Resin composition and cured resin

Abstract

To provide a resin composition and a resin cured product containing an epoxy resin, which are expected to exhibit high peel strength at low temperature.SOLUTION: Provided is a resin composition, comprising an epoxy resin (A) and a polymer (B), wherein the glass transition temperature of the polymer (B) is -90°C or less. Preferable is a resin composition, further comprising a polymer (C) having a first polymer segment, an SP value of which has a difference of 1.5 or less from the SP value of the polymer (A) and a second polymer segment, an SP value of which has a difference of 1.0 or less from the SP value of the polymer (B).SELECTED DRAWING: None

Description

Technical Field

[0001] The present invention relates to a resin composition and a cured resin, and particularly to a resin composition and a cured resin containing an epoxy resin.

Background Art

[0002] Resin compositions are preferably used as adhesives and the like, and such adhesives are used in various applications. On the other hand, epoxy resins have the problem of being hard and brittle. Therefore, as a method for improving the toughness of epoxy resins, a method of adding a specific polymer is known. For example, Patent Document 1 describes a resin composition containing an epoxy resin and a polybutadiene having hydroxyl groups at both ends for use as a sealing agent. Patent Document 2 describes an epoxy resin composition containing an epoxy resin and a core-shell rubber for use mainly as a structural adhesive in vehicle manufacturing.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0004] When attempting to use such a resin composition containing an epoxy resin as a structural adhesive for vehicles, it is necessary to consider the external environment. For example, in a harsh environment below freezing point, it is necessary to have high peel strength. However, according to the study by the present inventor, when attempting to use the epoxy resin-containing resin composition described in Patent Document 1 or 2 as an adhesive in a harsh environment below freezing point, it has been found that the peel strength may not be sufficient. Therefore, the present invention aims to improve the peel strength at low temperatures.

Means for Solving the Problems

[0005] As a result of intensive studies, the present inventors have found that the above problems can be solved by using an epoxy resin and a polymer having a specific glass transition temperature in combination, and have thus achieved the present invention. That is, the gist of the present invention is as follows.

[0006] [1] A resin composition containing an epoxy resin (A) and a polymer (B), wherein the glass transition temperature of the polymer (B) is -90°C or lower. [2] The resin composition according to [1], wherein the polymer (B) is a liquid compound. [3] The resin composition according to [1] or [2], wherein the polymer (B) contains 1,3-butadiene as a monomer unit. [4] The resin composition according to any one of [1] to [3], containing a polymer (C) having a first polymer segment with a difference from the SP value of the epoxy resin of 1.5 or less and a second polymer segment with a difference from the SP value of the polymer (B) of 1.0 or less. [5] The resin composition according to [4], wherein the SP value of the first polymer segment is larger than the SP value of the second polymer segment. [6] The resin composition according to [4] or [5], wherein the polymer (C) is a macromonomer copolymer. [7] The resin composition according to any one of [4] to [6], wherein the polymer (C) has (meth)acrylate as a constituent unit. [8] A resin cured product containing an epoxy resin (A), wherein the glass transition temperature determined as the peak value of tanδ in dynamic viscoelasticity measurement is -90°C or lower. [9] The resin cured product according to claim 8, further containing a polymer (B) having a glass transition temperature of -90°C or lower.

[10] The resin cured product according to [9], wherein the average domain size of the polymer (B) is 1000 nm or less.

[11] The resin cured product according to [9] or

[10] , wherein the polymer (B) contains 1,3-butadiene as a monomer unit.

[12] The resin cured product according to any one of [9] to

[11] , containing a polymer (C) having a first polymer segment with a difference from the SP value of the epoxy resin of 1.5 or less and a second polymer segment with a difference from the SP value of the polymer (B) of 1.0 or less.

[13] The resin cured product according to

[12] , wherein the SP value of the first polymer segment is greater than the SP value of the second polymer segment.

[14] The resin cured product according to

[12] or

[13] , wherein the polymer (C) is a macromonomer copolymer.

[15] The resin cured product according to any one of

[12] to

[14] , wherein the polymer (C) has a (meth)acrylate as a constitutional unit.

Advantages of the Invention

[0007] According to the present invention, it is possible to provide a resin composition and a resin cured product containing an epoxy resin that can be expected to have high peel strength at low temperatures.

Embodiments for Carrying Out the Invention

[0008] Hereinafter, this embodiment will be described in detail. Note that what is described below is one embodiment of the present invention, and the present invention is not limited to the following configuration.

[0009] <1. Resin Composition> The resin composition according to this embodiment has at least an epoxy resin (A) and a polymer (B) having a glass transition temperature of -90°C or lower. Note that the resin composition may further contain a polymer (C) and / or other components (D) as necessary. In addition, a curable resin composition can be prepared by adding a curing agent or a curing aid to the resin composition, or by blending the resin composition of the present invention with another curable resin composition.

[0010] <1-1. Epoxy Resin (A)> The epoxy resin (A) is a compound having an average epoxy equivalent of 300 g / equivalent or less and having 1.1 or more epoxy groups in the molecule, and known ones can be used.

[0011] Among these, the average epoxy equivalent of the epoxy resin (A) is preferably 150 g / equivalent or more, more preferably 160 g / equivalent or more, and particularly preferably 170 g / equivalent or more in order to improve the peel strength. On the other hand, although there is no particular limitation on the average epoxy equivalent of the epoxy resin (A), it is preferably 280 g / equivalent or less, and particularly preferably 250 g / equivalent or less. The epoxy equivalent of the epoxy resin (A) can be measured according to JIS K7236.

[0012] Examples of the epoxy resin (A) include bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol AD type epoxy resin, bisphenol E type epoxy resin, naphthalene type epoxy resin, biphenyl type epoxy resin, dicyclopentadiene type epoxy resin, phenol novolac type epoxy resin, alicyclic epoxy resin, and glycidylamine type epoxy resin. Further, modified epoxy resins such as rubber-modified epoxy resin, urethane-modified epoxy resin, and chelate-modified epoxy resin are also included. Furthermore, prepolymers of the above-mentioned epoxy resins, copolymers of the above-mentioned epoxy resins and other polymers such as polyether-modified epoxy resin and silicone-modified epoxy resin, and those in which a part of the above-mentioned epoxy resin is substituted with a reactive diluent having an epoxy group can also be mentioned.

[0013] Examples of the reactive diluent include monoglycidyl compounds such as resorcin diglycidyl ether, t-butylphenyl glycidyl ether, 2-ethylhexyl glycidyl ether, allyl glycidyl ether, phenyl glycidyl ether, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropylmethyldimethoxysilane, 1-(3-glycidoxypropyl)-1,1,3,3,3-pentamethylsiloxane, N-glycidyl-N,N-bis[3-(trimethoxysilyl)propyl]amine, and monocyclic epoxy compounds such as 2-(3,4)-epoxycyclohexyl)ethyltrimethoxysilane. The epoxy resin may be used alone or in combination of two or more.

[0014] Among these, it is preferable to select one or more from the group consisting of bisphenol A type epoxy resin and bisphenol F type epoxy resin as the epoxy resin (A).

[0015] The weight average molecular weight of the epoxy resin (A) is not particularly limited, but in order to improve the peel strength, it is preferably 250 or more, more preferably 300 or more, and particularly preferably 350 or more. On the other hand, in order to improve the operability, it is preferably 1000 or less, more preferably 700 or less, and particularly preferably 500 or less. The weight average molecular weight of the epoxy resin can be measured by gel permeation chromatography (GPC) using polystyrene as the reference resin.

[0016] The SP value of the epoxy resin (A) is not particularly limited, but in order to improve the peel strength, it is preferably 9.5 or more, more preferably 9.7 or more, and particularly preferably 9.8 or more. On the other hand, in order to improve the operability, it is preferably 12.0 or less, more preferably 11.5 or less, and particularly preferably 11.0 or less. In the present invention, the SP value means the SP value calculated by the Hoy method. Specifically, it is described in H.L. Hoy, J. Paint Tech., 42

[0540] , P76-118 (1970). It means the value calculated according to the loaded method. In addition, when the epoxy resin is an epoxy resin composed of a plurality of types, the SP value of the epoxy resin shall mean the value calculated by the following formula (1). S = Σ(Ni × Si) ··· (1) (In formula (1), S is the SP value of the epoxy resin, Ni is the molar fraction of epoxy resin i, and Si is the SP value of the single substance of epoxy resin i.)

[0017] <1-2. Polymer (B)> As described above, the resin composition according to the present embodiment contains a polymer (B) having a glass transition temperature of -90°C or lower. Generally, the cured product of an epoxy resin tends to be hard and brittle. Therefore, by adding a polymer (B) with a low glass transition temperature (Tg), toughness can be imparted to the cured product of the resin composition.

[0018] Specifically, the cured product of the epoxy resin-containing composition is assumed to be used as various adhesives, and some of them are assumed to be used in harsh environments below freezing point. Therefore, a high peel strength is required in an environment of approximately -40°C. Here, in order to modify the physical properties of the obtained cured product, a method of improving the peel strength by adding a component having a glass transition temperature of -40°C or lower to the epoxy resin-containing resin composition is common, but the effect of improving the peel strength is limited. As a result of intensive studies, the inventors have found that a high peel strength can be achieved by using a polymer having a glass transition temperature of -90°C or lower. Although this mechanism is not clear, if the glass transition temperature is -90°C or lower, it is considered that a large toughness can be imparted to the obtained cured product in an environment of approximately -40°C, and as a result, the peel strength is improved.

[0019] The glass transition temperature of the polymer (B) is preferably -90°C or lower, more preferably -92°C or lower, and particularly preferably -95°C or lower, because the peel strength under an environment of approximately -40°C is improved. On the other hand, for improving workability, it is preferably -200°C or higher, more preferably -150°C or higher, and particularly preferably -120°C or higher. When the glass transition temperature of the resin cured product obtained by curing the resin composition containing the polymer (B) is measured based on the method described in the examples below, one or more peaks are obtained. Among these, the temperature of the peak derived from the polymer (B) is regarded as the glass transition temperature of the polymer (B) in the resin composition.

[0020] The polymer (B) is preferably a liquid compound. When the polymer (B) is a liquid compound, since the peel strength at low temperatures is excellent, it preferably does not have a crosslinked structure. In the present invention, being a liquid compound means that the melt viscosity at 37°C is 0.01 Pa·s or more. Among them, the melt viscosity at 37°C is preferably 0.02 Pa·s or more, and particularly preferably 0.05 Pa·s or more. On the other hand, for improving workability, it is preferably 500 Pa·s or less, and particularly preferably 100 Pa·s or less. The melt viscosity at 37°C can be measured by an E-type viscometer.

[0021] There are no particular restrictions on the monomer units constituting the polymer (B), but preferably, vinyl compounds having 2 or more and 20 or less carbon atoms may be mentioned. For example, 1,3 - butadiene, isoprene, 1,3 - pentadiene, 2 - ethyl - 1,3 - butadiene, 2,3 - dimethylbutadiene, 2 - methylpentadiene, 4 - methylpentadiene, 2,4 - hexadiene, chloroprene, ethylene, propylene, acrylonitrile, etc. may be mentioned. Note that the polymer (B) may be a homopolymer or a copolymer. Among these, it is preferable that the polymer (B) contains 1,3 - butadiene as a monomer unit. When the polymer (B) is composed of a butadiene monomer, the ratio of the butadiene monomer to all the constituent units of the polymer (B) has no particular restrictions, but in order to improve the peel strength at low temperatures, it is preferably 20 mol% or more, and particularly preferably 50 mol% or more.

[0022] When the polymer (B) contains 1,3 - butadiene as a monomer unit, it is preferable that the polymer contains more cis - 1,4 structure because the glass transition temperature becomes lower. The ratio of the cis - 1,4 structure in the 1,3 - butadiene monomer units constituting the polymer (B) has no particular restrictions, but since the glass transition temperature is likely to be - 90°C or lower, it is preferably 30 mass% or more, more preferably 50 mass% or more, and particularly preferably 85 mass% or more. On the other hand, the upper limit is 100 mass%.

[0023] There are no particular restrictions on the weight - average molecular weight of the polymer (B), but in order to improve the peel strength, it is preferably 1000 or more, more preferably 2000 or more, and particularly preferably 3000 or more. On the other hand, the weight - average molecular weight of the polymer (B) is preferably 100000 or less, more preferably 70000 or less, and particularly preferably 50000 or less in order to improve the operability. Note that the weight - average molecular weight of the polymer (B) can be measured by gel permeation chromatography (GPC) using polystyrene as a reference resin.

[0024] The polymer (B) is not limited in chemical structure as long as its glass transition temperature is -90°C or lower. However, for the purpose of assisting the dispersion of the polymer (B) in the resin composition in a minute size, the polymer (B) may have a carboxyl group, a hydroxyl group, an epoxy group, an amino group, or the like.

[0025] In the resin composition, the ratio of the polymer (B) to 100 parts by mass of the epoxy resin (A) is not particularly limited. However, for improving the peel strength at low temperature, it is preferably 0.01 part by mass or more, more preferably 1 part by mass or more, and particularly preferably 1.5 parts by mass or more. On the other hand, for improving the peel strength at low temperature, it is preferably 100 parts by mass or less, more preferably 50 parts by mass or less, and particularly preferably 40 parts by mass or less. Further, the resin composition of the present invention may be used as a masterbatch when blending with other curable resin compositions.

[0026] The SP value of the polymer (B) is not particularly limited. However, for improving the peel strength, it is preferably 8.3 or more, more preferably 8.5 or more, and particularly preferably 8.7 or more. On the other hand, for improving the operability, it is preferably 9.5 or less, more preferably 9.3 or less, and particularly preferably 9.1 or less. The SP value of the polymer (B) can be calculated by the same method as the SP value of the above-described epoxy resin (A).

[0027] <1-3. Polymer (C)> The resin composition may further contain a polymer (C). The polymer (C) is a polymer composed of a monomer composition different from that of the polymer (B). Among them, the polymer (C) is a polymer having two or more polymer segments, that is, the polymer (C) is a polymer having at least a first polymer segment and a second polymer segment. The polymer is preferably a block copolymer or a graft copolymer. In the present invention, polymer segments obtained by a polymerization reaction under the same conditions of monomer type and charging ratio are collectively referred to as one polymer segment, and polymer segments obtained under conditions with different monomers and charging ratios are respectively referred to as different polymer segments. Note that the monomer constituting one polymer segment may be one type or two or more types.

[0028] As a method for synthesizing a block copolymer, a known method can be used. For example, a living anionic polymerization method using a metal catalyst and a Lewis base, a radical polymerization (NMP) method via a nitroxide, an atom transfer radical polymerization (ATRP) method, a reversible addition-fragmentation chain transfer (RAFT) polymerization method, a ring-opening polymerization method, a method using transesterification, a method using a macromonomer, etc. can be mentioned.

[0029] As a method for synthesizing a graft copolymer, a known method can be used. For example, a method using a macromonomer, a method using a hydrogen abstraction reaction from a polymer chain, etc. can be mentioned.

[0030] Further, the polymer (C) is preferably a macromonomer copolymer containing at least a structural unit derived from a macromonomer. That is, in the polymer (C), one of the first polymer segment and the second polymer segment is a structural unit derived from the macromonomer (c), and the other is preferably a copolymer containing a structural unit derived from a vinyl monomer (x) copolymerizable with the macromonomer (c). In the present invention, the macromonomer means a polymer having a polymerization degree of 2 or more and having a radically polymerizable group and / or an addition-reactive functional group. As the monomers constituting the first polymer segment and the second polymer segment, that is, the monomers constituting the macromonomer and the vinyl monomer (x), the monomers described later can be used.

[0031] Further, the polymer (C) preferably has a first polymer segment with a difference in SP value from the epoxy resin (A) of 1.5 or less, and a second polymer segment with a difference in SP value from the polymer (B) of 1.0 or less. That is, it is preferable that the difference between the SP value of the first polymer segment and the SP value of the epoxy resin (A) is 1.5 or less, and the difference between the SP value of the second polymer segment and the SP value of the polymer (B) is 1.0 or less. The SP values of the first polymer segment and the second polymer segment can be calculated by the same method as the SP value of the above-mentioned epoxy resin (A). Generally, the polymer (B) tends to be difficult to disperse in the epoxy resin. However, if the relationship between the SP values of the epoxy resin (A), the polymer (B), and the polymer (C) is within the above range, the polymer (C) will have an appropriate affinity with each of the epoxy resin (A) and the polymer (B). As a result, it is considered that the polymer (B) is well dispersed in the epoxy resin (A), and better low-temperature peel strength characteristics can be obtained. In this case, in order to further improve the dispersibility of the polymer (B) in the epoxy resin (A), it is preferable that the SP value of the first polymer segment is larger than the SP value of the second polymer segment.

[0032] Among the above, the difference between the SP value of the first polymer segment and the SP value of the epoxy resin is more preferably 1.3 or less, particularly preferably 1.0 or less, in order to further improve the dispersion of the polymer (B) in the epoxy resin. On the other hand, there is no particular lower limit.

[0033] Similarly, the difference between the SP value of the second polymer segment and the SP value of the polymer (B) is preferably 0.9 or less, particularly preferably 0.7 or less, in order to further improve the dispersion of the polymer (B) in the epoxy resin. On the other hand, there is no particular lower limit.

[0034] The SP value of the first polymer segment is not particularly limited, but in order for polymer (C) to be well dispersed in the epoxy resin, it is preferably 9.4 or more, more preferably 9.5 or more, and particularly preferably 9.6 or more. On the other hand, in order for polymer (C) to be well dispersed in the epoxy resin, it is preferably 11.5 or less, more preferably 11.0 or less, and particularly preferably 10.8 or less.

[0035] The SP value of the second polymer segment is not particularly limited, but in order for polymer (B) to be well dispersed in the epoxy resin, it is preferably 10.0 or less, more preferably 9.8 or less, and particularly preferably 9.6 or less. On the other hand, in order for polymer (B) to be well dispersed in the epoxy resin, it is preferably 8.5 or more, more preferably 8.7 or more, and particularly preferably 8.9 or more.

[0036] The difference between the SP value of the first polymer segment and the SP value of polymer (B) is not particularly limited, but in order to improve the dispersibility of polymer (B), it is preferably 0.3 or more, and more preferably 0.5 or more. Also, in order to improve the peel strength, it is preferably 3.0 or less, and more preferably 2.5 or less.

[0037] The difference between the SP value of the second polymer segment and the SP value of epoxy resin (A) is not particularly limited, but in order to improve the dispersibility of polymer (B), it is preferably 0.3 or more, and more preferably 0.5 or more. Also, in order to improve the peel strength, it is preferably 3.0 or less, and more preferably 2.5 or less.

[0038] The monomers constituting the first polymer segment and the second polymer segment are not particularly limited, and examples thereof include vinyl monomers as described below. That is, as the monomers constituting the above-mentioned macromonomer (c) and the vinyl monomer (x), the vinyl monomers described below can be mentioned.

[0039] There are no particular restrictions on the vinyl monomer. For example, vinyl monomers having an ester group, a hydroxyl group, a carboxyl group, an acid anhydride, an amide group, an epoxy group, an amino group, a silyl group, an isocyanato group, a halogen atom, or a poly(alkylene oxide) group can be mentioned. Note that the vinyl monomer may have only one of these groups or two or more of them. Also, it may be polyfunctional.

[0040] There are no particular restrictions on the vinyl monomer having an ester group, and examples thereof include (meth)acrylate, maleic acid derivatives having an ester group, vinyl acetate, vinyl propionate, and the like.

[0041] Examples of the (meth)acrylic acid ester include methyl (meth)acrylate, ethyl (meth)acrylate, n-propyl (meth)acrylate, isopropyl (meth)acrylate, n-butyl (meth)acrylate, isobutyl (meth)acrylate, t-butyl (meth)acrylate, isoamyl (meth)acrylate, hexyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, octyl (meth)acrylate, isooctyl (meth)acrylate, nonyl (meth)acrylate, isononyl (meth)acrylate, decyl (meth)acrylate, isodecyl (meth)acrylate, lauryl (meth)acrylate, hexadecyl (meth)acrylate, stearyl (meth)acrylate, isostearyl (meth)acrylate, phenyl (meth)acrylate, benzyl (meth)acrylate, cyclohexyl (meth)acrylate, tetrahydrofurfuryl (meth)acrylate, isobornyl (meth)acrylate, 3,5,5-trimethylcyclohexyl (meth)acrylate, dicyclopentanyl (meth)acrylate, dicyclopentenyl (meth)acrylate, dicyclopentenyl oxyethyl (meth)acrylate, terpene acrylate and its derivatives, hydrogenated rosin acrylate and its derivatives, docosyl (meth)acrylate, ethylene glycol di(meth)acrylate, 1,3-butylene glycol di(meth)acrylate, 1,4-butanediol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, diethylene glycol di(meth)acrylate, triethylene glycol di(meth)acrylate, tetraethylene glycol di(meth)acrylate, polyethylene glycol di(meth)acrylate, tripropylene glycol di(meth)acrylate, neopentyl glycol di(meth)acrylate, 1,9-nonanediol di(meth)acrylate, 1,10-decanediol di(meth)acrylate, trimethylolpropane tri(meth)acrylate, pentaerythritol tetra(meth)acrylate, dipentaerythritol hexa(meth)acrylate, allyl (meth)acrylate, (3-ethyloxetane-3-yl)methyl acrylate, 2-methyl-2-ethyl-1,(3 - dioxolan - 4 - yl)methyl acrylate, cyclic trimethylolpropane formal acrylate, methoxyethyl (meth)acrylate, ethoxyethyl (meth)acrylate, n - butoxyethyl (meth)acrylate, isobutoxyethyl (meth)acrylate, t - butoxyethyl (meth)acrylate, ethoxyethoxyethyl (meth)acrylate, phenoxyethyl (meth)acrylate, nonylphenoxyethyl (meth)acrylate, 3 - methoxybutyl (meth)acrylate, acetoxyethyl (meth)acrylate, "Placcel FM" (a caprolactone - added monomer manufactured by Daicel Chemical Industries, Ltd., trade name), "Blemmer PME - 100" (methoxypolyethylene glycol methacrylate (with a chain of ethylene glycol being 2) manufactured by NOF Corporation, trade name), "Blemmer PME - 200" (methoxypolyethylene glycol methacrylate (with a chain of ethylene glycol being 4) manufactured by NOF Corporation, trade name), "Blemmer PME - 400" (methoxypolyethylene glycol methacrylate (with a chain of ethylene glycol being 9) manufactured by NOF Corporation, trade name), "Blemmer 50POEP - 800B" (octoxypolyethylene glycol - polypropylene glycol - methacrylate (with a chain of ethylene glycol being 8 and a chain of propylene glycol being 6) manufactured by NOF Corporation, trade name), "Blemmer 20ANEP - 600" (nonylphenoxy(ethylene glycol - polypropylene glycol)monoacrylate manufactured by NOF Corporation, trade name), "Blemmer AME - 100" (manufactured by NOF Corporation, trade name), "Blemmer AME - 200" (manufactured by NOF Corporation, trade name) and "Blemmer 50AOEP - 800B" (manufactured by NOF Corporation, trade name), 1 - butoxyethyl (meth)acrylate, 1-(2 - ethylhexyloxy)ethyl (meth)acrylate, 1-(cyclohexyloxy)ethyl methacrylate), 2 - tetrahydropyranyl (meth)acrylate may be mentioned., Examples of maleic acid derivatives having an ester group include dimethyl maleate, dibutyl maleate, dimethyl fumarate, dibutyl fumarate, dipaperfluorocyclohexyl fumarate, diallyl maleate.,

[0042] There is no particular limitation on the vinyl monomer having a hydroxyl group, and examples thereof include (meth)acrylic acid esters having a hydroxyl group. Examples of the (meth)acrylic acid ester having a hydroxyl group include 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 2-hydroxybutyl (meth)acrylate, 3-hydroxybutyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, and glycerol (meth)acrylate.

[0043] There is no particular limitation on the vinyl monomer having a carboxyl group, and examples thereof include (meth)acrylic acid, fumaric acid, maleic acid, itaconic acid, (meth)acrylic acid esters having a carboxyl group, fumaric acid derivatives having a carboxyl group, maleic acid derivatives having a carboxyl group, and itaconic acid having a carboxyl group. Examples of the (meth)acrylic acid ester having a carboxyl group include 2-(meth)acryloyloxyethyl hexahydrophthalic acid, 2-(meth)acryloyloxypropyl hexahydrophthalic acid, 2-(meth)acryloyloxyethyl phthalic acid, 2-(meth)acryloyloxypropyl phthalic acid, 2-(meth)acryloyloxyethyl maleic acid, 2-(meth)acryloyloxypropyl maleic acid, 2-(meth)acryloyloxyethyl succinic acid, and 2-(meth)acryloyloxypropyl succinic acid. Examples of the fumaric acid derivative having a carboxyl group include monomethyl fumarate, monoethyl fumarate, monobutyl fumarate, monooctyl fumarate, and monoethyl citraconate. Examples of the maleic acid derivative having a carboxyl group include monomethyl maleate, monoethyl maleate, and monooctyl maleate. Examples of the itaconic acid derivative having a carboxyl group include monomethyl itaconate, monoethyl itaconate, monobutyl itaconate, and monooctyl itaconate.

[0044] The vinyl monomer having an acid anhydride is not particularly limited, and examples thereof include maleic acid derivatives having an acid anhydride and itaconic acid derivatives having an acid anhydride. Examples of the maleic acid derivative having an acid anhydride include maleic anhydride. Examples of the itaconic acid derivative having an acid anhydride include itaconic anhydride.

[0045] The vinyl monomer having an amide group is not particularly limited, and examples thereof include (meth)acrylamide, (meth)acryloylmorpholine, N-vinylpyrrolidone, N-vinyl-ε-caprolactam, maleimide, N-vinylacetamide, maleic amide, and the like. Examples of (meth)acrylamide include (meth)acrylamide, N,N-dimethyl(meth)acrylamide, N,N-diethyl(meth)acrylamide, N-isopropyl(meth)acrylamide, N-t-butyl(meth)acrylamide, N-t-octyl(meth)acrylamide, N-methylol(meth)acrylamide, hydroxyethyl(meth)acrylamide, N-methoxymethyl(meth)acrylamide, N-butoxymethyl(meth)acrylamide, diacetone(meth)acrylamide, N,N-dimethylaminoethyl(meth)acrylamide, N,N-dimethylaminopropyl(meth)acrylamide, and N,N'-methylenebis(meth)acrylamide.

[0046] The vinyl monomer having an epoxy group is not particularly limited, and examples thereof include (meth)acrylic acid esters having an epoxy group. Examples of the (meth)acrylic acid ester having an epoxy group include glycidyl (meth)acrylate, glycidyl α-ethylacrylate, glycidyl β-methyl(meth)acrylate, 3,4-epoxybutyl (meth)acrylate, and 3,4-epoxycyclohexylmethyl (meth)acrylate.

[0047] The vinyl monomer having an amino group is not particularly limited, and examples thereof include (meth)acrylic acid esters having an amino group. Examples of the (meth)acrylic acid ester having an amino group include dimethylaminoethyl (meth)acrylate and diethylaminoethyl (meth)acrylate.

[0048] The vinyl monomer having a silyl group is not particularly limited, and examples thereof include (meth)acrylic acid esters having a silyl group, maleic acid derivatives having a silyl group, fumaric acid derivatives having a silyl group, and the like. Examples of (meth)acrylic acid esters having a silyl group include 3-(meth)acryloxypropyltrimethoxysilane, 3-(meth)acryloxypropylmethyldiethoxysilane, 3-(meth)acryloxypropyltriethoxysilane, 3-acryloxypropyltrimethoxysilane, trimethylsilyl (meth)acrylate, triethylsilyl (meth)acrylate, tri-n-propylsilyl (meth)acrylate, tri-n-butylsilyl (meth)acrylate, tri-n-amylsilyl (meth)acrylate, tri-n-hexylsilyl (meth)acrylate, tri-n-octylsilyl (meth)acrylate, tri-n-dodecylsilyl (meth)acrylate, triphenylsilyl (meth)acrylate, tri-p-methylphenylsilyl (meth)acrylate, tribenzylsilyl (meth)acrylate, triisopropylsilyl (meth)acrylate, triisobutylsilyl (meth)acrylate, tri-s-butylsilyl (meth)acrylate, tri-2-methylisopropylsilyl (meth)acrylate, tri-t-butylsilyl (meth)acrylate, ethyldimethylsilyl (meth)acrylate, n-butyldimethylsilyl (meth)acrylate, diisopropyl-n-butylsilyl (meth)acrylate, n-octyldi-n-butylsilyl (meth)acrylate, diisopropylstearylsilyl (meth)acrylate, dicyclohexylphenylsilyl (meth)acrylate, t-butyldiphenylsilyl (meth)acrylate, lauryldiphenylsilyl (meth)acrylate, Silaplane FM-0711 (trade name, manufactured by JNC Corporation), Silaplane FM-0721 (trade name, manufactured by JNC Corporation), Silaplane FM-0725 (trade name, manufactured by JNC Corporation), Silaplane TM-0701 (trade name, manufactured by JNC Corporation), Silaplane TM-0701T (trade name, manufactured by JNC Corporation), X-22-174ASX (trade name, manufactured by Shin-Etsu Chemical Co., Ltd.), X-22-174BX (trade name, manufactured by Shin-Etsu Chemical Co., Ltd.), KF-2012 (trade name, manufactured by Shin-Etsu Chemical Co., Ltd.), X-22-2426 (trade name, manufactured by Shin-Etsu Chemical Co., Ltd.), X-22-2404 (trade name, manufactured by Shin-Etsu Chemical Co., Ltd.), 4-methacryloyloxybenzophenone, and the like. Examples of maleic acid derivatives having a silyl group include triisopropylsilylmethyl maleate, triisopropylsilylamyl maleate, tri-n-butylsilyl-n-butyl maleate, t-butyldiphenylsilylmethyl maleate, and t-butyldiphenylsilyl-n-butyl maleate. Examples of fumaric acid derivatives having a silyl group include, for example, triisopropylsilylmethyl fumarate, triisopropylsilylamyl fumarate, tri-n-butylsilyl-n-butyl fumarate, t-butyldiphenylsilylmethyl fumarate, and t-butyldiphenylsilyl-n-butyl fumarate.

[0049] The vinyl monomer having an isocyanato group is not particularly limited, and examples thereof include (meth)acrylic acid esters having an isocyanato group. Examples of the (meth)acrylic acid ester having an isocyanato group include 2-isocyanatoethyl (meth)acrylate.

[0050] The vinyl monomer having a halogen atom is not particularly limited, and examples thereof include (meth)acrylic acid esters having a halogen atom, halogenated olefins, and the like. Examples of the (meth)acrylic acid ester having a halogen atom include 2,2,2-trifluoroethyl (meth)acrylate, 2,2,3,3,3-pentafluorophenyl (meth)acrylate, 2-(perfluorobutyl)ethyl (meth)acrylate, 3-(perfluorobutyl)-2-hydroxypropyl (meth)acrylate, 2-(perfluorohexyl)ethyl (meth)acrylate, 3-perfluorohexyl-2-hydroxypropyl (meth)acrylate, 3-(perfluoro-3-methylbutyl)-2-hydroxypropyl (meth)acrylate, 2,2,3,3-tetrafluoropropyl (meth)acrylate, 1H,1H,5H-octafluoropentyl (meth)acrylate, 1H,1H,5H-octafluoropentyl (meth)acrylate, 1H,1H,2H,2H-tridecafluorooctyl (meth)acrylate, 1H-1-(trifluoromethyl)trifluoroethyl (meth)acrylate, 1H,1H,3H-hexafluorobutyl (meth)acrylate, and 1,2,2,2-tetrafluoro-1-(trifluoromethyl)ethyl (meth)acrylate. Examples of the halogenated olefin include vinyl chloride, vinylidene chloride, vinyl fluoride, vinylidene fluoride, and chlorotrifluoroethylene.

[0051] The vinyl monomer having a poly(alkylene oxide) group is not particularly limited, and examples thereof include (meth)acrylic acid esters having a poly(alkylene oxide) group. Examples of the (meth)acrylic acid ester having a poly(alkylene oxide) group include polyethylene glycol (meth)acrylate and polypropylene glycol (meth)acrylate.

[0052] In addition to the above, monomers such as styrene, α-methylstyrene, vinyltoluene, (meth)acrylonitrile, divinylbenzene, triallyl cyanurate, polypropylene glycol diallyl ether, vinylpyridine, and vinylcarbazole can also be used.

[0053] Among them, the polymer (C) preferably contains a methacrylic acid ester as a constituent unit.

[0054] Among them, when increasing the SP value of the first polymer segment, it is preferable to use a vinyl monomer having a carboxyl group, a hydroxyl group, an amide group, an amino group, and an epoxy group. When decreasing the SP value, it is preferable to use a vinyl monomer not having the above groups.

[0055] As described above, the first polymer segment and the second polymer segment may each be a homopolymer or a random copolymer and / or a block copolymer.

[0056] Generally, since the SP value of an epoxy resin is 9.5 to 12.0, in order to make the difference from the SP value of the epoxy resin (A) 1.5 or less, the total proportion of vinyl monomers having a carboxyl group, a hydroxyl group, an amide group, an amino group, and an epoxy group with respect to the total number of monomer units constituting the first polymer segment is preferably 5% by mass or more, and the total proportion of vinyl monomers not having the above groups is preferably 95% by mass or less.

[0057] Among them, the total proportion of vinyl monomers having a carboxyl group, a hydroxyl group, an amide group, an amino group, and an epoxy group with respect to the total number of monomer units constituting the first polymer segment is preferably 10% by mass or more, and particularly preferably 15% by mass or more. On the other hand, the total proportion of vinyl monomers not having the above groups is preferably 90% by mass or less, and particularly preferably 85% by mass or less.

[0058] The number average molecular weight (Mn) of the first polymer segment is preferably from 500 to 100,000, more preferably from 1,500 to 20,000, and even more preferably from 2,000 to 10,000. If the number average molecular weight of the first polymer segment is at least the lower limit of the above range, the dispersibility of the polymer (C) in the epoxy resin is more excellent, and the dispersion of the polymer (C) in the resin composition becomes easier. If the number average molecular weight of the first polymer segment is at most the upper limit of the above range, the resin composition can be made to have a lower viscosity. The number average molecular weight of the first polymer segment is measured by gel permeation chromatography (GPC) using polystyrene as a reference resin.

[0059] The glass transition temperature of the first polymer segment (hereinafter also referred to as "Tgc") is not particularly limited, but is preferably 150°C or lower, more preferably 120°C or lower, and particularly preferably 100°C or lower. On the other hand, it is preferably 0°C or higher, more preferably 10°C or higher, and particularly preferably 30°C or higher. If Tgc is at least the lower limit of the above range, the adhesive strength is more excellent. If Tgc is at most the upper limit of the above range, the resin composition can be made to have a lower viscosity. Incidentally, Tgc can be measured by a differential scanning calorimeter (DSC). Further, Tgc can be adjusted by the composition of the monomer forming the first polymer segment or the like.

[0060] Generally, since the SP value of the polymer (B) is from 8.3 to 9.5, in order to make the difference from the SP value of the polymer (B) 1.0 or less, the total proportion of vinyl monomers having a carboxyl group, a hydroxyl group, an amide group, an amino group and an epoxy group is 10% by mass or less with respect to the total number of units constituting the second polymer segment, and the total proportion of vinyl monomers not having the above groups is preferably 90% by mass or more.

[0061] Among the above, it is particularly preferable that the total proportion of vinyl monomers having a carboxyl group, a hydroxyl group, an amide group, an amino group and an epoxy group is 5% by mass or less with respect to the total number of units constituting the second polymer segment, and the total proportion of vinyl monomers not having the above groups is 95% by mass or more.

[0062] Among these, the polymer (C) preferably contains a (meth)acrylate as a constituent unit, and the ratio of the (meth)acrylate unit to the total amount of all constituent units constituting the polymer (C) is not particularly limited, but is preferably 20% by mass or more, particularly preferably 40% by mass or more, and on the other hand, 100% by mass or less. While adjusting the SP values of the first polymerizable segment and the second polymerizable segment, it is preferable to appropriately select the monomers constituting the first polymerizable segment and the second polymer segment so as to fall within this range.

[0063] In the polymer (C), a composition in which a difference in SP value occurs between the first polymer segment and the second polymer segment is preferable.

[0064] As an example of a composition in which a difference in SP value occurs, an example is a case where the first polymer segment contains a constituent unit derived from glycidyl methacrylate and the second polymer segment contains a monomer (x1) having 2 or more carbon atoms in the alkyl (meth)acrylate. In this case, since the carbon number of the alkyl group is large, the SP value is lower than that of glycidyl methacrylate. By adopting such a composition, a difference in SP value occurs between the first polymer segment and the second polymer segment, and the second polymer segment has a lower SP value than the first polymer segment. In this example, the ratio of the constituent unit derived from glycidyl methacrylate to the total of all constituent units constituting the first polymer segment is preferably 5% by mass or more, more preferably 10% by mass or more. Also, the ratio of the monomer (x1) to the total amount of the second polymer segment is preferably 30% by mass or more, more preferably 40% by mass or more. If it is within the above range, the polymer (B) is likely to be dispersed when the resin composition is cured. When the polymer (C) contains a monomer unit containing an epoxy group such as glycidyl methacrylate, the epoxy equivalent of the polymer (C) preferably exceeds 300 g / equivalent, more preferably exceeds 350 g / equivalent, and particularly preferably exceeds 400 g / equivalent. By the epoxy equivalent exceeding 300 g / equivalent, the dispersibility-imparting effect of the polymer (C) is likely to be exhibited.

[0065] The glass transition temperature (Tgx) of the second polymer segment is not particularly limited, but is preferably 25°C or lower, more preferably 10°C or lower, particularly preferably 0°C or lower, and on the other hand, preferably -150°C or higher. If Tgx is within the above range, the adhesive strength of the cured product of the resin composition is more excellent.

[0066] Here, Tgx is the glass transition temperature of the homopolymer of the vinyl monomer when there is one kind of vinyl monomer, and when there are a plurality of kinds of vinyl monomers, it means a value calculated by Fox's formula from the glass transition temperatures and mass fractions of the homopolymers of each of the plurality of kinds of vinyl monomers. The Fox formula is a calculated value obtained by the following formula and can be obtained using the values described in Polymer Handbook [Polymer HandBook, J. Brandrup, Interscience, 1989] (Tg in the formula corresponds to Tgx). 1 / (273 + Tg) = Σ(Wi / (273 + Tgi)) (In the formula, Wi represents the mass fraction of monomer i, and Tgi represents the glass transition temperature (°C) of the homopolymer of monomer i.)

[0067] From the viewpoint that the characteristics of each of the first polymer segment and the second polymer segment can be sufficiently exhibited, the above-mentioned Tgc and Tgx preferably have the relationship of the following formula (2). That is, it is preferably Tgc - Tgx > 0°C. Tgc > Tgx ···(2) Among the above, more preferably Tgc - Tgx > 40°C, and most preferably Tgc - Tgx > 50°C.

[0068] <Content of each structural unit> The content of the structural unit derived from the first polymer segment in the polymer (C) is preferably 10 to 80% by mass, more preferably 20 to 70% by mass, based on the total mass of all the structural units constituting the polymer (C). If the content of the structural unit derived from the first polymer segment is within the above range, the dispersibility of the polymer (C) in the resin composition can be improved.

[0069] The content of the second polymer segment structural unit in the polymer (C) is preferably 20 to 90% by mass, more preferably 30 to 80% by mass, based on the total mass of all the structural units constituting the polymer (C). If the content of the structural unit derived from the second polymer segment is within the above range, the dispersibility of the polymer (B) is improved, and the peel strength of the cured product of the resin composition is improved.

[0070] <Weight-average molecular weight> The weight-average molecular weight (Mw) of the polymer (C) is not particularly limited, but is preferably 10,000 or more, more preferably 15,000 or more, particularly preferably 20,000 or more. On the other hand, it is preferably 1,500,000 or less, more preferably 1,200,000 or less, particularly preferably 1,000,000 or less. If the weight-average molecular weight of the polymer (C) is at least the lower limit value of the above range, the adhesive strength is more excellent. If the weight-average molecular weight of the polymer (C) is at most the upper limit value of the above range, the dispersibility of the polymer (C) is improved. The weight-average molecular weight of the polymer (C) is a value in terms of standard polystyrene measured by gel permeation chromatography (GPC). Specifically, it is measured by the method described in the examples below.

[0071] The polymer segment derived from the macromonomer (c) in the polymer (C) may be the aforementioned first polymer segment or the second polymer segment as described above. In order to improve the dispersity of the polymer (C), the polymer segment derived from the macromonomer (c) is preferably the first polymer segment. On the other hand, the polymer segment composed of vinyl monomer (x) units may be the aforementioned first polymer segment or the second polymer segment. Therefore, in order to improve the dispersity of the polymer (B), the polymer segment derived from the vinyl monomer (x) is preferably the second polymer segment.

[0072] As described above, the macromonomer (c) has a radically polymerizable group and / or an addition-reactive functional group. That is, the macromonomer (c) may have either one of the radically polymerizable group and the addition-reactive functional group or both groups. When the macromonomer (c) has a radically polymerizable group, the number of radically polymerizable groups possessed by the macromonomer (c) is not particularly limited, but is preferably one. When the macromonomer (c) has an addition-reactive functional group, the number of addition-reactive functional groups possessed by the macromonomer (c) is not particularly limited, but is preferably one. When the macromonomer (c) has both a radically polymerizable group and an addition-reactive functional group, the number of the radically polymerizable group and the addition-reactive functional group possessed by the macromonomer (c) is not particularly limited, but is preferably one each.

[0073] When the macromonomer (c) has a radically polymerizable group, the macromonomer (c) and the vinyl monomer (x) can be copolymerized by radical polymerization to obtain the polymer (C). On the other hand, when the macromonomer (c) has an addition-reactive functional group, the polymer (C) can be obtained by reacting the functional group of the polymer composed of the constitutional units derived from the vinyl monomer (x) with the macromonomer having the addition-reactive functional group.

[0074] Examples of the addition-reactive functional group include a hydroxyl group, an isocyanate group, an epoxy group, an acid anhydride group, a thiol group, a carbodiimide group, and the like. In particular, preferred combinations of the addition-reactive functional group and a functional group capable of reacting with the functional group include, for example, a combination of a hydroxyl group and a carboxyl group or an acid anhydride group, a combination of an isocyanate group and one selected from the group consisting of a hydroxyl group, a thiol group, and a carboxyl group, a combination of an epoxy group and an amino group, a combination of a carboxyl group and an epoxy group or a carbodiimide group, a combination of an amino group and a carboxyl group, a combination of an amide group and a carboxyl group, and a combination of a thiol group and an epoxy group.

[0075] Among these, the macromonomer (c) preferably has a radical polymerizable group in view of copolymerizability with the vinyl monomer (x). When the polymer (C) is a copolymer of the macromonomer (c) having a radical polymerizable group and the vinyl monomer (x), compared with the case where the polymer (C) is a copolymer of the macromonomer having the addition-reactive functional group and the vinyl monomer (x), when the polymer (C) is blended in the resin composition, the viscosity of the resin composition tends to be kept low, and further, there is an advantage that the introduction amount of the macromonomer (c) is also easily controlled.

[0076] As the radical polymerizable group, a group having an ethylenically unsaturated bond is preferable. Examples of the group having an ethylenically unsaturated bond include, for example, CH 2 =C(COOR)-CH 2 -, a (meth)acryloyl group, a 2-(hydroxymethyl)acryloyl group, a vinyl group, and the like. Here, R represents a hydrogen atom, an alkyl group which may have a substituent, an alicyclic group which may have a substituent, an aryl group which may have a substituent, a heteroaryl group which may have a substituent, a non-aromatic heterocyclic group which may have a substituent, an aralkyl group which may have a substituent, an alkaryl group which may have a substituent, an organosilyl group which may have a substituent, or a (poly)organosiloxane group which may have a substituent.

[0077] Examples of the alkyl group include branched or linear alkyl groups having 1 to 22 carbon atoms. Specific examples of the branched or linear alkyl group having 1 to 22 carbon atoms include methyl group, ethyl group, n-propyl group, i-propyl group, n-butyl group, t-butyl group, i-butyl group, pentyl group (amyl group), i-pentyl group, hexyl group, heptyl group, 2-ethylhexyl group, octyl group, i-octyl group, nonyl group, i-nonyl group, decyl group, i-decyl group, undecyl group, dodecyl group (lauryl group), tridecyl group, tetradecyl group, pentadecyl group, hexadecyl group, heptadecyl group, octadecyl group (stearyl group), i-octadecyl group, nonadecyl group, icosyl group, docosyl group and the like.

[0078] The alicyclic group may be monocyclic or polycyclic, and examples thereof include alicyclic groups having 3 to 20 carbon atoms. The alicyclic group is preferably a saturated alicyclic group, and specific examples thereof include cyclopropyl group, cyclobutyl group, cyclopentyl group, cyclohexyl group, cycloheptyl group, bicyclo[2.2.1]heptyl group, cyclooctyl group, and adamantyl group and the like.

[0079] Examples of the aryl group include aryl groups having 6 to 18 carbon atoms. Specific examples of the aryl group having 6 to 18 carbon atoms include phenyl group, naphthyl group and the like. Examples of the heteroaryl group include pyridyl group, carbazolyl group and the like. Examples of the non-aromatic heterocyclic group include pyrrolidinyl group, pyrrolidone group, lactam group and the like. Examples of the aralkyl group include benzyl group, phenylethyl group and the like.

[0080] Examples of the organosilyl group include a group represented by -SiR 1 R 2 R 3 In the formula, R 1 ~R 3Each independently represents an alkyl group which may have a substituent, an alicyclic group which may have a substituent, or an aryl group which may have a substituent. R 1 ~R 3 The alkyl group which may have a substituent, the alicyclic group which may have a substituent, and the aryl group which may have a substituent in 3 respectively include the alkyl group which may have a substituent, the alicyclic group which may have a substituent, and the aryl group which may have a substituent as described for R above. Note that R 1 ~R 3 may each be the same group or different groups.

[0081] Examples of the (poly)organosiloxane group include a group represented by -SiR 4 R 5 -OR 6 , or -(SiR 7 R 8 -O-) m -R 9 . R 4 ~R 9 each independently represents an alkyl group which may have a substituent, an alicyclic group which may have a substituent, or an aryl group which may have a substituent, and m represents an integer from 1 to 100. R 4 ~R 9 The alkyl group, alicyclic group, and aryl group in 9 respectively include the same groups as those listed for R 1 ~R 3 .

[0082] There are no particular restrictions on the substituents that these groups may have. Examples include at least one selected from the group consisting of an alkyl group, an aryl group, -COOR 10 , a cyano group, -OR 11 , -NR 12 R 13 , -CONR 14 R 15 , a halogen atom, an allyl group, an epoxy group, a siloxy group, and a group exhibiting hydrophilicity or ionic properties. Here, R 10 ~R15 each represents a hydrogen atom, an alkyl group which may have a substituent, an alicyclic group which may have a substituent, or an aryl group which may have a substituent. R 10 ~R 15 The alkyl group, alicyclic group and aryl group in 1 ~R 3 are the same groups as those exemplified for R In addition, as R 10 in -COOR 10 , a hydrogen atom or an unsubstituted alkyl group is preferable. As the unsubstituted alkyl group, preferably an alkyl group having 1 to 12 carbon atoms is exemplified, for example, a methyl group. As R 11 in -OR 11 , a hydrogen atom or an unsubstituted alkyl group is preferable. As the unsubstituted alkyl group, preferably an alkyl group having 1 to 12 carbon atoms is exemplified, for example, a methyl group. As R 12 and R 13 in -NR 12 R 13 , each independently, a hydrogen atom or an unsubstituted alkyl group is preferable. As the unsubstituted alkyl group, preferably an alkyl group having 1 to 12 carbon atoms is exemplified, for example, a methyl group. As R 14 and R 15 in -CONR 14 R 15 , each independently, a hydrogen atom or an unsubstituted alkyl group is preferable. As the unsubstituted alkyl group, preferably an alkyl group having 1 to 12 carbon atoms is exemplified, for example, a methyl group. Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom and an iodine atom. Examples of the poly(alkylene oxide) group include poly(alkylene oxide) groups such as a polyethylene oxide group and a polypropylene oxide group.

[0083] In the above kana, R is preferably an alkyl group which may have a substituent, or an alicyclic group which may have a substituent, more preferably an unsubstituted alkyl group, an unsubstituted alicyclic group, or an alicyclic group having an alkyl group as a substituent, and preferably a methyl group, an ethyl group, an n-propyl group, an i-propyl group, an n-butyl group, a t-butyl group, a pentyl group, a hexyl group, a heptyl group, an octyl group, a cyclopropyl group, a cyclobutyl group, an isobornyl group and an adamantyl group, and more preferably a methyl group, an ethyl group, an n-propyl group, an i-propyl group, an n-butyl group, a t-butyl group, a cyclopropyl group, a cyclobutyl group, an isobornyl group and an adamantyl group.

[0084] Among the above, the macromonomer (c) is preferably a macromonomer in which a radically polymerizable group is introduced at the terminal of a polymer having a polymerization degree of 2 or more, and more preferably a macromonomer represented by the following formula (3). When the resin composition is a macromonomer copolymer of the macromonomer represented by the following formula (3) and a vinyl monomer as the polymer (C), the viscosity of the resin composition can be further reduced.

[0085]

Chemical formula

[0086] In formula (3), R represents a hydrogen atom, an alkyl group which may have a substituent, an alicyclic group which may have a substituent, an aryl group which may have a substituent, a heteroaryl group which may have a substituent, a non-aromatic heterocyclic group which may have a substituent, an aralkyl group which may have a substituent, an alkaryl group which may have a substituent, an organosilyl group which may have a substituent, or a (poly)organosiloxane group which may have a substituent, Q represents a monomer unit, n means the number of repeating units and is an integer of 2 or more. Also, Z represents a terminal group.

[0087] Specific examples of R include the groups described for R in CH 2 =C(COOR)-CH 2 - mentioned above, and the preferred groups are the same. Q includes the monomer units described in the first polymer segment and the second polymer segment, and the preferred monomer units are the same. The number of monomer units constituting Q can be appropriately set in consideration of the number average molecular weight of the macromonomer (c), etc. Examples of Z include a hydrogen atom, a group derived from a radical polymerization initiator, a radically polymerizable group, etc., similar to the end groups of polymers obtained by known radical polymerizations.

[0088] When the macromonomer (c) has the addition-reactive functional group and this macromonomer is added to the functional group of a polymer composed of constitutional units derived from the vinyl monomer (x), the macromonomer (c) has one or more of the addition-reactive functional groups and is a polymer having a degree of polymerization of 2 or more when polymerized using the monomers described in the first polymer segment. In addition to the above macromonomer (c), a compound having a functional group can also be added to the functional group of a polymer composed of constitutional units derived from the vinyl monomer (x). Examples of the compound having a functional group include silicone-based compounds such as X-22-173BX (trade name, manufactured by Shin-Etsu Chemical Co., Ltd.), X-22-173DX (trade name, manufactured by Shin-Etsu Chemical Co., Ltd.), X-22-170BX (trade name, manufactured by Shin-Etsu Chemical Co., Ltd.), X-22-170DX (trade name, manufactured by Shin-Etsu Chemical Co., Ltd.), X-22-176DX (trade name, manufactured by Shin-Etsu Chemical Co., Ltd.), X-22-176F (trade name, manufactured by Shin-Etsu Chemical Co., Ltd.), X-22-173GX-A (trade name, manufactured by Shin-Etsu Chemical Co., Ltd.), etc.

[0089] The macromonomer (c) and the vinyl monomer (x) may each be those produced by known methods or commercially available ones. Examples of the method for producing the macromonomer (c) having a radically polymerizable group include a method using a cobalt chain transfer agent, a method using an α-substituted unsaturated compound such as α-methylstyrene dimer as a chain transfer agent, a method using an initiator, a method of chemically bonding a radically polymerizable group to a polymer, a method by thermal decomposition, etc. Among these, as a method for producing the macromonomer (c) having a radically polymerizable group, a method of production using a cobalt chain transfer agent is preferred in that the number of production steps is small and the chain transfer constant of the catalyst used is high. The macromonomer (c) produced using a cobalt chain transfer agent has a structure represented by the above formula (3).

[0090] Examples of the method for producing the macromonomer (c) using a cobalt chain transfer agent include bulk polymerization, solution polymerization, and aqueous dispersion polymerization methods such as suspension polymerization and emulsion polymerization. From the viewpoint of simplicity of the recovery process, the aqueous dispersion polymerization method is preferred. Examples of the method for chemically bonding a radically polymerizable group to a polymer include a method of producing by substituting a halogen group of a polymer having a halogen group with a compound having a radically polymerizable carbon-carbon double bond, a method of reacting a vinyl monomer having an acid group with a vinyl polymer having an epoxy group, a method of reacting a vinyl polymer having an epoxy group with a vinyl monomer having an acid group, a method of reacting a vinyl polymer having a hydroxyl group with a diisocyanate compound to obtain a vinyl polymer having an isocyanate group, and then reacting this vinyl polymer with a vinyl monomer having a hydroxyl group, etc. It may be produced by any method. The number average molecular weight of the macromonomer (c) can be adjusted by a polymerization initiator, a chain transfer agent, etc.

[0091] Examples of the method for producing the macromonomer (c) having an addition-reactive functional group such as a hydroxyl group, an isocyanate group, an epoxy group, a carboxyl group, an acid anhydride group, an amino group, an amide group, a thiol group, and a carbodiimide group include, for example, a method of copolymerizing a vinyl monomer having the functional group, and a method using a chain transfer agent such as mercaptoethanol, mercaptoacetic acid, and mercaptopropionic acid. In addition, there are methods using initiators capable of introducing functional groups such as 2,2'-azobis(propane-2-carboxamidine), 4,4'-azobis(4-cyanovaleric acid), 2,2'-azobis[N-(2-carboxyethyl)-2-methylpropionamidine], and 2,2'-azobis[2-(1-hydroxyethyl)-2-imidazolin-2-yl]propane.

[0092] As a method for producing the polymer (C), the polymer (C) is preferably a copolymer of the macromonomer (c) and the vinyl monomer (x). In such a copolymer, the structural units derived from the macromonomer (c) and the structural units derived from the vinyl monomer (x) are randomly arranged. That is, polymer chains derived from one or more macromonomers (c) are bonded throughout the main chain of the polymer (C). Such a polymer, for example, when compared with the case where the structural units derived from the macromonomer (c) are bonded only to the ends of the polymer chains composed of the structural units derived from the vinyl monomer (x), when compounded in the resin composition, the dispersibility of the polymer (B) is improved and tends to occur.

[0093] The preferred range of the monomer composition when producing the polymer (C), that is, the types of monomers to be polymerized and the content (% by mass) (charged amount) of each monomer with respect to the total mass of all monomers, is the same as the composition of the polymer (C), that is, the types of structural units derived from the monomers constituting the polymer (C) and the content (% by mass) of each structural unit with respect to the total mass of all structural units. For example, the content of the macromonomer (c) with respect to the total mass (100% by mass) of all monomers to be polymerized is preferably 10 to 80% by mass, more preferably 20 to 70% by mass.

[0094] The polymerization of the monomer may be carried out by a known method using a known polymerization initiator. For example, there is a method of reacting the macromonomer (c) and the vinyl monomer (x) at a reaction temperature of 60 to 120 °C for 1 to 14 hours in the presence of a radical polymerization initiator. During the polymerization, a chain transfer agent and an antioxidant may be used as necessary. As the polymerization method, for example, known polymerization methods such as solution polymerization method, suspension polymerization method, bulk polymerization method, emulsion polymerization method, etc. can be applied. The solution polymerization method is preferable in terms of productivity and coating film performance. Solution polymerization can be carried out, for example, by supplying a polymerization solvent, a monomer, and a radical polymerization initiator into a polymerization vessel and maintaining it at a predetermined reaction temperature. The monomer may be charged into the polymerization vessel in advance (before setting the inside of the polymerization vessel to the predetermined reaction temperature), may be supplied dropwise after setting the inside of the polymerization vessel to the predetermined reaction temperature, or a part may be charged into the polymerization vessel in advance and the remainder may be supplied dropwise.

[0095] In the resin composition, the ratio of the polymer (C) to 100 parts by mass of the epoxy resin (A) is not particularly limited, but in order to improve the peel strength, it is preferably 0.01 part or more, more preferably 0.1 part by mass or more, particularly preferably 1.0 part by mass or more. On the other hand, in order to improve the peel strength, it is preferably 50 parts by mass or less, more preferably 40 parts by mass or less, particularly preferably 30 parts by mass or less.

[0096] In the resin composition, the ratio of the polymer (C) to 100 parts by mass of the polymer (B) is not particularly limited, but in order to improve the peel strength, it is preferably 0.01 part by mass or more, more preferably 0.1 part by mass or more, particularly preferably 1 part by mass or more. On the other hand, in order to improve the peel strength, it is preferably 2500 parts by mass or less, more preferably 300 parts by mass or less, particularly preferably 200 parts by mass or less.

[0097] The resin composition may contain a flexible component (D) in order to further improve the peel strength.

[0098] The flexible component (D) is a compound having a Tg greater than -90°C and less than or equal to 0°C, a weight average molecular weight of less than 10,000, and containing any one of an epoxy group, a carboxyl group, a hydroxyl group, an epoxy group, an amino group, and an isocyanate group. The Tg of the flexible component (D) can be measured by a differential scanning calorimeter (DSC), and the weight average molecular weight can be measured by gel permeation chromatography (GPC) using polystyrene as a reference resin.

[0099] The flexible component (D) includes, for example, modified epoxy resins such as rubber-modified epoxy resins, urethane-modified epoxy resins, polyether-modified epoxy resins, and silicone-modified epoxy resins having the above physical properties, and further, those in which a part of the epoxy resin is replaced with a reactive diluent having an epoxy group or block urethane.

[0100] Note that among the flexible components (D), there are also compounds that can correspond to the epoxy resin (A). However, if the resin composition contains at least one compound corresponding to the epoxy resin (A) and at least one compound corresponding to the flexible component (D) having a structure different from that of the compound, an effect of further improving the above peel strength can be expected. That is, for example, when the resin composition contains two or more epoxy resins corresponding to the epoxy resin (A), if at least one of the two or more epoxy resins corresponds to the above flexible component (D), the resin composition contains the epoxy resin (A) and the flexible component (D), so an effect of further improving the above peel strength can be expected.

[0101] Here, the rubber-modified epoxy resin is a reaction product obtained by reacting a rubber with a compound containing an epoxy group, and on average per molecule, it has 1.1 or more, preferably 2 or more epoxy groups. Examples of the rubber include acrylonitrile-butadiene rubber (NBR), styrene-butadiene rubber (SBR), hydrogenated nitrile rubber (HNBR), ethylene-propylene rubber (EPDM), acrylic rubber (ACM), butyl rubber (IIR), butadiene rubber, polyoxyalkylene such as polypropylene oxide, polyethylene oxide, and polytetramethylene oxide, and other rubber-based polymers. The rubber-based polymer preferably has a reactive group such as an amino group, a hydroxy group, or a carboxyl group at its terminal. The product obtained by reacting these rubber-based polymers and an epoxy resin in an appropriate blending ratio by a known method is the rubber-modified epoxy resin used in the present invention. Among these, acrylonitrile-butadiene rubber-modified epoxy resin and polyoxyalkylene-modified epoxy resin are preferable from the viewpoints of the adhesiveness and impact peel adhesiveness of the resulting resin composition, and acrylonitrile-butadiene rubber-modified epoxy resin is more preferable. The acrylonitrile-butadiene rubber-modified epoxy resin is obtained, for example, by the reaction of carboxyl-terminated NBR (CTBN) and bisphenol A type epoxy resin.

[0102] The urethane-modified epoxy resin is a reaction product obtained by reacting a compound containing a group reactive with an isocyanate group and an epoxy group with a urethane prepolymer containing an isocyanate group, and on average per molecule, it has 1.1 or more, preferably 2 or more epoxy groups. For example, a urethane-modified epoxy resin can be obtained by reacting a hydroxy group-containing epoxy compound with a urethane prepolymer.

[0103] Blocked urethane is an elastomeric compound containing urethane groups and / or urea groups and having isocyanate groups at its terminals, and all or part of the terminal isocyanate groups are capped with various blocking agents having active hydrogen groups. In particular, a compound in which all of the terminal isocyanate groups are capped with a blocking agent is preferred. Such a compound can be obtained, for example, by reacting an organic polymer having an active hydrogen-containing group at its terminal with an excess of a polyisocyanate compound to form a polymer (urethane prepolymer) having urethane groups and / or urea groups in the main chain and isocyanate groups at its terminals, and then, or simultaneously, capping all or part of the isocyanate groups with a blocking agent having an active hydrogen group.

[0104] When the resin composition contains the flexible component (D), the proportion of the flexible component (D) with respect to 100% by mass of the epoxy resin (A) is preferably 1% by mass or more, more preferably 2% by mass or more. On the other hand, for improving the dispersibility of the polymer (B), it is preferably 30% by mass or less, more preferably 20% by mass or less.

[0105] The resin composition may further contain other components in addition to the above as long as the effects of the present invention are not impaired. Examples of other components include antioxidants; release agents such as silicone oil, natural wax, and synthetic wax; powders such as glass beads, crystalline silica, fused silica, calcium silicate, and alumina; fibers such as glass fiber and carbon fiber; flame retardants such as antimony trioxide; halogen trappers such as hydrotalcite and rare earth oxides; colorants such as carbon black and red iron oxide; silane coupling agents; defoaming agents, rheology modifiers, flame retardants, pigments, dyes, and the like.

[0106] The resin composition may contain a curing agent and / or a curing accelerator for curing the resin composition in addition to the above.

[0107] The curing agent cures the epoxy resin (A) and is used to adjust the curability and properties of the cured product of the epoxy resin composition. As the curing agent, those known as curing agents for epoxy resins can be used, and examples thereof include acid anhydrides, amine compounds, phenol compounds, latent curing agents, and the like.

[0108] Examples of the acid anhydride include phthalic anhydride, methyltetrahydrophthalic anhydride, methylhexahydrophthalic anhydride, hexahydrophthalic anhydride, tetrahydrophthalic anhydride, trialkyltetrahydrophthalic anhydride, methyl hymic anhydride, methylcyclohexene dicarboxylic anhydride, trimellitic anhydride, pyromellitic anhydride, benzophenone tetracarboxylic anhydride, ethylene glycol bistrimellitate, glycerol tristrimellitate, dodecenyl succinic anhydride, polyazelainic anhydride, and poly(ethyloctadecanedioic acid) anhydride, and the like. Among these, in applications where weather resistance, light resistance, heat resistance, etc. are required, methylhexahydrophthalic anhydride and hexahydrophthalic anhydride are preferred. These may be used alone or in combination of two or more.

[0109] Examples of amine compounds include 2,5(2,6)-bis(aminomethyl)bicyclo[2,2,1]heptane, isophoronediamine, ethylenediamine, diethylenetriamine, triethylenetetramine, tetraethylenepentamine, diethylaminopropylamine, bis(4-amino-3-methyldicyclohexyl)methane, diaminodicyclohexylmethane, bis(aminomethyl)cyclohexane, bis(aminomethyl)norbornane, bis(4-aminocyclohexyl)methane, metaphenylenediamine, diaminodiphenylmethane, diaminodiphenylsulfone, diaminodiethyldiphenylmethane, diethyltoluenediamine, 3,3'-diaminodiphenylsulfone (3,3'-DDS), 4,4'-diaminodiphenylsulfone (4,4'-DDS) and other diaminodiphenylsulfones, diaminodiphenyl ether (DADPE), bisaniline, dimethylaniline, triethylenediamine, dimethylbenzylamine, 2,4,6-tris(dimethylaminomethyl)phenol, benzyldimethylaniline, 3,3'-dichloro-4,4'-diaminodiphenylmethane (MOCA), 4,4'-diaminodiphenylmethane, 2,4'-diaminodiphenylmethane, 3,3'-diaminodiphenylmethane, 3,4'-diaminodiphenylmethane, 2,2'-diaminobiphenyl, 3,3'-diaminobiphenyl, 2,4-diaminophenol, 2,5-diaminophenol, o-phenylenediamine, m-phenylenediamine, p-phenylenediamine, m-xylylenediamine, 2,3-tolylenediamine, 2,4-tolylenediamine, 2,5-tolylenediamine, 2,6-tolylenediamine, 3,4-tolylenediamine, methylthiotoluenediamine, diethyltoluenediamine, dicyandiamide, etc. These may be used alone or in combination of two or more.

[0110] Examples of phenol compounds include phenol novolak resin, cresol novolak resin, bisphenol A, bisphenol F, bisphenol AD, and derivatives of diallyl compounds of these bisphenols. These may be used alone or in combination of two or more.

[0111] The latent curing agent is a compound that is solid at normal temperature and liquefies during the heat curing of the epoxy resin composition to act as a curing agent. Examples of the latent curing agent include organic acid hydrazides such as dicyandiamide, carbohydrazide, oxalic acid dihydrazide, malonic acid dihydrazide, succinic acid dihydrazide, iminodiacetic acid dihydrazide, adipic acid dihydrazide, pimelic acid dihydrazide, suberic acid dihydrazide, azelaic acid dihydrazide, sebacic acid dihydrazide, dodecane dihydrazide, hexadecane dihydrazide, maleic acid dihydrazide, fumaric acid dihydrazide, diglycolic acid dihydrazide, tartaric acid dihydrazide, malic acid dihydrazide, isophthalic acid dihydrazide, terephthalic acid dihydrazide, 2,6-naphthoic acid dihydrazide, 4,4'-bisbenzene dihydrazide, 1,4-naphthoic acid dihydrazide, Amicure VDH and Amicure UDH (both are trade names, manufactured by Ajinomoto Co., Inc.), and citric acid trihydrazide. These may be used alone or in combination of two or more.

[0112] As the curing accelerator, known ones used as heat curing catalysts for epoxy resins can be used. For example, urea compounds such as 3-(3,4-dichlorophenyl)-1,1-dimethylurea (DCMU), imidazole compounds such as 2-methylimidazole and 2-ethyl-4-methylimidazole; adducts of imidazole compounds and epoxy resins; organic phosphorus compounds such as triphenylphosphine; borates such as tetraphenylphosphine tetraphenylborate; and 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU), etc. These may be used alone or in combination of two or more.

[0113] In the resin composition, there is no particular limitation on the content ratio of the curing agent with respect to 100 parts by mass of the epoxy resin. However, for adjusting the curing rate, it is preferably 1 part or more, more preferably 2 parts or more, and particularly preferably 3 parts or more. On the other hand, for improving the peel strength, it is preferably 30 parts or less, more preferably 20 parts or less, and particularly preferably 15 parts or less.

[0114] In the resin composition, there is no particular limitation on the content ratio of the curing accelerator with respect to 100 parts by mass of the epoxy resin. However, for adjusting the curing rate, it is preferably 0.5 part or more, more preferably 0.75 part or more, and particularly preferably 1 part or more. On the other hand, for improving the peel strength, it is preferably 10 parts or less, more preferably 9 parts or less, and particularly preferably 5 parts or less.

[0115] The average domain size of the polymer (B) in the resin composition is not particularly limited. However, for ensuring the number of dispersion domains, it is preferably 1000 nm or less, more preferably 700 nm or less, and particularly preferably 500 nm or less. On the other hand, for improving the peel strength, it is preferably 10 nm or more, more preferably 20 nm or more, and particularly preferably 30 nm or more. The average domain size of the polymer (B) in the resin composition is regarded as the average domain size of the polymer (B) in the resin composition, which is calculated based on TEM observation in the resin cured product obtained by curing the resin composition. In the present invention, the domain size of the polymer (B) means the average value of the minor axis and the major axis of the domain of the polymer (B), and the average domain size of the polymer (B) means the average value of the domain sizes of five arbitrarily selected polymers (B).

[0116] The method for producing the resin composition is not particularly limited, and the epoxy resin (A) and the polymer (B) may be mixed. In addition, when producing a resin composition containing compounds other than the epoxy resin (A) and the polymer (B), these may be mixed. In that case, all of them may be mixed at once, or they may be mixed in multiple times. Further, only specific compounds may be mixed in advance, and then mixed with other compounds. When mixing, known mixers such as a rotating and revolving mixer, mixing rolls such as three-roll mills, and kneaders can be used.

[0117] The resin composition according to this embodiment is excellent in peel strength at low temperature and is useful as an adhesive. Examples of the adhesive include those for the structure of vehicles such as automobiles, for civil engineering and construction, for electronic materials, for general office use, for medical use, for industrial use, and the like. Examples of the adhesive for electronic materials include interlayer adhesives for multilayer substrates such as build-up substrates, die bonding agents, adhesives for semiconductors such as underfills, underfills for BGA reinforcement, anisotropic conductive films (ACF), and mounting adhesives such as anisotropic conductive pastes (ACP).

[0118] In addition, when the resin composition according to this embodiment is used as an adhesive, by curing the resin composition, the obtained cured resin is used as an adhesive layer for the above applications.

[0119] The curing method is not particularly limited, and known methods such as ultraviolet curing and thermal curing can be mentioned.

[0120] The curing temperature of the resin composition is not particularly limited, but for adjusting the curing rate, it is preferably 80°C or higher, more preferably 100°C or higher, and particularly preferably 150°C or higher. On the other hand, for improving the peel strength, it is preferably 250°C or lower, more preferably 220°C or lower, and particularly preferably 210°C or lower.

[0121] The cured resin obtained by curing the resin composition contains at least the epoxy resin (A).

[0122] The peak value of tanδ in the dynamic viscoelasticity measurement of the cured resin is preferably -90°C or lower, particularly preferably -95°C or lower, for improving the peel strength. On the other hand, for improving the workability, it is preferably -200°C or higher, more preferably -150°C or higher, and particularly preferably -120°C or higher. The glass transition temperature of the cured resin can be measured by the method described in the examples. If the peak of tanδ of the cured resin is -90°C or lower, it is considered that a large toughness can be imparted to the obtained cured product in an environment of approximately -40°C, and as a result, the peel strength is improved.

[0123] There is no particular limitation on the method of setting the peak value of tanδ in the dynamic viscoelasticity measurement of the cured resin to -90°C or lower. However, if the resin composition contains a polymer (B) having a glass transition temperature of -90°C or lower in order to obtain the cured resin, that is, if the cured resin contains a polymer (B) with a glass transition temperature of -90°C or lower, the peak value of tanδ in the dynamic viscoelasticity measurement of the cured resin can be set to -90°C or lower.

[0124] When the resin composition contains not only the epoxy resin (A) and the polymer (B) but also the polymer (C) and / or other components (D), the obtained cured resin also contains the polymer (C) and / or other components (D). The preferred form of the cured resin is the same as the preferred form described for the above resin composition. That is, the components and physical properties constituting the cured resin are the compounds and physical properties listed for the above resin composition, and the preferred compounds and physical properties are also the same. Also, the composition ratio, etc. of each component constituting the cured resin can refer to the composition ratio listed for the resin composition. In the cured resin, for example, the epoxy resin (A) and the polymer (C) may be crosslinked. In this case, the part derived from the epoxy resin (A) shall be referred to as the epoxy resin (A), and the part derived from the polymer (C) shall be referred to as the polymer (C).

[0125] In the cured resin, the size of the average domain of polymer (B) is not particularly limited, but in order to ensure the number of dispersed domains, it is preferably 1000 nm or less, more preferably 700 nm or less, and particularly preferably 500 nm or less. On the other hand, for improving the peel strength, it is preferably 10 nm or more, more preferably 20 nm or more, and particularly preferably 30 nm or more. The size of the average domain of polymer (B) may be calculated based on TEM observation.

[0126] Hereinafter, the present invention will be described in more detail with reference to examples. However, the following examples do not limit the scope of the present invention. In each of the following examples, "parts" means "parts by mass". The meanings of the abbreviations used in the following examples are as follows.

Examples

[0127] MMA: Methyl methacrylate (SP value: 9.49) GMA: Glycidyl methacrylate (SP value: 11.17) Peroct O: Trade name, 1,1,3,3 - tetramethylbutyl peroxy - 2 - ethylhexanoate, manufactured by NOF Corporation Niper BMT - K40: Trade name, benzoyl peroxide, manufactured by NOF Corporation n - BA: n - butyl acrylate (SP value: 9.56) 2 - EHA: 2 - ethylhexyl acrylate (SP value: 9.13) LA: Lauryl acrylate (SP value: 9.17) MEK: Methyl ethyl ketone DICY: Dicyandiamide (manufactured by Mitsubishi Chemical Corporation) DCMU: 3 - (3,4 - dichlorophenyl) - 1,1 - dimethylurea (manufactured by Hodogaya Chemical Co., Ltd.) jER828: Trade name, bisphenol A type epoxy resin, manufactured by Mitsubishi Chemical Corporation (SP value: 10.87), (weight molecular weight: 370), (epoxy equivalent: 190) LBR - 302: Trade name, polybutadiene, manufactured by Kuraray Co., Ltd. (SP value: 9.05, Tg = - 98°C) LBR-305: Product Name, Polybutadiene, manufactured by Kuraray Co., Ltd. (SP value: 9.05, Tg = -105°C) LBR-307: Product Name, Polybutadiene, manufactured by Kuraray Co., Ltd. (SP value: 9.05, Tg = -103 to -105°C) LBR-352: Product Name, Polybutadiene, manufactured by Kuraray Co., Ltd. (SP value: 8.94 - 9.05, Tg = -67°C) LBR-361: Product Name, Polybutadiene, manufactured by Kuraray Co., Ltd. (SP value: 8.94 - 9.05, Tg = -55°C) QR-9466: Product Name, Block Urethane, manufactured by ADEKA Corporation EPU-73B: Product Name, Urethane-Modified Epoxy Resin, manufactured by ADEKA Corporation (Epoxy Equivalent: 245) EPR-1630: Product Name, CTBN-Modified Epoxy Resin, manufactured by ADEKA Corporation (Epoxy Equivalent: 900) EPR-1415-1: Product Name, NBR-Modified Epoxy Resin, manufactured by ADEKA Corporation (Epoxy Equivalent: 400) J-100: Glass Beads J-100 for Blasting

[0128] (Measurement of Molecular Weight of Macromonomer) The number average molecular weight and weight average molecular weight of macromonomers {(c-1), (c-2), (c-4)} were calculated in terms of standard polystyrene conversion under the following conditions. Gel Permeation Chromatography (GPC) apparatus: manufactured by Tosoh Corporation, HLC-8320 Columns: manufactured by Tosoh Corporation (TSKgel SuperHZM-M × HZM-M × HZ2000, TSKguardcolumn SuperHZ-L) Sample solution: 10 μL of 0.2 mass% tetrahydrofuran (THF) solution of macromonomer Flow rate: 0.35 mL / min Eluent: THF (Stabilizer: Butylhydroxytoluene (BHT)) Column temperature: 40°C The number average molecular weight (Mn) and weight average molecular weight (Mw) of macromonomer (c-3) were calculated in terms of standard polymethyl methacrylate conversion under the following conditions. Gel Permeation Chromatography (GPC) apparatus: manufactured by Tosoh Corporation, HLC-8320 column Columns (TSK-guardcolumn SuperH-H (4.6×35 mm, manufactured by Tosoh Corporation) and two TSKgel Super HM-H (6.0×150 mm, manufactured by Tosoh Corporation) connected in series Sample solution: 10 μL of a tetrahydrofuran (THF) solution of macromonomer (sample concentration 0.02 g / 10 mL) Flow rate: 0.6 mL / min Eluent: THF (stabilizer: butylhydroxytoluene (BHT)) Column temperature: 40 °C

[0129] (Measurement of molecular weight of macromonomer copolymer) The number average molecular weight and weight average molecular weight of the macromonomer copolymers {(C-1) to (C-3), (C-5)} were calculated in terms of standard polystyrene under the following conditions. Gel Permeation Chromatography (GPC) apparatus: manufactured by Tosoh Corporation, HLC-8320 column Columns manufactured by Tosoh Corporation (TSKgel SuperHZM-M × HZM-M × HZ2000, TSKguardcolumn SuperHZ-L) Sample solution: 10 μL of a 0.2 mass% tetrahydrofuran (THF) solution of macromonomer Flow rate: 0.35 mL / min Eluent: THF (stabilizer: butylhydroxytoluene (BHT)) Column temperature: 40 °C The number average molecular weight and weight average molecular weight of the macromonomer copolymers {(C-4), (C-6)} were calculated in terms of standard polymethyl methacrylate under the following conditions. Gel Permeation Chromatography (GPC) apparatus: manufactured by Tosoh Corporation, HLC-8320 column Columns (TSK-guardcolumn SuperH-H (4.6×35 mm, manufactured by Tosoh Corporation) and two TSKgel Super HM-H (6.0×150 mm, manufactured by Tosoh Corporation) connected in series Sample solution: 10 μL of a tetrahydrofuran (THF) solution of macromonomer (sample concentration 0.02 g / 10 mL) Flow rate: 0.6 mL / min Eluent: THF (Stabilizer: Butylhydroxytoluene (BHT)) Column temperature: 40 °C

[0130] <Production of Dispersant 1> Into a polymerization apparatus equipped with a stirrer, a cooling tube, a thermometer, and a nitrogen gas inlet tube, 900 parts of deionized water, 60 parts of sodium 2-sulfoethyl methacrylate, 10 parts of potassium methacrylate, and 12 parts of MMA were placed and stirred. While purging the inside of the polymerization apparatus with nitrogen, the temperature was raised to 50 °C. Into this, 0.08 part of 2,2'-azobis(2-methylpropionamidine) dihydrochloride was added as a polymerization initiator, and the temperature was further raised to 60 °C. After the temperature rise, using a dropping pump, MMA was continuously dropped at a rate of 0.24 part / min for 75 minutes. After holding the reaction solution at 60 °C for 6 hours, it was cooled to room temperature to obtain Dispersant 1, which is a transparent aqueous solution with a solid content of 10% by mass.

[0131] <Production of Chain Transfer Agent 1> Into a synthesis apparatus equipped with a stirring device, under a nitrogen atmosphere, 1.00 g of cobalt(II) acetate tetrahydrate, 1.93 g of diphenylglyoxime, and 80 mL of diethyl ether that had been deoxygenated by nitrogen bubbling in advance were placed and stirred at room temperature for 30 minutes. Then, 10 mL of boron trifluoride diethyl ether complex was added, and stirring was continued for another 6 hours. The mixture was filtered, the solid was washed with diethyl ether, and vacuum dried for 15 hours to obtain 2.12 g of Chain Transfer Agent 1, which is a reddish-brown solid.

[0132] <Synthesis Example 1: Synthesis of Macromonomer> Into a polymerization apparatus equipped with a stirrer, a cooling tube, a thermometer, and a nitrogen gas inlet tube, 145 parts of deionized water, 0.1 part of sodium sulfate, and 0.25 part of Dispersant 1 (solid content 10% by mass) were placed and stirred to obtain a uniform aqueous solution. Next, 75 parts of MMA, 25 parts of GMA, 0.002 part of Chain Transfer Agent 1, and 0.8 part of Perocta O (registered trademark) as a polymerization initiator were added to obtain an aqueous suspension. Next, the inside of the polymerization apparatus was purged with nitrogen, heated to 80 °C, and reacted for 3.5 hours. To further increase the polymerization rate, the temperature was raised to 90 °C and maintained for 1 hour. Thereafter, the reaction solution was cooled to 40 °C to obtain an aqueous suspension containing the macromonomer. This aqueous suspension was filtered through a filter, and the residue remaining on the filter was washed with deionized water, dehydrated, and dried at 40 °C for 16 hours to obtain the macromonomer (c-1). The number average molecular weight and weight average molecular weight of this macromonomer (c-1) are shown in Table 1.

[0133] <Synthesis Examples 2 to 4> In Synthesis Example 1, macromonomers (c-2) to (c-4) were obtained in the same manner as in Synthesis Example 1, except that the charged amounts of the monomer, chain transfer agent, and polymerization initiator were as shown in Table 1. The molecular weights are shown in Table 1. Note that all units of the compounding amounts in Table 1 are parts by mass.

[0134]

Table 1

[0135] <Production Example 1: Production of Macromonomer Copolymer Which is Polymer (C)> Into a four-necked flask equipped with a stirrer, thermometer, condenser, and nitrogen gas inlet, 70 parts of methyl ethyl ketone and 50 parts of macromonomer (c-1) were placed as the initial charged solvent, and the external temperature was raised to 85 °C under nitrogen gas ventilation. After the external temperature reached 85 °C and the internal temperature stabilized, a mixture consisting of 15 parts of methyl ethyl ketone, 50 parts of 2-ethylhexyl acrylate (2-EHA), and 0.13 part of Niper BMT-K40, which is a polymerization initiator, was added dropwise over 4 hours. After holding for 1 hour after the completion of the dropwise addition, a mixture consisting of 0.5 part of Perocta O and 10 parts of methyl ethyl ketone was added over 1 hour. Thereafter, after holding for 2 hours, methyl ethyl ketone was added so that the solid content (the ratio of the charged amount of the monomer in (the charged amount of the monomer + solvent)) became 50% by mass, and then cooled to room temperature to obtain a solution of the macromonomer copolymer (C-1). The epoxy equivalent, number average molecular weight, and weight average molecular weight of the copolymer are shown in Table 2.

[0136] <Production Examples 2 to 6> A solution of macromonomer copolymers (C-2) to (C-6) was obtained in the same manner as in Production Example 1, except that the raw materials and their amounts used were changed as shown in Table 2. The number average molecular weight and weight average molecular weight of the copolymer in the solution are shown in Table 2. In Table 2, all units of the compounding amounts are parts by mass.

[0137]

Table 2

[0138] <Example 1> 10 parts of macromonomer copolymer (C-1, Production Example 1) (20 parts as a macromonomer copolymer solution with a solid content of 50% by mass) and 23.3 parts of an epoxy resin (jER828 (trade name)) were mixed, and dried under reduced pressure using a vacuum dryer to remove the solvent, obtaining a premix with the volatile components removed. This premix, 15 parts of LBR307 as polybutadiene which is polymer (B), 6 parts of DICY as a curing agent, 1 part of DCMU as a curing accelerator, and 44.7 parts of epoxy resin (jER828) were mixed using an Awa Taro ((Shinchi Co., Ltd.)) to prepare a resin composition.

[0139] <Examples 2 to 15, Comparative Examples 3 and 4> A resin composition was obtained in the same manner as in Example 1, except that the ratios of the respective components were changed as shown in Table 3. In Table 3, all units of the compounding amounts are parts by mass.

[0140] <Comparative Example 1> 25 parts of macromonomer copolymer (C-1, Production Example 1) (50 parts as a macromonomer copolymer solution with a solid content of 50% by mass) and 58.3 parts of an epoxy resin (jER828 (trade name)) were mixed, and dried under reduced pressure using a vacuum dryer to remove the solvent, obtaining a premix with the volatile components removed. This premix, 6 parts of DICY as a curing agent, 1 part of DCMU as a curing accelerator, and 9.7 parts of epoxy resin (jER828) were mixed using an Awa Taro ((Shinchi Co., Ltd.)) to prepare a resin composition. The average epoxy equivalent of the epoxy resin was 190 g / equivalent, and the weight average molecular weight was 370.

[0141] <Comparative Example 2> 15462.5 parts of MX (25 parts of CSR and 42.5 parts of epoxy resin (jER828 (trade name))), 6 parts of DICY as a curing agent, 1 part of DCMU as a curing accelerator, and 30.5 parts of epoxy resin (jER828) were mixed with a paint shaker (manufactured by Shinki Co., Ltd.) to prepare a resin composition.

[0142] (Method for Measuring Glass Transition Temperature) The resin compositions obtained in Examples 2, 4, 6 to 8, 11, 12, 14, 15 and Comparative Examples 2 to 4 were degassed by evacuation while mixing with a paint shaker (manufactured by Shinki Co., Ltd.), and then injected into a mold set to a thickness of 1 mm with a 1 mm thick Teflon (registered trademark) spacer. In an oven, it was heated at 170 °C for 30 minutes to obtain a cured resin product. The obtained cured resin product was molded into dimensions of 1 mm × 5 mm × 50 mm, and the temperature dependence of viscosity was measured under the following measurement conditions. The ratio of the storage modulus (G') to the loss modulus (G") (G" / G': loss tangent) obtained by this measurement was defined as tanδ. When tanδ was plotted against temperature, an upwardly convex curve, i.e., a peak, was obtained. The temperature at the apex of the peak was defined as the glass transition temperature, i.e., tanδ-Tg, and the maximum temperature of the peak with the lowest temperature among the peaks was regarded as the glass transition temperature of the cured resin product.

[0143] (Measurement Conditions for Dynamic Viscoelasticity of Cured Resin) DMS6100: Manufactured by Hitachi High-Tech Science Corporation Measurement mode: Tension Strain: 0.05% Measurement frequency: 10.0 Hz Distance between supports: 20 mm Heating rate: 2 °C / min (-110 °C to 150 °C) The results obtained are shown in Table 3.

[0144] Also, to 100 parts of each of the resin compositions obtained in Examples 1 to 15 and Comparative Examples 1 to 4, 1 part of glass beads J-100 (manufactured by Potters Ballotini) was added and mixed with a paint shaker (manufactured by Shinki Co., Ltd.). On one side of a steel plate (JIS G3141 SPCC-SD, manufactured by Engineering Test Services Co., Ltd.) with a width of 25 mm × a length of 150 mm × a thickness of 0.5 mm, the portion from one end in the length direction to 50 mm was left as a gripping margin, and the resin composition was applied to the other portion. On this applied surface, another steel plate of the same size was bonded, fixed so that the thickness of the resin composition layer became uniform, heated at 170 °C for 30 minutes, and the resin composition layer was cured to obtain a laminate. The overhang of the resin composition layer on the side surface of the laminate was scraped off, and the gripping margin portions of the two steel plates were bent at a right angle of 90° outward to obtain a T-shaped test piece. Using an autograph AG-Xplus (manufactured by Shimadzu Corporation, load cell 10 kN), the gripping margin portion of the obtained test piece was held vertically, the gripping margin portion was moved at a speed of 200 mm / min to measure the peel strength, and the average value of the peel strength excluding the first 25 mm and the last 25 mm was calculated. The measurement temperature was -40 °C. The results are shown in Table 3. In addition, based on the following criteria, the obtained peel strength values were classified. ◎: The peel strength is 170 N / 25 mm or more. 〇: The peel strength is 140 N / 25 mm or more and less than 170 N / 25 mm. ×: The peel strength is less than 140 N / 25 mm.

[0145]

Table 3

[0146] Further, the resin composition obtained in Example 1 was degassed by evacuation while being mixed with a mixer (manufactured by Shinki Co., Ltd.) and then injected into a mold set to a thickness of 200 μm with a 200-μm-thick Teflon (registered trademark) spacer. It was heated in an oven at 170 °C for 30 minutes to obtain a cured resin product. The obtained cured resin product was attached to an acrylic support, stained using osmium tetroxide (OsO4), sliced thinly, and a transmission electron image was obtained at a magnification of 100,000 under the following conditions using a transmission electron microscope (TEM), and the morphology was evaluated visually. As a result, the average domain size of polymer (B) was less than 1000 nm. Apparatus: H-7600 transmission electron microscope (manufactured by Hitachi, Ltd.) Accelerating voltage: 80 kV

[0147] In the same manner as the resin composition obtained in Example 1, TEM observation of the cured resin products of the resin compositions obtained in Examples 2 to 15 and Comparative Examples 2 to 4 was performed. As a result, the average domain size of polymer (B) in the cured resin products was less than 1000 nm.

[0148] Epoxy adhesives are assumed to be used in various environments. In particular, since use in harsh environments such as cold regions is also assumed, it is considered desirable for the adhesive to have a peel strength of 140 [N / 25 mm] or more at -40 °C. In Comparative Examples 1 to 4, the peel strength at -40 °C was lower than 140 [N / 25 mm], whereas in Examples 1 to 15, high peel strengths were obtained.

Claims

1. A composition comprising an epoxy resin (A), a polymer (B), and a polymer (C), wherein: the glass transition temperature of the polymer (B) is -90°C or lower; the polymer (C) has a first polymer segment having a (meth)acrylate as a constituent unit and a difference in SP value from the epoxy resin (A) of 1.5 or less, and a second polymer segment having a difference in SP value from the polymer (B) of 1.0 or less, the resin composition.

2. The resin composition according to claim 1, wherein the polymer (B) is a liquid compound.

3. The resin composition according to claim 1 or 2, wherein the polymer (B) contains 1,3-butadiene as a monomer unit.

4. The resin composition according to any one of claims 1 to 3, wherein the SP value of the first polymer segment is greater than the SP value of the second polymer segment.

5. The resin composition according to any one of claims 1 to 4, wherein the polymer (C) is a macromonomer copolymer.

6. A cured resin comprising an epoxy resin (A), a polymer (B), and a polymer (C), wherein: the glass transition temperature of the polymer (B) is -90°C or lower; the polymer (C) has a first polymer segment having a (meth)acrylate as a constituent unit and a difference in SP value from the epoxy resin (A) of 1.5 or less, and a second polymer segment having a difference in SP value from the polymer (B) of 1.0 or less; a cured resin having a glass transition temperature determined as the peak value of tanδ in dynamic viscoelasticity measurement of -90°C or lower.

7. The cured resin according to claim 6, wherein the average domain size of the polymer (B) is 1000 nm or less.

8. The cured resin according to claim 6 or 7, wherein the polymer (B) contains 1,3-butadiene as a monomer unit.

9. The cured resin according to any one of claims 6 to 8, wherein the SP value of the first polymer segment is greater than the SP value of the second polymer segment.

10. The cured resin according to any one of claims 6 to 9, wherein the polymer (C) is a macromonomer copolymer.

Images