JP6476045B2 - Curable resin composition containing fine polymer particles with improved adhesion - Google Patents

Description

  The present invention relates to a curable resin composition having an epoxy resin as a main component and having excellent adhesiveness.

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

  In Patent Document 1, the toughness and impact resistance of a cured product obtained are improved by dispersing polymer fine particles having a core-shell structure in a curable resin composition containing a curable resin such as an epoxy resin as a main component. Technology is disclosed.

  Patent Document 1 and Patent Document 2 have a description that a chain transfer agent is used to adjust the degree of cross-linking of the core layer of polymer fine particles having a core-shell structure. However, none of the patent documents suggests a relationship between the core-shell polymer fine particles having a core layer polymerized using a chain transfer agent and the adhesiveness of the resulting curable resin composition. Regarding the combination of core-shell polymer particles using chain transfer agent as an essential component and reinforcing agents other than core-shell polymer particles (blocked urethane, rubber-modified epoxy, etc.) or specific epoxy curing agent species and amount Not suggested.

  On the other hand, an adhesive having high adhesiveness using an epoxy resin composition has been used as a structural adhesive for steel plates of vehicles and the like, but higher adhesive strength is desired in the future. Moreover, with the need for vehicle weight reduction, improvement of the adhesive strength to difficult-to-adhere adherends such as aluminum plates and FRP plates is desired.

Special table 2009-506169 JP 2004-315572 A

  This invention is made | formed in view of the above-mentioned situation, and this invention is curable resin composition which has an epoxy resin as a main component, Comprising: Adhesiveness, such as T character peeling adhesive strength, of the hardened | cured material obtained An object is to provide an excellent curable resin composition.

As a result of intensive studies to solve such problems, the present inventor has found an epoxy resin (
A) In the curable resin composition containing polymer fine particles (B) having a core-shell structure in which the core layer is a diene rubber, the core layer is selected from the group consisting of blocked urethane, rubber-modified epoxy resin, and urethane-modified epoxy resin. When further containing one or more kinds (C), or when containing 4.5 to 6.5 parts by mass of dicyandiamide as the epoxy curing agent (D), the core layer of the component (B) is added to the chain transfer agent. The present invention has been completed by finding that the above-mentioned problems can be solved by using a diene rubber obtained by polymerization.

  That is, the present invention relates to 100 parts by mass of the epoxy resin (A), 1 to 100 parts by mass of polymer fine particles (B) having a core-shell structure whose core layer is a diene rubber, blocked urethane, rubber-modified epoxy resin, A curable resin composition containing 1 to 100 parts by mass of (C) selected from the group consisting of urethane-modified epoxy resins, wherein the core layer of component (B) is (b1) conjugated diene-based single 50 to 99.99% by weight of a monomer, (b2) 49.99 to 0% by weight of a vinyl monomer copolymerizable with a conjugated diene monomer, and (b3) 0.01 to 3% by weight of a chain transfer agent. It is a diene rubber obtained by polymerizing a monomer mixture comprising: a curable resin composition (I) characterized in that the core layer is a diene rubber with respect to 100 parts by mass of the epoxy resin (A). Rubber core A curable resin composition containing 1 to 100 parts by mass of polymer fine particles (B) having a gel structure and 4.5 to 6.5 parts by mass of dicyandiamide as an epoxy curing agent (D), comprising: The core layer comprises (b1) 50 to 99.99% by mass of a conjugated diene monomer, (b2) 49.99 to 0% by mass of a vinyl monomer copolymerizable with the conjugated diene monomer, and (b3 It relates to a curable resin composition (II) which is a diene rubber obtained by polymerizing a monomer mixture comprising 0.01 to 3% by mass of a chain transfer agent.

  It is preferable that curable resin composition (I) contains 1-80 mass parts of epoxy hardening | curing agents (D) further with respect to 100 mass parts of (A) component.

  The curable resin composition (II) is one or more selected from the group consisting of blocked urethane, rubber-modified epoxy resin, and urethane-modified epoxy resin with respect to 100 parts by mass of the component (A) (C) 1 It is preferable to contain -100 mass parts.

  It is preferable that the said curable resin composition contains 0.1-10 mass parts of hardening accelerators (E) further with respect to 100 mass parts of (A) component.

  The diene rubber is preferably butadiene rubber and / or butadiene-styrene rubber.

  The component (B) has a shell layer obtained by graft polymerizing one or more monomer components selected from the group consisting of an aromatic vinyl monomer, a vinyl cyan monomer, and a (meth) acrylate monomer on the core layer. preferable.

  The component (B) preferably has an epoxy group in the shell layer.

  (B) It is preferable that a component has a shell layer formed by graft-polymerizing the monomer component which has an epoxy group to a core layer.

  (B) It is preferable that content of the epoxy group in a component is 0.01-0.8 mmol / g.

  The component (B) is preferably dispersed in the state of primary particles in the curable resin composition.

  Preferably, it is a cured product obtained by curing any of the curable resin compositions.

  Preferably, it is a one-pack type curable resin composition.

  A structural adhesive is preferable.

  Preferably, a laminate obtained by bonding the members by curing the curable resin composition after the curable resin composition of the present invention is laminated between a plurality of members including an aluminum base. About.

  The curable resin composition of the present invention can improve adhesiveness such as T-peel adhesive strength of the obtained cured product.

  Hereinafter, the curable resin composition of the present invention will be described in detail.

  The curable resin composition of the present invention is a curable resin containing 1 to 100 parts by mass of polymer fine particles (B) having a core-shell structure in which the core layer is a diene rubber with respect to 100 parts by mass of the epoxy resin (A). (B) component conjugated diene monomer 50 to 99.99 mass%, (b2) vinyl monomer that is copolymerizable with conjugated diene monomer It is characterized by being a diene rubber obtained by polymerizing a monomer mixture comprising 49.99 to 0 mass% of a body and 0.01 to 3 mass% of (b3) chain transfer agent, preferably the first It is divided into either the embodiment or the second embodiment.

  In the first aspect, 1 or more types (C) of 1 to 100 mass selected from the group consisting of blocked urethane, rubber-modified epoxy resin, and urethane-modified epoxy resin with respect to 100 mass parts of the epoxy resin (A). Part of the curable resin composition (I).

  In the second aspect, the curable resin composition further contains 4.5 to 6.5 parts by mass of dicyandiamide as an epoxy curing agent (D) with respect to 100 parts by mass of the epoxy resin (A). (II).

  Any of these embodiments is advantageous in that particularly high adhesiveness can be obtained.

<Epoxy resin (A)>
An epoxy resin (A) is used as a main component of the curable resin composition of the present invention. As the epoxy resin, various hard epoxy resins can be used except for the rubber-modified epoxy resin and the urethane-modified epoxy resin described later, for example, 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, glycidyl amine 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 tetrabromobisphenol A glycidyl ether, p-oxybenzoic acid glycidyl ether ester type epoxy resin, m-aminophenol type epoxy Fatty, diaminodiphenylmethane epoxy resin, various alicyclic epoxy resins, N, N-diglycidylaniline, N, N-diglycidyl-o-toluidine, triglycidyl isocyanurate, divinylbenzene dioxide, resorcinol diglycidyl ether, polyalkylene Glycol diglycidyl ether, glycol diglycidyl ether, diglycidyl ester of aliphatic polybasic acid, glycidyl ether of polyhydric aliphatic alcohols such as glycerin, chelate-modified epoxy resin, hydantoin type epoxy resin, petroleum resin, etc. Epoxidized products of unsaturated polymers, such as aminoglycidyl ether resins, epoxy compounds obtained by adding bisphenol A (or F) or polybasic acids to the above epoxy resins, etc. Although shown, the invention is not limited to, epoxy resins may be used which are commonly used.

  More specifically, examples of the polyalkylene glycol diglycidyl ether include polyethylene glycol diglycidyl ether and polypropylene glycol diglycidyl ether. More specifically, examples of the glycol diglycidyl ether include neopentyl glycol diglycidyl ether, 1,4-butanediol diglycidyl ether, 1,6-hexanediol diglycidyl ether, and cyclohexanedimethanol diglycidyl ether. It is done. Specific examples of the diglycidyl ester of the aliphatic polybasic acid include dimer acid diglycidyl ester, adipic acid diglycidyl ester, sebacic acid diglycidyl ester, and maleic acid diglycidyl ester. More specifically, the glycidyl ether of the dihydric or higher polyhydric aliphatic alcohol includes trimethylolpropane triglycidyl ether, trimethylolethane triglycidyl ether, castor oil-modified polyglycidyl ether, propoxylated glycerin triglycidyl ether, sorbitol. And polyglycidyl ether. Examples of the epoxy compound obtained by addition reaction of polybasic acids with an epoxy resin include, for example, dimers of tall oil fatty acid (dimer acid) and bisphenol A type epoxy as described in the pamphlet of WO2010-098950. An addition reaction product with resin is mentioned. These epoxy resins may be used alone or in combination of two or more.

  The polyalkylene glycol diglycidyl ether, the glycol diglycidyl ether, the diglycidyl ester of the aliphatic polybasic acid, and the glycidyl ether of the divalent or higher polyhydric aliphatic alcohol are epoxy resins having a relatively low viscosity. When used in combination with other epoxy resins such as bisphenol A type epoxy resin and bisphenol F type epoxy resin, it functions as a reactive diluent and can improve the balance between the viscosity of the composition and the physical properties of the cured product. The content of the epoxy resin that functions as a reactive diluent is preferably 0.5 to 20% by mass, more preferably 1 to 10% by mass, and still more preferably 2 to 5% by mass in the epoxy resin (A) component. .

The chelate-modified epoxy resin is a reaction product of an epoxy resin and a compound containing a chelate functional group (chelate ligand), and added to the curable resin composition of the present invention to be used as an adhesive for vehicles. In this case, adhesion to the surface of a metal substrate contaminated with an oily substance can be improved. The chelate functional group is a functional group of a compound having a plurality of coordination sites capable of coordinating with metal ions in the molecule. For example, a phosphorus-containing acid group (for example, —PO (OH) ₂ ), a carboxylic acid group (— CO ₂ H), sulfur-containing acid groups (for example, —SO ₃ H), amino groups and hydroxyl groups (particularly, hydroxyl groups adjacent to each other in the aromatic ring). Examples of chelate ligands include ethylenediamine, bipyridine, ethylenediaminetetraacetic acid, phenanthroline, porphyrin, and crown ether. Examples of commercially available chelate-modified epoxy resins include Adeka Resin EP-49-10N manufactured by ADEKA.

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

  Among these epoxy resins, those having at least two epoxy groups in one molecule are preferable from the viewpoint of high reactivity and easy formation of a three-dimensional network upon curing.

  Among the above-mentioned epoxy resins, bisphenol A type epoxy resins and bisphenol F type epoxy resins are preferable because the obtained cured products have high elastic modulus, excellent heat resistance and adhesion, and are relatively inexpensive. Resins are particularly preferred.

  Among various epoxy resins, an epoxy resin having an epoxy equivalent of less than 220 is preferable because the resulting cured product has high elastic modulus and heat resistance, and the epoxy equivalent is more preferably 90 or more and less than 210, and more preferably 150 or more and less than 200. Is more preferable.

  In particular, bisphenol A-type epoxy resins and bisphenol F-type epoxy resins having an epoxy equivalent of less than 220 are preferable because they are liquid at room temperature and the curable resin composition obtained is easy to handle.

  It is obtained by adding a bisphenol A type epoxy resin or a bisphenol F type epoxy resin having an epoxy equivalent of 220 or more and less than 5000 to the component (A) in a range of preferably 40% by mass or less, more preferably 20% by mass or less. A cured product is preferred because of its excellent impact resistance.

<Polymer fine particles (B)>
In the curable resin composition of the present invention, the core layer is (b1) 50 to 99.99% by mass of the conjugated diene monomer and (b2) the conjugated diene monomer based on 100 parts by mass of the component (A). Core shell which is a diene rubber obtained by polymerizing a monomer mixture comprising 49.99 to 0% by mass of a vinyl monomer copolymerizable with a polymer and 0.01 to 3% by mass of (b3) a chain transfer agent 1 to 100 parts by mass of polymer fine particles (B) having a structure are used. Due to the effect of improving the toughness of the component (B), the resulting cured product is excellent in toughness and impact peel adhesion.

  Since the core layer of the component (B) is a diene rubber having a low affinity with the epoxy resin (A), no increase in viscosity due to swelling due to the component (A) is observed. In addition, since the core layer is a diene rubber, the impact peel adhesion strength of the cured product is higher than that of polymer fine particles having a polysiloxane rubber or acrylic rubber as the core layer. Furthermore, polymer fine particles obtained by polymerizing the core layer using a chain transfer agent, which is the component (B) of the present invention, are a blocked urethane, a rubber-modified epoxy resin, a urethane-modified component (C) described later. When one or more selected from the group consisting of epoxy resins are combined, or 4.5 to 6.5 parts by mass of dicyandiamide as an epoxy curing agent (D) described later with respect to 100 parts by mass of component (A) When combined, it has the effect of remarkably improving the adhesiveness such as T-peeling adhesiveness.

  As described above, in Japanese Translation of PCT International Publication No. 2009-506169, the combination of polymer fine particles having a core-shell structure and a reinforcing agent other than the core-shell polymer fine particles (blocked urethane, rubber-modified epoxy, etc.) There is a description of improving impact peel adhesion. In addition, the publication discloses that a chain transfer agent is used to adjust the degree of crosslinking of the core layer of polymer fine particles having a core-shell structure. However, the publication does not suggest the relationship between the core-shell polymer fine particles having a core layer polymerized using a chain transfer agent and the adhesiveness of the resulting curable resin composition.

  Furthermore, in the technology of the above publication, impact peel adhesion is improved at the same time as T-shaped peel adhesion, but even if the degree of cross-linking of the core layer of the core-shell polymer fine particles is adjusted using a chain transfer agent, the impact resistance is improved. It has been clarified by the present invention that the effect of improving the peel adhesion is very small and only the T-shaped peel adhesion is greatly improved. Therefore, it is estimated that the improvement mechanism disclosed in the above publication is greatly different from the improvement mechanism of the present invention.

  From the balance between easy handling of the resulting curable resin composition and toughness improving effect of the resulting cured product, component (B) is 1 to 100 parts by mass with respect to 100 parts by mass of component (A), 70 mass parts is preferable, 3-50 mass parts is more preferable, and 4-20 mass parts is still more preferable.

  When the epoxy group is contained in the component (B), the content of the epoxy group of the component (B) is from the viewpoint of making the impact-resistant peel adhesion of the obtained cured product and the storage stability of the composition compatible. 01-0.8 mmol / g is preferable, 0.02-0.6 mmol / g is more preferable, 0.04-0.4 mmol / g is still more preferable, 0.05-0.2 mmol / g is especially preferable. When the content of the epoxy group of the component (B) is less than 0.01 mmol / g, the impact-resistant peel adhesion of the obtained cured product tends to be lowered. If it exceeds 0.8 mmol / g, the viscosity of the composition after storage tends to increase.

  The particle diameter of the polymer fine particles is not particularly limited, but considering industrial productivity, the volume average particle diameter (Mv) is preferably 10 to 2000 nm, more preferably 30 to 600 nm, still more preferably 50 to 400 nm, and more preferably 100 to 200 nm. Is particularly preferred. The volume average particle diameter (Mv) of the polymer particles can be measured using Microtrac UPA150 (manufactured by Nikkiso Co., Ltd.).

  Component (B) is a curable resin obtained in the composition of the present invention, having a half-value width of 0.5 to 1 times the number average particle size in the number distribution of the particle size. It is preferable because the composition has a low viscosity and is easy to handle.

  From the viewpoint of easily realizing the specific particle size distribution described above, it is preferable that there are two or more maximum values in the number distribution of the particle size of the component (B), and from the viewpoint of labor and cost during production, the maximum It is more preferable that 2 to 3 values exist, and it is even more preferable that 2 maximum values exist. In particular, it is preferable to include 10 to 90% by mass of polymer fine particles having a volume average particle size 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 size of 150 nm to 2000 nm.

  The component (B) is preferably dispersed in the state of primary particles in the curable resin composition. In the present invention, “the polymer fine particles are dispersed in the state of primary particles in the curable resin composition” (hereinafter also referred to as primary dispersion) means that the polymer fine particles are substantially independent (contacted). The dispersion state is, for example, by dissolving a part of the curable resin composition in a solvent such as methyl ethyl ketone, and using a particle size measuring device or the like by laser light scattering. This can be confirmed by measuring the particle diameter.

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

  The volume average particle size (Mv) / number average particle size (Mn) can be determined by measuring using Microtrac UPA (manufactured by Nikkiso Co., Ltd.) and dividing Mv by Mn.

  In addition, “stable dispersion” of polymer fine particles means that the polymer fine particles are not aggregated, separated, or precipitated in the continuous layer, and are constantly under normal conditions over a long period of time. Mean that the distribution of the polymer fine particles in the continuous layer does not substantially change, and the viscosity is lowered by heating these compositions in a range that is not dangerous. It is preferable that “stable dispersion” can be maintained even if stirring is performed.

  (B) A component may be used independently and may be used together 2 or more types.

  The structure of the polymer fine particle is not particularly limited, but preferably has a core-shell structure of two or more layers. It is also possible to have a structure of three or more layers constituted by an intermediate layer covering the core layer and a shell layer further covering the intermediate layer.

Hereinafter, each layer will be specifically described.
≪Core layer≫
The core layer is composed of (b1) 50 to 99.99% by mass of a conjugated diene monomer, (b2) 49.99 to 0% by mass of a vinyl monomer copolymerizable with the conjugated diene monomer, and (b3 ) A diene rubber obtained by polymerizing a monomer mixture comprising 0.01 to 3% by mass of a chain transfer agent.

  The core layer is preferably an elastic core layer having properties as a rubber in order to increase the toughness of the cured product of the curable resin composition of the present invention. In order to have properties as rubber, the elastic core layer of the present invention preferably has a gel content of 60% by mass or more, more preferably 80% by mass or more, and further preferably 90% by mass or more. It is preferably 95% by mass or more. In addition, the gel content referred to in the present specification means that 0.5 g of crumb obtained by coagulation and drying is immersed in 100 g of toluene and left to stand at 23 ° C. for 24 hours, and then insoluble and soluble components are separated. The ratio of insoluble matter to the total amount of insoluble matter and soluble matter is meant.

  Examples of the (b1) conjugated diene monomer constituting the diene rubber used in the elastic core layer include 1,3-butadiene, isoprene, 2-chloro-1,3-butadiene, 2-methyl-1,3. -Butadiene and the like. These conjugated diene monomers may be used alone or in combination of two or more.

  The conjugated diene monomer (b1) must be in the range of 50 to 99.99% by mass of the core layer, and preferably in the range of 70 to 99.99% by mass, More preferably, it is in the range of .99% by mass. When the content of the conjugated diene monomer (b1) is less than 50% by mass, the adhesiveness of the obtained cured product tends to be lowered.

  (B2) Examples of the vinyl monomer copolymerizable with the conjugated diene monomer include vinyl arenes such as styrene, α-methyl styrene, monochlorostyrene, dichlorostyrene; vinyl such as acrylic acid and methacrylic acid. Carboxylic acids; Vinyl cyanides such as acrylonitrile and methacrylonitrile; Halogenated vinyls such as vinyl chloride, vinyl bromide and chloroprene; Vinyl acetates; Alkenes such as ethylene, propylene, butylene and isobutylene; Diallyl phthalate and triallyl cyanide Examples thereof include polyfunctional monomers such as nurate, triallyl isocyanurate, and divinylbenzene. These vinyl monomers may be used alone or in combination of two or more. Particularly preferred is styrene.

  It is essential that the vinyl monomer (b2) copolymerizable with the conjugated diene monomer is in the range of 0 to 49.99% by mass of the core layer, and 0 to 29.99% by mass. It is preferable that it is a range, and it is more preferable that it is the range of 0-9.99 mass%. When the content of the vinyl monomer (b2) copolymerizable with the conjugated diene monomer is 50% by mass or more, the adhesiveness of the obtained cured product tends to decrease.

  1,3-butadiene is used because it has a high toughness-improving effect and an impact-removing adhesiveness-improving effect, and because the affinity with the matrix resin is low, it is difficult for the core layer to swell to increase the viscosity over time. Butadiene rubber or butadiene-styrene rubber which is a copolymer of 1,3-butadiene and styrene is preferable, and butadiene rubber is more preferable. Also, butadiene-styrene rubber is more preferred because it can increase the transparency of the cured product obtained by adjusting the refractive index.

  (B3) Examples of the chain transfer agent include alkyl mercaptans such as n-dodecyl mercaptan and t-dodecyl mercaptan. These chain transfer agents may be used alone or in combination of two or more. Particularly preferred is t-dodecyl mercaptan.

  The chain transfer agent (b3) is essential to be in the range of 0.01 to 3% by mass of the core layer, preferably in the range of 0.1 to 2% by mass, and 0.2 to 1% by mass. % Is more preferable. If the content of the chain transfer agent (b3) exceeds 3% by mass, the impact resistance of the resulting cured product tends to decrease.

  In the present invention, the glass transition temperature of the core layer (hereinafter sometimes simply referred to as “Tg”) is preferably 0 ° C. or less, and −20 ° C. or less in order to increase the toughness of the obtained cured product. More preferably, −40 ° C. or lower is further preferable, and −60 ° C. or lower is particularly preferable.

  Further, the volume average particle diameter of the core layer is preferably 0.03 to 2 μm, more preferably 0.05 to 1 μm. In many cases, it is difficult to stably obtain a volume average particle size of less than 0.03 μm, and when it exceeds 2 μm, the heat resistance and impact resistance of the final molded product may be deteriorated. The volume average particle diameter can be measured using Microtrac UPA150 (manufactured by Nikkiso Co., Ltd.).

  The core layer is preferably 40 to 97% by mass, more preferably 60 to 95% by mass, still more preferably 70 to 93% by mass, and particularly preferably 80 to 90% by mass based on 100% by mass of the entire polymer particles. If the core layer is less than 40% by mass, the effect of improving the toughness of the cured product may be reduced. If the core layer is larger than 97% by mass, the polymer fine particles are likely to aggregate, and the curable resin composition has a high viscosity and may be difficult to handle.

  In the present invention, the core layer often has a single-layer structure, but may have a multilayer structure composed of layers having rubber elasticity. When the core layer has a multilayer structure, the polymer composition of each layer may be different within the scope of the disclosure.

≪Middle layer≫
In the present invention, an intermediate layer may be formed if necessary. In particular, the following rubber surface cross-linked layer may be formed as the intermediate layer. From the viewpoint of the effect of improving the toughness and the impact resistance improvement effect of the resulting cured product, it is preferable not to contain an intermediate layer, and in particular, not to contain the following rubber surface cross-linked layer.

  When the intermediate layer is present, the ratio of the intermediate layer to 100 parts by mass of the core layer is preferably 0.1 to 30 parts by mass, more preferably 0.2 to 20 parts by mass, and further preferably 0.5 to 10 parts by mass. 1 to 5 parts by mass is particularly preferable.

  The rubber surface cross-linked layer polymerizes rubber surface cross-linked layer components composed of 30 to 100% by mass of a multifunctional monomer having two or more radical polymerizable double bonds in the same molecule and 0 to 70% by mass of other vinyl monomers. The intermediate layer polymer thus formed has the effect of reducing the viscosity of the curable resin composition of the present invention and the effect of improving the dispersibility of the polymer fine particles (B) in the component (A). It also has the effect of increasing the crosslinking density of the core layer and increasing the grafting efficiency of the shell layer.

  Specific examples of the polyfunctional monomer do not include conjugated diene monomers such as butadiene, and include allylalkyl (meth) acrylates such as allyl (meth) acrylate and allylalkyl (meth) acrylate; allyloxyalkyl (meth) Acrylates; (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, etc. Examples of polyfunctional (meth) acrylates having two or more (meth) acrylic groups; diallyl phthalate, triallyl cyanurate, triallyl isocyanurate, divinylbenzene, etc. It is a Lil isocyanurate. In the present invention, (meth) acrylate means acrylate and / or methacrylate.

≪Shell layer≫
The outermost shell layer of the polymer fine particles is obtained by polymerizing the shell-forming monomer, and improves the compatibility between the polymer fine particle (B) component and the (A) component, and the curable resin composition of the present invention. Or a shell polymer that plays a role of allowing fine polymer particles to be dispersed in the form of primary particles in the cured product.

  Such a shell polymer is preferably grafted to the core layer and / or the intermediate layer. In the following description, “when grafted on the core layer” includes an aspect in which the intermediate layer is grafted when the intermediate layer is formed on the core layer. More precisely, the monomer component used to form the shell layer is grafted to the core polymer that forms the core layer (if the intermediate layer is included, of course, the intermediate layer polymer that forms the intermediate layer also means the same). It is preferable that the shell polymer and the rubber polymer are substantially chemically bonded by polymerization (in the case where the rubber polymer has an intermediate layer, of course, it is also preferable that the rubber polymer is chemically bonded to the intermediate layer polymer). That is, the shell polymer is preferably formed by graft polymerization of the shell-forming monomer in the presence of a core polymer (meaning the core polymer in which the intermediate layer is formed. In this way, the core polymer is graft-polymerized and covers a part or the whole of the core polymer. This polymerization operation can be carried out by adding a monomer which is a constituent component of the shell polymer to the core polymer latex prepared and present in an aqueous polymer latex state and polymerizing it.

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

  The total amount of the aromatic vinyl monomer, vinyl cyan monomer and (meth) acrylate monomer is preferably 10 to 99.5% by mass, and 50 to 99% by mass, in 100% by mass of the shell layer forming monomer. Is more preferable, 65-98 mass% is still more preferable, 67-80 mass% is especially preferable, and 67-85 mass% is the most preferable.

  From the viewpoint of chemically bonding with the component (A) in order to maintain a good dispersion without causing the component (B) to agglomerate in the cured product or polymer, an epoxy group, oxetane group, hydroxyl group is used as a shell layer forming monomer. A reactive group-containing monomer containing at least one selected from the group consisting of an amino group, an imide group, a carboxylic acid group, a carboxylic anhydride group, a cyclic ester, a cyclic amide, a benzoxazine group, and a cyanate ester group It is preferable to contain, and the monomer which has an epoxy group is preferable.

  The monomer having an epoxy group is preferably contained in an amount of 0.5 to 90% by mass in 100% by mass of the shell-forming monomer, more preferably 1 to 50% by mass, still more preferably 2 to 35% by mass, 3-20 mass% is especially preferable. When the monomer having an epoxy group is less than 0.5% by mass in the monomer for shell formation, the impact resistance improving effect of the cured product may be reduced, and the impact release adhesiveness of the curable resin composition may be reduced. There is. If the monomer having an epoxy group is larger than 90% by mass in the monomer for shell formation, the impact resistance improving effect may be lowered, and the storage stability of the curable resin composition and the impact peel resistance may be reduced. It may get worse.

  The monomer having an epoxy group is preferably used for forming a shell layer, and more preferably used only for the shell layer.

  Further, when a multifunctional monomer having two or more radical polymerizable double bonds is used as the shell layer forming monomer, swelling of the polymer fine particles in the curable resin composition is prevented, and the curable resin composition This is preferable because the viscosity of the resin tends to be low and the handleability tends to be improved. On the other hand, from the viewpoint of the effect of improving the toughness and impact-resistant peel adhesion of the resulting cured product, it is not necessary to use a multifunctional monomer having two or more radical polymerizable double bonds as the monomer for forming the shell layer. preferable.

  The polyfunctional monomer may be contained in 100% by mass of the shell-forming monomer, for example, 0 to 20% by mass, preferably 1 to 20% by mass, and more preferably 5 to 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 vinylcyan monomer include acrylonitrile and methacrylonitrile.

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

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

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

  In the present invention, for example, aromatic vinyl monomer (especially styrene) 0 to 50% by mass (preferably 1 to 50% by mass, more preferably 2 to 48% by mass), vinyl cyan monomer (especially acrylonitrile) 0 to 50% by mass. (Preferably 0 to 30% by mass, more preferably 10 to 25% by mass), (meth) acrylate monomer (especially methyl methacrylate) 0 to 100% by mass (preferably 0 to 90% by mass, more preferably 20 to 85% by mass) %), A monomer for forming a shell layer in which 0.5 to 50% by mass (preferably 1 to 30% by mass, more preferably 2 to 20% by mass) of an epoxy group-containing monomer (particularly glycidyl methacrylate) is combined (100 mass in total) %) Of the shell layer which is a polymer. Thereby, a desired toughness improving effect and mechanical properties can be realized in a well-balanced manner. In particular, it is considered that interfacial adhesion with the component (A) is improved by including glycidyl methacrylate as a constituent component.

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

  The shell layer may be formed including other monomer components in addition to the monomer components.

  The graft ratio of the shell layer is preferably 70% or more (more preferably 80% or more, and further 90% or more). When the graft ratio is less than 70%, the viscosity of the liquid resin composition may increase. In the present specification, the method for calculating the graft ratio is as follows.

  First, an aqueous latex containing polymer fine particles is coagulated and dehydrated, and finally dried to obtain polymer fine particle powder. Next, after 2 g of the polymer fine particle powder is immersed in 100 g of methyl ethyl ketone (MEK) at 23 ° C. for 24 hours, the MEK soluble component is separated from the MEK insoluble component, and the methanol insoluble component is further separated from the MEK soluble component. And the graft ratio is calculated by calculating | requiring the ratio of MEK insoluble content with respect to the total amount of MEK insoluble content and methanol insoluble content.

≪Method for producing polymer fine particles≫
(Manufacturing method of core layer)
The polymer forming the core layer constituting the polymer fine particle used in the present invention comprises at least one monomer (first monomer) selected from diene monomers (conjugated diene monomers) and (meth) acrylate monomers. In this case, the core layer can be formed by, for example, emulsion polymerization, suspension polymerization, microsuspension polymerization, etc., and for example, the method described in WO2005 / 028546 can be used.

In addition, when the polymer forming the core layer is configured to include a polysiloxane polymer, the formation of the core layer can be produced by, for example, emulsion polymerization, suspension polymerization, microsuspension polymerization, etc. The method described in the pamphlet of WO 2006/070664 can be used.
(Method for forming shell layer and intermediate layer)
The intermediate layer can be formed by polymerizing the monomer for forming the intermediate layer by a known radical polymerization. When the rubber elastic body constituting the core layer is obtained as an emulsion, the polymerization of the monomer having two or more radical polymerizable double bonds is preferably carried out by an emulsion polymerization method.

  The shell layer can be formed by polymerizing a shell layer forming monomer by known radical polymerization. When the polymer layer precursor formed by coating the core layer or the core layer with an intermediate layer is obtained as an emulsion, the polymerization of the monomer for forming the shell layer is preferably performed by an emulsion polymerization method, for example, WO2005 / 028546 pamphlet.

  As an emulsifier (dispersant) that can be used in emulsion polymerization, alkyl or aryl sulfonic acid represented by dioctylsulfosuccinic acid and dodecylbenzenesulfonic acid, alkyl or arylether sulfonic acid, alkyl or aryl represented by dodecylsulfuric acid, and the like. Sulfuric acid, alkyl or aryl ether sulfuric acid, alkyl or aryl substituted phosphoric acid, alkyl or aryl ether substituted phosphoric acid, N-alkyl or aryl sarcosine acid represented by dodecyl sarcosine acid, alkyl represented by oleic acid or stearic acid, or Various acids such as aryl carboxylic acids, alkyl or aryl ether carboxylic acids, anionic emulsifiers (dispersants) such as alkali metal salts or ammonium salts of these acids; Nonionic emulsifiers such as-substituted polyethylene glycol (dispersing agent); polyvinyl alcohol, alkyl substituted cellulose, polyvinyl pyrrolidone, dispersants such as polyacrylic acid derivatives. These emulsifiers (dispersants) may be used alone or in combination of two or more.

  As long as the dispersion stability of the aqueous latex of polymer particles is not hindered, it is preferable to reduce the amount of emulsifier (dispersant) used. Moreover, an emulsifier (dispersant) is so preferable that the water solubility is high. 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 the emulsion polymerization method is employed, a known initiator, that is, 2,2′-azobisisobutyronitrile, hydrogen peroxide, potassium persulfate, ammonium persulfate, or the like can be used as the thermal decomposition type initiator. .

  In addition, organic peroxides such as t-butylperoxyisopropyl carbonate, paramentane hydroperoxide, cumene hydroperoxide, dicumyl peroxide, t-butyl hydroperoxide, di-t-butyl peroxide, t-hexyl peroxide, etc. Oxides; peroxides such as inorganic peroxides such as hydrogen peroxide, potassium persulfate, and ammonium persulfate; reducing agents such as sodium formaldehyde sulfoxylate and glucose as necessary; and iron sulfate (II as necessary) ), A chelating agent such as disodium ethylenediaminetetraacetate if necessary, and a redox type initiator using a phosphorus-containing compound such as sodium pyrophosphate if necessary.

  When a redox type initiator system is used, the polymerization can be performed 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. Of these, organic peroxides such as cumene hydroperoxide, dicumyl peroxide, and t-butyl hydroperoxide are preferably used as the redox initiator. When the amount of the initiator used, or the redox type initiator is used, the amount of the reducing agent / transition metal salt / chelating agent used may be within a known range. In the polymerization of a monomer having two or more radical polymerizable double bonds, a known chain transfer agent can be used within a known range. In addition, a surfactant can be used, but this is also within a known range.

  The polymerization temperature, pressure, deoxygenation, and other conditions during the polymerization can be within the known ranges. The polymerization of the intermediate layer forming monomer may be performed in one stage or in two or more stages. For example, in addition to a method of adding an intermediate layer forming monomer to a rubber elastic emulsion constituting the elastic core layer at once, a method of continuously adding it, an elastic core layer is added to a reactor in which an intermediate layer forming monomer is charged in advance. For example, a method of carrying out polymerization after adding an emulsion of a rubber elastic body to be constituted can be employed.

<One or more selected from the group consisting of blocked urethane, rubber-modified epoxy resin, and urethane-modified epoxy resin (C)>
In the curable resin composition (I) which is the first aspect of the present invention, it is selected from the group consisting of blocked urethane, rubber-modified epoxy resin and urethane-modified epoxy resin with respect to 100 parts by mass of component (A). It is essential to contain 1 to 100 parts by mass of one or more (C). The component (C) is a cured product obtained by curing the curable resin composition obtained by combining with the polymer fine particles obtained by polymerizing the core layer as the component (B) with a chain transfer agent. Is remarkably excellent in adhesiveness such as T-shaped peel adhesive strength.

  In addition, (C) component can be used as needed also in curable resin composition (II) which is the 2nd aspect of this invention.

  (C) The usage-amount of a component is 1-100 mass parts with respect to 100 mass parts of (A) component, 2-50 mass parts is preferable, 3-40 mass parts is more preferable, 5-30 mass parts Is particularly preferred. If it is less than 1 part by mass, the resulting cured product may be brittle and may have low adhesiveness. If it is more than 100 parts by mass, the resulting cured product may have low heat resistance and / or elastic modulus (rigidity).

(C) A component may be used independently and may be used together 2 or more types.
≪Rubber modified epoxy resin≫
The rubber-modified epoxy resin is a reaction product obtained by reacting rubber with an epoxy group-containing compound and having an average of 1.1 or more, preferably 2 or more epoxy groups per molecule. Are acrylonitrile butadiene rubber (NBR), styrene butadiene rubber (SBR), hydrogenated nitrile rubber (HNBR), ethylene propylene rubber (EPDM), acrylic rubber (ACM), butyl rubber (IIR), butadiene rubber, polypropylene oxide and polyethylene oxide. And rubber polymers such as polyoxyalkylene such as polytetramethylene oxide. The rubber polymer is preferably one having a reactive group such as an amino group, a hydroxy group, or a carboxyl group at the terminal. The rubber-modified epoxy resin used in the present invention is a product obtained by reacting these rubber-based polymer and epoxy resin at an appropriate blending ratio by a known method. Among these, acrylonitrile-butadiene rubber-modified epoxy resin and polyoxyalkylene-modified epoxy resin are preferable from the viewpoint of adhesion of the resulting curable resin composition and impact peel resistance, and acrylonitrile-butadiene rubber-modified epoxy resin is preferred. More preferred. The acrylonitrile-butadiene rubber-modified epoxy resin can be obtained, for example, by a reaction between a carboxyl group-terminated NBR (CTBN) and a bisphenol A type epoxy resin.

  The content of the acrylonitrile monomer component in the acrylonitrile-butadiene rubber is preferably 5 to 40% by mass, and preferably 10 to 35% by mass, from the viewpoints of the adhesiveness and impact peel resistance of the resulting curable resin composition. Is more preferable, and 15-30 mass% is still more preferable. 20-30 mass% is especially preferable from a viewpoint of workability | operativity of the curable resin composition obtained.

  Further, for example, an addition reaction product of an amino group-terminated polyoxyalkylene and an epoxy resin (hereinafter also referred to as “addition product”) is also included in the rubber-modified epoxy resin. For example, as described in US Pat. No. 5,084,532 and US Pat. No. 6,015,865, the adduct can be easily manufactured by a known method. Examples of the epoxy resin used in the production of the adduct include specific examples of the component (A) exemplified in the present invention, and bisphenol A type epoxy resins and bisphenol F type epoxy resins are preferable, and bisphenol A A type epoxy resin is more preferable. The commercially available amino group-terminated polyoxyalkylene used in the production of the adduct is, for example, Jeffamine D-230, Jeffamine D-400, Jeffamine D-2000, Jeffamine D-4000 manufactured by Huntsman, Jeffamine T-5000 and the like.

  The average number of epoxide-reactive end groups per molecule in the rubber is preferably 1.5 to 2.5, and more preferably 1.8 to 2.2. The number average molecular weight of the rubber is preferably 1000 to 10000, more preferably 2000 to 8000, and particularly preferably 3000 to 6000 in terms of polystyrene-converted molecular weight measured by GPC.

  There is no restriction | limiting in particular about the manufacturing method of a rubber modified epoxy resin, For example, it can manufacture by making a rubber and an epoxy group containing compound react in a lot of epoxy group containing compounds. Specifically, it is preferable to produce by reacting 2 equivalents or more of an epoxy group-containing compound with respect to 1 equivalent of an epoxy-reactive terminal group in the rubber. It is more preferable to react an amount of the epoxy group-containing compound sufficient for the resulting product to be a mixture of an adduct of rubber and an epoxy group-containing compound and a free epoxy group-containing compound. For example, the rubber-modified epoxy resin is produced by heating to a temperature of 100 to 250 ° C. in the presence of a catalyst such as phenyldimethylurea or triphenylphosphine. The epoxy group-containing compound used in producing the rubber-modified epoxy resin is not particularly limited, but bisphenol A type epoxy resin and bisphenol F type epoxy resin are preferable, and bisphenol A type epoxy resin is more preferable. In the present invention, when an excessive amount of the epoxy group-containing compound is used during the production of the rubber-modified epoxy resin, the unreacted epoxy group-containing compound remaining after the reaction is included in the rubber-modified epoxy resin of the present invention. , Not included.

  In the rubber-modified epoxy resin, the epoxy resin can be modified by pre-reaction with a bisphenol component. The bisphenol component used for the modification is preferably 3 to 35 parts by mass, and more preferably 5 to 25 parts by mass with respect to 100 parts by mass of the rubber component in the rubber-modified epoxy resin. A cured product obtained by curing a curable resin composition containing a modified rubber-modified epoxy resin is excellent in adhesion durability after high-temperature exposure and excellent in impact resistance at low temperatures.

  The glass transition temperature (Tg) of the rubber-modified epoxy resin is not particularly limited, but is preferably −25 ° C. or lower, more preferably −35 ° C. or lower, still more preferably −40 ° C. or lower, and particularly preferably −50 ° C. or lower.

  The number average molecular weight of the rubber-modified epoxy resin is preferably 1500 to 40000, more preferably 3000 to 30000, and particularly preferably 4000 to 20000 in terms of polystyrene-converted molecular weight measured by GPC. 1-4 is preferable, as for molecular weight distribution (ratio of a weight average molecular weight and a number average molecular weight), 1.2-3 are more preferable, and 1.5-2.5 are especially preferable.

  The amount of the rubber-modified epoxy resin used is preferably 1 to 50 parts by weight, more preferably 2 to 40 parts by weight, still more preferably 5 to 30 parts by weight, and 10 to 20 parts by weight with respect to 100 parts by weight of the component (A). Part is particularly preferred. If the amount is less than 1 part by mass, the resulting cured product may be brittle and impact-resistant peel adhesion may be low. If the amount is more than 50 parts by mass, the resulting cured product may have low heat resistance and elastic modulus (rigidity).

  The rubber-modified epoxy resins can be used alone or in combination of two or more.

≪Urethane modified epoxy resin≫
The urethane-modified epoxy resin is obtained by reacting a compound containing a group having reactivity with an isocyanate group and an epoxy group with a urethane prepolymer containing an isocyanate group. A reaction product having 1.1 or more, preferably 2 or more. For example, a urethane-modified epoxy resin can be obtained by reacting a hydroxy group-containing epoxy compound with a urethane prepolymer.

  The number average molecular weight of the urethane-modified epoxy resin is preferably 1500 to 40000, more preferably 3000 to 30000, and particularly preferably 4000 to 20000 in terms of polystyrene-converted molecular weight measured by GPC. 1-4 is preferable, as for molecular weight distribution (ratio of a weight average molecular weight and a number average molecular weight), 1.2-3 are more preferable, and 1.5-2.5 are especially preferable.

  1-50 mass parts is preferable with respect to 100 mass parts of (A) component, as for the usage-amount of a urethane-modified epoxy resin, 2-40 mass parts is more preferable, 5-30 mass parts is still more preferable, 10-20 mass Part is particularly preferred. If the amount is less than 1 part by mass, the resulting cured product may be brittle and impact-resistant peel adhesion may be low. If the amount is more than 50 parts by mass, the resulting cured product may have low heat resistance and elastic modulus (rigidity).

  Urethane-modified epoxy resins can be used alone or in combination of two or more.

≪Blocked urethane≫
The blocked urethane is an elastomer type, and includes various blocks in which all or part of the terminal isocyanate group of the compound containing an urethane group and / or a urea group and having an isocyanate group at the terminal has an active hydrogen group. It is a compound capped with an agent. In particular, a compound in which all of the terminal isocyanate groups are capped with a blocking agent is preferable. Such a compound can be prepared, for example, by reacting an organic polymer having an active hydrogen-containing group at the terminal with an excess of a polyisocyanate compound to have a urethane group and / or a urea group in the main chain and an isocyanate group at the terminal. It is obtained by capping all or part of the isocyanate group with a blocking agent having an active hydrogen group after or simultaneously with the polymer (urethane prepolymer).

The blocked urethane is, for example, the following general formula (1):
^{A- (NR 2 -C (= O} ) -X) a (1)
(In the formula, each a ² R ² is independently a hydrocarbon group having 1 to 20 carbon atoms. A represents the average number of capped isocyanate groups per molecule, 1.1 or more. 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. Is a residue obtained by removing a terminal isocyanate group from an isocyanate-terminated prepolymer.

  The number average molecular weight of the blocked urethane is preferably from 4000 to 40000, more preferably from 3000 to 30000, and particularly preferably from 4000 to 20000 in terms of polystyrene-converted molecular weight measured by GPC. 1-4 is preferable, as for molecular weight distribution (ratio of a weight average molecular weight and a number average molecular weight), 1.2-3 are more preferable, and 1.5-2.5 are especially preferable.

(C-1 Organic polymer having an active hydrogen-containing group at the terminal)
As the main chain skeleton constituting the organic polymer having an active hydrogen-containing group at the terminal, a polyether polymer, a polyacrylic polymer, a polyester polymer, a polydiene polymer, a saturated hydrocarbon polymer (polyolefin) ) And polythioether polymers.

(Active hydrogen group)
Examples of the active hydrogen-containing group constituting the organic polymer having an active hydrogen-containing group at the 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 preferable from the viewpoint of availability, and a hydroxyl group is more preferable from the viewpoint of easy handling (viscosity) of the obtained 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), and a polyether polymer having an amino group and / or an imino group at the terminal (polyether amine). ), Polyacryl polyol, polyester polyol, diene polymer having a hydroxyl group at the terminal (polydiene polyol), saturated hydrocarbon polymer having a hydroxyl group at the terminal (polyolefin polyol), polythiol compound, polyamine compound, and the like. Among these, polyether polyol, polyether amine, and polyacryl polyol are excellent in compatibility with the component (A), the glass transition temperature of the organic polymer is relatively low, and the resulting cured product is low in temperature. It is preferable because of its excellent impact resistance. In particular, polyether polyols and polyether amines are more preferred because the resulting organic polymer has a low viscosity and good workability, and polyether polyols are particularly preferred.

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

The number average molecular weight of the organic polymer having an active hydrogen-containing group at the terminal is preferably from 800 to 7000, more preferably from 1500 to 5000, particularly preferably from 2000 to 4000, in terms of polystyrene equivalent molecular weight measured by GPC.
(Polyether polymer)
The polyether polymer essentially has the general formula (2):
—R ¹ —O— (2)
(Wherein R ¹ is a linear or branched alkylene group having 1 to 14 carbon atoms), and R ¹ in the general formula (2) is a carbon atom. A linear or branched alkylene group having 1 to 14 or 2 to 4 is preferable. Specific examples of the repeating unit represented by the general 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-, _{-CH 2 CH 2 CH 2 CH 2} O-
Etc. The main chain skeleton of the polyether polymer may be composed of only one type of repeating unit, or may be composed of two or more types of repeating units. In particular, a polymer composed mainly of a polypropylene glycol having a propylene oxide repeating unit of 50% by mass or more is preferable from the viewpoint of T-shaped peel adhesion strength. Polytetramethylene glycol (PTMG) obtained by ring-opening polymerization of tetrahydrofuran is preferred from the viewpoint of dynamic splitting resistance.

Moreover, when using together with (B) component, it is preferable that the ratio of (B) component and blocked urethane is 0.1-10, It is further more preferable that it is 0.2-5, 0.3 It is especially preferable that it is -1.
(Polyether polyol)
The polyether polyol is a polyether polymer having a hydroxyl group at the terminal, and the polyether amine is a polyether polymer having an amino group or an imino group at the terminal.

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

  Examples of the polyester polyol include polybasic acids such as maleic acid, fumaric acid, adipic acid, and phthalic acid, and acid anhydrides thereof, ethylene glycol, propylene glycol, 1,4-butanediol, 1,6-hexanediol, Examples thereof include polymers obtained by polycondensation with polyhydric alcohols such as diethylene glycol, dipropylene glycol and neopentyl glycol in the presence of an esterification catalyst in a temperature range of 150 to 270 ° C. Further, ring-opening polymers such as ε-caprolactone and valerolactone, and active hydrogen compounds having two or more active hydrogens such as polycarbonate diol and castor oil are also included.

(Polydiene polyol)
Examples of the polydiene polyol include polybutadiene polyol, polyisoprene polyol, polychloroprene polyol, and the like, and polybutadiene polyol is particularly preferable.

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

(C-2 polyisocyanate)
Specific examples of the polyisocyanate compound include aromatic polyisocyanates such as toluene (tolylene) diisocyanate, diphenylmethane diisocyanate, and xylylene diisocyanate; fats such as isophorone diisocyanate, hexamethylene diisocyanate, hydrogenated toluene diisocyanate, and hydrogenated diphenylmethane diisocyanate. Group polyisocyanates can be mentioned. Among these, aliphatic polyisocyanates are preferable from the viewpoint of heat resistance, and isophorone diisocyanate and hexamethylene diisocyanate are more preferable from the viewpoint of availability.

(C-3 blocking agent)
Examples of the blocking agent include a primary amine blocking agent, a secondary amine blocking agent, an oxime blocking agent, a lactam blocking agent, an active methylene blocking agent, an alcohol blocking agent, a mercaptan blocking agent, and an amide. Blocking agents, imide-based blocking agents, heterocyclic aromatic compound-based blocking agents, hydroxy-functional (meth) acrylate-based blocking agents, and phenol-based blocking agents. Among these, an oxime block agent, a lactam block agent, a hydroxy functional (meth) acrylate block agent, and a phenol block agent are preferable, and a hydroxy functional (meth) acrylate block agent and a phenol block agent are more preferable. A phenolic blocking agent is more preferable.

(Primary amine blocking agent)
Examples of the primary amine blocking agent include butylamine, isopropylamine, dodecylamine, cyclohexylamine, aniline, and benzylamine. Examples of the secondary amine blocking agent include dibutylamine, diisopropylamine, dicyclohexylamine, diphenylamine, dibenzylamine, morpholine, and piperidine. Examples of the oxime blocking agent include formaldoxime, acetoaldoxime, acetoxime, methyl ethyl ketoxime, diacetyl monooxime, cyclohexane oxime and the like. Examples of the lactam blocking agent include ε-caprolactam, δ-valerolactam, γ-butyrolactam, β-butyrolactam and the like. Examples of the active methylene-based blocking agent include ethyl acetoacetate and acetylacetone. Examples of the alcohol blocking agent include methanol, ethanol, propanol, isopropanol, butanol, amyl alcohol, cyclohexanol, 1-methoxy-2-propanol, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, propylene glycol monomethyl ether, and benzyl alcohol. Methyl glycolate, butyl glycolate, diacetone alcohol, methyl lactate, ethyl lactate and the like. Examples of the mercaptan-based blocking agent include butyl mercaptan, hexyl mercaptan, decyl mercaptan, t-butyl mercaptan, thiophenol, methylthiophenol, and ethylthiophenol. Examples of the amide blocking agent include acetic acid amide and benzamide. Examples of the imide-based blocking agent include succinimide and maleic imide. Examples of the heterocyclic aromatic compound-based blocking agent include imidazoles such as imidazole and 2-ethylimidazole, pyrroles such as pyrrole, 2-methylpyrrole, and 3-methylpyrrole, pyridine, 2-methylpyridine, and 4-methyl. Examples thereof include pyridines such as pyridine, and diazabicycloalkenes such as diazabicycloundecene and diazabicyclononene.

(Hydroxy-functional (meth) acrylate block agent)
The hydroxy functional (meth) acrylate blocking agent is a (meth) acrylate having one or more hydroxyl groups. Specific examples of the hydroxy functional (meth) acrylate blocking agent include 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, and 2-hydroxybutyl (meth). Acrylate, and the like.

(Phenolic block agent)
The phenolic blocking agent contains at least one phenolic hydroxyl group, that is, a hydroxyl group directly bonded to a carbon atom of an aromatic ring. The phenolic compound may have two or more phenolic hydroxyl groups, but preferably contains only one phenolic hydroxyl group. The phenolic compound may contain other substituents, but these substituents are preferably those that do not react with isocyanate groups under the conditions of the capping reaction, and are preferably alkenyl groups and allyl groups. Other substituents include linear, branched, or cycloalkyl alkyl groups; aromatic groups (eg, phenyl, alkyl-substituted phenyl, alkenyl-substituted phenyl, etc.); aryl-substituted alkyl groups; phenol-substituted alkyl groups Can be mentioned. Specific examples of the phenolic blocking agent include phenol, cresol, xylenol, chlorophenol, ethylphenol, allylphenol (especially o-allylphenol), resorcinol, catechol, hydroquinone, bisphenol, bisphenol A, bisphenol AP (1,1- Bis (4-hydroxylphenyl) -1-phenylethane), bisphenol F, bisphenol K, bisphenol M, tetramethylbiphenol and 2,2′-diallyl-bisphenol A, and the like.

  The blocking agent is preferably bonded to the end of the polymer chain of the urethane prepolymer in such a manner that the terminal to which it is bonded no longer has a reactive group.

  The blocking agent may be used alone or in combination of two or more.

  The blocked urethane may contain a residue of a crosslinking agent, a residue of a chain extender, or both.

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

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

  Specific examples of the crosslinking agent and chain extender include trimethylolpropane, glycerin, trimethylolethane, ethylene glycol, diethylene glycol, propylene glycol, dipropylene glycol, sucrose, sorbitol, pentaerythritol, ethylenediamine, triethanolamine, monoethanol. Examples include amine, diethanolamine, piperazine, and aminoethylpiperazine. Resorcinol, catechol, hydroquinone, bisphenol, bisphenol A, bisphenol AP (1,1-bis (4-hydroxylphenyl) -1-phenylethane), bisphenol F, bisphenol K, bisphenol M, tetramethylbiphenol, 2,2 Also included are compounds having two or more phenolic hydroxyl groups, such as' -diallyl-bisphenol A.

(Amount of blocked urethane)
The amount of blocked urethane is preferably 1 to 50 parts by mass, more preferably 10 to 40 parts by mass, and particularly preferably 10 to 35 parts by mass with respect to 100 parts by mass of (A) epoxy resin. If it is less than 1 part by mass, the modifying effects such as toughness, impact resistance and adhesiveness may not be sufficient. If it exceeds 50 parts by mass, the resulting cured product may have a low elastic modulus.

<Epoxy resin curing agent (D)>
In this invention, an epoxy resin hardening | curing agent (D) can be used as needed.

  When the curable resin composition of the present invention is used as a one-component composition (such as a one-component curable resin composition), the adhesive rapidly develops when heated to a temperature of 80 ° C. or higher, preferably 140 ° C. or higher. The component (D) is preferably selected so as to be cured. On the contrary, it is preferable to select the component (D) and the component (E) described later so that the curing is very slow even at room temperature (about 22 ° C.) or at least up to 50 ° C.

  (D) As a component, the component (it may be called a latent hardening | curing agent) which shows activity by heating can be used. As such a latent epoxy curing agent, an N-containing curing agent such as a specific amine curing agent (including an imine curing agent) can be used, for example, boron trichloride / amine complex, boron trifluoride / amine. Complexes, dicyandiamide, melamine, diallyl melamine, guanamine (eg acetoguanamine and benzoguanamine), aminotriazole (eg 3-amino-1,2,4-triazole), hydrazide (eg adipic acid dihydrazide, stearic acid dihydrazide, isophthalate) Acid dihydrazide, semicarbazide), cyanoacetamide, and aromatic polyamines (for example, metaphenylenediamine, diaminodiphenylmethane, diaminodiphenylsulfone, etc.). It is more preferable to use dicyandiamide, isophthalic acid dihydrazide, adipic acid dihydrazide, or 4,4'-diaminodiphenylsulfone, and dicyandiamide is particularly preferable.

  Among the curing agents (D), the latent epoxy curing agent is preferable because the curable resin composition of the present invention can be made into one component.

  In curable resin composition (II) which is the 2nd aspect of this invention, it is essential to contain 4.5-6.5 mass parts of dicyandiamide with respect to 100 mass parts of (A) component. The curable resin composition obtained by combining 4.5 to 6.5 parts by mass of dicyandiamide with polymer fine particles obtained by polymerizing the core layer as the component (B) with a chain transfer agent is used. The cured product obtained by curing is remarkably excellent in adhesiveness such as T-shaped peel adhesion strength.

  In addition, 4.5-6.5 mass parts dicyandiamide can be used as needed also in curable resin composition (I) which is a 1st aspect of this invention.

  The amount of dicyandiamide used in the curable resin composition (II) is 4.5 to 6.5 parts by mass, preferably 4.6 to 6 parts by mass, with respect to 100 parts by mass of the component (A). 7-5.5 mass parts is more preferable. If the amount is less than 4.5 parts by mass, curing may be insufficient and the adhesiveness may be low. If the amount is more than 6.5 parts by mass, the resulting cured product may have low adhesiveness.

  On the other hand, when using the curable resin composition of the present invention as a two-component or multi-component composition, other amine-based curing agents (including imine-based curing agents) and mercaptan-based curing agents (room temperature-curable curing) (Sometimes referred to as an agent) can be selected as the component (D) exhibiting activity at a relatively low temperature of about room temperature.

  Examples of the component (D) exhibiting activity at a relatively low temperature include chain aliphatic polyamines such as diethylenetriamine, triethylenetetramine, tetraethylenepentamine, dipropylenediamine, diethylaminopropylamine, and hexamethylenediamine; N- Aminoethylpiverazine, bis (4-amino-3-methylcyclohexyl) methane, mensendiamine, isophoronediamine, 4,4'-diaminodicyclohexylmethane, 3,9-bis (3-aminopropyl) -2,4 , 8,10-tetraoxaspiro [5.5] undecane (spiroacetal diamine), norbornanediamine, tricyclodecanediamine, cycloaliphatic polyamines such as 1,3-bisaminomethylcyclohexane; fats such as metaxylenediamine Aromatic Ami Polyamine epoxy resin adducts that are the reaction product of epoxy resin and excess polyamine; ketimines that are dehydration reaction products of polyamine and ketones such as methyl ethyl ketone and isobutyl methyl ketone; dimer of tall oil fatty acid ( And polyamidoamines produced by condensation of dimer acid) and polyamine; amidoamines produced by condensation of tall oil fatty acid and polyamine; and polymercaptans.

  An amine-terminated polyether containing a polyether main chain and having an average of 1 to 4 (preferably 1.5 to 3) amino groups and / or imino groups per molecule is also used as component (D). it can. Commercially available amine-terminated polyethers include Huntsman's Jeffamine D-230, Jeffamine D-400, Jeffamine D-2000, Jeffamine D-4000, Jeffamine T-5000, and the like.

  Further, an amine-terminated rubber containing a conjugated diene polymer main chain and having an average of 1 to 4 (more preferably 1.5 to 3) amino groups and / or imino groups per molecule is also (D ) Can be used as a component. Here, the main chain of the rubber is preferably a polybutadiene homopolymer or copolymer, more preferably a polybutadiene / acrylonitrile copolymer, and an acrylonitrile monomer content of 5 to 40% by mass (more preferably 10 to 35% by mass, still more preferably 15 to 15%). Polybutadiene / acrylonitrile copolymers that are 30% by weight) are particularly preferred. Examples of commercially available amine-terminated rubbers include Hypro 1300X16 ATBN manufactured by CVC.

  Among the amine curing agents that exhibit activity at a relatively low temperature such as room temperature, polyamide amines, amine-terminated polyethers, and amine-terminated rubbers are more preferable. Polyamide amines, amine-terminated polyethers, and amine-terminated rubbers are more preferable. It is particularly preferable to use them in combination.

  As the component (D), acid anhydrides and phenols can be used. Acid anhydrides and phenols require higher temperatures than amine-based curing agents, but have a longer pot life and cured products have a good balance of physical properties such as electrical, chemical, and mechanical properties. It is. Examples of acid anhydrides include polysebacic acid polyanhydride, polyazeline acid polyanhydride, succinic anhydride, citraconic acid anhydride, itaconic acid anhydride, alkenyl-substituted succinic acid anhydride, dodecenyl succinic acid anhydride, maleic acid anhydride, Tricarballylic anhydride, nadic anhydride, methyl nadic anhydride, linoleic acid adduct with maleic anhydride, alkylated terminal alkylene tetrahydrophthalic anhydride, methyl tetrahydrophthalic anhydride, tetrahydrophthalic anhydride, hexahydro Phthalic anhydride, pyromellitic dianhydride, trimellitic anhydride, phthalic anhydride, tetrachlorophthalic anhydride, tetrabromophthalic anhydride, dichloromaleic anhydride, chloronadoic anhydride, and chlorendic acid Anhydrides, as well as maleic anhydride-grafted polybutane Or the like can be mentioned ene. Examples of phenols include phenol novolak, bisphenol A novolak, and cresol novolak.

  (D) A component may be used independently and may be used together 2 or more types.

  Component (D) is used in an amount sufficient to cure the composition. Typically, sufficient curing agent is provided to consume at least 80% of the epoxide groups present in the composition. A large excess over that required for consumption of epoxide groups is usually not necessary. (D) The usage-amount of a component has preferable 1-80 mass parts with respect to 100 mass parts of (A) component, 2-40 mass parts is more preferable, 3-30 mass parts is still more preferable, 5-20 mass Part is particularly preferred. If it is less than 1 mass part, the sclerosis | hardenability of the curable resin composition of this invention may worsen. When the amount is more than 80 parts by mass, the storage stability of the curable resin composition of the present invention may be poor and difficult to handle.

<Curing accelerator (E)>
In this invention, a hardening accelerator (E) can be used as needed.

  The component (E) is a catalyst for promoting the reaction between the epoxy group and the epoxide reactive group on the other component of the curing agent or adhesive.

  Examples of the component (E) include p-chlorophenyl-N, N-dimethylurea (trade name: Monuron), 3-phenyl-1,1-dimethylurea (trade name: Phenuron), and 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) : Ureas such as Dyhard); 2,4 embedded in benzyldimethylamine, 2,4,6-tris (dimethylaminomethyl) phenol, 2- (dimethylaminomethyl) phenol, poly (p-vinylphenol) matrix , 6-Tris (dimethylaminomethyl) phenol, triethylenediamine, N, N-dimethyl Tertiary amines such as peridine; C1-C12 alkylene imidazole, N-aryl imidazole, 2-methylimidazole, 2-ethyl-2-methylimidazole, N-butylimidazole, 1-cyanoethyl-2-undecylimidazolium trimellitate , Imidazoles such as addition products of epoxy resin and imidazole, 6-caprolactam and the like. The catalyst may be encapsulated or may be a potential one that becomes active only when the temperature is raised.

  In addition, tertiary amines and imidazoles can improve the curing speed, physical properties of cured products, heat resistance, and the like when used in combination with the amine curing agent of component (D).

  (E) A component may be used independently and may be used together 2 or more types.

  (E) As for the usage-amount of a component, 0.1-10 mass parts is preferable with respect to 100 mass parts of (A) component, 0.2-5 mass parts is more preferable, 0.5-3 mass parts is further. 0.8 to 2 parts by mass is preferable. If it is less than 0.1 mass part, the sclerosis | hardenability of the curable resin composition of this invention may worsen. When the amount is more than 10 parts by mass, the storage stability of the curable resin composition of the present invention may be poor and difficult to handle.

<Inorganic filler>
In the curable resin composition of the present invention, silicic acid and / or silicate can be added as an inorganic filler.

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

  The dry silica, also called fumed silica, is a non-surface treated hydrophilic fumed silica and a hydrophobic fumed silica produced by chemically treating the silanol group portion of the hydrophilic fumed silica with silane or siloxane. In view of dispersibility in the component (A), hydrophobic fumed silica is preferable.

  Other inorganic fillers include reinforcing fillers such as dolomite and carbon black; colloidal calcium carbonate, heavy calcium carbonate, magnesium carbonate, titanium oxide, ferric oxide, aluminum fine powder, zinc oxide, activated zinc white, etc. Is mentioned.

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

  As for the usage-amount of an inorganic filler, 1-100 mass parts is preferable with respect to 100 mass parts of (A) component, 2-70 mass parts is more preferable, 5-40 mass parts is still more preferable, 7-20 mass parts Is particularly preferred.

  An inorganic filler may be used independently and may be used together 2 or more types.

<Calcium oxide>
Calcium oxide can be added to the curable resin composition of the present invention.

  Calcium oxide removes moisture by reaction with moisture in the curable resin composition, and solves various physical property problems caused by the presence of moisture. For example, it functions as an anti-bubble agent due to moisture removal and suppresses a decrease in adhesive strength.

  Calcium oxide can be surface treated with a surface treating agent. The surface treatment improves the dispersibility of the calcium oxide in the composition. As a result, the physical properties such as the adhesive strength of the obtained cured product are improved as compared with the case where calcium oxide not subjected to surface treatment is used. In particular, the T-shaped peel adhesion and impact resistance peel adhesion are significantly improved. The surface treatment agent is not particularly limited, but is preferably a fatty acid.

  The amount of calcium oxide used is preferably 0.1 to 10 parts by weight, more preferably 0.2 to 5 parts by weight, still more preferably 0.5 to 3 parts by weight, with respect to 100 parts by weight of component (A). 1 to 2 parts by mass is particularly preferable. If the amount is less than 0.1 parts by mass, the moisture removal effect may not be sufficient. If the amount is more than 10 parts by mass, the strength of the resulting cured product may be low.

  Calcium oxide may be used alone or in combination of two or more.

<Radical curable resin>
In this invention, the radical curable resin which has a 2 or more double bond in a molecule | numerator can be used as needed. If necessary, a low molecular compound having a molecular weight of less than 300 and having at least one double bond in the molecule can be added. The low molecular weight compound has a function of adjusting viscosity, physical properties of a cured product, and curing speed when used in combination with the radical curable resin, and functions as a so-called reactive diluent for the radical curable resin. Furthermore, a radical polymerization initiator can be added to the curable resin composition of the present invention. Here, the radical polymerization initiator is preferably a potential type that is activated when the temperature is increased (preferably, about 50 ° C. to about 150 ° C.).

  Examples of the radical curable resin include unsaturated polyester resins, polyester (meth) acrylates, epoxy (meth) acrylates, urethane (meth) acrylates, polyether (meth) acrylates, and acrylated (meth) acrylates. These may be used alone or in combination. Specific examples of the radical curable resin include compounds described in WO2014-115778 pamphlet. Specific examples of the low molecular weight compound and the radical polymerization initiator include the compounds described in WO2014-115778 pamphlet.

  As described in the pamphlet of WO2010-019539, if the radical polymerization initiator is activated at a temperature different from the curing temperature of the epoxy resin, partial curing of the curable resin composition can be performed by selective polymerization of the radical curable resin. It becomes possible. This partial curing can increase the viscosity of the composition after application and improve the wash-off resistance. In addition, in the washing shower process in a production line such as a vehicle, the uncured adhesive composition is partially dissolved, scattered, or deformed by the shower water pressure during the washing shower process. The corrosion resistance of the coated steel sheet may be adversely affected, and the rigidity of the steel sheet may be reduced. The “hardness to be washed off” means resistance to this problem. In addition, this partial curing can provide a function of temporarily fixing (temporarily adhering) the substrates to each other until the composition is completely cured. In this case, the free radical initiator is preferably activated by heating to 80 ° C to 130 ° C, more preferably 100 ° C to 120 ° C.

<Monoepoxide>
In the present invention, a monoepoxide can be used as necessary. The monoepoxide can function as a reactive diluent. Specific examples of the monoepoxide include aliphatic glycidyl ethers such as butyl glycidyl ether, or aromatic glycidyl ethers such as phenyl glycidyl ether and cresyl glycidyl ether, such as 2-ethylhexyl glycidyl ether. Ethers consisting of alkyl groups and glycidyl groups, for example ethers consisting of phenyl groups having 6 to 12 carbon atoms and glycidyl groups which can be substituted with alkyl groups having 2 to 8 carbon atoms such as p-tertbutylphenylglycidyl ether, such as dodecyl Ethers composed of alkyl groups having 12 to 14 carbon atoms and glycidyl groups such as glycidyl ether; aliphatic glycidyl esters such as glycidyl (meth) acrylate and glycidyl maleate; Glycol ester, neodecanoic acid glycidyl ester, glycidyl esters of aliphatic carboxylic acids having 8 to 12 carbon atoms such as lauric acid glycidyl ester; and p-t-butylbenzoic acid glycidyl ester.

  When using a monoepoxide, the usage-amount is preferable 0.1-20 mass parts with respect to 100 mass parts of (A) component, 0.5-10 mass parts is more preferable, 1-5 mass parts is Particularly preferred. If the amount is less than 0.1 parts by mass, the effect of reducing the viscosity may not be sufficient. If the amount is more than 20 parts by mass, physical properties such as adhesiveness may be deteriorated.

<Photopolymerization initiator>
Moreover, when photocuring the curable resin composition of this invention, you may add a photoinitiator. Such photopolymerization initiators include onium salts such as aromatic sulfonium salts and aromatic iodonium salts with anions such as hexafluoroantimonate, hexafluorophosphate, and tetraphenylborate, and light such as aromatic diazonium salts and metallocene salts. Examples include cationic polymerization initiators (photoacid generators). These photopolymerization initiators may be used alone or in combination of two or more.

<Other ingredients>
In this invention, another compounding component can be used as needed. Other compounding components include azo-type chemical foaming agents and expansion agents such as thermally expandable microballoons, fiber pulps such as aramid pulp, colorants such as pigments and dyes, extenders, ultraviolet absorbers, antioxidants, Stabilizer (anti-gelling agent), plasticizer, leveling agent, antifoaming agent, silane coupling agent, antistatic agent, flame retardant, lubricant, thinning agent, low shrinkage agent, organic filler, thermoplastic resin, A desiccant, a dispersing agent, etc. are mentioned.

<Method for producing curable resin composition>
The curable resin composition of the present invention is a composition containing polymer fine particles (B) in the curable resin composition containing the component (A) as a main component, preferably the polymer fine particles (B) are 1 It is a composition dispersed in the form of secondary particles.

  Various methods can be used to obtain such a composition in which the polymer fine particles (B) are dispersed in the form of primary particles. For example, polymer fine particles obtained in an aqueous latex state can be used as the component (A). Examples include a method of removing unnecessary components such as water after contact, and a method of once removing polymer fine particles into an organic solvent and then mixing with the component (A), and then removing the organic solvent. WO 2005/028546 It is preferable to use the method described in the pamphlet. The specific production method is as follows: an aqueous latex containing polymer fine particles (B) (specifically, a reaction mixture after producing polymer fine particles by emulsion polymerization) has a solubility in water at 20 ° C. of 5% by mass. After mixing with an organic solvent of 40% by mass or less and further mixing with excess water, the first step of aggregating the polymer particles, and separating and collecting the agglomerated polymer fine particles (B) from the liquid phase, A second step of mixing with an organic solvent to obtain an organic solvent solution of the polymer fine particles (B), and a third step of further distilling off the organic solvent after further mixing the organic solvent solution with the component (A). It is preferable to be prepared by.

  The component (A) is preferably liquid at 23 ° C. because the third step becomes easy. “Liquid at 23 ° C.” means that the softening point is 23 ° C. or lower, and indicates fluidity at 23 ° C.

  In the composition obtained by performing the above-described steps, in which the polymer fine particles (B) are dispersed in the state of primary particles in the component (A), the components (A), (C), (D), (E) The curable resin composition of the present invention in which the polymer fine particles (B) are dispersed in the form of primary particles can be obtained by further mixing the components and each of the other blending components as necessary.

  On the other hand, the powdered polymer fine particles (B) obtained by coagulation by a method such as salting out and the like are dried using a disperser having high mechanical shearing force such as three paint rolls, a roll mill, and a kneader. Thus, it can be redispersed in the component (A). In this case, the component (A) and the component (B) can disperse the component (B) efficiently by applying a mechanical shearing force at a high temperature. The temperature at the time of dispersion is preferably 50 to 200 ° C, more preferably 70 to 170 ° C, still more preferably 80 to 150 ° C, and particularly preferably 90 to 120 ° C. When the temperature is lower than 50 ° C., the component (B) may not be sufficiently dispersed. When the temperature is higher than 200 ° C., the component (A) or the component (B) may be thermally deteriorated.

  The curable resin composition of the present invention can be used as a one-component curable resin composition that is pre-blended with all compounding components, stored in a sealed state, and cured by heating or light irradiation after application. Moreover, it contains (A) component as a main component, further contains (B) component and A liquid containing (C) component as required, (D) component and (E) component, and further if necessary Prepared as a two-component or multi-component curable resin composition comprising a separately prepared B solution containing the component (B) and / or the component (C), and the A solution and the B solution are used. It can also be mixed before use. In addition, since the curable composition of this invention is excellent in storage stability, when it is used as a one-pack type curable resin composition, it is especially useful.

  The component (B) and the component (C) are only required to be contained in at least one of the liquid A and the liquid B, for example, only the liquid A, only the liquid B, It may be included in both.

<Hardened product>
The present invention includes a cured product obtained by curing the curable resin composition. In the case of a curable resin composition in which polymer fine particles are dispersed in the form of primary particles, a cured product in which the polymer fine particles are uniformly dispersed can be easily obtained by curing this. In addition, since the polymer fine particles hardly swell and the viscosity of the curable resin composition is low, a cured product can be obtained with good workability.

<Application method>
The curable resin composition of the present invention can be applied by any method. It can be applied at a low temperature of about room temperature, and can be applied by heating as necessary. Since the curable resin composition of the present invention is excellent in storage stability, it is particularly useful for a method of applying by heating.

  The curable resin composition of the present invention is extruded onto a substrate in the form of a bead, monofilament or swirl using a coating robot, or a mechanical coating method such as a caulking gun or other manual coating means. It can also be used. The composition can also be applied to the substrate using a jet spray method or a streaming method. The curable resin composition of the present invention is applied to one or both substrates, and the substrates are brought into contact with each other so that the composition is disposed between the substrates to be bonded, and bonded by curing. The viscosity of the curable resin composition is not particularly limited, and is preferably about 150 to 600 Pa · s at 45 ° C. in the extrusion bead method, and preferably about 100 Pa · s at 45 ° C. in the swirl coating method. In a high volume coating method using a high-speed flow device, about 20 to 400 Pa · s at 45 ° C. is preferable.

  When the curable resin composition of the present invention is used as an adhesive for vehicles, it is effective to increase the viscosity of the composition in order to improve the “hardness to be washed off”. The resin composition is preferable because it has high thixotropy and tends to have a high viscosity. A highly viscous composition can be adjusted to a viscosity that can be applied by heating.

  Further, in order to improve the “hardness to be washed off”, a polymer compound having a crystalline melting point near the coating temperature of the composition is used as described in WO 2005-118734 pamphlet. It is preferable to blend in. The composition has a low viscosity at the coating temperature (easy to apply), and a high viscosity at the temperature in the washing shower step, thus improving the “hardness to be washed off”. Examples of the polymer compound having a crystalline melting point near the coating temperature include various polyester resins such as crystalline or semicrystalline polyester polyols.

  Further, as another method for improving the “hardness to be washed off”, as described in WO 2006-093949 pamphlet, a curable resin composition is made into a two-pack type, and a curing agent to be used is amino. And a method of using a latent curing agent such as dicyandiamide, which exhibits activity at a high temperature, using a small amount of a curing agent capable of being cured at room temperature (room temperature curing curing agent) such as an amine-based curing agent having a group or an imino group. By using two or more types of curing agents having greatly different curing temperatures, partial curing proceeds immediately after application of the composition, resulting in a high viscosity at the time of the water-washing shower process and improving the “hardness to be washed off”. .

<Adhesive substrate>
When various substrates are bonded using the resin composition of the present invention, for example, wood, metal, plastic, glass or the like can be bonded. It is preferable to join automobile parts, more preferably joining of automobile frames or joining of an automobile frame and other automobile parts. Examples of the substrate include various plastic substrates such as steel materials such as cold-rolled steel and hot-dip galvanized steel, aluminum materials such as aluminum and coated aluminum, general-purpose plastics, engineering plastics, and composite materials such as CFRP and GFRP. .

  The curable resin composition of the present invention is excellent in adhesiveness. Therefore, the members obtained by curing the curable resin composition are bonded after the curable resin composition of the present invention is sandwiched between a plurality of members including an aluminum substrate. A laminated body is preferable in order to show high adhesive strength.

  Since the curable resin composition of the present invention is excellent in toughness, it is suitable for joining different kinds of substrates having different linear expansion coefficients.

  The curable resin composition of the present invention can also be used for joining aerospace components, particularly exterior metal components.

<Curing temperature>
The curing temperature of the curable resin composition of the present invention is not particularly limited, but when used as a one-component curable resin composition, 50 ° C to 250 ° C is preferable, and 80 ° C to 220 ° C is more preferable. 100 ° C to 200 ° C is more preferable, and 130 ° C to 180 ° C is particularly preferable. When used as a two-component curable resin composition, there is no particular limitation, but 0 ° C to 150 ° C is preferable, 10 ° C to 100 ° C is more preferable, 15 ° C to 80 ° C is further preferable, and 20 ° C to 20 ° C. 60 ° C. is particularly preferred.

  When the curable resin composition of the present invention is used as an automobile adhesive, after the adhesive is applied to an automobile member, a coating is then applied, and the adhesive is cured at the same time as the coating is baked and cured. Is preferable from the viewpoint of process shortening and simplification.

<Application>
The composition of the present invention is preferably a one-component curable resin composition from the viewpoint of handleability.

  The composition of the present invention includes structural adhesives for vehicles and aircraft, adhesives such as structural adhesives for wind power generation, paints, materials for lamination with glass fibers, printed wiring board materials, solder resists, interlayer insulation Films, build-up materials, adhesives for FPC, electrical insulation materials such as encapsulants for electronic components such as semiconductors and LEDs, die bond materials, underfills, semiconductor mounting materials such as ACF, ACP, NCF, NCP, liquid crystal panels, OLEDs It is preferably used for a sealing device for display devices and lighting devices such as lighting and OLED displays. In particular, it is useful as a structural adhesive for vehicles.

  Hereinafter, the present invention will be described in more detail with reference to examples and comparative examples. However, the present invention is not limited to these, and can be implemented with appropriate modifications within a range that can meet the gist of the preceding and following descriptions. These are all included in the technical scope of the present invention. In the following Examples and Comparative Examples, “parts” and “%” mean parts by mass or mass%.

Evaluation method First, the evaluation method of the curable resin composition manufactured by the Example and the comparative example is demonstrated below.

[1] Measurement of volume average particle diameter The volume average particle diameter (Mv) of the polymer particles dispersed in the aqueous latex was measured using Microtrac UPA150 (manufactured by Nikkiso Co., Ltd.). A sample diluted with deionized water was used as a measurement sample. The measurement was performed by inputting the refractive index of water and the refractive index of each polymer particle, and adjusting the sample concentration so that the measurement time was 600 seconds and the Signal Level was in the range of 0.6 to 0.8. .

[2] Measurement of viscosity The viscosity of the curable resin composition was measured using a digital viscometer DV-II + Pro type manufactured by BROOKFIELD. Measurement was performed at 23 ° C. using a spindle CPE-52.

1. Formation of Core Layer Production Example 1-1; Preparation of Polybutadiene Rubber Latex (R-1) In a pressure-resistant polymerization machine, 200 parts by mass of deionized water, 0.03 parts by mass of tripotassium phosphate, disodium ethylenediaminetetraacetate (EDTA) ) 0.002 part by mass, 0.001 part by mass of ferrous sulfate heptahydrate (FE), and 1.55 part by mass of sodium dodecylbenzenesulfonate (SDS), and sufficiently nitrogen while stirring After substituting and removing oxygen, 99.6 parts by mass of butadiene (BD) and 0.4 parts by mass of t-dodecyl mercaptan were added to the system, and the temperature was raised to 45 ° C. Polymerization was initiated by adding 0.03 parts by mass of paramentane hydroperoxide (PHP), followed by 0.10 parts by mass of sodium formaldehyde sulfoxylate (SFS). 0.025 parts by mass of PHP was added at 3, 5, and 7 hours from the start of polymerization. In addition, EDTA 0.0006 parts by mass and FE 0.003 parts by mass were added to polymerization at 4, 6 and 8 hours, respectively. At 15 hours after polymerization, the residual monomer was removed by devolatilization under reduced pressure to complete the polymerization, and a polybutadiene rubber latex (R-1) containing polybutadiene rubber as a main component was obtained. The volume average particle diameter of the polybutadiene rubber particles contained in the obtained latex was 0.08 μm.

Production Example 1-2; Preparation of Polybutadiene Rubber Latex (R-2) In Production Example 1-1, 99.6 parts by mass of butadiene (BD) and 0.4 mass of t-dodecyl mercaptan as the monomer component of the core layer A polybutadiene rubber latex (R-2) was obtained in the same manner as in Production Example 1-1 except that <100 parts by mass of butadiene (BD)> was used instead of <parts>. The volume average particle diameter of the polybutadiene rubber particles contained in the obtained latex was 0.08 μm.

2. Preparation of polymer fine particles (formation of shell layer)
Production Example 2-1: Preparation of Core-Shell Polymer Latex (L-1) A glass reactor having a thermometer, a stirrer, a reflux condenser, a nitrogen inlet, and a monomer addition device was prepared in Production Example 1-1. 250 parts by mass of polybutadiene rubber latex (R-1) (including 83 parts by mass of polybutadiene rubber particles) and 65 parts by mass of deionized water were charged and stirred at 60 ° C. while performing nitrogen substitution. After adding 0.004 parts by mass of EDTA, 0.001 part by mass of FE, and 0.2 parts by mass of SFS, a mixture of 17 parts by mass of methyl methacrylate (MMA) and 0.05 parts by mass of cumene hydroperoxide (CHP) was added. Added continuously over a period of minutes. After completion of the addition, 0.03 part by mass of CHP was added, and stirring was further continued for 2 hours to complete the polymerization to obtain an aqueous latex (L-1) containing a core-shell polymer. The polymerization conversion rate of the monomer component was 99% or more. The volume average particle diameter of the core-shell polymer contained in the obtained aqueous latex was 0.10 μm.

Production Example 2-2; Preparation of Core-Shell Polymer Latex (L-2) In Production Example 2-1, instead of <R-1) prepared in Production Example 1-1 as a polybutadiene rubber latex, <Production Example 1- A core-shell polymer aqueous latex (L-2) was obtained in the same manner as in Production Example 2-1, except that (R-2)> prepared in Step 2 was used. The volume average particle diameter of the core-shell polymer contained in the obtained aqueous latex was 0.10 μm.

3. Preparation of dispersion (M) in which polymer fine particles (B) are dispersed in a curable 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. While stirring, 132 g (corresponding to 40 g of polymer fine particles) of the core-shell polymer aqueous latex (L-1) obtained in Production Example 2-1 was charged. After mixing uniformly, 200 g of water was added at a feed rate of 80 g / min. When the stirring was stopped immediately after the completion of the supply, a slurry liquid composed of an aqueous phase partially containing a floating aggregate and an organic solvent was obtained. Next, an agglomerate containing a part of the aqueous phase was left, and 360 g of the aqueous phase was discharged from the discharge port at the bottom of the tank. 90 g of MEK was added to the obtained aggregate and mixed uniformly to obtain a dispersion in which the core-shell polymer was uniformly dispersed. To this dispersion, 80 g of epoxy resin (A-1: manufactured by Mitsubishi Chemical Corporation, JER828: liquid bisphenol A type epoxy resin) as component (A) was mixed. From this mixture, MEK was removed with a rotary evaporator. Thus, a dispersion (M-1) in which polymer fine particles were dispersed in an epoxy resin was obtained.

Production Example 3-2; Preparation of Dispersion (M-2) Production Example 3 except that (L-2) was used instead of (L-1) as the aqueous latex of the core-shell polymer in Production Example 3-1. As in -1, a dispersion (M-2) in which polymer fine particles were dispersed in an epoxy resin was obtained.
(Examples 1-5, Comparative Examples 1-7)
According to the formulation shown in Table 1, each component was weighed and mixed well to obtain a curable resin composition.

  Using each composition in Table 1, T-peel adhesion strength and dynamic splitting resistance were measured by the following methods. The results are shown in Table 1.

<T-peeling adhesive strength>
Applying the curable resin composition to two SPCC steel plates of dimensions: 25 × 200 × 0.5 mm, superimposing them so that the adhesive layer thickness is 0.25 mm, and curing them at 170 ° C. × 25 minutes, According to JIS K6854, the T-shaped peel adhesion strength at 23 ° C. was measured. The test results are shown in Table 1. Note that the test piece of Comparative Example 2 could not be measured because the adhesive layer was uncured.

Using the curable resin composition of Example 5 and Comparative Example 4, it was applied to two JIS standard aluminum plates (A2024P) with dimensions of 25 × 200 × 0.8 mm so that the adhesive layer thickness was 0.25 mm. And cured under conditions of 170 ° C. × 25 minutes, and T-peel adhesion strength at 23 ° C. was measured according to JIS K6854. The test results are shown in Table 1.
<Dynamic splitting resistance (impact peel resistance)>
The curable resin composition was applied to two SPCC steel plates, laminated so that the adhesive layer thickness was 0.25 mm, cured under the conditions of 170 ° C. × 25 minutes, and dynamically split at 23 ° C. according to ISO 11343. Resistance was measured. The test results are shown in Table 1. Note that the test piece of Comparative Example 2 could not be measured because the adhesive layer was uncured.

In addition, what was shown below was used for the various compounding agents in Table 1.
<Epoxy resin (A)>
A-1: JER828 (Mitsubishi Chemical, bisphenol A type epoxy resin that is liquid at room temperature, epoxy equivalent: 184 to 194)
A-2: YED216 (Mitsubishi Chemical, hexanediol diglycidyl ether, epoxy equivalent: 110-130)
<Dispersion (M) in which polymer fine particles (B) are dispersed in epoxy resin (A)>
M-1 to 2: Dispersion obtained in Production Examples 3-1 to 2 <Compounding agent containing component (C)>
C-1: QR-9466 (made by ADEKA, blocked urethane, block NCO equivalent: 220)
C-2: Hypox RA 1340 (manufactured by CVC, rubber-modified epoxy resin as component (C): 40 wt%, bisphenol A type epoxy resin concentration as component (A): 60 wt%, epoxy equivalent: 325-375)
C-3: EPU-73B (manufactured by ADEKA, urethane-modified epoxy resin as component (C): 40 wt%, bisphenol A type epoxy resin concentration as component (A): 60 wt%, epoxy equivalent: 245)
≪Heavy calcium carbonate≫
Whiteon SB (Shiraishi calcium, untreated heavy calcium carbonate, average particle size: 1.8μm)
≪Calcium oxide≫
CML # 31 (Omi Chemical Industries, calcium oxide surface-treated with fatty acid)
≪Carbon black≫
MONARCH 280 (manufactured by Cabot)
<Epoxy curing agent (D)>
Dyhard 100S (AlzChem, dicyandiamide)
<Curing accelerator (E)>
Dyhard UR300 (AlzChem, 1,1-dimethyl-3-phenylurea)

  From Table 1, the curable resin compositions (I) of Examples 1 to 3 containing the component (A), the component (B), and the component (C), which are the first embodiment of the present invention, are impact resistant. It can be seen that although the effect of improving the peel adhesion is small, it is excellent in T-shaped peel adhesion. In addition, the curable resin compositions (II) of Examples 4 to 5 containing the component (A), the component (B), and a specific amount of dicyandiamide (D) according to the second aspect of the present invention are also resistant to resistance. Although the improvement effect on impact peel adhesion is small, it can be seen that it is excellent in T-shaped peel adhesion. The amount of the component (A) contained in the curable resin composition in Table 1 is the sum of the component added as the epoxy resin and the component contained in the polymer fine particle dispersion (M) and component (C). Amount.

Claims (15)

1 to 100 parts by mass of polymer fine particles (B) having a core-shell structure in which the core layer is a diene rubber with respect to 100 parts by mass of the epoxy resin (A), a blocked urethane, a rubber-modified epoxy resin, and a urethane-modified epoxy resin. A curable resin composition containing 1 to 100 parts by mass of one or more selected from the group (C),
The epoxy resin (A) excludes a rubber-modified epoxy resin and a urethane-modified epoxy resin,
The (B) component core layer is (b1) 50-99.99 mass% of conjugated diene monomer, and (b2) vinyl monomer 49.99-0 copolymerizable with the conjugated diene monomer. Ri wt% and (b3) a diene rubber der obtained by polymerizing a monomer mixture consisting of a chain transfer agent 0.01-3% by weight,
The shell layer of the component (B) is obtained by polymerizing one or more monomer components selected from the group consisting of an aromatic vinyl monomer, a vinyl cyan monomer, and a (meth) acrylate monomer,
The curable resin composition (I), wherein the chain transfer agent (b3) is an alkyl mercaptan .   The curable resin composition (I) according to claim 1, further comprising 1 to 80 parts by mass of an epoxy curing agent (D) with respect to 100 parts by mass of the component (A). 1-100 parts by mass of polymer fine particles (B) having a core-shell structure in which the core layer is a diene rubber with respect to 100 parts by mass of the epoxy resin (A), and dicyandiamide 4.5-6.5 as the epoxy curing agent (D). A curable resin composition containing parts by mass,
The epoxy resin (A) excludes a rubber-modified epoxy resin and a urethane-modified epoxy resin,
The (B) component core layer is (b1) 50-99.99 mass% of conjugated diene monomer, and (b2) vinyl monomer 49.99-0 copolymerizable with the conjugated diene monomer. Ri wt% and (b3) a diene rubber der obtained by polymerizing a monomer mixture consisting of a chain transfer agent 0.01-3% by weight,
The shell layer of the component (B) is obtained by polymerizing one or more monomer components selected from the group consisting of an aromatic vinyl monomer, a vinyl cyan monomer, and a (meth) acrylate monomer,
The curable resin composition (II), wherein the chain transfer agent (b3) is an alkyl mercaptan . The component (A) 100 parts by weight, further characterized blocked urethane, rubber-modified epoxy resin, that contains at least one selected from the group consisting of urethane-modified epoxy resin (C) 1 to 100 parts by weight The curable resin composition (II) according to claim 3. The component (A) 100 parts by weight, further, the curable resin composition according to any one of claims 1 to 4, characterized in that it contains 0.1 to 10 parts by weight of the curing accelerator (E) .   The curable resin composition according to any one of claims 1 to 5, wherein the diene rubber is butadiene rubber and / or butadiene-styrene rubber.   The component (B) has a shell layer obtained by graft polymerizing one or more monomer components selected from the group consisting of an aromatic vinyl monomer, a vinyl cyan monomer, and a (meth) acrylate monomer on the core layer. A curable resin composition according to any one of claims 1 to 6.   (B) Component has an epoxy group in a shell layer, The curable resin composition in any one of Claim 1 to 7 characterized by the above-mentioned.   The curable resin composition according to any one of claims 1 to 8, wherein the component (B) has a shell layer obtained by graft polymerization of a monomer component having an epoxy group on the core layer.   (B) Content of the epoxy group in a component is 0.01-0.8 mmol / g, The curable resin composition in any one of Claim 1 to 9 characterized by the above-mentioned. The curable resin composition according to any one of claims 1 to 10, wherein the component (B) is dispersed in a state of primary particles in the curable resin composition.   A cured product obtained by curing the curable resin composition according to claim 1.   The one-component curable resin composition according to any one of claims 1 to 11.   A structural adhesive comprising the curable resin composition according to claim 1.   After the curable resin composition according to any one of claims 1 to 11 is sandwiched between a plurality of members including an aluminum base, the members are joined by curing the curable resin composition. A laminated body.