JP7224238B2 - cross-linking agent - Google Patents

Description

The present invention relates to crosslinkers. More particularly, it relates to a cross-linking agent that imparts long-lasting antibacterial properties to curable resins.

In recent years, antibacterial and antiviral coating films have been applied to a wide variety of products as the concept of hygiene in the living environment and the awareness of aesthetics have improved. Generally, as a method for imparting antibacterial and antiviral properties to a coating film, a method of forming a coating film using a coating material to which a quaternary ammonium salt is added in an amount as an active ingredient is known. A method of kneading a quaternary ammonium salt into a resin is also known for imparting antibacterial properties to plastics. However, coating films and plastics obtained by adding these quaternary ammonium salts have the problem that the quaternary ammonium salts are gradually eluted, making it difficult to maintain antibacterial and antiviral properties.

As a method to solve this problem, by adding a polycarboxylic acid to the paint together with the quaternary ammonium salt, the quaternary ammonium salt is suppressed from eluting from the coating film, forming an antibacterial and antiviral coating film. A method has been reported (Patent Document 1). However, this method does not completely immobilize the quaternary ammonium structure in the coating film, and is not sufficient as a technique for sustaining antibacterial and antiviral properties.

On the other hand, as a cross-linking agent having a quaternary ammonium structure, it is known to use a reaction product of a secondary amine compound and epihalohydrin as a water-absorbing resin cross-linking agent (Patent Document 2). However, as a result of studies by the inventors, it was found that when used as a cross-linking agent for a resin composition, the quaternary ammonium compound easily aggregates with the curable resin and is not suitable for applications such as coating agents. Moreover, the antibacterial properties of the water-absorbing resin cross-linking agent have not been studied.

JP 2015-67658 A JP-A-2002-60544

An object of the present invention is to provide a cross-linking agent capable of producing a cured product having excellent adhesion to a substrate and having sustained antibacterial properties.

The present inventors have found that a cross-linking agent having a specific structure does not cause aggregation with a curable resin, has excellent coating liquid stability, has excellent adhesion to the substrate, and has antibacterial properties of the resulting cured product. continued, and completed the cross-linking agent of the present invention.

（一般式（１）中、Ａは（ｍ＋ｎ＋２）価の炭素数１～６の多価アルコール残基を表し、Ｂは下記一般式（２）：

又は一般式（３）：

で表される置換基を表し、Ｒ^１は炭素数１～６の炭化水素基を表し、Ｒ^２は水素原子又は炭素数１～４の炭化水素基を表し、Ｘは４級アンモニウム基の対イオンであって塩化物イオン、臭化物イオン、硫酸イオン、硝酸イオン、リン酸イオン、又は水酸化物イオンを表し、ｍ、ｎはそれぞれ独立して０～４の整数を表し、同じ置換基Ａに結合しているｍ、ｎは０≦ｍ＋ｎ≦４を満たし、ｌは１～６であり、ｋは１以上の整数である。）
で表される化合物を含む架橋剤に関する。 That is, the present invention provides the following general formula (1):

(In the general formula (1), A represents a (m + n + 2) valent polyhydric alcohol residue having 1 to 6 carbon atoms, and B is the following general formula (2):

or general formula (3):

represents a substituent represented by R ¹ represents a hydrocarbon group having 1 to 6 carbon atoms, R ² represents a hydrogen atom or a hydrocarbon group having 1 to 4 carbon atoms, and X represents a pair of quaternary ammonium groups represents a chloride ion, a bromide ion, a sulfate ion, a nitrate ion, a phosphate ion, or a hydroxide ion; m and n each independently represent an integer of 0 to 4; Bonded m and n satisfy 0≦m+n≦4, l is 1 to 6, and k is an integer of 1 or more. )
It relates to a cross-linking agent containing a compound represented by.

Preferably, R ¹ is a methyl group.

Preferably, m and n satisfy 0≦m+n≦1.

The present invention also relates to a curable resin composition containing a curable resin and the cross-linking agent.

Further, the present invention provides the following steps 1 to 3:
(Step 1) General formula (4) below:
A-(OH) _m+2 (4)
(In the general formula (4), A represents a (m + n + 2)-valent polyhydric alcohol residue having 1 to 6 carbon atoms, m and n represent integers of 0 to 4, and satisfy 0 ≤ m + n ≤ 4.) a step of reacting an (m+n+2)-valent polyhydric alcohol represented by with epihalohydrin,
(Step 2) the reactant obtained in Step 1 and the following general formula (5):
^R12NH ₍ 5)
(In the general formula (5), R ¹ represents a hydrocarbon group having 1 to 6 carbon atoms.) A step of reacting with a secondary amine represented by;
(Step 3) The cross-linking agent, which comprises a step of converting the halogen atom in the reaction product obtained in Step 2 to a —OR ² group (R ² represents a hydrogen atom or a hydrocarbon group having 1 to 4 carbon atoms). related to the manufacturing method of

The cross-linking agent of the present invention imparts sustained antibacterial properties to the cured product of the curable resin. In addition, this cross-linking agent does not aggregate together with the curable resin, is excellent in coating liquid stability, and is excellent in adhesion to a substrate when used as a coating agent.

で表される化合物を含む架橋剤に関する。 (1) Crosslinking agent The present invention uses the following general formula (1):

It relates to a cross-linking agent containing a compound represented by.

In the general formula (1), A represents a (m+n+2)-valent polyhydric alcohol residue having 1 to 6 carbon atoms. m and n each independently represent an integer of 0 to 4, m and n bonded to the same substituent A satisfy 0 ≤ m + n ≤ 4, m + n is preferably 0 to 2, more preferably 0 to 1 preferable. Specific examples of the polyhydric alcohol in the polyhydric alcohol residue will be described later.

In general formula (1), R ¹ represents a hydrocarbon group having 1 to 6 carbon atoms, preferably 1 to 3 carbon atoms. Specific examples thereof include a methyl group, an ethyl group, a propyl group and an isopropyl group, preferably a methyl group and an ethyl group.

In general formula (1), R ² represents a hydrogen atom or a hydrocarbon group having 1 to 4 carbon atoms. Specific examples thereof include hydrogen atom, methyl group, ethyl group, propyl group, isopropyl group, n-butyl group, sec-butyl group, isobutyl group and tert-butyl group, and hydrogen atom, methyl group and ethyl group. is preferred.

In the general formula (1), X is a counter ion for the quaternary ammonium group and represents chloride ion, bromide ion, sulfate ion, nitrate ion, phosphate ion, or hydroxide ion. Further, l is 1 to 6 in the general formula (1). k represents the number of counter ions for the quaternary ammonium group and is an integer of 1 or more. The number of quaternary ammonium groups in the cross-linking agent is the same as k.

又は下記一般式（３）：

で表される置換基を表す。
一般式（２）及び一般式（３）において、Ｒ^１、Ｒ^２、Ａ、ｍ、ｎは一般式（１）について述べたのと同様である。一般式（２）及び一般式（３）の構造は、一般式（１）の化合物１分子中にそれぞれ２以上存在していてもよい。 In general formula (1), B is a hydroxyl group or the following general formula (2):

Or the following general formula (3):

Represents a substituent represented by
In general formulas (2) and (3), R ¹ , R ² , A, m and n are the same as described for general formula (1). Two or more structures of general formula (2) and general formula (3) may exist in one molecule of the compound of general formula (1).

(2) Method for producing a cross-linking agent The above-mentioned cross-linking agent has the following general formula (4):
A-(OH) _m+n+2 (4)
Step 1 of reacting an (m+n+2)-valent polyhydric alcohol represented by with epihalohydrin,
The reactant obtained in the step 1, and the following general formula (5):
^R12NH ₍ 5)
and a step 3 of converting the halogen atom in the reactant obtained in the step 2 to an —OR ² group.

In the general formula (4), A represents a (m + n + 2)-valent polyhydric alcohol residue having 1 to 6 carbon atoms, m and n each independently represent an integer of 0 to 4, and are bound to the same substituent A m and n satisfy 0≦m+n≦4. m+n is preferably 0 to 2, more preferably 0 to 1. Polyhydric alcohols in the polyhydric alcohol residue include ethylene glycol, diethylene glycol, propylene glycol, triethylene glycol, 1,3-propanediol, dipropylene glycol, glycerin, diglycerin, 2-butene-1,4-diol, 1,3-butanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,2-cyclohexanedimethanol, 1,2-cyclohexanediol, trimethylolpropane, diethanolamine, tri Mention may be made of ethanolamine, pentaerythritol, sorbitol. Among them, ethylene glycol, diethylene glycol, glycerin, diglycerin and the like are preferable. These may be used alone or in combination of two or more.

Specific examples of the secondary amine represented by the general formula (5) include dimethylamine, diethylamine, methylethylamine, dipropylamine, and diisopropylamine. Among them, dimethylamine and diethylamine are preferred, and dimethylamine is more preferred. These may be used alone or in combination of two or more.

Specific examples of epihalohydrin include epichlorohydrin, epibromohydrin, α-methylepichlorohydrin. Among them, epichlorohydrin is preferable because it is easily available. These may be used alone or in combination of two or more.

In step 1, it is preferable to react 0.2 to 2 equivalents, more preferably 0.3 to 1.5 equivalents, of epihalohydrin with respect to 1 equivalent of hydroxyl groups of the polyhydric alcohol. If the amount is less than 0.2 equivalents, the number of halohydrin groups in the resulting halohydrin compound is small, so the amount of quaternary ammonium structures in the cross-linking agent obtained in the subsequent steps is small, and there is a possibility that sufficient antibacterial properties cannot be exhibited. , unreacted epihalohydrin may remain in the obtained halohydrin compound, which is not preferable from the viewpoint of safety.

In step 1, a catalyst can be used for the reaction of polyhydric alcohol and epihalohydrin. Such catalysts include boron trifluoride diethyl ether complex, boron trifluoride butyl ethyl ether complex, boron trifluoride methanol complex, boron trifluoride ethylamine complex, boron trifluoride piperidine complex, zinc fluoroborate, Lewis acid catalysts such as copper chloride, tin dichloride, tin tetrachloride and aluminum chloride can be mentioned. The reaction temperature of polyhydric alcohol and epihalohydrin is preferably 30 to 200°C, more preferably 50 to 100°C.

（一般式（６）中、Ａは（ｍ＋ｎ＋２）価の炭素数１～６の多価アルコール残基を表し、Ｂは下記一般式（７）：

又は下記一般式（８）

で表される置換基を表し、Ｒ^１は炭素数１～６の炭化水素基を表し、Ｘは４級アンモニウム基の対イオンであって塩化物イオン、臭化物イオン、又は水酸化物イオンを表し、ｍ、ｎはそれぞれ独立して０～４の整数を表し、同じ置換基Ａに結合しているｍ、ｎは０≦ｍ＋ｎ≦４を満たし、ｌは１～６であり、ｋは１以上の整数である。）
で表される化合物が得られる。 The reaction mechanism in steps 1 and 2 will be explained using an example using epichlorohydrin as the epihalohydrin. In step 1, a chlorohydrin ether compound having two or more chlorohydrin groups is obtained by reacting the hydroxyl group of the polyhydric alcohol represented by the general formula (4) with epichlorohydrin. Here, when a secondary amine represented by general formula (5) is added in step 2, the amine reacts with the chlorohydrin group to form general formula (6):

(In the general formula (6), A represents a (m + n + 2)-valent polyhydric alcohol residue having 1 to 6 carbon atoms, and B is the following general formula (7):

or the following general formula (8)

represents a substituent represented by R ¹ represents a hydrocarbon group having 1 to 6 carbon atoms, X represents a counter ion of a quaternary ammonium group and represents a chloride ion, a bromide ion, or a hydroxide ion , m and n each independently represents an integer of 0 to 4, m and n bonded to the same substituent A satisfy 0≦m+n≦4, l is 1 to 6, and k is 1 or more. is an integer of )
A compound represented by is obtained.

In step 2, 0.05 to 1 equivalent of the secondary amine represented by the general formula (5) is reacted with 1 equivalent of the halohydrin group of the halohydrin ether compound, preferably 0.1 to 0. It is more preferable to react 0.5 equivalents. If the amount is less than 0.05 equivalent, there is a possibility that sufficient antimicrobial properties cannot be exhibited due to the small number of quaternary ammonium structures in the resulting cross-linking agent, and if the amount exceeds 1 equivalent, unreacted secondary amine may remain. This is not preferable from a safety point of view.

In step 2, the halohydrin group remains at the terminal in the compound of general formula (6) obtained. Step 3 converts the halogen atom of this halohydrin group to an ^OR2 group. Examples of the method for converting a halogen atom to an OR ² group include a method of hydrolyzing a halogen atom, a method of converting to an epoxy compound and then hydrolyzing it in an alcohol solvent, and a method of converting a halogen atom to another leaving group. A post-hydrolysis method may be mentioned. Halogen atoms are usually converted to hydroxyl groups in step 3, in which case ^R2 becomes a hydrogen atom. On the other hand, part or all of the halogen atoms may be converted to alkoxy groups by reacting with an alcohol solvent, in which case R ² will be a hydrocarbon group having 1 to 4 carbon atoms. For example, when step 3 is performed using methanol as a solvent, the halogen atom is converted to a hydroxyl group or a methoxy group, and ^R2 becomes a hydrogen atom or a methyl group.

After step 3, sulfuric acid, nitric acid or phosphoric acid may be added to adjust the pH of the aqueous solution. The sulfate ions, nitrate ions, and phosphate ions added in these steps serve as counter ions for the quaternary ammonium groups in the cross-linking agent of the present invention, and are represented by X in the compound of general formula (1). Other counter ions for the quaternary ammonium group include chloride ion, bromide ion and hydroxide ion derived from epihalohydrin added in step 1.

(3) Curable resin composition The present invention also relates to a curable resin composition containing a curable resin and the cross-linking agent.

The curable resin refers to a compound that is cured by a crosslinking reaction with the above-mentioned crosslinking agent due to heat (including room temperature), catalyst, light (ultraviolet rays, etc.), electron beams, etc., and has a carboxylic acid group in the molecule, It preferably has at least one or more functional groups selected from carboxylic acid groups, hydroxyl groups, epoxy groups, isocyanate groups, and amino groups. Specific examples include melamine resins, acrylic resins, epoxy resins, polyester resins, and polyurethane resins. Among these, melamine resins and epoxy resins are preferable from the viewpoint of excellent curability.

The content of the cross-linking agent in the curable resin composition is preferably 0.1 to 70% by weight, more preferably 5 to 55% by weight. The amount of the cross-linking agent is preferably 10 to 1000 parts by weight, more preferably 20 to 1000 parts by weight, with respect to 100 parts by weight of the curable resin. If it is less than 10 parts by weight, the antibacterial properties of the coating film may be insufficient, and if it exceeds 1000 parts by weight, the drying property tends to be insufficient.

The curable resin composition contains epoxy compounds, halohydrin compounds, amine compounds, aziridine compounds, isocyanate compounds, oxazoline compounds, etc., in addition to the cross-linking agent represented by the general formula (1), as long as the effects of the present invention are not impaired. may contain a cross-linking agent capable of reacting with the curable resin.

The curable resin composition may contain commonly used surfactants, solvents, antioxidants, catalysts, antifoaming agents, rheology control agents, adhesion imparting agents, thickeners, neutralizers, etc. .

The surfactant has a leveling function by adjusting the surface, and is not particularly limited. Siloxane compounds such as acrylic group-containing polydimethylsiloxane, polyester-modified acrylic group-containing polydimethylsiloxane, perfluoropolydimethylsiloxane, perfluoropolyether-modified polydimethylsiloxane, perfluoropolyester-modified polydimethylsiloxane; perfluoroalkylcarboxylic acid, etc. Polyether compounds such as polyoxyalkylene alkyl ethers and polyoxyethylene alkylphenyl ethers; Carboxylic acids such as coconut oil fatty acid amine salts; Phosphate esters, alkyl ether sulfates, sorbitan fatty acid esters, sulfonate esters , ester compounds such as succinic acid esters; sulfonate compounds such as alkylarylsulfonic acid amine salts and dioctyl sodium sulfosuccinate; phosphate compounds such as sodium lauryl phosphate; amide compounds such as coconut oil fatty acid ethanolamide; and the like. These surfactants may be used alone or in combination of two or more.

The content of the surfactant is preferably 0.001 to 10 parts by weight, more preferably 0.01 to 5 parts by weight, per 100 parts by weight of the curable resin. If it is less than 0.001 part by weight, the leveling property may be insufficient, and if it exceeds 10 parts by weight, the adhesion of the coating film may be insufficient.

As the solvent, either a water-based solvent or an organic solvent-based solvent can be suitably used. , acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone and other ketone solvents, methanol, ethanol, isopropanol, ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol and other alcohol solvents, methyl cellosolve, ethyl cellosolve, butyl cellosolve, methyl diglycol , ethyl diglycol, butyl diglycol, propylene glycol monomethyl ether, and other glycol ether solvents; ethyl acetate, butyl acetate, propylene glycol monomethyl ether acetate, and other ester solvents; and water. Moreover, Solvesso 100, Solvesso 150, Solvesso 200, etc. are mentioned as a commercial item which can be used as an aromatic-hydrocarbon-type solvent. These solvents may be used alone or in combination of two or more.

The content of the solvent is preferably 10 to 1,000 parts by weight, more preferably 20 to 400 parts by weight, based on 100 parts by weight of the curable resin, although it depends on the type of resin, the coating method, and the thickness of the cured coating film. . If the amount is less than 10 parts by weight, the viscosity may be high and uniform coating may not be possible.

The solid content concentration of the curable resin composition is not particularly limited, but is preferably 10 to 80% by weight, more preferably 15 to 50% by weight. If it exceeds 80% by weight, the viscosity may be high and uniform coating may not be possible.

(4) Applications of the curable resin composition The curable resin composition can be used for applications such as coating agents and paints.

When the curable resin composition is used as a coating agent or paint, the method for forming a coating film on the substrate is to apply the curable resin composition to at least one surface of the substrate, and then cure by heating. and the like.

The base material is not particularly limited to synthetic resins, metals, glass, etc. Examples include polyesters such as polyethylene terephthalate and polyethylene naphthalate, polyolefins such as polyethylene, polypropylene and polymethylpentene, polyamides such as nylon 6 and nylon 66, and polycarbonates. , polyvinyl acetate, polyimide, ABS resin, steel, aluminum, glass, and the like.

The method of applying the curable resin composition onto the substrate is not particularly limited, and examples thereof include bar coating, spin coating, spray coating, dip coating, nozzle coating, gravure coating, and reverse roll coating. method, die coating method, air doctor coating method, blade coating method, rod coating method, curtain coating method, knife coating method, transfer roll coating method, squeeze coating method, impregnation coating method, kiss coating method, calendar coating method, extrusion coating method, etc. is mentioned.

After coating the curable resin composition on the substrate, the heating temperature is preferably 60 to 250°C, more preferably 60 to 200°C. If the heating temperature is less than 60°C, curing may be poor, and if it exceeds 250°C, the shape of the base material may be impaired depending on the material of the resin base material. Also, the heating time is preferably 5 to 300 seconds, more preferably 20 to 120 seconds. If the heating time is less than 5 seconds, the curing may be poor, and if it exceeds 300 seconds, depending on the material of the resin substrate, the shape of the substrate may be impaired, and the time required for the process will be long. Therefore, it is not preferable from the viewpoint of productivity.

Although the thickness of the coating film after curing is not particularly limited, it is preferably 0.1 to 30 μm, more preferably 0.3 to 20 μm. If the thickness is less than 0.1 μm, the smoothness of the coating film may be insufficient, and if it exceeds 30 μm, the internal stress may increase, resulting in insufficient adhesion.

(Example 1) Preparation of a cross-linking agent 200 g (2.2 mol) of glycerin and 0.3 g of boron trifluoride etherate as a catalyst were placed in a 1000 mL separable flask, heated and stirred, and 442 g of epichlorohydrin ( 4.8 mol) was added dropwise and stirred. Further, 69 g (0.8 mol) of 50% aqueous solution of dimethylamine was added and stirred. After that, 62 g of 48.5% liquid caustic soda was added dropwise, followed by aging for 12 hours. After dissolving the obtained reactant in methanol, filtration was performed, and 168 g of 48.5% liquid caustic soda was added to the filtrate, stirred, and filtered. After the methanol in the filtrate was distilled off, distilled water was added to dissolve the concentration residue, 20 g of 98% sulfuric acid was added, and the mixture was stirred for 12 hours.

In the general formula (1), A is a glycerin residue, B is a substituent represented by the general formula (2) or general formula (3), R ¹ is a methyl group, R ² is a hydrogen atom or a methyl group, X is a counter ion of a quaternary ammonium group and represents a chloride ion, a sulfate ion, or a hydroxide ion, respectively, m and n are each 0 or 1, and m+n is 1; A cross-linking agent of the present invention in which l is 1-4 was obtained.

(Example 2 and Comparative Example 1) Preparation of coating composition The melamine resin, the cross-linking agent synthesized in Example 1 or the comparative cross-linking agent containing no alcohol skeleton, the surfactant, and the solvent were used in the weight ratios shown in Table 1 below. After mixing, the coating compositions of Example 2 and Comparative Example 1 were obtained.
In addition, the following were used as each component.
Melamine resin: Cymel 327 (imino group type methylated melamine resin, manufactured by Daicel Allnex Co., Ltd.)
Comparative cross-linking agent: Wistex H90 (dimethylamine/epichlorohydrin polycondensate, manufactured by Nagase ChemteX Corporation)
Solvent: Solmix AP-7 (alcohol solvent, manufactured by Japan Alcohol Sales Co., Ltd.)
Surfactant: Softanol 90 (polyoxyethylene alkyl ether, manufactured by Nippon Shokubai Co., Ltd.)

(Measurement example) Preparation of test pieces and evaluation of physical properties The coating compositions of Example 2 and Comparative Example 1 were applied onto a substrate using a bar coater (No. 2). A polyester (PET) film (E5100 (film thickness: 50 μm) manufactured by Toyobo Co., Ltd.) was used as the base material. The coated substrate was placed in a hot air dryer at 170° C. and dried for 1 minute. After drying, the substrate was allowed to stand still at room temperature, and the substrate was cooled to room temperature to obtain a test piece. In addition, the antibacterial properties of the base material itself to which no coating composition was applied were evaluated (Comparative Example 2). Using the obtained test piece, physical properties were evaluated by the method described later. Table 1 shows the results.

<Method for evaluating physical properties of cured coating>
1. After stirring the coating composition with a stirrer and allowing it to stand still for 1 minute, the appearance was checked and evaluated in two stages according to the following criteria.
○: No precipitation ×: Precipitation

2. Adhesion was confirmed by a cross-cut test (former JIS K5400) using a test piece immediately after adhesion, and evaluated in two stages according to the following criteria.
○: No peeling (100/100)
×: with peeling

3. An antibacterial test (JIS Z 2801) was performed using a test piece immediately after antibacterial property preparation. Escherichia coli was used as the test target bacterium. It was evaluated in two stages according to the following criteria.
○: Antibacterial activity value of 2.0 or more ×: Antibacterial activity value of less than 2.0

The coating composition of Example 2 obtained using the cross-linking agent of Example 1 has excellent coating liquid stability, the coating film has excellent adhesion to the substrate, and has sufficient antibacterial properties. rice field.

The coating composition of Comparative Example 1, which was obtained using a comparative cross-linking agent according to the prior art, caused sedimentation and had poor coating liquid stability. It is presumed that this is because the cross-linking agent does not contain a polyhydric alcohol skeleton and therefore easily aggregates with the curable resin. Since the coating composition of Comparative Example 1 precipitated, a good coating film could not be formed, and the adhesion of the coating film to the substrate and the antibacterial properties could not be measured. The substrate of Comparative Example 2, to which no coating composition was applied, had no antimicrobial properties.

Claims (5)

The following general formula (1):

(In the general formula (1), A represents a (m + n + 2) valent polyhydric alcohol residue having 1 to 6 carbon atoms,
B is the following general formula (2):

Or the following general formula (3):

represents a substituent represented by
R ¹ represents a hydrocarbon group having 1 to 6 carbon atoms,
R ² represents a hydrogen atom or a hydrocarbon group having 1 to 4 carbon atoms,
X is a counter ion of the quaternary ammonium group and represents a chloride ion, bromide ion, sulfate ion, nitrate ion, phosphate ion, or hydroxide ion;
m and n each independently represent an integer of 0 to 4, m and n bonded to the same substituent A satisfy 0 ≤ m + n ≤ 4,
l is 1 to 6,
k is an integer of 1 or more. )
A cross-linking agent containing a compound represented by The cross-linking agent according to claim ¹ , wherein said R1 is a methyl group. 3. The cross-linking agent according to claim 1, wherein m and n satisfy 0≦m+n≦1. A curable resin composition comprising a curable resin and the cross-linking agent according to any one of claims 1 to 3. Steps 1-3 below:
(Step 1) General formula (4) below:
A-(OH) _m+n+2 (4)
(In the general formula (4), A represents a (m + n + 2) valent polyhydric alcohol residue having 1 to 6 carbon atoms, m and n each independently represents an integer of 0 to 4, 0 ≤ m + n ≤ 4 satisfy.)
a step of reacting an (m+n+2)-valent polyhydric alcohol represented by with epihalohydrin,
(Step 2) the reactant obtained in Step 1 and the following general formula (5):
^R12NH ₍ 5)
(In general formula (5), R ¹ represents a hydrocarbon group having 1 to 6 carbon atoms.)
A step of reacting with a secondary amine represented by, and
Claim 1, comprising a step of (step 3) converting a halogen atom in the reactant obtained in step 2 to a —OR ² group (R ² represents a hydrogen atom or a hydrocarbon group having 1 to 4 carbon atoms). 4. A method for producing the cross-linking agent according to any one of items 1 to 3.