JP7277241B2 - Adhesion method using polymer fine particle-containing curable resin composition excellent in workability, and laminate obtained by using the adhesion method - Google Patents

Description

TECHNICAL FIELD The present invention relates to a curable resin composition having excellent workability and containing an epoxy resin as a main component.

Cured epoxy resins are excellent in many respects, such as dimensional stability, mechanical strength, electrical insulation properties, heat resistance, water resistance, and chemical resistance. However, the cured products of epoxy resins have low fracture toughness and may exhibit very brittle properties, and such properties often pose problems in a wide range of applications.

Patent Literature 1 discloses a technique of dispersing fine polymer particles having a core-shell structure in a curable resin composition containing a curable resin such as an epoxy resin as a main component.

Patent Documents 2, 3, and 4 disclose a combination of a curable resin composition containing an epoxy resin as a main component, polymer fine particles having a core-shell structure, and blocked urethane as a reinforcing agent other than the core-shell polymer fine particles. technology is disclosed.

On the other hand, a liquid curable resin composition containing an epoxy resin as a main component generally has a low viscosity when the temperature is high, such as in summer, and increases significantly when the temperature is low, such as in winter. Thus, the viscosity of the curable resin composition is temperature dependent.

In general, it is known that adhesives containing epoxy resin as a main component have higher adhesive strength such as shear adhesiveness when the thickness of the adhesive layer is reduced. Therefore, after the adhesive is applied to one adherend, the adhesive is spread thinly by using a spatula or the like.

As described in Patent Literature 5, there is known an epoxy-based adhesive that can be applied by heating and exhibits sufficient applicability when heated.

WO2009/034966 WO2016/159223 WO2016/159224 WO2016/163491 JP 2017-132953 A

However, the conventional techniques as described above have room for further improvement from the viewpoint of the temperature dependence of the viscosity of the curable resin composition and the workability of the bonding method using the curable resin composition.

One embodiment of the present invention has been made in view of the above circumstances, and an object of the present invention is to provide a bonding method excellent in workability by using a curable resin composition having a low temperature dependence of viscosity. do. Another object of one embodiment of the present invention is to provide a laminate obtained by the bonding method and a method for producing the laminate.

As a result of intensive studies to solve such problems, the present inventors have developed a curable resin composition containing an epoxy resin (A), polymer fine particles having a core-shell structure (B), and blocked urethane (C). In the bonding method used, the inventors have found that the above problems can be solved by selecting a blocked urethane (C) having a specific latent NCO % value, and completed the present invention.

That is, one embodiment of the present invention is as follows.
[1] (i) step 1 of heating the curable resin composition to a first temperature and applying it to one adherend in a first thickness; Step 2 of stretching the applied curable resin composition to a second thickness in an environment of a second temperature before or at the same time as bonding the adherends, and (iii) bonding 2 A step 3 of curing the curable resin composition sandwiched between the two adherends, wherein the first temperature is higher than the second temperature, and the second thickness is the first thickness The curable resin composition comprises an epoxy resin (A) and polymer fine particles (B) 1 having a core-shell structure including a core layer and a shell layer with respect to 100 parts by mass of the epoxy resin (A). A bonding method containing 1 to 100 parts by weight of blocked urethane (C) having a latent NCO % of 0.1 to 2.9% and 1 to 100 parts by weight.
[2] In [1], the ratio (W1/W2) of the mass (W1) of the polymer fine particles (B) to the mass (W2) of the blocked urethane (C) is 0.1 to 10.0 Adhesion method as described.
[3] The shell layer according to [1] or [2], wherein the shell layer has an epoxy group, and the content of the epoxy group relative to the total mass of the shell layer is 0.4 mmol/g to 5.0 mmol/g. Adhesion method.
[4] The curable resin composition further contains 1 part by mass to 80 parts by mass of an epoxy resin curing agent (D) with respect to 100 parts by mass of the epoxy resin (A) [1] to [3] The adhesion method according to any one of.
[5] The curable resin composition further contains 0.1 parts by mass to 10.0 parts by mass of a curing accelerator (E) with respect to 100 parts by mass of the epoxy resin (A) from [1] The bonding method according to any one of [4].
[6] The bonding method according to any one of [1] to [5], wherein the epoxy resin (A) is a bisphenol A type epoxy resin and/or a bisphenol F type epoxy resin having an epoxy equivalent of less than 220.
[7] The adhesion method according to any one of [1] to [6], wherein the core layer is butadiene rubber and/or butadiene-styrene rubber.
[8] The shell layer has a polymer obtained by graft-polymerizing at least one monomer component selected from the group consisting of an aromatic vinyl monomer, a vinyl cyanide monomer and a (meth)acrylate monomer to the core layer. The bonding method according to any one of [1] to [7].
[9] The bonding method according to any one of [1] to [8], wherein the shell layer comprises a polymer obtained by graft-polymerizing a monomer component having an epoxy group to the core layer.
[10] The adhesion method according to any one of [1] to [9], wherein the blocked urethane (C) is a compound obtained by capping a urethane prepolymer containing a polypropylene glycol structure with a blocking agent.
[11] The bonding method according to any one of [1] to [10], wherein the first temperature is 35°C to 80°C.
[12] The bonding method according to any one of [1] to [11], wherein the curing temperature in the step 3 is 50°C to 250°C.
[13] A laminate obtained by using the bonding method according to any one of [1] to [12].
[14] A method for producing a laminate, comprising the bonding method according to any one of [1] to [12] as one step.

The curable resin composition according to one embodiment of the present invention has a small temperature dependence of viscosity, and an adhesion method using the curable resin composition has an effect of being excellent in workability.

An embodiment of the invention will be described below, but the invention is not limited thereto. The present invention is not limited to each configuration described below, and various modifications are possible within the scope of the claims. Further, embodiments or examples obtained by appropriately combining technical means disclosed in different embodiments or examples are also included in the technical scope of the present invention. Furthermore, new technical features can be formed by combining the technical means disclosed in each embodiment. In addition, all the scientific literatures and patent documents described in this specification are used as references in this specification. In addition, unless otherwise specified in this specification, "A to B" representing a numerical range means "A or more (including A and greater than A) and B or less (including B and less than B)".

[1. Technical idea of one embodiment of the present invention]
The temperature dependence of the viscosity of the curable resin composition as described above poses a problem depending on the method of use of the curable resin composition, and is therefore desired to be improved.

The inventor of the present invention has studied the heat application type epoxy adhesive disclosed in Patent Document 5. The heat application type epoxy adhesive corresponds to the curable resin composition in one embodiment of the present invention. As a result, the present inventor found that when the temperature dependence of the viscosity of the hot application type epoxy adhesive is large, when the adhesive is heated and applied (hereinafter also referred to as "heat application") It was found that it is difficult to achieve both the workability of the adhesive and the workability of the applied adhesive under a room temperature environment. Specifically, the present inventor independently found that the following problems occur when the temperature dependency of the viscosity of an epoxy adhesive that is applied by heating is large. That is, (i) when the viscosity of the adhesive during application with heat is set low, the viscosity of the adhesive during application with heat is too low, and the applied adhesive may drip, and (ii) the adhesive. When the viscosity during hot application is set high, the temperature of the applied composition (adhesive) drops in a room temperature environment after hot application of the adhesive, and the viscosity of the adhesive increases significantly. The inventors have independently found that it can be difficult to roll the adhesive thin.

The subject of Patent Document 2 is the thixotropic property of the composition, the subject of Patent Document 3 is the storage stability of the composition, and the subject of Patent Document 4 is the impact resistance of a cured product obtained by curing the composition. None of the patent documents teaches any means for improving the temperature dependence of viscosity.

Accordingly, the present inventor has made it a subject to improve the temperature dependence of the viscosity of a curable resin composition. In a resin composition in which a particle component such as the polymer fine particles (B) according to one embodiment of the present invention is dispersed in a liquid matrix resin such as the epoxy resin (A), It is known that structural viscosity associated with weak interactions between the In order to improve the temperature dependence of the viscosity of the resin composition, the present inventor set a unique problem of obtaining a resin composition having a large structural viscosity at high temperatures as well as at low temperatures, and made earnest studies. did In the process, the present inventor independently discovered that the larger the difference between the polarity of the matrix resin and the polarity of the particle component, the greater the structural viscosity of the resin composition even at high temperatures. Specifically, the present inventor independently found that the structural viscosity of the resin composition increases even at high temperatures by lowering the polarity of the matrix resin and increasing the polarity of the particle component. .

As a result of further intensive studies based on such new findings, the present inventors have found that, in a curable resin composition containing an epoxy resin, the temperature dependence of the viscosity of the curable resin composition is due to polymer fine particles having a core-shell structure and blocked We have independently found that it changes depending on the combined use with urethane and the structure of blocked urethane. Based on such new findings, the present inventors have made intensive studies on polymer fine particles and blocked urethane, and as a result, have completed the present invention.

[2. Adhesion method (first adhesion method)]
A bonding method according to an embodiment of the present invention comprises (i) a step 1 of heating a curable resin composition to a first temperature and applying it to one adherend in a first thickness, (ii) Step 2 of stretching the applied curable resin composition to a second thickness under a second temperature environment before or at the same time as bonding the other adherend to the one adherend. and (iii) a step 3 of curing the curable resin composition sandwiched between the two bonded adherends. The first temperature is higher than the second temperature and the second thickness is less than the first thickness. The curable resin composition comprises an epoxy resin (A) and 1 mass of polymer fine particles (B) having a core-shell structure including a core layer and a shell layer per 100 parts by mass of the epoxy resin (A). parts to 100 parts by weight and 1 part to 100 parts by weight of blocked urethane (C) having a latent NCO % of 0.1% to 2.9%. This bonding method is also referred to as a first bonding method.

Since the first bonding method according to one embodiment of the present invention has the above configuration, it is excellent in workability.

(2-1. Curable resin composition)
Hereinafter, the curable resin composition used in the first bonding method according to one embodiment of the present invention will be described in detail.

The curable resin composition according to one embodiment of the present invention comprises an epoxy resin (A), and polymer fine particles having a core-shell structure containing a core layer and a shell layer with respect to 100 parts by mass of the epoxy resin (A) ( B) 1 to 100 parts by mass and 1 to 100 parts by mass of blocked urethane (C) having a latent NCO% of 0.1 to 2.9%.

The curable resin composition according to one embodiment of the present invention has low temperature dependence of viscosity, and is effective when used in the first bonding method according to one embodiment of the present invention.

Since the curable resin composition can be used to bond at least two adherends, the term "curable resin composition" can also be called an "adhesive." In this specification, the "curable resin composition" is also referred to as "curable epoxy resin composition", "composition" or "adhesive".

Although the reason why the temperature dependence of the viscosity of the curable resin composition according to one embodiment of the present invention is small is not clear, it is presumed as follows. A system in which a particle component such as the polymer fine particles (B) according to one embodiment of the present invention is dispersed in a liquid matrix resin such as the epoxy resin (A) is formed between the particle components (hereinafter also referred to as between particles). ) is known to easily develop structural viscosity associated with weak interactions. The interaction between particles appears to depend on the polarity of the matrix resin. In one embodiment of the present invention, the polarity of the matrix resin is controlled by blending the relatively low polar blocked urethane (C) with the highly polar epoxy resin (A). That is, in one embodiment of the present invention, the polarity of the matrix resin is lowered with respect to the polarity of the particle component by blending the blocked urethane (C) having relatively low polarity with the epoxy resin (A). . This is expected to result in a higher interaction between particles in one embodiment of the present invention. It is presumed that when the interaction between particles is enhanced, the particles are less likely to be separated even at high temperatures, and as a result, the structural viscosity is maintained even at high temperatures, and the temperature dependence of viscosity is reduced. An embodiment of the present invention is not limited to assumptions and expectations as described above.

<Epoxy resin (A)>
An epoxy resin (A) is used as the main component of the curable resin composition according to one embodiment of the present invention.

In this specification, the "epoxy resin (A)" is also referred to as "(A) component".

As the epoxy resin (A), various hard epoxy resins can be used, excluding rubber-modified epoxy resins and urethane-modified epoxy resins, which will be described later. Examples of the epoxy resin (A) include bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol AD type epoxy resin, bisphenol S type epoxy resin, glycidyl ester type epoxy resin, glycidylamine type epoxy resin, novolac type epoxy resin. , glycidyl ether type epoxy resin of bisphenol A propylene oxide adduct, hydrogenated bisphenol A (or F) type epoxy resin, fluorinated epoxy resin, flame retardant epoxy resin such as glycidyl ether of tetrabromobisphenol A, p-oxybenzoin Acid glycidyl ether ester type epoxy resin, m-aminophenol type epoxy resin, diaminodiphenylmethane type epoxy resin, various alicyclic epoxy resins, N,N-diglycidylaniline, N,N-diglycidyl-o-toluidine, triglycidyl isocyanate Nurate, divinylbenzene dioxide, resorcinol diglycidyl ether, polyalkylene glycol diglycidyl ether, glycol diglycidyl ether, diglycidyl esters of aliphatic polybasic acids, glycidyl ethers of dihydric or higher polyhydric aliphatic alcohols such as glycerin , chelate-modified epoxy resins, hydantoin-type epoxy resins, epoxidized products of unsaturated polymers such as petroleum resins, aminoglycidyl ether resins, and bisphenol A (or F) or polybasic acids in these epoxy resins. is exemplified by an epoxy compound obtained by addition reaction of The epoxy resin (A) is not limited to these, and commonly used epoxy resins can be used.

The "hard epoxy resin" intends an epoxy resin having a specific glass transition temperature (Tg), and includes, for example, an epoxy resin having a Tg of 50°C or higher.

More specific examples of the polyalkylene glycol diglycidyl ether include polyethylene glycol diglycidyl ether and polypropylene glycol diglycidyl ether. More specific examples of the glycol diglycidyl ether include neopentyl glycol diglycidyl ether, 1,4-butanediol diglycidyl ether, 1,6-hexanediol diglycidyl ether, cyclohexanedimethanol diglycidyl ether, and the like. be done. More specific examples of the diglycidyl esters of aliphatic polybasic acids include diglycidyl dimer, diglycidyl adipate, diglycidyl sebacate, and diglycidyl maleate. More specifically, the glycidyl ethers of dihydric or higher polyhydric aliphatic alcohols include trimethylolpropane triglycidyl ether, trimethylolethane triglycidyl ether, castor oil-modified polyglycidyl ether, propoxylated glycerol triglycidyl ether, and sorbitol. polyglycidyl ether and the like. Examples of epoxy compounds obtained by addition reaction of polybasic acids and the like to epoxy resins include, for example, tall oil fatty acid dimer (dimer acid) and bisphenol A type epoxy, as described in WO2010-098950. An addition reaction product with a resin can be mentioned. One type of these epoxy resins may be used alone, or two or more types may be used in combination.

The polyalkylene glycol diglycidyl ether, the glycol diglycidyl ether, the diglycidyl ester of the aliphatic polybasic acid, and the glycidyl ether of the dihydric or higher polyhydric aliphatic alcohol are epoxy resins having relatively low viscosity. . When these epoxy resins are used in combination with other epoxy resins such as bisphenol A type epoxy resins and bisphenol F type epoxy resins, these epoxy resins can function as reactive diluents. As a result, these epoxy resins can improve the balance between the viscosity of the composition and the physical properties of the cured product obtained from the composition. A curable resin composition according to one embodiment of the present invention may contain an epoxy resin that can function as a reactive diluent. The content of these epoxy resins that function as reactive diluents is preferably 0.5% by mass to 20% by mass, more preferably 1% by mass to 10% by mass, and 2% by mass in 100% by mass of the epoxy resin (A). % to 5% by mass is more preferred.

The chelate-modified epoxy resin is a reaction product of an epoxy resin and a compound containing a chelate functional group (chelate ligand). When a chelate-modified epoxy resin is added to the curable resin composition according to one embodiment of the present invention and used as an adhesive, the adhesiveness to the surface of metal substrates contaminated with oily substances can be improved. A chelate functional group is a functional group of a compound having _multiple coordination sites in the molecule that can coordinate to a metal ion. CO ₂ H), sulfur-containing acid groups (eg —SO ₃ H), amino groups and hydroxyl groups (especially hydroxyl groups adjacent to each other on an aromatic ring), and the like. Chelating ligands include ethylenediamine, bipyridine, ethylenediaminetetraacetic acid, phenanthroline, porphyrin, crown ether, and the like. Commercially available chelate-modified epoxy resins include ADEKA ADEKA ADEKA RESIN EP-49-10N.

The amount of the chelate-modified epoxy resin used in component (A) is preferably 0.1 to 10% by mass, more preferably 0.5 to 3% by mass.

In the present specification, the "use amount" of a certain component can be said to be the "addition amount" of the component, or the "content" of the component in the curable resin composition.

Among these epoxy resins, those having at least two epoxy groups in one molecule have high reactivity in curing of the resulting curable resin composition, and the resulting cured product tends to form a three-dimensional network. It is preferable from the point of view.

Among the epoxy resins described above, bisphenol A type epoxy resin and bisphenol F type epoxy resin are preferable because they have a high elastic modulus and give a cured product having excellent heat resistance and adhesiveness, and are relatively inexpensive. type epoxy resins are particularly preferred.

Among the various epoxy resins described above, epoxy resins having an epoxy equivalent of less than 220 are preferable because the resulting cured product has a high elastic modulus and heat resistance, and the temperature dependence of viscosity is small. Among the epoxy resins described above, epoxy resins having an epoxy equivalent of 90 or more and less than 210 are more preferable, and epoxy resins having an epoxy equivalent of 150 or more and less than 200 are even more preferable.

The epoxy resin (A) is preferably a bisphenol A type epoxy resin and/or a bisphenol F type epoxy resin having an epoxy equivalent of less than 220.

In particular, bisphenol A-type epoxy resins and bisphenol F-type epoxy resins having an epoxy equivalent of less than 220 are liquid at room temperature, and the viscosity of the resulting curable resin composition has little temperature dependency and is easy to handle. .

A bisphenol A type epoxy resin and a bisphenol F type epoxy resin having an epoxy equivalent of 220 or more and less than 5000 are added in an amount of preferably 40% by mass or less, more preferably 20% by mass or less, based on 100% by mass of component (A). is preferred. According to the above configuration, there is an advantage that the resulting cured product has excellent impact resistance.

<2-1-2. Polymer microparticles (B)>
In the curable resin composition according to one embodiment of the present invention, 1 part by mass to 100 parts by mass of fine polymer particles (B) having a core-shell structure including a core layer and a shell layer are added to 100 parts by mass of component (A). to use.

In the present specification, "polymer microparticles (B)" are also referred to as "polymer microparticles", "polymer particles", "core-shell polymer (B)" or "component (B)".

Due to the toughness-improving effect of component (B), the resulting cured product has excellent toughness and elongation properties.

Since the balance between the ease of handling of the curable resin composition obtained and the effect of improving the toughness of the obtained cured product is good, the amount of component (B) is 1 part by mass to 1 part by mass with respect to 100 parts by mass of component (A). 100 parts by mass is preferable, 3 to 70 parts by mass is more preferable, 5 to 50 parts by mass is even more preferable, and 10 to 40 parts by mass is particularly preferable.

A curable resin composition with low temperature dependence of viscosity can be obtained by combining fine polymer particles, which is the component (B) according to one embodiment of the present invention, with blocked urethane, which is the component (C) described below. .

The volume average particle diameter (Mv) of the polymer fine particles is not particularly limited, but considering industrial productivity, the volume average particle diameter (Mv) is preferably 10 nm to 2000 nm, more preferably 30 nm to 600 nm, and further 50 nm to 400 nm. Preferably, 100 nm to 200 nm is particularly preferred. The volume average particle diameter (Mv) of the polymer particles is determined by using a dynamic light scattering particle size distribution analyzer (for example, Microtrac UPA150 (manufactured by Nikkiso Co., Ltd.)) using an aqueous latex containing the polymer fine particles (B) as a sample. can be measured using

A method for measuring the volume average particle size of the polymer microparticles (B) will be described in detail in Examples below. In addition, the volume average particle diameter of the polymer fine particles (B) is obtained by cutting the cured product of the curable resin composition, imaging the cut surface using an electron microscope or the like, and using the obtained imaging data (captured image). can also be measured.

In the composition according to one embodiment of the present invention, the component (B) has a half width of 0.5 times or more and 1 time or less of the volume average particle size in the number distribution of the volume average particle size. However, it is preferable because the resulting curable resin composition has a low viscosity and is easy to handle.

From the viewpoint of easily realizing the above-mentioned specific particle size distribution, it is preferable that the number distribution of the volume average particle size of the component (B) has two or more maximum values, and from the viewpoint of labor and cost during production. , more preferably 2 to 3 maxima, and more preferably 2 maxima. Component (B) is particularly composed of 10% to 90% by mass of polymer fine particles having a volume average particle diameter of 10 nm or more and less than 150 nm and 90% to 10% by mass of polymer fine particles having a volume average particle diameter of 150 nm or more and 2000 nm or less. preferably included.

Component (B) is preferably dispersed in the form of primary particles in the curable resin composition. In one embodiment of the present invention, "the polymer fine particles are dispersed in the curable resin composition in the form of primary particles" (hereinafter also referred to as primary dispersion) means that the polymer fine particles are substantially independent of each other. means that it is dispersed (without contact). It can be confirmed by measuring the volume average particle size (Mv)/number average particle size (Mn) of the fine polymer particles (B) using a distribution measuring device or the like.

The value of volume average particle size (Mv)/number average particle size (Mn) by particle size measurement is not particularly limited, but is preferably 3 or less, more preferably 2.5 or less, and still more preferably 2 or less. , 1.5 or less are particularly preferred. If the volume average particle size (Mv)/number average particle size (Mn) is 3 or less, it is considered that the particles are well dispersed. Conversely, when the curable resin composition has a particle size distribution of more than 3, the resulting cured product may have poor physical properties such as impact resistance and adhesiveness.

The volume average particle size (Mv)/number average particle size (Mn) is obtained by measuring the volume average particle size (Mv) and the number average particle size (Mn) using Microtrac UPA (manufactured by Nikkiso Co., Ltd.). , Mv by Mn.

In addition, the "stable dispersion" of the polymer fine particles means that the polymer fine particles can be stably maintained for a long period of time under normal conditions without aggregating, separating, or precipitating in the continuous layer. , meaning the state of being dispersed. In addition, the distribution of the polymer fine particles in the continuous layer does not substantially change, and the continuous layer (for example, the curable resin composition) is heated within a safe range to lower the viscosity of the continuous layer and stir. It is preferable that the "stable dispersion" of the polymer fine particles (B) is maintained even if the dispersion is carried out.

Component (B) may be used alone or in combination of two or more.

Although the structure of the fine polymer particles is not particularly limited, it preferably has a core-shell structure of two or more layers. Further, the fine polymer particles (B) may have a structure of three or more layers composed of an intermediate layer covering the core layer and a shell layer further covering the intermediate layer.

It can also be said that the fine polymer particles (B) preferably have a core-shell structure comprising one or more core layers and one or more shell layers.

Each layer will be specifically described below.

≪Core layer≫
The core layer of the core-shell polymer (B) according to one embodiment of the present invention consists of (i) natural rubber, (ii) (a) a diene-based monomer (also referred to as a conjugated diene-based monomer) and a (meth)acrylate-based monomer. 50 to 100% by mass of at least one monomer selected from the group (also referred to as the first monomer), and (b) another vinyl-based monomer copolymerizable with the first monomer (also referred to as the second monomer) is 0 Rubber elastomer obtained by polymerizing a monomer mixture containing up to 50% by mass, (iii) polysiloxane rubber-based elastomer, and (iv) a combination thereof.

A polysiloxane rubber-based elastic body is also referred to as an organosiloxane-based rubber.

Polymerizing a monomer mixture containing 50 to 100% by mass of at least one monomer selected from the group consisting of diene monomers and 0 to 50% by mass of another vinyl monomer copolymerizable with the diene monomer. The rubber elastic body obtained by this is also called a diene rubber.

Contains 50 to 100% by weight of at least one monomer selected from the group consisting of (meth)acrylate monomers and 0 to 50% by weight of other vinyl monomers copolymerizable with (meth)acrylate monomers A rubber elastomer obtained by polymerizing a monomer mixture is also called a (meth)acrylate rubber.

The core layer preferably contains one or more selected from the group consisting of diene-based rubbers, (meth)acrylate-based rubbers, and organosiloxane-based rubbers.

The core layer has a high effect of improving the toughness of the resulting cured product, and since it has a low affinity with the matrix resin, it is difficult for the core layer to increase in viscosity over time due to swelling. system rubber is preferred. The core layer is preferably made of (meth)acrylate-based rubber using (meth)acrylate-based monomers, because a wide range of polymer designs are possible by combining various types of monomers. In order to improve the impact resistance at low temperatures without lowering the heat resistance of the cured product, the elastic core layer is preferably made of a polysiloxane rubber-based elastic body. In this specification, (meth)acrylate means acrylate and/or methacrylate. Also, the "elastic core layer" intends a core layer having rubber properties.

(Core layer (diene rubber))
Examples of the diene-based monomer (conjugated diene-based monomer) of the first monomer include 1,3-butadiene, isoprene (2-methyl-1,3-butadiene), 2-chloro-1,3-butadiene, and the like. be done. These diene-based monomers may be used singly or in combination of two or more.

The core layer is preferably butadiene rubber and/or butadiene-styrene rubber.

Butadiene rubber using 1,3-butadiene or 1,3- Butadiene-styrene rubber, which is a copolymer of butadiene and styrene, is preferred, and butadiene rubber is more preferred. Further, butadiene-styrene rubber is more preferable because it can improve the transparency of the cured product obtained by adjusting the refractive index.

(Core layer (acrylic rubber))
Examples of the (meth)acrylate-based monomer of the first monomer include (i) methyl (meth)acrylate, ethyl (meth)acrylate, butyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, octyl (meth)acrylate, ) Alkyl (meth)acrylates such as acrylate, dodecyl (meth)acrylate, stearyl (meth)acrylate and behenyl (meth)acrylate; (ii) Aromatic ring-containing compounds such as phenoxyethyl (meth)acrylate and benzyl (meth)acrylate ( meth)acrylates; (iii) hydroxyalkyl (meth)acrylates such as 2-hydroxyethyl (meth)acrylate and 4-hydroxybutyl (meth)acrylate; (iv) glycidyl (meth)acrylate and glycidylalkyl (meth)acrylate (v) alkoxyalkyl (meth)acrylates; (vi) allylalkyl (meth)acrylates, such as allyl (meth)acrylate and allylalkyl (meth)acrylate; (vii) mono polyfunctional (meth)acrylates such as ethylene glycol di(meth)acrylate, triethylene glycol di(meth)acrylate, tetraethylene glycol di(meth)acrylate, and the like; These (meth)acrylate monomers may be used singly or in combination of two or more. Particularly preferred (meth)acrylate monomers are ethyl (meth)acrylate, butyl (meth)acrylate and 2-ethylhexyl (meth)acrylate.

(Second monomer)
Examples of the other vinyl-based monomer (second monomer) copolymerizable with the first monomer include (i) vinylarenes such as styrene, α-methylstyrene, monochlorostyrene, and dichlorostyrene; (ii) acrylic (iii) vinyl cyanides such as acrylonitrile and methacrylonitrile; (iv) vinyl halides such as vinyl chloride, vinyl bromide and chloroprene; (v) vinyl acetate; (vi) ) alkenes such as ethylene, propylene, butylene and isobutylene; and (vii) polyfunctional monomers such as diallyl phthalate, triallyl cyanurate, triallyl isocyanurate and divinylbenzene. These vinyl monomers may be used singly or in combination of two or more. Styrene is particularly preferred because it can easily increase the refractive index.

(Polysiloxane rubber elastic body)
Examples of the polysiloxane rubber-based elastic material include (i) alkyl- or aryl-disubstituted silyloxy such as dimethylsilyloxy, diethylsilyloxy, methylphenylsilyloxy, diphenylsilyloxy, and dimethylsilyloxy-diphenylsilyloxy. and (ii) a polysiloxane system composed of alkyl- or aryl-monosubstituted silyloxy units, such as organohydrogensilyloxy in which some of the side chain alkyls are substituted with hydrogen atoms. polymers. These polysiloxane-based polymers may be used singly or in combination of two or more. Among them, dimethylsilyloxy, methylphenylsilyloxy and dimethylsilyloxy-diphenylsilyloxy are preferable because they can impart heat resistance to the cured product, and dimethylsilyloxy is most preferable because it is easily available and economical. . In the embodiment in which the core layer is formed of a polysiloxane rubber-based elastic body, the polysiloxane-based polymer portion is 80% by mass or more (more preferably 90% by mass or more) is preferably contained.

(Crosslinking of core layer)
A crosslinked structure is preferably introduced into the core layer of the core-shell polymer (B) from the viewpoint of maintaining the dispersion stability of the core-shell polymer (B) in the curable epoxy resin composition. As a method for introducing a crosslinked structure, a generally used known method can be adopted.

For example, as a method of introducing a crosslinked structure into a polymer component obtained by polymerizing the first monomer and the second monomer, a crosslinkable monomer such as a polyfunctional monomer and/or a mercapto group-containing compound is added to the polymer component. , followed by polymerization. Methods for introducing a crosslinked structure into a polysiloxane polymer include, for example, (i) a method in which a polyfunctional alkoxysilane compound is partially used during polymerization, and (ii) a reaction with a vinyl reactive group, a mercapto group, or the like. A method of introducing a functional group into a polysiloxane polymer and then adding a vinyl polymerizable monomer or an organic peroxide to cause a radical reaction, or (iii) adding a polyfunctional monomer and/or a mercapto A method of adding a crosslinkable monomer such as a group-containing compound, followed by polymerization, and the like.

(Polyfunctional monomer)
Examples of the polyfunctional monomer include (i) allylalkyl (meth)acrylates such as allyl (meth)acrylate and allylalkyl (meth)acrylate; (ii) allyloxyalkyl (meth)acrylates; (iii) (poly ) ethylene glycol di (meth) acrylate, butanediol di (meth) acrylate, ethylene glycol di (meth) acrylate, triethylene glycol di (meth) acrylate, tetraethylene glycol di (meth) acrylate (meth) acrylic group Polyfunctional (meth)acrylates having two or more; (iv) diallyl phthalate, triallyl cyanurate, triallyl isocyanurate, divinylbenzene and the like. Allyl methacrylate, triallyl isocyanurate, butanediol di(meth)acrylate, and divinylbenzene are particularly preferred.

(Gel content of core layer)
The core layer of the core-shell polymer (B) according to one embodiment of the present invention preferably has rubber properties in order to increase the toughness of the cured product of the curable epoxy resin composition. The gel content of the core layer of the core-shell polymer (B) according to one embodiment of the present invention is preferably 60% by mass or more, more preferably 80% by mass or more, from the viewpoint of the toughness of the cured product. It is more preferably 90% by mass or more, and particularly preferably 95% by mass or more.

In addition, the gel content in the present specification means that 0.5 g of crumbs obtained by coagulation and drying (granules containing polymer fine particles (B)) are immersed in 100 g of toluene and allowed to stand at 23° C. for 24 hours. , means the ratio of the insoluble matter to the total amount of the insoluble matter and the soluble matter when the insoluble matter and soluble matter are separated into toluene.

(Tg of core layer)
In one embodiment of the present invention, the glass transition temperature (hereinafter sometimes simply referred to as “Tg”) of the core layer of the core-shell polymer (B) is set at 0° C. or lower in order to increase the toughness of the resulting cured product. It is preferably -20°C or lower, more preferably -40°C or lower, and particularly preferably -60°C or lower.

On the other hand, when it is desired to suppress a decrease in rigidity (also referred to as a decrease in elastic modulus) of the resulting cured product, the Tg of the core layer is preferably higher than 0°C, more preferably 20°C or higher, and more preferably 50°C. It is more preferably 80° C. or higher, particularly preferably 80° C. or higher, and most preferably 120° C. or higher.

As a polymer capable of forming a core layer having a Tg greater than 0°C and capable of suppressing a decrease in rigidity of the resulting cured product, at least one monomer having a homopolymer Tg greater than 0°C is used in an amount of 50 to 100 masses. % (more preferably 65 to 99% by mass), and a monomer mixture containing 0 to 50% by mass (more preferably 1 to 35% by mass) of at least one monomer whose Tg of the homopolymer is less than 0 ° C. Examples include polymers obtained by polymerizing

Even when the Tg of the core layer is higher than 0° C., the core layer preferably has a crosslinked structure. Methods for introducing the crosslinked structure include the methods described above.

Examples of the monomer whose homopolymer Tg is higher than 0° C. include various compounds described in paragraph [0084] of the specification of WO2014-196607.

(Volume average particle diameter of core layer)
The volume average particle size of the core layer of the core-shell polymer (B) according to one embodiment of the present invention is preferably 0.03 μm to 2 μm, more preferably 0.05 μm to 1 μm. When the volume average particle size of the core layer of the core-shell polymer (B) is (a) 0.03 μm or more, it is often easy to stably obtain the core layer, and (b) is 2 μm or less. In this case, the heat resistance and impact resistance of the final molded product (cured product) do not deteriorate.

(ratio of core layer)
The core layer of the core-shell polymer (B) according to one embodiment of the present invention is preferably 40 to 97% by mass, more preferably 60 to 95% by mass, and 70 to 93% by mass, based on 100% by mass of the entire core-shell polymer (B). % is more preferred, and 80 to 90% by mass is particularly preferred. When the core layer is (a) 40% by mass or more in 100% by mass of the core-shell polymer (B), the effect of improving the toughness of the cured product is sufficiently exhibited, and when it is (b) 97% by mass or less, polymer fine particles has the advantage that it is difficult to aggregate, and the curable epoxy resin composition has a low viscosity and is easy to handle.

(Multilayer structure of core layer)
In one embodiment of the invention, the core layer may be a multi-layer structure. Moreover, when the core layer has a multilayer structure, each layer may have a different polymer composition.

≪Middle layer≫
The core-shell polymer (B) according to one embodiment of the invention may have an intermediate layer between the core layer and the shell layer. Core-shell polymer (B) may have, in particular, the following rubber surface crosslinked layer as an intermediate layer. From the standpoint of improving the toughness and impact resistance to peeling adhesion of the resulting cured product, the core-shell polymer (B) preferably does not contain the following rubber surface crosslinked layer as an intermediate layer.

The rubber surface crosslinked layer is formed by polymerizing a rubber surface crosslinked layer component comprising 30 to 100% by mass of a polyfunctional monomer having two or more radical double bonds in the same molecule and 0 to 70% by mass of other vinyl monomers. The intermediate layer consists of a polymer. The rubber surface cross-linked layer has the effect of reducing the viscosity of the curable epoxy resin composition according to one embodiment of the present invention and the effect of improving the dispersibility of the core-shell polymer (B) in component (A). The rubber surface crosslinked layer also has the effect of increasing the crosslink density of the core layer and the effect of increasing the graft efficiency of the shell layer.

Specific examples of the polyfunctional monomer include the same monomers as the polyfunctional monomers described above, preferably allyl methacrylate and triallyl isocyanurate.

≪Shell layer≫
The outermost shell layer of the fine polymer particles is made of a shell polymer obtained by polymerizing a shell layer-forming monomer. The shell polymer, that is, the shell layer, (a) plays a role of improving the compatibility between the fine polymer particles (B) and (A), and (b) the curable resin composition according to one embodiment of the present invention, or the It plays a role of enabling the fine polymer particles (B) to be dispersed in the state of primary particles in the cured product of the curable resin composition.

Such shell polymers are preferably grafted onto the core layer. More precisely, the monomer component used for forming the shell layer is graft-polymerized to the core polymer forming the core layer, and the core polymer and the shell polymer forming the shell layer are substantially chemically bonded. preferable. Preferably, the shell polymer is formed by graft-polymerizing a shell layer-forming monomer to the core polymer in the presence of the core polymer. By forming a shell polymer in this manner, the shell polymer is graft polymerized to the core polymer and may cover part or all of the core polymer. This polymerization operation can be carried out by adding the monomers constituting the shell polymer to the latex of the core polymer which is prepared in the form of an aqueous polymer latex and polymerizing it.

As the shell layer-forming monomer, from the viewpoint of compatibility and dispersibility in the curable resin composition of the component (B), for example, aromatic vinyl monomers, vinyl cyanide monomers and (meth)acrylate monomers are preferable. More preferred are meth)acrylate monomers. These shell layer-forming monomers may be used alone or in combination as appropriate.

The shell layer preferably contains a polymer obtained by graft-polymerizing at least one monomer component selected from the group consisting of an aromatic vinyl monomer, a vinyl cyanide monomer and a (meth)acrylate monomer to the core layer. . This configuration has the advantage that the component (B) has excellent compatibility and dispersibility in the curable resin composition.

The total amount of the aromatic vinyl monomer, vinyl cyanide monomer and (meth)acrylate monomer is preferably 10 to 95% by mass, more preferably 30 to 92% by mass, based on 100% by mass of the shell layer-forming monomer. Preferably, 50 to 90% by mass is more preferable, 60 to 87% by mass is particularly preferable, and 70 to 85% by mass is most preferable.

In the shell layer of component (B), the content of cyano groups with respect to the total mass of the shell layer is not particularly limited. From the viewpoint of impact strength, 1.0 mmol/g to 13.0 mmol/g is preferable, 1.5 mmol/g to 11.0 mmol/g is more preferable, and 2.0 mmol/g to 10.0 mmol/g is more preferable. , more preferably 2.5 mmol/g to 9.0 mmol/g, more preferably 5.0 mmol/g to 10.0 mmol/g, even more preferably 5.5 mmol/g to 9.5 mmol/g, and 7.0 mmol /g to 9.0 mmol/g is particularly preferred.

The shell layer is preferably chemically bonded to component (A) so that component (B) does not agglomerate in the cured product and/or polymer and maintains a good dispersed state. From the viewpoint of chemically bonding the shell layer to component (A), shell layer-forming monomers include epoxy groups, hydroxy groups, oxetane groups, amino groups, imide groups, carboxylic acid groups, carboxylic anhydride groups, cyclic esters, cyclic It is preferable to contain a reactive group-containing monomer which is a monomer containing one or more selected from the group consisting of an amide, a benzoxazine group, and a cyanate ester group. As the reactive group-containing monomer, a monomer having an epoxy group is more preferable.

The content of the epoxy group with respect to the total mass of the shell layer of component (B) is not particularly limited, but by setting it to 0.4 mmol/g to 5.0 mmol/g, the temperature dependence of the viscosity becomes smaller and curability A resin composition is obtained. When the content of epoxy groups with respect to the total mass of the shell layer of component (B) is (a) 0.4 mmol/g or more, the temperature dependence of the viscosity of the resulting curable resin composition becomes small, and (b ) When it is 5.0 mmol/g or less, there is no possibility that the storage stability of the curable resin composition is deteriorated.

Preferably, the shell layer has epoxy groups, and the content of the epoxy groups with respect to the total mass of the shell layer is 0.4 mmol/g to 5.0 mmol/g. According to this configuration, the shell layer can be chemically bonded with the (A) component, and the (B) component can be maintained in a good dispersion state without agglomeration in the cured product and/or the polymer. It has the advantage that a curable resin composition having a smaller temperature dependence of is obtained.

The epoxy group content relative to the total amount of the shell layer of the component (B) is 0.4 mmol/g to 5, since the temperature dependence of the viscosity of the resulting curable resin composition is small and the storage stability is excellent. 0.0 mmol/g, more preferably 0.5 to 4.0 mmol/g, still more preferably 0.6 to 3.5 mmol/g, particularly preferably 0.7 to 3.0 mmol/g, and 0.0 mmol/g. 8 mmol/g to 2.5 mmol/g are most preferred.

The shell layer preferably contains a polymer obtained by graft-polymerizing a monomer component having an epoxy group to the core layer. According to this configuration, it has the advantage that (i) component (B) has excellent compatibility and dispersibility in the curable resin composition, and (ii) component (B) is chemically bonded to component (A). This has the advantage that the component (B) does not aggregate in the cured product and/or the polymer and can maintain a good dispersion state.

Specific examples of the epoxy group-containing monomer include glycidyl group-containing vinyl monomers such as glycidyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate glycidyl ether, and allyl glycidyl ether.

Further, when a polyfunctional monomer having two or more radically polymerizable double bonds is used as the shell layer-forming monomer, swelling of the fine polymer particles in the curable resin composition can be prevented, and the curable resin composition can be improved. It is preferable because it has a low viscosity and tends to be easy to handle. On the other hand, from the viewpoint of improving the toughness of the resulting cured product and improving the impact resistance to peeling adhesion, it is recommended not to use a polyfunctional monomer having two or more radically polymerizable double bonds as the shell layer-forming monomer. preferable.

The polyfunctional monomer may be contained in an amount of, for example, 0 to 20% by weight, preferably 1 to 20% by weight, more preferably 5 to 20% by weight, based on 100% by weight of the shell layer-forming monomer. 15% by mass.

Specific examples of the aromatic vinyl monomer include vinylbenzenes such as styrene, α-methylstyrene, p-methylstyrene and divinylbenzene.

Specific examples of the vinyl cyan monomer include acrylonitrile, methacrylonitrile, and the like.

Specific examples of the (meth)acrylate monomer include (i) (meth)acrylic acid alkyl esters such as methyl (meth)acrylate, ethyl (meth)acrylate and butyl (meth)acrylate; (ii) hydroxyethyl (meth) Examples include hydroxyalkyl (meth)acrylates such as acrylates and hydroxybutyl (meth)acrylate.

Specific examples of the monomer having a hydroxy group include (i) 2-hydroxyethyl (meth)acrylate, hydroxypropyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate and other hydroxy straight-chain alkyl (meth)acrylates; Acrylates (especially hydroxy linear C1-6 alkyl (meth)acrylates); (ii) caprolactone-modified hydroxy (meth)acrylates; (iii) (a) α-(hydroxymethyl)methyl acrylate, α-(hydroxymethyl) Hydroxy-branched alkyl (meth)acrylates such as ethyl acrylate, and (b) polyester diols (particularly saturated polyester diols) obtained from dihydric carboxylic acids (phthalic acid, etc.) and dihydric alcohols (propylene glycol, etc.) ( and hydroxyl group-containing (meth)acrylates such as meth)acrylates.

Specific examples of the polyfunctional monomer having two or more radically polymerizable double bonds include the same monomers as the polyfunctional monomers described above, preferably allyl methacrylate and triallyl isocyanurate.

In one embodiment of the present invention, for example, 0 to 50% by weight (preferably 1 to 50% by weight, more preferably 2 to 48% by weight) of aromatic vinyl monomers (especially styrene), 0 vinyl cyan monomers (especially acrylonitrile) ~50% by mass (preferably 0 to 30% by mass, more preferably 10 to 25% by mass), (meth)acrylate monomer (especially methyl methacrylate) 0 to 90% by mass (preferably 5 to 85% by mass, more preferably 20 to 80% by mass), and 5 to 90% by mass (preferably 10 to 50% by mass, more preferably 15 to 30% by mass) of a monomer having an epoxy group (especially glycidyl methacrylate). 100% by mass) of the polymer for the shell layer. Thereby, a curable resin composition having a low temperature dependence of viscosity can be obtained.

These monomer components may be used singly or in combination of two or more.

The shell layer may be formed by containing other monomer components in addition to the above monomer components.

The graft ratio of the shell layer is preferably 70% or more (more preferably 80% or more, furthermore 90% or more). If the graft ratio is less than 70%, the viscosity of the liquid resin composition may increase. In addition, in this specification, the calculation method of a graft ratio is as follows.

First, an aqueous latex containing polymer microparticles is coagulated and dewatered, and finally dried to obtain a powder of polymer microparticles. Then, 2 g of polymer fine powder is immersed in 100 g of methyl ethyl ketone (MEK) at 23° C. for 24 hours. After that, the mixture (soaked material) is separated into MEK-soluble and MEK-insoluble components, and the methanol-insoluble components are further separated from the MEK-soluble components. Then, the ratio of the MEK-insoluble matter to the total amount of the MEK-insoluble matter and the methanol-insoluble matter is calculated to calculate the graft ratio.

<<Method for producing fine polymer particles>>
(Manufacturing method of core layer)
The polymer forming the core layer constituting the polymer fine particles used in one embodiment of the present invention is at least one monomer (first monomer) selected from diene-based monomers (conjugated diene-based monomers) and (meth)acrylate-based monomers. is formed, the formation of the core layer can be produced by, for example, emulsion polymerization, suspension polymerization and microsuspension polymerization. In this case, the method described in WO2005/028546, for example, can be used to form the core layer.

When the polymer forming the core layer contains a polysiloxane-based polymer, the core layer can be produced by, for example, emulsion polymerization, suspension polymerization, microsuspension polymerization, and the like. In this case, the method described in WO2006/070664, for example, can be used to form the core layer.

(Method for Forming Shell Layer and Intermediate Layer)
The intermediate layer can be formed by polymerizing an intermediate layer-forming monomer by known radical polymerization. When the rubber elastomer constituting the core layer is obtained as an emulsion (also called aqueous latex), the formation of the intermediate layer, that is, the polymerization of the monomer having two or more radically polymerizable double bonds, should be carried out by emulsion polymerization. is preferred.

The shell layer can be formed by polymerizing a shell layer-forming monomer by known radical polymerization. When the core layer or the polymer particle precursor composed of the core layer coated with the intermediate layer is obtained as an emulsion (also referred to as an aqueous latex), the shell layer-forming monomer is polymerized by an emulsion polymerization method. preferably. The shell layer can be manufactured, for example, according to the method described in WO2005/028546.

Examples of emulsifiers (dispersants) that can be used in emulsion polymerization include various emulsifiers described in paragraph [0073] of the specification of WO2016-163491. These emulsifiers (dispersants) may be used singly or in combination of two or more.

The amount of the emulsifier (dispersant) used is preferably small as long as it does not affect the dispersion stability of the aqueous latex of the polymer particles. Further, the emulsifier (dispersant) is preferably as high in water solubility as possible. If the water solubility is high, the emulsifier (dispersant) can be easily removed by washing with water, and adverse effects on the finally obtained cured product can be easily prevented.

When an emulsion polymerization method is employed, known initiators such as 2,2′-azobisisobutyronitrile, hydrogen peroxide, potassium persulfate and ammonium persulfate can be used as thermal decomposition initiators. .

In the production of polymer fine particles (B), (i) (a) t-butylperoxyisopropyl carbonate, paramenthane hydroperoxide, cumene hydroperoxide, dicumyl peroxide, t-butyl hydroperoxide, di - peroxides such as organic peroxides such as t-butyl peroxide, t-hexyl peroxide, and (b) inorganic peroxides such as hydrogen peroxide, potassium persulfate, ammonium persulfate; sodium formaldehyde sulfoxylate, a reducing agent such as glucose, and optionally a transition metal salt such as iron (II) sulfate, and optionally a chelating agent such as disodium ethylenediaminetetraacetate, and optionally It is also possible to use a redox initiator in combination with a phosphorus-containing compound such as sodium pyrophosphate.

When a redox type initiator is used, polymerization can be carried out at a low temperature at which the peroxide is not substantially thermally decomposed, and the polymerization temperature can be set in a wide range, which is preferable. Among them, organic peroxides such as cumene hydroperoxide, dicumyl peroxide and t-butyl hydroperoxide are more preferably used as redox initiators. The amount of the initiator used, and the amount of the reducing agent, transition metal salt, chelating agent, etc. used when a redox initiator is used, can be used within a known range. Moreover, when polymerizing a monomer having two or more radically polymerizable double bonds, a known chain transfer agent can be used within a known range. If necessary, a surfactant can be additionally used, and the surfactant can also be used within a known range.

Conditions in the polymerization such as polymerization temperature, pressure and deoxidization can be applied within a known range. The polymerization of the intermediate layer-forming monomer may be carried out in one step or in two or more steps. Polymerization of the intermediate layer-forming monomer is carried out, for example, by (i) adding the intermediate layer-forming monomer at once to the emulsion (aqueous latex) of the rubber elastomer constituting the elastic core layer; A method of continuously adding the monomer, or (iii) a method of adding an emulsion of the rubber elastomer constituting the elastic core layer to a reactor charged with the intermediate layer-forming monomer in advance and then conducting the polymerization. can be done.

<2-1-3. Blocked urethane (C)>
In the curable resin composition according to one embodiment of the present invention, 1 part by mass of blocked urethane (C) having a latent NCO% of 0.1% to 2.9% per 100 parts by mass of component (A) It is essential to contain up to 100 parts by mass.

In this specification, "blocked urethane (C)" is also referred to as "blocked urethane" or "component (C)".

Due to the toughness-improving effect of the component (C), the resulting cured product has excellent toughness and elongation properties.

By combining the component (C) with the fine polymer particles as the component (B) described above, the resulting curable resin composition has a small temperature dependence of viscosity and is remarkably excellent in workability.

The ratio (W1/W2) of the mass (W1) of the polymer fine particles (B) to the mass (W2) of the blocked urethane (C) is preferably 0.1 to 10.0, more preferably 0.2 to 7.0. It is more preferably 1.5 to 7.0, still more preferably 1.8 to 5.0, even more preferably 2.0 to 4.0, and particularly preferably 2.5 to 3.5. The W1/W2 may be 0.2 to 5.0, may be 0.3 to 4.0, may be 0.4 to 3.0, or may be 0.5 to 2 .0. When the W1/W2 is within the above range, there is an advantage that the temperature dependence of the viscosity of the resulting curable resin composition can be made smaller. Further, when W1/W2 is 1.5 or more, there is an advantage that the impact resistant peel adhesion at low temperatures of the cured product obtained by curing the curable resin composition does not deteriorate.

A blocked urethane is an elastomer type compound containing a urethane group and/or a urea group, and having an isocyanate group at the end of a compound in which all or part of the terminal isocyanate group has an active hydrogen group. It is an agent-capped compound. Particularly preferred is a compound in which all of the terminal isocyanate groups are capped with a blocking agent. Such a compound can be obtained, for example, by the following method: (i) reacting an organic polymer having an active hydrogen-containing group at its end with an excess of a polyisocyanate compound to obtain a urethane compound in the main chain; and/or a urea group and a terminal isocyanate group (urethane prepolymer); All or part of is reacted with a blocking agent having an active hydrogen group, and all or part of the isocyanate group is capped with the blocking agent.

The blocked urethane is represented, for example, by the following general formula (1):
A—(NR ² —C(═O)—X) _a General formula (1);
(In general formula (1), a R ² is each independently a hydrocarbon group having 1 to 20 carbon atoms. a represents the average number of capped isocyanate groups per molecule, and 1 1 or more is preferable, 1.5 to 8 is more preferable, 1.7 to 6 is still more preferable, and 2 to 4 is particularly preferable, and X is a residue obtained by removing an active hydrogen atom from the blocking agent. A is a residue obtained by removing the terminal isocyanate group from an isocyanate-terminated prepolymer (for example, a urethane prepolymer having an isocyanate group at the terminal).

The isocyanate group capped with the blocking agent is regenerated by heating, and the regenerated isocyanate group reacts with the active hydrogen-containing compound in the composition to improve the toughness of the resulting cured product. The latent NCO % is defined as the weight % of isocyanate groups regenerated by heating with respect to 100% by weight of the blocked urethane. The reaction between the urethane prepolymer and the blocking agent is considered to proceed almost quantitatively. Therefore, when a blocking agent having active hydrogen groups equivalent to or more than the isocyanate groups of the urethane prepolymer is reacted, the latent NCO% can be calculated by NCO titration of the urethane prepolymer before capping with the blocking agent. . Also, when a blocking agent having an active hydrogen group less than the equivalent weight of the isocyanate group of the urethane prepolymer is reacted, the latent NCO % can be calculated from the reacted amount of the blocking agent.

By setting the latent NCO % of the component (C) to 0.1 to 2.9%, a curable resin composition with low temperature dependence of viscosity can be obtained. If the latent NCO % of component (C) is less than 0.1%, the toughness of the cured product obtained by curing the curable resin composition tends to deteriorate. When the latent NCO % of the component (C) is more than 2.9%, the temperature dependence of the viscosity of the resulting curable resin composition tends to increase.

Potential NCO % can also be expressed using the unit "mmol/g". For latent NCO, the unit "mmol/g" means the molar amount (mmol) of isocyanate groups regenerated by heating per gram of blocked urethane. For latent NCO, "%" and "mmol/g" are interchangeable.

In one embodiment of the present invention, the latent NCO% of the component (C) is 0.1 to 2.9% from the viewpoint of the temperature dependence of the viscosity of the resulting curable resin composition and the toughness of the cured product. is essential, preferably 0.3 to 2.8 mmol/g, more preferably 0.5 to 2.7 mmol/g, still more preferably 1.0 to 2.5 mmol/g, and 1.5 to 2.3 mmol/ g is particularly preferred.

The number average molecular weight of the blocked urethane is preferably 2,000 to 40,000, more preferably 3,000 to 30,000, and particularly preferably 4,000 to 20,000 in terms of polystyrene equivalent molecular weight measured by gel permeation chromatography (GPC). The molecular weight distribution (ratio of weight average molecular weight to number average molecular weight) of the blocked urethane is preferably 1 to 4, more preferably 1.2 to 3, and particularly preferably 1.5 to 2.5.

The weight average molecular weight of blocked urethane can be measured by GPC.

(2-1-3-a. Organic polymer having an active hydrogen-containing group at the end)
Main chain skeletons constituting organic polymers having active hydrogen-containing groups at their terminals include polyether polymers, polyacrylic polymers, polyester polymers, polydiene polymers, saturated hydrocarbon polymers (polyolefin ), polythioether-based polymers, and the like.

(active hydrogen group)
Examples of the active hydrogen-containing group constituting the organic polymer having an active hydrogen-containing group at its terminal include a hydroxyl group, an amino group, an imino group and a thiol group. Among these, a hydroxyl group, an amino group and an imino group are preferred from the standpoint of availability, and a hydroxyl group is more preferred from the standpoint of ease of handling (viscosity) of the resulting blocked urethane.

Examples of the organic polymer having an active hydrogen-containing group at the terminal include a polyether polymer having a hydroxyl group at the terminal (polyether polyol), a polyether polymer having an amino group and/or an imino group at the terminal (polyether amine ), polyacrylic polyols, polyester polyols, diene polymers having terminal hydroxyl groups (polydiene polyols), saturated hydrocarbon polymers having terminal hydroxyl groups (polyolefin polyols), polythiol compounds, polyamine compounds, and the like. Among these, polyether polyols, polyether amines, and polyacrylic polyols have excellent compatibility with component (A), the glass transition temperature of the organic polymer is relatively low, and the resulting cured product can be obtained at low temperatures. It is preferable because it has excellent impact resistance. In particular, polyether polyols and polyether amines are more preferable because the obtained organic polymers have low viscosity and good workability, and polyether polyols are particularly preferable.

The organic polymer having an active hydrogen-containing group at the terminal, which is used when preparing the urethane prepolymer, which is a precursor of blocked urethane, may be used alone or in combination of two or more. good.

The number average molecular weight of the organic polymer having an active hydrogen-containing group at its terminal is preferably 800 to 7,000, more preferably 1,500 to 5,000, and particularly preferably 2,000 to 4,000 in terms of polystyrene molecular weight measured by GPC.

(Polyether polymer)
The polyether-based polymer essentially has the general formula (2):
—R ¹ —O— General formula (2)
(In general formula (2), R ¹ is a linear or branched alkylene group having 1 to 14 carbon atoms.). R ¹ in general formula (2) is preferably a linear or branched alkylene group having 1 to 14 carbon atoms, more preferably 2 to 4 carbon atoms. Specific examples of the repeating unit represented by formula (2) include:
-CH ₂ O-, -CH ₂ CH ₂ O-, -CH ₂ CH(CH ₃ )O-, -CH ₂ CH(C ₂ H ₅ )O-, -CH ₂ C(CH ₃ ) ₂ O-, _{-CH2CH2CH2CH2O- _ _ _}
etc. The main chain skeleton of the polyether-based polymer may consist of only one kind of repeating unit, or may consist of two or more kinds of repeating units. In particular, in 100% by mass of the organic polymer, a polyether polymer composed of a polymer mainly composed of polypropylene glycol having 50% by mass or more of propylene oxide repeating units has a T-shaped peel adhesive strength. It is preferable because it is excellent in Moreover, polytetramethylene glycol (PTMG) obtained by ring-opening polymerization of tetrahydrofuran is preferable because the resulting cured product has excellent dynamic splitting resistance.

The above-mentioned "essentially" means that the repeating unit of general formula (2) accounts for 40% by mass or more in 100% by mass of the organic polymer. The repeating unit of general formula (2) is more preferably 50% by mass or more, still more preferably 60% by mass or more, and particularly preferably 70% by mass or more in 100% by mass of the organic polymer.

The blocked urethane (C) is preferably a compound obtained by capping a urethane prepolymer containing a polyalkylene glycol structure with a blocking agent. It is more preferable because the resulting curable resin composition has a small temperature-sensitive characteristic of viscosity.

"Low temperature sensitivity of viscosity" means "small temperature dependence of viscosity".

(polyether polyols and polyether amines)
The polyether polyol is a polyether polymer having terminal hydroxyl groups. The polyether amine is a polyether polymer having an amino group or an imino group at its terminal.

(polyacrylic polyol)
Examples of the polyacrylic polyol include a polyol having a (meth)acrylic acid alkyl ester (co)polymer as a skeleton and having a hydroxyl group in the molecule. As the polyacrylic polyol, a polyacrylic polyol obtained by copolymerizing a hydroxyl group-containing (meth)acrylic acid alkyl ester monomer such as 2-hydroxyethyl methacrylate is particularly preferable.

As the polyester polyol, (i) one or more selected from the group consisting of polybasic acids such as maleic acid, fumaric acid, adipic acid and phthalic acid, and acid anhydrides thereof, and (ii) ethylene glycol and propylene One or more selected from the group consisting of polyhydric alcohols such as glycol, 1,4-butanediol, 1,6-hexanediol, diethylene glycol, dipropylene glycol, and neopentyl glycol in the presence of an esterification catalyst. , a polymer obtained by polycondensation at a temperature range of 150 to 270°C. Also included are (a) ring-opening polymers such as ε-caprolactone and valerolactone, and (b) active hydrogen compounds having two or more active hydrogens such as polycarbonate diols and castor oil.

(polydiene polyol)
Examples of the polydiene polyol include polybutadiene polyol, polyisoprene polyol, and polychloroprene polyol. Polybutadiene polyol is particularly preferred.

(polyolefin polyol)
Examples of the polyolefin polyol include polyisobutylene polyol and hydrogenated polybutadiene polyol.

(2-1-3-b. Polyisocyanate)
Specific examples of the polyisocyanate compound include (a) aromatic polyisocyanates such as toluene (tolylene) diisocyanate, diphenylmethane diisocyanate and xylylene diisocyanate; (b) isophorone diisocyanate, hexamethylene diisocyanate, hydrogenated toluene diisocyanate, hydrogen and aliphatic polyisocyanates such as diphenylmethane diisocyanate. Among these, aliphatic polyisocyanates are preferred from the viewpoint of heat resistance, and isophorone diisocyanate and hexamethylene diisocyanate are more preferred from the viewpoint of availability.

(2-1-3-c. Blocking agent)
The blocking agents include, for example, primary amine blocking agents, secondary amine blocking agents, oxime blocking agents, lactam blocking agents, active methylene blocking agents, alcohol blocking agents, mercaptan blocking agents, amides. blocking agents, imide-based blocking agents, heteroaromatic-based blocking agents, hydroxy-functional (meth)acrylate-based blocking agents and phenol-based blocking agents. Among these, oxime-based blocking agents, lactam-based blocking agents, hydroxy-functional (meth)acrylate-based blocking agents and phenolic-based blocking agents are preferred, and hydroxy-functional (meth)acrylate-based blocking agents and phenolic blocking agents are more preferred. , phenolic blocking agents are more preferred.

(Primary amine blocking agent)
Examples of the primary amine-based blocking agent include various compounds described in paragraph [0098] of the specification of WO2016-163491.

(Hydroxy-functional (meth)acrylate-based blocking agent)
The hydroxy-functional (meth)acrylate-based blocking agent is a (meth)acrylate having one or more hydroxyl groups. Specific examples of hydroxy-functional (meth)acrylate-based blocking agents include various compounds described in paragraph [0099] of the specification of WO2016-163491.

(Phenolic blocking agent)
The phenolic blocking agent contains at least one phenolic hydroxyl group, ie, a hydroxyl group directly attached to a carbon atom of an aromatic ring. The phenolic compound may have more than one phenolic hydroxyl group, but preferably contains only one phenolic hydroxyl group. The phenolic compound may contain other substituents, but these substituents are preferably those which do not react with isocyanate groups under the conditions of the capping reaction, alkenyl and allyl groups being preferred. Other substituents include (a) linear, branched or cycloalkyl alkyl groups; (b) aromatic groups (e.g., phenyl groups, alkyl-substituted phenyl groups, alkenyl-substituted phenyl groups, etc.); c) aryl-substituted alkyl groups; (d) phenol-substituted alkyl groups. Specific examples of phenolic blocking agents include various compounds described in paragraph [0100] of the specification of WO2016-163491.

Said blocking agent is preferably attached to the ends of the polymer chains of the urethane prepolymer in such a way that the ends to which it is attached no longer have reactive groups.

It can also be said that the polymer terminal obtained by binding the blocking agent to the terminal of the polymer chain of the urethane prepolymer preferably does not have a reactive group.

The blocking agents may be used singly or in combination of two or more.

The blocked urethane may contain crosslinker residues, chain extender residues, or both.

(crosslinking agent)
The molecular weight of the cross-linking agent is preferably 750 or less, more preferably 50-500. Said crosslinker is a polyol or polyamine compound having at least 3 hydroxyl, amino and/or imino groups per molecule. Cross-linking agents are useful for imparting branching to the blocked urethane and increasing the functionality (ie, number of capped isocyanate groups per molecule) of the blocked urethane.

(chain extender)
The molecular weight of the chain extender is preferably 750 or less, more preferably 50-500. Said chain extenders are polyol or polyamine compounds having two hydroxyl, amino and/or imino groups per molecule. Chain extenders are useful for increasing the molecular weight of blocked urethanes without increasing functionality.

Specific examples of the cross-linking agent and chain extender include various compounds described in paragraph [0106] of the specification of WO2016-163491.

(Amount of blocked urethane (C))
The amount of component (C) used is 1 to 100 parts by mass, preferably 2 to 50 parts by mass, more preferably 3 to 40 parts by mass, and 5 to 30 parts by mass with respect to 100 parts by mass of component (A). is particularly preferred. When the amount of component (C) used is 1 part by mass or more of (a) with respect to 100 parts by mass of component (A), there is no risk of deterioration in the toughness of the resulting cured product, and (b) is 100 parts by mass or less. When , the heat resistance and elastic modulus (rigidity) of the resulting cured product can be good.

Component (C) may be used alone or in combination of two or more.

<2-1-4. Epoxy resin curing agent (D)>
In one embodiment of the present invention, an epoxy resin hardener (D) can be used as needed.

In this specification, the "epoxy resin curing agent (D)" is also referred to as "(D) component".

If the curable resin composition according to one embodiment of the present invention is temporarily used as a one-component composition (such as a one-component curable resin composition), it is curable up to a temperature of 80 ° C. or higher, preferably 140 ° C. or higher. It is preferable to select the type and amount of component (D) so that the adhesive (the curable resin composition) cures rapidly when the resin composition is heated. Conversely, at room temperature (e.g., 22°C) and at temperatures up to at least 50°C, the types and amounts of component (D) and component (E) described below are adjusted so that, if at all, the curable resin composition cures very slowly. preferably selected.

As component (D), a component that exhibits activity upon heating (sometimes referred to as a latent epoxy curing agent) can be used. As such latent epoxy curing agents, N-containing curing agents such as specific amine curing agents (including imine curing agents) can be used. Component (D) includes, for example, boron trichloride/amine complex, boron trifluoride/amine complex, dicyandiamide, melamine, diallylmelamine, guanamine (e.g., acetoguanamine and benzoguanamine), aminotriazole (e.g., 3-amino- 1,2,4-triazoles), hydrazides (e.g. adipic acid dihydrazide, stearic acid dihydrazide, isophthalic acid dihydrazide, semicarbazide), cyanoacetamides, as well as aromatic polyamines (e.g. metaphenylenediamine, diaminodiphenylmethane, diaminodiphenylsulfone, etc.) is mentioned. As component (D), dicyandiamide, isophthalic acid dihydrazide, adipic acid dihydrazide and/or 4,4'-diaminodiphenylsulfone are more preferably used, and dicyandiamide is particularly preferred.

Among the epoxy resin curing agents (D), the latent epoxy curing agent is preferable because it enables the curable resin composition according to one embodiment of the present invention to be used as a one-component curable resin composition.

On the other hand, when the curable resin composition according to one embodiment of the present invention is used as a two-component or multi-component composition, amine-based curing agents other than the above (including imine-based curing agents) and / or mercaptan-based A curing agent (sometimes referred to as a room temperature curing agent) can be selected as component (D) that exhibits activity at relatively low temperatures such as room temperature.

Examples of the component (D) that exhibits activity at relatively low temperatures such as room temperature include various compounds described in paragraph [0113] of the specification of WO2016-163491.

Amine-terminated polyethers containing a polyether backbone and having an average of 1 to 4 (preferably 1.5 to 3) amino and/or imino groups per molecule are also used as component (D). can. Commercially available amine terminated polyethers include Jeffamine D-230, Jeffamine D-400, Jeffamine D-2000, Jeffamine D-4000, Jeffamine T-5000, manufactured by Huntsman.

Furthermore, an amine-terminated rubber containing a conjugated diene-based polymer backbone and having an average of 1 to 4 (more preferably 1.5 to 3) amino and/or imino groups per molecule (D ) component. Here, the main chain of the rubber, that is, the conjugated diene polymer main chain is preferably a homopolymer or copolymer of polybutadiene, more preferably a polybutadiene/acrylonitrile copolymer, and the acrylonitrile monomer content is 5 to 40% by mass (more preferably 10 to 35%). %, more preferably 15-30% by weight) are particularly preferred. Commercially available amine terminated rubbers include Hypro 1300X16 ATBN from CVC.

Among the amine-based curing agents that are active at relatively low temperatures such as room temperature, polyamidoamines, amine-terminated polyethers, and amine-terminated rubbers are more preferable. It is particularly preferable to use together.

Acid anhydrides and phenols can also be used as component (D). Acid anhydrides and phenols require a higher temperature than amine curing agents, but they have a longer pot life, and the resulting cured product has a good balance of physical properties such as electrical, chemical, and mechanical properties. becomes good. Examples of acid anhydrides include various compounds described in paragraph [0117] of the specification of WO2016-163491.

Component (D) may be used alone or in combination of two or more.

Component (D) can be used in an amount sufficient to cure the composition. Typically, a sufficient amount of component (D) can be used to consume at least 80% of the epoxide groups present in the composition. A large excess of component (D) over the amount required to consume the epoxide groups is usually not necessary.

In one embodiment of the present invention, the curable resin composition may further contain 1 part by mass to 80 parts by mass of an epoxy resin curing agent (D) with respect to 100 parts by mass of the epoxy resin (A). preferable.

More specifically, the amount of component (D) used is preferably 1 part by mass to 80 parts by mass, more preferably 2 parts by mass to 40 parts by mass, and 3 parts by mass with respect to 100 parts by mass of component (A). 30 parts by mass is more preferable, and 5 parts by mass to 20 parts by mass is particularly preferable. When the curable resin composition contains 1 part by mass or more of the epoxy resin curing agent (D) with respect to 100 parts by mass of the epoxy resin (A), the curable resin composition according to one embodiment of the present invention When (b) is 80 parts by mass or less, the storage stability of the curable resin composition according to one embodiment of the present invention is improved, and there is an advantage that it is easy to handle.

<2-1-5. Curing accelerator (E)>
In one embodiment of the present invention, a curing accelerator (E) can be used as needed.

In this specification, the "curing accelerator (E)" is also referred to as "(E) component".

Component (E) is a catalyst for promoting the reaction between epoxy groups and epoxide-reactive groups contained in the curing agent and other components of the adhesive.

Examples of components (E) include (i) p-chlorophenyl-N,N-dimethylurea (trade name: Monuron), 3-phenyl-1,1-dimethylurea (trade name: Fenuron), 3,4- Dichlorophenyl-N,N-dimethylurea (trade name: Diuron), N-(3-chloro-4-methylphenyl)-N',N'-dimethylurea (trade name: Chlortoluron), 1,1-dimethylphenylurea (trade name: Dyhard); (ii) benzyldimethylamine, 2,4,6-tris(dimethylaminomethyl)phenol, 2-(dimethylaminomethyl)phenol, poly(p-vinylphenol) matrix Tertiary amines such as incorporated 2,4,6-tris(dimethylaminomethyl)phenol, triethylenediamine, N,N-dimethylpiperidine; (iii) C1-C12 alkyleneimidazole, N-arylimidazole, 2-methyl imidazoles such as imidazole, 2-ethyl-2-methylimidazole, N-butylimidazole, 1-cyanoethyl-2-undecylimidazolium trimellitate, addition products of epoxy resins and imidazole; (iv) 6-caprolactam etc. The catalyst may be encapsulated or it may be a latent catalyst that becomes active only at elevated temperatures.

Tertiary amines and imidazoles can be used in combination with the amine-based curing agent (D) to improve the curing speed and the physical properties and heat resistance of the resulting cured product.

Component (E) may be used alone or in combination of two or more.

In one embodiment of the present invention, the curable resin composition further contains 0.1 to 10.0 parts by mass of a curing accelerator (E) with respect to 100 parts by mass of the epoxy resin (A). preferably.

More specifically, the amount of component (E) used is preferably 0.1 parts by mass to 10.0 parts by mass, more preferably 0.2 parts by mass to 5.0 parts by mass, per 100 parts by mass of component (A). is more preferably 0.5 to 3.0 parts by mass, and particularly preferably 0.8 to 2.0 parts by mass. When the curable resin composition contains 0.1 parts by mass or more of the curing accelerator (E) with respect to 100 parts by mass of the epoxy resin (A), the curable resin composition according to one embodiment of the present invention When the content of (b) is 10 parts by mass or less, the storage stability of the curable resin composition according to one embodiment of the present invention is improved, and there is the advantage of easy handling.

<2-1-6. Reinforcing agents other than components (B) and (C)>
In one embodiment of the present invention, for the purpose of further improving performance such as toughness, impact resistance, shear adhesion, and peel adhesion of the resulting cured product, reinforcement other than components (B) and (C) A rubber-modified epoxy resin or a urethane-modified epoxy resin can be used as the agent, if necessary.

The reinforcing agents other than the components (B) and (C) may be used alone or in combination of two or more.

As the rubber-modified epoxy resin, for example, resins described in paragraphs [0124] to [0132] of WO2016-163491 can be used.

As the urethane-modified epoxy resin, for example, resins described in paragraphs [0133] to [0135] of the specification of WO2016-163491 can be used.

<2-1-7. Inorganic filler>
The curable resin composition according to one embodiment of the present invention can use silicic acid and/or silicate as an inorganic filler.

Specific examples include dry silica, wet silica, aluminum silicate, magnesium silicate, calcium silicate, wollastonite, and talc.

Said fumed silica is also called fumed silica. Examples of the dry silica include surface-untreated hydrophilic fumed silica and hydrophobic fumed silica produced by chemically treating the silanol group portion of hydrophilic fumed silica with silane and/or siloxane. mentioned. As the dry silica, hydrophobic fumed silica is preferable because it is excellent in dispersibility in the component (A).

Other inorganic fillers include reinforcing fillers such as dolomite and carbon black, colloidal calcium carbonate, ground calcium carbonate, magnesium carbonate, titanium oxide, ferric oxide, fine aluminum powder, zinc oxide, active zinc oxide. etc.

The inorganic filler is preferably surface-treated with a surface treatment agent. The surface treatment improves the dispersibility of the inorganic filler in the composition, and as a result, various physical properties of the obtained cured product are improved.

The amount of the inorganic filler used is preferably 1 to 100 parts by mass, more preferably 2 to 70 parts by mass, still more preferably 5 to 40 parts by mass, and 7 to 20 parts by mass, relative to 100 parts by mass of component (A). is particularly preferred.

One type of inorganic filler may be used alone, or two or more types may be used in combination.

<2-1-8. Calcium oxide>
Calcium oxide can be used in the curable resin composition according to one embodiment of the present invention.

Calcium oxide removes water from the curable resin composition by reacting with the water in the curable resin composition, and can solve various physical property problems caused by the presence of water. Calcium oxide functions, for example, as an anti-foaming agent by removing moisture, and can suppress a decrease in adhesive strength of the obtained cured product.

Calcium oxide can be surface treated with a surface treatment agent. The surface treatment improves the dispersibility of calcium oxide in the composition. As a result, when surface-treated calcium oxide is used, physical properties such as adhesive strength of the obtained cured product are improved as compared with the case of using unsurface-treated calcium oxide. Surface-treated calcium oxide can significantly improve the T-peel adhesion and impact resistance peel adhesion of the resulting cured product. The surface treatment agent that can be used for the surface treatment of calcium oxide is not particularly limited, but fatty acids are preferred.

The amount of calcium oxide used is preferably 0.1 to 10 parts by mass, more preferably 0.2 to 5 parts by mass, and even more preferably 0.5 to 3 parts by mass, based on 100 parts by mass of component (A). 1 to 2 parts by weight is particularly preferred. When the amount of calcium oxide used is (a) 0.1 parts by mass or more, the effect of removing water is sufficient, and when it is (b) 10 parts by mass or less, there is no fear that the strength of the resulting cured product will be lowered. .

One type of calcium oxide may be used alone, or two or more types may be used in combination.

The curable resin composition may contain a dehydrating agent other than calcium oxide.

Examples of dehydrating agents other than calcium oxide include various compounds described in paragraph [0155] of the specification of WO2014-196607.

<2-1-9. Other Compounding Ingredients>
In one embodiment of the present invention, other formulation ingredients may be used as desired. Other ingredients include radical curing resins, monoepoxides, photopolymerization initiators, organic fillers, pigments, flame retardants, dispersants, antifoaming agents, plasticizers, solvents, tackifiers, leveling agents, thixotropic properties imparting agents, antioxidants, light stabilizers, ultraviolet absorbers, silane coupling agents, titanate coupling agents, aluminate coupling agents, release agents, antistatic agents, lubricants, low shrinkage agents, azo type chemicals expansion agents such as thermal foaming agents and thermally expandable microballoons; fiber pulps such as aramid pulp; and thermoplastic resins.

Specific examples of radical curable resins, monoepoxides and photopolymerization initiators include, for example, paragraphs [0143] to [0144], [0146], and [0148] of the specification of WO2016-163491. and various compounds described in. Specific examples of pigments, flame retardants, dispersants, defoamers, plasticizers, solvents, tackifiers, leveling agents, thixotropic agents, antioxidants, light stabilizers, ultraviolet absorbers and silane coupling agents For example, [0124], [0126] to [0127], [0129] to [0130], [0132], [0134], [0136], [0139] in the specification of WO2014-196607, respectively ], [0141], [0143], [0147], [0149], [0151], and [0153].

<2-1-10. Temperature dependence of viscosity>
The temperature dependence of the viscosity of the curable resin composition according to one embodiment of the present invention is preferably small. The smaller the temperature dependence of the viscosity of the curable resin composition, the better the workability of the first bonding method using the curable resin composition. The temperature dependence of the viscosity is evaluated by the ratio of the viscosity at 60°C and the viscosity at 25°C. A more specific method for measuring the viscosity will be described in detail in Examples below. The larger the value of the ratio of the viscosity at 60° C. to the viscosity at 25° C., in other words, the closer to 1, the smaller the temperature dependence of the viscosity.

The ratio of the viscosity at 60° C. to the viscosity at 25° C. of the curable resin composition according to one embodiment of the present invention is preferably 0.03 or more, more preferably 0.05 or more, It is more preferably 0.07 or more, and particularly preferably 0.10 or more.

(2-2. Method for producing curable resin composition)
A curable resin composition according to one embodiment of the present invention is a composition containing fine polymer particles (B) in a curable resin composition containing component (A) as a main component, preferably polymer fine particles This is a composition in which (B) is dispersed in the form of primary particles in component (A).

The "composition in which the fine polymer particles (B) are dispersed in the component (A) in the form of primary particles" is hereinafter sometimes referred to as the "fine polymer particle composition".

Various methods can be used to obtain such a composition in which the fine polymer particles (B) are dispersed in the component (A) in the form of primary particles. Examples of such methods include (a) a method in which polymer fine particles obtained in an aqueous latex state are brought into contact with component (A), and then unnecessary components such as water are removed from the mixture; A method of once extracting with an organic solvent, mixing the extracted polymer fine particles with the component (A), and then removing the organic solvent from the mixture, and the like. As the method, it is preferable to use the method described in WO2005/028546. As a specific method for producing the polymer fine particle composition, (1) an aqueous latex containing the polymer fine particles (B) (specifically, a reaction mixture after the polymer fine particles are produced by emulsion polymerization) is heated at 20°C. After mixing with an organic solvent having a solubility in water of 5% by mass or more and 40% by mass or less, the resulting mixture is further mixed with excess water to aggregate the polymer particles; a second step of separating and recovering the polymer fine particles (B) from the liquid phase and then mixing the polymer fine particles (B) with the organic solvent again to obtain an organic solvent solution in which the polymer fine particles (B) are dispersed; 3) A method including a third step of further mixing the resulting organic solvent solution with component (A) and then distilling off the organic solvent from the mixture. Preferably, the polymer microparticle composition is prepared by the method.

The component (A) is preferably liquid at 23° C. so that the third step can be easily performed. "Component (A) is liquid at 23°C" means that the softening point of component (A) is 23°C or lower, and component (A) exhibits fluidity at 23°C.

The component (C) is mixed with the composition obtained by the method including the above first to third steps, in which the fine polymer particles (B) are dispersed in the state of primary particles in the component (A), and further (A) component, (C) component, (D) component, (E) component, and each component of the above-mentioned other compounding components are further added as necessary and mixed to obtain polymer fine particles (B) (A ) to obtain a curable resin composition according to an embodiment of the present invention dispersed in the state of primary particles in the component.

On the other hand, using an aqueous latex containing the polymer fine particles (B), after coagulating the polymer fine particles (B) by a method such as salting out, the resulting coagulate is dried to obtain powdery polymer fine particles (B ) can be obtained. The obtained powdery polymer fine particles (B) can be redispersed in the component (A) using a dispersing machine having a high mechanical shearing force such as a three-roll paint roll, a roll mill, or a kneader. be. At this time, component (B) can be efficiently dispersed in component (A) by applying a mechanical shearing force at a high temperature to the mixture of component (A) and component (B). The temperature when dispersing (the temperature when shearing force is applied) is preferably 50°C to 200°C, more preferably 70°C to 170°C, still more preferably 80°C to 150°C, and particularly preferably 90°C to 120°C. . When the temperature when dispersing is (a) 50° C. or higher, the component (B) can be sufficiently dispersed, and (b) when it is 200° C. or lower, the components (A) and (B) are There is no risk of thermal deterioration.

(2-3. Applications)
In one embodiment of the present invention, the curable resin composition is preferably a one-component curable resin composition from the viewpoint of handleability.

A composition according to one embodiment of the present invention is useful as an adhesive.

(2-4. One-component curable resin composition)
The curable resin composition according to one embodiment of the present invention can be used as a one-component curable resin composition. The one-component curable resin composition is (i) capable of being sealed and stored without being cured after all the ingredients have been blended in advance, and (ii) after applying the curable resin composition, heating and / Or means a curable resin composition that is cured by light irradiation. Moreover, the curable resin composition according to one embodiment of the present invention can also be used as a two-component or multi-component curable resin composition. That is, (i) A solution containing (A) component as a main component, and (B) component and optionally (C) component is prepared, and (ii) (D) component and / or (E ) component and, optionally, component (B) and/or component (C) are prepared separately from solution A, and the solution A and solution B are mixed before use. can also be used. At least one kind of each of liquid A and liquid B may be prepared, and a plurality of types of either or both liquids may be prepared. In addition, since the curable composition according to one embodiment of the present invention is excellent in storage stability, it is particularly useful when used as a one-component curable resin composition.

Component (B) and component (C) may each be contained in at least one of liquid A or liquid B, for example, may be contained only in liquid A or only in liquid B. and B liquid.

(2-5. Cured product)
One embodiment of the present invention includes a cured product obtained by curing the curable resin composition. In the curable resin composition according to one embodiment of the present invention, fine polymer particles are uniformly dispersed in the component (A) in the form of primary particles. Therefore, by curing the curable resin composition, a cured product in which the fine polymer particles are uniformly dispersed can be easily obtained. In addition, in the curable resin composition according to one embodiment of the present invention, the polymer fine particles are less likely to swell and the viscosity of the curable resin composition is low, so that a cured product can be obtained with good workability.

Various adherends can be bonded using the first bonding method according to an embodiment of the present invention. In this specification, the "adherend" is also referred to as "substrate" or "bonded substrate".

(2-6. Adhesion substrate)
When bonding various substrates using the curable resin composition according to one embodiment of the present invention, for example, wood, metal, plastic, glass, etc. can be bonded. Substrates include (i) steel materials such as cold-rolled steel and hot-dip galvanized steel, (ii) aluminum materials such as aluminum and coated aluminum, and (iii) composite materials such as general-purpose plastics, engineering plastics, CFRP and GFRP. various plastic substrates, and the like.

A curable resin composition according to an embodiment of the present invention has excellent adhesiveness. Therefore, the member obtained by sandwiching the curable resin composition according to one embodiment of the present invention between a plurality of members containing an aluminum base material, and then curing the curable resin composition. A laminate obtained by bonding is preferable because it exhibits high adhesive strength.

Since the curable resin composition according to one embodiment of the present invention has excellent toughness, it is suitable for joining different types of base materials having different coefficients of linear expansion.

In addition, the curable resin composition according to one embodiment of the present invention can also be used for bonding aerospace components, particularly exterior metal components.

(2-7. Adhesion method)
Specific aspects of the steps included in the first bonding method according to one embodiment of the present invention will be described below.

<Step 1 (coating method)>
Step 1 is a step of applying a curable resin composition to one adherend.

The curable resin composition according to one embodiment of the invention can be applied by any method.

The curable resin composition according to one embodiment of the present invention can also be applied by extruding onto a substrate in the form of beads, monofilaments or swirls using a coating robot, or can be applied using a mechanical application such as a caulking gun. Other application methods and other manual application means can also be used. The composition can also be applied to the substrate using a jet spray method or a streaming method. A curable resin composition according to an embodiment of the present invention is applied to one or both substrates, the substrates are brought into contact so that the composition is disposed between the substrates to be bonded, and the substrates are bonded by curing. .

The viscosity of the curable resin composition is not particularly limited. The viscosity of the curable resin composition is (a) preferably about 150 to 600 Pa s at 45° C. in the extrusion bead method, and (b) preferably about 100 Pa s at 45° C. in the swirl coating method. (c) In the high-volume coating method using a high-speed flow device, the viscosity is preferably about 20 to 400 Pa·s at 45°C.

The first temperature is not particularly limited as long as it is higher than the second temperature. The "first temperature" can also be said to be "the temperature of the composition when the curable resin composition is applied to one adhesive substrate". The first temperature may be room temperature. Preferably, the first temperature is higher than room temperature.

"Room temperature" in one embodiment of the present invention refers to the room temperature of the surrounding environment when the curable resin composition is applied to the first thickness or stretched to the second thickness. The “room temperature” in one embodiment of the present invention is generally 5° C. to 45° C., preferably 10° C. to 40° C., more preferably 15° C. to 34° C., most preferably 20° C. to 30°C.

The first temperature is, for example, preferably 35°C to 80°C, more preferably 40°C to 70°C, and particularly preferably 45°C to 60°C. When the first temperature is (a) 35° C. or higher, the viscosity of the composition is low, which has the advantage of facilitating the coating work. There is no fear that the part will start to react and the viscosity will increase, and there is an advantage that the application work is easy.

The first thickness is not particularly limited as long as it is thicker than the second thickness. The first thickness is, for example, preferably 0.5 mm to 10 mm, more preferably 1 mm to 7 mm, even more preferably 1.5 mm to 5 mm, particularly preferably 2 mm to 4 mm.

<Step 2>
Step 2 is a step of stretching the curable resin composition applied in the first thickness to the second thickness. Step 2 is also a step of bonding the other adherend to the one adherend.

The second temperature is not particularly limited as long as it is lower than the first temperature. The "second temperature" can also be said to be the "environmental temperature when the curable resin composition is stretched to the second thickness". The second temperature may be room temperature.

The second temperature is, for example, preferably 0°C to 34°C, more preferably 5°C to 30°C, and particularly preferably 10°C to 25°C. When the second temperature is (a) 0° C. or higher, the viscosity of the composition is low, which has the advantage of facilitating the operation of stretching to the second thickness, and (b) when it is 34° C. or lower. , there is no possibility that the storage stability of the composition is deteriorated when the composition is stored for a long period of time.

The second thickness is not particularly limited as long as it is thinner than the first thickness. The second thickness is, for example, preferably 0.001 mm to 5 mm, more preferably 0.01 mm to 1 mm, particularly preferably 0.1 mm to 0.3 mm.

A specific method for stretching the curable resin composition applied in the first thickness to the second thickness in step 2 is not particularly limited. The method includes, for example, (i) a method in which the curable resin composition applied in a first thickness is extended to a second thickness using a spatula or the like, and (ii) a method in which the curable resin composition is applied. When the other adherend is attached to one of the adherends, the two adherends are brought close to each other with the curable resin composition sandwiched between them, so that the first thickness is applied. and a method of spreading and stretching the cured resin composition to a second thickness with two adherends.

<Step 3>
Step 3 is a step of curing the curable resin composition sandwiched between the two bonded adherends. Through step 3, a laminate in which two adherends are bonded with the curable resin composition can be obtained.

<Curing temperature>
In step 3, the curing temperature of the curable resin composition according to one embodiment of the present invention is not particularly limited. The curing temperature in step 3 is preferably 50°C to 250°C, more preferably 80°C to 220°C, even more preferably 100°C to 200°C, and 130°C to 180°C. is particularly preferred.

<Adhesion method>
As a bonding method according to an embodiment of the present invention, the following method is also available. That is, the curable resin composition according to one embodiment of the present invention is heated to a temperature higher than room temperature and applied to one adherend because the temperature dependence of the viscosity of the composition is small and the workability is good. After that, before or at the same time as bonding the other adherend, the applied curable resin composition is thinly stretched under a room temperature environment, and the sandwiched between the two adherends. Suitable for adhesion methods that cure curable resin compositions. The timing of thinly stretching the applied curable resin composition under a room temperature environment may be before or at the time of bonding the other adherend.

[3. Adhesion method (second adhesion method)]
A bonding method according to another embodiment of the present invention comprises (i) a first step of heating the curable resin composition to a temperature higher than room temperature and applying it to one adherend in a first thickness. 1, (ii) before or at the same time as bonding the other adherend to the one adherend, the applied curable resin composition is subjected to a second under a second room temperature environment. and (iii) step 3 of curing the curable resin composition sandwiched between the two bonded adherends. The second thickness is less than the first thickness. The curable resin composition comprises an epoxy resin (A) and 1 mass of polymer fine particles (B) having a core-shell structure including a core layer and a shell layer per 100 parts by mass of the epoxy resin (A). parts to 100 parts by weight and 1 part to 100 parts by weight of blocked urethane (C) having a latent NCO % of 0.1% to 2.9%. This bonding method is also referred to as a second bonding method.

Since the second bonding method according to one embodiment of the present invention has the configuration described above, it is excellent in workability.

In one embodiment of the present invention, the temperature at which the curable resin composition is applied to one adherend in the first thickness in step 1 is referred to as "first room temperature", and in step 2, The room temperature at which the curable resin composition is stretched to the second thickness may be referred to as "second room temperature". The "first room temperature" is generally 5 to 45°C, preferably 10 to 40°C, more preferably 15 to 34°C, most preferably 20 to 30°C. The "second room temperature" is also usually 5 to 45°C, preferably 10 to 40°C, more preferably 15 to 34°C, most preferably 20 to 30°C. The "first room temperature" and the "second room temperature" may be the same temperature or different temperatures.

Regarding the bonding method (second bonding method) according to one embodiment of the present invention, other than the above-described items, [2. Adhesion method (first adhesion method)] is incorporated. For example, aspects of the curable resin composition used in the second bonding method according to one embodiment of the present invention include preferred aspects, and are described in the section (2-1. Curable resin composition). It may be the same as the embodiment of the curable resin composition.

[4. Laminate]
A laminate according to an embodiment of the present invention can be obtained by applying the curable resin composition according to an embodiment of the present invention using the above bonding method.

A laminate according to an embodiment of the present invention is described in [2. Adhesion method (first adhesion method)] or [3. Adhesion method (second adhesion method)]. Since it has the said structure, the laminated body which concerns on one Embodiment of this invention can be obtained with good workability. Moreover, since the laminate according to one embodiment of the present invention has such a configuration, it exhibits high adhesive strength.

The thickness of the adhesive layer of the laminate is preferably 0.001 to 5 mm, more preferably 0.01 to 1 mm, particularly preferably 0.1 to 0.3 mm, from the viewpoint of the adhesive strength of the laminate.

In other words, the thickness of the adhesive layer of the laminate can be said to be the thickness of the cured product between the adherends.

[5. Laminate manufacturing method]
A method for manufacturing a laminate according to an embodiment of the present invention includes [2. Adhesion method (first adhesion method)] or [3. Adhesion method (second adhesion method)] is included as one step. Since the manufacturing method of the laminated body which concerns on one Embodiment of this invention has the said structure, workability|operativity is good and a laminated body can be obtained. Moreover, since the method for manufacturing a laminate according to one embodiment of the present invention has the configuration, it is possible to provide a laminate exhibiting high adhesive strength.

A method for manufacturing a laminate according to an embodiment of the present invention includes [4. Laminate]. In other words, [4. Laminate] is preferably manufactured by the method for manufacturing a laminate according to an embodiment of the present invention described in this section.

Regarding the method for manufacturing a laminate according to an embodiment of the present invention, the matters other than those described above are appropriately described in [2. Adhesion method (first adhesion method)], [3. Adhesion method (second adhesion method)] and [4. Laminate] is incorporated herein.

An embodiment of the present invention may have the following configuration.
[1] 1 to 100 parts by mass of fine polymer particles (B) having a core-shell structure per 100 parts by mass of epoxy resin (A), and blocked urethane (C) having a latent NCO% of 0.1 to 2.9% 1 to 100 parts by mass, a bonding method using a curable resin composition containing,
After the curable resin composition is heated to a temperature higher than room temperature and applied to one adherend, the curable resin composition applied before or at the same time as bonding the other adherend is thinly stretched under a room temperature environment, and the curable resin composition sandwiched between two bonded adherends is cured.
[2] The adhesion method according to [1], wherein the ratio (W1/W2) of the mass (W1) of the polymer fine particles (B) to the mass (W2) of the blocked urethane (C) is 0.1-10.
[3] [1] or [2], wherein the polymer fine particles (B) having a core-shell structure have an epoxy group in the shell layer, and the epoxy group content relative to the total amount of the shell layer is 0.4 to 5 mmol/g; Adhesion method described in .
[4] The bonding method according to any one of [1] to [3], which further contains 1 to 80 parts by mass of the epoxy curing agent (D) with respect to 100 parts by mass of the epoxy resin (A).
[5] The bonding method according to any one of [1] to [4], further comprising 0.1 to 10 parts by mass of a curing accelerator (E) with respect to 100 parts by mass of the epoxy resin (A).
[6] The bonding method according to any one of [1] to [5], wherein the epoxy resin (A) is a bisphenol A type epoxy resin and/or a bisphenol F type epoxy resin having an epoxy equivalent of less than 220.
[7] The fine polymer particles (B) having a core-shell structure have at least one core layer selected from the group consisting of diene-based rubbers, (meth)acrylate-based rubbers, and organosiloxane-based rubbers [1] to [ 6].
[8] The bonding method according to [7], wherein the diene rubber is butadiene rubber and/or butadiene-styrene rubber.
[9] Polymer fine particles (B) having a core-shell structure are prepared by graft-polymerizing at least one monomer component selected from the group consisting of aromatic vinyl monomers, vinyl cyanide monomers, and (meth)acrylate monomers onto the core layer. The bonding method according to any one of [1] to [8], which has a shell layer consisting of
[10] The adhesion method according to any one of [1] to [9], wherein the fine polymer particles (B) having a core-shell structure have a shell layer obtained by graft-polymerizing a monomer component having an epoxy group onto the core layer.
[11] The adhesion method according to any one of [1] to [10], wherein the blocked urethane (C) is a compound obtained by capping a urethane prepolymer containing a polyalkylene glycol structure with a blocking agent.
[12] The adhesion method according to any one of [1] to [11], wherein the blocked urethane (C) is a compound obtained by capping a urethane prepolymer containing a polypropylene glycol structure with a blocking agent.
[13] According to any one of [1] to [12], the curable resin composition is heated to a temperature higher than room temperature and applied to one of the bonding substrates at a temperature of 35 to 80°C. Adhesion method.
[14] The bonding method according to any one of [1] to [13], wherein the curable resin composition is cured at a curing temperature of 50 to 250°C.
[15] A bonding method using the one-component curable resin composition according to any one of [1] to [14].
[16] A laminate obtained by using the bonding method according to any one of [1] to [15].
[17] 1 to 100 parts by mass of fine polymer particles (B) having a core-shell structure per 100 parts by mass of the epoxy resin (A), and a blocked urethane (C) having a latent NCO% of 0.1 to 2.9% 1 to 100 parts by mass, a bonding method using a curable resin composition containing,
After the curable resin composition is heated to a temperature higher than the first room temperature and applied to one adherend, the applied curable resin composition is applied before or at the same time as bonding the other adherend. A second adhesion method in which the resin composition is thinly stretched in an environment at room temperature, and the curable resin composition sandwiched between two bonded adherends is cured.

EXAMPLES Hereinafter, one embodiment of the present invention will be described in more detail with reference to Examples and Comparative Examples, but the present invention is not limited to these. One embodiment of the present invention can be carried out by appropriately changing the following examples as long as it is compatible with the above and the gist of the postscript. Any embodiment implemented by appropriately modifying the following examples is included in the technical scope of the present invention. In the following examples, comparative examples and tables, "parts" and "%" mean parts by mass and % by mass, respectively.

(Evaluation method)
First, methods for evaluating the curable resin compositions produced in Examples and Comparative Examples will be described below.

[1] Measurement of Volume Average Particle Size The volume average particle size (Mv) of the polymer fine particles (B) dispersed in the aqueous latex was measured using Microtrac UPA150 (manufactured by Nikkiso Co., Ltd.). An aqueous latex diluted with deionized water was used as a measurement sample. For the measurement, the refractive index of water and the refractive index of the polymer fine particles (B) obtained in each production example are input, the measurement time is 600 seconds, and the Signal Level is within the range of 0.6 to 0.8. was performed by adjusting the sample concentration.

[2] Measurement of Viscosity Using a rheometer, the viscosity at a shear rate of 5 s ^-1 of each curable resin composition obtained in Examples and Comparative Examples was measured at 60°C and 25°C. The larger the ratio of the viscosity at 60° C. to the viscosity at 25° C. (the closer it is to 1), the smaller the temperature dependency of the viscosity and the better the workability.

1. Formation of core layer Production Example 1-1; Preparation of polybutadiene rubber latex (R-1) 200 parts by mass of deionized water, 0.03 parts by mass of tripotassium phosphate, and dihydrogen phosphate in a pressure-resistant polymerization machine with a volume of 100 L. Potassium 0.25 parts by mass, disodium ethylenediaminetetraacetate (EDTA) 0.002 parts by mass, ferrous sulfate heptahydrate (FE) 0.001 parts by mass and sodium dodecylbenzenesulfonate (SDS) 1 as an emulsifier .5 parts by mass were added. Next, oxygen was sufficiently removed from the inside of the pressure-resistant polymerizer by replacing the gas inside the pressure-resistant polymerizer with nitrogen while stirring the introduced raw materials. After that, 100 parts by mass of butadiene (BD) was put into the pressure-resistant polymerization vessel, and the temperature inside the pressure-resistant polymerization vessel was raised to 45°C. After that, 0.015 parts by mass of paramenthane hydroperoxide (PHP) was charged into the pressure-resistant polymerization vessel, and then 0.04 parts by mass of sodium formaldehyde sulfoxylate (SFS) was charged into the pressure-resistant polymerization vessel to initiate polymerization. started. After 10 hours from the initiation of the polymerization, devolatilization was carried out under reduced pressure to devolatilize and remove residual monomers that were not used in the polymerization, thereby completing the polymerization. During polymerization, each of PHP, EDTA and FE was added into the pressure-resistant polymerization vessel at arbitrary amounts and at arbitrary times. Through the polymerization, a latex (R-1) containing a core layer (polybutadiene rubber particles) containing polybutadiene rubber as a main component was obtained. The volume average particle size of the polybutadiene rubber particles contained in the obtained latex was 0.10 μm.

Production Example 1-2; Preparation of polybutadiene rubber latex (R-2) In a pressure-resistant polymerization machine with a volume of 100 L, 7 parts by mass of the solid content of the polybutadiene rubber latex (R-1) obtained in Production Example 1-1 was removed. 200 parts by mass of ionized water, 0.03 parts by mass of tripotassium phosphate, 0.002 parts by mass of EDTA, and 0.001 parts by mass of FE were added. Next, oxygen was sufficiently removed from the inside of the pressure-resistant polymerizer by replacing the gas inside the pressure-resistant polymerizer with nitrogen while stirring the introduced raw materials. After that, 93 parts by mass of BD was charged into the pressure-resistant polymerization vessel, and the temperature inside the pressure-resistant polymerization vessel was raised to 45°C. After that, 0.02 parts by mass of PHP was charged into the pressure-resistant polymerization vessel, and then 0.10 parts by mass of SFS was charged into the pressure-resistant polymerization vessel to initiate polymerization. After 30 hours from the start of the polymerization, the polymerization was completed by devolatilizing under reduced pressure to devolatilize and remove residual monomers that were not used in the polymerization. During polymerization, each of PHP, EDTA and FE was added into the pressure-resistant polymerization vessel at arbitrary amounts and at arbitrary times. Through the polymerization, a latex (R-2) containing a core layer (polybutadiene rubber particles) containing polybutadiene rubber as a main component was obtained. The volume average particle size of the polybutadiene rubber particles contained in the obtained latex was 0.20 μm.

2. Preparation of polymer fine particles (B) (formation of shell layer)
Production Example 2-1; Preparation of core-shell polymer latex (L-1) 262 parts by mass of the polybutadiene rubber latex (R-2) prepared in Production Example 1-2 (containing 87 parts by mass of polybutadiene rubber particles) was placed in a glass reactor. ), and 57 parts by mass of deionized water were added. Here, the glass reactor contained a thermometer, stirrer, reflux condenser, nitrogen inlet, and monomer addition device. The gas in the glass reactor was replaced with nitrogen, and the charged raw materials were stirred at 60° C. while performing the nitrogen replacement. Next, 0.004 parts by weight of EDTA, 0.001 parts by weight of FE, and 0.2 parts by weight of SFS were added into the glass reactor. After that, a monomer for forming the shell layer (hereinafter also referred to as a graft monomer) (5 parts by weight of styrene (ST), 2 parts by weight of acrylonitrile (AN) and 6 parts by weight of glycidyl methacrylate (GMA)) and cumene hydroper A mixture with 0.04 parts by weight of oxide (CHP) was continuously added into the glass reactor over 120 minutes. After the addition was completed, 0.04 part by mass of CHP was added into the glass reactor, and the mixture in the glass reactor was stirred for another 2 hours to complete the polymerization. By the above operation, an aqueous latex (L-1) containing polymer fine particles (B) (core-shell polymer) was obtained. The polymerization conversion rate of the monomer component was 99% or more. The volume average particle size of the core-shell polymer contained in the obtained aqueous latex was 0.21 μm.

Production Example 2-2; Preparation of core-shell polymer latex (L-2) In Production Example 2-1, instead of <5 parts by mass of ST, 2 parts by mass of AN, and 6 parts by mass of GMA> as graft monomers, <1 mass of methyl methacrylate (MMA) A water-based latex (L-2) containing a core-shell polymer was obtained in the same manner as in Production Example 2-1, except that 6 parts by mass of ST, 2 parts by mass of AN, and 4 parts by mass of GMA> were used. The volume average particle size of the core-shell polymer contained in the obtained aqueous latex was 0.21 μm.

Production Example 2-3: Preparation of Core-Shell Polymer Latex (L-3) In Production Example 2-1, <MMA 3 parts by mass, ST 6 parts by mass> was used instead of <ST 5 parts by mass, AN 2 parts by mass, and GMA 6 parts by mass> as graft monomers. , AN 2 parts by mass, and GMA 2 parts by mass> were used in the same manner as in Production Example 2-1 to obtain an aqueous latex (L-3) containing a core-shell polymer. The volume average particle size of the core-shell polymer contained in the obtained aqueous latex was 0.21 μm.

Production Example 2-4; Preparation of core-shell polymer latex (L-4) In Production Example 2-1, <MMA 4 parts by mass, ST 6 parts by mass> instead of <ST 5 parts by mass, AN 2 parts by mass, and GMA 6 parts by mass> as graft monomers , 2 parts by mass of AN and 1 part by mass of GMA> were used in the same manner as in Production Example 2-1 to obtain an aqueous latex (L-4) containing a core-shell polymer. The volume average particle size of the core-shell polymer contained in the obtained aqueous latex was 0.21 μm.

Production Example 2-5; Preparation of core-shell polymer latex (L-5) In Production Example 2-1, <MMA 4.5 parts by mass, ST6> instead of <ST5 parts by mass, AN 2 parts by mass, and GMA 6 parts by mass> as graft monomers A water-based latex (L-5) containing a core-shell polymer was obtained in the same manner as in Production Example 2-1, except that parts by mass, 2 parts by mass of AN, and 0.5 parts by mass of GMA> were used. The volume average particle size of the core-shell polymer contained in the obtained aqueous latex was 0.21 μm.

Production Example 2-6; Preparation of core-shell polymer latex (L-6) In Production Example 2-1, <5 parts by mass of MMA, 6 parts by mass of ST> instead of <5 parts by mass of ST, 2 parts by mass of AN, and 6 parts by mass of GMA> as graft monomers An aqueous latex (L-6) containing a core-shell polymer was obtained in the same manner as in Production Example 2-1 except that AN and 2 parts by mass> were used. The volume average particle size of the core-shell polymer contained in the obtained aqueous latex was 0.21 μm.

3. Preparation of Dispersion (M) in which Polymer Fine Particles (B) are Dispersed in Curing Resin Production Example 3-1; Preparation of Dispersion (M-1) 132 g of methyl ethyl ketone (MEK) was introduced into a 1 L mixing tank at 25°C. . Next, while stirring the MEK, 132 g of the aqueous latex (L-1) containing the core-shell polymer obtained in Production Example 2-1 (equivalent to 40 g of the fine polymer particles (B)) was put into the mixing tank. After uniformly mixing the raw materials in the mixing tank, 200 g of water was introduced into the mixing tank at a supply rate of 80 g/min while stirring the raw materials in the mixing tank. After the supply of water was completed, the stirring was promptly stopped to obtain a slurry liquid consisting of aggregates containing the polymer fine particles (B) and an aqueous phase containing a small amount of organic solvent. The aggregates were buoyant. Next, 360 g of the water phase was discharged from the discharge port at the bottom of the mixing tank so that the aggregate containing a part of the water phase remained in the mixing tank. 90 g of MEK was added to the obtained agglomerates and mixed uniformly to obtain a dispersion in which the core-shell polymer was uniformly dispersed in MEK. 60 g of the epoxy resin (A-1) as the component (A) was added to the obtained dispersion, and they were uniformly mixed. The epoxy resin (A-1) will be detailed below. MEK was removed from the resulting mixture using a rotary evaporator. Thus, a dispersion (M-1) in which the fine polymer particles (B) are dispersed in the epoxy resin (A) was obtained.

Production Example 3-2; Preparation of Dispersion (M-2) In Production Example 3-1, instead of (L-1) 132 g as the aqueous latex containing the core-shell polymer, (L-2) 132 g (polymer fine particles (B) A dispersion (M-2) in which polymer fine particles are dispersed in the epoxy resin (A) was obtained in the same manner as in Production Example 3-1, except for using 40 g equivalent).

Production Example 3-3; Preparation of Dispersion (M-3) In Production Example 3-1, instead of 132 g of (L-1) as the aqueous latex containing the core-shell polymer, 132 g of (L-3) (polymer fine particles (B) A dispersion (M-3) in which polymer fine particles are dispersed in the epoxy resin (A) was obtained in the same manner as in Production Example 3-1, except for using 40 g equivalent).

Production Example 3-4; Preparation of Dispersion (M-4) In Production Example 3-1, instead of 132 g of (L-1) as the aqueous latex containing the core-shell polymer, 132 g of (L-4) (polymer fine particles (B) A dispersion (M-4) in which polymer fine particles are dispersed in the epoxy resin (A) was obtained in the same manner as in Production Example 3-1, except for using 40 g equivalent).

Production Example 3-5; Preparation of Dispersion (M-5) In Production Example 3-1, instead of 132 g of (L-1) as the aqueous latex containing the core-shell polymer, 132 g of (L-5) (polymer fine particles (B) A dispersion (M-5) in which polymer fine particles are dispersed in the epoxy resin (A) was obtained in the same manner as in Production Example 3-1, except for using 40 g equivalent).

Production Example 3-6; Preparation of Dispersion (M-6) In Production Example 3-1, instead of (L-1) 132 g as the aqueous latex containing the core-shell polymer, (L-6) 132 g (polymer fine particles (B) A dispersion (M-6) in which polymer fine particles are dispersed in the epoxy resin (A) was obtained in the same manner as in Production Example 3-1, except for using 40 g equivalent).

(Examples 1 to 9, Comparative Examples 1 to 5)
According to the formulations (formulations) shown in Tables 1 to 3, each component was weighed and thoroughly mixed to obtain a curable resin composition. Tables 1 to 3 show the viscosity test results of the obtained curable resin compositions.

The various compounding agents in Tables 1 to 3 were used as shown below.
<Epoxy resin (A)>
A-1: JER828 (manufactured by Mitsubishi Chemical, liquid bisphenol A type epoxy resin at room temperature, epoxy equivalent: 184 to 194)
<Dispersion (M) in which fine polymer particles (B) are dispersed in epoxy resin (A)>
M-1 to 6: Dispersions <blocked urethane (C)> obtained in Production Examples 3-1 to 3-6
C-1: Takenate B-7055 (manufactured by Mitsui Chemicals, blocked urethane, latent NCO%: 2.0%)
C-2: Takenate B-7010S (manufactured by Mitsui Chemicals, blocked urethane, latent NCO%: 2.3%)
C-3: Takenate B-7005 (manufactured by Mitsui Chemicals, blocked urethane, latent NCO%: 2.7%)
C-4: Takenate B-7030 (manufactured by Mitsui Chemicals, blocked urethane, latent NCO%: 3.4%)
C-5: Takenate B-7037 (manufactured by Mitsui Chemicals, blocked urethane, latent NCO%: 3.3%)
C-6: Takenate B-7075 (manufactured by Mitsui Chemicals, blocked urethane, latent NCO%: 3.9%)
<Epoxy resin curing agent (D)>
Dyhard 100S (manufactured by AlzChem, dicyandiamide)
<Curing accelerator (E)>
Dyhard UR300 (manufactured by AlzChem, 1,1-dimethyl-3-phenylurea)
<Other ingredients>
≪Heavy calcium carbonate≫
Whiten SB (manufactured by Shiraishi Calcium, untreated heavy calcium carbonate, average particle size: 1.8 μm)
≪Calcium oxide≫
CML#31 (manufactured by Ohmi Chemical Industry, calcium oxide surface-treated with fatty acid)

From Tables 1 and 2, the components (A), (B), and (C) according to one embodiment of the present invention are contained, and the latent NCO% of the (C) component is 0.1% to It can be seen that the curable resin compositions of Examples 1 to 9, which are 2.9%, have small temperature dependence of viscosity.

In addition, coating workability was evaluated when each composition in Tables 1 to 3 was heated to 60° C. and coated on a steel plate. Specifically, after applying a curable resin composition heated to 60 ° C. to a thickness of 3 mm, each composition in Tables 1 to 3 is applied with a spatula under a room temperature environment of 25 ° C. on the steel plate. The workability with a spatula was evaluated when the film was stretched thinly (until the thickness reached 0.2 mm). After stretching the curable resin composition thinly (until the thickness reaches 0.2 mm), another steel plate is attached and cured at 180 ° C. for 60 minutes to form two steel plates. Laminates bonded with each composition of No. 3 were obtained.

The coating workability of the curable resin compositions of Examples 1 to 9 when heated to 60 ° C. is such that the curable resin composition after application does not drip because the curable resin composition has an appropriate viscosity. It was good. In addition, the spatula workability of the curable resin compositions of Examples 1 to 9 at 25° C. is good because the temperature dependence of the viscosity of the curable resin composition is small and the viscosity is relatively low even at 25° C. there were.

On the other hand, the curable resin composition of Comparative Example 1 exhibited a very high viscosity at 25° C. and was difficult to work with a spatula. In addition, the curable resin compositions of Comparative Examples 2 to 5 exhibited low viscosity at 60° C., so that the curable resin compositions tended to sag after application, making the application work difficult.

Laminates in which two steel plates were bonded with the curable resin compositions of Examples 1 to 9 all exhibited good adhesiveness.

The amount (parts by mass) of component (A) contained in the curable resin compositions in Tables 1 to 3 is the amount described in the column for component (A), that is, the amount of component (A) added as an epoxy resin. It is the sum of the amount and the amount described in the column of (A) component + (B) component, that is, the amount of component (A) contained in dispersion (M) of fine polymer particles (B). In addition, the (C) component according to one embodiment of the present invention means a blocked urethane that satisfies a predetermined latent NCO %.

According to one embodiment of the present invention, the curable resin composition has low temperature dependence of viscosity, and the adhesion method using the curable resin composition is excellent in workability. Therefore, the bonding method according to one embodiment of the present invention can be suitably used for bonding iron plates, CFRP, aluminum plates and concrete. An embodiment of the present invention can be advantageously used in the mechanical, electrical, architectural and civil engineering fields.

Claims (13)

(i) step 1 of heating the curable resin composition to a first temperature and applying it to one adherend in a first thickness;
(ii) Before or at the same time as bonding the other adherend to the one adherend, the applied curable resin composition is increased to a second thickness in an environment at a second temperature. Stretching step 2, and (iii) having step 3 of curing the curable resin composition sandwiched between the two bonded adherends,
the first temperature is higher than the second temperature and the second thickness is less than the first thickness;
The curable resin composition is
Epoxy resin (A), and 1 to 100 parts by mass of polymer fine particles (B) having a core-shell structure including a core layer and a shell layer per 100 parts by mass of the epoxy resin (A) and latent NCO% A bonding method containing 1 to 100 parts by mass of blocked urethane (C), which is 0.1% to 2.9%. The adhesion according to claim 1, wherein the ratio (W1/W2) of the mass (W1) of the polymer fine particles (B) to the mass (W2) of the blocked urethane (C) is 0.1 to 10.0. Method. 3. The bonding method according to claim 1, wherein the shell layer has epoxy groups, and the content of the epoxy groups with respect to the total mass of the shell layer is 0.4 mmol/g to 5.0 mmol/g. 4. Any one of claims 1 to 3, wherein the curable resin composition further contains 1 part by mass to 80 parts by mass of an epoxy resin curing agent (D) with respect to 100 parts by mass of the epoxy resin (A). Adhesion method described in . 5. Any one of claims 1 to 4, wherein the curable resin composition further contains 0.1 to 10.0 parts by mass of a curing accelerator (E) with respect to 100 parts by mass of the epoxy resin (A). 1. The bonding method according to 1. The bonding method according to any one of claims 1 to 5, wherein the epoxy resin (A) is a bisphenol A type epoxy resin and/or a bisphenol F type epoxy resin having an epoxy equivalent of less than 220. The bonding method according to any one of claims 1 to 6, wherein the core layer is butadiene rubber and/or butadiene-styrene rubber. 2. The shell layer comprises a polymer obtained by graft-polymerizing at least one monomer component selected from the group consisting of an aromatic vinyl monomer, a vinyl cyanide monomer and a (meth)acrylate monomer onto the core layer. 8. The bonding method according to any one of 7. 9. The bonding method according to any one of claims 1 to 8, wherein the shell layer comprises a polymer obtained by graft-polymerizing a monomer component having an epoxy group to the core layer. 10. The bonding method according to any one of claims 1 to 9, wherein the blocked urethane (C) is a compound obtained by capping a urethane prepolymer containing a polypropylene glycol structure with a blocking agent. The bonding method according to any one of claims 1 to 10, wherein the first temperature is 35°C to 80°C. The bonding method according to any one of claims 1 to 11, wherein the curing temperature in the step 3 is 50°C to 250°C. A method for manufacturing a laminate, comprising the bonding method according to any one of claims 1 to 12 as one step.