JPH03204109A - Method for forming projecting and recessing pattern on surface of dull roll for rolling steel sheet - Google Patents

Abstract

PURPOSE:To form the projecting and recessing pattern of high quality on the surface of dull roll for rolling steel sheet by obtaining the hardened layer of a liquid resist by preheating the surface of roll at a desired temp., covering it with a liquid resist and controlling the thickness of film. CONSTITUTION:When the projecting and recessing pattern is formed on the surface of a dull roll for rolling sheet, the surface of a work roll 1 for rolling is preheated at 40 - 100 deg.C, held at the desired temp., covered with a liquid photosensitive resist 10 of the viscosity of 100 - 300 cP and the film thickness is controlled <= 100 mum. This photosensitive resist layer 9 is irradiated with an argon laser 4 and a continuous and local hardened rage is formed. Next, it is developing treated with a developing solution from a sprayer 7 and a recessed motif 11 is formed by washing away unhardened parts. In this way, the projecting and recessing pattern with a strong adhesion 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 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 blast 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. 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 hardened by irradiating the resist layer, and the unhardened portion of the roll is exposed 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 bits on the roll base material were proposed.

(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 r value of the steel plate and the mechanical properties of the elongated tongue. In addition, steel plate surface roughness and lubricating oil 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. After curing, the uncured portion of the roll is washed to form one or more motifs on the roll surface, a hard metal plating layer is formed on the motif, and then the hardened resist layer is peeled off to form an uneven pattern. A steel plate characterized in that the roll surface of a rolling work roll is preheated and maintained at a desired temperature, the roll surface is coated with a liquid photosensitive resist having a viscosity of 100 to 300 cP, and the thickness of the coating layer is controlled. This is a method of forming an uneven pattern on the surface of a dull roll for rolling, in which a roll with one or more motifs formed on the roll surface is anisotropically etched with a chemical etching agent to form etch bits on the roll base material. including.

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 1O 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.

In the present invention, the roll surface is preheated to a desired temperature by a heat source 12. The preheating temperature is 40°C to 100°C, preferably 50°C. As the preheating means, hot air, infrared heaters (including far infrared rays), and laser spot heating are used.

A photosensitive resist agent 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 commercially available photoresists can also be used. .

The photosensitive resist agent is preferably a liquid resist having a viscosity of 100 to 300 cP, preferably 2QOcP.

By coating a preheated roll with a photosensitive resist agent of an appropriate viscosity, the degree of adhesion of the resist layer to the roll surface can be increased. Further, the thickness of the resist layer is controlled. The resist film thickness should be 100 μs or less, and the resist film thickness should be 100 μs or less.
A rigid squeegee such as a ring or a fluid squeegee such as a hot air squeegee may be used.

The photosensitive resist layer 9 uniformly coated on the roll 1 is irradiated with a high density energy source. As a high-density nine-energy source, for example, ultraviolet rays or an Ar laser 4 can be used and irradiated intermittently via a chopper 5. When the chopper 5 is given a desired rotational motion, the slit 6 provided in the chopper 5 irradiates the laser beam at a constant pitch.

Therefore, by intermittent irradiation of laser light 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 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, it is possible to form a hardened layer by laser irradiation if the resist film thickness is 100 mm or less.

Further, if a normal rolling roll requires an unevenness level difference of 10 mm or more due to anisotropic etching, the resist film thickness should preferably be in the range of 15 to 30 nm.

In the present invention, etching is performed using a known steel corrosive agent, and the etching is imparted with anisotropy. Etch bits 21 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.

For example, Cr1 or N1 after pattern formation by resist layer.
Plating the hard metal of the base. The plating may be either immersion plating or electroplating.

According to experiments conducted by the present inventors, it is preferable that the flatness ratio A≧85%, which 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. Yes (JIS Z 8741). The flatness A of the present invention is measured at 60'' mirror bending degree.

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, 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 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.

2 to 4 show other examples of the present invention.

Figure 2 shows the liquid resist IO on the preheating roll 1 in the hopper 2.
The liquid is stored in the air and is atomized from the nozzle 14 in the form of a spray.

A dryer 13 is provided on the opposite side from the nozzle 14 to perform drying and control film thickness.

In FIG. 3, the liquid resist IO is stored in a tank 20, the roll 1 is partially immersed, and the roll is rotated. Dryer 1
A dryer 3-1 is used for drying the resist, and a dryer 13-2 controls the film thickness.

Further, in FIG. 4, a liquid resist 10 is stored in a tank 20,
Partially immersing the dipping roll 15 in the tank, the 10th roll 1
6. Roll coat the liquid resist 10 on the rolling roll 1 via the 20th roll 17.

Next, further examples of the present invention will be described.

According to this example, after pattern formation using a resist film, anisotropic etching is performed using a chemical etching agent.

In the present invention, etching is performed using a known steel corrosive agent, which imparts anisotropy to the etching. Etch bits are formed in the base material by anisotropic etching, and the desired anisotropic etching can be obtained, for example, when spraying ferric chloride in a shower.

When etch bits 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.

(Effects of the Invention) The present invention preheats the roll surface to a desired temperature and coats the roll surface with an appropriate amount of liquid resist to control the film thickness. Strong adhesion.

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 an explanatory diagram 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, and Fig. 4 is a further detailed explanatory diagram of the present invention. . agent

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 method in which one or more motifs are formed on the surface of the roll by cleaning the uncured part of the roll, a hard metal plating layer is formed on the motif, and then the hardened resist layer is peeled off to form an uneven pattern, Preheat the roll surface of the rolling work roll and maintain it at a desired temperature,
A method for forming an uneven pattern on the surface of a dull roll for rolling a steel plate, comprising coating the roll surface with a liquid photosensitive resist having a viscosity of 100 to 300 cP and controlling the thickness of the coating layer. 2. The method according to claim 1, wherein the roll having one or more motifs formed on the roll surface is subjected to anisotropic etching using a chemical etching agent to form etch bits on the roll base material.