JP2881405B2 - Water-based one-pack polyester resin paint - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an aqueous one-pack type polyester resin paint which can be applied to a plastic material to form a high-performance coating film. The present invention relates to a water-based one-pack polyester resin paint in which most or all of the solvent and the diluent solvent in the paint are replaced with water, in place of the conventional paint in which both the paint and the thinner used for dilution at the time of coating are organic solvents. Yes, taking into account global environmental issues. The present invention also relates to various resin molded products, for example, acrylic resin, A
Water-based, one-pack type that adheres well to BS resin, polycarbonate resin, etc., and has the coating film performance required for automotive parts, home appliances, etc., such as coating film hardness, water resistance, moisture resistance, acid resistance, and alkali resistance. It relates to a polyester resin paint.

[0002]

2. Description of the Related Art Conventionally, emulsion-type paints have been used on the exterior or interior wall surfaces of apartment houses and single-family houses that have undergone construction work. These buildings have a very large surface area, and in many cases, houses and the like are adjacent to these buildings. Solvent-based paints that generate a large amount of organic solvent gas during painting pose a risk of environmental pollution, odor pollution and fire. Therefore, the use of water-based paint is customary.

[0003] When a water-based paint for construction distributed on the market is applied to a plastic material such as an automobile part, a home appliance or a computer exterior using a molded product such as an acrylic resin, an ABS resin, or a polycarbonate resin, the adhesion to the material is poor. In addition, the performance of various coatings required for use in these applications cannot be satisfied.

[0004] Automobile parts, home electric appliances and the like are all painted in a painting factory by means of painting such as air spray, airless spray, electrostatic, etc., and the health care of paint workers in the painting line and the danger of fire In consideration of
At present, a duct is installed at the painting site to forcibly suck the organic solvent gas that evaporates from the paint.

[0005] The method of treating the sucked organic solvent gas includes a method of naturally diffusing to the outside, a method of temporarily absorbing the adsorbent such as activated carbon and burning it with an appropriate apparatus, and a method of treating the sucked organic solvent gas at the place. There are methods such as direct incineration treatment, but none of them still generate organic solvent gas, and in order to solve this problem, make the organic solvent contained in the paint itself a very small amount or do not include it I needed to.

[0006] The coating properties required for coating automotive parts and home appliances using plastic moldings as materials are listed in Table 1.
However, in order to satisfy these properties, use of a solvent-based two-pack type polyurethane resin paint is common.

[0007]

[Table 1]

In addition, there are one-pack type acrylic resin coatings and acrylic-modified alkyd resin coatings as plastic coatings, but these coatings do not satisfy the above-mentioned coating film performance standards.

[0009] The solvent-based two-pack type polyurethane resin paint is mainly composed of an acrylic resin or a polyester resin having a hydroxyl group (-OH group) in a skeleton, and an isocyanate group (-NCO group) on a curing agent side. In this coating, the solvent component first evaporates during the drying step, and then the hydroxyl group and the isocyanate group form a urethane bond, which is partially tough due to an allophanate bond or a burette bond. Form a coating. However, this paint system has a problem of pot life, which can be said to be a fate of the two-pack type, that is, the pot life. If the paint is not used within several hours after mixing the two-pack type, the paint will thicken abnormally and gel.

[0010] On the other hand, since organic solvents are used, there is a restriction on the health care of coating workers, the danger of fire at coating sites, and the handling of dangerous materials as hazardous materials under the Fire Service Law. Bring. Thorough viscosity control by the painter is necessary for the successive thickening after mixing the two liquids. Not only makes it extremely difficult, but also causes a significant decrease in the performance of the coated film after drying.

[0011]

DISCLOSURE OF THE INVENTION The present invention has been made in view of the state of the art, and its object is to provide good adhesion to various resin moldings, and to improve coating film hardness, water resistance, moisture resistance, and the like. An object of the present invention is to provide a water-based paint which satisfies the properties of a coating film such as acid resistance and alkali resistance.

[0012]

Means for Solving the Problems The present inventor has conducted intensive studies on a spreading agent, a thickener, a thickening aid, a curing accelerator and the like used in a water-based paint in order to achieve the above object. Was completed.

That is, the present invention relates to a water-based one-pack type polyester resin paint containing a pigment, which comprises a colloidal dispersion type polyester resin (molecular weight: 7000 to 500).
00) as a spreading agent in an amount of 50 to 90% by weight,
Emissions, silica mosquitoes, at least one thickener selected from the group consisting of organic modified bentonite and fatty amide wax 0.1-5.0% by weight, dipropylene glycol
n-butyl ether, tripropylene glycol n-
0.5 to 5.0% by weight of at least one film-forming auxiliary selected from the group consisting of butyl ether and propylene glycol n-butyl ether, and at least one type of curing accelerator selected from carbodiimide , aziridine and derivatives thereof. A water-based one-pack type polyester resin paint characterized by containing 0.1 to 1.0% by weight of an agent.

Further, the present invention provides an aqueous one-pack type polyester resin paint characterized in that the pigment is dispersed using an aqueous solution of an acrylic or polyester resin which is completely compatible with the colloidal dispersion type polyester resin as a medium. is there.

Further, the present invention is characterized in that a water-based aluminum powder, a water-soluble aluminum powder or a water-soluble one obtained by mixing a water-soluble solvent with a solvent-soluble aluminum powder or a surface-treated aluminum powder is used. It is a polyester resin paint.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below by showing the progress up to the completion of the water-based paint of the present invention.
First, an aqueous polyurethane resin (Spensol L-50, L
-51, L-55, L-512, manufactured by Dainippon Ink and Chemicals, Superflex 100, 107, 110, 15
0, 190 Daiichi Kogyo Seiyaku, Olestar 100N, Mitsui Toatsu Chemicals, Neo Reds R-960, polyvinyl chemical), etc., and the composition shown in Table 2 was used to form a paint, which was then converted to an acrylic (AC) resin and an ABS resin. And polycarbonate (PC) resin were applied to each substrate so as to form a coating film having a thickness of 10 to 20 μm, dried at 75 ° C. for 30 minutes, and then checked for adhesion. As is clear from the results of the adhesion test in Table 3, none of them adhered to the acrylic resin substrate at all.

[0017]

[Table 2]

[0018]

[Table 3]

Next, a water-based acrylic resin (Watersol S-720, S-725, S-726, A-751 manufactured by Dainippon Ink and Chemicals, Neocreel A-623 manufactured by Polyvinyl Chemical) and an emulsion type acrylic resin (Boncoat EC- 740, DV-759 (manufactured by Dainippon Ink and Chemicals, Inc.), and the coating compositions were tried as shown in Table 4 to perform various coating film performance tests. As is clear from the results of the coating film performance test in Table 5, Watersol S-720 was the best in terms of adhesion, hardness, gloss, and impact resistance. When used, it showed unsatisfactory results in resistance to chemicals such as acid and alkali, and water resistance.

[0020]

[Table 4]

[0021]

[Table 5]

Accordingly, a curing accelerator is mixed and used in these paints. However, a curing agent which does not react at room temperature is used to avoid viscosity increase after mixing two components such as a solvent-based two-component polyurethane resin paint. To make a coating film using aziridine and its derivative (TAZO Mutual Pharmaceutical Co., Ltd.)
Various coating performance tests were performed. As is clear from the test results in Table 6, among the test items, unsatisfactory results were obtained in the accelerated weathering test.

[0023]

[Table 6]

From the above process, it was judged that it was difficult to satisfy the required performance in the use of the water-based acrylic resin, and as the water-based polyester resin-based metallic paint, the water-based polyester resin (Pesthresin KS-216, 2250, 300) was used.
0, 124G made by Takamatsu Yushi, Finetex ES-6
50, ES-675, ES-850 (manufactured by Takamatsu Oil & Fat Co., Ltd.), and the coating composition was tested in the composition shown in Table 7 to perform a coating film performance test. As is clear from the test results in Table 7, almost satisfactory results were obtained with Pesresin 124G (manufactured by Takamatsu Oil & Fat) except for the inter-paper peeling of the aluminum powder pigment blended in the paint. Pesresin 124G is polyester /
It is a colloidal dispersion obtained by graft polymerization at an acrylic ratio of 60 to 65/35 to 40.

[0025]

[Table 7]

Next, a water-soluble aluminum paste was separately selected in accordance with the formulation examples shown in Table 8 in order to improve the inter-paper peeling of the aluminum powder pigment. Since the resin 124G blended in the prototype paint is a colloidal dispersion, when the pigment is dispersed by a method of mechanically applying a shear such as a ball mill or a roll mill, the colloidal resin particles are broken, and when the coating is formed, the coating is dried. At the same time, the viscosity and the like were remarkably impaired, and the viscosity increased rapidly and the gel was formed in an extremely short time.

Therefore, the resin used for the pigment dispersion was a water-soluble acrylic resin Watersol S-720 completely compatible with Pesresin 124G, and the primary colors kneaded thereby were used for toning.

Also, from the test results in Table 8, the aluminum powder pigment used as the metallic paint was used to avoid inter-paper peeling.
It has been found that it is preferable to select an aluminum powder whose surface is coated with a polymer compound.

[0029]

[Table 8]

As is clear from the test results in Table 9, the coating performance for toning and the use of the aluminum powder pigment could meet most of the required items, but in water discoloration resistance, tackiness and storage stability. The results required improvement.

[0031]

[Table 9]

Therefore, in order to improve these items, Table 1
0, the applied resin was Watersol S-72.
A water-dispersed high-molecular polyester resin having a glass transition point higher than 0, Vironal MD-1100 (manufactured by Toyobo),
At the same time, a prototype was produced by changing the coloring method to a surfactant dispersion type. In order to improve the alcohol rubbing resistance at the same time, one-of essence unchanged, as a reaction accelerator in the coating material formulation, since strong toxicity in the aziridine derivative, a carbodiimide alternative thereto (XL-29SE from Union Carbide Company). As a result of confirming the coating film performance of the coating material thus obtained, only the non-adhesion was poor as shown in Table 11.

[0033]

[Table 10]

[0034]

[Table 11]

In order to improve the non-adhesiveness, it is desired to satisfy the adhesion to various plastic materials and to increase the hardness of the coating film. For that purpose, Vironal M
A part of D-1100 was replaced with the same Vironal MD-1200, and three colors of metallic paint were trial-produced. At this time, since the non-volatile content of the resin 124G was low and the glass transition point was low, the bon coat having a high non-volatile content and high glass transition point was used. 180 (manufactured by Dainippon Ink and Chemicals) was blended as shown in Table 12.

[0036]

[Table 12]

In this case, Vylonal MD-1100 /
After setting the resin solid content ratio of Vironal MD-1200 to 1/1, Boncoat 1 for Vironal MD-1200 was used.
The ratio to 80 was changed in four ways as described in Table 13, and the coating film performance was compared. As apparent from the performance results in Table 13, Boncoat 180 / Vylonal MD-1100,
The best performance was obtained when the ratio of MD-1200 (1: 1) was 80/20, but it did not satisfy all the required performances.

[0038]

[Table 13]

Based on the results of the above investigations, it was determined that the causes of the poor alkali discoloration resistance and hot water resistance were due to the use of untreated aluminum pigments and the amount of the hydrophilic dispersant contained in the toning primary colors. This point was further elaborated.

First, a predetermined amount of a water-soluble solvent, butyl cellosolve, was gradually added dropwise to a solvent-type surface-treated aluminum paste while mechanically stirring the paste to make it water-soluble. Next, Bon Coat 180 was changed to Bon Coat 195 having better water resistance, and
Vylonal MD with excellent adhesion instead of -1200
1100 was applied. At the same time, in order to minimize the amount of surfactant in the pigment dispersion, the dispersant dispersion type was changed to a water-soluble resin dispersion type. In addition, as the water-soluble solvent, in addition to the above butyl cellosolve, ethyl cellosolve, isopropyl alcohol, ethanol, and methanol can be used.

In this case, in order to maintain warm water resistance, it is preferable to select a film-forming auxiliary used that does not contain a hydrophilic group or that has a very small amount even if it contains a hydrophilic group. In addition, in order to prevent paint dripping or prevent precipitation of pigments and the like, it is essential to select a hydrophobic thickener. According to these prescriptions, sufficient coating film performance can be obtained with only one liquid of the main agent without separately mixing and using a curing agent.

In order to impart film forming properties at a low temperature to the water-dispersed paint, ethylene glycol n-butyl ether, diethylene glycol n-butyl ether and the like have been conventionally used, but these have relatively high minimum film forming temperatures. Since the amount of the mixture required for the paint is large, if these remain in the dried coating film, they may cause deterioration of various properties such as water resistance, hardness and chemical resistance.

Therefore, the present inventor decided to use Dowanol PnB (propylene glycol n-butyl ether), TPnB
(Tripropylene glycol n-butyl ether),
An attempt was made to apply DPnB (dipropylene glycol n-butyl ether), and in particular, the mixing amount necessary to obtain a film formed at 5 ° C. was as low as about 1% by weight.
Was most preferred.

The water-dispersion type paint is one in which fine resin particles are dispersed in water, and its viscosity is clearly lower than that of the water-soluble type, so that it is difficult to form a thick film at the time of coating, or it is applied to the object to be coated. It is necessary to apply a thickening agent because the paint that hangs down easily cannot make the coating thickness uniform.

As a thickener, organically modified bentonite (T
-320, T-317 manufactured by Yamamune Chemical Co., Ltd., fatty acid amide wax (Disparon 6900-20X, manufactured by Kusumoto Kasei), hydrophilic silica (Aerosil 200 manufactured by Nippon Aerosil Co., Ltd.), hydrophobic silica (Aerosil R-972 manufactured by Nippon Aerosil Co., Ltd.) ) And a polyurethane-based thickener (Schwegopore 8050, manufactured by Bernd Schwegman) were examined. As a result, the best results were obtained with a small amount of Schwegopore 8050, which has a large thickening effect and does not lower the water resistance.

The composition examples are as shown in Table 14.

[Table 14]

Table 15 shows the results of examination of the relationship between drying conditions (temperature) and coating film performance. 7 from the results in Table 15
It can be seen that the drying condition at 5 ° C. is preferable. In the paint of the present invention, the drying conditions are an ambient temperature of 50 to 80 ° C. and 10 to 30.
Minutes are most preferred.

[Table 15]

Table 1 shows the overall evaluation of coating film performance.
As described in No. 6, all the items were satisfactory.

[Table 16]

Further, the coating films having the compositions shown in Table 14 obtained the target results in the accelerated weathering test, as apparent from Table 17.

[Table 17]

As discussed above, examples of formulations for obtaining the required coating film performance for automobile parts, home electric appliances, etc. are shown in, for example, Table 14.
In applying these paints, any of an air spray method, an airless spray method, an air electrostatic coating method, and a complete electro atomization electrostatic coating method can be applied. It can be applied to a wide range such as acrylic resin, ABS resin, acrylic styrene resin and polycarbonate resin.

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int. Cl. ⁶ , DB name) C09D 167/00-167/08 C09D 7/00-7/14 C09D 175/00-175/16

Claims (3)

(57) [Claims] 1. A water-based one-pack type polyester resin paint containing a pigment, 50 to 90 wt% colloidal dispersion type polyester resin (molecular weight 7,000 to 50,000) as a spreading agent, polyurethane emissions, silica mosquitoes, organomodified 0.1 to at least one thickener selected from the group consisting of bentonite and fatty acid amide wax
5.0% by weight of at least one film-thickening aid selected from the group consisting of dipropylene glycol n-butyl ether, tripropylene glycol n-butyl ether, and propylene glycol n-butyl ether.
A water-based one-pack type polyester resin paint characterized in that it contains 0.1 to 1.0% by weight of at least one curing accelerator selected from carbodiimide , aziridine and derivatives thereof in an amount of 5 to 5.0% by weight. 2. The aqueous one-pack polyester resin according to claim 1, wherein the pigment is dispersed in an aqueous solution of an acrylic or polyester resin which is completely compatible with the colloidal dispersion type polyester resin. paint. 3. The aqueous system according to claim 1, wherein the pigment is water-soluble aluminum powder, water-soluble aluminum powder mixed with a water-soluble solvent, and surface-treated aluminum powder. Liquid type polyester resin paint.