JP6613642B2 - Anti-counterfeit media - Google Patents

Description

  The present invention relates to an anti-counterfeit medium used for certificates, securities, cash vouchers and the like. The anti-counterfeit medium of the present invention has a secret image that is difficult to recognize by naked eye observation, and the secret image can be easily recognized by irradiating the anti-counterfeit medium with ultraviolet rays. Whether or not the forgery prevention medium is authentic can be determined based on the presence or absence of the secret image.

  Anti-counterfeit media having a secret image that can be easily recognized by UV irradiation are well known. This anti-counterfeit medium is generally obtained by printing the secret image with a colorless and transparent printing ink containing a phosphor excited by ultraviolet rays. Since this secret image is printed with a colorless and transparent printing ink, it is difficult to recognize it under normal light. On the other hand, when the excitation light is irradiated, the phosphor in the ink absorbs the excitation light and emits visible light, so that the secret image is visualized and easily recognized.

  By the way, in order to increase the whiteness of the certificate paper, a bluing agent or a fluorescent whitening agent may be added. In general, these papers deteriorate with time and change so as to absorb blue light having a short wavelength, and with this deterioration, the paper becomes brown, which is a complementary color of blue. Therefore, by adding a phosphor that emits blue light with ultraviolet light as excitation light to the paper as the bluing agent or fluorescent whitening agent, the blue light component absorbed with time deterioration is compensated, and the paper is made white. I will show you.

  In this way, when the secret image is printed on the paper to which the phosphor is added, when the excitation light (ultraviolet light) is irradiated to the secret image, the secret image is emitted and the entire surface of the paper is also emitted. There was a problem that it was difficult to recognize.

  For this reason, Patent Document 1 proposes a forgery prevention medium in which a secret image is printed and formed on a sheet to which a phosphor is added using ink that absorbs excitation light. When the anti-counterfeit medium is irradiated with excitation light (ultraviolet light), the entire surface of the paper emits light, but the secret image provided in a part of the medium does not emit light, so that the secret image looks black. For this reason, the secret image can be easily recognized.

JP 11-34564 A

  By the way, these cash vouchers and the like are often printed with thin lines with thin lines. Since these tint blocks are printed with UV-absorbing ink, when the secret image is printed on the tint block with UV-absorbing ink to create a cash voucher, etc., if the gold voucher is irradiated with excitation light (ultraviolet rays) In addition to the secret image, the background pattern also appears black. For this reason, there is a problem that it is difficult to recognize the secret image.

  Therefore, the present invention presupposes a base material sheet containing a phosphor, regardless of whether or not a tint block is printed on the base material sheet. The object is to provide a prevention medium.

That is, the invention according to claim 1 is configured to include a base sheet containing a phosphor, and a secret image and a visible image provided on the base sheet,
The secret image is composed of a colorless and transparent ink that absorbs the excitation light of the phosphor, and is composed of a latent image portion and a background portion around the latent image portion. The line for the latent image)
The visible image is made of colored ink that absorbs the excitation light of the phosphor, and is formed across the latent image portion and the background portion. It is a forgery-preventing medium characterized by being composed of shifted lines (visualized lines).
Next, the invention according to claim 2 is configured to include a base sheet containing a phosphor, and a secret image and a visible image provided on the base sheet,
The secret image is composed of a colorless and transparent ink that absorbs the excitation light of the phosphor, and is composed of a latent image portion and a background portion around the latent image portion. The line for the latent image)
The visible image is made of colored ink that absorbs the excitation light of the phosphor, and is formed across the latent image portion and the background portion, and crosses the latent image line. This is a forgery prevention medium characterized by being composed of lines (visualized lines).

  According to the first aspect of the present invention, the secret image and the visible image are formed on the base material sheet containing the phosphor. And since this secret image is comprised with the colorless and transparent ink, it is difficult to recognize this under normal light.

  In addition, since this secret image is composed of ink that absorbs the excitation light of the phosphor, when the excitation light is irradiated, the entire surface of the substrate sheet emits light, but the secret image does not emit light. Therefore, it is visualized as a black color image. Further, since the visible image is also composed of ink that absorbs the excitation light, when the excitation light is irradiated, the visible image is also visualized as a black color image. That is, when the excitation light is irradiated, the secret image and the visible image appear black in the emitted base material sheet.

  The secret image is composed of a latent image portion composed of lines for latent images and a background portion around the latent image portion. The visible image is extended across the latent image portion and the background portion. Since the line is composed of visualized lines having a pitch shift, the latent image line is located between the visualized lines in the latent image portion. On the other hand, since there is no latent image line between the visualized lines in the background part, the line density of the latent image part and the line density of the background part are different. It becomes easy.

  Even if this image for image constitutes a copy-forgery-inhibited pattern or a copy-forgery-inhibited pattern is printed separately from the image for visible image, the secret image can be easily recognized when irradiated with excitation light. .

  Next, the invention according to claim 2 is directed to a visible image that intersects the latent image line, instead of forming the visualized image by a visualized line that is shifted in pitch from the latent image line. It is composed of chemical lines.

  When this forgery prevention medium is irradiated with excitation light, the latent image lines intersect with the visualized lines in the latent image portion, so that moire is generated. On the other hand, since there are no latent image lines in the background, no moire occurs. As a result, the secret image can be easily recognized. Of course, it is easy to recognize the secret image even if the image for image constitutes a background pattern or the background pattern is printed separately from the image for visualization.

It is a top view which shows the example of the forgery prevention medium of this invention. It is explanatory drawing which shows the 1st example of the secret image of this invention. It is explanatory drawing which shows the 1st example of the image for visible images of this invention. It is explanatory drawing which shows the state which printed both the 1st example of the secret image, and the 1st example of the image for visible images. It is explanatory drawing which shows the 2nd example of the secret image of this invention. It is explanatory drawing which shows the 2nd example of the image for visible images of this invention. It is explanatory drawing which shows the state which printed both the 2nd example of the secret image, and the 2nd example of the image for visible images.

  Hereinafter, the present invention will be described by way of specific examples. FIG. 1 shows a receipt as an example of an anti-counterfeit medium. Of course, in addition to the receipt, securities, cash vouchers, identification cards, and the like may be used as a forgery prevention medium.

  This anti-counterfeit medium is configured by forming a printed image on a base sheet. The base sheet needs to contain a phosphor such as a so-called bluing agent or a fluorescent brightening agent. For example, it is a paper substrate made by adding phosphor and making paper. Moreover, the base material sheet comprised by apply | coating fluorescent substance with the resin binder on the surface may be sufficient.

  As can be seen from FIG. 1, various printed images are formed on the forgery prevention medium. In this example, image 1 (characters of “receipt”) indicating the type of the forgery prevention medium is printed. In this example, the tint block 2 is printed. The receipt shown in FIG. 1 displays a receipt amount and the like, which is displayed for convenience of explanation, and of course is entered when the receipt is issued.

  And the secret image needs to be formed in the forgery prevention medium of this invention. In FIG. 1, reference numeral 3 denotes an area where the secret image is formed, and the letter “N” of the alphabet is provided as the secret image. In addition to this, the forgery prevention medium of the present invention needs to have a visible image formed thereon, and the tint block can also be used as the visible image. However, a visible image may be formed separately from the tint block.

  The secret image N is printed with a colorless and transparent ink that absorbs the excitation light of the phosphor. This ink can be produced with a resin binder and a colorless and transparent ultraviolet absorber as main components. Examples of the colorless and transparent UV absorber include salicylic acid UV absorbers, benzophenone UV absorbers, benzotriazole UV absorbers, and cyanoacrylate UV absorbers. All are known ultraviolet absorbers. Commercially available UV absorbers include UVINUL3035 manufactured by BASF.

The secret image N is composed of a latent image portion and a surrounding background portion, and the latent image needs to be composed of lines (latent image lines). The background portion may be plain or may be provided with a line (background line) having a pitch shifted from the latent image line. FIG. 1 shows an example of a secret image N in which a latent image line 31a is formed by straight parallel lines, and a background line 31b is formed by linear parallel lines shifted by a half pitch. The pitch of the latent image parallel lines 31a and the pitch of the background parallel lines 31b are the same, and the extending direction is also the same. In this example, the two are shifted from each other by about 1/2 pitch, but the present invention is not limited to this, and may be shifted by 1/3 pitch. In this example, both the latent image line 31a and the background line 31b are composed of straight lines, but may be curved lines such as wavy lines. For example, among the many curves that make up the tint block, it is possible to configure the curve of a part of the area by shifting the pitch with respect to the surrounding curves, and this area can be used as the latent image part and the surrounding area as the background part. It is. In FIG. 2, these lines 31a and 31b are shown for convenience, but they are both colorless and transparent and are difficult to identify with the naked eye.

  Next, the visible image is formed by printing with colored ink that absorbs the excitation light of the phosphor. As such an ink, an ink containing various colored pigments can be used. It may be an ink usually used for printing.

  The visible image is formed across the latent image portion and the background portion, and needs to be configured by a line (visualized line) 32b having a pitch shifted from the latent image line. Yes (see FIG. 3). When the secret image N has the background line 31b, the visualized line 32b needs to be printed over the background line 31b. For this reason, when the background line 31b is composed of straight parallel lines, the visualized line 32b is also composed of linear parallel lines, and the pitch, the extending direction and the position are also background lines. It is the same as 31b.

  As described above, a tint block composed of thin lines can also be used as this image for visible image. The same applies to the case where the tint block is composed of curves. That is, a large number of curves having the same bending method are arranged to form a curved line, and a tint block composed of the curved line can be used as the visible image 32b.

  FIG. 4 shows a state in which these visible image and secret image N are printed in an overlapping manner. As can be seen from this figure, the latent image line 31a is positioned between the visualized lines 32b in the latent image portion. On the other hand, in the background portion, the latent image line 31a does not exist between the visualized lines 32b, and the visualized line 32b and the background line 31b overlap, so the line density and background of the latent image portion overlap. The linear density of the part will be different. However, since the latent image line 31a is colorless and transparent and is difficult to recognize, only the visible image composed of the visualized line 32b can be observed with the naked eye.

  Then, when the secret image forming area 3 in which both the visible image and the secret image N are formed is irradiated with excitation light, the phosphor contained in the base material sheet absorbs the excitation light and emits visible light. To do. For example, blue light having a short wavelength among visible light. On the other hand, since both the visible image and the secret image N absorb and block the excitation light, both the visible image and the secret image are visualized as black images. As can be seen from FIG. 4, the secret image N having a high linear density can be easily recognized.

  In addition, when a transparent film on which the same image as the secret image N is printed with colored ink is aligned and superimposed on the secret image formation region 3, the secret image N can be easily recognized without irradiating excitation light. Is possible.

  Next, FIG. 5 to FIG. 7 are examples in which both the background lines and the visualized lines are configured by lines intersecting the latent image lines, and FIG. FIG. 6 shows a visible image. FIG. 7 shows a state in which the visible image and the secret image N are overprinted.

  In this example, the latent image portion is composed of a latent image line 31c extending in the vertical direction (see FIG. 5). On the other hand, the background portion around the latent image portion is composed of a background line 31d that intersects the latent image line 31c at an angle of about 30 degrees (see FIG. 5).

  The visualized image is composed of visualized lines 32d printed on the background lines 31b. That is, the visualized line 32d has the same pitch, extending direction, and position as the background line 31d.

A fluorescent ink having the following composition was printed on the entire surface of high-quality paper (basis weight 81.4 g / m ² ) to obtain a base sheet.

  And the secret image was printed on this base material sheet with the colorless and transparent ultraviolet absorptive ink of the following composition. This secret image is composed of a latent image portion and a surrounding background portion. As shown in FIG. 2, the latent image portion is composed of lines (latent image lines). This latent image line is constituted by a line (background line) shifted by 1/2 pitch.

  Next, a visible image was printed on the entire surface of the base material sheet across the latent image portion and the background portion by using a red ultraviolet absorbing ink having the following composition. This visible image is composed of lines (visualized lines) printed on the background lines and forms a background pattern as a whole.

[Fluorescent ink composition]
10 parts by weight of BASF fluorescent pigment (TINOPAL OB) 90 parts by weight of medium (FD Carton X medium) manufactured by Toyo Ink Co., Ltd.

[Transparent UV-absorbing ink composition]
BASF UV absorber (UVINUL3035) 10 parts by weight Toyo Ink Mfg. Medium (FD Carton X Medium) 90 parts by weight.

[Red UV absorbing ink composition]
9 parts by weight of an ultraviolet absorber manufactured by BASF (UVINUL 3035) 89 parts by weight of a medium (FD Carton X medium) manufactured by Toyo Ink Manufacturing Co., Ltd. 2 parts by weight of a pigment (FD Carton X red) manufactured by Toyo Ink Manufacturing Co., Ltd.

  The anti-counterfeit medium thus obtained can only recognize a visible image printed with a red UV-absorbing ink as a background pattern under ordinary light, and cannot recognize a secret image.

  When this anti-counterfeit medium was irradiated with ultraviolet rays having a wavelength of about 365 nm, the entire surface of the substrate sheet emitted light, and both the visible image and the secret image looked black. Then, the latent image line of the secret image is located between the visualized lines of the image for visualization, and the line density of the latent image part becomes larger than the line density of the surrounding background part, thereby clarifying the secret image. I was able to recognize.

  Next, the same image as the secret image is printed on a 50 μm-thick transparent film with process black ink, and this transparent film is superimposed on a forgery prevention medium, so that the secret image N is clearly recognized even under ordinary light. I was able to.

1: Print image indicating the type of anti-counterfeit medium 2: Background pattern 3: Secret image forming area 31a: Latent image parallel line 31b: Background parallel line 32b: Filter parallel line 31c: Latent image parallel line 31d: Background parallel line 32d: Parallel line for filter

Claims (2)

A substrate sheet containing a phosphor, and a secret image and a visible image provided on the substrate sheet,
The secret image is composed of a colorless and transparent ink that absorbs the excitation light of the phosphor, and is composed of a latent image portion and a background portion around the latent image portion. The line for the latent image)
The visible image is made of colored ink that absorbs the excitation light of the phosphor, and is formed across the latent image portion and the background portion. An anti-counterfeit medium characterized by being composed of misaligned lines (visualized lines). A substrate sheet containing a phosphor, and a secret image and a visible image provided on the substrate sheet,
The secret image is composed of a colorless and transparent ink that absorbs the excitation light of the phosphor, and is composed of a latent image portion and a background portion around the latent image portion. The line for the latent image)
The visible image is made of colored ink that absorbs the excitation light of the phosphor, and is formed across the latent image portion and the background portion, and crosses the latent image line. An anti-counterfeit medium characterized by comprising lines (visualized lines).

Images