JPH08337646A - Copolyester resin - Google Patents

Abstract

PURPOSE: To obtain a copolyester resin useful as a base resin of a coating material, an ink, etc., and excellent in processibility, water resistance, and adhesive properties by forming a copolyester resin having a specified mol.wt. from an acid component mainly comprising an arom. dicarboxylic acid and a specific alcohol component. CONSTITUTION: This copolyester resin is formed from an acid component comprising 80-100mol% arom. dicarboxylic acid and 20-0mol% other dicarboxylic acid and an alcohol component comprising 0.5-20mol% diol represented by the formula (wherein R1 is a 14C or higher alkylene), 99.5-70mol% other diol, and 0-10mol% trihydric or higher alcohol and has a number average mol.wt. of 3,000-50,000. When a conventional copolyester resin is used as an ink or an anchor coat on a film, the Tg is needed to be lowered to improve the adhesive properties, causing the problem of poor blocking resistance. This resin is excellent in processibility, water resistance, adhesive properties, and blocking resistance and is useful for a coating material, an ink, an adhesive, etc.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a copolyester resin, and more particularly, to a copolyester resin having excellent processability, water resistance, adhesion and blocking resistance which are useful as a base resin for paints, inks, adhesives and the like. It relates to a polymerized polyester resin.

[0002]

2. Description of the Related Art Copolyester resins which are soluble in organic solvents have a good balance of processability and hardness, and also have excellent adhesion to various plastics and metals. It is used for such purposes.

However, in coating applications for precoated steel sheets, which require particularly high workability, a copolymerized polyester resin having a low glass transition temperature (hereinafter abbreviated as Tg) is used as a base resin in order to improve workability. Although it is used in combination with a melamine resin and a block isocyanate, it has a drawback that the hardness, stain resistance, moisture resistance, corrosion resistance, etc. of the coating film are reduced.

Further, as a resin for an adhesive for laminating and adhering various plastic films such as a polyvinyl chloride film and a polyester film to a steel plate, a stainless plate, an aluminum plate, etc., a copolyester resin and an isocyanate are used. Although an adhesive that uses a combination of and is used, it has the drawback of poor water resistance.

When a copolyester resin is used as an ink or anchor coat for various films, it is necessary to lower the Tg in order to improve the adhesiveness. Sex matters.

[0006]

An object of the present invention is to provide a copolymerized polyester resin which is useful as a base resin for paints, inks, adhesives and the like and which is excellent in processability, water resistance, adhesion and blocking resistance. To do.

[0007]

Means for Solving the Problems As a result of intensive studies aimed at achieving the above object, the present inventors have used a specific amount of a specific component for an acid component and an alcohol component and have a molecular weight within a specific range. The inventors have found that a copolyester resin can achieve the object, and completed the present invention.

That is, according to the present invention, 80 to 100 mol% of (A) aromatic dicarboxylic acid (a-1) and 20 to 0 mol% of dicarboxylic acid (a-2) other than aromatic dicarboxylic acid.
An acid component consisting of (B) 0.5 to 20 mol% of a diol (b-1) represented by the following formula (I), and another diol (b)
-2) an alcohol component consisting of 99.5 to 70 mol% and a polyhydric alcohol (b-3) of 3 or more valences (b-3) and having a number average molecular weight of 3,000 to 50,000.
It is a copolyester resin characterized by being 0.

[0009]

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The acid component (A) used to obtain the copolyester resin of the present invention is an aromatic dicarboxylic acid (a).
-1) and dicarboxylic acids other than aromatic dicarboxylic acids (a-
2) (hereinafter abbreviated as other dicarboxylic acid (a-2)).

The aromatic dicarboxylic acid (a-1) used as the acid component (A) includes terephthalic acid, isophthalic acid, phthalic acid, 1,4-naphthalenedicarboxylic acid,
2,6-naphthalenedicarboxylic acid, and their acid anhydrides, acid halides, lower alkyl esters and the like. Examples of the lower alkyl ester of the aromatic dicarboxylic acid include esters such as methyl, ethyl, propyl and butyl, and the methyl ester is preferably used in terms of cost and handling. These aromatic dicarboxylic acids (a-1) can be used alone or in combination of two or more.

The other dicarboxylic acid (a-2) used as the acid component (A) is, for example, sebacic acid,
Aliphatic dicarboxylic acids such as succinic acid, maleic acid, fumaric acid, adipic acid and azelaic acid, alicyclic dicarboxylic acids such as hexahydrophthalic acid, hexahydroisophthalic acid and hexahydroterephthalic acid, and acid anhydrides thereof,
Examples thereof include acid halides and lower alkyl esters. These can be used alone or in combination of two or more.

The ratio of the aromatic dicarboxylic acid (a-1) to the other dicarboxylic acid (a-2) in the acid component (A) is 80 to 100 mol% of the aromatic dicarboxylic acid (a-1). Dicarboxylic acid (a-2) of 20 to 0 mol%, the amount of aromatic dicarboxylic acid (a-1) is 80 mol%
If it is less than 1, the hardness, stain resistance, and water resistance of the coating film will be deteriorated.

Next, the alcohol component (B) used for obtaining the copolyester resin of the present invention includes a diol (b-1) represented by the above formula (I), another diol (b-2) and Trihydric or higher polyhydric alcohol (b-3)
Consists of

The diol (b-1) represented by the above formula (I) used in the present invention is a component which imparts processability, moisture resistance and adhesiveness to the resin. Specific examples thereof include the following formula ( II) and a mixture of diols represented by (III).

[0016]

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[0017]

[Chemical 4]

The diol represented by the above formula (I) (b-
1) is 0.5 to 20 mol% in the alcohol component (B),
Preferably 0.5 to 15 mol%, more preferably 1 to 1
It is contained in the range of 0 mol% and its content is 0.5 mol%
If it is less than 20%, the effect cannot be obtained, and if it exceeds 20 mol%, a predetermined molecular weight cannot be obtained.

The other diol (b-2) used as the alcohol component (B) is, for example, ethylene glycol, neopentyl glycol, 1,2-propanediol, 1,3-propanediol, 1,4. -Butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,7-heptanediol, 1,8-octanediol, 1,9-nonanediol, 1,10-
Decanediol, diethylene glycol, triethylene glycol, 2-methyl-2-ethyl-1,3-propanediol, 2,2-ethyl-1,3-propanediol, 2-butyl-2-ethyl-1,3-propane Aliphatic diols such as diols, alicyclic diols such as 1,4-cyclohexanedimethanol, ethylene oxide or propylene oxide adducts of bisphenol A, and aromatic diols such as ethylene oxide or propylene oxide adducts of bisphenol S. To be These can be used alone or in combination of two or more.

The other diol (b-2) is 99.5 to 70 mol% in the alcohol component (B), preferably 99.5.
To 85 mol%, more preferably 99.0 to 80 mol%, and if the content exceeds 99.5 mol%, the processability, moisture resistance and adhesion of the resin become insufficient, and If it is less than 70 mol%, the productivity of the resin will decrease.

The trihydric or higher polyhydric alcohol (b-3) used in the present invention is a component that imparts processability to the resin, and is used as necessary. Examples of the trihydric or higher polyhydric alcohol used include, for example, sorbitol, 1,2,3,6-hexanetetralol, 1,4-
Sorbitan, pentaerythritol, dipentaerythritol, tripentaerythritol, sucrose, 1,2,4
Examples include butanetriol, glycerol, 2-methylpropanetriol, 2-methyl-1,2,4-butanetriol, trimethylolethane, trimethylolpropane and 1,3,5-trihydroxymethylbenzene. These can be used alone or in combination of two or more.

The polyhydric alcohol having a valence of 3 or more (b-3) is
0 to 10 mol% in the alcohol component (B), preferably 0
It is contained in the range of ˜8 mol%, more preferably 0 to 6 mol%, and when the content exceeds 10 mol%, the resin gels and it becomes difficult to take it out from the reaction vessel and it becomes difficult to dissolve in the solvent. .

In the copolyester resin of the present invention having the above constitution, the number average molecular weight is 3,000-5.
It is important that the number average molecular weight is in the range of 10,000, preferably 4,000 to 40,000, and more preferably 5,000 to 30,000. If the number average molecular weight is less than 3,000, sufficient performance is not exhibited. On the other hand, when it exceeds 50,000, when it is used as a base resin for paints and adhesives, the viscosity becomes high and handling becomes difficult.

The method for producing the copolyester resin of the present invention is not particularly limited, but known polymerization methods described below can be applied. For example, first, the monomer is charged into a reaction kettle and heated to raise the temperature to carry out an esterification reaction or a transesterification reaction to remove water or alcohol produced in this reaction. At this time, if necessary, an esterification catalyst used in a normal esterification reaction or a transesterification reaction such as sulfuric acid, titanium butoxide, dibutyltin oxide, magnesium acetate, manganese acetate, zinc acetate can be used.

Next, a polycondensation reaction is subsequently carried out. At this time, polymerization is carried out under a vacuum of 150 mmHg or less while distilling and removing the diol component. In the polymerization, known polymerization catalysts such as titanium butoxide, dibutyltin oxide, tin acetate, zinc acetate, tin disulfide, antimony trioxide and germanium dioxide can be used. Further, the polymerization temperature and the amount of catalyst are not particularly limited and may be arbitrarily set as necessary.

The copolyester resin obtained by the present invention is useful for applications such as paints, inks and adhesives,
Further, according to the desired performance, a melamine resin, an isocyanate compound, a cross-linking agent such as a block isocyanate compound or an epoxy resin, a phenol resin, a urethane resin, a vinyl chloride resin, or a fibrin resin should be blended and used. You can

Inorganic and organic pigments such as titanium oxide, carbon black and phthalocyanine, and rust preventive pigments such as strontium chromate and zinc chromate, surface smoothing agents, defoaming agents and coupling agents such as titanium and silicon. Can also be compounded.

The copolyester resin of the present invention is used by being dissolved in an organic solvent, and as the usable organic solvent, benzene, toluene, xylene, mineral terpene, acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, petroleum benzine, Ethyl acetate, butyl acetate, methyl cellosolve, butyl cellosolve, cellosolve acetate, isophorone, methanol,
Various solvents such as ethanol, butanol, Solvesso 100 and 150 can be used, and one or a mixture of two or more thereof can be selected from these in consideration of solubility and evaporation rate.

[0029]

The present invention will be described in detail below with reference to examples, but the present invention is not limited to these examples. In addition, the evaluation of the performance in the following examples and comparative examples was performed using the following methods.

(1) Resin composition analysis The composition was analyzed by NMR.

(2) Number average molecular weight The number average molecular weight in terms of GPC polystyrene was determined.

(3) Hardness The coated steel sheet was measured according to JIS K-5400 using a high-grade pencil defined in JIS S-6006.

(4) Contamination resistance A red magic ink was applied on the coating film, and after 2 hours, the ink was wiped off with a gauze impregnated with a solvent of petroleum benzine / ethanol = 1/1 (weight ratio). The contamination state was evaluated based on the following 5 points. 5: No abnormalities 4: Very slight pollution 3: Little pollution 2: Very pollution 1: Severe pollution

(5) Workability A plate having the same thickness as the evaluation plate was clamped on the coated plate with a vise and bent, and the workability was judged by whether or not cracks were generated in the coating film at the bent portion (test (5 sheets each). The numbers in the table indicate the number of cracks.

(6) Water resistance The state of the coating film after the coated plate was immersed in warm water at 50 ° C. for 1 week was evaluated. ○: No abnormality △: Swelling slightly ×: Swelling, whitening

(7) Initial peeling strength: The adhered steel plate was cut into a width of 2 cm and the 180 degree peeling strength was measured.

(8) Peeling strength after water resistance: The adhered steel plate was cut into a width of 2 cm and immersed in boiling water at 100 ° C for 2 hours, and then the 180-degree peeling strength was measured.

(9) Adhesion workability: The polyvinyl chloride film surface of the adhered steel sheet was cut and bent with a bending tester of 2 mmφ, and the peeling state of the sheet surface was evaluated by the following 5 points. 5: No peeling 4: Slight peeling 3: Half peeling 2: Most peeling 1: Whole peeling

(10) Adhesion: Evaluated by a cross-cut cellophane tape peeling test.

(11) Blocking resistance: Gauze was placed on the coated surface, a load of 500 g was placed thereon, and the gauze trace after 5 hours at 50 ° C. was judged according to the following criteria. ○: No gauze traces △: Slight gauze traces ×: Gauze traces

The abbreviations in the table represent the following compounds. IPA: isophthalic acid TPA: terephthalic acid ADA: adipic acid SA: sebacic acid EG: ethylene glycol NPG: neopentyl glycol DEG: diethylene glycol TMP: trimethylolpropane diol b-1: represented by the above formulas (II) and (III) Mixture of diols (composition; formula (II) / (III) = 75/2
5 (weight ratio)).

Example 1 2.93 mol parts of isophthalic acid, 0.73 mol parts of terephthalic acid, 1.99 mol parts of ethylene glycol, 2.22 mol parts of neopentyl glycol and 0.001 mol parts of zinc acetate were reacted. The mixture was charged into a container and the esterification reaction was carried out while distilling water at an internal temperature of 230 to 265 ° C. After confirming that the esterification reaction product was transparent, 0.19 mol part of diol b-1 and 0.0016 mol part of antimony trioxide were added, and the internal temperature was controlled at 255 to 260 ° C. 30 inside
The pressure was reduced to 1.0 mmHg over minutes, and the condensation reaction was carried out for 1.5 hours while distilling the excess glycol component.
Table 1 shows the measurement results of the resin composition and the number average molecular weight of the obtained copolyester resin A-1.

Then, this copolymerized polyester resin A-
1 was dissolved in a solvent of xylene / cyclohexanone = 80/20 (weight ratio) so that the solid content was 40%, and Sumimar M-40S (Sumitomo Chemical Co., Ltd., methylated melamine) was added to the obtained resin solution. Resin) so that the ratio of the copolyester resin / melamine resin is 80/20 (solid content ratio), and then applied to a tin plate having a thickness of 0.3 mm so that the film thickness is 20 μm, and at 180 ° C. A test panel was prepared by drying for 10 minutes. Table 2 shows the evaluation results of the coating film performance of this panel board.

Examples 2 to 3 Copolymerization polyester resins A-2 to A-3 were obtained in the same manner as in Example 1 except that the composition for polymerization was changed as shown in Table 1. Table 1 shows the compositional analysis results and the number average molecular weight measurement results of the copolymerized polyester resins A-2 to A-3.

Next, the above-mentioned copolymerized polyester resin A-
A test panel was prepared using 2 to A-3 in the same manner as in Example 1 and evaluated. Table 2 shows the evaluation results.

Example 4 A resin solution having a solid content of 40% was prepared by dissolving the copolyester resin A-1 of Example 1 in a toluene-cyclohexane mixed solution (toluene / cyclohexane = 80/20 (weight ratio)). Was prepared. Next, this solution and Desmodur PFE (manufactured by Sumitomo Bayer Polyurethane Co., Ltd., polyisocyanate) have a solid content ratio of copolyester resin A-1 / polyisocyanate = 100.
/ 1 and applied to a chemical conversion treated steel plate (Nippon Test Panel Co., Bonderite # 3960) to a film thickness of 4 μm, then heat-dried at a plate temperature of 160 ° C., and then a polyvinyl chloride sheet Were adhered, and after cooling, the adhesiveness was evaluated. The evaluation results are shown in Table 3.

Example 5 A copolymerized polyester resin A-4 was obtained by the same procedure as in Example 1 except that the composition for polymerization was changed as shown in Table 1. Table 1 shows the composition analysis results and the number average molecular weight measurement results of the obtained copolyester resin A-4.

Next, this copolymerized polyester resin A-4
Was dissolved in a xylene-methyl isobutyl ketone mixed solution (xylene / methyl isobutyl ketone = 80/20 (weight ratio)) to prepare a resin solution having a solid content concentration of 40%. Next, this solution and titanium oxide (R-55 manufactured by Ishihara Sangyo Co., Ltd.)
0) to prepare a white ink in which titanium oxide having a pigment concentration of 50% by weight is dispersed. This white ink was applied to a PET film (Lumirror T type manufactured by Toray Industries, Inc.) and dried to evaluate its performance. Table 4 shows the evaluation results.

[Comparative Examples 1 to 3] Copolymerized polyester resins A-5 and A-7 were obtained in the same manner as in Example 1 except that the composition for polymerization was as shown in Table 1. The copolyester resin A-6 gelled during production and could not be taken out of the reactor. Table 1 shows the composition analysis results and the number average molecular weight measurement results of the obtained copolyester resins A-5 and A-7.

Next, the above-mentioned copolymerized polyester resin A-
5 and A-7 were used to prepare a test panel in the same manner as in Example 1 and evaluated. Table 2 shows the evaluation results.

[Comparative Example 4] The copolyester resin A-5 obtained in Comparative Example 1 was blended with an adhesive in the same formulation as in Example 4 to evaluate the adhesiveness. The evaluation results are shown in Table 3.

[Comparative Example 5] A copolymerized polyester resin A-8 was obtained in the same manner as in Example 1 except that the composition for polymerization was changed as shown in Table 1. Table 1 shows the composition analysis results and the number average molecular weight measurement results of the obtained copolyester resin A-8.

Then, this copolymerized polyester resin A-
8 was used to prepare a white ink in the same manner as in Example 5, and the performance was evaluated by the same method as in Example 5. Table 4 shows the evaluation results.

[0054]

[Table 1]

[0055]

[Table 2]

[0056]

[Table 3]

[0057]

[Table 4]

[0058]

The copolymerized polyester resin of the present invention is excellent in processability, water resistance, adhesion and blocking resistance, and is useful for applications such as paints, inks and adhesives.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Tajiri Zouun 2-4-1, Ushikawa-dori, Toyohashi-shi, Aichi Sanryo Rayon Co., Ltd. Toyohashi Plant

Claims (1)

[Claims] 1. An aromatic dicarboxylic acid (a-1) 8 (A)
An acid component composed of 0 to 100 mol% and 20 to 0 mol% of a dicarboxylic acid (a-2) other than the aromatic dicarboxylic acid;
(B) Diol (b-1) represented by the following formula (I): 0.
5-20 mol%, other diol (b-2) 99.5-7
0 mol% and trihydric or higher polyhydric alcohol (b-3) 0
A copolymerized polyester resin comprising an alcohol component of 10 to 10 mol% and having a number average molecular weight of 3,000 to 50,000. Embedded image