WO2020241475A1

WO2020241475A1 - Plated steel sheet

Info

Publication number: WO2020241475A1
Application number: PCT/JP2020/020241
Authority: WO
Inventors: 敬士二葉; 後藤　靖人; 史生柴尾; くるみ久米; 拓哉横道; 卓哉宮田
Original assignee: 日本製鉄株式会社
Priority date: 2019-05-24
Filing date: 2020-05-22
Publication date: 2020-12-03
Also published as: CN113825640B; CN113825640A; KR102592017B1; KR20210152501A

Abstract

A plated steel sheet according to one embodiment of the present invention comprises a base material steel sheet having a base material texture on the surface, a galvanized layer formed on the surface having the base material texture of the base material steel sheet, and a colored resin layer formed on the surface of the galvanized layer, wherein a plating texture is formed on the surface of the galvanized layer, the colored resin layer includes a colorant, the plating texture has a plurality of protrusions and a plurality of depressions, the depression bottom three-dimensional average roughness Sas is more than 200 nm and equal to or less than 2000 nm, DKmin × CK is 15.0 or less, and (DKmax - DKmin) × CK is greater than 1.0. A plated steel sheet according to another embodiment of the present invention includes a base material steel sheet, a galvanized layer formed on the surface of the base material steel sheet, and a colored resin layer formed on the galvanized layer, wherein a texture extending in one direction is formed on the surface of the galvanized layer, the colored resin layer includes a colorant, the three-dimensional average roughness Saave' is more than 5 nm and equal to or less than 200 nm, and DKmin' × CK' is 15.0 or less, and (DKmax' - DKmin') × CK' is larger than 1.0.

Description

Plated steel sheet

The present invention relates to a plated steel sheet.
This application applies to Japanese Patent Application No. 2019-171166 filed in Japan on September 20, 2019, Japanese Patent Application No. 2019-171137 filed in Japan on September 20, 2019, and Japan on May 24, 2019. Claim the priority based on Japanese Patent Application No. 2019-098050 filed in Japan, the contents of which are incorporated herein by reference.

Electrical equipment, building materials, and articles such as automobiles may be required to have a design. As a method of enhancing the design of the article, there are a method of painting the surface of the article and a method of attaching a film.

Recently, there is a tendency for materials that take advantage of the texture of metal to be preferred, especially in Europe and the United States, which are nature-oriented. When utilizing the texture of metal, stainless steel plates and aluminum plates, which have excellent corrosion resistance even when unpainted, are used as materials. Further, for the purpose of further expressing the metallic feeling of the stainless steel plate and the aluminum plate, a stainless steel plate and an aluminum plate having a texture typified by a hairline formed on the surface are also provided. However, stainless steel plates and aluminum plates are expensive. Therefore, there is a demand for inexpensive materials that can replace stainless steel plates and aluminum plates.

As one of the alternative materials for such stainless steel sheets and aluminum plates, plated steel sheets having a zinc plating layer on the surface are being studied. In the present specification, the zinc plating layer also includes a zinc alloy plating layer. Like stainless steel sheets and aluminum plates, plated steel sheets have appropriate corrosion resistance and are also excellent in workability. Therefore, the plated steel sheet is suitable for applications such as electrical equipment and building materials. Therefore, various proposals have been made for the purpose of enhancing the design of the plated steel sheet.

For example, in Japanese Patent Application Laid-Open No. 2006-124824 (Patent Document 1), after hairline finishing is performed on a galvanized steel sheet, a transparent resin film is formed on the surface of the galvanized layer on which the hairline is formed. As a result, the surface of the plating layer can be visually recognized while maintaining corrosion resistance, and the design is enhanced.

Further, in Japanese Patent Application Laid-Open No. 2013-536901 (Patent Document 2), after rolling a galvanized steel sheet to form a texture on the surface of the galvanized layer, the surface roughness becomes within a certain range. The surface of the galvanized layer is coated with a film (resin). As a result, the surface of the plating layer is visible and the design is enhanced while maintaining the corrosion resistance.

Japanese Patent Application Laid-Open No. 2006-124824 Japan Special Table 2013-536901

Recently, there has been a growing demand for materials that have a colored appearance while taking advantage of the texture of metal. More specifically, there is a demand for a plated steel sheet having a colored appearance and a visible texture on the surface of the galvanized layer.

An object of the present invention is to provide a plated steel sheet in which the texture of the surface of the galvanized layer can be visually recognized while having a colored appearance.

(1) The plated steel sheet according to one aspect of the present invention includes a base material steel sheet having a base material texture on the surface, a zinc plating layer formed on the surface of the base material steel sheet having the base material texture, and the above. The zinc plating layer includes a colored resin layer formed on the zinc plating layer, the zinc plating layer has a plating texture on the surface thereof, the coloring resin layer contains a coloring agent, and the plating textures are plural. When the rolling direction of the base steel sheet is defined as the first direction, and the direction orthogonal to the first direction is defined as the second direction on the surface of the plated steel sheet, including the convex portion and the plurality of concave portions. , The plated steel sheet satisfies the following (A) to (C).
(A) When the roughness profile of the plating texture in the range of 1000 μm in the second direction is measured, and the lowest position in each of the recesses in the measured roughness profile is defined as the recess bottom point. Among the plurality of recess bottom points of the roughness profile, 10 recess bottom points are identified in ascending order, and a three-dimensional average of a minute region of 1 μm × 1 μm centered on the identified recess bottom points. When the roughness Sa is measured and the arithmetic average value of the measured 10 three-dimensional average roughness Sa is defined as the concave bottom three-dimensional average roughness Sa, the concave bottom three-dimensional average roughness Sa is more than 200 nm and 2000 nm or less. Is.
(B) In the range of 100 μm length in the second direction, the minimum thickness (μm) of the colored resin layer is defined as DKmin, and the content (area%) of the colorant in the colored resin layer is CK. When F1 is defined by the equation (1), the F1 is 15.0 or less.
F1 = DKmin x CK (1)
(C) When the maximum thickness (μm) of the colored resin layer is defined as DKmax and F2 is defined by the formula (2) in the range of 100 μm length in the second direction, the F2 is 1.0. Is also big.
F2 = (DKmax-DKmin) x CK (2)
(2) The plated steel sheet according to (1) above may further satisfy the following (D).
(D) The roughness profile of the plating texture in the range of 1000 μm in the second direction is measured, and the highest position in each of the convex portions in the measured roughness profile is defined as the convex portion top point. When this is done, 10 of the convex top points of the roughness profile are specified in descending order of the highest, and a minute size of 1 μm × 1 μm centered on the specified convex top points. When the three-dimensional average roughness Sa of the region is measured and the arithmetic average value of the measured ten three-dimensional average roughness Sa is defined as the convex top three-dimensional average roughness Sa, the convex top three-dimensional average roughness The Sah is more than 5 nm and 200 nm or less.
(3) In the plated steel sheet according to (2) above, the plurality of the convex portions and the plurality of the concave portions extend in the first direction, and the plurality of the convex portions and the plurality of the concave portions are the said. It may be arranged in the second direction.
(4) In the plated steel sheet according to (3) above, the base material texture is a hairline, the plated texture is a hairline, and the plated steel sheet further satisfies the following (E) and (F). Good.
(E) The surface roughness Ra of the colored resin layer in the first direction is defined as Ra (CL), the surface roughness Ra of the colored resin layer in the second direction is defined as Ra (CC), and F3. Is defined by the equation (3), the F3 is 1.10 or more.
F3 = Ra (CC) / Ra (CL) (3)
(F) When the surface roughness of the galvanized layer in the second direction is defined as Ra (MC), Ra (MC) is 0.30 μm or more.
(5) In the plated steel sheet according to any one of (1) to (4) above, the brightness L ^* (SCI) when the plated steel sheet is viewed from the colored resin layer side is 45 or less. May be good.
(6) In the plated steel sheet according to any one of (1) to (5) above, F1 may be 13.5 or less.
(7) In the plated steel sheet according to any one of (1) to (6) above, F2 may be larger than 2.0.
(8) In the plated steel sheet according to any one of (4) to (7) above, the F3 may be 1.15 or more.
(9) In the plated steel sheet according to any one of (1) to (8) above, the base iron exposure rate of the galvanized layer may be less than 5%.
(10) In the plated steel sheet according to (2) above, the plurality of the convex portions are formed by polishing the surface of the galvanized layer, and the plurality of the concave portions may not be polished.
(11) The plated steel sheet according to another aspect of the present invention includes a base steel sheet, a galvanized layer formed on the surface of the base steel sheet, and a colored resin layer formed on the galvanized layer. The galvanized layer has a texture extending in one direction on its surface, and the colored resin layer contains a colorant, and all of the following (A') to (C'). Meet.
(A') A roughness profile in a length range of 1000 μm in a direction perpendicular to the extending direction of the texture is measured, and 10 points are specified in ascending order of height among the measured positions on the roughness profile. The determined position is defined as the concave bottom point, and among the measured positions on the roughness profile, the positions specified by 10 points in descending order of height are defined as the convex apex, and each concave bottom point and each convex apex are defined. When the three-dimensional average roughness Sa'of a minute region of 1 μm × 1 μm centered on the above is measured and the arithmetic average value of the measured three-dimensional average roughness Sa'is defined as the three-dimensional average roughness Saave', it is cubic. The original average roughness Save'is more than 5 nm and 200 nm or less.
(B') The minimum thickness (μm) of the colored resin layer is defined as DKmin'in the range of 100 μm length in the direction orthogonal to the extending direction of the texture, and the colorant in the colored resin layer. When the content (area%) is defined as CK', the formula (1') is satisfied.
DKmin'× CK'≤15.0 (1')
(C') The formula (2') is satisfied when the maximum thickness (μm) of the colored resin layer is defined as DKmax'in the range of 100 μm in the direction perpendicular to the extending direction of the texture.
(DKmax'-DKmin') x CK'> 1.0 (2')
(12) In the plated steel sheet according to (11) above, the texture is a hairline and may satisfy the following (D') and (E').
(D') The surface roughness Ra of the colored resin layer in the extending direction of the texture is defined as Ra (CL)', and the surface roughness Ra of the colored resin layer in the direction perpendicular to the extending direction of the texture is defined. Is defined as Ra (CC)', the equation (3') is satisfied.
Ra (CC)'≧ Ra (CL)' × 1.10 (3')
(E') When the surface roughness of the galvanized layer in the direction orthogonal to the extending direction of the texture is defined as Ra (MC)', Ra (MC)'is 0.30 μm or more.
(13) In the plated steel sheet according to the above (11) or (12), the base iron exposure rate of the galvanized layer may be less than 5%.
(14) In the plated steel plate according to any one of (1) to (13) above, the colored resin layer is a laminated resin layer, and the laminated resin layer is in the normal direction of the surface of the base steel plate. The plurality of colored resin layers are the product of the content (area%) of the colorant in the colored resin layer and the thickness (μm) of the colored resin layer in the plurality of colored resin layers. The total of the above is 15.0 area% · μm or less, and among the plurality of colored resin layers, the content (area%) of the colorant in the colored resin layer and the thickness (μm) of the colored resin layer. The colored resin layer having the maximum product with is defined as the darkest colored resin layer, and the colored resin having the second largest product between the content of the colorant in the colored resin layer and the thickness of the colored resin layer is the second largest. When the layer is defined as the second dark colored resin layer, the content of the colorant in the darkest colored resin layer C _1ST (area%) and the thickness of the darkest colored resin layer D _1ST (μm). The content C _2ND (area%) of the colorant in the second dark colored resin layer and the thickness D _2ND (μm) of the second dark colored resin layer satisfy the formula (4). May be good.
1.00 <(C _1ST x D _1ST ) / (C _2ND x D _2ND ) ≤ 4.00 (4)
(15) In the plated steel sheet according to (14) above, the thickness of the laminated resin layer may be 10.0 μm or less.
(16) In the plated steel sheet according to the above (14) or (15), the laminated resin layer further includes one or a plurality of transparent resin layers containing no colorant, and the laminated resin layer is a plurality of the above. The colored resin layer of No. 1 may be formed by laminating the one or more transparent resin layers.

The plated steel sheet according to the present disclosure has a colored appearance, but the texture of the surface of the galvanized layer can be visually recognized.

FIG. 1 is a schematic view of a cross section perpendicular to the first direction of the plated steel sheet of the first embodiment. FIG. 2 is a cross-sectional view of the plated steel sheet of the first embodiment. FIG. 3 is an enlarged view of the colored resin layer shown in FIG. FIG. 4 is a plan view of the galvanized layer in which hairlines are formed as a texture on the surface. FIG. 5 is a diagram showing a roughness profile of a plating texture formed on the surface of a zinc plating layer. FIG. 6A is a schematic view for explaining a micro-recessed bottom region on the surface of the galvanized layer. FIG. 6B is a schematic view for explaining a micro-convex top region on the surface of the galvanized layer. FIG. 7 is a cross-sectional view perpendicular to the first direction in the portion near the surface of the galvanized layer. FIG. 8 is a cross-sectional view perpendicular to the first direction in the portion near the surface of the galvanized layer of the first embodiment. FIG. 9 is a schematic view of a cross section perpendicular to the extending direction of the texture in the plated steel sheet of the second embodiment. FIG. 10 is a cross-sectional view of the plated steel sheet of the second embodiment. FIG. 11 is an enlarged view of the colored resin layer shown in FIG. FIG. 12 is a plan view of the galvanized layer in which hairlines are formed as a texture on the surface. FIG. 13 is a diagram showing the roughness profile of the texture formed on the surface of the galvanized layer. FIG. 14A is a schematic view for explaining a micro-recessed region on the surface of the galvanized layer. FIG. 14B is a schematic view for explaining a micro-convex region on the surface of the galvanized layer. FIG. 15A is a schematic view of the cut surface CS. FIG. 15B is a schematic view of the cut surface CS. FIG. 16 is a schematic view for explaining a method for evaluating color unevenness when the surface of the galvanized layer of the designable galvanized steel sheet of the present embodiment has a hairline as a texture. FIG. 17 is a schematic view for explaining a method for evaluating color variation when the surface of the galvanized layer of the designable galvanized steel sheet of the present embodiment has a hairline as a texture.

(First Embodiment)
The present inventors have studied a plated steel sheet in which the surface texture of the galvanized layer (hereinafter referred to as “plated texture”) can be visually recognized while having a colored appearance. As described in Patent Documents 1 and 2, a galvanized steel sheet in which a transparent resin layer is formed on a galvanized layer has already been proposed. Therefore, the present inventors first attempted to produce a galvanized steel sheet in which the resin layer formed on the galvanized layer was colored by containing a colorant containing a pigment and / or a dye.

As a result, it was found that when the resin layer contains a colorant, the plating texture formed on the surface of the zinc plating layer may not be visible depending on the conditions. Therefore, the present inventors have investigated and investigated factors that affect the visibility of the plating texture when the resin contains a colorant. As a result, the present inventors obtained the following findings. In the following description, the rolling direction of the base steel sheet is defined as the first direction RD. Further, on the surface of the plated steel sheet, a direction orthogonal to the first direction (width direction of the plated steel sheet) is defined as a second direction WD. The direction orthogonal to the first direction RD and the second direction WD (the thickness direction of the plated steel sheet) is defined as the third direction TD.

When a colored resin layer containing a colorant is formed on a zinc plating layer having a plating texture formed on the surface, the content of the colorant in the colored resin layer and the thickness of the colored resin layer are visually recognized as the plating texture. Affects. Specifically, if the content of the colorant in the colored resin layer is too large, the plating texture cannot be visually recognized. Further, if the colored resin layer is too thick, the plating texture cannot be visually recognized.

Further, in the cross section perpendicular to the first direction RD, the thickness of the resin formed on the plating texture varies depending on the unevenness of the plating texture. FIG. 1 is a schematic view of a cross section of the plated steel sheet of the first embodiment perpendicular to the first direction RD. With reference to FIG. 1, the plated steel sheet 1 includes a base steel sheet 100, a galvanized layer 10, and a colored resin layer 11. The base steel plate 100 has a texture 100S on its surface. Hereinafter, the texture 100S is referred to as a base material texture 100S. The zinc plating layer 10 has a plating texture 10S on its surface. The plating texture 10S includes a plurality of convex portions 10CO (Convex) and a plurality of concave portions 10RE (Recess). The convex portion 10CO and the concave portion 10RE are arranged alternately. In FIG. 1, a plurality of convex portions 10CO and a plurality of concave portions 10RE are alternately arranged in the second direction WD.

The colored resin layer 11 is formed on the surface of the galvanized layer 10. Therefore, although the uneven pattern (shape of the concave portion 10RE and the convex portion 10CO) of the plating texture 10S is reflected to some extent on the surface 11S of the colored resin layer 11, it is flatter than the plating texture 10S. Specifically, the convex portion 11CO is formed on the portion of the surface 11S of the colored resin layer 11 corresponding to the convex portion 10CO of the plating texture 10S. The height of the convex portion 11CO is lower than the height of the convex portion 10CO. That is, the surface 11S of the colored resin layer 11 is flatter than the surface of the plating texture 10S.

Here, the maximum thickness (μm) of the colored resin layer 11 is defined as DKmax in the range of 100 μm length in the second direction WD. Further, the minimum thickness (μm) of the colored resin layer 11 is defined as DKmin. In order to make the plating texture 10S visible even when colored by the colored resin layer 11, the colorant content CK (area%) in the colored resin layer 11 and the colored resin layer 11 are as described above. Limit the thickness of the to some extent. Then, under the restricted conditions, the difference between the maximum thickness DKmax and the minimum thickness DKmin of the colored resin layer 11 is reflected in the visible brightness difference of the plating texture. Specifically, by increasing the difference between the maximum thickness DKmax and the minimum thickness DKmin of the colored resin layer 11 to some extent, a difference in brightness is generated between the concave portion 10RE and the convex portion 10CO of the plating texture 10S. As a result, the plating texture 10S can be visually recognized even when the colored resin layer 11 is formed.

Further, it is preferable that the colored resin layer 11 has high adhesion to the zinc plating layer 10. Therefore, the present inventors have studied a method for improving the adhesion of the colored resin layer 11 to the galvanized layer 10. As a result, the surface roughness of the convex portion 10CO and the concave portion 10RE of the plating texture 10S, particularly the minute region in the concave portion 10RE, is made rough to some extent (specifically, the concave bottom three-dimensional average roughness Sas described later is more than 200 nm and 2000 nm. It has been found that the adhesion of the colored resin layer 11 to the galvanized layer 10 can be improved by (the following).

Based on the above findings, the present inventors have made the surface roughness of the minute region of the concave portion 10RE of the convex portion 10CO and the concave portion 10RE of the plating texture 10S to some extent, and (B) the colored resin layer. The thickness of 11 and the colorant content are adjusted, and (C) the difference between the maximum thickness DKmax and the minimum thickness DKmin of the colored resin layer 11 in the cross section orthogonal to the first direction is adjusted to a certain size. As a result, it has been found that a plated steel sheet can be obtained in which the plating texture on the surface of the galvanized layer can be visually recognized while having a colored appearance, and the adhesion of the colored resin layer is excellent.

The plated steel sheet of the first embodiment completed based on the above findings has the following configuration.

The plated steel sheet of [1] is
A base steel plate with a base material texture on the surface and
A zinc-plated layer formed on the surface of the base steel sheet having the base material texture,
A colored resin layer formed on the galvanized layer is provided.
The galvanized layer has a plating texture on its surface.
The colored resin layer contains a colorant and
The plating texture is
With multiple protrusions,
Including multiple recesses
When the rolling direction of the base steel sheet is defined as the first direction and the direction orthogonal to the first direction is defined as the second direction on the surface of the plated steel sheet, the plated steel sheet has the following (A) to ( C) is satisfied.
(A) When the roughness profile of the plating texture in the range of 1000 μm in the second direction is measured, and the lowest position in each of the recesses in the measured roughness profile is defined as the recess bottom point. Among the plurality of recess bottom points of the roughness profile, 10 recess bottom points are specified in ascending order, and a three-dimensional average of a minute region of 1 μm × 1 μm centered on the identified recess bottom points. When the roughness Sa is measured and the arithmetic average value of the measured 10 three-dimensional average roughness Sa is defined as the concave bottom three-dimensional average roughness Sa, the concave bottom three-dimensional average roughness Sa is more than 200 nm and 2000 nm or less. Is.
(B) In the range of 100 μm length in the second direction, the minimum thickness (μm) of the colored resin layer is defined as DKmin, and the content (area%) of the colorant in the colored resin layer is CK. When F1 is defined by the equation (1), the F1 is 15.0 or less.
F1 = DKmin x CK (1)
(C) When the maximum thickness (μm) of the colored resin layer is defined as DKmax and F2 is defined by the formula (2) in the range of 100 μm length in the second direction, the F2 is 1.0. Is also big.
F2 = (DKmax-DKmin) x CK (2)

The plated steel sheet of [2] is
The plated steel sheet according to [1] may further satisfy the following (D).
(D) The roughness profile of the plating texture in the range of 1000 μm in the second direction is measured, and the highest position in each of the convex portions in the measured roughness profile is defined as the convex portion top point. When this is done, 10 of the convex top points of the roughness profile are specified in descending order of the highest, and a minute size of 1 μm × 1 μm centered on the specified convex top points. When the three-dimensional average roughness Sa of the region is measured and the arithmetic average value of the measured ten three-dimensional average roughness Sa is defined as the convex top three-dimensional average roughness Sa, the convex top three-dimensional average roughness The Sah is more than 5 nm and 200 nm or less.

The roughness of the plating texture affects the visibility of the plating texture. When a plating texture is formed on the surface of the galvanized layer, not only the unevenness of the plating texture on the surface of the galvanized layer, but also the minute unevenness (roughness) due to the galvanized crystals on the surface of the plating texture. ) Also exists. If the minute irregularities caused by the galvanized crystals are small, the diffused reflection of light due to the minute irregularities caused by the galvanized crystals is suppressed. In this case, the gloss of the plating texture is increased and the whitening of the plating texture is suppressed. In the plated steel sheet of [2], the roughness of the concave portion in the microscopic region of the plating texture is maintained as coarse as 200 nm or more, and the roughness of the convex portion in the microscopic region is suppressed to 200 nm or less. Therefore, the concave portion of the plating texture can maintain the adhesion of the colored resin layer, and the convex portion can further enhance the visibility of the plating texture.

The plated steel sheet of [3] is
The plated steel sheet according to [2].
The plurality of protrusions and the plurality of recesses may extend in the first direction.
The plurality of the convex portions and the plurality of the concave portions may be arranged in the second direction.

The plated steel sheet of [4] is
The plated steel sheet according to [3].
The base material texture may be a hairline
The plating texture may be a hairline
The plated steel sheet is further
The following (E) and (F) may be satisfied.
(E) The surface roughness Ra of the colored resin layer in the first direction is defined as Ra (CL), the surface roughness Ra of the colored resin layer in the second direction is defined as Ra (CC), and F3. Is defined by the equation (3), the F3 is 1.10 or more.
F3 = Ra (CC) / Ra (CL) (3)
(F) When the surface roughness of the galvanized layer in the second direction is defined as Ra (MC), Ra (MC) is 0.30 μm or more.

The plated steel sheet of [5] is
The plated steel sheet according to any one of [1] to [4].
The brightness L ^* (SCI) when the plated steel sheet is viewed from the colored resin layer side may be 45 or less.

The plated steel sheet of [6] is
The plated steel sheet according to any one of [1] to [5].
F1 may be 13.5 or less.

The plated steel sheet of [7] is
The plated steel sheet according to any one of [1] to [6].
F2 may be greater than 2.0.

The plated steel sheet of [8] is
The plated steel sheet according to any one of [4] to [7].
The F3 may be 1.15 or more.

The plated steel sheet of [9] is
The plated steel sheet according to any one of [1] to [8].
The base iron exposure rate of the galvanized layer may be less than 5%.

The plated steel sheet of [10] is
The plated steel sheet according to [2].
The plurality of convex portions may be formed by polishing the surface of the galvanized layer.
The plurality of recesses may not be polished.

Hereinafter, the plated steel sheet of the first embodiment will be described in detail.

[About galvanized steel sheet 1]
FIG. 2 is a cross-sectional view of the plated steel sheet 1 of the first embodiment. With reference to FIG. 2, the plated steel sheet 1 of the first embodiment includes a base steel sheet 100, a galvanized layer 10, and a colored resin layer 11. The galvanized layer 10 is formed on the base material texture 100S on the surface of the base material steel plate 100. The colored resin layer 11 is formed on the surface (texture) 10S of the galvanized layer 10. The galvanized layer 10 is arranged between the base steel plate 100 and the colored resin layer 11. Hereinafter, the base steel plate 100, the galvanized layer 10, and the colored resin layer 11 will be described.

[About base steel sheet 100]
As the base steel sheet 100, a known steel sheet applied to the plated steel sheet may be used according to each mechanical property (for example, tensile strength, workability, etc.) required for the plated steel sheet to be manufactured. For example, as the base steel plate 100, a steel plate for electrical equipment may be used, or a steel plate for automobile outer panels may be used. The base steel plate 100 may be a hot-rolled steel plate or a cold-rolled steel plate.

A texture 100S (base material texture 100S) is formed on the surface of the base material steel plate 100. That is, the base material steel plate 100 has a texture 100S (base material texture 100S) on its surface. The plating texture 10S described later may be formed along the base material texture 100S. In this case, the pattern of the plating texture 10S is similar to the pattern of the base material texture 100S. For example, when the base material texture 100S is dull, the plating texture 10S is also dull. When the base material texture 100S is a hairline, the plating texture 10S is also a hairline. On the other hand, the base material texture 100S and the plating texture 10S may have different patterns. For example, the base material texture 100S may be dull and the plating texture 10S may be a hairline.

[About the galvanized layer 10]
The galvanized layer 10 is formed on the surface of the base steel plate 100. In the first embodiment, the galvanized layer 10 is arranged between the base steel plate 100 and the colored resin layer 11. The galvanized layer 10 is formed by a well-known galvanized method. Specifically, the zinc plating layer 10 is formed by, for example, an electroplating method. In the present specification, the zinc plating layer 10 also includes a zinc alloy plating layer.

It is sufficient for the galvanized layer 10 to have a well-known chemical composition. For example, the Zn content in the chemical composition of the galvanized layer 10 may be 65% or more in mass%. When the Zn content is 65% or more in mass%, the sacrificial anticorrosion function is remarkably exhibited, and the corrosion resistance of the plated steel sheet 1 is remarkably enhanced. The preferable lower limit of the Zn content in the chemical composition of the galvanized layer 10 is 70%, more preferably 80%.

The chemical composition of the galvanized layer 10 is one element or two selected from the element group consisting of Al, Co, Cr, Cu, Fe, Ni, P, Si, Sn, Mg, Mn, Mo, V, W and Zr. It is preferable to contain more than an element and Zn. When the zinc plating layer 10 is an electrogalvanized layer, the chemical composition contains at least one element selected from the element group consisting of Fe, Ni, and Co in a total amount of 5 to 20% by mass. Is even more preferable. When the galvanized layer 10 is a hot-dip galvanized layer, the chemical composition preferably contains at least one element selected from the group consisting of Mg, Al, and Si in a total amount of 5 to 20% by mass. .. In these cases, the galvanized layer 10 further exhibits excellent corrosion resistance.

The galvanized layer 10 may contain impurities. Here, the impurities are those that are mixed in the raw material or are mixed in the manufacturing process. Impurities are, for example, Ti, B, S, N, C, Nb, Pb, Cd, Ca, Pb, Y, La, Ce, Sr, Sb, O, F, Cl, Zr, Ag, W, H and the like. .. In the chemical composition of the galvanized layer 10, the total content of impurities is preferably 1% or less.

The chemical composition of the galvanized layer 10 can be measured by, for example, the following method. The colored resin layer 11 of the plated steel sheet 1 is removed with a solvent that does not attack the galvanized layer 10 or a release agent such as a remover (for example, trade name: Neo River S-701 manufactured by Sansai Kako Co., Ltd.). Then, the galvanized layer 10 is dissolved with hydrochloric acid containing an inhibitor. The lysate is subjected to ICP analysis using an ICP (Inductively Coupled Plasma) emission spectroscopic analyzer to determine the Zn content. If the obtained Zn content is 65% or more, it is determined that the plating layer to be measured is the zinc plating layer 10.

[Adhesion amount of galvanized layer 10]
The amount of adhesion of the zinc plating layer 10 is not particularly limited, and a well-known amount of adhesion is sufficient. The preferable adhesion amount of the galvanized layer 10 is 5.0 to 120.0 g / m ² . When the adhesion amount of the galvanized layer 10 is 5.0 g / m ² or more, it is possible to suppress the exposure of the base iron (base steel sheet 100) when the galvanized layer 10 is given the plating texture described later. A more preferable lower limit of the adhesion amount of the galvanized layer 10 is 7.0 g / m ² , and even more preferably 10.0 g / m ² . The upper limit of the amount of adhesion of the galvanized layer 10 is not particularly limited. From the viewpoint of economy, in the case of the galvanized layer 10 by the electroplating method, the upper limit of the preferable adhesion amount is 40.0 gm ² , the more preferable upper limit is 35.0 g / m ² , and more preferably 30.0 g. / M ² .

[About the colored resin layer 11]
The colored resin layer 11 is formed on the surface (plating texture) 10S of the zinc plating layer 10. FIG. 3 is an enlarged view of the colored resin layer 11 shown in FIG. With reference to FIG. 3, the colored resin layer 11 includes a resin 31 and a colorant 32. The colorant 32 is contained in the resin 31. Hereinafter, the resin 31 and the colorant 32 will be described.

[About resin 31]
The resin 31 is a translucent resin. In the first embodiment, the “translucent resin” is a plated steel sheet 1 provided with a colored resin layer 11 containing a colorant 32 and a resin 31 in an environment equivalent to sunlight (illuminance of about 65,000 lux) in fine morning. Means that the plating texture 10S of the galvanized layer 10 can be visually recognized when the above is placed. The resin 31 functions as a binder for fixing the colorant 32.

The resin 31 is not particularly limited as long as it has the above-defined translucency, and a well-known natural resin or a well-known synthetic resin can be used. The resin 31 is, for example, an epoxy resin, a urethane resin, a polyester resin, a phenol resin, a polyether sulfone resin, a melamine alkyd resin, an acrylic resin, a polyamide resin, a polyimide resin, a silicone resin, or a poly. One or more selected from the group consisting of vinyl acetate-based resin, polyolefin-based resin, polystyrene-based resin, vinyl chloride-based resin, and vinyl acetate-based resin.

[About Colorant 32]
The colorant 32 is contained in the above-mentioned resin 31 to color the colored resin layer 11. The colorant 32 is well known. The colorant 32 has a chromatic color. A chromatic color means a color having the attributes of hue, lightness, and saturation. The colorant 32 comprises, for example, one or more selected from the group consisting of inorganic pigments, organic pigments, and dyes. From the viewpoint of durability against ultraviolet rays, the colorant 32 is more preferably pigment-based (inorganic pigment and / or organic pigment).

When the colorant 32 is an inorganic pigment, the colorant 32 is, for example, a neutralized precipitate pigment (sulfate, carbonate, etc.) and / or a fired pigment (metal sulfide, metal oxide, polyvalent metal composite oxide). Etc.). When the colorant 32 is an organic pigment, the colorant 32 is, for example, a chlorine pigment, an azo pigment (dissolved azo lake pigment, insoluble azo pigment, etc.), an acid condensing pigment, a polycyclic pigment (phthalocyanine pigment, an indigo type pigment). , Kinacridone type pigment, anthraquinone type pigment, etc.), and one or more selected from the group consisting of metal complex pigments (azochelate pigment, transition metal complex pigment, etc.). When the colorant 32 is a dye, the colorant 32 is, for example, one or more selected from the group consisting of azo dyes, indigo dyes, anthraquinone dyes, sulfide dyes, and carbonium dyes.

The color of the colorant 32 is not particularly limited. The colorant 32 is, for example, black such as carbon black (C) and iron black (Fe ₃ O ₄ ). However, the colorant 32 is not limited to black, and may be a colorant 32 of another color (white, purple-red, yellow, green-blue, red, orange, yellow, green, blue, indigo, purple, etc.). Good.

When the colorant 32 is a pigment, the particle size is not particularly limited. When the colorant 32 is a pigment, the maximum value of the primary particle size is, for example, 3 nm to 1000 nm.

[About the plating texture 10S formed on the surface of the zinc plating layer 10]
A plating texture 10S is formed on the surface of the galvanized layer 10 of the plated steel sheet 1. That is, the galvanized layer 10 of the plated steel sheet 1 has a plating texture 10S on its surface. In the first embodiment, the “texture” means an uneven pattern formed on the surface of the base steel sheet 100 and / or the surface of the galvanized layer 10 by a physical or chemical method. That is, the texture (base material texture 100S, plating texture 10S) has a plurality of convex portions and a plurality of concave portions. The protrusions and recesses may or may not extend in one direction. The texture is, for example, dull and hairline. A preferred texture is a hairline. The hairline is a linear uneven pattern extending in one direction.

[When the plating texture 10S is a hairline]
FIG. 4 is a plan view of the galvanized layer 10 in which a hairline is formed as a plating texture 10S on the surface. With reference to FIG. 4, the hairline 10S is a linear uneven pattern formed on the surface of the galvanized layer 10. The hairline 10S includes a plurality of grooves 10L extending in the first direction. The extending directions of the plurality of grooves 10L of the hairline 10S are substantially the same. The substantially same direction here is orthogonal to the extending direction of the groove 10L of the hairline 10S when the zinc plating layer 10 is viewed in the thickness direction TD (that is, in a plan view as shown in FIG. 4). It means that 90% or more of the angles formed by the adjacent grooves 10L arranged in the second direction WD is less than ± 5 °.

[Requirements (A) to (C)]
The plated steel sheet 1 of the first embodiment having the above-described configuration further satisfies the following (A) to (C).
Requirement (A):
The roughness profile in the range of 1000 μm in the second direction WD of the plating texture 10S is measured, and the lowest position in each recess 10RE in the measured roughness profile is defined as the recess bottom point, and the roughness profile is defined. Of the plurality of recess bottom points, 10 recess bottom points are specified in ascending order, and the three-dimensional average roughness Sa of a minute region of 1 μm × 1 μm centered on the specified recess bottom point is measured and measured. When the arithmetic average value of the 10 three-dimensional average roughness Sa is defined as the concave bottom three-dimensional average roughness Sa, the concave bottom three-dimensional average roughness Sa is more than 200 nm and 2000 nm or less.
Requirement (B):
Within the range of 100 μm length in the second direction WD, the minimum thickness (μm) of the colored resin layer 11 is defined as DKmin, and the content (area%) of the colorant 32 in the colored resin layer 11 is defined as CK. , F1 is defined by the equation (1), F1 is 15.0 or less.
F1 = DKmin x CK (1)
Requirement (C):
When the maximum thickness (μm) of the colored resin layer 11 is defined as DKmax and F2 is defined by the formula (2) in the range of 100 μm length of the second direction WD, F2 is larger than 1.0.
F2 = (DKmax-DKmin) x CK (2)
Each requirement will be described in detail below.

[About the surface roughness of texture irregularities]
FIG. 5 is a diagram showing a roughness profile of the plating texture 10S formed on the surface of the zinc plating layer 10. With reference to FIG. 5, an arbitrary 1000 μm length range of the second direction WD of the plating texture 10S is selected. The roughness profile of the plating texture 10S is measured in the selected 1000 μm length range. It is assumed that the obtained roughness profile has a shape as shown in FIG.

[About concave bottom three-dimensional average roughness Sas]
Note each recess 10RE in the measured roughness profile. In each recess 10RE, the position having the lowest height is defined as the recess bottom point PRE. Of the plurality of recessed bottom points PRE in the roughness profile in the 1000 μm length range, 10 recessed bottom points PRE1, PRE2, ..., PRE10 are specified in ascending order from the lowest recessed bottom point PRE1.

As shown in FIG. 6A, the surface of the galvanized layer 10 is viewed in a plan view, and a 1 μm × 1 μm minute recess bottom region 200 centered on each defined recess bottom point PREk (k is 1 to 10) is specified. In FIG. 6A, the vertical direction of the minute concave bottom region 200 is parallel to the extending direction RD of the plating texture 10S, and the horizontal direction of the minute concave bottom region 200 is parallel to the width direction WD. However, if the micro-recess bottom region 200 is a surface including the extending direction RD and the width direction WD, each side of the micro-recess bottom region 200 does not have to be parallel to the extending direction RD or the width direction WD.

The three-dimensional average roughness Sa is measured in each of the 10 minute recess bottom regions 200 specified by the above method. The three-dimensional average roughness Sa is the arithmetic average roughness defined by ISO 25178, which is an extension of Ra (arithmetic mean roughness of lines) defined by JIS B 0601 (2013) to a surface. The arithmetic mean value of the 10 measured three-dimensional average roughness Sa is defined as the concave bottom three-dimensional average roughness Sa.

[About the three-dimensional average roughness Sah at the top of the convex part]
With reference to FIG. 5, attention is paid to each convex portion 10CO in the roughness profile of any 1000 μm length range of the second direction WD of the plating texture 10S. In each convex portion 10CO, the position having the highest height is defined as the convex portion top point PCO. Among the plurality of convex top points PCOs in the roughness profile in the 1000 μm length range, 10 convex top points PCO1, PCO2, ..., PCO10 are specified in descending order from the highest convex top point PCO1.

As shown in FIG. 6B, the surface of the galvanized layer 10 is viewed in a plan view, and a 1 μm × 1 μm microconvex top region 300 centered on each defined convex top point PCok (k is 1 to 10) is specified. To do. In FIG. 6B, the vertical direction of the micro-convex top region 300 is parallel to the extending direction RD of the plating texture 10S, and the lateral direction of the micro-convex top region 300 is parallel to the width direction WD. However, if the micro-convex top region 300 is a surface including the extending direction RD and the width direction WD, even if each side of the micro-convex top region 300 is not parallel to the extending direction RD or the width direction WD. Good.

The three-dimensional average roughness Sa is measured in each of the ten microconvex top regions 300 identified by the above method. The three-dimensional average roughness Sa is the arithmetic average roughness defined by ISO 25178, which is an extension of Ra (arithmetic mean roughness of lines) defined by JIS B 0601 (2013) to a surface. The arithmetic mean value of the 10 measured three-dimensional average roughness Sa is defined as the convex top three-dimensional average roughness Sa.

[About requirement (A)]
The concave bottom three-dimensional average roughness Sa determined by the above definition is more than 200 nm and 2000 nm or less (requirement (A)). This roughness can be based on galvanized crystals. Therefore, the plurality of galvanized recesses need not be polished. In the unevenness of the plating texture 10S, if at least the concave bottom three-dimensional average roughness Sas is coarse to some extent and is more than 200 nm and 2000 nm or less, the adhesion of the colored resin layer 11 to the zinc plating layer 10 can be improved. The lower limit of the concave bottom three-dimensional average roughness Sas is preferably 250 nm, and more preferably 300 nm. The upper limit of the three-dimensional average roughness Sas of the recess bottom is 1500 nm, more preferably 1000 nm, and further preferably 800 nm.

Of the plating texture 10S, the value of the three-dimensional average roughness Sah at the top of the convex portion is not particularly limited as long as the concave bottom three-dimensional average roughness Sas is more than 200 nm and 2000 nm or less. The three-dimensional average roughness Sah at the top of the convex portion is, for example, 2000 nm or less. As long as Sah is not limited, the plurality of convex portions may or may not be formed by polishing the surface of the galvanized layer. The shape of the unevenness of the plating texture 10S is also not particularly limited.

FIG. 7 is a cross-sectional view perpendicular to the first direction RD in the portion near the surface of the galvanized layer 10. With reference to FIG. 7, in the concave portion 10RE and the convex portion 10CO of the plating texture 10S formed on the surface of the galvanized layer 10, before polishing, the surface of the concave portion 10RE and the surface of the convex portion 10CO have a plating crystal. There are nanometer-level micro-concavities and convexities (micro-concave SRE and micro-convex SCO) caused by this. In this case, both the concave bottom three-dimensional average roughness Sas and the convex top three-dimensional average roughness Sah are more than 200 nm and 2000 nm or less.

[About requirement (B)]
With reference to FIG. 1, attention is paid to a cross section in an arbitrary 100 μm length range of the second direction WD orthogonal to the first direction RD of the plating texture 10S. A cross section in this 100 μm length range (FIG. 1) is defined as an observation cross section. In the observation cross section, the minimum thickness of the colored resin layer 11 is defined as DKmin (μ). In the observation cross section, the maximum thickness of the colored resin layer 11 is defined as DKmax (μm).

Further, in the observation cross section, the content (area%) of the colorant in the colored resin layer 11 is defined as CK. As described above, in the present specification, the colorant content CK is indicated by the area ratio (area%) of the colorant in the observed cross section.

Here, F1 is defined by the equation (1).
F1 = DKmin x CK (1)
At this time, F1 is 15.0 or less.

F1 is an index of the coloring concentration of the colored resin layer 11. When F1 exceeds 15.0, the thickness of the colored resin layer 11 is too thick, or the colorant content CK is too large. In this case, the coloring of the colored resin layer 11 is too dark, and the plating texture 10S of the zinc plating layer 10 is difficult to see. If F1 is 15.0 or less, the plating texture 10S on the surface of the zinc plating layer 10 can be sufficiently visually recognized while having an appearance colored by the colored resin layer 11 on condition that the requirements (A) and (C) are satisfied. it can. The preferred upper limit of F1 is 14.0, more preferably 13.5, still more preferably 13.0, still more preferably 12.5. The lower limit of F1 is not particularly limited. The lower limit of F1 is, for example, 4.0.

The thickness of the colored resin layer 11 is measured by the following method. A sample having a cross section orthogonal to the first direction RD of the plating texture 10S on the surface is taken. Of the sample, an observation cross section in a length range of 100 μm in the second direction WD is observed with a 2000 times reflected electron image (BSE) using a scanning electron microscope (SEM). In the observation with the reflected electron image (BSE) of the scanning electron microscope (SEM), the base steel plate 100, the galvanized layer 10, and the colored resin layer 11 can be easily distinguished by the contrast. In the observation cross section, the thickness of the colored resin layer 11 is measured at a pitch of 0.5 μm in the second direction WD. Of the measured thicknesses, the smallest thickness is defined as the minimum thickness DKmin (μm). Of the measured thicknesses, the maximum thickness is defined as the maximum thickness DKmax (μm). When it is necessary to determine whether or not it is the colored resin layer 11 (that is, whether or not the resin contains a colorant), it may be determined whether or not it is the colored resin layer 11 by TEM observation described later.

The colorant content CK (area%) in the colored resin layer 11 is determined by the following method. A sample having a cross section orthogonal to the first direction RD of the plating texture 10S on the surface is taken. Of the samples, the cross section orthogonal to the first direction RD of the plating texture 10S is defined as the observation surface. From the sample, a thin film sample in which the colored resin layer 11 and the zinc plating layer 10 on the observation surface can be observed is prepared by using a focused ion beam (FIB). The thickness of the thin film sample is 50 to 200 nm. Of the observation surfaces of the prepared thin film sample, the length in the direction perpendicular to the thickness direction of the colored resin layer 11 (that is, the second direction WD) is 3 μm, and the length in the thickness direction of the colored resin layer (that is, that is). , Third direction TD), a field having a length including the entire colored resin layer is observed using a transmission electron microscope (TEM: Transmission Electron Microscope). In the TEM observation, the resin 31 and the colorant 32 in the colored resin layer 11 can be distinguished by the contrast. The total area A1 (μm ² ) of the plurality of colorants in the colored resin layer 11 in the field of view is determined. Further, the area (μm ² ) of the colored resin layer 11 in the visual field is determined. Based on the obtained total area A1 and area A0, the colorant content (area%) in the colored resin layer 11 is obtained by the following formula.
CK = A1 / A0 × 100

[About requirement (C)]
F2 is defined by the equation (2) in the cross section of the plating texture 10S perpendicular to the first direction RD and in the observation cross section of the plating texture 10S in the second direction WD of 100 μm length range.
F2 = (DKmax-DKmin) x CK (2)
At this time, F2 is larger than 1.0.

F2 is an index of the contrast of brightness in the colored resin layer 11. When F2 is 1.0 or less, the contrast of brightness in the colored resin layer 11 is low. In this case, the contrast of the brightness of the colored resin layer 11 cannot be fully utilized for visually recognizing the plating texture 10S. Therefore, the plating texture 10S under the colored resin layer 11 is difficult to see.

If F2 is higher than 1.0, the contrast of brightness in the colored resin layer 11 is sufficiently high. In this case, the contrast of the brightness of the colored resin layer 11 can be fully utilized for visually recognizing the plating texture 10S. As a result, the plating texture 10S under the colored resin layer 11 can be sufficiently visually recognized on the premise that the requirements (A) and (B) are satisfied.

The preferable lower limit of F2 is 2.0 or more than 2.0, more preferably 2.2, still more preferably 2.4. The upper limit of F2 is not particularly limited. The upper limit of F2 is, for example, 15.0.

[Brightness L ^* (SCI) when the plated steel sheet is viewed from the colored resin layer side]
The brightness of the entire surface of the plated steel sheet 1 of the first embodiment is not particularly specified as long as F2 or the like, which is an index of the contrast of brightness in the concave portion and the convex portion, satisfies the above-mentioned requirements. Therefore, the upper and lower limits of the brightness L ^* (SCI) when the plated steel sheet is viewed from the colored resin layer side are not particularly specified. On the other hand, the brightness L ^* (SCI) when the plated steel sheet is viewed from the colored resin layer side may be 45 or less. The lower the brightness L ^* (SCI) of the plated steel sheet, the greater the blackness of the plated steel sheet as seen by the naked eye. In a normal plated steel sheet, if the surface brightness L ^* (SCI) is 45 or less, it becomes difficult to visually recognize the plated texture. On the other hand, since the plated steel sheet 1 of the first embodiment satisfies the above requirements (A) to (C), even if the lightness L ^* (SCI) when the plated steel sheet is viewed from the colored resin layer side is 45 or less. , The texture of the surface of the galvanized layer is visible.

Brightness L ^* (SCI) is the brightness measured by the SCI method. The SCI method is called a specularly reflected light inclusion method, and means a method of measuring color without removing specularly reflected light. A method for measuring brightness according to the SCI method is specified in JIS Z 8722 (2009). In the SCI method, since the measurement is performed without removing the specularly reflected light, it becomes the actual color of the object (so-called object color). The CIELAB display color is a uniform color space defined in JIS Z 8781 (2013). The three coordinates of CIELAB are indicated by L ^* value, a ^* value, and b ^* value. The L ^* value indicates the brightness and is indicated by 0 to 100. When the L ^* value is 0, it means black, and when the L ^* value is 100, it means a diffuse color of white.

[About the thickness of the colored resin layer 11]
In the plated steel sheet 1 of the first embodiment, the average thickness of the colored resin layer 11 is preferably 10.0 μm or less. If the thickness of the colored resin layer 11 exceeds 10.0 μm, smoothing (leveling) is easily performed only by the colored resin layer 11, and the impression of reflection on the surface of the colored resin layer 11 and the impression of the visible plating texture 10S are obtained. The divergence becomes large. In this case, the metallic feeling of the plated steel sheet 1 is reduced. If the average thickness of the colored resin layer 11 is 10.0 μm or less, the plating texture 10S of the zinc plating layer 10 can be visually recognized on the premise that all of the above requirements (A) to (C) are satisfied. At the same time, the metallic feeling is sufficiently enhanced. A more preferable upper limit of the average thickness of the colored resin layer 11 is 9.0 μm, and even more preferably 8.0 μm.

Further, the preferable lower limit of the average thickness of the colored resin layer 11 is 0.5 μm. When the average thickness of the colored resin layer 11 is 0.5 μm or more, the corrosion resistance is further enhanced. The lower limit of the average thickness of the colored resin layer 11 is 0.7 μm, more preferably 1.0 μm, still more preferably 2.0 μm, and even more preferably 3.0 μm.

The average thickness of the colored resin layer 11 is measured by the following method. The arithmetic mean value of the thickness measured at a pitch of 0.5 μm in the second direction WD in the above-mentioned observation cross section is defined as the average thickness (μm) of the colored resin layer 11.

[About requirement (D)]
In the plated steel sheet 1 of the first embodiment, preferably, the three-dimensional average roughness Sah at the top of the convex portion is more than 5 nm and 200 nm or less (requirement (D)).

With reference to FIG. 7, in the concave portion 10RE and the convex portion 10CO of the plating texture 10S formed on the surface of the galvanized layer 10, before polishing, the surface of the concave portion 10RE and the surface of the convex portion 10CO have a plating crystal. There are nanometer-level micro-concavities and convexities (micro-concave SRE and micro-convex SCO) caused by this. That is, the roughness of the micro-concavities and convexities (micro-concave SRE and micro-convex SCO) in the convex portion 10CO is as coarse as the roughness of the micro-concavities and convexities (micro-concave SRE and micro-convex SCO) in the concave-convex 10RE. Therefore, in the convex portion 10CO, light is diffusely reflected by the minute unevenness as in the concave portion 10RE.

Therefore, in the requirement (D), the three-dimensional average roughness Sah at the top of the convex portion is made smaller than the three-dimensional average roughness Sah at the bottom of the concave portion. Specifically, as described above, the concave bottom three-dimensional average roughness Sas may be 200 nm or more, whereas the convex top three-dimensional average roughness Sah may be more than 5 nm and 200 nm or less. In this case, the concave portion 10RE tends to reflect light diffusely, whereas the convex portion 10CO has a lower roughness than the concave portion 10RE, and the light is less likely to be diffusely reflected. Therefore, in the plating texture 10S of the zinc plating layer 10, the convex portion 10CO is easily visible. For example, as shown in FIG. 8, the peak of the convex portion 10CO is polished to form the convex portion 10CO into a trapezoidal shape. As a result, the roughness of the minute irregularities (micro concave portion SRE and minute convex portion SCO) at the convex portion 10CO can be made smaller than the roughness of the minute irregularities (micro concave concave SRE and minute convex portion SCO) at the concave portion 10 RE.

If the three-dimensional average roughness Sah at the top of the convex portion is 200 nm or less, diffused reflection of light in the vicinity of the apex of the convex portion can be suppressed. In this case, in the plated steel sheet 1 of the first embodiment having the colored resin layer 11, the plating texture 10S becomes more visible. It is preferable that the three-dimensional average roughness Sah at the top of the convex portion is smaller. However, it is extremely difficult to make the three-dimensional average roughness Sah at the top of the convex portion 5 nm or less. Therefore, in the first embodiment, the three-dimensional average roughness Sah at the top of the convex portion is more than 5 nm and 200 nm or less. The upper limit of the three-dimensional average roughness Sah at the top of the convex portion is preferably 190 nm, more preferably 180 nm, and further preferably 170 nm.

[About other forms of the colored resin layer 11]
The colored resin layer 11 of the plated steel sheet 1 of the first embodiment may further contain an additive in order to impart corrosion resistance, slidability, conductivity and the like to the colored resin layer 11. Additives for imparting corrosion resistance are, for example, well-known rust inhibitors and inhibitors. Additives for imparting slidability are, for example, well-known waxes and beads. The additive for imparting conductivity is, for example, a well-known conductive agent.

[About the surface shape of the colored resin layer 11 when the plating texture 10S is a hairline (about requirement (E))]
The colored resin layer 11 may have a surface shape as described in detail below due to the type of plating texture 10S formed on the surface of the lower zinc plating layer 10.

Here, it is assumed that the plating texture 10S is a hairline. The surface roughness Ra of the colored resin layer 11 in the first direction RD of the plating texture 10S is defined as Ra (CL). The surface roughness Ra of the colored resin layer 11 in the second direction WD of the plating texture 10S is defined as Ra (CC). Then, F3 is defined by the equation (3).
F3 = Ra (CC) / Ra (CL)
In this case, F3 may be 1.10 or more.

F3 is an index related to the metallic feeling of the plated steel sheet when the plating texture 10S is a hairline. When F3 is less than 1.10, the difference between the impression received from the plating texture 10S (hairline) in the absence of the colored resin layer 11 and the impression of light reflection on the surface of the colored resin layer 11 becomes too large. .. In this case, the metallic feeling is lost. When the plating texture 10S is a hairline, if F3 is 1.10 or more, the impression received from the plating texture 10S (hairline) in the absence of the colored resin layer 11 and the reflection of light on the surface of the colored resin layer 11 It is possible to suppress the deviation from the impression of. Therefore, a sufficient metallic feeling can be obtained. The preferred lower limit of F3 is 1.15, more preferably 1.20, and even more preferably 1.25.

The surface roughness Ra (CL) is measured by the arithmetic mean roughness measuring method specified in JIS B 0601 (2013). Specifically, on the surface 11S of the colored resin layer 11, any 10 points are set as measurement points. The arithmetic mean roughness Ra is measured at each measurement point with an evaluation length extending in the first direction RD of the plating texture 10S. The evaluation length is 5 times the reference length (cutoff wavelength). The arithmetic average roughness Ra is measured using a stylus type roughness meter, and the measurement speed is 0.5 mm / sec. Of the 10 arithmetic mean roughness Ras obtained, the largest arithmetic mean roughness Ra, the second largest arithmetic mean roughness Ra, the smallest arithmetic mean roughness Ra, and the second smallest arithmetic mean roughness Ra. The arithmetic mean value of the six arithmetic mean roughness Ra excluding the above is defined as the surface roughness Ra (CL).

Similarly, the surface roughness Ra (CC) is measured by the arithmetic mean roughness measuring method specified in JIS B 0601 (2013). Specifically, on the surface 11S of the colored resin layer 11, any 10 points are set as measurement points. At each measurement point, the arithmetic mean roughness Ra is measured by the evaluation length extending in the second direction WD of the plating texture 10S. The evaluation length is 5 times the reference length (cutoff wavelength). The arithmetic average roughness Ra is measured using a stylus type roughness meter, and the measurement speed is 0.5 mm / sec. Of the 10 arithmetic mean roughness Ras obtained, the largest arithmetic mean roughness Ra, the second largest arithmetic mean roughness Ra, the smallest arithmetic mean roughness Ra, and the second smallest arithmetic mean roughness Ra. The arithmetic mean value of the six arithmetic mean roughness Ra excluding the above is defined as the surface roughness Ra (CC).

[About the surface shape of the galvanized layer 10 when the plating texture 10S is a hairline (requirement (F))]
Similar to the requirement (E), the requirement (F) is also a requirement when the plating texture 10S is a hairline. The surface roughness Ra of the surface of the galvanized layer 10 on which the plating texture 10S is formed in the second direction WD is defined as Ra (MC). When the plating texture 10S is a hairline, the surface roughness Ra (MC) may be 0.30 μm or more. When the surface roughness Ra (MC) is 0.30 μm or more, a sufficient metallic feeling can be obtained when the plating texture 10S is viewed from above the colored resin layer 11. The preferable lower limit of the surface roughness Ra (MC) is 0.35 μm, and more preferably 0.40 μm. The upper limit of the surface roughness Ra (MC) is not particularly limited. However, it may be difficult for industrial production to excessively increase the surface roughness Ra (MC). Therefore, the upper limit of the surface roughness Ra (MC) is, for example, 2.00 μm. The upper limit of the surface roughness Ra (MC) may be, for example, 1.00 μm.

The surface roughness Ra (MC) is measured by the arithmetic mean roughness measuring method specified in JIS B 0601 (2013). Specifically, the colored resin layer 11 of the plated steel sheet 1 is removed with a solvent that does not attack the galvanized layer 10 or a release agent such as a remover (for example, trade name: Neo River S-701 manufactured by Sansai Kako Co., Ltd.). .. In the plating texture 10S of the zinc plating layer 10 after the colored resin layer 11 is removed, any 10 points are set as measurement points. At each measurement point, the arithmetic mean roughness Ra is measured by the evaluation length extending in the second direction WD. The evaluation length is 5 times the reference length (cutoff wavelength). The arithmetic average roughness Ra is measured using a stylus type roughness meter, and the measurement speed is 0.5 mm / sec. Of the 10 arithmetic mean roughness Ras obtained, the largest arithmetic mean roughness Ra, the second largest arithmetic mean roughness Ra, the smallest arithmetic mean roughness Ra, and the second smallest arithmetic mean roughness Ra. The arithmetic mean value of the six arithmetic mean roughness Ra excluding the above is defined as the surface roughness Ra (MC).

[About the base iron exposure rate]
Preferably, the base iron exposure rate of the galvanized layer 10 of the plated steel sheet 1 is less than 5%. In the first embodiment, the corrosion resistance is sufficiently ensured by the galvanized layer 10 (galvanized or zinc alloy plated). However, if the surface of the galvanized layer 10 is ground when the plating texture 10S is applied and the base iron is exposed, the corrosion resistance (long-term corrosion resistance) for a long period of time may be lowered due to the influence of galvanic corrosion. Such a decrease in long-term corrosion resistance is often remarkable when the base iron exposure rate is 5% or more. Therefore, in the first embodiment, the preferable base iron exposure rate is less than 5%.

If the base iron exposure rate of the galvanized layer 10 is less than 5%, extremely good corrosion resistance that is excellent in long-term corrosion resistance can be obtained in addition to the appropriate corrosion resistance generally required for steel materials. The upper limit of the exposure rate of the base iron of the galvanized layer 10 is preferably 3% or less, more preferably 2%, further preferably 1%, still more preferably 0%.

The base iron exposure rate is measured by the following method. Specifically, the colored resin layer 11 of the plated steel sheet 1 is removed with a solvent that does not attack the galvanized layer 10 or a release agent such as a remover (for example, trade name: Neo River S-701 manufactured by Sansai Kako Co., Ltd.). .. On the surface of the galvanized layer 10, five arbitrary rectangular regions of 1 mm × 1 mm are selected. An EPMA analysis is performed on the selected rectangular area. By image analysis, a region in which Zn is not detected (Zn undetected region) in each rectangular region is specified. In the first embodiment, a region in which the detection intensity of Zn is 1/16 or less when the standard sample (pure Zn) is measured is recognized as a Zn undetected region. The ratio (area%) of the total area of the Zn undetected region in the five rectangular regions to the total area of the five rectangular regions is defined as the base iron exposure rate (area%).

[About other coatings]
The plated steel sheet 1 of the first embodiment may have an inorganic film or an organic-inorganic composite film formed between the colored resin layer 11 and the zinc-plated layer 10 for the purpose of improving corrosion resistance or adhesion. The inorganic coating is translucent. The inorganic coating is, for example, an amorphous silica coating, a zirconia coating, or a phosphate coating. The organic-inorganic composite film has translucency. The organic-inorganic composite film contains, for example, a silane coupling agent and an organic resin. The organic-inorganic composite film has translucency.

[About texture morphology]
In FIG. 4, a hairline is shown as an example of the texture. However, as mentioned above, the morphology of the texture is not limited to hairlines. The texture may have a plurality of convex portions and a plurality of concave portions. Therefore, the protrusions and recesses may or may not extend in one direction. The texture may be hairline, dull, or other form. The texture may have an uneven pattern.

[Production method]
An example of the manufacturing method of the plated steel sheet 1 of the first embodiment will be described. The manufacturing method described below is an example for manufacturing the plated steel sheet 1 of the first embodiment. Therefore, the plated steel sheet 1 having the above-described configuration may be manufactured by a manufacturing method other than the manufacturing methods described below. However, the manufacturing method described below is a preferable example of the manufacturing method of the plated steel sheet 1 of the first embodiment.

The manufacturing method of the first embodiment includes a preparatory step (S1) for preparing the base metal plate 100, a base material surface texture forming step (S2) for forming the base material texture 100S on the surface of the base material steel plate 100, and a base material. A zinc plating treatment step (S3) for forming the galvanized layer 10 on the steel plate 100, and a zinc plated surface texture forming step (S3) that is an arbitrary step and is performed when the surface of the galvanized layer 10 is further textured. S4) and an arbitrary step, a polishing step (S5) of polishing the peak of the convex portion 10CO of the galvanized layer 10 as needed, and a colored resin layer 11 forming a colored resin layer 11 on the galvanized layer 10. The forming step (S6) is included. Hereinafter, each step will be described.

[Preparation step (S1)]
In the preparation step (S1), the base steel sheet 100 is prepared. The base steel plate 100 may be a steel plate or may have another shape. When the base steel plate 100 is a steel plate, the base steel plate 100 may be a hot-rolled steel plate or a cold-rolled steel plate.

[Base material surface texture forming step (S2)]
In the base material surface texture forming step (S2), the base material texture 100S is formed on the surface of the base material. At this time, the plated steel sheet has the configuration shown in FIG. In the base material surface texture forming step (S2), the base material texture 100S is formed on the surface of the base material steel plate 100 by performing a well-known texture processing on the surface of the base material steel plate 100. When the base material texture 100S is a hairline, a well-known hairline process is performed. The hairline processing method includes, for example, a method of polishing the surface with a well-known polishing belt to form a hairline, a method of polishing the surface with a well-known abrasive grain brush to form a hairline, and a method of rolling and transferring with a roll having a hairline shape. There is a method of forming a hairline and the like. The length, depth, and frequency of the hairline can be adjusted by adjusting the particle size of the well-known polishing belt, the particle size of the well-known abrasive grain brush, and the surface shape of the roll.

[Zinc plating process (S3)]
In the galvanizing treatment step (S3), the prepared base steel sheet 100 is subjected to galvanizing treatment to form the galvanized layer 10 on the surface of the base steel sheet 100.

The zinc plating treatment may be carried out by a well-known method. For example, the galvanized layer 10 is formed using a well-known electroplating method. In this case, it is sufficient to use a well-known bath for the electric zinc plating bath and the electric zinc alloy plating bath. The electroplating bath is, for example, a sulfuric acid bath, a chloride bath, a zincate bath, a cyanide bath, a pyrophosphate bath, a boric acid bath, a citric acid bath, another complex bath, or a combination thereof. In addition to Zn ions, the electrozinc alloy plating bath contains, for example, one or more monatomic ions or complex ions selected from Co, Cr, Cu, Fe, Ni, P, Sn, Mn, Mo, V, W, and Zr. contains.

The chemical composition, temperature, flow velocity, and conditions (current density, energization pattern, etc.) of the electrogalvanizing bath and the electrogalvanizing alloy plating bath in the electrogalvanizing treatment can be appropriately adjusted. The thickness of the zinc plating layer 10 in the electrogalvanizing treatment can be adjusted by adjusting the current value and the time within the range of the current density in the electrogalvanizing treatment.

A base material texture 100S is formed on the base material steel plate 100. Therefore, if the base material steel plate 100 is subjected to a zinc plating treatment to form the zinc plating layer 10, a plating texture 10S along the base material texture 100S is formed on the surface of the zinc plating layer 10. Through the above manufacturing process, a plated steel sheet including the base steel sheet 100 on which the base material texture 100S is formed and the galvanized layer 10 on which the plating texture 10S is formed is manufactured.

[About the galvanized surface texture forming step (S4) and polishing step (S5)]
The galvanized surface texture forming step (S4) and the polishing step (S5) are both arbitrary steps. That is, it is not necessary to carry out the galvanizing surface texture forming step (S4) and the polishing step (S5). It is not necessary to carry out the galvanizing surface texture forming step (S4) and not to carry out the polishing step (S5). The polishing step (S5) may be carried out without carrying out the galvanizing surface texture forming step (S4). The galvanized surface texture forming step (S4) and the polishing step (S5) may be carried out. When the galvanizing surface texture forming step (S4) and the polishing step (S5) are carried out, either of them may be carried out first. Both the galvanizing surface texture forming step (S4) and the polishing step (S5) are steps of scraping the peak of the convex portion 10CO of the plating texture 10S of the galvanizing layer 10. Hereinafter, each step will be described.

[Galvanized surface texture forming step (S4)]
The galvanized surface texture forming step (S4) is an arbitrary step. That is, the galvanized surface texture forming step (S4) may or may not be carried out. When this is carried out, in the galvanizing surface texture forming step (S4), of the plating texture 10S on the surface of the galvanizing layer 10 shown in FIG. 7, the peak of the convex portion 10CO is shaved to form a trapezoid as shown in FIG. The three-dimensional average roughness Sah at the top of the convex portion is set to more than 5 nm and 200 nm or less. Specifically, in the galvanized surface texture forming step (S4), the surface of the galvanized layer 10 (plating texture 10S) of the plated steel sheet is subjected to a well-known texture processing to obtain the top of the convex portion of the plated texture 10S. The three-dimensional average roughness Sah is set to more than 5 nm and 200 nm or less. At this time, the recesses of the plating texture 10S are hardly scraped. Therefore, the concave bottom three-dimensional average roughness Sas is maintained at more than 200 nm and 2000 nm or less.

When the plating texture 10S is a hairline, a well-known hairline process is performed. The hairline processing method includes, for example, a method of polishing the surface with a well-known polishing belt to form a hairline, a method of polishing the surface with a well-known abrasive grain brush to form a hairline, and a method of rolling and transferring with a roll having a hairline shape. There is a method of forming a hairline and the like. The degree of grinding of the peak of the convex portion 10CO of the plating texture 10S on the surface of the galvanized layer 10 can be adjusted by adjusting the particle size of the well-known polishing belt, the particle size of the well-known abrasive grain brush, and the surface shape of the roll. is there. That is, by adjusting the particle size of the well-known polishing belt, the particle size of the well-known abrasive grain brush, and the surface shape of the roll, the concave bottom three-dimensional average roughness Sas is maintained at more than 200 nm and 2000 nm or less, and the convex portion top is tertiary. The original average roughness Sah can be adjusted to more than 5 nm and 200 nm or less. When the hairline processing is performed in the galvanized surface texture forming step (S4), the concave bottom three-dimensional average roughness Sa is maintained at more than 200 nm and 2000 nm or less, and the convex top three-dimensional average roughness Sah is more than 5 nm and 200 nm. In addition to the following adjustments, a new hairline can be added to the plating texture 10S. The base iron exposure rate can also be adjusted by adjusting the particle size of the well-known polishing belt in the galvanizing surface texture forming step (S4), the particle size of the well-known abrasive grain brush, and the surface shape of the roll.

[Polishing step (S5)]
The polishing step (S5) is an arbitrary step. That is, the polishing step (S5) does not have to be performed. In the polishing step (S5), of the plating texture 10S on the surface of the galvanized layer 10 shown in FIG. 7, the peak of the convex portion 10CO is polished to form a trapezoidal shape as shown in FIG. The top three-dimensional average roughness Sah is set to more than 5 nm and 200 nm or less. By this polishing treatment, the three-dimensional average roughness Sah at the bottom of the concave portion is maintained at more than 200 nm and 2000 nm or less, and the three-dimensional average roughness Sah at the top of the convex portion is adjusted to more than 5 nm and 200 nm or less. The polishing treatment includes, for example, a method of polishing the surface with a well-known polishing belt, a method of polishing the surface with a well-known abrasive grain brush, and the like. The shape of the convex portion 10CO and the surface roughness of the convex portion 10CO can be adjusted by adjusting the particle size of the well-known polishing belt and the particle size of the well-known abrasive grain brush. That is, the three-dimensional average roughness Sah on the top of the convex portion can be adjusted by adjusting the particle size of the well-known polishing belt and the particle size of the well-known abrasive grain brush. The polishing step (S5) has a smaller grinding amount (polishing amount) than the galvanized surface texture forming step (S4). The base iron exposure rate can also be adjusted by adjusting the particle size of the well-known polishing belt in the polishing step (S5) and the particle size of the well-known abrasive grain brush.

The polishing step (S5) may be performed at the same time as the above-mentioned galvanized surface texture forming step (S4). Production efficiency can be improved by performing at the same time.

[Colored resin layer forming step (S6)]
In the colored resin layer forming step (S6), the colored resin layer 11 is formed on the zinc plating layer 10 of the plated steel sheet on which the plating texture 10S is formed. Hereinafter, the colored resin layer forming step (S6) will be described in detail.

It is preferable that the paint used for forming the colored resin layer 11 follows the surface shape of the steel material at the moment when it is applied to the plated steel sheet, and the leveling once reflecting the surface shape of the steel material is slow. That is, when the shear rate is high, the viscosity is low, and when the shear rate is low, the viscosity is high. Specifically, when the shear rate is 0.1 [1 / sec], the viscosity is 10 [Pa · s] or more, and when the shear rate is 1000 [1 / sec], 0.01 [ It is preferable to have a shear viscosity of [Pa · s] or less.

The shear viscosity of the paint can be adjusted by the following method. When the paint is a water-based emulsion paint, it can be adjusted by adding a well-known hydrogen-bonding viscosity modifier. Such hydrogen-bonding viscosity modifiers bind each other by hydrogen bonds at low shear rates. Therefore, the viscosity of the paint can be increased. On the other hand, hydrogen bonds are broken at high shear rates. Therefore, the viscosity of the paint decreases.

By adjusting the shear viscosity of the paint used to form the colored resin layer 11, the surface shape of the colored resin layer 11 can be adjusted.

The method of forming the colored resin layer 11 on the galvanized layer 10 may be a well-known method. For example, the viscosity-adjusted paint is applied onto the galvanized layer 10 by a spraying method, a roll coater method, a curtain coater method, or a dipping pulling method. Then, the paint on the galvanized layer 10 is naturally dried or baked to form the colored resin layer 11. The drying temperature, drying time, seizure temperature, and seizure time can be adjusted as appropriate. By adjusting the shear viscosity of the paint used to form the colored resin layer 11 and the amount of coating on the galvanized layer 10, the three-dimensional average roughness Save, the minimum thickness DKmin of the colored resin layer 11, and the maximum thickness DKmax Can be adjusted. Further, the colorant content CK in the colored resin layer 11 can be adjusted by adjusting the content of the colorant in the paint.

The plated steel sheet 1 of the first embodiment can be manufactured by the above manufacturing process. The plated steel sheet 1 of the first embodiment is not limited to the above manufacturing method, and if the plated steel sheet 1 having the above configuration can be manufactured, the plated steel sheet 1 of the first embodiment can be manufactured by a manufacturing method other than the above manufacturing method. May be manufactured. However, the above manufacturing method is suitable for manufacturing the plated steel sheet 1 of the first embodiment.

(Second Embodiment)
In the plated steel sheet according to the first embodiment, it was attempted to improve both the adhesion of the colored resin layer and the visibility of the surface texture of the galvanized layer. However, depending on the use of the plated steel sheet, texture visibility may be prioritized over adhesion of the colored resin layer. The present inventors have studied a plated steel sheet having a colored appearance but having a higher visibility of the texture of the surface of the galvanized layer. As described in Patent Documents 1 and 2, a galvanized steel sheet in which a transparent resin layer is formed on a galvanized layer has already been proposed. Therefore, the present inventors first attempted to produce a galvanized steel sheet in which a resin layer formed on the galvanized layer was colored by containing a colorant.

As a result, it was found that when the resin layer contains a colorant, the texture formed on the surface of the galvanized layer may not be visible depending on the conditions. Therefore, the present inventors have investigated and investigated factors that affect the visual recognition of the texture when the resin contains a colorant. As a result, the present inventors obtained the following findings.

When a colored resin layer containing a colorant is formed on a zinc-plated layer having a texture formed on the surface, the content of the colorant in the colored resin layer and the thickness of the colored resin layer affect the visibility of the texture. give. Specifically, if the content of the colorant in the colored resin layer is too large, the texture cannot be visually recognized. Further, if the colored resin layer is too thick, the texture cannot be visually recognized.

Furthermore, the shape of the texture also affects the visibility of the texture. When a texture is formed on the surface of the galvanized layer, not only the unevenness of the texture but also the fine unevenness due to the galvanized crystals is present on the surface of the texture. If the fine irregularities caused by the galvanized crystals are large, the light is diffusely reflected by the fine irregularities caused by the galvanized crystals. In this case, the gloss of the texture is reduced and the texture is whitened. Therefore, when the colored resin layer is formed on the galvanized layer, the texture becomes difficult to see. Therefore, from the viewpoint of further improving the visibility of the texture, it is better to suppress the roughness (micro unevenness) in the microscopic region at the peak (convex part) or bottom (concave part) of the texture extending in one direction. Is preferable.

Furthermore, in the cross section perpendicular to the extending direction of the texture, the thickness of the resin formed on the texture varies depending on the unevenness of the texture. FIG. 9 is a schematic view of a cross section perpendicular to the extending direction of the texture in the plated steel sheet of the present embodiment. With reference to FIG. 9, the plated steel sheet includes a galvanized layer 10'and a colored resin layer 11'. A texture 10S'is formed on the surface of the galvanized layer 10'. The texture 10S'includes a convex portion 10CO'(Convex) and a concave portion 10RE'(Recess).

The colored resin layer 11'is formed on the surface of the galvanized layer 10'. Therefore, although the unevenness of the texture 10S'is reflected to some extent on the surface 11S'of the colored resin layer 11', it is flatter than the texture 10S'. Specifically, the convex portion 11CO'is formed on the portion of the surface 11S'of the colored resin layer 11' that corresponds to the convex portion 10CO'of the texture 10S'. The height of the convex portion 11CO'is lower than the height of the convex portion 10CO'. That is, the surface 11S'of the colored resin layer 11'is flatter than the surface of the texture 10S'.

Here, the maximum thickness (μm) of the colored resin layer 11'is defined as DKmax'in the range of 100 μm length in the direction perpendicular to the extending direction of the texture 10S'. Further, the minimum thickness (μm) of the colored resin layer 11'is defined as DKmin'. In order to make the texture 10S'visible even when it is colored by the colored resin layer 11', as described above, the content of the colorant in the colored resin layer 11'and the thickness of the colored resin layer 11' Limit the plastic to some extent. Then, under the restricted conditions, the difference between the maximum thickness DKmax'and the minimum thickness DKmin'of the colored resin layer 11'is reflected in the difference in brightness. Specifically, by increasing the difference between the maximum thickness DKmax'and the minimum thickness DKmin' of the colored resin layer 11'to some extent, a difference in brightness is generated between the concave portion 10RE'and the convex portion 10CO'of the texture 10S'. .. As a result, the texture 10S'can be visually recognized even when the colored resin layer 11'is formed.

Based on the above findings, the present inventors adjusted the roughness of the convex portion 10CO'and the concave portion 10RE'of the (A') texture 10S' in a minute region, and adjusted the roughness of the (B') colored resin layer 11'. By adjusting the thickness and the colorant content, the difference between the maximum thickness DKmax'and the minimum thickness DKmin' of the colored resin layer 11'in the cross section orthogonal to the extending direction of the (C') texture 10S' is set to some extent. It was found that the galvanized steel sheet can be made into a galvanized steel sheet in which the surface texture of the galvanized layer can be visually recognized while having a colored appearance.

The plated steel sheet of the second embodiment completed based on the above findings has the following configuration.

The plated steel sheet of [11] is
Base steel plate and
The galvanized layer formed on the surface of the base steel sheet and
A colored resin layer formed on the galvanized layer is provided.
The galvanized layer has a texture extending in one direction on its surface.
The colored resin layer contains a colorant and
All of the following (A') to (C') are satisfied.
(A') A roughness profile in a length range of 1000 μm in a direction perpendicular to the extending direction of the texture is measured, and 10 points are specified in ascending order of height among the measured positions on the roughness profile. The determined position is defined as the concave bottom point, and among the measured positions on the roughness profile, the position where 10 points are specified in descending order of height is defined as the convex apex, and each concave bottom point and each convex apex are defined. When the three-dimensional average roughness Sa'of a minute region of 1 μm × 1 μm centered on the above is measured and the arithmetic average value of the measured three-dimensional average roughness Sa'is defined as the three-dimensional average roughness Saave', it is cubic. The original average roughness Save'is more than 5 nm and 200 nm or less.
(B') The minimum thickness (μm) of the colored resin layer is defined as DKmin'in the range of 100 μm length in the direction orthogonal to the extending direction of the texture, and the colorant in the colored resin layer. When the content (area%) is defined as CK', the formula (1') is satisfied.
DKmin'× CK'≤15.0 (1')
(C') The formula (2') is satisfied when the maximum thickness (μm) of the colored resin layer is defined as DKmax'in the range of 100 μm in the direction perpendicular to the extending direction of the texture.
(DKmax'-DKmin') x CK'> 1.0 (2')

The plated steel sheet of [12] is
The plated steel sheet according to [11].
The texture may be a hairline
The following (D') and (E') may be satisfied.
(D') The surface roughness Ra of the colored resin layer in the extending direction of the texture is defined as Ra (CL)', and the surface roughness Ra of the colored resin layer in the direction perpendicular to the extending direction of the texture is defined. Is defined as Ra (CC)', the equation (3') is satisfied.
Ra (CC)'≧ Ra (CL)' × 1.10 (3')
(E') When the surface roughness of the galvanized layer in the direction orthogonal to the extending direction of the texture is defined as Ra (MC)', Ra (MC)'is 0.30 μm or more.

The plated steel sheet of [13] is
The plated steel sheet according to [11] or [12].
The base iron exposure rate of the galvanized layer may be less than 5%.

Hereinafter, the plated steel sheet of the second embodiment will be described in detail.

[About galvanized steel sheet 1']
FIG. 10 is a cross-sectional view of the plated steel sheet 1'of the second embodiment. In FIG. 10, the direction perpendicular to the paper surface is defined as the extending direction of the texture 10S'(that is, the rolling direction of the plated steel sheet 1') RD'. The thickness direction of the plated steel sheet 1'is defined as the thickness direction TD'. Of the plated steel sheets 1', the direction perpendicular to the texture extending direction RD'and the thickness direction TD' is defined as the width direction WD'. In addition, RD', TD', and WD'by this definition are substantially the same concept as RD, TD, and WD in the first embodiment.

With reference to FIG. 10, the plated steel sheet 1'of the second embodiment includes a base steel sheet 100', a galvanized layer 10', and a colored resin layer 11'. The galvanized layer 10'is formed on the surface of the base steel sheet 100'. The colored resin layer 11'is formed on the surface (texture) 10S' of the galvanized layer 10'. The galvanized layer 10'is arranged between the base steel plate 100'and the colored resin layer 11'. Hereinafter, the base steel plate 100', the galvanized layer 10', and the colored resin layer 11' will be described.

[About base steel sheet 100']
The base steel sheet 100'is a plated steel sheet (electrogalvanized steel sheet, electrogalvanized steel sheet, hot-dip galvanized steel sheet, etc.) according to each mechanical property (for example, tensile strength, workability, etc.) required for the plated steel sheet to be manufactured. , Known steel sheets applied to alloyed hot-dip galvanized steel sheets, etc.) may be used. For example, as the base steel plate 100', a steel plate for electrical equipment may be used, or a steel plate for automobile outer panels may be used. The base steel plate 100'may be a hot-rolled steel plate or a cold-rolled steel plate.

[About galvanized layer 10']
The galvanized layer 10'is formed on the surface of the base steel sheet 100'. In the second embodiment, the galvanized layer 10'is arranged between the base steel plate 100'and the colored resin layer 11'. The galvanized layer 10'is formed by a well-known galvanized method. Specifically, the zinc plating layer 10'is formed by, for example, either an electroplating method or a hot-dip plating method. In the present specification, the zinc plating layer 10'also includes a zinc alloy plating layer. More specifically, the zinc plating layer 10'is a concept including an electrogalvanizing layer, an electrogalvanizing alloy plating layer, a hot-dip galvanizing layer, and an alloyed hot-dip galvanizing layer.

It suffices that the galvanized layer 10'in the second embodiment has a well-known chemical composition. For example, the Zn content in the chemical composition of the galvanized layer 10'may be 65% or more in mass%. When the Zn content is 65% or more in mass%, the sacrificial anticorrosion function is remarkably exhibited, and the corrosion resistance of the plated steel sheet 1'is remarkably enhanced. The preferable lower limit of the Zn content in the chemical composition of the galvanized layer 10'is 70%, more preferably 80%.

The chemical composition of the galvanized layer 10'is one element selected from the element group consisting of Al, Co, Cr, Cu, Fe, Ni, P, Si, Sn, Mg, Mn, Mo, V, W and Zr. It preferably contains two or more elements and Zn. When the zinc plating layer 10'is an electrogalvanizing layer, the chemical composition of the zinc plating layer 10'is 5 to at least one element selected from the element group consisting of Fe, Ni, and Co in total. It is more preferably contained in an amount of 20% by mass, and the balance is made of Zn and impurities. When the zinc-plated layer 10'is a hot-dip galvanized layer, the chemical composition of the zinc-plated layer 10'is a total of 5 to 20 masses of at least one element selected from the element group consisting of Mg, Al, and Si. It is more preferable that the content is% and the balance is composed of Zn and impurities. In these cases, the galvanized layer 10'also exhibits excellent corrosion resistance.

The galvanized layer 10'may contain impurities. Here, the impurities are those that are mixed in the raw material or are mixed in the manufacturing process. Impurities are, for example, Ti, B, S, N, C, Nb, Pb, Cd, Ca, Pb, Y, La, Ce, Sr, Sb, O, F, Cl, Zr, Ag, W, H and the like. .. In the chemical composition of the galvanized layer 10', the total content of impurities is preferably 1% or less.

The chemical composition of the galvanized layer 10'can be measured by, for example, the following method. The colored resin layer 11'of the plated steel sheet 1'is removed with a solvent that does not attack the galvanized layer 10'or a release agent such as a remover (for example, trade name: Neo River S-701 manufactured by Sansai Kako Co., Ltd.). Then, the galvanized layer 10'is dissolved using hydrochloric acid containing an inhibitor. The lysate is subjected to ICP analysis using an ICP (Inductively Coupled Plasma) emission spectroscopic analyzer to determine the Zn content. If the obtained Zn content is 65% or more, it is determined that the plating layer to be measured is the zinc plating layer 10'.

[Adhesion amount of galvanized layer 10']
The amount of adhesion of the galvanized layer 10'is not particularly limited, and a well-known amount of adhesion is sufficient. The preferable adhesion amount of the galvanized layer 10'is 5.0 to 120.0 g / m ² . When the adhesion amount of the galvanized layer 10'is 5.0 g / m ² or more, it is possible to suppress the exposure of the base iron (base steel plate 100') when the texture described later is applied to the galvanized layer 10'. .. A more preferable lower limit of the adhesion amount of the galvanized layer 10'is 7.0 g / m ² , and even more preferably 10.0 g / m ² . The upper limit of the amount of adhesion of the galvanized layer 10'is not particularly limited. From the viewpoint of economy, in the case of the galvanized layer 10'by the electroplating method, the upper limit of the preferable adhesion amount is 40.0 gm ² , the more preferable upper limit is 35.0 g / m ² , and more preferably 30. It is 0 g / m ² .

[About colored resin layer 11']
The colored resin layer 11'is formed on the surface (texture) 10S' of the galvanized layer 10'. FIG. 11 is an enlarged view of the colored resin layer 11'shown in FIG. With reference to FIG. 11, the colored resin layer 11'includes a resin 31' and a colorant 32'. The colorant 32'is contained in the resin 31'. Hereinafter, the resin 31'and the colorant 32' will be described.

[About resin 31']
Resin 31'is a translucent resin. In the second embodiment, the "translucent resin" includes a colored resin layer 11'containing a colorant 32'and a resin 31'in an environment equivalent to sunlight (illuminance of about 65,000 lux) in fine morning. It means that the texture 10S'of the galvanized layer 10'can be visually recognized when the plated steel sheet 1'is placed. The resin 31'functions as a binder for fixing the colorant 32'.

The resin 31'is not particularly limited as long as it is a resin having the above-defined translucency, and a well-known natural resin or a well-known synthetic resin can be used. The resin 31'in the second embodiment is, for example, an epoxy resin, a urethane resin, a polyester resin, a phenol resin, a polyether sulfone resin, a melamine alkyd resin, an acrylic resin, a polyamide resin, or a polyimide resin. , Silicone resin, polyvinyl acetate resin, polyolefin resin, polystyrene resin, vinyl chloride resin, vinyl acetate resin, one or more selected from the group.

[About colorant 32']
The colorant 32'is contained in the above-mentioned resin 31'to color the colored resin layer 11'. The colorant 32'in the second embodiment is well known and widely includes inorganic pigments, organic pigments, dyes and the like used for coloring the resin layer formed on the surface of the steel sheet. The colorant 32'is a chromatic colorant. A chromatic color means a color having the attributes of hue, lightness, and saturation. The colorant 32'consist of, for example, one or more selected from the group consisting of inorganic pigments, organic pigments, and dyes. From the viewpoint of durability against ultraviolet rays, the colorant 32'is more preferably a pigment type (inorganic pigment and / or organic pigment).

When the colorant 32'is an inorganic pigment, the colorant 32'is, for example, a neutralized precipitate pigment (sulfate, carbonate, etc.) and / or a fired pigment (metal sulfide, metal oxide, polyvalent metal composite). Oxides, etc.). When the colorant 32'is an organic pigment, the colorant 32'is, for example, a chlorine pigment, an azo pigment (dissolved azo lake pigment, insoluble azo pigment, etc.), an acid condensing pigment, a polycyclic pigment (phthalocyanine pigment, indigo). One or more selected from the group consisting of type pigments, quinacridone type pigments, anthraquinone type pigments, etc.) and metal complex pigments (azochelate pigments, transition metal complex pigments, etc.). When the colorant 32'is a dye, the colorant 32'is, for example, one or more selected from the group consisting of azo dyes, indigo dyes, anthraquinone dyes, sulfide dyes, and carbonium dyes.

The color of the colorant 32'is not particularly limited. The colorant 32'is, for example, the black color of carbon black (C') or iron black (Fe ₃ O ₄ ). However, the colorant 32'is not limited to black, but is a colorant 32'of another color (white, purple-red, yellow, green-blue, red, orange, yellow, green, blue, indigo, purple, etc.). You may.

When the colorant 32'is a pigment, the particle size is not particularly limited. When the colorant 32'is a pigment, the maximum value of the primary particle size is, for example, 3 nm to 1000 nm.

[About the texture 10S'formed on the surface of the galvanized layer 10']
A texture 10S'is formed on the surface of the galvanized layer 10'of the plated steel sheet 1'. That is, the galvanized layer 10'of the plated steel sheet 1'has a texture 10S' on its surface. The texture 10S'extends in one direction. In the second embodiment, the "texture" means an uneven pattern formed on the surface of the galvanized layer 10'by a physical or chemical method. A preferred texture is a hairline. The hairline is a linear uneven pattern extending in one direction.

[When texture 10S'is a hairline]
FIG. 12 is a plan view of the galvanized layer 10'with a hairline formed as a texture 10S' on the surface. With reference to FIG. 12, the hairline 10S'is a linear uneven pattern formed on the surface of the galvanized layer 10'. The extending direction RD'of the hairline 10S'is the same direction. The same direction here means the direction WD perpendicular to the extending direction RD'of the hairline 10S' when the zinc-plated layer 10'is viewed in the thickness direction TD' (that is, in a plan view as shown in FIG. 12). It means that 90% or more of the angles formed by adjacent hairlines arranged in'is less than ± 5 °.

[Requirements (A') to (C')]
The plated steel sheet 1'of the second embodiment having the above-described configuration further satisfies all of the following (A') to (C').
Requirement (A'):
Measure the roughness profile in the range of 1000 μm in the direction WD'orthogonal to the extending direction RD'of the texture 10S', and identify 10 points in ascending order of height among the positions on the measured roughness profile. The determined position is defined as the bottom point of the recess, and among the positions on the measured roughness profile, the position where 10 points are specified in descending order of height is defined as the apex of the convex portion. The three-dimensional average roughness Sa'of a minute region of 1 μm × 1 μm centered on the bottom point of each concave portion and the apex of each convex portion is measured. The arithmetic mean value of the measured three-dimensional average roughness Sa'is defined as the three-dimensional average roughness Sa'. At this time, the three-dimensional average roughness Save'is more than 5 nm and 200 nm or less.
Requirement (B'):
The minimum thickness (μm) of the colored resin layer 11'is defined as DKmin'in the range of 100 μm length in the direction WD'orthogonal to the extending direction RD' of the texture 10S'. Further, the content (area%) of the colorant 32'in the colored resin layer 11'is defined as CK'. At this time, the minimum thickness DKmin'of the colored resin layer 11'and the content CK'of the colorant 32' satisfy the formula (1').
DKmin'× CK'≤15.0 (1')
Requirement (C'):
The maximum thickness (μm) of the colored resin layer 11'is defined as DKmax'in the range of 100 μm length in the direction WD'orthogonal to the extending direction RD' of the texture 10S'. At this time, the maximum thickness DKmax'of the colored resin layer 11', the minimum thickness DKmin' of the colored resin layer 11', and the content CK'of the colorant 32' satisfy the formula (2').
(DKmax'-DKmin') x CK'> 1.0 (2')
Each requirement will be described in detail below.

[About requirements (A')]
FIG. 13 is a diagram showing a roughness profile of the texture 10S'formed on the surface of the galvanized layer 10'. With reference to FIG. 13, an arbitrary 1000 μm length range of the direction WD'orthogonal to the extending direction RD' of the texture 10S'is selected. The roughness profile of the texture 10S'is measured in the selected 1000 μm length range. It is assumed that the obtained roughness profile has a shape as shown in FIG.

Among the positions on the measured roughness profile, 10 points with the lowest height are specified in ascending order from the lowest height position. The identified positions are defined as recess bottom points PRE1', PRE2', ..., PRE10' in ascending order of height. Further, among the positions on the measured roughness profile, 10 points having the highest height are specified in order from the highest height position to the highest height position. The identified positions are defined as convex apex PCO1', PCO2', ..., PCO10' in descending order of height.

As shown in FIG. 14A, the surface of the galvanized layer 10'is viewed in a plan view, and a 1 μm × 1 μm minute recess region 200'centered on each defined recess bottom point PREk' (k is 1 to 10) is specified. To do. In FIG. 14A, the vertical direction of the minute concave region 200'is parallel to the extending direction RD'of the texture 10S', and the horizontal direction of the minute concave region 200'is parallel to the width direction WD'. However, if the micro-concave region 200'is a surface including the extending direction RD'and the width direction WD', each side of the micro-concave region 200'is not parallel to the extending direction RD'or the width direction WD'. You may.

Similarly, as shown in FIG. 14B, when the surface of the galvanized layer 10'is viewed in a plan view, a 1 μm × 1 μm microconvex region centered on each defined convex vertex PCok'(k is 1 to 10). Identify 300'. In FIG. 14B, the vertical direction of the micro-convex region 300'is parallel to the extending direction RD'of the texture 10S', and the horizontal direction of the micro-convex region 300'is parallel to the width direction WD'. However, if the micro-convex region 300'is a surface including the extending direction RD'and the width direction WD', each side of the micro-convex region 300'is parallel to the extending direction RD'or the width direction WD'. It does not have to be.

The three-dimensional average roughness Sa'is measured in the 10 minute concave region 200'and the 10 minute convex region 300' identified by the above method. The three-dimensional average roughness Sa'is the arithmetic mean height defined by ISO 25178, which is an extension of Ra (arithmetic mean height of lines) defined by JIS B 0601 (2013) to a surface. The arithmetic mean value of the measured 20 three-dimensional average roughness Sa'is defined as the three-dimensional average roughness Sa'. At this time, the arithmetic average roughness Save'is more than 5 nm and 200 nm or less.

There are nanometer-level minute irregularities (hereinafter referred to as minute irregularities) caused by galvanized crystals in the portion of the texture 10S'near the apex of the convex portion or the portion near the bottom point of the concave portion. When the minute unevenness has a certain size, the light is diffusely reflected by the minute unevenness. In this case, the gloss of the texture is reduced and the texture is whitened. Therefore, when the colored resin layer is formed on the galvanized layer, the texture becomes difficult to see. Therefore, from the viewpoint of further improving the visibility of the texture, it is preferable that the minute irregularities in the minute regions 200'and 300'are as small as possible.

In the second embodiment, the three-dimensional average roughness Save'based on the above definition is more than 5 nm and 200 nm or less. When the three-dimensional average roughness Save'is 200 nm or less, diffused reflection of light in the vicinity of the apex of the convex portion and the vicinity of the bottom point of the concave portion can be further suppressed. In this case, in the plated steel sheet 1'of the second embodiment having the colored resin layer 11', the texture 10S'is more easily visible. The smaller the three-dimensional average roughness Save', the more preferable it is. However, it is extremely difficult to set the three-dimensional average roughness Save'to 5 nm or less. Therefore, in the second embodiment, the three-dimensional average roughness Save'is more than 5 nm and 200 nm or less. The preferred upper limit of the three-dimensional average roughness Save'is 190 nm, more preferably 180 nm, and even more preferably 170 nm.

[About requirements (B')]
With reference to FIG. 9, attention is paid to a cross section in an arbitrary 100 μm length range in the direction WD'orthogonal to the extending direction RD' of the texture 10S'. This cross section in the 100 μm length range (FIG. 9) is defined as an observation cross section. In the observation cross section, the minimum thickness of the colored resin layer 11'is defined as DKmin'(μ). In the observation cross section, the maximum thickness of the colored resin layer 11'is defined as DKmax'(μm).

Further, in the observation cross section, the content (area%) of the colorant in the colored resin layer 11'is defined as CK'. As described above, in the present specification, the colorant content CK'is indicated by the area ratio (area%) of the colorant in the observed cross section.

As described above, when the minimum thickness DKmin'(μm), the maximum thickness DKmax'(μm), and the colorant content CK'(area%) of the colored resin layer 11'are defined, the minimum thickness of the colored resin layer 11' is defined. The thickness DKmin'and the content CK'of the colorant 32' satisfy the formula (1').
DKmin'× CK'≤15.0 (1')

If the formula (1') is not satisfied, that is, if the product of the minimum thickness DKmin'and the colorant content CK' exceeds 15.0, the thickness of the colored resin layer 11'is too thick or colored. The agent content CK'is too high. In this case, the colored resin layer 11'is too darkly colored, and the texture 10S'of the galvanized layer 10'is difficult to see. If the product of the minimum thickness DKmin'and the colorant content CK' is 15.0 or less, the color is colored by the colored resin layer 11'on the condition that the requirements (A') and the requirement (C') are satisfied. Despite its appearance, the surface texture 10S'of the galvanized layer 10'can be sufficiently visually recognized. The preferred upper limit of DKmin'x CK' is 14.0, more preferably 13.0, still more preferably 12.0. The lower limit of DKmin'x CK' is not particularly limited. The lower limit of DKmin'x CK' is, for example, 4.0.

The thickness of the colored resin layer 11'in the second embodiment is measured by the following method. A sample having a cross section on the surface orthogonal to the extending direction RD'of the texture 10S'is taken. Of the samples, an observation cross section in a length range of 100 μm in the direction WD'orthogonal to the extending direction RD' of the texture 10S' was observed by a scanning electron microscope (SEM) at a magnification of 2000 times with a reflected electron image (BSE). Observe. In the observation with a backscattered electron image (BSE) of a scanning electron microscope (SEM), the base steel plate 100', the galvanized layer 10', and the colored resin layer 11'can be easily distinguished by the contrast. In the observation cross section, the thickness of the colored resin layer 11'is measured at a pitch of 0.5 μm in the direction WD'. Of the measured thicknesses, the smallest thickness is defined as the minimum thickness DKmin'(μm). Of the measured thicknesses, the maximum thickness is defined as the maximum thickness DKmax'(μm). When it is necessary to judge whether or not it is the colored resin layer 11'(that is, whether or not the resin contains a colorant), even if it is judged whether or not it is the colored resin layer 11'by TEM observation described later. Good.

The colorant content CK'(area%) in the colored resin layer 11'is determined by the following method. A sample having a cross section on the surface orthogonal to the extending direction RD'of the texture 10S'is taken. Of the samples, the cross section orthogonal to the extending direction RD'of the texture 10S'is defined as the observation surface. From the sample, a thin film sample in which the colored resin layer 11'and the zinc plating layer 10'on the observation surface can be observed is prepared by using a focused ion beam device (FIB). The thickness of the thin film sample is 50 to 200 nm. Of the observation surfaces of the prepared thin film sample, the length in the direction perpendicular to the thickness direction of the colored resin layer 11'(that is, the direction WD') is 3 μm, and the thickness direction of the colored resin layer 11'. (That is, in the direction TD'), a field having a length including the entire colored resin layer 11'is observed using a transmission electron microscope (TEM: Transmission Electron Microscope). In the TEM observation, the resin 31'in the colored resin layer 11'and the colorant 32' can be distinguished by the contrast. The total area A1'(μm ² ) of the plurality of colorants 32'in the colored resin layer 11'in the above field of view is determined. Further, the area A0'(μm ² ) of the colored resin layer 11'in the field of view is determined. Based on the obtained total area A1'and area A0', the colorant content (area%) in the colored resin layer 11'is determined by the following formula.
CK = A1'/ A0'x100

[About requirements (C')]
The maximum thickness of the colored resin layer 11'in the observation cross section in the 100 μm length range of the direction WD'that is perpendicular to the extending direction RD'of the texture 10S'and is orthogonal to the extending direction RD' of the texture 10S' The DKmax', the minimum thickness DKmin' of the colored resin layer 11', and the content CK'of the colorant 32' satisfy the formula (2').
(DKmax'-DKmin') x CK'> 1.0 (2')

(DKmax'-DKmin') × CK'is an index of the contrast of brightness in the colored resin layer 11'. When (DKmax'-DKmin') × CK'is 1.0 or less, the contrast of brightness in the colored resin layer 11'is low. In this case, the contrast of the brightness of the colored resin layer 11'cannot be fully utilized for visually recognizing the texture 10S'. Therefore, the texture 10S'under the colored resin layer 11'is difficult to see.

If (DKmax'-DKmin') x CK'is higher than 1.0, the contrast of brightness in the colored resin layer 11'is sufficiently high. In this case, the contrast of the brightness of the colored resin layer 11'can be fully utilized for visually recognizing the texture 10S'. As a result, the texture 10S'under the colored resin layer 11'can be sufficiently visually recognized on the premise that the requirement (A') and the requirement (B') are satisfied.

The preferable lower limit of (DKmax'-DKmin') x CK'is 1.2, more preferably 1.5, still more preferably 1.8, and even more preferably 2.0. The upper limit of (DKmax'-DKmin') x CK'is not particularly limited. The upper limit of (DKmax'-DKmin') x CK'is, for example, 15.0.

[Thickness of colored resin layer 11']
In the plated steel sheet 1'of the second embodiment, the average thickness of the colored resin layer 11' is preferably 10.0 μm or less. If the thickness of the colored resin layer 11'exceeds 10.0 μm, smoothing (leveling) is easily performed only by the colored resin layer 11', and the impression of reflection on the surface of the colored resin layer 11'and the visible texture 10S' The divergence from the impression of is large. In this case, the metallic feeling of the plated steel sheet 1'is reduced. If the average thickness of the colored resin layer 11'is 10.0 μm or less, the texture 10S'of the galvanized layer 10'is visually recognized on the premise that all of the above requirements (A') to (C') are satisfied. It is possible, and the metallic feeling is sufficiently enhanced. A more preferable upper limit of the average thickness of the colored resin layer 11'is 9.0 μm, and even more preferably 8.0 μm.

Further, the preferable lower limit of the average thickness of the colored resin layer 11'is 0.5 μm. When the average thickness of the colored resin layer 11'is 0.5 μm or more, the corrosion resistance is further enhanced. A further preferable lower limit of the average thickness of the colored resin layer 11'is 0.7 μm, more preferably 1.0 μm, still more preferably 2.0 μm, still more preferably 3.0 μm.

The average thickness of the colored resin layer 11'is measured by the following method. The arithmetic mean value of the thickness measured at a pitch of 0.5 μm in the direction WD'in the above-mentioned observation cross section is defined as the average thickness (μm) of the colored resin layer 11'.

[About other forms of colored resin layer 11']
The colored resin layer 11'of the plated steel sheet 1'of the second embodiment may further contain an additive in order to impart corrosion resistance, slidability, conductivity and the like to the colored resin layer 11'. Additives for imparting corrosion resistance are, for example, well-known rust inhibitors and inhibitors. Additives for imparting slidability are, for example, well-known waxes and beads. The additive for imparting conductivity is, for example, a well-known conductive agent.

[Preferable surface shape of colored resin layer 11'(requirement (D'))]
Preferably, the colored resin layer 11'has a surface shape as described in detail below due to the type of texture 10S'formed on the surface of the underlying galvanized layer 10'.

The surface roughness Ra of the colored resin layer 11'in the extending direction RD' of the texture 10S'is defined as Ra (CL)'. When the texture 10S'is a hairline, the surface roughness Ra of the colored resin layer 11'in the direction WD' orthogonal to the extending direction RD' of the texture 10S'is defined as Ra (CC)'. At this time, preferably, the surface roughness Ra (CC)'and the surface roughness Ra (CL)' satisfy the formula (3').
Ra (CC)'≧ Ra (CL)' × 1.10 (3')

When the surface roughness Ra (CC)'of the colored resin layer 11'is less than 1.10 times the surface roughness Ra (CL)', it is received from the texture 10S'without the colored resin layer 11'. The gap between the impression and the impression of light reflection on the surface of the colored resin layer 11'becomes too large. In this case, the metallic feeling is lost. If the surface roughness Ra (CC)'is 1.10 times or more the surface roughness Ra (CL)', the impression received from the texture 10S'without the colored resin layer 11'and the colored resin layer It is possible to suppress the deviation from the impression of light reflection on the surface of 11'. Therefore, a sufficient metallic feeling can be obtained. More preferably, the surface roughness Ra (CC)'of the colored resin layer 11'is 1.15 times or more, more preferably 1.20 times or more, still more preferably 1.20 times or more of the surface roughness Ra (CL)'. It is 1.25 times or more.

The surface roughness Ra (CL)'is measured by the arithmetic mean roughness measuring method specified in JIS B 0601 (2013). Specifically, on the surface 11S'of the colored resin layer 11', any 10 points are set as measurement points. At each measurement point, the arithmetic mean roughness Ra is measured at the evaluation length extending in the extending direction RD'of the texture 10S'. The evaluation length is 5 times the reference length (cutoff wavelength). The arithmetic average roughness Ra is measured using a stylus type roughness meter, and the measurement speed is 0.5 mm / sec. Of the 10 arithmetic mean roughness Ras obtained, the largest arithmetic mean roughness Ra, the second largest arithmetic mean roughness Ra, the smallest arithmetic mean roughness Ra, and the second smallest arithmetic mean roughness Ra. The arithmetic mean value of the six arithmetic mean roughness Ra excluding the above is defined as the surface roughness Ra (CL)'.

Similarly, the surface roughness Ra (CC)'is measured by the arithmetic mean roughness measuring method specified in JIS B 0601 (2013). Specifically, on the surface 11S'of the colored resin layer 11', any 10 points are set as measurement points. At each measurement point, the arithmetic mean roughness Ra is measured by the evaluation length extending in the direction WD'orthogonal to the extending direction RD' of the texture 10S'. The evaluation length is 5 times the reference length (cutoff wavelength). The arithmetic average roughness Ra is measured using a stylus type roughness meter, and the measurement speed is 0.5 mm / sec. Of the 10 arithmetic mean roughness Ras obtained, the largest arithmetic mean roughness Ra, the second largest arithmetic mean roughness Ra, the smallest arithmetic mean roughness Ra, and the second smallest arithmetic mean roughness Ra. The arithmetic mean value of the six arithmetic mean roughness Ra excluding the above is defined as the surface roughness Ra (CC)'.

[About the surface shape of the galvanized layer 10'(About the requirement (E'))]
The surface roughness Ra of the surface of the galvanized layer 10'on which the texture 10S'is formed in the direction WD' orthogonal to the extending direction of the texture 10S'is defined as Ra (MC)'. When the texture 10S'is a hairline, the surface roughness Ra (MC)' is preferably 0.30 μm or more. If the surface roughness Ra (MC)'is less than 0.30 μm, it is difficult to visually recognize the texture 10S' from above the colored resin layer 11'. When the surface roughness Ra (MC)'is 0.30 μm or more, the texture 10S'can be sufficiently visually recognized from above the colored resin layer 11'. A more preferable lower limit of the surface roughness Ra (MC)'is 0.35 μm, more preferably 0.40 μm. The upper limit of the surface roughness Ra (MC)'is not particularly limited. However, it may be difficult for industrial production to excessively increase the surface roughness Ra (MC)'. Therefore, the upper limit of the surface roughness Ra (MC)'is, for example, 2.00 μm. The upper limit of the surface roughness Ra (MC)'may be, for example, 1.00 μm.

The surface roughness Ra (MC)'is measured by the arithmetic mean roughness measuring method specified in JIS B 0601 (2013). Specifically, a solvent that does not attack the galvanized layer 10'or a release agent such as a remover (for example, a trade name of Neo River S-701 manufactured by Sansai Kako Co., Ltd.) is used to use a colored resin layer 11'of the plated steel sheet 1'. To remove. In the texture 10S'of the galvanized layer 10'after removing the colored resin layer 11', any 10 points are set as measurement points. At each measurement point, the arithmetic mean roughness Ra is measured by the evaluation length extending in the direction WD'orthogonal to the extending direction RD'of the texture 10S'. The evaluation length is 5 times the reference length (cutoff wavelength). The arithmetic average roughness Ra is measured using a stylus type roughness meter, and the measurement speed is 0.5 mm / sec. Of the 10 arithmetic mean roughness Ras obtained, the largest arithmetic mean roughness Ra, the second largest arithmetic mean roughness Ra, the smallest arithmetic mean roughness Ra, and the second smallest arithmetic mean roughness Ra. The arithmetic mean value of the six arithmetic mean roughness Ra excluding the above is defined as the surface roughness Ra (MC)'.

[About the base iron exposure rate]
Preferably, the base iron exposure rate of the galvanized layer 10'of the plated steel sheet 1'is less than 5%. In the second embodiment, the corrosion resistance is sufficiently ensured by the galvanized layer 10'(galvanized or zinc alloy plated). However, if the surface of the galvanized layer 10'is ground when the texture 10S'is applied and the base iron is exposed, the corrosion resistance (long-term corrosion resistance) for a long period of time may be lowered due to the influence of galvanic corrosion. Such a decrease in long-term corrosion resistance is often remarkable when the base iron exposure rate is 5% or more. Therefore, in the second embodiment, the preferable base iron exposure rate is less than 5%.

If the base iron exposure rate of the galvanized layer 10'is less than 5%, extremely good corrosion resistance such as excellent long-term corrosion resistance can be obtained in addition to the appropriate corrosion resistance generally required for steel materials. The preferable upper limit of the base iron exposure rate of the galvanized layer 10'is 3% or less, more preferably 2%, further preferably 1%, still more preferably 0%.

The base iron exposure rate is measured by the following method. Specifically, a solvent that does not attack the galvanized layer 10'or a release agent such as a remover (for example, a trade name of Neo River S-701 manufactured by Sansai Kako Co., Ltd.) is used to use a colored resin layer 11'of the plated steel sheet 1'. To remove. On the surface of the galvanized layer 10', five arbitrary rectangular regions of 1 mm × 1 mm are selected. An EPMA analysis is performed on the selected rectangular area. By image analysis, a region in which Zn is not detected (Zn undetected region) in each rectangular region is specified. In the second embodiment, a region in which the detection intensity of Zn is 1/16 or less when the standard sample (pure Zn) is measured is recognized as a Zn undetected region. The ratio (area%) of the total area of the Zn undetected region in the five rectangular regions to the total area of the five rectangular regions is defined as the base iron exposure rate (area%).

In the plated steel sheet 1'of the second embodiment, an inorganic film or an organic-inorganic composite film may be formed between the colored resin layer 11'and the zinc-plated layer 10'for the purpose of improving corrosion resistance or adhesion. Good. The inorganic coating is translucent. The inorganic coating is, for example, an amorphous silica coating, a zirconia coating, or a phosphate coating. The organic-inorganic composite film has translucency. The organic-inorganic composite film contains, for example, a silane coupling agent and an organic resin. The organic-inorganic composite film has translucency.

[Production method]
An example of the manufacturing method of the plated steel sheet 1'of the second embodiment will be described. The manufacturing method described below is an example for manufacturing the plated steel sheet 1'of the second embodiment. Therefore, the plated steel sheet 1'having the above-described configuration may be manufactured by a manufacturing method other than the manufacturing methods described below. However, the manufacturing method described below is a preferable example of the manufacturing method of the plated steel sheet 1'of the second embodiment.

The manufacturing method of the second embodiment includes a step of preparing the base steel plate 100'(preparation step: S1') and a step of forming a galvanized layer 10'on the base steel plate 100'(galvanizing process: S2'), a step of forming a texture on the surface of the galvanized layer 10'(texture processing step: S3'), and a step of forming a colored resin layer 11'on the plated steel plate (colored resin layer forming step: S4). ') And include. Hereinafter, each step will be described.

[Preparation process (S1')]
In the preparation step (S1'), the base steel plate 100'is prepared. The base steel plate 100'may be a steel plate or may have another shape. When the base steel plate 100'is a steel plate, the base steel plate 100' may be a hot-rolled steel plate or a cold-rolled steel plate.

[Zinc plating process (S2')]
In the galvanizing treatment step (S2'), the prepared base steel sheet 100'is subjected to galvanizing treatment to form a zinc plating layer 10'on the surface of the base steel sheet 100'.

The zinc plating treatment may be carried out by a well-known method. For example, a well-known electroplating method is used to form the galvanized layer 10'. In this case, it is sufficient to use a well-known bath for the electric zinc plating bath and the electric zinc alloy plating bath. The electroplating bath is, for example, a sulfuric acid bath, a chloride bath, a zincate bath, a cyanide bath, a pyrophosphate bath, a boric acid bath, a citric acid bath, another complex bath, or a combination thereof. In addition to Zn ions, the electrozinc alloy plating bath contains, for example, one or more monatomic ions or complex ions selected from Co, Cr, Cu, Fe, Ni, P, Sn, Mn, Mo, V, W, and Zr. contains.

The chemical composition, temperature, flow velocity, and conditions (current density, energization pattern, etc.) of the electrogalvanizing bath and the electrogalvanizing alloy plating bath in the electrogalvanizing treatment can be appropriately adjusted. The thickness of the galvanized layer 10'in the electrogalvanizing treatment can be adjusted by adjusting the current value and the time within the range of the current density in the electrogalvanizing treatment.

The zinc plating layer 10'may be formed by hot dip galvanizing treatment or alloying hot dip galvanizing treatment. Also in this case, a well-known galvanized bath is prepared. For example, the zinc plating bath may contain Zn as a main component and one or more elements selected from Mg, Al, and Si. When the galvanized layer 10'is used as a hot-dip galvanized layer, the base steel sheet 100' is immersed in a galvanized bath in which the bath temperature and the chemical composition of the bath are adjusted, and zinc is placed on the surface of the base steel sheet 100'. A plating layer 10'(hot-dip galvanizing layer) is formed. When the galvanized layer 10'is used as an alloyed hot-dip galvanized layer, the base steel plate 100' on which the hot-dip galvanized layer is formed is subjected to a well-known heat treatment in a well-known alloying furnace to carry out a well-known heat treatment. 10'is used as an alloyed hot-dip galvanized layer. The thickness of the zinc plating layer 10'in the hot-dip galvanizing treatment can be adjusted by adjusting the immersion time in the zinc plating bath and the amount of zinc plating removed by gas wiping. Before the plating treatment, the base steel sheet 100'may be subjected to a well-known degreasing treatment such as electrolytic degreasing.

Through the above manufacturing process, a plated steel sheet 1'with a base steel sheet 100'and a galvanized layer 10' is manufactured.

[Texture processing process (S3')]
In the texture processing step (S3'), a well-known texture processing is performed on the surface of the galvanized layer 10'of the plated steel sheet to form the texture 10S'on the surface of the galvanized layer 10'.

If the texture 10S'is a hairline, perform a well-known hairline process. The hairline processing method includes, for example, a method of polishing the surface with a well-known polishing belt to form a hairline, a method of polishing the surface with a well-known abrasive grain brush to form a hairline, and a method of rolling and transferring with a roll having a hairline shape. There is a method of forming a hairline and the like. The length, depth, and frequency of the hairline can be adjusted by adjusting the particle size of the well-known polishing belt, the particle size of the well-known abrasive grain brush, and the surface shape of the roll. That is, the arithmetic mean roughness Ra (MC)'and the base iron exposure rate can be adjusted by adjusting the particle size of the well-known polishing belt, the particle size of the well-known abrasive grain brush, and the surface shape of the roll. As a method for imparting a hairline, it is preferable to polish the surface with a polishing belt or an abrasive brush to form a hairline from the viewpoint of surface quality. Since this manufacturing method does not include a step of forming a texture on the surface of the base material and does not have a texture on the surface of the base material, the surface of the plating before the start of the texture processing step (S3') is relatively flat. is there. Therefore, the concave portion of the texture is formed by polishing or the like in the texture processing step (S3'). At this time, the recess is formed so that the three-dimensional average roughness Save'is more than 5 nm and 200 nm or less.

Through the above manufacturing process, the plated steel sheet 1'that includes the base steel sheet 100'and the galvanized layer 10'and has a texture 10S'extending in one direction formed on the surface of the galvanized layer 10'. Manufactured.

[Colored resin layer forming step (S4')]
In the colored resin layer forming step (S4'), the colored resin layer 11'is formed on the zinc-plated layer 10'of the plated steel sheet on which the texture 10S'is formed. Hereinafter, the colored resin layer forming step (S4') will be described in detail.

It is preferable that the paint used for forming the colored resin layer 11'follows the surface shape of the steel material at the moment when it is applied to the plated steel sheet, and the leveling once reflecting the surface shape of the steel material is slow. That is, when the shear rate is high, the viscosity is low, and when the shear rate is low, the viscosity is high. Specifically, when the shear rate is 0.1 [1 / sec], the viscosity is 10 [Pa · s] or more, and when the shear rate is 1000 [1 / sec], 0.01 [ It is preferable to have a viscosity of Pa · s] or less.

By adjusting the shear viscosity of the paint used to form the colored resin layer 11', the surface shape of the colored resin layer 11' can be adjusted.

The method of forming the colored resin layer 11'on the galvanized layer 10'may be a well-known method. For example, the viscosity-adjusted paint is applied onto the galvanized layer 10'by a spraying method, a roll coater method, a curtain coater method, or a dipping pulling method. Then, the paint on the galvanized layer 10'is air-dried or baked to be dried to form the colored resin layer 11'. The drying temperature, drying time, seizure temperature, and seizure time can be adjusted as appropriate. By adjusting the shear viscosity of the paint used to form the colored resin layer 11'and the amount of coating on the galvanized layer 10', the three-dimensional average roughness Save'and the minimum thickness DKmin'of the colored resin layer 11' , Maximum thickness DKmax'can be adjusted. Further, by adjusting the content of the colorant in the paint, the colorant content CK'in the colored resin layer 11'can be adjusted.

By the above manufacturing process, the plated steel sheet 1'of the second embodiment can be manufactured. The plated steel sheet 1'of the second embodiment is not limited to the above manufacturing method, and if the plated steel sheet 1'having the above configuration can be manufactured, the plating of the second embodiment can be performed by a manufacturing method other than the above manufacturing method. Steel plate 1'may be manufactured. However, the above manufacturing method is suitable for manufacturing the plated steel sheet 1'of the second embodiment.

Although each of the first embodiment and the second embodiment of the present invention has been described above, it is not hindered to appropriately combine the configurations of the first embodiment and the configurations of the second embodiment. The specific embodiment exemplified in the description of the first embodiment may be applied to the plated steel sheet of the second embodiment, and vice versa.

In the plated steel sheet 1 of the first embodiment and the plated steel sheet 1'of the second embodiment of the present invention, the colored resin layer may be a laminated resin layer. As a result, the visibility of the surface of the galvanized layer can be further enhanced, and fluctuations in color tone can be suppressed. This is because by using the colored resin layer as the laminated resin layer, it is possible to suppress fluctuations in the local thickness of the colored resin layer. Fluctuations in thickness correlate with fluctuations in colorant (pigment) concentration. Therefore, by suppressing the fluctuation of the thickness, the fluctuation of the colorant concentration can be suppressed, and the fluctuation of the color tone can be suppressed.

Further, the total product of the colorant content CK _N and the thickness DK _N in each colored resin layer may be 15.0 area% · μm or less. That is, the content CK _N and the thickness DK _N of the colorant in each colored resin layer may satisfy the following formula.
Σ [k = 1 → n] (CK _k × DK _k ) ≦ 15.0
As a result, the laminated resin layer can be colored to the extent that the surface of the zinc plating layer can be visually recognized. Then, the visibility of the surface of the zinc plating layer can be further improved, and color tone fluctuations such as color unevenness and color variation can be sufficiently suppressed. The preferable upper limit of the total product of the colorant content CK _N and the thickness DK _{N in} each colored resin layer is 12.0 area% · μm, 10.0 area% · μm, or 8.0 area% ·. It is μm.

Further, the content (area%) of the colorant in the darkest colored resin layer is defined as "C _1ST ", the thickness (μm) of the _darkest colored resin layer is defined as "D _1ST ", and the second When the colorant content (area%) of the dark colored resin layer is defined as "C _2ND " and the thickness (μm) of the second dark colored resin layer is defined as "D _2ND ", the laminated resin layer May satisfy the following equation (4).
1.00 <(C _1ST x D _1ST ) / (C _2ND x D _2ND ) ≤ 4.00 (4)
That is, the ratio of the color density index I _1ST (= C _1ST × D _1ST ) of the _darkest colored resin layer to the color density index I _2ND (= C _2ND × D _2ND ) of the second dark colored resin layer is 4 It may be less than .00. Hereinafter, (C _1ST × D _1ST ) / (C _2ND × D _2ND ) will be referred to as “color density ratio RF”.

When the color density ratio RF is 4.00 or less, the color density of the darkest colored resin layer and the color density of the second dark colored resin layer are not so different. Therefore, when the resin layer is colored to the extent that the surface of the zinc plating layer can be visually recognized, the surface of the zinc plating layer can be visually recognized, and color tone fluctuations such as color unevenness and color variation can be sufficiently suppressed.

The preferred upper limit of the color density ratio RF is 3.80, more preferably 3.50, still more preferably 3.00, still more preferably 2.50, still more preferably 2.00. The color density ratio RF is preferably closer to 1.00. Therefore, the lower limit of the color density ratio RF is more than 1.00. When each of the plurality of colored resin layers LK contains a plurality of types of colorants having different hues, the RF may be 4.00 or less for each colorant having the same hue.

The thickness (total thickness) of the laminated resin layer is not particularly limited, but may be, for example, 10.0 μm or less. If the thickness of the laminated resin layer is 10.0 μm or less, the surface of the galvanized layer can be colored so that the surface of the galvanized layer can be visually recognized on the premise that the above requirements are satisfied. Can be visually recognized, color fluctuations such as color unevenness and color variation can be sufficiently suppressed, and the metallic feeling is sufficiently enhanced. A more preferable upper limit of the thickness of the laminated resin layer is 9.0 μm, and even more preferably 8.0 μm.

Further, the lower limit of the preferable laminated resin layer is 0.5 μm. When the laminated resin layer is 0.5 μm or more, the corrosion resistance is further enhanced. The lower limit of the laminated resin layer is more preferably 0.7 μm, further preferably 1.0 μm, still more preferably 2.0 μm, still more preferably 3.0 μm.

In the laminated resin layer 30, one or a plurality of transparent resin layers containing no colorant may be laminated between the plurality of colored resin layers. The "transparent resin layer" is made of a translucent resin that does not contain a colorant. A translucent resin is a design-type galvanized steel sheet comprising a colored resin layer containing a colorant and a resin and a laminated resin layer containing a transparent resin layer in an environment equivalent to sunlight in the morning on a clear day (illuminance of about 65,000 lux). This means that the surface of the base steel plate can be visually recognized when the steel plate is placed. The stacking order of the colored resin layer and the transparent resin layer is not particularly limited. A plurality of transparent resin layers may be continuously laminated in the laminated resin layer.

(Example 1)
Hereinafter, the effects of one aspect of the present invention will be described in more detail with reference to Examples. The conditions in the following examples are one condition example adopted for confirming the feasibility and effect of the plated steel sheet 1 of the first embodiment of the present invention. Therefore, the present invention is not limited to this one-condition example. The present invention may adopt various conditions as long as the gist of the present invention is not deviated and the object of the present invention is achieved.

The galvanized steel sheet with the test number shown in Table 1 was prepared. The base steel sheet of each galvanized steel sheet was SPCC specified in JIS G 3141 (2017), and the thickness was 0.6 mm.

A base material surface texture forming step was carried out on each base material steel plate to form various forms of base material texture (hairline or dull) on the surface of the base material. In Test Nos. 1, 18, 23, and 28, no texture was formed on the surface of the base material. In the column “Base material texture” in Table 1, the presence / absence and type of the base material surface texture forming step in each test number are shown.

Pre-plating was performed on each base steel sheet. Specifically, each steel material is electrolytically degreased using a Na ₄ SiO ₄ treatment liquid having a concentration of 30 g / L, with a treatment liquid temperature of 60 ° C., a current density of 20 A / dm ² , and a treatment time of 10 seconds. , Washed with water. The steel material after electrolytic degreasing was immersed in an aqueous H ₂ SO ₄ solution at 60 ° C. and a concentration of 50 g / L for 10 seconds and washed with water.

The following plating treatment was carried out on the steel sheets of each test number after the pre-plating treatment to form an electrogalvanized layer. Specifically, in test numbers 1 to 17, an electrogalvanized layer was formed by electroplating. Specifically, a plating bath containing 1.0 mol / L of Zn sulphate heptahydrate and 50 g / L of anhydrous sodium sulfate and adjusting the pH to 2.0 was prepared. In electroplating, the bath temperature was set to 50 ° C. and the current density was set to 50 A / dm ² . The plating time was adjusted so that the adhesion amount was about 30.0 g / m ² . By the above steps, an electrogalvanized layer was formed (denoted as "EG" in the "plating type" column in Table 1).

In test numbers 18 to 22, an electrogalvanized layer containing Ni was formed as the galvanized layer. Specifically, it contains a total of 1.2 mol / L of Zn sulphate heptahydrate and Ni sulphate hexahydrate, and further contains 50 g / L of anhydrous sodium sulfate, and the pH is adjusted to 2.0. A plating bath was prepared. In electroplating, the bath temperature was 50 ° C. and the current density was 50 A / dm ² . The plating time was adjusted so that the adhesion amount was about 30.0 g / m ² . Through the above steps, an electrogalvanized layer containing 12% Ni by mass% and the balance consisting of Zn and impurities was formed (denoted as "Zn-12% Ni" in the "Plating type" column in Table 1). ).

In test numbers 23 to 27, an electrogalvanized layer containing Fe was formed as the galvanized layer. Specifically, it contains a total of 1.2 mol / L of Zn sulfate heptahydrate and Fe (II) sulfate heptahydrate, and further contains 50 g / L of anhydrous sodium sulfate, and has a pH of 2.0. A conditioned plating bath was prepared. In electroplating, the bath temperature was 50 ° C. and the current density was 50 A / dm ² . The plating time was adjusted so that the adhesion amount was about 30.0 g / m ² . Through the above steps, an electrogalvanized layer containing 14% Fe by mass% and the balance being Zn and impurities was formed (denoted as "Zn-14% Fe" in the "Plating type" column in Table 1). ).

In test numbers 28 to 32, an electrogalvanized layer containing Co was formed as the galvanized layer. Specifically, it contains a total of 1.2 mol / L of Zn sulphate heptahydrate and Co sulphate hexahydrate, and further contains 50 g / L of anhydrous sodium sulfate, and the pH is adjusted to 2.0. A plating bath was prepared. In electroplating, the bath temperature was 50 ° C. and the current density was 50 A / dm ² . The plating time was adjusted so that the adhesion amount was about 30.0 g / m ² . Through the above steps, an electrogalvanized layer containing 2% Co in mass% and the balance consisting of Zn and impurities was formed (denoted as "Zn-2% Co" in the "Plating type" column in Table 1). ).

In the electroplating treatment of each test number, the plating solution was flowed so that the relative flow velocity was 1 m / sec. The composition of the obtained electrogalvanized layer was measured by the following method. The steel sheet on which the electroplating layer was formed was immersed in 10% by mass hydrochloric acid containing an inhibitor (NO.700AS manufactured by Asahi Chemical Co., Ltd.) to dissolve and peel off the electrogalvanizing layer. Then, ICP analysis was performed on the solution in which the electrogalvanized layer was dissolved to confirm the composition of the electrogalvanized layer.

After forming the galvanized layer, in test numbers 2 to 4, 6 to 17, 19 to 22, 24 to 27, and 29 to 32, a galvanized surface texture forming step was carried out, and further, a polishing step was carried out. The peak of the convex part of the galvanized layer was ground and polished. In the galvanized surface texture forming step and the polishing step, polishing belts of various particle sizes were pressed against the peaks of the convex portions of the galvanized layer, and grinding and polishing were performed by changing the rolling force and the number of polishings. In the galvanizing surface texture forming step, a polishing belt having a coarser grain size than the polishing step was used. In Test Nos. 1, 5, 18, 23 and 28, the galvanized surface texture forming step and the polishing step were not carried out. In the column “Plating texture” in Table 1, the presence / absence and type of the galvanized surface texture forming step in each test number are shown.
It should be noted that even a plated steel sheet obtained without undergoing the galvanized surface texture forming step has a plating texture as long as the base metal texture is formed through the base metal surface texture forming step. .. This is because if a galvanized steel sheet having a base material texture is subjected to a zinc plating treatment to form a zinc plating layer, a plating texture along the base material texture is formed on the surface of the zinc plating layer. .. For example, the plated steel sheet of Test No. 5 was manufactured without going through the galvanized surface texture forming step. Therefore, regarding test number 5, "None" is described in the column "Plating texture" in Table 1. However, since the plated steel sheet of Test No. 5 was manufactured through the base material surface texture forming step, it had a plated texture.

Galvanized steel sheets with hairlines formed (test numbers 2 to 17, 19 to 22, 24 to 17, 29 to 32) and galvanized steel sheets without hairlines (

test numbers

1, 18, 23, 28) On the other hand, a colored resin layer was formed. Among the colored resin layers, paints having various concentrations and viscosities in which a urethane resin (manufactured by ADEKA Corporation, HUX-232) was dispersed in water as an organic resin were prepared. Pigments of various concentrations (carbon black) were added to the paint. For carbon black, trade name # 850 manufactured by Mitsubishi Chemical Corporation was used.

The paint was scooped up with a roll and applied to the surface of the galvanized layer of the galvanized steel sheet of each test number. The paint after application was baked and dried. Specifically, the galvanized steel sheet coated with the paint was placed in a furnace kept at 250 ° C. The galvanized steel sheet was held in a furnace for 1 to 5 minutes until the temperature reached by the galvanized steel sheet reached 210 ° C. After holding, the galvanized steel sheet was taken out of the furnace and cooled.

The viscosity of the above paint was adjusted using a viscosity modifier (manufactured by Big Chemie, trade name: BYK-425). Specifically, at a shear rate of 0.1 (1 / sec), the paint viscosity is 10 (Pa · s) or more, and at a shear rate of 1000 (1 / sec), the paint viscosity is 0.01 (Pa · s) or less. The viscosity of the paint was adjusted so as to be. By the above steps, a colored resin layer was formed on the galvanized layer of each test number.

The galvanized steel sheet of each test number was manufactured by the above manufacturing method. In Test No. 18, 0.5 μm of a pigment-free urethane resin (manufactured by ADEKA Corporation, HUX-232) was applied between the colored resin layer and the galvanized layer. Then, a colored resin layer was formed.

[Evaluation test]
[Concave bottom three-dimensional average roughness Sas and convex top three-dimensional average roughness Sah measurement test]
The maximum three-dimensional average roughness of the surface texture (hairline) of the galvanized layer of the galvanized steel sheet of each test number was measured by the following method. First, the colored resin layer of the galvanized steel sheet was removed using a solvent that does not attack the galvanized layer (trade name: Neo River S-701 manufactured by Sansai Kako Co., Ltd.). From the surface of the galvanized layer, one arbitrary 1000 μm length range in the second direction orthogonal to the extending direction (first direction) of the texture (hairline) was selected. The texture roughness profile was measured in the selected 1000 μm length range. The roughness profile was measured with a three-dimensional surface roughness measuring machine (Surfcom 1500DX3 manufactured by Tokyo Seimitsu Co., Ltd.).

Attention was paid to each recess 10RE in the measured roughness profile. In each recess 10RE, the position having the lowest height was defined as the recess bottom point PRE. Among the plurality of recessed bottom points PRE in the roughness profile in the 1000 μm length range, 10 recessed bottom points PRE1, PRE2, ..., PRE10 were identified in ascending order from the lowest recessed bottom point PRE1.

As shown in FIG. 6A, the surface of the galvanized layer was viewed in a plan view, and a 1 μm × 1 μm minute recess bottom region centered on each defined recess bottom point PREk (k is 1 to 10) was specified. Three-dimensional average roughness Sa was measured in each of the 10 micro-recess bottom regions identified. The three-dimensional average roughness Sa is the arithmetic average roughness defined by ISO 25178, which is an extension of Ra (arithmetic mean roughness of lines) defined by JIS B 0601 (2013) to a surface. The arithmetic mean value of the 10 measured three-dimensional average roughness Sas was defined as the concave bottom three-dimensional average roughness Sas (μm).

Similarly, attention was paid to each convex portion 10CO in the measured roughness profile. In each convex portion 10CO, the position having the highest height was defined as the convex portion top point PCO. Among the plurality of convex peak point PCOs in the roughness profile in the 1000 μm length range, 10 convex peak points PCO1, PCO2, ..., PCO10 were identified in descending order from the highest convex peak point PCO1.

As shown in FIG. 6B, the surface of the galvanized layer was viewed in a plan view, and a 1 μm × 1 μm microconvex top region centered on each defined convex top point PCok (k is 1 to 10) was specified. Three-dimensional average roughness Sa was measured in each of the 10 microconvex top regions identified. The three-dimensional average roughness Sa is the arithmetic average roughness defined by ISO 25178, which is an extension of Ra (arithmetic mean roughness of lines) defined by JIS B 0601 (2013) to a surface. The arithmetic mean value of the 10 measured three-dimensional average roughness Sas was defined as the convex top three-dimensional average roughness Sah (μm).

[DKmin, DKmax measurement test]
The thickness (DKmin, DKmax) of the colored resin layer of the galvanized steel sheet of each test number was measured by the following method. In the galvanized steel sheet of each test number, a sample having a cross section orthogonal to the first direction of the texture (hairline) on the surface was taken. Among the samples, an observation cross section in a length range of 100 μm in a direction orthogonal to the extending direction of the texture (hairline) was observed with a 2000 times reflected electron image (BSE) using a scanning electron microscope (SEM). In the observation cross section, the thickness of the colored resin layer was measured at a pitch of 0.5 μm in the direction WD. Of the measured thicknesses, the smallest thickness was defined as the minimum thickness DKmin (μm). Of the measured thicknesses, the maximum thickness was defined as the maximum thickness DKmax (μm).

[Colorant content CK measurement test]
The colorant content (area%) in the colored resin layer of the galvanized steel sheet of each test number was determined by the following method. A sample having a cross section on the surface orthogonal to the first direction of the texture (hairline) was taken. In the sample, the cross section orthogonal to the first direction of the texture (hairline) was used as the observation surface. From the sample, a thin film sample in which the colored resin layer and the galvanized layer on the observation surface could be observed was prepared using FIB. The film thickness of the thin film sample was 150 nm. Of the observation surfaces of the prepared thin film sample, the length in the direction perpendicular to the thickness direction of the colored resin layer (that is, the second direction WD) is 3 μm, and the length in the thickness direction of the colored resin layer (that is, that is). In the third direction TD), a visual field having a length including the entire colored resin layer was observed using TEM. In the TEM observation, the resin and the pigment in the colored resin layer could be distinguished by the contrast. The total area A1 (μm ² ) of the plurality of pigments in the colored resin layer in the observed cross section was determined. Further, the area (μm ² ) of the colored resin layer in the observed cross section was determined. Based on the obtained total area A1 and area A0, the colorant content (area%) in the colored resin layer 11 was determined by the following formula.
CK = A1 / A0 × 100

[Roughness Ra (CC) and Ra (CL) measurement test of colored resin layer]
The roughness Ra (CC) and Ra (CL) in the colored resin layer of the galvanized steel sheet of each test number were determined by the following method.

The surface roughness Ra (CL) was measured by the method for measuring the arithmetic mean roughness specified in JIS B 0601 (2013). On the surface of the colored resin layer, any 10 points were set as measurement points. At each measurement point, the arithmetic mean roughness Ra was measured by the evaluation length extending in the first direction of the texture (hairline). The evaluation length was set to 5 times the reference length (cutoff wavelength). The arithmetic average roughness Ra was measured using a three-dimensional surface roughness measuring machine (Surfcom 1500DX3 manufactured by Tokyo Seimitsu Co., Ltd.), and the measuring speed was 0.5 mm / sec. Of the 10 arithmetic mean roughness Ras obtained, the largest arithmetic mean roughness Ra, the second largest arithmetic mean roughness Ra, the smallest arithmetic mean roughness Ra, and the second smallest arithmetic mean roughness Ra. The arithmetic mean value of the six arithmetic mean roughness Ra excluding the above was defined as the surface roughness Ra (CL).

Similarly, the surface roughness Ra (CC) was measured by the method for measuring the arithmetic mean roughness specified in JIS B 0601 (2013). On the surface of the colored resin layer, any 10 points were set as measurement points. At each measurement point, the arithmetic mean roughness Ra was measured by the evaluation length extending in the second direction of the texture (hairline). The evaluation length was set to 5 times the reference length (cutoff wavelength). The arithmetic average roughness Ra was measured using the above-mentioned three-dimensional surface roughness measuring machine, and the measurement speed was 0.5 mm / sec. Of the 10 arithmetic mean roughness Ras obtained, the largest arithmetic mean roughness Ra, the second largest arithmetic mean roughness Ra, the smallest arithmetic mean roughness Ra, and the second smallest arithmetic mean roughness Ra. The arithmetic mean value of the six arithmetic mean roughness Ra excluding the above was defined as the surface roughness Ra (CC).

[Surface roughness Ra (MC) measurement test of galvanized layer]
The surface roughness Ra (MC) of the galvanized layer of the galvanized steel sheet of each test number was determined by the following method.

The surface roughness Ra (MC) was measured by the method for measuring the arithmetic mean roughness specified in JIS B 0601 (2013). The colored resin layer of the galvanized steel sheet was removed using a solvent that does not attack the galvanized layer (trade name: Neo River S-701 manufactured by Sansai Kako Co., Ltd.). In the texture (hairline) of the galvanized layer after removing the colored resin layer, any 10 points were set as measurement points. At each measurement point, the arithmetic mean roughness Ra was measured with the evaluation length extending in the second direction. The evaluation length was set to 5 times the reference length (cutoff wavelength). The arithmetic average roughness Ra was measured using the above-mentioned three-dimensional surface roughness measuring machine, and the measurement speed was 0.5 mm / sec. Of the 10 arithmetic mean roughness Ras obtained, the largest arithmetic mean roughness Ra, the second largest arithmetic mean roughness Ra, the smallest arithmetic mean roughness Ra, and the second smallest arithmetic mean roughness Ra. The arithmetic mean value of the six arithmetic average roughness Ra excluding the above was defined as the surface roughness Ra (MC) (μm).

[Base iron exposure rate measurement test]
The base iron exposure rate of the galvanized steel sheet of each test number was measured by the following method. A galvanized steel sheet from which the colored resin layer had been removed was prepared. Five arbitrary rectangular regions of 1 mm × 1 mm were selected on the surface of the galvanized layer. An EPMA analysis was performed on the selected rectangular area. By image analysis, a region in which Zn was not detected (Zn undetected region) in each rectangular region was identified. The region where the detection intensity of Zn was 1/16 or less when the standard sample (pure Zn) was measured was recognized as the Zn undetected region. The ratio (area%) of the total area of the Zn undetected region in the five rectangular regions to the total area of the five rectangular regions was defined as the base iron exposure rate (area%).

[Texture visibility test]
The galvanized steel sheet of each test number was placed in an environment equivalent to sunlight (illuminance of about 65,000 lux) on a clear morning. Then, the angle between the light source, the steel plate, and the line of sight was changed and observed, and it was confirmed whether or not the texture could be visually recognized. If the texture could be visually recognized at all angles from 5 ° to 80 ° with respect to the vertical direction of the steel sheet surface, it was evaluated as very good and passed (evaluation "A" in Table 1). Further, if the texture could be visually recognized at a part of the angles from 5 ° to 80 ° with respect to the vertical direction of the steel sheet surface, it was evaluated as acceptable (evaluation "B" in Table 1). On the other hand, if the texture was not visible at all, it was evaluated as rejected (evaluation "C" in Table 1).

[Brightness measurement test]
For the galvanized steel sheet of each test number, the brightness L ^* value was measured as a reference value by the following method. A colorimeter (trade name: CM-2600d) manufactured by Konica Minolta Co., Ltd. was used for the measurement. In the measurement, a CIE standard light source D65 was used as a light source, the viewing angle was 10 °, and the L ^* value was obtained in the CIELAB display color by the SCI method.

Here, the CIE standard light source D65 is specified in JIS Z 8720 (2000) "Illuminite for color measurement (standard light) and standard light source", and ISO 10526 (2007) also has the same specification. CIE is an abbreviation for Commission International de l'Eclairage, which means the International Commission on Illumination. The CIE standard illuminant D65 is used to display the color of an object illuminated by daylight. The viewing angle of 10 ° is specified in JIS Z 8723 (2009) "Visual comparison method of surface color", and ISO / DIS 3668 also has the same specification.

The SCI method is called a specularly reflected light inclusion method, and means a method of measuring color without removing the specularly reflected light. The brightness measurement method according to the SCI method is specified in JIS Z 8722 (2009). In the SCI method, since the measurement is performed without removing the specularly reflected light, the color is the actual color of the object.

The CIELAB display color is a uniform color space recommended in 1976 and defined in JIS Z 8781 (2013) for measuring the color difference due to the difference between perception and the value measured by the device. The three coordinates of CIELAB are indicated by L ^* value, a ^* value, and b ^* value. The L ^* value indicates the brightness and is indicated by 0 to 100. When the L ^* value is 0, it means black, and when the L ^* value is 100, it means a diffuse color of white.

[Corrosion resistance evaluation test]
Corrosion resistance (long-term corrosion resistance) was evaluated for the galvanized steel sheets of each test number by the following method. A 75 mm × 100 mm test piece was taken from the galvanized steel sheet of each test number. The end face and back surface of the test piece were protected with a tape seal. Then, a salt spray test of 5% NaCl kept at 35 ° C. was carried out in accordance with JIS Z 2371 (2015). The test was carried out for 240 hours, and the rust generation rate after the test was determined. If the rust occurrence rate was 0%, it was judged as corrosion resistance evaluation A, and if the rust occurrence rate was more than 0% and 5% or less, it was judged as corrosion resistance evaluation B, and it was evaluated as having good corrosion resistance. If the rust generation rate was more than 5%, it was judged to be corrosion resistance evaluation C. However, the main problem of the present invention is to improve the visibility of texture. Therefore, even if the corrosion resistance evaluation is C, the example of the test number that passed the texture visual inspection test was determined to be the example of the present invention.

[Adhesion test]
The adhesion of the colored resin layer was evaluated for the galvanized steel sheet of each test number by the following method. From the galvanized steel sheets of each test number, test pieces having a width of 50 mm and a length of 50 mm were prepared. The obtained test piece was bent at 180 °. After the bending process, a tape peeling test was performed on the outside of the bent portion. The appearance of the tape peeled portion was observed with a magnifying glass having a magnification of 10 times. Then, it was evaluated according to the following evaluation criteria. The bending process was carried out in an atmosphere of 20 ° C. with a 0.6 mm spacer in between. The results obtained are shown in Table 1 below.
(Evaluation criteria)
A: No peeling is observed on the coating film B: Peeling is observed on a very small part of the coating film (peeling area ≤ 2%)
C: Peeling is observed on some coating films (2% <peeling area ≤ 20%)
D: Peeling is observed on the coating film (peeling area> 20%)
When the evaluation was A to C, it was judged that the adhesion was excellent. When the evaluation was D, it was judged that the adhesion was low. However, the main problem of the present invention is to improve the texture visibility. Therefore, even if the adhesion is determined to be D, the example of the test number that has passed the texture visibility test is determined to be the example of the present invention.

[Metallic feeling evaluation test]
The metallic feeling of the galvanized steel sheet of each test number was measured by the following method. At any point of the plated steel sheet 1 of each test number, the glossiness G60 (Gl) in the direction parallel to the texture (hairline) and the glossiness G60 (Gc) in the direction perpendicular to the texture (hairline) are measured with a gloss meter. did. As the gloss meter, a gloss meter (trade name: UGV-6P) manufactured by Suga Test Instruments Co., Ltd. was used. Gc / Gl was determined based on the obtained glossiness Gl and the glossiness Gc. If the texture can be visually recognized and Gc / Gl ≦ 0.70, it is judged that an excellent metallic feeling is obtained (evaluation “A” in Table 1). If the texture can be visually recognized and 0.70 <Gc / Gl ≦ 0.90, it is judged that a good metallic feeling is obtained (evaluation “B” in Table 1). If the texture cannot be visually recognized, or if the texture is visible but 0.90 <Gc / Gl, it is determined that the metallic feeling is not obtained (evaluation "C" in Table 1). However, the main problem of the present invention is to improve the texture visibility. Therefore, even if the metallic feeling is determined to be C, the example of the test number that passed the texture visibility test was determined to be the example of the present invention.

[Evaluation results]
With reference to Table 1, in test numbers 4, 5, 8 to 17, 20 to 22, 25 to 27, and 30 to 32, the concave bottom three-dimensional average roughness Sas was more than 200 nm and 2000 nm or less. Furthermore, in these test numbers, F1 was 15.0 or less and F2 was greater than 1.0. Therefore, in these test numbers, even if the brightness was 50 or less, the texture could be visually recognized in the texture visibility test (evaluation A or B). Furthermore, these test numbers were also excellent in adhesion. Test number 2 was outside the range of the first embodiment, and the corrosion resistance was slightly lower than that of other invention examples, but it was within the range of the second embodiment, had a high metallic feeling, and had a good aesthetic appearance. Was.

Of the test numbers 4, 5, 8 to 17, 20 to 22, 25 to 27, and 30 to 32, the test numbers excluding test number 5 have a convex top top three-dimensional average roughness Sah of more than 5 nm and 200 nm or less. there were. Therefore, in

test numbers

4, 10 to 17, 20 to 22, 25 to 27, and 30 to 32, the texture was visible even if the brightness was lower than that of test number 5.

Of the test numbers 4, 5, 8 to 17, 20 to 22, 25 to 27, and 30 to 32, the base iron exposure rate was less than 5% for the test numbers other than the

test numbers

4 and 10. Therefore, in test numbers 5, 8, 9, 11 to 17, 20 to 22, 35 to 27, and 30 to 32, the rust generation rate was less than 5% in the corrosion resistance evaluation test, and sufficient corrosion resistance was obtained ( Evaluation A or B).

On the other hand, in test number 1, no plating texture was formed. Therefore, the maximum thickness DKmax of the colored resin layer, the minimum thickness DKmin, and the colorant content CK did not satisfy the formula (2). Further, the surface roughness Ra (CL) and the surface roughness Ra (CC) did not satisfy the formula (3). Therefore, the texture could not be visually recognized in the texture visibility test (evaluation C).

In test numbers 3 and 6, the minimum thickness DKmin of the colored resin layer and the colorant content CK in the colored resin layer did not satisfy the formula (1). Therefore, the texture could not be visually recognized in the texture visibility test (evaluation C).

In test number 7, the maximum thickness DKmax of the colored resin layer, the minimum thickness DKmin, and the colorant content CK did not satisfy the formula (2). Therefore, the texture could not be visually recognized in the texture visibility test (evaluation C).

In test number 18, no plating texture was formed. Therefore, the maximum thickness DKmax of the colored resin layer, the minimum thickness DKmin, and the colorant content CK did not satisfy the formula (2). Therefore, the texture could not be visually recognized in the texture visibility test (evaluation C).

In test number 19, the minimum thickness DKmin of the colored resin layer and the colorant content CK in the colored resin layer did not satisfy the formula (1). Therefore, the texture could not be visually recognized in the texture visibility test (evaluation C).

In test number 23, no plating texture was formed. Therefore, the maximum thickness DKmax of the colored resin layer, the minimum thickness DKmin, and the colorant content CK did not satisfy the formula (2). Therefore, the texture could not be visually recognized in the texture visibility test (evaluation C).

In test number 24, the minimum thickness DKmin of the colored resin layer and the colorant content CK in the colored resin layer did not satisfy the formula (1). Therefore, the texture could not be visually recognized in the texture visibility test (evaluation C).

In test number 28, no plating texture was formed. Therefore, the maximum thickness DKmax of the colored resin layer, the minimum thickness DKmin, and the colorant content CK did not satisfy the formula (2). Therefore, the texture could not be visually recognized in the texture visibility test (evaluation C).

In test number 29, the minimum thickness DKmin of the colored resin layer and the colorant content CK in the colored resin layer did not satisfy the formula (1). Therefore, the texture could not be visually recognized in the texture visibility test (evaluation C).

The first embodiment of the present invention has been described above. However, the embodiments described above are merely examples for carrying out the present invention. Therefore, the present invention is not limited to the above-described embodiment, and the above-described embodiment can be appropriately modified and implemented without departing from the spirit of the present invention.

(Example 2)
Next, various examples manufactured for confirming the feasibility and effect of the plated steel sheet 1'of the second embodiment of the present invention will be described below.
Galvanized steel sheets with test numbers shown in Table 2 were prepared. The steel material (steel plate) of each galvanized steel sheet was SPCC specified in JIS G 3141 (2017), and the thickness was 0.6 mm.

Each steel material was pretreated for plating. Specifically, each steel material is electrolytically degreased using a Na ₄ SiO ₄ treatment liquid having a concentration of 30 g / L at a treatment liquid temperature of 60 ° C., a current density of 20 A / dm ² , and a treatment time of 10 seconds. , Washed with water. The steel material after electrolytic degreasing was immersed in an aqueous solution of H ₂ SO ₄ at a concentration of 50 g / L at 60 ° C. for 10 seconds and washed with water.

The following plating treatment was carried out on the steel materials of each test number after the pre-plating treatment to form an electrogalvanized layer. Specifically, in test numbers 1'to 16', an electrogalvanized layer was formed by electroplating. Specifically, a plating bath containing 1.0 mol / l of Zn sulphate heptahydrate and 50 g / L of anhydrous sodium sulfate and adjusting the pH to 2.0 was prepared. In electroplating, the bath temperature was 50 ° C. and the current density was 50 A / dm ² . The plating time was adjusted so that the adhesion amount was about 30.0 g / m ² . By the above steps, an electrogalvanized layer was formed (denoted as "EG" in the "plating type" column in Table 2).

In test numbers 17'to 20', an electrogalvanized layer containing Ni was formed as the galvanized layer. Specifically, it contains a total of 1.2 mol / l of Zn sulphate heptahydrate and Ni sulphate hexahydrate, and further contains 50 g / L of anhydrous sodium sulfate, and the pH is adjusted to 2.0. A plating bath was prepared. In electroplating, the bath temperature was 50 ° C. and the current density was 50 A / dm ² . The plating time was adjusted so that the adhesion amount was about 30.0 g / m ² . Through the above steps, an electrogalvanized layer containing 12% Ni by mass% and the balance consisting of Zn and impurities was formed (denoted as "Zn-12% Ni" in the "Plating type" column in Table 2). ).

In test numbers 21'to 24', an electrogalvanized layer containing Fe was formed as the galvanized layer. Specifically, it contains a total of 1.2 mol / l of Zn sulfate heptahydrate and Fe (II) sulfate heptahydrate, and further contains 50 g / L of anhydrous sodium sulfate, and has a pH of 2.0. A conditioned plating bath was prepared. In electroplating, the bath temperature was 50 ° C. and the current density was 50 A / dm ² . The plating time was adjusted so that the adhesion amount was about 30.0 g / m ² . Through the above steps, an electrogalvanized layer containing 14% Fe by mass% and the balance being Zn and impurities was formed (denoted as "Zn-14% Fe" in the "Plating type" column in Table 2). ).

In test numbers 25'to 28', an electrogalvanized layer containing Co was formed as the galvanized layer. Specifically, it contains a total of 1.2 mol / l of Zn sulphate heptahydrate and Co sulphate hexahydrate, and further contains 50 g / L of anhydrous sodium sulfate, and the pH is adjusted to 2.0. A plating bath was prepared. In electroplating, the bath temperature was 50 ° C. and the current density was 50 A / dm ² . The plating time was adjusted so that the adhesion amount was about 30.0 g / m ² . Through the above steps, an electrogalvanized layer containing 2% Co in mass% and the balance consisting of Zn and impurities was formed (denoted as "Zn-2% Co" in the "Plating type" column in Table 2). ).

After forming the galvanized layer, in test numbers 2'to 16', 18' to 20', 22' to 24', and 26' to 28', the galvanized steel sheet is subjected to the rolling direction RD of the steel sheet. , Texture processing was carried out to impart hairlines to the surface of the galvanized layer. Specifically, polishing papers of various particle sizes were pressed against the surface of the galvanized layer, and various hairlines were imparted by changing the rolling force and the number of times of polishing. In the column "Texture" in Table 2, the presence / absence and type of texture processing in each test number are shown.

Galvanized steel sheets with hairlines formed (test numbers 2'-16', 18'-20', 22'-24', 26'-28') and galvanized steel sheets without hairlines (test numbers) A colored resin layer was formed on 1', 17', 21'and 25'). Among the colored resin layers, paints having various concentrations and viscosities in which a urethane resin (manufactured by ADEKA Corporation, HUX-232) was dispersed in water as an organic resin were prepared. Colorants (carbon black) of various concentrations were added to the paint. For carbon black, trade name # 850 manufactured by Mitsubishi Chemical Corporation was used.

The galvanized steel sheet of each test number was manufactured by the above manufacturing method. In Test No. 16', 0.5 μm of a urethane resin (manufactured by ADEKA Corporation, HUX-232) containing no colorant was applied between the colored resin layer and the galvanized layer. Then, a colored resin layer was formed.

[Evaluation test]
[Three-dimensional average roughness Save'measurement test]
The maximum three-dimensional average roughness of the surface texture (hairline) of the galvanized layer of the galvanized steel sheet of each test number was measured by the following method. First, the colored resin layer of the galvanized steel sheet was removed using a solvent that does not attack the galvanized layer (trade name: Neo River S-701 manufactured by Sansai Kako Co., Ltd.). From the surface of the galvanized layer, one arbitrary 1000 μm length range in the direction orthogonal to the extending direction of the texture (hairline) was selected. The texture roughness profile was measured in the selected 1000 μm length range. The roughness profile was measured with a three-dimensional surface roughness measuring machine (Surfcom 1500DX3 manufactured by Tokyo Seimitsu Co., Ltd.). Among the positions on the measured roughness profile, 10 points with lower heights are specified in ascending order of height, and recessed bottom points PRE1', PRE2', ..., PRE10' are defined in ascending order of height. did. Among the positions on the measured roughness profile, 10 points with higher heights are specified in descending order of height, and convex vertices PCO1', PCO2', ..., PCO10'are defined in descending order of height. did.

As shown in FIG. 14A, the surface of the galvanized layer was viewed in a plan view, and a 1 μm × 1 μm minute recess region centered on each defined recess bottom point PREk'(k is 1 to 10) was specified. Similarly, as shown in FIG. 14B, the surface of the galvanized layer is viewed in a plan view, and a 1 μm × 1 μm microconvex region centered on each defined convex apex PCok'(k is 1 to 10) is specified. did.

The three-dimensional average roughness Sa'was measured in the 10 micro-concave regions and the 10 micro-convex regions specified by the above method. A laser microscope (trade name: VK-9710) manufactured by KEYENCE CORPORATION was used for identifying the micro-concave region and the micro-convex region and measuring the three-dimensional average roughness Sa'. In VK-9710, the display resolution in the height direction was 1 nm or more, and the display resolution in the width direction was 1 nm or more. The arithmetic mean value of the measured 20 (10 micro-concave regions and 10 micro-convex regions) three-dimensional average roughness Sa'was defined as the three-dimensional average roughness Sa'.

[DKmin', DKmax' measurement test]
The thickness (DKmin', DKmax') of the colored resin layer of the galvanized steel sheet of each test number was measured by the following method. For the galvanized steel sheet of each test number, a sample having a cross section orthogonal to the extending direction of the texture (hairline) was taken. Among the samples, an observation cross section in a length range of 100 μm in a direction orthogonal to the extending direction of the texture (hairline) was observed with a 2000 times reflected electron image (BSE) using a scanning electron microscope (SEM). In the observation cross section, the thickness of the colored resin layer was measured at a pitch of 0.5 μm in the direction WD'. Of the measured thicknesses, the smallest thickness was defined as the minimum thickness DKmin'(μm). Of the measured thicknesses, the maximum thickness was defined as the maximum thickness DKmax'(μm).

[Colorant content CK'measurement test]
The colorant content (area%) in the colored resin layer of the galvanized steel sheet of each test number was determined by the following method. A sample having a cross section on the surface orthogonal to the extending direction of the texture (hairline) was taken. In the sample, the cross section orthogonal to the extending direction of the texture (hairline) was used as the observation surface. From the sample, a thin film sample in which the colored resin layer and the galvanized layer on the observation surface could be observed was prepared using FIB. The film thickness of the thin film sample was 150 nm. Of the observation surfaces of the prepared thin film sample, the length in the direction perpendicular to the thickness direction of the colored resin layer (that is, the direction WD') is 3 μm, and the length in the thickness direction (that is, the direction) of the colored resin layer. In TD'), a visual field having a length including the entire colored resin layer was observed using TEM. In the TEM observation, the resin in the colored resin layer and the colorant could be distinguished by the contrast. The total area A1'(μm ² ) of the plurality of colorants in the colored resin layer in the observed cross section was determined. Further, the area A0'(μm ² ) of the colored resin layer in the observed cross section was determined. Based on the obtained total area A1'and area A0', the colorant content (area%) in the colored resin layer 11 was determined by the following formula.
CK'= A1' / A0'x100

[Roughness Ra (CC)'and Ra (CL)' measurement test of colored resin layer]
The roughness Ra (CC)'and Ra (CL)'in the colored resin layer of the galvanized steel sheet of each test number were determined by the following method.

The surface roughness Ra (CL)'was measured by the method for measuring the arithmetic mean roughness specified in JIS B 0601 (2013). On the surface of the colored resin layer, any 10 points were set as measurement points. At each measurement point, the arithmetic mean roughness Ra was measured by the evaluation length extending in the extending direction of the texture (hairline). The evaluation length was set to 5 times the reference length (cutoff wavelength). The arithmetic average roughness Ra was measured using a three-dimensional surface roughness measuring machine (Surfcom 1500DX3 manufactured by Tokyo Seimitsu Co., Ltd.), and the measuring speed was 0.5 mm / sec. Of the 10 arithmetic mean roughness Ras obtained, the largest arithmetic mean roughness Ra, the second largest arithmetic mean roughness Ra, the smallest arithmetic mean roughness Ra, and the second smallest arithmetic mean roughness Ra. The arithmetic mean value of the six arithmetic mean roughness Ras excluding the above was defined as the surface roughness Ra (CL)'.

Similarly, the surface roughness Ra (CC)'was measured by the method for measuring the arithmetic mean roughness specified in JIS B 0601 (2013). On the surface of the colored resin layer, any 10 points were set as measurement points. At each measurement point, the arithmetic mean roughness Ra was measured by the evaluation length extending in the direction orthogonal to the extending direction of the texture (hairline). The evaluation length was set to 5 times the reference length (cutoff wavelength). The arithmetic average roughness Ra was measured using the above-mentioned three-dimensional surface roughness measuring machine, and the measurement speed was 0.5 mm / sec. Of the 10 arithmetic mean roughness Ras obtained, the largest arithmetic mean roughness Ra, the second largest arithmetic mean roughness Ra, the smallest arithmetic mean roughness Ra, and the second smallest arithmetic mean roughness Ra. The arithmetic mean value of the six arithmetic mean roughness Ra excluding the above was defined as the surface roughness Ra (CC)'.

[Surface roughness Ra (MC)'measurement test of galvanized layer]
The surface roughness Ra (MC)'of the galvanized layer of the galvanized steel sheet of each test number was determined by the following method.

The surface roughness Ra (MC)'was measured by the arithmetic mean roughness measuring method specified in JIS B 0601 (2013). The colored resin layer of the galvanized steel sheet was removed using a solvent that does not attack the galvanized layer (trade name: Neo River S-701 manufactured by Sansai Kako Co., Ltd.). In the texture (hairline) of the galvanized layer after removing the colored resin layer, any 10 points were set as measurement points. At each measurement point, the arithmetic mean roughness Ra was measured by the evaluation length extending in the direction orthogonal to the extending direction of the texture (hairline). The evaluation length was set to 5 times the reference length (cutoff wavelength). The arithmetic average roughness Ra was measured using the above-mentioned three-dimensional surface roughness measuring machine, and the measurement speed was 0.5 mm / sec. Of the 10 arithmetic mean roughness Ras obtained, the largest arithmetic mean roughness Ra, the second largest arithmetic mean roughness Ra, the smallest arithmetic mean roughness Ra, and the second smallest arithmetic mean roughness Ra. The arithmetic mean value of the six arithmetic average roughness Ra excluding the above was defined as the surface roughness Ra (MC)'(μm).

[Brightness measurement test]
The galvanized steel sheet of each test number was measured by the following method using the brightness L ^* value as a reference value. A colorimeter (trade name: CM-2600d) manufactured by Konica Minolta Co., Ltd. was used for the measurement. In the measurement, a CIE standard light source D65 was used as a light source, the viewing angle was 10 °, and the L ^* value was obtained in the CIELAB display color by the SCI method.

[Corrosion resistance evaluation test]
Corrosion resistance (long-term corrosion resistance) was evaluated for the galvanized steel sheets of each test number by the following method. A 75 mm × 100 mm test piece was taken from the galvanized steel sheet of each test number. The end face and back surface of the test piece were protected with a tape seal. Then, a salt spray test of 5% NaCl kept at 35 ° C. was carried out in accordance with JIS Z 2371 (2015). The test was carried out for 240 hours, and the rust generation rate after the test was determined. When the rust occurrence rate was 0%, it was judged as corrosion resistance evaluation A, and when the rust occurrence rate was more than 0% and 5% or less, it was judged as corrosion resistance evaluation B, and it was evaluated as having good corrosion resistance. If the rust generation rate was more than 5%, it was judged to be corrosion resistance evaluation C. However, the main object of the present invention is to improve the aesthetic appearance such as texture visibility. Therefore, even if the corrosion resistance evaluation is C, the example of the test number that passed the texture visual inspection test was determined to be the example of the present invention.

[Metallic feeling evaluation test]
The metallic feeling of the galvanized steel sheet of each test number was measured by the following method. At any point of the plated steel sheet 1 of each test number, the glossiness G60 (Gl) in the direction parallel to the texture (hairline) and the glossiness G60 (Gc) in the direction perpendicular to the texture (hairline) are measured with a gloss meter. did. As the gloss meter, a gloss meter (trade name: UGV-6P) manufactured by Suga Test Instruments Co., Ltd. was used. Gc / Gl was determined based on the obtained glossiness Gl and the glossiness Gc. If the texture can be visually recognized and Gc / Gl ≦ 0.70, it is judged that an excellent metallic feeling is obtained (evaluation “A” in Table 1). If the texture can be visually recognized and 0.70 <Gc / Gl ≦ 0.90, it is judged that a good metallic feeling is obtained (evaluation “B” in Table 1). If the texture cannot be visually recognized, or if the texture is visible but 0.90 <Gc / Gl, it is judged that the metallic feeling is not obtained (evaluation "C" in Table 1). However, the main problem of the present invention is to improve the texture visibility. Therefore, even if the metallic feeling is determined to be C, the example of the test number that passed the texture visibility test was determined to be the example of the present invention.

[Evaluation results]
With reference to Table 1, in test numbers 3', 6'-16', 19', 20', 23', 24', 27' and 28', the three-dimensional average roughness Save'is greater than 5 nm and less than 200 nm. Yes, the minimum thickness DKmin'of the colored resin layer and the colorant content CK'in the colored resin layer satisfied the formula (1'). Further, the maximum thickness DKmax', the minimum thickness DKmin', and the colorant content CK'of the colored resin layer satisfy the formula (2'). Therefore, the texture was visible in the texture visibility test (evaluation A or B).

Of the test numbers 3', 6'to 16', 19', 20', 23', 24', 27'and 28', the base iron exposure rate is 5% for the test numbers other than the test number 3'. Was less than. Therefore, in the corrosion resistance evaluation test, the rust generation rate was less than 5%, and sufficient corrosion resistance was obtained (evaluation A).

On the other hand, in test number 1', the three-dimensional average roughness Save' was too large. Further, the maximum thickness DKmax', the minimum thickness DKmin', and the colorant content CK'of the colored resin layer did not satisfy the formula (2'). Therefore, the texture could not be visually recognized in the texture visibility test (evaluation C).

In test number 2', the minimum thickness DKmin'of the colored resin layer and the colorant content CK'in the colored resin layer did not satisfy the formula (1'). Therefore, the texture could not be visually recognized in the texture visibility test (evaluation C).

In test number 4', the minimum thickness DKmin'of the colored resin layer and the colorant content CK'in the colored resin layer did not satisfy the formula (1'). Therefore, the texture could not be visually recognized in the texture visibility test (evaluation C).

In test number 5', the maximum thickness DKmax', the minimum thickness DKmin', and the colorant content CK'of the colored resin layer did not satisfy the formula (2'). Therefore, the texture could not be visually recognized in the texture visibility test (evaluation C).

In test number 17', the maximum thickness DKmax', the minimum thickness DKmin', and the colorant content CK'of the colored resin layer did not satisfy the formula (2'). Therefore, the texture could not be visually recognized in the texture visibility test (evaluation C).

In test number 18', the minimum thickness DKmin'of the colored resin layer and the colorant content CK'in the colored resin layer did not satisfy the formula (1'). Therefore, the texture could not be visually recognized in the texture visibility test (evaluation C).

In test number 21', the maximum thickness DKmax', the minimum thickness DKmin', and the colorant content CK'of the colored resin layer did not satisfy the formula (2'). Therefore, the texture could not be visually recognized in the texture visibility test (evaluation C).

In test number 22', the minimum thickness DKmin'of the colored resin layer and the colorant content CK'in the colored resin layer did not satisfy the formula (1'). Therefore, the texture could not be visually recognized in the texture visibility test (evaluation C).

In test number 25', the maximum thickness DKmax', the minimum thickness DKmin', and the colorant content CK'of the colored resin layer did not satisfy the formula (2'). Therefore, the texture could not be visually recognized in the texture visibility test (evaluation C).

In test number 26', the minimum thickness DKmin'of the colored resin layer and the colorant content CK'in the colored resin layer did not satisfy the formula (1'). Therefore, the texture could not be visually recognized in the texture visibility test (evaluation C).

(Example 3)
Of Example 1 and Example 2, test numbers 12, 14-16, 20-21, 25-26, 30-31, 13'-16', 19'-20', 23'-24', 27' The same paint was used for each of ~ 28', and the colored resin layers were coated in a plurality of times so as to have the same total film thickness to form a laminated resin layer. Those coated with the laminated resin are listed in Tables 3A and 3B by adding # to the original test number. In the laminated resin layer forming step, a production line including a resin layer production apparatus combining a colored resin coating apparatus and a baking furnace was used. When the resins were laminated, the resin layer was manufactured a plurality of times using the resin layer manufacturing apparatus. In test numbers 15 # and 15'#, a clear resin layer containing no coloring pigment was laminated as a third layer, and the number of laminated resin layers was set to 3 ("3" in the "number of layers" column of the "laminated resin layer" column. "). In test numbers 16 # and 16'#, a clear resin layer containing no coloring pigment was laminated as the first layer, and the number of laminated resin layers was set to 3 ("3" in the "number of layers" column of the "laminated resin layer" column. "). In the other test numbers for using laminated resin, the number of colored resin layers in the laminated resin layer was set to 2 (described as "2" in the "number of laminated resin" column in the "laminated resin layer" column).

[Evaluation test]
[Measurement of pigment content CK and thickness DK in each colored resin layer LK]
The pigment content CK and thickness DK of each colored resin layer of the laminated resin layer of each test number were measured by the following methods. With reference to FIG. 15A, the designable galvanized steel sheet was cut in the normal direction ND to prepare a cut surface CS including the normal direction ND and the plate width direction TD. With reference to FIG. 15B, in the cut surface CS, the direction perpendicular to the normal direction ND (plate width direction TD in this embodiment) is defined as the cut surface width direction CD. The cut surface CS was divided into three equal parts along the cut surface width direction CD. In each of the three equal compartments X1 to X3, a sample SA including the laminated resin layer 30 was collected at the center position of the CD in the width direction of the cut surface. Each of the three sample SAs contained at least a laminated resin layer 30 and a galvanized layer 10. The length of the CD in the width direction of the cut surface was 10 mm, and the length in the direction perpendicular to the ND in the normal direction and the CD in the width direction of the cut surface was 10 mm. A sample in which the laminated resin layer 30 and the galvanized layer 10 can be observed with a transmission electron microscope was prepared for the cut out sample SA by using a focused ion beam device (FIB).

The surface (observation surface) including the normal direction ND and the cut surface width direction CD of the sample SA was observed with a 2000 times reflected electron image (BSE) using a scanning electron microscope (SEM). In the observation with the backscattered electron image (BSE) of the scanning electron microscope (SEM), the base steel plate, the galvanized layer, and the laminated resin layer could be easily distinguished by the contrast. Further, among the laminated resin layers, each colored resin layer was identifiable by its contrast because resin layers having different compositions were used.
After identifying each colored resin layer, the content CK (volume%) of the pigment in each colored resin layer and the average thickness DK of each colored resin layer were determined by the following method.

In the observation with a transmission electron microscope, the total area A1 (μm ² ) of the plurality of pigments in the colored resin layer on the observation surface was determined. Then, the area A0 (μm ² ) of the colored resin layer on the observation surface was determined. Based on the obtained total area A1 and area A0, the area ratio (area%) of the pigment in the colored resin layer was determined by the following formula.
Area ratio = A1 / A0 × 100

The area ratios of the pigments described above were obtained in three samples, and the average of the obtained three area ratios was defined as the pigment content CK (volume%) of the colored resin layer.

Further, in each sample SA, the thickness (μm) was measured at any one point of each colored resin layer. The average of the three thicknesses obtained in the three sample SAs was defined as the thickness DK (μm) of the colored resin layer. By the above method, the pigment content CK (area%) and the thickness DK (μm) of each of the identified colored resin layers were determined.

Based on the pigment content CK and the thickness DK of each colored resin layer, the color density index IK, which is an index of the color density of each colored resin layer, was obtained by the following formula.
Color density index IK = CK x DK

In addition, the total value of the color density index of each colored resin layer was obtained. The obtained total value is shown in the "total color density index" column of the "laminated resin layer" column in Tables 3A and 3B.

[Measurement of thickness of laminated resin layer]
The thickness of the laminated resin layer 30 was measured by the following method. With reference to FIGS. 15A and 15B, in the cut surface CS, the direction perpendicular to the normal direction ND is defined as the cut surface width direction CD (corresponding to the plate width direction TD in this embodiment). The cut surface CS was divided into three equal parts along the cut surface width direction CD. In each of the three equal compartments X1 to X3, a sample SA including the laminated resin layer 30 was collected at the center position of the CD in the width direction of the cut surface. Each of the three sample SAs contained at least a laminated resin layer 30 and a galvanized layer 10. The length of the CD in the width direction of the cut surface was 10 mm. Of the sample SA, the length in the direction perpendicular to the normal direction ND and the cut surface width direction CD was set to 10 mm. Gold vapor deposition was applied to the cut surface CS of the cut-out sample SA. After that, the sample SA was sandwiched between the backing plates, embedded in the resin, and polished to prepare an observation sample having the cut surface CS as the observation surface. The observation surface of the observation sample was observed with a 2000x backscattered electron image (BSE) using a scanning electron microscope (SEM). The base steel plate 100, the galvanized layer 10, and the laminated resin layer 30 could be easily distinguished by the contrast in the observation with the reflected electron image (BSE) of the scanning electron microscope (SEM). In each sample SA, the thickness of the laminated resin layer 30 was measured at 10 points at a pitch of 100 μm in the cut surface width direction CD. The average value of the thicknesses (30 points in total) measured by the three sample SAs was defined as the thickness (μm) of the laminated resin layer 30. The measured thickness (μm) of the laminated resin layer is shown in the “total film thickness” in the “laminated resin layer” column in Table 1.

[Selection of the _darkest colored resin layer L _1ST and the second dark colored resin layer L _2ND ]
Among the colored resin layers, the colored resin layer having the largest color density index IK is defined as "the _darkest colored resin layer L _1ST ", and the coloring having the highest color density index IK next to the _darkest colored resin layer L _1ST. The resin layer, that is, the colored resin layer having the second highest color density index IK was defined as "second dark colored resin layer L _2ND ". The pigment content (area%) of the _darkest colored resin layer L _1ST was defined as "C _1ST ", and the thickness (μm) of the _darkest colored resin layer L _1ST was defined as "D _1ST ". Pigment content of the second dark colored resin layer _{L 2ND} (area%) is defined as _{"C 2ND",} thickness of the second dark colored resin layer _{L 2ND} the ([mu] m) is defined as _{"D 2ND".} The thickest colored resin layer _{L 1ST} pigment content _{C 1ST,} thickness _{D 1ST,} pigment content of the second dark colored resin layer _{L 2ND} _{C 2ND,} the thickness _{(μm) D 2ND} in Table 3A and Table 3B Shown. The "lamination position" in the " _darkest colored resin layer L _1ST " column in Tables 3A and 3B indicates how many layers the _darkest colored resin layer L _1ST was. For example, test number 12 # indicates that the _darkest colored resin layer _L1ST was the first layer. Similarly, the “lamination position” in the “second dark colored resin layer L _2ND ” column in Tables 3A and 3B indicates how many layers the second dark colored resin layer L _2ND was. For example, test number 12 # indicates that the second dark colored resin layer L _2ND was the second layer.

Further, by using the thickest colored resin layer _{L 1ST} pigment content _{C 1ST,} thickness _{D 1ST,} pigment content of the second dark colored resin layer _{L 2ND} _{C 2ND,} the thickness _{(μm) D 2ND,} following The color density ratio RF was determined by the formula.
Color density ratio RF = (C _1ST x D _1ST ) / (C _2ND x D _2ND )
The obtained color density ratio RF is shown in the "color density ratio RF" column of the "laminated resin layer" column in Tables 3A and 3B.

[Galvanized layer surface visibility test]
Each sample was placed in an environment equivalent to sunlight (illuminance of about 65,000 lux) in the morning on a clear day, and it was judged whether or not the surface of the base steel sheet 100 could be visually recognized.

[Color unevenness evaluation test]
The color unevenness of the designable galvanized steel sheet of each test number was evaluated by the following method. With reference to FIG. 16, 81 measurement points (P1 to P81) at an arbitrary measurement line segment OD1 of 1200 mm perpendicular to the extending direction HD of the hairline 23 of the designable galvanized steel sheet 1 of each test number at a pitch of 15 mm. ) Was identified. At each measurement point P1 to P81, the L ^* a ^* b ^* color system's L ^* value, a ^* value, and b ^* value were determined. Then, the ΔL ^* value, the Δa ^* value, and the Δb * value at the two adjacent measurement points Pi and Pi + 1 (i is a natural number of 1 to 80) were obtained by the following equations.
ΔL ^* = L ^* i-L ^* i + 1
Δa ^* = a ^* i-a ^* i + 1
Δb ^* = b ^* i-b ^* i + 1

Then, based on the obtained ΔL ^* , Δa ^* , and Δb ^* , the color difference ΔE ^* at two adjacent measurement points was obtained by the following equation.
ΔE * = ((ΔL ^* ) ² + (Δa ^* ) ² + (Δb ^* ) ² )

Based on the obtained 80 ΔE ^* , the color unevenness was evaluated as follows.
Score G: 90% or more of the color difference ΔE ^* between two adjacent points is 2.0 or less Score P: 11% or more of the color difference ΔE ^* between two adjacent points is more than 2.0

The obtained results are shown in the "color unevenness" column of the "evaluation test" column in Tables 3A and 3B.

[Color variation evaluation test]
The color variation of the designable galvanized steel sheet of each test number was evaluated by the following method. With reference to FIG. 17, in the designable galvanized steel sheet 1 of each test number, 20 measurement positions S1 to S20 were specified at a pitch of 50,000 mm (50 m pitch) in the rolling direction RD. Then, at each of the measurement positions S1 to S20, the color difference ΔE ^* of the measurement points Q1 and Q2 at intervals of 1000 mm in the direction orthogonal to the extending direction HD of the hairline (orthogonal direction OD) was obtained.

Based on the obtained 20 color differences ΔE ^* , the color variations were evaluated as follows.
Score G: All 20 points are ΔE * ≤ 3.0
Score P: 1 or more ΔE *> 3.0 out of 20 points

The obtained results are shown in the "Color variation" column of the "Evaluation test" column in Table 1.

In the color unevenness evaluation test and the color variation evaluation test, the L ^* values, a ^* values, and b ^* values of the measurement points P1 to P81, Q1 and Q2 are colorimeters manufactured by Konica Minolta Co., Ltd. Product name: CM-2600d) was used. In the measurement, a CIE standard light source D65 was used as a light source, the viewing angle was 10 °, and the L ^* value, a ^* value, and b ^* value were obtained in the CIELAB display color by the SCE method.

The SCE method is called a specular light removal method, and means a method of measuring color by removing specular light. The definition of the SCE method is defined in JIS Z 8722 (2009). In the SCE method, since the specularly reflected light is removed for measurement, the color is close to the color seen by the actual human eye (so-called visual color).

The CIELAB display color is a uniform color space recommended in 1976 and defined in JIS Z 8781 (2013) for measuring color differences due to differences in perception and equipment. The three coordinates of CIELAB are indicated by L ^* value, a ^* value, and b ^* value. The L ^* value indicates the brightness and is indicated by 0 to 100. When the L ^* value is 0, it means black, and when the L ^* value is 100, it means a diffuse color of white. a ^* Value indicates a color between red and green. If the a ^* value is negative, it means a color closer to green, and if it is positive, it means a color closer to red. b ^* Value means a color between yellow and blue. If b ^* is negative, it means a color closer to blue, and if it is positive, it means a color closer to yellow.
[Evaluation results]

With reference to Tables 3A and 3B, the test numbers that were not laminated resinized (those not marked with #) were rated "P" for either "color unevenness" or "color variation", or both. On the other hand, all the test numbers (marked with #) made of laminated resin were evaluated as "G" for both "color unevenness" and "color variation".

1, 1'plated steel sheet 10, 10'zinc plated layer 10S, 10S'texture 11, 11'colored resin layer 30 laminated resin layer 31, 31'resin 32, 32'colorant 100, 100'base steel sheet

Claims

It is a plated steel sheet
A base steel plate with a base material texture on the surface and
A zinc-plated layer formed on the surface of the base steel sheet having the base material texture,
A colored resin layer formed on the galvanized layer is provided.
The galvanized layer has a plating texture on its surface.
The colored resin layer contains a colorant and
The plating texture is
With multiple protrusions,
Including multiple recesses
When the rolling direction of the base steel sheet is defined as the first direction and the direction orthogonal to the first direction is defined as the second direction on the surface of the plated steel sheet, the plated steel sheet has the following (A) to ( C) is satisfied
Plated steel plate.
(A) When the roughness profile of the plating texture in the range of 1000 μm in the second direction is measured, and the lowest position in each of the recesses in the measured roughness profile is defined as the recess bottom point. Among the plurality of recess bottom points of the roughness profile, 10 recess bottom points are specified in ascending order, and a three-dimensional average of a minute region of 1 μm × 1 μm centered on the identified recess bottom points. When the roughness Sa is measured and the arithmetic average value of the measured 10 three-dimensional average roughness Sa is defined as the concave bottom three-dimensional average roughness Sa, the concave bottom three-dimensional average roughness Sa is more than 200 nm and 2000 nm or less. Is.
(B) In the range of 100 μm length in the second direction, the minimum thickness (μm) of the colored resin layer is defined as DKmin, and the content (area%) of the colorant in the colored resin layer is CK. When F1 is defined by the equation (1), the F1 is 15.0 or less.
F1 = DKmin x CK (1)
(C) When the maximum thickness (μm) of the colored resin layer is defined as DKmax and F2 is defined by the formula (2) in the range of 100 μm length in the second direction, the F2 is 1.0. Is also big.
F2 = (DKmax-DKmin) x CK (2)
The plated steel sheet according to claim 1, further satisfying the following (D).
Plated steel plate.
(D) The roughness profile of the plating texture in the range of 1000 μm in the second direction is measured, and the highest position in each of the convex portions in the measured roughness profile is defined as the convex portion top point. When this is done, 10 of the convex top points of the roughness profile are specified in descending order of the highest, and a minute size of 1 μm × 1 μm centered on the specified convex top points. When the three-dimensional average roughness Sa of the region is measured and the arithmetic average value of the measured ten three-dimensional average roughness Sa is defined as the convex top three-dimensional average roughness Sa, the convex top three-dimensional average roughness The Sah is more than 5 nm and 200 nm or less.
The plated steel sheet according to claim 2.
The plurality of the convex portions and the plurality of the concave portions extend in the first direction.
The plurality of protrusions and the plurality of recesses are arranged in the second direction.
Plated steel plate.
The plated steel sheet according to claim 3.
The base material texture is a hairline
The plating texture is a hairline
The plated steel sheet is further
Satisfy the following (E) and (F),
Plated steel plate.
(E) The surface roughness Ra of the colored resin layer in the first direction is defined as Ra (CL), the surface roughness Ra of the colored resin layer in the second direction is defined as Ra (CC), and F3. Is defined by the equation (3), the F3 is 1.10 or more.
F3 = Ra (CC) / Ra (CL) (3)
(F) When the surface roughness of the galvanized layer in the second direction is defined as Ra (MC), Ra (MC) is 0.30 μm or more.
The plated steel sheet according to any one of claims 1 to 4.
The brightness L * (SCI) when the plated steel sheet is viewed from the colored resin layer side is 45 or less.
Plated steel plate.
The plated steel sheet according to any one of claims 1 to 5.
F1 is 13.5 or less,
Plated steel plate.
The plated steel sheet according to any one of claims 1 to 6.
F2 is greater than 2.0,
Plated steel plate.
The plated steel sheet according to any one of claims 4 to 7.
The F3 is 1.15 or more.
Plated steel plate.
The plated steel sheet according to any one of claims 1 to 8.
The base iron exposure rate of the galvanized layer is less than 5%.
Plated steel plate.
The plated steel sheet according to claim 2.
The plurality of convex portions are formed by polishing the surface of the galvanized layer.
The plurality of recesses are not polished,
Plated steel plate.
It is a plated steel sheet
Base steel plate and
The galvanized layer formed on the surface of the base steel sheet and
A colored resin layer formed on the galvanized layer is provided.
The galvanized layer has a texture extending in one direction on its surface.
The colored resin layer contains a colorant and
Satisfy all of the following (A') to (C'),
Plated steel plate.
(A') The roughness profile in the range of a length of 1000 μm in the direction perpendicular to the extending direction of the texture is measured, and 10 points are specified in ascending order of height among the measured positions on the roughness profile. The determined position is defined as the concave bottom point, and among the measured positions on the roughness profile, the position where 10 points are specified in descending order of height is defined as the convex apex, and each concave bottom point and each convex apex are defined. When the three-dimensional average roughness Sa'of a minute region of 1 μm × 1 μm centered on the above is measured and the arithmetic average value of the measured three-dimensional average roughness Sa'is defined as the three-dimensional average roughness Saave', it is cubic. The original average roughness Save'is more than 5 nm and 200 nm or less.
(B') The minimum thickness (μm) of the colored resin layer is defined as DKmin'in the range of 100 μm length in the direction orthogonal to the extending direction of the texture, and the colorant in the colored resin layer. When the content (area%) is defined as CK', the formula (1') is satisfied.
DKmin'× CK'≤15.0 (1')
(C') The formula (2') is satisfied when the maximum thickness (μm) of the colored resin layer is defined as DKmax'in the range of 100 μm in the direction perpendicular to the extending direction of the texture.
(DKmax'-DKmin') x CK'> 1.0 (2')
The plated steel sheet according to claim 11.
The texture is a hairline
Satisfy the following (D') and (E'),
Plated steel plate.
(D') The surface roughness Ra of the colored resin layer in the extending direction of the texture is defined as Ra (CL)', and the surface roughness Ra of the colored resin layer in the direction perpendicular to the extending direction of the texture is defined. Is defined as Ra (CC)', the equation (3') is satisfied.
Ra (CC)'≧ Ra (CL)' × 1.10 (3')
(E') When the surface roughness of the galvanized layer in the direction orthogonal to the extending direction of the texture is defined as Ra (MC)', Ra (MC)'is 0.30 μm or more.
The plated steel sheet according to claim 11 or 12.
The base iron exposure rate of the galvanized layer is less than 5%.
Plated steel plate.
The plated steel sheet according to any one of claims 1 to 13.
The colored resin layer is a laminated resin layer.
The laminated resin layer is
A plurality of colored resin layers laminated in the normal direction of the surface of the base steel plate are provided.
In the plurality of colored resin layers, the total product of the content (area%) of the colorant in the colored resin layer and the thickness (μm) of the colored resin layer is 15.0 area% · μm or less. Yes,
Among the plurality of colored resin layers, the colored resin layer having the maximum product of the content (area%) of the colorant in the colored resin layer and the thickness (μm) of the colored resin layer is the darkest color. When defined as a colored resin layer, and the colored resin layer having the second largest product of the content of the colorant in the colored resin layer and the thickness of the colored resin layer is defined as the second dark colored resin layer,
The content of the colorant in the darkest colored resin layer C 1ST (area%), the thickness D 1ST (μm) of the darkest colored resin layer, and the colorant of the second dark colored resin layer. The content C 2ND (area%) and the thickness D 2ND (μm) of the second dark colored resin layer satisfy the formula (4).
Plated steel plate.
1.00 <(C 1ST x D 1ST ) / (C 2ND x D 2ND ) ≤ 4.00 (4)
The plated steel sheet according to claim 14.
The thickness of the laminated resin layer is 10.0 μm or less.
Plated steel plate.
The plated steel sheet according to claim 14 or 15.
The laminated resin layer further
Contains one or more transparent resin layers that do not contain the colorant
The laminated resin layer is
The plurality of colored resin layers and the one or a plurality of transparent resin layers are laminated and formed.
Plated steel plate.