JP5660741B1 - Epoxy resin coating composition and coated body using the same - Google Patents

Abstract

An epoxy resin coating composition having a sufficiently long pot life and excellent curability after coating is provided. A solvent (A) having a mixed aniline point or an aniline point within a range of 12 to 70 ° C. and an epoxy resin component (B) soluble in the solvent (A), wherein the epoxy group is a molecule. An epoxy resin component (B) containing at least two epoxy resins in the interior thereof, an amine curing agent (C) soluble in the solvent (A), and a solvent (D) having a carbonyl group in the molecule An epoxy resin coating composition comprising: Formula (I): X = P / Q, Formula (II): P = (Blend amount of solvent (D)) / (Molecular weight of solvent (D)) and Formula (III) : Q = (Amine value of amine curing agent (C))? (Amount of amine curing agent (C)) / 56110 The value X on the left side of formula (I) is 0.5 to 10 An epoxy resin coating composition characterized by that. [Selection figure] None

Description

  The present invention relates to an epoxy resin coating composition and a coated body using the epoxy resin coating composition, and particularly relates to an epoxy resin coating composition having a sufficiently long pot life and excellent curability after coating. .

  Conventionally, in exterior wall materials for construction and building materials (ceramic siding (for example, wood fiber reinforced cement board, fiber reinforced cement board, fiber reinforced cement / calcium silicate board), mortar, lightweight cellular concrete, metal siding, tile, etc.) In order to improve the adhesion of the top coat film and the durability of the base material, an undercoat paint is applied to the surface of the base material. Moreover, even when the deteriorated old coating film remains on the base material when the base material is renovated, the undercoat is applied as it is.

  In such undercoat paints, two-part curable paints that contain an epoxy resin and an amine curing agent as the main components and contain organic solvents are often used. In recent years, environmental protection laws such as the PRTR method and the paint market In response to market needs accompanying the expansion of the market, two-component curable paints using an epoxy resin that is soluble in organic solvents that have a relatively low environmental impact, for example, weak solvents such as mineral spirits, have been developed ( For example, Patent Documents 1 to 4).

  Patent Document 1 discloses a two-part curable coating composition using a modified epoxy resin obtained by reacting an epoxy resin with an aliphatic monocarboxylic acid and then a diisocyanate compound as an epoxy resin that can be dissolved in a weak solvent. Things are disclosed. Patent Document 2 discloses a two-part solution using a modified epoxy resin obtained by reacting an epoxy resin with an aliphatic monocarboxylic acid and an alkylphenol and then reacting a diisocyanate compound as an epoxy resin that can be dissolved in a weak solvent. A curable coating composition is disclosed.

  Patent Document 3 uses a polyglycidyl ether of a novolac type epoxy resin obtained by a condensation reaction of phenol or a polyhydric phenol and an aldehyde as an epoxy resin, and is obtained by reacting an aliphatic monocarboxylic acid with the epoxy resin. Discloses a two-component curable coating composition using a modified epoxy resin.

  Patent Document 4 discloses a two-part curable epoxy resin coating composition containing two types of weak solvent-soluble epoxy resins having different viscosities.

Japanese Patent Laid-Open No. 03-115318 Japanese Patent Laid-Open No. 04-039320 Japanese Patent Laid-Open No. 11-092709 JP 2001-323212 A

  However, the weak solvent type two-component curable epoxy resin coating composition disclosed in Patent Documents 1 to 4 tends to have a relatively short pot life. Therefore, studies have been made so far to increase the pot life, but in general, if the pot life is lengthened, the curability after painting tends to decrease. It was difficult to satisfy both sexes.

  Accordingly, an object of the present invention is to provide an epoxy resin coating composition that solves the above-described problems of the prior art, has a sufficiently long pot life, and is excellent in curability after coating. Moreover, the other objective of this invention is to provide a coating body provided with the coating film obtained by the said epoxy resin coating composition.

  The present inventor, in a coating composition comprising a specific mixed aniline point or a weak solvent having an aniline point, an epoxy resin soluble in the solvent and an amine curing agent, a solvent having a carbonyl group in the molecule, It has been found that the pot life can be extended without lowering the curability after coating by blending so as to satisfy a specific relational expression established with the amine curing agent, and the present invention has been completed. It was.

That is, the epoxy resin coating composition of the present invention is soluble in the solvent (A) having a mixed aniline point or aniline point defined in JIS K 2256 within a range of 12 to 70 ° C., and the solvent (A). An epoxy resin component (B), which includes at least an epoxy resin having two or more epoxy groups in the molecule, and an amine curing agent (C) soluble in the solvent (A) And an epoxy resin coating composition containing a solvent (D) having a carbonyl group in the molecule,
The following formulas (I) to (III):
X = P / Q (I)
P = (Amount of solvent (D)) / (Molecular weight of solvent (D)) (II)
Q = (Amine value of amine curing agent (C)) × (Amount of amine curing agent (C)) / 56110 (III)
[In formula (II), the compounding amount of the solvent (D) is the compounding amount (parts by mass) of the solvent (D) with respect to 100 parts by mass of the epoxy resin component (B), and the amine value of the amine curing agent (C). Is the total amine value specified in JIS K 7237, and the compounding amount of the amine curing agent (C) is the compounding amount (part by mass) of the amine curing agent (C) to 100 parts by mass of the epoxy resin component (B). )], The value X on the left side of the formula (I) is 0.5 to 10.

In a preferred example of the epoxy resin coating composition of the present invention, the solvent (D) is represented by the following general formula (IV):
R ₁ C (═O) R ₂ (IV)
[Wherein, R ₁ and R ₂ are each independently an alkyl group or an aryl group, or R ₁ and R ₂ are united to form a cyclic structure, provided that R ₁ and R ₂ carbon atoms The sum of the numbers is 3 to 9.].

  In another preferable example of the epoxy resin coating composition of the present invention, a pigment (E) is further contained.

  Moreover, the 1st coating body of this invention is equipped with the base material and the coating film formed in this base-material surface, and this coating film was obtained with said epoxy resin coating composition. Features.

  Furthermore, the 2nd coating body of this invention was equipped with the coating base material covered with the old coating film, and the coating film formed in this coating base material surface, and was formed in this coating base material surface The coating film is obtained by the epoxy resin coating composition described above.

  According to the epoxy resin coating composition of the present invention, an epoxy resin coating composition having a sufficiently long pot life and excellent curability after coating can be provided. Moreover, according to the coated body of this invention, a coated body provided with the coating film obtained by the said epoxy coating composition can be provided.

  Below, the epoxy resin coating composition of this invention is demonstrated in detail. The epoxy resin coating composition of the present invention comprises a solvent (A) having a mixed aniline point or aniline point defined in JIS K 2256 within a range of 12 to 70 ° C., and an epoxy soluble in the solvent (A). An epoxy resin component (B) containing at least an epoxy resin having two or more epoxy groups in the molecule, and an amine-based curing agent (C) soluble in the solvent (A), An epoxy resin coating composition containing a solvent (D) having a carbonyl group in the molecule, formula (I): X = P / Q, formula (II): P = (blending amount of solvent (D)) / (Molecular weight of solvent (D)) and formula (III): Q = (amine value of amine curing agent (C)) × (blending amount of amine curing agent (C)) / 56110 [in formula (II), The compounding quantity of a solvent (D) is with respect to 100 mass parts of epoxy resin components (B). It is the compounding amount (part by mass) of the agent (D), the amine value of the amine curing agent (C) is the total amine value defined in JIS K 7237, and the compounding amount of the amine curing agent (C) is The value X on the left side of the formula (I) determined from the compounding amount (parts by mass) of the amine curing agent (C) with respect to 100 parts by mass of the epoxy resin component (B) is 0.5 to 10. Features.

  The solvent (A) used in the epoxy resin coating composition of the present invention requires that the mixed aniline point or aniline point specified in JIS K 2256 is in the range of 12 to 70 ° C. Less organic solvent. The aniline point and the mixed aniline point are a kind of index representing the solvent dissolving power, and the higher the aniline point or the mixed aniline point, the weaker the dissolving power. The aniline point is the lowest temperature at which equal volumes of solvent and aniline exist as a homogeneous solution, and the mixed aniline point is the lowest temperature at which 1 volume of solvent, 1 volume of heptane and 2 volumes of aniline exist as a uniform solution. . When the mixed aniline point or the aniline point is less than 12 ° C., the solvent has too strong dissolving power, and therefore, when the epoxy resin coating composition is applied to a coated substrate, the coating already covering the substrate (old coating) Is undesirably invaded by the solvent (specifically, the old coating film dissolves or swells) and may cause problems such as lifting. On the other hand, if the mixed aniline point or the aniline point exceeds 70 ° C., the solvent is too weak, so that an epoxy resin having practical performance cannot be dissolved.

  The said solvent (A) will not be restrict | limited especially if the mixed aniline point or aniline point prescribed | regulated to JISK2256 exists in the range of 12-70 degreeC. Moreover, the said solvent (A) may be used individually by 1 type, and 2 or more types may be mixed and used for it. Examples of the solvent (A) include hydrocarbon organic solvents such as aliphatic solvents, naphthene solvents, and aromatic naphthas. Specific examples of the hydrocarbon organic solvent include methylcyclohexane (aniline point: 40 ° C), ethylcyclohexane (aniline point: 44 ° C), mineral spirit (aniline point: 56 ° C), turpentine oil (aniline point: 44 ° C). Is mentioned. In addition, the hydrocarbon organic solvents include those commercially available as petroleum hydrocarbons, such as HAWS (manufactured by Shell Chemicals Japan, aniline point: 17 ° C.), LAWS (manufactured by Shell Chemicals Japan, aniline point). : 44 ° C.), Essonaphtha No. 6 (ExxonMobil, aniline point: 43 ° C), Pegasol 3040 (ExxonMobil, aniline point: 55 ° C), Pegasol AN45 (ExxonMobil, aniline point 42 ° C), A Solvent (Shin Nippon Oil Co., Ltd.) Manufactured, aniline point: 45 ° C.), Clensol (manufactured by Nippon Oil Corporation, aniline point: 64 ° C.), mineral spirit A (manufactured by Nippon Oil Corporation, aniline point: 43 ° C.), Hyalom 2S (manufactured by Nippon Oil Corporation, Aniline point: 44 ° C.), Exol D30 (exxon mobile, aniline point: 64 ° C.), Exol D40 (exxon mobile, aniline point: 69 ° C.), Newsol DX Hisoft (manufactured by Nippon Oil Corporation, aniline point) : 68 ° C), Solvesso 100 (manufactured by ExxonMobil, mixed aniline point: 14 ° C), Solvesso 150 (Ex Manufactured by NMobil, mixed aniline point: 18.3 ° C., Swazol 100 (manufactured by Maruzen Petrochemical Co., Ltd., mixed aniline point: 24.6 ° C.), swazol 200 (manufactured by Maruzen Petrochemical Co., Ltd., mixed aniline point: 23.8 ° C.) ), Swazol 1000 (Maruzen Petrochemical Co., Ltd., mixed aniline point: 12.7 ° C.), Swazol 1500 (Maruzen Petrochemical Co., Ltd., mixed aniline point: 16.5 ° C.), Swazol 1800 (Maruzen Petrochemical Co., Ltd., mixed) Aniline point: 15.7 ° C.), Idemitsu Ipsol 100 (produced by Idemitsu Kosan Co., Ltd., mixed aniline point: 13.5 ° C.), Idemitsu Ipsol 150 (produced by Idemitsu Kosan Co., Ltd., mixed aniline point: 15.2 ° C.), Pegazole ARO- 80 (manufactured by ExxonMobil, mixed aniline point: 25 ° C.), pegasol R-100 (manufactured by ExxonMobil, mixed aniline point: 14 ° C.) Tetrazole (Shell Chemicals Japan Ltd., mixed aniline point: 12.6 ° C.), Nisseki Hisol (Nippon Oil Co., mixed aniline point: 17 ° C. or less) and the like.

  In the epoxy resin coating composition of the present invention, the content of the solvent (A) is not particularly limited, and can be appropriately adjusted so that the state and viscosity of the coating are within an appropriate range. For example, the epoxy resin coating composition It is preferable that it is 20-90 mass% inside.

  In the epoxy resin coating composition of the present invention, the epoxy resin component (B) is required to contain at least an epoxy resin having two or more epoxy groups in the molecule, but an epoxy resin having one epoxy group in the molecule. The content of the epoxy resin having two or more epoxy groups in the epoxy resin component (B) is preferably 50% by mass or more, and more preferably 70% by mass or more.

  Moreover, the said epoxy resin component (B) needs to be soluble in the said solvent (A). In addition, when a modified epoxy resin is contained in the epoxy resin component (B), the epoxy equivalent before modification is preferably 250 or less. If the epoxy equivalent before modification is 250 or less, the solubility of the modified epoxy resin in the solvent (A) can be sufficiently ensured. Here, the epoxy equivalent is defined in JIS K 7236.

  Examples of the epoxy resin that can constitute the epoxy resin component (B) include glycidyl ether type epoxy resins, glycidyl ester type epoxy resins, and alicyclic epoxy resins. Further, these epoxy resins are alkylphenols or / Also included are modified epoxy resins modified with fatty acids, alkylphenyl glycidyl ethers obtained by reacting alkylphenols with epichlorohydrin, alkylphenol novolac epoxy resins obtained by reacting novolac type alkylphenol resins with epichlorohydrin, and the like. These epoxy resin components (B) may be used individually by 1 type, and may be used in combination of 2 or more type.

  Examples of the glycidyl ether type epoxy resin include epoxy resins having a glycidyl ether group obtained by reacting a hydroxyl group-containing compound such as polyhydric alcohol and polyhydric phenol with an epoxy group-containing compound such as epichlorohydrin. Specific examples of the polyhydric alcohol include ethylene glycol, polyethylene glycol, propylene glycol, polypropylene glycol, neopentyl glycol, 1,2-butanediol, 1,4-butanediol, 1,6-hexanediol, glycerin, triglyceride, Examples include methylolpropane, pentaerythritol, dipentaerythritol, sorbitol and the like. Specific examples of the polyhydric phenol include 2,2-bis (4-hydroxyphenyl) propane [generic name: bisphenol A], 2,2-bis (2-hydroxyphenyl) propane, 2- (2- Hydroxyphenyl) 2- (4-hydroxyphenyl) propane, halogenated bisphenol A, bis (4-hydroxyphenyl) methane [generic name: bisphenol F], tris (4-hydroxyphenyl) propane, resorcin, tetrahydroxyphenylethane, Examples include 1,2,3-tris (2,3-epoxypropoxy) propane, novolak type polyhydric phenol, cresol type polyhydric phenol, and the like.

  Examples of the glycidyl ester type epoxy resin include phthalic acid diglycidyl ester, hexahydrophthalic acid diglycidyl ester, tetrahydrophthalic acid diglycidyl ester, and dimer acid diglycidyl ester. Examples of the alicyclic epoxy resin include (3,4-epoxycyclohexyl) methyl-3,4-epoxycyclohexanecarboxylate, (3,4-epoxy-6-methylcyclohexyl) methyl-3,4-epoxy. Examples thereof include 6-methylcyclohexanecarboxylate and bis (3,4-epoxycyclohexylmethyl) adipate.

  The alkylphenol is preferably a phenol having an alkyl group having 2 to 18 carbon atoms. Specific examples include 4-t-butylphenol, 4-t-pentylphenol, 4-neopentylphenol, 4-octylphenol, 4- Nonylphenol and the like can be mentioned. Further, the fatty acid is preferably a dry oil fatty acid, a semi-dry oil fatty acid, etc. Specific examples include linseed oil fatty acid, safflower oil fatty acid, soybean oil fatty acid, sesame oil fatty acid, eno oil fatty acid, tung oil fatty acid, corn oil fatty acid. , Sunflower oil fatty acid, cottonseed oil fatty acid, fish oil fatty acid, tall oil fatty acid, dehydrated castor oil fatty acid, and high diene fatty acid.

  The reaction for modifying the epoxy resin using the alkylphenol or fatty acid as a modifying agent is not particularly limited and can be performed by a conventionally known method. In addition, a modifier | denaturant may be used individually by 1 type, and may be used in combination of 2 or more type.

  Among the epoxy resin components (B), a modified epoxy resin obtained by modifying a bisphenol A epoxy resin with an alkylphenol or / and a fatty acid, or an alkylphenol novolac type epoxy resin is preferable from the viewpoints of adhesion and toughness of a coating film. .

  In the epoxy resin coating composition of the present invention, the amine curing agent (C) is a curing agent for the epoxy resin component (B). Further, since the amine curing agent needs to be soluble in the solvent (A), for example, ethylenediamine, propylenediamine, butylenediamine, hexamethylenediamine, diethylenetriamine, triethylenetetramine, tetraethylenepentamine, penta Aliphatic polyamines such as ethylenehexamine, aromatic polyamines such as metaxylylenediamine, diaminodiphenylmethane, and phenylenediamine, alicyclic polyamines such as 1,3-bis (aminomethyl) cyclohexane, isophoronediamine, and these polyamines Examples thereof include modified polyamines obtained by performing a modification reaction such as polyamidation, epoxy adduct formation, Mannich formation, ketiminization and the like by known methods. These amine curing agents (C) may be used alone or in combination of two or more.

  In the epoxy resin coating composition of the present invention, the amine curing agent (C) preferably has 0.5 to 3.0 equivalents of active hydrogen with respect to 1 equivalent of the epoxy group of the epoxy resin component (B). And more preferably 0.6 to 1.5 equivalents of active hydrogen. The compounding amount of the amine-based curing agent (C) within the above specified range is preferable from the viewpoints of the curability, non-adhesiveness and adhesion of the coating film. In the epoxy resin coating composition of the present invention, the total content of the epoxy resin component (B) and the amine curing agent (C) is preferably 10 to 80% by mass.

  Further, as described later, the amine-based curing agent (C) has a value X of 0.5 to 10 on the left side of the relational formula (I) established between the amine-based curing agent (C) and the solvent (D) having a carbonyl group in the molecule. Selected to be. For this reason, it is preferable that the amine value (total amine value prescribed | regulated to JISK7237) of amine type hardening | curing agent (C) exists in the range of 50-1000, and, thereby, the solvent (( Selection of D) is further facilitated.

  In the epoxy resin coating composition of the present invention, the solvent (D) having a carbonyl group in the molecule is used to extend the pot life without reducing the curability after coating of the epoxy resin coating composition of the present invention. The solvent used. In addition, pot life means the longest time which can maintain the state which can be painted, after mixing an amine-type hardener with an epoxy resin component in an epoxy resin coating composition.

The inventor has found that the carbonyl group of the solvent (D) can extend the pot life by masking the lone pair of electrons on the nitrogen atom of the amine curing agent (C). Relational expressions (I) to (III) established between the agent (C) and the solvent (D):
X = P / Q (I)
P = (Amount of solvent (D)) / (Molecular weight of solvent (D)) (II)
Q = (Amine value of amine curing agent (C)) × (Amount of amine curing agent (C)) / 56110 (III)
[In formula (II), the compounding amount of the solvent (D) is the compounding amount (parts by mass) of the solvent (D) with respect to 100 parts by mass of the epoxy resin component (B), and the amine value of the amine curing agent (C). Is the total amine value specified in JIS K 7237, and the compounding amount of the amine curing agent (C) is the compounding amount (part by mass) of the amine curing agent (C) with respect to 100 parts by mass of the epoxy resin component (B). ). Here, P in the formula (II) is an indicator of the number of molecules of the solvent (D) contained in the epoxy resin coating composition of the present invention, and Q in the formula (III) is an epoxy resin coating composition of the present invention. This is an index of the number of lone pairs of the amine curing agent (C) contained in the product. In addition, it is considered that the “amine value of the amine-based curing agent (C)” is substantially equal to “the number of lone pairs”, and in order to unify the unit with the solvent (D), 56110 [= 56.11. Formula (II) was derived using (KOH molecular weight) × 1000 (mg converted to g)] as a constant.

  And in the epoxy resin coating composition of this invention, the value X of the left side of Formula (I) calculated | required from said Formula (I)-(III) needs to be 0.5-10, and 1.0 It is preferable that it is -5.0. If X is 0.5 to 10, the number of molecules of the carbonyl compound is sufficient with respect to the number of lone electrons on the nitrogen atom of the amine-based curing agent, so that the pot life is sufficiently long and the curability after coating. It is possible to provide a coating composition that is also good. Also, if X is less than 0.5, the number of molecules of the carbonyl compound is insufficient with respect to the number of lone electrons on the nitrogen atom of the amine curing agent, so that the pot life is shortened, causing problems in construction, If it exceeds 10, the number of molecules of the carbonyl compound will be excessive, so that the curability after coating will decrease, or lifting may occur during coating on the old paint film due to the relatively strong solvent (D). .

In the epoxy resin coating composition of the present invention, the solvent (D) having a carbonyl group in the molecule is not particularly limited, but the following general formula (IV):
R ₁ C (═O) R ₂ (IV)
[Wherein, R ₁ and R ₂ are each independently an alkyl group or an aryl group, or R ₁ and R ₂ are united to form a cyclic structure, provided that R ₁ and R ₂ carbon atoms The total of the numbers is 3 to 9.] is preferable.

Examples of the alkyl group include a methyl group, an ethyl group, an isobutyl group, and an isoamyl group. Examples of the aryl group include a phenyl group. Incidentally, the total number of carbon atoms of R ₁ and R ₂ is required to be 3 to 9, preferably a 5-8 from the viewpoint of odor and inflammability.

  Specific examples of the solvent (D) include acetone, methyl ethyl ketone, diethyl ketone, methyl isobutyl ketone, methyl isoamyl ketone, diisobutyl ketone, cyclohexanone, isophorone, propiophenone, acetophenone, and the like. Among these, methyl isobutyl ketone, methyl isoamyl ketone, diisobutyl ketone, and cyclohexanone are preferable because they have relatively mild odor and flammability and are easily available industrially.

  The epoxy resin coating composition of the present invention may further contain a pigment (E) such as a color pigment, an extender pigment, and a rust preventive pigment. By containing the pigment (E), the coating film can be easily identified, which is useful for painting work. In particular, a color pigment is preferable because it is highly effective even in a small amount. Specific examples of the color pigment include titanium oxide, zinc oxide, carbon black, black iron oxide, red iron oxide, yellow iron oxide, titanium yellow, chrome green, cobalt blue and other inorganic color pigments, azo-based, phthalocyanine-based, Organic colored pigments such as condensed polycyclic systems are mentioned. Specific examples of extender pigments include calcium carbonate, barium sulfate, aluminum silicate, magnesium silicate, barium carbonate, and silicon oxide. Furthermore, specific examples of the rust preventive pigment include zinc phosphate, aluminum tripolyphosphate, aluminum phosphomolybdate, zinc molybdate, calcium calcium molybdate, zinc phosphite and the like. These pigments (E) may be used individually by 1 type, and may be used in combination of 2 or more type. In the epoxy resin coating composition of the present invention, the content of the pigment (E) is not particularly limited as long as the coating film has a concealability within an appropriate range. 50 mass% is preferable.

  In the epoxy resin coating composition of the present invention, additives such as a reactive diluent, a non-reactive diluent, a thickener, a dispersant, and an antifoaming agent are not harmed as the other components. It can select suitably and mix | blend within the range. As these additives, commercially available products can be suitably used.

The epoxy resin coating composition of the present invention comprises the solvent (A), the epoxy resin component (B), the amine curing agent (C) and the solvent (D), and various additives appropriately selected as necessary. It can be prepared by mixing. Moreover, the coating method of the epoxy resin coating composition of the present invention is not particularly limited, and general coating means such as brush coating, roller coating, spray coating, various automatic coating machines, and the like can be used. Furthermore, since the application amount of the epoxy resin coating composition of the present invention depends on the degree of suction by the base material and the deterioration of the old coating film, it is difficult to define this, but usually 0.05 to 1 0.0 kg / m ² , preferably 0.1 to 0.5 kg / m ² .

  Next, the coated body of the present invention will be described in detail. The first coated body of the present invention comprises a base material and a coating film formed on the surface of the base material, and the coating film is obtained by the above-described epoxy resin coating composition. To do. Here, the base material is not particularly limited. For example, wood fiber reinforced cement board, fiber reinforced cement board, ceramic siding such as fiber reinforced cement / calcium silicate board, mortar, lightweight cellular concrete, metal Examples include exterior wall materials for construction and building materials such as siding and tiles.

  The 2nd coating body of this invention is equipped with the coating base material covered with the old coating film, and the coating film formed in this coating base material surface, The coating film formed in this coating base material surface Is obtained by the above-mentioned epoxy resin coating composition. The above-mentioned epoxy resin coating composition contains a mixed aniline point or a solvent (A) having an aniline point in the range of 12 to 70 ° C. as defined in JIS K 2256. It is possible to provide a coated body that hardly causes film shrinkage and has an excellent coating film appearance. In addition, an old coating film means the coating film which has already covered the base material at the time of the application of the said epoxy resin coating composition as above-mentioned. In addition, the coated substrate means a substrate in which a part or all of the substrate surface is covered with a coating film, and the substrate is, for example, in the first coated body of the present invention. What has been described.

  Hereinafter, the present invention will be described in more detail with reference to examples. However, the present invention is not limited to the following examples.

Example 1
100 parts by weight of “jER168V70”, 80 parts by weight of mineral spirit, and 10 parts by weight of methyl isobutyl ketone were sequentially charged in a container, and mixed and stirred until uniform, and this was used as the main agent. To this main agent, 17 parts by mass of “Fujicure FXP-8086” as a curing agent was added and mixed and stirred to obtain a coating composition.

(Examples 2-4 and Comparative Examples 1-2)
A coating composition was obtained in the same manner as in Example 1 except that the raw material according to the formulation according to Tables 1 and 2 was used.

(Example 5)
In a container, 100 parts by weight of “jER168V70”, 80 parts by weight of mineral spirit, 40 parts by weight of titanium oxide, 60 parts by weight of talc, and 10 parts by weight of methyl isobutyl ketone are sequentially charged and kneaded for 1 hour using a paint conditioner. Was the main ingredient. To this main agent, 17 parts by mass of “Fujicure FXP-8086” as a curing agent was added and mixed and stirred to obtain a coating composition.

(Examples 6-8 and Comparative Examples 3-4)
A coating composition was obtained in the same manner as in Example 5 except that the raw material according to the formulation according to Tables 1 and 2 was used.

(Comparative Example 5)
A commercially available “Mighty Epo Sealer Clear” (manufactured by Dainippon Paint Co., Ltd., strong solvent two-pack type epoxy resin sealer) was used. In addition, about 38 mass% of xylene (mixed aniline point: 10 degreeC) is contained in the coating material, and the solvent and pigment which a mixed aniline point or an aniline point exists in the range of 12-70 degreeC are not contained.

(Comparative Example 6)
A commercially available “Mighty Epo Sealer White” (manufactured by Dainippon Paint Co., Ltd., a strong solvent two-pack type epoxy resin sealer) was used. In addition, about 28 mass% of xylene (mixed aniline point: 10 degreeC) is contained in the coating material, and the solvent in which the mixed aniline point or aniline point exists in the range of 12-70 degreeC is not contained. Moreover, the said coating material contains a total of about 36 mass% of titanium dioxide, barium sulfate, and a talc as a pigment.

Below, the compounding agent used in Table 1 and Table 2 is demonstrated.
(Note 1) “jER168V70”: An epoxy resin having a mineral spirit solution of a modified bisphenol A type epoxy resin, solid content of 70% by mass, and two or more epoxy groups in the epoxy resin component (B), manufactured by Mitsubishi Chemical Corporation. Content of about 65% by mass, epoxy equivalent of epoxy resin component (B) 460, mineral spirit aniline point 43 ° C.
(Note 2) “Epicron 5920-70MS”: manufactured by DIC, mineral spirit solution of alkylphenol novolac type epoxy resin, solid content 70% by mass, epoxy having two or more epoxy groups in the epoxy resin component (B) in the molecule The resin content is about 60% by mass, the epoxy equivalent of the epoxy resin component (B) is 650, and the aniline point of mineral spirit is 43 ° C.
(Note 3) “Mineral spirit”: aniline point: 43 ° C.
(Note 4) “Methyl isobutyl ketone”: molecular weight 100.
(Note 5) “Diisobutylketone”: molecular weight 142.
(Note 6) “Fujicure FXP-8086”: manufactured by T & K TOKA, modified with epoxy adduct of 1,3-bis (aminomethyl) cyclohexane, amine value 210

  Subsequently, regarding the said coating composition, sclerosis | hardenability, old coating-film suitability, pot life, and identification of the coating film were evaluated by the following method. The results are shown in Tables 3-4.

<Curing property>
A tin plate was coated with a coating composition using a 4 mil applicator, and the coating composition was dried for 4 hours in an atmosphere at a temperature of 23 ° C. and a humidity of 50% RH. Evaluation was performed according to the test method of K5600-3-2. Evaluation criteria are shown below.
○: Balotini is lightly brushed and can be removed without scratching the surface of the coating.
Δ: When the ballotini is lightly brushed, the surface of the coating film is scratched, but the ballotini can be removed.
X: Even if the ballotini is lightly brushed, the ballotini cannot be removed.

<Formality of old paint film>
“Acrytop DX” (manufactured by Dainippon Paint Co., Ltd., acrylic resin enamel) was applied to the tin plate and dried for 7 days to prepare a coated tin plate. Next, the coating composition is brush-coated on the coated tin plate so that the coating composition becomes 0.15 kg / m ^2, and the coating composition is used in an atmosphere at a temperature of 23 ° C. and a humidity of 50% RH. The product was dried for 4 hours, and further, the coating composition was brush-coated on the obtained coating film so that the coating composition was 0.15 kg / m ^2, and the atmosphere was at a temperature of 23 ° C. and a humidity of 50% RH. Under the condition, the coating composition was dried for 4 hours to prepare a coated tin plate. The coated surface state of the coated tin plate was evaluated. Evaluation criteria are shown below.
○: The painted surface is smooth and there is no abnormality.
X: There is a itch on the painted surface.

<Pot life>
After mixing the main agent and the curing agent, the coating composition is allowed to stand in an atmosphere at a temperature of 23 ° C. and a humidity of 50% RH for 7 hours, and then brushed on a tin plate, at a temperature of 23 ° C. and a humidity of 50% RH. Under an atmosphere, the coating composition was dried for 4 hours to prepare a coated tin plate. The coated surface state of the coated tin plate was evaluated. Evaluation criteria are shown below.
○: The painted surface is smooth and there is no abnormality.
X: The coated surface is not uniform or cannot be painted.

<Identification of coating film>
A tin plate was coated with the coating composition using a 4 mil applicator, and the coating composition was dried for 4 hours in an atmosphere of a temperature of 23 ° C. and a humidity of 50% RH to prepare a coated tin plate. The coated surface state of the coated tin plate was visually evaluated. Evaluation criteria are shown below.
○: Easy to distinguish between painted and unpainted areas.
Δ: Although it is not easy to distinguish between a painted part and an unpainted part, it can be distinguished by careful observation.
X: The painted part and the unpainted part cannot be distinguished.

Claims (3)

A solvent (A) having a mixed aniline point or aniline point defined in JIS K 2256 within a range of 12 to 70 ° C., and an epoxy resin component (B) soluble in the solvent (A), the epoxy An epoxy resin component (B) containing at least an epoxy resin having two or more groups in the molecule, an amine-based curing agent (C) soluble in the solvent (A), and a molecule different from the solvent (A). A solvent (D) having a carbonyl group , which has the following general formula (IV):
R ₁ C (═O) R ₂ (IV)
[Wherein, R ₁ and R ₂ are each independently an alkyl group or an aryl group, or R ₁ and R ₂ are united to form a cyclic structure, provided that R ₁ and R ₂ carbon atoms The sum of the numbers is 3 to 9] is an epoxy resin coating composition containing a solvent (D) which is a carbonyl compound represented by the following formula:
The following formulas (I) to (III):
X = P / Q (I)
P = (Amount of solvent (D)) / (Molecular weight of solvent (D)) (II)
Q = (Amine value of amine curing agent (C)) × (Amount of amine curing agent (C)) / 56110 (III)
[In formula (II), the compounding amount of the solvent (D) is the compounding amount (parts by mass) of the solvent (D) with respect to 100 parts by mass of the epoxy resin component (B), and the amine value of the amine curing agent (C). Is the total amine value specified in JIS K 7237, and the compounding amount of the amine curing agent (C) is the compounding amount (part by mass) of the amine curing agent (C) with respect to 100 parts by mass of the epoxy resin component (B). The epoxy resin coating composition is characterized in that the value X on the left side of the formula (I) determined from A coated body comprising a base material and a coating film formed on the surface of the base material, wherein the coating film is obtained from the epoxy resin coating composition according to claim 1 . The epoxy resin according to claim 1, comprising: a coated base material covered with an old coating film; and a coating film formed on the surface of the coated base material, wherein the coating film formed on the surface of the coated base material. A coated body obtained by using a coating composition.