Curable resin composition and cured product

Abstract

The curable resin composition of the present invention is a curable resin composition containing a radical polymerizable compound, and after the curable resin composition is applied with an air dispenser, it is irradiated with 365 nm ultraviolet light at 1000 mJ / cm 2 from an LED lamp. 2 After 16 hours in an environment of 25°C and 50% RH, the ratio of coating height to line width is 0.6 or more, and the LED lamp emits 365 nm ultraviolet light at 1000 mJ / cm. 2 After irradiation, a load of 0.03 MPa is applied, and the thickness change rate before and after the load is 40% or less.

Description

[Technical Field]

[0001] The present invention relates to a curable resin composition and a cured product thereof, and more particularly to a curable resin composition used, for example, as an adhesive for electronic devices, and a cured product thereof. [Background technology]

[0002] 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 sometimes bonded together via an adhesive layer to form a semiconductor chip stack. Furthermore, with the widespread use of mobile devices with various display elements, such as mobile phones and portable game consoles, there is a demand for smaller display elements. One method for miniaturizing display elements is to narrow the frame of the image display area (hereinafter, also referred to as "narrow frame design"). Stacking small semiconductor chips and narrow frame design require a bonding technique using a thin adhesive line width, such as that applied using a dispenser.

[0003] A semiconductor chip stack is manufactured, for example, by applying an adhesive to one semiconductor chip, semi-curing it by light irradiation, stacking the other semiconductor chip via the semi-cured adhesive to temporarily bond the semiconductor chips, and then fully curing the adhesive to bond the chips. Similarly, for narrow frame designs, a method of semi-curing the applied adhesive and then fully curing it is being considered. The use of a photo-moisture-curable resin composition as an adhesive for semiconductor chip stacking applications and narrow frame design applications is being considered.

[0004] Known examples of photo-moisture-curable resin compositions used as adhesives include radically curable urethane resin compositions containing a radically polymerizable unsaturated group-containing compound, a moisture-curable urethane prepolymer, and a thixotropy-imparting agent, as disclosed in Patent Document 1 (see, for example, Patent Document 1). Patent Document 1 shows that the inclusion of a predetermined amount of a thixotropy-imparting agent in the resin composition improves adhesion to the substrate and also prevents resin dripping. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Laid-Open No. 2004-18621 Summary of the Invention [Problem to be solved by the invention]

[0006] However, when a conventional photo-curable resin composition is used to bond the housing of a mobile phone, for example, there is a problem of peeling between the adhesive and the housing. Furthermore, the applied adhesive must maintain a constant gap between adherends when a load is applied, for example, in a semi-cured state (i.e., B-stage state) after photo-curing.

[0007] Therefore, an object of the present invention is to make it difficult for the adherends to peel off while maintaining a constant gap between the adherends when they are bonded together. [Means for solving the problem]

[0008] As a result of their investigations, the inventors found that housings used in mobile phones and the like are sometimes uneven due to minute distortions, and that because the adhesive is applied along these unevennesses, cavities form when the materials are bonded together. As a result of further investigations, the inventors found that the above-mentioned problems can be solved by adjusting the formulation so that the rate of thickness change after photocuring is small and that the cured product has a specific shape after being applied and cured with a dispenser, and thus completed the present invention. That is, the present invention provides the following [1] to [8]. [1] A curable resin composition containing a radical polymerizable compound, After applying the curable resin composition with an air dispenser, ultraviolet rays of 365 nm were applied from an LED lamp at 1000 mJ / cm 2 After 16 hours of exposure to light at 25°C and 50% RH, the ratio of coating height to line width is 0.6 or more, and LED lamp emits 365nm UV light at 1000mJ / cm 2 A curable resin composition that, after irradiation, exhibits a change in thickness of 40% or less when a load of 0.03 MPa is applied. [2] The curable resin composition according to [1] above, wherein the storage modulus of the cured product of the curable resin composition is 500 MPa or less. [3] The curable resin composition according to [1] or [2] above, which contains a moisture-curable resin. [4] The curable resin composition according to any one of the above [1] to [3], which has a viscosity of 100 Pa·s or more and 1000 Pa·s or less, measured using a cone-plate viscometer at 25°C and 1 rpm. [5] The curable resin composition according to any one of the above [1] to [4], which has a thixotropy index of 1.7 or more and 5.0 or less. [6] The curable resin composition according to any one of the above [1] to [5], which contains a filler. [7] The curable resin composition according to any one of the above items [1] to [6], which is used as an adhesive for electronic devices. [8] A cured product of the curable resin composition according to any one of the above [1] to [7]. [Effects of the Invention]

[0009] According to the curable resin composition of the present invention, the gap between the adherends is maintained constant while the voids between the adhesive and the adherend are reduced, making peeling of the adherend less likely to occur. DETAILED DESCRIPTION OF THE INVENTION

[0010] The present invention will be described in detail below. [Curable resin composition] The curable resin composition of the present invention is a curable resin composition containing a radically polymerizable compound, and satisfies both the following first and second requirements. First requirement: After applying the curable resin composition with an air dispenser, 1000 mJ / cm of 365 nm ultraviolet light is applied from an LED lamp. 2After irradiation and further 16 hours in an environment of 25°C and 50% RH, the ratio of the coating height to the line width (hereinafter also referred to as the aspect ratio) becomes 0.6 or more. Second requirement: For the curable resin composition, 365 nm ultraviolet light is irradiated with an LED lamp at 1000 mJ / cm 2 Immediately after irradiation, a load of 0.03 MPa is applied, and the thickness change rate before and after the load is 40% or less. The application conditions for the air dispenser in the first requirement are as follows: Clearance 1.0 mm, nozzle inner diameter 0.4 mm, discharge pressure 0.38 MPa, application speed 1.0 mm / sec, application length 25 mm In measuring the second requirement, the curable resin composition is applied to a width of 1 mm and a thickness of 0.2 mm, and the thickness change rate is measured in an environment of 25°C.

[0011] In the present invention, as described in the first requirement above, the aspect ratio after coating and curing is high. If the aspect ratio after coating and curing is high, even if the adherend is distorted or has minute irregularities and the curable resin composition conforms to the irregularities, voids between the adherend and the curable resin composition are reduced, making peeling of the adherend less likely to occur. From the viewpoint of further reducing voids, the aspect ratio is preferably 0.60 or more, more preferably 0.70 or more, and even more preferably 0.80 or more. The aspect ratio is not particularly limited, but is preferably 1.0 or less from the viewpoint of making it easier to maintain a constant distance between the caps on the adherends after bonding.

[0012] The application conditions specified in the first requirement above are assumed to be standard application conditions when applying an adhesive in narrow frame designs, etc., and the shape of the curable resin composition after application and curing under the application conditions of the first requirement above shows the shape of a standard adhesive after application and curing. Therefore, by adjusting the formulation of the curable resin composition to satisfy the first requirement above, it is possible to reduce voids between the adhesive and the adherend in narrow frame designs, etc.

[0013] Furthermore, in the present invention, as described above, when the aspect ratio is increased, the curable resin composition generally tends to be compressed between adherends, and it may become difficult to maintain the gap between the adherends at a certain distance or more. However, by setting the thickness change rate to 40% or less, as in the second requirement above, it becomes possible to maintain the gap at a certain distance or more. From the viewpoint of improving gap retention, the thickness change rate is preferably 30% or less, more preferably 20% or less. Also, from the viewpoint of gap retention, the smaller the thickness change rate, the better, and 0% or more is sufficient, but from the viewpoint of ensuring adhesion and cohesion between adherends, it is preferably 3% or more, more preferably 7% or more. In the present invention, as will be described later, the first and second requirements can be satisfied by adjusting, for example, the type and amount of the radical polymerizable compound contained in the curable resin composition, and the amount of the filler contained therein.

[0014] As described in the first requirement above, the curable resin composition is irradiated with light in the measurement of the aspect ratio. Therefore, when the aspect ratio is measured, the curable resin composition is photocured by polymerization of the radical polymerizable compound. Furthermore, since the curable resin composition is left for a predetermined time after the light irradiation, if the curable resin composition is moisture-curable as described below, it will also be cured by moisture. On the other hand, the thickness change rate in the second requirement is measured immediately after light irradiation. Therefore, even in the case of a moisture-curable resin composition, which will be described later, the thickness change rate is measured for a curable resin composition in a so-called B-stage state that is photocured but not moisture-cured.

[0015] (storage modulus) The storage modulus at 25°C of the cured product of the curable resin composition of the present invention is preferably 500 MPa or less. When the storage modulus of the cured product is 500 MPa or less, it is easier to absorb impacts and the like acting on the adherend. It also makes it easier to reduce voids during lamination. From the viewpoint of impact absorption and reducing voids during lamination, the storage modulus is more preferably 100 MPa or less, even more preferably 50 MPa or less, and even more preferably 10 MPa or less. Furthermore, from the viewpoint of imparting a certain level of mechanical strength and the like to the cured product, the storage modulus is preferably 0.1 MPa or more, more preferably 1 MPa or more. The storage modulus was measured by irradiating the curable resin composition with a mercury lamp at 3000 mJ / cm 2 The storage modulus is measured on the cured product obtained by irradiating the sample with light and then leaving it for 3 days in an environment of 23°C and 50% RH. Details of the method for measuring the storage modulus are as shown in the examples below.

[0016] (viscosity) The viscosity of the curable resin composition of the present invention is preferably 100 Pa·s or more and 1000 Pa·s or less. When the viscosity is within this range, the workability and applicability are improved when the curable resin composition is applied to an adherend, and further, the aspect ratio described above is easily increased. Furthermore, when applied with a dispenser, it is easy to apply a thin line width. From these viewpoints, the viscosity is more preferably 200 Pa·s or more, even more preferably 300 Pa·s or more, and more preferably 800 Pa·s or less, even more preferably 600 Pa·s or less. In this specification, the viscosity is measured using a cone-plate type (E type) viscometer at 1 rpm and 25°C.

[0017] (TI value) The curable resin composition of the present invention preferably has a thixotropy index (TI value) of 1.7 or more. When the TI value is 1.7 or more, the fluidity is increased during application, while the fluidity can be reduced after application, thereby improving the application properties and increasing the aspect ratio. From this viewpoint, the TI value is more preferably 2.0 or more, even more preferably 2.5 or more, and even more preferably 3.0 or more. From the viewpoint of practicality, the TI value is preferably 5.0 or less, more preferably 4.7 or less, and even more preferably 4.5 or less. In this specification, the thixotropy index (TI value) refers to the value obtained by dividing the viscosity measured using a cone-plate viscometer at 25°C and 1 rpm by the viscosity measured using a cone-plate viscometer at 25°C and 10 rpm. The storage modulus, viscosity, and TI value described above can be adjusted by appropriately changing the type and amount of each component used in the radical polymerizable compound and moisture-curable resin, and the type and amount of additives such as fillers, as described in detail below.

[0018] The curable resin composition of the present invention preferably contains a moisture-curable resin in addition to a radically polymerizable compound. Here, by containing a moisture-curable resin, the curable resin composition becomes a photo-moisture-curable resin composition that cures upon light irradiation and moisture. By containing a moisture-curable resin in addition to a radically polymerizable compound, the curable resin composition can be cured without heating. Therefore, when curing the curable resin composition, damage to the adhesive joint or electronic components around the adhesive joint due to heating can be prevented. Furthermore, the presence of a moisture-curable resin facilitates increasing the adhesive strength after full curing. The photo-curable resin composition can be first photo-cured to a B-stage state, giving it relatively low adhesive strength (tackiness), and then left in the air or the like to cure with moisture, resulting in a cured product with sufficient adhesive strength. This allows adherends to be temporarily bonded together before being permanently bonded.

[0019] <Radical polymerizable compound> The radical polymerizable compound contained in the curable resin composition is not particularly limited as long as it is a radical polymerizable compound having photopolymerizability, and is a compound having a radical polymerizable functional group in the molecule. Among them, a compound having an unsaturated double bond as the radical polymerizable functional group is preferred, and a compound having a (meth)acryloyl group (hereinafter also referred to as "(meth)acrylic compound") is particularly preferred.

[0020] Examples of the (meth)acrylic compound include (meth)acrylic acid ester compounds, epoxy (meth)acrylates, urethane (meth)acrylates, etc. The urethane (meth)acrylates have no residual isocyanate groups. In addition, in this specification, "(meth)acryloyl group" means an acryloyl group or a (meth)acryloyl group, "(meth)acrylate" means an acrylate or a methacrylate, and the same applies to other similar terms.

[0021] The (meth)acrylic acid ester compound may be monofunctional, bifunctional, trifunctional or higher functional. Examples of monofunctional (meth)acrylic acid ester compounds include 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, and lauryl (meth)acrylate. alkyl (meth)acrylates such as isomyristyl (meth)acrylate and stearyl (meth)acrylate; (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; 2-hydroxyethyl (meth)acrylate and 2-hydroxypropyl (meth)acrylate; acrylate, (meth)acryloylethylene-butylamide, hydroxyalkyl (meth)acrylates such as 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.

[0022] The (meth)acrylic acid ester compound may have an aromatic ring, and examples thereof include phenyl alkyl (meth)acrylates such as benzyl (meth)acrylate and 2-phenylethyl (meth)acrylate, and phenoxy alkyl (meth)acrylates such as phenoxyethyl (meth)acrylate, etc. Furthermore, the (meth)acrylate may be a (meth)acrylate having multiple benzene rings such as a fluorene skeleton or a biphenyl skeleton, and specific examples thereof include fluorene type (meth)acrylate and ethoxylated o-phenylphenol acrylate. Other examples include phenoxypolyoxyethylene (meth)acrylates such as phenoxydiethylene glycol (meth)acrylate, phenoxypolyethylene glycol (meth)acrylate, nonylphenoxydiethylene glycol (meth)acrylate, and nonylphenoxypolyethylene glycol (meth)acrylate. Furthermore, examples of the (meth)acrylic acid ester compound having an aromatic ring include phthalimide acrylates such as N-acryloyloxyethylphthalimide.

[0023] Furthermore, examples of the monofunctional (meth)acrylic acid ester compound include (meth)acrylates having a heterocyclic structure such as tetrahydrofurfuryl (meth)acrylate, alkoxylated tetrahydrofurfuryl (meth)acrylate, cyclic trimethylolpropane formal (meth)acrylate, 3-ethyl-3-oxetanylmethyl (meth)acrylate, various imide (meth)acrylates, 2,2,2-trifluoroethyl (meth)acrylate, 2,2,3,3-tetrafluoropropyl (meth)acrylate, 1,2,3,4 ... Other examples include H,1H,5H-octafluoropentyl (meth)acrylate, dimethylaminoethyl (meth)acrylate, diethylaminoethyl (meth)acrylate, 2-(meth)acryloyloxyethyl succinate, 2-(meth)acryloyloxyethyl hexahydrophthalate, N-acryloyloxyethyl hexahydrophthalimide, 2-(meth)acryloyloxyethyl-2-hydroxypropyl phthalate, glycidyl (meth)acrylate, and 2-(meth)acryloyloxyethyl phosphate. In addition to the above-mentioned various imide (meth)acrylates, examples thereof include not only the above-mentioned phthalimide acrylates and hexahydrophthalimides such as N-acryloyloxyethylhexahydrophthalimide, but also succinimide acrylates such as (meth)acryloxysuccinimide, maleimide acrylates such as maleimide (meth)acrylate, and various acrylimides having an imide group and a (meth)acryloyl group.

[0024] 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, polypropylene glycol di(

[0033] Examples of suitable di(meth)acrylates include ethylene oxide-added bisphenol A di(meth)acrylate, propylene oxide-added bisphenol A di(meth)acrylate, ethylene oxide-added bisphenol F di(meth)acrylate, dimethyloldicyclopentadienyl di(meth)acrylate, neopentyl glycol di(meth)acrylate, ethylene oxide-modified isocyanuric acid 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.

[0025] Furthermore, examples of the (meth)acrylic acid ester compounds having three or more functional groups 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, ethylene oxide-added isocyanuric acid 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.

[0026] The (meth)acrylic acid ester compound is preferably a monofunctional (meth)acrylic acid ester compound, and among them, as described below, those having an alicyclic structure or an aromatic ring are preferred. Suitable examples of (meth)acrylates having an alicyclic structure include 4-tert-butylcyclohexyl (meth)acrylate, 3,3,5-trimethylcyclohexyl (meth)acrylate, isobornyl (meth)acrylate, dicyclopentenyl (meth)acrylate, and hexahydrophthalimides such as N-acryloyloxyethylhexahydrophthalimide. Suitable examples of (meth)acrylic acid ester compounds having an aromatic ring include phenoxyalkyl (meth)acrylates and phthalimide acrylates. The monofunctional (meth)acrylic acid ester compound preferably contains a (meth)acrylate having an imide group. Examples of the (meth)acrylate having an imide group include, in addition to the above-mentioned hexahydrophthalimide acrylates and phthalimide acrylates, succinimide acrylates, maleimide acrylates, and acrylimides.

[0027] The epoxy (meth)acrylate may be, for example, a product of reacting an epoxy compound with (meth)acrylic acid. The reaction between the epoxy compound and (meth)acrylic acid may be carried out in the presence of a basic catalyst according to a conventional method. The epoxy (meth)acrylate may be monofunctional or multifunctional, such as bifunctional, but multifunctional is preferred. Examples of epoxy compounds that can be used as raw materials for synthesizing the above-mentioned epoxy (meth)acrylates include bisphenol A type epoxy resins, bisphenol F type epoxy resins, bisphenol S type epoxy resins, 2,2'-diallyl bisphenol A type epoxy resins, hydrogenated bisphenol type epoxy resins, propylene oxide-added bisphenol A type epoxy resins, resorcinol type epoxy resins, biphenyl type epoxy resins, sulfide type epoxy resins, diphenyl ether type epoxy resins, dicyclopentadiene type epoxy resins, naphthalene type epoxy resins, phenol novolac type epoxy resins, ortho-cresol novolac type epoxy resins, dicyclopentadiene novolac type epoxy resins, biphenyl novolac type epoxy resins, naphthalene phenol novolac type epoxy resins, glycidyl amine type epoxy resins, alkyl polyol type epoxy resins, rubber-modified epoxy resins, glycidyl ester compounds, and bisphenol A type episulfide resins.

[0028] Commercially available epoxy (meth)acrylates include, for example, EBECRYL860, EBECRYL3200, EBECRYL3201, EBECRYL3412, EBECRYL3600, EBECRYL3700, EBECRYL3701, EBECRYL3702, EBECRYL3703, EBECRYL3800, EBECRYL6040, and EBECRYL Examples of suitable acrylates include RDX63182 (all manufactured by Daicel-Allnex Corporation), EA-1010, EA-1020, EA-5323, EA-5520, EACHD, and EMA-1020 (all manufactured by Shin-Nakamura Chemical Co., Ltd.), Epoxy Ester M-600A, Epoxy Ester 40EM, Epoxy Ester 70PA, Epoxy Ester 200PA, Epoxy Ester 80MFA, Epoxy Ester 3002M, Epoxy Ester 3002A, Epoxy Ester 1600A, Epoxy Ester 3000M, Epoxy Ester 3000A, Epoxy Ester 200EA, and Epoxy Ester 400EA (all manufactured by Kyoeisha Chemical Co., Ltd.), Denacol Acrylate DA-141, Denacol Acrylate DA-314, and Denacol Acrylate DA-911 (all manufactured by Nagase ChemteX Corporation).

[0029] The urethane (meth)acrylate can be, for example, a product obtained by reacting an isocyanate compound with a (meth)acrylic acid derivative having a hydroxyl group. Here, a catalytic amount of a tin-based compound or the like can 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 bifunctional is preferred. 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. The isocyanate compound may also be a chain-extended polyisocyanate compound 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, and polycaprolactone diol.

[0030] 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.

[0031] Commercially available examples of the above urethane (meth)acrylates include M-1100, M-1200, M-1210, and M-1600 (all manufactured by Toagosei Co., Ltd.), EBECRYL230, EBECRYL270, EBECRYL8402, EBECRYL8411, EBECRYL8412, EBECRYL8413, EBECRYL8804, EBECRYL8803, EBECRYL8807, EBECRYL8808, EBECRYL8809, EBECRYL8810, EBECRYL8811, EBECRYL8812, EBECRYL8813, EBECRYL8814, EBECRYL8815, EBECRYL8816, EBECRYL8817, EBECRYL8818, EBECRYL8819, EBECRYL8816, EBECRYL8819 ... ECRYL9270, 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-1200 TPK, 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, UA-7100, 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).

[0032] As the radical polymerizable compound, other radical polymerizable compounds other than those mentioned above can also be used as appropriate. Examples of other radical polymerizable compounds include (meth)acrylamide compounds such as N,N-dimethyl(meth)acrylamide, N-(meth)acryloylmorpholine, N-hydroxyethyl(meth)acrylamide, N,N-diethyl(meth)acrylamide, N-isopropyl(meth)acrylamide, and N,N-dimethylaminopropyl(meth)acrylamide, and vinyl compounds such as styrene, α-methylstyrene, N-vinyl-2-pyrrolidone, and N-vinyl-ε-caprolactam.

[0033] In the present invention, it is preferable to use a radical polymerizable compound having a relatively low viscosity among the above-mentioned compounds, and for example, it is preferable to use a monofunctional (meth)acrylic acid ester compound. If a compound having a low viscosity is used, as will be described later, the viscosity of the curable resin composition can be made low even if the content of the filler is relatively large, and the coating property becomes good. From the above viewpoints, as mentioned above, the monofunctional (meth)acrylic acid ester compound is preferably one having at least one of an aromatic ring and an alicyclic structure, and it is also preferable to use a (meth)acrylic acid ester compound having an aromatic ring in combination with a (meth)acrylic acid ester compound having an alicyclic structure. The content of the monofunctional (meth)acrylic acid ester compound having at least one of an aromatic ring and an alicyclic structure is preferably 30% by mass or more, more preferably 50% by mass or more, based on the total amount of the radical polymerizable compound. Although not particularly limited, the upper limit is preferably 100% by mass. Furthermore, as described above, when the radical polymerizable compound contains a (meth)acrylate having an imide group, the content of the (meth)acrylate having an imide group is preferably 5% by mass or more, more preferably 12% by mass or more, and even more preferably 24% by mass or more, based on the total amount of the radical polymerizable compound. Furthermore, the content of the (meth)acrylate having an imide group is preferably 50% by mass or less, more preferably 40% by mass or less, based on the total amount of the radical polymerizable compound. The (meth)acrylate having an imide group may have an aromatic ring, an alicyclic structure, or neither, but is preferably monofunctional.

[0034] <Moisture-curing resin> Examples of the moisture-curable resin used in the present invention include moisture-curable urethane resins, hydrolyzable silyl group-containing resins, and moisture-curable cyanoacrylate resins. Moisture-curable urethane resins and hydrolyzable silyl group-containing resins are preferred, and moisture-curable urethane resins are particularly preferred. The moisture-curable urethane resin has an isocyanate group. The moisture-curable urethane resin cures when the isocyanate group in the molecule reacts with moisture in the air or on the adherend. The moisture-curable urethane resin may have only one isocyanate group per molecule, or may have two or more isocyanate groups. In particular, it is preferable for the resin to have isocyanate groups at both ends of the main chain of the molecule.

[0035] 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], within the range of 2.0 to 2.5.

[0036] As the polyol compound serving as a raw material for the moisture-curable urethane resin, known polyol compounds commonly used in the production of polyurethanes can be used, such as polyester polyols, polyether polyols, polyalkylene polyols, polycarbonate polyols, etc. These polyol compounds may be used alone or in combination of two or more. Examples of the polyester polyol include polyester polyol obtained by reacting a polycarboxylic acid with a polyol, and poly-ε-caprolactone polyol obtained by ring-opening polymerization of ε-caprolactone. Examples of the polycarboxylic acid that can be used as a raw material for 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, decamethylenedicarboxylic acid, and dodecamethylenedicarboxylic 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.

[0037] Examples of polyether polyols include ethylene glycol, propylene glycol, ring-opening polymers of tetrahydrofuran, ring-opening polymers of 3-methyltetrahydrofuran, random copolymers or block copolymers of these or their derivatives, and bisphenol-type polyoxyalkylene modified products. Here, the bisphenol-type polyoxyalkylene modified product is a polyether polyol obtained by addition reaction of an alkylene oxide (e.g., ethylene oxide, propylene oxide, butylene oxide, isobutylene oxide, etc.) with the active hydrogen moiety of a bisphenol-type molecular skeleton. The polyether polyol may be a random copolymer or a block copolymer. The bisphenol-type polyoxyalkylene modified product preferably has one or more alkylene oxides added to both ends of the bisphenol-type molecular skeleton. The bisphenol type is not particularly limited, and examples thereof include A-type, F-type, S-type, etc., with bisphenol A-type being preferred.

[0038] Examples of polyalkylene polyols include polybutadiene polyols, hydrogenated polybutadiene polyols, and hydrogenated polyisoprene polyols. Examples of polycarbonate polyols include polyhexamethylene carbonate polyol and polycyclohexanedimethylene carbonate polyol.

[0039] As the polyisocyanate compound serving as a raw material for 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 diphenylmethane diisocyanate, polymeric MDI, tolylene diisocyanate, and naphthalene-1,5-diisocyanate. Examples of aliphatic polyisocyanate compounds include hexamethylene diisocyanate, trimethylhexamethylene diisocyanate, lysine diisocyanate, norbornane diisocyanate, transcyclohexane-1,4-diisocyanate, isophorone diisocyanate, hydrogenated xylylene diisocyanate, hydrogenated diphenylmethane diisocyanate, cyclohexane diisocyanate, bis(isocyanatomethyl)cyclohexane, and dicyclohexylmethane diisocyanate. Of these, diphenylmethane diisocyanate and modified products thereof are preferred as the polyisocyanate compound, from the viewpoint of increasing adhesive strength after full curing. The polyisocyanate compounds may be used alone or in combination of two or more kinds.

[0040] The moisture-curable urethane resin is preferably one obtained using a polyol compound having a structure represented by the following formula (1): By using a polyol compound having a structure represented by the following formula (1), a curable resin composition having excellent adhesive properties and a cured product having flexibility and good elongation can be obtained, and the compatibility with the radical polymerizable compound is excellent. Furthermore, the storage modulus can be easily adjusted to fall within the desired range. Among these, polyether polyols made of a ring-opening polymerized compound of propylene glycol, a tetrahydrofuran (THF) compound, or a tetrahydrofuran compound having a substituent such as a methyl group are preferred. Furthermore, a ring-opening polymerized compound of a tetrahydrofuran compound is more preferred, and polytetramethylene ether glycol is particularly preferred.

[0041] [ka] In formula (1), R represents a hydrogen atom, a methyl group, or an ethyl group, l is an integer of 0 to 5, m is an integer of 1 to 500, and n is an integer of 1 to 10. l is preferably an integer of 0 to 4, m is preferably an integer of 50 to 200, and n is preferably an integer of 1 to 5. When l is 0, this means that the carbon bonded to R is directly bonded to oxygen. Among the above, the sum of n and l is more preferably 1 or more, and further preferably 3 to 6. Furthermore, R is more preferably a hydrogen atom or a methyl group, and particularly preferably a hydrogen atom.

[0042] 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 per molecule, or may have two or more hydrolyzable silyl groups per molecule, and it is particularly preferred that the resin has hydrolyzable silyl groups at both ends of the main chain of the molecule. The hydrolyzable silyl group-containing resin does not include those having an isocyanate group.

[0043] The hydrolyzable silyl group is represented by the following formula (2). [ka] In formula (2), R 1 each independently represents an optionally substituted alkyl group having 1 to 20 carbon atoms, an aryl group having 6 to 20 carbon atoms, an aralkyl group having 7 to 20 carbon atoms, or -OSiR 2 3(R 2 are each independently a hydrocarbon group having 1 to 20 carbon atoms. In formula (2), X is each independently a hydroxy group or a hydrolyzable group. In formula (2), a is an integer of 1 to 3.

[0044] The hydrolyzable group is not particularly limited, and examples thereof include a halogen atom, an alkoxy group, an alkenyloxy group, an aryloxy group, an acyloxy group, a ketoximate group, an amino group, an amide group, an acid amide group, an aminooxy group, and a mercapto group. Among these, a halogen atom, an alkoxy group, an alkenyloxy group, and an acyloxy group are preferred because of their high activity. Furthermore, alkoxy groups such as a methoxy group and an ethoxy group are more preferred because of their mild hydrolysis and ease of handling, and a methoxy group and an ethoxy group are even more preferred. Furthermore, from the viewpoint of safety, an ethoxy group and an isopropenoxy group are preferred because the compounds eliminated by the reaction are ethanol and acetone, respectively.

[0045] The number of the hydroxy groups or hydrolyzable groups bonded to one silicon atom may be in the range of 1 to 3. When two or more hydroxy groups or hydrolyzable groups are bonded to one silicon atom, these groups may be the same or different.

[0046] In terms of curability, a in the above formula (2) is preferably 2 or 3, and particularly preferably 3. In terms of storage stability, a is preferably 2. In addition, R in the above formula (2) 1 Examples of the alkyl group include alkyl groups such as methyl and ethyl groups, cycloalkyl groups such as cyclohexyl groups, aryl groups such as phenyl groups, aralkyl groups such as benzyl groups, trimethylsiloxy groups, chloromethyl groups, methoxymethyl groups, etc. Of these, a methyl group is preferred.

[0047] Examples of the hydrolyzable silyl group include a methyldimethoxysilyl group, a trimethoxysilyl group, a triethoxysilyl group, a tris(2-propenyloxy)silyl group, a triacetoxysilyl group, a (chloromethyl)dimethoxysilyl group, a (chloromethyl)diethoxysilyl group, a (dichloromethyl)dimethoxysilyl group, a (1-chloroethyl)dimethoxysilyl group, a (1-chloropropyl)dimethoxysilyl group, a (methoxymethyl)dimethoxysilyl group, and a (methoxymethyl)diethoxysilyl group. silyl group, (ethoxymethyl)dimethoxysilyl group, (1-methoxyethyl)dimethoxysilyl group, (aminomethyl)dimethoxysilyl group, (N,N-dimethylaminomethyl)dimethoxysilyl group, (N,N-diethylaminomethyl)dimethoxysilyl group, (N,N-diethylaminomethyl)diethoxysilyl group, (N-(2-aminoethyl)aminomethyl)dimethoxysilyl group, (acetoxymethyl)dimethoxysilyl group, (acetoxymethyl)diethoxysilyl group, and the like.

[0048] Examples of the hydrolyzable silyl group-containing resin include hydrolyzable silyl group-containing (meth)acrylic resins, organic polymers having a hydrolyzable silyl group at the molecular chain terminal or at the molecular chain terminal position, and hydrolyzable silyl group-containing polyurethane resins. The hydrolyzable silyl group-containing (meth)acrylic resin preferably has repeating units derived from a hydrolyzable silyl group-containing (meth)acrylic acid ester and / or a (meth)acrylic acid alkyl ester in the main chain.

[0049] Examples of hydrolyzable silyl group-containing (meth)acrylic acid esters include 3-(trimethoxysilyl)propyl (meth)acrylate, 3-(triethoxysilyl)propyl (meth)acrylate, 3-(methyldimethoxysilyl)propyl (meth)acrylate, 2-(trimethoxysilyl)ethyl (meth)acrylate, 2-(triethoxysilyl)ethyl (meth)acrylate, 2-(methyldimethoxysilyl)ethyl (meth)acrylate, trimethoxysilylmethyl (meth)acrylate, triethoxysilylmethyl (meth)acrylate, and (methyldimethoxysilyl)methyl (meth)acrylate. Examples of the (meth)acrylic acid alkyl ester include methyl (meth)acrylate, ethyl (meth)acrylate, n-propyl (meth)acrylate, isopropyl (meth)acrylate, n-butyl (meth)acrylate, isobutyl (meth)acrylate, tert-butyl (meth)acrylate, n-pentyl (meth)acrylate, n-hexyl (meth)acrylate, cyclohexyl (meth)acrylate, n-heptyl (meth)acrylate, n-octyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, n-nonyl (meth)acrylate, n-decyl (meth)acrylate, n-dodecyl (meth)acrylate, and stearyl (meth)acrylate.

[0050] Specific examples of methods for producing hydrolyzable silyl group-containing (meth)acrylic resins include the method for synthesizing hydrolyzable silicon group-containing (meth)acrylic acid ester polymers described in WO 2016 / 035718. The organic polymer having a hydrolyzable silyl group at or in a molecular chain terminal position has the hydrolyzable silyl group at at least one of the main chain terminal and the side chain terminal. The skeleton structure of the main chain is not particularly limited, and examples thereof include saturated hydrocarbon polymers, polyoxyalkylene polymers, and (meth)acrylic acid ester polymers.

[0051] Examples of the polyoxyalkylene polymer include polymers having a polyoxyethylene structure, a polyoxypropylene structure, a polyoxybutylene structure, a polyoxytetramethylene structure, a polyoxyethylene-polyoxypropylene copolymer structure, and a polyoxypropylene-polyoxybutylene copolymer structure. Specific examples of methods for producing organic polymers having hydrolyzable silyl groups at or in the molecular chain terminals include the method for synthesizing organic polymers having crosslinkable silyl groups only at or in the molecular chain terminals described in WO 2016 / 035718. Other methods for producing organic polymers having hydrolyzable silyl groups at or in the molecular chain terminals include the method for synthesizing reactive silicon group-containing polyoxyalkylene polymers described in WO 2012 / 117902.

[0052] Examples of methods for producing the hydrolyzable silyl group-containing polyurethane resin include a method in which a polyol compound and a polyisocyanate compound are reacted with a silyl group-containing compound such as a silane coupling agent to produce a polyurethane resin. Specific examples include the method for synthesizing a urethane oligomer having a hydrolyzable silyl group described in JP 2017-48345 A.

[0053] Examples of the silane coupling agent include vinyltrichlorosilane, vinyltriethoxysilane, vinyltris(β-methoxyethoxy)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, and 3-isocyanatepropyltriethoxysilane. Among these, γ-mercaptopropyltrimethoxysilane, 3-isocyanatepropyltrimethoxysilane, and 3-isocyanatepropyltriethoxysilane are preferred. These silane coupling agents may be used alone or in combination of two or more.

[0054] 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. 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 from the viewpoint of reactivity with the isocyanate group, it is preferable to use a silane coupling agent having an amino group or a mercapto group. Preferred specific examples include N-(β-aminoethyl)-γ-aminopropyltrimethoxysilane, N-(β-aminoethyl)-γ-aminopropyltrimethyldimethoxysilane, N-phenyl-γ-aminopropyltrimethoxysilane, γ-mercaptopropyltrimethoxysilane, γ-aminopropyltrimethoxysilane, 3-isocyanatepropyltrimethoxysilane, etc.

[0055] 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, a (meth)acryloyl group is more preferable in terms of reactivity. 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.

[0056] The moisture-curable resin may be selected from the various resins described above and used alone or in combination of two or more. When two or more types are used in combination, for example, it is preferable to use two or more urethane resins in combination, and it is preferable to use a hydrolyzable silyl group-containing moisture-curable urethane resin in combination with the above-mentioned moisture-curable urethane resin having a urethane bond and an isocyanate group.

[0057] 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 30000. When the weight-average molecular weight is within this range, the storage modulus, viscosity, etc. of the curable composition can be easily adjusted to fall within the above-mentioned ranges. The weight-average molecular weight of the moisture-curable resin preferably has a lower limit of 2000 and an upper limit of 25000, an even more preferable lower limit of 2500, and an even more preferable upper limit of 20000. The weight-average molecular weight in this specification is a value determined by measuring with gel permeation chromatography (GPC) and converting it into polystyrene. An example of a column used for measuring the weight-average molecular weight converted into polystyrene by GPC is Shodex LF-804 (manufactured by Showa Denko KK). An example of a solvent used in GPC is tetrahydrofuran.

[0058] In the curable resin composition, the total content of the radical polymerizable compound and the moisture-curable resin is preferably 60 parts by mass or more, more preferably 75 parts by mass or more, and even more preferably 80 parts by mass or more, relative to 100 parts by mass of the curable resin composition. The total content may be 100 parts by mass or less, preferably 98 parts by mass or less, and even more preferably 95 parts by mass or less, relative to the total amount of the curable resin composition. By setting the total content of the radical polymerizable compound and the moisture-curable resin within a predetermined range, it becomes easier to adjust the aspect ratio, thickness change rate, etc., within the above-mentioned range. In the present invention, the curable resin composition may not contain a moisture-curable resin. In such a case, the total content means the content of the radical polymerizable compound alone.

[0059] When the curable resin composition contains a moisture-curable resin, the mass ratio of the moisture-curable resin to the radical polymerizable compound is preferably 0.3 or more and 6 or less, more preferably 0.5 or more and 4 or less, and more preferably 0.75 or more and 3 or less. In the present invention, by adjusting the blending amounts of the radical polymerizable compound and the moisture-curable resin within the above ranges, a certain hardness is imparted in the B-stage state, and the thickness change rate can be easily adjusted within the above range. In addition, moisture curing makes it easier to increase the adhesive strength at the time of full curing, and the storage modulus can also be easily adjusted within the desired range.

[0060] In the present invention, in order to reduce the storage modulus of the cured product as described above, it is preferable to include a component that reduces the elastic modulus in the cured product. Specific examples of such components include radical polymerizable compounds such as phenoxyalkyl (meth)acrylate, alkyl (meth)acrylate, furfuryl (meth)acrylate, and polyether acrylate urethane acrylate. Examples of moisture-curable resins include moisture-curable urethane resins derived from polyether polyols. In the present invention, it is preferable that either the radical polymerizable compound or the moisture-curable resin contains a component that reduces the elastic modulus, but both may also contain a component that reduces the elastic modulus.

[0061] (filler) The curable resin composition of the present invention preferably contains a filler. By containing a filler, the TI value and viscosity of the curable resin composition of the present invention can be easily adjusted to fall within the above-mentioned ranges. In addition, the shape retention after application is improved, and the aspect ratio can be increased. The filler may be in the form of particles. The primary particle diameter of the filler is preferably 1 nm or more and 100 nm or less. When the primary particle diameter of the filler is within this range, the coating properties of the resulting curable resin composition are good. In addition, the shape retention after coating is excellent, and the aspect ratio described above can be easily increased. The primary particle diameter of the filler is more preferably 3 nm or more and 80 nm or less, and even more preferably 5 nm or more and 50 nm or less. The primary particle size of the filler can be measured by dispersing the filler in a solvent (water, organic solvent, etc.) using a particle size distribution measuring device such as NICOMP 380ZLS (manufactured by PARTICLE SIZING SYSTEMS).

[0062] The filler is preferably an inorganic filler, such as silica, talc, titanium oxide, zinc oxide, alumina, calcium carbonate, etc. Among these, silica is preferred because the resulting light-and-moisture-curable resin composition has excellent ultraviolet transmittance.

[0063] The filler is preferably subjected to a hydrophobic surface treatment. The hydrophobic surface treatment improves the shape retention of the resulting curable resin composition after application, making it easier to increase the aspect ratio. Examples of hydrophobic surface treatments include silylation treatment, alkylation treatment, and epoxidation treatment. Among these, from the viewpoint of increasing the aspect ratio, silylation treatment is preferred, and trimethylsilylation treatment is more preferred.

[0064] Examples of methods for hydrophobically treating the filler include a method of treating the surface of the filler with a surface treating agent such as a silane coupling agent. For example, the trimethylsilylated silica can be prepared by synthesizing silica by a method such as a sol-gel method, and then spraying hexamethyldisilazane onto the fluidized silica; or by adding silica to an organic solvent such as alcohol or toluene, adding hexamethyldisilazane and water, and then evaporating and drying the water and organic solvent in an evaporator.

[0065] The content of the filler is, for example, 5 parts by mass or more, preferably 8 parts by mass or more, relative to 100 parts by mass of the curable resin composition. By using 8 parts by mass or more, it is possible to use the above-mentioned low-viscosity radical polymerizable compound or moisture-curable resin from the viewpoint of workability and application property, while also improving shape stability after application and facilitating a large aspect ratio. From these viewpoints, the content of the filler is preferably 9 parts by mass or more, more preferably 10 parts by mass or more. Furthermore, from the viewpoint of coatability, adhesiveness, etc., the content of the filler is preferably 25 parts by mass or less, more preferably 20 parts by mass or less, and even more preferably 16 parts by mass or less, per 100 parts by mass of the curable resin composition. The fillers may be used alone or in combination of two or more.

[0066] (Photoradical polymerization initiator) The curable resin composition of the present invention preferably contains a photoradical polymerization initiator to ensure photocurability. Examples of photoradical polymerization initiators include benzophenone-based compounds, acetophenone-based compounds such as α-aminoalkylphenones and α-hydroxyalkylphenones, acylphosphine oxide-based compounds, titanocene-based compounds, oxime ester-based compounds, benzoin ether-based compounds, and thioxanthone. Among these, acetophenone-based compounds are preferred, and α-aminoalkylphenones are more preferred, from the viewpoint of easily adjusting the tack value and storage modulus within a predetermined range. Among the above-mentioned photoradical polymerization initiators, commercially available ones include, for example, IRGACURE184, IRGACURE369, IRGACURE379, IRGACURE379EG, IRGACURE651, IRGACURE784, IRGACURE819, IRGACURE907, IRGACURE2959, IRGACURE OXE01, Lucirin TPO (all manufactured by BASF), benzoin methyl ether, benzoin ethyl ether, and benzoin isopropyl ether (all manufactured by Tokyo Chemical Industry Co., Ltd.).

[0067] The content of the photoradical polymerization initiator in the curable resin composition is preferably 0.01 to 10 parts by mass, more preferably 0.5 to 5 parts by mass, relative to 100 parts by mass of the radical polymerizable compound. By ensuring that the content of the photoradical polymerization initiator is within this range, the resulting curable resin composition will have excellent photocurability and storage stability. Furthermore, by ensuring that the content is within the above range, the photoradical polymerization compound is appropriately cured, making it easier to adjust the storage modulus, aspect ratio, and thickness change rate described above to within the specified ranges.

[0068] (Moisture cure catalyst) The curable resin composition may contain a moisture-cure-accelerating catalyst that accelerates the moisture-cure reaction of the moisture-curable resin. By using the moisture-cure-accelerating catalyst, the curable resin composition can have better moisture curability and higher adhesive strength. Specific examples of moisture-cure-accelerating catalysts that can be used include tin compounds such as di-n-butyltin dilaurate, di-n-butyltin diacetate, and tin octoate; amine compounds such as triethylamine, U-CAT651M (manufactured by San-Apro Co., Ltd.), U-CAT660M (manufactured by San-Apro Co., Ltd.), U-CAT2041 (manufactured by San-Apro Co., Ltd.), 1,4-diazabicyclo[2.2.2]octane, and 2,6,7-trimethyl-1,4-diazabicyclo[2.2.2]octane; zinc compounds such as zinc octoate and zinc naphthenate; zirconium tetraacetylacetonate, copper naphthenate, and cobalt naphthenate. The content of the moisture-cure-accelerating catalyst is preferably 0.01 to 10 parts by mass, more preferably 0.1 to 7 parts by mass, relative to 100 parts by mass of the curable resin composition. When the content of the moisture-cure-accelerating catalyst is within this range, the effect of accelerating the moisture-cure reaction is excellent without deteriorating the storage stability of the curable resin composition.

[0069] (coupling agent) The curable resin composition may contain a coupling agent. By containing a coupling agent, adhesive strength is easily improved. Examples of coupling agents include silane coupling agents, titanate coupling agents, and zirconate coupling agents. Among them, silane coupling agents are preferred because of their excellent effect of improving adhesiveness. The above coupling agents may be used alone or in combination of two or more. The content of the coupling agent is preferably 0.05 parts by mass or more and 5 parts by mass or less, and more preferably 0.2 parts by mass or more and 3 parts by mass or less, relative to 100 parts by mass of the curable resin composition. By setting the content of the coupling agent within these ranges, adhesive strength can be improved without affecting various physical properties. In addition to the components described above, the curable resin composition may contain other additives such as wax particles, ionic liquid, colorant, foamed particles, expanded particles, and reactive diluents.

[0070] The curable resin composition of the present invention may be diluted with a solvent, if 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, i.e., the parts by mass excluding the solvent.

[0071] The curable resin composition of the present invention can be produced by mixing a radical polymerizable compound, a moisture-curable resin, and other additives, such as a photoradical polymerization initiator and a filler, which are added as needed, using a mixer. Examples of the mixer include a homodisper, a homomixer, a universal mixer, a planetary mixer (planetary stirring device), a kneader, and a three-roll mill.

[0072] [Method of using the curable resin composition] The curable resin composition of the present invention is cured and used as a cured product. The curable resin composition of the present invention is photocured at least by light irradiation. The curable resin composition of the present invention can bond the adherends by, for example, being placed between the adherends and cured. In this case, it is preferable to apply the curable resin composition to one of the adherends, and then overlap the other adherend with the applied curable resin composition interposed therebetween.

[0073] In the case of a photo-moisture-curing type, it is preferable to photo-cure it by irradiating it with light to, for example, bring it to a B-stage state (semi-cured state), and then further cure it by moisture to fully cure it. Here, when a photo-moisture-curing curable resin composition is placed between adherends and the adherends are bonded together, it is applied to one of the adherends, and then photo-cured by irradiating it with light to, for example, bring it to a B-stage state. The other adherend is then placed on top of the photo-cured curable resin composition, and the adherends are temporarily bonded with an appropriate adhesive strength (initial adhesive strength). Thereafter, the B-stage curable resin composition is fully cured by curing the moisture-curable resin with moisture, and the adherends layered together via the curable resin composition are bonded with sufficient adhesive strength.

[0074] The curable resin composition is preferably applied to an adherend using a dispenser, including, but not limited to, an air dispenser, a jet dispenser, a mono-pump dispenser, a screw dispenser, and a hand gun dispenser. The light to be irradiated during photocuring is not particularly limited as long as it is light that cures the radical polymerizable compound, but ultraviolet light is preferred. When the curable resin composition is fully cured by moisture, it may be left in the atmosphere for a predetermined period of time.

[0075] 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 components constituting electronic devices. Examples of various components constituting electronic devices 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 metal, glass, plastic, or the like. The shape of the adherend is not particularly limited, and examples thereof include a film, sheet, plate, panel, tray, rod, box, or housing.

[0076] 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 assembly. The assembly thus obtained comprises 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, at least one electronic component is attached to each of the first and second substrates.

[0077] The curable resin composition of the present invention is preferably used in narrow-frame applications. For example, in various mobile devices with display elements, such as mobile phones such as smartphones and portable game consoles, an adhesive is applied to a base having a narrow rectangular frame (i.e., a narrow frame), and a display panel, a touch panel, or the like is attached via the adhesive. In the present invention, the curable resin composition is used as the adhesive. Furthermore, the curable resin composition of the present invention is preferably used in semiconductor chip applications, for example, to bond semiconductor chips together.

[0078] In applications such as semiconductor chips and narrow frame applications, adhesives must be applied in narrow widths of, for example, 0.2 to 2 mm, preferably 0.3 to 1.0 mm. The curable resin composition of the present invention, possessing the various properties (TI value, viscosity, etc.) described above, enables application in such narrow widths. Furthermore, even when applied in narrow widths, satisfying the first requirement reduces voids between the curable resin composition and the adherend, making peeling of the adherend less likely to occur. Furthermore, satisfying the second requirement prevents the curable resin composition from changing significantly in thickness even when a load is applied, making it possible to maintain a constant gap between the adherends. [Example]

[0079] The present invention will be explained in more detail by way of examples, but the present invention is not limited to these examples in any way.

[0080] In the present examples, the measurements and evaluations of various physical properties were carried out as follows. <Viscosity and TI value> The viscosity was measured using a cone-plate viscometer (trade name TVE-35, manufactured by Toki Sangyo Co., Ltd.) at 1 rpm and 25° C. The TI value was calculated by dividing the viscosity measured using the same cone-plate viscometer at 25° C. and 1 rpm by the viscosity measured at 25° C. and 10 rpm.

[0081] <Storage modulus> The curable resin composition is poured into a Teflon (registered trademark) mold having a width of 3 mm, a length of 30 mm, and a thickness of 1 mm, and cured to obtain a cured product. The curable resin composition is cured using a mercury lamp at 3000 mJ / cm. 2 The composition was then exposed to light for photo-curing, and then left to stand for 3 days in an environment of 23°C and 50% RH for moisture curing. The dynamic viscoelasticity of the obtained cured product was measured in the temperature range of -100°C to 150°C using a dynamic viscoelasticity measuring device (manufactured by IT Measurement Control Co., Ltd., product name "DVA-200"), and the storage modulus at room temperature (25°C) was determined. The measurement conditions were: deformation mode: tensile, set strain: 1%, measurement frequency: 1 Hz, and heating rate: 5°C / min.

[0082] <Aspect ratio> Resin heated to 50°C was applied to a polycarbonate substrate (product name "Iupilon GSH2010LR-Y082 GF10%" manufactured by Mitsubishi Engineering Plastics Corporation) using an air dispenser ("SHOTMASTER200DS" manufactured by Musashi Engineering Co., Ltd.). The application conditions were a clearance of 1.0 mm, a nozzle inner diameter of 0.4 mm, a discharge pressure of 0.38 MPa, a speed of 1.0 mm / sec, and an application length of 25 mm. Five seconds after application was completed, the curable resin composition was exposed to 1000mJ / cm 365nm ultraviolet light from an LED lamp (trade name "EXECURE H-1VC2", manufactured by HOYA CANDEO OPTRONICS, head unit "H-1VH-01" was used). 2 After leaving the specimen in an environment of 25°C and 50% RH for 16 hours, the width (maximum width) and height (maximum height) of the cured resin were measured using a laser microscope (product name "VK-X200", manufactured by Keyence Corporation), and the ratio of the height to the width of the cured resin was calculated as the aspect ratio.

[0083] <Thickness change rate> An aluminum substrate (length 72 mm, width 52 mm, thickness 2 mm) was prepared, and a curable resin composition was applied to one side of the substrate along the entire periphery of the substrate. The curable resin composition was applied to a line width of 1 mm and a thickness of 0.2 mm. Next, 365 nm ultraviolet light was irradiated onto the applied curable resin composition using an LED lamp at 1000 mJ / cm. 2 The composition was then photocured by irradiation. A glass substrate of the same size as the aluminum substrate was then placed on top of the photocured curable resin composition in an environment of 25°C, and a 280 g weight was applied to apply a load of 0.03 MPa to measure the thickness change rate. The thickness of the curable resin composition before the glass substrate was placed on top was designated A, and the thickness of the curable resin composition 10 seconds after the glass substrate was placed on top and the 280 g weight was applied was designated B. The thickness change rate was measured by (AB) / A x 100. Furthermore, the gap formability was evaluated as follows: a thickness change rate of 30% or less was designated AA; a thickness change rate of more than 30% and less than 40% was designated A; and a thickness change rate of more than 40% was designated B. The thickness of the curable resin composition was measured by observation using a digital microscope (trade name "KH-7800", manufactured by Hirox Corporation).

[0084] <Vacancies when bonded> An aluminum substrate (length 72 mm, width 52 mm, thickness 2 mm) was prepared, and the curable resin composition was applied to the substrate so that the outer circumference was 70 mm x 48 mm. The curable resin composition was applied so that the line width was 0.4 mm. Next, 365 nm ultraviolet light was irradiated onto the applied curable resin composition using an LED lamp at 1000 mJ / cm. 2 The test piece was irradiated with light and photocured. Then, a glass substrate of the same size as the aluminum substrate was placed on top of the photocured curable resin composition, and a 200 g weight was applied for 10 seconds. The test piece was observed with a digital microscope (product name "KH-7800", manufactured by Hirox Corporation). If at least one cavity was found, it was rated B, and if not, it was rated A.

[0085] Moisture-curable urethane resin A was prepared according to Synthesis Example 1 below. [Synthesis Example 1] 100 parts by mass of polytetramethylene ether glycol (manufactured by Mitsubishi Chemical Corporation, trade name "PTMG-2000") as a polyol compound 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, and 26.5 parts by mass of diphenylmethane diisocyanate (manufactured by Nisso Shoji Co., Ltd., trade name "Pure MDI") as a polyisocyanate compound was added, followed by stirring at 80°C for 3 hours to allow the reaction to occur, yielding a moisture-curable urethane resin (weight average molecular weight 2700).

[0086] Moisture-curable urethane resin B was prepared according to Synthesis Example 2 below. [Synthesis Example 2] 100 parts by mass of polycaprolactone (manufactured by Daicel Corporation, trade name "Placcel H1P") as a polyol compound 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, and 5.3 parts by mass of diphenylmethane diisocyanate (manufactured by Nisso Shoji Co., Ltd., trade name "Pure MDI") as a polyisocyanate compound was added, followed by stirring at 80°C for 3 hours to allow the reaction to occur, yielding a moisture-curable urethane resin (weight average molecular weight 12,000).

[0087] The components other than the moisture-curable urethane resin used in each of the Examples and Comparative Examples were as follows: Monofunctional acrylate 1: phenoxyethyl acrylate (Kyoeisha Chemical Co., Ltd., "Light Acrylate PO-A") Monofunctional acrylate 2: isobornyl acrylate (manufactured by Daicel-Allnex Co., Ltd., "IBOAB") Monofunctional acrylate 3: N-acryloyloxyethylhexahydrophthalimide (manufactured by Toagosei Co., Ltd., "Aronix M-140") Photoradical polymerization initiator: 2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)-butanone-1 (BASF, "IRGACURE369") Moisture cure accelerator catalyst: U-CAT660M (San-Apro Co., Ltd.) Filler: Trimethylsilylated silica (Nippon Aerosil Co., Ltd., "R812", primary particle size 7 nm)

[0088] [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 stirring device (Thinky Corporation, "Awatori Rentaro"), and then uniformly mixed at a temperature of 50°C using a ceramic three-roll mill to obtain the curable resin compositions of Examples 1 to 6 and Comparative Examples 1 to 3.

[0089] [Table 1]

[0090] As shown in Examples 1 to 6 above, the curable resin composition has an aspect ratio of 0.6 or more after application and curing, which reduces voids during bonding and makes it less likely to peel off. Furthermore, even when a load is applied, the thickness change rate is small, so it is easy to form a certain gap between adherends despite the large aspect ratio. In contrast, in Comparative Examples 1 to 3, the curable resin compositions had a small aspect ratio after application and curing, so that voids could not be reduced during lamination, and peeling was likely to occur.

Claims

1. A curable resin composition comprising a radical polymerizable compound, a moisture-curable urethane resin, a photoradical polymerization initiator, and a filler, the total content of the radical polymerizable compound and the moisture-curable urethane resin is 60 parts by mass or more and 91 parts by mass or less per 100 parts by mass of the curable resin composition; a mass ratio of the moisture-curable urethane resin to the radical polymerizable compound is 1 or more and 2.5 or less; the content of the filler is 5 parts by mass or more relative to 100 parts by mass of the curable resin composition, The curable resin composition was applied using an air dispenser, and then irradiated with 365 nm ultraviolet light at 1000 mJ / cm using an LED lamp. ２ After 16 hours of exposure to light at 25°C and 50% RH, the ratio of the coating height to the line width is 0.6 or more, and The LED lamp emits 365 nm ultraviolet light at 1000 mJ / cm ２ A curable resin composition, wherein when a load of 0.03 MPa is applied after irradiation, the rate of change in thickness before and after the load is 40% or less.

2. the storage modulus of the cured product of the curable resin composition is 500 MPa or less; The curable resin composition according to claim 1, wherein the storage modulus is determined by measuring a cured product obtained by irradiating the curable resin composition with 3000 mJ / cm 2 using a mercury lamp and then leaving the cured product in an environment of 23°C and 50% RH for 3 days.

3. 3. The curable resin composition according to claim 1, wherein the viscosity measured using a cone-plate viscometer at 25°C and 1 rpm is 100 Pa·s or more and 1000 Pa·s or less.

4. a thixotropy index of 1.7 or more and 5.0 or less; The curable resin composition according to any one of claims 1 to 3, wherein the thixotropy index is a value obtained by dividing a viscosity measured using a cone-plate viscometer at 25°C and 1 rpm by a viscosity measured using a cone-plate viscometer at 25°C and 10 rpm.

5. The curable resin composition according to any one of claims 1 to 4, which is used as an adhesive for electronic devices.

6. A cured product of the curable resin composition according to any one of claims 1 to 5.

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