JPH0280513A - Metal plate for exterior - Google Patents

Abstract

PURPOSE:To improve removability of dirt and utility value for exterior by forming fine recessed part specifying shape and distribution on bare surface of a metal plate specifying surface roughness. CONSTITUTION:The surface of the metal plate, such as steel plate, is made to <=3mum Rmax of the roughness. This bare surface 1 is rolled with a dull roll, etc., and the recessed parts 2 having 5-15mum Rmax are uniformly distributed. This recessed parts 2 are formed so as to satisfy the relations W/h >=1, -20mum<=l<=200mum, W>=5mum, at the time of using W for the max. width, (h) for depth and (l) for interval between the adjoining recessed parts. As this metal plate has excellent designing, difficult to soiling and good removability of the attached dirt, this can be used for various kinds of exteriors.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a metal plate with excellent stain removability and suitable for use without painting as an exterior panel (exterior material) of vehicles, buildings, etc.

(Prior Art) Recently, the exterior panels of vehicles, buildings, office equipment, kitchen equipment, etc. are often used without painting, taking advantage of the beauty of the metal base as a design. This is because, along with changes in the aesthetic appeal of general consumers, product manufacturers are aiming to reduce costs by omitting the painting process.

For example, unpainted stainless steel is widely used for vehicle exterior panels, and unpainted stainless steel plates, titanium plates, etc. are also used for the walls of buildings.

If the surface of these metal plates is given a so-called prite finish, the metallic luster will be too strong, the depth will be poor, and there will be problems with light reflection, so it is usually dull finished (with minute irregularities on the surface).

It is used in a satin finish (also called a satin finish).

Metal plates like the one above take advantage of the beauty of their base material, but it is inevitable that they will get dirty with hand marks and dust during use, and the surface needs to be cleaned periodically or when dirt becomes noticeable. It is. As can be seen in the example of railway vehicles, cleaning work must be carried out efficiently, with simple water washing,
Alternatively, it is desirable that dirt can be removed by wiping with a cloth.

However, although this dirt removal property is good for bright finished materials, it is extremely poor for dull finished materials because dirt gets into the minute irregularities on the surface.

(Problems to be Solved by the Invention) The present invention provides a metal plate that must be given a dull finish from the viewpoint of design and light reflection, and which is resistant to stains such as hand marks and dust. The purpose of the present invention is to provide a metal plate from which dirt can be easily removed (collectively referred to as "stain removability").

The metal plates to which the present invention is applied are, in principle, those used without coating, but metal plates to which thin clear coating, printing, etc. have been applied are also applicable. This is because even if such a thin coating is subjected to hI, the influence of minute irregularities on the surface of the metal plate remains, and dirt removal becomes a problem.

(Means for solving problems) The gist of the present invention is the following metal plate.

'R■aX on a base surface with a roughness of Rmax of 3μ or less
is a metal plate made of 5-15μ steel with uniformly distributed recesses, the maximum width of the recess is W, the depth is R, and the interval between adjacent recesses is 2, then the following ■, ■, and Exterior metal plate with excellent dirt removal ability that satisfies the following relationship: ■ W/h ≧ 1 ■ -20ueA ≦2≦200 μm ■ W ≧ 5 μm The dull processing on the surface of the metal plate has a microscopic effect on the surface. This is usually done by rolling with a roll (tall roll) with unevenness and transferring the unevenness on the roll surface to the surface of the metal plate. The dull roll itself is manufactured by shot blasting or electric discharge machining, and the roll surface obtained by this process has a dull surface with irregular minute irregularities. Naturally, the surface of the metal plate onto which this has been transferred also has irregular minute irregularities distributed randomly.

The present inventor conducted an investigation based on the belief that the poor dirt removal properties of conventional dull surfaces of metal plates are caused by the shape and distribution of minute irregularities. As a result, for metal plates rolled with ordinary rolls (dull rolls), the ability to remove dirt is correlated with the roughness R+may of the surface of the metal plate, and it is possible to improve the ability to remove dirt by reducing Rax. I found out that it can be done. However, if Rmax is made too small, the surface of the metal plate becomes close to a bright finish, which causes problems in terms of design and light reflection.

In the present invention, the surface roughness and the shape and distribution of micro-irregularities are precisely adjusted to determine a surface condition that does not have problems with design or light reflection and has good dirt removal properties.

As mentioned above, the metal plate of the present invention has a surface roughness Rm
Along with ax, the shape and distribution state of the recesses distributed in the base material are specified. Such surface states can be created using high energy density beams (
For example, it can be manufactured by dulling a roll using a laser beam and rolling a metal plate with the roll. (For the processing of rolls using a laser beam, for example, Japanese Patent Publication No. 62-11922
It is disclosed in the publication No. ) (Function) FIG. 1 is an enlarged schematic diagram of the surface of the metal plate of the present invention, and (a
) is a plan view, and (b) is a sectional view taken along the line B-B of (a).

In FIG. 1, 1 is the base surface of the metal plate, and 2 is the concave portions distributed on the base surface. The metal plate shown in this figure was rolled using the laser-beam-processed dull roll described above. In this case, the roll surface has crater-like unevenness formed by a ring-shaped protrusion and four parts surrounded by the ring-shaped protrusion. Therefore, a ring-shaped recess 2 as shown in the figure is formed in the metal plate rolled by the roll. Note that the portion 3 in FIG. 1 corresponds to the depression of the crater of the roll, and usually the surface condition (bright surface) of the plate before rolling remains as it is. This part does not affect dirt removal performance and has a small area ratio, so it does not have a large effect on the design of the board.

Here, if the roughness of the base surface 1 is Rmax of 3 μ■ or less, the maximum width of the recess 2 is W, the depth is h, and the interval between adjacent recesses 2 is 2, then ■ W/ The shape and distribution of the four parts are adjusted so as to satisfy the following relationships: h ≧ 1 ■ -20 μl ≦l≦200 μl ■ W≧5 μl.

Figure 2 shows RIIIa of the base surface before adding the above-mentioned recesses.
These are the results of investigating the relationship between x and dirt removal performance.

That is, a JIS 5IIS 304 stainless steel plate is rolled with a roll that has been dulled by shot blasting, and colored grease is applied to the surface adjusted to various Rmax.
After leaving it for 3 days, it was wiped off with a rag and the remaining dirt was visually observed. Based on the area where dirt is hardly noticeable, as shown in Figure 2, Rmax of 3μm or less is considered "good".From this result, the roughness of the base surface is Rmax of 3μm or less.
The following is specified.

Figure 3 shows the R of the base surface in the above stainless steel plate.
After setting the max to 1.0 μm, the film was rolled using a roll with unevenness by laser beam processing to form recesses of different W and h, and the relationship between W/h and stain removal performance was observed. W
When /h is 1 or more, the dirt removability is "good". This means that if the depth (h) is too large relative to the maximum width (W) of the recess, the four parts become steep and the inside of the recess becomes steep. This is because it becomes difficult to remove the dirt that has entered the recess.The cross-sectional shape of the recess, for example the radius of curvature of the bottom of the recess, is also thought to affect the dirt removal ability, especially when the surface of the metal plate is rolled with a laser beam processing roll. The recess has a relatively smooth cross-sectional curve as shown in FIG. 1, and has no substantial effect when W/h is 1 or more.

Figure 4 shows W/h=
These are the results of investigating the relationship between the distance HC1) between four adjacent parts and the glossiness on the surface of a stainless steel plate with four concave parts.

If the gloss level is too high, the design will be impaired and there will be problems with light reflection. In this study, stainless steel plates (Rmax 10 to 11μ) commonly used for vehicle exterior panels were used.
Based on the gloss level of fin-like roughness), the range with lower gloss level was defined as "good".

As shown in Figure 4, when 2 is less than 200 μm, the gloss level is “
Since the metal plate of the present invention has a relatively small Rmax on the base surface and has a high gloss level, it is necessary to distribute the concave portions at a certain high density.

The standard is l≦200μm. On the other hand, if the distribution density of the recesses is too high, not only will the gloss become too low, but the recesses will overlap each other to a large extent, making the shape of the recesses irregular and causing disorder. As a result, dirt removal performance deteriorates. Therefore, P should be -20μ1 or more. In addition, -2
The 0μ view means that a certain amount of overlap in the recess is allowed.

The reason why the maximum width (W) of the recess is set to 5 μm or more is because if it is smaller than this, there is no point in adjusting the glossiness by creating a recess.

As mentioned above, when rolled with a roll that has been dulled with a laser beam, the recesses on the surface of the metal plate are generally ring-shaped as shown in Figure 1. However, the shape of the recesses is not limited to this. For example, it may be half-moon or crescent-shaped.Also, there are no particular restrictions on the outer diameter (d) of the recess, but if it is too large, the recess will become too conspicuous and undesirable from a design standpoint.Generally, it is less than 500μm. is the desired range.

It is desirable that the above-mentioned recesses are distributed as evenly as possible on the surface of the metal plate.In a roll that has been dulled with a laser beam, it is desirable that the above-mentioned craters are regularly formed at equal intervals. Although it is common, the microscopic arrangement does not necessarily have to be regular; when the arrangement of the recesses is microscopically irregular, l is the average spacing between adjacent recesses.

(Example) JIS SO3304 stainless steel plate (thickness 0.8+s
A sample was prepared with a dull finish on the surface under the conditions described below, and the stain removability and surface glossiness were measured using the sample. The results are shown in Table 1.

1. Sample Preparation Comparative Sample: Rolled with a roll that was dulled by shot blasting to give an Rmax of 6 to 8μ intestine surface (
Sample Na1) and a temporary (sample N[L2) with a bright finish rolled with a blind roll were also prepared.

Samples of examples of the present invention (including some comparative examples): The roll surface was first adjusted to various roughnesses by shot blasting, and then dulled with a laser beam to form various uneven patterns. A stainless steel plate was rolled using the roll, and samples having various base surface roughnesses and concave shapes as shown in Samples Nos. 3 to 11 in Table 1 were prepared.

In addition, l! The recesses of samples N113 to 1O except No. 19 are the first
It is ring-shaped as shown in the figure, and the concave portion of Nα9 is crescent-shaped.

ii. Evaluation method Stain removability: Based on the same evaluation method as the test shown in FIG. 2 above. Table 1 shows “゛゛゛゛゛゛Poor.

is indicated with an x.

Glossiness: Based on the method of JIS Z8741. Sample N
[The glossiness of Ll (28%) is considered to be standard in terms of design and other aspects. Here, if the glossiness is 40% or less, it is considered that there is no problem in practical use, so it is rated as good (0).

As is clear from Table 1, when the R-ax of the base surface is 4 μm or more (kl and 5), dirt removal is poor, and even if the Rmax of the base surface is 1.5 μm, W/h Nα11 with a value smaller than 1 also has poor stain removal properties.

On the other hand, the bright finishing material of Seed 2 is out of the question, and the gloss of No. 8 where the interval 2 between the recesses is 250 μm is also not good (the gloss is too high).

From these results, it can be seen that the metal plate that satisfies the conditions of the roughness of the base surface and the shape and distribution of the recesses defined by the present invention is excellent in both gloss and stain removability.

(Hereinafter, blank space) (Effects of the Invention) The present invention provides a metal plate that is excellent in design, is resistant to dirt, and is easy to remove dirt. A cold rolled steel plate, stainless steel
It can be manufactured from many metals, including 14 plates, titanium plates, copper plates, and other materials, and is highly useful for various exterior applications that are often exposed to the outside air and human hands.

[Brief explanation of the drawing]

FIG. 1 is an enlarged schematic view of the surface layer of an example of the metal plate of the present invention, in which (a) is a plan view and (b) is a cross-sectional view taken along line B--B of (a). Figure 2 is a diagram showing the relationship between the roughness (Relax) of the metal plate surface and lη peeling resistance. Figure 3 is a diagram showing the maximum width (W) and depth (h) of the recess on the metal plate surface.
) and the dirt removability, and FIG. 4 is a diagram showing the relationship between the interval (N) of the recesses on the surface of the metal plate and the glossiness.

Claims (1)

[Claims] R_m_a_x is R on a base surface with a roughness of 3 μm or less.
It is a metal plate in which recesses with _m_a_x of 5 to 15 μm are uniformly distributed, the maximum width of the recesses is W, the depth is h,
When the interval between adjacent recesses is l, the following (1), (
An exterior metal plate that satisfies the relationships of 2) and (3) and has excellent dirt removal properties. (1) W/h≧1 (2) -20μm≦l≦200μm (3) W≧5μm