JP3421381B2 - Falsification prevention sheet - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a falsification prevention sheet, and more particularly, to a visually feasible sheet suitable for use in various tickets, gift certificates, stock certificates, custody certificates, and the like. The present invention relates to a falsification preventing sheet that can easily identify falsification of print information. 2. Description of the Related Art In a conventional printing sheet, a print image fixing layer is generally provided on the sheet, and printing is performed using toner on the print image fixing layer. However, conventionally, the fixability of the toner is high, and there is no stable print image fixing agent layer.
Although various improvements have been attempted, a print image fixing layer that is sufficiently satisfactory has not yet been proposed. Due to the insufficient fixability of such a toner, it is not a difficult task to scrape off the printed portion with the toner fixed to the print image fixing layer together with the print image fixing layer without damaging the sheet base material. . [0003] For this reason, conventionally, printing such as the amount of money of various tickets, gift certificates, stock certificates, security deposit certificates, etc., prepared by printing predetermined information on a printing sheet. There is a possibility that various tickets, gift certificates, stock certificates, protection deposit certificates, and the like may be falsified by shaving off portions and newly entering numbers and characters in the shaved portions. However, in order to visually identify such tampering, careful observation by a skilled person is required, and there has been an inconvenience that it is extremely difficult to find tampering at a use site where quick processing is required. [0004] It is an object of the present invention to solve this inconvenience and to provide a falsification preventing sheet that can easily identify the presence or absence of tampering visually. [0005] A sheet for falsification prevention according to the present invention is provided with a print image fixing layer comprising a composition of silica and a binder on at least a predetermined portion of a sheet substrate,
A plasticizer capsule is added to this print image fixing layer. The plasticizer capsule may be added to the print image fixing layer in a state of mixing as a whole or in a state of mixing only in the surface portion. [0006] When the printed portion of the toner fixed on the print image fixing layer is scraped off, the plasticizer capsule is destroyed together with the print image fixing layer, and the plasticizer and the toner come into contact with each other.
Upon dissolution, the dirt diffuses and penetrates the sheet, leaving traces of tampering. With this trace, the presence or absence of tampering can be easily and quickly identified visually. A preferred embodiment in which the present invention is applied to a deposit receipt will be described in detail with reference to the accompanying drawings. Here, FIG. 1 is a schematic cross-sectional view of a filing certificate before printing, which is a falsification prevention sheet, FIG. 2 is a schematic plan view showing the printed filing certificate, and FIG. 3 is a cross-sectional view taken along line AA of FIG. FIG. 4 is a schematic partially enlarged plan view showing a tampered state. As shown in FIG. 1, a falsification preventing sheet 1 to be used as a receipt is provided with a print image fixing layer 3 on the entire surface of a sheet material 2 made of paper. In 3, a plasticizer capsule 4 is entirely mixed. The print image fixing layer 3 is made of fine silica powder 50 to
It is formed by applying a composition consisting of 95% by dry weight and 5 to 50% by dry weight of a binder.
About 2% of fine silica powder dispersed at 20% solids in water
5 to 45%, partially hydrolyzed polyvinyl alcohol in a 10% solution as a binder 5 to 50%, and water about 25 to
45%. More specifically, Cabo Sperse S-109 (trade name) is used as fine silica powder.
5.95%, 10% Vinol 5 as binder
28.10% for 40 (trade name) and 35.95% for water
And the coating weight was adjusted to 0.4 to 2.
It is formed by coating at 8 g / m ² , for example, 1.1 g / m ² / side. The application of the composition to the two surfaces of the sheet substrate can be performed by a conventionally used general method such as flexo, gravure, reverse roll, or air knife. On the other hand, the solvent used for the plasticizer capsule 4 is a hydrophobic organic solvent having a boiling point of 40 ° C. or higher.
Preferred are those capable of dissolving image forming materials such as electrophotographic toners and inks. Examples thereof include phthalic acid esters, adipic acid esters, sebacic acid esters, phosphoric acid esters, mineral oils, aliphatic hydrocarbons and aromatic hydrocarbons. Hydrogen hydrocarbon solvents can be mentioned. The plasticizer capsule 4 has a particle size of 0.1 to 20 μm, preferably 1 to 20 μm.
10 to 10 μm, more preferably 3 to 7 μm. The breaking strength of the plasticizer capsule 4 is set so as not to be broken by a normal handling or printing operation, but to be broken when an unusually strong force such as shaving at the time of falsification is applied. Next, four examples of preparation of the plasticizer capsule 4 will be described. In the first example, dibutyl phthalate (DB) was dissolved in 300 parts of an aqueous solution prepared by dissolving a styrene-maleic anhydride copolymer (trade name: Clipset-520) together with a small amount of sodium hydroxide and adjusting to 5% by weight and pH 4.1.
P) After emulsifying and dispersing 200 parts, to obtain an O / W type emulsion, 20 parts of melamine was added to 38.6 parts of a 37% aqueous formaldehyde solution, and the pH was adjusted to 9.0 with an aqueous sodium hydroxide solution. The melamine-formalin prepolymer, which was heated to 80 ° C. in 15 minutes and dissolved therein, was added with stirring, the temperature of the system was raised to 80 ° C., kept for 2 hours, then cooled while stirring, and cooled with melamine resin. Was used as a wall material to obtain a DBP-encapsulated microcapsule dispersion having an average particle size of 5.0 μm. A second example is a methyl vinyl ether maleic anhydride copolymer (trade name GANTREZ AN-16).
9) was dissolved and 200 parts of dimethyl phthalate (DMP) was emulsified and dispersed in 300 parts of an aqueous solution adjusted to 6% by weight to obtain an O / W emulsion. 0
20 parts of urea and 2 parts of resorcinol were added to 37 parts of a 37% aqueous formaldehyde solution, the pH was adjusted to 9.0 with an aqueous sodium hydroxide solution, and a prepolymer heated and dissolved to 80 ° C. in 15 minutes was added with stirring. The temperature of the system was raised to 80 ° C., kept for 2 hours, and then cooled with stirring. The urea / phenol resin was used as a wall material and the average particle size was 6.
A microcapsule dispersion containing 0 μm DMP was obtained. In a third example, a partially saponified polyvinyl alcohol (trade name: UP-240G) was dissolved in 291.6 parts of an aqueous solution adjusted to 3% by weight, and dioctyl phthalate (DOP) was added to 137.2 parts. Terephthalic acid chloride (T
(PC) A solution in which 15 parts were dissolved was emulsified and dispersed to obtain an O / W emulsion, and 6.9 parts of diethylenetriamine, 5.7 parts of sodium carbonate, and 0.7 parts of sodium hydroxide were added to the dispersion. Of a solution dissolved in 53 parts of ion-exchanged water is added with stirring, and the mixture is sufficiently reacted with stirring for 20 hours.
This is a dispersion containing the encapsulated microcapsules. In a fourth example, 137.2 parts of dioctyl adipate (DOA) was dissolved in 291.6 parts of an aqueous solution prepared by dissolving partially saponified polyvinyl alcohol (trade name: UP-240G) and adjusting to 3% by weight. A solution in which 31.7 parts of polymethylene polyphenyl isocyanate (trade name: MR-200) was dissolved was emulsified and dispersed to obtain an O / W emulsion, and 11.8 parts of diethylenetriamine was added to the dispersion. Of a solution dissolved in a part of ion-exchanged water is added while stirring.
The mixture was sufficiently reacted with stirring for 0 hour to obtain a DOA-encapsulated microcapsule dispersion having an average particle size of 5.5 μm using a polyurea resin as a wall material. In the falsification prevention sheet 1 described above, a title 5 "Deposit certificate", an issue number 6, and an amount entry column 7 indicate amount information 8, a confirmation statement 9, a deposit date 10, an issuing company name 11, The person's name 12 is printed using a known printer, and when the person in charge stamps it, the deposit certificate 1 shown in FIGS.
3 is created. Here, assuming that the numeral "0" of the tens place of the money amount information 8 which is a part of the printed portion of the deposit certificate 13 is removed and a new numeral 14, for example, "5" is printed, the numeral " Since the plasticizer capsule 4 is also destroyed when the "0" is scraped off, as shown in FIG. 4, a portion corresponding to the destroyed plasticizer capsule 4 at a portion where a new numeral 14, "5" is printed. Means that the toner is softened / dissolved, the dirt spreads and penetrates into the sheet substrate 2,
Thus, the new numeral 14 of “5” can be visually and easily identified as falsified. The present invention is not limited to the above embodiments. For example, the material of the sheet substrate 2 may be paper, plastic film, synthetic paper, laminated sheet of paper and plastic sheet, or the like. It can be appropriately selected from various possible materials and used. Further, the plasticizer capsule 4 may be added only to a portion where information to be prevented from being tampered, such as the money amount entry column 7, is printed. Further, the present invention can be used in combination with other tampering prevention techniques. As is apparent from the above description,
According to the present invention, if the printed portion of the toner fixed to the print image fixing layer is scraped off, the plasticizer capsule is also destroyed, so that the newly printed toner is softened and dissolved by the plasticizer, and the stain spreads. Thus, the presence or absence of tampering can be visually and easily and quickly identified, thereby contributing to the prevention of tampering.

[Brief description of the drawings] FIG. 1 is a schematic sectional view of a tampering prevention sheet. FIG. 2 is a schematic plan view showing a printed receipt. FIG. 3 is a sectional view taken along line AA of FIG. 2; FIG. 4 is a schematic partial enlarged plan view showing a tampered state. [Explanation of symbols] 1 Falsification prevention sheet 2 Sheet substrate 3 Printed image fixing layer 4 plasticizer capsule 7 Amount entry field 8 Amount information 13 Certificate of deposit 14 New numbers 15 Bleed

Claims (1)

(57) [Claim 1] A print image fixing layer comprising a composition of silica and a binder is provided on at least a predetermined portion of at least one surface of a sheet substrate, and a plasticizer capsule is provided on the print image fixing layer. A sheet for falsification prevention characterized by having been added.