JP4406502B2 - Scratch sheet - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a scratch sheet obtained by providing a cover layer that can be removed from scratch on confidential information provided on a sheet surface and performing a concealing operation. More specifically, the present invention relates to a scratch sheet in which a transparent film is used for a scratch-removable coating layer, but confidential information applied to the sheet surface to be concealed cannot be discriminated from the surface.
[0002]
[Prior art]
As a means for temporarily concealing character information written on the surface of various forms, there is a method of concealing by pasting an opaque sealing material, for example, a black seal. Notifications that contain information about individuals, for example, when a notification of address change is sent with a dedicated reply post instead of a sealed letter, such personal information can be removed later so that it cannot be read by unspecified third parties. A method of covering with a sealing material is used.
[0003]
For the same purpose, there is also a method of temporarily covering information with an opaque color, for example, silver scratch ink, in order to place the information in an unreadable state. This method of applying the scratch ink can be used for a large amount of printed matter and is widely used as a simple concealing means. This is used for scratching lots and the like because the silver scratch ink can be scraped off with coins to reveal the information printed inside.
[0004]
As a scratch ink used for a conventional scratch sheet, a silver scratch ink having high opacity is used because it is necessary to conceal the information written under the area where the scratch ink is applied. In these conventional scratch sheets, a sheet base material on which a predetermined design is printed in advance is used, and confidential information is printed in a predetermined blank frame, and then the scratch ink is solid-printed so as to cover the predetermined blank frame. . Such blank frames are generally sufficiently wide and at least twice as large as the size of character information or the like printed therein.
[0005]
[Problems to be solved by the invention]
In this way, compared to the size of the confidential information, the diameter (one side) of the area hidden by the solid printing of the opaque scratch ink is usually twice or more larger, but the area exceeding the range of the confidential information itself is not necessarily It is not necessary to be opaque, and it is desirable to have a configuration in which a predetermined design printed on the lower sheet substrate from the surface can be seen. If possible, the scratch ink coating layer itself is transparent, but the confidential information itself described below is desired to develop a scratch sheet that is substantially concealed. Yes.
[0006]
SUMMARY OF THE INVENTION The present invention solves the above-mentioned problems, and an object of the present invention is to use a transparent film for the scratch-removable coating layer, but to use a method in which confidential information cannot be visually recognized from the surface. To provide a sheet. More specifically, although a transparent film is used for the scratch-removable coating layer, in the state covered with the coating layer, the confidential information shows a color tone that cannot determine the shape, but the coating layer is scratch-removed. In some cases, the present invention is to provide a scratch sheet having a new configuration that exhibits a color tone whose shape can be clearly discriminated.
[0007]
[Means for Solving the Problems]
The present inventor has intensively studied to solve the above problems, and as a result, a variable color dye composition whose color tone clearly changes depending on the presence or absence of oxygen, and an oxygen-impermeable material that can be placed in an oxygen-free state. The idea was to use a protective coating layer. Specifically, for example, secret information consisting of characters, designs, etc. is formed using a variable color pigment composition that exhibits a white or colorless color tone in an anaerobic state and a colored color tone in an aerobic state, Alternatively, the background portion of the secret information colored in the same color tone as the color tone in the anaerobic state is drawn, the boundary between the background portion and the secret information is made difficult to visually recognize, and the variable color pigment composition is brought into the aerobic state. We focused on the fact that confidential information can be made visible by changing the color tone to be presented. Further studies were made, and the present invention could be realized by making the coating layer an oxygen-impermeable transparent film capable of scratch removal.
[0008]
That is, the scratch sheet of the present invention is a sheet in which confidential information and a scratch-removable coating layer that covers the information are provided on a predetermined portion of the sheet base material surface, and the confidential information includes the presence or absence of oxygen. A variable color pigment composition that is formed using a variable color pigment composition that reversibly changes color tone, and that the coating layer is formed of an oxygen-impermeable transparent film and that forms the confidential information. The object is characterized by exhibiting a color tone in an anoxic state.
[0009]
Further, the scratch sheet of the present invention is further provided with a background portion of the secret information, wherein the color tone of the variable color pigment composition in an oxygen-free state and the color tone of the background portion are substantially the same. .
[0010]
In the present invention, the scratch-removable coating layer itself is made of an oxygen-impermeable transparent film, so that the entire design is considered in consideration of the presence of the coating layer without hiding the lower design. There is an advantage that it is possible to select more arbitrarily. In particular, since a coating layer made of a transparent film is used, a considerable portion under the transparent film layer can also be used for description and the like, and physical restrictions are greatly eased. Furthermore, there are many advantages that the design is not restricted from the aesthetic point of view of the entire scratch sheet.
[0011]
Hereinafter, the scratch sheet of the present invention will be described in more detail.
In the scratch sheet of the present invention, the confidential information is formed using a variable color dye composition that reversibly changes color tone in the presence or absence of oxygen. Any variable color dye composition as long as its color tone changes clearly in an atmosphere having an oxygen concentration of contained and an oxygen-free atmosphere, and the color tone change due to the presence or absence of oxygen is reversible However, it is preferable to use a variable color dye composition that is used for a so-called “oxygen indicator” that has been conventionally used for confirming anoxic conditions in a sealed package. In general, the oxygen indicator includes a redox dye, a reducing agent for the redox dye, an alkaline substance, and water. The oxygen indicator is prepared in an ink form, and is prepared as a water-based ink or an oil-based ink depending on the printing surface and printing method.
[0012]
In the variable color dye composition, reversible color tone changes with the oxygen concentration, but the main component is that the redox dye is oxidized in an environment with a high oxygen concentration. When placed in the oxygen state, the state once reduced by the action of the coexisting reducing agent is changed from the state once oxidized by oxygen. This oxidation / reduction is reversible, the coexisting reducing agent is consumed, and the reversibility is maintained until it is depleted. Alkaline substance and water form a field for the above-mentioned oxidation / reduction reaction, and are also used to maintain a pH range for inducing a color tone change accompanying the reaction.
[0013]
Examples of the redox dye include thiazine dyes such as methylene blue and indicosulfonic acid described in JP-B-55-47820, JP-B-56-24906, JP-A-56-8647, and the like. Indigo pigments such as potassium, thioindigo pigments, and indophenol pigments described in JP-A-2-138866 can be used. In particular, this indophenol dye is more preferable when it is left for a long time under light irradiation, and its degree of fading is significantly less than that of a methylene blue dye. As a reducing agent used when reducing the oxidized form of the redox dye, it is preferable to use a reducing saccharide such as glucose, fructose, xylose, or maltose. In addition, since the reduction | restoration by the said reducing saccharide advances on alkaline conditions, alkaline substances, such as magnesium hydroxide, and a certain amount of water are required, for example.
[0014]
Here, an example of a variable color dye composition using a methylene blue dye as shown below is shown. An alkaline substance using methylene blue, which is a redox dye, and D-glucose as a reducing agent, as a reducing agent. Was selected from magnesium hydroxide that does not have properties such as deliquescence and high water absorption, and a composition in which necessary water was added thereto.
[0015]
[An example of a variable color dye composition using a methylene blue dye]
Magnesium hydroxide 96.95 parts by weight D-glucose 1.0 parts by weight Methylene blue 0.05 parts by weight Water 2.0 parts by weight
Furthermore, an example of a variable color dye composition using an indophenol dye is shown as follows. 2,6-Dichloroindophenol sodium salt, which is a redox dye, and D-glucose as a reducing saccharide as a reducing agent thereof, sodium carbonate as an alkaline substance, and necessary water were added thereto. It was set as the composition. In this example, methyl alcohol is added as a solvent in order to make the whole into a solution. In addition, 2,6-dichloroindophenol sodium salt itself is almost colorless (white) in an anoxic state. Therefore, by adding Acid Red (food red No. 106) as an indicator dye, the anaerobic state is obtained. Exhibits a red color tone, while in an aerobic state it exhibits a blue color tone.
[0017]
[An example of variable color dye composition using indophenol dye]
2,6-dichloroindophenol sodium salt 0.5 parts by weight Acid Red (food red No. 106) 0.1 parts by weight sodium carbonate 25.0 parts by weight D-glucose 2.0 parts by weight water 2.0 parts by weight methyl Alcohol 70.4 parts by mass
Further, such a variable color pigment composition is preferably prepared as an ink composition, and secret information having a predetermined color tone is formed on the surface of the sheet substrate by screen printing or flexographic printing. Such an ink composition is appropriately prepared according to each printing method in consideration of the state of the sheet surface to be printed, wettability with ink, and the like. And here, four examples as shown below of the composition of the ink which can be utilized are illustrated. In addition, in the scratch sheet | seat of this invention, of course, it is not restricted to what is illustrated here.
[0019]
[Example of composition of ink containing variable color pigment composition (1)]
Variable color pigment composition 35 parts by weight ethyl hydroxyethyl cellulose (EHEC) 5 parts by weight rosin pentaerythritol ester 10 parts by weight mineral spirit 20 parts by weight aromatic hydrocarbon solvent 20 parts by weight cellosolve 10 parts by weight
[Example of Composition of Ink Containing Variable Color Dye Composition (2)]
Variable color pigment composition 36.5 parts by weight Styrenated alkyd resin 45.0 parts by weight Cobalt naphthenate dryer 1.0 part by weight Aromatic hydrocarbon solvent 15.0 parts by weight Gelling agent 2.5 parts by weight
[Example of composition of ink containing variable color pigment composition (3)]
Variable color dye composition 18.5 parts by weight High acid value maleic acid resin 17.5 parts by weight Isopropyl alcohol 13.0 parts by weight Water 43.5 parts by weight Urea 1.0 part by weight Dimethylethanolamine 4.0 parts by weight Polyethylene wax 2.0 parts by mass of defoaming agent 0.5 parts by mass
[Example of Composition of Ink Containing Variable Color Dye Composition (4)]
Variable Color Dye Composition 14.0 parts by weight High acid value maleic resin 5.0 parts by weight Styrene acrylic emulsion 30.0 parts by weight Isopropyl alcohol 10.0 parts by weight Water 1.0 part by weight Urea 35.5 parts by weight 28% Ammonia water 1.0 part by weight Morpholine 1.0 part by weight Polyethylene wax 2.0 part by weight Antifoaming agent 0.5 part by weight
Next, as the oxygen-impermeable transparent film, for example, polyvinylidene chloride film, biaxially stretched polyvinylidene chloride film, acrylonitrile film, polycarbonate film, ceramic-deposited polyethylene terephthalate film, biaxially stretched polyvinyl alcohol Examples thereof include a film, an ethylene / vinyl alcohol copolymer film, a nylon film, and a polyvinyl alcohol film. The thickness is selected as appropriate in consideration of the thickness and flexibility of the target sheet base material or the glossiness of the surface. When the transparent film is brought into close contact with the sheet base material, the covered region becomes anoxic, and the color tone of the secret information of the covered region exhibits the color tone in the anoxic state.
[0024]
In order to make the region covering the oxygen-impermeable transparent film oxygen-free, the sheet base material itself needs to have no oxygen permeability or use a very low material. In the case of using a material having a high value, a surface treatment for eliminating oxygen permeability may be performed.
[0025]
Furthermore, although the said coating layer can also utilize the said transparent film, it can also be set as the transparent film using the transparent resin which can be silkscreen printed and apply | coated. As this transparent resin, for example, a kneaded material obtained by adding an appropriate amount of a petroleum solvent to 30 parts by mass of a rubber resin and 20 parts by mass of a pigment can be used. In particular, when the coating layer itself is colorless and transparent, it is necessary to clearly specify the site to be scratched, but the coating layer can be provided not only in the area where the confidential information is provided but also in a wider range. The coating layer has a function to prevent oxygen inflow by using a colorless polymer material having no oxygen permeability, and to block oxygen and keep it in an oxygen-free state. May be. That is, the film having the deoxygenation function is stably maintained in an oxygen-free state even when a small amount of oxygen permeates through the gap in the pasting.
[0026]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, the present invention will be described in more detail by giving examples in which the scratch sheet of the present invention is configured as a “speed lot”. Here, FIG. 1 is a schematic plan view of a first embodiment of the scratch sheet of the present invention, FIG. 2 is a sectional view taken along the line AA in FIG. 1, and FIG. 3 is an explanatory diagram of the state of the scratch sheet in FIG. 4 is a schematic plan view of a second embodiment of the scratch sheet of the present invention, FIG. 5 is a sectional view taken along line AA in FIG. 4, and FIG. 6 is an explanatory diagram of the state of the scratch sheet in FIG. In addition, the code | symbol in drawing of each Example shall be common to each Example.
[0027]
As shown in FIG. 1, the scratch sheet 1 of the present embodiment has a predetermined print 6 such as a figure or pattern designed for the purpose of explanation or overall decoration on a predetermined portion of the sheet base 2 side. In addition, secret information 3 (1, *, x) is applied with an ink containing a variable color pigment composition that reversibly changes color tone with or without oxygen. Then, as shown in FIG. 2, the secret information 3 is covered with a rectangular oxygen-impermeable transparent film 4 so as to be in an oxygen-free state, and the color tone of the variable color pigment composition in the covered region is covered. Is white.
[0028]
The ink containing the variable color dye composition in this example is the same as the ink composition example (1) of the ink containing the variable color dye composition described above. Although the composition using the above-mentioned 2,6-dichloroindophenol sodium salt was used, it was assumed to exhibit a white color without adding a colored pigment.
In addition, as the oxygen-impermeable transparent film 4, a biaxially stretched film (Eval EF-XL / 15 μm manufactured by Kuraray Co., Ltd. is used, and the sheet substrate 2 is provided with a roll coat / varnish ink as a coating layer on the surface, A high-quality paper processed to prevent oxygen ingress was used.
[0029]
Thus, in this example, since the secret information 3 is formed in white of the same color as the surface of the sheet base material 2, it is visible in a state where the oxygen-impermeable transparent film 4 is coated in an oxygen-free state. Difficult to do. However, by removing the scratch from the transparent film 4, the confidential information 3 is exposed to an aerobic state as shown in FIG. 3, and the color tone of the variable color pigment composition changes from white to blue and becomes visible. .
[0030]
Next, a scratch sheet according to a second embodiment of the present invention will be described.
The scratch sheet 1 of this embodiment is basically the same in configuration as the first embodiment, but is characterized in that a background portion 5 is provided in the confidential information 3 as shown in FIGS. The background portion 5 is printed with the background pattern printed with the general ink having the same color tone as the color tone of the variable color pigment composition forming the confidential information 3 in an oxygen-free state, and the two cannot be distinguished.
The ink containing the variable color pigment composition in this example uses the same [Ink composition example (1) containing variable color pigment composition] as in the first example. However, unlike the first embodiment, a red pigment (acid red) added is used so that red is displayed in an oxygen-free state and blue in an aerobic state. Further, the background portion 5 may be solid printing or halftone printing as long as it is difficult to distinguish between the background pattern printing in the present embodiment and the background portion 5.
[0031]
As described above, in this embodiment, in the oxygen-free state, the secret information 3 and the background portion 5 both have a red color so that the oxygen-impermeable transparent film 4 covers the oxygen-impermeable state. In such a state, it is difficult to distinguish the secret information 3 and the background portion 5, and the secret information 3 cannot be visually recognized. However, by removing the scratch on the transparent film 4, the confidential information 3 is exposed to an aerobic state, and the color tone of the variable color pigment composition changes from red to blue as shown in FIG. Since it exhibits a different color tone, it becomes visible.
[0032]
【The invention's effect】
As described above, in the scratch sheet of the present invention, the coating layer which can be removed from scratch is made of an oxygen-impermeable transparent film, so that the entire design is considered without covering the lower printing surface. Without having to do so. In particular, when a plurality of coating layers are provided, the ratio occupied by the scratch ink application area has increased in the past, which has been a physical limitation on the description described in the empty portion. Therefore, a considerable portion under the transparent film layer can be used for description and the like, and physical restrictions are greatly eased. Furthermore, from the aesthetic point of view of the entire scratch sheet, the design is not constrained.
[Brief description of the drawings]
FIG. 1 is a schematic plan view of a first embodiment of a scratch sheet of the present invention.
FIG. 2 is a cross-sectional view taken along line AA in FIG.
3 is a state explanatory diagram of the scratch sheet of FIG. 1 during scratching.
FIG. 4 is a schematic plan view of a second embodiment of the scratch sheet of the present invention.
5 is a cross-sectional view taken along line AA in FIG.
6 is a state explanatory view of the scratch sheet of FIG. 4 at the time of scratching.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Scratch sheet 2 Sheet base material 3 Secret information 4 Oxygen-impervious transparent film 5 Background part 6 Predetermined printing

Claims (2)

In a predetermined portion of the sheet base material surface, the cover is provided with confidential information and a scratch-removable coating layer that covers the information,
The secret information is formed using a variable color pigment composition that reversibly changes color tone with or without oxygen, and the covering layer is formed of an oxygen-impermeable transparent film, and the secret information A scratch sheet, wherein the variable color pigment composition forming information exhibits a color tone in an oxygen-free state. The scratch sheet according to claim 1, further comprising a background portion of the secret information, wherein the color tone of the variable color pigment composition in an oxygen-free state is substantially the same as the color tone of the background portion.

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