JP3317400B2 - Method for producing polyester resin and resin composition for paint using the same - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a polyester resin set.
It is about an adult . The production of polyester resins, especially high molecular weight polyester resins having a number average molecular weight of 2,000 or more, usually involves three steps: esterification, initial polymerization, and late polymerization.
It is carried out by a can method or a two-can method in which this polymerization step is one stage. Since the manufacturing know-how is determined in consideration of the cycle balance of each process, the cycle time (reaction time) of each process varies from lot to lot and poses a serious problem in manufacturing. Also, foaming during esterification, transesterification and polymerization under reduced pressure causes a serious problem because the resin and raw materials during polymerization overflow from the reaction vessel.

[0002]

2. Description of the Related Art A polyester resin using a bisphenol A and / or bisphenol F alkylene oxide adduct as a raw material, mainly for a coating resin, is known. For example, as a coating resin, Japanese Patent Publication No. 62-54
No. 67, Japanese Unexamined Patent Publication No. 3-217471, and the like are known.

[0003]

However, in the case of producing a polyester resin using such an alkylene oxide adduct of bisphenol A and / or bisphenol F as a raw material, the polymerization time is long, and typified by polyethylene terephthalate. There is a problem that the polymerization time varies greatly depending on the lot, which is not observed in a normal monomer system, and improvement is demanded. In addition, these resin systems may foam remarkably regardless of the time of esterification, transesterification, and polymerization under reduced pressure, which is a serious problem.

Further, there is a problem that the physical properties of the coating film vary, and the physical properties of the coating film are insufficient in boiling water resistance, corrosion resistance, and pressure mark resistance.
In recent years, it has become difficult to withstand the strict required characteristics.

[0005]

Means for Solving the Problems In view of these problems, the present inventors have conducted intensive studies, and as a result, a trace amount of phosphorus contained in an alkylene oxide adduct of bisphenol A and / or bisphenol F has a large amount of polymerization rate and coating film properties. And reached the present invention.

That is, in the present invention, the acid component is represented by the general formula (1) as 50 to 100 mol% of an aromatic dicarboxylic acid, 0 to 50 mol% of an aliphatic and / or alicyclic dicarboxylic acid, and a glycol component. The alkylene oxide adduct of bisphenol A and / or bisphenol F is 5
-100 mol%, other polyols are 0-95 mol%
In the polyester resin (B) consisting of, as a raw material, a polyester resin obtained by using bisphenol A and / or alkylene oxide adducts of bisphenol F content of phosphorus is less than 150 ppm (A) (B) and / or More modified polyester tree
Fat (C) and a curing agent (D) capable of reacting with these resins.
It is a resin composition for paints that is combined .

Embedded image (Wherein R ₁ , R ₂ and R ₃ are hydrogen or a methyl group;
m and n are each 1 or more, and at the same time, 2 ≦ m + n
≦ 8. )

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Polyester resin used in the present invention
As glycol component, bisphenol A and /
Or, it is applied when the alkylene oxide adduct (A) of bisphenol F is contained in an amount of 5 to 100 mol%.

The alkylene oxide adduct (A) of bisphenol A and / or bisphenol F is prepared by adding an alkylene oxide to bisphenol A and / or F in the presence of an alkali catalyst and then neutralizing with an acid. At this time, phosphoric acid is usually used as a neutralizing agent. The phosphate generated at this time is removed by filtration,
It cannot be completely removed.

In the polyester resin used in the present invention , the residual amount of phosphorus derived from phosphate or the like of the catalyst residue is 150 ppm or less based on the alkylene oxide adduct (A) of bisphenol A and / or bisphenol F. Is required, and is preferably 70 ppm or less, more preferably 25 ppm or less. When the content of phosphorus exceeds 150 ppm, a problem that the polymerization rate is remarkably reduced occurs.For example, when used as a paint or a coating agent, as a coating film physical property, boiling water resistance, corrosion resistance, and pressure mark resistance are reduced. .

In the polymerization of polyethylene terephthalate, it is known that a phosphorus compound such as phosphoric acid, phosphorous acid or phosphonic acid is added to suppress a side reaction. It is known to decrease. See, for example, Journal of Polymers, P293, 36
(1979). However, unlike ethylene glycol and the like, the polyester resin of the present invention contains an alkylene oxide adduct of bisphenol A and / or bisphenol F as a glycol component, so that the presence of a phosphorus compound is more remarkable than in the case of ethylene glycol. Was found to adversely affect the polymerization rate. The reason is that ethylene glycol and the like are easily distilled during polymerization, so that ethylene glycol is quickly removed from the system, a deglycolization reaction between molecules is likely to occur, and the polymerization rate is considerably high, but bisphenol A and / or This is because the alkylene oxide adduct of bisphenol F is not volatilized at all even under a high vacuum, so that the polymerization rate is low.

As a method for reducing the phosphorus content, there are a method of filtering a catalyst residue and a method of using an organic acid such as a carboxylic acid without using phosphoric acid as a neutralizing agent. Either method may be used. . As a filtration method, adsorption filtration is particularly preferred.

The polyester resin used in the present invention is useful as a coating resin or a coating agent, and is particularly preferably used as a resin for a primer coating of a metal steel sheet or as an image recording medium such as a thermal sublimation transfer type image receiving paper. In addition, those produced by the conventional method have problems such as foaming at the time of production, lack of physical properties of coating films, and large variations, in addition to the polymerization rate. For example, there is a problem that the corrosion resistance and the appearance defect after the boiling water test vary, and the recent demands for strict coating physical properties include insufficient corrosion resistance and pressure mark resistance.

The cause of these troubles or the lack of physical properties of the coating film has not been known for a long time. However, as a result of extensive studies by the present inventors, if the above-mentioned phosphate remains in the coating film, corrosion resistance and boiling water resistance are particularly high. It was found that the pressure mark resistance was adversely affected. This seems to be due to the fact that the alkali metal phosphate remaining in the coating causes a part of the coating to become relatively hydrophilic, or that pinholes occur in the coating. However, details are unknown.

When synthesizing an alkylene oxide adduct of bisphenol A and / or bisphenol F, isopropenylphenol and vinylphenol, which are decomposition products of bisphenol A or bisphenol F, are formed. Was found to form an alkylene oxide adduct of isopropenyl phenol or an alkylene oxide adduct of vinyl phenol, and found that when these impurities remained in a certain amount or more, they foamed or adversely affected the physical properties of the coating film. Was. The present inventors have also confirmed that the higher the reaction temperature at the time of adding an alkylene oxide, the more these impurities are generated.

The content of the alkylene oxide adduct of isopropenylphenol and / or the alkylene oxide adduct of vinylphenol is 20,000 ppm or less based on the amount of the alkylene oxide adduct of bisphenol A and / or bisphenol F used. Preferably, more preferably 10,000p
pm, more preferably 5,000 ppm or less, and most preferably 2,000 ppm or less. If the content of these by-products exceeds 20,000 ppm, there is a high possibility that foaming will occur considerably, and there is a high possibility that the physical properties of the coating film will deteriorate.

The alkylene oxide adduct (A) of bisphenol A and / or bisphenol F used in the polyester resin used in the present invention is 5 to 100 mol%, preferably 15 to 100 mol%, based on all glycol components.
80 mol%, more preferably 25 to 60 mol%. If it is less than 5 mol%, the effect of residual phosphorus is less likely to be obtained, but the excellent properties of the glycol (A) such as corrosion resistance and workability cannot be obtained.

The smell of the polyester resin used in the present invention
The acid component used in the produced polyester resin (B) is an aromatic dicarboxylic acid of 50 to 100 mol%, preferably 70 to 100 mol%, more preferably 80 to 100 mol%.
Mol%. If the amount of the aromatic dicarboxylic acid is less than 50 mol%, good acid resistance, chemical resistance, corrosion resistance and scratch resistance cannot be obtained.

The aromatic dicarboxylic acid copolymerized with the polyester resin (B) of the present invention includes terephthalic acid, isophthalic acid, orthophthalic acid and 2,6-naphthalenedicarboxylic acid. As the aromatic dicarboxylic acid, it is particularly preferable to use terephthalic acid and isophthalic acid together in view of the properties of the coating film and the solubility. The content of the aromatic dicarboxylic acid is preferably from 50 to 100 mol%, more preferably from 70 to 100 mol%, and still more preferably from 80 to 100 mol%.
Mol%.

The aliphatic and / or alicyclic dicarboxylic acids 0 to 50 copolymerized with the polyester resin (B) of the present invention.
Mol%, preferably 0 to 30 mol%. These dicarboxylic acids are not essential, but by copolymerizing,
Mainly flexibility can be provided, so that processability can be improved.

The aliphatic dicarboxylic acid copolymerized with the polyester resin (B) of the present invention includes succinic acid, glutaric acid, adipic acid, sebacic acid, dodecandionic acid, azelaic acid, dimer acid and the like. Examples of the alicyclic dicarboxylic acid copolymerized with the polyester resin (A) include alicyclic dicarboxylic acids such as 1,2-cyclohexanedicarboxylic acid, 1,3-cyclohexanedicarboxylic acid, and 1,4-cyclohexanedicarboxylic acid. Of these, adipic acid, sebacic acid, and 1,4-cyclohexanedicarboxylic acid are more preferable from the viewpoint of processability, and the content is preferably 30 mol% or less from the viewpoint of acid resistance.

As the glycol component copolymerized with the polyester resin (B), other glycols other than the ethylene oxide and / or propylene oxide adducts of bisphenol A and / or bisphenol F represented by the general formula (I) are usually used. Use in combination.

Other glycols include ethylene glycol, neopentyl glycol, propylene glycol, 1,3-propanediol, 2-methyl-1,3-
Propanediol, 2-butyl-2-ethyl-propanediol, 1,4-butanediol, 1,2-butanediol, 1,3-butanediol, 1,5-pentanediol, 1,6-hexanediol, , 7-octanediol, 1,9-nonanediol, 3-methyl-1,
5-pentanediol, 3-methyl, 8-methyl-1,
Alkylene glycols such as 8-octanediol,
Examples thereof include alicyclic glycols such as 1,4-cyclohexanedimethanol, 1,2-cyclohexanedimethanol, and TCD glycol, diethylene glycol, polyethylene glycol, and polypropylene glycol.
Other glycols are appropriately selected from economics, physical properties of the coating film, etc., and ethylene glycol, neopentyl glycol, diethylene glycol, 1,4-cyclohexanedimethanol, 1,5-pentanediol, 1,6-hexanediol and the like are used. preferable.

Further, a polyvalent carboxylic acid such as trimellitic acid or pyromellitic acid or a polyvalent polyol such as trimethylolethane, trimethylolpropane, glycerin or pentaerythritol is used in an amount of 0.1 to 3 with respect to the total acid or glycol. The use of mol% can further improve the acid resistance.

Polyester resin used in the present invention
Te, direct polymerization method for polymerizing by direct esterification of dicarboxylic acid with a glycol in the normal pressure or pressurization, as exemplified in the present embodiment, Ya transesterification method of polymerizing dimethyl ester and glycol dicarboxylic acid after transesterification It is synthesized by a known method such as a method of adding a small amount of xylene and performing a dehydration reaction at normal pressure. Further, as the polymerization catalyst, known catalysts such as a titanium compound such as tetrabutyl titanate shown in this embodiment, a zinc compound, an antimony compound, a tin compound, and a germanium compound are used.

Although the resin properties of the polyester resin (B) of the present invention can be changed depending on the application, the glass transition temperature is preferably from 0 to 80 ° C. If the temperature is lower than 0 ° C., workability is good, but scratch resistance, chemical resistance, boiling water resistance, blocking resistance and the like may be reduced, which is not preferable. If the temperature exceeds 80 ° C., the acid resistance is good, but the processability may decrease, which is not preferable. The polyester resin (B) of the present invention preferably has a number average molecular weight of 2,000 or more, more preferably 5,000 to 35,000.
If the number average molecular weight is less than 2,000, physical properties such as workability and impact resistance may be reduced.

In the polyester resin (B) of the present invention, a dicarboxylic acid or a glycol containing a sulfonic acid metal base may be used in a range of 5 mol% or less. Examples of the dicarboxylic acid containing a sulfonic acid metal base include metal salts such as sulfoterephthalic acid, 5-sulfoisophthalic acid, 4-sulfonaphthalene-2,7-dicarboxylic acid, and 5 [4-sulfophenoxy] isophthalic acid. it can.
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. Metal salts include Li, Na, K, Mg, Ca, C
and salts such as u and Fe.

The polyester resin (B) of the present invention may be modified with vinyl with a vinyl polymerizable monomer, modified with an epoxy resin with an epoxy compound, or modified with urethane with an isocyanate compound. When a polyester resin is vinyl-modified with a vinyl polymerizable monomer, an unsaturated double bond containing an unsaturated double bond such as fumaric acid or oleic acid is copolymerized with the polyester resin to introduce an unsaturated double bond into the polyester resin. Then, a method of radically polymerizing the unsaturated double bond and a vinyl compound such as (meth) acrylate, styrene, or vinyl acetate in a solution, or a method in which one end synthesized from (meth) acrylate, styrene, etc. It is synthesized by a known method such as directly copolymerizing a macromonomer containing two hydroxy groups into a polyester.

The epoxy resin-modified polyester resin is modified at its terminal carboxy by adding an acid anhydride such as trimellitic anhydride or phthalic anhydride to the terminal hydroxy group of the polyester resin. It can be synthesized by a known method such as a method of epoxy modification in the presence of a catalyst such as phosphine.
Further, a carboxyl group may be introduced by using any carboxyl group-containing glycol of dimethylolpropionic acid as a chain extender.

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. Further, 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 polyester resin (B) of the present invention and / or
Alternatively, a modified polyester (C) obtained by modifying these and a curing agent (D) capable of reacting with them can be blended and used for coating. By adding a curing agent, solvent resistance can be imparted, and various coating film properties such as workability, hardness, stain resistance, chemical resistance, and corrosion resistance can be improved. The amount of the curing agent (D) is {(B) + (C)} / (D) = 95 /
5-60 / 40 is preferable, and 90/10 is more preferable.
７０70/30 (weight ratio). When the blending amount of {(B) + (C)} exceeds 95/5, the coating film properties such as chemical resistance, corrosion resistance, and scratch resistance become poor, and when it is less than 60/40, good workability cannot be obtained. There is.

As a curing agent capable of reacting with the polyester resin (B) and / or the modified polyester resin (C), alkyl etherified aminoformaldehyde resin,
Epoxy compounds, isocyanate compounds, phenolic resins and the like can be mentioned. Of these, alkyl etherified aminoformaldehyde resins and isocyanate compounds are preferred from the viewpoint of processability. Further, an isocyanate compound is particularly preferable from the viewpoint of acid resistance, and it is preferable to use the isocyanate compound after blocking it from storage stability.

As the isocyanate compound, there are aromatic and aliphatic diisocyanates and polyisocyanates having a valency of 3 or more, 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 Amount and, for example, ethylene glycol, propylene glycol, trimethylolpropane, glycerin, sorbitol, ethylenediamine, monoethanolamine, diethanolamine, low molecular active hydrogen compounds such as triethanolamine or various polyester polyols,
Examples of the compound include a terminal isocyanate group-containing compound obtained by reacting a polyether polyol, a polyamide with a polymer active hydrogen compound, or the like.

The isocyanate compound is preferably a blocked isocyanate. Examples of the isocyanate blocking agent include phenols such as phenol, thiophenol, methylthiophenol, ethylthiophenol, cresol, xylenol, resorcinol, nitrophenol, chlorophenol, acetoxime, methylethylketoxime, oximes such as cyclohexanone oxime, methanol, ethanol,
Alcohols such as propanol and butanol, halogen-substituted alcohols such as ethylene chlorohydrin and 1,3-dichloro-2-propanol, t-butanol,
tertiary alcohols such as t-pentanol, lactams such as ε-caprolactam, δ-valerolactam, γ-butyrolactam, β-propyrolactam, and other aromatic amines, imides, and the like. Active methylene compounds such as acetylacetone, acetoacetate and malonic acid ethyl ester, 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.

Alkyl etherified aminoformaldehyde resins include, for example, formaldehyde or paraformaldehyde alkyletherified with an alcohol having 1 to 4 carbon atoms such as methanol, ethanol, n-propanol, isopropanol, n-butanol, and urea. Condensation products with N, N-ethylene urea, dicyandiamide, aminotriazine and the like; Butoxylated methylolmelamine, methoxylated / butoxylated mixed methylolmelamine, butoxylated methylolbenzoguanamine and the like. It preferred from the viewpoint of workability, methoxylated methylolmelamine, butoxy methylol melamine or methoxylated / butoxylated mixed melamine, may be used alone, or in combination.

As the epoxy compound, bisphenol A
Diglycidyl ethers and their oligomers, hydrogenated bisphenol A diglycidyl ethers and their oligomers, 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, Triglycidyl citrate, triglycidyl isocyanurate, 1,4-diglycidyloxybenzene, diglycidyl propylene urea, glycerol triglycidyl ether, trimethylolethane triglycidyl ether, trimethylolpropane triglycidyl ether, pentaerythritol tetraglycidyl ether And glycerol alkylene oxide adduct triglycidyl ether.

Examples of the phenol resin include a resol type resin obtained by reacting an aldehyde with a phenol in the presence of an alkali catalyst and a novolak type resin obtained by reacting an aldehyde with a phenol in the presence of an acidic catalyst. And a resol type resin is 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. A condensate thereof, an alkyl etherified product thereof, or a product obtained by subjecting them to various modifications such as epoxy modification, oil modification, melamine modification, and amide modification can be used.

It is preferable to use a known curing agent or accelerator selected according to the type of these curing agents in combination.

The baking temperature of the (modified) polyester resin of the present invention is arbitrarily selected depending on the size and thickness of the metal plate, the capability of the baking furnace, the curability of the paint, 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 painting is selected as appropriate.

The (modified) resin composition of the present invention may be used in accordance with the purpose and use thereof, depending on the purpose, such as extender pigments such as titanium oxide, talc, barium sulfate and clay; chromium-containing rust preventive pigments such as zinc chromate, strontium chromate and calcium chromate; Silica, tripolyphosphate such as aluminum tripolyphosphate, zinc phosphate, phosphite, phosphomolybdate, molybdate, non-calcium cyanamide zinc, borate, calcium silica A chromium-based rust-preventive pigment, a known coloring agent, additives such as silica and wax, a flame retardant, glass fiber and the like can be blended.

The resin composition for coatings of the present invention is usually used in the form of a solution in an organic solvent. However, when an ionic group such as the above-mentioned sulfonic acid metal base is introduced, it may be used as an aqueous dispersion. Can also be used. As the organic solvent, for example, toluene, xylene, Solvesso 100,
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, dibasic ester, etc. Is appropriately selected in consideration of solubility and evaporation rate. When the (modified) polyester resin of the present invention is used for paints, it shows sufficient performance even if it is applied and baked itself, so that it is suitable for a backside coat of a coated metal plate, etc., but is further used as a primer. Preferably, a topcoat known as a topcoat may be applied for the purpose of improving weather resistance, stain resistance, alkali resistance and the like. The (modified) polyester resin of the present invention can be used as an image recording medium by coating it on paper or a plastic film. As compared with the prior art, excellent properties such as printability and fingerprint resistance are obtained.

[0041]

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 was in accordance with 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. Determination of Molecular Weight of Polyester and Addition Number of Bisphenol A or Bisphenol F Alkylene Oxide by Gel Filtration Chromatography (GPC) was performed using tetrahydrofuran as a solvent and polystyrene as a standard sample. The column is Shodec KF when measuring molecular weight.
802, KF804 and KF806 (Showa Denko KK) were connected in series and used. When measuring the number of moles of alkylene oxide added, use TSKgel SUPERH4000, H
3000 and H2000 (manufactured by Tosoh Corporation) were connected in series and used. The detector used was RI.

3. Determination of alkylene oxide adduct of isopropenylphenol and alkylene oxide adduct of vinylphenol as impurities Impurities were measured by gel filtration chromatography (GPC) using tetrahydrofuran as a solvent. The column is TSKg
el SUPERH4000, H3000, H2000
(Manufactured by Tosoh Corporation) were used in series. The detector used UV (254 nm).

4. Glass transition point temperature Measured at a heating rate of 20 ° C./min using a differential scanning calorimeter (DSC). As a sample, 5 mg of a sample was placed in an aluminum holding lid type container and crimped.

5. 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.

6. Determination of Phosphorus Content A 0.2 g sample was precisely weighed in an Erlenmeyer flask, and 3 ml of sulfuric acid, 0.5 ml of perchloric acid and 3.5 ml of nitric acid were added, and the mixture was gradually heated and decomposed on a hot plate to obtain sulfuric acid white smoke. After allowing to cool to room temperature, the mixture was diluted to about 15 ml with water. One drop of a 0.2% paranitrophenol solution was added, and ammonia water was gradually added while cooling with running water to neutralize sulfuric acid. Then, transfer all the contents to a 50 ml volumetric flask while washing with water, add 5 ml of a 2% ammonium molybdate solution and 2 ml of a 0.2% hydrazine sulfate solution, and adjust the marked lines with water. Mixed. Then, the flask was placed in a boiling water bath for 10 minutes to heat and develop color, and this was cooled to room temperature with water to obtain a test solution. An empty experiment was performed in the same manner. The obtained test solution was measured with a spectrophotometer at a wavelength of 830 nm.
The absorbance was measured using the blank test solution as a control, and the phosphorus content was quantified using a previously prepared calibration curve. As the phosphorus standard solution, a solution prepared by dissolving reagent potassium dihydrogen phosphate in water was used.

7. Workability 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 a bent portion, and 0T refers to a case where the sheet is folded 180 degrees without sandwiching the board.

8. Boiling water resistance The coated steel sheet was immersed in boiling water for 3 hours, and the state of blister generation on the coated surface was evaluated according to ASTM D714-56. When there was no abnormality, it was set to 10.

9. Corrosion resistance The coated steel sheet is a method described in JIS K5400,
A 5% NaCl salt spray test was performed at 35 ° C. for 1000 hours, and the occurrence of blisters was visually determined. The corrosion resistance was measured for the cross cut portion, the 1T processed portion, and the end face portion.
The evaluation criteria are shown below. 1T processed part or 2T processed part ：: No abnormality ：: Almost no blister ブ リ: Blister generation X: Notable blister generation Cross cut part (blister blister width) ： １: 1 mm or less ：: 1 to 5 mm ：: 5 to 10 mm ×: 10 mm or more End face (blister blister width) ◎: 1 mm or less ○: 1 to 5 mm △: 5 to 10 mm ×: 10 mm or more

10. Pressure Mark Resistance A styrene foam cut into a cube having a side of 1 cm was placed on a coated steel sheet, and a weight of 1 kg / cm ² was applied thereto and left at 60 ° C. for 2 hours. It was determined by the appearance of the coating film after the test. ：: No abnormality ○: Styrofoam traces slightly appear ×: Styrofoam traces clearly appear XX: Styrofoam traces are noticeable, sometimes Styrofoam adheres to painted surface

11. Preparation of Top Coating Paint (I) Commercially available high molecular weight polyester dissolved in advance, Byron 300, 80 solid parts, Byron 200, 20 solid parts (all manufactured by Toyobo Co., Ltd.), methyl etherified methylolmelamine, Sumimar M40S (non-volatile 80%,
25 parts of Sumitomo Chemical Co., Ltd.), 2.5 parts of a 10% benzyl alcohol solution of p-toluenesulfonic acid, 125 parts of titanium oxide, and Polyflow S (manufactured by Kyoeisha Yushi Kagaku Kogyo KK) as a surface smoothing agent. The mixture was dispersed with a glass bead-type high-speed shaker for 8 hours to prepare an overcoat. The solvent used was an appropriate amount of a mixture of cyclohexanone / solvesso 150 = 50/50.

12. Preparation of Topcoat Paint Polyester Resins A to C of the Present Invention
Or comparative polyester resins I to K, 30 solids, methyl etherified methylol melamine, Sumimar M40S
(Non-volatile content 80%, manufactured by Sumitomo Chemical Co., Ltd.) 10 parts, p
-0.5 parts of a 20% benzyl alcohol solution of toluenesulfonic acid, 40 parts of titanium oxide, and 0.2 parts of Polyflow S (manufactured by Kyoeisha Yushi Kagaku Kogyo Co., Ltd.) as a surface smoothing agent were added, and the mixture was kneaded for one day in a ball mill. A top coat was prepared. The solvent was cyclohexanone / solvesso 150 =
An appropriate amount of the 50/50 mixture was used.

13. Preparation of Painted Steel Sheet (Specimen) A predetermined primer is applied to a zinc phosphate-treated zinc-coated steel sheet having a thickness of 0.5 mm to a dry film thickness of 5 μm.
Baking was performed at 20 ° C. for 60 seconds. Then, 11. Apply the top coat paint prepared in Step 2 so that the dry film thickness becomes 20 μm.
The coated steel sheet was prepared by baking at 30 ° C. for 60 seconds.

Synthesis of bisphenol A ethylene oxide adduct (a) According to a known method, 2.3 mol of ethylene oxide was added to bisphenol A under pressure using potassium hydroxide as a catalyst, and then neutralized with phosphoric acid. . After the reaction, the catalyst residue was filtered by adsorption filtration. The content of phosphorus in the obtained bisphenol A ethylene oxide adduct was measured and found to be 5 ppm. The content of ethylene oxide adduct of isopropenyl phenol is 120
ppm. The results are shown in Table 1.

Synthesis of Bisphenol A Ethylene Oxide Adduct (d) According to a known method, an average of 4.0 mol of ethylene oxide was added to bisphenol A using triethylamine as a catalyst, and then neutralized with succinic acid. After the reaction, it was used without filtration. When the phosphorus content of the obtained bisphenol A ethylene oxide adduct was measured, it was less than 2 ppm (below the measurement limit). The content of the ethylene oxide adduct of isopropenyl phenol was 260 ppm. Table 1 shows the results.

The alkylene oxide adducts (b) to (j) of bisphenol A or bisphenol F shown in Tables 1 and 2 were synthesized in the same manner. Synthesis examples (f) to (j) in Table 2 are comparative synthesis examples. In any of the catalysts using potassium hydroxide as a catalyst, the catalyst residue was removed by adsorption filtration, but in the comparative synthesis example, the filtration was insufficient and the phosphorus content was high. The amount of the alkylene oxide adduct of isopropenylphenol or vinylphenol as an impurity is changed by adjusting the reaction temperature. As the reaction temperature is higher, bisphenol A or F is decomposed, and the amount of these impurities increases.

[0058]

[Table 1]

[0059]

[Table 2]

In Tables 1 and 2, bis A: bisphenol A bis F: bisphenol F EO: ethylene oxide PO: propylene oxide KOH: potassium hydroxide TEA: triethylamine.

Synthesis Example 1 of Polyester ( Synthesis of Polyester Resin A) 485 parts of dimethyl terephthalate, 485 parts of dimethyl isophthalate, 512 parts of ethylene glycol, and 2.3 parts of ethylene oxide of bisphenol A were placed in a reaction vessel equipped with a stirrer, a condenser and a thermometer. Molar adduct (a) 9
07 parts, zinc acetate 0.44 parts, antimony trioxide 0.4
Three parts were charged and transesterification was performed from 140 ° C. to 220 ° C. over 4 hours. Then, the pressure inside the system was gradually reduced, and the pressure was reduced to 1 mmHg over 60 minutes. Further, the polycondensation reaction was performed at 270 ° C. under a reduced pressure of 0.1 to 0.3 mmHg. In minutes, the reduced viscosity reached 0.64 dl / g and the number average molecular weight reached 21,000. As a result of composition analysis such as NMR, the obtained polyester resin (A) has an acid component in a molar ratio of terephthalic acid / isosophtalic acid = 50/50, and a glycol component in a molar ratio of ethylene glycol / bisphenol A ethylene oxide.2. 3 mol adduct = 45/55. Also,
The acid value was 12 equivalent / 10 ⁶ g and the glass transition temperature was 76 ° C. There was no abnormal foaming during transesterification and polymerization. This polyester resin (A) is treated with cyclohexanone /
Solvesso 150 (Exxon Chemical Co., Ltd.) = 50/5
0 (weight ratio) at a solid content of 40% to give a varnish with a transparent hue (APHA) of 100. Table 3 shows the results.

Thereafter, polyester synthesis examples 2 to 7 were carried out in the same manner to synthesize polyester resins (B) to (G). The results are shown in Tables 3 and 4. In each case, a good polymerization rate was obtained. In addition, those having low acid value and low hue were obtained. However, in Polyester Synthesis Example 3 using a raw material containing a large amount of an ethylene oxide adduct of isopropenylphenol, which is an impurity, more foaming was observed than in the case where the impurity was small.

[0063]

[Table 3]

[0064]

[Table 4]

Polyester Synthesis Example 8 ( Synthesis of Polyester Resin H) 415 parts of terephthalic acid, 415 parts of isophthalic acid, 384 parts of ethylene glycol, and 2.2 mol of bisphenol F ethylene oxide were placed in a reaction vessel equipped with a stirrer, a condenser, and a thermometer. 1128 parts of the adduct (e) and 0.51 part of tetrabutyl titanate were charged, and the mixture was heated from 140 ° C to 220
The esterification reaction was performed for 4 hours up to ° C. Then, the pressure inside the system was gradually reduced, and then reduced to 1 mmHg over 60 minutes.
When the polycondensation reaction was carried out at 70 ° C., the polymer was rapidly polymerized, and reached a reduced viscosity of 0.55 dl / g and a number average molecular weight of 16,000 in 90 minutes. As a result of composition analysis such as NMR, the obtained polyester resin (H) was found to have a molar ratio of terephthalic acid / isosophtalic acid = 50/50 in an acid component and ethylene glycol / bisphenol F ethylene oxide in a glycol ratio of 2. 2 mol adduct = 24 /
76. Further, the acid value was 13 equivalent / 10 ⁶ g and the glass transition temperature was 68 ° C. There was no abnormal foaming during both esterification and polymerization. The polyester resin (H) was dissolved in cyclohexanone / solvesso 150 (manufactured by Exxon Chemical Co., Ltd.) = 50/50 (weight ratio) at a solid content of 40% to obtain a varnish having a transparent hue (APHA) 150. Table 4 shows the results.

Polyester Comparative Synthesis Example 1 ( Synthesis of Comparative Polyester Resin (I)) In a reaction vessel equipped with a stirrer, a condenser, and a thermometer, 485 parts of dimethyl terephthalate, 485 parts of dimethyl isophthalate, 512 parts of ethylene glycol, and ethylene of bisphenol A were added. 2.3 mol of oxide adduct (f) 9
07 parts, zinc acetate 0.44 parts, antimony trioxide 0.4
Three parts were charged and transesterification was performed from 140 ° C. to 220 ° C. over 4 hours. Then, the pressure inside the system was gradually reduced, and the pressure was reduced to 1 mmHg over 60 minutes. Further, the polycondensation reaction was performed at 270 ° C. under a reduced pressure of 0.1 to 0.3 mmHg, and the reduced viscosity was 0.64 dl /. g, 120 minutes was required to reach a number average molecular weight of 21,000. This polymerization time was clearly slower than that of the polyester synthesis example 1. As a result of composition analysis such as NMR, the obtained polyester resin (I) has a molar ratio of terephthalic acid / isosophthalic acid = 50/50 in an acid component, and ethylene glycol / bisphenol A ethylene oxide in a glycol component in a molar ratio of 2. 3 mol adduct =
45/55. Also, an acid value of 40 equivalents / 10 ⁶ g,
Glass transition temperature was 76 ° C. In addition, there was no abnormal foaming during transesterification and polymerization. This polyester resin (A) is mixed with cyclohexanone / solvesso 150
(Exxon Chemical Co., Ltd.) = 50/50 (weight ratio) dissolved at 40% solids, transparent hue (APHA)
400 varnishes were obtained. This polyester (I) is known from JP-B-62-54 in consideration of polymerization time, composition and resin properties.
It corresponds to polyester resin A of JP-A-67-67. Table 5 shows the results.

In the same manner, comparative polyester synthesis examples 2 to 8
Was done. The results are shown in Tables 5 and 6. In each case, the polymerization rate was considerably lower than that of the polyester synthesis example under the same conditions, and thus both the hue and the acid value were high. Further, in Comparative Polyester Synthesis Example 3, the polymerization rate was low, and the reduced viscosity was 0.35 d even when the polymerization time was 240 minutes.
It rose only to 1 / g. In addition, at the time of transesterification and during the polymerization, the foaming during the polymerization was the same as that of the comparative polyester synthesis example 1 and the polyester.
Or a both Except ester Comparative Synthesis Example 8 bad, or become likely to overflow from the reaction vessel, polyester comparative case
In adult Example 2 part of the course of the reaction of the polyester overflowed from the reaction vessel. Further, the polyester (L) of Comparative Polyester Synthesis Example 4 corresponds to the polyester resin A of JP-A-3-217471 in view of the polymerization time, composition and resin properties. It can be seen that the polymerization rate is considerably lower than those of polyester synthesis examples 5 and 6.

[0068]

[Table 5]

[0069]

[Table 6]

In Tables 3-6, the time required for polymerization was gradually reduced after esterification or transesterification, and 0.5 mmH after initial polymerization under reduced pressure to 1 mmHg over 1 hour.
The time required for the main polymerization in g or less is shown.

Example 1 (Evaluation of Physical Properties of Coating Film) 100 parts of a dissolved product of polyester resin (A) were mixed with 40 parts of titanium oxide and 40 parts of strontium chromate, and methyl etherified methylolmelamine as a curing agent (trade name: Sumimar M40S, 10 parts of a nonvolatile content of 80%, manufactured by Sumitomo Chemical Co., Ltd.) and 2.5 parts of a 10% benzyl alcohol solution of p-toluenesulfonic acid as a curing catalyst were added, and dispersed by a bead disperser for 8 hours to prepare a primer coating. . This primer coating composition is used for 13. The coated steel sheet was prepared by applying and baking in the order of the primer and the top coat according to the method described in (1), and a predetermined test was performed. In addition, the top coat used was the top coat (I). Table 7 shows the results. As described above, it can be seen that the resin composition for coatings according to the production method of the present invention is excellent in workability, corrosion resistance, and boiling water resistance, and particularly excellent in corrosion resistance and boiling water resistance as compared with the corresponding comparative examples.

Hereinafter, coating compositions of Examples 2 to 7 and Comparative Examples 1 to 6 were prepared in the same manner with the compositions shown in Tables 7 to 9, and applied and baked. Tables 7 to 9 show the test results of the obtained coated steel sheets. All examples show better coating film properties than the corresponding comparative examples, and polyester (I),
It can be seen that polyester (L) and the like have considerably lower corrosion resistance and boiling water resistance than the corresponding examples. Also in the examples, it can be seen that those using a high-purity raw material containing a small amount of an alkylene oxide adduct of isopropenyl phenol or vinyl phenol, which are impurities of the raw material, are more remarkably excellent in corrosion resistance and boiling water resistance.

[0073]

[Table 7]

[0074]

[Table 8]

[0075]

[Table 9]

Example 8 (Evaluation as Top Coating Paint) Using a melt of the polyester resin (A),
A top coat was prepared by the method described in (1). This is referred to in 11. Dry film thickness of 20 without primer
It was applied to a thickness of 230 μm and baked at 230 ° C. for 30 seconds to produce a coated steel sheet. When the pressure-mark resistance of this product was evaluated, it was very good and ◎ without any trace. Also, it has excellent boiling water resistance. Table 10 shows the results.

The coating compositions of Examples 9 and 10 and Comparative Examples 7 to 9 were prepared in the same manner with the compositions shown in Table 10, and applied and baked. Table 10 shows the test results of the obtained coated steel sheets. All examples show better pressure mark resistance than the corresponding comparative examples, and it can be seen that the polyester (I), polyester (J), and the like have considerably lower pressure mark resistance than the examples. Further, also in the examples, those using a high-purity raw material containing a small amount of an alkylene oxide adduct of isopropenylphenol or vinylphenol, which are impurities of the raw material, are more remarkably excellent in pressure-mark resistance and boiling water resistance. I understand.

[0078]

[Table 10]

Example 11 (Evaluation as Sublimation Type Thermal Transfer Image-Receiving Layer) The polyester resin (A) was dissolved in a mixed solvent of toluene / methyl ethyl ketone (50/50) to prepare a 20% solution. An epoxy-modified silicone oil (KF-102 manufactured by Shin-Etsu Chemical Co., Ltd.) was added to this solution at 10% by weight based on the resin.
Compounded, 150 μm thick synthetic paper manufactured by Oji Yuka: YUPO PP
G-150) using a wire bar, and then applied at 120 ° C.
For 30 minutes to obtain a sublimation type thermal transfer image receptor having a dyeing layer having a thickness of 4 μm. It was a sublimation type thermal transfer image receptor having high whiteness. A photographic image was recorded thereon using a commercially available video printer. An image having an excellent color tone without discomfort in both the white portion and the colored portion was obtained. As the evaluation of the durability of the image receiving body, the image receiving body on which the image was recorded was placed in a dark place at an environment of 60 ° C. for 1 hour.
It was left for 68 hours. In addition, the image receiver on which an image was recorded was left for two weeks on a window (room) exposed to direct sunlight. In each case, discoloration, fading, etc. were not observed, and the image receiver was highly durable. Also, on the surface of the image receiving body on which the image is recorded,
Press your thumb hard so that the fingerprint remains on the image surface,
The image receiver was left in an environment at 40 ° C. After 48 hours, the image was taken out and the image was observed. As a result, there was no aggregation of the dye, no discoloration (color loss), no residue after the fingerprint, and the like, and the image receptor was excellent in fingerprint resistance.

[0080]

According to the production method of the present invention, a rapid polymerization rate can be obtained, and furthermore, the obtained polyester resin has less lot variation, and the productivity is greatly improved as compared with the prior art. For this reason, the hue and the acid value of the resin can be kept small. In addition, bisphenol A and / or
Alternatively, by reducing the content of the alkylene oxide adduct of isophenol or vinylphenol, which is an impurity contained in the alkylene oxide adduct of bisphenol F, it is possible to improve the coating properties such as corrosion resistance and boiling water resistance. is there. Also, the effect of suppressing foaming during the reaction is great. Therefore, by using the coating resin of the present invention as a primer, excellent workability, corrosion resistance, and boiling water resistance can be obtained as compared with the conventional polyester resin or epoxy resin. Refrigerators, washing machines,
It is useful for home appliances such as air conditioner outdoor units and fan heaters, and for building materials such as metal siding. Further, it is also useful as a top coat or a one-coat paint that also serves as a primer and a top coat, and has excellent boiling water resistance and pressure mark resistance. Furthermore, it can be used as an image recording medium by applying it to paper or a plastic film. By coating with the resin of the present invention, superior color tone, printability and fingerprint resistance can be obtained as compared with the prior art.

Claims (1)

(57) [Claims] 1. The method according to claim 1, wherein the acid component is 50 to 1 aromatic dicarboxylic acid.
0 mol%, 0 to 50 mol% of aliphatic and / or alicyclic dicarboxylic acid, bisphenol A and / or bisphenol F represented by the general formula (1) as a glycol component
Alkylene oxide adducts 5 to 100 mol%, in the polyester resin and other polyols consists of 0 to 95 mol% (B), as a raw material, the content of phosphorus is 1
Bisphenol A and / or bisphenol F alkylene oxide adduct (A) of 50 ppm or less
And / or polyester resin (B) obtained using
Is a modified polyester resin (C) and these resins
Resins for paints containing a curing agent (D) that can react with fat
Composition. Embedded image (Wherein R ₁ , R ₂ and R ₃ are hydrogen or a methyl group;
m and n are each 1 or more, and at the same time, 2 ≦ m + n
≦ 8. )