JPH11120624A - Protective coating film on printed surface of optical disk and its production - Google Patents

Abstract

PROBLEM TO BE SOLVED: To form a protective film on a printed surface by covering the surface of an optical disk printed by heat transfer or ink jet method with a UV-curing transparent ink by screen printing and then hardening the ink. SOLUTION: Optical disks in a small lot are produced by forming recorded faces by heat transfer or ink jet method. The printed surface of the optical disk thus produced is easily scratched. Therefore, a transparent UV ink is applied as a thin layer only on the printed part of the optical disk and then irradiated with UV rays to form a strong film so as to protect the printed surface from scratches. For example, by using a screen having 355 polyester fibers per one inch and by selecting any colorless or color ink from transparent UV inks commercially available, the coloring effect can be further improved. Irradiation of UV rays is carried out for several seconds and a disk which is highly practical and is hardly scratched can be easily produced.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to a protective film on a printed surface of an optical disk by thermal transfer or an ink jet method.

[0002]

2. Description of the Related Art There is a reflective film formed by scattering of gold, silver, aluminum or the like on a signal surface of an optical disk, and a donut-shaped paper is printed as a label on a protective film that protects the reflective film. There are things that are pasted together,
There is a drawback that the optical disc surface is warped due to the adhesive on the paper surface.

In order to protect the reflective film of the optical disk and form the printing surface, instead of the label printed on the paper, a UV-curable UV lacquer is uniformly applied, and the cured film is irradiated with ultraviolet rays. Is formed, and printing is performed on this.

[0004] As one of the printing methods, screen printing is performed. Since this printing has a thick ink film, it is excellent in weather resistance and chemical resistance and can express unevenness. However, in principle, it is difficult to reproduce the design by two-color printing, especially in the case of dot printing. It tends to be irregular, making it difficult to faithfully express gradations and reproduce colors. Also,
Dot gain frequently occurs, advanced hair removal is not possible,
I am not good at expressing thin ruled lines, and in particular, there are many restrictions on the expression of photographic originals. In short, it is not suitable for fine design.

[0005] On the other hand, the four-color-based offset printing allows free expression of colors and allows any design, but it requires a lot of time for color calibration, and costly printing for small unit quantities. Do not fit.

[0006] On the other hand, when printing small quantities such as personal use, 4
Color-based thermal transfer printing is now possible. this is,
First, printing is performed on a thermal transfer film, and then the printed portion is transferred to the printing surface of the optical disk by heating and pressing. However, it takes time to print the thermal transfer film, and after thermal transfer, the print surface wears due to use,
There is a problem of spoiling aesthetics. The fact that it takes a long time to print the thermal transfer film can be solved to some extent by increasing the number of printing machines. Further, as an attempt to improve the wear of the printing surface, attempts have been made to reduce the abrasion by making the base of the printing surface uneven beforehand, but it is hardly sufficient.

Along with the thermal transfer printing, the color ink jet printing can be used for the same purpose. This method is a method of printing directly on an optical disk, and has a drawback that printing speed is high and print reproducibility is slightly inferior to that of a thermal transfer method, but it can be put to practical use. However, a drawback common to the thermal transfer type printing is that, although somewhat worse than that of the thermal transfer type printing, the use thereof causes a problem in that the printed surface is worn and the appearance is impaired.

[0008]

SUMMARY OF THE INVENTION An object of the present invention is to provide an effective protective film for protecting the printed surface from abrasion in thermal transfer or ink jet printing suitable for optical discs of small unit printing. is there.

[0009]

Here, the present inventors have developed an optical disk printing surface obtained by coating a printing surface of an optical disk by thermal transfer or ink jet method with an ultraviolet curable transparent ink by screen printing and curing with an ultraviolet light. Of a protective coating and its manufacturing method.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS For level printing of a small lot of optical disks of about 100 or less, thermal transfer or printing by an ink jet method is suitable. Since color proofing is not required, printing can be started immediately, and there is no printing loss of the optical disk, which is economical. In the case of printing by the thermal transfer method, first, a design to be printed is input using personal computer software. This is converted into a reverse image, and then directly printed on a dedicated transparent film by a commercially available color thermal transfer printer. This is separated into four colors of Y (yellow), M (magenta), C (cyan) and K (black) by a color ribbon and printed like offset printing. Although the print quality depends on the print design and the resolution of the printer, the quality of the print is good, and a resolution of 600 dpi is sufficient. Then, the printed film is passed through a pressurized heat transfer machine according to the protective film on the reflection surface of the optical disk to be printed, and after cooling, the film is peeled off to obtain the printed surface of the optical disk. According to this method, no special composition is required, and the contents can be easily changed. Printers and thermal transfer machines are commercially available at relatively low cost.

On the other hand, in the case of printing by the ink jet method, a UV curing type UV lacquer is applied uniformly to protect the reflective film of the optical disk and form the printing surface.
A UV ink containing a thixotropic component or a matte UV ink is further applied on the cured film obtained by irradiating ultraviolet rays to improve the printing effect, thereby forming a fine uneven surface. Such a state can be applied to printing by a thermal transfer method. After inputting a design to be printed on the obtained optical disk using personal computer software, the design can be printed immediately.

The printed surface of the optical disk obtained in this manner has been found to be weak against friction, and is liable to be damaged by contact with other parts, and has the disadvantage of impairing the appearance. Therefore, if the printing surface can be protected, the practicality is enhanced. As a result of various examinations, screen printing
They have found that it is sufficient to apply transparent UV ink to the printing surface of the optical disk.

When screen printing is used, a transparent UV ink can be easily applied to a thin layer only on a printed portion of an optical disk. In screen printing, for example, a screen using 355 polyester fibers per inch is used, and colorless or colored ones are arbitrarily selected from commercially available transparent UV inks to further enhance the color effect. You can also. By applying a transparent UV ink to a thin layer and irradiating with ultraviolet rays, a strong coating film can be easily obtained.

[0014]

The present invention will be described more specifically with reference to the following examples. (A) Printing of optical disc by thermal transfer method To protect the aluminum reflective film of 12cm optical disc and to configure the printing surface, after applying UV curable UV lacquer uniformly using a centrifugal force with a top coat machine. First, a cured film is formed by irradiating ultraviolet rays. On the cured film, a photo-color printer manufactured by Alps Electric Co., Ltd., a heating type thermal transfer machine using MD-2300J and a heat-sensitive roller, the optical disk is housed in a special jig, and a special jig for thermal transfer is provided. A desired color design is thermally transferred by applying a transparent film. It takes less than 7 minutes to print one optical disk, but mass production is possible by using additional printers.

(B) Printing of an optical disk by the ink jet method An optical disk having a fine uneven surface formed on the printing surface of the optical disk of (a), CP-1000 manufactured by Expert Magnetics Co., Ltd. as a color printer. Alternatively, a desired color design can be directly printed using the automatic continuous printing machine DP-404.

(C) Preparation of a protective film An optical disk, which has been subjected to label printing by thermal transfer or ink-jet method, is prepared by passing it through upright pins in units of 100 sheets, and is then suction-moved one by one to a predetermined jig and stored. Apply a screen of a screen printing machine to the printing surface, and use a light yellow UV ink, SSD manufactured by Dainippon Ink Co., Ltd. so that the protective coating has a thickness of 8 microns and sufficiently covers the printing surface. / TY-
After applying No. 05, move it in the rotation direction or horizontal direction, irradiate it with ultraviolet light for several seconds and cure it,
A protective coating is obtained, and the printed surface is less likely to be scratched.

[0017]

The printed surface of an optical disk according to the present invention can be protected from frictional scratches on the printed surface of the optical disk by thermal transfer or ink-jet printing by the protective coating on the optical disk printed surface. It is possible.

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[Procedure amendment]

[Submission date] November 12, 1997

[Procedure amendment 1]

[Document name to be amended] Statement

[Correction target item name] 0002

[Correction method] Change

[Correction contents]

[0002]

2. Description of the Related Art There is a reflective film formed by sputtering of gold, silver, aluminum or the like on a signal surface of an optical disk, and a label printed on a donut-shaped paper as a label is laminated on a protective film that protects the reflective film. There are some drawbacks, but they are aesthetically difficult and have the drawback that the optical disc surface is warped by the paper adhesive.

[Procedure amendment 2]

[Document name to be amended] Statement

[Correction target item name] 0008

[Correction method] Change

[Correction contents]

[0008]

SUMMARY OF THE INVENTION It is an object of the present invention to provide an effective method for protecting the printed surface from abrasion in thermal transfer or ink-jet printing suitable for optical disks of small unit printing. .

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification code FI G11B 7/26 531 G11B 7/26 531

Claims (2)

[Claims] 1. A protective coating for an optical disk printing surface obtained by coating a printing surface of an optical disk by thermal transfer or ink jet method with an ultraviolet curable transparent ink by screen printing and curing with an ultraviolet ray. 2. A method for producing a protective film for a printed surface of an optical disk, comprising coating a printed surface of the optical disk by thermal transfer or an ink jet method with an ultraviolet-curable transparent ink by screen printing and curing with an ultraviolet light.