JPH0649671A - Roll marking method - Google Patents

Abstract

PURPOSE:To form fine patterns having etching depths of plural levels on a roll surface by coating the roll surface with an acid resistant resin film and irradiating this film with impulsive laser beams to partially evaporate the film and etching the film to form the patterns on the roll surface. CONSTITUTION:Regions 1 formed with ordinary laser dots by changing the pulse pitch of the laser beams, regions 2 formed with the off states of the laser beams at every other dot and regions 3 not subjected to irradiation with the laser beams are formed and are etched, by which the patterns varying in depths are obtd.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a roll marking method for imparting a fine uneven pattern on the surface of a metal roll.

[0002]

2. Description of the Related Art Conventionally, an acid resistant resin coating is applied to the surface of a roll, and a pulsed laser beam is emitted from a YAG laser with a Q switch to evaporate the coating so that a part of the coating has a desired pattern. There is a roll marking technique for forming an uneven pattern on the roll surface by etching (irradiation step) and then etching the exposed portion of the roll surface by an etching treatment (etching step) (JP-A-2-175882).

[0003]

In the roll marking method for imparting a fine uneven pattern to the surface of a metal roll, when the acid resistant resin film is evaporated in a desired pattern, for example, a size of 5 dots × 5 dots, After irradiating a dot portion (25 dots) of laser light to remove the acid-resistant resin film on the irradiated portion, the exposed portion was etched to form a pattern with a certain depth on the roll surface.

The present invention is a further improvement of the above method, and an object of the present invention is to provide a technique for forming a pattern depth in a plurality of steps. That is, as a pattern made of a decorative steel plate or the like used in a building material or the like, for example, in the case of a photograph, it is conventionally a binarized dot pattern and cannot be realistically expressed.

[0005]

The present invention is a method of applying an acid resistant resin coating on a roll surface, irradiating a pulsed laser beam to partially vaporize the coating, and forming a pattern on the roll surface by etching. The roll marking method is characterized in that the pulse pitch of the laser light is changed to form the pattern depth in a plurality of steps. In this case, it is preferable to set the pulse pitch of the laser light to 10 to 100 μm.

In the present invention, when the roll irradiation data is created, the pitch of the data is adjusted so as to make the etching rate different in the subsequent etching process.

[0007]

[Function] When the acid-resistant resin coating applied to the roll surface is irradiated with pulsed laser light to be evaporated,
When the pulse pitch of the laser beam is changed, the residual degree of the acid resistant resin coating varies, the resin coating completely disappears in the portion where the pulse pitch is dense, and the coating remains in the portion where the pulse pitch is coarse. When this difference is generated, it appears as a difference in erosion depth during etching. That is,
Even if etching is performed under the same etching conditions, the etching depth differs depending on the dot spacing of the laser light pulse. The present invention utilizes this difference to process a pattern having a plurality of steps of unevenness with different depths by a single etching process.

As the material of the acid resistant resin coating, for example, an acrylic resin described in Japanese Patent Application No. 3-44816 to which carbon black and a cellulose derivative are added may be used. This is because the absorption efficiency of laser light can be increased, and irradiation processing can be effectively performed even with low energy. The pulse pitch of the laser light is based on the type of acid resistant resin coating,
Depending on the thickness, type of etching solution, etching conditions, etc.,
It can be determined experimentally. Usually 10-100 μm
Is suitable.

[0009]

Embodiments of the present invention will now be described in detail with reference to the drawings. FIG. 1 is a plan view of the surface of a roll schematically showing an example of marking according to an embodiment of the present invention. The laser light irradiation condition is a power of 50 μJ and a repetition rate of 50.
It was performed at kHz. A region 1 is a region where normal laser dot irradiation is performed, a region 2 is a region where laser light is turned off every other dot, and a region 3 is a region where laser light is not irradiated. A cross-sectional view of the vicinity of the surface of the roll 10 after laser light irradiation is shown in FIG. In the region 3, the acid resistant resin film 4 remains as it is, and in the region 1, the acid resistant resin film is completely removed. On the other hand, in the region 2, the acid resistant resin film 4 remains in a porous shape.

FIG. 3 shows a cross-sectional view of the vicinity of the surface of the roll 10 after etching the roll of FIG. 2 to remove the acid resistant resin film. Corrosion is weaker in the region 12 corresponding to the portion of the region 2 irradiated with the laser beam every other dot than in the region 11 corresponding to the portion of the region 1 irradiated with the normal laser dot, and the recessed portion has a shallow depth. I was able to make a roll. FIG. 5 shows an example of the relationship between the laser dot interval and the etching depth. As shown in FIG. 3, the region 13 not irradiated with the laser is not etched, and the region 11 is 10 to 15
The region 12 has a depth of 5 to 10 μm.

FIG. 4 shows a steel plate 2 rolled by using this roll.
0 shows the cross-sectional shape near the surface of the roll.
A convex portion 21 having an unevenness opposite to 0 and a concave portion 2 having a depth of 2 to 5 μm
2. A recess 23 having a depth of 5 to 10 μm is formed.

[0012]

According to the present invention, a fine pattern having a plurality of levels of etching depth can be formed on the surface of the roll. Using this roll, a steel sheet having a halftone pattern can be easily manufactured. That is, it is possible to express a delicate contrast by changing the depth of the convex portion. Further, for example, since it becomes easy to manufacture a steel sheet having a pattern having a plurality of levels of depth, steel sheets having different press formability (deep drawability) can be produced from one type of steel sheet. Therefore, it is possible to supply a small number of steel sheets to a large number of steel sheets according to the press formability, which contributes to simplification of the plate making process and rationalization of the transportation process to the user. Is large.

[Brief description of drawings]

FIG. 1 is a schematic diagram showing a laser beam irradiation pattern on a roll surface.

FIG. 2 is a cross-sectional view (in the direction of arrow AA in FIG. 1) near the roll surface after laser light irradiation.

FIG. 3 is a cross-sectional view near the roll surface after etching.

FIG. 4 is a cross-sectional view of the surface of a steel sheet rolled by using the roll of the example.

FIG. 5 is a graph showing the relationship between the pulse dot interval of laser light and the etching depth.

[Explanation of symbols]

 1, 2, 3, 11, 12, 13 Region 4 Acid-Resistant Resin Coating 10 Roll 20 Steel Plate 21 Convex Part 22, 23 Concave

Claims (2)

[Claims] 1. A roll surface is coated with an acid-resistant resin coating, which is irradiated with pulsed laser light to partially vaporize the coating,
A method of forming a pattern on a roll surface by etching by etching, wherein a roll marking method is characterized in that a pulse pitch of laser light is changed to form a pattern depth in a plurality of steps. 2. A laser light having a pulse pitch of 10 to 100.
The roll marking method according to claim 1, wherein the roll marking method is μm.