GB2294783A

GB2294783A - Stainless steel plate having designs and fabricating method thereof

Info

Publication number: GB2294783A
Application number: GB9521881A
Authority: GB
Inventors: Jae Hyun Kim; Sang Jin Lee
Original assignee: LG Industrial Systems Co Ltd
Current assignee: LS Electric Co Ltd
Priority date: 1994-10-25
Filing date: 1995-10-25
Publication date: 1996-05-08
Anticipated expiration: 2015-10-25
Also published as: CN1131620A; CN1051503C; GB2294783A8; KR0125475B1; JPH08302482A; GB2294783B; JP2771486B2; GB9521881D0

Abstract

A stainless steel plate having designs thereon produced by (a): inco coloring (9) the overall surface of a mirror stainless steel plate, or exposing a portion to be inco-colored and masking the remaining portion to expose only an unmasked portion; (b) photomechanically producing two silk screens having a portion where the photoresist is removed and a hardened portion; (c) applying one of the screens to the coloured plate and electrolytically stripping the steel plate in the unmasked areas to form a stripped portion (11) (d) and then applying the second screen; and engraving a hair line (14) on the unmasked portion (13) and removing the screen. <IMAGE>

Description

STAINLESS STEEL PLATE HAVING COLORED AND TOPOGRAPHICAL SURFACE AND FABRICATING METHOD THEREOF The present invention relates to a stainless steel plate having a topographical surface and a fabricating method thereof, and more particularly, to a stainless steel plate and a fabricating method thereof wherein an inco color portion, strippped potion and hair line portion are formed harmoniously to thereby display a topographical (threedimensional) optical effect with their colors.

Presently, various figures and shapes are displayed in the surface of a sheet of stainless steel plate utilized as a decorative design of elevators by means of a technique such as painting, silk screen and etching. Here, etching is the most widely available process.

The etching is performed in the sequence of FIGs. la to ld. First, a black and shift draft film as shown in FIG. la is put on a silk screen 1 having frames 2 consistently coated with a negative photoresist as shown in FIG. ib to be closely attached to each other by a pressure applied thereto. An exposure is executed upon the resultant structure and the draft film is taken away. Then, silk screen 1 is washed to have a portion 3 without the photcresist layer since it is dissolved due to failing to receive light and a portion 4 with the photoresist thereon hardened by receiving the light.

The silk screen prepared as above is put on a sheet of stainless steel plate, and an acid-resistant ink is coated on the whole surface. After removing the silk screen, an area 5 masked with the ink and an area 6 without being masked with the ink are provided on the stainless steel plate as shown in FIG. lo.

Successively, the resultant structure is immersed into ferric-chloride to etch area 6 without involving the ink, which is then subjected to drying, delaminating, washing, neutralizing, etc. Therefore, an etched portion 7 of a lackluster surface is formed in the stainless steel plate having a glossy mirror surface as shown in Fig. id.

However, when chemical corrosion is employed to produce one-dimensional depth, it is insufficient to express a three-dimensional optical effect of a ridgy plane.

Meanwhile, techniques to color the surface of the stainless steel plate are disclosed in Japanese Patent Publication No. sho 52-32621 and Japanese Laid-open Patent Publication No. Hei 2-107798. According to these references, when a stainless steel plate is immersed and electrolyzed in an aqueous solution of Cr03 and H,SO4, its color varies in the sequence of brown, blue, yellow, purple and green. This allows a predetermined color to be obtained (called inco color). Using such an inco color technique, the same surface is masked in various portions to obtain a variety of colors.

However, the stainless steel plate obtained from the abovedescribed technique is formed in a simple step height (due to etching) or mixed with various colors due to the inco color processing, lacking a three-dimensional effect and optical illusion effect according to angles viewed.

Therefore, unlike the conventional technology of simple topographical effect in which step height is given by simple etching or colors are simply arranged, embodiments of the present invention seek to provide a stainless steel plate having a topographical (threedimensional) optical effect and a fabricating method thereof wherein an inco color portion, stripped portion and hair line are harmoniously matched to thereby display the optical illusion effect three-dimensionally.

According to a first aspect of the present invention, there is provided a stainless steel plate having a colored and topographical surface wherein an inco color is formed on the surface of a mirror stainless steel plate, a stripped portion is formed on its surface except part of the inco color portion, and a hair line is formed on part of the stripped portion.

According to a second aspect of the present invention, there is provided a method of fabricating a stainless steel plate having a colored and topographical surface comprising the steps of: (a) inco coloring the overall surface of a mirror stainless steel plate, or exposing a portion to be incocolored and masking the remaining portion to expose only a unmasked portion; (b) putting a plurality of draft films having image patterns on silk screens coated with photoresist, and exposing and washing them to thereby obtain a plurality of silk screens having a portion where the photoresist is removed and a hardened portion; (c) putting one of the silk screens obtained in step (b) which can mask the stainless steel plate except part of the inco color, on the stainless steel plate obtained in step (a), to thereby form a masked portion and unmasked portion; (d) stripping the steel plate in an electrolyte solution to form a stripped portion on the unmasked portion, and then removing the mask from the masked portion; (e) putting another of the silk screens which can mask the steel plate except part of the stripped portion as in step (d) on the steel plate as in step (d masking the steel plate to thereby form a masked portion and unmasked portion; and (f) forming a hair line on the unmasked portion, and removing the mask from the masked portion.

For a better understanding of the present invention, and to show how it may be carried into effect, reference will now be made, by way of example, to the accompanying drawings, in which: FIGs. la to id show a conventional etching process, wherein FIG. la shows a draft black & hite film; FIG. lb shows a state of a silk screen after exposure and washing; FIG.Ic shows a state where a photoresist is masked on a stainless steel plate; FIG. ld shows a state where the masked photoresist is removed after etching; FIGs. 2a-2g show a fabrication process of the present invention, wherein FIG. 2a shows a state of a draft film; FIG. 2b shows a state of a silk screen after exposure and washing; FIG. 2c shows a state in which an inco color is coated on a mirror stainless steel plate; FIG. 2d shows a state in which masking and stripping are finished on the steel plate after the third step; FIG. 2e shows a state in which the steel plate is masked after the fourth step; and Fig. 2f shows a finished product.

Hereinafter, a preferred embodiment of the present invention will be described in detail with reference to the attached drawings.

One embodiment of the present invention is to make a stainless steel plate in which an inco color portion 9 is formed on the surface of a mirror stainless steel plate, a stripped portion 11 is formed on the steel plate except part of the inco color portion, and a hair line 14 is formed on part of the inco color portion. If necessary, a gold-plated layer may be formed on hair line 14. The gold-plated layer may be retinted or discolored to match purple or green. According to an image pattern, hair line 14 may overlap stripped portion 11.

In this embodiment, though one kind of image pattern is represented, the present invention is not confined to it but can select a variety of patterns as the case may be.

Referring to FIG. 2a, two sheets of draft films A and B are put on silk screens (which are tightly supported to their frames) on the overall surface of which a photoresist is uniformly coated. Then, the draft films are exposed and then removed. When the silk screens are washed, the silk screens A' and B' having photoresist-free portion 3 and hardened portion 5, respectively, are obtained as shown in FIG. 2b. Thus prepared silk screens A'- B' are used in masking the stainless steel plate.

First, as shown in FIG. 2c, a mirror stainless steel plate 8 is inco color processed in an ordinary electrolyzing method to obtain an inco color portion 9. This inco color processing is performed in an electrolyte solution of 250300g/e of Cr03 and 500-600g/e of HzSO4 at 80-90"C for several minutes to tens of minutes. The visual characteristic of inco color portion 9 is to cause an optical illusion due to the scattering of light. In the electrolysis, the inco color portion varies in the sequence of brown, blue, yellow and green, resulting in the optical illusion required.

On the thus obtained inco color portion of FIG. 2c, silk screen A' is put and acid-resistant ink is masked thereon.

Then, the resultant structure is exposed and silk screen A' is removed so that an exposed inco color portion 9 and masked portion 10 hiding the inco color portion are formed, as shown in A" of FIG. 2d.

In inco color processing, a silk screen opposite to silk screen A' of FIG. 2b, which exposes a portion requiring the inco color and masks the remaining portion, not inco color processing the overall surface of the resultant structure as shown in FIG. 2c, may be used for masking and inco color processing only a unmasked portion. In this case, when acid resistant ink is removed, A" process of FIG. 2d is carried out.

When steel plate A" is stripped in an electrolyte solution, part of the inco color is cut to form a semi-glossy portion. This goes well with the internal inco color portion 6, allowing stripped portion 11 to have an optical illusion.

Here, the electrolyte solution is composed of 10-40% of sulfuric acid, 5-25% of nitric acid and water. The anode is Pb and the cathode is the steel plate of A". The electrolyzing is performed in the electrolyte solution for several minutes to tens of minutes.

After the electrolysis, when acid-resistant ink is removed, inco color portion 9 and stripped portion 11 are formed as shown in A" of FIG. 2d.

Sequentially, a silk screen B' of FIG. 2b is put on A"' and acid-resistant ink is masked. In this situation, when silk screen B' is removed, masked portion 12 and unmasked portion 13 are formed as shown in FIG. 2e. On this unmasked portion 13, a well-known hair line is formed using a hair line machine. As the case may be, a gold-plated layer may be formed on the hair line.

After this process, when the masked acid-resistant ink is removed, inco color portion 9, a finish product is obtained having semi-glossy stripped portion 11 formed by cutting part of the inco color and displaying optical illusion with the internal inco color, and another hair line formed on the stripped portion, if necessary, including gold-plated layer 15 on the hair line.

As described above, the present invention complexly processes a stainless steel plate having a mirror through inco coloring, stripping, hair lining and gold plating, so that a semi-glossy portion with dazzling colors, a hair line formed between the glossy portion and semi-glossy portion, and a gold-plated layer are formed. This exhibits the optical illusion having a three-dimensional effect.

Claims

1. A stainless steel plate having a colored and topographical surface wherein an inco color is formed on the surface of a mirror stainless steel plate, a stripped portion is formed on its surface except part of the inco color portion, and a hair line is formed on part of said stripped portion.

2. A stainless steel plate having a colored and topographical surface as claimed in claim 1, wherein a goldplated layer is formed on said hair line.

3. A stainless steel plate having a colored and topographical surface as claimed in claim 1 or claim 2, wherein said gold-plated layer is formed and retinted to match purple or green.

4. A method of fabricating a stainless steel plate having a colored and topographical surface comprising the steps of: (a) inco coloring the overall surface of a mirror stainless steel plate, or exposing a portion to be incocolored and masking the remaining portion to expose only a unmasked portion; (b) putting a plurality of draft films having image patterns on silk screens coated with photoresist, and exposing and washing them to thereby obtain a plurality of silk screens having a portion where the photoresist is removed and a hardened portion; (c) putting one of said silk screens obtained in step (b) which can mask said stainless steel plate except part of the inco color, on said stainless steel plate obtained in step (a), to thereby form a masked portion and unmasked portion;; (d) stripping the steel plate in an electrolyte solution to form a stripped portion on the unmasked portion, and then removing the mask from the masked portion; (e) putting another of said silk screens which can mask the steel plate except part of the stripped portion as in step (d) on the steel plate as in step (d), masking the steel plate to thereby form a masked portion and unmasked portion; and (f) forming a hair line on the unmasked portion, and removing the mask from the masked portion.

5. A method of fabricating a stainless steel plate having a colored and topographical surface as claimed in claim 4, wherein said hair line is gold-plated.

6. A method of fabricating a stainless steel plate having a colored and topographical surface as claimed in claim 4, wherein said gold-plated layer is electrolyzed to match purple or green.

7. A stainless steel plate as claimed in claim 1, substantially as hereinbefore described with reference to or as shown in the accanpanying drawings.

8. A method of fabricating a stainless steel plate according to claim 4, substantially as hereinbefore described with reference to or as shown in the accompanying drawings.