JP7625259B2 - Seal and stamp pad or vermilion ink - Google Patents

Description

The present invention relates to improvements to ink pads and other devices used when stamping with seals and stamps, and is concerned with ink pads or vermilion ink pads that aim to clearly indicate when ink should be refilled.

Conventionally, ink pads used when stamping seals and stamps have come in a variety of shapes, such as round ink pads with pads impregnated with vermilion ink (vermilion oil) and round ink pads with pads impregnated with black, red, or other ink pad ink. In addition, as in Patent Document 1, ink pads with company logos, addresses, etc. printed on the surface of the pad are used. Such printed ink pads are intended for advertising and publicity, and it has been customary to make the ink colors of the two different, for example, the impregnated ink color red and the printed ink color black, so that users can clearly see the printed logo, address, etc.

On the other hand, users of ink pads and the like want a clear indication of when to refill the ink when using an ink pad and the like. The user brings the ink contained in the ink pad's ink pad into contact with the printing surface of a rubber stamp or other stamp, and the ink adhering to the printing surface is stamped and transferred to a paper medium or the like. When the above-mentioned stamping operation is repeated several thousand times, the ink contained in the ink pad provided in the ink pad gradually decreases, and even when the printing surface of a rubber stamp or other stamp is brought into contact with the ink pad, not enough ink adheres to the printing surface, resulting in a phenomenon in which the impression stamped on the paper medium is faint and faded. This state indicates that it is time to refill the ink, and users who feel that the impression stamped is faint refill the ink pad with ink to eliminate the above-mentioned problem. In other words, the user can only know when it is time to refill the ink by actually stamping on paper media. For example, if a user stamps an important document such as a contract without realizing when it is time to refill the ink, the user may end up with a significantly faded seal on the contract, and may have to apply for the contract to be reissued.

The desire to clarify when to refill the ink also becomes apparent at stamp rally events. Stamp rally organizers cannot constantly monitor the ink impressions made by stamp rally participants using the stamp pad. As a result, it is usually the participants who discover when it is time to refill the ink, which can lead to situations where participants who were looking forward to collecting stamps as a memento of their participation in the stamp rally event cannot have their needs met. There was a need for a stamp pad that would allow users to determine when to refill the ink before actually stamping on paper media, etc.

Furthermore, Patent Document 2 discloses a stamping device that is equipped with a stamping counter as an ink pad that can objectively determine when to refill ink, and that can automatically refill a certain amount of ink when a set number of stamps is exceeded. However, this requires a power source, the device is large, and the cost is high, so there is little flexibility in where it can be installed.

Actual opening 06-63337 Patent Publication No. 2016-203568

In order to solve the above problems, the present invention aims to provide an ink pad or ink pad with said ink pad that can be used for an ink pad or ink pad with a high degree of freedom in installation while maintaining printing quality, and that allows the user to determine when to refill the ink before stamping on a paper medium, etc.

The invention of claim 1 is a printing pad impregnated with ink, which has a display portion and a non-display portion on the surface of the printing pad, and when in a state ready for stamping, the display color of the display portion and the display color of the non-display portion are the same color, and as the ink contained in the printing pad is consumed, the display color of the display portion and the display color of the non-display portion no longer become the same color .

The invention of claim 2 is a printing pad as described in claim 1, characterized in that the color difference ΔE00 between the display color of the display portion and the display color of the non-display portion on the surface of the printing pad is 1.59 or less, and as the ink contained in the printing pad is consumed, the color difference ΔE00 between the display color of the display portion and the display color of the non-display portion becomes 1.6 or more.

According to the present invention, when the ink pad is unused or in its initial state (state where it can be used for stamping), the display area 6 and non-display area 7 on the surface of the stamp pad are the same color to the naked eye, making it impossible to visually recognize the display area. However, as the amount of ink impregnated on the surface of the stamp pad decreases with use over time, the color of the ink other than the display area of the stamp pad changes, making the display area visible. This makes it possible for the user to determine when to refill the ink before stamping on paper media, etc.

FIG. 2 is a perspective view of the ink pad of the present invention in use. FIG. 2 is a front view of the ink pad of the present invention in use. FIG. 2 is a cross-sectional view along line A-A of the ink pad of the present invention when in use. FIG. 3 is a B-B cross-sectional view of the ink pad of the present invention when in use. A portion of the printed image in the display portion of the present invention is the printing pad surface that has been omitted by halftone processing. 13 shows another embodiment of the display unit of the present invention. 13 shows another embodiment of the display unit of the present invention.

An embodiment of the present invention will be described below.
In an embodiment of the present invention, in order to explain the positional relationship of the ink pad in which the printing body is housed, as shown in Figures 2 and 3, the bottom 2a side of the base box 2 is defined as the lower side, the outer fabric 3a side of the printing pad 3 is defined as the upper side, the hinge side is defined as the rear side, the opposite side is defined as the front side, the right side when viewed from the front of the ink pad is defined as the right side, and the left side is defined as the left side.

Figure 1 is a perspective view of an ink pad 1 according to an embodiment of the present invention when in use, Figure 2 is a front view of the ink pad 1 when in use, and Figure 3 is a cross-sectional view taken along the line A-A when in use. The ink pad 1 has a rectangular shape with the ink pad 3 impregnated with vermilion ink (ink), and is made up of a base box 2, the ink pad 3 housed within the base box 2, a lid 4 that covers the ink pad 3, and a hinge 5 that pivots the lid 4 to the base box 2 so that it can be opened and closed freely.

The base box 2 of the present invention is composed of a bottom surface portion 2a having a substantially square plate shape and a wall surface portion 2b extending vertically upward so as to surround the outer edge of the square plate-shaped bottom portion, but the shape of the bottom surface portion 2a of the base box 2 is not limited to a square plate shape, and various shapes such as a round shape, a rectangular shape, a polygonal shape, etc. In addition, the bottom surface portion 2a does not have to be a plate shape, and the bottom surface portion 2a may be provided with ribs or may have a wave shape, etc.
A printing pad surface frame 8 having an L-shaped cross section and a claw at its upper end that extends inward is fitted inside the wall surface 2b of the base box 2. The printing pad surface frame 8 fits into a cover cloth pasting frame 9 (described later) and serves to fix the printing pad 3 in place.

The ink pad 3 is accommodated in the inner space of the case 2 formed by the bottom surface portion 2a and the wall surface portion 2b. The ink pad in the present invention means a pad for storing ink or various inks, such as a pad for ink pads or a pad for stamps. The ink pad 3 accommodated in the case 2 has a two-layer structure of an ink-impregnated body 3b having continuous pores and a surface cloth 3a. In the ink pad 3 in the embodiment of the present invention, felt is used for the ink-impregnated body 3b and synthetic fiber made of polyester is used for the surface cloth 3a, but it is not necessarily required to have a two-layer structure and can be either a single layer or a multi-layer structure. The ink pad 1 used in the embodiment of the present invention is equipped with a surface cloth attachment frame 9 having approximately the same shape as the outer periphery of the surface cloth 3a. The surface cloth 3a and the surface cloth attachment frame 9 are integrated with each other by a hot melt adhesive applied to the periphery of the back surface of the surface cloth 3a (not shown). In addition, the ink pad 1 in this embodiment of the present invention is provided with an ink pad body plate surface frame 8 on the inside of the wall portion 2 b of the base box 2 .
In the embodiment of the present invention, the ink pad 1 is configured such that the ink impregnated body 3b is placed on the top of the bottom 2a of the base box 2, the outer cloth pasting frame 9 integrated with the outer cloth 3a surrounds the outer periphery of the ink impregnated body 3b, and the upper end of the outer cloth pasting frame 9 and the plate frame 8 are fitted together to fix the ink pad 3, but if the object of the present invention is achieved, a hot melt adhesive may be directly applied and bonded between the outer cloth 3a and the ink impregnated body 3b, or between the bottom surface 2a of the base box 2 and the ink impregnated body 3b. In addition, the shape of the ink pad 3 is not limited to a square, and can take various shapes depending on the shape of the base box. In addition, the ink pad 3 is preferably white, which is easily reflected in the ink color by impregnation with ink, but it does not matter whether it is colored or not as long as the ink color is reflected by impregnation with ink. Furthermore, the ink-impregnated body 3b can be made of a nonwoven fabric such as a rubber porous material, compressed urethane, or felt. The surface fabric can also be appropriately selected from synthetic fibers such as polyester and natural fibers such as cotton. In the embodiment of the present invention, the surface fabric 3a having the display unit 6 is preferably white, which is impregnated with ink and easily reflects the ink color as it is, but as long as the ink color is reflected by the ink impregnation, the surface of the printing body may or may not be colored. Furthermore, the display unit 6 may be displayed on the surface of the printing body and may achieve the object of the present invention. Therefore, the display unit does not necessarily have to be displayed on the surface fabric, and for example, the printing body may be configured as a single-layer structure of ink-impregnated body, with the display unit provided on the surface of the ink-impregnated body 3b.

The cover 4 is made up of a square plate-shaped top surface 4a, which is approximately the same shape as the bottom surface 2a of the base box 2, and a wall surface 4b extending downward vertically from the outer edge of the top surface. The shape of the top surface 4a of the cover 4 is not limited to a square plate shape, as with the bottom surface 2a, and can be a variety of shapes such as round, rectangular, and polygonal. The top surface 4a does not have to be plate-shaped, and may have ribs or a corrugated shape. The ink pad 1 of the present invention does not have a locking member that fixes the cover in a closed state, especially when the ink pad is not in use. However, for example, a locking mechanism may be provided in which a protrusion is provided on the wall surface 4b of the cover 4 and a locking member with a claw-shaped tip is provided on the wall surface 2b of the base box 2, and when the ink pad is not in use, the tip of the protrusion and the tip of the locking member fit together without any gaps. This prevents the ink impregnated in the printing pad 3 from volatilizing or spilling out, and prevents users from accidentally touching the printing pad 3 and getting their hands dirty. The engagement between the base box 2 and the lid 4 is not limited to a recessed/projected engagement, and many other forms are possible, such as a screw engagement. However, depending on the properties of the ink impregnated in the printing pad 3, it is not necessarily necessary to engage the base box 2 and the lid 4.

Figure 4 is a B-B cross-sectional view of the ink pad in use. The hinge section 5 is composed of hinge bearing sections 10, which are provided on both the left and right sides of the rear side of the base box 2 and have a circular exterior and a roughly concentric hollow interior, a hinge joint section 11, which is provided in the center of the rear side of the base box 2 and has a circular exterior and a roughly concentric hollow interior, and a vertically elongated cylindrical hinge shaft 12 inserted and fitted into the circular hollow sections of the hinge bearing section 10 and the hinge joint section 11. The circular hollow sections of the hinge bearing section 10 and the hinge joint section 11 are fitted together in a nearly perfect match at the rear of the lid section and the rear of the base box 2, and the hinge shaft 12 is fitted so as to pass through each hollow interior section, making the lid section 4 rotatable relative to the base box 2. The ink pad of the present invention is configured to have the hinge portion 5 as described above, and the lid portion 4 can be opened and closed by allowing it to rotate relative to the base box 2, but the opening and closing configuration of the lid portion 4 is not limited, and many other configurations are possible, such as a configuration in which the lid is fitted and detached to a fitting portion provided on the outer periphery of the base box without a hinge portion, or a configuration in which the base box and the lid are attached and detached by screwing them together. Furthermore, if there is no need to consider dirt on the printing pad or evaporation of the ink contained in the printing pad, then a lid is not necessary.

In the present invention, the ink components impregnated in the printing pad 3 are typical castor oil-based oil pigments and vermilion ink, but they can be oil-based/water-based, or pigment/dye. The viscosity of the oil-based pigment is preferably 500 to 5,000 Pas·S (60 rpm, 25°C).

When using oil-based inks, the solvent to be used may be a solvent made of a polyhydric alcohol derivative, such as diethylene glycol monohexyl ether, diethylene glycol mono 2-ethylhexyl ether, diethylene glycol monobutyl ether acetate, dipropylene glycol, dipropylene glycol monobutyl ether, dipropylene glycol monobutyl ether acetate, triethylene glycol, triethylene glycol monomethyl ether, triethylene glycol monoethyl ether, triethylene glycol monobutyl ether, triethylene glycol dimethyl ether, tetraethylene glycol, tetraethylene glycol monobutyl ether, polyethylene glycol, polyethylene glycol monomethyl ether, polyethylene glycol monoethyl ether, polyethylene glycol monobutyl ether, polyethylene glycol alkyl ether, Examples of suitable solvents include glycol-based solvents such as polyoxyethylene glycol, polypropylene glycol monomethyl ether, polypropylene glycol monoethyl ether, polypropylene glycol monobutyl ether, polypropylene glycol alkyl ether, polyoxyethylene polyoxypropylene glycol, polyoxyethylene polyoxypropylene monomethyl ether, polyoxyethylene polyoxypropylene monoethyl ether, polyoxyethylene polyoxypropylene monobutyl ether, and polyoxyethylene polyoxypropylene alkyl ether; higher fatty acids such as oleic acid, linoleic acid, and linolenic acid; castor oil; castor oil fatty acid polyhydric alcohol ethers obtained by modifying castor oil with alkylene oxide; and castor oil fatty acid derivatives such as castor oil fatty acid alkyl esters obtained by modifying castor oil with alcohol; liquid paraffin, machine oil, and glycerin. In the present invention, the above solvents can be used alone or in combination, and the amount of the solvent is preferably 20 to 95% by weight based on the total amount of the ink.

When using water-based ink, the solvent is water, but water may be used in combination with a wetting agent. Examples of water include ion-exchanged water from which ions have been removed, pure water from which various impurities have been removed from natural water, and tap water. Wetting agents include glycerin, diglycerin, triglycerin, and various glycols such as ethylene glycol, diethylene glycol, and propylene glycol, and these may be used in combination. The above wetting agents may be used alone or in combination, and the amount of the wetting agents to be used is preferably 20 to 95% by weight of the total amount of ink.

The coloring material used may be any coloring material that dissolves or disperses in a solvent, and conventionally known dyes and pigments may be used. Dyes include oil-soluble and water-soluble dyes such as basic dyes, acid dyes, and direct dyes. Pigments include carbon black, ultramarine, Prussian blue, red iron oxide, cadmium red, cadmium yellow, industlon blue, phthalocyanine blue, phthalocyanine green, lake red, lithol red, Hansa yellow, titanium oxide, fluorescent pigments, organic pigments, inorganic pigments, pearl pigments, and chelate pigments with metallic luster. In addition, processed pigments treated with synthetic resins, wax, etc., may be used to improve the dispersibility of the pigment. One or more coloring materials may be used in combination, and the amount used is appropriately 3 to 20% by mass based on the total amount of the ink composition.

The ink of the present invention may further contain, as appropriate, dye dissolving aids such as higher fatty acids, higher fatty acid esters, and alkyl ether phosphate esters, surfactants such as polyoxypropylene glycol and glycerin polyoxypropylene triol, known pH adjusters, preservatives and fungicides, rust inhibitors, polymer dispersants, thickeners, and the like.

In addition, the printing pad and ink used in the present invention may be those used in commercially available stamp pads and vermilion ink pads. For example, Shachihata's extra large ink pad (HGN-4-V, R, B, K, OR, G, BR, P, LB, Y), water-based pigment ink pad large (HKN-3-R, B, K), Shachihata's extra large ink pad quick-drying Shachihata vermilion compact type No. 30 (MQC-30-1, 2), quick-drying Shachihata vermilion compact type No. 40 (MQC-40-1, 2), Shachihata's various color patterns (HAC-1-R, P, CY, OCG, DYG, G, TQ, B, RV, BR, GR, K, OR, LP, PP, Y, YG, PG, PB, LB, CB, PV, PBR, LBR), etc.

Furthermore, the outer cloth 3a, which is the surface of the printing pad 3 used in the present invention, is provided with a display portion 6. The display portion 6 may be any display portion that is displayed on the surface of the printing pad and achieves the object of the present invention. Therefore, the display portion does not necessarily have to be displayed on the outer cloth, and for example, the printing pad may be configured as a single-layer structure of an ink-impregnated body, with the display portion provided on the surface of the ink-impregnated body 3b.
The display section 6 is usually represented by characters and symbols, and the stamp pad of this embodiment has a character section of "Please refill ink" and a drop mark representing ink drops as a symbol section. The font and size of the characters and symbols used in the display section 6 are not important. The method of forming the display section 6 is not important as long as the ink impregnated in the printing body 3 and the ink used to form the display section 6 are not compatible and the object of the present invention can be achieved. As a method of forming the display section 6, for example, formation by printing ink or handwritten characters is considered, but in consideration of the visibility of the display characters, it is preferable to form the display section by printing ink. The printing method may be any printing method, such as pad printing, offset printing, gravure printing, silk printing, screen printing, electrophotographic printing, inkjet printing, etc., as long as the printing ink is fixed to the fibers of the plate surface cloth 5 and the printing ink does not affect the quality of the imprinting.

The colorant that may be contained in the ink composition used to form the display portion 6 may be any component that imparts coloring power and has been used in the preparation of ink compositions up to now. Examples of such colorants include inorganic color pigments, organic color pigments, luster pigments, dyes, fluorescent pigments, colored resin particles, etc., and the state of the colorant may be particles or a dispersion liquid. In order to achieve a desired color tone, two or more types of colorants may be mixed and used.
Among these, particles such as pigments and colored resin particles may be surface-treated with a surface treatment agent such as a rosin-based compound, a silane coupling agent, a resin, or a pigment derivative, or may be untreated.

In the present invention, the printing ink component of the display portion 6 printed on the outer fabric 3a is a typical oil-based pigment, but it can be oil-based/water-based, pigment/dye.

The solvent contained in the printing ink composition is a liquid component that has been used in the preparation of ink compositions, and is used to dissolve a resin to form a varnish or to adjust the viscosity of the ink composition.
Such liquid components are those that are in a liquid state at the printing temperature (usually 10°C to 40°C), and include at least one liquid compound such as animal and vegetable oils and/or animal and vegetable oil derivatives, organic solvents, mineral oils, and water.

The colorant contained in the printing ink composition may be inorganic and/or organic coloring pigments of various colors, such as red, blue, yellow, green, purple, black, white, orange, brown, special gloss colors such as gold and silver pearl, and fluorescent colors, which have been conventionally used in ink compositions, and two or more inorganic and/or organic coloring pigments are used to obtain a desired color tone. The colorant contained in the printing ink composition may be a dye, and oil-soluble dyes and water-soluble dyes such as basic dyes, acid dyes, and direct dyes are used.
Examples of inorganic coloring pigments that can be used include carbon black, iron black, titanium oxide, zinc oxide, white lead, yellow lead, zinc yellow, cadmium yellow, red iron oxide, cadmium red, ultramarine blue, Prussian blue, chromium oxide green, cobalt green, and composite oxides (nickel-titanium, chromium-titanium, bismuth-vanadium, cobalt-aluminum, cobalt-aluminum-chromium, and ultramarine blue).

Furthermore, the printing ink composition may contain one or more additives that are commonly used in the field of ink compositions, such as dispersants, surfactants, stabilizers, defoamers, polymerization initiators, anti-friction agents (wax), gelling agents, viscosity modifiers, plasticizers, polymerization inhibitors, antioxidants, pH adjusters, bactericides/fungicides, and silane coupling agents.

The printing ink may be a commercially available printing ink, for example, Seiko Advance's screen printing series, solvent type ink/vinyl-based LOV(E), LOV(E)YS, ACT, SG720, HIP(Z), SG700(Z), SG700(Z)YS, polyester-based PAL Matte 8, GAP Shin, RAM(R), SG590, acrylic/PC-based 2500(R), 2500YS, 2500H(R), CAV Meiban(E), CAV Meiban(E)YS, SG240, SG75, urethane-based VIC(Z), SG740, SG460, HF HSD, HF S-PAD, SG410, SG410 YS, RUX, MS8, HAC, MP-4(Z), MP-4 slow drying (Z), HF GV2, polyolefin-based OP22, 60A, 70B, 70B-AM, PP, PPT(N), PP acid-resistant, SPP, epoxy-based 1000, 1300, 1300HK, 1400N, 1400Q, 1690N, fluorescent V Lumino(Z), Seiko Advance's screen printing/mirror ink series OSP RX25, OSH RX01, SG429B, 500N, HFGV2, HFGV3, SG460 super slow drying, VIC(Z), HAC, BMR, GAP new, Seiko Advance's screen printing/UV type ink series ULA, UVA, HUG, RIG Examples include FP, PZU, SOX, UV Special, Medium, SPU, UAD, UPG, UVM, US125, US180NS, UVK100C, UV5412, UC410, UV406M, UV8606A modified, UV BOND, TJN Medium F, UV Texture Ink, UVP RX01, BLL/BLL, UV, UV Soft Touch RX01, etc.

The present invention is characterized in that the display color of the display section and the display color of the non-display section are the same color, but the same color in this invention means that the colors of the two can be recognized as the same by visual recognition.
The range in which the two colors can be recognized as the same is determined by the color difference ΔE value. Color difference ΔE*ab is an index that expresses the difference in color determined by the distance between two points in the L*a*b* space, which was established by the CIE (Comite Internationale des Indépendants d'Etudes et de l'Etudes) in 1976. However, ΔE*ab may not correlate with the human sense of color value depending on the color saturation and hue (visual attributes such as red, green, and blue).
Color difference ΔE00 is an index that was improved from the conventional color difference formula ΔE*ab to obtain a correlation with human color difference perception, which was recommended by CIE in 2001 and adopted in CIE No. 15:2004. ΔE00 performs correction of low chroma areas in the CIELAB space, adoption of weighting coefficients for lightness and chroma, and color difference correction of the blue area, so that it can obtain a better correlation with color difference perception.
In the present invention, the color difference ΔE00 is used as an index to determine the range in which the colors of both can be recognized as the same. Specifically, the display portion 6 (the portion of the characters and symbols printed on the surface of the print body) and the non-display portion 7 (the portion other than the characters and symbols printed on the surface of the print body) provided on the surface of the print body 3 in this embodiment were measured with a microsurface spectrophotometer, and the ΔE00 value was obtained from the obtained XYZ values and L*a*b* values. As a result of the research, it was found that the value of the ΔE00 was significantly reduced when the stamp ink was impregnated.
The range in which the colors of both can be recognized as the same, when the entire display area 6 can be included in the measurement visual field, requires that the average value of the ΔE00 value under ink impregnation is 0 or more and less than 1.59. On the other hand, when the average color difference ΔE00 value between the display area 6 (the characters and symbols printed on the surface of the print pad) and the non-display area 7 (the area other than the characters and symbols printed on the surface of the print pad) is 1.6 or more, the display area 6 on the surface of the ink pad 3 can be recognized visually.
The present invention makes use of the above-mentioned phenomenon, and when there is no need to refill ink on the printing pad 3, such as when the ink pad is not in use or when it is being used for the first time (referred to as a state in which it is ready to be stamped), the color difference ΔE00 between the display area 6 and the non-display area 7 is set to 1.59 or less, so that the colors of the two are recognized to be the same when observed by the naked eye.However, as the amount of ink impregnated on the surface of the printing pad decreases with use over time, the color difference ΔE00 between the display area 6 and the non-display area 7 becomes 1.6 or more, and the letters and symbols in the display area become visible, so that it is possible to determine when to refill ink simply by visually inspecting the surface of the ink pad.
In addition, the printing pad in a state ready for stamping refers to a time when there is no need to refill the printing pad 3 with ink, as described above, that is, a state in which when a stamp is made using the printing pad in a state ready for stamping, the print does not rub off and can be clearly seen.

Furthermore, the display portion 6 of the printing body 3 of the present invention may be formed by a printed image, and a part of the printed image may be omitted. A printed image usually expresses information in a binary state of whether ink is placed or left as is for each point on a printing medium such as an outer cloth. In that case, ink is placed continuously without gaps in the character and symbol portions, and ink is not placed in other portions. However, for example, by using a halftone technique, it is possible to arrange the ink placed in the character portions as a pattern of small dots at regular intervals, and a state in which a part of the printed image is omitted refers to a state in which the ink placed in the character and symbol portions is not placed continuously without gaps, but is placed discretely. Specific examples of a state in which a part of the printed image is omitted include, but are not limited to, halftone processing and halftone processing. In the present invention, when a printed image or the like is omitted, the part of the printed image where ink is placed is defined as a display portion, and the part where ink is not placed is defined as a non-display portion.
The abbreviated printed image is produced by arranging the ink deposited in the text portion as a pattern of small discrete dots at regular intervals, such as by using a halftone dot technique, to make the text portion less noticeable.
The above-mentioned effect allows a wider range of colors to be selected for the printed image to be displayed on the display unit 6. It is more preferable that the omission of a portion of the printed image is performed at a fixed interval, and specifically, omission by halftone processing or halftone processing is ideal. The proportion of the printed image to be omitted, i.e., the proportion of the portion of the character portion and the symbol portion where no ink is placed (non-display portion), is preferably 20% to 80%. If the proportion is less than 20%, the effect of making the boundary between the display unit 6 and the non-display portion 7 difficult to recognize is not achieved. On the other hand, if the proportion of the omitted portion is more than 80%, the user will have difficulty recognizing the characters when it is time to refill the ink.
The printed image in the present invention includes images formed by, for example, pad printing, offset printing, gravure printing, silk printing, screen printing, electrophotographic printing, inkjet printing, etc., as well as image formation by a stamping tool and image formation by burning.

Fig. 5 is a diagram showing a state where a printed image is omitted by halftone processing. In Fig. 5, five combinations of "light and dark" characters and a symbol with a mesh grid in a circular frame are arranged, and the five patterns differ in the percentage of the printed image omitted by halftone processing. From the left in Fig. 5, the percentages of omitted are arranged in order of 80%, 60%, 40%, 20%, and 0% (no omission).
Figures 6 and 7 show another embodiment of the display section of the present invention. Figure 6 is formed of a character frame section 13 and a blank section 14, and halftone processing is applied to the character frame section 13. Figures 6 and 7 differ in the form of the character frame section 13. In the present invention, the blank section 14 corresponds to a non-display section, and the part of the character frame section 13 where ink is placed corresponds to a display section.

In all of the samples used in the examples and comparative examples, the display portion 6 is formed by printing ink on the surface of the ink pad of an extra-large ink pad manufactured by Shachihata Co., Ltd. The combinations of ink pads and printing inks used in the examples and comparative examples are shown below. The ink pad ink used in the extra-large ink pad manufactured by Shachihata Co., Ltd. is an oil-based pigment.
The printed images used in the Examples and Comparative Examples were the "Please refill ink" and "Diagram showing ink droplets" printed on the surface of the printing pad in Fig. 1. The printing ink was used to form the display portion 6 by screen printing. The printing pad of the pre-test stamp pad used in the Examples and Comparative Examples was impregnated with 45% stamp ink (oil-based pigment) by weight relative to the maximum impregnation amount.
The main solvent of the stamp ink used was polyoxyalkylene glycerol ether. The samples used in the examples and comparative examples used polyester synthetic fibers. The maximum ink impregnation amount was calculated by a hanging test. Specifically, after the ink was impregnated into the printing pad used for the stamp, the printing pad was left hanging at a certain height using a string, and the weight of the ink contained in the printing pad when the ink weight and the ink-holding force of the printing pad were balanced and the ink no longer dripped from the printing pad was determined as the maximum ink impregnation amount.

Example 1
Ink pad Shachihata extra large ink pad purple (HGN-4-V)
Printing ink: Seiko Advance solvent-based ink, purple (SG410 495 Violet MATTE)

Example 2
Ink pad Shachihata ink pad extra large red (HGN-4-R)
Printing ink: Solvent-based ink made by Seiko Advance, red (SG410 510 American Red MATTE)

Example 3
Ink pad Shachihata Ink pad Extra large Indigo (HGN-4-B)
Printing ink: Seiko Advance solvent-based ink, indigo (SG410 440 Blue MATTE)

Example 4
Ink pad Shachihata ink pad extra large black (HGN-4-K)
Printing ink: Seiko Advance solvent-based ink, purple (SG410 495 Violet MATTE)

Comparative Example 1
Ink pad Shachihata ink pad extra large black (HGN-4-K)
Printing ink: Seiko Advance Co., Ltd. solvent-based ink, silver (SG410 607A 300M)

Comparative Example 2
Ink pad Shachihata ink pad extra large red (HGN-4-R)
Printing ink: Seiko Advance white solvent-based ink (SG410 120 White MATTE)

Comparative Example 3
Ink Pad Shachihata Extra Large Ink Pad Green (HGN-4-G)
Printing ink: Seiko Advance solvent-based ink, green (SG410 350 Green MATTE)

(Unused: Not refilled, visual evaluation of ink pad color)
In the examples and comparative examples, the color difference between the display area 6 and the non-display area 7 near the display area 6 on the surface of the ink pad of an unused ink pad was visually confirmed. The ink amount of the ink pad samples in each of the examples and comparative examples was about 45%. If there was no color difference between the two and the display area 6 and the non-display area 7 could be recognized as the same color even when enlarged or stared at, or if it was judged that the boundary between the display area 6 and the non-display area 7 could only be faintly recognized by enlarging or staring at it, it was evaluated as ◯. If the boundary between the display area 6 and the non-display area 7 could be clearly recognized without enlarging or staring at the characters and symbols displayed on the display area, it was evaluated as ×.
(Initial use: visual evaluation of ink pad color before refilling)
In the examples and comparative examples, the difference in color between the display area 6 on the surface of the ink pad printing pad in a state where the ink pad had been used 2000 times in advance and the non-display area 7 near the display area 6 was visually confirmed. The evaluation criteria were the same as those for the visual evaluation of the ink pad color when it was unused. A round stamp with a diameter of 40 mm was used for stamping.
(After 5,000 impressions, time to refill, visual evaluation of ink pad color)
In the examples and comparative examples, the ink pad was used 5,000 times in advance, and the color difference between the display area 6 and the non-display area 7 near the display area 6 on the surface of the ink pad when it was time to refill the ink was visually confirmed. When there was a color difference between the two, the boundary between the display area 6 and the non-display area 7 could be recognized, and the characters and symbols displayed on the display area could be clearly recognized, it was evaluated as ◯. On the other hand, when there was no color difference between the two, and the characters and symbols on the display area 6 could not be recognized at least without magnifying or staring, it was evaluated as ×.
(Color difference ΔE value between the display part and non-display part of the printed surface)
In each of the Examples and Comparative Examples, the color difference ΔE00 between the display area 6 and non-display area 7 on the surface of the ink pad sample used was determined using a microsurface spectrophotometer C50μ type (manufactured by Suga Test Instruments Co., Ltd.). In addition, the L* value, a* value, and b* value in the L*a*b* space defined by the CIE were also measured as auxiliary characteristic values. For Examples 1 to 4 and Comparative Examples 1 to 3, measurements were performed so that the non-display area was not included in the measurement viewing angle.
The display portion 6 was measured in three ways in each of the examples and comparative examples. The first was the color difference ΔE00 value between the non-display portion 7 impregnated with ink and before the stamping test, and the display portion 6 in a state not impregnated with ink (ΔE00 before ink impregnation). The second was the ΔE value 00 between the display portion 6 and the non-display portion 7 in a state impregnated with ink and before the stamping test (ΔE00 before the stamping test in the ink impregnated state). The third was the color difference ΔE00 value between the display portion 6 and the non-display portion 7 in a state impregnated with ink and after 5000 stamping tests were performed (ΔE00 after 5000 stampings in the ink impregnated state).
Furthermore, when the non-display portion 7 of the ink pad sample after 5000 impressions in the ink-impregnated state was measured, the obtained L*a*b* values were displayed as auxiliary characteristic values.
In addition, after 5,000 stamping tests, the stamped prints of each color were rubbed off and became difficult to read, so it was time to refill the ink.
<Measurement conditions>
Light source: Standard light C, viewing angle: 2 degrees, measurement hole diameter: Φ0.4mm

実施例１～４及び比較例３における未使用スタンプ台色彩の目視評価及び使用初期のスタンプ台色彩の目視評価は、〇であったのに対し、比較例１～３における未使用スタンプ台色彩の目視評価は×となった。
補充時期のスタンプ台色彩の目視評価については、実施例１～４、比較例１～３はいずれも、スタンプ台の５０００回の使用によって、印褥体表面のインキが減少することにより、表示部に形成される文字・記号がはっきりと認識されるようになった。
色差△Ｅ００について、インキ含浸前の△Ｅ００と比較し、インキ含浸状態捺印試験前の△Ｅ００の値は、著しく低い値となった。これは、表示部が含浸インキによって濡れることで、表示部の色彩が変化してるものと考えられる。
また、実施例１～４及び各比較例のインキ含浸状態捺印試験前の△Ｅ００の値及び、インキ含浸状態５０００回捺印後の△Ｅ００の値から、表示部と非表示部を認識可能となる色差は１．６が閾値となるものと考えられる。 Table 1 shows a list of the evaluation results of the examples and comparative examples.

The visual evaluation of the unused ink pad colors and the visual evaluation of the ink pad colors immediately after use in Examples 1 to 4 and Comparative Example 3 was rated as "good," whereas the visual evaluation of the unused ink pad colors in Comparative Examples 1 to 3 was rated as "poor."
Regarding visual evaluation of the ink pad color when it was time to refill, in all of Examples 1 to 4 and Comparative Examples 1 to 3, after 5,000 uses of the ink pad, the ink on the surface of the printing pad had decreased, and the letters and symbols formed on the display area had become clearly recognizable.
Regarding the color difference ΔE00, the value of ΔE00 before the ink impregnation test was significantly lower than that before the ink impregnation test. This is thought to be because the color of the display part changed as the display part became wet with the impregnated ink.
In addition, based on the ΔE00 values before the ink-impregnated stamping test for Examples 1 to 4 and each comparative example, and the ΔE00 values after 5,000 stampings in the ink-impregnated state, it is considered that the threshold value for the color difference at which the display area and non-display area can be recognized is 1.6.

The present invention has been described above in relation to the embodiment that is believed to be the most practical and preferable at this time, however, the present invention is not limited to the embodiment disclosed in the specification of this application, and may be modified as appropriate within the scope of the claims and the gist or concept of the invention as can be read from the entire specification, and the specifications of the ink pad that involve such modifications must also be understood to be included within the technical scope.

1 Ink pad 2 Base box 2a Bottom surface portion 2b Wall surface portion 3 Print pad 3a Surface cloth 3b Ink-impregnated body 4 Lid portion 4a Bottom surface portion 4b Wall surface portion 5 Hinge portion 6 Display portion 7 Non-display portion 8 Print pad surface frame 9 Surface cloth pasting frame 10 Hinge bearing portion 11 Hinge joint portion 12 Hinge shaft 13 Character frame portion 14 White portion

Claims (2)

A printing pad impregnated with ink, the printing pad having a display portion and a non-display portion on its surface, the display color of the display portion and the display color of the non-display portion being the same color when in a stampable state, and the display color of the display portion and the display color of the non-display portion becoming different colors as the ink contained in the printing pad is consumed. A printing body as described in claim 1 , characterized in that the color difference ΔE00 between the display color of the display portion and the display color of the non-display portion on the surface of the printing body is 1.59 or less, and as the ink contained in the printing body is consumed, the color difference ΔE00 between the display color of the display portion and the display color of the non-display portion becomes 1.6 or more.

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