Decorative metal plate and method for manufacturing decorative metal plate

Abstract

To provide a decorative metal plate and a method for manufacturing a decorative metal plate which can simply and largely suppress various appearance defects of a surface at low cost.SOLUTION: In a decorative metal plate 10 having a base material 11 which is made of metal and has a plate shape, a substrate layer 13 provided on the surface side of the base material 11, a colored layer 14 provided on the surface side of the substrate layer 13, a pattern layer 15 provided on the surface side of the colored layer 14, and a surface protective layer 16 provided on the surface side of the pattern layer 15, and the surface protective layer 16 is made of a coating material having viscosity measured by Ford cup No. 4 according to ISO 2431 of 25 seconds or more and 50 seconds or less, and has thickness of 6 μm or more and 12 μm or less.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a decorative metal plate having a pattern or the like printed on the surface of a metal plate material and a method for manufacturing the decorative metal plate.

Background Art

[0002] Decorative metal plates with patterns or the like printed on the surface of metal plate materials are widely used in various applications, including building materials such as doors, shutters, and siding for buildings, and surface materials for home appliances. Such a decorative metal plate is formed by providing a base coloring layer via an underlayer on the surface of a plate-shaped metal substrate having a chemical conversion film, and then printing a pattern layer on the coloring layer. Then, a paint of a material for surface protection is applied on the pattern layer and dried to form a surface protection layer, thereby manufacturing the decorative metal plate.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the decorative metal plate as described above, when applying the paint, a method using a roll coater (for example, a gravure offset printing method, etc.) is mainly applied. When applying the paint using such a roll coater, streak patterns and film thickness unevenness (also referred to as "rooping" or "roll marks") along the rotation direction of the roll are likely to occur when applying from the roll, which may cause defects such as poor appearance.

[0005] Therefore, for example, it is conceivable to ensure the leveling property of the coating film by adding a leveling agent to the paint. However, when a leveling agent is added to the paint, the paint is likely to foam, and there is a risk of causing new appearance defects due to the bouncing of the foam. Therefore, it is also conceivable to further add an antifoaming agent, but these additives are likely to bleed to the surface of the coating film and may cause new appearance defects. In particular, when enhancing the distinctness of image of the surface, it is necessary to greatly suppress various appearance defects as described above.

[0006] In view of such circumstances, an object of the present invention made is to provide a decorative metal plate and a method for manufacturing a decorative metal plate capable of easily and greatly suppressing various appearance defects on the surface at low cost.

Means for Solving the Problems

[0007] The decorative metal plate according to the present invention for solving the above-described problems includes a base material having a plate shape made of metal, an underlayer provided on the surface side of the base material, a colored layer provided on the surface side of the underlayer, a pattern layer provided on the surface side of the colored layer, and a surface protection layer provided on the surface side of the pattern layer. In the decorative metal plate, the surface protection layer is made of a paint having a viscosity measured by Ford Cup No. 4 defined in ISO 2431 of 25 seconds or more and 50 seconds or less, and has a thickness of 6 μm or more and 12 μm or less.

[0008] Further, in the decorative metal plate according to the present invention, it is preferable that a back surface coating layer is provided on the back surface side of the base material in the above-described decorative metal plate.

[0009] Further, in the decorative metal plate according to the present invention, it is preferable that chemical conversion coating layers are provided on the front and back surfaces of the base material in the above-described decorative metal plate.

[0010] Further, in the decorative metal plate according to the present invention, it is preferable that the base material has metal coatings formed on the front and back surfaces of a steel plate in the above-described decorative metal plate.

[0011] In order to solve the above problems, a method for manufacturing a decorative metal plate according to the present invention includes a base layer forming step of providing a base layer on the surface side of a base material having a plate shape made of metal, a colored layer forming step of providing a colored layer on the surface side of the base layer, a pattern layer forming step of providing a pattern layer on the surface side of the colored layer, and a surface protection layer forming step of providing a surface protection layer on the surface side of the pattern layer. In the method for manufacturing a decorative metal plate, the surface protection layer forming step is a step of providing the surface protection layer having a thickness of 6 μm or more and 12 μm or less by applying a paint having a viscosity measured by Ford Cup No. 4 defined in ISO 2431 of 25 seconds or more and 50 seconds or less to the surface of the pattern layer.

[0012] Further, in the method for manufacturing a decorative metal plate according to the present invention, in the method for manufacturing a decorative metal plate described above, it is preferable to perform a back surface coating layer forming step of providing a back surface coating layer on the back surface side of the base material.

[0013] Further, in the method for manufacturing a decorative metal plate according to the present invention, in the method for manufacturing a decorative metal plate described above, it is preferable to perform a chemical conversion coating layer forming step of providing a chemical conversion coating layer on the front and back surfaces of the base material.

[0014] Further, in the method for manufacturing a decorative metal plate according to the present invention, in the method for manufacturing a decorative metal plate described above, it is preferable to perform a base material forming step of obtaining the base material by forming a metal coating by plating the front and back surfaces of a steel sheet.

Advantages of the Invention

[0015] According to the present invention, since the thickness of the surface protection layer made of a paint having a viscosity measured by Ford Cup No. 4 defined in ISO 2431 is 6 μm or more and 12 μm or less, even when the paint is applied from a roll coater such as gravure offset printing, the occurrence of streak patterns and film thickness unevenness along the rotation direction of the roll is suppressed, and a leveling agent and an antifoaming agent are not required. Therefore, it is possible to provide a decorative metal plate and a method for manufacturing a decorative metal plate capable of easily and greatly suppressing various appearance defects on the surface at low cost.

Brief Description of the Drawings

[0016]

Figure 1

Figure 2

Embodiments for Carrying Out the Invention

[0017] Embodiments of the decorative metal plate and the manufacturing method of the decorative metal plate according to the present invention will be described based on the drawings. Note that the present invention is not limited only to the following embodiments described based on the drawings, and various technical matters described in each embodiment can be appropriately combined or replaced as needed.

[0018] [Main Embodiments] Main embodiments of the decorative metal plate and the manufacturing method of the decorative metal plate according to the present invention will be described based on FIGS. 1 and 2.

[0019] 〈Overall Configuration of Decorative Metal Plate〉 As shown in FIG. 1, chemical conversion coating layers 12 are respectively provided on the front surface (the upper surface in FIG. 1) and the back surface (the lower surface in FIG. 1) of a substrate 11 having a plate shape made of metal. A base layer 13 is provided on the surface (the upper surface in FIG. 1) of the chemical conversion coating layer 12 on the front surface side of the substrate 11. A colored layer 14 is provided on the surface (the upper surface in FIG. 1) of the base layer 13. A pattern layer 15 is provided on the surface (the upper surface in FIG. 1) of the colored layer 14. A transparent surface protection layer 16 is provided on the surface (the upper surface in FIG. 1) of the pattern layer 15. Further, a back surface coating layer 17 is provided on the back surface (the lower surface in FIG. 1) of the chemical conversion coating layer 12 on the back surface side of the substrate 11. The decorative metal plate 10 according to such an embodiment will be described in more detail.

[0020] 〈Substrate 11〉 The base material 11 is a metallic material in a plate shape, with a thickness of 0.25 mm or more and 6 mm or less. Examples of the metallic material include a steel plate, an aluminum plate, etc. It is preferable that a metal coating is formed on the front and back surfaces of the steel plate in order to improve adhesion and corrosion resistance. The total thickness of the metal coating on both sides is 8 μm or more and 110 μm or less, and it can be formed by various plating methods such as hot-dip galvanizing, electro-galvanizing, and alloy plating.

[0021] 〈Conversion coating layer 12〉 The conversion coating layer 12 is provided on the front and back surfaces of the base material 11 by a conversion treatment in order to improve the white rust resistance of the base material 11, and the amount thereof is 50 mg / m 2 or more and 150 mg / m 2 or less. Examples of the conversion treatment include chromate treatment, chromium-free treatment, etc. In particular, chromium-free treatment is very preferable because it can reduce the environmental load. By this chromium-free treatment (non-chromate treatment), the conversion coating layer 12 of a chromium-free coating (non-chromate coating) can be formed.

[0022] Examples of the treatment liquid used in the chromium-free treatment include a treatment liquid that does not contain hexavalent chromium, for example, a zinc phosphate treatment liquid, a treatment liquid containing Zr or Ti or salts of both of them, or a treatment liquid containing a silane coupling agent. By the chromium-free treatment using such a treatment liquid, a chromium-free conversion coating containing Ti, Zr, P, Ce, Si, Al, Li, etc. as main components and not containing chromium can be formed on the metal coating of the plating. That is, the chromium-free conversion coating contains, for example, Ti, Zr, P, Ce, Si, Al, or Li or any combination thereof.

[0023] 〈Underlayer 13〉 The underlayer 13 is provided to improve the adhesion between the base material 11 (chemical conversion coating layer 12) and the colored layer 14 and the corrosion resistance of the base material 11, and has a thickness of 1 μm or more and 15 μm or less. Examples of the material of the underlayer 13 include known resin coatings for underlayers containing epoxy resins, polyester resins, urethane resins, melamine resins, alkyd resins, phenol resins, acrylic resins, and the like. The underlayer 13 can also contain a rust preventive pigment for further improving the corrosion resistance.

[0024] 〈Colored layer 14〉 The colored layer 14 is provided to impart an undercolor to the pattern of the pattern layer 15, and has a thickness of 10 μm or more and 30 μm or less. Examples of the material of the colored layer 14 include known resin coatings for coloring containing a binder resin composed of polyester resins, melamine resins, urethane resins, epoxy resins, alkyd resins, phenol resins, acrylic resins, and the like, and a pigment for the undercolor.

[0025] The colored layer 14 preferably contains at least one of an ultraviolet absorber (UVA) and a light stabilizer (HALS) to improve the weather resistance. UVA and HALS are preferably contained in the range of 0.5% by mass or more and 1.5% by mass or less, respectively, based on the total mass of the colored layer 14. Examples of UVA include hydroxyphenyltriazine-based ones, and examples of HALS include N-OR type hindered amine-based ones.

[0026] The coloring layer 14 preferably further contains an antioxidant. The antioxidant is preferably contained in the range of 0.5% by mass or more and 1.5% by mass or less with respect to the total mass of the coloring layer 14. Examples of the antioxidant include hindered phenols. Examples of hindered phenols include pentaerythritol tetrakis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate], 2,2-thiodiethylene bis[3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate], and the like. The antioxidant and HALS preferably have an addition ratio of 1:2 in terms of weather resistance.

[0027] 〈Pattern layer 15〉 The pattern layer 15 is provided to impart design properties by the pattern and has a thickness of 0.1 μm or more and 3 μm or less. Examples of the material of the pattern layer 15 include inks or paints in which colorants such as pigments and dyes are dissolved or dispersed in a diluent together with a binder resin. Examples of the binder resin include known binder resins for patterns such as the types mentioned in the description of the underlayer 13 above. Examples of the pigment include titanium oxide, zinc white, carbon black, iron composite oxides, iron oxide, organic pigments, metallic pigments, pearl pigments, and the like. In particular, iron composite oxides are used as heat shielding pigments.

[0028] The pattern layer 15 is formed, for example, by printing with ink by various printing methods such as the gravure printing method, the offset printing method, and the inkjet printing method, or by applying a paint by various coating methods such as the gravure coating method and the roll coating method. In the case of the inkjet printing method, the thickness of the pattern layer 15 becomes thicker than the above-described range. Examples of the pattern include wood grain patterns, stone grain patterns, cloth grain patterns, abstract patterns, geometric patterns, characters, symbols, solid single colors, or combinations of two or more of these, but are not limited thereto.

[0029] 〈Surface protection layer 16〉 The surface protective layer 16 is provided to impart weather resistance, bendability, scratch resistance, cleanability, etc., and has a thickness of 6 μm or more and 12 μm or less. If it is less than 6 μm, streak patterns will occur, and if it exceeds 12 μm, looping will occur. The surface protective layer 16 preferably contains a main component made of a resin material such as a polyester-based resin or an acrylic-based resin, and sub-components such as inorganic-based or organic-based matte additives such as silica and resin beads, and weather-resistant additives such as UVA, HALS, and antioxidants.

[0030] As UVA, for example, it is preferable to use two types of hydroxyphenyltriazine-based compounds having different maximum absorption wavelengths in combination, as this can exhibit a synergistic effect and achieve higher weather resistance. As the two types of hydroxyphenyltriazine-based UVA, for example, it is preferable to apply a first ultraviolet absorber having a maximum absorption wavelength of 330 nm or more and 340 nm or less, and a second ultraviolet absorber having a maximum absorption wavelength of 315 nm or more and 325 nm or less. From the balance between performance and cost, the first ultraviolet absorber and the second ultraviolet absorber are preferably contained within the range of 2.0% by mass or more and 5.0% by mass or less, respectively, based on the total mass of the surface protective layer 16, and more preferably within the range of 1.0% by mass or more and 3.0% by mass or less.

[0031] Examples of HALS include N-OR type hindered amine-based compounds. Examples of hindered amine-based compounds include bis(2,2,6,6-tetramethyl-1-(octyloxy)-4-piperidinyl) decanedioate, 2,4-bis[N-butyl-N-(1-cyclohexyloxy-2,2,6,6-tetramethylpiperidin-4-yl)amino]-6-(2-hydroxyethylamino)-1,3,5-triazine, etc. HALS is preferably contained within the range of 1.0% by mass or more and 3.0% by mass or less based on the total mass of the surface protective layer 16.

[0032] Examples of the antioxidant include hindered phenols. Examples of the hindered phenols include pentaerythritol tetrakis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate], 2,2-thiodiethylene bis[3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate], and the like. The antioxidant is preferably contained in the range of 1.0% by mass or more and 3.0% by mass or less based on the total mass of the surface protection layer 16. From the viewpoint of weather resistance, the addition ratio of the antioxidant and HALS is preferably 1:2.

[0033] The surface protection layer 16 is formed by drying and curing a paint in which the main component of the above-described resin material and auxiliary components such as a matting additive and a weather resistance additive are dispersed in a dispersion medium. The viscosity of this paint, measured with a Ford cup No. 4 defined in ISO 2431, is 25 seconds or more and 50 seconds or less. If the viscosity is less than 25 seconds, film thickness unevenness is likely to occur over a wide range and roping becomes conspicuous, which is not preferable. If the viscosity exceeds 50 seconds, transfer failure is likely to occur and streak patterns are likely to occur, which is not preferable.

[0034] Furthermore, it is more preferable that the heating residue of the paint is 45% by mass or more and 55% by mass or less. When the heating residue is 45% by mass or more, the occurrence of film thickness unevenness is more reliably suppressed over a wide range, and the conspicuousness of roping is more reliably suppressed. When the heating residue is 55% by mass or less, the occurrence of transfer failure is more reliably suppressed, and the occurrence of streak patterns is more reliably suppressed. The heating residue is the solid content generated when the paint is dried and cured to remove the dispersion medium, and the ratio is represented by the ratio of the mass of the solid content to the mass of the paint including the dispersion medium.

[0035] The dispersion medium is a liquid capable of dispersing the above-described main components and sub-components. The dispersion medium preferably has a boiling point of 100°C or higher and 290°C or lower (particularly 108°C or higher and 210°C or lower). If the boiling point is less than 100°C, it is likely to volatilize and difficult to apply. If it exceeds 290°C, it is difficult to volatilize and requires time for drying and curing, which is not preferable. Examples of such a dispersion medium include high-boiling aromatic naphtha, ethylbenzene, xylene, isobutyl alcohol, etc. Among them, high-boiling aromatic naphtha is particularly preferable.

[0036] 〈Back coating layer 17〉 The back coating layer 17 is provided to protect the back surface of the base material 11 (chemical conversion coating layer 12) from corrosion, etc., and has a thickness of 2 μm or more and 8 μm or less. Examples of the material for the back coating layer 17 include known resin paints for coating such as those mentioned in the description of the underlayer 13 above. The back coating layer 17 can also contain a rust preventive pigment for further improving corrosion resistance.

[0037] 〈Manufacturing method of the decorative metal sheet 10〉 The manufacturing method of the decorative metal sheet 10 according to this embodiment will be described based on FIG. 2.

[0038] First, after obtaining the base material 11 (base material forming step S11) by plating a steel sheet to form a metal coating on the front and back surfaces, a chemical conversion treatment such as a non-chromate treatment is applied to the base material 11 to form a chemical conversion coating layer 12 on the front and back surfaces of the base material 11 (chemical conversion coating layer forming step S12). Next, after applying a resin paint for underlayer on the chemical conversion coating layer 12 on the surface side of the base material 11 and drying and curing it to provide an underlayer 13 (underlayer forming step S13), a resin paint for coloring is applied on the surface of the underlayer 13 and dried and cured to provide a coloring layer 14 (coloring layer forming step S14). Subsequently, an ink or paint for pattern is printed or applied on the surface of the coloring layer 14 and dried and cured to provide a pattern layer 15 (pattern layer forming step S15).

[0039] Then, a paint prepared by dispersing the main component of the resin material for surface protection, the auxiliary component, etc. in a dispersion medium so that the viscosity measured with a Ford Cup No. 4 specified in ISO 2431 is 25 seconds or more and 50 seconds or less is applied onto the surface of the pattern layer 15 by a method using a roll coater such as gravure offset printing and dried and cured, thereby providing a surface protection layer 16 with a thickness of 6 μm or more and 12 μm or less (surface protection layer forming step S16). Finally, a resin coating material for coating is applied onto the chemical conversion coating layer 12 on the back side of the base material 11 and dried and cured to provide a back coating layer 17 (back coating layer forming step S17), whereby the decorative metal plate 10 according to the present embodiment can be obtained.

[0040] In such a present embodiment, even when applying a paint from a roll coater such as gravure offset printing, it is possible to suppress the occurrence of streak patterns and film thickness unevenness along the rotation direction of the roll, and a leveling agent and an antifoaming agent become unnecessary.

[0041] Therefore, according to the present embodiment, various appearance defects on the surface can be easily and greatly suppressed at low cost, and the distinctness of image on the surface can be easily enhanced.

[0042] [Other Embodiments] For example, when the pattern of the pattern layer 15 is a wood grain, if a matte layer of the pattern of the conduit is printed onto the pattern layer 15 and provided between the pattern layer 15 and the surface protection layer 16, the design property can be further improved, which is more preferable. [Examples]

[0043] Examples of the decorative metal plate and the method for manufacturing the decorative metal plate according to the present invention will be specifically described, but the present invention is not limited only to the following examples specifically described.

[0044] [Preparation of Test Specimens and Comparative Specimens] 〈Test Specimen 1〉 First, a steel sheet with a thickness of 0.4 mm compliant with Japanese Industrial Standard "JIS G 3302" was prepared, and hot-dip galvanization was applied to this steel sheet to form a zinc metal coating (total thickness of both sides: 26 μm) on the front and back surfaces of the steel sheet, thereby obtaining a base material (base material forming step). Subsequently, a non-chromate treatment was applied to the base material to form a non-chromate chemical conversion coating layer (86 mg / m 2 ) on the front and back surfaces of the base material (chemical conversion coating layer forming step).

[0045] Next, a polyester-based resin paint was applied to the chemical conversion coating layer on the surface side of the base material and dried and cured to provide an underlayer (thickness: 1.5 μm) (underlayer forming step). After that, a polyester-based resin paint containing an inorganic pigment and a weathering agent was applied to the surface of the underlayer and dried and cured to provide a colored layer (thickness: 15 μm) (colored layer forming step).

[0046] Subsequently, an ink for patterns, which was a mixture of a polyester-based binder resin and an inorganic pigment, was printed on the surface of the colored layer by the gravure offset printing method and dried and cured to provide a pattern layer (thickness: 1 μm) (pattern layer forming step).

[0047] Then, 21.9 parts by mass of a matting additive was mixed and dispersed in a dispersion medium with respect to 100 parts by mass of a surface protection polyester-based resin, and the paint was adjusted so that the viscosity measured with a Ford cup No. 4 defined in ISO2431 was 28.7 seconds (heating residue: 47% by mass). This paint was applied to the surface of the pattern layer 15 through a roll coater from a gravure offset printing plate capable of solid printing by the gravure offset printing method and dried and cured to provide a surface protection layer with a thickness of 8 μm (surface protection layer forming step). Thereby, a test piece 1 of a decorative metal plate was obtained.

[0048] 〈Test piece 2〉 A test piece 2 of a decorative metal plate was obtained by making it the same as test piece 1 except that a paint (heating residue: 45% by mass) adjusted so that the viscosity measured with a Ford cup No. 4 defined in ISO2431 was 25.0 seconds was used in the surface protection layer forming step.

[0049] <Specimen 3> A specimen 3 of a decorative metal sheet was obtained by making it the same as specimen 1, except that in the surface protective layer forming step, a paint (heating residue: 53% by mass) adjusted so that the viscosity measured with Ford cup No. 4 specified in ISO 2431 was 50.0 seconds was used.

[0050] <Specimen 4> A specimen 4 of a decorative metal sheet was obtained by making it the same as specimen 1, except that in the surface protective layer forming step, the paint was applied so that the thickness of the surface protective layer was 6 μm.

[0051] <Specimen 5> A specimen 5 of a decorative metal sheet was obtained by making it the same as specimen 1, except that in the surface protective layer forming step, the paint was applied so that the thickness of the surface protective layer was 12 μm.

[0052] <Comparative Specimen 1> A comparative specimen 1 of a decorative metal sheet was obtained by making it the same as specimen 1, except that in the surface protective layer forming step, a paint (heating residue: 44% by mass) adjusted so that the viscosity measured with Ford cup No. 4 specified in ISO 2431 was 18.6 seconds was used.

[0053] <Comparative Specimen 2> A comparative specimen 2 of a decorative metal sheet was obtained by making it the same as specimen 1, except that in the surface protective layer forming step, a paint (heating residue: 43% by mass) adjusted so that the viscosity measured with Ford cup No. 4 specified in ISO 2431 was 12.5 seconds was used.

[0054] <Comparative Specimen 3> A comparative specimen 3 of a decorative metal sheet was obtained by making it the same as specimen 1, except that in the surface protective layer forming step, a paint (heating residue: 56% by mass) adjusted so that the viscosity measured with Ford cup No. 4 specified in ISO 2431 was 65.0 seconds was used.

[0055] <Comparative Specimen 4> In the surface protective layer forming step, a comparative body 4 of the decorative metal plate was obtained by making it the same as test body 1 except that the paint was applied so that the thickness of the surface protective layer became 4 μm.

[0056] 〈Comparative body 5〉 In the surface protective layer forming step, a comparative body 5 of the decorative metal plate was obtained by making it the same as test body 1 except that the paint was applied so that the thickness of the surface protective layer became 15 μm.

[0057] [Evaluation method] 〈Roping evaluation〉 The surfaces (surface protective layers) of test bodies 1 to 5 and comparative bodies 1 to 5 were visually inspected to evaluate the roping state. The results are shown in Table 1. In Table 1, "○" indicates that almost no roping was confirmed, "△" indicates that roping was slightly confirmed, and "×" indicates that roping was clearly confirmed.

[0058] 〈Streak pattern evaluation〉 The surfaces (surface protective layers) of test bodies 1 to 5 and comparative bodies 1 to 5 were visually inspected to evaluate the streak pattern state. The results are shown in Table 1. In Table 1, "○" indicates that almost no streak pattern was confirmed, "△" indicates that the streak pattern was slightly confirmed, and "×" indicates that the streak pattern was clearly confirmed.

[0059] [Evaluation results] The evaluation results for test bodies 1 to 5 and comparative bodies 1 to 5 are shown in Table 1 below.

[0060]

Table 1

[0061] As can be seen from Table 1, in comparative bodies 1 and 2 with a viscosity of less than 25 seconds and comparative body 5 with a thickness exceeding 12 μm, roping was "×", and in comparative body 3 with a viscosity exceeding 50 seconds and comparative body 4 with a thickness less than 6 μm, the streak pattern was "×". Therefore, the overall evaluation of comparative bodies 1 to 5 was "×".

[0062] On the other hand, in Test Specimens 1 to 5, since neither roping nor streak patterns were clearly confirmed, the comprehensive evaluation was "△" or higher. In particular, in Test Specimens 1 to 4, since almost no roping or streak patterns were confirmed, the comprehensive evaluation was "○".

[0063] From the above, it was recognized that the present invention can provide a decorative metal sheet and a method for manufacturing a decorative metal sheet that can easily and greatly suppress various surface appearance defects at low cost.

Industrial Applicability

[0064] The present invention can provide a decorative metal sheet and a method for manufacturing a decorative metal sheet that can easily and greatly suppress various surface appearance defects at low cost, and can be extremely beneficially used in various industries including the construction industry.

Explanation of Reference Numerals

[0065] 10 Decorative metal sheet 11 Base material 12 Chemical conversion coating layer 13 Underlayer 14 Coloring layer 15 Pattern layer 16 Surface protection layer 17 Back surface coating layer

Claims

1. A base material having a plate shape made of metal, An underlayer provided on the surface side of the base material, A colored layer provided on the surface side of the underlayer, A pattern layer provided on the surface side of the colored layer, And a surface protection layer provided on the surface side of the pattern layer In the decorative metal plate provided with, The surface protection layer is made of a paint having a viscosity measured by Ford Cup No. 4 defined in ISO 2431 of 25 seconds or more and 50 seconds or less, and has a thickness of 6 μm or more and 12 μm or less A decorative metal plate characterized by this.

2. A back surface coating layer is provided on the back surface side of the base material The decorative metal plate according to claim 1, characterized by this.

3. A chemical conversion coating layer is provided on the front and back surfaces of the base material The decorative metal plate according to claim 1, characterized by this.

4. The base material is one in which metal coatings are formed on the front and back surfaces of a steel plate The decorative metal plate according to claim 1, characterized by this.

5. An underlayer forming step of providing an underlayer on the surface side of a base material having a plate shape made of metal, A colored layer forming step of providing a colored layer on the surface side of the underlayer, A pattern layer forming step of providing a pattern layer on the surface side of the colored layer, And a surface protection layer forming step of providing a surface protection layer on the surface side of the pattern layer In the manufacturing method of the decorative metal plate which performs, The surface protection layer forming step is a step of providing the surface protection layer having a thickness of 6 μm or more and 12 μm or less by applying a paint having a viscosity measured by Ford Cup No. 4 defined in ISO 2431 of 25 seconds or more and 50 seconds or less to the surface of the pattern layer A manufacturing method of a decorative metal plate characterized by this.

6. A back coating layer forming step of providing a back coating layer on the back side of the base material is performed. The method for manufacturing a decorative metal plate according to claim 5, characterized in that.

7. A chemical conversion coating layer forming step of providing a chemical conversion coating layer on the front and back surfaces of the base material is performed. The method for manufacturing a decorative metal plate according to claim 5, characterized in that.

8. A base material forming step of obtaining the base material by plating the front and back surfaces of a steel sheet to form a metal coating is performed. The method for manufacturing a decorative metal plate according to claim 5, characterized in that.

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