JP2005074676A - Porous printing element - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a porous printing element which has a non-collapsible printing part even under an applied excess pressing force; can prevent a printed image from feathering during initial imprinting due to the discharge of a surplus amount of ink; can obtain an irregularity-free deep and clear printed image; and is free from the deterioration of physical property over a long time. <P>SOLUTION: This porous printing element is of a three layer structure such as a printing part, an intermediate part and an ink holding part laminated in that order and has a capillary action relationship of the intermediate part>the printing part>the ink holding part. In addition, the printing part shows an utmost hardness among the three layers. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

    The present invention relates to a porous printed body having open cells used for a penetrating mark with a built-in ink.

A stamp using a porous printed material made of a porous material having an infinite number of open cells can be continuously printed without using a stamp stand each time it is printed. Humans have also disclosed No. 31-002912. Such a porous printing body can contain a large amount of ink even if it is a pigment ink having a relatively high viscosity, and boasts a good ink discharge amount.
However, conventional porous prints have innumerable open cells and thus have low hardness, and if excessive pressure is applied to the prints during printing, the print surface is crushed and the stored stamp ink flows out excessively. As a result, the printed mark becomes thicker or smeared, and there is a drawback that it is difficult to perform clear marking.
Therefore, in order to solve such drawbacks and improve the hardness of the printing body, the present applicant mixed a porous printing body (Japanese Patent Publication No. 57-50675) blended with a phenol resin and an organic synthetic fiber. A porous printed body (Japanese Patent Laid-Open No. 08-230295) has been proposed.
However, while it is a sponge-like printed body having countless open cells, it is difficult to set the hardness high, and in the former, the rubber and the phenol resin begin to separate over time, and the spring property decreases or becomes brittle. The physical properties of the porous printed material are greatly reduced due to cracking, and the latter is not compatible with rubber and organic synthetic fibers. As a result, the physical properties of the porous printed material, such as cracks, are greatly reduced.
Therefore, it has been desired to produce a porous printed body by an approach other than blending conventional additives.

Japanese Utility Model Publication No. 31-002912 Japanese Examined Patent Publication No. 57-050675 Japanese Patent Application Laid-Open No. 08-230295

  The present invention, even if an excessive pressing force is applied, the printed part is not crushed, can prevent the blurring of the imprint at the initial stamping due to excessive ink discharge, can obtain a dark and clear imprint without unevenness, And the porous printed body which a physical property does not fall over a long time is provided.

  It is a porous printing body with a three-layer structure in the order of the printing part, intermediate part, and ink holding part, and the capillary force has a relationship of intermediate part> printing part> ink holding part, and printing is performed in three layers. A porous printed material characterized in that the hardness of the part is the highest.

Since the porous printing body of the present invention stores excess ink in the intermediate portion, the ink content of the printing portion can be always kept at an appropriate amount of about 60 to 80%, and therefore, the initial amount due to discharge of excessive ink can be maintained. It is possible to prevent blurring of the imprint at the time of stamping and obtain a dark and clear imprint with no unevenness. In the case of continuous printing, since the ink is supplied from the intermediate portion to the printing portion by the pump action, the ink content in the printing portion can always be kept at an appropriate amount of about 60 to 80%, and there is no bleeding. A clear imprint can be obtained continuously. Further, when the ink content in the intermediate portion is reduced, the ink is transferred from the ink holding portion to the intermediate portion by capillary force, and the intermediate portion can always maintain 100% ink content.
Furthermore, since the hardness of the ink holding part is relatively lowest, a cushioning action works and a soft printing feel can be obtained.

The porous printed body of the present invention is a printed body composed of a porous body having innumerable open cells, and is used for a so-called penetrating stamp. Stamps include a rotation mark that faces an endless belt print body with date frames from a hole in the master print body, an address mark created on the print body with an address, a name stamp created on the print body, and the like. .
In particular, the porous printing body of the present invention is a porous printing body having a three-layer structure in the order of a printing portion, an intermediate portion, and an ink holding portion, and the capillary force has a relationship of intermediate portion> printing portion> ink holding portion. And the print portion has the highest hardness among the three layers.

A porous print body consisting of a two-layer structure of a conventional print section and ink holding section is set so that the capillary force of the print section is greater than the capillary force of the ink hold section, and maximizes the capillary force of the print body. As a result, the ink content of the printed body was always 100%, and the imprint was blurred during the initial stamping.
Therefore, in the present invention, the capillary force at the intermediate portion is set to be the largest, the capillary force at the printing portion is subsequently increased, and the capillary force at the ink holding portion is set to be the smallest. By setting in this way, even if the porous printing body is impregnated with penetrating ink, excess ink is stored in the middle part, so the ink content of the printed part is always kept at an appropriate amount of about 60 to 80%. Therefore, blurring of the imprint at the initial printing due to excessive ink ejection can be prevented, and a dark and clear imprint with no unevenness can be obtained.
In the case of continuous printing, since the ink is supplied from the intermediate portion to the printing portion by the pump action, the ink content in the printing portion can always be kept at an appropriate amount of about 60 to 80%, and there is no bleeding. A clear imprint can be obtained continuously. Further, when the ink content in the intermediate portion is reduced, the ink is transferred from the ink holding portion to the intermediate portion by capillary force, and the intermediate portion can always maintain 100% ink content.
The difference in capillary force between layers is set by changing the porosity to be larger or smaller, or by setting the pore diameter to be larger or smaller.

  Further, in the present invention, the hardness in the measurement value of the spring type hardness test C-type hardness tester is set so that the printed portion is the highest among the three layers of the printed portion, the intermediate portion, and the ink holding portion. Either the intermediate part or the ink holding part may have a higher hardness or the same hardness, but both must be lower than the printing part. By setting in this way, the cushioning action of the intermediate part and the ink holding part works, and a soft seal feeling can be obtained.

Here, the porous printed body of the present invention includes natural rubber, SBR, NBR, EPDM, silicone rubber and other synthetic rubbers, thermoplastic resins such as polyethylene, polypropylene, polyethylene terephthalate, polybutylene terephthalate, polylactic acid, and polyolefin-based heat. All raw materials known as printing materials for printing such as thermoplastic elastomers, thermoplastic elastomers such as polyurethane-based thermoplastic elastomers, and thermosetting resins such as phenolic resins can be used. An elution method in which a soluble material is kneaded and vulcanized or melted, and then a soluble material is eluted to form a porous body, or a raw material is kneaded with a foaming material and vulcanized or melted to form a porous body, or particleized It can be obtained by, for example, a sintering method in which a raw material is heated and compressed to form a porous body. At this time, it is necessary to have a three-layer structure in the order of the printing portion, the intermediate portion, and the ink holding portion, and the porosity and the pore diameter are set so that the capillary force of each layer is in the relationship of intermediate portion> printing portion> ink holding portion. Each is adjusted to create a difference in capillary force. In addition, the porous mark is set so that the hardness of each layer is in the following relationship: printing part> intermediate part> ink holding part, printing part> intermediate part = ink holding part, printing part> ink holding part> intermediate part The composition of the font is adjusted to create a difference in hardness.
The penetrating ink used in the present invention is not limited to pigments and dye colorants, and all known inks for stamps such as volatile oil inks, nonvolatile oil inks and water-based inks may be used. it can.

Hereinafter, the porous printed body of the present invention will be described in detail with reference to Examples. FIG. 1 illustrates the first embodiment.
The porous printing body of this example has a three-layer structure of a printing part 1 made of NBR porous rubber, an intermediate part 2 of NBR porous rubber, and an ink holding part 3 made of NBR porous rubber. Part 1 has a thickness of 0.5 mm, a hardness of 60 ° (measured by a spring-type hardness test C-type hardness meter), a porosity of 70%, and a pore diameter of 40 to 60 μm. 0.0 mm, hardness 50 ° (measured value of spring type hardness test C-type hardness meter), porosity 80%, pore diameter 30-40 μm, ink holding part 3 is 2.0 mm thick, hardness 40 ° (Spring hardness test C-type hardness tester), porosity 90%, pore diameter 150-250μm, capillary force has the relationship of middle part> printing part> ink holding part In addition, the hardness is set to have a relationship of printing portion> intermediate portion> ink holding portion.
Specifically, it was manufactured as follows.
Raw material NBR 100 parts, sulfur 5 parts, zinc white 5 parts, vulcanization accelerator 5 parts, softener 30 parts, carbon black 50 parts, anti-aging agent 2 parts, 40-60 μm sodium chloride 500 parts, 50-60 μm potato 100 parts of starch was kneaded to prepare a master batch A, which was a flat sheet A having a thickness of 0.5 mm. Apart from this, the raw material NBR 100 parts, sulfur 5 parts, zinc white 5 parts, vulcanization accelerator 5 parts, softener 30 parts, carbon black 50 parts, anti-aging agent 2 parts, 30-40 μm sodium chloride 700 parts, 100 parts of potato starch having a size of 30 to 40 μm was added and kneaded to prepare a master batch B, which was a flat sheet B having a thickness of 1.0 mm. Separately, the raw material NBR 100 parts, sulfur 5 parts, zinc white 5 parts, vulcanization accelerator 5 parts, softener 30 parts, carbon black 50 parts, anti-aging agent 2 parts, sodium chloride 900 of 150-250 μm Part, 100 parts of 70-100 μm potato starch was added and kneaded to make a master batch C, which was a flat sheet C having a thickness of 2.0 mm.
Next, the sheet A, the sheet B, and the sheet C are overlapped in this order, and this is accommodated in a smooth mold. Then, a pressure of about 200 kg / cm ² is applied and sandwiched between the heating plates, Vulcanization was carried out for 60 minutes under temperature. After vulcanization, the mold was released, washed thoroughly with water until sodium chloride and potato starch were completely removed, dehydrated and dried to obtain a porous rubber sheet.
The porous rubber sheet produced in this way becomes a single sheet in which the sheet A, the sheet B, and the sheet C are integrated, and after engraving from the sheet A side to a depth of 1.0 mm by a carbon dioxide laser processing machine, When cut to the required size, the sheet C part formed an ink holding part that occludes a large amount of ink, and the sheet A part obtained a porous rubber printed body having a printing part on which a printing surface was formed.

Next, when the porous rubber printing body is filled with 500 to 2000 mPa · S (25 ° C.) high-viscosity ink, the excess ink in the printing area is absorbed in the middle area, and the ink content in the printing area is contained. The amount could be maintained at about 60 to 80%, and the intermediate portion and the ink holding portion could have an ink content of 100%. Next, as a result of printing, since the ink content in the printed portion was slightly less, there was no blurring of the imprint at the initial printing due to excessive ink ejection, and a dark and clear imprint with no unevenness could be obtained.
In addition, after printing, ink is supplied from the intermediate part to the printing part by the pump action, so that the ink content of the printing part can always be kept at an appropriate amount of about 60 to 80%, and even if it is continuously printed, the ink bleeds. It was possible to obtain a clear imprint without any defects.
Further, when the ink content in the intermediate part is reduced, the ink is transferred from the ink holding part to the intermediate part by capillary force, so that the intermediate part can always keep the ink content of 100%.
In addition, since the hardness of the printed part is the hardest, it is possible to obtain a sharply imprinted image, and since the hardness of the intermediate part and the ink holding part is small, the cushioning action of both parts works, and the soft impression of printing And the pumping action from the intermediate part to the printing part was not hindered.

The porous printing body of Example 2 shown in FIG. 2 has a three-layer structure of a printing part 11 made of SBR porous rubber, an intermediate part 12 made of SBR porous rubber, and an ink holding part 13 made of SBR porous rubber. The printing portion 1 is set to have a thickness of 0.5 mm, a hardness of 60 ° (measured value of a spring type hardness test C-type hardness meter), a porosity of 70%, and a pore diameter of 40 to 60 μm. 2 is set to a thickness of 1.0 mm, a hardness of 40 ° (measured value of a spring-type hardness test C-type hardness meter), a porosity of 80%, and a pore diameter of 30 to 40 μm. 0.0 mm, hardness 50 ° (measured value of spring type hardness test C-type hardness meter), porosity 90%, pore diameter 150-250 μm, capillary force is intermediate part> printing part> ink holding part And the hardness has a relationship of printing part> ink holding part> intermediate part It is the sea urchin set.
Specifically, it was manufactured as follows.
Raw material SBR 100 parts, sulfur 5 parts, zinc white 5 parts, vulcanization accelerator 5 parts, softener 30 parts, carbon black 50 parts, anti-aging agent 2 parts, 40-60 μm sodium chloride 500 parts, 50-60 μm potato 100 parts of starch was kneaded to prepare a master batch A, which was a flat sheet A having a thickness of 0.5 mm. Separately from this, the raw material SBR 100 parts, sulfur 5 parts, zinc white 5 parts, vulcanization accelerator 5 parts, softener 30 parts, carbon black 50 parts, anti-aging agent 2 parts, 30-40 μm sodium chloride 900 parts, 100 parts of potato starch having a size of 30 to 40 μm was added and kneaded to prepare a master batch B, which was a flat sheet B having a thickness of 1.0 mm. Separately from this, the raw material SBR 100 parts, sulfur 5 parts, zinc white 5 parts, vulcanization accelerator 5 parts, softener 30 parts, carbon black 50 parts, anti-aging agent 2 parts, sodium chloride 500 to 150-250 μm Part, 100 parts of 70-100 μm potato starch was added and kneaded to make a master batch C, which was a flat sheet C having a thickness of 2.0 mm.
Next, the sheet A, the sheet B, and the sheet C are overlapped in this order, and this is accommodated in a smooth mold. Then, a pressure of about 200 kg / cm ² is applied and sandwiched between the heating plates, Vulcanization was carried out for 60 minutes under temperature. After vulcanization, the mold was released, washed thoroughly with water until sodium chloride and potato starch were completely removed, dehydrated and dried to obtain a porous rubber sheet.
The porous rubber sheet produced in this way becomes a single sheet in which the sheet A, the sheet B, and the sheet C are integrated, and after engraving from the sheet A side to a depth of 1.5 mm with a carbon dioxide laser processing machine, When cut to the required size, the sheet C part formed an ink holding part that occludes a large amount of ink, and the sheet A part could obtain a porous rubber printed body having a printing part on which a printing surface was formed.

Next, when the porous rubber printing body is filled with 500 to 2000 mPa · S (25 ° C.) high-viscosity ink, the excess ink in the printing area is absorbed in the middle area, and the ink content in the printing area is contained. The amount could be maintained at about 60 to 80%, and the intermediate portion and the ink holding portion could have an ink content of 100%. Next, as a result of printing, since the ink content in the printed portion was slightly less, there was no blurring of the imprint at the initial printing due to excessive ink ejection, and a dark and clear imprint with no unevenness could be obtained.
In addition, after printing, ink is supplied from the intermediate part to the printing part by the pump action, so that the ink content of the printing part can always be kept at an appropriate amount of about 60 to 80%, and even if it is continuously printed, the ink bleeds. It was possible to obtain a clear imprint without any defects.
Further, when the ink content in the intermediate part is reduced, the ink is transferred from the ink holding part to the intermediate part by capillary force, so that the intermediate part can always keep the ink content of 100%.
In addition, since the hardness of the printed part is the hardest, it is possible to obtain an imprint with a sharp outline, and since the hardness of the intermediate part is the smallest, the cushioning action of the intermediate part works to obtain a soft printing feel. The pumping action from the intermediate part to the printing part was not hindered.
As described above, the porous printed material of this example had a sufficient ink occlusion amount, and was able to perform clear printing without bleeding or fading over a long period of time.

FIG. 3 is a cross-sectional image diagram of Example 1. FIG. 6 is a cross-sectional image diagram of Example 2.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Printing part 2 Intermediate part 3 Ink holding part 11 Printing part 12 Intermediate part 13 Ink holding part

Claims (1)

  It is a porous printing body with a three-layer structure in the order of the printing part, intermediate part, and ink holding part, and the capillary force has a relationship of intermediate part> printing part> ink holding part, and printing is performed in three layers. A porous printed material characterized in that the hardness of the part is the highest.

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