JPS5976999A - Forgery preventing paper - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to anti-counterfeiting devices. More particularly, the present invention relates to a paper for producing printed matter that is difficult to forge, or a paper that allows forgery to be easily detected in the event of forgery.

2. Description of the Related Art Conventionally, pieces of paper that have a currency exchange function, such as various certificates, train tickets, and voting tickets, have been sometimes forged, and various methods have been proposed to prevent this. For example, Tokuko Sho 56-1
Publication No. 8719 discloses the use of pyrazololidone compounds and the like. Also, JP-A-55-1377
No. 10 discloses a tampering prevention technology that combines a fluoran compound and acid clay. however.

Paper obtained by these conventional techniques did not necessarily have sufficient storage stability.

The inventors of the present invention discovered that it is possible to obtain anti-counterfeiting paper that does not have such drawbacks and has excellent performance through simple operations, and has completed the present invention.

That is, the first invention of the present invention is based on the following general formula (1)% formula% (wherein R represents an aryl group or a lower alkyl group, and R2, R3, R4 and R8 are a hydrogen atom or an aryl group. or a lower alkyl group, and X represents a sulfur or oxygen atom.
This anti-counterfeiting paper is characterized by containing the essentially colorless compound represented by 1) and a chlorate.

In the above general formula (1) used in the present invention, when X is a sulfur atom, it is an essentially colorless compound called phenothiazine, and when X is oxygen, it is an essentially colorless compound called phenooxazine. be. These phenothiazine or phenooxazine compounds are leuco dyes that are generally used as coloring agents in pressure-sensitive copying paper.

In addition to the above, various types of leuco dyes such as triallylmethane compounds, diphenylmethane compounds, xanthine compounds, and spiropyran compounds are used as coloring agents for pressure-sensitive copying paper.

The present inventors investigated the use of these leuco dyes in anti-counterfeit paper, and found that only phenothiazine and/-): or phenooxazine compounds represented by the above general formula (1) were used as leuco dyes of other types. The invention was based on the discovery that the storage stability as a paper is extremely superior compared to that of paper, and as will be described later, it can be easily colored by simple operations, and once colored images do not disappear even when oxidized or reduced. completed.

The anti-counterfeit paper of the first aspect of the present invention is the general L +
A phenothiazine and/or phenooxazine leuco dye represented by 11 is made into fine particles by ball milling with water, or a solution of these leuco dyes in a hydrophilic solvent such as dimethylformamide or tetrahydrofuran is diluted with water. , 0001-0.01% of fine particles as leuco dye based on the weight of paper,
Preferably about 0.0005% is mixed into pulp to make paper, or
The fine particles of this phenooxazine and/or phenothiazine leuco dye are mixed with polyvinyl alcohol,
Alternatively, it can be obtained by applying an aqueous dispersion of a sizing material such as starch in an amount of 0.001 to 1.0%, preferably about 0.1%, to the surface of paper and drying it. The quality of paper used does not need to be particularly selected, but the surface must not be coated with a hydrophobic resin.

The paper of the present invention obtained in this way can be prepared by dripping an aqueous solution of a mineral acid or an organic acid, such as mineral acid, sulfuric acid, acetic acid, citric acid, phosphoric acid, oxalic acid, tartaric acid, malic acid, etc. ,
By applying it, it is possible to clearly detect the development of color to purple after 5 to 10 minutes.

In order to increase the color development speed in the anti-counterfeiting paper of the first invention, chlorates, such as potassium chlorate, are used.
It is preferable to use sodium chlorate, ammonium chlorate, etc. in a range of about 0.001 to 0.01% based on the paper. The thus obtained paper of the second invention of the present invention can instantly turn a clear blue to blue color by spotting or applying acid.
By observing the bluish-purple color development, it becomes easy to detect printed matter, paper, etc. that are made with counterfeit buttons. This second invention is...

For example, when using hypochlorite or chlorite, the color development of leuco dyes occurs during paper storage, which has the disadvantage of -1:5, and perchlorate has the effect of accelerating the color development of leuco dyes due to acid. I couldn't see it. Furthermore, when using persulfates, percarbonates, and perborates, the paper develops color during storage, and hydrogen peroxide similarly has the disadvantage that color develops in a short period of time during paper storage.

The areas of the paper mixed with or coated with the phenooxazine-based or phenothiazine-based leuco dye according to the present invention that are colored by acid have good light resistance and will not fade even if slight discoloration is observed after 72 hours of direct sunlight. This can be clearly confirmed.

Furthermore, the areas colored by acid are not erased by solutions of sodium hypochlorite or calcium hypochlorite, but also by solutions of sodium percarbonate or sodium perborate. Furthermore, it is not possible to erase the colored portion with an aqueous solution of sodium hydrosulfide or acidic sodium sulfite to the extent that the colored portion cannot be recognized.

On the other hand, instead of the phenothiazine and/or phenooxazine dye represented by the general formula (1) used in the present invention, other types of leuco dyes, such as triphenylmethane-phthalide yarn, indolylphthalide yarn, and When using leuco dyes of the yuko auramine series, spiropyran series, rhodamine lactam series, triphenylmethane series, chromenoindole series, and triazene series, there was no collapse.
The stability of the leuco dye mixed or applied to the paper may be affected, resulting in coloration or discoloration, or the application of an aqueous solution of dilute mineral acid or organic acid, or spotting (which may have disadvantages such as not easily developing color). It was something.

In the present invention, if necessary, the pyran derivative pyranine (10-hydroxy-3.
5.8. trisodium pyrenetrisulfonic acid), or a dye that is soluble in organic solvents (toluene, alcohol, etc.) and insoluble in water, fileni? It is also possible to use Subiron dye (Hodogaya Chemical Industry Co., Ltd. Shoyanagi) or the like in combination.

The leuco dye of the phenothiazine and/or phenooxazine yarn which can be used in the general formula (1) for anti-counterfeit paper washing of the present invention is as follows.

Next, examples will be given, but the present invention will be explained by the following examples.
There are no restrictions. Note that % in the text is % by weight.

Example 1 CtO-1CLO from chlorine bleach used for bleaching
;, chlorine oxides such as ClO2, and oxyacids are reduced with sodium sulfite to eliminate any residue (pH
Add 0.005% of phenothiazine-based leuco dye 3.7-bis-(dimethylamino)-i o-benzoylphenothiazine to the pulp and mix well. The paper was made using a paper machine according to the general paper making method.The paper obtained had good white discoloration and did not change color even after aging. We observed the development of the KW color.This colored part cannot be completely erased by rubbing or using a commercially available ink eraser or a sheet of Losulfite Putolium, and the color changes and cannot be tampered with, making it difficult to counterfeit. For (・Leaked β) 8II item.

Detecting paper was easy.

Example 2 In the same manner as in Example 1, cto-, cto2-, ct
There is no residual oxidizing agent such as O2.
0-benzoylphenothiazine in tetrahydrofuran 1
0% solution of leuco dye deposited against bulb 0, OD 5%
, and 0.01% sodium chlorate were added, and then paper was made using a paper machine according to a general method. The obtained paper had good self-illumination and showed no discoloration even after being stored for -2 years or more. No matter which of dilute hydrochloric acid, 3% phosphoric acid solution, or 5% citric acid solution was dripped or applied to this paper, a clear blue color was observed in that area.

This colored area withstood direct sunlight for 24 hours in the summer, and the colored area could not be erased by abrasion, and some discoloration (dirty blue) was observed by ink erasure and sodium hydrosulfide, but it could not be erased.

Therefore, by detecting the printed matter or paper used for counterfeiting,
A counterfeit-proof paper that can prevent counterfeiting and cannot be tampered with has been obtained.

Example 3 Phenooxazine-based leuco dye made into fine particles using a ball mill in advance 3.7-bis-(dimethylamino)-10-benzoylphenooxazine polyvinyl N-7N, 2.5% water-soluble in water! A well-dispersed solution containing 0.1% of jVc was applied onto the surface of map paper (80 f/rr?) by roll coating and dried.

At this time, the amount of leuco dye is approximately o, o o i% based on the paper.
Met. This paper also had good self-illumination, and no change in self-illumination was observed even after storage for many years. Dilute hydrochloric acid or 6% phosphoric acid solution was dripped or applied to this paper, and a blue color was observed in the area. This colored area cannot be erased with ink, hydrosulfite, paint thinner, or other harsh solvents, and it is possible to detect not only tampering but also printed matter or paper used for forgery.

Example 4 Similar to Example 3, 6 and 7 were made into fine particles using a ball mill in advance.
-Bis-(dimethylaba))-io-n-butyroylphenothiazine is dispersed at 0.2% in an aqueous solution of 2.5% polyvinyl alcohol, and sodium chlorate is added at 0.2% in this solution.
The dispersion containing the above was applied to the surface of the paper by roll coating and dried. The percentage of leuco dye and sodium chlorate relative to paper is approximately 0001% and 0.001%, respectively.
Met. The self-illumination of this paper was good, and the self-illumination did not change even after more than - years had passed. When diluted hydrochloric acid, 6% phosphoric acid solution, or 6% acetic acid solution was dripped or applied to this paper, a 1R color was instantly seen in the area.

This colored area could not be erased by ink eraser, sodium 11-hydrosulfite solution, 1% sodium hydroxide solution, or methyl ethyl ketone, even if discoloration was observed. Therefore, it is of course not possible to falsify it.
, printed matter used for forgery, and f1 paper can be detected.

Example 5 When making paper, organic solvent soluble dyes, Eisenspiron Orange GRH, Subesial Oyohi Eizenspiron Blue GNH, were added to Bulb at a ratio of 0002% each, mixed uniformly, and then subjected to 5K paper making. A phenothiazine-based leuco dye, 3,7-bi
% aqueous solution, add 0.2% and disperse, further add 10-hydroxy-filtrate, trisodium salt of 5.8-pyrene trisulfonic acid (pyranine) and 0.01% sodium chlorate.
2% was added and dissolved, and then the pH was adjusted to 5-55, and this solution was applied to paper by roll coating and dried. The self-illumination of this paper was good, and furthermore, no discoloration was observed even after more than -2 years had passed. By dripping dilute hydrochloric acid or 6% citric acid onto this paper, a clear blue color was observed in the area m.

Furthermore, by dripping or coating a solution of 0.2% sodium hydroxide on this paper, pyranine develops a fluorescent yellow color, and by dripping alcohol or methyl ethyl ketone, the organic solvent-soluble dye dispersed in the paper dissolves. The paper is colored blue and orange, making it easy to check the paper.

Furthermore, it cannot be tampered with with acids, alkalis, bleaches, or solvents.

In place of the leuco dyes used in Examples 1 to 5, the following phenothiazine-based and phenooxazine leuco dyes, 5.7-bis-(methylamino)-10-benzoylphenothiazine, 5.7-bis-dimethylamino-10 -butyroylphenothiazine, 3.7-bis-(methylphenyla 1))-10-penzoylphenoocadine + 3.7-bis-(diethylamino)-10-butyroylphenoochidine, As with the two or more types of examples, there are problems with the self-storage of one paper, storage stability, color development with acid, and resistance to erasure of colored areas, and tampering is impossible.1. C forgery prevention was obtained.

Aizen Co., Ltd.

Claims (1)

[Claims] 1.1 General formula (wherein R is an aryl group or a lower alkyl group, R2, R3, R4 and R5 are a hydrogen atom, an aryl or a lower alkyl group, and X is a sulfur or oxygen atom) An anti-counterfeiting paper characterized by containing an essentially colorless compound represented by: 2 The following general formula % formula % (where RI represents an aryl group or a lower alkyl group, R2, R3, R4 and R5 represent a hydrogen atom, an aryl group or a lower alkyl group, and X is a sulfur or oxygen atom) An anti-counterfeiting paper characterized by containing an essentially colorless compound represented by: