JPH03204108A - Method for forming projecting and recessing pattern on surface of dull roll for rolling steel sheet - Google Patents

Abstract

PURPOSE:To improve the ease of the shape control of a recessed motif by forming a hot-dipped covering layer on the recessed motif of roll surface which is formed by radiating a laser beam on the covering of photosensitive resist and developing treating. CONSTITUTION:The photosensitive resist is applied on the surface of work roll 1 for rolling and the resist layer 9 is hardened by radiating the laser beam 4 while revolving the roll 1 and the motif is formed on the surface of roll by washing unhardened parts of the roll 1. Next, after a hard metallic plating layer 15 is formed on that motif, the hardened resist layer is stripped. In this way, the shape control of recessed motif 11 can be facilitated and a surface treated steel sheet with the high rate of flatness can be manufactured.

Description

[Detailed description of the invention] (Industrial application field) This invention has good formability during press processing etc.
The present invention also relates to a method for forming an uneven pattern on the surface of a dull roll for rolling a steel plate for producing a steel plate or a surface-treated steel plate having paint clarity.

(Conventional technology) It is known that steel plates used in automobiles and home appliances are required to have good paint clarity to increase product value. Conventionally, improvement in paint clarity has been achieved only by improving the paint or coating method. has been given importance.

On the other hand, in order to improve paint adhesion and press workability, automotive steel sheets are rolled using dull rolls with minute irregularities during the manufacturing process to give them a certain surface roughness.

To dull the surface of a work roll, a shot blasting method in which a steel grid is projected onto the roll surface, and an electrical discharge machining method in which the roll surface is melted with electrical discharge energy to form irregularities have been put into practical use.

In addition, in recent years, a laser dull processing method using a laser beam with excellent controllability as an energy source for dull processing has been proposed, for example, in Japanese Patent Publication No. 11922/1982 or Japanese Patent Application Laid-Open No. 11/1982.
There is a publication No. 2088.

(Problem to be solved by the invention) In rolling, steel plates are manufactured by transferring the uneven pattern on the roll surface onto the steel plate surface, but the press formability of the steel plate depends on the mechanical properties such as the r value and elongation of the steel plate. In addition, steel plate surface roughness and lubricating oil have a large influence. Generally, the lubricating oil accumulated in the concave portions of the concavo-convex pattern is evenly supplied to the convex portions, thereby improving lubrication conditions and improving press formability, that is, preventing mold galling.

On the other hand, increasing the surface roughness reduces the sharpness of the steel sheet and affects its commercial value, so it is considered difficult to achieve both press formability and sharpness.

The present invention proposes a method for forming an uneven pattern on the surface of a dull roll for producing a steel plate or a surface-treated steel plate that has excellent press formability such as deep drawing and has near-mirror sharpness.

(Means for Solving the Problems) The present invention coats the surface of a rolling work roll with a photosensitive resist agent or film, and intermittently irradiates high-density energy while rotating the roll, thereby forming a resist layer. It is characterized by curing, cleaning the uncured portion of the roll to form one or more motifs on the roll surface, forming a hard metal plating layer on the motif, and then peeling off the hardened resist layer. This is a method of forming an uneven pattern on the surface of a dull roll for rolling a steel plate, in which a hard metal plating film is formed on the surface of a work roll for rolling, the surface of the plating film is coated with a photosensitive resist agent or film, and the roll is The resist layer is cured by intermittently irradiating high-density energy while rotating, and the uncured portion of the roll is evaporated to form one or more motifs on the roll surface, and the motif is coated with hard metal. This method includes a method of forming a plating layer to form a two-layer plating layer.

The present invention will be explained below with reference to the drawings.

FIG. 1 shows an example of the flow of the present invention.

The rolling work roll 1 is placed on a rotary table and rotated, and a photosensitive resist agent IO is supplied from a hopper 2 during rotation. A squeegee 3 is provided at the bottom in the rotational direction of the roll to form a uniform layer of the photosensitive resist agent. The hopper 2 and the squeegee 3 are synchronously controlled and moved in the roll axis direction.

A photosensitive resist agent is composed of a polymerization initiator, a photosensitive 7-mer, a binder polymer, etc. The photo-sensitive 7-mer molecules are polymerized by irradiated light energy to form a polymer, and a commercially available photoresist is used. You can also do that.

The roll 1 is then uniformly coated with a photosensitive resist layer 9.
is irradiated with a high-density energy source. As a high-density energy source, for example, ultraviolet rays or an A laser 4 can be used to irradiate intermittently through the chopper 5. When the chopper 5 is given a desired rotational movement, the chopper 5
Laser light is irradiated at a constant pitch through the slits 6 provided in the. Therefore, by intermittent irradiation of the laser beam corresponding to the rotation of the chopper 5, locally hardened regions are continuously formed in the resist layer.

The resist layer provided with continuous locally hardened areas is then developed using a developer such as trichloroethane 8 with a sprayer 7 to wash away unhardened areas and form motifs.

That is, as shown in FIG. 2, a concave motif (main motif) 11 consisting of the roll surface 1' and the hardened resist layer 9 is formed on the roll surface.

In addition, since the boundary between the hardened layer and the non-hardened resist layer is formed very sharply, the sharpness of the base material can be obtained during post-treatment plating, which is effective in increasing the flatness area ratio. .

According to experiments, if the resist film thickness is 100 m or less, it is possible to form a hardened layer by laser irradiation.

After forming the pattern with the resist layer, for example, Cr or Ni
Plating the hard metal of the base. The plating may be either immersion plating or electroplating.

FIG. 3 is a schematic diagram of a cross section of a roll provided with a plating layer.

1 is a roll surface, 9 is a resist hardening layer, and 15 is a plating layer.

According to an experiment, the surfaces of the hardened resist layer 9 and the plated layer 15 have a step t, and the step t may be 10% of the hardened resist layer.

According to experiments conducted by the present inventors, it is preferable that the flatness ratio A≧85% is required to ensure high image clarity.

In general, baking is defined as the gloss of the painted surface, and gloss is defined as the degree to which the mirror image of the object reflected on the surface is clear and sharp. (JIS Z 8741). The flatness ratio A of the present invention is measured at 60° specular gloss.

In addition, no steel plate has been found to have a flatness ratio A≧85% among conventional steel plates.

In the present invention, after a hard metal plating layer is formed on the roll base material in a concave motif, the hardened resist area is removed with a cleaning solution, for example, a strong alkaline solution. On the surface of the resulting roll, an uneven pattern consisting of a hard metal plating layer is obtained over the entire roll area.

The formation of motifs is regular in a certain pattern, but is not necessarily limited to this. That is, they may be formed in a discontinuous manner.

In addition, the steel plate or surface-treated steel plate rolled with dull rolls produced by the method of the present invention has the etch bits formed on the roll surface transferred, improving the retention of processing oil during processing and exhibiting a good degree of processing. This retention requires various sizes and densities depending on the viscosity of the processing oil, but the present invention allows these to be controlled arbitrarily.

Although the work rolls for temper rolling are generally high carbon forged steel hardened rolls, the dull rolls of the present invention may be coated with a plating layer using a hard metal plating, such as a Cr or NI based plating bath.

Next, the present invention will be explained in detail.

A method of plating hard chrome on the surface of a work roll is known, but in the present invention, the first coating layer of hard metal is formed by hard chromium plating for 20 to 50 μs. Next, using the method described above, the surface of the plating roll is coated with a photosensitive resist agent or a layer, the resist layer is cured by irradiation with high-density energy, and the roll is developed with a developer to create a pattern composed of motifs. pattern is formed. A hard chromium plating layer is formed on the concave motif obtained by washing out the unhardened resist layer to form a two-layer plating layer, and then the hardened resist layer is removed with a cleaning solution, such as a strong alkaline solution. On the roll surface, a convex shape of two plating layers and four parts after peeling off of the hardened resist layer are formed.

(Effects of the Invention) The present invention irradiates a photosensitive resist agent or film with laser light and develops it with a developer to obtain one or more concave motifs on the roll surface. Since a coating layer of hot-dip plating is formed on the surface, the shape of the concave motif can be easily controlled.

Therefore, it is possible to produce a steel plate or a surface-treated steel plate with extremely high flatness, and it is possible to produce a steel plate or a surface-treated steel plate that has both press workability and image clarity.

[Brief explanation of drawings]

FIG. 1 is an explanatory diagram of the present invention, FIG. 2 is an enlarged explanatory diagram of section A in FIG. 1, and FIG. 3 is a detailed explanatory diagram of the present invention.

Claims (1)

[Claims] 1. The surface of a rolling work roll is coated with a photosensitive resist agent or film, and the resist layer is cured by intermittently irradiating high-density energy while rotating the roll. A dull roll for steel sheet rolling, characterized in that one or more motifs are formed on the surface of the roll by cleaning the unhardened part of the roll, a hard metal plating layer is formed on the motif, and then the hardened resist layer is peeled off. A method of forming an uneven pattern on the surface of. 2. By forming a hard metal plating film on the surface of a rolling work roll, coating the surface of the plating film with a photosensitive resist agent or film, and intermittently irradiating high-density energy while rotating the roll. Claim 1: Curing the resist layer, cleaning the uncured portion of the roll to form one or more motifs on the roll surface, and forming a hard metal plating layer on the motif to form a two-layer plating layer. Method described. 3. The method according to claim 1 or 2, wherein the surface of the dull roll from which the cured resist film layer has been peeled off is coated with a different material.