JP2015186882A - Scratch sheet and medium for scratch - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a scratch sheet on which even a hand-writing confidential image becomes visible by scratching with a coin, and the confidential image is not visible before scratch and becomes visible only after the scratch, and provide a medium for scratch for creating this.SOLUTION: A scratch sheet has a confidential image which is colored so as to be patterned and becomes visible by scratching with a coin. The scratch sheet includes a scratch print layer printed on a high-quality paper with white ink containing coin-scratching oxide particles and aqueous varnish for paint, and the confidential image is created with transparent or white ink, or toner on it.

Description

  The present invention relates to a scratch sheet that can be visually recognized by being colored like a secret image by rubbing with a coin, and a scratch medium for obtaining the scratch sheet, and in particular, a scratch capable of giving a secret image even in handwriting. The present invention relates to a sheet and a scratch medium for obtaining the sheet.

  Even if characters or images are printed with white ink containing inorganic oxide particles such as hard titanium dioxide on white paper, it cannot be seen as it is, but if the printed part is rubbed with coins etc., inorganic oxidation in the white ink will occur. The coins are scraped off by the object particles to produce metal powder (file effect), and the metal powder adheres to the printed portion and is colored black so that the image can be visually recognized.

  However, a fluorescent whitening agent is included in the printing paper in order to increase its whiteness, and when it is irradiated with ultraviolet light such as black light, it emits blue-white fluorescence. On the other hand, white ink containing inorganic oxide particles having a coin rubbing property such as titanium dioxide does not transmit such ultraviolet light and does not emit fluorescence. For this reason, when the scratch printed matter is irradiated with ultraviolet light, an image printed with white ink floats black like a shadow while the printing paper emits light blue. That is, there arises a problem that the secret image can be visually recognized without being scratched by coins.

On the other hand, a so-called negative-type scratch print was developed, in which white ink containing coin-abrasive inorganic oxide particles was solid-printed on white paper and coated (coated) so as to image the same. . For example, in Patent Document 1, a ground layer is solid-printed on a paper medium with a white ink containing titanium oxide, which is a coin-scratching inorganic oxide particle, and an image is formed thereon with a mat varnish containing at least a white agent. There has been disclosed a negative-type scratch print provided with negative pattern printing so as to appear.
When such a scratch printed material is irradiated with ultraviolet light, the entire undercoat layer printed in black and white while the printing paper emits light blue appears to be black, and the image given in the negative pattern by matte varnish cannot be seen. By rubbing with, the metal powder of the coin adheres only to the white ink portion that is not coated with the mat varnish, and the image is visible.

  In the negative-type scratch printed matter, a coat (coating) with a transparent varnish or a mat varnish containing a whitening agent is obtained by printing with a general ink or the like. Further, an image to be colored can be freely determined depending on the design of coat printing. In other words, if you are supplied with paper that has been printed with white ink containing titanium oxide, you can perform only the process of printing the coat separately in a place with general printing equipment, and freely determine the image to be colored. Scratch prints can be manufactured. That is, on-demand scratch printing is possible.

  However, in Patent Document 1, since the boundary line between the solid printing with the white ink containing titanium oxide and the coat (secret image portion) thereon is colored, the color difference at the boundary line and The gloss difference must be eliminated or reduced. Especially in on-demand printing, the equipment and environment for coating can vary greatly, so that the color difference and gloss difference at the boundary can be kept within a certain range without strict printing conditions. is necessary.

  Therefore, Patent Document 2 states that “a scratch printed matter that is made visible by coloring a secret image by rubbing with a coin, and a sheet in which colored ink is mixed into white ink containing inorganic oxide particles for rubbing coins. A scratch printed matter comprising: a base layer provided on the body, and a negative print layer provided on the body so as to imitate the secret image with a negative color ink of the same color as the base layer '' Disclosed, “Within a certain range without greatly depending on the printing state of the negative printing layer, the color difference that can be recognized at the border line of the secret image before rubbing without suppressing coloring of the secret image by rubbing with a coin In particular, it is possible to provide a scratch print having a configuration suitable for on-demand printing. "

JP 2013-49136 A JP 2013-75508 A

  In both Patent Documents 1 and 2, a secret image is printed and given, but there is a demand for making it possible even by handwriting. Since handwritten text can give a secret image more easily and freely, for example, a message that you want to keep secret can be freely handwritten at any time, and a message that has been hidden by the person who received it scraping with coins can be used. Applications such as enabling reading are conceivable.

  Therefore, the present invention is a scratch sheet that can be visually recognized even in a secret image of a handwriting by rubbing with a coin, the secret image cannot be visually recognized before rubbing, and the secret image can be visually recognized only after rubbing. An object of the present invention is to provide a scratch sheet that can be used, and a scratch medium for providing the same.

  As a result of intensive studies, the present inventor has developed a coin fretting property when printed with a white ink containing coin rubbing inorganic oxide particles and an aqueous varnish for coating on high-quality paper. It was found that when a secret image was handwritten or printed with this ink, it was not visually recognized before rubbing without being provided with a camouflage image layer, but after rubbing, and the following inventions (1) to (7) were completed.

(1) The scratch sheet of the present invention is a scratch sheet that can be visually recognized by being colored so as to represent a secret image by rubbing with a coin,
A scratch printing layer printed with white ink containing coin-scratching inorganic oxide particles and a water-based varnish for paint on fine paper is provided.
Further, the secret image is provided with transparent or white ink or toner.

  In this invention, if a paper having a scratch printing layer is prepared in advance, an image to be concealed with a transparent or white ink or toner is printed or handwritten with a transparent or white ink. A sheet can be obtained.

If the paper used as the medium is high-quality paper, the white ink used can be used to make the scratch printed layer appear to be scratched and it is difficult to see the concealed image before rubbing without the camouflage image layer. It is necessary to include inorganic oxide particles and an aqueous coating varnish.
That is, when high-quality paper is used, the printed ink penetrates into the paper, thereby reducing the difference in gloss between the scratch print layer printed with the ink containing the coin-scratching inorganic oxide and the secret image provided thereon. Or it can be lost, but the scratch-coating of the scratch print layer is lost.
However, the present inventor has found that when a small amount of the aqueous varnish for paint is mixed with the ink of the scratch printing layer, the scratching property of the scratch printing layer is reproduced, and the gloss difference from the secret image does not change.

This phenomenon is considered to be similar to the phenomenon caused by “Dossa Liquid” used to prevent bleeding of Japanese paper and picture silk in the field of Japanese painting. That is, the “Dosa liquid” is pre-processed on Japanese paper or picture silk and used to prevent the paint from bleeding during drawing, and does not prevent the paint from being fixed to the Japanese paper or picture silk.
The “dosage liquid” is processed in advance, and in the present invention, it is different where it is used by mixing with white ink.

(2) The scratch sheet of the present invention is characterized in that, in the invention described in (1), the scratch printing layer is printed with halftone dots.

  In the present invention, since the scratch printing layer is printed with halftone dots, there is an effect of making it impossible to visually recognize a secret image handwritten or printed thereon due to a subtle gloss difference between the halftone dot portions and the gaps between them.

(3) The scratch sheet of the present invention is characterized in that, in the invention described in (1) or (2), the scratch printing layer is further printed with a camouflage pattern.

  In the present invention, since the scratch printing layer is halftone and camouflaged, the effect of making the secret image handwritten or printed thereon invisible is enhanced.

(4) A scratch medium of the present invention is a scratch medium for providing the scratch sheet according to any one of (1) to (3), wherein coin-scratching inorganic oxide particles and A scratch printing layer printed with a white ink containing an aqueous varnish for paint is provided.

(5) The scratch medium of the present invention is characterized in that, in the invention described in (4), the scratch printing layer is printed with halftone dots.

(6) The scratch medium of the present invention is characterized in that, in the invention described in (4) or (5), the scratch printing layer is further printed with a camouflage pattern.
It is.

(7) The white ink of the present invention is a white ink for printing and giving the scratch printing layer according to any one of (1) to (6). It contains varnish.

  In the present invention, by mixing an aqueous varnish for paint with general ink, the penetrability to fine paper is reduced to prevent bleeding, and at the same time, the coin scratching property is developed. Further, since printing is performed on high-quality paper, the increase in gloss of the scratch printing layer is small.

According to the present invention, it is not possible to visually recognize the concealed image before rubbing, it is possible to give a scratch sheet that can clearly see the concealed image after rubbing, like a scratch sheet provided with a concealing layer with conventional aluminum-containing ink, Does not cause scratching or peeling off before rubbing.
In addition, since the scratch printing layer of the present invention is printed on the high quality paper with a white ink having a “wetting liquid” effect, the permeability to the high quality paper becomes appropriate, compared with the printing on the coated paper. As a result, the increase in gloss is suppressed and the coin fretting property is exhibited. Furthermore, since the secret image that is handwritten or printed with transparent or white ink on the scratch print layer also penetrates the paper, the increase in gloss is suppressed, so that the secret image cannot be visually recognized. When handwritten, the secret image is glossy and visible before drying, so it can be handwritten while confirming the characters and images.

  Hereinafter, embodiments for carrying out the present invention will be described in detail. Note that this embodiment is merely an embodiment for carrying out the present invention, and the present invention is not limited by this embodiment, and various modified embodiments can be made without departing from the gist of the present invention. Is possible.

  The scratch sheet of the present invention is a scratch sheet that can be visually recognized by being colored like a secret image by rubbing with a coin, and comprises a coin-scratching inorganic oxide particle and an aqueous varnish for paint on a high-quality paper A scratch print layer printed with a white ink containing the above-mentioned image is provided, and the secret image is provided thereon with a transparent or white ink or toner.

  The scratch printing layer of the present invention is provided by dot printing with a white ink containing coin-rubbing inorganic oxide particles and an aqueous coating varnish on high-quality paper as a medium.

The paper used as the medium is preferably high-quality paper having ink absorbability.
In the present invention, both the scratch printing layer and the secret image are suppressed from being visually recognized by eliminating the gloss difference between the two by suppressing the gloss. For this purpose, the paper used as the medium is preferably a high-quality paper that has ink absorbability and does not easily show gloss. However, the high-quality paper does not exhibit scratching properties even when printing ink containing coin-scratching inorganic oxide particles. .

The present invention makes it possible to achieve both the ink absorbability and the rubbing property by applying the concept of “Dosai Liquid” used when drawing on Japanese paper or picture silk. That is, “Dossa liquid” is treated in advance on a woven fabric or the like to prevent bleeding of the paint, but an aqueous varnish for paint is selected as having the same action, and contains coin-abrasive inorganic oxide particles. By using white ink, it was possible to suppress the penetration into fine paper and reproduce the coin scratching property.
The aqueous varnish for paint used here may be commercially available at general stores, but can be used as long as it has the same composition as that.

  The aqueous varnish for paint is preferably contained in an amount of 1 to 5% by weight in the white ink containing the coin-abrasive inorganic oxide particles and the aqueous varnish for paint. If it is less than 1% by weight, the effect of preventing bleeding is small, and if it exceeds 5% by weight, not only the physical properties of the ink become suitable for printing, but also the printing press may be adversely affected.

  In addition, as the coin rubbing inorganic oxide particles, any material harder than coins can be used, but generally one or more of titanium dioxide, aluminum oxide, silica and the like are used, and the content thereof Considering the colorability due to coin rubbing, it is preferably 40% by weight or more in the white ink, and preferably 65% by weight or less in order to obtain physical properties that can be used as ink.

  The white ink is produced, for example, by mixing an aqueous varnish for paint with a white ink for offset printing containing coin-scratching inorganic oxide particles.

  The scratch printing layer is printed with halftone dots, and the density is preferably 60 to 90%. If it exceeds 90%, the concealed image may be visually recognized before rubbing, and if it is less than 40%, it may be difficult to visually recognize because the color is small when rubbing with coins. Further, it is preferable to print the scratch print layer with a camouflage pattern because the secret image becomes more difficult to visually recognize due to the camouflage effect.

In the present invention, the secret image is printed on the scratch printing layer with a transparent or white ink or toner, or handwritten with a transparent or white ink.
In the case of handwriting, it is preferable to use transparent or white ink as a writing instrument. For example, using a transparent varnish as a pen or using a white pencil can be used.

  The scratch sheet of the present invention is printed on a high-quality paper with a white ink containing coin-scratching inorganic oxide particles and an aqueous coating varnish using an offset printing machine, and a secret image is handwritten on the obtained scratch medium. Or manufactured by printing.

Claims (7)

It is a scratch sheet that can be visually recognized by coloring it like a secret image by rubbing with a coin,
A scratch printing layer printed with white ink containing coin-scratching inorganic oxide particles and a water-based varnish for paint on fine paper is provided.
A scratch sheet, wherein the secret image is provided with transparent or white ink or toner thereon.   The scratch sheet according to claim 1, wherein the scratch printing layer is printed with halftone dots.   The scratch sheet according to claim 1 or 2, wherein the scratch printing layer is further printed with a camouflage pattern.   A scratch medium for providing the scratch sheet according to any one of claims 1 to 3, wherein the scratch is printed on a high-quality paper with a white ink containing coin-scratching inorganic oxide particles and an aqueous coating varnish. A scratch medium comprising a printing layer.   5. The scratch medium according to claim 4, wherein the scratch printing layer is printed with halftone dots.   6. The scratch medium according to claim 4, wherein the scratch printing layer is further printed with a camouflage pattern.   A white ink for printing and providing the scratch printing layer according to any one of claims 1 to 6, wherein the white ink contains coin-abrasive inorganic oxide particles and an aqueous coating varnish.