JPH08120201A - Coating composition and decorative metal plate coated with same - Google Patents

Abstract

PURPOSE: To prepare a decorative metal plate, which is uneven to the touch and elaborately designed, only by coating without the need for post-processing steps such as embossing. CONSTITUTION: This composition comprises a polyester and/or an acrylic resin or a resin formed by modifying either of the two with a silicone resin and having a weight-average molecular weight of 2,000-10,000 as a binder and 0.1-5% amide aggregate having a melting point of 110-170 deg.C and an average particle size of 15-200μ. A raw metal plate surface-treated in advance is finished with the composition by baking to prepare a decorative metal plate having an uneven pattern.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a paint composition for producing a novel decorative metal plate having a concavo-convex pattern by baking coating on a material metal plate which has been preliminarily subjected to a base treatment, and the paint composition. The present invention relates to a decorative metal plate coated with. Furthermore, the present invention relates to a decorative metal plate having a design property increased by providing a base paint layer and a printing layer between the material metal plate and the coating film.

[0002]

2. Description of the Related Art A conventional decorative metal plate has been prepared by applying a base paint to a material metal plate which has been preliminarily treated with a base paint, printing the surface of the base paint, and then applying a clear paint to protect the surface. However, since the surface of the coating film is smooth, the three-dimensional effect is poor and the coldness peculiar to the metal plate is disadvantageous.
Therefore, it has been devised to give a three-dimensional effect and a thick feeling by embossing the decorative metal plate as a post-process. Silicone-based auxiliaries have also been used for forming a three-dimensional pattern in the painting process. However, embossing adds to the manufacturing process. In addition, although silicone-based auxiliaries have fulfilled their original purpose of forming uneven patterns, the production of paints,
It is difficult to sufficiently wash in the process such as painting and easily become impurities, which often causes defects such as cissing in the subsequent paint production and painting. Therefore, there is a concern about the high cost of the entire series of steps of manufacturing, coating, and device cleaning, and there has been a demand for a coating that does not use a silicone-based auxiliary agent.

[0003]

DISCLOSURE OF THE INVENTION The present invention provides a coating composition for a decorative metal plate and a baking coating of the coating composition for forming a concavo-convex pattern without using a post-processing step and a silicone-based auxiliary agent as described above. It is to provide a decorative metal plate that has been subjected to.

[0004]

In order to solve the above-mentioned problems, the present invention provides a material metal plate which has been preliminarily subjected to a base treatment,
Polyester and / or acrylic resin or one of them modified with silicone resin to give a weight average molecular weight of about 200.
The resin composition in the range of 0 to 10000 is used as a binder, and the aggregate of amides having a melting point of 110 to 170 ° C. and an average particle size of 15 to 200 μm is added to the coating composition by 0.1.
An uneven pattern is formed by baking and coating a coating composition characterized by containing 5% to 5%. In addition, the base paint is baked and coated on the material metal plate, printing is performed on it by gravure offset or other method, and then the paint composition is baked and coated to form an uneven pattern giving further designability. Obtain a decorative metal plate.

As the material metal plate, various metal plates conventionally used for pre-coated steel plates such as zinc iron plate, zinc aluminum alloy plated steel plate, stainless steel plate and aluminum plate can be used. Also, for the base treatment, various conventional treatment agents suitable for various materials can be applied.

The coating composition of the present invention uses as a binder a polyester and / or an acrylic resin which has good workability and is suitable for a precoated metal plate, or a resin obtained by modifying one of them with a silicone resin. Taking a polyester resin as an example, a resin composed of a polyhydric alcohol such as neopentylglycol and ethyleneglycol and a polybasic acid represented by isophthalic acid, tertiary phthalic acid and adipic acid is used. As the curing agent, methylated melamine, block urethane and the like can be used. The weight average molecular weight of these binders is preferably in the range of about 2000 to 10,000. When the molecular weight is less than 2000, the strength as a coating film is insufficient, and when it is more than 10,000, curing at the time of baking is slow and the uneven pattern becomes unclear.

Examples of aggregates of amides that are contained in the coating composition together with the above-mentioned resin in order to obtain an uneven pattern include saturated fatty acid monoamide, unsaturated fatty acid monoamide, saturated fatty acid bisamide, unsaturated fatty acid bisamide, aromatic bisamide and the like. Of these, methylene bisamide or ethylene bisamide is preferable because it has a melting point of about 140 ° C. and can be used particularly preferably. The melting point of amides is 1
10-170 degreeC is preferable and the range of 120-150 degreeC is more preferable. If the melting point is less than about 110 ° C. or higher than about 170 ° C., the evaporation of the solvent and the melting of the amide cannot be balanced during baking, and the uneven pattern becomes unclear, resulting in a decrease in commercial value. Further, it is preferable to use amides having an average particle size of 15 to 200 μm, more preferably 60 to 200 μm.
A range of 120 microns is good. If the particle size is about 10 microns, the uneven pattern becomes small, and if it exceeds 200 microns, the uneven pattern becomes unclear, and the commercial value is lowered.

The above-mentioned amides are added to the coating composition in a weight ratio of 0.1 to 5%, more preferably 0.5 to 2% and sufficiently dispersed. If it is less than 0.1%, irregularities are scattered, and if it exceeds 5%, the irregular patterns interfere with each other and the pattern becomes unclear. Isobutanol as the dispersion medium,
Alcohol such as normal butanol, boiling point is 120 to 2
Aromatic solvents and esters and ketones at about 20 ° C can be used.

When the coating composition is baked on the above-mentioned raw metal plate at an ultimate plate temperature of 200 to 230 ° C. to a film thickness of about 5 to 20 μm, a coating film having an uneven pattern can be obtained. it can.

As a mechanism for forming an uneven pattern, it is generated by the difference between the surface tension of the amides after dissolution and the surface tension of the resin binder, and therefore the greater the difference between the two, the more clearly the unevenness is seen. Therefore, the resin binder preferably has a weight average molecular weight of about 2000 to 10,000.
The curing agent is preferably a fast-drying one such as methylated melamine type and block urethane. When the wet coating film has unevenness due to the difference in surface tension, it quickly cures and helps fix its shape.

Further, not only is it directly applied on the material metal plate, but the base paint is baked and applied on the material metal plate which has been preliminarily subjected to surface treatment such as chemical conversion treatment, and then gravure offset or other method is applied thereto. After printing, baking coating of the above coating composition, or baking coating of a base coating on a raw metal plate, baking coating of the above coating composition thereon, and further providing a printing layer Further, it is possible to form a concavo-convex pattern to which design is further imparted.

As the base coating, a coating containing a rust preventive pigment may be used, but it is also possible to use a base coating containing no rust preventive after applying a primer containing the rust preventive. Further, in the case of a stainless steel material or the like, a base paint containing no rust preventive agent can also be used. Polyester resin is mainly used as the main resin as the resin composition of the base coating, and methylated melamine or block urethane resin is mainly used as the curing agent, but it is necessary to consider the interlayer adhesion between the ink and the coating layer. For example, in baking, in order to secure adhesion with the upper coating film, it is necessary to avoid complete curing and to keep the primary curing level. The specific baking temperature is preferably about 180 to 210 ° C. in terms of the ultimate plate temperature.

As a printing method, printing by a gravure roll or flexographic printing can be applied, and both online and offline can be used. As the pattern, there are various patterns such as an abstract pattern, a stone pattern, etc. in addition to the woodgrain pattern. As the ink, an oil-free alkyd resin or an acrylic resin to which various colored pigments and extender pigments are added as a binder is used. Solvents and auxiliaries are added to the ink in order to impart printability.

A low gloss coating film can be realized by adding a matting agent to the coating composition. As a matting agent,
Synthetic silica having a particle size of about 0.2 to 20 microns is suitable, and 0.1 to 5% is preferably added to the coating composition. Particle size 10
In the case of synthetic silica of about 20 μm, the unevenness of the coating film can be further emphasized. Further, a colored paint obtained by adding 0.1 to 5% of a coloring pigment to the above-mentioned paint composition can be applied onto the printing of the stone pattern and the ricin-like abstract pattern. By coloring the paint, you can reproduce the quail egg pattern and granite pattern. Since the coloring paint becomes a repellent pattern and the film thickness becomes non-uniform, the degree of hiding the color tone of the base is slightly different depending on the place, and it is possible to impart a design property that gives the impression of multicolor printing.

[0015]

EXAMPLES The present invention will be specifically described below with reference to examples. All parts and% in the examples are by weight.

The coating composition of the present invention was prepared by a conventional method with the composition shown in Tables 1 and 2. The coating material shown in Tables 1 and 2 was applied by a bar coater on a 0.4 mm thick aluminum-zinc alloy-plated steel sheet that had been subjected to coating type chromate treatment as a material metal plate to a film thickness of 10 microns, and the temperature reached 220 ° C (maximum reached). Plate temperature)
Burned in. The concavo-convex pattern of the finished coating film was visually evaluated according to the following criteria. The results are shown in the same table. ⊚: A large-sized uneven pattern is clearly formed. ○: The uneven pattern is clearly formed. Δ: The size of the uneven pattern is small and not suitable for practical use. X: The uneven pattern is unclear.

A 0.4 mm-thick aluminum-zinc alloy-plated steel sheet which has been subjected to coating-type chromate treatment as a metal plate,
The base paint having the composition shown in Table 3 was applied to a film thickness of 15 with a bar coater.
It was applied to have a size of micron and baked at 200 ° C. (maximum plate temperature). Next, an ink having the composition shown in Table 4 was used to print a wood grain pattern by gravure offset and lightly dry.

The printed test metal pieces obtained above were coated with various aggregate-containing paints having the compositions shown in Tables 1 and 2 by a bar coater so as to have a film thickness of 10 microns, and at 220 ° C. (maximum plate temperature reached). Burned

[0019]

[Table 1]

[0020]

[Table 2]

* 1 to * 6 in Tables 1 and 2 indicate the following chemicals. * 1: Beckolite 47-335 oil-free alkyd resin (molecular weight 2000) non-volatile content 60% * 2: Beckolite M-6401 oil-free alkyd resin (molecular weight 5000) non-volatile content 50% * 3: Beckolite 57-206 oil-free Alkyd resin (molecular weight 10,000) non-volatile content 40% * 4: Beckolite M-6801 oil-free alkyd resin (molecular weight 15,000) non-volatile content 40% or more, Dainippon Ink and Chemicals, Inc. * 5: Methylated melamine as a curing agent 15 parts (nonvolatile content 60%) and I-butanol..1, Solveso # 10
20 parts of a mixed solvent of 0 ... 2 and cyclohexanone ... * 6: Melting point 100 ° C. is monostearic acid amide: Melting point 140 ° C. is bisstearic acid amide

[0022]

[Table 3]

[0023]

[Table 4]

As shown in Examples 1 to 3 of Table 1, a resin having a weight average molecular weight of about 2000 to 10,000, a melting point of amide of about 140 ° C., and an average particle size of about 60 to 120 microns has a large uneven pattern on a raw metal plate. Can be formed, and further Table 2
As shown in Example 4, it is understood that the uneven pattern can be clearly formed even when the average particle size is about 30 μm. The formation of the concavo-convex pattern itself does not depend on the presence of the base coating film, the printing layer, etc. on the material metal plate, but it is possible to further improve the designability by having the base coating film or the base coating film and the printing layer. Needless to say.

As shown in Comparative Example 1 in Table 1, when the weight average molecular weight of the resin binder exceeds about 10,000, the curing reaction at the time of baking is slow and the uneven pattern becomes unclear. Also, Table 2
As shown in Comparative Example 2), when the average particle size of amide is about 10 microns, the uneven pattern is small and the commercial value is remarkably reduced. Further, when the melting point of the amides is about 100 ° C., the uneven pattern becomes unclear as shown in Comparative Example 3, and the commercial value is also lowered.

[0026]

In the present invention, the weight average molecular weight obtained by modifying the polyester and / or the acrylic resin or one of them with the silicone resin on the raw metal plate has a weight average molecular weight of 2000 to
Using a resin in the range of 10,000 as the binder and a melting point of 11
An amide type aggregate having an average particle size of 0 to 170 ° C. and an average particle size of 15 to 200 μm is added in an amount of 0.1 to 5 in a coating composition.
By baking-coating a paint characterized by containing 100% by weight, it is possible to obtain an uneven pattern only by painting without performing a post-process such as embossing. Furthermore, by using amides without using a silicone-based auxiliary agent, it is possible to remarkably simplify the washing process in the production and coating process of the paint. Further, by interposing the base coating film and the printing layer, it is possible to obtain a decorative metal plate having a three-dimensional pattern with further improved design.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI Technical display location B05D 7/14 G B32B 15/08 GH C09D 7/12 PSL 133/00 PGC 167/00 PKX PLK (72) Inventor Jun Furukawa 3-30-16 Sakashita, Itabashi-ku, Tokyo (72) Inventor Akio Tashiro 4-1-1 Minamihonmachi, Chuo-ku, Osaka-shi, Osaka Inside Yodogawa Steel Works, Ltd.

Claims (5)

[Claims] 1. A polyester and / or acrylic resin, or a resin obtained by modifying one of them with a silicone resin and having a weight average molecular weight of 2000 to 10,000 as a binder, a melting point of 110 to 170 ° C., and an average particle diameter. The coating composition is characterized by containing 0.1 to 5% of an aggregate of amides having a particle size of 15 to 200 microns in the coating composition. 2. The coating composition according to claim 1, wherein the amide is methylene bisamide or ethylene bisamide. 3. A material metal plate which has been preliminarily subjected to a base treatment,
A decorative metal plate obtained by baking-coating the coating composition according to claim 1. 4. The decorative metal plate according to claim 3, wherein after the base paint layer or the base paint layer and the printing layer are provided on the raw metal plate, the paint composition is baked and applied. 5. The decorative metal sheet according to claim 3, wherein a base coating is baked and coated on the material metal sheet, the coating composition is baked on the base coating, and a printing layer is further provided.