JPH01214887A - Sheet protected from copy, recording method, and recorded material protected from copy - Google Patents

Abstract

PURPOSE:To prevent a recording sheet from being copied by an elec- trophotographic copying machine by approximating the reflection factor of a color part protected from copy on the recording sheet and that of a recorded information part to each other and making them different in hue. CONSTITUTION:Dots, lines, characters, etc., are used as shapes of color parts protected from copy which are formed on at least one face of a plastic sheet, a synthetic paper, or the like by gravure printing, offset printing, or the like. Color parts and recording parts are formed with coloring matters whose reflection factor is approximately equal to recording parts but is different in hue from those. That is, V10Y (hue: yellow) and N7 (hue: gray), V5G (Hue: green) and V5YR (hue: yellowish red), or the like are used. Thus, though recorded information can be read by naked eyes because of the difference of hue, recorded information is difficult to read when being copied by the electrophotographic system because they are copied with the same density.

Description

Detailed Description of the Invention (Industrial Field of Application) The present invention relates to a copy prevention sheet recording method and a copy prevention recorded material, and more specifically, the present invention relates to a copy prevention sheet recording method and a copy prevention recorded material, and more specifically, depending on the ordinary electrophotographic copying machine, it is difficult to clearly print or record information. This invention relates to a copy-preventing sheet, a recording method, and a copy-preventing recorded material that is difficult to copy.

(Prior art) Conventionally, with the development of copying technology, it has become easy to copy all kinds of things, and for example, problems such as counterfeiting of expensive books, securities, banknotes, etc., duplication or secret leakage of important documents, secret documents, etc. problems occur frequently.

In order to prevent such forgery and secret leaks, anti-copying sheets have been proposed, but conventional anti-copying sheets are made by, for example, coloring the surface of a base sheet such as paper. The printed or recorded information can be read with the naked eye, but when it is copied using an electrophotographic copying machine, the entire surface is copied in black, making the copied characters difficult to read or illegible.

(Problem to be solved by the invention) The above-mentioned conventional anti-copying sheet has a colored surface, and the coloring absorbs light source light from an electrophotographic copying machine, and absorbs it by printed or recorded characters. The colored portion is colored, for example, dark brown, so that it can absorb most of the light from the light source, because it becomes difficult to read the characters and the like on the copy when the light source is brought close to the light source.

Therefore, there is a drawback that characters printed or recorded in black ink or the like are very difficult to read with the naked eye.

Therefore, there is a need for the development of a copy prevention technique that can prevent copying, but also allows printed or recorded information to be easily read with the naked eye.

Therefore, an object of the present invention is to provide a copy-preventing sheet, a recording method, and a copy-preventing recorded material that can sufficiently prevent copying without excessively coloring the print or recording surface.

(Means for Solving the Problems) The above objects of the present invention have been achieved by the following present invention.

That is, the present invention consists of four inventions, and the first invention is that the surface of at least one of the recording sheets is regularly and/or irregularly coated with a dye that has almost the same reflectance as the dye used for recording but has a different hue. A second invention is a copy prevention sheet characterized by forming regular colored areas, and a second invention provides a surface of the copy prevention sheet of the first invention with a reflectance substantially the same as that of the colored areas provided on the surface. A recording method is characterized in that information is recorded using dyes having different hues, and the third invention is a recording method that records information on the surface of a recording sheet,
A recording method is characterized in that regular or irregular colored areas are formed on the recording surface using a dye having substantially the same reflectance as the dye used for recording but having a different hue, and the fourth invention is These are recorded materials obtained according to the second and third inventions above.

(Function) By bringing the reflectance of the anti-copying colored part of the recording sheet closer to the recording information part and changing the hue of both, information can be read with the naked eye by the difference in hue, but electrophotographic copying machines Since the entire image is copied at the same density, the recorded information is difficult or impossible to read from the copy.

(Preferred Embodiments) Next, the present invention will be described in more detail by citing preferred embodiments of the present invention.

The recording sheet used in the present invention is generally used for recording numerically (such as general paper, plastic film, synthetic paper, etc.).
For example, it may be used for printing, printing, writing, etc., and is not particularly limited.

The colored portion for preventing copying formed on at least one side of the recording sheet may be in any shape such as solid printing, dots, lines, letters, symbols, patterns, background patterns, etc., but dots, lines, letters, etc. are particularly preferable. Or it is a background pattern.

The pigment that forms the colored part is determined by its relationship with the pigment used for recording, and it is necessary that the colored part and the recording part have almost the same reflectance and have different hues. be. Specific examples of dyes having such a relationship include those shown in the first diagram.

Referring to Figure 1, for example, VIOY (hue: yellow)
and N7 (hue: gray) or V2C (hue: green and V5YR
(Hue: yellow-red), but its reflectance (co
py density (vertical axis) are almost the same, and by forming the colored part and the recording part using pigments with such a relationship, recorded information can be read with the naked eye by the difference in hue, but electrophotography Since the colored portion and the recorded portion are mixed and reproduced with substantially the same density, it becomes difficult or impossible to read the recorded information.

Another example of dyes having such a relationship is to select and combine dyes located on the right side and left side of the curve with similar reflectances, as shown in Figure 1. Just use it. The pigment groups represented by symbols in FIG. 1 and their hues are as follows. In the present invention, having substantially the same reflectance means that the difference in copy density values on the vertical axis in FIG. This is undesirable because the copy-preventing colored portion and the recorded information are copied at different densities in the product, making the recorded information legible with the naked eye.

VIOYR Disazo Yellow Yellow Red Carmine 6B VIOY Disazo Yellow Yellow VIORP
Carmine 6B Tsua Yuab, - Red Purple V5RP Carmine 6B Cyanine Blue Red Purple VIOP Carmine 6B
#'Cyanip7. - Red-purple V5R Carmine 6B Surezoie. -Red VIOR Carmine 6B Disazo Yellow Red V5PB Cyan Blue Blue Purple Carmine 6
B VIOGY Disazoi xg-Green Cyanine Blue 5G Cyanine Blue Disazo Yellow Green VIOBG Cyanine Green Blue Cyanine Blue VIOB 'A0'Gree' Blue Cyanine Blue V5Y Disazo Yellow Coloring to prevent copying on at least one surface of the yellow recording sheet The copy may be formed by any method such as gravure printing, offset printing, letterpress printing, flexo printing, various printers, handwriting, etc. In the case of printing, overprinting with a single color machine, multicolor with a two color machine or more Overprinting may be performed on the machine, and it is preferable that the shape of the colored part overlaps at least a portion of the recorded information, so if it is not solid, the space should be at least narrower than the normal character size. Preferably, lines, symbols, characters, background patterns, etc.

One example of the recording method of the present invention is to use one of the dyes having the above-mentioned relationship on the surface of the above-mentioned anti-copying sheet,
This is a method of recording information by printing, a printer, or writing. Another recording method of the present invention is to record information in advance on a recording sheet using one of the related pigments as described above, and then to record information on the surface with another pigment. These are methods of forming a colored portion to prevent copying, and both methods can achieve the same effect.

In the present invention, the density of the printing ink or other ink forming the anti-copying colored area and the recorded information area is determined by adjusting the density of the dye used so that the reflectance of both the colored area and the recorded information area are close to each other. It is necessary to adjust the concentration.

(Effects) According to the present invention as described above, by bringing the reflectance of the anti-copying colored portion of the recording sheet closer to the recording information portion and further changing the hue of both, information cannot be read with the naked eye based on the difference in hue. However, with an electrophotographic copying machine, the entire image is copied at the same density, making it difficult or impossible to read the recorded information from the copy.

Next, the present invention will be specifically explained with reference to Examples.

Example 1 A film for plate making was obtained by photographing a newspaper. This film was layered with a 133L, 15°, 80% flat screen film to create a background printing plate using 23 plate (manufactured by Fuji Film). Using this plate, print ink A with the following composition on each of high-quality paper, book paper, mud coat paper, and art paper so that the solid printing part filter density is 0.45. A copy prevention sheet was obtained.

Next, text was printed using printing ink B having the following composition and a normal letter plate so that the blue filter density was 0.57.

m To soil Dish bottom Ecarbon black 5.6% Calcium carbonate 20.0% Manganese octylate 0.5% Varnish
73.9% I2j''l Cyanine Blue 2.4% Disazo Yellow 2.8% Titanium Oxide
19.2% manganese octylate 0.5% varnish
75.1% The text printed on the above printed matter was easily legible with the naked eye, but this was not possible with an electrophotographic copying machine (
FUJI

Example 2 Similar results were obtained even if the ink used in Example 1 was reversed.

Example 3 A film for plate making was obtained by photographing a newspaper. This film was layered with a 100L, 45°, 80% flat screen film to create a background printing plate using 28 plate (Fuji Film Group). This plate was used to print on high-quality paper, book paper, mud coated paper, and art paper using printing ink C having the following composition so that the blue filter density of the solid printing area was 0.60. A copy prevention sheet was obtained.

When this sheet was used as a copy paper and ordinary characters were copied, the copied characters were legible with the naked eye, but when this sheet was copied again, it was impossible to read with the naked eye.

Lz Dotategumi Bottom Nidiane Blue 2.6% Disazo Yellow 3.0% Calcium Carbonate 17.0% Manganese Octylate
0.5% varnish
76.9% Example 4 Flat screen 40L, 15°, 50% film and flat screen 150L
, 75° and 80% film to create a background printing plate using a PS plate (Fuji Film Group). Using this plate and printing ink D having the following composition, high-quality paper, book paper,
A copy prevention sheet of the present invention was obtained by printing on mud coat paper and art paper so that the blue filter density of the solid area was 0.59.

Next, text was printed using printing ink E having the following composition using a normal letter plate so that the red filter density of the solid area was 0.53.

m Royal dish bottom dianine blue 2.4% disazo yellow 2.8% glass fine powder 15.0% manganese octylate
0.5% varnish
79.3% Edangumi Kabu Yujisu Azo Yellow 6.6% Carmine 6B 6.2% Manganese octylate 0.5% Varnish
86.7% The printed text on the above printed matter was easily legible with the naked eye, but it was printed using an electrophotographic copying machine (F[JJI XEROX 3870)"l'
When copying, some of the letters were copied overlapping the large halftone dots, making the letters printed later illegible.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing preferred combinations of hues used in the present invention. Applicant Taniguchi Ink Manufacturing Co., Ltd.

Claims (4)

[Claims] (1) A recording sheet is characterized in that regular and/or irregular colored areas are formed on at least one surface of the recording sheet using a pigment that has approximately the same reflectance as the pigment used for recording but has a different hue. Anti-copying sheet. (2) Information is recorded on the surface of the sheet according to claim (1) using a pigment that has almost the same reflectance as the colored portion provided on the surface but has a different hue. recording method. (3) Recording information on the surface of a recording sheet, and forming regular or irregular colored areas on the recording surface using a dye that has approximately the same reflectance as the dye used for recording but has a different hue. A recording method characterized by. (4) A copy-protected recorded material obtained by the method described in claim (2) or (3).