JPH07150073A - Resist material for marking surface of metal roll for rolling - Google Patents

Abstract

PURPOSE:To obtain a resist material for marking the surface of a metal roll for rolling free from retention of a thin filmy resist in the circumferential part of a laser beam spot by adding carbon black and an infrared absorbing dye to a resin composition comprising an acrylic synthetic resin and a cellulose derivative. CONSTITUTION:This resist material is obtained by forming a resist material layer prepared by adding carbon black to a resin component comprising an acrylic synthetic resin and a cellulose derivative (e.g. nitrocellulose, cellulose acetate or cellulose butyl acetate) on the top of a resist material layer made by adding a dye (e.g. cyanine dye squarylium dye, methine dye, naphthoquinone dye, quinoneimine dye, quinonediimine dye, phthalocyanine dye or naphthalocyanine dye) having infrared light absorbing ability to a resin component composed of the acrylic synthetic resin and the cellulose derivative.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a resist material used for imparting a predetermined uneven pattern on the surface of a rolling metal roll.

[0002]

2. Description of the Related Art The inventors of the present invention have disclosed a method for applying a pattern having a predetermined unevenness on the surface of a rolling metal roll.
No. 175882, a coating consisting of an acid-corrosion-resistant resin and a light absorber is applied in a thin film on the roll surface, and then a low output Y
A method of irradiating the AG laser beam in a pulse shape by a Q switch to evaporate and remove the thin film at the irradiated portion and processing the exposed roll surface with an etching solution has been disclosed.

After that, the inventors of the present invention disclosed in JP-A-4-2832.
In Japanese Patent Laid-Open No. 73-73, as a coating material used in the above method, an acrylic synthetic resin as a base resin containing a small amount of nitrocellulose and 2 to 15 wt% of carbon black is disclosed. However, the above coating materials have the following problems. As the first problem, the following things became clear. When the acid-resistant resin (resist) film applied to the surface of the metal rolling roll is partially evaporated and removed by the low-power laser light, the transparent acrylic resin alone does not absorb the YAG laser light, so the carbon Black is added. It is considered that this causes the laser light energy to be absorbed by the added carbon black fine particles and generate heat so that the temperature becomes a temperature at which the surrounding acrylic resin can be thermally decomposed and evaporated.

From this fact, since the irradiation energy is high at the center of the beam spot where the laser beam is applied to the resist film, the resin which is the main component of the resist film has its molecular bonds destroyed, so that the resist film is formed. Can be completely removed from the roll surface. However, as shown in FIG. 2, the thin film-like resist remains at the interface with the roll around the beam spot with low energy. This is because even if the temperature of the fine particles of carbon black itself rises near the interface with the roll, the transparent acrylic resin is in contact with the roll, so it is cooled from the metal roll surface and the resin is thermally decomposed and evaporated. It is considered that the film does not reach a temperature sufficient to keep the temperature and remains as a thin film of only the resin on the interface. Therefore, since the resist remaining during the etching process protects the roll surface from the etching solution at the initial stage of etching, as shown in FIG. Cause.

Particularly, when a large etching amount is taken,
The thickness of the resist film must be increased in order to increase the etching resistance, and the resist film tends to remain.
Next, the second problem is the etching resistance of conventionally used resist films. That is, FIG. 4 shows the results of investigating the correlation between the film thickness of the resist film and the etching liquid resistance by performing etching processing after laser processing. It should be noted that the region below the curve in this figure is peeled off from the roll surface.

As a result, when the temperature of the etching liquid is 30 ° C., the thickness of the resist film must be 6 μm or more in order to secure the immersion time in the etching liquid for 10 minutes. Furthermore, in order to shorten the etching time, if the temperature of the etching solution is raised, the same resist film thickness is used to further shorten the immersion time in the etching solution or to secure the same etching time. It will increase the thickness. When the thickness of the resist film increases, the laser light irradiation time and the laser light irradiation energy for partial evaporation and removal with the laser light increase, which increases the processing time by the laser light and improves the capability of the laser generator. Cause a decrease in economic efficiency and productivity.

[0007]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a resist material for marking on the surface of a metal roll for rolling, in which the thin film resist hardly remains around the laser beam spot. Another object of the present invention is to
In addition to the above objects, it is an object of the present invention to provide a resist material for marking on the surface of a metal roll for rolling, which is excellent in peeling resistance during etching.

[0008]

The present invention is directed to a surface of a metal roll for rolling, characterized in that a resin component comprising an acrylic synthetic resin and a cellulose derivative contains carbon black and a dye capable of absorbing infrared rays. Is a marking resist material, and has a resist material layer in which carbon black is added to a resin component consisting of an acrylic synthetic resin and a cellulose derivative, and an infrared absorbing ability to a resin component consisting of an acrylic synthetic resin and a cellulose derivative. It is a resist material for marking on the surface of a metal roll for rolling, which is formed on the upper side of a resist material layer to which a dye is added, and it is desirable that the acrylic synthetic resin has a crosslinked structure.

[0009]

In the present invention, since a dye having an infrared absorbing ability is contained in addition to carbon black as a material having a light absorbing function, a thin film generated near the interface between the rolling roll surface and the resist film is also irradiated with the laser. It will be heated by light. Since carbon black has a larger light absorbing function than the above-mentioned dye, most of the resist film is removed by laser light due to the action of carbon black.
The role of the dye is to remove the thin film formed near the interface between the surface of the rolling roll and the resist film.

The dye to be used in the present invention includes:
For example, a YAG laser or the like that can absorb laser light having a wavelength corresponding to an infrared region of 0.8 μm to 25 μm is desirable. Specific examples include cyanine dyes, squarylium dyes, methine dyes, naphthoquinone dyes, quinoneimine dyes, quinonediimine dyes, phthalocyanine dyes, and naphthalocyanine dyes.

Although these dyes are not dissolved in the acrylic resin used in the present invention, it is sufficient that they are dispersed uniformly in the resin as ultrafine particles, and the primary particle diameter is preferably 0.5 μm or less. In addition to the above-mentioned dyes, oil-soluble dyes having a large infrared absorption ability such as blue 11, green 3, brown 3, black 5 and the like, which are soluble in the resin component, can be used. These dyes are preferably contained in the range of 0.1 to 20% by weight, more preferably 0.5 to 10% by weight, based on the resin component.

In the present invention, as shown in FIG. 1 (a), the object can be achieved by forming a resist film in which carbon black and a dye having an infrared absorbing ability are mixed with a base resin on the surface of a metal roll. it can. Further, in the present invention, as shown in FIG. 1 (b), a two-layer type coating may be used in which a resist material layer containing carbon black is formed on the upper side of the resist material layer containing a dye having an infrared absorbing ability. . In this case, it is preferable that the resist layer on the lower side is coated so that the film thickness is 1/3 or less as compared with the resist layer on the upper side.

Further, in the present invention, it is desirable to form a crosslinked structure in the acrylic resin. This reduces the water absorption of the entire resist film, and as a result, the etching resistance of the resist film is improved. Specifically, a copolymer of a hydroxyl group-containing acrylic or methacrylic monomer and another vinyl compound is synthesized, and melamine, benzoguanamine, urea or the like as a low molecular weight crosslinking agent and formaldehyde A crosslinked structure can be formed by heating after adding a small amount of the addition condensate. In the present invention, only the etching resistance of the resist film needs to be improved as the degree of forming the crosslinked structure, while the formation of the crosslinked structure also has a problem that the peelability of the resist film after etching is reduced, and therefore, the normal heat The cross-linking structure in the resist film of the present invention may be slight as compared with the cured coating material. The method for forming the crosslinked structure is, in addition to the above-mentioned method, synthesizing a copolymer of an acrylic and methacrylic monomer containing three or more double bonds in one molecule and another vinyl compound, It is possible to add a divinyl compound such as divinylbenzene and an organic peroxide which is a reaction catalyst to this.

A method of using the resist of the present invention for roll surface processing will be described below. 1) A resist material (acid-corrosion-resistant resin coating material) according to the present invention is uniformly applied to the roll surface. 2) A pulsed YAG laser beam controlled by Q switch is irradiated to evaporate and remove the acid-corrosion-resistant resin coating material on the target film-like portion. 3) By etching, the exposed portion (pattern) of the roll surface is corroded, and an arbitrary concavo-convex pattern (pattern) is imparted to the roll surface by the aggregate of the formed recesses. 4) Remove the acid corrosion resistant resin coating on the roll surface.

The resist material of the present invention satisfies the characteristics of the acid-corrosion-resistant resin coating material required in these steps. First of all, it is easy to evaporate by the irradiation of laser light, it exists as a strong barrier between the roll base and the corrosive liquid during the etching process without peeling, and the paint after etching is rolled without special measures such as polishing and grinding. It can be removed from the surface.

The cellulose derivative used in the present invention may be nitrocellulose, cellulose acetate, cellulose butyl acetate or the like as long as it is compatible with the acrylic synthetic resin. Further, as the acrylic synthetic resin used in the present invention, a polymer mainly composed of methyl methacrylate, which is used as a room temperature drying type coating vehicle, and the like are suitable.

[0017]

【Example】

Example 1 As a base resin component, a copolymer of methyl methacrylate and ethyl acrylate was used as an acrylic resin, and nitrocellulose (nitrogen content: 11%) was added to the acrylic resin.
Preliminarily prepare a blend of 15 parts by weight with respect to 100 parts by weight.

A color black is selected as the carbon black, and a naphthalocyanine dye (primary particle system has an average of 0.3 μm) as an infrared absorbing dye and an oil-soluble dye Black 5 are added at the addition amounts shown in Table 1, Adjust the resist material. This resist material is solidified with thinner
Dilute to 10% and use DME and LPG as propellants.
The mixture of the above is spray-painted on the surface of the steel rolling roll. The thickness of the resist film after drying at room temperature is 8 μm on average.

Marking treatment was performed by irradiating a metal roll coated with a resist with a beam diameter of the Q switch-controlled YAG laser light having a beam diameter of 50 μm. Then, the surface of the marked roll was etched using an aqueous ferric chloride solution as an etching solution, and finally the resist film remaining on the roll surface was removed by a brush. Example 2 As a base resin component, an acrylic resin was a copolymer of methyl methacrylate and ethyl acrylate, to which nitrocellulose (nitrogen content 11%) was added.
Preliminarily prepare a blend of 15 parts by weight with respect to 100 parts by weight. As the carbon black, a resist material A in which only 8% by weight of color black is added as a resin solid content ratio
And a resist material B in which only 10% by weight of oil-soluble dye black 5, which is a pigment having an infrared absorbing ability, is added. These resist materials diluted with thinner are spray-painted on the surface of the steel rolling roll. At that time, the resist material B was first spray-coated on the surface of the steel rolling roll, and the average thickness of the resist film after drying at room temperature was 1 μm.
Paint so that. Next, the resist material A is spray-coated on the surface of the steel rolling roll, and the resist film is dried at room temperature so that the average thickness of the resist film is 6 μm.

[0020]

[Table 1]

Example 3 A copolymer of an acrylic monomer having a hydroxyl group and methyl methacrylate was synthesized and blended with nitrocellulose (nitrogen content: 11%) in the same proportion as in Example 1 to prepare in advance. . A resist material is prepared by adding 8% by weight of carbon black, 10% by weight of dye black 5 having an infrared absorbing ability, and 6% by weight of a water-soluble melamine resin. Hereinafter, the same method as in Example 1 was tested. As a result, the diameter after removing the resist film is 30
With respect to the etching resistance, under the conditions that the temperature of the etching solution is 50 ° C. and the immersion time in the etching solution is 10 minutes, no peeling of the resist film during etching is observed, and The peeling property was good.

As a comparative example, the above resin containing only 8% by weight of color black as carbon black was spray-coated on the surface of a steel rolling roll, and the thickness of the resist film after drying at room temperature was average. Paint to a thickness of 7 μm. The metal roll coated with the resist was irradiated with the Y-AG laser light controlled by the Q switch to perform the marking process. After that, the marked roll surface was etched using a second aqueous chloride solution as an etching solution, and finally the resist film remaining on the roll surface was removed with a brush.

As a result, when the diameter of the laser beam is 50 μm, the diameter of the exposed metal portion where the resin is completely removed from the roll surface is 10 μm in the conventional method as shown in FIG. When the resist material of No. 3 was used, the diameter of the exposed metal part where the resin was completely removed from the roll surface was greatly improved to 30 μm. Since the thin film-like residual resist portion shown in FIG. 2 is eliminated, a highly accurate etching process is enabled.

[0024]

According to the first and second aspects of the present invention, the evaporation removal characteristic by the laser beam is significantly improved as compared with the conventional resist material, and the marking portion can be etched more uniformly. Further, according to the third aspect of the present invention, it has an excellent effect that the etching resistance is improved as compared with the conventional resist material, the etching depth can be increased and the etching process can be speeded up.

[Brief description of drawings]

FIG. 1A and FIG. 1B are cross-sectional views showing a state in which a resist material of the present invention is applied to a metal roll surface.

FIG. 2 is a cross-sectional view showing a removal state of a resist film after laser light irradiation.

FIG. 3 shows a cross-sectional shape of a metal roll surface after etching.

FIG. 4 shows the relationship between the coating film thickness of a resist material and the immersion time in an etching solution regarding the etching resistance.

Claims (3)

[Claims] 1. A resist material for marking on the surface of a metal roll for rolling, characterized in that a resin component comprising an acrylic synthetic resin and a cellulose derivative contains carbon black and a dye having an infrared absorbing ability. 2. A resist material layer in which carbon black is added to a resin component composed of an acrylic synthetic resin and a cellulose derivative, and a dye having infrared absorption ability is added to a resin component composed of an acrylic synthetic resin and a cellulose derivative. A resist material for marking on the surface of a metal roll for rolling, which is formed on the upper side of the resist material layer. 3. The resist material for marking on the surface of a rolling metal roll according to claim 1, wherein the acrylic synthetic resin has a crosslinked structure.