JP2001021550A - Counterfeit paper money detection liquid for porous rubber stamp - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make detectable a counterfeit paper money by applying a liquid containing iodine to a paper money and observing the change in color of a part with the liquid applied thereto a prescribed time later. SOLUTION: A liquid is applied to a paper money to detect a counterfeit paper money and the change in color of a part with the liquid applied thereto is observed visually a prescribed time later so that a genuine paper money is identified from a counterfeit paper money. When being the genuine one, the color before applying the liquid and the color after the lapse of a prescribed time is the same, however, when being the counterfeit one, the color before applying the liquid and the color after the lapse of the prescribed time is different. The part with the liquid applied thereto is changed into dark blown or bluish purple so as to identify one from the other. The liquid composed of iodine and appropriate solvent, and single or a plurality of solvents selected from the group composed of water, ketone group, ester group, ether group, alcohol group, and alkali metal iodide solution are suited thereto. Among the ketone group usable to the liquid are acetone, methyl ethyl ketone, diethyl ketone, propyl ketone, etc.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a detection liquid for a built-in liquid type porous rubber stamp for detecting a fake bill.

[0002]

BACKGROUND OF THE INVENTION Since banknotes were conceived and used, governments around the world have been worried about the problem of fake bills. Forgery of banknotes in economic activities and social life is a serious problem as disrupting social order. Banknotes are copied and printed, and in recent years the development of electronic copy technology has made it more difficult to distinguish between genuine and fake. While counterfeiting is becoming a more social problem, along with devices, devices, and machines that detect fake tags, special invisible drugs are included or printed on paper and detected by light or magnetism. A way to do this has been devised. However, many of these devices and systems are also not reliable, are mechanically expensive, and in some cases are bulky and often complex in design.

[0003]

SUMMARY OF THE INVENTION The basic object of the present invention is to provide a reliable and quick and simple operation using an easy-to-handle and inexpensive tool without the need for expensive and large equipment or complicated operations. Another object of the present invention is to provide a method for detecting a fake tag by using a small amount of a safe liquid which can be made from a chemical substance which can be easily obtained, and a liquid therefor.

[0004]

According to the present invention, a liquid is applied to a banknote to detect a fake bill, and furthermore, after waiting for a required time, a color change of a portion to which the liquid is applied can be observed and observed. By distinguishing between genuine and imitation, the problem is solved.

[0005] In the case of a genuine bill, the color before liquid application and the color after the required time have elapsed are the same. After the required time, the part to which the liquid is applied turns black from dark brown to grayish blue-purple, so that both can be distinguished.

[0006] Since banknotes were conceived and used, the fake bill problem for government agencies around the world that issue banknotes not only impaired the economic activities of nations, but also led to inter-national issues, including imports and exports. Has continued to plague government officials as a matter of trust. In addition, exchange of security papers describing private rights and obligations is indispensable in economic activities and social life, and forgery of these is also a serious social problem as disturbing the public interest order and peace of business of society. Thus, the counterfeiting problem is a major problem to be solved for security paper as well as banknotes.

The security paper is a document in which private rights and obligations having a property value are described or a paper used for the document. Typical examples of the use of this paper include checks, travelers checks, money orders, bank notes, bearer bills, bonds, stock certificates, stamps, postal money orders, identification cards, registration certificates, various government agencies. Certificates of issuance, certificates such as driving licenses, licenses and permits, ballot papers for elections, passbooks, passports, lottery tickets, admission tickets, travel tickets, receipts, coupons, vouchers, bills of lading, banks Vouchers, signature fields of credit cards, bank cards, ID cards, and the like.

[0008] The most required to detect and authenticate the authenticity of these bills and security papers is, for example,
Banks, post offices, airline tellers, sports facilities,
He is also a direct sales clerk at ticket offices and ticket collectors at theaters and in general retailing. For people in such a position, large devices, expensive devices, and complicated operations are not suitable for easily detecting and authenticating the authenticity of bills and security paper.

Banknotes and security papers are also more difficult to distinguish between genuine and fake due to the development of copying, printing and, more recently, electronic copy technology.
While the fake tag issue has become a more social issue and more secure transactions of security papers are being demanded, along with devices, devices, machines, etc. that detect fake tags and authenticate security papers, special Methods have been devised in which various chemicals are included in paper or printed, and these are detected and detected by light or magnetism such as an ultraviolet lamp or a black light. However, many of these devices and systems are also not reliable, are mechanically expensive, and in some cases are bulky and often complex in design. Therefore, there is a need for a method for detecting fake bills and imitation / counterfeit security paper by a quick and simple method.

[0010] It is well known that starch is used as a sizing agent in the production of paper. Also, James P. Casey “Pu, et al. States that treating paper with an iodine-potassium iodide solution can produce a blue color as a method of quantitatively evaluating the amount of starch as a composition in the paper.
lp and Paper Chemistry and Chemical Technology ”3r
d. vol. 3, 1894 pp (1981). However, the use of an iodine-starch reaction with an iodine-potassium iodide solution for quantitative and qualitative determination of the amount of starch in a banknote or the fact that starch is not contained or contained in a banknote contains only trace amounts chemically. There is no description about whether or not. The present inventor performed a quantitative detection of the amount of starch in a banknote by an iodine-starch reaction using an iodine-potassium iodide solution.
They found that starch in Singapore, China and Australia is almost free of starch. In addition, it was found that the paper used in the check book of the Ministry of Posts and Telecommunications, the stamp, and the paper used in the column on the back of the driver's license issued by the Public Safety Commission did not contain starch. On the other hand, commercially available general paper, for example, copy paper, bond paper,
It was also found that any paper such as form paper, imitation paper, drawing paper, and stationery contains a large amount of starch. Furthermore, various types of stock certificates and checkbooks issued by city banks were also checked for the presence of starch.Many of these security papers contained starch, and all of the security papers mentioned above contained starch. It turned out that it was not possible. Some security papers contain starch even if they are authentic, but the liquid of the present invention is effective for security papers that do not contain starch with higher security. It is obvious that whether or not the effects of the present invention can be used as security paper can be easily and quickly confirmed by actually applying the liquid of the present invention to the paper.

Based on these facts, the present inventor has completed the present invention as a method for verifying the authenticity of bills and papers requiring security, particularly the authenticity of bills.

The basic principle of the present invention is to detect and identify the authenticity of a banknote by detecting the starch in the banknote. Heretofore, many chemical reactions showing color development, discoloration or decoloration have been known. Among these numerous reactions, as a system that reflects the purpose of the present invention in the above-described reaction to starch, the materials used are inexpensive and affordable, and the detection and detection are sharp and pale to dark brown to gray-blue-purple. Attention was paid to the iodine starch reaction, which is a color change that is easily recognized as a change to a darker color. The liquid of the present invention is a yellow-brown liquid, and when applied to paper containing no starch, the color of the applied portion remains the same as the color of the paper, and the portion to which the liquid has been applied even after the required time has elapsed. Does not change color.
This is due to the fact that starch which can form a dark brown to gray-blue violet complex with the liquid is not present in genuine banknotes. On the other hand, when the liquid of the present invention is attached to a fake tag prepared using easily available paper, the liquid of the present invention reacts with starch to form a brown to gray-blue-violet complex, and the color of the liquid-applied portion changes to black. .

An important point in detecting the authenticity of a bill is to mark the bill. According to the laws of many countries, any kind of marking is often not allowed on banknotes. For this reason, the liquid of the present invention needs to be erased without leaving a trace after being stamped on a bill and subjected to detection and authentication. The liquid of the present invention also keeps this in mind, and consideration of its composition indicates how excellent the present invention is.
That is, as long as the banknote is genuine, the liquid of the present invention does not leave any trace of the liquid even when it is applied to the banknote, and the chemical component of the liquid of the present invention, which is the composition of the liquid, changes over time from the site where the liquid is applied Specifically, it is composed of a substance that is physiologically and environmentally safe and is colorless even after the substance that can be volatilized and other components are volatilized, and furthermore, the liquid of the present invention has a physiological And a concentration range that is environmentally safe for the human body.

The liquid of the present invention is harmless to the human body, has a low environmental load, and contributes to social public interest and peace of business.

The liquid of the present invention comprises iodine and a suitable solvent, and a solvent selected from the group consisting of water, ketones, esters, ethers, alcohols and alkali metal iodide solutions or a plurality of solvents is preferred. .

The ketones that can be used in the liquid of the present invention include acetone, methyl ethyl ketone, diethyl ketone, propyl ketone, isopropyl ketone, and the like.
Esters include alkyl, methyl, ethyl, propyl, isopropyl, butyl, isobutyl, pentyl,
Isopentyl, monohydric alcohols such as so-called amyl and glycerol, ethylene glycol, propylene glycol, diethylene glycol, hexylene glycol, sorbitol, alcohols selected from among polyhydric alcohols such as 1,3-propanediol, formic acid, acetic acid, There are propionic acid, lactic acid ester and the like, and ethers include alkyl alkyl ether to dialkyl ether comprising an alkyl group such as methyl, ethyl, propyl, butyl, isopropyl and isobutyl, and ethylene glycol, propylene glycol, hexylene glycol, 1, Monoalkyl ethers and dialkyl ethers of dihydric alcohols such as 3-propanediol, diethylene glycol, and triethylene glycol, etc. In addition to monohydric alcohols such as ethanol, propanol, butanol, pentanol, isopropyl alcohol, isobutyl alcohol and so-called amyl alcohol, ethylene glycol, propylene glycol, hexylene glycol, 1,3-propanediol, diethylene glycol, triethylene glycol, etc. Examples thereof include dihydric alcohols, trihydric alcohols such as glycerol, and polyhydric alcohols such as sorbitol. The term “alkali metal iodide solution” refers to an appropriate concentration of alkali metal iodide water and / or the above-mentioned ketones and esters. At least one solvent solution selected from the group consisting of, ethers and alcohols.

The alkali metal iodide in the liquid of the present invention is preferably selected from the group consisting of sodium iodide and potassium iodide.

In the liquid of the present invention, a good performance effect can be obtained by using only water as a solvent. However, alcohol such as ethanol and isopropyl alcohol, smooth writing properties, and stamping are used to enhance the quick drying property of the liquid. The polyhydric alcohols such as ethylene glycol and glycerin are used in a weight ratio to ensure smooth fluidity during permeation and to maintain the penetration of porous rubber stamps into fine continuous pores and to prevent solidification by drying the liquid on the felt core. It is also particularly preferred to include it in a proportion of about 15% to about 80%.

A particularly preferred composition of the liquid of the present invention is about 0.02% to about 3.2% by weight of iodine and alkali metal iodide, about 20% to about 85% water, about 15% to about 85%. Consists of about 80% alcohols. By changing the composition of the content composition in various ways, it is possible to vary the color tone, color density, and the time required for color development at the site where the solution of the present invention discolors when attached to starch-containing paper or fake paper. It is possible to change it.

According to an embodiment of the present invention, a liquid is applied, and after a required time, a change in color at a site subjected to the test is observed. The time required for the color change depends on the solvent composition of the liquid, the amount of starch contained in the paper and the paper surface condition of the paper, but when tested on banknotes or security paper, the liquid of the present invention is iodine-free within a few seconds to several seconds. A sharp coloration of the starch reaction is seen. If the paper does not contain any paper money or starch, or contains only trace amounts of chemicals, color change from light color to light yellowish brown due to liquid wetting of the paper at the site where the liquid is applied does not occur, and the paper money is fake In the case of paper containing starch or starch, the color of the tested site changes from colorless to pale light yellow-brown to dark brown to dark blue-purple. Iodine
-This darkening and sharp coloration of the starch reaction
Even if a small amount of the liquid of the present invention is printed as a spot, its color change can be visually observed.

Such a color change coloration is due to the fact that iodine in the liquid reacts with the starch in the fake tag or the starch in the paper containing starch to form a dark brown to gray-blue-purple dark complex. In contrast, genuine banknotes and more secure papers that do not contain starch do not react with iodine in the liquid because they contain little starch or contain only trace amounts of chemicals, and color No change is observed.

Not only are reagents and industrial chemicals iodine and alkali metal iodides used to produce iodine-containing liquids, but also povidone-iodine, which is a solution of a compound of polyvinylpyrrolidone and iodine, as a preparation containing iodine, or It has been found that it is possible to use iodine tincture, which is an iodine refiner composed of iodine, potassium iodide, ethanol, and water. Povidone-iodine (PVP-I) which is a compound of polyvinylpyrrolidone and iodine described in the 11th Revised Japanese Pharmacopoeia Commentary (1986) includes, for example, isodine (Meiji Seika Co., Ltd.), neo-yojin (Iwaki Pharmaceutical Co., Ltd.), Popiral (Asgen Pharmaceutical Co., Ltd.),
It is sold under the name of Mast Clean (Iwaki Pharmaceutical Co., Ltd.) and is an easily obtainable drug, which is widely used as a germicidal disinfectant for hulls and a mouthwash. A commercially available gargle (gargle) using povidone-iodine may be described as containing 70 mg of povidone-iodine (7 mg of effective iodine) in 1 ml as a component amount.
The gargle is diluted 15 to 30 times with water. Also, it is used as a disinfectant by using ethanol and water in appropriate amounts based on the method for producing alcoholic beverages specified in the Japanese Pharmacopoeia. In addition, iodine 5.7-6.3W / V% and potassium iodide 3.8-4.2W
Iodine tincture made from an appropriate amount of ethanol at 70 / V% and 70V / V% is used for skin disinfection at the surgical site and for the treatment of skin diseases caused by bacteria and fungi in the dermatology area. In addition, it may be used internally or as a gargle as an antiemetic. However, it has not yet been known that a preparation containing povidone-iodine and tincture of iodine can be used for detecting and authenticating the bill or security paper of the present invention.

The present inventor described in the Japanese Pharmacopoeia manual a solution of such a compound of polyvinylpyrrolidone and iodine, for example, a preparation containing povidone iodine, or an iodine purified, for example, iodine consisting of iodine, potassium iodide, ethanol and water. The method is to dissolve in ethanol or a mixture of ethanol and water, and further dilute with water and a solvent selected from the group consisting of ketones, esters, ethers, and alcohols. After applying the liquid obtained on the bill to the banknote and observing the change in the color of the area to which the liquid was applied after the required time, the fake card changed the initial color of the area to which the liquid was applied from dark brown to grayish blue purple. However, the starch included in the fake bill, which indicates that the genuine banknote does not change the color of the area where the liquid is applied, Also found that it is possible to obtain a liquid that matches the purpose of the present invention for detecting a liquid containing iodine.

When a preparation or iodine tincture containing povidone-iodine is diluted with a method for producing alcoholic beverages, that is, ethanol or a mixture of ethanol and water, or alone from the group consisting of water and the above-defined ketones, esters, ethers, and alcohols. Alternatively, the composition of iodine and potassium iodide when diluted with a plurality of selected solvents is preferably about 0.02% to about 3.2% by weight. If the concentration is too low, the color density of the color development is low and it is difficult to discriminate and identify, and the storage stability of the liquid over time deteriorates. If the concentration is too high, if a genuine banknote is liquored, it may leave a trace of light brown liquor on the paper for a short period of time.

As a solvent for dilution, good performance effects can be obtained not only with 70 V / V% ethanol of the local government but also with water alone. However, alcohols such as ethanol and isopropyl alcohol are used to enhance the quick drying property of the liquid. In addition, smooth writability, smooth fluidity during stamping, and a large amount of ethylene glycol and glycerin to ensure that porous rubber stamps retain permeation into the fine continuous pores and prevent solidification due to drying of the liquid on the felt core It is also particularly preferable to include a polyhydric alcohol at a ratio of about 15% to about 80% by weight.

In recent years, porous rubber stamps with a built-in ink have been conveniently used in various aspects of real life. The stamp and the stamp stand are integrated, and ink is built into the stamp. The main working mechanism of this stamp is that a rubber-like elastic body having continuous pores, that is, a porous rubber is impregnated with ink, and when this is pressed against the target surface, the ink moves from the opening of the continuous pores to the target surface, and the stamp is pressed. The surface shape is transferred. The portion where transfer is not desired is usually a concave portion, or its opening is closed to prevent ink from adhering to the target surface. The porous rubber is placed at the bottom of the ink reservoir, which is further housed in a stamp case with the porous rubber exposed. The exposed surface is covered with a cap to prevent drying of the ink when not in use and contamination due to accidental contact. For the first time, the manufacturing technology for rubber-like elastic bodies having fine continuous pores has been established, and this type of stamp has been put into practical use. By the way, the ink used for this porous rubber stamp is satisfactorily impregnated with the ink in fine continuous pores and has good fluidity during stamping,
After stamping, it is required that it penetrates into the absorbing surface such as paper at an appropriate speed, and that it does not attack the stamper material.
Pigment inks satisfying such required performances have also been developed. As described above, the ink which has overcome the above-mentioned problems is usually used for the porous rubber stamp, but the liquid of the present invention also clears the required problems of the porous rubber stamp, and the liquid of the present invention is It has not been known until now that a porous rubber stamp that can be used for this porous rubber stamp and has been used only for the purpose of stamping can be easily used for detecting a fake bill. Furthermore, the fact that the fake label can be more easily detected with the liquid of the present invention by using this stamper is an excellent point as a useful and effective embodiment of the liquid of the present invention. That is, for example, if "fake" or "fake bill" can be marked on the stamp print, the authenticity of the bill can be identified and identified at a glance. In addition, the liquid of the present invention can be filled into containers of various sizes and forms little by little and can be marked by a known existing method. For example, it can be packed in a writing implement container such as a pen or a brush, and can be used quickly and simply by marking the same as a marker pen. Also,
By using the ink jet type marking system, it is possible to detect and authenticate a large number of banknotes and security papers. Further, as a preference at the time of use, a suitable amount of a fragrance prepared from ketones, esters, ethers, and alcohols described in the Perfume Chemistry Directory (by Osamu Okuda, Hirokawa Shoten) in the detection liquid of the present invention. It is also possible to mix and perfume.

Hereinafter, the present invention will be described with reference to examples.

[0028]

Example 1 An aqueous solution 4 of 4.0 g of potassium iodide was placed in a brown bottle.
80 g is added, and 2.0 g of iodine is added and dissolved therein. 128 g of ethanol, 140 g of isopropyl alcohol, 100 g of diethylene glycol, and 150 g of ethylene glycol are added to make a detection liquid. Put this liquid in a felt-tip pen and mark the length of 1 cm on the printing margin of the genuine banknote,
Attached to check papers, stamps and photocopy papers, stationery issued by the Ministry of Posts and Telecommunications of Japan. No genuine banknotes from Japan, the United States, Singapore, China, and Italy, or check paper or stamps issued by the Ministry of Posts and Telecommunications of Japan show any color change in the printed area even after 30 seconds. However, in the case of photocopy paper and stationery, the marked portion printed instantaneously changes from dark brown to gray-blue purple. Even if this liquid is stored in a dark 50 ° C constant temperature bath and the same test is performed six months later, there is no change in the color development and discoloration performance of the detection liquid, and genuine banknotes from Japan, the United States, Singapore, China, Italy, and the Ministry of Posts and Telecommunications of Japan No change in color was observed in the printed portion of the check paper or stamp even after 30 seconds, and in the photocopy paper and stationery, the marked portion printed and instantly changed from dark brown to grayish blue-violet.

[0029]

Example 2 A brown bottle was charged with 100 ml of a povidone-iodine solution as a compound solution of polyvinylpyrrolidone and iodine, for example, isodine gaggle (manufactured by Meiji Seika Co., Ltd.), and 100 ml of 70% V / V ethanol, 100 ml of water, and ethylene glycol were added. Add 100 ml to make detection solution. This liquid is filled into a felt-tip pen, and a mark of 1 cm length is attached to the print margin of the genuine banknote, check paper, stamp and photocopy paper, and stationery issued by Japan Post. No genuine banknotes from Japan, the United States, Singapore, China, and Italy, or check paper or stamps issued by the Ministry of Posts and Telecommunications of Japan show any color change in the printed area even after 30 seconds. However, in the case of photocopy paper and stationery, the marked portion printed instantaneously changes from dark brown to gray-blue purple. Even if this solution is stored in a dark 50 ° C constant temperature bath and the same test is performed six months later, there is no change in the coloring and discoloration performance of the solution, and genuine banknotes from Japan, the United States, Singapore, China, Italy and the Ministry of Posts and Telecommunications of Japan No change in color was found in the printed portion of the check paper or stamp even after 30 seconds, and in the photocopy paper and stationery, the marked portion printed and instantly changed from dark brown to grayish blue-violet.

[0030]

Example 3 In a brown bottle, a dilute tincture of Japanese Pharmacopoeia, i.e., dilute tincture of iodine such as dilute tincture of Japanese Pharmacopoeia, obtained by diluting iodine tincture of the Japanese Pharmacopoeia, iodine consisting of iodine, potassium iodide, ethanol and water, twice with 70V / V% ethanol Showa ”P
100 ml (manufactured by Showa Pharmaceutical Co., Ltd.) is added, and 450 ml of an aqueous solution of 5 g of potassium iodide, 75 g of ethanol, 150 g of isopropyl alcohol, and 150 g of diethylene glycol are added as a detection liquid. This liquid is filled into the ink reservoir of the porous rubber stamp and stamped on the print margin of genuine banknotes, check paper, stamps and photocopy paper issued by the Ministry of Posts and Telecommunications of Japan, and stationery, and the authenticity of Japan, the United States, Singapore, China and Italy For bills and check papers and stamps issued by the Ministry of Posts and Telecommunications of Japan, no color change is observed in the stamped area even after 30 seconds of stamping. However, in the photocopy paper and the stationery, the dark brown to gray-blue purple characters "fake tag" stamped instantaneously appear clearly. Even if this detection solution is stored in a dark 50 ° C constant temperature bath and the same test is performed six months later, there is no change in the color development and discoloration performance of the solution.
No genuine banknotes from China and Italy, and check paper or stamps issued by the Ministry of Posts and Telecommunications of Japan showed no color change in the stamped area even after 30 seconds of stamping. Brown to gray-blue purple letters appeared.

[0031]

Example 4 An aqueous solution of 6 g of potassium iodide 480 was placed in a brown bottle.
g, and 8 g of iodine is added and dissolved. 120 g of ethanol, 140 g of isopropyl alcohol, 126 g of diethylene glycol, and 126 g of ethylene glycol are added to make a detection liquid. This liquid is filled into the ink reservoir of the porous rubber stamp and stamped on the print margin of genuine banknotes, check paper, stamp and photocopy paper, stationery issued by the Ministry of Posts and Telecommunications, Japan, the United States, Singapore,
No genuine banknotes from China and Italy and check papers and stamps issued by the Ministry of Posts and Telecommunications of Japan show any color change in the stamped area even after 30 seconds of stamping. However, in the photocopy paper and the stationery, the dark brown to gray-blue purple characters "fake tag" stamped instantaneously appear clearly. Even if this detection solution is stored in a dark 50 ° C constant temperature bath and the same test is performed six months later, there is no change in the coloring and discoloration performance of the solution, and genuine banknotes from Japan, the United States, Singapore, China, Italy, and the Ministry of Posts and Telecommunications of Japan No change in color was observed in the stamped area of the check paper or stamp even after 30 seconds of stamping, and gray-purple letters appeared on the photocopy paper and stationery immediately stamped and stamped.

[0032]

Comparative Example 2.8 g of iodine was placed in a brown bottle, and 20 ml of an aqueous solution of 8 g of potassium iodide was added thereto and dissolved. Add water to make 1000 ml. This detection solution is filled in a felt-tip pen, and a mark of 1 cm length is attached to the print margin of the genuine banknote, check paper, stamp and photocopy paper, and stationery issued by the Ministry of Posts and Telecommunications of Japan. Japan, United States,
No genuine banknotes from Singapore, China, and Italy, and check paper or stamps issued by the Ministry of Posts and Telecommunications of Japan show no color change in the printed area even after 30 seconds. However, in the case of photocopy paper and stationery, the marked portion printed instantaneously changes from dark brown to gray-blue purple. This solution is dark
When stored in a 50 ° C constant temperature bath for one month, the color of the solution changes from brown to pale yellow, and the color change due to the solution is recognized even if the same test is performed on genuine banknotes, check paper, stamps, as well as photocopy paper and stationery. I couldn't.

[0033]

The chemical substance which is reliable, does not require expensive and large equipment or complicated operations, is easy to handle and uses inexpensive tools, for example, a porous rubber stamp, is a chemical substance which can be obtained quickly and easily and easily. It is possible to provide a method capable of detecting a fake label by using a small amount of a liquid that can be used with confidence that can be made from a liquid, and a liquid therefor.

Claims (9)

[Claims] 1. Applying a liquid containing iodine to a banknote and observing a change in the color of a portion to which the liquid is applied after a required time. In a fake bill, the initial color of the portion to which the liquid is applied is dark brown to grayish blue purple. A method for detecting fake bills, wherein starch contained in fake bills is detected with a liquid containing iodine, wherein the color of the portion to which the liquid is applied does not change with a genuine banknote, but a liquid for that. 2. The method according to claim 1, wherein a liquid comprising iodine is used. 3. The method according to claim 1, wherein a liquid comprising iodine and a solvent selected from the group consisting of water, ketones, esters, ethers, alcohols and alkali metal iodide solutions is used. 4. The method according to claim 1, wherein the solvent is a liquid selected from the group consisting of water, ketones, esters, ethers and alcohols. 5. The method according to claim 1, wherein a liquid comprising iodine, water, an alkali metal iodide selected from the group consisting of sodium iodide and potassium iodide, and a solvent selected from alcohols is used. 6. The method of claim 1 wherein the weight ratio of iodine and alkali metal iodide is from about 0.02% to about 3.2% and water is from about 20% to about 85%.
2. The method of claim 1, wherein the liquid comprises about 15% to about 80% alcohol. 7. After a required time, a comparison is made between the portion to which the liquid is applied and a predetermined standard, and the result is that there is no change in the color of a genuine banknote, and the color of the fake bill changes from dark brown to grayish blue purple. 2. The method of claim 1, wherein the method occurs. 8. A solution of a compound of iodine and polyvinylpyrrolidone, or iodine tincture, which is an iodine refiner consisting of iodine, potassium iodide, ethanol and water, is treated with water,
The method according to claim 1, wherein the liquid is obtained by diluting with one or more solvents selected from the group consisting of ketones, esters, ethers, and alcohols. 9. The liquid of claim 1 wherein a porous rubber stamp is used as a means for achieving the method of claim 1.