JP6886641B2 - Epoxy resin curing agent, epoxy resin composition, paint, civil engineering and building materials, cured product and composite material, and manufacturing method of epoxy resin curing agent. - Google Patents

Description

The present invention relates to an epoxy resin curing agent, an epoxy resin composition using the same, a paint, a member for civil engineering and construction, a cured product and a composite material, and a method for producing an epoxy resin curing agent.

Epoxy resins give cured products with excellent moldability, mechanical strength, adhesion, etc. by curing with various curing agents. Therefore, casting materials, adhesives, molding materials, laminated materials, composite materials, etc. It is used for various purposes in the form of. For example, a fiber-reinforced composite material using epoxy resin as a matrix resin, especially a carbon fiber-reinforced composite material using carbon fiber, has light weight and excellent mechanical properties, so that it can be used in sports fields such as golf clubs, tennis rackets, and fishing rods. It is used in a wide range of fields, including structural materials for aircraft and vehicles, and reinforcement of concrete structures. In recent years, it has been used not only for excellent mechanical properties but also for housings of electronic and electrical equipment such as notebook computers and video cameras because composite materials with carbon fibers have excellent electromagnetic wave blocking properties. This is useful for thinning the housing and reducing the weight of equipment. Such a carbon fiber reinforced composite material is generally obtained by laminating a prepreg obtained by impregnating a reinforcing fiber with an epoxy resin.

It is widely known that various polyamino compounds are used as epoxy resin curing agents and their raw materials. As a typical polyamino compound, an aliphatic polyamino compound having an aromatic ring (for example, xylylene diamine); an aliphatic polyamino compound (for example, ethylenediamine, diethylenetriamine (DETA), triethylenetetramine (TETA), etc.); Formula polyamino compounds (for example, isophoronediamine (IPDA), bis (aminomethyl) cyclohexane, etc.) and the like can be mentioned. These polyamino compounds have unique characteristics due to the reactivity of each amino group, that is, active hydrogen, and the epoxy resin is cured by using these polyamino compounds as they are or after subjecting them to modifications suitable for each polyamino compound. It is used as an agent.

Among the aliphatic polyamino compounds, DETA, TETA and the like are generally known to have a larger calorific value when a large amount is blended as compared with other polyamino compounds. Further, among alicyclic polyamino compounds, IPDA has a difference in reactivity between two amino groups, so that curing is slow, and a curing accelerator is generally used in combination (Non-Patent Document 1). ..

Further, 1,3-bis (aminomethyl) cyclohexane has good curability, but has high reactivity with an epoxy resin, and tends to generate a large amount of heat.

For example, Patent Document 1 proposes an epoxy resin curing agent containing a polyamino compound and a phenethylated polyamino compound. Further, Patent Document 2 proposes a technique of using an amino compound obtained by an addition reaction between a polyamino compound and styrene as an epoxy resin curing agent. Further, Patent Document 3 also proposes a technique of using a polyamino compound obtained by reacting a polyamino compound with styrene as an epoxy resin. Further, Patent Document 4 proposes a technique of using an amino compound obtained by an addition reaction of a polyamino compound and acrylonitrile as an epoxy resin.

Further, for example, in Patent Document 5, an epoxy resin curing agent obtained by blending a polyamine compound containing 1,3-bis (aminomethyl) cyclohexane or a modified product thereof and an alkylamine compound having 16 to 18 carbon atoms is used. Proposed. In Patent Document 6, a polyamine compound containing 1,3-bis (aminomethyl) cyclohexane and / or a modified product thereof, an aliphatic compound containing a component having an alkyl group having 12 carbon atoms or having an iodine value of 50 or more. An epoxy resin curing agent composed of an amine compound and a curing accelerator has been proposed. Further, as another aliphatic polyamino compound having no aromatic ring, an epoxy resin curing agent made from DETA, TETA, IPDA or the like is also used.

Japanese Unexamined Patent Publication No. 2012-219115 Japanese Patent No. 5140900 Japanese Patent No. 5509743 Special Publication No. 47-001114 Japanese Unexamined Patent Publication No. 08-003282 Japanese Unexamined Patent Publication No. 2001-163955

Review Epoxy resin, by Hiroshi Kakiuchi (2003)

However, there is still room for improvement in the above-mentioned techniques for epoxy resins and their curing agents. First, it is still insufficient to achieve both suppression of the curing heat generation temperature and improvement of the curing rate. The curing reaction between the epoxy resin and the curing agent is usually an exothermic reaction and releases a large amount of heat. Then, in order to improve the curing rate, attempts have been made to increase the blending amount of the curing agent per resin unit, but there is a problem that heat is easily generated when the blending amount of the curing agent is increased. Such a problem becomes remarkable when the cured product is thick or when it is a large molded product. When intense heat is generated, the molded product is cracked due to the distortion of internal stress, resulting in a defective product or deterioration of the components of the molding mold. On the other hand, if the amount of the curing agent or curing accelerator added is reduced in order to suppress heat generation, the molding cycle becomes long, and there arises a problem that productivity and economy are inferior. Further, if the amount of the curing agent or curing accelerator added is small, the degree of curing becomes insufficient, and the strength of the molded product may be inferior. Especially when it is used as a prepreg, the curing rate tends to be an important factor. If the curing time can be shortened by improving the curing rate, it can be expected that the productivity can be improved without increasing the number of molding dies (molds) when molding the product. Such a demand becomes remarkable especially when manufacturing a large-sized molded product.

In this respect, for example, the technique disclosed in Patent Document 1 has a problem that the curing rate of the curing agent and the epoxy resin is slow, and the productivity is low when used for molding a prepreg or the like. Further, the technique disclosed in Patent Document 2 has a problem that the curing rate is slow and the productivity is lowered. Further, since it is difficult to reduce the residual amount of the unreacted amino compound, there is also a problem that when the epoxy resin is cured with such a curing agent, intense heat generation due to the remaining unreacted amino compound occurs. .. Further, the technique disclosed in Patent Document 3 has a problem that it is inferior in mechanical properties, although the curing heat generation temperature is improved. Further, the technique disclosed in Patent Document 4 gives a good coating film appearance, but has a problem that it is inferior in mechanical properties.

Further, the epoxy resin curing agent disclosed in Patent Document 5 has a problem that heat generation suppression at the time of curing and improvement of curing speed are insufficient. In addition to that, there is also a problem that crystals such as alkylamine are precipitated during storage and solidify as a curing agent, resulting in inferior storage stability. The epoxy resin curing agent disclosed in Patent Document 6 has improved storage stability to some extent, but also has a problem that heat generation suppression during curing and improvement in curing speed are insufficient. Further, even with an epoxy resin curing agent made from an aliphatic amine compound such as DETA, TETA and IPDA, it is insufficient to suppress heat generation during curing and improve the curing rate. As described above, an epoxy resin curing agent that cures quickly without excessive heat generation and gives good mechanical properties has not yet been realized.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide an epoxy resin curing agent that cures quickly without excessive heat generation and gives good mechanical properties.

As a result of diligent studies, the present inventors have found that, surprisingly, rapid curing can be performed without excessive heat generation by using an epoxy resin curing agent containing a specific amino compound having at least an aminopropyl group. , The present invention has been completed.

That is, the present invention is as follows.
[1]
An epoxy resin curing agent containing an amino compound represented by the following formula (1).

^{_{R 1 HN-H 2 C-}} A-CH 2 -NHR 2 (1)

(In the formula (1), A is an o-phenylene group, an m-phenylene group, a p-phenylene group, a 1,2-cyclohexylene group, a 1,3-cyclohexylene group or a 1,4-cyclohexylene group. , R ¹ and R ² are hydrogen atoms or aminopropyl groups. R ¹ and R ² may be the same or different, but ^{at least one of R 1} and R ² is an aminopropyl group.)
[2]
The epoxy resin curing agent according to the above [1], wherein A is an o-phenylene group, an m-phenylene group or a p-phenylene group.
[3]
The epoxy resin curing agent according to the above [1], wherein A is a 1,2-cyclohexylene group, a 1,3-cyclohexylene group or a 1,4-cyclohexylene group.
[4]
Epoxy resin and
The epoxy resin curing agent according to any one of [1] to [3] above,
Epoxy resin composition containing.
[5]
A paint containing the epoxy resin composition according to the above [4].
[6]
A member for civil engineering and construction containing the epoxy resin composition according to the above [4].
[7]
A cured product obtained by curing the epoxy resin composition according to the above [4].
[8]
With the cured product described in [7] above,
With fiber
Composite material including.
[9]
o-Xylylenediamine, p-xylylenediamine, m-xylylenediamine, 1,2-bis (aminomethyl) cyclohexane, 1,3-bis (aminomethyl) cyclohexane and 1,4-bis (aminomethyl) cyclohexane A step of adding acrylonitrile to at least one selected from the group consisting of cyano compound to obtain a cyano compound.
The step of obtaining the amino compound represented by the formula (1) by hydrogenating the cyano compound, and
A method for producing an epoxy resin curing agent, which comprises the above amino compound.

^{_{R 1 HN-H 2 C-}} A-CH 2 -NHR 2 (1)

(In the formula (1), A is an o-phenylene group, an m-phenylene group, a p-phenylene group, a 1,2-cyclohexylene group, a 1,3-cyclohexylene group or a 1,4-cyclohexylene group. , R ¹ and R ² are hydrogen atoms or aminopropyl groups. R ¹ and R ² may be the same or different, but ^{at least one of R 1} and R ² is an aminopropyl group.)

The epoxy resin curing agent according to the present invention has a low curing heat generation temperature and a high curing rate. Further, the epoxy resin composition using the epoxy resin curing agent according to the present invention gives good epoxy resin cured physical properties and is suitable for epoxy resin civil engineering / building applications and fiber-reinforced composite material applications.

Hereinafter, embodiments for carrying out the present invention (hereinafter, simply referred to as “the present embodiment”) will be described in detail. The following embodiments are examples for explaining the present invention, and are not intended to limit the present invention to the following contents. The present invention can be appropriately modified and implemented within the scope of the gist thereof.

The epoxy resin curing agent of the present embodiment is an epoxy resin curing agent containing an amino compound represented by the following formula (1).

^{_{R 1 HN-H 2 C-}} A-CH 2 -NHR 2 (1)

(In the formula (1), A is an o-phenylene group, an m-phenylene group, a p-phenylene group, a 1,2-cyclohexylene group, a 1,3-cyclohexylene group or a 1,4-cyclohexylene group. , R ¹ and R ² are hydrogen atoms or aminopropyl groups. R ¹ and R ² may be the same or different, but ^{at least one of R 1} and R ² is an aminopropyl group.)

By containing the amino compound represented by the formula (1), the epoxy resin curing agent of the present embodiment can suppress excessive heat generation when curing the epoxy resin, and the curing speed is high. In conventional epoxy resin curing agents, metaxylylenediamine and the like are widely used as the main component, but in such conventional epoxy resin curing agents, carbon dioxide and water vapor in the atmosphere are absorbed, and carbamic acids and carbonates are used. Is likely to occur, so that the physical properties of the cured epoxy resin are likely to deteriorate. In particular, a whitening phenomenon of the cured product may occur, and a drawback of inferior appearance may occur. In this respect, the epoxy resin curing agent of the present embodiment is particularly excellent in quick-curing property, and can give a cured product having excellent appearance and flexibility.

The amino compound in this embodiment can be obtained, for example, by the following method. First, at least one selected from the group consisting of o-xylylenediamine, p-xylylenediamine and m-xylylenediamine (hereinafter, these may be collectively referred to as "xylylylenediamine"), or 1, At least one selected from the group consisting of 2-bis (aminomethyl) cyclohexane, 1,3-bis (aminomethyl) cyclohexane and 1,4-bis (aminomethyl) cyclohexane (hereinafter, these are referred to as "bis (aminomethyl)". (Sometimes collectively referred to as "cyclohexane") and acrylonitrile are subjected to an addition reaction to obtain a cyano compound containing a nitrile group. Then, the amino compound can be obtained by hydrogenating this cyano compound. In this case, the amino compound may be a mixture of each adduct. Here, each adduct is ^{an adduct (1 adduct) in which any one of R 1} and R ² is an aminopropyl group and the remaining one is a hydrogen atom in the formula (1), and all of them are amino. It means an adduct (2 adduct) which is a propyl group. In the epoxy resin curing agent of the present embodiment, the content of the diadduct is preferably 25% by mass or more, more preferably 50% by mass or more, further preferably 70% by mass or more, and 85% by mass. It is particularly preferable that the mass is% or more. When the content of the diadduct in the epoxy resin curing agent is 25% by mass or more, quick curing tends to be easily exhibited.

The total content of the compound represented by the formula (1) (total of 1 adduct and 2 adducts) in the epoxy resin curing agent of the present embodiment is 60 to 100% by mass from the viewpoint of developing quick curability. It is preferably 70 to 100% by mass, more preferably 80 to 100% by mass.

The epoxy resin curing agent of the present embodiment may contain unreacted xylylenediamine, bis (aminomethyl) cyclohexane, or the like in addition to the above-mentioned amino compounds. The content of xylylenediamine or bis (aminomethyl) cyclohexane in the epoxy resin curing agent is preferably less than 30% by mass, more preferably less than 20% by mass, and less than 5% by mass. More preferred. The lower limit of the content of xylylenediamine or bis (aminomethyl) cyclohexane is not particularly limited. By setting the content of this xylylenediamine or bis (aminomethyl) cyclohexane to less than 30% by mass, the curing delay of the epoxy resin composition is further increased when the epoxy resin composition is prepared by using it as an epoxy resin curing agent. It tends to be suppressed.

The method for producing the epoxy resin curing agent in the present embodiment is not particularly limited, but is a step (first step) of obtaining a cyano compound by addition-reacting xylylenediamine or bis (aminomethyl) cyclohexane with acrylonitrile, and this cyano. A method including a step (second step) of obtaining an amino compound represented by the formula (1) by hydrogenating the compound is preferable.

Examples of the xylylenediamine include ortho (o-) xylylenediamine, meta (m-) xylylenediamine, para (p-) xylylenediamine and the like. Among these, meta (m-) xylylenediamine is preferable.

Examples of bis (aminomethyl) cyclohexane include 1,2-bis (aminomethyl) cyclohexane, 1,3-bis (aminomethyl) cyclohexane, and 1,4-bis (aminomethyl) cyclohexane. , 1,3-bis (aminomethyl) cyclohexane is preferred.

The above reaction carried out in the first step may be a homogeneous reaction or a heterogeneous reaction such as a two-layer reaction, but from the viewpoint of suppressing by-products, it is a homogeneous reaction. It is preferable to have. The homogeneous reaction can be carried out without a solvent, but it is preferable to use a solvent from the viewpoint that the reaction temperature can be controlled with high accuracy.

The solvent used in the first step is not particularly limited, but for example, it is preferable to use an alcohol solvent such as isopropanol, an ether solvent such as tetrahydrofuran, an aromatic solvent such as toluene, and the like. Among these, an alcohol solvent is more preferable, and isopropanol is further preferable, from the viewpoint of solubility of xylylenediamine or bis (aminomethyl) cyclohexane as a raw material and a solvent that can be used in the second step. The amount of the solvent used is usually preferably 0 to 200% by mass, more preferably 50 to 180% by mass, and more preferably 80, based on the total mass of xylylenediamine or bis (aminomethyl) cyclohexane and acrylonitrile. It is more preferably ~ 160% by mass.

The reaction molar ratio of acrylonitrile to xylylenediamine or bis (aminomethyl) cyclohexane in the first step (acrylonitrile / xylylenediamine or bis (aminomethyl) cyclohexane) is preferably 0.5 to 3.0, and 0. It is more preferably 8 to 2.5, and even more preferably 1.0 to 2.0. When the lower limit of the reaction molar ratio is 0.5 or more, the amount of unreacted xylylenediamine or bis (aminomethyl) cyclohexane can be suppressed, so that unreacted xylylenediamine or bis (aminomethyl) cyclohexane can be removed. It tends to be easier. Furthermore, when purifying a cyano compound by distillation, there is a tendency that unreacted xylylenediamine or bis (aminomethyl) cyclohexane can be efficiently removed. On the other hand, when the upper limit of the reaction molar ratio is 3.0 or less, there is a tendency that an unfavorable side reaction can be effectively suppressed.

The reaction temperature in the first step is not particularly limited, but is preferably 20 to 85 ° C. from the viewpoint of the solubility of the raw material and the boiling point of the solvent or the like. Further, from the viewpoint of ease of controlling the reaction temperature, it is more preferably 25 to 75 ° C.

In the first step, at least xylylenediamine or bis (aminomethyl) cyclohexane and acrylonitrile are used, but the reaction between xylylenediamine or bis (aminomethyl) cyclohexane and acrylonitrile is an exothermic reaction. Therefore, in order to keep the reaction temperature constant, it is preferable to control the temperature rise caused by heat generation. For example, the temperature rise can be controlled by dropping acrylonitrile within a constant reaction temperature range and adding it. .. The time required for dropping acrylonitrile is not particularly limited, but it tends to be possible to obtain the desired cyanide compound easily and in a high yield by dropping the acrylonitrile so that the reaction temperature does not rise sharply.

The second step is a step of reducing the nitrile group of the cyano compound obtained in the first step to an amino group, and can be carried out, for example, by a heterogeneous catalytic hydrogenation (hydrogenation) reaction. The hydrogenation reaction is not particularly limited, but is preferably a reaction carried out in the presence of a transition metal catalyst. Examples of such a catalyst include a sponge metal catalyst such as sponge nickel and sponge cobalt, and a supported catalyst in which a catalyst metal such as cobalt, palladium, platinum, rhodium and ruthenium is supported on a carrier such as carbon. Among these, a sponge nickel catalyst is preferable from the viewpoint of shortening the reaction time and reaction selectivity.

The amount of the catalyst used is usually preferably 10 to 50% by mass, more preferably 15 to 45% by mass, based on the total amount of the raw material compounds. By setting the amount of the catalyst used within the above range, the reaction rate can be controlled to a suitable rate, and the economy tends to be excellent.

As the solvent used in the second step, an alcohol solvent such as isopropanol, an ether solvent such as tetrahydrofuran, an ammonia solvent and the like are preferable, an alcohol solvent is more preferable, and isopropanol is further preferable, from the viewpoint of reaction selectivity. .. When the solvent used in the first step is a solvent that can also be used in the second step, the solvent used in the first step can be continuously used in the second step. The amount of the solvent used is preferably 0 to 200% by mass, more preferably 50 to 180% by mass, and even more preferably 80 to 160% by mass with respect to the total mass of the cyano compound.

The reaction temperature in the second step is not particularly limited, but is usually preferably 30 to 150 ° C, more preferably 40 to 100 ° C, and even more preferably 40 to 80 ° C. By setting the lower limit of the reaction temperature to 30 ° C. or higher, the hydrogenation reaction rate of the cyano compound tends to be increased. By setting the upper limit of the reaction temperature to 150 ° C. or lower, there is a tendency that adverse side reactions can be effectively suppressed. It is preferable to appropriately select the reaction temperature in consideration of the reaction ratio of each component used in the second step, the type of catalyst, the amount used, and the like.

As the epoxy resin curing agent of the present embodiment, the amino compound represented by the formula (1) may be used alone or mixed with other amino compounds. Other amino compounds to be mixed include aliphatic polyamine compounds (for example, ethylenediamine, diethylenetriamine, etc.); aliphatic polyamine compounds having an aromatic ring (for example, xylylene diamine, etc.); alicyclic polyamine compounds (for example, mensendiamine). Etc.); Aromatic polyamine compounds (for example, phenylenediamine, diaminodiphenylmethane, etc.); Other polyether skeleton polyamino compounds (for example, norbornan skeleton polyamino compounds, etc.) and the like can be mentioned. These may be mixed without modification, or modified such as amide modification by reaction with a compound having a carboxyl group, adduct modification by addition reaction with an epoxy compound, and Mannich modification by reaction between formaldehyde and phenols. After that, it may be mixed.

The epoxy resin composition of the present embodiment contains an epoxy resin and an epoxy resin curing agent. The epoxy resin used in the epoxy resin composition of the present embodiment is an epoxy resin having a glycidyl group capable of reacting with active hydrogen derived from an amino group of the epoxy resin curing agent of the present embodiment and cross-linking. It may be a saturated or unsaturated aliphatic compound, an alicyclic compound, an aromatic compound, or a heterocyclic compound. Specifically, an epoxy resin having a glycidyl ether moiety derived from bisphenol A type, an epoxy resin having a glycidyl ether moiety derived from bisphenol F type, and glycidyl derived from 1,3-bis (aminomethyl) cyclohexane. Epoxy resin with amine moiety, epoxy resin with glycidylamine moiety derived from diaminodiphenylmethane, epoxy resin with glycidylamine moiety derived from paraaminophenol, epoxy resin with glycidyl ether moiety derived from phenol novolac, and Included is at least one epoxy resin selected from the group consisting of epoxy resins having glycidyl ether moieties derived from resorcinol. Among these, an epoxy resin having a glycidyl ether moiety derived from bisphenol A type is particularly preferable.

Further, the epoxy resin composition of the present embodiment includes a filler, a modifying component such as a plasticizer, a reactive or non-reactive diluent, a flow adjusting component such as a shaking modifier, and a pigment, depending on the intended use. Ingredients such as a tackifier and additives such as an epoxy inhibitor, a spreading agent, a defoaming agent, an ultraviolet absorber, a light stabilizer, and a curing accelerator can be used as long as the effects of the present invention are not impaired. ..

The blending amount of the epoxy resin curing agent in the epoxy resin composition of the present embodiment is preferably 0.6 to 1.2 as the ratio of the active hydrogen equivalent of the epoxy resin curing agent to the epoxy equivalent of the epoxy resin, and is 0. It is more preferably .7 to 1.0. When the ratio of active hydrogen equivalents is 0.6 or more, the degree of cross-linking of the cured product tends to be sufficient. When the ratio of active hydrogen equivalents is 1.2 or less, the introduction of hydrophilic amino groups can be appropriately suppressed, so that the water resistance tends to be further improved.

Epoxy resin compositions are used in the fields of paints such as anticorrosion paints for ships, bridges, and land and sea iron structures, lining, reinforcement, and repair of concrete structures, flooring materials for buildings, linings for water and sewage facilities, paving materials, and adhesives. It is widely used in civil engineering and construction fields, fiber-reinforced composite materials, etc. The epoxy resin cured product obtained by curing the epoxy resin composition of the present embodiment has excellent flexibility and can reduce brittleness, so that it is possible to provide a molded product having good mechanical characteristics. In particular, the required characteristics in the field of fiber-reinforced composite materials such as prepregs have become stricter in recent years, but by using the epoxy resin composition of the present embodiment, the mechanical strength is further improved and the elastic modulus is low. It can be fully expected to improve the physical properties such as chemical conversion.

The epoxy resin composition can be used for various purposes, and among them, it can be suitably used as a coating material from the viewpoint of having a good coating film appearance. That is, the paint of the present embodiment is a paint containing this epoxy resin composition. It is particularly desired that the paint has an excellent appearance when it is made into a coating film, such as gloss and transparency, but the paint of the present embodiment is also excellent in such an appearance when it is made into a coating film. ..

Further, the epoxy resin composition can be suitably used as a member for civil engineering and construction from the viewpoint of having good cured physical characteristics. That is, the civil engineering / building member of the present embodiment is a civil engineering / building member containing this epoxy resin composition. It is particularly desired that the civil engineering and building members have excellent mechanical strength, but the civil engineering and building members of the present embodiment are particularly excellent in mechanical strength.

The epoxy resin composition of the present embodiment can be cured by a known method to obtain an epoxy resin cured product (hereinafter, also referred to as “cured product”). The curing conditions are appropriately selected according to the intended use as long as the effects of the present invention are not impaired, and are not particularly limited.

The epoxy resin composite material of the present embodiment (hereinafter, also referred to as “composite material”) includes the cured product and fibers. Specifically, it is composed of an epoxy resin composition and a fiber base material, and the fiber base material is an inorganic fiber woven fabric or non-woven fabric such as glass or boron fiber woven fabric, or an organic fiber woven fabric or non-woven fabric such as polyester or aramid. And so on. Then, a reinforcing fiber base material such as a strand, a woven fabric, a mat, a knit, or a blade is placed in the mold prior to resin injection. The reinforcing fiber base material may be cut into a desired shape, laminated, and if necessary, placed directly in the mold together with other materials such as a core material. Furthermore, even if a preform in which the reinforcing fiber base material is activated in a desired shape is placed in the mold by stitching after cutting and laminating, or by applying a small amount of binding resin and heating / pressurizing. Good. Further, as the preform, a combination of a reinforcing fiber base material and a material other than the reinforcing fiber base material such as a core material can also be used.

The present invention will be described in more detail with reference to the following examples and comparative examples, but the present invention is not limited to the following examples. The evaluation methods adopted in this example and the comparative example are as follows.

<Unreacted amine and each adduct>
Analysis was performed using gas chromatography (hereinafter referred to as GC).
Column: Agilent DB-1 (length 30 m, inner diameter 0.53 mm, film thickness 1.5 μm)
Column temperature: 100 ° C / 15 minutes → (5 ° C / min) → 150 ° C → (10 ° C / min) → 280 ° C / 15 minutes

<Identification of amino compounds>
It was identified using a gas chromatograph / mass spectrum (hereinafter, GC / MS).
Column: Agilent DB-1MS (length 30 m, inner diameter 0.25 mm, film thickness 0.25 μm)
Column temperature: 100 ° C / 15 minutes → (5 ° C / min) → 150 ° C → (10 ° C / min) → 280 ° C / 15 minutes Ion source temperature: 200 ° C
Interface temperature: 250 ° C

<Appearance evaluation>
The epoxy resin composition was coated on the steel sheet to a thickness of 200 μm under the conditions of 23 ° C. and 50% RH. The appearance (gloss, transparency) of the coating film 7 days after curing was visually evaluated, and the stickiness (dryness) was evaluated by touch.
◎: Excellent ○: Good △: Slightly bad ×: Bad

<Fast curing, curing heat generation temperature>
50 g of the epoxy resin composition was placed in a 100 mL polypropylene cup, mixed for about 1 minute, and immediately the curing exotherm-time curve was measured with a platinum thermocouple. The fast curing property was evaluated by the time to the maximum heat generation temperature of this curve.

<Evaluation of mechanical properties of cured product>
The epoxy resin composition was cured under the conditions of 23 ° C. and 50% RH for 7 days, and then cured at 80 ° C. for 1 hour to prepare each test piece. Specifically, test pieces were prepared as follows.
An epoxy resin composition was poured between two aluminum plates and cured under the above conditions to prepare one plate. After that, it was processed into the shape of a test piece with a cutting machine.
Tensile strength: Compliant with JIS K7161.
Flexural modulus: Compliant with JIS K7171.

<Synthesis example 1>
(1) M-xylylenediamine (manufactured by Mitsubishi Gas Chemicals Corporation, hereinafter referred to as "MXDA") in a round-bottom flask having an internal volume of 100 mL equipped with a stirrer, a thermometer, an argon introduction tube, a dropping funnel and a cooling tube. 9.5 g and 20.0 g of 2-propanol (manufactured by Wako Pure Chemical Industries, Ltd.) were charged, and after sufficiently stirring under an argon stream, 7.4 g of acrylonitrile (manufactured by Aldrich) was added dropwise over 10 minutes. After completion of the dropping, the temperature was raised to 65 ° C., held for 1 hour, and then cooled to room temperature.
(2) A tubular vertical hydrogenation reactor (glass, inner diameter 10 mmφ) and a hydrogenation catalyst having a cobalt content of 15% by mass (three-leaf type, diameter 1.2 mmφ, manufactured by Johnson Massey Japan; HTC Co 2000). Was charged with 7.0 g and held at 120 ° C. under a hydrogen stream for 1 hour, then the temperature was raised to 240 ° C. and held for 4 hours or more to reduce and activate. After cooling, 14.8 g of 2-propanol, the above catalyst and the reaction solution of (1) were charged in an autoclave (capacity: 150 mL, material: SUS316 L) equipped with a stirrer and a heater, and the gas phase portion was replaced with hydrogen. After pressurizing to 3.5 MPaG with hydrogen, the temperature was started while stirring, the liquid temperature was adjusted to 80 ° C. in 20 minutes, and then the pressure was adjusted to 8.0 MPaG. Then, under the condition of the liquid temperature of 80 ° C., the reaction was continued for 3 hours while supplying hydrogen at any time so as to keep the pressure at 8.0 MPaG. The reaction mixture was completely concentrated under vacuum to obtain 17.2 g of concentrate A.
The viscosity of the concentrate A was 53 mPa · s / 25 ° C. The content of the diadduct having two aminopropyl groups in the molecule (amino compound represented by the following formula (i)) was 89% by mass with respect to the total amount of concentrate A. The content of one adduct having one aminopropyl group in the molecule (amino compound represented by the following formula (ii)) was 5% by mass with respect to the total amount of concentrate A.
The GC / MS identification data for each amino compound is shown below.
1 adduct; MS (SCI) [M + H] ⁺ 194
2 Adducts; MS (SCI) [M + H] ⁺ 251

<Synthesis example 2>
(1) MXDA 9.5 g, 2-propanol (manufactured by Wako Pure Chemical Industries, Ltd.) 20.0 g in a round bottom flask with an internal volume of 100 mL equipped with a stirrer, thermometer, argon introduction tube, dropping funnel and cooling tube. After charging and stirring sufficiently under an argon stream, 3.7 g of acrylonitrile (manufactured by Aldrich) was added dropwise over 5 minutes. After completion of the dropping, the mixture was held at 25 ° C. for 1 hour.
(2) A tubular vertical hydrogenation reactor (glass, inner diameter 10 mmφ) and a hydrogenation catalyst having a cobalt content of 15% by mass (three-leaf type, diameter 1.2 mmφ, manufactured by Johnson Massey Japan; HTC Co 2000). Was filled with 5.3 g and held at 120 ° C. for 1 hour under a hydrogen stream, then the temperature was raised to 240 ° C. and held for 4 hours or more to reduce and activate. After cooling, 8.6 g of 2-propanol, the catalyst and the reaction solution of (1) were charged in an autoclave (capacity: 150 mL, material: SUS316 L) equipped with a stirrer and a heater, and the gas phase portion was replaced with hydrogen. After pressurizing to 3.5 MPaG with hydrogen, the temperature was started while stirring, the liquid temperature was adjusted to 80 ° C. in 20 minutes, and then the pressure was adjusted to 8.0 MPaG. Then, under the condition of the liquid temperature of 80 ° C., the reaction was continued for 3 hours while supplying hydrogen at any time so as to keep the pressure at 8.0 MPaG. The reaction mixture was completely concentrated under vacuum to obtain 13.2 g of concentrate B.
The viscosity of the concentrate B was 37 mPa · s / 25 ° C. The content of the diadduct having two aminopropyl groups in the molecule (amino compound represented by the above formula (i)) was 27% by mass with respect to the total amount of concentrate B. The content of one adduct having one aminopropyl group in the molecule (amino compound represented by the above formula (ii)) was 50% by mass based on the total amount of concentrate B. In addition, m-xylylenediamine was contained in an amount of 18% by mass based on the total amount of concentrate B.
The GC / MS identification data for each amino compound is shown below.
MXDA; MS (SCI) [MH] ⁺ 135
1 adduct; MS (SCI) [M + H] ⁺ 194
2 Adducts; MS (SCI) [M + H] ⁺ 251

<Synthesis example 3>
(1) 14.3 g of MXDA and 28.6 g of 2-propanol (manufactured by Wako Pure Chemical Industries, Ltd.) in a round bottom flask with an internal volume of 100 mL equipped with a stirrer, a thermometer, an argon introduction tube, a dropping funnel and a cooling tube. After charging and stirring sufficiently under an argon stream, 11.1 g of acrylonitrile (manufactured by Aldrich) was added dropwise over 10 minutes. After completion of the dropping, the temperature was raised to 65 ° C., held for 1 hour, and then cooled to room temperature.
(2) In an autoclave equipped with a stirrer and a heater (capacity 150 mL, material: SUS316 L), 10.2 g of a sponge nickel catalyst (manufactured by Johnson Massey Japan; A-4000) and the reaction solution of (1) were charged in the whole amount. The phase part was replaced with hydrogen. After pressurizing to 3.5 MPaG with hydrogen, the temperature was started while stirring, the liquid temperature was adjusted to 60 ° C. in 20 minutes, and then the pressure was adjusted to 8.0 MPaG. Then, under the condition of the liquid temperature of 60 ° C., the reaction was continued for 3 hours while supplying hydrogen at any time so as to keep the pressure at 8.0 MPaG. The reaction mixture was completely concentrated under vacuum to obtain 25.4 g of concentrate C.

<Synthesis example 4>
(1) 14.3 g of MXDA and 28.6 g of 2-propanol (manufactured by Wako Pure Chemical Industries, Ltd.) in a round bottom flask with an internal volume of 100 mL equipped with a stirrer, a thermometer, an argon introduction tube, a dropping funnel and a cooling tube. After charging and stirring sufficiently under an argon stream, 5.6 g of acrylonitrile (manufactured by Aldrich) was added dropwise over 5 minutes. After completion of the dropping, the mixture was held at 25 ° C. for 1 hour.
(2) In an autoclave equipped with a stirrer and a heater (capacity 150 mL, material: SUS316 L), 8.0 g of a sponge nickel catalyst (manufactured by Johnson Massey Japan; A-4000) and the reaction solution of (1) are all charged and the mixture is charged. The phase part was replaced with hydrogen. After pressurizing to 3.5 MPaG with hydrogen, the temperature was started while stirring, the liquid temperature was adjusted to 60 ° C. in 20 minutes, and then the pressure was adjusted to 8.0 MPaG. Then, under the condition of the liquid temperature of 60 ° C., the reaction was continued for 3 hours while supplying hydrogen at any time so as to keep the pressure at 8.0 MPaG. The reaction mixture was completely concentrated under vacuum to obtain 19.9 g of concentrate D.

An epoxy resin composition was prepared by using the concentrate obtained in each synthesis example as a curing agent (each example and each comparative example).

<Example 1>
Concentrate A obtained in Synthesis Example 1 and bisphenol A type liquid epoxy resin (trade name "Epicoat 828", epoxy equivalent 186, manufactured by Mitsubishi Chemical Corporation, hereinafter "epoxy resin (Epoxycoat 828)" in a 200 mL polypropylene cup. ”) Was blended in the proportions shown in Table 1 to prepare an epoxy resin composition. The appearance, quick-curing property, maximum heat generation temperature and mechanical properties of the cured coating film of the obtained epoxy resin composition were evaluated. The evaluation results are shown in Table 1.

<Example 2>
An epoxy resin composition was prepared in the same manner as in Example 1 except that the concentrate B obtained in Synthesis Example 2 and the epoxy resin (Epicoat 828) were blended in a 200 mL polypropylene cup in the ratio shown in Table 1. did. Then, the performance was evaluated in the same manner as in Example 1. The evaluation results are shown in Table 1.

<Comparative example 1>
MXDA and an epoxy resin (Epicoat 828) were blended in a 200 mL polypropylene cup at the ratio shown in Table 1 to prepare an epoxy resin composition. Then, the performance was evaluated in the same manner as in Example 1. The evaluation results are shown in Table 1.

<Comparative example 2>
Table 1 shows an epoxy resin curing agent ( reaction product of MXDA and acrylonitrile , trade name "Gascamin 229 (G-229)", manufactured by Mitsubishi Gas Chemicals Co., Ltd.) and an epoxy resin (Epicoat 828) in a 200 mL polypropylene cup. The epoxy resin composition was prepared by blending in the ratio shown. The appearance, quick-curing property, and maximum heat generation temperature of the cured coating film of the obtained epoxy resin composition were evaluated. The evaluation results are shown in Table 1.

<Comparative example 3>
Table 1 shows an epoxy resin curing agent ( reaction product of MXDA and styrene , trade name "Gascamin 240 (G-240)", manufactured by Mitsubishi Gas Chemicals Co., Ltd.) and an epoxy resin (Epicoat 828) in a 200 mL polypropylene cup. The epoxy resin composition was prepared by blending in the ratio shown. Then, the performance was evaluated in the same manner as in Comparative Example 2. The evaluation results are shown in Table 1.

<Synthesis example 5>
(1) In a round-bottom flask with an internal volume of 100 mL equipped with a stirrer, a thermometer, an argon introduction tube, a dropping funnel and a cooling tube, 1,3-bis (aminomethyl) cyclohexane (manufactured by Mitsubishi Gas Chemicals Corporation, hereinafter " It is described as "1,3-BAC".) 10.0 g, 2-propanol (manufactured by Wako Pure Chemical Industries, Ltd.) 20.0 g was charged, and after sufficiently stirring under an argon stream, 7.5 g of acrylonitrile (manufactured by Aldrich). Was added dropwise over 10 minutes. After completion of the dropping, the temperature was raised to 65 ° C., held for 1 hour, and then cooled to room temperature.
(2) A tubular vertical hydrogenation reactor (glass, inner diameter 10 mmφ) and a hydrogenation catalyst having a cobalt content of 15% by mass (three-leaf type, diameter 1.2 mmφ, manufactured by Johnson Massey Japan; HTC Co 2000). Was charged with 7.0 g and held at 120 ° C. under a hydrogen stream for 1 hour, then the temperature was raised to 240 ° C. and held for 4 hours or more to reduce and activate. After cooling, 14.8 g of 2-propanol, the above catalyst and the reaction solution of (1) were charged in an autoclave (capacity: 150 mL, material: SUS316 L) equipped with a stirrer and a heater, and the gas phase portion was replaced with hydrogen. After pressurizing to 3.5 MPaG with hydrogen, the temperature was started while stirring, the liquid temperature was adjusted to 80 ° C. in 20 minutes, and then the pressure was adjusted to 8.0 MPaG. Then, under the condition of the liquid temperature of 80 ° C., the reaction was continued for 3 hours while supplying hydrogen at any time so as to keep the pressure at 8.0 MPaG. The reaction mixture was completely concentrated under vacuum to obtain 17.5 g of concentrate E.
The viscosity of the concentrate E was 69 mPa · s / 25 ° C. The content of the diadduct having two aminopropyl groups in the molecule (amino compound represented by the following formula (iii)) was 89% by mass with respect to the total amount of concentrate E. The content of one adduct having one aminopropyl group in the molecule (amino compound represented by the following formula (iv)) was 5% by mass based on the total amount of concentrate E.
The GC / MS identification data for each amino compound is shown below.
1 adduct (stereoisomer-1); MS (SCI) [M + H] ⁺ 200
1 adduct (stereoisomer-2); MS (SCI) [M + H] ⁺ 200
2 adduct (stereoisomer-1); MS (SCI) [M + H] ⁺ 257
2 adduct (stereoisomer-2); MS (SCI) [M + H] ⁺ 257

<Synthesis example 6>
(1) 1,3-BAC 10.0 g, 2-propanol (manufactured by Wako Pure Chemical Industries, Ltd.) in a round bottom flask with an internal volume of 100 mL equipped with a stirrer, a thermometer, an argon introduction tube, a dropping funnel and a cooling tube. After 20.0 g was charged and the mixture was sufficiently stirred under an argon stream, 3.7 g of acrylonitrile (manufactured by Aldrich) was added dropwise over 5 minutes. After completion of the dropping, the mixture was held at 25 ° C. for 1 hour.
(2) A tubular vertical hydrogenation reactor (glass, inner diameter 10 mmφ) and a hydrogenation catalyst having a cobalt content of 15% by mass (three-leaf type, diameter 1.2 mmφ, manufactured by Johnson Massey Japan; HTC Co 2000). Was charged with 5.7 g and held at 120 ° C. under a hydrogen stream for 1 hour, then the temperature was raised to 240 ° C. and held for 4 hours or more to reduce and activate. After cooling, 8.6 g of 2-propanol, the catalyst and the reaction solution of (1) were charged in an autoclave (capacity: 150 mL, material: SUS316 L) equipped with a stirrer and a heater, and the gas phase portion was replaced with hydrogen. After pressurizing to 3.5 MPaG with hydrogen, the temperature was started while stirring, the liquid temperature was adjusted to 80 ° C. in 20 minutes, and then the pressure was adjusted to 8.0 MPaG. Then, under the condition of the liquid temperature of 80 ° C., the reaction was continued for 3 hours while supplying hydrogen at any time so as to keep the pressure at 8.0 MPaG. The reaction mixture was completely concentrated under vacuum to obtain 13.7 g of concentrate F.
The viscosity of the concentrate F was 39 mPa · s / 25 ° C. The content of the diadduct having two aminopropyl groups in the molecule (amino compound represented by the above formula (iii)) was 27% by mass with respect to the total amount of the concentrate F. The content of one adduct having one aminopropyl group in the molecule (amino compound represented by the above formula (iv)) was 49% by mass based on the total amount of concentrate F. In addition, 1,3-BAC was contained in an amount of 19% by mass based on the total amount of concentrate F.
The GC / MS identification data for each amino compound is shown below.
1,3-BAC (stereoisomer-1); MS (SCI) [M + H] ⁺ 143
1,3-BAC (stereoisomer-2); MS (SCI) [M + H] ⁺ 143
1 adduct (stereoisomer-1); MS (SCI) [M + H] ⁺ 200
1 adduct (stereoisomer-2); MS (SCI) [M + H] ⁺ 200
2 adduct (stereoisomer-1); MS (SCI) [M + H] ⁺ 257
2 adduct (stereoisomer-2); MS (SCI) [M + H] ⁺ 257

<Synthesis example 7>
(1) 1,3-BAC 14.9 g, 2-propanol (manufactured by Wako Pure Chemical Industries, Ltd.) in a round-bottom flask with an internal volume of 100 mL equipped with a stirrer, a thermometer, an argon introduction tube, a dropping funnel and a cooling tube. 29.8 g was charged, and after sufficiently stirring under an argon stream, 11.1 g of acrylonitrile (manufactured by Aldrich) was added dropwise over 10 minutes. After completion of the dropping, the temperature was raised to 65 ° C., held for 1 hour, and then cooled to room temperature.
(2) In an autoclave equipped with a stirrer and a heater (capacity 150 mL, material: SUS316 L), 10.4 g of a sponge nickel catalyst (manufactured by Johnson Massey Japan; A-4000) and the reaction solution of (1) were charged in the whole amount. The phase part was replaced with hydrogen. After pressurizing to 3.5 MPaG with hydrogen, the temperature was started while stirring, the liquid temperature was adjusted to 60 ° C. in 20 minutes, and then the pressure was adjusted to 8.0 MPaG. Then, under the condition of the liquid temperature of 60 ° C., the reaction was continued for 3 hours while supplying hydrogen at any time so as to keep the pressure at 8.0 MPaG. The reaction mixture was completely concentrated under vacuum to obtain 26.0 g of concentrate G.

<Synthesis Example 8>
(1) 1,3-BAC 14.9 g, 2-propanol (manufactured by Wako Pure Chemical Industries, Ltd.) in a round-bottom flask with an internal volume of 100 mL equipped with a stirrer, a thermometer, an argon introduction tube, a dropping funnel and a cooling tube. 29.8 g was charged, and after sufficiently stirring under an argon stream, 5.6 g of acrylonitrile (manufactured by Aldrich) was added dropwise over 5 minutes. After completion of the dropping, the mixture was held at 25 ° C. for 1 hour.
(2) In an autoclave (capacity: 150 mL, material: SUS316 L) equipped with a stirrer and a heater, 8.2 g of a sponge nickel catalyst (manufactured by Johnson Massey Japan; A-4000) and the reaction solution of (1) were charged in the total amount. The phase part was replaced with hydrogen. After pressurizing to 3.5 MPaG with hydrogen, the temperature was started while stirring, the liquid temperature was adjusted to 60 ° C. in 20 minutes, and then the pressure was adjusted to 8.0 MPaG. Then, under the condition of the liquid temperature of 60 ° C., the reaction was continued for 3 hours while supplying hydrogen at any time so as to keep the pressure at 8.0 MPaG. The reaction mixture was completely concentrated under vacuum to obtain 20.5 g of concentrate H.

An epoxy resin composition was prepared by using the concentrate obtained in each synthesis example as a curing agent (each example and each comparative example).

<Example 3>
An epoxy resin composition was prepared by blending the concentrate E obtained in Synthesis Example 5 and an epoxy resin (Epicoat 828) in a ratio shown in Table 2 in a 200 mL polypropylene cup. The appearance, quick-curing property, maximum heat generation temperature and mechanical properties of the cured coating film of the obtained epoxy resin composition were evaluated. The evaluation results are shown in Table 2.

<Example 4>
An epoxy resin composition was prepared in the same manner as in Example 3 except that the concentrate F obtained in Synthesis Example 6 and the epoxy resin (Epicoat 828) were blended in a 200 mL polypropylene cup in the ratio shown in Table 2. did. Then, the performance was evaluated in the same manner as in Example 3. The evaluation results are shown in Table 2.

<Comparative example 4>
An epoxy resin composition was prepared by blending 1,3-BAC and an epoxy resin (Epicoat 828) in a ratio shown in Table 2 in a 200 mL polypropylene cup. Then, the performance was evaluated in the same manner as in Example 3. The evaluation results are shown in Table 2.

<Comparative example 5>
An epoxy resin composition was prepared by blending isophorone diamine (IPDA) and an epoxy resin (Epicoat 828) in a ratio shown in Table 2 in a 200 mL polypropylene cup. Then, the performance was evaluated in the same manner as in Example 3. The evaluation results are shown in Table 2.

<Comparative Example 6>
A 200 mL polypropylene cup was mixed with diethylenetriamine (DETA; manufactured by Wako Pure Chemical Industries, Ltd.) and an epoxy resin (Epicoat 828) in the proportions shown in Table 2 to prepare an epoxy resin composition. Then, the performance was evaluated in the same manner as in Example 3. The evaluation results are shown in Table 2.

<Comparative Example 7>
Triethylenetetramine (TETA; manufactured by Tokyo Chemical Industry Co., Ltd.) and an epoxy resin (Epicoat 828) were blended in a 200 mL polypropylene cup at the ratio shown in Table 2 to prepare an epoxy resin composition. Then, the performance was evaluated in the same manner as in Example 3. The evaluation results are shown in Table 2.

From the above, it was confirmed at least that the heat generation temperature at the time of curing could be suppressed and the curing rate was high by using the epoxy resin curing agent of each example. Furthermore, it was confirmed that the physical properties of the cured product obtained by this were also excellent.

This application is based on a Japanese patent application filed on March 31, 2015 (Japanese Patent Application No. 2015-0735333 and Japanese Patent Application No. 2015-073541), the contents of which are incorporated herein by reference.

The epoxy resin curing agent of the present invention can rapidly cure a large-sized or thick-walled molded product at a relatively low temperature without excessive heat generation. Further, since the obtained epoxy resin cured product also has high mechanical properties and coating film performance, it is useful as a thermosetting resin cured product and has high industrial value.

Claims (9)

An epoxy resin curing agent containing an amino compound represented by the following formula (1) .

_{^{R 1 HN-H 2 C-}} A-CH 2 -NHR 2 (1)

(In the formula (1), A is an o-phenylene group, an m-phenylene group, a p-phenylene group, a 1,2-cyclohexylene group, a 1,3-cyclohexylene group or a 1,4-cyclohexylene group. , R ¹ and R ² are hydrogen atoms or aminopropyl groups. R ¹ and R ² may be the same or different, but ^{at least one of R 1} and R ² is an aminopropyl group.)
An ^{adduct (1 adduct) in which any one of} R 1 and R ² is an aminopropyl group and the remaining one is a hydrogen atom,
Both R ¹ and R ² contain an adduct (2 adduct) in which an aminopropyl group is used.
An epoxy resin curing agent in which the total content of the 1 adduct and the 2 adducts in the epoxy resin curing agent is 60 to 100% by mass. The epoxy resin curing agent according to claim 1, wherein A is an o-phenylene group, an m-phenylene group or a p-phenylene group. The epoxy resin curing agent according to claim 1, wherein A is a 1,2-cyclohexylene group, a 1,3-cyclohexylene group or a 1,4-cyclohexylene group. Epoxy resin and
The epoxy resin curing agent according to any one of claims 1 to 3 and
Epoxy resin composition containing. A coating material containing the epoxy resin composition according to claim 4. A member for civil engineering and construction containing the epoxy resin composition according to claim 4. A cured product obtained by curing the epoxy resin composition according to claim 4. The cured product according to claim 7 and
With fiber
Composite material including. o-Xylylenediamine, p-xylylenediamine, m-xylylenediamine, 1,2-bis (aminomethyl) cyclohexane, 1,3-bis (aminomethyl) cyclohexane and 1,4-bis (aminomethyl) cyclohexane A step of adding acrylonitrile to at least one selected from the group consisting of cyano compound to obtain a cyano compound.
The step of obtaining the amino compound represented by the formula (1) by hydrogenating the cyano compound, and
The method for producing an epoxy resin curing agent according to any one of claims 1 to 3, which comprises the amino compound.

_{^{R 1 HN-H 2 C-}} A-CH 2 -NHR 2 (1)

(In the formula (1), A is an o-phenylene group, an m-phenylene group, a p-phenylene group, a 1,2-cyclohexylene group, a 1,3-cyclohexylene group or a 1,4-cyclohexylene group. , R ¹ and R ² are hydrogen atoms or aminopropyl groups. R ¹ and R ² may be the same or different, but ^{at least one of R 1} and R ² is an aminopropyl group.)