JP2022157698A - Vinyl-modified epoxy resin composition, and aqueous coating - Google Patents

Abstract

To provide a vinyl-modified epoxy resin composition that gives an aqueous coating being well dispersible in water and having excellent dryability.SOLUTION: A vinyl-modified epoxy resin composition contains a polymer having the following (A) and (B) as essential reaction components: (A) a modified epoxy resin that is a reaction product comprising an epoxy resin containing a bisphenol-type epoxy resin (a1), an amine (a2) and a glycidyl group-containing vinyl monomer (a3); and (B) a monomer component containing a methacrylamide (b1).SELECTED DRAWING: None

Description

The present invention relates to a vinyl-modified epoxy resin composition and an aqueous coating agent.

Conventionally, coating films obtained by water-based coating agents have inferior rust-preventing properties to solvent-based coating agents. A vinyl-modified epoxy ester obtained by polymerizing a solid is known (Patent Document 1). Since the vinyl-modified epoxy ester uses an epoxy resin as a raw material, it has relatively good rust resistance, and can be expected to cure at room temperature due to the fatty acid component. It has the characteristic that it is possible.

However, as the application fields of water-based coating agents expand, the required performance of water-based coating agents increases, and there is a demand for improved levels of rust prevention and water resistance, and high initial hardness of the coating film. Such requirements cannot be satisfied with esters and the like. For example, the hardness of the coating film increases with the oxidative polymerization of the fatty acid component in the resin, but it takes a long time to dry, and even if the coating film is obtained, the hardness does not reach the target value. Since several days are required for the coating film formation, damage at the initial stage of coating film formation tends to be a problem, and the phenomenon that the coating film prepared from the resin whitens when immersed in water (hereinafter referred to as water whitening) has also been a problem. Such resistance to water whitening can be improved by increasing the ratio of the fatty acid component in the vinyl-modified epoxy ester, but there is a problem that the hardness of the coating film is further reduced.

Therefore, the present applicant has developed an aromatic epoxy resin composition as a vinyl-modified epoxy resin composition that can be dried in a short time (has excellent drying properties), gives a coating film with high hardness, and is less likely to be whitened by water. A vinyl-modified epoxy resin water-based product was proposed in which a resin and an aliphatic epoxy resin are used in combination (Patent Document 2). However, the vinyl-modified epoxy resin water-based product is difficult to disperse in water when preparing an aqueous coating agent, and has poor drying properties.

JP-A-11-269249 JP-A-2005-120340

SUMMARY OF THE INVENTION An object of the present invention is to provide a vinyl-modified epoxy resin composition that disperses well in water and provides an aqueous coating agent that is excellent in drying properties.

As a result of intensive studies, the present inventors have found that a vinyl-modified epoxy resin composition copolymerized with a vinyl monomer having a specific functional group solves the above problems, and have completed the present invention. That is, the present invention relates to the following vinyl-modified epoxy resin composition and aqueous coating agent.

1. A vinyl-modified epoxy resin composition containing a polymer having the following (A) and (B) as essential reaction components.
(A) a modified epoxy resin (B) (meth)acrylamides (b1) which is a reaction product of an epoxy resin (a1) containing a bisphenol type epoxy resin, an amine (a2) and a glycidyl group-containing vinyl monomer (a3); monomer component containing

2. 2. The vinyl-modified epoxy resin composition according to the preceding item 1, wherein the component (a2) contains an alkanolamine.

3. 1 or 2 above, wherein the component (b1) is at least one selected from the group consisting of N,N-dialkyl(meth)acrylamides, N,N-dialkylaminoalkyl(meth)acrylamides, and diacetone(meth)acrylamides; A vinyl-modified epoxy resin composition as described.

4. 4. The vinyl-modified epoxy resin composition according to any one of the preceding items 1 to 3, wherein the amount of component (b1) used is 0.4 to 30 parts by weight in terms of non-volatile content per 100 parts by weight of component (A). .

5. 5. The vinyl-modified epoxy resin composition according to any one of the preceding items 1 to 4, wherein the component (B) further contains a carboxyl group-containing vinyl monomer and/or its ester (b2).

6. 6. The vinyl-modified epoxy resin composition according to item 5, wherein the ratio of component (b1) and component (b2) used is (b1)/(b2)=0.01 to 30 in terms of weight of non-volatile matter.

7. An aqueous coating agent comprising the vinyl-modified epoxy resin composition according to any one of 1 to 6 above.

According to the vinyl-modified epoxy resin composition of the present invention, when preparing an aqueous coating agent, it disperses well in water and has excellent drying properties. In addition, a coating film prepared using the water-based coating agent has excellent primary adhesion, water whitening resistance, and water resistance adhesiveness.

The vinyl-modified epoxy resin composition of the present invention comprises (A) a specific modified epoxy resin (hereinafter referred to as component (A)) and (B) a specific monomer component (hereinafter referred to as component (B)). It contains a polymer. Each component will be described in detail below.

[About component (A)]
The component (A) includes an epoxy resin (a1) containing a bisphenol-type epoxy resin (hereinafter referred to as component (a1)), amines (a2) (hereinafter referred to as component (a2)), and a glycidyl group-containing vinyl monomer (a3). (hereinafter referred to as component (a3)).

The bisphenol-type epoxy resin is not particularly limited, and examples thereof include reaction products of bisphenols and haloepoxides such as epichlorohydrin or 2-methylepichlorohydrin.

Bisphenols are not particularly limited, and reaction products of phenol or 2,6-dihalophenol (hereinafter referred to as phenols) and aldehydes (e.g., formaldehyde, acetaldehyde, etc.); phenols and ketones (e.g., acetone , acetophenone, cyclohexanone, benzophenone, etc.); oxidation reaction product of dihydroxyphenyl sulfide with peracid; etherification reaction product between hydroquinones; hydroxyphenyl)propane (bisphenol Α), bis(4-hydroxyphenyl)methane (bisphenol F) and the like. These may be used alone or in combination of two or more. Among them, 2,2-bis(4-hydroxyphenyl)propane (bisphenol A) is preferable from the viewpoint of excellent coating film hardness and rust resistance.

The component (a1) may contain an epoxy resin other than the bisphenol type epoxy resin (hereinafter also referred to as other epoxy resin). By using other epoxy resins, the glass transition temperature and weight-average molecular weight of the vinyl-modified epoxy resin composition can be adjusted, and the coating film tends to be excellent in rust prevention and water-resistant adhesion. Specific examples of other epoxy resins are not particularly limited, and include aliphatic epoxy resins, aromatic epoxy resins, and the like. These may be used alone or in combination of two or more.

The aliphatic epoxy resin is not particularly limited, and examples thereof include resins containing glycidyl esters of aliphatic dibasic acids, glycidyl ethers of aliphatic polyols, glycidyl ethers of polyether polyols, and the like.

The aliphatic dibasic acid is not particularly limited, and examples thereof include sebacic acid, azelaic acid, dodecanoic acid, malonic acid, succinic acid, glutaric acid, adipic acid, 8,11-dimethyl-7,11-octadecadien- 1,18-dicarboxylic acid, 7-ethyloctadecanedicarboxylic acid, 1,4-cyclohexanedicarboxylic acid and the like.

Aliphatic polyols are not particularly limited, and examples include 1,4-butanediol, 1,6-hexanediol, 1,7-heptanediol, 1,8-octanediol, 1,9-nonanediol, 1, and 10-decanediol.

Polyether polyols are not particularly limited, and examples include diethylene glycol, triethylene glycol, tetraethylene glycol, pentaethylene glycol, hexaethylene glycol, heptaethylene glycol, octaethylene glycol, dipropylene glycol, tripropylene glycol, and tetrapropylene glycol. , pentapropylene glycol, hexapropylene glycol, polyethylene glycol, polypropylene glycol, polyoxyethylene polyoxypropylene glycol, polybutylene glycol and the like.

The aromatic epoxy resin is not particularly limited, and includes cresol novolac epoxy resin, phenol novolak epoxy resin, triphenolmethane epoxy resin, triphenolethane epoxy resin, trisphenol epoxy resin, diphenyl ether epoxy resin, biphenyl type epoxy resin and the like.

The ratio of the bisphenol type epoxy resin and the other epoxy resin to be used is not particularly limited, but is preferably about (bisphenol type epoxy resin)/(other epoxy resin)=30/70 to 100/0 in terms of weight of non-volatile matter.

As for the physical properties of component (a1), the epoxy group concentration is preferably about 0.4×10 ⁻³ to 3.5×10 ⁻³ eq/g, and 0.5×10 ⁻³ to 2.5×10 ⁻ About ³ eq/g is more preferable, and about 0.8×10 ⁻³ to 2.1×10 ⁻³ eq/g is particularly preferable. If the epoxy group concentration is within the above range, the coating film will have high hardness and excellent rust resistance by reacting with the component (a2).

The epoxy group concentration of component (a1) is represented by the number of epoxy groups contained per 1 g of component (a1).

The epoxy group concentration when one type of component (a1) is used is calculated by the reciprocal of the epoxy equivalent (=1/epoxy equivalent of component (a1)).

When two types of (a1) component are used, the epoxy group concentration of the (a1) component is calculated from (Equation 1) using each charge weight and epoxy equivalent. The two types of (a1) components are represented by (a1-1) component and (a1-2) component, respectively.

(Formula 1)

Similarly, when n kinds of (a1) component are used, the epoxy group concentration of the (a1) component is calculated from (Equation 2).

(Formula 2)

Component (a2) is not particularly limited, and various known ones can be used. Examples include alkanolamines, aliphatic amines, alicyclic amines, aromatic amines and the like. These may be used alone or in combination of two or more. By using the component (a2), the component (A) having a high molecular weight can be obtained, and when it is formed into a coating film, it is imparted with antirust properties and water-resistant adhesion.

The alkanolamine is not particularly limited, and examples thereof include primary alkanolamine such as monoethanolamine and monoisopropanolamine; diethanolamine, diisopropanolamine, di-2-hydroxybutylamine, N-methylethanolamine, N-ethylethanol secondary alkanolamines such as amines and N-benzylethanolamine; and tertiary alkanolamines such as triethanolamine and tripropanolamine. These may be used alone or in combination of two or more.

The aliphatic amine is not particularly limited, and examples include ethylamine, n-propylamine, n-butylamine, n-hexylamine, n-octylamine, n-laurylamine, n-stearylamine, n-palmitylamine, primary aliphatic monoamines such as n-oleylamine and 2-ethylhexylamine; secondary aliphatic monoamines such as diethylamine, di-n-propylamine and di-n-butylamine; ethylenediamine, propylenediamine, hexamethylenediamine, 2,2 ,4-trimethylhexanediamine, 2,4,4-trimethylhexanediamine, isophoronediamine and other aliphatic diamines. These may be used alone or in combination of two or more.

The alicyclic amine is not particularly limited, and examples thereof include cyclopentylamine, cyclohexylamine, norbornylamine and the like. These may be used alone or in combination of two or more.

The aromatic amine is not particularly limited, and examples thereof include toluidine, xylidine, coumidine (isopropylaniline), hexylaniline, nonylaniline, dodecylaniline, benzylamine, phenethylamine and the like. These may be used alone or in combination of two or more.

Among these components (a2), alkanolamine is preferably included, and monoethanolamine is more preferably included, because the coating film has excellent hardness. When alkanolamine is used, the amount of use is not particularly limited, and is usually 1 to 90% by weight, preferably 1 to 60% by weight, based on 100% by weight of the total of component (a2). Within this range, the coating film has excellent primary adhesion and water-resistant adhesion.

Component (a3) is not particularly limited, and various known ones can be used. Examples of component (a3) include glycidyl (meth)acrylate, 2-methylglycidyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate glycidyl ether, 3,4-epoxycyclohexylmethyl (meth)acrylate, 1,2 -epoxy-4-vinylcyclohexane and the like, and these may be used alone or in combination of two or more. Among them, glycidyl acrylate and glycidyl methacrylate are preferred.

The ratio of components (a1), (a2) and (a3) used is {(number of epoxy groups in component (a1)) + (number of epoxy groups in component (a3))}/(amino groups in component (a2) active hydrogen number) is about 100/120 to 100/80, preferably about 100/110 to 100/90, more preferably about 100/105 to 100/95. By setting it as the said range, (A) component is obtained at a high yield and it becomes easy to exhibit the outstanding coating film performance.

The number of epoxy groups of component (a1) is a value obtained by dividing the charged weight of component (a1) by the epoxy equivalent of component (a1). When n types of (a1-1) component, (a1-2) component, . .

(Formula 3)

The number of epoxy groups of component (a3) can also be calculated by the same method as the number of epoxy groups of component (a1) described above.

The active hydrogen number of the amino group of component (a2) is the value obtained by dividing the charged weight of component (a2) by the amine equivalent of component (a2). When there are multiple components (a2), the number of active hydrogens is calculated from (Equation 4).

(Formula 4)

Moreover, you may use a polyisocyanate for the structural component of (A) component as needed.

The polyisocyanate is not particularly limited, and examples thereof include aromatic polyisocyanate, aliphatic polyisocyanate, alicyclic polyisocyanate, blocked isocyanate and the like. These may be used alone or in combination of two or more.

The aromatic polyisocyanate is not particularly limited. Benzyl isocyanate, dialkyldiphenylmethane diisocyanate, tetraalkyldiphenylmethane diisocyanate, 1,3-phenylene diisocyanate, 1,4-phenylene diisocyanate, tolylene diisocyanate, orthotoluidine diisocyanate, polyphenylpolyisocyanate and the like. These may be used alone or in combination of two or more.

The aliphatic polyisocyanate is not particularly limited, and examples include butane-1,4-diisocyanate, hexamethylene diisocyanate, 2,2,4-trimethylhexamethylene diisocyanate, 2,4,4-trimethylhexamethylene diisocyanate, and lysine diisocyanate. etc. These may be used alone or in combination of two or more.

The alicyclic polyisocyanate is not particularly limited, and examples include cyclohexane-1,4-diisocyanate, dicyclohexylmethane-4,4'-diisocyanate, 1,3-bis(isocyanatomethyl)cyclohexane, methylcyclohexane diisocyanate, and isophorone diisocyanate. etc. These may be used alone or in combination of two or more.

The blocked isocyanate is not particularly limited, and examples thereof include compounds obtained by blocking the above polyisocyanate with various known blocking agents. The blocking agent is not particularly limited, and examples include phenolic blocking agents such as phenol and cresol; oxime blocking agents such as methyl ethyl ketone oxime and acetone oxime; lactam blocking agents such as ε-caprolactam and γ-butyrolactam; and acetoacetic acid. Active methylene blocking agents such as ethyl, acetylacetone and ethyl malonate; alcohol blocking agents such as methanol and ethanol; other amine blocking agents, imine blocking agents, imide blocking agents, imidazole blocking agents and mercaptan blocking agents. blocking agents and the like. These may be used alone or in combination of two or more.

The amount of polyisocyanate to be used is not particularly limited, but the usage ratio of {number of isocyanate groups in polyisocyanate}/{number of hydroxyl groups in components (a1) to (a3)} is preferably about 0.005 to 2, and 0.05. About 0.5 is more preferable.

The number of isocyanate groups of polyisocyanate is a value obtained by multiplying the molar amount of polyisocyanate charged by the number of isocyanate groups per molecule of polyisocyanate. In addition, when there are multiple polyisocyanates, the number of isocyanate groups is the total number of isocyanate groups of each component.

The number of hydroxyl groups in component (a1) can be calculated by multiplying the charged molar amount of component (a1) by the number of hydroxyl groups per molecule including hydroxyl groups generated when the epoxy groups in component (a1) are ring-opened. In addition, when the (a1) component contains a plurality of components, the number of hydroxyl groups of the (a1) component is the total number of hydroxyl groups of each component. The number of hydroxyl groups of component (a3) is the same.

The number of hydroxyl groups in component (a2) can be calculated by multiplying the molar amount of component (a2) charged by the number of hydroxyl groups per molecule of component (a2). In addition, when the (a2) component contains a plurality of components, the number of hydroxyl groups of the (a2) component is the total number of hydroxyl groups of each component.

Component (A) can be obtained by various known production methods using components (a1), (a2) and (a3) and, if necessary, epoxy resins other than (a1) and polyisocyanate. . The production conditions are not particularly limited, and for example, the reaction temperature is usually about 50 to 250°C, preferably about 80 to 150°C. The reaction time is also not particularly limited, and depending on the reaction temperature, it is usually about 3 to 12 hours, preferably 3 to 8 hours.

Various known solvents can be used in the production method. The solvent is not particularly limited, and examples thereof include aromatic hydrocarbons such as toluene and xylene; ketones such as methyl ethyl ketone, methyl isobutyl ketone and cyclohexanone; esters such as ethyl acetate and butyl acetate; propylene glycol monomethyl ether and propylene glycol monoethyl. ethers such as ethers, propylene glycol mono-n-butyl ether and propylene glycol mono-t-butyl ether; cellosolves such as methyl cellosolve, ethyl cellosolve, n-butyl cellosolve and t-butyl cellosolve; cellosolve acetates such as methyl cellosolve acetate and ethyl cellosolve acetate; These may be used alone or in combination of two or more. Alcohols such as isopropyl alcohol and n-butyl alcohol can also be used as a diluting solvent after production of the present invention. The amount of solvent used is not particularly limited, and may be adjusted so that the reaction concentration is about 30 to 80% by weight.

As for the physical properties of the obtained component (A), the amine value is usually 15-90 mgKOH/g, preferably 40-60 mgKOH/g. The amine value here is a value measured according to JIS K-7237.

[About component (B)]
Component (B) is a monomer component containing (meth)acrylamides (b1) (hereinafter referred to as component (b1)). The use of the component (b1) makes it easier to disperse the vinyl-modified epoxy resin composition in water when preparing an aqueous coating agent. In addition, the hardness, water whitening resistance, and water resistance adhesion of a coating film are likely to be excellent.

Examples of component (b1) include N-methyl(meth)acrylamide, N-ethyl(meth)acrylamide, Nn-propyl(meth)acrylamide, N-isopropyl(meth)acrylamide, N-tert-butyl (meth)acrylamide, ) N-alkyl (meth)acrylamides such as acrylamide; N,N-dialkylacrylamides such as N,N-dimethyl (meth)acrylamide, N,N-diethyl (meth)acrylamide, N,N-diisopropyl (meth)acrylamide; N such as N,N-dimethylaminomethyl(meth)acrylamide, N,N-dimethylaminoethyl(meth)acrylamide, N,N-dimethylaminopropyl(meth)acrylamide, N,N-dimethylaminoisopropyl(meth)acrylamide , N-dialkylaminoalkyl (meth)acrylamide; (meth)acrylamide having a hydroxy group such as N-methylol (meth)acrylamide and N-hydroxyethyl (meth)acrylamide; methacrylamide, acrylamide, diacetone (meth)acrylamide, etc. is mentioned. These may be used alone or in combination of two or more. Among them, N,N-dialkyl (meth)acrylamide, N, N-dialkylaminoalkyl (meth)acrylamide and diacetone (meth)acrylamide are preferred, and N,N-dimethyl (meth)acrylamide, N,N-dimethylaminopropyl (meth)acrylamide and diacetone (meth)acrylamide are more preferred. .

The amount of component (b1) to be used is 100 parts by weight of component (A) in terms of non-volatile content, since the vinyl-modified epoxy resin composition is well dispersed in water when preparing an aqueous coating agent. It is preferably about 0.4 to 30 parts by weight, more preferably about 0.8 to 10 parts by weight.

Component (B) may further contain a carboxyl group-containing vinyl monomer and/or its ester (b2) (hereinafter referred to as component (b2)) as a monomer component.

Of the component (b2), carboxyl group-containing vinyl monomers include, for example, α,β-unsaturated monocarboxylic acids such as (meth)acrylic acid and crotonic acid; maleic acid, fumaric acid, itaconic acid, muconic acid, citracone α,β-unsaturated dicarboxylic acids such as acids; anhydrides of the above carboxylic acids; and alkali metal salts such as sodium salts and potassium salts of the above carboxylic acids. These may be used alone or in combination of two or more. Among them, (meth)acrylic acid, maleic acid, fumaric acid, and itaconic acid are preferable, and methacrylic acid and acrylic acid are preferable, since the vinyl-modified epoxy resin composition is well dispersed in water when preparing an aqueous coating agent. is more preferred.

Examples of (b2) esters of carboxyl group-containing vinyl monomers include methyl (meth)acrylate, ethyl (meth)acrylate, n-propyl (meth)acrylate, and n-(meth)acrylate. -butyl, isobutyl (meth)acrylate, t-butyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, lauryl (meth)acrylate and the like, and these may be used alone or in combination of two or more. Also good. Among them, methyl (meth)acrylate, n-butyl (meth)acrylate, isobutyl (meth)acrylate, and t-butyl (meth)acrylate are preferable because they tend to provide excellent water-resistant adhesion of the coating film.

The amount of component (b2) to be used is 100 parts by weight of component (A) in terms of non-volatile content, since the vinyl-modified epoxy resin composition is well dispersed in water when preparing an aqueous coating agent. It is preferably about 1 to 40 parts by weight, more preferably about 1 to 10 parts by weight.

In addition, the ratio of the components (b1) and (b2) used is determined by the weight of the non-volatile matter, since the vinyl-modified epoxy resin composition is well dispersed in water when preparing the aqueous coating agent. /(b2)=0.01 to 30 is preferred, (b1)/(b2)=0.02 to 10 is more preferred, and 0.05 to 2 is even more preferred.

(b2) When using a component, you may use carbodiimide as needed.

Carbodiimides include, for example, poly(4,4'-diphenylmethanecarbodiimide), poly(tolylcarbodiimide), poly(p-phenylenecarbodiimide), poly(m-phenylenecarbodiimide), poly(3,3'-dimethyl-4, 4′-diphenylmethanecarbodiimide), poly(naphthylenecarbodiimide), poly(1,6-hexamethylenecarbodiimide), poly(1,4-tetramethylenecarbodiimide), poly(1,3-cyclohexylenecarbodiimide), poly(1 ,4-cyclohexylenecarbodiimide), poly(1,3,5-triethylphenylenecarbodiimide), poly(4,4′-methylenebiscyclohexylcarbodiimide), poly(1,3-diisopropylphenylenecarbodiimide), poly(1-methyl -3,5-diisopropylphenylenecarbodiimide), poly(isopropylphenylenecarbodiimide), N,N'-dicyclohexylcarbodiimide, N,N'-diisopropylcarbodiimide, N,N'-diisopropylphenylcarbodiimide, N-ethyl-N'-( 3-dimethylaminopropyl)-carbodiimide hydrochloride and the like. Commercially available products include "Carbodilite E-02", "Carbodilite V-02", and "Carbodilite V-04" (manufactured by Nisshinbo Chemical Co., Ltd.). These may be used alone or in combination of two or more.

The amount of carbodiimide used is preferably about 0.005 to 3, more preferably about 0.05 to 2, in terms of {number of imide groups in carbodiimide}/{number of carboxylic acid groups in component (b1)}.

The number of imide groups in carbodiimide is a value obtained by multiplying the molar amount of charged carbodiimide by the number of imide groups per carbodiimide molecule. When there are multiple carbodiimides, the number of imide groups is the total number of imide groups of each component.

The number of carboxylic acid groups in component (b2) is a value obtained by multiplying the molar amount of component (b2) charged by the number of carboxylic acid groups per molecule of component (b2). When there are multiple components (b2), the number of carboxylic acid groups is the total number of carboxylic acid groups of each component.

As component (B), a monomer component (b3) (hereinafter referred to as component (b3)) other than components (b1) and (b2) may be used as required.
Examples of component (b3) include sulfones such as styrenesulfonic acid, methallylsulfonic acid, methallyloxybenzenesulfonic acid, allyloxybenzenesulfonic acid, acrylamido-2-methylpropanesulfonic acid, and acrylamido-t-butylsulfonic acid. acids; sulfo group-containing vinyl monomers such as alkali metal salts such as sodium salts and potassium salts of these sulfonic acids;
Styrenes such as styrene, α-methylstyrene, t-butylstyrene, dimethylstyrene, acetoxystyrene, hydroxystyrene, vinyltoluene, chlorovinyltoluene;
vinyl acetate, 2-hydroxyethyl (meth)acrylate, glycidyl (meth)acrylate, (meth)acrylonitrile and the like. These may be used alone or in combination of two or more.

The amount of component (b3) used is 40 parts by weight per 100 parts by weight of component (A) because the vinyl-modified epoxy resin composition is well dispersed in water when preparing an aqueous coating agent. The following is preferable, and 20 parts by weight or less is more preferable.

The method of polymerizing components (A) and (B) is not limited, but solution polymerization is preferred. The conditions are not particularly limited. For example, the temperature is about 60 to 150° C., preferably about 70 to 140° C. in the presence of a polymerization initiator, and the time is about 1 to 8 hours, preferably 2 to 6 hours. about an hour. Also, a solvent may be used in the system.

The polymerization initiator is not particularly limited. Organic peroxides such as cumene hydroperoxide, t-butyl hydroperoxide, t-butylperoxy-2-ethylhexanoate, dicumyl peroxide, lauroyl peroxide, and the like, and these may be used alone or in combination of two or more. may be combined.

The amount of the polymerization initiator to be used is not particularly limited, but is preferably about 1 to 10 parts by weight with respect to 100 parts by weight of components (A) and (B) combined.

The solvent is not particularly limited, and includes, for example, those listed in the section on the method for producing component (A). The amount of solvent used is not particularly limited, and may be adjusted so that the reaction concentration is about 30 to 90% by weight. The polymer obtained by the above production method may contain a solvent, but it is preferable that the content is less than 20% by weight by appropriately removing the solvent by distillation under reduced pressure or the like.

The vinyl-modified epoxy resin composition obtained by the production method may be neutralized with an acid or base.

Examples of acids include inorganic acids such as hydrochloric acid, sulfuric acid and phosphoric acid; organic acids such as formic acid, acetic acid, citric acid, malic acid, aspartic acid tartaric acid, and the like. Examples of the base include ammonia; amines such as methylamine, ethylamine, dimethylamine, diethylamine, trimethylamine, triethylamine and N,N-dimethylethanolamine; alkali metal hydroxides such as potassium hydroxide and sodium hydroxide; and these may be used alone or in combination of two or more.

When used as an aqueous coating agent, the vinyl-modified epoxy resin composition of the present invention is dissolved or dispersed by adding water. is neutralized with a base (that is, the vinyl-modified epoxy resin composition is neutralized with a base). The pH after neutralization is preferably about 7-10. Further, as such a base, ammonia and amines are preferable, and ammonia is more preferable, since they are easily volatilized during drying.

The physical properties of the vinyl-modified epoxy resin composition of the present invention are not particularly limited. About 250,000 is preferable, and about 20,000 to 200,000 is more preferable. The non-volatile content is not particularly limited, and may be appropriately determined in consideration of the viscosity, but is usually about 30 to 45% by weight.

In addition, the non-volatile content is 35% by weight and the viscosity at a temperature of 23° C. is usually about 800 to 4000 mPa·s, preferably about 1000 to 3000 mPa·s.

The aqueous coating material of the present invention contains the vinyl-modified epoxy resin composition. The water-based coating agent of the present invention can be applied to paints, surface treatment agents, etc. for various raw materials such as wood, paper, textiles, plastics, ceramics, iron and non-ferrous metals.

Color pigments such as carbon black and titanium oxide; extender pigments such as talc, calcium carbonate and barium sulfate; rust preventive pigments such as aluminum phosphomolybdate, zinc phosphate and zinc oxide; compounds, metal compounds such as nickel compounds and zirconium compounds; silane coupling agents, colloidal silica and the like can be appropriately blended. Curing agents such as melamine resins, urea resins, isocyanates, blocked isocyanates, and carbodiimides, and additives such as various known solvents, colorants, plasticizers, and rust preventives may also be blended, if necessary. The nonvolatile content of the aqueous coating material is not particularly limited, but is preferably about 5 to 80% by weight, more preferably about 10 to 60% by weight.

The physical properties of the aqueous coating material of the present invention are not particularly limited. is.

EXAMPLES The present invention will be described in more detail below with reference to examples. However, the present invention is not limited to these examples. Also, in each example and comparative example, parts or percentages are shown on a weight basis.

Example 1
In a reactor equipped with a stirrer, a cooler, a thermometer and a nitrogen gas inlet tube, 80 parts of t-butyl cellosolve, YD-014 (manufactured by Nippon Steel Chemical & Materials Co., Ltd., trade name: "Epotote YD-014", Epoxy equivalent: 950 g/eq) 70 parts, YD-011 (manufactured by Nippon Steel Chemical & Materials Co., Ltd., trade name: "Epotato YD-011", epoxy equivalent: 475 g/eq) 130 parts and glycidyl methacrylate 1 part were added. After dissolving at 120 ° C. under a nitrogen stream, 2.0 parts of monoethanolamine, 4.0 parts of diethanolamine, 4.0 parts of di-n-butylamine and 30.0 parts of stearylamine are added and reacted for 7 hours to obtain a modified epoxy. A resin (A-1) was obtained. Next, a dropping funnel is charged with a mixture of 8 parts of acrylic acid, 6 parts of n-butyl acrylate, 3 parts of methyl methacrylate, 4 parts of glycidyl methacrylate and 15 parts of t-butyl peroxy-2-ethylhexanoate, It was dropped into the reaction system over 1 hour and kept warm for 3 hours. After cooling to 80° C., 5 parts of an aqueous ammonia solution (non-volatile content: 28%) and 370 parts of water were sequentially added and mixed to obtain a vinyl-modified epoxy resin composition having a non-volatile content of 35%. The physical properties of the composition are shown in Table 1 (same below).

[Weight Average Molecular Weight of Vinyl-Modified Epoxy Resin Composition]
Apparatus: HLC-8220 (manufactured by Tosoh Corporation)
Column: TSKgel α-2500×1, α-3000×1
Separating solvent: DMF (containing LiBr 5 mmol/kg),
Flow rate: 1 ml/min Temperature: 40°C
Standard: Polystyrene

Examples 2 to 6, Comparative Example 1
Compositions shown in Table 1 were synthesized in the same manner as in Example 1 to obtain vinyl-modified epoxy resin compositions.

(dryness)
Coated on a degreased dull steel plate (trade name: “SPCC-SD”, 0.8 x 70 x 150 mm) (hereinafter referred to as SPCC-SD) with a bar coater so that the film thickness after drying is 15 to 20 μm. The coating film was dried at room temperature, and the time required for no marks to remain when the coating film was lightly touched with a finger (drying time to the touch) was determined. Dryness was evaluated according to the following criteria. Table 1 shows the results.
(Evaluation criteria)
○: 10 minutes or less △: over 10 minutes and 20 minutes or less ×: over 20 minutes

(Preparation of aqueous coating agent)
Aqueous coating agents were prepared by kneading mixtures having the compositions shown below with a paint shaker. The resulting water-based coating agent was applied onto SPCC-SD with a bar coater so that the film thickness after drying was 25 to 30 μm. A coating film was prepared by allowing it to stand for 6 days in an environment with a humidity of 60%. Using the obtained coating film, the following tests were performed.

(composition)
Epoxy resin composition of each example and comparative example 200 parts Talc 38 parts Carbon black 4 parts Zinc oxide 2.7 parts Zinc phosphate rust preventive pigment 8 parts Calcium carbonate 18 parts Ion-exchanged water 5 parts

(Evaluation test of coating film)
(1) Dispersibility The particle size of each water-based coating agent blended with the above composition was measured using a grind gauge (manufactured by Taiyu Kizai Co., Ltd.) and evaluated according to the following criteria. The results are shown in Table 1 (same below).
(Evaluation criteria)
○: less than 20 μm △: 20 μm or more and less than 50 μm ×: 50 μm or more (2) Pencil hardness The hardness of the coating film was measured according to JIS K5600-5-4.

(3) Primary Adhesion According to JIS K5600-5-6, the cross-cut adhesion when peeling off the coating film cured for 6 days in an environment of 23 ° C. and 50% humidity after coating is taken as 100. evaluated. The aqueous coating agent prepared using the vinyl-modified epoxy resin composition of Comparative Example 1 was not evaluated (the same applies hereinafter).

(4) Water-resistant Adhesion The test was conducted according to JIS K5600-6-2, and the cross-cut adhesion was evaluated as 100 when the coating film was immersed in hot water at a temperature of 40° C. for 10 days and peeled off.

(5) Water-whitening resistance Each water-based coating agent is applied on SPCC-SD with a bar coater so that the film thickness after drying is 25 to 30 μm, and forced for 20 minutes in a circulating air dryer at a temperature of 100 ° C. After drying, it was allowed to stand for 6 days in an environment with a temperature of 20° C. and a humidity of 60% to prepare a coating film. In accordance with JIS K5600-6-2, the appearance of the coating film after being immersed in hot water at a temperature of 40° C. for 10 days was visually observed. Evaluation criteria are shown below.
(Evaluation criteria)
○: Not whitened △: Partially whitened ×: Completely whitened

[(A) component]
(a1) Component YD-014: Bisphenol A type epoxy resin (manufactured by Nippon Steel Chemical & Materials Co., Ltd., trade name: "Epotato YD-014", epoxy equivalent: 950 g / eq)
・ YD-011: Bisphenol A type epoxy resin (manufactured by Nippon Steel Chemical & Materials Co., Ltd., trade name: “Epotato YD-011”, epoxy equivalent: 475 g / eq)
(a2) component MEA: monoethanolamine (amine equivalent: 30.5 g / eq)
・ DEA: diethanolamine (amine equivalent: 105.1 g / eq)
· DBA: di-n-butylamine (amine equivalent: 129.3 g / eq)
· SA: stearylamine (amine equivalent: 134.8 g / eq)
(a3) component GMA: glycidyl methacrylate (epoxy equivalent: 142.2 g/eq)
[(B) component]
(b1) component DAAM: diacetone acrylamide DMAA: N,N-dimethylacrylamide DMAPAA: N,N-dimethylaminopropylacrylamide (b2) component AA: acrylic acid BA: n-butyl acrylate MMA: Methyl methacrylate [Others]
・ NH3: aqueous ammonia solution (non-volatile content: 28%)
・TEA: Triethylamine

Claims (7)

A vinyl-modified epoxy resin composition containing a polymer having the following (A) and (B) as essential reaction components.
(A) a modified epoxy resin (B) (meth)acrylamides (b1) which is a reaction product of an epoxy resin (a1) containing a bisphenol type epoxy resin, an amine (a2) and a glycidyl group-containing vinyl monomer (a3); monomer component containing 2. The vinyl-modified epoxy resin composition according to claim 1, wherein component (a2) contains alkanolamine. Component (b1) is at least one member selected from the group consisting of N,N-dialkyl(meth)acrylamides, N,N-dialkylaminoalkyl(meth)acrylamides, and diacetone(meth)acrylamides. Vinyl-modified epoxy resin composition according to. The vinyl-modified epoxy resin composition according to any one of claims 1 to 3, wherein component (b1) is used in an amount of non-volatile content of 0.4 to 30 parts by weight per 100 parts by weight of component (A). thing. The vinyl-modified epoxy resin composition according to any one of claims 1 to 4, wherein the component (B) further contains a carboxyl group-containing vinyl monomer and/or its ester (b2). 6. The vinyl-modified epoxy resin composition according to claim 5, wherein the ratio of component (b1) and component (b2) used is (b1)/(b2)=0.01 to 30 in terms of weight of non-volatile matter. An aqueous coating agent comprising the vinyl-modified epoxy resin composition according to any one of claims 1 to 6.