Photo- and moisture-curable hot melt resin composition, adhesive for electronic parts and cured body

Abstract

To provide a photo- and moisture-curable hot melt resin composition that offers superior oil resistance and ensures adequate open time for bonding work, while also expressing high initial adhesive force quickly.SOLUTION: A photo- and moisture-curable hot melt resin composition includes a urethane prepolymer (A), a radical polymerizable compound (B), and a photopolymerization initiator (C), where the (A) urethane prepolymer is synthesized from raw materials that at least include a polyol with a linear hydrocarbon structure including 4 or more carbon atoms (a-1), a polyol with a polycarbonate skeleton (a-2), and a polyisocyanate (a-3).SELECTED DRAWING: None

Description

[Technical field]

[0001] The present invention relates to a light- and moisture-curable hot-melt resin composition, an adhesive for electronic components comprising the light- and moisture-curable hot-melt resin composition, and a cured product of the light- and moisture-curable hot-melt resin composition. [Background technology]

[0002] Traditionally, double-sided tape has often been used to bond and assemble parts of smart devices such as wearable devices. However, in recent years, as smart devices have become smaller and curved, adhesives have come to be used to reduce the bonding area and to accommodate complex bonding surfaces.

[0003] On the other hand, various types of adhesive compositions have been proposed in the past. For example, Patent Document 1 discloses a moisture-curable urethane hot melt resin composition containing a urethane prepolymer having an isocyanate group, and a photopolymerization initiator, the essential raw materials of which are a polyol including a polyacrylic polyol, a polyisocyanate, and a compound having one or more (meth)acryloyl groups and one hydroxyl group. Furthermore, Patent Document 2 discloses a reactive hot melt adhesive composition containing a urethane prepolymer, a urethane (meth)acrylate having a (meth)acryloyl group, and a photopolymerization initiator. Furthermore, Patent Document 3 discloses a resin composition characterized by containing a moisture-curable hot-melt urethane composition (1) containing a urethane prepolymer (a-1) having an isocyanate group, and an ultraviolet-curable pressure-sensitive adhesive composition (2) containing a urethane (meth)acrylate (b-1), a (meth)acrylic monomer (b-2), and a photopolymerization initiator (b-3). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent Publication No. 2021-004280 [Patent Document 2] JP 2019-006854 A [Patent Document 3] International Publication No. 2015 / 056478 Summary of the Invention [Problem to be solved by the invention]

[0005] Since wearable devices are constantly worn and in direct contact with the skin, the adhesives used in the wearable devices are particularly required to be resistant to sweat and sebum (oil and fat). However, conventional hot melt type adhesives such as those disclosed in Patent Documents 1 to 3 have a high affinity with oil and fat, which causes a problem of reduced adhesive strength. In addition, high productivity (efficiency and speed) is required to meet the rapidly increasing demand for wearable devices in recent years. To increase productivity, adhesives that combine short open time and early adhesive strength development are required, but urethane adhesives have the problem of a trade-off between open time and early adhesive strength.

[0006] Therefore, an object of the present invention is to provide a light-and-moisture-curable hot-melt resin composition that has excellent oil resistance and can exhibit high initial adhesive strength in a short period of time while ensuring sufficient open time for lamination work. [Means for solving the problem]

[0007] As a result of extensive investigations, the present inventors have found that the above-mentioned problems can be solved by adding (B) a radical polymerization compound and (C) a photoinitiator to a specific urethane prepolymer, and have thus completed the present invention. The present invention provides the following [1] to

[10] . [1] A photo-curable hot-melt resin composition comprising a urethane prepolymer (A), a radically polymerizable compound (B), and a photopolymerization initiator (C), wherein the urethane prepolymer (A) is a reaction product of raw materials comprising at least a polyol (a-1) having a polycarbonate skeleton, a polyol (a-2) having a linear hydrocarbon structure having 4 or more carbon atoms and different from the polyol (a-1) having a polycarbonate skeleton, and a polyisocyanate (a-3). [2] The photo-curable, moisture-curable hot melt resin composition according to [1], further comprising a coupling agent (D) and a moisture-cure accelerating catalyst (E). [3] The light-curable, moisture-curable hot melt resin composition according to [1] or [2], wherein the polyol (a-2) is a polyester polyol. [4] The light-curable and moisture-curable hot-melt resin composition according to any one of [1] to [3], wherein the polyol (a-1) is a polyether polycarbonate polyol. [5] The light-and-moisture-curable hot-melt resin composition according to any one of [1] to [4], wherein the ratio of an ether skeleton to a carbonate skeleton in the polyol (a-1) is in the range of 2:8 to 8:2, the polyol (a-2) has a linear aliphatic hydrocarbon skeleton having 4 or more carbon atoms, and the polyisocyanate (a-3) has an aromatic skeleton. [6] The light-curable, moisture-curable hot-melt resin composition according to any one of [1] to [5], wherein the radically polymerizable compound (B) contains a radically polymerizable compound having an aromatic ring. [7] The photo-curable hot-melt resin composition according to [6], wherein the content of the radical polymerizable compound having a linear hydrocarbon structure having 8 or more carbon atoms is less than 5 mass% based on the total amount of the photo-curable hot-melt resin composition. [8] The light-curable, moisture-curable hot-melt resin composition according to any one of [1] to [7], wherein the radically polymerizable compound (B) contains a radically polymerizable compound having a vinyl group. [9] An adhesive for electronic components, comprising the light-curable, moisture-curable hot melt resin composition according to any one of [1] to [8].

[10] A cured product of the light-curable, moisture-curable hot-melt resin composition according to any one of [1] to [8]. Effect of the Invention

[0008] According to the present invention, it is possible to provide a light-and-moisture-curable hot-melt resin composition that has excellent oil resistance and can exhibit high initial adhesive strength in a short period of time while ensuring sufficient open time for lamination work. [Brief description of the drawings]

[0009] [Figure 1] FIG. 1 is a schematic diagram showing a method for evaluating initial adhesive strength, in which FIG. 1(a) is a plan view and FIG. 1(b) is a side view. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] Hereinafter, the present invention will be described with reference to embodiments. <Urethane prepolymer (A)> The light-curable, moisture-curable hot melt resin composition of the present invention contains a urethane prepolymer (A). The urethane prepolymer (A) is a reaction product of raw materials including at least a polyol (a-1) having a polycarbonate skeleton, and a polyol (a-2) having a linear hydrocarbon structure with 4 or more carbon atoms, and a polyisocyanate (a-3).

[0011] The urethane prepolymer (A) of the present invention is a reaction product of a polyol (Aa) including a polyol (a-1) and a polyol (a-2) and a polyisocyanate (a-3), and has an isocyanate group. The urethane prepolymer (A) can impart moisture curing properties to the resin composition by having an isocyanate group of the polyisocyanate (a-3). In addition, the urethane prepolymer (A) preferably contains a plurality of isocyanate groups in one molecule, and more preferably contains two isocyanate groups in one molecule. The reaction between the polyol (Aa) and the polyisocyanate (a-3) is carried out, for example, in a molar ratio of hydroxyl groups (OH) in the polyol to isocyanate groups (NCO) in the polyisocyanate, [NCO] / [OH], within the range of 1.5 to 2.5.

[0012] (Polyol (a-1) Having a Polycarbonate Skeleton) As described above, the polyol used as a raw material for obtaining the urethane prepolymer (A) includes a polyol (a-1) having a polycarbonate skeleton (hereinafter, also referred to as "polyol (a-1)"). By using the polyol (a-1), it is possible to impart excellent oil resistance to the light-curable hot melt resin composition. The polyol (a-1) is preferably liquid at room temperature (25° C.). By making the polyol (a-1) liquid at room temperature (25° C.), it becomes easier to make the open time of the adhesive to an appropriate length.

[0013] The polyol (a-1) is preferably a polyether polycarbonate polyol. By using a polyether polycarbonate polyol, it is easy to improve the initial adhesive strength and extend the open time (pot life). The polyether polycarbonate polyol has a polyether skeleton and a carbonate bond. The polyether polycarbonate polyol is a compound having two or more hydroxyl groups in the molecule. In addition, the polyether polycarbonate polyol preferably has two or more carbonate bonds in the molecule.

[0014] In the polyether polycarbonate polyol, the ether skeleton typically has a structure in which divalent hydrocarbon groups are linked by ether bonds. The divalent hydrocarbon group is not particularly limited, but has, for example, 2 to 12 carbon atoms, preferably 3 to 8 carbon atoms. The divalent hydrocarbon group may be an aliphatic hydrocarbon group or an aromatic hydrocarbon group having an aromatic ring, but is preferably an aliphatic hydrocarbon group. The aliphatic hydrocarbon group may be linear, branched, or may have an alicyclic structure, but is preferably linear.

[0015] Moreover, the polyether polycarbonate polyol preferably has a linear alkylene group having 3 to 8 carbon atoms. By having a linear alkylene group having 3 to 8 carbon atoms, the polyether polycarbonate polyol does not make the pot life of the adhesive too long, and the adhesive is likely to rapidly crystallize and solidify after bonding, thereby making it easier to develop adhesive strength and to make the initial adhesive strength good. The alkylene group is preferably contained in an ether skeleton, and the divalent hydrocarbon group in the ether skeleton is preferably a linear alkylene group having 3 to 8 carbon atoms. Therefore, the ether skeleton preferably has a structure in which linear alkylene groups having 3 to 8 carbon atoms are linked via ether bonds, and the alkylene group more preferably has 3 to 5 carbon atoms, and most preferably has 4 carbon atoms.

[0016] The polyether polycarbonate polyol (a1) may have a structure in which a plurality of ether skeletons are bonded via carbonate bonds. The polyether polycarbonate polyol (a1) is preferably a polyether polycarbonate diol having two hydroxyl groups in one molecule. The polyether polycarbonate diol may have hydroxyl groups at both ends of the molecule. Specifically, the polyether polycarbonate polyol (a1) is more preferably a compound represented by the following formula (1).

[0017] [ka] In the above formula (1), R represents a divalent hydrocarbon group having 2 to 12 carbon atoms, n is an integer from 2 to 90, and m is an integer from 1 to 35. In addition, in formula (1), multiple R may be the same or different.

[0018] In the above formula (1), R preferably has 2 to 10 carbon atoms, more preferably 3 to 8 carbon atoms, even more preferably 3 to 5 carbon atoms, and most preferably 4 carbon atoms. R may be an aliphatic hydrocarbon group or an aromatic hydrocarbon group having an aromatic ring, but is preferably an aliphatic hydrocarbon group, more preferably an aliphatic saturated hydrocarbon group, and even more preferably a linear alkylene group having 3 to 8 carbon atoms. Therefore, specific preferred examples of R include a trimethylene group, a tetramethylene group, a pentamethylene group, a hexamethylene group, a heptamethylene group, and an octamethylene group, and among these, a trimethylene group, a tetramethylene group, and a pentamethylene group are more preferred, and a tetramethylene group is the most preferred. These alkylene groups may be used alone or in combination of two or more kinds. In the above (1), n ​​is 2 to 90, preferably 2 to 45, more preferably 2 to 15, even more preferably 2 to 10, and most preferably 2 to 5. Also, m is 1 to 35, preferably 1 to 15, more preferably 1 to 10, even more preferably 1 to 6, and most preferably 2 to 6.

[0019] The polyether polycarbonate polyol preferably has an existence ratio of ether skeleton to carbonate skeleton in the range of 2:8 to 8:2. When the ratio of the ether skeleton is a certain level or more, it is easy to impart excellent adhesive strength and flexibility to the light-moisture curing hot melt resin composition. In addition, when the ratio of the polycarbonate skeleton is a certain level or more, it is easy to impart good oil resistance to the light-moisture curing hot melt resin composition. The existence ratio is more preferably in the range of 3:7 to 7:3. The existence ratio here means the ratio of the number of ether bonds constituting the ether skeleton to the number of carbonate bonds constituting the carbonate skeleton.

[0020] The polyether polycarbonate polyol is preferably produced by known methods such as phosgene method and ester exchange method using polyoxyalkylene glycol as a raw material.Therefore, the above-mentioned polyether skeleton is preferably derived from polyoxyalkylene glycol.Preferred specific examples of polyoxyalkylene glycol include polypropylene glycol, polytetramethylene ether glycol, and copolymerized polyether glycol of propylene oxide and tetrahydrofuran, and among these, polytetramethylene ether glycol (PTMG) is more preferable. The polyoxyalkylene glycol may be used alone or in combination of two or more kinds.

[0021] The number average molecular weight (Mn) of the polyether polycarbonate polyol (a1) is not particularly limited, but is, for example, 600 or more, preferably 800 or more, more preferably 1,000 or more, and even more preferably 1,500 or more, and is, for example, 6,000 or less, preferably 5,000 or less, more preferably 4,000 or less, and even more preferably 3,500 or less. When the number average molecular weight of the polyether polycarbonate polyol (a1) is within the above range, it is easy to improve the oil resistance, impact resistance, and the like while improving the handleability.

[0022] As the polyol (a-1), a polyol other than a polyether polycarbonate polyol may be used, and a specific example thereof is a polycarbonate polyol having no ether skeleton (hereinafter, referred to as polycarbonate polyol (A1)).

[0023] The polycarbonate polyol having no ether skeleton may be synthesized by using a polyhydroxy compound having no ether skeleton as a raw material. The polyhydroxy compound having no ether skeleton is generally a dihydroxy compound. The polyhydroxy compound having no ether skeleton may include a linear aliphatic polyol, an aliphatic polyol having a branched structure, an alicyclic polyol having an alicyclic structure, and an aromatic polyhydroxy compound. The method for producing the polycarbonate polyol (A1) is not particularly limited, and it may be produced by a known method such as a phosgene method or an ester exchange method.

[0024] The polycarbonate polyol (A1) is preferably a polycarbonate diol, and a specific example of the polycarbonate diol is a compound represented by the following formula (2).

[0025] [ka] In formula (2), R is a divalent hydrocarbon group having 4 to 16 carbon atoms, and n is an integer from 2 to 120.

[0026] In formula (2), R is preferably an aliphatic saturated hydrocarbon group. When R is an aliphatic saturated hydrocarbon group, heat resistance and flexibility tend to be good. R consisting of an aliphatic saturated hydrocarbon group may have a chain structure or a cyclic structure, but preferably has a chain structure. In addition, R of the chain structure may be either linear or branched. n is preferably 2-50, more preferably 2-25, further preferably 5-20, and most preferably 5-15. In the urethane prepolymer, the R contained in the polycarbonate polyol may be used alone or in combination of two or more kinds.

[0027] Preferred specific examples of R may be linear, such as a tetramethylene group, a pentamethylene group, a hexamethylene group, a heptamethylene group, an octamethylene group, a nonamethylene group, a decamethylene group, an undecamethylene group, or a dodecamethylene group, or may be branched, such as a methylpentylene group, e.g., a 3-methylpentylene group, or a methyloctamethylene group. The polycarbonate polyols may be used alone or in combination of two or more kinds.

[0028] (Polyol (a-2) having a linear hydrocarbon structure having 4 or more carbon atoms) The polyol for synthesizing the urethane prepolymer (A) includes a polyol (a-2) having a linear hydrocarbon structure with 4 or more carbon atoms (hereinafter, simply referred to as "polyol (a-2)"). By using the polyol (a-2), the resin composition can be made into a hot melt, and high initial adhesive strength can be easily imparted. The polyol (a-2) may be any polyol having a linear hydrocarbon structure with 4 or more carbon atoms and different from the polyol used as the polyol (a-1) in the light moisture curable hot melt resin composition. Examples of the polyol (a-2) include polyester polyols and polycarbonate polyols different from the polycarbonate polyol used as the polyol (a-1), and polyester polyols are preferred. In addition, the polyol (a-2) is preferably a solid at room temperature.

[0029] The linear hydrocarbon structure having 4 or more carbon atoms is not particularly limited, but for example, has 18 or less carbon atoms, preferably has 16 or less carbon atoms, more preferably has 14 or less carbon atoms, and further preferably has 12 or less carbon atoms. In addition, the linear hydrocarbon structure having 4 or more carbon atoms is a linear aliphatic hydrocarbon skeleton, and is preferably a linear saturated aliphatic hydrocarbon skeleton. Furthermore, the polyol (a-2) may have a branched hydrocarbon structure in addition to the linear hydrocarbon structure having 4 or more carbon atoms, but it is preferable that it does not have a branched hydrocarbon structure.

[0030] When a polyester polyol is used, the linear hydrocarbon structure having 4 or more carbon atoms may be derived from a polycarboxylic acid, a polyol, or a lactone compound, as described below. In addition, the linear hydrocarbon structure means a linear structure consisting of only carbon and hydrogen, and does not include carbon atoms such as oxygen atoms and carbon atoms bonded to atoms other than hydrogen atoms. Therefore, for example, the structural unit derived from adipic acid has a linear hydrocarbon structure except for the carbon atoms at both ends, and the structural unit derived from adipic acid has a linear hydrocarbon structure with four carbon atoms. In addition, for example, the structural unit derived from 1,6-hexanediol has a linear hydrocarbon structure with four carbon atoms. The linear hydrocarbon structure may be bonded to other structures at both ends, such as the structural unit derived from 1,6-hexanediol or the structural unit derived from adipic acid.

[0031] Examples of polyester polyols include polyester polyols obtained by reacting polycarboxylic acids with polyols, and polylactone polyols obtained by ring-opening polymerization of lactone compounds, such as poly-ε-caprolactone polyols obtained by ring-opening polymerization of ε-caprolactone. The polyester polyols may be used alone or in combination of two or more kinds.

[0032] Examples of polycarboxylic acids that are raw materials for polyester polyols include divalent aromatic carboxylic acids such as terephthalic acid, isophthalic acid, 1,5-naphthalic acid, and 2,6-naphthalic acid, divalent aliphatic carboxylic acids such as succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, decamethylene dicarboxylic acid, and dodecamethylene dicarboxylic acid, trivalent or higher aromatic carboxylic acids such as trimellitic acid, trimesic acid, pyromellitic acid, and naphthalene tricarboxylic acid, and trivalent or higher aliphatic carboxylic acids such as cyclohexane tricarboxylic acid and hexane tricarboxylic acid. These polycarboxylic acids may be used alone or in combination of two or more.

[0033] Examples of polyols that can be used as raw materials for polyester polyols include linear aliphatic polyols, aliphatic polyols having a branched structure such as neopentyl glycol, and aliphatic polyols having a cyclic skeleton such as cyclohexanediol. Examples of the linear aliphatic polyol include alkanediols having hydroxyl groups at both ends, such as ethylene glycol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,7-heptanediol, 1,8-octanediol, 1,9-nonanediol, and 1,10-decanediol, and linear aliphatic polyols other than alkanediols having hydroxyl groups at both ends, such as propylene glycol and diethylene glycol. These polyols may be used alone or in combination of two or more kinds.

[0034] Among the above, the polyester polyol is preferably a polyester polyol obtained by the reaction of a polycarboxylic acid with a polyol, and more preferably a polyester diol. In these cases, the linear hydrocarbon structure having 4 or more carbon atoms may be contained in one or both of the structural units derived from polycarboxylic acid and the structural units derived from polyol. Among the structural units derived from polycarboxylic acid and the structural units derived from polyol, the structural units containing the linear hydrocarbon structure having 4 or more carbon atoms are preferably 50% by mass or more and 100% by mass or less, more preferably 70% by mass or more and 100% by mass or less, even more preferably 90% by mass or more and 100% by mass or less, and most preferably 100% by mass.

[0035] Among the above, the polycarboxylic acid used in the polyester polyol is preferably a linear polycarboxylic acid. By using a linear polycarboxylic acid, the crystallinity is easily increased and the set time is easily shortened. Therefore, the initial adhesive strength is increased and the impact resistance is easily improved. In the polyester polyol, the linear polycarboxylic acid may be used alone as the polycarboxylic acid, or may be used in combination with a polycarboxylic acid other than the linear polycarboxylic acid.

[0036] The linear polycarboxylic acid may be a divalent linear aliphatic carboxylic acid having carboxyl groups at both ends. The divalent linear aliphatic carboxylic acid is preferably a linear saturated aliphatic dicarboxylic acid. Examples of linear polycarboxylic acids include aliphatic dicarboxylic acids having 4 to 20 carbon atoms, and among these, aliphatic dicarboxylic acids having 6 or more carbon atoms are more preferred, and aliphatic dicarboxylic acids having 6 to 10 carbon atoms are even more preferred. As described above, the aliphatic dicarboxylic acid has carboxyl groups at both ends, and is preferably a saturated aliphatic dicarboxylic acid. Therefore, among the above, the polycarboxylic acid is preferably adipic acid, pimelic acid, suberic acid, azelaic acid, or sebacic acid, and particularly preferably adipic acid or sebacic acid.

[0037] The polyester polyol preferably contains a structural unit derived from a linear saturated aliphatic dicarboxylic acid having 6 or more carbon atoms, and the content thereof is, for example, 75 mol % or more and 100 mol % or less, preferably 85 mol % or more and 100 mol % or less, more preferably 95 mol % or more and 100 mol % or less, and most preferably 100 mol %, based on the total amount of structural units derived from all polycarboxylic acids.

[0038] The polyester polyol preferably contains a structural unit derived from a polycarboxylic acid selected from the group consisting of adipic acid and sebacic acid, and the content thereof is, for example, 75 mol % or more and 100 mol % or less, preferably 85 mol % or more and 100 mol % or less, more preferably 95 mol % or more and 100 mol % or less, and most preferably 100 mol %, based on the total amount of structural units derived from polycarboxylic acid. The linear polycarboxylic acids may be used alone or in combination of two or more kinds.

[0039] Among the above, the polyol used in the polyester polyol is preferably a linear polyol, and more preferably a linear alkanediol having hydroxyl groups at both ends. By using a linear polyol, particularly an alkanediol having hydroxyl groups at both ends, the crystallinity is easily increased and the set time is easily shortened. Therefore, the initial adhesive strength is increased, and the impact resistance is easily improved. In the polyester polyol, the linear alkanediol having hydroxyl groups at both ends may be used alone as the polyol, but may be used in combination with a polyol other than the linear alkanediol having hydroxyl groups at both ends.

[0040] As described above, the polyester polyol preferably contains a structural unit derived from a linear alkanediol having hydroxyl groups at both ends, and the content thereof is, for example, 75 mol % or more and 100 mol % or less, preferably 85 mol % or more and 100 mol % or less, more preferably 95 mol % or more and 100 mol % or less, and most preferably 100 mol %, based on the total amount of structural units derived from the polyol. In addition, in the polyester polyol, from the viewpoint of increasing the crystallinity, it is preferable to use a linear polyol as the polyol and a linear polycarboxylic acid as the polycarboxylic acid. Among them, it is more preferable to use a linear alkanediol having hydroxyl groups at both ends as the polyol and a structural unit derived from a linear saturated aliphatic dicarboxylic acid as the polycarboxylic acid.

[0041] The straight-chain alkanediol having hydroxyl groups at both ends is preferably, for example, a straight-chain alkanediol having 3 to 12 carbon atoms, more preferably a straight-chain alkanediol having 6 to 10 carbon atoms, and most preferably a straight-chain alkanediol having 6 carbon atoms. Preferred specific examples of the straight-chain alkanediol having hydroxyl groups at both ends include 1,6-hexanediol, 1,7-heptanediol, 1,8-octanediol, 1,9-nonanediol, and 1,10-decanediol, and among these, 1,6-hexanediol is the most preferred. Therefore, it is preferable that the polyester polyol contains a structural unit derived from 1,6-hexanediol, and the content thereof is, for example, 75 mol % or more and 100 mol % or less, preferably 85 mol % or more and 100 mol % or less, more preferably 95 mol % or more and 100 mol % or less, and most preferably 100 mol %, based on the total amount of structural units derived from the polyol. The linear polyols may be used alone or in combination of two or more kinds.

[0042] In the polyol (Aa), it is preferable that the polyol (a1) is contained in an amount of 15% by mass to 85% by mass, and the polyol (a2) is contained in an amount of 15% by mass to 85% by mass. When the contents of the polyol (a1) and the polyol (a2) are within the above ranges, the polyol (a1) makes it easier to improve the oil resistance while extending the pot life, and the polyol (a2) makes it easier to increase the initial adhesive strength. From the above viewpoints, the content of polyol (a1) in polyol (Aa) is more preferably 20% by mass or more, even more preferably 30% by mass or more, and even more preferably 35% by mass or more, and is more preferably 80% by mass or less, even more preferably 70% by mass or less, and even more preferably 65% ​​by mass or less. The content of polyol (a2) in polyol (Aa) is more preferably 20% by mass or more, even more preferably 30% by mass or more, even more preferably 35% by mass or more, and is more preferably 80% by mass or less, even more preferably 70% by mass or less, and even more preferably 65% ​​by mass or less.

[0043] In addition, the polyol (Aa) may contain polyols (other polyols) other than the polyols (a1) and (a2) as long as the effects of the present invention are not impaired. In the polyol (Aa), the content of the other polyols is, for example, 0% by mass or more and 20% by mass or less, preferably 0% by mass or more and 10% by mass or less, more preferably 0% by mass or more and 5% by mass or less, and most preferably 0% by mass.

[0044] (Polyisocyanate (a-3)) Examples of the polyisocyanate include polyisocyanates having an aromatic skeleton and aliphatic polyisocyanates. Examples of the polyisocyanate having an aromatic skeleton include diphenylmethane diisocyanate, a liquid modified product of diphenylmethane diisocyanate, tolylene diisocyanate, and naphthalene-1,5-diisocyanate. Examples of the aliphatic polyisocyanate include hexamethylene diisocyanate, trimethylhexamethylene diisocyanate, lysine diisocyanate, norbornane diisocyanate, transcyclohexane-1,4-diisocyanate, isophorone diisocyanate, hydrogenated xylylene diisocyanate, hydrogenated diphenylmethane diisocyanate, cyclohexane diisocyanate, bis(isocyanatemethyl)cyclohexane, and dicyclohexylmethane diisocyanate.

[0045] The isocyanate compound may be a polymerized isocyanate or may be polymeric MDI. In addition, the isocyanate compound may be a chain-extended polyisocyanate compound (polyol modified product) obtained by reacting a polyol with an excess of an isocyanate compound, or an isocyanurate modified product of a polyisocyanate. Examples of the polyol include ethylene glycol, propylene glycol, glycerin, sorbitol, trimethylolpropane, carbonate diol, polyether diol, polyester diol, and polycaprolactone diol.

[0046] In the present invention, as the polyisocyanate (a-3), it is preferable to use a polyisocyanate having an aromatic skeleton, and among them, at least one selected from diphenylmethane diisocyanate (MDI) and tolylene diisocyanate (TDI) is more preferable. By using a polyisocyanate having an aromatic skeleton, it is easy to improve the oil resistance of the light moisture curable hot melt resin composition. In this specification, a polyisocyanate having an aromatic skeleton is a polyisocyanate having an aromatic ring, and an aliphatic polyisocyanate is a polyisocyanate not having an aromatic ring.

[0047] The content of the urethane prepolymer (A) in the photo-curable hot melt resin composition is not particularly limited, but is, for example, 40% by mass or more, preferably 50% by mass or more, more preferably 60% by mass or more, based on the total amount of the photo-curable hot melt resin composition. By making the content of the urethane prepolymer equal to or more than the above lower limit, it becomes easier to impart impact resistance to the photo-curable hot melt resin composition. In addition, the resin composition can be appropriately moisture-cured by the urethane prepolymer (A). The content of the urethane prepolymer may be 90% by mass or less, but in order to appropriately contain the radical polymerizable compound (B) component, the photopolymerization initiator (C) component, and other components, it is preferably 85% by mass or less, more preferably 75% by mass or less.

[0048] <Radical polymerizable compound (B)> The photo-curable hot melt resin composition of the present invention contains a radical polymerizable compound (B). The photo-curable hot melt resin composition contains the radical polymerizable compound (B) and is cured by irradiation with active energy rays such as ultraviolet rays. The photo-curable hot melt resin composition has a certain adhesive strength by simply irradiating light, so that a certain initial adhesive strength can be ensured. In addition, the radical polymerizable compound (B) acts as a plasticizer before photocuring to suppress the crystallinity of the photo-curable hot melt resin composition, thereby delaying the time until the adhesive loses fluidity due to crystallization and cannot be bonded, thereby extending the usable time. Furthermore, by irradiating the radical polymerizable compound (B) with active energy rays such as ultraviolet rays a certain time before the timing of bonding, the plasticizer effect of the radical polymerizable compound (B) is lost, the crystallinity of the urethane prepolymer (A) is restored, and the adhesive strength due to crystallization solidification after bonding is quickly expressed, thereby improving the initial adhesive strength. In addition, the temperature when applying by heating can be lowered to improve workability. The radical polymerizable compound (B) may have a radical polymerizable functional group in the molecule. The radical polymerizable functional group is preferably a compound having an unsaturated double bond, such as a (meth)acryloyl group, a vinyl group, a styryl group, or an allyl group.

[0049] Among the above, from the viewpoint of adhesiveness, (meth)acryloyl group or vinyl group is suitable, that is, the radical polymerizable compound (B) preferably contains a compound having a (meth)acryloyl group. It is also preferable that the radical polymerizable compound (B) contains a radical polymerizable compound having a vinyl group. In addition, a compound having a (meth)acryloyl group will be hereinafter also referred to as a "(meth)acrylic compound". In addition, in this specification, "(meth)acryloyl group" means an acryloyl group or a (meth)acryloyl group, "(meth)acrylic" means an acrylic or methacrylic, and the same applies to other similar terms.

[0050] The radically polymerizable compound (B) may be a monofunctional radically polymerizable compound or a polyfunctional radically polymerizable compound. Examples of the monofunctional radically polymerizable compound include a radically polymerizable compound having an aromatic ring, a radically polymerizable compound having an alicyclic structure, an alkyl (meth)acrylate, a compound containing a nitrogen atom (nitrogen-containing compound), and a cyclic ether group-containing (meth)acrylate.

[0051] Examples of the radical polymerizable compound having an aromatic ring include aromatic ring-containing (meth)acrylates. Examples of the aromatic ring-containing (meth)acrylates include phenyl alkyl (meth)acrylates such as benzyl (meth)acrylate and 2-phenylethyl (meth)acrylate, phenoxy alkyl (meth)acrylates such as phenoxyethyl (meth)acrylate, and phenoxybenzyl (meth)acrylate.

[0052] Examples of the radical polymerizable compound having an alicyclic structure include (meth)acrylates containing an alicyclic structure. Examples of the (meth)acrylates containing an alicyclic structure include (meth)acrylates having an alicyclic structure such as cyclohexyl (meth)acrylate, 4-tert-butylcyclohexyl (meth)acrylate, 3,3,5-trimethylcyclohexyl (meth)acrylate, isobornyl (meth)acrylate, and dicyclopentenyl (meth)acrylate. The alicyclic structure referred to here is a ring structure whose ring constituent elements are carbon atoms.

[0053] Examples of the alkyl (meth)acrylate include alkyl (meth)acrylates having an alkyl group with a carbon number of 1 to 18, such as methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, n-butyl (meth)acrylate, isobutyl (meth)acrylate, t-butyl (meth)acrylate, n-octyl (meth)acrylate, isooctyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, isononyl (meth)acrylate, isodecyl (meth)acrylate, lauryl (meth)acrylate, isomyristyl (meth)acrylate, and stearyl (meth)acrylate.

[0054] Examples of the nitrogen-containing compound include nitrogen-containing compounds having a cyclic structure and nitrogen-containing compounds having a chain structure. Specific examples of the nitrogen-containing compound include nitrogen-containing compounds having a lactam structure such as N-vinylpyrrolidone and N-vinyl-ε-caprolactam, compounds containing a morpholine skeleton such as N-acryloylmorpholine, and cyclic imide compounds such as N-(meth)acryloyloxyethylhexahydrophthalimide.

[0055] Examples of chain nitrogen-containing compounds include chain amino group-containing (meth)acrylates such as dimethylamino(meth)acrylate, diethylamino(meth)acrylate, aminomethyl(meth)acrylate, aminoethyl(meth)acrylate, and dimethylaminoethyl(meth)acrylate; chain (meth)acrylamide compounds such as diacetoneacrylamide, N,N-dimethylacrylamide, N,N-diethylacrylamide, N-isopropylacrylamide, N-hydroxyethylacrylamide, acrylamide, and methacrylamide; and N-vinylacetamide.

[0056] The chain-like nitrogen-containing compound may be a monofunctional urethane (meth)acrylate. By using a monofunctional urethane (meth)acrylate, the compatibility with the urethane prepolymer (A) is improved, and the initial adhesive strength is easily improved. In addition, urethane (meth)acrylate has a relatively high polarity, which makes it easier to increase the adhesive strength to glass.

[0057] As the monofunctional urethane (meth)acrylate, for example, one obtained by reacting an isocyanate compound with a (meth)acrylic acid derivative having a hydroxyl group can be used. Examples of the (meth)acrylic acid derivative having a hydroxyl group include mono(meth)acrylates of dihydric alcohols such as ethylene glycol, propylene glycol, 1,3-propanediol, 1,3-butanediol, 1,4-butanediol, and polyethylene glycol, and mono(meth)acrylates of trihydric alcohols such as trimethylolethane, trimethylolpropane, and glycerin.

[0058] Examples of the isocyanate compound used to obtain the urethane (meth)acrylate include alkane monoisocyanates such as butane isocyanate, hexane isocyanate, and decane isocyanate, and aliphatic monoisocyanates such as cyclic aliphatic monoisocyanates such as cyclopentane isocyanate, cyclohexane isocyanate, and isophorone monoisocyanate. More specifically, the monofunctional urethane (meth)acrylate is preferably a urethane (meth)acrylate obtained by reacting the above-mentioned monoisocyanate compound with a mono(meth)acrylate of a dihydric alcohol, and a suitable specific example thereof is 1,2-ethanediol 1-acrylate 2-(N-butylcarbamate). Of the above, the chain nitrogen-containing compound preferably contains a monofunctional urethane (meth)acrylate, and it is also preferable to use a monofunctional urethane (meth)acrylate in combination with a compound other than the monofunctional urethane (meth)acrylate, such as a (meth)acrylamide compound.

[0059] Examples of the cyclic ether group-containing (meth)acrylate include (meth)acrylates having an epoxy ring, an oxetane ring, a tetrahydrofuran ring, a dioxolane ring, a dioxane ring, and the like. Examples of epoxy ring-containing (meth)acrylates include glycidyl (meth)acrylate. Examples of oxetane ring-containing (meth)acrylates include (3-ethyloxetane-3-yl)methyl (meth)acrylate. Examples of tetrahydrofuran ring-containing (meth)acrylates include tetrahydrofurfuryl (meth)acrylate, and (meth)acrylic acid polymeric esters of tetrahydrofurfuryl alcohol. Examples of the dioxolane ring-containing (meth)acrylate include (2-methyl-2-ethyl-1,3-dioxolane-4-yl)methyl (meth)acrylate, (2,2-cyclohexyl-1,3-dioxolane-4-yl)methyl (meth)acrylate, etc. Examples of the (meth)acrylate having a dioxane ring include cyclic trimethylolpropane formal (meth)acrylate, etc. As the cyclic ether group-containing (meth)acrylate, it is preferable to use either an oxetane ring-containing (meth)acrylate or a tetrahydrofuran ring-containing (meth)acrylate, but it is also preferable to use them in combination.

[0060] In addition, the monofunctional radical polymerizable compound may be one other than the above. For example, hydroxyalkyl (meth)acrylates such as 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 2-hydroxybutyl (meth)acrylate, and 4-hydroxybutyl (meth)acrylate, alkoxyalkyl (meth)acrylates such as 2-methoxyethyl (meth)acrylate, 2-ethoxyethyl (meth)acrylate, and 2-butoxyethyl (meth)acrylate, alkoxyethylene glycol (meth)acrylates such as methoxyethylene glycol (meth)acrylate and ethoxyethylene glycol (meth)acrylate, methoxydiethylene glycol (meth)acrylate, methoxytriethylene glycol (meth)acrylate, methoxypolyethylene glycol (meth)acrylate, ethyl carbitol (meth)acrylate, ethoxydiethylene glycol (meth)acrylate, ethoxytriethylene glycol (meth)acrylate, and polyoxyethylene (meth)acrylates such as ethoxypolyethylene glycol (meth)acrylate may also be used. Furthermore, as the monofunctional radically polymerizable compound, a carboxyl-containing (meth)acrylic compound such as acrylic acid or methacrylic acid may be used.

[0061] Examples of the polyfunctional radically polymerizable compound include difunctional (meth)acrylic acid ester compounds, trifunctional or higher functional (meth)acrylic acid ester compounds, and difunctional or higher functional urethane (meth)acrylates.

[0062] The bifunctional (meth)acrylic acid ester compound may, for example, have an aromatic ring, and specific examples thereof include ethylene oxide-added bisphenol A di(meth)acrylate, propylene oxide-added bisphenol A di(meth)acrylate, and ethylene oxide-added bisphenol F di(meth)acrylate. In addition to the above, examples of the bifunctional (meth)acrylic acid ester compound 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, Examples of the dipropylene glycol di(meth)acrylate include dipropylene glycol di(meth)acrylate, tripropylene glycol di(meth)acrylate, polypropylene glycol di(meth)acrylate, dimethylol dicyclopentadienyl di(meth)acrylate, neopentyl glycol di(meth)acrylate, 2-hydroxy-3-(meth)acryloyloxypropyl (meth)acrylate, carbonate diol di(meth)acrylate, polyether diol di(meth)acrylate, polyester diol di(meth)acrylate, polycaprolactone diol di(meth)acrylate, and polybutadiene diol di(meth)acrylate.

[0063] Examples of the trifunctional or higher (meth)acrylic acid ester compound include trimethylolpropane tri(meth)acrylate, ethylene oxide-added trimethylolpropane tri(meth)acrylate, propylene oxide-added trimethylolpropane tri(meth)acrylate, caprolactone-modified trimethylolpropane tri(meth)acrylate, pentaerythritol tri(meth)acrylate, glycerin tri(meth)acrylate, propylene oxide-added glycerin tri(meth)acrylate, tris(meth)acryloyloxyethyl phosphate, ditrimethylolpropane tetra(meth)acrylate, pentaerythritol tetra(meth)acrylate, dipentaerythritol penta(meth)acrylate, and dipentaerythritol hexa(meth)acrylate.

[0064] The di- or higher functional urethane (meth)acrylate may be, for example, one obtained by reacting an isocyanate compound with a (meth)acrylic acid derivative having a hydroxyl group. Examples of the (meth)acrylic acid derivative having a hydroxyl group include mono(meth)acrylates of dihydric alcohols such as ethylene glycol, propylene glycol, 1,3-propanediol, 1,3-butanediol, 1,4-butanediol, and polyethylene glycol; mono(meth)acrylates or di(meth)acrylates of trihydric alcohols such as trimethylolethane, trimethylolpropane, and glycerin; and epoxy(meth)acrylates such as bisphenol A-type epoxy(meth)acrylate.

[0065] Examples of the isocyanate compound used to obtain the urethane (meth)acrylate include polyisocyanate compounds such as isophorone diisocyanate, 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, hexamethylene diisocyanate, trimethylhexamethylene diisocyanate, diphenylmethane diisocyanate (MDI), hydrogenated MDI, polymeric MDI, 1,5-naphthalene diisocyanate, norbornane diisocyanate, tolidine diisocyanate, xylylene diisocyanate (XDI), hydrogenated XDI, lysine diisocyanate, triphenylmethane triisocyanate, tris(isocyanatephenyl)thiophosphate, tetramethylxylylene diisocyanate, and 1,6,11-undecane triisocyanate.

[0066] Also, as the isocyanate compound, a chain-extended polyisocyanate compound (polyol modified product) obtained by reacting a polyol with an excess of an isocyanate compound, an isocyanurate modified product of a polyisocyanate, etc. can be used. Here, examples of the polyol include ethylene glycol, propylene glycol, glycerin, sorbitol, trimethylolpropane, carbonate diol, polyether diol, polyester diol, polycaprolactone diol, etc. By using these polyisocyanate compounds, polyfunctional urethane (meth)acrylates can be obtained.

[0067] From the viewpoint of imparting good oil resistance to the photo-curable hot melt resin composition, the radical polymerizable compound (B) preferably contains a radical polymerizable compound having an aromatic ring, and more preferably contains an aromatic ring-containing (meth)acrylate. As the aromatic ring-containing (meth)acrylate, a monofunctional aromatic ring-containing (meth)acrylate is preferable, and specific examples thereof are as described above.

[0068] In the photo-curable hot melt resin composition of the present invention, the content of the radical polymerizable compound having an aromatic ring relative to 100 parts by mass of the radical polymerizable compound (B) is preferably 50 parts by mass or more, more preferably 60 parts by mass or more, even more preferably 70 parts by mass or more, and even more preferably 80 parts by mass or more, from the viewpoint of improving the oil resistance of the photo-curable hot melt resin composition. In addition, the content of the radical polymerizable compound having an aromatic ring may be 100 parts by mass or less, but when an appropriate amount of a radical polymerizable compound not having an aromatic ring is contained, it may be, for example, 95 parts by mass or less, or 90 parts by mass or less.

[0069] The radical polymerizable compound (B) preferably contains a radical polymerizable compound having a vinyl group. When the radical polymerizable compound having a vinyl group is contained, the curability of the urethane prepolymer (A) is improved, and it becomes easy to impart excellent initial adhesive strength to the light moisture curable hot melt resin composition. As the radically polymerizable compound having a vinyl group, monofunctional nitrogen-containing compounds such as N-vinylpyrrolidone, N-vinyl-ε-caprolactam, and N-vinylacetamide are preferred, and among these, N-vinyl-ε-caprolactam is preferred.

[0070] In the photo-curable hot melt resin composition of the present invention, the content of the radical polymerizable compound having a vinyl group relative to 100 parts by mass of the radical polymerizable compound (B) is preferably 5 parts by mass or more, more preferably 8 parts by mass or more, even more preferably 10 parts by mass or more, and even more preferably 15 parts by mass or more, from the viewpoint of improving the initial adhesive strength of the photo-curable hot melt resin composition. In addition, the content of the radical polymerizable compound having a vinyl group is preferably 30 parts by mass or less, more preferably 20 parts by mass or less, in order to contain an appropriate amount of the radical polymerizable compound having an aromatic ring.

[0071] The photo-curable hot melt resin composition of the present invention preferably does not contain a radical polymerizable compound having a linear hydrocarbon structure having 8 or more carbon atoms, or contains only a small amount of the radical polymerizable compound. By not containing a radical polymerizable compound having a linear hydrocarbon group having 8 or more carbon atoms, or containing only a small amount of the radical polymerizable compound, the oil resistance and initial adhesive strength of the photo-curable hot melt resin composition can be easily improved. Specifically, the content of the radical polymerizable compound having a linear hydrocarbon structure having 8 or more carbon atoms is preferably less than 5 mass % based on the total amount of the light-moisture-curable hot melt resin composition, more preferably 3.5 mass % or less, and even more preferably 3 mass % or less.

[0072] The content of the radical polymerizable compound (B) in the photo-moisture curable hot melt resin composition is, for example, 10% by mass or more, preferably 15% by mass or more, more preferably 20% by mass or more, based on the total amount of the photo-moisture curable hot melt resin composition. By making the content of the radical polymerizable compound (B) equal to or more than the above lower limit, it becomes easier to extend the usable time of the photo-moisture curable hot melt resin composition and ensure a certain level of initial adhesive strength. In addition, the content of the radical polymerizable compound (B) is preferably 40% by mass or less, more preferably 35% by mass or less, from the viewpoint of making the photo-curability of the photo-moisture curable hot melt resin composition appropriate.

[0073] In the photo-curable hot melt resin composition of the present invention, the mass ratio (A / B) of the urethane prepolymer (A) to the radical polymerizable compound (B) is preferably 50 / 50 or more and 95 / 10 or less, more preferably 55 / 45 or more and 85 / 15 or less, and even more preferably 60 / 40 or more and 78 / 22 or less. When A / B is equal to or more than the lower limit, the composition can contain a certain amount of the urethane prepolymer (A), which makes it easier to impart good crystallinity to the composition. In addition, the radical polymerizable compound (B) is not excessively contained, which makes it easier to impart good pressure-bonding properties to the composition. On the other hand, when A / B is equal to or less than the upper limit, the composition can contain a certain amount of the radical polymerizable compound (B), which makes it possible to extend the pot life of the composition and impart appropriate photocurability. In addition, by setting A / B within the above range, it is easier to ensure initial adhesive strength.

[0074] <Photopolymerization initiator (C)> The light- and moisture-curable hot-melt resin composition of the present invention contains a photopolymerization initiator (C). By containing the photopolymerization initiator (C), the light- and moisture-curable hot-melt resin composition is appropriately imparted with photocurability. Examples of the photopolymerization initiator (C) include benzophenone-based compounds, acetophenone-based compounds, alkylphenone-based photopolymerization initiators, acylphosphine oxide-based compounds, titanocene-based compounds, oxime ester-based compounds, benzoin ether-based compounds, and thioxanthone. Examples of commercially available photopolymerization initiators (C) include IRGACURE184, IRGACURE369, IRGACURE379, IRGACURE379EG, IRGACURE651, IRGACURE784, IRGACURE819, IRGACURE907, IRGACURE2959, IRGACURE OXE01, IRGACURE TPO (all manufactured by BASF), benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether (all manufactured by Tokyo Chemical Industry Co., Ltd.), Omnirad TPO (manufactured by IGM Resins BV), and the like.

[0075] The content of the photopolymerization initiator (C) in the photo-curable hot melt resin composition is 0.1% by mass or more and 10% by mass or less, more preferably 0.3% by mass or more and 5% by mass or less, and even more preferably 0.4% by mass or more and 3% by mass or less, based on the total amount of the photo-curable hot melt resin composition. By making the content of the photopolymerization initiator (C) within these ranges, the obtained photo-curable hot melt resin composition has excellent photocurability. In addition, by making it within the above range, the photo-curable hot melt resin composition is appropriately cured, and the adhesive strength is easily improved.

[0076] The photo-curable hot melt resin composition of the present invention preferably contains a coupling agent (D) and a moisture-curing accelerating catalyst (E) in addition to the urethane prepolymer (A), the radical polymerizable compound (B), and the photopolymerization initiator (C). By containing the coupling agent (D), it becomes easier to improve the adhesive strength. In addition, by containing the moisture-curing accelerating catalyst (E), the photo-curable hot melt resin composition has better moisture curability and is easier to increase the adhesive strength.

[0077] <Coupling agent (D)> Examples of the coupling agent (D) include silane coupling agents, titanate coupling agents, and zirconate coupling agents. Among the coupling agents (D), silane coupling agents are preferred because they have excellent effect of improving adhesion.Furthermore, among the silane coupling agents, mercaptan-based silane coupling agents and amine-based silane coupling agents are preferred because they have excellent effect of improving impact resistance, amine-based silane coupling agents are more preferred, amine-containing silane coupling agents having aromatic rings in molecules are even more preferred, and aromatic amine-containing silane coupling agents having aromatic amines are particularly preferred.

[0078] Examples of the amine-based silane coupling agent include N-phenyl-3-aminopropyltrimethoxysilane, 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 3-(2-aminoethyl)aminopropyltrimethoxysilane, 3-(2-aminoethyl)aminopropyltriethoxysilane, 3-(2-aminoethyl)aminopropylmethyldimethoxysilane, etc. Among these, N-phenyl-3-aminopropyltrimethoxysilane is preferred. Examples of the mercaptan-based silane coupling agent include 3-mercaptopropyltrimethoxysilane, 3-mercaptopropylmethyldimethoxysilane, 3-mercaptopropyltriethoxysilane, and 3-mercaptopropylmethyldiethoxysilane.

[0079] As the silane coupling agent, silane coupling agents other than the mercaptan-based silane coupling agent and the amine-based silane coupling agent may be used. Other silane coupling agents include, for example, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropylmethyldimethoxysilane, 3-glycidoxypropyltriethoxysilane, 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, 3-glycidoxypropylmethyldiethoxysilane, 3-(meth)acryloyloxypropyltrimethoxysilane, 3-(meth)acryloyloxypropyltriethoxysilane, 3-(meth)acryloyloxypropylmethyldimethoxysilane, 3-(meth)acryloyloxypropylmethyldiethoxysilane, vinyltrimethoxysilane, and vinyltriethoxysilane. , 3-isocyanatepropyltrimethoxysilane, 3-isocyanatepropylmethyldimethoxysilane, 3-isocyanatepropyltriethoxysilane, 3-isocyanatepropylmethyldiethoxysilane, methyltrimethoxysilane, dimethyldimethoxysilane, phenyltrimethoxysilane, methyltriethoxysilane, dimethyldiethoxysilane, phenyltriethoxysilane, n-propyltrimethoxysilane, n-propyltriethoxysilane, hexyltrimethoxysilane, hexyltriethoxysilane, octyltriethoxysilane, tedyltrimethoxysilane, 1,6-bis(trimethoxysilyl)hexane, and the like.

[0080] Examples of the titanate coupling agent include titanium diisopropoxybis(acetylacetonate), titanium tetraacetylacetonate, and titanium diisopropoxybis(ethylacetoacetate). Examples of the zirconate coupling agent include zirconium tetra-normal-propoxide and zirconium tetra-normal-butoxide. The coupling agent (D) may be used alone or in combination of two or more kinds.

[0081] The content of the coupling agent (D) is preferably 0.05 parts by mass or more and 8 parts by mass or less, more preferably 0.2 parts by mass or more and 6 parts by mass or less, and even more preferably 0.5 parts by mass or more and 4 parts by mass or less, relative to 100 parts by mass of the urethane prepolymer (A). By keeping the content of the coupling agent within these ranges, it becomes easier to improve the adhesive strength without affecting various performances of the cured product.

[0082] <Moisture curing catalyst (E)> The moisture-curing catalyst (E) accelerates the moisture-curing reaction of the urethane prepolymer (A). By using the moisture-curing catalyst (E), the moisture-curable hot-melt resin composition has better moisture curing properties and is more likely to have higher adhesive strength. Specific examples of the moisture curing accelerating catalyst (E) include amine compounds and metal catalysts, and amine compounds are preferred. Examples of the amine compounds include compounds having a morpholine skeleton such as di(methylmorpholino)diethyl ether, 4-morpholinopropylmorpholine, and bis(2-morpholinoethyl)ether, dimethylamino group-containing amine compounds having two dimethylamino groups such as bis(2-dimethylaminoethyl)ether and 1,2-bis(dimethylamino)ethane, triethylamine, 1,4-diazabicyclo[2.2.2]octane, and 2,6,7-trimethyl-1,4-diazabicyclo[2.2.2]octane. Examples of the metal catalyst 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 tetraacetylacetonate, copper naphthenate, and cobalt naphthenate. The content of the moisture-cure-accelerating catalyst (E) is preferably from 0.01 to 5 parts by mass, more preferably from 0.03 to 3 parts by mass, and even more preferably from 0.05 to 2 parts by mass, per 100 parts by mass of the urethane prepolymer (A).

[0083] <Filler (F)> The photo-curable hot melt resin composition of the present invention may contain a filler (F). By containing the filler (F), the photo-curable hot melt resin composition of the present invention has a suitable thixotropy and can adequately retain its shape after application. As the filler, a particulate filler may be used. The filler (F) is not particularly limited, but inorganic fillers are preferred, such as silica, talc, titanium oxide, zinc oxide, calcium carbonate, etc. Among them, silica is preferred because the resulting photo-and-moisture curable hot melt resin composition has excellent ultraviolet transmittance. The filler (F) may be subjected to hydrophobic surface treatment such as silylation treatment, alkylation treatment, and epoxidation treatment. The filler (F) may be used alone or in combination of two or more kinds. The content of the filler (F) is not particularly limited, but is preferably from 1 to 25% by mass, more preferably from 2 to 20% by mass, based on the total amount of the light-and-moisture-curable hot-melt resin composition.

[0084] <Coloring agent> The photo-curable hot melt resin composition of the present invention may contain a colorant. Examples of the colorant include iron oxide, titanium black, aniline black, cyanine black, fullerene, carbon black, and resin-coated carbon black. The photo-curable hot melt resin composition contains a colorant, which improves the light-shielding properties. Among these, titanium black is preferred. Titanium black has the property of sufficiently blocking light with wavelengths in the visible light region while transmitting light with wavelengths near the ultraviolet region, so that the photo-curing properties of the photo-curable hot melt resin composition can be prevented from decreasing. The content of the colorant in the photo- and moisture-curable hot melt resin composition is not particularly limited, but is preferably 0.05% by mass to 8% by mass, more preferably 0.1% by mass to 2% by mass, based on the total amount of the photo- and moisture-curable hot melt resin composition. By keeping the content of the colorant within these ranges, the photo- and moisture-curable hot melt resin composition can be provided with appropriate light-shielding properties while maintaining good adhesion.

[0085] <Other ingredients> The light-and-moisture-curable hot melt resin composition of the present invention may contain, in addition to the above-mentioned urethane prepolymer (A) and radically polymerizable compound (B), a curable resin that is cured by heat, active energy rays, moisture, etc., such as a thermosetting resin, a photocurable resin, or a moisture-curable resin, or may contain a thermoplastic resin.

[0086] The photo-curable hot melt resin composition of the present invention may contain additives (also referred to as "other additives") other than the photopolymerization initiator (C), the coupling agent (D), and the moisture curing accelerating catalyst (E). Examples of the other additives include plasticizers, tackifiers, colorants such as pigments and dyes, fillers, antioxidants, surfactants, flame retardants, wax particles, ionic liquids, foamed particles, expanding particles, and reactive diluents.

[0087] <Initial adhesive strength> The initial adhesive strength is the adhesive strength measured after melting a photo- and moisture-curable hot-melt resin composition, applying it to an adherend, irradiating it with ultraviolet (UV) rays of a predetermined energy, and then laminating and pressing the applied and irradiated photo- and moisture-curable hot-melt resin composition to another adherend, and allowing 1 to 5 minutes to pass. The photo-curable hot melt resin composition of the present invention has an initial adhesive strength of preferably 0.5 MPa or more, more preferably 0.7 MPa or more, and even more preferably 1.0 MPa or more after 3 minutes of pressure bonding. It is also preferable that the photo-curable hot melt resin composition of the present invention has an initial adhesive strength of 0.5 MPa or more after 1 minute of pressure bonding. If the initial adhesive strength 3 minutes after compression is 0.5 MPa or more, it becomes easier to prevent the adherends from shifting apart due to slight external force, or to prevent the adherends from floating apart due to repulsive force from parts built into the adherends. Furthermore, the light-curable, moisture-curable hot-melt resin composition of the present invention preferably has an initial adhesive strength 5 minutes after pressure bonding of 0.5 MPa or more, more preferably 0.7 MPa or more, and even more preferably 1.0 MPa or more. Specifically, the initial adhesive strength can be measured by the method described in the Examples. When measuring the initial adhesive strength, the photo- and moisture-curable hot melt resin composition is irradiated with ultraviolet light. The amount of ultraviolet light irradiation may be selected so that the radical polymerizable compound is substantially completely cured, for example, 1000 to 1500 mJ / cm. 2 The same applies to the measurements of adhesive strength, adhesive strength retention rate, and pot life after immersion in oleic acid described below.

[0088] The initial adhesive strength can be adjusted, for example, by the components constituting the urethane prepolymer (A), and as described above, it is easy to make it equal to or greater than a certain value by giving the light-moisture-curable hot melt resin composition moderate crystallinity. More specifically, the initial adhesive strength can be increased by using a polyol having moderate crystallinity for the polyol (a2) that is the raw material of the urethane prepolymer (A). In addition, by using a polyol with low crystallinity (preferably liquid) for the polyether polycarbonate polyol (a1), moderate flexibility can be obtained, making it easier to increase the initial adhesive strength. The initial adhesive strength can also be adjusted by the component composition and amount of the radically polymerizable compound (B).

[0089] <Swelling rate> The swelling ratio of the photo-curable hot melt resin composition of the present invention is preferably 130% or less, more preferably 125% or less, and even more preferably 120% or less. The swelling ratio is an index showing the weight increase caused by the photo-curable hot melt resin composition absorbing oil such as fatty acid. In the present invention, the swelling ratio is expressed as the ratio of the weight of the cured body of the photo-curable hot melt resin composition after immersing it in oleic acid and leaving it in an environment of 65°C and 90 RH% for 72 hours to the weight before immersion. The swelling ratio can be measured by the method described in the examples below. If the swelling ratio is equal to or less than the upper limit, swelling of the cured body of the photo- and moisture-curable hot melt resin composition during use due to oils contained in skin care products and sebum is suppressed, and excellent oil resistance can be exhibited. Note that, from the viewpoint of oil resistance, the lower the swelling ratio of the photo- and moisture-curable hot melt resin composition, the more preferable it is, and although there is no lower limit, it is usually 100% or more.

[0090] <Adhesive strength after immersion in oleic acid> The photo-curable hot melt resin composition of the present invention has an adhesive strength of 1.0 N / 25 mm or more after immersion in oleic acid, more preferably 1.5 N / 25 mm or more, and even more preferably 2.0 N / 25 mm or more. If the adhesive strength after immersion in oleic acid is equal to or more than the above lower limit, the photo-curable hot melt resin composition will exhibit adhesive strength even after exposure to oil, and will have excellent oil resistance. In addition, the upper limit of the adhesive strength after immersion in oleic acid is not particularly limited, but from a practical viewpoint, it is, for example, 20 N / 25 mm or less, preferably 15 N / 25 mm or less. The adhesive strength after immersion in oleic acid can be measured by the method described in the examples described later.

[0091] <Adhesion maintenance rate> The photo-curable hot melt resin composition of the present invention preferably has an adhesive strength maintenance rate of 40% or more, more preferably 45% or more, even more preferably 65% ​​or more, and even more preferably 75% or more. When the adhesive strength maintenance rate is equal to or more than the above lower limit, the adhesive strength of the photo-curable hot melt resin composition is suppressed from decreasing even after it is exposed to oil, and the composition has excellent oil resistance. In addition, the upper limit of the adhesive strength after immersion in oleic acid is not particularly limited, and may be 100% or less, but from a practical viewpoint, it is, for example, 98% or less. The adhesive strength maintenance rate can be calculated by the method described in the examples described later. Specifically, it can be calculated by the following formula. Adhesive strength retention rate (%) = (adhesive strength after immersion in oleic acid / adhesive strength before immersion in oleic acid) x 100

[0092] <Pot life> The photo-curable hot melt resin composition of the present invention is typically used in a bonding process in which the photo-curable hot melt resin composition is melted and applied to a first adherend, irradiated with UV of a predetermined energy, and then a second adherend is bonded and pressure-bonded via the applied and UV-irradiated photo-curable hot melt resin composition. In the bonding process, the first adherend is melt-coated, UV is irradiated, and the second adherend is pressure-bonded one minute after UV irradiation, and the pot life is the time that the composition can be left standing from the completion of melt coating until UV irradiation. More specifically, the pot life is defined as the time that the composition can be left after being applied to the first polycarbonate substrate and before being irradiated with UV rays, in which the composition is applied to a first polycarbonate substrate with a line width of 1.0 mm and then irradiated with UV rays at a predetermined dose, and one minute after the end of the UV irradiation, the second polycarbonate substrate is pressed against the first polycarbonate substrate at 0.04 MPa for 10 seconds. The photo-curable hot melt resin composition of the present invention has a pot life of 3 minutes or more and 20 minutes or less, preferably 4 minutes or more and 15 minutes or less, and more preferably 5 minutes or more and 12 minutes or less. If the pot life is equal to or greater than the above lower limit, when it is necessary to precisely adjust the attachment position of the second adherend relative to the first adherend, sufficient time is ensured for the position adjustment, making it easier to prevent defects due to misalignment of the attachment position. On the other hand, by having a pot life of equal to or less than the above upper limit, the development of initial adhesive strength after compression bonding is not delayed, and excellent initial adhesive strength is easily developed.

[0093] <Manufacturing method> In the production of the photo-curable hot melt resin composition of the present invention, first, a urethane prepolymer (A) is prepared. As described above, the urethane prepolymer (A) can be obtained by reacting a polyol (a-1) having a linear hydrocarbon structure with 4 or more carbon atoms and a polyol (a-2) having a polycarbonate skeleton with a polyisocyanate (a-3). Thereafter, a radical polymerizable compound (B), a photopolymerization initiator (C), and, if necessary, a moisture curing accelerator catalyst, a coupling agent, and other components other than these are added to the urethane prepolymer (A) and mixed with a known mixer to obtain a photo-curable hot melt resin composition. The mixture may be appropriately heated during mixing. The mixer is not particularly limited, but examples thereof include a homodisper, a homomixer, a universal mixer, a planetary mixer, a planetary stirring device, a kneader, and a three-roll mixer.

[0094] <How to use> The photo-curable hot melt resin composition of the present invention is cured and used as a cured product. The photo-curable hot melt resin composition of the present invention is used, for example, as an adhesive, and the cured photo-curable hot melt resin composition may be used to bond, for example, a pair of adherends.

[0095] The photo-curable hot melt resin composition of the present invention may be, for example, heated until melted, applied in a molten state to one of the adherends, and then irradiated with light after the applied photo-curable hot melt resin composition, and the other adherend may be superimposed on the one of the adherends. As a result, the adherends are temporarily fixed by the photo-curable hot melt resin composition that has been cooled and solidified. The photo-curable hot melt resin composition may be heated to, for example, 40°C or higher and 130°C or lower, preferably 50°C or higher and 100°C or lower, and melted. Thereafter, by irradiating light, the photopolymerization initiator (C) is activated, and the radically polymerizable compound (B) undergoes a polymerization reaction, thereby eliminating the plasticizer effect and promoting the crystallization of the urethane prepolymer (A). After bonding to the adherends, the urethane prepolymer (A) quickly solidifies, temporarily fixing the adherends. Thereafter, the photo- and moisture-curable hot-melt resin composition is hardened by moisture, for example, by being left in the atmosphere, and the adherends are fixed together with a higher adhesive strength (final adhesive strength) by the hardened photo- and moisture-curable hot-melt resin composition than at the time of temporary fixation.

[0096] The photo-curable hot melt resin composition of the present invention is preferably used as an adhesive for electronic components, for example. The adherend is not particularly limited, but is preferably various electronic components constituting electronic devices, more preferably electronic components constituting portable electronic devices. The material of the adherend may be any of metal, glass, plastic, etc. In addition, the shape of the adherend is not particularly limited, and examples thereof include a film, sheet, plate, panel, tray, rod (rod), box, and housing. Examples of portable electronic devices include, but are not limited to, mobile phones such as smartphones, digital cameras, wearable devices, portable game devices, tablet computers, notebook computers, and action cameras, with smartphones and wearable devices being preferred among these.

[0097] Electronic components generally have a substrate, and therefore electronic devices such as portable electronic devices in which the photo-curable hot melt resin composition of the present invention is used may have a cured product of the photo-curable hot melt resin composition and a substrate. Various electronic circuits are generally provided on the substrate.

[0098] In electronic devices, for example, substrates may be used as adherends and bonded to each other via the photo-moisture-curable hot-melt resin composition of the present invention, or the substrate may be bonded to other electronic components (e.g., a housing) of the electronic device via the photo-moisture-curable hot-melt resin composition of the present invention. For example, the light-curable hot melt resin composition of the present invention may be used to obtain an assembled part by, for example, bonding substrates together inside an electronic device, etc. The assembled part thus obtained has a first substrate, a second substrate, and the cured 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 cured body. EXAMPLES

[0099] The present invention will be described in more detail below using examples, but the present invention is not limited to these examples.

[0100] In the present examples, various physical properties were measured as follows.

[0101] (Pot life) The first polycarbonate substrate, whose temperature was adjusted to 25°C, was coated with the paste at a line width of 1.0 mm at the temperature shown in Table 1, and left for a predetermined time. After that, UV was irradiated under the conditions shown in Table 1 using a 365 nm UV-LED as a light source, and one minute after the end of the UV irradiation, the second polycarbonate substrate was pressed at 0.04 MPa for 10 seconds. This operation was repeated with the predetermined time from coating to UV irradiation being initially 1 minute, and then gradually lengthened every minute, and the maximum length that could be bonded by the above pressure bonding was defined as the usable time. Here, whether or not bonding was possible was judged by whether or not the total thickness after bonding exceeded the sum of the thicknesses of the first substrate, the second substrate, and the spacer. When UV irradiation was not performed, the pot life was determined as the time from application to lamination of the polycarbonate substrate.

[0102] (Initial adhesive strength) As shown in FIG. 1(a), a first substrate 11 measuring 90 mm×50 mm and 5 mm thick with a circular hole 11A with a diameter of 12 mm in the center, and a second substrate 12 measuring 50 mm×50 mm and 5 mm thick were prepared. Both the first substrate 11 and the second substrate 12 were polycarbonate plates. Spacers 15A and 15B were attached to both side ends of the second substrate 12 (see FIG. 1(b)). The spacers 15A and 15B were tapes measuring 3 mm wide, 50 mm long, and 0.15 mm thick. The photo-curable hot melt resin composition 10, which had been heated and melted at the temperature shown in Table 1, was applied to the hole 11A of the first substrate 11 at the center thereof in a circular shape of φ25 mm at a coating speed of 12 mm / s, a width of 1 mm±0.2 mm, and a height of 0.15 mm±0.05 mm using a dispenser (Musashi Engineering Co., Ltd., "Shotmaster200DS").

[0103] The time when the above coating was completed was set to 0 seconds, and within a specified pot time, the coated light-and-moisture-curable hot-melt resin composition was irradiated with UV light using a 365 nm UV-LED as a light source so that the UV irradiation amount was the amount shown in Table 1.

[0104] The first and second substrates 11 and 12 were overlapped on the first substrate 11 through the photo-curable hot melt resin composition 10 so that the centers of the substrates 11 and 12 were aligned with each other, and a weight of 250 g was placed on the second substrate 12 for 10 seconds, and a pressure of about 0.03 MPa was applied to press the first and second substrates 11 and 12 through the photo-curable hot melt resin composition 10 to obtain a measurement sample 13. At this time, the distance between the first and second substrates 11 and 12 was kept at 0.15 mm by the spacers 15A and 15B. The 250 g weight was removed from the measurement sample 13, and the measurement sample 13 was left at 25° C. and 50% RH. Next, the measurement sample 13 was arranged so that the first substrate 11 was on the upper side and the second substrate 12 was on the lower side, and in a state in which the first substrate 11 was supported by a stainless steel jig, a rod-shaped member 14 having a circular cross section with a diameter of 10 mm was inserted into the hole 11A. Then, as shown in FIG. 1(b), the second substrate 12 was pressed vertically downward by the rod-shaped member 14 at a speed of 10 mm / min, and the stress when the second substrate 12 peeled off from the first substrate 11 was measured and used as the initial adhesive strength. The initial adhesive strength was measured 1, 3, and 5 minutes after the start of compression bonding by adjusting the time left at 25°C and 50% RH. The period from application to measurement of the initial adhesive strength was performed under an environment of 25°C and 50% RH. When UV irradiation was not performed, the UV irradiation was omitted, and the second substrate 12 was superimposed within a predetermined pot life.

[0105] In the dispenser, the photo-curable hot melt resin composition was filled in a 30cc syringe (Musashi Engineering, "PSY-30F"), and a needle with an inner diameter of 0.66 mm (Musashi Engineering, "PN-20G-A") was set at the tip of the syringe. The syringe heating holder and temperature control unit used were "TCU-02" manufactured by Musashi Engineering. The method of discharging the photo-curable hot melt resin composition from the syringe was a method of pushing with air pressure, and the air pressure control unit used was "ML-5000XII" manufactured by Musashi Engineering. The discharge amount of the photo-curable hot melt resin composition was adjusted by varying the air pressure between 0.01 and 0.30 MPa.

[0106] (Oleic acid swelling rate) The photo-curable hot melt resin composition was poured into a Teflon (registered trademark) mold 10 mm wide, 50 mm long, and 0.5 mm thick, and cured to obtain a cured film. The photo-curable hot melt resin composition was cured by irradiating it with ultraviolet light using a UV-LED (wavelength 365 nm) in the amount shown in Table 1, and then leaving it at 25°C and 50% RH for 24 hours to cause moisture curing. 200 g of oleic acid (reagent, Fujifilm Wako Pure Chemical Industries, Ltd.) was placed in a glass container, and the cured film was immersed in the oleic acid in the container for 72 hours under an atmosphere of 65°C and 90% RH. The area of ​​the cured film after immersion was then measured within 3 hours after immersion, and the ratio (%) of the area of ​​the cured film after immersion to the area of ​​the cured film before immersion was calculated and defined as the swelling ratio with oleic acid.

[0107] (Adhesive strength before immersion in oleic acid) The measurement sample 13 obtained in the above-mentioned measurement process of the initial adhesive strength was left in an environment of 25°C and 50 RH% for 48 hours, and then the adhesive strength was measured in the same manner as the initial adhesive strength, and this was used as the adhesive strength before immersion in oleic acid.

[0108] (Adhesive strength after immersion in oleic acid) The measurement sample 13 obtained in the above measurement process of the initial adhesive strength was left for 48 hours in an environment of 25°C and 50% RH. In addition, 200 g of oleic acid (reagent, Fujifilm Wako Pure Chemical Industries, Ltd.) was placed in a container, and the measurement sample 13 after the above-mentioned leaving was immersed in the oleic acid in the container for 72 hours in an atmosphere of 65°C and 90% RH. The adhesive strength of the adhesive test sample after the immersion was measured in the same manner as the initial adhesive strength within 3 hours after the end of the immersion, and this was taken as the adhesive strength after immersion in oleic acid.

[0109] (Adhesion strength maintenance rate) The adhesive strength retention rate of the light-and-moisture-curable hot-melt resin composition was calculated by the following formula. Adhesive strength retention rate (%) = (adhesive strength after immersion in oleic acid / adhesive strength before immersion in oleic acid) x 100

[0110] The components used in each of the Examples and Comparative Examples were as follows. <Polyol> (Polyether polycarbonate polyol) PEPCD: Polyether polycarbonate diol, polyether polycarbonate diol (polyether skeleton: derived from PTMG), manufactured by Mitsubishi Chemical Corporation, "PEPCD NT-2002", liquid at room temperature, Mn=2000

[0111] (Polyester polyol) PEsD1: Polyester polyol A, Toyokuni Oil Co., Ltd., "HS 2H-200S", polyol: 1,6-hexanediol (HD), polycarboxylic acid: sebacic acid (SA), solid at room temperature, Mn=2000 PEsD2: Polyester polyol B, Toyokuni Oil Co., Ltd., "HS 2H-351A", polyol: 1,6-hexanediol (HD), polycarboxylic acid: adipic acid (AA), solid at room temperature, Mn=3500

[0112] <Polyisocyanate> Tosoh Corporation's "Millionate MT", diphenylmethane diisocyanate (MDI)

[0113] <Radical polymerizable compound> Kyoeisha Chemical Co., Ltd., "POB-A", m-phenoxybenzyl acrylate Rahn AG, "G-1122", urethane acrylate KJ Chemicals, "DEAA", diethylacrylamide ISP Japan, "Vcap", vinyl monomer, N-vinyl-ε-caprolactam

[0114] <Photopolymerization initiator> "Omnirad TPO" manufactured by IGM Resin BV, diphenyl (2,4,6-trimethylbenzoyl) phosphine oxide

[0115] <Coupling Agent> Shin-Etsu Chemical Co., Ltd. "KBM-573", N-phenyl-3-aminopropyltrimethoxysilane <Moisture curing catalyst> San-Apro "U-cat660M", bis(2-morpholinoethyl) ether

[0116] [Example 1] 60 parts by mass of PEPCD and 40 parts by mass of PEsD1 were placed in a 500 mL separable flask. The flask was stirred under vacuum (20 mmHg or less) at 110°C until the moisture content was 200 ppm or less, and dehydrated and mixed. Nitrogen was then sealed in to return to normal pressure, and 43 parts by mass of diphenylmethane diisocyanate was placed in the flask as an aromatic ring-containing polyisocyanate, and the mixture was further stirred at 80°C for 3 hours to react, obtaining a urethane prepolymer (A) having an isocyanate group. To the obtained urethane prepolymer (A), an aromatic ring-containing acrylate as the radical polymerizable compound (B), diphenyl(2,4,6-trimethylbenzoyl)phosphine oxide as the photopolymerization initiator (C), a coupling agent and a moisture curing catalyst were added in the proportions shown in Table 1, and the mixture was stirred at a temperature of 80°C using a planetary mixer (Thinky Corporation, "Awatori Rentaro") to obtain the light-moisture curing hot melt resin composition of Example 1.

[0117] [Examples 2 to 9, Comparative Examples 1 to 2] The same procedure as in Example 1 was carried out, except that the type and amount of the polyol and the radical polymerizable compound (B) used in the synthesis of the urethane prepolymer (A) were changed as shown in Table 1, as well as the amount of UV irradiation.

[0118] [Table 1]

[0119] As shown in Table 1, the light-and-moisture-curable hot-melt resin compositions of the respective Examples had high initial adhesive strength, oleic acid swelling ratio, and adhesive strength retention rate, and had excellent oil resistance. They were also able to develop high initial adhesive strength in a short period of time while ensuring sufficient pot life. In contrast, the photo-curable hot melt resin compositions prepared in Comparative Examples 1 and 2 did not use a polyol (a-1) having a polycarbonate skeleton as the raw material for the urethane prepolymer (A), and did not contain a radically polymerizable compound (B), and therefore could not exhibit excellent oil resistance. Therefore, peeling occurred after immersion in oleic acid, and the adhesive strength and adhesive strength maintenance rate after immersion in oleic acid could not be measured or calculated. In addition, the photo-curable hot melt resin compositions of each Comparative Example had a shorter pot life than the photo-curable hot melt resin compositions of each Example.

Claims

1. A light-curable, moisture-curable hot melt resin composition comprising a urethane prepolymer (A), a radical polymerizable compound (B), and a photopolymerization initiator (C), The urethane prepolymer (A) is at least A polyol (a-1) having a polycarbonate skeleton, a polyol (a-2) having a linear hydrocarbon structure having 4 or more carbon atoms, which is different from the polyol (a-1) having a polycarbonate skeleton; A light-curable, moisture-curable hot melt resin composition which is a reaction product of a raw material containing polyisocyanate (a-3).

2. The photo-curable hot melt resin composition according to claim 1 , further comprising a coupling agent (D) and a moisture curing accelerating catalyst (E).

3. The photo-curable hot melt resin composition according to claim 1 or 2, wherein the polyol (a-2) is a polyester polyol.

4. The photo-curable hot melt resin composition according to claim 1 or 2, wherein the polyol (a-1) is a polyether polycarbonate polyol.

5. In the polyol (a-1), the ratio of the ether skeleton to the carbonate skeleton is in the range of 2:8 to 8:2; The polyol (a-2) has a linear aliphatic hydrocarbon skeleton having 4 or more carbon atoms, The light-curable, moisture-curable hot melt resin composition according to claim 1 or 2, wherein the polyisocyanate (a-3) has an aromatic skeleton.

6. The photo-curable and moisture-curable hot melt resin composition according to claim 1 or 2, wherein the radical polymerizable compound (B) comprises a radical polymerizable compound having an aromatic ring.

7. 7. The photo-curable hot melt resin composition according to claim 6, wherein the content of the radical polymerizable compound having a linear hydrocarbon structure having 8 or more carbon atoms is less than 5 mass% based on the total amount of the photo-curable hot melt resin composition.

8. The photo-curable and moisture-curable hot melt resin composition according to claim 1 or 2, wherein the radical polymerizable compound (B) comprises a radical polymerizable compound having a vinyl group.

9. 3. An adhesive for electronic components comprising the photo- and moisture-curable hot melt resin composition according to claim 1 or 2.

10. A cured product of the light-curable, moisture-curable hot melt resin composition according to claim 1 or 2.

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