JPH03142084A - Decorative metallic sheet - Google Patents

Abstract

PURPOSE:To obtain marks which are resistant to flawing with excellent productivity by irradiating the front surface of the coating layer of the decorative metallic sheet having the coating layer on the front surface of a metallic sheet material with a laser beam, and thereby producing the marks on the coating layer. CONSTITUTION:The marks M are formed on the coating layer 4 itself by utilizing the radiation energy of the laser beam 18. Marking materials, such as ink and labels, which are heretofore indispensable, are saved in this way. The marks M are formed by the evaporation of resin components, a change of the coloration state of pigments, etc.; in addition, the marks M can be formed on a non- projecting state on the surface part of the coating layer. The laser beam 18 with which the resin coating layer 4 is irradiated transmits the transparent resin layer and is absorbed in the resin coating layer 4 if the resin coating layer 4 is applied and formed on the metallic sheet material 1 and a transparent resin film 23 or the transparent resin layer consisting of a clear coating film is laminated and formed thereon. The marks M are thus formed. The decorative steel sheet having the excellent productivity is obtd. without requiring the marking materials in this way.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention is directed to decorative metal sheets, such as painted steel sheets and laminated steel sheets, in which the resin coating film or the laminated film (
It is characterized by markings such as letters, symbols, patterns, etc. on the surface of the coating layer (hereinafter collectively referred to as the coating layer).

[Conventional technology]

Conventional methods for marking the coating layer include direct transfer, attaching labels with pre-printed marks to the coating layer, and inkjet printing methods in a non-contact manner on the surface of the coating layer. There was a form of forming a mark.

Specific examples of arcs include standard marks, company marks, production loft numbers, and in some cases, small figures for design.

[Problems to be Solved by the Invention] This conventional method requires marking materials such as printing ink and labels for marking, and has the drawback of high marking costs.

Furthermore, in the case of a decorative metal plate having a transparent resin film adhered to the outer surface of the resin coating layer, for example, the film must be peeled off before marking, making the marking work cumbersome. Furthermore, once the transparent resin film has been removed, the decorative metal plate has the disadvantage of being easily scratched afterwards.

The present invention was proposed to solve these conventional problems, and its purpose is to achieve low cost, high productivity,
To obtain a decorative metal plate capable of producing marks on a coating layer that are excellent in preventing scratches.

Another object of the present invention is that even when a transparent resin layer such as a transparent resin film or a clear coating film is laminated on the resin coating layer, a mark can be made to appear on the resin coating layer through the transparent resin layer. There is a way to get a metal plate.

[Means to solve the problem]

The present invention removes or alters a part of the coating layer by irradiating the surface of the coating layer such as a resin coating layer on a metal plate material with a laser beam, thereby marking the coating layer with characters, figures, etc. The purpose is to make it appear.

Specifically, for example, as illustrated in FIG.
i. The laser beam 18 emitted from the machine 15 is passed through an exposure mask 16 having a predetermined mask pattern, and the laser beam 18 transmitted through the mask 16 is passed through a lens 19 to remove the resin coating layer 4 on the metal plate material 1, etc. By irradiating the surface of the coating layer, a mark M corresponding to the mask pattern is marked on the coating layer.

For example, a predetermined mark M can also be made to appear on the surface of the coating layer by a scanning marking method in which a condensing point is moved using a galvanometer type scanner.

Naturally, the metal plate l side may be moved two-dimensionally to move the laser beam focal point on the surface of the coating layer.

The decorative metal plate of the present invention includes both a painted metal plate and a laminated metal plate. As the metal plate material 1, a general-purpose metal plate such as a galvanized steel plate, a stainless steel plate, a zinc-aluminum alloy plated steel plate, a cold rolled steel plate, an aluminum plate, etc. is used.

The coating layer is generally a resin coating layer 4 formed by coating on a metal plate l, and a transparent resin film 23 is laminated on the outer surface of this resin coating layer 4 as shown in FIG. Also includes those in which a clear coating film is laminated on the outer surface of the coating layer 4. This transparent resin film 23 is generally laminated to prevent scratches during bending and to provide design. Further, the coating layer includes a colored resin film laminated on the metal plate l.

Therefore, when the resin coating layer 4 is exposed on the metal plate material 1, the resin coating layer 4 is exposed to the radiant energy of the laser beam 18.
The mark M can be made to appear by discoloring or, so to speak, altering the outer surface of the material, or it is also possible to make the mark M appear directly by evaporating (removing) the resin component on the surface.

Further, a transparent resin film 23 is provided on the surface of the resin coating layer 4.
When the resin coating layer 4 is laminated, a mark M is formed on the surface of the resin coating layer 4 by actively coloring the pigment in the resin coating layer 4 or by thermally denaturing the pigment. Furthermore, when marking the colored resin film of the inner or outer layer, the mark M can be made to appear on the film by actively coloring the dye or pigment in the colored resin film or by simply denaturing it with heat.

[Effect]

Since the marks M are formed on the coating layer itself using the radiation energy of the laser beam 18, marking materials such as ink and labels that were indispensable in the past can be omitted. In addition, marks M may be caused by evaporation of resin components or changes in the coloring state of pigments.
Moreover, the mark M can be formed in a non-protruding state on the surface of the coating layer.

When a resin coating layer 4 is applied and formed on the metal plate material 1, and a transparent resin layer made of a transparent resin film 23 or a clear coating film is laminated thereon, the irradiated laser beam 18 covers the transparent resin layer. It passes through and is absorbed into the resin coating layer 4. Therefore, even when such a transparent resin layer is used as a covering, the mark M can be formed on the resin coating layer 4 through the transparent resin layer.

[First Embodiment] FIGS. 1 to 5 show a first embodiment of the present invention in which markings are made on the surface of a painted steel plate by a mask marking method using a YAG laser.

In FIG. 2, the painted steel sheet is processed through a pretreatment step 3 in which a chemical conversion film 2 is formed on both the front and back surfaces of a metal sheet material 1 made of a galvanized steel sheet, a painting step 6 in which a resin coating layer 4 is formed, and a resin coating layer 4 A marking step 7 is performed in which a mark M is formed on the surface of the sheet.

The pretreatment step 3 has a treatment tank 8, and the metal plate 1 is passed through the treatment tank 8 and subjected to chemical conversion treatment with zinc phosphate and chromic acid.
A chemical conversion film 2 is formed on both the front and back surfaces of a metal plate material 1.

The coating process 6 includes a first coating process 6A in which an undercoat resin coating layer 5 is formed on the surface of the metal plate material 1, and a second coating process 6B in which a resin coating layer 4 is formed on the undercoat resin coating layer 5. Both processes 6A and 6B include roll coaters 10 and 11 and baking furnace 1.
Baking paint is applied in order in steps 2 and 13.

In the first coating step 6A, a resin paint is applied onto the chemical conversion film 2 on the surface side of the metal plate material 1 using a roll coater 10, and is baked and dried in a baking oven 12 to form an undercoat resin coating layer 5. . The resin paint applied in this step 6A is an epoxy-based, fluorine thread, acrylic-based, or polyester-based paint.

In the second coating step 6B, on the surface of the undercoat resin coating layer 5,
A resin paint is applied with a roll coater 11 and baked and dried in a baking oven 13 to form a resin coating layer 4 as an overcoat layer. As the resin pigment applied here, known paints such as acrylic and polyester paints can be appropriately used.

The pigment contained in the resin paint constituting the resin coating layer 4 may be either a colored pigment or a rust-preventing pigment, or both. As coloring pigments, inorganic pigments such as titanium dioxide, carbon, iron oxide, etc., inorganic pigments such as metal oxides, organic pigments such as cyanine blue, quinacridone red, cyanine green, and other extender pigments such as talc and barium sulfate are used. be able to. Zinc chromate is used as a rust-preventing pigment.
Strontium chromate or the like can be used.

As shown by the imaginary line in FIG. 2, an undercoat resin film is also applied to the back side of the chemical conversion coating 2 of the metal plate l in the first coating process 6A using a roll coater 10a, and in the second coating process 6B. A top coat resin film is applied on the base coat resin film using a roll coater.
The undercoat and topcoat resin coatings are omitted from illustration.

In the marking step 7, a laser oscillator 15 and an exposure mask 16 are used. A laser beam 18 is irradiated through an exposure mask 16 to form a mark M on the surface of the resin coating layer 4 of a painted metal plate l that is fed at a predetermined speed.

That is, the laser oscillator 15 has an output of 15 to 1, for example.
It consists of an 80 joule YAG laser and oscillates a 12 PPS laser beam 18. The laser beam 18 from this laser oscillator 15 is passed through an exposure mask 16, the laser beam I8 transmitted through the mask 16 is passed through a lens 19, and the laser beam 18 focused by the lens 19 is applied to the resin coating layer 4. It irradiates the surface.

In FIGS. 1 and 3, the exposure mask 16 is formed by forming an aluminum vapor deposition layer 16b on one side of a transparent glass plate 16a to form a predetermined mask pattern 20, and the laser beam 18 is applied only to the non-evaporation surface. allow passage of. The exposure mask 16 and the lens 19 are arranged above the conveyance path of the metal plate material 1, and the laser beam 18 that passes only through the mask pattern 20 is imaged by the lens 19 and irradiated onto the resin coating N4. At this time, the amount of laser energy is adjusted depending on conditions such as the arrangement position of the exposure mask 16 and the lens 19, the aspect of the mask pattern 20, and the material of the resin coating layer 4.

By irradiating the laser beam 18 adjusted in this manner, an exposed area according to the mask pattern 20 is formed on the surface of the resin coating layer 4, and only that area is evaporated, resulting in the surface of the resin coating layer 4 as shown in FIG. At the same time, the coloring state of the pigment contained in the resin coating layer 4 changes. In this way, a mark M consisting of these minute recesses and discolored portions was made to appear.

The depth of the mark forming portion is limited to the resin coating layer 4, and is designed to prevent it from reaching the undercoat resin coating N5. This is to prevent the metal plate material 1 from rusting from the mark forming area.

[Second Embodiment] FIG. 6 shows a second embodiment of the present invention. In this case, on the resin coating layer 4 formed through the same process as in the first embodiment,
A coated steel plate was prepared by pasting and laminating a transparent resin film 23, and a mark M was made to appear on the resin coating layer 4 through a marking process.

The irradiated laser beam 18 passes through the transparent resin film 23 and is absorbed only on the surface of the resin coating layer 4, so the mark M is made only on the resin coating layer 4 with the film 23 attached. It can appear through thermal denaturation.

Note that the resin film 23 may be attached inseparably, or may be peeled off afterwards.

[Third Example] A laminated steel plate is formed by pasting a colored resin film with enhanced design on the surface of a metal plate l, and a marking process is performed to mark the outer surface of the colored resin film, which is a coating layer. It was possible to change color and make the mark M appear. It was also possible to form concave marks M by evaporating the resin component on the surface.

[Fourth Example] A transparent resin film was laminated on the colored resin film of the third example, and the outer surface of the colored resin film serving as the inner layer was coated with
The dye or pigment contained in this was thermally denatured to make the mark M appear.

[Another embodiment example]

The resin coating layer 4 in the first example and the second example is
The undercoat resin film layer 5 may be omitted and formed by coating on the metal plate material 1.

When forming a clear coating on the outer surface of the resin coating layer 4, the marks M can be made to appear by irradiating the resin coating layer 4 with a laser beam through the clear coating.

The mask pattern 20 of the i-light mask 16 may be formed by an etching method, a vapor deposition method, or other methods.

In the present invention, it is not necessary to perform marking in a series of manufacturing processes of a decorative metal plate, and marking may be performed, for example, in the process of cutting a decorative metal plate to a specified length. It can also be applied to the case where a mark M is attached to a decorative metal plate after cutting to a fixed length. Of course, the mark M may be attached to the molded product after bending the decorative metal plate after cutting it to a specified length.

〔Effect of the invention〕

As explained above, in the present invention, the coating layer on the metal plate material is irradiated with a laser beam to physically or chemically make a mark appear on the coating layer. Marking costs can be reduced without the need for other marking materials.

Since the mark can appear directly on the surface of the coating layer in a non-protruding state, it is possible to form marks on the decorative metal plate at low cost, with excellent productivity, and which are hard to scratch. Since the marks can be formed in the coating layer at a depth that does not reach the surface of the metal plate material, a decorative metal plate with excellent rust prevention (corrosion resistance) can be obtained.

Even if a transparent resin layer such as a transparent resin film or clear coating is laminated on the outer surface of the coating layer, the irradiated laser beam will pass through the transparent resin layer and be absorbed only by the coating layer. Marks can be exposed on the coated layer through the transparent resin layer in a protected state covered with the transparent resin layer. In particular, in the case of a transparent resin film, there is no need to peel it off, and markings can be efficiently performed on the decorative metal plate. When marking is performed in a series of manufacturing processes of decorative metal plates, the productivity of the decorative metal plates does not decrease due to the marking work.

[Brief explanation of the drawing]

1 to 5 show a first embodiment of the present invention, FIG. 1 is a partial vertical sectional view of the main part, FIG. 2 is a schematic side view illustrating the manufacturing process of the decorative metal plate, 3 is a sectional view of the exposure mask, FIG. 4 is a plan view illustrating marks appearing on the decorative metal plate, and FIG. 5 is a sectional view taken along the line A--A in FIG. 4. FIG. 6 is a sectional view of a decorative metal plate showing a second embodiment of the present invention. 1...Metal plate material, 4...Resin coating layer, 7...Marking process, 15...Laser oscillator, 16...N light Mask, 18...Laser beam, 20...Mask pattern, 23...Transparent resin film, M...Mark.

Claims (1)

[Claims] 1. A decorative metal plate having a coating layer on the surface of the metal plate material, wherein marks are made to appear on the coating layer by irradiating the surface of the coating layer with a laser beam. A decorative metal plate featuring: 2. The decorative metal plate according to claim 1, wherein the coating layer is a resin coating layer formed by coating on the metal plate material. 3. The decorative metal plate according to claim 2, wherein a transparent resin layer is laminated on the surface of the resin coating layer. 4. The decorative metal plate according to claim 1, wherein the coating layer is a colored resin film laminated on the metal plate material.