JP2002047390A - Aqueous cationic epoxy resin composition and its use - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a resin composition useful for coatings, adhesives and a material for cement having an excellent adhesion property, a rust proof property and chemical resistance. SOLUTION: The aqueous cationic epoxy resin composition comprises (A) amine modified epoxy resin, (B) an acid compound, (C) water soluble organic solvent and (D) water. The amine modified epoxy resin (A) is composed of an adduct of a epoxy resin having one or more epoxy groups in one molecular chain and multifunctional amine. The addition reaction is carried out in such a way as the molar ratio a1/a2 of active hydrogen (a1) in the multifunctional amine to the epoxy group (a2) is kept in the range of 1.0 and 2.0. The acid compound (B) is added of which the active hydrogen is in the range of 0.5-4.0 equivalent per 1.0 that of nitrogen in the amine modified epoxy resin (A).

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a cationic type which exhibits excellent functions such as strength, chemical resistance and rust prevention when applied as a coating composition, an adhesive composition or a composition for a cement material. The present invention relates to an aqueous epoxy resin composition and its use.

[0002]

2. Description of the Related Art A resin composition comprising an epoxy resin has good corrosion resistance and adhesion, and is widely used as a sealer or a rust preventive paint in the fields of metals and inorganic building materials. However, most of them are solids or viscous liquids, and are dissolved by adding an organic solvent or adjusted by using a reactive or non-reactive diluent in order to adjust to the proper use viscosity. It may be used after adjusting to a high viscosity. When the whole amount is dissolved in an organic solvent and used, the organic solvent volatilizes during drying, so that the environmental load is large. On the other hand, when a diluent is used, the low molecular weight compound derived from the diluent, which is not related to the performance, remains in the target material such as paint or adhesive, so that the corrosion resistance, which is the original performance of epoxy resin, is often used. And the adhesion is reduced.

[0003] Therefore, it has been desired to employ an epoxy resin which does not contain a low molecular diluent and which can use water having a low environmental load as a solvent.

For example, Japanese Patent Application Laid-Open No. 11-172194 discloses that
An acrylic modified epoxy resin obtained by reacting at least a part of the epoxy group in the aromatic epoxy resin with the carboxyl group in the carboxyl group-containing acrylic resin in the presence of a basic catalyst was dispersed in an aqueous medium. Aqueous resin dispersions have been proposed. Further, Japanese Patent Application Laid-Open No.
In No. 1, an aqueous epoxide resin composition is composed of an epoxide compound having an average of more than 1.0 epoxide groups in a molecule and a newly synthesized polyamine derivative. This newly synthesized polyamine derivative is a mixture of one or more polyamines selected from alicyclic polyamines, aromatic nucleus-containing polyamines and heterocyclic polyamines, which are three types of polyamines having a ring structure in the molecule, and a polyethylene polyamine. Or a method of reacting a polyethylene epoxide alone with a hydrophobic epoxide compound, a hydrophilic epoxide compound, and a single epoxide or a mixture thereof selected from monoepoxide and acrylonitrile.
In all of these systems, an aqueous resin other than the epoxy resin is used as an additive to the epoxy resin in order to make the aqueous solution or water dispersion. As similar methods, JP-A-10-130372, JP-A-10-36762, JP-A-9-176292, JP-A-7-252402 and JP-A-5-178967 are mentioned. Each of these systems contains a compound that does not contribute to the intrinsic rust prevention and adhesion of the epoxy resin. Therefore, for example, when used as a coating film, its performance may be reduced. On the other hand, JP-A-9-67425 discloses an esterified modified epoxy resin for a coating agent obtained by reacting an epoxy resin with a fatty acid having 6 or more carbon atoms and an acid anhydride. An aqueous epoxy resin composition obtained by dissolving or dispersing a partially or completely neutralized substance in water, and using the esterified modified epoxy resin in an amount of 5 to 95% by weight based on the solid content of the resin, and further using another epoxy resin in water There has been proposed an aqueous epoxy resin composition dispersed in water. JP-A-9-241482 discloses a polyethylene glycol having a number average molecular weight of 400 to 20,000, a bisphenol-type epoxy resin, a compound having one active hydrogen in one molecule, and two or more active hydrogens in one molecule. Compound having an isocyanate group, and an amine addition-modified epoxy resin obtained by the reaction of an amine compound having active hydrogen, an active hydrogen-containing hydrophobic polyamine compound, and an aqueous epoxy resin curing agent comprising water and an epoxy resin aqueous dispersion. An aqueous epoxy resin curable composition characterized by mixing is proposed. In these systems, a skeleton for imparting water or dispersing in water is incorporated in the skeleton in the epoxy resin. These also include factors that lower the original performance of the epoxy resin, similarly to the above-mentioned addition system.

[0005]

An object of the present invention relates to a resin composition and its use. More specifically, an object of the present invention is to provide an epoxy resin composition which has an epoxy resin skeleton, does not contain a low-molecular diluent, has a low environmental load, and can use water as a majority of the solvent. It is another object of the present invention to provide an application utilizing the properties of epoxy resin such as rust prevention, adhesion and strength.

[0006]

Means for Solving the Problems The inventors of the present invention have made intensive studies to solve the above-mentioned problems, and as a result, a resin obtained by reacting an epoxy resin with a polyfunctional amine compound at a specific ratio is contained in a water-soluble organic solvent. Further, the present inventors have found that the above-mentioned problems can be solved by adding an acid compound and adding water thereto, and have completed the present invention. Further, they have found that the composition of the present invention is useful for a coating film, an adhesive layer, a metal surface treatment agent, a plastic coating agent, and a composition for a cement material. That is, the present invention provides [1]
(A) an amine-modified epoxy resin, (B) an acid compound,
A cationic aqueous epoxy resin composition comprising (C) a water-soluble organic solvent and (D) water, wherein the (A) amine-modified epoxy resin has one or more epoxy groups in one molecular chain. The ratio a ₁ / a ₂ of the number of moles of the epoxy group (a ₂ ) to the number of moles of the active hydrogen (a ₁ ) in the polyfunctional amine is 1.0.
And the addition reaction is performed in a range of 2.0 or less,
And the cationic aqueous epoxy resin composition is (A) 1.0 equivalent of nitrogen atom in the amine-modified epoxy resin,
(B) active hydrogen equivalent in the acid compound is 0.5 equivalent or more,
It is a cationic aqueous epoxy resin composition characterized by being added in a range of 4.0 equivalents or less, [2] (B)
The acid compound is an organic acid compound [1]
It is a cationic aqueous epoxy resin composition described in,
[3] The cationic aqueous epoxy resin composition according to [2], wherein the organic acid compound is an oxycarboxylic acid, wherein the cation according to any one of [4] [1] to [3]. A coating composition containing the cationic water-based epoxy resin composition described in [5] and [4], and a coating composition for plastics containing the cationic water-based epoxy resin composition described in [5] and [4]. A rust preventive coating composition comprising the cationic aqueous epoxy resin composition described in [4], wherein the cationic aqueous epoxy resin composition described in any of [7] [1] to [3] is used. A composition for an adhesive comprising: [8] [1] to [3]
A composition for a cement-based material comprising the cationic aqueous epoxy resin composition according to any one of the above,
[9] The composition further comprises a crosslinking agent capable of reacting with a hydroxyl group or a hydrogen atom directly bonded to a nitrogen atom.
[7] The composition according to any of [7], wherein the crosslinking agent is an amino resin, a urethane resin, a block urethane resin,
The composition according to [9], which is a crosslinking agent selected from the group consisting of epoxy resins.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail.

The amine-modified epoxy resin (A) of the present invention is preferably a modified epoxy resin obtained by an addition reaction of an epoxy resin and a polyfunctional amine. Here, as the epoxy resin used, bisphenol A-diglycidyl ether, bisphenol F-diglycidyl ether, novolac glycidyl ether, glycidyl hexahydrophthalate, glycidyl dimer, tetraglycidylaminodiphenylmethane,
3,4-epoxy-6-methylcyclohexylmethyl carboxylate, triglycidyl isocyanurate,
3,4-epoxycyclohexylmethyl carboxylate, polypropylene diglycidyl ether, polybutadiene or polysulfide-modified diglycidyl ether at both ends, polysulfide-modified epoxy resin, etc., preferably bisphenol A-diglycidyl ether, bisphenol F-di Glycidyl ether. These may be used alone or in combination of two or more. Further, those obtained by reacting these epoxy resins with a compound having a phenolic hydroxyl group in the presence of an alkali catalyst to form a polymer can also be used.

On the other hand, as a polyfunctional amine, active hydrogen is 1
Amines having two or more in the molecule. Specifically, isopropanolamine, monopropanolamine, monobutanolamine, monoethanolamine, diethylenetriamine, ethylenediamine, butylamine, propylamine, isophoronediamine, tetrahydrofurfurylamine, xylenediamine, diaminediphenylmethane, diaminosulfone, octylamine, metaphenylene Diamine, amylamine, hexylamine, nonylamine, decylamine, triethylenetetramine, tetramethylenepentamine, dimethylaminopropylamine,
N-aminoethylpiperazine, methadenediamine, diaminodiphenylsulfone and the like can be mentioned. Alkanolamines are particularly preferred because of their good solubility in water.

The amine-modified epoxy resin of the present invention comprises the above-mentioned epoxy resin and polyfunctional amine in a state where the number of moles of active hydrogen in the polyfunctional amine is excessive with respect to the number of moles of epoxy group in the epoxy resin. It is obtained by performing an addition reaction. Specifically, it is composed of the above-mentioned epoxy resin having one or more epoxy groups in one molecular chain and a polyfunctional amine, and the number of moles of the epoxy group to the number of moles of active hydrogen (a ₁ ) in the polyfunctional amine ( The ratio a ₁ / a ₂ of a ₂ ) is 1.0
And in the range of 2.0 or less. At this time, of course, when a ₁ / a ₂ is 1.0, when the reaction between the epoxy resin and the amine compound proceeds, the polymerization becomes too advanced,
Becomes insoluble. If a ₁ / a ₂ exceeds 2.0, the polyfunctional amine that has not reacted with the epoxy resin will remain in the system, and the performance of the coating film or adhesive layer will be reduced.

As a polymerization solvent for reacting the above-described epoxy resin with an amine compound, toluene, xylene, cyclohexanone, methyl ethyl ketone, n-butyl alcohol, propylene glycol monomethyl ether acetate, or the like can be used. At this time,
The water-soluble organic solvent (C) shown below can be used alone or as a mixture with the above-mentioned organic solvent.

(C) Examples of the water-soluble organic solvent include alcohols such as acetone, methanol, ethanol and isopropyl alcohol, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monoisopropyl ether, ethylene glycol monobutyl ether and ethylene glycol. Cellosolves such as monoisobutyl ether and propylene glycol monomethyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monoisopropyl ether,
Carbitols such as diethylene glycol monobutyl ether and diethylene glycol monoisobutyl ether, cyclic ethers such as 1,3-dioxane and 1,4-dioxane, cyclic carbonates such as ethylene carbonate, ethylene glycol dimethyl ether, ethylene glycol diethyl ether, diethylene glycol dimethyl ether, Examples of the water-soluble organic solvent include glymes such as diethylene glycol diethyl ether. The solubility of the organic solvent in water is preferably 30% or more, and more preferably, a water-soluble organic solvent that can be mixed with water at any ratio. Among them, glymes of aprotic water-soluble organic solvents are most preferable from the viewpoint of water resistance.

These reactions are carried out by dissolving the epoxy resin in a polymerization solvent and / or (C) a water-soluble organic solvent.
The reaction is performed at 60 to 120 ° C. by adding a polyfunctional amine compound.

When (C) the water-soluble organic solvent and the above-mentioned organic solvent are mixed and used, the organic solvent is distilled off by elevating the boiling point of the organic solvent at a temperature higher than the boiling point of the organic solvent or, if necessary, by reducing the pressure. There is a need to. Therefore, it is preferable to perform a polyaddition reaction between the epoxy resin and the polyfunctional amine compound using only the water-soluble organic solvent (C) as a polymerization solvent.

At this time, (A) the amine-modified epoxy resin is
(C) Obtained in a water-soluble organic solvent, wherein (A)
The amine-modified epoxy resin is preferably liquid during (C) neutralization with an acid compound in a water-soluble organic solvent and (D) phase inversion with water. Specifically, (A) an amine-modified epoxy resin in a water-soluble organic solvent is
It suffices if it is liquid at 00 ° C. There is no particular limitation on the weight ratio of (A) the amine-modified epoxy resin to (C) the water-soluble organic solvent. However, from the viewpoint of the stirring property at the time of production and the performance when the obtained cationic aqueous epoxy resin composition is used as a paint, an adhesive or a composition for a cement material, (A)
The mass ratio of the amine-modified epoxy resin to the (C) water-soluble organic solvent may be such that (A) the amine-modified epoxy resin / (C) the water-soluble organic solvent is 99/1 to 50/50, preferably 95/50. 5 to 60/40, more preferably 9
It is in the range of 0/10 to 75/25.

Next, the acid compound (B) used in the present invention includes formic acid, acetic acid, lactic acid, citric acid monohydrate, 2,2-
Dimethyl-3-hydroxypropionic acid, 9,10-dihydroxyoctadecanoic acid, glycolic acid, 2-hydroxyisobutyric acid, (a) -3-hydroxyoctanoic acid, L (+)-tartaric acid, malic acid, propionic acid, boric acid, Butyric acid, dimethylolpropionic acid, hydrochloric acid, sulfuric acid, phosphoric acid, dimethyl phosphite, N
-Acetylglycine, N-acetyl-ε-alanine, sulfamic acid, thiomalic acid, thioglycolic acid and the like. Among these acids, the organic acid compound has good mixability with the (A) amine-modified epoxy resin. Further, from the viewpoint of the solubility of the resin, oxycarboxylic acids having both a hydroxyl group and a carboxyl group in the skeleton are preferable, and lactic acid is more preferable.

These (B) acid compounds are dissolved in the above-mentioned (C) water-soluble organic solvent (A). (A) The amine-modified epoxy resin is cationized by adding the active hydrogen equivalent therein at a temperature of about 0.5 to 4.0 equivalents at a temperature from room temperature to about 90 ° C. By adding water (D) such as water, a cationic aqueous epoxy resin composition is obtained.

At this time, (C) a nitrogen atom in the amine-modified epoxy resin (A) dissolved in a water-soluble organic solvent.
If the equivalent of (B) active hydrogen in the acid compound is less than 0.5 equivalent to 0 equivalent, (A) the amine-modified epoxy resin becomes insufficiently ionized, and (D) the system coagulates when water is added. I do. On the other hand, (C) the nitrogen atom in the amine-modified epoxy resin (A) dissolved in a water-soluble organic solvent is 1.0%.
(B) The active hydrogen equivalent in the acid compound is 4.
When used in excess of 0 equivalents, there is no problem with aqueous conversion,
A problem arises in the adhesion after a water resistance test when forming a coating film or an adhesive layer. From the above, the active hydrogen equivalent in the acid compound (B) is added in a range of 0.5 equivalent or more and 4.0 equivalent or less with respect to 1 equivalent of nitrogen atom in the amine-modified epoxy resin (A). Preferably, it is used in a range of 1.0 equivalent or more and 3.0 equivalents or less.

The cationic water-based epoxy resin composition thus obtained can be converted into a microdispersion from a dispersed one, depending on the molecular weight of the amine-modified epoxy resin, the amine value, and the type and amount of the water-soluble organic solvent. Various forms are obtained, including melted ones, which can be used as coating compositions, adhesive compositions, and compositions for cement-based materials.

Specifically, when used as a paint, the composition is diluted with water to an appropriate coating viscosity and then applied by a conventional application method such as brush application, roller application, spray application, doctor blade application, or the like. it can.

Examples of applicable materials include various metal materials, such as cold-rolled steel sheets, galvanized steel sheets, alloyed galvanized steel sheets, chrome-plated steel sheets, aluminum steel sheets, tin-plated steel sheets, lead-plated steel sheets, nickel-plated steel sheets, and aluminum. Examples include a steel plate, a titanium steel plate, a stainless steel plate, a magnesium alloy, a plastics material, and an inorganic material.

When used as a rust preventive paint composition among paint compositions, the coating film after treatment with a chemical such as an alkali treatment has excellent rust preventive properties. At this time, as a material to be coated, a metal plate such as a galvanized steel plate (an electrogalvanized steel plate, a hot-dip galvanized steel plate, or the like) may be used.

Among the paint compositions, when used as a paint for plastics, epoxy resins exhibit properties such as high hardness, adhesion, solvent resistance, and chemical resistance. Also,
Examples of the plastic material for coating the cationic waterborne epoxy resin composition include various plastic materials such as ABS, acrylic, noryl, polystyrene, polycarbonate, polyethylene terephthalate, polyester, polypropylene, polyethylene, polyphenylene sulfide or polyamide. . Above all, it is suitable for ABS, polystyrene, polycarbonate, polyethylene terephthalate, polyphenylene sulfide, etc. having a benzene skeleton having good affinity for epoxy resin. The shape of the object to be coated is not particularly limited to a shape to be coated, such as a molded product such as a block, a film, and a fiber.

When used as the above coating composition,
A crosslinking agent capable of reacting with a hydrogen atom directly bonded to a hydroxyl group or a nitrogen atom in the cationic aqueous epoxy resin composition can be used in combination. When a crosslinking agent is used in combination,
Hardness, adhesion, solvent resistance and chemical resistance can be improved.

Among the crosslinking agents used in the present invention, examples of the crosslinking agent capable of reacting with a hydroxyl group in the cationic aqueous epoxy resin composition include amino resins, urethane resins and block urethane resins. There is no particular limitation as long as it is a crosslinking agent that reacts with a hydroxyl group in the resin composition skeleton. However, amino resins, urethane resins, block urethane resins are preferred from the viewpoint of versatility, and furthermore,
Amino resins are more preferred.

Specific examples of the amino resin in the crosslinking agent are not particularly limited, but include melamine, benzoguanamine,
Further, a resin obtained by reacting an amino compound such as urea with an aldehyde such as formaldehyde and paraformaldehyde and further addition-polymerizing various alcohols can be included. The most typical example of an amino resin is a melamine resin. In the present invention, the amino resin is not particularly limited. Further, there are functional groups in the amino resin, that is, a complete alkyl type, a methylol group, an imino group type, a methylol / imino group type, and the like.
There is no particular limitation, and an amino resin having a functional group suitable for desired physical properties may be used. In applications where baking is required at low temperatures, such as plastics, a methylol group, an imino group type, or a methylol / imino group type is necessarily preferred, and an imino group type or a methylol / imino group type is more preferred. At this time, a catalyst usually used for curing an amino resin can be used in combination.

In the present invention, a urethane resin which can react with a hydroxyl group or a hydrogen atom directly bonded to a nitrogen atom in the cationic aqueous epoxy resin composition can be used as a crosslinking agent. The urethane resin in this case refers to an isocyanate compound monomer or a product obtained by reacting an isocyanate monomer, an active hydrogen compound, and an isocyanate group at such a ratio that an isocyanate group remains. That is, as the isocyanate compound, aliphatic isocyanates such as hexamethylene diisocyanate and trimethylhexamethylene diisocyanate; aromatic diisocyanates such as xylylene diisocyanate, 2,4-tolylene diisocyanate, and 2,6-tolylene diisocyanate; Alicyclic diisocyanates such as isophorone diisocyanate are exemplified. In addition, multimers such as these nurate compounds can also be used. On the other hand, active hydrogen compounds include ethylene glycol, propylene glycol, 1,2-butylene glycol, 1,3-butylene glycol, 1,6-hexanediol, diethylene glycol, dipropylene glycol, neopentyl glycol, and hydroxybivalic acid esters. , Triethylene glycol,
Dihydric alcohols such as xylylene glycol and 1,4-butylene glycol; trihydric alcohols such as glycerin, trimethylolethane, trimethylolpropane and 1,2,6-hexanetriol; low molecular weight polyols such as pentaerythritol; Polyether polyols such as propylene oxide or ethylene oxide adducts; and high molecular weight polyols such as those modified with fatty acids when producing a polyester polyol obtained by reacting a low molecular weight polyol with a dicarboxylic acid. These may be used alone or as a mixture. When using a urethane resin as a cross-linking agent, it is preferable that the urethane resin is mixed with the cationic aqueous epoxy resin composition immediately before being applied to an object to be coated.

In the present invention, a block urethane resin obtained by blocking the isocyanate group of the urethane resin described above can also be used in order to reduce the complexity of mixing immediately before use. As the blocking agent, any of phenol-based, lactam-based, oxime-based, imine-based, active methylene-based, acid amide-based, imide-based, and sulfite-based ones can be used, but preferably phenol-based, lactam-based, It is an oxime-based or imine-based blocking agent. Specific examples of these include phenol, cresol, xylenol, nitrophenol, chlorophenol, ethylphenol, p-hydroxydiphenyl, t-butylphenol, o-isopropylphenol, o-sec-butylphenol, p-nonylphenol, pt- Phenolic blocking agents such as octylphenol, hydroxybenzoic acid and hydroxybenzoic acid ester; ε-caprolactam, ε-palerolactam, ε-butyrolactam, ε-
Lactam blocking agents such as propiolactam; oxime blocking agents such as formamide oxime, acetoaldoxime, acetoxime, methyl ethyl ketoxime, diacetyl monooxime, benzophenone oxime and cyclohexanone oxime; imine blocking agents such as ethyleneimine and propyleneimine Is mentioned. When this block urethane resin is used as a cross-linking agent, the cross-linking agent and the cationic water-based epoxy resin composition can be mixed before coating.

In the present invention, the above-mentioned crosslinking agent can be used in an arbitrary ratio with the cationic aqueous epoxy resin composition. In addition, as a preferable usage amount, a crosslinking agent / cationic type aqueous epoxy resin composition =
5/95 to 40/60, preferably 10/90 to 30
/ 70, more preferably 15/85 to 20/80.

The production of a paint using the thus obtained paint composition containing the cationic aqueous epoxy resin composition of the present invention is carried out by a known method. That is, a rust preventive pigment, an extender pigment, a leveling agent, and various additives may be added to the above resin composition, and the mixture may be kneaded and dispersed using a disper, a sand mill, a ball mill, or the like.

Further, it is used as an additive in other known aqueous resin-based coating compositions (for example, acrylic resin, urethane resin, polyester resin, alkyd resin, amino resin, etc.), and has good adhesion to this known resin system. Rust resistance, alkali resistance, etc. can be imparted.

On the other hand, when the cationic aqueous epoxy resin composition of the present invention is used as an adhesive composition, the adhesiveness between the adhesive layer and the surface of an object to be bonded such as a metal surface is remarkably improved. Is noted. Moreover, it is suitable as an adhesive composition between cement-based materials having an alkaline surface, or a metal material.

When applied as a coating composition and an adhesive composition containing the cationic aqueous epoxy resin composition of the present invention, it is preferable to bake after heating and drying.
For example, when applied to a rust preventive paint for steel sheets, the baking temperature is 60 ° C. or higher, preferably 100 ° C. or higher, and more preferably 120 ° C. or higher, but is not particularly limited.

The cationic aqueous epoxy resin composition of the present invention can be used for a composition for a cement material. Specifically, it is possible to impart waterproofness, abrasion, anticorrosion and the like to cement-based materials such as concrete, mortar, and slate. In addition, in the conventional composition for an emulsion-based cement-based material, a low-molecular-weight alkali-based emulsifier present in the composition is released due to a strong alkali component in the cement, thereby destabilizing the emulsion. However, the amine-modified epoxy resin of the present invention has excellent alkali resistance because the resin skeleton itself is alkaline, and has a feature that it is stable because the above-mentioned low molecular weight is not released.

Function: The resin composition of the present invention can suppress the content of the organic solvent, and has the same workability, adhesiveness, and anticorrosion properties as those of a conventional solvent-type epoxy resin.
It can be used as a primer or sealer for metals, inorganic building materials, plastic materials, and the like. It can also be used as an adhesive or a resin composition for cement-based materials.

[0036]

The present invention will be described in more detail with reference to the following examples.

Production Example 1 of Cationic Aqueous Epoxy Resin Composition Bisphenol A-diglycidyl ether was placed in a 5 L glass four-necked flask (with a stirrer, thermometer, external heater, cooling tube, condenser and nitrogen inlet tube). Epoxy resin (epoxy equivalent 475 g / eq) (trade name: EPOMIC R30)
2: 1000 parts by weight of Mitsui Chemicals, Inc.), 479.3 parts by weight of ethylene glycol dimethyl ether (trade name: Hisolve MMM: manufactured by Toho Chemical Co., Ltd.) are added, and the mixture is heated to 60 ° C. and dissolved. Next, 118.4 parts by mass of 3-1-aminopropanol was added, the temperature was raised to 85 ° C, and after 4 hours and 5 hours, samples were taken and the viscosity was measured. After confirming that the viscosity was constant, the temperature was raised to 70 ° C. Cool, add 284.0 parts by mass of lactic acid and mix for 30 minutes,
Further, 2591.9 parts by mass of ion-exchanged water were added in 5 divisions with stirring every 5 minutes, and the solid content was 25% and the viscosity was 52%.
A 0 cps colloidal dispersion resin solution was obtained.

Production Examples 2 to 14 of Cationic Aqueous Epoxy Resin Composition Raw material epoxy resin, solvent, polyfunctional amine,
The synthesis was carried out according to Production Example 1 of the cationic aqueous epoxy resin composition except that the neutralizing acid and the dilution water were changed.

[Test Method] The resin composition obtained in the preparation example of the cationic water-based epoxy resin composition was adjusted to a rust-preventive coating composition and a plastic coating composition by the following method. It was evaluated by the test method.

[Adhesion] JIS-K-5400.6.
The adhesiveness of the coating film on the test plate is evaluated according to a grid test of No. 15.

[Rust prevention] A test piece was subjected to a salt spray test (according to JIS Z-2371) with 5% saline solution.
The state of rust after 120 hours was observed, and evaluated on a scale of 5 out of 5 (5 points: excellent to 1 point: poor).

[Solvent Resistance] The test piece was subjected to a 50 reciprocal rubbing test with gauze impregnated with methyl ethyl ketone (MEK), and the surface condition was visually observed.
(Point: excellent to 1 point: poor). Similarly, isopropyl alcohol (IPA) was used.

[Alkali Resistance] The alkali resistance was evaluated by visually observing the remaining state and surface state of the coating film after immersing the test piece in a 5% aqueous solution of sodium hydroxide at 60 ° C. for 2 minutes. (Excellent to 1 point: poor).

[Preparation of Rust Prevention Coating Composition] Production Examples 1-1
Ion exchange water was added to the cationic aqueous epoxy resin composition obtained in 4 to adjust the nonvolatile content to 20%, and 500 ppm of Surflon S-145 (manufactured by Asahi Glass) as a wetting agent
Was added and mixed to prepare a composition for a rust preventive paint. Using a # 3 bar coater, apply this paint on a 0.8 mm thick electrogalvanized steel sheet, and dry at 140 ° C. for 2 minutes to obtain a dry coating having a thickness of about 1 to 3 μm. A plate was obtained and used as a test piece. The test piece was evaluated for adhesion, alkali resistance, and rust prevention. Table 2 shows the test results.

[Preparation of Plastic Coating Composition] The cationic aqueous epoxy resin compositions obtained in Production Examples 1 to 14 were added to a methylol / imino group type methylated melamine resin (a high solid type amino resin manufactured by Mitsui Cytec Co., Ltd.).・
Mycoat 776) in a ratio of cationic aqueous epoxy resin composition / methylol / imino-type methylated melamine resin = 8/2 at a solid content ratio, and further, ion-exchanged water is added to reduce non-volatile content. The composition was adjusted to 20% to prepare a plastic coating composition. This paint was applied on a pet film using a # 3 bar coater, and
The coated film having a cured coating film having a thickness of about 1 to 3 μm was obtained by baking and curing at 2 ° C. for 2 minutes, and used as a test piece. The test piece was evaluated for adhesion and solvent resistance, and the test results are shown in Table 3.

[Preparation of Cementitious Material Composition] Dibutyl phthalate and ethylene glycol monoisopropyl ether were added to the cationic aqueous epoxy resin compositions obtained in Production Examples 1 to 14 as mortar sealers as cementitious material compositions. Is blended at a mass ratio of cationic aqueous epoxy resin composition / dibutyl phthalate / ethylene glycol monoisopropyl ether = 100/1/3,
Further, the solid content was adjusted to 20% using pure water, applied to one side of a slate plate (15 × 5 cm) using a # 10 bar coater, left to dry at room temperature for one day, and dried to a thickness of about 1 to 3 days.
A slate plate having a μm dried coating film was obtained and used as a test piece. The test piece was evaluated for adhesion after immersion in water for 24 hours, and the test results are shown in Table 4.

Comparative Production Example 15 of Cationic Aqueous Epoxy Resin Composition Bisphenol A-diglycidyl was placed in a 5 L glass four-necked flask (with a stirrer, thermometer, external heater, condenser, condenser and nitrogen inlet tube). Ether type epoxy resin (epoxy equivalent 475 g / eq) (trade name: EPOMIC R30)
2: 1000 parts by mass of Mitsui Chemicals, Inc.), 1119 parts by mass of ethylene glycol dimethyl ether (trade name: Hisolve MMM: manufactured by Toho Chemical Industry Co., Ltd.) are added, and the mixture is heated to 60 ° C. and dissolved. Next, 119 parts by mass of 3-1-aminopropanol was added, the temperature was raised to 85 ° C., and the gel was formed after 4 hours.

Comparative Production Examples of Cationic Aqueous Epoxy Resin Compositions 16 to 18 Raw material epoxy resin, solvent, polyfunctional amine,
The synthesis was carried out according to Production Example 1 of the cationic aqueous epoxy resin composition except that the neutralizing acid and the dilution water were changed.

The resin compositions synthesized in Comparative Production Examples 16 to 18 were used in the same manner as in the Examples as a rust preventive paint composition, a plastic paint composition, and a cement material composition.
Each was similarly evaluated and the results were shown.

For comparison, a solvent type epoxy resin (trade name: EPOKEY 861: manufactured by Mitsui Chemicals, Inc.) in Comparative Example 6 and an acrylic emulsion (trade name: Almatex E264: manufactured by Mitsui Chemicals, Inc.) in Comparative Example 5 Were evaluated as a rust-preventive coating composition and a cement-based material composition, respectively.

Similarly, as a comparative example of a plastic coating composition, a solvent-type acrylic resin (trade name: Almatex L1060: manufactured by Mitsui Chemicals, Inc.) in Comparative Example 5 and a solvent-type epoxy resin (trade name) in Comparative Example 6 (Epokey 813: manufactured by Mitsui Chemicals, Inc.) and solidified with a methylol / imino group type methylated melamine resin (manufactured by Mitsui Cytec Co., Ltd./high solid type amino resin / mycoat 776) as a curing agent in the same manner as in the example The cationic aqueous epoxy resin composition / methylol / imino-type methylated melamine resin was blended in a ratio of 8/2 in terms of the fractional ratio, and the corresponding thinner was added to adjust the nonvolatile content to 20%. Then, a composition for plastic paint was prepared. The above evaluation results are shown in Tables 2, 3 and 4.

[0052]

[Table 1]

[0053]

[Table 2]

[0054]

[Table 3]

[0055]

[Table 4]

[0056]

[Table 5]

Consideration of Results The following items are apparent from the above Examples and Comparative Examples.

When the resin composition of the present invention was used in a rust-preventive coating composition, Examples 1 to 14 exhibited adhesion, alkali resistance and rust resistance equivalent to those of the solvent-type epoxy resin described in Comparative Example 6. It was an excellent thing to have. On the other hand, Comparative Example 2 is excellent in adhesion and alkali resistance, but poor in rust prevention. Comparative Example 3 is inferior in adhesion, alkali resistance and rust resistance. All of these are presumed to be due to the low molecular weight compound remaining in the coating film. In Comparative Example 4, the state of the coating film was poor, and the portion where the coating film was formed was excellent in alkali resistance, but poor in adhesion and rust prevention.

The acrylic resin emulsion of Comparative Example 5, which is another resin, is excellent in adhesion, but is inferior in alkali resistance and rust resistance, which are related to the water resistance characteristic of an aqueous resin.

When the resin composition of the present invention was used for a composition for plastic coating, Examples 1 to 14 all exhibited good adhesion and excellent solvent resistance to methyl ethyl ketone and isopropyl alcohol. These results were equivalent in performance to the solvent type epoxy resin described in Comparative Example 6.

On the other hand, since Comparative Examples 2 and 3 contain a large amount of low molecular weight compounds, the solvent resistance to polar solvents methyl ethyl ketone and isopropyl alcohol is extremely reduced. In Comparative Example 4, the solvent resistance was impaired because the film-forming properties were poor. Further, the solvent-type acrylic resin described in Comparative Example 5 is excellent in adhesion, but inferior in solvent resistance.

As an evaluation of the composition for cementitious materials, the adhesion of a test plate coated on a slate plate as a sealer for mortar after immersion in water for 24 hours was the same as that of the solvent type epoxy resin of Comparative Example 6. In addition, no decrease in adhesion was observed in any of Examples 1 to 14.

On the other hand, those listed in Comparative Examples 2 and 3
After all, the low molecular weight compound lowers the water resistance and lowers the adhesion. Comparative Example 4 also has poor permeability as a sealer and poor adhesion. Acrylic emulsions have a problem in water resistance.

[0064]

When the resin composition according to the present invention is applied to a coating composition, the adhesion between the coating film and a base (for example, a metal surface) is remarkably improved. It is particularly noteworthy that the alkali resistance when the lubricating oil applied during processing is alkali-degreased is remarkably improved, and a coating film excellent in rust prevention can be obtained without using a chromium compound. Therefore, it is clear that it is useful as a main component of a rust-preventive paint for a metal, particularly a galvanized steel sheet. In addition, when used for a plastic material, especially PET or ABS having a benzene skeleton, good adhesion and solvent resistance can be imparted. On the other hand, when applied to an adhesive composition, it is particularly noteworthy that the adhesion between the adhesive layer and the surface of the adherend (for example, a metal surface) is significantly improved. Cement-based materials are excellent in secondary adhesion after a remarkable water resistance test.

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) C09D 5/08 C09D 5/08 163/00 163/00 C09J 163/00 C09J 163/00 F-term (reference) 4J002 CC131 CD051 CD061 CD101 CD141 CD181 CD201 CK051 DE028 DF026 DG046 DH026 EC037 ED027 ED037 EE037 EF036 EL107 EV096 EV266 EW066 FD149 FD206 FD207 4J036 AD08 AF06 AG04 AG06 AJ18 412 AK03 CB12 DG03 CB03 HA366 HA416 HA476 JA19 JA26 JA27 JA33 JA37 JA67 JC15 JC24 KA03 KA06 MA08 MA09 NA03 NA04 NA11 PB12 PC01 PC02 PC08 4J040 DL152 EB092 EC331 EF052 EF112 EF292 EF302 HA086 HA126 HA256 HA286 HA326 HB09 HB15 MA02 HA02 MA02

Claims (10)

[Claims] (1) an amine-modified epoxy resin, (B)
A cationic waterborne epoxy resin composition comprising an acid compound, (C) a water-soluble organic solvent and (D) water;
The amine-modified epoxy resin comprises an addition reaction product of an epoxy resin having one or more epoxy groups in one molecular chain and a polyfunctional amine, wherein the epoxy group is based on the number of moles of active hydrogen (a ₁ ) in the polyfunctional amine. Of the number of moles (a ₂ ) of a ₁ /
The addition reaction is carried out with a ₂ being in the range of more than 1.0 and not more than 2.0, and the cationic water-based epoxy resin composition is characterized in that (A) the nitrogen atom in the amine-modified epoxy resin is not more than 1.0.
The active hydrogen equivalent in the acid compound (B) is 0.1 to the equivalent.
A cationic aqueous epoxy resin composition, which is added in a range of 5 equivalents or more and 4.0 equivalents or less. 2. The cationic aqueous epoxy resin composition according to claim 1, wherein the acid compound (B) is an organic acid compound. 3. The cationic aqueous epoxy resin composition according to claim 2, wherein the organic acid compound is oxycarboxylic acid. 4. A coating composition comprising the cationic aqueous epoxy resin composition according to claim 1. 5. A coating composition for plastics comprising the cationic aqueous epoxy resin composition according to claim 4. 6. A rust preventive paint composition comprising the cationic water-based epoxy resin composition according to claim 4. 7. An adhesive composition comprising the cationic aqueous epoxy resin composition according to claim 1. 8. A composition for a cement-based material, comprising the cationic aqueous epoxy resin composition according to any one of claims 1 to 3. 9. The composition according to claim 4, further comprising a crosslinking agent capable of reacting with a hydrogen atom directly bonded to a hydroxyl group or a nitrogen atom. 10. The crosslinking agent is an amino resin, a urethane resin,
The composition according to claim 9, which is a crosslinking agent selected from the group consisting of a block urethane resin and an epoxy resin.