JP2001002905A - Polyester-based resin composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a resin composition capable of providing good curability and making processability compatible with various characteristics such as excellent corrosion resistance, sanitariness and resistance to contents at a high level by including a specific polyester resin and a phenol resin. SOLUTION: This resin composition is obtained by including (A) (i) a polyester resin containing an aromatic ring to which an electron donative group is bonded and/or (ii) a modified polyester resin using the component (i) and (B) a phenol resin as a curing agent. A structure represented by the formula Ph-O-R [R is a (poly)alkylene; and Ph is phenylene] is preferably contained in the component A. The component A preferably has 20-100 deg.C glass transition temperature, >=0.3 dL/g molecular weight expressed in terms of reduced viscosity and 5,000-25,000 number-average molecular weight. The compounding ratio of the components A and B is preferably (95/5) to (60/40), more preferably (80/20) to (70/30) of the components A/B expressed in terms of weight ratio.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a polyester resin composition and, more particularly, to a resin composition for a paint and an adhesive for a metal material. More specifically, it is excellent in processability and corrosion resistance, and is excellent in chemical resistance such as acid resistance, hygiene (small amount of extraction), heat resistance and the like. The present invention provides coatings for coatings, coatings for inner and outer surfaces of metal cans, coatings for repairing seam portions of metal cans, adhesives for metal materials, and the like.

[0002]

2. Description of the Related Art Among pre-painted metal sheets, so-called pre-coated metal sheets take advantage of their economical efficiency, productivity, workability, etc., in the field of construction materials such as roof materials and wall materials, outdoor equipment such as storage, radiator units, VTRs, and the like. Widely used in home appliances such as washing machines and refrigerators. First as a painted metal plate
Is required to have excellent bending workability. Alkyd resins, acrylic resins, epoxy resins, etc. are currently used as paint resins, but these have problems in workability, and high-molecular-weight polyesters are used in fields requiring high workability. That is the current situation.

[0003] At present, epoxy resin is mainly used as a primer resin for a coated metal plate. However, since epoxy resin lacks flexibility, it cannot withstand advanced processing, and cracks occur in the coating film of the processed portion. It has the disadvantage of easily corroding. In addition, epoxy resin is generally recognized as having good corrosion resistance, but is poor in impact resistance, and has a problem of poor corrosion resistance of the end face because a small coating is formed on the end face when cutting a coated metal plate. There is. Due to the above problem, there is a serious drawback that the advantage cannot be used as a high processing primer, and when a high molecular weight polyester resin with good workability is used for the overcoat, the adhesion between the primer and the overcoat is poor. There is also a problem.

[0004] As a solution to such a problem,
JP-B-62-5467, JP-A-6-256712, JP-A-8-1137581 and the like are known, and workability, corrosion resistance, chemical resistance and the like are compatible to some extent, but the performance is still insufficient. It is hard to say that I was satisfied.

On the other hand, a combination of an epoxy resin and a phenol resin is widely used as a metal can inner coating. These have good retort resistance, content resistance,
It is widely used because of its sanitary properties. However, it is inferior in drawability or ironing process. is there. Therefore, when pre-coating with a roll coat, it is limited to three-piece cans.
Improvement of workability is strongly desired.

[0006] Considering such a problem,
JP-A-56-4664, JP-A-1-245065
JP-A-11-5941 and JP-A-11-5941 are known, and workability and hygiene, content resistance, retort resistance and the like are compatible to some extent, but are still insufficient and almost not practical. Not reached.

[0007]

However, the characteristics required for painted metal sheets have become stricter year by year, and workability and corrosion resistance, hardness, various stain resistance, chemical resistance, weather resistance, etc., regardless of construction materials and home appliances. Are required to be highly compatible with each other. Furthermore, it has been required to guarantee the corrosion resistance of the end face or the processed portion and the drawability. In the above-described conventional technology, the workability, the drawability and the corrosion resistance of the cross cut portion and the end face, or the workability. And the chemical resistance is no longer being satisfied.

That is, Japanese Patent Publication No. 62-5467 proposes an aromatic polyester obtained by copolymerizing an alkylene oxide adduct of bisphenol A, which has better processability and corrosion resistance than epoxy resin. Compared with epoxy resins, they have insufficient scratch resistance, and their corrosion resistance is also insufficient to meet recent requirements.

Japanese Patent Application Laid-Open No. 6-256712 proposes a low Tg polyester resin containing an alkylene oxide adduct of an aliphatic dicarboxylic acid and bisphenol A as a main component. Although it has good end face corrosion resistance, it is basically a soft resin having a small amount of aromatic components, so that it has poor scratch resistance, poor corrosion resistance at the cross cut portion, and poor chemical resistance.

Japanese Patent Application Laid-open No. Hei 8-1137581 proposes an aromatic polyester resin containing an alicyclic glycol and an alkylene oxide of bisphenol A as main components. The transition temperature must be 40 ° C or higher,
In this region, although good corrosion resistance of the cross cut portion can be obtained, there is a problem that the end surface and the processed portion have poor corrosion resistance.

As described above, it is extremely difficult to satisfy various required characteristics such as workability, corrosion resistance at the cross-cut portion, corrosion resistance at the end face, chemical resistance, and scratch resistance. In particular, both corrosion resistance at the cross-cut portion and the end face are compatible. It was difficult. Although overcoating resins have also been eagerly studied for such required properties, compatibility between workability and other coating film properties is insufficient, and satisfactory properties can still be obtained in combination with a conventional primer. Therefore, there has been a demand for the development of an excellent primer resin that has never existed before.

Improvements in processability have also been studied mainly as metal can inner surface paints, but the properties required are strict because they are used for food and beverages. Absent. That is, as an improved drawability, Japanese Patent Application Laid-Open No. 56-4664 discloses a copolymerized polyester containing terephthalic acid and propylene glycol as main components, but is excellent in hygiene and flavor. Poor toughness due to non-crystalline thermoplastic resin,
Inferior in workability, impact resistance, and content resistance, it has not been put to practical use. Japanese Unexamined Patent Publication (Kokai) No. 1-245065 discloses a compound in which a similar polyester and amino resin are blended. However, it has good workability, but is inferior in hygiene and poor in resistance to contents, and its use is limited. Japanese Patent Application Laid-Open No. H11-5941 discloses a composition in which an epoxy-modified polyester and a phenol resin are blended. However, the composition has relatively good hygiene properties, but is inferior in curability and does not have sufficient workability.

[0013]

In view of these problems, the present inventors have developed a resin for a primer paint having excellent corrosion resistance, workability, chemical resistance, and scratch resistance for a coated metal plate. As a coating material, as a result of intensive studies as an inner coating having both drawability and hygiene, content resistance, and retort resistance, a polyester resin containing an aromatic ring to which an electron donating group is bonded and / or a polyester resin containing By blending the modified polyester resin and phenol resin used, good curability was obtained, and it was found that excellent properties such as excellent corrosion resistance, hygiene, content resistance, and workability could be highly compatible, and reached the present invention. .

That is, the present invention relates to a polyester resin containing an aromatic ring to which an electron donating group is bonded and / or a modified polyester resin (A) using the polyester resin.
And a phenolic resin (B).

The polyester resin of the present invention and / or the modified polyester resin (A) using the polyester resin needs to contain an aromatic ring having an electron donating group bonded in the polyester skeleton. If it does not contain an aromatic ring to which an electron donating group is bonded, the reactivity with the phenolic resin (B) is extremely poor, and the processability is particularly poor.

The electron donating group includes an amino group, an alkylamino group, a hydroxyl group, an alkoxy group such as a methoxy group, an ethoxy group and a butoxy group, a hydroxy (poly) alkoxy group, an acetamino group, a phenyl group, a methyl group and an ethyl group. Alkyl groups such as methylene group and tert-butyl group, alkylene groups such as methylene group, propylene group and isopropylidene group, and polycyclic aromatic hydrocarbon groups containing naphthalene ring and fluorene ring. Must be linked to

Specific examples of the compound having an aromatic ring to which an electron-donating group which can be introduced into the polyester resin of the present invention and / or a modified polyester resin (A) using the polyester resin are represented by the following general formula (II): Alkylene oxide adducts of bisphenol A and / or bisphenol F having a hydroxyalkyl group and an alkylene group as electron-donating groups, 4-hydroxyisophthalic acid, p-oxybenzoic acid, dimethylolphenol, bisphenoxyethanolfluorene, oxydiene Hydroxyl group-containing aromatic compounds such as phenol, pyrocatechol, resorcinol, hydroquinone and / or
Or an alkylene oxide adduct thereof, an aniline derivative such as N-phenyldiethanolamine, or the like. Of these, an alkylene oxide adduct of bisphenol A and / or bisphenol F is particularly preferred from the viewpoint of curability and processability.

[0018]

Embedded image

(In the formula, R ₁ , R ₂ , and R ₃ are hydrogen or a methyl group, m and n each are 1 or more and 2 ≦ m + n ≦ 8.)

The method of introducing these compounds into the polyester resin is not limited, but can be copolymerized into the polyester resin by a known polycondensation method. The preferred content is 10 to 100 mol%, more preferably 30 to 60 mol%, based on the total acid or glycol component. If it is less than 10 mol%, the reactivity with the phenolic resin (B) decreases, and the processability may decrease.

As the polyester resin of the present invention and / or the modified polyester resin (A) using the polyester resin, the glass transition temperature is preferably 20 to 100 ° C. from the viewpoint of corrosion resistance, retort resistance, content resistance and the like. Adjust and use depending on the application. The molecular weight is preferably 0.3 dl / g or more in terms of reduced viscosity, more preferably 0.4 to 0.7 dl / g. 0.3dl reduced viscosity
If it is less than / g, workability may be reduced. Preferred number average molecular weight is 5,000 to 25,000.

Hereinafter, the polyester resin of the present invention and / or
Alternatively, the modified polyester resin (A) using the polyester resin will be described. The acid component to be copolymerized is, as the acid component other than the compound having an aromatic ring to which the above-mentioned electron donating group is bonded, 20 to 100% by mole of an aromatic dicarboxylic acid, 0 to 100% of an aliphatic and / or alicyclic dicarboxylic acid. 80
Preferably it is mol%. 2 aromatic dicarboxylic acids
If it is less than 0 mol%, corrosion resistance, scratch resistance, chemical resistance, flavor, and content resistance may not be obtained.

Examples of the aromatic dicarboxylic acid component of the polyester resin of the present invention and / or the modified polyester resin (A) using the polyester resin include terephthalic acid, isophthalic acid, orthophthalic acid and 2,6-naphthalenedicarboxylic acid. No. As the aromatic dicarboxylic acid, it is particularly preferable to use terephthalic acid and isophthalic acid in combination from the viewpoint of the properties of the coating film and the solubility.

The aliphatic dicarboxylic acid component of the polyester resin of the present invention and / or the modified polyester resin (A) using the polyester resin includes succinic acid,
Glutaric acid, adipic acid, sebacic acid, dodecanedioic acid, azelaic acid, dimer acid and the like. Of these, adipic acid and sebacic acid are particularly preferred in view of workability, corrosion resistance, and chemical resistance. As the alicyclic dicarboxylic acid component of the polyester resin of the present invention and / or the modified polyester resin (A) using the polyester resin,
Alicyclic dicarboxylic acids such as 2-cyclohexanedicarboxylic acid, 1,3-cyclohexanedicarboxylic acid, and 1,4-cyclohexanedicarboxylic acid are exemplified. this house,
1,4-cyclohexanedicarboxylic acid is preferred from the viewpoint of processability.

The glycol components other than the above-mentioned compound having an aromatic ring to which an electron-donating group is bonded in the polyester resin of the present invention and / or the modified polyester resin (A) using the polyester resin include ethylene glycol, diethylene glycol, Neopentyl glycol, propylene glycol, 1,3-propanediol, 2-methyl, 1,3-propanediol, 1,4-
Butanediol, 1,5-pentanediol, 1,6-
Hexanediol, 3-methyl, 1,7-octanediol, 8-methyl-1,8-octanediol, 2-butyl-2-ethyl-propanediol, 1,4-cyclohexanedimethanol, tricyclodecanedimethanol, Examples include polyethylene glycol and polypropylene glycol. Other glycols are appropriately selected from economics and physical properties of the coating film, but ethylene glycol, diethylene glycol and 1,4-cyclohexanedimethanol are particularly preferred.

Further, within a range not to impair the content of the invention, polycarboxylic acids such as trimellitic acid and pyromellitic acid or trimethylolethane, trimethylolpropane,
Polyhydric polyols such as glycerin and pentaerythritol may be used in combination. By copolymerizing an appropriate amount of such a trivalent or higher polycarboxylic acid or polyol, chemical resistance can be further improved.

The polyester resin of the present invention and / or
Alternatively, in the modified polyester resin (A) using the polyester resin, a dicarboxylic acid or glycol containing a sulfonic acid metal base may be used in a range of 5 mol% or less. As the dicarboxylic acid containing a sulfonic acid metal base,
Examples thereof include metal salts such as sulfoterephthalic acid, 5-sulfoisophthalic acid, 4-sulfonaphthalene-2,7-dicarboxylic acid, and 5 [4-sulfophenoxy] isophthalic acid. Examples of the glycol containing a sulfonic acid metal base include metal salts such as 2-sulfo-1,4-butanediol, 2,5-dimethyl-3-sulfo-2, and 5-hexanediol. As the metal salt, Li, Na, K, M
g, Ca, Cu, and salts such as Fe.

The polyester resin of the present invention and / or a modified polyester resin (A) using the polyester resin may be modified by graft polymerization with a vinyl polymerizable monomer such as a (meth) acrylate monomer or styrene, modified with an epoxy resin, or urethane with an isocyanate compound. Denaturation may be performed. The modified polyester resin by a vinyl polymerizable monomer copolymerizes a polyester resin with a dicarboxylic acid containing an unsaturated double bond such as fumaric acid or oleic acid to introduce an unsaturated double bond into the polyester resin. Radical polymerization of a double bond and a vinyl compound such as (meth) acrylate, styrene or vinyl acetate in a solution, or two hydroxy groups at one end synthesized from (meth) acrylate or styrene It is synthesized by a known method such as directly copolymerizing the contained macromonomer with the polyester.

The polyester resin modified with an epoxy resin is modified with a terminal carboxy modification by adding an acid anhydride such as trimellitic anhydride or phthalic anhydride to the terminal hydroxy group of the polyester resin, and then the carboxyl group and the epoxy resin are treated with tricarboxylic acid. It can be synthesized by a known method such as a method of epoxy modification in the presence of a catalyst such as phenylphosphine. Further, a carboxyl group may be introduced by using a carboxyl group-containing glycol such as dimethylolpropionic acid.

The urethane-modified polyester resin is synthesized by a known method such as blending a low molecular weight polyester diol with a chain extender if necessary and reacting with a diisocyanate compound. In addition, a carboxyl group may be introduced into a side chain by using a carboxyl group-containing diol such as dimethylolpropionic acid as a chain extender.

The resin composition for paints and adhesives according to the present invention must contain a polyester resin and / or a modified polyester resin (A) using the polyester resin and a phenol resin (B). By using the phenolic resin (B) as a curing agent, corrosion resistance, chemical resistance, and sanitation (extraction resistance) are significantly improved. The preferred amount of the phenolic resin (B) is (A) / (B) = 9.
5/5 to 60/40, more preferably (A) / (B)
= 80/20 to 70/30 (all by weight).
If the compounding amount of (A) exceeds 95 (A) / 5 (B), the curability will be insufficient, and the coating properties such as good corrosion resistance, chemical resistance, and scratch resistance will be poor, and 60 (A) / 40. If it is less than (B), good workability may not be obtained.

The phenolic resin (B) used in the resin composition for paints and adhesives of the present invention is not particularly limited, but a resole-type resin obtained by reacting phenols with an aldehyde in the presence of an alkali catalyst, phenol Novolak resins obtained by reacting aldehydes with aldehydes in the presence of acidic catalysts, and resol resins suitable as crosslinking agents are particularly preferable. Phenols used in these phenolic resins include phenol, o-cresol, p-cresol, m-cresol, m-methoxyphenol, 2,3
-Xylenol, 2,5-xylenol, p-tert
-Butylphenol, p-ethylphenol, bisphenol A, bisphenol F and the like, and alkylphenols are preferable from the viewpoint of compatibility with polyester. Mono- to trimethylol compounds of these phenols and condensates thereof, or alkyl ether compounds thereof, preferably butyl ether compounds, or those obtained by subjecting these to various modifications such as epoxy modification, oil modification, melamine modification, and amide modification are used. it can.

For the purpose of improving the curability, a phenol resin (B) and another curing agent such as an amino resin, an epoxy resin and an isocyanate compound may be used in combination as long as other properties such as hygiene are not reduced.

Examples of the amino resin include formaldehyde adducts such as urea, melamine and benzoguanamine;
Further, there may be mentioned alkyl ether compounds of alcohols having 1 to 6 carbon atoms. Specifically, methoxymethylolated urea, methoxylated methylol-N,
N-ethylene urea, methoxymethylol dicyandiamide, methoxylated methylol melamine, methoxylated methylol benzoguanamine, butoxylated methylol melamine, butoxylated methylol benzoguanamine, and the like, preferably methoxylated methylol melamine, butoxylated methylol melamine, and methylolated Benzoguanamine, each of which can be used alone or in combination

As the epoxy compound, bisphenol A
Diglycidyl ethers and oligomers thereof, diglycidyl ethers of hydrogenated bisphenol A and oligomers thereof, diglycidyl orthophthalate, diglycidyl isophthalate, diglycidyl terephthalate, diglycidyl p-oxybenzoate, tetrahydrophthalate Acid diglycidyl ester, hexahydrophthalic acid diglycidyl ester, succinic acid diglycidyl ester, adipic acid diglycidyl ester, sebacic acid diglycidyl ester, ethylene glycol diglycidyl ether, propylene glycol diglycidyl ether, 1,4-butanediol di Glycidyl ether, 1,6-hexanediol diglycidyl ether and polyalkylene glycol diglycidyl ethers, trime Triglycidyl citrate, triglycidyl isocyanurate, 1,4-diglycidyloxybenzene, diglycidyl propylene urea, glycerol triglycidyl ether, trimethylol ethane triglycidyl ether, trimethylol propane triglycidyl ether, pentaerythritol tetraglycidyl ether And glycerol alkylene oxide adduct triglycidyl ether.

Further, as the isocyanate compound, there are aromatic and aliphatic diisocyanates and trivalent or higher polyisocyanates, and either low molecular weight compounds or high molecular weight compounds may be used. For example, tetramethylene diisocyanate, hexamethylene diisocyanate, toluene diisocyanate, diphenylmethane diisocyanate, hydrogenated diphenylmethane diisocyanate, xylylene diisocyanate, hydrogenated xylylene diisocyanate, isophorone diisocyanate or trimers of these isocyanate compounds, and excess of these isocyanate compounds And the amount of low molecular active hydrogen compounds such as ethylene glycol, propylene glycol, trimethylolpropane, glycerin, sorbitol, ethylenediamine, monoethanolamine, diethanolamine, triethanolamine or various polyester polyols, polyether polyols, polyamides Anti-polymer active hydrogen compounds It includes terminal isocyanate group-containing compounds obtained by.

The isocyanate compound is preferably a blocked isocyanate. As the isocyanate blocking agent, for example, phenol, thiophenol, methylthiophenol, ethylthiophenol,
Phenols such as cresol, xylenol, resorcinol, nitrophenol, chlorophenol, acetoxime, methyl ethyl ketoxime, oximes such as cyclohexanone oxime, alcohols such as methanol, ethanol, propanol and butanol, ethylene chlorohydrin, 1,3-dichloro Halogen-substituted alcohols such as -2-propanol, tertiary alcohols such as t-butanol and t-pentanol, ε
Lactams such as caprolactam, δ-valerolactam, γ-butyrolactam, β-propyrolactam, and other active methylenes such as aromatic amines, imides, acetylacetone, acetoacetate, and malonic acid ethyl ester. Compounds, mercaptans, imines, ureas, diaryl compounds and sodium bisulfite are also included. The blocked isocyanate can be obtained by subjecting the above isocyanate compound to an isocyanate blocking agent to undergo an addition reaction by a conventionally known appropriate method.

A known curing agent or accelerator selected according to the type can be used in combination with these crosslinking agents.

Other resins may be used in combination with the polyester resin of the present invention and / or the modified polyester resin (A) using the polyester resin as long as the properties are not deteriorated.

The resin composition of the present invention is also suitable as an adhesive. Excellent adhesion and corrosion resistance to various metal materials,
Heat resistance is obtained.

The curing temperature of the resin composition for paints and adhesives of the present invention is arbitrarily selected depending on the size and thickness of the metal material, the capability of a baking furnace, the curability of the paint or adhesive, and the like. A mixer such as a roll mill, a ball mill, a sand mill, and a blender is used for the production of the coating composition. Roller coating, roll coater,
Spray coating, electrostatic coating, etc. are selected as appropriate.

The coating resin composition of the present invention may be provided with extenders such as titanium oxide, talc, barium sulfate, zinc chromate, strontium chromate, etc.
Anticorrosive pigments such as calcium chromate and colloidal silica, known colorants, additives such as silica and wax, and glass fibers can be blended.

The coating composition and the resin composition for an adhesive of the present invention are used in the form dissolved in an organic solvent. Examples of the organic solvent include toluene, xylene, Solvesso 1
00, 150, ethyl acetate, butyl acetate, methyl cellosolve, ethyl cellosolve, butyl cellosolve, ethyl carbitol, butyl carbitol, methyl cellosolve acetate, ethyl cellosolve acetate, butyl cellosolve acetate, methyl carbitol acetate, butyl carbitol acetate, methyl ethyl ketone, cyclohexanone , Isophorone, N-methylpyrrolidone, 2
It is appropriately selected from basic acid esters and the like in consideration of solubility and evaporation rate.

The coating composition and the resin composition for adhesives of the present invention exhibit sufficient performance even if they are applied and baked themselves, so that they are suitable for the backside coating of painted metal plates, etc. It is also possible to apply a topcoat known as a top coat for the purpose of improving weather resistance, stain resistance, alkali resistance and the like. When used as a paint for metal cans, it is suitable for inner surfaces because of its sanitary properties and content resistance, but it can of course be used for outer surfaces.

[0045]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to embodiments. In the examples, “parts” means “parts by weight”. Each measurement item followed the following method.

1. Reduced viscosity ηsp / c (dl / g) 0.10 g of a polyester resin was dissolved in 25 cc of a mixed solvent of phenol / tetrachloroethane (volume ratio: 6/4) and measured at 30 ° C.

2. Glass transition temperature Measured at a heating rate of 20 ° C./min using a differential scanning calorimeter (DSC). The sample was prepared by placing 5 mg of the sample in an aluminum holding lid type container and crimping it.

3. Acid value 0.2 g of sample was precisely weighed and dissolved in 20 ml of chloroform. Then, it was determined by titration with 0.01 N potassium hydroxide (ethanol solution). Phenolphthalein was used as the indicator.

4. Number average molecular weight It was measured by gel filtration chromatography (GPC) using a polystyrene standard sample for calibration.

5. Workability-1 The coated steel sheet was bent at 180 degrees, and cracks generated at the bent portions were observed and judged with a 10-fold loupe. 3T refers to a case where three sheets of the same thickness are sandwiched in the bent portion, and 0T refers to a case where the sheet is folded 180 degrees without sandwiching the board.

6. Workability-2 Painted tinplate is similarly bent at 1T, and the processed part is 1% N
It was evaluated by the current value when a voltage of 5 V was applied by bringing the sponge into contact with a sponge immersed in an aCl aqueous solution. The smaller the energization value, the better.

7. Drawing Workability The painted tin plate was drawn in two stages to form a cylindrical can with L (depth) / D (diameter at the bottom) = 2, and the state of cracks and whitening on the inner surface was visually evaluated. ：: No whitening and no cracks Δ: No cracking but whitening ×: Clear cracking or remarkable whitening

8. Acid-resistant coated steel sheet was immersed in 5% HCl at 40 ° C. for 48 hours, and the appearance of blisters on the coated surface was checked according to ASTM D714-56.
It evaluated according to. When there was no abnormality, it was set to 10.

9. Corrosion resistance The coated steel sheets were subjected to a 5% NaCl salt spray test at 35 ° C. for a predetermined time, and the occurrence of blisters was visually determined. The corrosion resistance was measured in a cross cut portion, a 2T processed portion in 1000 hours, and the end face (cut portion) in 500 hours. The evaluation criteria are shown below. 2T processed part ◎: No abnormality ○: Almost no blister △: Blister generation ×: Notable blister generation Cross cut part (blister blister width) ◎: 1 mm or less ○: 1 to 5 mm △: 5 to 10 mm ×: 10 mm or more XX : Many blisters generated End face (blister blister width) ： １: 1 mm or less ○: 1 to 5 mm △: 5 to 10 mm ×: 10 mm or more

10. Scratchability The coated steel sheet was evaluated at a load of 1 kg using a scratch tester equipped with a 10-yen coin. The evaluation criteria are shown below. ：: The primer surface is hardly visible. ○: The primer surface is visible but the metal base is not visible. X: The metal base is visible. XX: The metal base is significantly visible.

11. Retort Resistance After the test piece was treated under steam at 130 ° C. for 30 minutes, the state of whitening and blistering of the coating film was visually determined. ：: good (no whitening, no blister) △: slight (within 5% of the entire area) or blisters ×: significant (5% or more of the entire areas) whitening or blisters

12. Content resistance The test piece was treated in an aqueous solution containing 3 wt% of sodium chloride and 3 wt% of lactic acid at 130 ° C. for 30 minutes, and then the whitening of the coating film and the state of the blister were visually determined. ：: good (no whitening, no blister) △: slight (within 5% of the entire area) or blisters ×: significant (5% or more of the entire areas) whitening or blisters

13. Hygiene test A test piece having a coating area of 100 cm ² was immersed in 100 cc of a 20% aqueous ethanol solution, and was pressed under pressure at 120 ° C. for 60 hours.
After performing an immersion treatment for a minute, the extract after the immersion treatment was measured for an ultraviolet absorption spectrum at a wavelength of 200 to 300 nm with a U-3210 type spectrophotometer manufactured by Hitachi, Ltd., and evaluated by the maximum value of the absorption value (%). . The smaller the value, the better.

14. Preparation of Topcoat Paint Commercially dissolved high-molecular-weight polyester Byron 300 60 solid parts, Byron 200 40 solid parts (all manufactured by Toyobo Co., Ltd.), methyl etherified methylolmelamine Sumimar M40S (nonvolatile content 80%,
31 parts, manufactured by Sumitomo Chemical Co., Ltd.), 2.5 parts of a 10% benzyl alcohol solution of p-toluenesulfonic acid, and 125 parts of titanium oxide, and mixed with a glass bead-type high-speed shaker.
After time dispersion, a top coat was prepared. The solvent used was an appropriate amount of a cyclohexanone / solvesso 150 = 50/50 mixture.

15. Preparation of Painted Steel Sheet (Specimen) A 0.5 mm-thick hot-dip galvanized steel sheet having a basis weight of 60 g / m ² and subjected to a chromate treatment was used as a base material. A predetermined primer composition was applied to the substrate so that the dry film thickness became 5 μm, and baked at 210 ° C. for 50 seconds. Then, 14. The dry film thickness is 20μm
And baked at 230 ° C. for 60 seconds to produce a coated steel sheet.

16. Preparation of Painted Tinplate (Test Piece) The paint composition was applied to a 0.3 mm thick tinplate with a bar coater so that the film thickness became 10 to 15 μm, and cured and baked at 200 ° C. for 10 minutes. This was used as a test piece.

Synthesis Example (A) A reaction vessel equipped with a stirrer, condenser, and thermometer was placed in a reaction vessel.
137 parts of phthalic acid, 121 parts of isophthalic acid, sebacine
Acid 177 parts, ethylene glycol 190 parts, bispheno
DA-350 which is an ethylene oxide adduct of
613 parts (manufactured by NOF Corporation), tetrabutyl titanate
0.25 parts, and pressurize at 160 ° C under nitrogen atmosphere
To 240 ° C for 4 hours.
Was. Then gradually depressurize the system and take 50 minutes
Reduce the pressure to 5 mmHg and further reduce the pressure to 0.3 mmHg or less.
The polycondensation reaction was performed at 260 ° C. for 60 minutes under air. Get
Polyester resin (A) was analyzed by composition analysis such as NMR.
As a result, the molar ratio of the acid component is terephthalic acid / isosophtalic acid /
Sebacic acid = 34/30/36, glycol component
Are ethylene glycol / DA-350 = 26 /
74. The measured reduced viscosity was 0.4
6 dl / g, acid value 17 equivalent / 10 ⁶g, number average
The molecular weight was 12,000 and the glass transition temperature was 12 ° C. This
Cyclohexanone / Solvesso
150 (manufactured by Exxon Chemical Co., Ltd.) = 50/50 (weight)
Ratio) dissolved at 40% solids,
I got a varnish. The results are shown in Table 1.

Hereinafter, the polyester resins (B) having the compositions shown in Tables 1 and 2 were prepared by the method according to Synthesis Example (A).
(C), (E) and (G) to (J) were synthesized. (H) ~
(J) is a comparative synthesis example.

Synthesis Example (D) In a reaction vessel equipped with a stirrer, a condenser, and a thermometer, 127 parts of terephthalic acid, 228 parts of isophthalic acid, 1,4-
Cyclohexanedicarboxylic acid 158 acid, 322 parts of ethylene glycol, 459 parts of BD-500 (manufactured by NOF CORPORATION) which is a 4.4 mol adduct of bisphenol A with propylene oxide, and 0.30 of tetrabutyl titanate
Charge 6 parts, and pressurize from 160 ° C to 240
The esterification reaction was performed for 4 hours up to ° C. Then, the pressure inside the system was gradually reduced, and then reduced to 5 mmHg over 50 minutes, and further reduced to 260 mm under a vacuum of 0.3 mmHg or less.
The polycondensation reaction was performed at 60 ° C. for 60 minutes. Then, the mixture was cooled to 200 ° C. in a nitrogen atmosphere, 6 parts of trimellitic anhydride was charged, and an addition reaction was performed for 30 minutes. As a result of composition analysis such as NMR, the obtained copolymerized polyester was found to have an acid component in a molar ratio of terephthalic acid / isosophtalic acid / 1,4-cyclohexanedicarboxylic acid / trimellitic acid = 25/45/30 /
1, the glycol component is ethylene glycol / BD-500 = 70/30 in molar ratio, and the reduced viscosity is 0.3.
6 dl / g, acid value 72 equivalents / 10 ⁶ g, glass transition temperature 45 ° C.

Synthesis Example (F) In the same manner as in Synthesis Example (A), the acid component was in a molar ratio of terephthalic acid / isophthalic acid / sebacic acid = 40/45/15, and the glycol component was in a molar ratio of ethylene glycol / D
A-350 = 45/55, and reduced viscosity 0.15d
A polyester resin having 1 / g, an acid value of 10 equivalents / 10 ⁶ g, and a number average molecular weight of 2,500 was obtained. Then, 100 parts of the obtained polyester resin and 7 parts of neopentyl glycol were mixed with cyclohexanone / solvesso 150 (manufactured by Exxon Chemical Co., Ltd.) = 50/50 (weight ratio) to obtain a solid content of 40%.
And heated to 80 ° C. under a nitrogen stream. Then, 26.5 parts of diphenylmethane diisocyanate was charged and stirred for 1 hour, and then 0.03 part of dibutyltin dilaurate was charged and reacted for 2 hours to obtain a urethane-modified polyester (F). The obtained resin was measured for reduced viscosity to be 0.82 dl / g, and had an acid value of 15 equivalents / 10 ⁶ g,
Glass transition temperature was 50 ° C.

Comparative Synthesis Example (K) In the same manner as in Synthesis Example (D), 66.4 parts of terephthalic acid
66.4 parts of isophthalic acid, 29.2 parts of adipic acid, 37.2 parts of ethylene glycol, propylene glycol 2
9.6 parts were charged, and then 2.9 parts of trimellitic anhydride were charged and a polyester resin having a number average molecular weight of 23,000, an acid value of 160 equivalents / 10 ⁶ g, and a glass transition temperature of 43 ° C. was synthesized by an addition reaction. . Then, this is Solvesso 1
50 (manufactured by Exxon Chemical Co., Ltd.) / Cyclohexanone = 5
It was dissolved in a 0/50 mixed solvent so that the solid content was 40%. Twenty-four parts of Epicoat 1004 (manufactured by Yuka Shell Epoxy Co., Ltd.), which is a bisphenol A epoxy resin, was mixed and dissolved in 120 parts of this resin solution, 1 part of dimethylethanolamine was added, and the mixture was heated to 120 ° C. for 3 hours. The reaction was performed to obtain an epoxy-modified polyester resin solution (K).

Example 11 1) Preparation of Primer Paint Titanium oxide 5 was added to 70 solid portions of polyester resin (B) solution.
0 parts, zinc chromate 35 parts, resole type phenolic resin (trade name: CKM1634, manufactured by Showa High Polymer Co., Ltd.)
30 solid parts and 2.5 parts of a 10% benzyl alcohol solution of p-toluenesulfonic acid were added, and dispersed with a glass bead type high-speed shaker for 5 hours to prepare a primer coating.

This coating composition was used for 15. A coated steel plate was prepared by applying and baking according to the method described in (1), and a predetermined test was performed. The results are shown in Table 3. As described above, the polyester resin containing an aromatic ring having an electron donating group bonded thereto has good reactivity with the phenol resin, good workability, and the corrosion resistance is significantly improved in both the cross-cut portion, the end face, and the processed portion. I have. Also, the acid resistance is very good.

The coating compositions of Examples 2 to 6 and Comparative Examples 1 to 6 were prepared in the same manner with the compositions shown in Tables 3 and 4, and applied and baked. Tables 3 and 4 show the test results of the obtained coated steel sheets. However, the mixing ratio of the paint was shown in terms of solid content. It can be seen that all of the examples have good workability, excellent corrosion resistance and chemical resistance, and are remarkably superior to those cured with an amino resin or an isocyanate compound.

Example 7 80 solid parts of the polyester resin prepared in Synthesis Example B and 20 solid parts of a resol type phenol resin (trade name: CKM1634, manufactured by Showa Polymer Co., Ltd.), 10% of dodecylbenzenesulfonic acid as a catalyst 1. Benzyl alcohol solution
Five parts were mixed to prepare a clear paint. This is 16.
Was applied to a tin plate and cured by the method described in (1). Table 5 shows the obtained results. The resulting coating film has excellent workability and retort resistance, and particularly excellent content resistance and hygiene.

Examples 8 to 10 and Comparative Examples 7 to 12 were carried out in the same manner as in Example 7. The results are shown in Tables 5 and 6.

Example 11 A solid portion of the urethane-modified polyester resin 70 prepared in Synthesis Example (F) and a resol-type phenol resin (trade name: CK)
An adhesive was prepared by mixing 30 solid parts of M1634, manufactured by Showa Polymer Co., Ltd.) and 0.25 parts of dodecylbenzenesulfonic acid as a catalyst. This was applied to a 0.5 mm-thick cold-rolled steel sheet which had been degreased and coated with a chromate treatment, so as to have a dry film thickness of 20 μm, and dried at 120 ° C. for 10 minutes. Subsequently, the same cold-rolled steel sheets were bonded and pressed at 230 ° C. for 2 minutes to bond. When the shear adhesive strength was measured, it was found to be 150 kg /
cm ² and excellent adhesive strength. This was treated at 60 ° C. and a relative humidity of 95% for 250 hours, but no decrease in the adhesive strength was observed, and good moisture resistance was obtained.

[0073]

[Table 1]

1) 2.2 mol adduct of bisphenol A with ethylene oxide (manufactured by NOF Corporation) 2) 4.4 mol adduct of bisphenol A with propylene oxide (manufactured by NOF Corporation) 3) bisphenoxyethanol fluorene (Osaka Gas Co., Ltd.) 4) N-phenyldiethanolamine (Meisei Chemical Industry Co., Ltd.)

[0075]

[Table 2]

[0076]

[Table 3]

1) Resol type phenol resin, CKM1
634 (manufactured by Showa Polymer Co., Ltd.) * Evaluated MEK rubbing with primer only (no overcoat)

[0078]

[Table 4]

1) Bisphenol A epoxy resin, Epicoat 1007 (manufactured by Yuka Shell Epoxy Co., Ltd.) 2) Resol type phenol resin, CKM1634 (manufactured by Showa Polymer Co., Ltd.) 3) Methylated melamine, Sumimar M40S (Sumitomo Chemical Co., Ltd.) 4) Hexamethylene diisocyanate block isocyanate compound, Coronate 2507 (manufactured by Nippon Polyurethane Industry Co., Ltd.) * Evaluated MEK rubbing with primer only (no overcoat)

[0080]

[Table 5]

1) Resol type phenol resin, CKM1
634 (manufactured by Showa Polymer Co., Ltd.)

[0082]

[Table 6]

1) Bisphenol A epoxy resin, Epicoat 1009 (manufactured by Yuka Shell Epoxy Co., Ltd.) 2) Resol type phenol resin, CKM1634 (manufactured by Showa Kogaku Co., Ltd.) 3) Resol type phenol resin, phenodia PR40
1 (manufactured by Hoechst) 4) Methylated melamine, Sumimar M40S (manufactured by Sumitomo Chemical Co., Ltd.)

[0084]

The resin composition for coatings and adhesives of the present invention can be used in combination with a phenolic resin, which has been difficult with conventional epoxy resins, by introducing an aromatic ring having an electron donating group bonded to a polyester resin. And a good reactivity can be obtained. Therefore, various physical properties such as workability and corrosion resistance, chemical resistance and hygiene can be highly compatible. Therefore, by using the coating resin composition of the present invention as a primer,
Compared with conventional polyester resin or epoxy resin, excellent corrosion resistance and excellent acid resistance are obtained regardless of cross cut part, processed part, end face, and highly compatible with coating properties such as workability and scratch resistance It becomes possible. In particular, it can be widely used not only for building materials and outdoor equipment, but also for home appliances that require corrosion resistance such as refrigerators, washing machines, and air conditioner outdoor units, as well as high corrosion resistance is required due to the excellent corrosion resistance of the processed parts and end faces. it can. In addition, by using the resin composition for a paint of the present invention for the inner surface of a can, excellent workability and drawability can be obtained, and furthermore, the content resistance and hygiene are excellent. Pre-coating is possible for cans. Furthermore, when the resin composition of the present invention is used for an adhesive, excellent adhesiveness and durability can be obtained. Further, the resin composition of the present invention is not only for metal materials, but also various base materials, for example, coating agents and adhesives such as polyimide, polyamide imide, polyamide, and plastic films such as polyethylene terephthalate, conductive paste, It can also be used as a binder resin for electronic materials such as a sealant.

Continued on the front page F-term (reference) 4J002 BN17W CC04X CC05X CC06X CD20W CF03W CF04W CF05W CF10W CF13W CF14W CK03W GH01 GJ01 4J029 AA03 AB07 AC02 AD01 AD07 AE11 AE13 BA02 BA03 BA04 BA05 BA07 BB01 BB01 BB01 BB11 BBA BBA BBA BF25 BF26 BH01 BH02 CA02 CA04 CA05 CA06 CA09 CB04A CB05A CB05B CB06A CC06A CD03 CH02 CH06 DA02 DB02 EB05A FC03 FC05 FC08 FC33 FC35 FC36 GA12 GA14 GA41 HA01 HB01 JE182 KB02 KD01 KD07 KE03 KE05 K01

Claims (2)

[Claims] 1. A resin composition comprising a polyester resin containing an aromatic ring to which an electron donating group is bonded and / or a modified polyester resin (A) using the polyester resin and a phenol resin (B). . 2. The resin composition according to claim 1, wherein the polyester resin and / or a modified polyester resin (A) using the polyester resin contains a structure represented by the following general formula (I). -Ph-OR- (I) (R in the formula represents an alkylene group, a polyalkylene group, and Ph represents a phenylene group.)