JP7470054B2 - Photo-curable moisture-curable resin composition and cured product - Google Patents

Description

The present invention relates to a photo-curable moisture-curable resin composition and a cured product thereof.

In recent years, there has been a demand for higher integration and miniaturization of electronic components such as semiconductor chips. For example, multiple thin semiconductor chips are bonded together via an adhesive layer to form a semiconductor chip stack. In addition, in today's world where mobile devices with various display elements are widespread, a method of miniaturizing display elements is to narrow the frame of the image display section (hereinafter referred to as "narrow frame design"). Narrow frame design requires a technology for bonding with a thin line width of adhesive using a dispenser or the like.

A semiconductor chip stack may be manufactured, for example, by applying an adhesive onto one semiconductor chip, semi-curing it by exposure to light, stacking the other semiconductor chip via the semi-cured product to temporarily bond the semiconductor chips together, and then fully curing the adhesive to permanently bond the chips together. Similarly, for narrow frame designs, a method is being considered in which temporary bonding is performed with an applied adhesive, followed by permanent bonding. The use of a photo-moisture curable resin composition is being considered as an adhesive for semiconductor chip stacking and narrow frame design applications.

It is known that photo-curable resin compositions generally contain radical polymerizable compounds, moisture-curable urethane resins, or hydrolyzable silyl group-containing resins. It is known that photo-curable resin compositions contain a thixotropic agent to prevent resin dripping after application, or a modified silicone resin having two or more hydrolyzable silyl groups in one molecule to improve adhesion (see Patent Documents 1 and 2).
Also known as photo-curable moisture-curable resin compositions are those comprising a crosslinkable silicon group-containing organic polymer, a photobase generator, a fluorine-based compound, and a polyfunctional compound having more than one (meth)acryloyl group in one molecule, as disclosed in Patent Document 3.

JP 2004-18621 A JP 2018-2925 A International Publication No. 2016/104787

As mentioned above, photo-curable resin compositions used in applications such as stacking semiconductor chips and designing narrow frames often temporarily bond the adherend before the actual bonding. For this reason, it is desirable to increase not only the adhesive strength during the actual bonding when moisture curing has progressed sufficiently after a certain amount of time has passed since photo-curing, but also the so-called initial adhesive strength during the semi-curing stage immediately after photo-curing. However, with conventional photo-curable resin compositions, it is often difficult to improve the adhesive strength during the actual bonding while also achieving an initial adhesive strength of a certain value or more.

Therefore, the objective of the present invention is to provide a photo-curable moisture-curable resin composition that can achieve an initial adhesive strength of a certain value or more immediately after photocuring.

As a result of intensive research, the present inventors have found that the above-mentioned problems can be solved by setting the SP value of the radical polymerizable compound and the moisture-curable resin contained in the photo-curable resin composition to a certain value or less, and have completed the present invention. That is, the present invention provides the following [1] to [7].
[1] A composition comprising a radical polymerizable compound, a moisture-curable resin, and a photopolymerization initiator,
A photo-curable moisture-curable resin composition, wherein a difference in SP value between the radical polymerizable compound and the moisture-curable resin is 1.0 or less.
[2] The photo-curable moisture-curable resin composition according to the above [1], wherein the moisture-curable resin has an SP value of 9.5 or more.
[3] The photo-curable moisture-curable resin composition according to [1] or [2] above, wherein the moisture-curable resin contains either a compound having a polycarbonate skeleton or a compound having a polyester skeleton.
[4] The photo-curable moisture-curable resin composition according to any one of [1] to [3] above, wherein the moisture-curable resin comprises a moisture-curable urethane resin.
[5] The photo-curable moisture-curable resin composition according to any one of the above [1] to [4], wherein the radical polymerizable compound contains a compound having a (meth)acryloyl group.
[6] The mass ratio of the radical polymerizable compound to the moisture-curable resin (radical polymerizable compound/moisture-curable resin) is 20/80 or more and 90/10 or less, [1] to [5]. The photo-curable resin composition according to any one of the above.
[7] A cured product of the curable resin composition according to any one of [1] to [6] above.

According to the present invention, a photo-curable moisture-curable resin composition is provided that can achieve an initial adhesive strength of a certain value or more immediately after photo-curing.

FIG. 1 is a schematic diagram showing an adhesion test method, in which FIG. 1( a ) is a plan view and FIG. 1( b ) is a side view.

The present invention will be described in detail below.
<Curable resin composition>
The curable resin composition of the present invention contains a radical polymerizable compound, a moisture curable resin, and a photopolymerization initiator, and the SP value difference between the radical polymerizable compound and the moisture curable resin is 1.0 or less.
In the present invention, by making the SP value difference 1.0 or less, the initial adhesive strength immediately after photocuring of the photo-curable resin composition can be improved. The principle is not clear, but is presumed to be as follows. When the SP value difference is 1.0 or less, the compatibility of the radical polymerizable compound and the moisture-curable resin becomes excellent. Therefore, in the curable resin composition after photocuring, the so-called bleed-out, in which the uncured moisture-curable resin seeps out to the interface with the adherend, is suppressed, and it is presumed that the initial adhesive strength is improved.

On the other hand, if the SP value difference between the radical polymerizable compound and the moisture-curable resin is greater than 1.0, it is presumed that the compatibility between the radical polymerizable compound and the moisture-curable resin decreases, making it impossible to suppress bleed-out and thus making it impossible to sufficiently improve the initial adhesive strength.
The SP value difference between the radical polymerizable compound and the moisture-curable resin is preferably 0.8 or less, more preferably 0.6 or less, from the viewpoint of suppressing bleed-out and improving the initial adhesive strength. The smaller the SP value difference, the better, and it is sufficient if it is 0 or more, but since a certain difference usually occurs, it is practically 0.01 or more.

In the present invention, the SP value of the moisture-curable resin is preferably 9.5 or more. If the SP value of the moisture-curable resin is 9.5 or more, it is easy to reduce the difference in SP value with the radical polymerizable compound. From such a viewpoint, the SP value of the moisture-curable resin is more preferably 10.0 or more.
In addition, the SP value of the moisture-curable resin is preferably 12.0 or less, more preferably 11.5 or less, and even more preferably 11.0 or less. If the SP value of the moisture-curable resin is set to these upper limits or less, the SP value difference with the radical polymerizable compound can be reduced while the curing performance can be sufficiently ensured. In addition, by setting the SP value within the above range, the adhesion to the adherend can be improved.

On the other hand, the SP value of the radical polymerizable compound is preferably 9.0 or more, more preferably 9.5 or more, and is preferably 12.0 or less, more preferably 11.5 or less, and even more preferably 11.0 or less. By setting the SP value of the radical polymerizable compound within these ranges, it becomes easier to improve the curing performance and adhesion to the adherend while reducing the SP value difference with the moisture-curable resin.

In the present invention, the SP values of the radical polymerizable compound and the moisture-curable resin are calculated by the Fedors method. In the case of a blend of a plurality of components, the SP values of the components are proportionally allocated to the respective component ratios (mass%) and the weighted average is calculated. The SP value difference is the absolute value obtained by subtracting the SP value of the moisture-curable resin from the SP value of the radical polymerizable compound. The unit of the SP value is (cal/ ^cm3 ) ^1/2 .

The photo-curable resin composition of the present invention preferably has an initial adhesive strength of 0.3 MPa or more. Also, the photo-curable resin composition of the present invention preferably has an adhesive strength of 2.0 MPa or more 24 hours after photocuring.
The initial adhesive strength means the adhesive strength at 25° C. after photocuring of the photo-curable resin composition. The adhesive strength 24 hours after photocuring means the adhesive strength 24 hours after photocuring of the photo-curable resin composition. The details of the method for measuring the initial adhesive strength and the adhesive strength 24 hours after photocuring are as described in the examples below.
When the photo-curable resin composition has an initial adhesive strength of 0.3 MPa or more at 25° C., it can appropriately temporarily bond adherends to each other. When the adhesive strength 24 hours after photo-curing is 2.0 MPa or more, it can firmly bond adherends to each other in the main adhesion, for example.

The photo-curable resin composition preferably has an initial adhesive strength of 0.8 MPa or more in order to enhance adhesive stability during temporary adhesion. Also, the initial adhesive strength is preferably less than 2.0 MPa in order to facilitate re-adhesion during temporary adhesion.
In addition, in order to bond the adherends more firmly during the main adhesion, the photo-curable resin composition has an adhesive strength of preferably 3.5 MPa or more, more preferably 4.0 MPa or more, 24 hours after photo-curing. The higher the adhesive strength is, the better, but it is not particularly limited, and may be, for example, 20 MPa or less, or 10 MPa or less.

Each component contained in the photo-curable resin composition will be described in more detail below.
[Radical polymerizable compound]
The photo-curable resin composition of the present invention contains a radical polymerizable compound. The photo-curable resin composition is given photocurability by containing a radical polymerizable compound. Since the photo-curable resin composition has photocurability, a certain adhesive strength can be imparted to the composition simply by irradiating the composition with light, and therefore the above-mentioned initial adhesive strength can be easily ensured.
The radical polymerizable compound may have a radical polymerizable functional group in the molecule. The radical polymerizable functional group is preferably a compound having an unsaturated double bond, and examples of the radical polymerizable functional group include a (meth)acryloyl group, a vinyl group, a styryl group, and an allyl group.

Among the above, from the viewpoint of adhesion and from the viewpoint of easily setting the SP value within the above-mentioned range, the (meth)acryloyl group is preferred, that is, the radical polymerizable compound preferably contains a compound having a (meth)acryloyl group. In addition, the compound having a (meth)acryloyl group is also referred to as "(meth)acrylic compound" hereinafter.
The content of the (meth)acrylic compound is preferably 50% by mass or more, more preferably 55% by mass or more, and even more preferably 60% by mass or more, based on the total amount of the radical polymerizable compounds. The upper limit is not particularly limited, but is 100% by mass.

The radical polymerizable compound may contain one or both of a monofunctional compound having one radical polymerizable functional group in one molecule and a polyfunctional compound having two or more radical polymerizable functional groups in one molecule, but from the viewpoint of improving the initial adhesive strength of the photo-curable resin composition, it is preferable that the amount of the polyfunctional compound is small. Specifically, the content of the polyfunctional compound based on the total amount of the radical polymerizable compound is preferably 25% by mass or less, more preferably 20% by mass or less, and even more preferably 5% by mass or less, and it is also preferable that it is 0% by mass, i.e., no polyfunctional compound is contained.

(Nitrogen-containing compounds)
The radical polymerizable compound of the present invention preferably contains a nitrogen-containing compound. By using a nitrogen-containing compound, the initial adhesive strength of the photo-curable resin composition is improved. After being applied to an adherend, the photo-curable resin composition is photocured by irradiating it with active energy rays such as ultraviolet rays, and in this case, it is generally photocured in the presence of oxygen as described below. When the radical polymerizable compound contains a nitrogen-containing compound, it is presumed that the composition is appropriately photocured even in the presence of oxygen, thereby improving the initial adhesive strength.
The nitrogen-containing compound may be a compound having a nitrogen atom and a radical polymerizable functional group, and may be a (meth)acrylic compound or a compound other than a (meth)acrylic compound. The nitrogen-containing compound may be a monofunctional compound having one radical polymerizable functional group, or may be a polyfunctional compound having two or more radical polymerizable functional groups. However, from the viewpoint of increasing the initial adhesive strength, the light moisture curable resin composition should have a low content of the polyfunctional compound as described above, and the polyfunctional compound based on the total amount of the radical polymerizable compound should be adjusted to be within the above range.

The nitrogen-containing compound may contain one or both of a chain-like nitrogen-containing compound and a nitrogen-containing compound having a cyclic structure, but from the viewpoint of improving the initial adhesive strength of the photo-moisture-curable resin composition, it is preferable to contain a nitrogen-containing compound having a cyclic structure, and it is more preferable to use a chain-like nitrogen-containing compound and a nitrogen-containing compound having a cyclic structure in combination.

Examples of nitrogen-containing compounds having a cyclic structure include nitrogen-containing compounds having a lactam structure such as N-vinylpyrrolidone and N-vinylcaprolactam, morpholine skeleton-containing compounds such as N-acryloylmorpholine, and cyclic imide compounds such as N-(meth)acryloyloxyethylhexahydrophthalimide. Among these, more specifically, amide group or imide group-containing compounds such as N-vinylcaprolactam and N-(meth)acryloyloxyethylhexahydrophthalimide are more preferred, and amide group-containing compounds such as N-vinylcaprolactam are even more preferred.

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 diacetone acrylamide, N,N-dimethylacrylamide, N,N-diethylacrylamide, N-isopropylacrylamide, N-hydroxyethylacrylamide, acrylamide, and methacrylamide; and N-vinylacetamide.

The chain-like nitrogen-containing compound may be urethane (meth)acrylate. For example, the urethane (meth)acrylate may be obtained by reacting an isocyanate compound with a (meth)acrylic acid derivative having a hydroxyl group. In this case, a catalytic amount of a tin-based compound or the like may be used as a catalyst for the reaction between the isocyanate compound and the (meth)acrylic acid derivative. The urethane (meth)acrylate may be monofunctional or multifunctional such as bifunctional, but as described above, monofunctional is preferred.

Examples of (meth)acrylic acid derivatives having the above-mentioned 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.

Examples of isocyanate compounds used to obtain urethane (meth)acrylate include polyisocyanate compounds such as isophorone diisocyanate, 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, hexamethylene diisocyanate, trimethylhexamethylene diisocyanate, diphenylmethane-4,4'-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.

Also usable as the isocyanate compound are chain-extended polyisocyanate compounds obtained by reacting a polyol with an excess of an isocyanate compound. 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.

Examples of isocyanate compounds used to obtain 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. By using these monoisocyanate compounds, a monofunctional urethane (meth)acrylate can be obtained.
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).

Among the above urethane (meth)acrylates, commercially available ones include, for example, M-1100, M-1200, M-1210, M-1600 (all manufactured by Toagosei Co., Ltd.), EBECRYL230, EBECRYL270, EBECRYL8402, EBECRYL8411, EBECRYL8412, EBECRYL8413, EBECRYL8804, EBECRYL8803, EBECRYL8807, EBECRYL9. 270, EBECRYL210, EBECRYL4827, EBECRYL6700, EBECRYL220, EBECRYL2220 (all manufactured by Daicel-Allnex), Art Resin UN-9000H, Art Resin UN-9000A, Art Resin UN-7100, Art Resin UN-1255, Art Resin UN-330, Art Resin UN-3320HB, Art Resin UN-1200TPK, Art Resin SH -500B (all manufactured by Negami Chemical Industries), U-2HA, U-2PHA, U-3HA, U-4HA, U-6H, U-6LPA, U-6HA, U-10H, U-15HA, U-122A, U-122P, U-108, U-108A, U-324A, U-340A, U-340P, U-1084A, U-2061BA, UA-340P, UA-4100, UA-4000, UA-4200, UA-4400, UA-5201P, U-7 100, UA-7200, UA-W2A (all manufactured by Shin-Nakamura Chemical Co., Ltd.), AI-600, AH-600, AT-600, UA-101I, UA-101T, UA-306H, UA-306I, UA-306T (all manufactured by Kyoeisha Chemical Co., Ltd.), CN-902, CN-973, CN-9021, CN-9782, CN-9833 (all manufactured by Arkema), and Viscoat #216 (Osaka Organic Chemical Industry Co., Ltd.).

Of the above, the chain nitrogen-containing compound preferably contains a urethane (meth)acrylate, and as described above, the urethane (meth)acrylate is preferably monofunctional, but may also contain a polyfunctional urethane (meth)acrylate such as a bifunctional urethane (meth)acrylate in addition to the monofunctional one.

The content of the nitrogen-containing compound based on the total amount of the radically polymerizable compound is preferably 10% by mass or more, more preferably 30% by mass or more, even more preferably 50% by mass or more, and most preferably 60% by mass or more, from the viewpoint of improving the initial adhesive strength of the moisture-curable resin composition. In addition, the content of the nitrogen-containing compound may be 100% by mass or less, but in order to contain an appropriate amount of radically polymerizable compounds other than the nitrogen-containing compound, it is preferably 95% by mass or less, more preferably 90% by mass or less.

When a chain-like nitrogen-containing compound and a nitrogen-containing compound having a cyclic structure are used in combination, from the viewpoint of improving the initial adhesive strength of the photo-curable resin composition, the mass ratio of the nitrogen-containing compound having a cyclic structure to the chain-like nitrogen-containing compound (cyclic/chain) is preferably 0.1 or more, more preferably 0.2 or more, and even more preferably 0.4 or more. From the same viewpoint as above, the mass ratio of the nitrogen-containing compound having a cyclic structure to the chain-like nitrogen-containing compound (cyclic/chain) is preferably 2.0 or less, more preferably 1.5 or less, and even more preferably 1.2 or less.

(Radical polymerizable compounds other than nitrogen-containing compounds)
The radical polymerizable compound of the present invention preferably contains a compound other than the above-mentioned nitrogen-containing compounds (hereinafter also referred to as a nitrogen-free compound).
The nitrogen-free compound may be a monofunctional compound having one radical polymerizable functional group, or a polyfunctional compound having two or more radical polymerizable functional groups, or may contain both of these, but from the viewpoint of increasing the initial adhesive strength of the photo-curable resin composition, it is preferable that the polyfunctional compound is less, and it is more preferable that it is not contained. Specifically, as described above, it is preferable to adjust the content of the polyfunctional compound based on the total amount of the radical polymerizable compound within the above-mentioned range.

The nitrogen-free compound is not particularly limited as long as it is a compound having a radical polymerizable functional group, but (meth)acrylic compounds are preferred, and among them, (meth)acrylic acid ester compounds are preferred. As described above, the (meth)acrylic acid ester compound may be either monofunctional or polyfunctional, but monofunctional is preferred. The polyfunctional compound may be bifunctional or may be trifunctional or more.
Examples of the monofunctional (meth)acrylic acid ester compound include alkyl (meth)acrylates, alicyclic structure-containing (meth)acrylates, and aromatic ring-containing (meth)acrylates.

Examples of the alkyl (meth)acrylate include alkyl (meth)acrylates having an alkyl group of 1 to 18 carbon atoms, 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.
Examples of the alicyclic structure-containing (meth)acrylate 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.
Examples of aromatic ring-containing (meth)acrylates include phenylalkyl (meth)acrylates such as benzyl (meth)acrylate and 2-phenylethyl (meth)acrylate, and phenoxyalkyl (meth)acrylates such as phenoxyethyl (meth)acrylate.

In addition, as the monofunctional (meth)acrylic acid ester compound, a cyclic ether group-containing (meth)acrylate may be used. 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-ethyloxetan-3-yl)methyl (meth)acrylate. Examples of tetrahydrofuran ring-containing (meth)acrylates include tetrahydrofurfuryl (meth)acrylate and (meth)acrylic acid ester of tetrahydrofurfuryl alcohol. The (meth)acrylic acid ester of tetrahydrofurfuryl alcohol may be a polymeric ester of (meth)acrylic acid (e.g., molecular weight of about 150 to 550). Examples of dioxolane ring-containing (meth)acrylates include (2-methyl-2-ethyl-1,3-dioxolane-4-yl)methyl (meth)acrylate and (2,2-cyclohexyl-1,3-dioxolane-4-yl)methyl (meth)acrylate. Examples of the (meth)acrylate having a dioxane ring include cyclic trimethylolpropane formal (meth)acrylate.

Examples of the monofunctional (meth)acrylic acid ester compound include 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; and polyoxyethylene (meth)acrylates such as 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 ethoxypolyethylene glycol (meth)acrylate.
Furthermore, as the monofunctional (meth)acrylic compound, a carboxyl-containing (meth)acrylic compound such as acrylic acid or methacrylic acid may be used.

Examples of bifunctional (meth)acrylic acid ester compounds 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, dipropylene glycol di(meth)acrylate, tripropylene glycol di(meth)acrylate, poly Examples of the di(meth)acrylate include propylene glycol di(meth)acrylate, ethylene oxide-added bisphenol A di(meth)acrylate, propylene oxide-added bisphenol A di(meth)acrylate, ethylene oxide-added bisphenol F 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.

Examples of trifunctional or higher (meth)acrylic acid ester compounds 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.

As described above, the nitrogen-free compound is preferably monofunctional and preferably contains at least one selected from acrylic (meth)acrylates, alicyclic structure-containing (meth)acrylates, and aromatic ring-containing (meth)acrylates. In addition to these, it is also preferable to contain a cyclic ether group-containing (meth)acrylate, such as an oxetane ring-containing (meth)acrylate, from the viewpoint of improving adhesive strength.

The content of the nitrogen-free compound based on the total amount of the radical polymerizable compounds may be 0% by mass or more, but from the viewpoint of improving the initial adhesive strength of the photo-curable resin composition, it is preferably 5% by mass or more, more preferably 10% by mass or more. It is also preferably 90% by mass or less, more preferably 70% by mass or less, even more preferably 50% by mass or less, and most preferably 40% by mass or less.

The content of the radical polymerizable compound in the photo-curable resin composition is preferably 20% by mass or more based on the total amount of the photo-curable resin composition. When the content of the radical polymerizable compound is 20% by mass or more, the photo-curable resin composition can be given appropriate photocurability and the initial adhesive strength is good. From these viewpoints, the content of the radical polymerizable compound is more preferably 30% by mass or more, and even more preferably 55% by mass or more.
In addition, the content of the radical polymerizable compound is preferably 80% by mass or less based on the total amount of the photo-curable resin composition. If the content of the radical polymerizable compound is 80% by mass or less, it is possible to include a certain amount or more of the moisture-curable resin in the photo-curable resin composition, and it is easy to impart appropriate moisture curing properties. From such a viewpoint, the content of the radical polymerizable compound is more preferably 75% by mass or less, and even more preferably 70% by mass or less.

[Moisture-curing resin]
The photo-curable resin composition of the present invention contains a moisture-curable resin, which imparts moisture curing properties. When the composition has moisture curing properties, the composition can be cured without heating, so that when the composition is cured, the adherend, such as an electronic component or the like, at the adhesive portion or around the adhesive portion can be prevented from being damaged by heating. In addition, the composition is moisture-curable, which makes it easier to increase the adhesiveness when cured, and makes it easier to increase the adhesive strength after 24 hours of photocuring, as described above.

Examples of the moisture-curable resin used in the present invention include moisture-curable urethane resins and hydrolyzable silyl group-containing resins, and among these, moisture-curable urethane resins are preferred.
In addition, the moisture-curable resin preferably contains either a compound having a polycarbonate skeleton or a compound having a polyester skeleton. By having either of these, the moisture-curable resin has an SP value within the desired range described above, and it is easy to reduce the difference with the SP value of the radical polymerizable compound. The moisture-curable resin may be a compound having a polycarbonate skeleton and a compound having a polyester skeleton, but it is preferable to use either one of them.
In addition, in the case of a moisture-curing resin, for example, by using a polycarbonate polyol or a polyester polyol as a polyol compound constituting a urethane resin as described below, a polycarbonate skeleton or a polyester skeleton can be introduced into the moisture-curing resin.

(Moisture-curing urethane resin)
The moisture-curing urethane resin has an isocyanate group. The moisture-curing urethane resin cures when the isocyanate group in the molecule reacts with moisture in the air or the adherend. The moisture-curing urethane resin may have only one isocyanate group in one molecule, or may have two or more isocyanate groups. In particular, it is preferable that the moisture-curing urethane resin has isocyanate groups at both ends of the main chain of the molecule.

The moisture-curable urethane resin can be obtained by reacting a polyol compound having two or more hydroxyl groups in one molecule with a polyisocyanate compound having two or more isocyanate groups in one molecule.
The reaction between the polyol compound and the polyisocyanate compound is usually carried out in a molar ratio of hydroxyl groups (OH) in the polyol compound to isocyanate groups (NCO) in the polyisocyanate compound, [NCO]/[OH], in the range of 2.0 to 2.5.

As the polyol compound serving as the raw material of the moisture-curable urethane resin, a known polyol compound usually used in the production of polyurethane can be used, such as polyester polyol, polyether polyol, polyalkylene polyol, polycarbonate polyol, etc. These polyol compounds may be used alone or in combination of two or more.
Among these, as described above, it is preferable to use polyester polyol or polycarbonate polyol from the viewpoint of reducing the SP value difference with the radical polymerizable compound. Among these, polycarbonate polyol is preferable. By using polycarbonate polyol, it is possible to provide a photo-moisture curable resin composition having excellent weather resistance, heat resistance, moisture resistance, etc. of the cured product.

Examples of the polyester polyol include polyester polyols obtained by reacting polyvalent carboxylic acids with polyols, and polycaprolactone polyols such as poly-ε-caprolactone diol obtained by ring-opening polymerization of ε-caprolactone.
Examples of the polyvalent carboxylic acid that is a raw material for the polyester polyol include terephthalic acid, isophthalic acid, 1,5-naphthalic acid, 2,6-naphthalic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, decamethylene dicarboxylic acid, and dodecamethylene dicarboxylic acid.
Examples of polyols that can be used as raw materials for polyester polyols include ethylene glycol, propylene glycol, 1,3-propanediol, 1,4-butanediol, neopentyl glycol, 1,5-pentanediol, 1,6-hexanediol, diethylene glycol, and cyclohexanediol.

As the polycarbonate polyol, a polycarbonate diol is preferred, and a preferred example of a polycarbonate diol is a compound represented by the following formula (1):

式（１）においてＲは炭素数４～１６の二価の炭価水素基、ｎは１～５００の整数である。

In formula (1), R is a divalent hydrocarbon group having 4 to 16 carbon atoms, and n is an integer of 1 to 500.

In formula (1), R is preferably an aliphatic saturated hydrocarbon group. When R is an aliphatic saturated hydrocarbon group, heat resistance is easily improved. In addition, yellowing due to thermal deterioration is less likely to occur, and weather resistance is also improved. R consisting of an aliphatic saturated hydrocarbon group may have a chain structure or a cyclic structure, but from the viewpoint of easily improving stress relaxation properties and flexibility, it is preferable to have a chain structure. In addition, R of the chain structure may be either linear or branched.
n is preferably 5-200, more preferably 10-150, and further preferably 20-50.
In addition, the R contained in the polycarbonate polyol constituting the moisture-curable urethane resin (a1) may be used alone or in combination of two or more. When using two or more, it is preferable that at least a part of the R is a chain-like aliphatic saturated hydrocarbon group having 6 or more carbon atoms, and more preferably at least a part of the R is a chain-like aliphatic saturated hydrocarbon group having 7 or more carbon atoms.
The inclusion of a linear aliphatic saturated hydrocarbon group having 7 or more carbon atoms facilitates the improvement of stress relaxation properties and flexibility. When the polycarbonate diol is a compound represented by the above formula (1), the proportion of the linear aliphatic saturated hydrocarbon group having 7 or more carbon atoms is preferably 20 mol % or more and 100 mol % or less, more preferably 30 mol % or more and 100 mol % or less, and even more preferably 50 mol % or more and 100 mol % or less, relative to R contained in the entire polycarbonate diol.
The linear aliphatic saturated hydrocarbon group having 7 or more carbon atoms preferably has 8 to 12 carbon atoms, and more preferably has 8 to 10 carbon atoms.
Specific examples of R may be linear, such as tetramethylene, pentylene, hexamethylene, heptamethylene, octamethylene, nonamethylene, and decamethylene, or branched, such as methylpentylene and methyloctamethylene groups, such as 3-methylpentylene. A plurality of R in one molecule may be the same or different. Thus, one molecule may contain two or more types of R, and in this case, one molecule preferably contains two or three types of R. For example, the polycarbonate polyol may be a copolymer containing an R having 6 or less carbon atoms and an R having 7 or more carbon atoms in one molecule, and in this case, it is preferable that each R is a linear aliphatic saturated hydrocarbon group.
Furthermore, R may contain a linear aliphatic saturated hydrocarbon group or a branched aliphatic saturated hydrocarbon group. In the polycarbonate polyol, R may be a combination of branched and linear R, or a linear R may be used alone.
The polycarbonate polyols may be used alone or in combination of two or more kinds.

As the polyisocyanate compound serving as the raw material of the moisture-curable urethane resin, an aromatic polyisocyanate compound or an aliphatic polyisocyanate compound is preferably used.
Examples of aromatic polyisocyanate compounds include diphenylmethane diisocyanate, liquid modified products of diphenylmethane diisocyanate, polymeric MDI, tolylene diisocyanate, and naphthalene-1,5-diisocyanate.
Examples of the aliphatic polyisocyanate compound 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.
Among the polyisocyanate compounds, aromatic polyisocyanate compounds are preferred from the viewpoint of increasing the adhesive strength after full curing, and diphenylmethane diisocyanate and its modified products are more preferred. Furthermore, aliphatic polyisocyanate compounds are preferred from the viewpoint of easily imparting stress relaxation properties, flexibility, etc. to the cured product of the photo-curable resin composition.
The polyisocyanate compounds may be used alone or in combination of two or more kinds.

(Hydrolyzable silyl group-containing resin)
The hydrolyzable silyl group-containing resin used in the present invention is cured when the hydrolyzable silyl group in the molecule reacts with moisture in the air or on the adherend.
The hydrolyzable silyl group-containing resin may have only one hydrolyzable silyl group in one molecule, or may have two or more hydrolyzable silyl groups. In particular, it is preferable that the hydrolyzable silyl group is present at both ends of the main chain of the molecule. Note that the hydrolyzable silyl group-containing resin does not include those having an isocyanate group.

式（２）中、Ｒ^１は、それぞれ独立に、置換されていてもよい炭素数１以上２０以下のアルキル基、炭素数６以上２０以下のアリール基、炭素数７以上２０以下のアラルキル基、又は、－ＯＳｉＲ^２ _３（Ｒ^２は、それぞれ独立に、炭素数１以上２０以下の炭化水素基である）で示されるトリオルガノシロキシ基である。また、式（２）中、Ｘは、それぞれ独立に、ヒドロキシ基又は加水分解性基である。さらに、式（２）中、ａは、１～３の整数である。 The hydrolyzable silyl group is represented by the following formula (2).

In formula (2), R ¹ 's are each independently an optionally substituted alkyl group having from 1 to 20 carbon atoms, an aryl group having from 6 to 20 carbon atoms, an aralkyl group having from 7 to 20 carbon atoms, or a triorganosiloxy group represented by -OSiR ² ₃ (each R ² is independently a hydrocarbon group having from 1 to 20 carbon atoms). In formula (2), each X is independently a hydroxyl group or a hydrolyzable group. In formula (2), a is an integer from 1 to 3.

The hydrolyzable group is not particularly limited, and examples thereof include halogen atoms, alkoxy groups, alkenyloxy groups, aryloxy groups, acyloxy groups, ketoximate groups, amino groups, amide groups, acid amide groups, aminooxy groups, and mercapto groups. Among these, halogen atoms, alkoxy groups, alkenyloxy groups, and acyloxy groups are preferred because of their high activity. In addition, alkoxy groups such as methoxy groups and ethoxy groups are more preferred because of their mild hydrolysis and ease of handling, and methoxy groups and ethoxy groups are even more preferred. In addition, from the viewpoint of safety, ethoxy groups and isopropenoxy groups are preferred, in which the compounds that are eliminated by the reaction are ethanol and acetone, respectively.

The hydroxyl groups or hydrolyzable groups may be bonded to one silicon atom in the range of 1 to 3. When two or more hydroxyl groups or hydrolyzable groups are bonded to one silicon atom, those groups may be the same or different.

In the above formula (2), from the viewpoint of curability, a is preferably 2 or 3, and particularly preferably 3. In addition, from the viewpoint of storage stability, a is preferably 2.
Examples of ^R1 in the above formula (2) include alkyl groups such as a methyl group and an ethyl group, cycloalkyl groups such as a cyclohexyl group, aryl groups such as a phenyl group, aralkyl groups such as a benzyl group, a trimethylsiloxy group, a chloromethyl group, a methoxymethyl group, etc. Among these, a methyl group is preferred.

Examples of the hydrolyzable silyl group include methyldimethoxysilyl group, trimethoxysilyl group, triethoxysilyl group, tris(2-propenyloxy)silyl group, triacetoxysilyl group, (chloromethyl)dimethoxysilyl group, (chloromethyl)diethoxysilyl group, (dichloromethyl)dimethoxysilyl group, (1-chloroethyl)dimethoxysilyl group, (1-chloropropyl)dimethoxysilyl group, (methoxymethyl)dimethoxysilyl group, (methoxymethyl)diethoxysilyl group, and Examples of such silyl groups include an aryl group, an (ethoxymethyl)dimethoxysilyl group, a (1-methoxyethyl)dimethoxysilyl group, an (aminomethyl)dimethoxysilyl group, an (N,N-dimethylaminomethyl)dimethoxysilyl group, an (N,N-diethylaminomethyl)dimethoxysilyl group, an (N,N-diethylaminomethyl)diethoxysilyl group, an (N-(2-aminoethyl)aminomethyl)dimethoxysilyl group, an (acetoxymethyl)dimethoxysilyl group, and an (acetoxymethyl)diethoxysilyl group.

Examples of the hydrolyzable silyl group-containing resin include hydrolyzable silyl group-containing polyurethane resins.
Examples of the method for producing the hydrolyzable silyl group-containing polyurethane resin include a method in which a polyol compound and a polyisocyanate compound are reacted with each other to produce a polyurethane resin, and then a silyl group-containing compound such as a silane coupling agent is further reacted with the polyurethane resin. Specific examples of the method include the method for synthesizing a urethane oligomer having a hydrolyzable silyl group described in JP 2017-48345 A.
The polyol compound and polyisocyanate compound used in the hydrolyzable silyl group-containing polyurethane resin are similar to the polyol compound and polyisocyanate compound used in the moisture-curable urethane resin described above, and therefore their description will be omitted.

Examples of the silane coupling agent include vinyltrichlorosilane, vinyltriethoxysilane, vinyltris(β-methoxy-ethoxy)silane, β-(3,4-epoxycyclohexyl)-ethyltrimethoxysilane, γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropylmethyldiethoxysilane, γ-methacryloxypropyltrimethoxysilane, N-(β-aminoethyl)-γ-aminopropyltrimethoxysilane, N-(β-aminoethyl)-γ-aminopropyltrimethyldimethoxysilane, N-phenyl-γ-aminopropyltrimethoxysilane, γ-chloropropyltrimethoxysilane, γ-mercaptopropyltrimethoxysilane, γ-aminopropyltrimethoxysilane, 3-isocyanatepropyltrimethoxysilane, 3-isocyanatepropyltriethoxysilane, etc. Among them, γ-mercaptopropyltrimethoxysilane, 3-isocyanatepropyltrimethoxysilane, and 3-isocyanatepropyltriethoxysilane are preferred. These silane coupling agents may be used alone or in combination of two or more kinds.

The moisture-curable urethane resin may have both an isocyanate group and a hydrolyzable silyl group. The moisture-curable urethane resin having both an isocyanate group and a hydrolyzable silyl group is preferably produced by first obtaining a moisture-curable urethane resin having an isocyanate group by the above-mentioned method, and then reacting the moisture-curable urethane resin with a silane coupling agent.
The details of the moisture-curable urethane resin having an isocyanate group are as described above. The silane coupling agent to be reacted with moisture curing may be appropriately selected from those listed above, but it is preferable to use a silane coupling agent having an amino group or a mercapto group from the viewpoint of reactivity with the isocyanate group. Preferred specific examples include N-(β-aminoethyl)-γ-aminopropyltrimethoxysilane, N-(β-aminoethyl)-γ-aminopropyltrimethyldimethoxysilane, N-phenyl-γ-aminopropyltrimethoxysilane, γ-mercaptopropyltrimethoxysilane, γ-aminopropyltrimethoxysilane, and 3-isocyanatepropyltrimethoxysilane.

Furthermore, the moisture-curable resin may have a radically polymerizable functional group. As the radically polymerizable functional group that the moisture-curable resin may have, a group having an unsaturated double bond is preferable, and in particular, from the viewpoint of reactivity, a (meth)acryloyl group is more preferable. Note that the moisture-curable resin having a radically polymerizable functional group is not included in the above-mentioned radically polymerizable compound, and is treated as a moisture-curable resin.
The moisture-curable resin may be appropriately selected from the various resins described above and used alone or in combination of two or more kinds.

The weight-average molecular weight of the moisture-curable resin is not particularly limited, but the preferred lower limit is 800 and the preferred upper limit is 20,000. When the weight-average molecular weight is within this range, the storage modulus, viscosity, etc. of the curable composition can be easily adjusted to be within the above-mentioned ranges.
The weight average molecular weight of the moisture-curable resin is more preferably 1,500 in lower limit and 12,000 in upper limit, still more preferably 2,000 in lower limit and still more preferably 8,000 in upper limit.
In this specification, the weight average molecular weight is a value obtained by measuring by gel permeation chromatography (GPC) and converting the weight average molecular weight into polystyrene equivalent. An example of a column used for measuring the weight average molecular weight converted into polystyrene equivalent by GPC is Shodex LF-804 (manufactured by Showa Denko KK). An example of a solvent used in GPC is tetrahydrofuran.

The content of the moisture-curable resin in the photo-curable resin composition is preferably 15% by mass or more based on the total amount of the photo-curable resin composition. When the moisture-curable resin is 15% by mass or more, the moisture-curable resin is given an appropriate moisture curing property, and the adhesive strength after 24 hours of photocuring is easily increased. From these viewpoints, the content of the photo-curable resin is more preferably 20% by mass or more, and more preferably 25% by mass or more.
In addition, the content of the moisture-curable resin is preferably 75% by mass or less based on the total amount of the photo-moisture-curable resin composition. When the content of the photo-moisture-curable resin is 75% by mass or less, it is possible to include a certain amount or more of the radical polymerizable compound in the photo-moisture-curable resin composition, which makes it easier to impart appropriate photocurability. In addition, it also makes it easier to improve the initial adhesive strength. From this viewpoint, the content of the radical polymerizable compound is more preferably 60% by mass or less, and even more preferably 40% by mass or less.

In the photo-curable resin composition, the mass ratio of the radical polymerizable compound to the moisture-curable resin (radical polymerizable compound/moisture-curable resin) is preferably 20/80 or more and 90/10 or less, and more preferably 30/70 or more and 80/20 or less. By setting the mass ratio within these ranges, the photo-curable resin composition can be imparted with a well-balanced photocurability and moisture-curability, and both the initial adhesive strength and the adhesive strength after 24 hours of photocuring can be easily adjusted within the desired range. In addition, from the viewpoint of increasing the initial adhesive strength, the content of the radical polymerizable compound is preferably high, and more specifically, it is more preferably greater than 50/50 and 80/20 or less, and even more preferably 60/40 or more and 80/20 or less.

(Photopolymerization initiator)
The photo-curable resin composition of the present invention further contains a photopolymerization initiator. By containing the photopolymerization initiator, the curable resin composition is appropriately imparted with photocurability.
Examples of the photopolymerization initiator 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.
Among the above photopolymerization initiators, commercially available ones include, for example, IRGACURE 184, IRGACURE 369, IRGACURE 379, IRGACURE 379EG, IRGACURE 651, IRGACURE 784, IRGACURE 819, IRGACURE 907, IRGACURE 2959, IRGACURE OXE01, IRGACURE TPO (all manufactured by BASF Corporation), benzoin methyl ether, benzoin ethyl ether, and benzoin isopropyl ether (all manufactured by Tokyo Chemical Industry Co., Ltd.).

The content of the photopolymerization initiator in the curable resin composition is preferably 0.01 parts by mass or more and 10 parts by mass or less, more preferably 0.5 parts by mass or more and 5 parts by mass or less, relative to 100 parts by mass of the radical polymerizable compound. When the content of the photopolymerization initiator is within these ranges, the obtained curable resin composition has excellent photocurability and storage stability. Furthermore, by keeping it within the above range, the photoradical polymerization compound is properly cured, making it easier to improve the adhesive strength.

(Moisture curing catalyst)
The curable resin composition preferably contains a moisture curing catalyst that accelerates the moisture curing reaction of the moisture curable resin. By using the moisture curing catalyst, the curable resin composition has better moisture curability and is more likely to have high adhesive strength.
Specific examples of the moisture curing accelerating catalyst include amine compounds, metal catalysts, etc. Examples of the amine compounds include compounds having a morpholine skeleton such as di(methylmorpholino)diethyl ether, 4-morpholinopropylmorpholine, and 2,2'-dimorpholinodiethyl 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.
Of the above-mentioned moisture curing accelerating catalysts, amine-based compounds are preferred, and compounds having a morpholine skeleton are more preferred.

The content of the moisture curing catalyst is preferably 0.01 parts by mass or more and 8 parts by mass or less, and more preferably 0.1 parts by mass or more and 5 parts by mass or less, relative to 100 parts by mass of the moisture curing resin. By having the content of the moisture curing catalyst within the above range, the effect of promoting the moisture curing reaction is excellent without deteriorating the storage stability, etc. of the curable resin composition.

(Coupling Agent)
The curable resin composition may contain a coupling agent. By including a coupling agent in the curable resin composition, the adhesive strength is easily improved. Examples of the coupling agent include a silane coupling agent, a titanate coupling agent, and a zirconate coupling agent. Among them, the silane coupling agent is preferable because it has an excellent effect of improving adhesiveness.

Examples of silane coupling agents include 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropylmethyldimethoxysilane, 3-glycidoxypropyltriethoxysilane, 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, 3-glycidoxypropylmethyldiethoxysilane, 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 3-(2-aminoethyl)aminopropyltrimethoxysilane, 3-(2-aminoethyl)aminopropyltriethoxysilane, 3-(2-aminoethyl)aminopropylmethyldimethoxysilane, 3-(meth)acryloyloxypropyltrimethoxysilane, 3-(meth)acryloyloxypropyltriethoxysilane, 3-(meth)acryloyloxypropylmethyldimethoxysilane, 3-(meth)acryloyloxypropylmethyldiethoxysilane, vinyltrimethy ... vinyltrimethyoxypropyltrimethoxysilane, 3-(meth)acryloyloxypropyltriethoxysilane, vinyltrimethyoxypropyltrimethoxysilane, 3-(meth)acryloyloxypropyltriethoxysilane, vinyltrimethyoxypropyltrimethoxysilane, vinyltrimethyoxypropyltriethoxysilane, vinyltrimethyoxypropyltriethoxysilane, vinyltrimethyoxypropyltriethoxysilane, vinyltrimethyoxypropyltriethoxysilane, vinyltrimethyoxypropyltriethoxysil xysilane, vinyltriethoxysilane, 3-isocyanatepropyltrimethoxysilane, 3-isocyanatepropylmethyldimethoxysilane, 3-isocyanatepropyltriethoxysilane, 3-isocyanatepropylmethyldiethoxysilane, 3-mercaptopropyltrimethoxysilane, 3-mercaptopropylmethyldimethoxysilane, 3-mercaptopropyltriethoxysilane, 3-mercaptopropylmethyldiethoxysilane, methyltrimethoxysilane, dimethyldimethoxysilane, phenyltrimethoxysilane, methyltriethoxysilane, dimethyldiethoxysilane, phenyltriethoxysilane, n-propyltrimethoxysilane, n-propyltriethoxysilane, hexyltrimethoxysilane, hexyltriethoxysilane, octyltriethoxysilane, tedyltrimethoxysilane, 1,6-bis(trimethoxysilyl)hexane, and the like.

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 is preferably a silane coupling agent, and among the silane coupling agents, an isocyanate group-containing silane coupling agent such as 3-isocyanatepropyltrimethoxysilane, 3-isocyanatepropylmethyldimethoxysilane, 3-isocyanatepropyltriethoxysilane, or 3-isocyanatepropylmethyldiethoxysilane is preferred.
The coupling agent may be used alone or in combination of two or more kinds.

When the photo-curable resin composition contains a coupling agent, the content of the coupling agent is preferably 0.05 parts by mass or more and 10 parts by mass or less, more preferably 0.2 parts by mass or more and 5 parts by mass or less, and even more preferably 0.5 parts by mass or more and 3 parts by mass or less, relative to 100 parts by mass of the total amount of the radical polymerizable compound and the moisture curable resin. By keeping the content of the coupling agent within these ranges, it becomes easier to improve the adhesive strength.

(filler)
The curable resin composition of the present invention may contain a filler. By containing a filler, the curable resin composition of the present invention has a suitable thixotropy and can sufficiently retain its shape after application. As the filler, a particulate filler may be used.
As the filler, inorganic fillers are preferred, such as silica, talc, titanium oxide, zinc oxide, calcium carbonate, etc. Among them, silica is preferred because the resulting curable resin composition has excellent ultraviolet transmittance. In addition, the filler may be subjected to hydrophobic surface treatment such as silylation treatment, alkylation treatment, and epoxidation treatment.
The fillers may be used alone or in combination of two or more.
The content of the filler is preferably 1 part by mass or more and 25 parts by mass or less, more preferably 2 parts by mass or more and 20 parts by mass or less, and even more preferably 3 parts by mass or more and 15 parts by mass or less, relative to 100 parts by mass of the total amount of the radical polymerizable compound and the moisture-curable resin.

The curable resin composition of the present invention may contain other additives such as wax particles, ionic liquid, colorant, foamed particles, expanded particles, and reactive diluents in addition to the components described above.
The curable resin composition may be diluted with a solvent as necessary. When the curable resin composition is diluted with a solvent, the parts by mass of the curable resin composition are based on the solid content, that is, the parts by mass excluding the solvent.

Methods for producing the curable resin composition of the present invention include a method of using a mixer to mix a moisture-curable resin, a radically polymerizable compound, and a photopolymerization initiator, as well as other additives such as a moisture-curing-accelerating catalyst, a filler, and a coupling agent, which are added as necessary. Examples of mixers include a homodisper, a homomixer, a universal mixer, a planetary mixer (planetary mixing device), a kneader, and a three-roll mill.

[Hardened body]
The photo-curable resin composition of the present invention is cured and used as a cured product. The photo-curable resin composition of the present invention can bond the adherends together by being cured while being placed between the adherends, for example.
Specifically, the photo-curable resin composition is applied to one of the adherends, and then photocured by light irradiation to, for example, a B-stage state (i.e., semi-cured). One of the adherends is placed on the other adherend via the semi-cured photo-curable resin composition, and the adherends are temporarily bonded together. In the present invention, the photo-curable resin composition has good adhesive strength (i.e., initial adhesive strength) immediately after semi-curing, so that the adherends can be temporarily bonded together with an appropriate adhesive strength.
Generally, the photo-curable resin composition applied to one of the adherends is photocured before being superimposed on the other adherend. Therefore, the photo-curable resin composition is photocured in a state where most of the composition is exposed to the atmosphere (i.e., in a state where the composition is in contact with oxygen), but as described above, the radical polymerizable compound contains a nitrogen-containing compound, so that the initial adhesive strength is good even when the composition is cured in the presence of oxygen.
Thereafter, the semi-cured curable resin composition is fully cured by curing the moisture-curable resin with moisture, and the overlapping adherends are bonded with sufficient adhesive strength via the curable resin composition.

The curable resin composition may be applied to the adherend using, for example, a dispenser, but this is not limited thereto. The light irradiated during photocuring is not particularly limited as long as it is an active energy ray capable of curing the radical polymerizable compound, but ultraviolet light is preferred. When the curable resin composition is to be fully cured by moisture, it may be left in the air for a predetermined period of time.

The curable resin composition of the present invention is preferably used as an adhesive for electronic devices. Therefore, the adherend is not particularly limited, but is preferably various parts constituting an electronic device. The various parts constituting an electronic device include electronic components or substrates on which electronic components are attached, and more specifically, various electronic components provided in display elements, substrates on which electronic components are attached, and semiconductor chips. 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 film, sheet, plate, panel, tray, rod (rod-shaped body), box, and housing shapes.

For example, the curable resin composition of the present invention is used inside an electronic device, for example, to bond substrates together to obtain an assembled part. The assembled part thus obtained has a first substrate, a second substrate, and the cured product 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 product. Preferably, the first substrate and the second substrate each have at least one electronic component attached thereto.

In addition, the curable resin composition of the present invention is preferably used for narrow frame applications. For example, in various display element devices such as display devices for mobile phones such as smartphones, an adhesive is applied onto a base having a narrow rectangular frame (i.e., a narrow frame), and a display panel, a touch panel, etc. are assembled via the adhesive, and the curable resin composition of the present invention is preferably used as the adhesive.
Furthermore, the curable resin composition of the present invention is preferably used in semiconductor chip applications. In semiconductor chip applications, the curable resin composition of the present invention is used, for example, to bond semiconductor chips together.

The present invention will now be described in further detail with reference to examples, but the present invention is not limited to these examples in any way.

In the present examples, various physical properties were evaluated as follows.
(Initial adhesive strength)
1(a) and (b), a photo-curable resin composition 10 was applied to an aluminum substrate 11 using a dispenser to a width of 1.0±0.1 mm, a length of 25±2 mm, and a thickness of 0.4±0.1 mm, and photo-cured by irradiating with ultraviolet light from a mercury lamp at 3,000 mJ/ ^cm2 . Thereafter, a glass plate 12 was bonded to the aluminum substrate 11, a 100 g weight was placed on the substrate, and the substrate was left to stand at 25°C and 50 RH% for 10 minutes to be moisture-cured, thereby obtaining a sample 13 for evaluating adhesion.
Thereafter, using a tensile tester ("Autograph AG-X", manufactured by Shimadzu Corporation) in an atmosphere of 25°C, the specimen was pulled in the shear direction S at a speed of 5 mm/sec, and the strength at which the aluminum substrate 11 and the glass plate 12 peeled off was measured and used as the initial adhesive strength.
The initial adhesive strength was evaluated according to the following criteria.
AA: 0.8 MPa or more A: 0.3 MPa or more and less than 0.8 MPa B: Less than 0.3 MPa

(Adhesive strength after 24 hours of light curing)
A sample was prepared in the same manner as for the initial adhesive strength, and the photo-curable resin composition 10 was photocured. Thereafter, a glass plate 12 was attached to an aluminum substrate 11, a weight of 100 g was placed on the glass plate, and the sample was left to stand at 25° C. and 50% RH for 24 hours for moisture curing, thereby obtaining a sample 13 for evaluating adhesiveness.
Using the adhesiveness evaluation sample 13, the sample 13 was pulled in the shear direction S in the same manner as in the measurement of the initial adhesive strength, and the strength at which the aluminum substrate 11 and the glass plate 12 peeled off was measured and defined as the adhesive strength 24 hours after photocuring. The adhesive strength 24 hours after photocuring was evaluated according to the following evaluation criteria.
A: 2.0 MPa or more B: Less than 2.0 MPa

The moisture-curable urethane resins used in the respective Examples and Comparative Examples were prepared according to the following Synthesis Examples.
[Synthesis Example 1]
Polyol compound A (hydroxyl value: 110 mg KOH, Mitsubishi Chemical Corporation, "BENEBiOL NL1010DB") was prepared. 100 parts by mass of polyol compound A and 0.01 parts by mass of dibutyltin dilaurate were placed in a 500 mL separable flask and stirred and mixed under vacuum (20 mmHg or less) at 100 ° C. for 30 minutes. After that, the pressure was returned to normal, and 52 parts by mass of diphenylmethane diisocyanate (Nisso Shoji Co., Ltd., "Pure MDI") was added as a polyisocyanate compound, and the mixture was stirred and reacted at 80 ° C. for 3 hours to obtain a polycarbonate skeleton urethane (weight average molecular weight 6,600).

[Synthesis Example 2]
100 parts by mass of polyol compound B (hydroxyl value: 212 mg KOH, Daicel Chemical Industries, Ltd., "Placcel 205U", polycaprolactone polyol) and 0.01 parts by mass of dibutyltin dilaurate were placed in a 500 mL separable flask and stirred and mixed under vacuum (20 mmHg or less) at 100° C. for 30 minutes. The pressure was then returned to normal, and 100 parts by mass of diphenylmethane diisocyanate (Nisso Shoji Co., Ltd., "Pure MDI") was added as a polyisocyanate compound, and the mixture was stirred and reacted at 80° C. for 3 hours to obtain a polyester skeleton urethane (weight average molecular weight 6,300).

[Synthesis Example 3]
100 parts by mass of polyol compound C (polytetramethylene ether glycol, manufactured by Mitsubishi Chemical Corporation, "PTMG-2000") and 0.01 parts by mass of dibutyltin dilaurate were placed in a 500 mL separable flask and mixed by stirring under vacuum (20 mmHg or less) at 100° C. for 30 minutes. The pressure was then returned to normal pressure, and 26.5 parts by mass of diphenylmethane diisocyanate (manufactured by Nisso Shoji Co., Ltd., "Pure MDI") was added as a polyisocyanate compound, followed by stirring at 80° C. for 3 hours to react, thereby obtaining a polyether skeleton urethane (weight average molecular weight 2,700).

The components other than the moisture-curable urethane resin used in each of the Examples and Comparative Examples were as follows.
(Radically polymerizable compound)
Cyclic nitrogen-containing compound: N-vinyl-ε-caprolactam (manufactured by Tokyo Chemical Industry Co., Ltd., product name "NVC")
Monofunctional acrylate (1): Butyl acrylate (manufactured by Tokyo Chemical Industry Co., Ltd., monofunctional)
Monofunctional acrylate (2): (meth)acrylic acid polymer ester of tetrahydrofurfuryl alcohol (manufactured by Osaka Organic Chemical Industry Ltd., product name "Viscoat #150D", monofunctional)
Monofunctional urethane acrylate: 1,2-ethanediol 1-acrylate 2-(N-butylcarbamate) (manufactured by Osaka Organic Chemical Industry Ltd., product name "Viscoat #216", monofunctional)
Bifunctional urethane acrylate: Trade name "EBECRYL8413" manufactured by Daicel Allnex Co., Ltd. Bifunctional urethane acrylate Photopolymerization initiator (1): 2-(dimethylamino)-2-(4-methylbenzyl)-1-(4-morpholinophenyl)butan-1-one, Trade name "Irgacure 379EG" manufactured by BASF Corporation
Photopolymerization initiator (2): diphenyl(2,4,6-trimethylbenzoyl)phosphine oxide, product name "Irgacure TPO" manufactured by BASF Corporation
Moisture curing catalyst: 2,2'-dimorpholinodiethyl ether, San-Apro Co., Ltd., product name "U-CAT 660M"
Filler: Trimethylsilylated silica (manufactured by Nippon Aerosil Co., Ltd., "RY 200S", primary particle size 7 nm)

[Examples 1 to 6, Comparative Examples 1 to 3]
According to the compounding ratios shown in Table 1, each material was stirred at a temperature of 50°C using a planetary stirrer (Thinky Corporation, "Awatori Rentaro"), and then uniformly mixed at a temperature of 50°C using a ceramic triple roll to obtain the curable resin compositions of Examples 1 to 6 and Comparative Examples 1 to 3.

As shown in each of Examples 1 to 6, the initial adhesive strength could be made sufficiently high by reducing the SP value difference (ΔSP value) between the radical polymerizable compound and the moisture-curable resin. In contrast, in the comparative example, the SP value difference was large, so the initial adhesive strength could not be made high.

Claims (8)

A composition comprising a radical polymerizable compound, a moisture curable resin, and a photopolymerization initiator,
A photo-moisture-curable resin composition, wherein the SP value difference between the radical polymerizable compound and the moisture-curable resin, calculated by the Fedors method , is 1.0 or less, and the SP value of the radical polymerizable compound, calculated by the Fedors method, is 9.5 or more . The photo-curable moisture-curable resin composition according to claim 1 , wherein the moisture-curable resin has an SP value of 9.5 or more as calculated by the Fedors method . The photo-curable moisture-curable resin composition according to claim 1 or 2, wherein the moisture-curable resin contains either a compound having a polycarbonate skeleton or a compound having a polyester skeleton. The photo-curable moisture-curable resin composition according to any one of claims 1 to 3, wherein the moisture-curable resin includes a moisture-curable urethane resin. The photo-curable moisture-curable resin composition according to any one of claims 1 to 4, wherein the radical polymerizable compound contains a compound having a (meth)acryloyl group. The photo-curable moisture-curable resin composition according to any one of claims 1 to 5, wherein the mass ratio of the radical polymerizable compound to the moisture-curable resin (radical polymerizable compound/moisture-curable resin) is 20/80 or more and 90/10 or less. The photo-curable moisture-curable resin composition according to any one of claims 1 to 6, wherein the SP value difference between the radical polymerizable compound and the moisture-curable resin calculated by the Fedors method is 0.6 or less. A cured product of the curable resin composition according to any one of claims 1 to 7 .

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