JP2001150780A - Penetrable seal and material for face of seal - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a penetrable seal, with which no strain in the print of a seal develops due to the strength of the impressing thereof, no change in the density of a seal impression develops and which has a face developing neither smoke nor stink, nor engraving refuse, nor stick during laser working thereof. SOLUTION: The face of the penetrable seal is made of the porous body of a thermoplastic resin or of a thermosetting resin having the porosity of 40 to 95% and the durometer hardness according to the C method of JIS K 6301 of 50 or more. In order to form the face of the seal, the material of the face of the seal of the penetrable seal is engraved with laser beams.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a seal (hereinafter referred to as "penetrable seal") in which ink is supplied from the inside of a stamp face and does not need to be adhered to each time stamping is performed, and a material for the stamp face. The present invention relates to a permeable seal stamp engraved on a stamp surface with light.

[0002]

2. Description of the Related Art Conventionally, a permeable seal is mainly composed of a stamp face, an ink absorbing section, a grip section, and an exterior, and a flexible porous body such as rubber is used as a material of the stamp face and the ink absorbing section. ing. In such a penetrable seal, the ink stored in the porous body of the ink storage portion penetrates from the back side of the stamp surface portion to the stamp surface and is supplied, and is in a state where the seal can be performed. In recent years, a desk-top numerically controlled laser processing machine using a small-output laser oscillator has been developed for forming a stamped surface, and it has become possible to engrave a rubber-made stamping material in a short time.

[0003]

However, if the stamp surface is formed of a flexible material such as the rubber described above, the stamp surface portion is deformed by the pressing at the time of stamping, and there is a drawback that the stamp image is not constant. Depending on the strength of the power, shading appears on the seal,
If it is too strong, the ink will seep out, and if it is too weak, it will fade. In such a case, it cannot be adopted as a seal for authentication.

When using the above laser processing machine,
A small portion of the stamp surface is burned out by using the high heat of the laser beam to form a concave portion. At this time, gas, smoke, engraving scum, and stickiness due to depolymerized rubber are generated. Because of this,
After engraving, remove the engraving residue and stickiness with an alkaline solution,
After washing and removing the alkaline liquid permeated into the inside of the porous material, the porous material is dried to complete the stamp face. Such post-engraving processing is not only troublesome, but also undesirably causes deformation of the stamp face.
Further, smoke emission requires a smoke exhaust dust deodorizing device from the viewpoint of bad smell and safety, which hinders installation in ordinary stores and the like. Separately, a seal has been proposed in which a porous body made of a fusible inorganic material such as glass is used as a stamp face, but engraving is performed by melting the porous body with a high-power laser beam to form a concave portion. However, there is a disadvantage that the stamp face is not sharpened, and the apparatus is also large.

[Problems to be solved by the invention]

SUMMARY OF THE INVENTION An object of the present invention is to provide a seal that eliminates the above-mentioned drawbacks and eliminates the need to apply ink every time a stamp is made. That is, it is an object of the present invention to provide a permeable seal stamp having a stamped surface which is free from shading due to the strength of pressing, does not produce shading, and does not generate smoke, odor, engraving residue and stickiness during laser processing.

[0006]

According to the present invention, the stamp surface of a rigid seal using a conventional aggregate or wood must be attached each time ink is stamped. Paying attention to the fact that it does not come out, it was completed as a result of earnest research to make this ink permeability. That is, the invention of claim 1 is made of a thermoplastic resin or a thermosetting resin, and has a porosity of 40 to 95% and a durometer hardness (JIS K6).
(C method 301) This is a seal surface material for a permeable seal stamp comprising 50 or more porous bodies.

According to a second aspect of the present invention, there is provided a permeable seal stamp in which a stamp face is formed by processing the stamp face material of the permeable seal stamp according to the first embodiment.

According to a third aspect of the present invention, there is provided a permeable seal stamp formed by engraving the material for the seal surface of the permeable seal stamp according to the first embodiment with a laser beam to form a seal surface.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION The seal face of a permeable seal in the present invention is made of a porous body made of resin,
As this resin, various natural or synthetic resins can be used, and a hard resin that does not distort the imprint is used. For example, a thermoplastic resin or a thermosetting resin can be used. The thermoplastic resin is preferably non-crystalline. The non-crystalline resin has a glass transition temperature relatively close to the melting temperature, and the resin is less likely to be melted during laser engraving, so that the stamp face is clearly engraved. The glass transition temperature of these resins is preferably 50 ° C. or higher,
More preferably, it is 100 ° C. or higher, and more preferably, one which melts or condenses without showing a clear transition temperature. Further, those having a melting temperature of 170 ° C. or higher are preferable, more preferably 200 ° C. or higher, and further preferably, thermal decomposition is performed before melting. When the resin is irradiated with laser light, the resin locally becomes high in temperature and melts or decomposes, evaporates, and burns. Also carbon-
Resins having a carbon double bond cause stickiness due to depolymerization, and resins containing a sulfur element are undesirable because they give off odor.

[0010] Thus, the resin used as the stamp face material is melted during laser engraving, and the stamp face becomes unclear, and the stickiness of the depolymerized product does not occur, so that it is not necessary to perform the removal treatment with an alkali solution. In the case of a crystalline resin, it is easy to melt during engraving because of its low glass transition temperature. However, even a crystalline resin can be preferably used as long as the glass transition temperature and the melting temperature are in the above ranges.

Specific examples of the resin include a natural resin such as a cellulose resin such as cellulose butyrate acetate, a coumarone resin,
For thermosetting resin, epoxy resin, phenol resin, melamine resin, alkyd resin, unsaturated polyester resin, for thermoplastic resin, polystyrene, acrylic resin,
Examples include a vinyl resin, a polyurethane, an ionomer resin, an acetal resin, a polyester resin, and a polyamide resin. Even if these resins are used alone,
A mixture of more than one species can be used.

Further, these resins can be crosslinked as required. By crosslinking, the glass transition temperature can be increased and the melting temperature can be increased. This prevents melting during laser engraving and prevents stickiness. In addition, by cross-linking, the seal can be made hard, and a seal having no distortion at the time of stamping can be obtained. By further crosslinking, various chemicals contained in the ink,
In particular, a material that does not swell with respect to glycols can be used.

As a method of crosslinking, a thermosetting resin can be cross-linked by heating, and a thermoplastic resin can be cross-linked by irradiating ultraviolet rays or radiation, or can be cross-linked by a cross-linking agent. As the crosslinking agent, an isocyanate compound, an epoxy compound, a melamine resin, a urea resin, an acrylate compound, an organic peroxide, and the like are preferable, and a sulfur compound is not preferable because it generates a bad smell and harmful substances.

In order to make these resins porous, a method suitable for various resins can be used as appropriate. For example, if the raw material is water-soluble, a denaturing agent and starch are added to the aqueous solution, and the starch is gelatinized by heating, and at the same time, the resin is insolubilized by a denaturing reaction, and then the starch is washed and removed. be able to. In the case of a solvent-soluble resin, it can be prepared by dissolving in a water-miscible solvent and coagulating in water.
Further, it can be prepared by kneading and mixing water-soluble salts and eluting the salt after resin molding. Alternatively, it can also be prepared by adjusting resin fine particles and joining the particles to each other by sintering, an adhesive or the like. Although not limited to the above-mentioned production methods, the porous body obtained by these production methods has pores in a communicating state, has liquid permeability, and is suitable as a material for a stamp surface of a permeable seal.

The porous body thus obtained preferably has a maximum pore diameter of 100 μm or less, more preferably 50 μm or less. The average pore diameter is preferably 50 μm or less, and more preferably 10 μm or more. This is because if the pore diameter is too large, a missing portion will be formed in the print, and if the pore diameter is too small, the ink will not easily penetrate and blur will occur during continuous imprinting.

Further, the porosity is preferably from 40 to 95%, more preferably from 50 to 85%. If the porosity is less than this, it is difficult for the ink to penetrate, and if it is higher than this, the strength is insufficient and the durability is lost. The hardness is a hardness that is strong and not deformed when stamped, and is 50 in durometer hardness (C method of JIS K6301) represented by a penetration depth of a steel ball.
Or more, more preferably 70 or more and 98
It is as follows. If it is softer than this, the imprint when imprinting is not constant. If it is harder than this, durability will be lost due to brittleness. Further, the porous body preferably has resilience, and is particularly necessary for those having low hardness. If the durometer hardness is 50 to 70, it is preferable that the intrusion trace of the steel ball at the time of hardness measurement disappears within one second.

The printing material forming the printing surface of the present invention contains various additives such as a pigment, a colorant, a plasticizer, an antioxidant, an ultraviolet absorber, a nucleating agent, a pore adjusting agent, a crosslinking agent, a curing agent and a modifying agent. Can be added. The additive can be added to the resin or impregnated after the formation of the porous body. Examples of the above pigments include calcium carbonate, talc, silica, alumina, clay, crystallite, graphite, molybdenum disulfide, resin fine powder such as nylon and polyethylene, and fluororesin, diatomaceous earth, etc. It is possible to improve the performance and adjust the amount of ink adhered. The crosslinking agent crosslinks the resin, the curing agent promotes the crosslinking reaction, and the modifying agent changes the chemical structure of the resin.

The method for processing a stamped surface according to the present invention has an output 100
A small laser processing machine of W or less is suitable. A very small laser beam heats the illuminated part of the sign surface,
The part will burn out. Thereby, a concave portion of the stamp surface is formed. The depth of the concave portion can be adjusted by adjusting the irradiation time of the laser beam. High power laser processing machines are not suitable because the beam diameter is large or the irradiation time cannot be controlled. At this time, the stamping material forming the stamping surface of the present invention emits little smoke and does not generate odor. Further, at this time, there is no stickiness and there is little generation of engraving residue. These are due to the fact that the material of the present invention uses a specific resin, and the resin molecule has carbon, oxygen, hydrogen, and nitrogen as a skeleton,
That there are few carbon-carbon double bonds, that no sulfur atoms are bonded, and that the glass transition temperature of the resin is high,
This is because the melting temperature of the resin is high, and the resin is locally heated to a high temperature by a laser beam and burned out. Further, after engraving, if an ink occluding body is provided behind the stamp surface and a grip portion is attached, a seal is obtained, and the seal can be performed while supplying ink from the ink occluding body. Also, the stamped surface can be formed by performing mechanical cutting engraving without using laser light, and a two-dimensional or three-dimensional cutting machine equipped with hand engraving or an end mill can be used. Furthermore, the seal can be simply attached to the shaft wood. In this case, the ink is permeated and absorbed on the stamp surface by pressing it against a stamp base or the like, and then is imprinted, whereby a plurality of imprints corresponding to the ink absorbed and absorbed can be performed.

[0019]

Example 1 As a raw material, 100 parts by weight of a thermoplastic resin, polyvinyl alcohol (Gohsenol HN-18, manufactured by Nippon Synthetic Chemical Industry Co., Ltd.), was dispersed in water and dissolved while increasing the temperature to a total amount of 800 parts by weight. Separately, 45 parts by weight of corn starch was dispersed in water, heated and gelatinized to a total amount of 4 parts.
50 parts by weight. The two were mixed and brought to a temperature of 45 ° C. Here, 40 parts by weight of formaldehyde and 30 parts by weight of sulfuric acid were mixed as a denaturing agent, and the mixture was made uniform.
The mixture was allowed to stand for 4 hours to carry out a formalization reaction to make it insoluble.
This was washed with water to remove acid, starch and residual formaldehyde, and dehydrated and dried. Thus, a porous body of an acetal resin of polyvinyl formal was obtained.

An aqueous solution of a melamine resin (Sumitex M3, manufactured by Sumitomo Chemical Co., Ltd.) was impregnated with 100 parts by weight of the porous body and dried with 50 parts by weight of a solid content. Then, it was heat-treated at 130 ° C. for 60 minutes with a hot-air drier to be cured. The obtained porous body was hard, had a C durometer hardness according to JIS K6301 (C method of JIS K6301) of 72, and the durometer's steel ball penetration marks disappeared almost instantaneously. Almost all pores had a diameter of 45 μm or less and had a porosity of 65%. This porous body was cut out to a thickness of 3 mm, and was engraved with a laser beam machine (produced by Universal Co., USA, output 25 W) to form a stamped surface with a concave depth of 0.7 mm. An elastic porous body having a thickness of 6 mm was adhered to the back side of the stamp surface, and a dye-based ink for penetrating stamp (XR-2, vermilion, manufactured by Shachihata Industry Co., Ltd.) was absorbed and absorbed to form an ink storage portion. This was mounted on a shank, which is a grip, to give a seal appearance.

[0021]

Example 2 350 parts by weight of anhydrous sodium sulfate having an average particle diameter of 20 μm were mixed and dispersed in 100 parts by weight of polymethyl methacrylate, which is a thermoplastic resin. This was extruded with an extruder to a thickness of 4 mm. The obtained plate-shaped resin composition was immersed in water for 7 days to elute sodium sulfate. Thereafter, it was dried to obtain a porous body. The pores of this porous body were in a communicating state, most of the pore diameter was 50 μm or less, and the porosity was 60%. The C durometer hardness was 80, and the steel ball intrusion trace was not found with the naked eye. The surface was smoothed to form a stamped surface, and laser engraving was performed in the same manner as in Example 1 to obtain a seal.

[0022]

Example 3 500 parts by weight of sodium chloride having an average particle diameter of 30 μm and 1 part by weight of benzoyl peroxide were added to 100 parts by weight of a 60% styrene solution of an unsaturated polyester resin (phthalic acid, maleic acid polymer) as a thermosetting resin. Was mixed and dispersed. This was mixed with a 5% styrene solution of cobalt naphthenate, molded to a thickness of 5 mm, and placed in a room at a temperature of 40 ° C. The resin composition was cured after one day. The obtained plate-shaped resin composition was immersed in water for 7 days to elute sodium chloride. Thereafter, it was dried to obtain a porous body. The pores of this porous body are in communication with each other, and most of the pores have a diameter of 50 μm.
Below, the porosity was 81%. The C durometer hardness was 86, and the steel ball penetration mark was not found with the naked eye.
The surface was smoothed to form a stamped surface, and laser engraving was performed in the same manner as in Example 1 to obtain a seal.

The seals of Examples 1 to 3 clearly show details, and a fixed seal was obtained irrespective of the intensity of pressing. In addition, it was possible to continuously seal without supplying ink every time. At the time of laser engraving of the stamp surface, there was no generation of offensive odor, stickiness, and engraving residue, which were observed when engraving the rubber stamp surface. The generation of smoke was also slight. For this reason, it was not washed with an alkali as when it was made of rubber.

[0024]

Example 4 The porous body of Examples 1 to 3 was engraved to a depth of 0.7 mm with a two-dimensional cutting machine (PNC-2100, manufactured by Roland D.G. Co., Ltd.) equipped with an end mill to produce a stamped surface. A shaft was attached to this to give the appearance of the seal. When these were adhered with ink from a stamp stand and stamped, the details were clearly seen, and a constant imprint was obtained irrespective of the intensity of pressing. In addition, 5
The seal of the times was completed.

[0025]

According to the material for the seal face of the permeable seal stamp and the seal made of this material according to the first to third aspects of the present invention, the seal imprint is clearly visible in detail when stamping, and the seal imprint is not distorted by the strength of the pressing. It can be used as a seal for authentication. In addition, a fixed density imprint can be obtained without bleeding of ink due to the strength of the pressing. This can save labor such as office work. In addition to these effects, claim 3
In the engraving by the laser beam in the invention of the section, there was no generation of bad smell or dust and little generation of smoke, which was observed when engraving the rubber stamp, and the working environment was well maintained. Also, unlike the case of using a rubber-made stamping material, engraving residue and stickiness do not appear, so that it is not necessary to wash with an alkaline solution to remove the engraving residue and stickiness, and a stamp can be created quickly.
In this way, it is possible to quickly create and provide a seal by individual order.

Claims (3)

[Claims] A porosity of 40 to 95% and a durometer hardness (JIS) comprising a thermoplastic resin or a thermosetting resin.
(C method of K6301) A material for a seal surface of a permeable seal, comprising a porous body of 50 or more. 2. A permeable seal stamp, wherein a stamp face is formed by processing the seal face material of the permeable seal stamp according to claim 1. 3. A permeable seal stamp, wherein the material for a seal surface of the permeable seal stamp according to claim 1 is engraved with a laser beam to form a seal surface.