing resin (B) with specific structures, maintaining high adhesion even after oil contact. Furthermore, as shown in Examples 3-5, the adhesive composition, in addition to containing moisture-curing resins (A) and (B), also contains a free radical polymerizable compound (C), resulting in good shape retention. The hardened body formed by the adhesive composition ensures a certain spacing between the bonded elements. In contrast, in Comparative Examples 1-3, although the adhesive composition successfully ensured a certain level of adhesion by containing moisture-curing resin (B), it could not improve oil resistance and impact resistance because it did not contain moisture-curing resin (A).

[0097] 10: Adhesive composition 11: 1st substrate 11A: Hole 12: 2nd substrate 13: Samples for determination 14: Rod-shaped component 15: Heavy objects 16:Jig 16A: Rod-shaped part 16B: Flat plate section

Claims

1. An adhesive composition comprising: a moisture-curing resin (A) having at least one of a polycarbonate backbone and a polyester backbone, and having an isocyanate group and a (meth)acrylic group; and a moisture-curing resin (B) having an isocyanate group and not having a (meth)acrylic group, wherein the moisture-curing resin (A) has one isocyanate group per molecule; wherein, when the adhesive composition contains a free radical polymerizable compound, the content of the moisture-curing resin (A) is 0.1 parts by mass or more and 30 parts by mass or less relative to 100 parts by mass of the total amount of the moisture-curing resin and the free radical polymerizable compound in the adhesive composition; wherein, when the adhesive composition does not contain a free radical polymerizable compound, the content of the moisture-curing resin (A) is 0.1 parts by mass or more and 30 parts by mass or less relative to 100 parts by mass of the total amount of the moisture-curing resin in the adhesive composition.

2. The adhesive composition as claimed in claim 1, wherein, The aforementioned moisture-curing resin (B) has at least one of a polycarbonate backbone and a polyester backbone.

3. The adhesive composition as claimed in claim 1, wherein, The aforementioned moisture-curing resin (B) has a polycarbonate backbone.

4. The adhesive composition of any one of claims 1 to 3, wherein, The moisture-curing resin (B) described above has isocyanate groups at both ends.

5. The adhesive composition of any one of claims 1 to 3, wherein, When the adhesive composition contains a free radical polymerizable compound, the content of the moisture-curing resin (B) is 45 parts by mass or more and 94 parts by mass or less relative to the total amount of moisture-curing resin and free radical polymerizable compound in the adhesive composition, per 100 parts by mass; when the adhesive composition does not contain a free radical polymerizable compound, the content of the moisture-curing resin (B) is 45 parts by mass or more and 94 parts by mass or less relative to the total amount of moisture-curing resin in the adhesive composition, per 100 parts by mass.

6. The adhesive composition of any one of claims 1 to 3, wherein, The moisture-curing resin (A) described above has a polycarbonate backbone.

7. The adhesive composition of any one of claims 1 to 3, wherein, The moisture-curing resin (A) described above has aromatic isocyanate groups.

8. The adhesive composition of any one of claims 1 to 3 further contains a free radical polymerizable compound (C) that does not contain an isocyanate group.

9. The adhesive composition as claimed in claim 8, wherein, The aforementioned free radical polymerizable compound (C) contains at least one of the following: free radical polymerizable compounds selected from the group consisting of free radical polymerizable compounds having an aromatic ring and free radical polymerizable compounds having an amide ring.

10. The adhesive composition as claimed in claim 9, wherein, The content of the compounds selected from the group consisting of free radical polymerizable compounds with aromatic rings and free radical polymerizable compounds with amide rings is 50% by mass or more relative to the total amount of the free radical polymerizable compound (C).

11. An adhesive for electronic components, comprising an adhesive composition of any one of claims 1 to 10.

12. An adhesive for portable electronic devices, comprising the adhesive composition of any one of claims 1 to 10.

13. A cured body, which is a cured body of the adhesive composition of any one of claims 1 to 10.

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