JPH0542653A - Production of rubber stamp by laser machining - Google Patents

Abstract

PURPOSE:To produce a clean rubber stamp having no clog with high efficiency by a method wherein an engraved part is formed on the surface of a rubber material by laser machining and, thereafter, treated with alkali solution. CONSTITUTION:In a production of rubber stamps, a manuscript of a printing pattern is formed by phototypesetting. This printing pattern is processed to data by a scanning image scanner. An operation of a laser light directly emitted to a rubber material based on the data is processed by a computer. As the laser light, normally a carbon dioxide gas laser is used. The rubber material machined by the laser is dipped in alkali solution, whereby the surface of the rubber material is cleaned. In this manner, a residue remaining as a clog in the recessed part of the engraved part is easily removed, and the surface tackiness of a printing surface is eliminated. As the rubber material, a material containing 50-150 pts.wt. filler per 1.00 pts.wt. of a raw rubber is used.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of producing or processing a stamp or stamp having a printing surface by forming an engraved portion on the surface of a rubber material.

[0002]

2. Description of the Related Art As a conventional method for producing a rubber stamp, first, a negative of a printing pattern is produced, and an original plate of a photocurable resin is irradiated (exposed) with the negative and then washed with a jet water stream to form a convex pattern. After being formed, it is dried, re-exposed and cured to produce a prototype. Next, using a master mold, heat-press on a phenol resin plate to form a concave pattern to make a master mold, put a rubber material on the master mold and heat press to make a stamp plate with a convex printing surface. I am producing. However, in the conventional method, there are problems in that it takes time and effort to manufacture a master mold, a master mold, and a rubber stamp plate, production efficiency is poor, and material costs are high and cost is high.

[0003]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a rubber stamp processing method which solves the above problems.

[0004]

Means for Solving the Problems As a result of intensive studies, the present inventors have succeeded in efficiently producing a clean rubber stamp without clogging by laser processing a rubber stamp material and washing it with a specific treating agent. The present invention has been completed and the present invention has been completed. That is,

The method for producing a rubber stamp of the present invention is characterized in that an engraved portion is formed on the surface of a rubber material by laser processing and then washed with an alkaline solution.

The rubber material used in the rubber stamp manufacturing method of the present invention is a material usually used as a rubber stamp, and the filler is about 50 to 150 per 100 parts by weight of the raw rubber.
It is preferable to contain by weight. Examples of the raw material rubber include natural rubber, styrene, butadiene rubber (SBR) and acrylonitrile-butadiene copolymer rubber (NBR).

The rubber material is usually mixed with the raw material rubber 10
50 to 150 fillers, preferably 5 fillers per 0 parts by weight
It is 0 to 100 parts by weight. Other compounding materials are composed of zinc white 3 to 5, stearic acid 0: 5 to 2, several kinds of crosslinking accelerators 1 to 2, sulfur 1 to 3, and plasticizer 0 to 10 in a weight ratio. Examples of the filler include gourd powder (shellfish), clay, calcium carbonate, talc (magnesium silicate) and the like.

In the method of forming the engraved portion by laser processing in the manufacturing method of the present invention, that is, the method of forming the printing surface, first of all, a type original is formed and a document of the printing pattern is prepared, and then this printing pattern is scanned. Data is processed by an image scanner, and a rubber material is directly irradiated with laser light based on the data to engrave a pattern. The operation is processed by a computer. A carbon dioxide laser is usually used as the laser light, and the intensity is 200 to 4
00W, the size of the spot is 50 to 100 μ.

The alkali treatment in the manufacturing method of the present invention usually comprises immersing the rubber material after laser processing in an alkali solution to wash the surface of the rubber material. As the alkali used, sodium hydroxide, potassium hydroxide,
Examples include calcium hydroxide. The concentration of the alkaline solution is 5 to 40%, preferably 20 to 30%, and an aqueous solution is preferred. The treatment temperature is 50 to 90 ° C, preferably 70 to 80 ° C. Then wash with water, 5-10%
Neutralize with hydrochloric acid for about 1 minute at room temperature and wash with water again to complete. Hydrochloric acid is suitable for the neutralization treatment, and nitric acid, for example, may deteriorate the rubber. Further, depending on the case, it is optimal to carry out washing with a jet water jet washing machine for about 5 minutes after the above washing with water. The neutralization treatment is preferably neutralized in consideration of compatibility with ink (wettability of ink, etc.) and changes with time of the ink, but neutralization by neutralization is not always necessary. Absent.

Usually, when a rubber material is laser-processed, most of the compounding components in the engraved portion are volatilized, but some remain as a residue in the concave portion of the engraved portion. The residue is in a state where the filler, the rubber depolymerization component and the additive are mixed, and the odor of the rubber depolymerization component remains. Although the residue can be removed by jet water flow or brushing, it is difficult to reliably remove the residue clogged in the engraving portion, and a great deal of work time is required.

However, in the manufacturing method of the present invention, the filler mixed in the rubber material becomes powdery with the depolymerization component, and the residue is easily removed by immersing the filler in the alkaline solution to reduce the stickiness of the printed surface. .. Therefore, the engraving portion is not clogged, and the remaining material can be reliably removed, and the working time can be significantly shortened.

By the laser processing of the manufacturing method of the present invention, a clear printing surface which has not been obtained in the past is formed, and compared with the conventional method, there is no labor for preparing a master or a master and for heating press. Since it can be operated by computer control, the productivity is greatly improved.

The rubber stamp of the present invention is used for a stamp or a stamp which is stuck to a handle or the like, pressed against a stamp stand impregnated with ink to adsorb ink, and pressed against a document or the like to imprint.

EXAMPLES The present invention will be described in more detail with reference to the following examples, but the present invention is not limited to these examples. Example 1 a) A rubber plate (thickness: 5 mm) for printing material was processed with the following composition. SBR 100 parts by weight Zinc white 5 parts by weight Stearic acid 1 part by weight Dibenzothiazyl disulfide 1 part by weight Tetramethylthiuram monosulfide 0.2 parts by weight Sulfur 1.2 parts by weight Filler (clay) 50 parts by weight Filler (salt) 50 parts by weight Department

B) Data processing was carried out by an image scanner by a prefabricated printing pattern and a computer operation, and the rubber plate was irradiated with laser based on this data to engrave the pattern. As the laser conditions, a carbon dioxide gas laser was used, and the intensity was 300 W and the spot size was 80 μm. A print pattern was engraved on the rubber material by the laser processing, and most of the removed portion was scattered, but some remained on the marking surface, leaving a butadiene odor.

C) The rubber material engraved with the print obtained in b) was immersed in a 25% aqueous sodium hydroxide solution at 60 ° C. for 2 minutes. Then, it was washed with water, neutralized with a 5% hydrochloric acid aqueous solution for 1 minute, and then washed with an automatic washing machine for 5 minutes to produce a rubber stamp. There was no butadiene odor, and the residue on the marking surface was completely removed.

Comparative Example 1 A rubber stamp was produced in the same manner as in Example 1 except that silicic acid anhydride was 100 parts by weight. After the laser processing, sticky powder remained on the marking surface and was sticky. After the alkaline solution treatment, stickiness remained and the filler remained on the marking surface.

Comparative Example 2 A rubber stamp was produced in the same manner as in Example 1 except that the hydrous silicic acid was 100. The rubber was inferior in reinforcing property and was not suitable as a printing material. In addition, a large amount of dry powdery substances remained on the marking surface after laser processing.

[0019]

The method of manufacturing a rubber stamp of the present invention is a method of processing a rubber stamp, which has never been done by engraving the printed surface by laser processing. The manufacturing method of the present invention can control the computer, eliminates the labor-intensive work of the related art, and significantly improves the productivity.

Claims (2)

[Claims] 1. A method for producing a rubber stamp, characterized in that an engraved portion is formed on the surface of a rubber material by laser processing and then treated with an alkaline solution. 2. The method for producing a rubber stamp according to claim 1, wherein the rubber material contains 50 to 150 parts by weight of filler with respect to 100 parts by weight of the raw material rubber.