JPH0624114A - Stamp and its manufacture - Google Patents

Abstract

PURPOSE:To continuously press a stamp by a method wherein an ink penetration preventive thin membrane layer is heat-formed on a surface of an open-cell foamed plastic substrate, and a stamp face which allows ink to penetrate and communicates with open-cells protrudes from the thin membrane layer. CONSTITUTION:A foamed plastic substrate 1 having fine open-cells is made of rigid polyolefin, etc., and a thin membrane layer 3 which prevents ink from penetrating is formed on a surface of the plastic substrate 1. The thin membrane layer 3 is formed in such a manner that the surface of the plastic substrate 1 is heated so that open-cells on the surface are melted and turned in to a thin membrane layer. A stamp face 2 is formed so that it communicates with the open-cells to allow ink to penetrate and protrudes from the thin membrane 2. The stamp face 2 is formed as a remainder part which remains unmelted when the thin membrane part 3 is heat-formed. That is, the thin membrane part 3 and the stamp face 2 are formed on the surface of the substrate 1 by using a mother plate in which characters are formed as recessed parts.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a stamp which can be continuously stamped and a method of manufacturing the stamp.

[0002]

2. Description of the Related Art Conventionally, in printing plates such as rubber stamps, a negative film having an imprint of a seal is placed on a photosensitive resin layer formed on a substrate and exposed to ultraviolet rays and the unexposed portion is washed with warm water or the like. And dry it, and further irradiate it with ultraviolet rays to completely cure the photosensitive resin to create a letterpress plate, and then use this letterpress plate to form a master mold of phenol resin, etc., and form a rubber stamp, etc. from this master mold. Was.

Regarding a stamp capable of continuous imprinting, a raw material rubber is mixed with sodium chloride crystals or the like to form a rubber stamp, and then sodium chloride crystals are washed away to make it porous.
It is known that a sponge or the like is in close contact with an ink holding portion that absorbs ink from the back side of the printing surface. In addition, there is known a technique in which the pore diameter of the porous rubber used for the convex portion for print formation is made smaller than the pore diameter of the porous substrate rubber in order to make the imprint more clear.

[0004]

As described above, in order to form a stamp, the steps of letterpress and intaglio must be performed, and the manufacturing method is complicated. In addition, since the conventional continuous stampable stamp uses porous rubber, if there is a thin line in the imprint, it is reflected in the dotted line due to the influence of the holes on the rubber surface, and if there is a thick line, the ink will be printed. There was a problem that it came out too much and blurred.

[0005]

In order to solve the above problems, the stamp of the present invention is a foamed plastic substrate having open cells, and a thin film layer formed on one surface of the substrate for blocking the permeation of ink formed by heating. And a printing portion protruding from the thin film layer that allows the ink to pass therethrough by communicating with the continuous bubbles inside the substrate.

Further, in the stamp of the present invention, a mother die in which a print transfer portion for characters, figures, etc. is a concave portion is preheated, and one surface of a foamed plastic substrate having open cells is brought into contact with the mother die and melted. It is manufactured by solidifying, forming a thin film layer for blocking the permeation of ink, and making the remaining portion a printing part for permitting the permeation of ink.

[0007]

Since the printed portion side of the foamed plastic substrate having the open cells is formed of the thin film layer for blocking the permeation of ink and the protruding portion holding the open cells, the ink is not formed on the back surface side of the substrate. If the holding part is arranged, the ink permeates through the continuous bubbles and exudes only from the protruding part.
It is possible to imprint continuously.

[0008]

Embodiments of the present invention will be described below with reference to the accompanying drawings. Here, FIG. 1 is a front view showing an example of the stamp of the present invention, and FIG. 2 is a sectional view taken along the line AA of FIG. Further, FIG. 3 is a process drawing showing an example of manufacturing the stamp of the present invention.

As shown in FIGS. 1 and 2, the stamp of the present invention has a printing portion 2 and a thin film layer 3 on one surface of a foamed plastic substrate 1.
And are formed. The foamed plastic substrate 1 is a rigid or semi-rigid polyolefin having fine open cells,
Particularly, polyethylene foam is preferably used. Polyurethane, vinyl chloride resin, ABS resin, ethylene-
A plastic foam having fine open cells made of vinyl acetate copolymer or other resin can also be used. These plastic foams are used by slicing into a flat plate shape after removing the outer skin covering the outer surface after foaming.

The printing portion 2 is a portion which remains without being melted by heat when the stamp is formed, and projects from the thin film layer 3 to represent a character or figure form. Since the printing portion 2 is not melted by heat, it is in communication with the open cells in the foamed plastic substrate 1 and holds the open cells. Further, the thin film layer 3 is a portion that is melted by heat and contracted by crushing bubbles, and ink cannot pass through. Since the ink does not leak from the thin film layer 3 in this manner, there is no concern that the thin film layer 3 will be contaminated even if the thin film layer 3 comes into contact with a print medium such as paper during transfer. Therefore, it is not necessary to make the protrusion of the printing portion 2 so high, and it is sufficient that it is within 1 mm. Further, as in the case of using the conventional porous rubber, a guide is provided so that the portion other than the printing portion does not come into contact with the printing medium. No need.

Further, since the open cells of the foamed plastic substrate 1 are fine, even if the protruding portion of the printing portion 2 has a narrow portion, its details can be accurately transferred without fading.
Further, even if there is a wide portion, the ink can be clearly transferred without dropping or bleeding on the medium. Further, when the colored foamed plastic substrate 1 is used, the thin film layer 3 in which bubbles are collapsed to form a layer has a deep color, while
Since the printing portion 2 is still in the original color tone, the color contrast between the printing portion 2 and the thin film layer 3 is improved and the appearance is improved.

The stamp of the present invention described above can be put into a case 4 made of plastic, metal or the like for use. Since the end of the foamed plastic substrate 1 is cut by a heat cutter as described later, permeation of ink is blocked like the thin film layer 3. This end is fixed to the case 4 by the adhesive layer 5. An ink holding layer 6 made of sponge or the like is placed on the back surface of the foamed plastic substrate 1, and the ink is constantly fed from here.
Since it is supplied to, continuous imprinting is possible.

The stamp of the present invention is manufactured by using a mother die 10 made of, for example, a photosensitive resin as shown in FIG. 3 (a). The mother die 10 is formed with a concave print transfer portion 11 for characters and figures. Since the printing portion 2 of the present invention does not have the height of the protruding portion as described above, the print transfer portion 11 can be made much shallower than the conventional master mold. Therefore, the exposure time and the cleaning time can be shortened, and the amount of resin used can be reduced, which is very economical. Further, since it is used as a mold for plastic foam, it does not need to be particularly strong. Therefore, unlike the conventional case, the complicated process of first making a relief printing plate and then making a durable phenol resin intaglio printing plate is unnecessary, and the mother die 10 can be made from the beginning. Mother mold 10
The material may be a metal such as aluminum in addition to the above-mentioned photosensitive resin.

The mother die 10 needs to be heated in advance, but the heating temperature can be appropriately changed according to the material of the foamed plastic substrate 1, and in the case of semi-rigid polyethylene foam, for example, 130 to 150 ° C. Keep it at.
In this heated state, the foamed plastic substrate 1 is placed and lightly pressed as shown in FIG. Since the pressure 12 may be light, no special pressure device is required, but it is preferable to place a surface plate on the back surface of the foamed plastic substrate 1 to maintain the flatness of the substrate 1.

The stamp material released from the mother die 10 is shown in FIG.
It has a shape having a printing portion 2 and a thin film layer 3 as shown in FIG. A large number of printing parts 2 are formed on the foamed plastic substrate 1.
It is convenient to form the above, and at the stage of releasing the mold, separate each with a heat cutter and
And the seal of the present invention.

According to the stamp manufacturing method of the present invention, it is possible to manufacture a printing plate for pad printing, a printing plate for a rotary press, or the like.

[0017]

As described above, in the stamp of the present invention, the ink permeates only from the printing portion and does not exude from the thin film layer. Therefore, even if the protrusion is not so high, a medium such as paper can be formed by the ink. There is no need to worry about getting dirty. Therefore, it is not necessary to provide a guide so that only the printing portion comes into contact with the medium as in the case of using the conventional porous rubber. In addition, since it is formed of plastic foam with fine open cells, even if there is a narrow portion of the protruding part of the printing part, the details can be accurately transferred without fading, and even if there is a wide part, the ink Can be clearly transferred without dropping or bleeding on the medium.

Further, according to the manufacturing method of the present invention, since the height of the protruding portion of the printing portion is not high as described above, the print transfer portion of the intaglio mold can be made much shallower than the conventional one. . Therefore, the exposure time and the cleaning time can be shortened, and the amount of resin used can be reduced, which is very economical. Further, since it is used as a mold for plastic foam, it does not need to be particularly strong. Therefore, first make a letterpress as before,
Next, a complicated process such as making a tough intaglio plate made of phenolic resin is unnecessary, and a mother die can be made from the beginning. Furthermore, since the pieces can be cut by a heat cutter, if the cut pieces are arranged and fixed in a case, the pieces can be color-coded.

[Brief description of drawings]

FIG. 1 is a front view showing an example of a stamp of the present invention.

FIG. 2 is a sectional view taken along line AA of FIG.

FIG. 3 is a process drawing showing an example of manufacturing a stamp according to the present invention.

[Explanation of symbols]

1 ... Foamed plastic substrate, 2 ... Printed part, 3 ... Thin film layer,
4 ... Case, 6 ... Ink holding layer, 10 ... Mother mold, 11 ... Print transfer part.

Claims (2)

[Claims] 1. A foamed plastic substrate having open cells, a thin film layer formed on one surface of the substrate for blocking the permeation of ink by heating, and communicating with the open cells inside the substrate to allow the permeation of ink. A stamp having a printed portion protruding from the thin film layer. 2. A mother die in which a print transfer portion for characters, figures, etc. is a concave portion is heated, one surface of a foamed plastic substrate having open cells is brought into contact with the mother die, and the contacted portion is melted and solidified. A method for producing a stamp, comprising a thin film layer that blocks ink permeation, and a remaining portion serving as a printing portion that allows ink permeation.