JPH10176135A - Copolymer saturated polyester resin for coating - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a copolymer satd. polyester resin for coating which is useful as a base resin for a coating material, an ink, an adhesive or the like, is excellent in coating properties, such as appearance of coating, impact resistance, formability, and water resistance, and has excellent adhesion. SOLUTION: This copolymer satd. polyester resin comprises: an acid moiety comprising 0 to 80mol% arom. dicarboxylic acid and 100 to 20mol% dicarboxylic acid other than arom. dicarboxylic acid; and an alcohol moiety comprising 30 to 100mol% 6 C or higher aliph. diol, 0 to 10mol% trivalent or higher polyvalent alcohol, and 0 to 70mol% other diol, the polyester resin having an no. average mol.wt. of 1,000 to 30,000 and a viscosity of 200 to 10,000cP at 25 deg.C. The nonvolatile content is pref. not less than 90%.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a copolymerized saturated polyester resin for coating, and more particularly to a copolymerized saturated polyester resin useful as a base resin for paints, inks, adhesives and the like.

[0002]

2. Description of the Related Art Conventionally, copolymer polyesters soluble in organic solvents have a good balance between processability and hardness, and have excellent adhesion to various plastics and metals, so that paints, inks, adhesives, etc. It is used for applications.

[0003] However, in recent years, interest in the global environment has increased, and the use of organic solvents has been restricted due to the danger of harming the health of workers. Measures have been put in place.

[0004] Resin systems used for solvent-free can be broadly classified into precursor systems and polymer systems. The precursor system is a low-viscosity liquid because a low-molecular-weight monomer or prepolymer is used, and a conventional coating film forming method can be used as it is. However, in a precursor system containing a low molecular weight substance in the composition, further improvement in safety and hygiene such as scattering of the low molecular weight substance is desired. In terms of physical properties,
In the case of a coating composed of a resin in the oligomer region, it is known that it is difficult to control the properties of the cured product, and it is desired to increase the molecular weight while maintaining low viscosity.

On the other hand, in the case of a polymer system, it is necessary to make the solid polymer liquid by some method or to change the method of forming a coating film. As a typical method of forming a liquid without using an organic solvent, there is a plastisol system that is liquefied with a non-volatile plasticizer, but this method has a problem that a hard cured product is difficult to obtain and a plasticizer is transferred. Has been pointed out.

[0006] In latex systems such as emulsions and hydrosols, problems have been pointed out such as inhomogeneity of cured products and slow drying speed. Even the most effective water-soluble resin system at present has problems such as low drying speed, water resistance, and wastewater treatment. Most water-soluble resin systems contain 10% or more of an organic solvent to improve pigment dispersibility and workability. In the case of powder or hot-melt resin, it is necessary to introduce new equipment because it differs from the conventional coating film forming method.

[0007]

DISCLOSURE OF THE INVENTION The present invention has been made in view of the above-mentioned prior art, and has as its object the purpose of being useful as a base resin for paints, inks, adhesives and the like without solvent. An object of the present invention is to provide a copolymerized saturated polyester resin for coating excellent in coating film performance such as coating film appearance, impact resistance, processability, and water resistance and adhesion.

[0008]

Means for Solving the Problems As a result of intensive studies to achieve 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 specific range of molecular weight and viscosity. The present inventors have found that a copolymerized saturated polyester resin having the formula (1) can achieve the object and completed the present invention.

That is, the present invention relates to a dicarboxylic acid component comprising (A) 0 to 80 mol% of an aromatic dicarboxylic acid (a-1) and 100 to 20 mol% of a dicarboxylic acid (a-2) other than an aromatic dicarboxylic acid. , (B) 30 to 100 mol% of an aliphatic diol having 6 or more carbon atoms (b-1), 0 to 10 mol% of a trihydric or higher polyhydric alcohol (b-2), and another diol (b-3) 0 to 70 mol%, and has a number average molecular weight of 1,000 to 30,0.
And a viscosity at 25 ° C. of 200 to 10,000.
It is a copolymerized saturated polyester resin for coating characterized by having 0 cP.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Acid component (A) used to obtain the copolymerized saturated polyester resin for coating of the present invention
Is composed of an aromatic dicarboxylic acid (a-1) and a dicarboxylic acid (a-2) other than the aromatic dicarboxylic acid (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, diphenic acid, 4,
4'-biphenyldicarboxylic acid, and their acid anhydrides, acid halides or lower alkyl esters. Examples of lower alkyl esters of aromatic dicarboxylic acids include esters such as methyl, ethyl, propyl or butyl, but methyl esters are preferred 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) includes, for example, sebacic acid,
Aliphatic dicarboxylic acids such as succinic acid, maleic acid, fumaric acid, adipic acid, azelaic acid, dodecenyl succinic acid,
Examples include branched acids such as dimer acids, and alicyclic dicarboxylic acids such as hexahydrophthalic acid, hexahydroisophthalic acid, and hexahydroterephthalic acid, and acid anhydrides, acid halides, and lower alkyl esters thereof. These can be used alone or in combination of two or more.

The ratio of the aromatic dicarboxylic acid (a-1) and the other dicarboxylic acid (a-2) in the acid component (A) is 0 to 80 mol% of the aromatic dicarboxylic acid (a-1). The dicarboxylic acid (a-2) is in the range of 100 to 20 mol%, and when the aromatic dicarboxylic acid (a-1) exceeds 80 mol%, the viscosity of the resin becomes too high, which is not preferable.
Preferably, it is in the range of 100 to 50 mol% of the other dicarboxylic acid (a-2) with respect to 0 to 50 mol% of the aromatic dicarboxylic acid (a-1). More preferably, 0 to 45 mol% of the aromatic dicarboxylic acid (a-1) to 100 to 55 mol% of the other dicarboxylic acid (a-2), and still more preferably 0 to 40 mol% of the aromatic dicarboxylic acid (a-1). The other dicarboxylic acid (a-2) is 100 to 60 mol% with respect to the mol%.

Next, the alcohol component (B) used to obtain the copolymerized saturated polyester resin for coating of the present invention comprises an aliphatic diol (b-
1) Consisting of a trihydric or higher polyhydric alcohol (b-2) and another diol (b-3).

Specific examples of the aliphatic diol (b-1) having 6 or more carbon atoms used in the present invention include 1,6
-Hexanediol, 1,7-heptanediol, 1,
8-octanediol, 1,9-nonanediol, 1,
Linear aliphatic diols such as 10-decanediol;
Methyl-1,3-propanediol, 2-methyl-2-
Ethyl-1,3-propanediol, 2,2-diethyl-1,3-propanediol, 2-butyl-2-ethyl-1,3-propanediol, 2,2,4-trimethyl-1,3-pentane Examples thereof include branched aliphatic diols such as diols, and alicyclic aliphatic diols such as 1,4-cyclohexanedimethanol. These can be one or two
Although it is possible to use more than one kind in combination, to reduce the resin viscosity without lowering the water resistance, a branched aliphatic diol and an alicyclic aliphatic diol are preferable, and a branched aliphatic diol and an alicyclic aliphatic diol are preferable. It is more preferable to use a combination of aliphatic diols. Among the branched aliphatic diols, 2-butyl-2-ethyl-1,3-propanediol is preferred, and the alicyclic aliphatic diol is preferably 1,4-cyclohexanedimethanol. Further, it is preferable to use a hydrogenated dimer diol which is a mixture of a branched aliphatic diol and an alicyclic aliphatic diol.

Aliphatic diol having 6 or more carbon atoms (b-1)
Is contained in the alcohol component (B) in the range of 30 to 100 mol%, and if the content is small, the viscosity of the resin becomes high. Preferably 40 to 100 mol%, more preferably 50 to 100 mol%
Mol%, more preferably 60 to 100 mol%.

Specific examples of the trihydric or higher polyhydric alcohol (b-2) used in the present invention include sorbitol, 1,2,3,6-hexanetetralol, 1,4-
Sorbitan, pentaerythritol, dipentaerythritol, tripentaerythritol, sucrose, 1,2,4
-Butanetriol, 1,2,5-pentatriol,
Glycerol, 2-methylpropanetriol, 2-methyl1,2,4-butanetriol, trimethylolethane, trimethylolpropane, 1,3,5-trihydroxymethylbenzene, Plaxel 308 (manufactured by Daicel Chemical Industries, Ltd. ε-caprolactone triol) and the like. These can be used alone or in combination of two or more.

The trihydric or higher polyhydric alcohol (b-2) is
0 to 10 mol%, preferably 0 to 0 mol% in the alcohol component (B)
If the content exceeds 10 mol%, the resin gels and the viscosity becomes high, which is not preferable.

Specific examples of other diols (b-3) used in the present invention include ethylene glycol, neopentyl glycol, 1,2-propanediol,
1,3-propanediol, 1,4-butanediol,
Examples thereof include aliphatic diols such as 1,5-pentanediol and diethylene glycol, aromatic diols such as ethylene oxide or propylene oxide adduct of bisphenol A, and ethylene oxide or propylene oxide adduct of bisphenol S. These can be used alone or in combination of two or more.

The other diol (b-3) is contained in the alcohol component (B) in the range of 0 to 70 mol%, preferably 0 to 50 mol%, more preferably 0 to 40 mol%,
If the content exceeds 70 mol%, the viscosity of the resin increases, which is not preferable.

In the copolymerized saturated polyester resin for coating of the present invention having the above constitution, the number average molecular weight needs to be 1,000 to 30,000, and if the number average molecular weight is less than 1,000, it is insufficient. On the other hand, if it exceeds 30,000, the viscosity of the paint or the adhesive becomes too high and handling becomes difficult. Preferably it is 2,000-25,000, More preferably, it is 3,000-20,000.

The copolymerized saturated polyester resin of the present invention has a viscosity of 200 to 10,000 cP at 25 ° C.
If the viscosity is less than 200 cP, a coating film exhibiting sufficient performance cannot be obtained.
If it exceeds 0 cP, the viscosity of the paint or adhesive becomes high, and handling becomes difficult. Preferably 300 to 9,000 cP
And more preferably 400 to 8,000 cP.

The method for producing the copolymerized saturated polyester resin of the present invention is not particularly limited, but the following known polymerization methods can be applied. For example, first, the above-mentioned monomer is charged into a reactor, heated and heated to perform an esterification reaction or a transesterification reaction, and water or alcohol generated in the reaction is removed. At this time, if necessary, an esterification catalyst such as sulfuric acid, titanium butoxide, dibutyltin oxide, magnesium acetate, manganese acetate, and zinc acetate, which is used in a normal esterification reaction or transesterification reaction, can be used.

Subsequently, a polycondensation reaction is subsequently carried out. At this time, polymerization is carried out while distilling and removing the alcohol component under a vacuum of 150 mmHg or less. 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 the catalyst are not particularly limited, and may be arbitrarily set as needed.

The copolymerized saturated polyester resin obtained by the present invention is useful for coating applications such as paints, inks, adhesives, etc. Further, depending on the purpose and required performance, melamine resins, isocyanate compounds, block isocyanate compounds A cross-linking agent such as, for example, an epoxy resin, a phenol resin, a urethane resin, a vinyl chloride resin, and a cellulose resin can be used.

Also, inorganic and organic pigments such as titanium oxide, carbon black and phthalocyanine, rust preventive pigments such as strontium chromate and zinc chromate, surface smoothing agents, antifoaming agents, and coupling agents such as titanium and silicon based. Can also be blended.

The copolymerized saturated polyester resin for coating of the present invention can be used by adding a small amount of an organic solvent according to workability. Organic solvents that can be used include:
Benzene, toluene, xylene, mineral terpene, acetone, methyl ethyl ketone, methyl isobutyl ketone, ethyl acetate, butyl acetate, methyl cellosolve, butyl cellosolve, cellosolve acetate, isophorone, methanol, ethanol, butanol, solvesso 10
0, various solvents such as Solvesso 150 can be used.
Species can be used or two or more can be selected and used.
The amount of the solvent to be added can be changed according to the workability.However, in order to consider environmental issues and to avoid a decrease in the appearance of the coating film due to boiling at the time of baking the coating film, the copolymer saturation of the present invention is reduced. The nonvolatile content of the polyester resin is preferably 90% or more. It is more preferably at least 95%, further preferably at least 99%.

[0028]

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

(1) Resin composition analysis Composition analysis was performed by NMR.

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

(3) Appearance of the coating film The state of the coating film after baking was visually judged.

(4) Impact resistance Evaluated by Dupont impact test (JIS K-5400).

(5) Workability The Erichsen test (JIS K-5400) was used to evaluate the workability.

(6) Water Resistance The state of the coating film after immersing the coated plate in warm water of 50 ° C. for one week was visually judged.

The coating film appearance, impact resistance, workability and water resistance were evaluated according to the following criteria. ◎: Excellent ○: Good △: Acceptable ×: Not Acceptable

(7) Initial peeling strength The bonded steel sheet was cut into a width of 2 cm, and the 180 ° peeling strength was measured.

(8) Peeling Strength After Water Resistance The bonded steel sheet was cut into a width of 2 cm, immersed in boiling water at 100 ° C. for 2 hours, and the 180 ° peeling strength was measured.

(9) Adhesive processability The surface of the polyvinyl chloride film of the bonded steel plate is cut,
The sheet was peeled off with a bending tester of 2 mmφ to evaluate the peeling state of the sheet on a scale of 1 to 5 below. 5: No peeling 4: Slight peeling 3: Half peeling 2: Most peeling 1: Full peeling

(10) Non-volatile Content 1 g of the copolymerized saturated polyester resin was sampled on an aluminum dish, and the residue ratio (%) after drying at 105 ° C. for 2 hours was indicated.

The abbreviations used in Tables 1 and 2 and Tables 5 and 6 represent the following compounds. IPA: isophthalic acid TPA: terephthalic acid ADA: adipic acid SA: sebacic acid CHDA: hexahydroterephthalic acid EG: ethylene glycol NPG: neopentyl glycol HDO: 1,6-hexanediol DEPD: 2,2-diethyl-1,3 -Propanediol BEPD: 2-butyl-2-ethyl-1,3-propanediol BP5P: Bisphenol A propylene oxide 5 mol adduct CHDM: 1,4-cyclohexanedimethanol TMP: Trimethylolpropane P308: Plaxel 308 (Daicel Chemical) Industrial Co., Ltd.
HP-1000: hydrogenated dimer diol (manufactured by Toagosei Co., Ltd.)

Example 1 0.36 mol part of isophthalic acid, 0.36 mol part of terephthalic acid, 2.94 adipic acid
Into a reaction vessel were charged mol parts, 0.4 mol parts of ethylene glycol, 2.01 mol parts of neopentyl glycol, 2.01 mol parts of 1,6-hexanediol and 0.001 mol parts of zinc acetate, and the internal temperature was 230 ° C. or higher. The esterification reaction was performed while distilling water at 265 ° C. or lower. After confirming that the esterification reaction product was transparent, 0.0016 mol of antimony trioxide was added, and the internal temperature was raised to 200 ° C.
The temperature in the reaction system was controlled to 40 ° C. or lower, the pressure in the reaction system was reduced to 1.0 mmHg over 30 minutes, and the condensation reaction was carried out for 1.5 hours while distilling off the excess diol component. Table 2 shows the results of the composition analysis of the obtained copolymerized saturated polyester resin A-1 and the results of measurement of the number average molecular weight, viscosity, and nonvolatile content.

Next, Sumimar M-40S (Sumitomo Chemical Co., Ltd.) was added to the copolymerized saturated polyester resin A-1.
(Methylated melamine resin) is mixed so as to have a copolymerized saturated polyester A-1 / melamine resin = 70/30 (solid content ratio), and then this is applied to a tin plate having a thickness of 0.5 mm to a thickness of 20 μm. And dried at 200 ° C. for 10 minutes to produce a test panel. Table 3 shows the results of the evaluation of the coating properties of this panel plate.

Examples 2 to 4 Copolymerized saturated polyester resins A-2 to A-4 were obtained in the same manner as in Example 1 except that the monomer composition for polymerization was changed as shown in Table 1. Table 2 shows the results of the composition analysis of the copolymerized saturated polyester resins A-2 to A-4, and the results of measurement of the number average molecular weight, viscosity, and nonvolatile content.

Next, the copolymerized saturated polyester resin A
Using -2 to A-4, a test panel was produced in the same manner as in Example 1, and the coating film performance was evaluated. Table 3 shows the evaluation results.

Example 5 The copolymerized saturated polyester resin A-1 of Example 1 and Desmodule RFE (polyisocyanate, manufactured by Sumitomo Bayer Polyurethanes Co., Ltd.) having a solid content ratio of copolymerized polyester resin A-1 were used. / Polyisocyanate = 50/1, applied to a chemical conversion-treated steel sheet (Bonderite # 3960, manufactured by Nippon Test Panel Co., Ltd.) so as to have a thickness of 4 μm, and then heated and dried at a sheet temperature of 180 ° C. Then, a polyvinyl chloride sheet was bonded, and after cooling, the bonded steel sheet was evaluated for adhesion (initial peeling strength, peeling strength after water resistance, bonding workability). Table 4 shows the obtained evaluation results.

Comparative Examples 1 to 4 Copolymerized saturated polyester resins A-5 to A-7 were obtained in the same manner as in Example 1 except that the composition of charged monomers was changed as shown in Table 1. The obtained copolymer saturated polyester resin A-5 to A-
Table 2 shows the results of the composition analysis of No. 7 and the measurement results of the number average molecular weight, the viscosity, and the nonvolatile content. These copolymerized saturated polyester resins A-5 to A-7 were solid at ordinary temperature, and it was impossible to measure the viscosity and adjust them to paints and adhesives. Further, the copolymerized saturated polyester resin A-6 gelled during the reaction, and the resin could not be taken out of the reactor.

Comparative Example 5 The copolymerized saturated polyester resin A-5 produced above was dissolved in a solvent of Solvesso 150: cyclohexanone = 50: 50 so that the nonvolatile content was 40%. The viscosity of the obtained resin solution is 5,000 cP
(25 ° C.). Next, a test panel was prepared using this resin solution in the same manner as in Example 1, and the coating film performance was evaluated. Table 3 shows the evaluation results.

[0048]

[Table 1]

[0049]

[Table 2]

[0050]

[Table 3]

[0051]

[Table 4]

Examples 6 to 9 Copolymerized saturated polyester resins A-8 to A-11 were obtained in the same manner as in Example 1, except that the monomer composition for polymerization was changed as shown in Table 5. Table 6 shows the results of composition analysis of the copolymerized saturated polyester resins A-8 to A-11, and the results of measurement of the number average molecular weight, viscosity, and nonvolatile content.

Next, the above-mentioned copolymerized saturated polyester resin A
Using -8 to A-11, a test panel was produced in the same manner as in Example 1, and the coating film performance was evaluated. Table 7 shows the evaluation results.
It was shown to.

Example 10 The same operation as in Example 5 was carried out except that the copolymerized saturated polyester resin A-8 was used, and the adhesion was evaluated. Table 8 shows the obtained evaluation results.

[0055]

[Table 5]

[0056]

[Table 6]

[0057]

[Table 7]

[0058]

[Table 8]

[0059]

According to the present invention, it is possible to provide a solvent-free type copolymerized saturated polyester resin for coating without environmental pollution. The copolymerized saturated polyester resin for coating of the present invention is excellent in coating film appearance, impact resistance, processability, coating film performance such as water resistance and adhesion, and can be used for coatings, inks, adhesives, etc. without solvent. It can be used as a base resin to obtain.

Claims (2)

[Claims] (A) Aromatic dicarboxylic acid (a-1) 0
And a dicarboxylic acid component consisting of 100 to 20 mol% of dicarboxylic acid (a-2) other than aromatic dicarboxylic acid and (B) an aliphatic diol having 6 or more carbon atoms (b).
-1) 30 to 100 mol%, trihydric or higher polyhydric alcohol (b-2) 0 to 10 mol% and other diol (b-
3) an alcohol component consisting of 0 to 70 mol%, having a number average molecular weight of 1,000 to 30,000;
And a copolymerized saturated polyester resin having a viscosity at 25 ° C. of 200 to 10,000 cP. 2. The copolymerized saturated polyester resin for coating according to claim 1, wherein the nonvolatile content is 90% or more.