JPH10249272A - Manufacture of metal plate with design characteristics and metal plate with design characteristics - Google Patents

Abstract

PROBLEM TO BE SOLVED: To manufacture a metal plate with a design which is well comparable with the design of an inorganic material such as cement. SOLUTION: This metal plate with design characteristics is manufactured through (I) a step to form a colored base coating which contain [(A) polyester resin or (B) polyester resin and acrylic resin] and [(C) melamine resin and/or a blocked polyisocyanate compound] as a vehicle, with a dry coating thickness of 10-25μm, (II) a step to form a dry coating with a design which contains [(D) an inorganic particle with a Mohs hardness of 5 or less] and[(E) a urethane organic particle which has a tensile modulus of 50-500kg/cm<2> and is different from the coating of (I) step], with a dry coating thickness of 15-30μm, using [(A) polyester resin or (B) polyester resin and acrylic resin] and [(C) melamine resin and/or a blocked polyisocyanate compound] as a vehicle, (III) a step to emboss the coatings as described above after drying, and (IV) a step to form the coatings using a roll former and/or a press, as a sequence of processing steps.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a decorative metal plate and a method for producing a decorative metal siding, particularly for a building material or a household article.

[0002]

2. Description of the Related Art In recent years, in order to apply a matte (for example, velvety) surface to a surface of a household article or the like to give a soft feeling,
A method of bonding a sheet having a matte appearance to the surface of household goods, and a method of using a decorative veneer for artificially expressing the appearance of natural stone or the like on the outer wall, fence, or partition of a building have been proposed.

Conventionally, when a pattern is applied to the exterior of a building, in particular, the surface of an inorganic material such as concrete, mortar, PC board, ALC board, block or the like is made uneven so that the appearance of the texture of natural stone or the like is artificial. Was expressed in.

[0004] However, the work process has become complicated, and the work period has tended to be prolonged. So, in recent years,
Attention has been paid to a building exterior method in which a decorative veneer for building is attached to the surface of a building or the like to give a texture such as natural stone. As this decorative veneer, a ceramic product which exhibits a texture similar to that of the above-mentioned inorganic materials in terms of artificially expressing the appearance of a natural stone or the like has attracted particular attention. For example, a ceramic product having a natural stone texture is manufactured by first forming irregularities by embossing or the like at the time of semi-solidification, and then painting the surface thereof.

[0005] However, the above ceramic articles are easily broken, heavy and poor in workability. Therefore, it was difficult to significantly shorten the construction period.

[0006] Further, there is also a method of producing a decorative board which expresses the texture of natural stone, for example, by applying a paint to a plate-like body. For example, after applying a sealer paint as necessary to the surface of the plate-like body, apply a color paint, apply the paint in the form of a spot on the upper surface of the lower coating layer of the color paint, and apply a speckled paint film. This is a method of forming a layer. Although the decorative board manufactured by this method has a stone grain, there is a gap from an actual thing, and particularly, the touch of the stone cannot be obtained. Therefore, luxury,
There was no feeling of ceramic industry. In addition, since the coating did not stretch and did not have a deep dent as a coating film, three-dimensional embossing could not be performed.

[0007] Japanese Patent Application Laid-Open No. Hei 7-89006 discloses a "method of manufacturing a decorative veneer for a building". A transparent or translucent paint mixed with a granular aggregate having a particle size of 100 to 200 mesh and a color tone different from that of the colored opaque paint of the lower coat layer is sprayed on the upper surface of the paint film layer by spraying. There has been proposed a method of forming a membrane layer and manufacturing a decorative board for construction. The decorative board manufactured by the above-described method has a stone-like color, but the upper coating layer containing the granular aggregate cannot increase the unevenness in consideration of the adhesion during coating processing. However, it was still difficult to approach the texture of natural stone both visually and tactilely.

[0008] Furthermore, although not a decorative veneer for construction, several methods have been proposed for producing a decorative veneer by forming a special coating on the surface of a plate-like body.

For example, Japanese Unexamined Patent Publication (Kokai) No. 4-82736 discloses "a suede-like sheet and a method for producing the same". A bead pigment and a base sheet having a wetting index in the range of 38 to 60 dyne / cm are provided. A method has been proposed in which a matte paint film is formed by adding a synthetic resin bead to a vehicle of a two-part curable resin.

Japanese Patent Application Laid-Open No. 4-215873 discloses a "method of manufacturing a pre-coated steel sheet", in which 100% by weight of a paint containing a rust-preventive pigment and a coloring pigment is coated on at least one surface of the steel sheet. After applying and baking an undercoat containing 1 to 20 parts by weight of the coalesced and forming an undercoat coating of 3 to 10 μm, based on 100 parts by weight of the binder, the average particle diameter of the same system color as the undercoat is 1 to 80 μm. 15 colored particles
A top coat containing 0 to 200 parts by weight is applied and baked.
A method for forming a topcoat of ２５25 μm is disclosed.

Further, the "coating composition" of JP-A-3-86771 includes (I) at least one resin selected from a polyester resin and an acrylic resin having a hydroxyl value of 5 to 150, and (II) a hydroxyl value. Is a polyester resin of 10 to 200, silicone-modified acrylic resin, at least one resin selected from silicone-modified polyester resin and acrylic resin, (III) at least one cross-linking resin selected from methylated and butylated melamine resin, (IV) a sulfonic acid blocked with a tertiary amine having a boiling point of 80 to 150 ° C, (V) a tertiary amine having a boiling point of 80 to 150 ° C,
(VI) (a) organic polymer particles having a particle size of 0.001 to 30 μm, (b) organic polymer particles having a particle size of 31 to 100 μm, (C) silica particles having a particle size of 5 μm or less, (d) Inorganic particles having a particle size of 6 to 30 μm, (e) particle size of 31 to 10
0 μm inorganic particles, and (f) 20 to 300 μm in length
Discloses a coating composition containing, as an essential component, at least two kinds of particulates selected from the group of fibers having a diameter of 30 mμ or less.

[0012]

However, the production method disclosed in Japanese Patent Application Laid-Open No. Hei 4-82736 described above produces a rough texture by forming a single coating film. difficult.

Further, in the manufacturing method disclosed in Japanese Patent Application Laid-Open No. 4-215873, there is a problem that although the undercoating paint and the topcoating paint have the same system color, the stone tone is not obtained, although the unevenness is felt.

The coating composition disclosed in Japanese Patent Application Laid-Open No. 3-87771 is a composition that forms a uniform skin by controlling the difference in the curing reaction rate between the upper and lower layers of one coating film. Therefore, it has been difficult to reproduce large irregularities on the surface of the natural stone.

The present invention has been made in view of the above-mentioned conventional problems, and an object of the present invention is to provide a method of manufacturing a metal plate capable of resisting a design (particularly, stone texture) using an inorganic material such as cement, and a design metal plate. It is to provide.

[0016]

Means for Solving the Problems In order to achieve the above-mentioned object, the method for producing a designable metal sheet of the present invention is a production method in which the following steps (I) to (IV) are sequentially performed.

The colored base coating film containing (I) [(A) a polyester resin or (B) a polyester resin and an acrylic resin] and [(C) a melamine resin and / or a blocked polyisocyanate compound] as a vehicle has a dry film thickness. Step of forming at 10 to 25 μm, (II)
Using [(A) polyester resin or (B) polyester resin and acrylic resin] and [(C) melamine resin and / or block polyisocyanate compound] as a vehicle, [(D) inorganic particles having a Mohs hardness of 5 or less], [( E)
(I) Step at a tensile elasticity of 50 to 500 kg / cm ² , a step of forming a design-added coating film containing a urethane-based organic particle of a different color from the coating film at a dry coating film thickness of 15 to 30 μm;
(III) a step of embossing after coating film drying, (I
V) Step of roll forming and / or press forming.

After the colored base coating film is formed in the above step (I), the color base coating film further contains, on the colored base coating film, particles which form fine irregularities in a different color from the colored base coating film in the step (II). Since the applied coating film is formed, fine irregularities and a design such as stone texture are simultaneously formed. Furthermore,
In the above (III) step, after forming fine irregularities by embossing, since large irregularities are formed by a roll former and / or press molding in the above (IV) step, for example, to obtain a surface close to the tactile sensation of natural stone Can be. In addition, embossing, pressing, and the like are performed after the coating film is formed, so that the coating film adhesion to the metal plate and the adhesion between the coating films are improved. Furthermore, according to the production method of the present invention, [(E) tensile modulus of elasticity of 50 to 500 kg / c
Since a urethane-based organic particles on the unique and step (I) coating m ^{2, and} the by embossing or roll formers and / or press-forming, together with the unevenness of the surface becomes smooth, unique coloration The organic particles are stretched randomly and expand unevenly. For this reason, it can be made to more closely resemble, for example, a natural stone tone. Therefore, according to the production method of the present invention, it is possible to form a desired design, for example, a design very close to natural stone, on a metal plate.

Further, the method for producing a decorative metal sheet of the present invention is characterized in that the component (C) in the step (II) is the same as the component (C) in the step (I).

Accordingly, the adhesion between the colored base coating film and the design-imparting coating film is improved.

Further, the decorative metal plate of the present invention is characterized by being manufactured by any one of the above manufacturing methods.

Accordingly, a metal plate provided with a desired design can be manufactured.

[0023]

BEST MODE FOR CARRYING OUT THE INVENTION A method for manufacturing a design metal sheet according to the present invention will be specifically described below.

(I) Colored base coating film forming step: In consideration of durability, [(A) polyester resin or (B) polyester resin and acrylic resin] is used as a binder resin (or a base resin) as a skeleton resin. . In addition, the resins of the above components (A) and (B) have a hydroxyl value of 5 to 5.
200 is preferred. The following resins are preferable as the resin used for the above-mentioned components (A) and (B).

<Polyester Resin> The polyester resin used in the present invention is preferably one synthesized from a polyhydric alcohol and a polybasic acid (synthesis by an ester condensation reaction). Specifically, for example, polyhydric alcohol components include ethylene glycol, diethylene glycol, polyethylene glycol, propylene glycol, dipropylene glycol, polypropylene glycol, neopentyl glycol, 1,2-butanediol, 1,3-butanediol, 1,3-butanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,4-cyclohexanedimethanol,
2,2-dimethyl-3-hydroxypropyl-2,2-
Dimethyl-3-hydroxypropionate, N, N-bis (2-hydroxyethyl) dimethylhydantoin, polytetramethylene ether glycol, polycaprolactone polyol, glycerin, sorbitol, annitol, trimethylolethane, trimethylolpropane, trimethylolbutane Hexanetriol, pentaerythritol, dipentaerythritol, tris (hydroxyethyl) isocyanate, 1,9-nonanediol, and the like. Two or more of these polyhydric alcohols can be used in combination. As the polybasic acid, phthalic acid, phthalic anhydride, tetrahydrophthalic acid, tetrahydrophthalic anhydride hexahydrophthalic acid, hexahydrophthalic anhydride, methyltetrahydrophthalic acid, methyltetrahydrophthalic anhydride, hymic anhydride, trimetic acid, Trimetic anhydride, pyromellitic acid, pyromellitic anhydride, isophthalic acid, terephthalic acid, maleic acid, maleic anhydride, fumaric acid, itaconic acid, adibic acid, azelaic acid, sebacic acid, succinic acid, succinic anhydride, lactic acid, Dotenyl succinic acid, dotenyl succinic anhydride, cyclohexane-1,4-dicarboxylic acid, endo acid anhydride and the like can be mentioned, and two or more of these polybasic acids may be used in combination. Further, as a modifier for the polyester resin, for example, long-chain monoevoxide (trade name: Kadura E, manufactured by Shell Co., Ltd.) or AOEX24 (manufactured by Daicel Corporation) may be used.

Further, oil-modified polyester resins, urethane-modified polyester resins, silicon-modified polyester resins, and the like can be used.

<Acrylic Resin> The acrylic resin used in the present invention can be prepared by, for example, polymerizing from the following monomers by an ordinary method and adjusting the hydroxyl value within a predetermined range.

(I) Ethylene having a hydroxyl group such as hydroxymethyl (meth) acrylate, hydroxyethyl (meth) acrylate, hydroxypropyl (meth) acrylate, hydroxybutyl (meth) acrylate, N-methylolacrylamine, etc. Monomer, (ii) ethylenic monomer having a carboxyl group such as (meth) acrylic acid, crotonic acid, itaconic acid, fumaric acid, maleic acid, etc., (iii) methyl (meth) acrylate, ethyl (meth) acrylate , Propyl (meth) acrylate,
Butyl acrylate, n-propyl acrylate, n-butyl acrylate, isobutyl acrylate, 2-acrylate
Ethylenic monomers such as ethyl hexyl, n-octyl acrylate, alkyl (meth) acrylates such as n-dodecyl acrylate and the like, and ethylenic monomers copolymerizable with the above monomers (i) and (ii), and (meth) acrylonitrile; Styrene or the like is used.

Further, a silicone-modified acrylic resin can be used. [(C) Melamine resin and / or block polyisocyanate compound] can be used as a curing agent for curing the above components (A) and (B).

<Blocked Polyisocyanate Compound> Examples of the blocked polyisocyanate compound include aliphatic polyfunctional isocyanates such as non-yellowing hexamethylene diisocyanate (HMDI), alicyclic polyfunctional isocyanates such as isophorone diisocyanate (IPDI), and the like. Diphenylmethane-4,4'-diisocyanate (MD
Use is made of a polyisocyanate compound such as I) or hydrogenated MDI in which a functional group is partially or completely blocked.

As a blocking agent, acetone oxime,
Cyclohexanone oxime, acetophenone oxime,
Oxime blocking agents such as benzophenone oxime,
Further, a blocking agent such as methyl acetoacetate, ethyl acetoacetate, and methanol is used.

Further, aromatic monoalcohols, hydroxy tertiary amines, phenols, cresols, and lactam blocking agents can also be used. If an oxime-based blocking agent or a non-oxime-based blocking agent is used, yellowing of the coating film can be prevented.

As the blocked polyisocyanate compound, in particular, I-blocked with methyl ethyl ketone oxime
PDI is preferred.

<Melamine resin> As the melamine resin,
An alkoxymethylmelamine resin can be used.
Specifically, a methylated melamine resin, an ethylated melamine resin, an n-butylated melamine resin, an isobutylated melamine resin, or the like using a methkin group, an ethoxy group, an n-butoxy group, an isobutoxy group, or the like as an alkoxy group. .

For example, the average degree of polymerization of the melamine resin is 1.1.
~ 3. If the average degree of polymerization is less than 1.1, the stain resistance decreases. On the other hand, if it exceeds 3, the workability will decrease. The preferred average degree of polymerization is 1.1 to 2.6.

When the block polyisocyanate compound and the melamine resin are used in combination, the solid content weight ratio (B) / (M) of the block polyisocyanate (B) and the melamine resin (M) is 90/10 to 10%. 10/90 is preferred. If (B) / (M) is less than 10/90, the workability is reduced. On the other hand, when (B) / (M) exceeds 90/10, the stain resistance decreases. The preferable range of (B) / (M) is 4/6 to 6/4.

The solid content weight ratio of the amount of the polyester resin (P), or the amount of the polyester resin and the acrylic resin (P + A), and the amount of the block polyisocyanate (B) and / or the melamine resin (M) as the curing agent component [ (P) or (P + A)] / [(B) and / or (M)] is 95 /
5-50 / 50 is preferred. If this ratio is less than 50/50, workability is poor. On the other hand, if the ratio exceeds 95/5, curing of the coating film becomes insufficient, and good curing of the coating film cannot be obtained.

Further, the colored base coating film may contain an optional amount of a rust preventive pigment and / or a colored pigment, if necessary.

<Rust preventive pigment> A rust preventive pigment is added to impart corrosion resistance to a coating film. The addition amount is preferably from 1 to 29% by weight based on the solid content of the coating film. Examples of the rust preventive pigment include a chromium type such as strontium chromate and zinc chromate, and a non-chromium type such as phosphomolybdic acid and phosphovanadate.

When the metal plate is made of aluminum, it does not need to use a rust-preventive pigment because it itself has rust-preventive properties.

<Coloring Pigment> Any type can be used as long as the purpose of imparting hue can be achieved.

<Thickness> The thickness of the colored base coating film is 10 to
It is preferably 25 μm. When the film thickness is less than 10 μm, the concealing property is reduced at the same time as the corrosion resistance is reduced,
There is a disadvantage that a desired color is not produced, while the film thickness is 25
If it exceeds μm, there is a disadvantage that the adhesion at the time of processing is reduced and the desired color is deviated.

<Coating method> Any method may be used as long as it is a conventionally used method. For example, roll coater,
A method applicable to a coil or a sheet steel plate such as a curtain flow coater can be used.

<Baking Conditions> As in the conventional case, it is preferable that the maximum attained plate temperature is 180 to 350 ° C. and the baking time is about 20 to 60 seconds.

If the maximum temperature of the reached plate is less than 180 ° C., there is a disadvantage that the curing is poor and the corrosion resistance is poor. There is an inconvenience that it deviates. Further, if the baking time is less than 20 seconds, there is a disadvantage that corrosion resistance is poor, and if it exceeds 60 seconds, there is a disadvantage that workability is reduced.

(II) Design-added coating film formability step: The vehicles [(A) polyester resin or (B) polyester resin and acrylic resin] and [(C) melamine resin and / or block polyisocyanate compound] Since the same components as those in the step (I) can be used in the same ratio, the description is omitted.

The resin and the curing agent of the above-mentioned step (I),
The combination of the resin and the curing agent in the step (II) is preferably as shown in Table 1 below. In particular, the curing agents used in the steps (I) and (II) are preferably the same. By using the same type, the adhesion of the colored base coating film design-designed coating film is improved.

[0048]

[Table 1] Note) P: Polyester resin A: Acrylic resin MF: Melamine resin NCO: Blocked polyisocyanate (II) The design-imparting coating film is a so-called clear coating film containing only particles for imparting design to the transparent layer.

As the above particles, [(D) Mohs hardness of 5
The following inorganic particles], [(E) Tensile elastic modulus 50 to 500 k
g / cm ² and the urethane-based organic particles of a different color from the (I) step coating film]. By adding organic particles of a color different from that of the colored base coating film, a stone-like tone is achieved. Also,
By using the above-mentioned inorganic particles and organic particles, it is possible to make the touch a desired design, for example, the touch of a stone surface. Therefore, it is possible to visually and tactilely approximate a desired design, for example, natural stone.

<Inorganic particles> As the inorganic particles, barium sulfate, other calcium sulfate, calcium carbonate, magnesium carbonate and the like can be used. Preferably, it is barium sulfate. It is preferable that the shape of the inorganic particles is substantially spherical or an irregular shape close to a scale, and that each of the primary particles is agglomerated. In the aggregated state, the irregularities become larger and the matting increases.

The Mohs hardness of the inorganic particles is preferably 5 or less, more preferably 2-3. As described above, the color of the inorganic particles is preferably transparent or colorless in the coating film so that the organic particles give a stone-like tone and the inorganic particles give a mainly uneven feeling. Therefore, coloring is not preferred.

When the Mohs hardness of the inorganic particles exceeds 5, the blades of the cutting machine are damaged at the time of cutting, and the stacked coatings are damaged by stacking during storage or transfer of the finished coated plate. There are inconveniences.

It is preferable that the inorganic particles are contained in an amount of 5 to 25% by volume based on the solid content of the coating film provided with the design. When it is less than 5% by volume, there is a disadvantage that the unevenness of the coating film does not appear and the rough feeling does not appear.
If it exceeds, there is an inconvenience of lowering the workability.

The Mohs hardness was based on the composition hardness of the raw material described in the scientific chronological table.

<Organic Particles> The organic particles are added for blocking and preventing scratches on the metal plate, and for forming, for example, a spotted pattern of natural stone.

As the composition of the organic particles, urethane is used. If it is another resin, it does not have a soft feeling and does not have the effect of preventing blocking and damage.

The color of the organic particles is selected according to the desired design. For example, in order to obtain a stone texture, the color is different from that of the colored base coating film, and is preferably black, white, or a mixed color of white and black.

It is preferable that the organic particles are contained in an amount of 5 to 25% by volume based on the solid content of the coating film provided with the design. 5
If the content is less than 25% by volume, there is an inconvenience that no stone tone is produced. On the other hand, if the content is more than 25% by volume, the colored portion is increased as a whole.

The tensile elastic modulus of the organic particles is 50 to 500 k.
g / cm ² is preferred. 50 kg of tensile modulus of organic particles
/ In the case of cm less than ^2, there is disadvantage that play a role as anti-scratching, whereas 500 kg / cm ²
When the number exceeds the above, there is an inconvenience that the overlapping coating films at the time of stacking are damaged.

The tensile modulus of the organic particles is determined according to JIS.
Using Tensilon (manufactured by Toyo Baldwin Co., Ltd.) in accordance with K7113, a pulling speed at 20 ° C. of 20 m / m
Measured in minutes.

<Film Thickness> The dry film of the design-added film is
It is preferably 15 to 30 μm.

Since the coating method and the baking conditions are the same as in the above (I), the description is omitted.

(III) Embossing: After forming the design-imparting film, an embossing roller having an arbitrary or predetermined pattern is used to form an uneven pattern on the metal plate formed up to the design-imparting coating film.

This embossing is performed in order to form small irregularities to give a three-dimensional effect.

The patterns include stitch pull, yuzu skin,
Craters, stucco, melons, lattices (thin and thick), bricks, dulls, Kazama, turtle shells, and the like.

(IV) Roll former and / or press forming step: After embossing, large irregularities are formed by a roll former and / or press to give a three-dimensional effect.
Examples of the pattern include a horizontal groove, a vertical groove, and a brick shape. The metal plate used in the present invention is a metal plate such as a galvanized steel plate, a galvanized alloy steel plate, an aluminum plate, an aluminum plated plate, a cold-rolled steel plate, and may be in any of a sheet shape and a coil shape.

The decorative metal plate of the present invention is manufactured using the above-mentioned metal plate based on the above-mentioned manufacturing method.

Further, another preferred embodiment of the present invention will be described below.

1. Solid content weight ratio of the amount of the polyester resin (P) or the amount of the polyester resin and the acrylic resin (P + A) and the amount of the block polyisocyanate (B) and / or the melamine resin (M) as the curing agent component [(P) Or (P + A)] / [(B) and / or (M)] is 95
/ 5 to 50/50.

2. Solid content weight ratio of blocked polyisocyanate (B) and melamine resin (M) (B) / (M)
Is 90/10 to 10/90.

3. The rust preventive pigment is added in an amount of 1 to 29% by weight based on the solid content of the colored base coating film.

4. (I) the resin and the curing agent in the step, and (I)
The combination of the resin and the curing agent in the step I) is shown in Table 1 above.
It is as follows.

5. The inorganic particles contained in the design imparting coating film are preferably barium sulfate.

6. It is preferable that the inorganic particles are contained in an amount of 5 to 25% by volume based on the solid content of the design-added coating film.

7. The Mohs hardness of the inorganic particles is more preferably 2-3.

8. The color of the organic particles is preferably black or white,
It is a mixed color of white and black.

9. It is preferable that the organic particles be contained in an amount of 5 to 25% by volume based on the solid content of the design-added coating film.

10. The inorganic particles contained in the design-added coating film are barium sulfate, and are contained in an amount of 5 to 25% by volume based on the solid content of the design-added coating film, and have a Mohs hardness of 2 to 3%.
On the other hand, the organic particles are contained in an amount of 5 to 25% by volume based on the solid content of the design-added coating film.

11. (I) a resin and a curing agent of the step,
The combination of the resin and the curing agent in the step (II) is as shown in Table 1 above, and the inorganic particles contained in the design-added coating film are barium sulfate, which is 5 to 5% based on the solid content of the design-added coating film. It contains 25% by volume and has a Mohs' hardness of 2 to 3, while the organic particles are contained in an amount of 5 to 25% by volume based on the solid content of the coating film provided with the design.

[0080]

Next, the present invention will be described in detail with reference to examples and comparative examples. Note that the present invention is not limited by these examples.

<Examples 1 to 10 and Comparative Examples 1 to 9> (1) Metal sheet: galvanized steel sheet: hot-dip galvanized steel sheet (JIS G 3302),
Thickness: 0.27mm galvanized alloy steel sheet: zinc / aluminum alloy plated steel sheet, thickness: 0.27mm aluminum sheet: 5052, 3005 (JIS H 400
0), thickness: 0.3mm Aluminum plated plate: thickness: 0.35mm Cold rolled steel plate (JIS G 3141): thickness: 0.3mm (2) Production of decorative metal plate: after degreasing the above metal plate , Coating type chromate (“Surfcoat NRC300” manufactured by Nippon Paint Co., Ltd .; coating amount: 10 to 15 mg in terms of chromium amount)
/ M ² ), a test plate was prepared under the conditions shown in Tables 2 to 4.

Further, the baking temperature of the colored base coating film (referred to as “first layer” in the table) was set to a maximum ultimate plate temperature of 220 ° C.
C. and the time were 40 seconds, while the baking temperature of the design-added coating film (referred to as "second layer" in the table) was set to a maximum reached plate temperature of 240 ° C. and the time was set to 50 seconds.

(3) Evaluation Method and Evaluation Criteria (i) Design Appearance (as Final Product) a) Design Properties (determined after processing of coating film surface such as embossing, etc.); Very good design, such as stone texture: ◎ There is a sense of ceramics in appearance, and there is design, such as stones: ○ There are only a few in design, such as ceramics, stones, etc .: △ Ceramics, stones, etc. There is no design property at all: × b) Contact sensitivity; touched feeling of ceramics, stone, etc .: ○ Touched feeling of ceramics, stone, etc. A little: △ Touched, no feeling of ceramics, stone, etc .: X C) Glossiness (Before embossing = Judged in the state of a flat plate); Judgment by mirror glossiness according to JIS K 5400 7.6 Glossy ceramic feeling and stone matte feeling without gloss: ○ Gloss is reduced , The matte feeling of stone is not enough: △ Glossy, stone feeling is not appearing : × (ii) Weather resistance (before embossing) SST (salt water spray test) In accordance with JIS K 5400 9.1, blisters (rubbing), rust, etc. were observed at cut and bent parts (bend 3T). Was determined based on the occurrence length ratio.

No occurrence of blaster (bulging), rust, etc .: ○ Occurrence of 5% or less of blaster (bulging), rust, etc .: △ Generation of blaster (bulging), rust, etc. of 6% or more to entire surface: × (iii) Workability (embossing) Before) a) Bendability: After sandwiching the same painted plate as the one to be tested in the place where it is desired to bend into three sheets and performing 180 ° bending with a vice, judgment was made by looking at the state of cracking in the bent part coating film. .

No crack generation: ○ Some cracks occurred: △ Cracks occurred over almost the entire area: × b) Scratches (scratch resistance); Pressure equivalent to 1 kg on 10-yen coins without jaggedness , And slide on the surface of the coating film in the surface direction, and determine the peeling state of the coating film.

No peeling of the coating film: ○ There was peeling in the middle of the coating film, but it did not reach the metal substrate: △ The coating film peeled and the metal substrate was visible: × c) Scratching and scratching (Rotation scratch resistance): The painted surfaces are combined, a load equivalent to 10 kg / cm ² is applied thereto, and one of the 90 ° plates is rotated. .

No peeling of the coating film: ○ There was peeling in the middle of the coating film, but it did not reach the metal substrate: △ The coating film peeled and the metal substrate was visible: × d) Compression restoration of the coating film The surface coating (main coating) and the back coating coated with the paint normally used for coating colored steel sheets are combined together and the temperature is 50 ° C with a hot press machine. After applying a pressure equivalent to 100 kg / cm ² , the film was removed after 24 hours, and the state of the design of the coating film was compared with that before the test.

No difference from the state before the test: ○ The surface is slightly flatter than before the test: △ The surface is compressed and the design is completely lost: × Note that Δ is less than the target is there.

Table 5 shows the evaluation results.

[0090]

[Table 2]

[Table 3]

[Table 4]

[Table 5] From these results, it was found that according to the method for producing a designable metal plate of the present invention, a designable metal plate having excellent designability, weather resistance, and excellent workability can be produced.

[0091]

As described above, according to the method for manufacturing a decorative metal sheet according to the present invention, after the colored base coating film is formed in the above step (I), (II) is further formed on the colored base coating film. In the process, since a design imparting coating film containing particles that form fine irregularities in a color different from that of the colored base coating film is formed, fine irregularities and a design such as stone texture can be formed. Furthermore,
In the above (III) step, after forming fine irregularities by embossing, since large irregularities are formed by a roll former and / or press molding in the above (IV) step, for example, to obtain a surface close to the tactile sensation of natural stone Can be. In addition, embossing, pressing, and the like are performed after the coating film is formed, so that the coating film adhesion to the metal plate and the adhesion between the coating films are improved. Furthermore, according to the production method of the present invention, [(E) tensile modulus of elasticity of 50 to 500 kg / c
Since a urethane-based organic particles on the unique and step (I) coating m ^{2, and} the by embossing or roll formers and / or press-forming, together with the unevenness of the surface becomes smooth, unique coloration The organic particles are stretched randomly and expand unevenly. For this reason, it can be made to more closely resemble, for example, a natural stone tone. Therefore,
ADVANTAGE OF THE INVENTION According to the manufacturing method of this invention, a desired design, for example, a design very similar to natural stone, can be formed on a metal plate.

Further, when the component (C) in the step (II) is of the same type as the component (C) in the step (I), the adhesion between the colored base coating film and the design-added coating film is good. Becomes

Claims (3)

[Claims] 1. A method for producing a decorative metal plate, comprising sequentially performing the following steps (I) to (IV): (I) [(A) polyester resin or (B) polyester resin and acrylic resin] And a colored base coating film containing [(C) a melamine resin and / or a blocked polyisocyanate compound] as a vehicle.
(II) [(A) polyester resin or (B) polyester resin and acrylic resin] and [(C) melamine resin and / or block polyisocyanate compound] as a vehicle, [(D) Mohs hardness 5 or less inorganic particles],
(E) Step (I) Step of forming a design-added coating film having a tensile elasticity of 50 to 500 kg / cm ² and a dry coating film of 15 to 30 μm containing urethane-based organic particles different in color from the coating film; ) A step of embossing after drying of the coating film, and (IV) a step of roll forming and / or press forming. 2. A method for producing a decorative metal sheet, wherein the component (C) in the step (II) according to claim 1 is the same as the component (C) in the step (I). 3. A designable metal plate manufactured by the manufacturing method according to claim 1.