JPH06206366A - Artificial material for seals and seal - Google Patents

Abstract

PURPOSE:To enhance the sharpness of a print of a seal, in an artificial material for seals having a high water absorbability, by forming a molded cured article based on a synthetic resin and a powder of an org. natural fiber. CONSTITUTION:An artificial material for seals is formed by molding and curing a compsn. based on a general-purpose thermosetting or thermoplastic resin, for example, a phenol resin and a powder of an animal or vegetable org. natural fiber composed of silk, hemp or wool. The particle size of the powder is set to the range of about 10-500mum and the compounding ratio of the powder of the org. natural fiber to the synthetic resin is set to about 3-90wt.%. In the kneading with the synthetic resin, a monomer may be polymerized after the mixing with the powder of the org. natural fiber. This artificial material for seals is carved to be formed into a seal.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an artificial printing material which is particularly excellent in water absorption and a stamp obtained by processing the artificial printing material.

[0002]

2. Description of the Related Art Recently, there is a shortage of natural printing materials due to the so-called Washington Convention ban on ivory and the like.
It is said that a practical printing material needs various performances such as hardness, strength, water absorption, abrasion resistance, and engraving workability, but up to now, there is no clear standard for printing material. Therefore, conventionally, attention has been paid to its specific physical properties as an alternative to natural printing materials, and, for example, an artificial material similar to ivory has been proposed in which a specific synthetic resin is mixed with an inorganic filler or egg shell powder (Japanese Patent Laid-Open Publication No. Sho. 53-8651, Japanese Patent Laid-Open No. 4-202344, etc.).

[0003]

However, although the above-mentioned known artificial materials are satisfied to some extent with respect to physical properties such as strength, the stamps obtained by processing these artificial stamps are slippery and clear when imprinted. It is difficult to get shadows. It is thought that this is mainly due to the water absorption of the artificial material,
Conventionally known artificial materials are significantly inferior to natural materials in terms of water absorption. Specifically, the water absorption rate of the synthetic resin artificial material is 0.1% while the water absorption rate of ivory is 9.5%, the water absorption rate of black buffalo is 3.9%, and the water absorption rate of Sheephorn is 3.2%. Most are less than%. It is an object of the present invention to improve the water absorbency of an artificial printing material and to significantly improve the sharpness of the imprint of a stamp obtained by engraving the artificial printing material.

[0004]

In order to achieve the above object, the artificial printing material of the present invention comprises a molded and hardened product containing a synthetic resin and a powder of organic natural fiber as main components. The seal stamp of the present invention is formed by engraving this artificial stamp material.

As the synthetic resin in the present invention, any of general-purpose thermosetting resins, thermoplastic resins, engineering plastics and the like can be used. As the thermosetting resin, for example, phenol resin, urea resin, melamine resin, unsaturated polyester resin, epoxy resin,
Examples thereof include alkyd resin and furan resin. Examples of the thermoplastic resin include polyethylene, polystyrene, ABS resin, polypropylene, polyvinyl chloride,
Examples thereof include polyvinylidene chloride, methacrylic resin, polyamide, polyamideimide, polyimide, polyacetal, polycarbonate, polyethylene terephthalate, and polybutylene terephthalate. Examples of engineering plastics include polybutylene terephthalate, polyphenylene oxide, polyphenylene sulfide, polyether sulfone, polyarylate, polyallyl sulfone, polyoxybenzylene,
Examples thereof include polysulfone, polymethylpentene, polyetheretherketone, and polyetherimide.

The powder of organic natural fiber in the present invention is
It is a powder obtained by drying (drying) fibers of animal or vegetable organic natural substances such as silk, hemp, wool, collagen, and bamboo. The particle size of this powder is preferably in the range of 10 to 500 μm, more preferably in the range of 50 to 200 μm. The blending ratio of the organic natural fiber powder to the synthetic resin is 3 to.
The range of 90 wt% is preferable, and the range of 10-45 wt% is more preferable.

In the present invention, various additives such as a vulcanizing agent (polymerization initiator), an inorganic or organic filler, and a coloring agent may be blended in addition to the above-mentioned synthetic resin and organic natural fiber powder. . The above-mentioned powder of organic natural fiber and additives to be added as necessary can be kneaded with a polymer of a synthetic resin or mixed with a monomer of a synthetic resin and then polymerized to produce a molded and cured product. When a molded and cured product is produced by molding after kneading, it is necessary to sufficiently disperse the powder of the organic natural fiber in the synthetic resin and appropriately select molding conditions such as molding temperature and molding pressure. .

[0008]

EXAMPLES The present invention will be described in more detail with reference to Examples and Comparative Examples. Examples 1 to 7 Methyl methacrylate monomer, ammonium persulfate as a vulcanizing agent, particle size of 50 to 2 as organic natural fiber powder
00 μm silk powder, hemp powder, wool powder or collagen powder, and pigment were uniformly stirred and mixed at the weight ratio shown in Table 1. This mixture is placed in a mold at a temperature of 15
Molding and curing were performed for 10 to 30 minutes under the conditions of 0 ° C. and a pressure of 100 MPa to manufacture a square pillar-shaped stamp material of 20 mm × 20 mm × 60 mm. Regarding the water absorption of the stamp obtained by molding, the water content (g / m ² ) was measured according to the method described in JIS K7209. Furthermore, 20m of this printing material
Grooves having a width of 1 mm were provided in the longitudinal direction and the transverse direction at intervals of 1 mm on a bottom surface of m × 20 mm to form orthogonal grooves, that is, a stamp having 100 cells. I stamped this seal with vermilion on high-quality paper, observed the impression of the impression with a magnifying glass, and checked the number of squares with the impression of imprint. This test was performed 5 times, and the average number of blind cells was calculated. Table 1 shows the measurement results of the compounding composition and water absorption of the printing material-forming raw material, and the average number of blister cells of the stamp. Comparative Example 1 A printing material was molded in the same manner as in Example 1 except that the powder of the organic natural fiber was not mixed, and the water absorption was measured. Further, in the same manner as in Example 1, a seal stamp was formed and the average number of blind stitches was determined. Table 1 shows the measurement results of the compounding composition and water absorption of the printing material-forming raw material, and the average number of blister cells of the stamp.

[Table 1]

[0009]

As described above, according to the present invention, by selecting various synthetic resins within the scope of the present invention, various basic properties required as a stamp material such as hardness, strength, abrasion resistance and engraving workability are obtained. And an artificial printing material which is particularly excellent in water absorption. Further, the seal obtained by engraving the artificial printing material of the present invention has a water absorption rate close to that of the natural printing material, so that the ride of the red meat is remarkably improved, and a markedly clear imprint is obtained when imprinted. . As a result, it becomes possible to economically and stably provide a practical substitute for a natural printing material which is scarce in resources in Japan.

Claims (2)

[Claims] 1. An artificial printing material comprising a molded and hardened material containing a synthetic resin and a powder of an organic natural fiber as main components. 2. A seal stamp obtained by engraving the artificial stamp material according to claim 1.