JPH03210906A - Method for forming irregular pattern on surface of dull roll for rolling steel sheet - Google Patents

Abstract

PURPOSE:To improve the quality of dull pattern by covering the seam of resist dry film which is continuously spirally wound on the surface of a dull roll with a liquid resist and controlling the thickness of film. CONSTITUTION:By using the method that a photosensitive resist film with which the surface of a work roll for rolling is covered is hardened with high- density energy irradiation and hard plating is performed on a motif that is formed by washing the unhardened part and, after that, the pattern is formed by stripping the hardened part and, after that, the pattern is formed by stripping the hardened layer, the liquid photosensitive resist 10 of 100 - 300 cp viscosity is sprayed on the seam 32 from a hopper 2 and the thickness of covering layer is controlled during the roll 1 on which the spirally wound dry film 30 is adhered is revolved. In this way, the irregular pattern of good quality can be formed on the surface of roll.

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 or a surface-treated steel plate for producing a steel plate or a surface-treated steel plate having paint clarity.

(Conventional technology) Steel plates used in automobiles and home appliances are required to have good paint clarity, which is known to increase product value. Conventionally, improvement in paint clarity has been achieved by improving paints or painting methods. has been emphasized.

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. 82-11922 or Japanese Patent Application Laid-Open No. 63-11.
There is a publication No. 2086.

The present inventors first formed a hard metal plating film on the surface of a rolling work roll, coated the surface of the plating film with a photosensitive resist agent or film, and intermittently applied high-density energy while rotating the roll. The resist layer is cured by irradiating the resist layer, the uncured portion of the roll is cleaned to form one or more motifs on the roll surface, and a hard metal plating layer is formed on the motif to form two-layer plating. A method of forming a layer and a method of forming one or more motifs on the roll surface and then performing anisotropic etching with a chemical etching agent to form etch pits on the roll base material were proposed.

(Problem to be solved by the invention) In rolling, dull 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 to this, the surface roughness of the steel plate, lubricating oil, etc. also have a large influence.

Generally, the lubricating oil accumulated on the four parts of the concavo-convex pattern is evenly supplied to the convex parts, 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. cure, clean the uncured portion of the roll to form one or more motifs on the roll surface, form a hard metal plating layer on the motif, and then peel off the resist hardened layer to form a pattern. In the method of This is a method of forming an uneven pattern on the surface of a dull roll for steel plate rolling, which is characterized by thickness control, and involves anisotropic etching of a roll with one or more motifs formed on the roll surface using a chemical corrosive agent. The method includes a method of forming etch pits in a roll base material.

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

The photosensitive resist agent used in the present invention is composed of a polymerization initiator, a photosensitive monomer, a binder polymer, etc. The photosensitive monomer molecules are polymerized by irradiated light energy to form a polymer, and a commercially available photoresist is used. be able to.

Generally, a dry film of a photosensitive resist agent coated with an adhesive on one side is known, but in the present invention, as shown in FIG. 1, a dry film 30 is spirally wound around a rolling roll 1. The dry film 30 is provided leaving a seam 32 with the adjacent film. In the present invention, since the dry film is spirally wound leaving a seam, unevenness due to overlapping of the dry film can be prevented.

Next, the roll 1 with the dry film pasted thereon is placed on a rotating table (not shown) and rotated, and during rotation, the liquid photosensitive resist agent 10 is sprayed onto the seam 32 from the hopper 2. 31 is a control valve. The photosensitive resist agent has a viscosity of 100 to 300 ep, preferably 200 ep.
CP liquid resist is good.

The liquid resist solidifies at the seams of the dry film of the roll, giving the dry film thickness and creating a uniform surface. For this reason, thickness control is performed.

FIG. 2 shows an example in which a dryer 13 dries a liquid resist to be supplied to a joint of a dry film.

FIG. 3 shows an example in which the thickness of the liquid resist is controlled using a squeegee 3. 12 is a heat source.

The dry film and the liquid resist at its joints have a film thickness of I.
D0m or less. The thickness of the liquid resist may be controlled by a rigid squeegee such as a flat plate, a curved plate, or a ring, or a fluid squeegee such as a hot air squeegee.

In the present invention, a pre-adjusted dry film is spirally wound leaving a seam with the adjacent film, and liquid resist is replenished at the seam, so that a resist layer can be formed with a uniform thickness over the entire roll area.

FIG. 4 is a flowchart for forming a concave motif.

The photosensitive resist layer 9 uniformly coated on the roll 1 is irradiated with a high density energy source. For example, an ultraviolet ray or an Ar laser 4 is used as a high-density energy source, and a chopper 5 is used as a high-density energy source.
It can be irradiated intermittently via. chopper 5
When a desired rotational movement is applied to the chopper 5, a slit 6 provided in the chopper 5 irradiates the laser beam at a constant pitch. Therefore, by intermittent irradiation of the laser beam corresponding to the rotation of the chopper 5, hardened regions are continuously formed in the resist layer.

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

Concave motif (main tone) created by cleaning uncured areas of resist
11 is formed on the roll surface.

In addition, since the boundary between the hardened layer and the unhardened resist layer is formed very sharply, the sharpness of the base material can be obtained during anisotropic etching in the post-processing, and the flatness area ratio can be increased. It becomes effective.

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

Further, if a normal rolling roll requires an uneven step of 1011 nm or more due to anisotropic etching, the resist film thickness should preferably be in the range of 15 to 30 L.

After forming a pattern using a resist layer, plating with a hard metal such as Cr or N1 is performed. Plating is immersion plating,
Either electroplating is acceptable.

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 image clarity and gloss are measured as the degree to which the mirror image of the object reflected on the surface is clear and sharp. (Its Z 8741).The loss rate A of the present invention is measured at 60°1! surface 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 layer is removed using a cleaning solution, for example, a strong alkaline solution.

On the surface of the resulting roll, a concavo-convex pattern consisting of a hard metal plating layer is obtained over the entire roll. 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 manufactured by the method of the present invention has etch pits formed on the roll surface transferred, improves the retention of processing oil during processing, and exhibits 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 roll for temper rolling is generally a high carbon forged steel hardened roll, the dull roll 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.

Another example of the present invention is to perform anisotropic etching using a chemical etching agent after forming a pattern using a resist film.

In the present invention, etching is performed using a known steel corrosive agent, and the etching is imparted with anisotropy.

Etch pits are formed in the base material by anisotropic etching. For example, when ferric chloride is sprayed in a shower, the desired anisotropic etching can be obtained.

When etch pits are formed by etching, the hardened resist layer is peeled off using, for example, a strong alkaline solution. A discontinuous uneven pattern is formed on the surface of the obtained roll.

(Example) A photosensitive resist was coated on the surface of a high-carbon forged steel quench roll to form a 40-layer film layer. Afterwards, laser light was irradiated with an Ar laser oscillator.

After forming a hardened area of φ1100I on the photosensitive resist on the roll surface, development treatment was performed using a weak alkaline solution. Next, wet etching (main agent: ferric chloride) is performed,
A round band pattern (FIG. 5) was formed on the roll.

As a result of crystalline rolling (reduction ratio 0.8%) of an extremely thick 0.7 m cold-rolled steel sheet for automobiles using the dull roll of the present invention, the flatness ratio of the steel sheet was A-90%, press formability, and paint clarity. It was confirmed that the durability was superior to that of conventional dull rolls (steel ball shot blasting method).

(Effects of the Invention) In the present invention, a dry film of photosensitive resist is continuously wound spirally on the roll surface, leaving a seam, and the seam is coated with an appropriate amount of liquid resist to control the film thickness. The layer can be formed to a uniform thickness over the entire roll.

Therefore, during the formation of a concavo-convex pattern by plating or chemical corrosion using a concave motif, there is no fear that the hardened resist layer will peel off from the roll surface, making it possible to obtain an excellent dull pattern.

[Brief explanation of drawings]

FIG. 1 is a perspective view of the present invention, FIG. 2 is a detailed explanatory diagram of the present invention, FIG. 3 is an explanatory diagram of still another example of the present invention, FIG. 4 is a flow diagram of the present invention, and FIG. is a photograph of the roll of the present invention. Agent: Patent Attorney Tatsuo Chanoki Figure 4: Written amendment (method) % formula % 2. Name of the invention: Method for forming an uneven pattern on the surface of a dull roll for rolling steel plates 3. Case of the person making the amendment Relationship Patent applicant address 2-6-3 Otemachi, Chiyoda-ku, Tokyo Name (6
65) Nippon Steel Corporation Representative Zen Yamamoto 4, Agent Address 3-4-5 Kuramae, Taito-ku, Tokyo April 2, 1990
4th, 6th, Subject of amendment 7, Contents of amendment (1) ``Photograph'' in line 5 of page 12 of the specification is amended to ``schematic drawing.''

Claims (2)

[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 irradiating high-density energy at a constant pitch while rotating the roll, and the uncured portion of the roll is cleaned. A method in which one or more motifs are formed on the surface of a roll, a hard metal plating layer is formed on the motif, and a hardened resist layer is then peeled off to form a pattern. For steel plate rolling, characterized in that the film is continuously wound spirally on the surface, leaving a seam with the adjacent film, and the seam of the dry film is coated with a liquid photosensitive resist having a viscosity of 100 to 300 cp to control the thickness of the coating layer. A method of forming an uneven pattern on the surface of a dull roll. 2. Forming an uneven pattern on the surface of the dull roll for steel sheet rolling according to claim 1, wherein the roll having one or more motifs formed on the roll surface is anisotropically etched with a chemical etching agent to form etch pits on the roll base material. how to.