JPH03296580A - Coating composition - Google Patents

Abstract

PURPOSE:To obtain a coating composition capable of providing a coating film improved in strength, corrosion resistance, water resistance, scratch resistance and processability by incorporating a specific epoxy-modified polyester resin, an amino resin and/or a polyisocyanate compound as essential ingredients. CONSTITUTION:An epoxy-modified polyester resin derived from a polyester which is obtained by using an aromatic dibasic acid (e.g. terephthalic acid) as an essential acid component and an alkylene oxide (e.g. ethylene oxide) adduct of bisphenol A (e.g. a reaction product of this polyester and a diglycidyl ether of neopentyl glycol) as an essential alkaline component, an amino resin and/or a polyisocyanate compound (e.g. methyl-etherified melamine resin) are used as essential ingredients.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a novel and useful coating composition. More specifically, the present invention comprises a specific epoxy-modified polyester resin and a specific curing agent component (crosslinking agent component).
Alternatively, the present invention relates to a coating composition comprising a specific epoxy-modified polyester resin, a specific curing agent component (crosslinking agent component), and a pigment as essential components.

The coating composition of the present invention can be used primarily as a coating for painted steel plates, especially as a coating for coated steel plates that require good workability.

[Conventional technology]

Currently, the most required performance for coated steel sheets is workability during bending.

And, as a paint for this painted steel plate, so far,
A large number of paints have been used, including alkyd resins, oil-free alkyd resins, acrylic resins, epoxy resins, vinyl resins, and fluorine resins.
However, the current situation is that all of these methods have limitations in terms of use due to poor balance in terms of performance, in which if emphasis is placed on the workability of the upper girder, other performances are inferior.

Among these, oil-free alkyd resin paints have the best balance between processability and other performance, but they are still not in a satisfactory state.

Conventionally, the main methods of improving processability have been to increase the amount of aliphatic acids and aliphatic alcohols in the resin, or to increase the molecular weight and reduce the crosslinking points of the polyester resin. Two methods have been adopted, such as providing flexibility.

If workability is increased in this way, in the former case, corrosion resistance inevitably decreases, and in the latter case, water resistance inevitably decreases.

Therefore, various attempts have been made to improve the physical properties of oil-free alkyd resins.

For example, an alkylene oxide adduct of bisphenol A (hereinafter referred to as BPAO) has been used as a glycol raw material for a long time in order to improve processability and corrosion resistance, but it is not sufficient.

There are also attempts to improve corrosion resistance and adhesion by combining gepoxide and polyester resin.
Special Publication No. 49-40863, Special Publication No. 1-20192
(Publication), this is also not sufficient.

Furthermore, attempts have been made to improve corrosion resistance and scratch resistance by using a combination of a polyester resin using BPAO and a hisphenol A-epichlorohydrin type epoxy resin. A part is also disclosed in JP-A-60-141768.

However, it still has not reached the level of sufficient improvement.

[Problem to be solved by the invention]

In this way, as long as conventional techniques such as those mentioned above are followed, paints with high workability and other physical properties such as corrosion resistance and water resistance, which are so-called practical paints, have been developed. The reality is that resins and, by extension, coating compositions have not yet been found.

Therefore, the present inventors have begun earnest research in an effort to provide a coating composition for coated steel plates that satisfies the above-mentioned properties such as workability.

Therefore, the problem to be solved by the present invention is to provide a material that not only has high workability but also has excellent other physical properties such as corrosion resistance and water resistance. The object of the present invention is to provide a highly practical coating composition.

[Means to solve the problem]

Therefore, the inventors of the present invention focused on the problems to be solved by the invention as described above, and as a result of repeated studies,
An extremely useful paint for painted steel sheets that can solve problems by using a specific modified polyester resin obtained by reacting a polyester resin with a specific composition and structure with a specific polyepoid as an essential component. By obtaining the composition, the present invention was completed.

That is, the present invention aims to provide a coating composition containing a specific epoxy-modified polyester resin (A) and an amino resin and/or a polyisocyanate compound (B) as essential components; The present invention aims to provide a coating composition comprising a specific epoxy-modified polyester resin (A), an amino resin and/or a polyisocyanate compound (B), and a pigment, respectively, as essential components.

Here, first, the above-mentioned epoxy-modified polyester resin refers to, for example, a polyester (a-1) containing an aromatic dibasic acid, an alkylene oxide adduct of bisphenol A, and an alkylene glycol as essential components, and an aliphatic and/or fatty acid. Cyclic polyvalent epoxide (a-2
), but among these raw material components, first of all, such polyester is obtained by using a large amount of aromatic acid and BPAO, and has particularly excellent corrosion resistance. , terephthalic acid, isophthalic acid, orthophthalic acid, 2.
6-naphthalene dicarboxylic acid, 4,4'-diphenyldicarboxylic acid or dimethyl ester thereof, etc.
Of course, these may be used alone or in combination of two or more.

On the other hand, examples of particularly representative aliphatic dibasic acids include succinic acid, glutaric acid, adipic acid, azelaic acid, pimelic acid, speric acid, and sebacic acid. Typical examples of cyclic dibasic acids include tetrahydrophthalic acid (anhydride), methyltetrahydrophthalic acid (anhydride), hexhydrophthalic acid (anhydride), and hexahydrothele (anhydrous). Phthalic acid, methyltetrahydrophthalic acid, endomethylenetetrahydrophthalic acid,
methylendomethylenetetrahydrophthalic acid,
(Anhydrous) maleic acid, fumaric acid, itaconic acid, etc., and it goes without saying that these may be used alone or in combination of two or more types.

On the other hand, with respect to such acid components, only representative alkylene oxide adducts of bisphenol A as alcohol components used in the present invention are listed. As an adduct, the number of moles of alkylene oxide added is 2 to 8 moles per 1 mole of bisphenol A, and it can be used singly or as a mixture of two or more.

This is because if the number of moles of alkylene oxide added exceeds 8, the water resistance will inevitably deteriorate.
Preferably, 2 to 6 moles of ethylene oxide adduct to bisphenol A, 2 to 6 moles of propylene oxide adduct to bisphenol A, and more preferably 2 to 4 moles of ethylene oxide adduct to bisphenol A. It is.

To exemplify only particularly representative alkylene glycols, ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, dipropylene glycol, trimethylene glycol, 1,4-butanediol, 1,3- These include butanediol, 1.5-bentanediol, isopentyl glycol, 1.6-hexanediol, neopentyl glycol, etc., and it goes without saying that these may be used alone or in combination of two or more.

In addition, in obtaining the epoxy-modified polyester resin, glycol components that can be used as necessary in the preparation of polyester (a-1) include 1,4-cyclohexane dimetatool, bis-hydroxyethyl terephthalate, and hydrogenated bisphenol. Examples include aromatic glycols such as alkylene oxide adducts of A or hydrogenated bisphenol A, as well as well-known and commonly used alicyclic glycols.

It goes without saying that a monoepoxy compound can also be used as the glycol component.

Particularly representative polybasic acids with trifunctionality or more are trimellitic acid (anhydride), pyromellitic acid (anhydride), trimesic acid, or cyclopentanetetracarboxylic acid, and polyhydric alcohols with trifunctionality or more. Particularly representative are glycerin, trimethylolethane, trimethylolpropane, pentaerythritol, dipentaerythritol or Manlift.

The amount of these polyester components used depends on the purpose of use.
Although selected as appropriate, aromatic acids preferably account for 60 mol% or more of the total acid component and account for 35% of the total alcohol component.
Preferably, BPAO occupies a range of 95 mol %. In cases where the aromatic acid content is less than 60 mol%, or when B
If PAO is less than 35 mol% and the content of aromatic nuclei is low, corrosion resistance and adhesion will inevitably be inferior, whereas if BPAO is more than 95 mol%, reactivity will be poor. Either case is undesirable because it will become inferior.

The usage amounts of trifunctional or higher polybasic acid and polyhydric alcohol are as follows:
It is desirable that both amounts be 3 mol % or less in the total acid components or the total alcohol components.

This is because if the amount exceeds 3 mol %, processability inevitably deteriorates.

The molecular weight of the polyester thus obtained is preferably 5,000 or more in terms of number average molecular weight. 5,0
If it is less than 0.00, sufficient workability cannot be obtained, and more preferably 7,000
That's all. However, the molecular weight is 20.000
If it exceeds the above range, the number of crosslinking reaction points in the polymer will be significantly reduced and the reactivity will be poor, so that water resistance, adhesion, etc. will be deteriorated, which is not preferable.

The terminal functional groups of polyester require a large number of acid groups for the purpose of modification with polyhydric epoxide in the subsequent reaction. Therefore, its acid value is 3 or more and 3
It is preferably in the range of less than 0 (K OHm g/g). If the acid value is less than 3, the effect of polyvalent epoxide modification cannot be sufficiently obtained, and if the acid value is 30 or more, the processability becomes poor, which is not preferable. More preferably, 5
The acid value is within the range of 20 or more.

In order to obtain such a polyester resin, any of the polyester synthesis methods known for boat fishing can be applied. Industrially, esterification using a solvent method and polycondensation reaction under high vacuum are preferred.

Next, to describe the composition of the aliphatic and/or alicyclic polyepoxide (a-2) used in preparing the epoxy-modified polyester resin, this polyvalent epoxide (a-2) is as follows: It refers to a polymer that can impart reactivity to the end of the polymer and give flexibility to the crosslinking reaction site. Therefore, it is preferable to use an epoxide of the type having an aromatic nucleus or a type of epoxide having a high hydroxyl value, and specifically, an epoxy resin of the epichlorohydrin-bisphenol A type is not preferable.

Compositions include aliphatic ether type such as glycerin diglycidyl ether and neopentyl glycol diglycidyl ether; hydrogenated bisphenol A-epichlorohydrin type such as Epiclon 750J [product of Dainippon Ink & Chemicals Co., Ltd.]; “Aracast CY
-184 or CY-192J (product of Ciba Geigy); alicyclic glycol ester types such as adipic acid diglycidyl ester or sebacate diglycidyl ester; Bunacol EX-830J [Nagase Polyethylene glycol glycidyl ether type products such as Kasei Kogyo Co., Ltd. products; Polypropylene glycol glycidyl ether type products such as Bunacol EX-930J (product of the same company); Aracast CY-350J
Hydantoin-type products such as (Ciba Geigy product);
“Butadiene-modified products such as Epiclon EXA-140J [product of Dainippon Ink and Chemicals Co., Ltd.];
Typical examples include cyclic oxirane type products such as Aragyasto CY-175J (product of Ciba Geigy); and polyhydric alcohol ether type products such as Epiclon 707J [product of Dainippon Ink & Chemicals Co., Ltd.]. It is used as one kind or a mixture of two or more of the above polyvalent epoxides.

Regarding the number of functional groups in one molecule of such polyvalent epoxide, it is preferable that the average number of functional groups in the polyvalent epoxide mixture is 3 or less, preferably 2.5 or less. If the number of functional groups greatly exceeds 3, there is a risk of gelation during epoxy modification.

The epoxy equivalent of this polyvalent epoxide is 600
The following are appropriate: If it exceeds 600, the water resistance inevitably becomes poor, which is not preferable.

From the viewpoint of the balance of coating film properties such as processability and water resistance, it is preferable to use aliphatic and/or alicyclic diglycidyl ethers.

Alternatively, the use of aliphatic and/or cycloaliphatic digly, cidyl esters is preferred.

Thus, each polyester (a-1) used in obtaining the epoxy-modified polyester resin
As for the ratio of the acid groups in the polyepoxide (a-2) and the epoxy groups in the polyvalent epoxide (a-2) during modification, it is appropriate that the equivalent ratio of acid groups:epoxy groups is within the range of 1:0, 5 to 1:2. It is.
If this equivalent ratio is less than 0.5, sufficient reactivity and processability cannot be obtained, and if it exceeds 2, unreacted epoxide with the polyester will remain, and as a result, the effects of the present invention will not be as expected. . More preferably, this equivalent ratio is within the range of 1:0.8 to 1:2.

The obtained epoxy-modified polyester resin can be subjected to various modifications such as acid addition, amino resin collinearity, urethanization, etc., as with ordinary polyesters, as long as the effects of the present invention are not departed from.

Typical examples of organic solvents used in the present invention include benzene, toluene, xylene, Swasol 1000, 1500 or 1800.
Aromatic hydrocarbons such as J [Maruzen Petrochemical Co., Ltd. products]; methyl ethyl ketone, methyl isobutyl ketone,
Ketones such as cyclohexanone and isophorone; esters such as ethyl acetate, butyl acetate, and cellosolve acetate; It goes without saying that these solvents may be used alone or in combination of two or more.

Furthermore, an ether solvent can also be used if necessary.

However, if an alcoholic solvent is used before modification with a polyhydric epoxide, it may delay various reactions or cause side reactions, so special care should be taken in this regard.

When discussing the amino resin and/or polyisocyanate compound (B) constituting the coating composition of the present invention, firstly, only particularly representative amino resins are exemplified, such as melamine, benzoguanamine, Compounds such as acetoguanamine, urea, thiourea, ethylene urea or "CTU guanamine" [guanamine having a spiroacetal ring manufactured by Fuji Kasei Kogyo Co., Ltd.], formaldehyde or its equivalent substance, by a known and commonly used method. It is a condensate obtained by the reaction, or a condensate obtained by etherifying these condensates with alcohol.

These amino resins may be used alone or as a mixture of two or more.

On the other hand, only typical examples of polyisocyanate compounds include aliphatic diisocyanates such as hexamethylene diisocyanate and trimethylhexamethylene diisocyanate; aromatic diisocyanates such as xylene diisocyanate, tolylene diisocyanate, and diphenylmethane diisocyanate. ; or nuclear water additives of these aromatic diisocyanates;
These include alicyclic isocyanates such as isophorone diisocyanate, and further include polymers of these diisocyanates or adducts with polyhydric alcohols.

In addition, flocs of these diisocyanates can be used, and the pro-thickening agents include phenols, lactams, active methylenes, alcohols, mercaptans, acid amides, imides, Commonly known and commonly used compounds are exemplified by compounds selected from amine, amidazole, urea, oxime, and sulfite compounds.

When an amino resin is used as a curing agent, a coating film with high hardness is formed, while when a polyisocyanate compound is used, a coating film with high processability is formed. These various resins can be appropriately selected and used.

Further, as the above-mentioned pigment (C), to exemplify only typical ones, base coloring pigments such as titanium oxide and carbon black; extender pigments such as kaolin clay;
Zinc chromate, strontium chromate, zinc phosphate,
Pigments that are normally used in paints for baking include anticorrosion pigments such as aluminum phosphomolybdate, lead chromate, and zinc white.

In the present invention, epoxy modified polyester resin (A)
, the amino resin and/or polyisocyanate compound (B), and the pigment (C) used as necessary:
It may be selected as appropriate depending on the application and required performance, as long as it does not depart from the effects of the present invention.

In addition, the coating composition of the present invention may contain coating additives such as a leveling agent, a rheology control agent, a face F4 dispersant, a thickener, a surfactant, a plasticizer, a flame retardant, and an ultraviolet absorber, as necessary. In order to obtain the coating composition of the present invention, the above-mentioned (
Components A), (B), and optionally (C) may be mixed using various mixers such as a ball mill, a sand mill, a roll kneader, or a blender.

Further, the composition of the present invention obtained in this manner may be applied as appropriate by means such as a roller, roll footer spray coating, or electrostatic coating.

Furthermore, other resins such as epoxy resins and acrylic resins can be blended into the coating composition of the present invention as long as they do not deviate from the objectives and effects of the present invention.

There are no particular restrictions regarding painting conditions or baking conditions, but
Preferably, a 2-coat, 2-bake method is used in which a top coat paint and a flamer coat paint are combined.

〔Example〕

Next, the present invention will be explained by reference examples, examples, and comparative examples.
- Layers, specifically explained.

Note that all parts and percentages are based on weight unless otherwise specified.

Reference Example 1 [Example of Preparation of Epoch Modified Polyester Resin (A)] In a reaction apparatus equipped with a heating device, a stirrer, a reflux device, a water separator, a thermometer, and a dropping device, 313% of terephthalic acid was added.
parts, 156 parts of isophthalic acid, 64 parts of sebacic acid, 95 parts of ethylene glycol, "Nukol BPE-2"
0J (Bisphenol A manufactured by Sanyo Chemical Industries, Ltd.)
482 parts of 2 mole adduct of ethylene oxide] were charged into a reaction vessel, and then dibutyltin oxide was added to
The reaction was carried out by raising the temperature to 230°C over 8 hours under a nitrogen stream.

Next, after maintaining the temperature at 230°C for 2 hours, xylene was added to the reactor and the reaction was continued in the presence of a solvent to obtain a saturated polyester resin having an acid value of 12°3. The number average molecular weight of this product was 8,000.

Afterwards, this saturated polyester was
00J/cyclohexanone = 65/35 (weight ratio) to adjust the nonvolatile content to 50%, and add "Bunacol 211J [neopentyl glycol dichloromethane sold by Nagase Chemical Industries, Ltd.]". glycidyl ether] and 0.2 parts of 2-methylimidazole.
5 parts were added, the temperature was raised to 130°C, and the reaction was carried out by heating for 10 hours.

After the reaction, Swazol 1500J and cyclohexanone were added to make the non-volatile content 40% to obtain a solution of the target resin with an acid value of 1.8.Hereinafter, this was abbreviated as modified polyester resin solution (A-1). do.

Reference Example 2 (same as above) 248 parts of terephthalic acid, 124 parts of isophthalic acid, 50 parts of sebacic acid, and 131 parts of ethylene glycol were added to a reaction apparatus equipped with a heating device, a stirrer, a condenser, a thermometer, and a dropping device. and “Ninicall BPE-4
0J (Bisphenol A manufactured by Sanyo Chemical Industries, Ltd.)
520 parts of ethylene oxide 4 mole adduct] and 0.7 parts of zinc acetate were charged into a reaction vessel, and under a nitrogen stream,
The temperature was raised to 230°C over 8 hours to allow reaction.

Next, after keeping it at 230℃ for 6 hours, it was heated for 2 hours.
While increasing the temperature to 50℃, reduce the pressure to 2 torr and heat to 25℃.
The polycondensation reaction was carried out by keeping at 0°C for 2 hours. After the temperature was lowered to 190° C., the pressure was returned to normal pressure, 15 parts of phthalic anhydride was added, and the mixture was kept for 1 hour to carry out an addition reaction to obtain a saturated polyester resin having an acid value of 6.1. The number average molecular weight of this product was 15,000. Further, the obtained saturated polyester resin had a composition as shown in Table 1 according to NMR analysis.

From then on, "Bunacol EX-2114 [Ebichron 7
The same operation as in Reference Example 1 was carried out except for changing to 38 parts of 50J (hydrogenated bisphenol A-epichlorohydrin type diglycidyl ether), and the nonvolatile content was 40%.
A target resin solution having an acid value of 2.0 was obtained. Hereinafter, this will be referred to as a modified polyester resin solution (A-2).

Reference Examples 3 to 5 (same as above) Modified polyester resin solutions (A-3) to (A-5) having the compositions shown in Table 1 were obtained in the same manner as in Reference Example 1.

Reference Example 6 (Preparation Example of Control Epoch Modified Polyester Resin) A modified polyester resin solution (A'-1) having the composition shown in Table 1 was obtained in the same manner as in Reference Example 1.

Reference Example 7 (Example of Preparation of Control Polyester Resin) A polyester resin solution (A' -2) was obtained.

Examples 1-6 and Comparative Examples 1 and 2 Reference Examples 1-
Various modified polyester resin solutions obtained in 7 (A-1
) to (A-5), a modified polyester resin solution for control (A''-1), and an unmodified polyester resin solution (A'-2). Isocyanate compound (B),
Add the amount shown in Table 2, and add 3 of titanium oxide (C).
After kneading in a sand mill for 1 hour, 0.3% of para-toluenesulfonic acid was added to obtain various coating compositions.

Next, each of these various coating compositions was applied to a zinc phosphate-treated steel plate so that the dry film thickness was 15 μm, and then baked at 270° C. for 1 minute.

Physical property tests were conducted on each of the coating films thus obtained.

The test results are summarized in Table 2.

(Test method) Gloss---Measurement of 60 degree specular reflectance.

Pencil hardness - m - Painted surface measured according to JIS X-5400 using a high-grade pencil specified in Month SS-6006.

Flexibility---A coated steel plate is bent 180 degrees and cracks at the bent part are determined.

2T is the same as the test plate at the bending part. sandwiching two steel plates of the same thickness shows.

○---No cracks.

×-11 There are cracks.

Boiling water resistance - m - Visual judgment of the condition of the coated surface after immersing the coated film in boiling water for 2 hours.

○---Good.

x--1 defective.

Xylene resistance---Displayed by the number of times the coated surface is wiped with gauze moistened with xylene until the base is exposed.

Corrosion resistance---based on JIS K-5400, 500
Judgment is based on the corrosion width from the cut part after a certain period of time.

0--Good.

×-m-defective.

Coin scratch resistance - m - Scratch the painted surface at an angle of about 45 degrees with a 10 yen coin and judge by the difficulty of scratching off the paint film.

0--1 Hard to be scraped off.

×-11 Easily scraped off.

Footnotes to Table 1 1) 6 moles of ethylene oxide adduct of bisphenol A, manufactured by Sanyo Chemical Industries, Ltd. 2) 3 moles of propylene oxide adduct of bisphenol A, manufactured by the same company 3) Nagase Chemical Industries, Ltd. 4) Diglycidyl ester of hydroxyethylphthalic acid, manufactured by Ciba Geigy, Switzerland 5) Bisphenol A-epichlorohydrin type epoxy resin, manufactured by Dainippon Ink & Chemicals Co., Ltd. 6) Marked with ○ This means that it is a polyvalent epoxide used.

Footnotes to Table 2 1) The respective amounts of amino resin and polyisocyanate compound are in parts by weight.

2) Methyl etherified melamine resin manufactured by Dainippon Ink & Chemicals Co., Ltd. 3) Butyl etherified melamine resin manufactured by Dainippon Ink & Chemicals Co., Ltd. 4) Methyl etherified methylol manufactured by Susumu Chemical Industry Co., Ltd. Melamine resin 5) Blocked isocyanate manufactured by Dainippon Ink & Chemicals Co., Ltd. 6) Aliphatic incyanate prepolymer manufactured by Dainippon Ink & Chemicals Co., Ltd. [Effects of the invention] The present invention obtained as described above The coating composition itself is a cross-linking reaction of a polymer in which the terminal end of a strong saturated polyester containing a large amount of aromatic nuclei and having excellent corrosion resistance and water resistance is modified with a flexible polyvalent epoxide. The point has adhesion and flexibility, so to speak.
By using a specific resin as the main component that itself has toughness, adhesion, and flexibility, it is strong, has excellent corrosion resistance, water resistance, and even scratch resistance, and is also easy to process. It is possible to form a coating film that

Claims (1)

[Scope of Claims] 1. Epoxy-modified polyester resin (A ) and an amino resin and/or a polyisocyanate compound (B) as essential components. 2. An epoxy-modified polyester resin (A) derived from a polyester obtained by using an aromatic dibasic acid as an essential acid component and an alkylene oxide adduct of bisphenol A as an essential alcohol component, an amino resin and A coating composition comprising a polyisocyanate compound (B) and a pigment (C) as essential components. 3. The epoxy modified polyester resin (A) described above is
A polyester (a-1) containing an aromatic dibasic acid, an alkylene oxide adduct of bisphenol A, and an alkylene glycol as essential components, and an aliphatic and/or alicyclic polyepoxide (a-2) are reacted. The coating composition according to claim 1 or 2, which is a coating composition according to claim 1 or 2. 4. The epoxy modified polyester resin (A) described above is
Polyester (a-1) comprising an aromatic dibasic acid, an aliphatic dibasic acid and/or an alicyclic dibasic acid, an alkylene oxide adduct of bisphenol A, and an alkylene glycol as essential components, and an aliphatic and/or alicyclic The coating composition according to claim 1 or 2, which is obtained by reacting the formula polyvalent epoxide (a-2). 5. The epoxy modified polyester resin (A) described above is
An aromatic dibasic acid, an aliphatic dibasic acid and/or an alicyclic dibasic acid, a trifunctional or higher functional polybasic acid and/or a trifunctional or higher functional polyhydric alcohol, an alkylene oxide adduct of bisphenol A, and an alkylene glycol. The coating composition according to claim 1 or 2, which is obtained by reacting polyester (a-1) as an essential component with aliphatic and/or alicyclic polyepoxide (a-2). 6. The epoxy modified polyester resin (A) described above is
The coating composition according to claims 1 to 5, which is obtained using polyester (a-1) having a number average molecular weight of 5,000 or more. 7. The epoxy modified polyester resin (A) described above is
The coating composition according to claims 1 to 6, which is obtained using the polyvalent epoxide (a-2) consisting of an aliphatic and/or alicyclic diglycidyl ether. 8. The epoxy modified polyester resin (A) described above is
The coating composition according to claims 1 to 6, which is obtained using the polyvalent epoxide (a-2) consisting of an aliphatic and/or alicyclic diglycidyl ester. 9. The epoxy modified polyester resin (A) described above is
60 mol% or more of the total acid component is an aromatic dibasic acid,
The coating composition according to any one of claims 1 to 6, which is obtained using a polyester (a-1) in which 30 to 95 mol% of the total alcohol component is an alkylene oxide adduct of bisphenol A.