KR20010056214A - Process for preparing security paper discolorable by chemicals - Google Patents

Abstract

PURPOSE: A process for preparing a safety paper which shows a change of color at a position where chemicals such as organic solvent, bleaching agent, alkali component or the like contact is provided. Whereby, the safety paper is prevented from forgery and alteration. CONSTITUTION: This safety paper is obtained by the process consisting of: preparing wet paper by adding one kind or more of dyes being insoluble but dissolved in an organic solvent to paper; drying in the first stage; surface-treating with a surface treating solution containing a coloring agent reacting with a bleaching agent or an alkali component; and drying. The dye is used in an amount of 0.005 to 0.1% by weight based on pulp dry weight.

Description

Production method of chemical discoloration security paper {PROCESS FOR PREPARING SECURITY PAPER DISCOLORABLE BY CHEMICALS}

The present invention relates to a method for producing a chemically discolored security paper in which the color of the site in contact with a chemical such as an organic solvent, a bleach, or an alkaline component changes.

Securities such as bank notes, checks, and gift certificates, lotteries, and confidential documents are forged by counterfeiters, and alterations are also made to change the printing state of originals by modulators. In particular, in the case of a check in which a user directly inputs a signature or amount of money, the contents may be altered and distributed by a forgery agent. In this case, much effort is required to determine the authenticity of the contents. Therefore, there is an urgent need for security papers that prevent counterfeiting and tampering of securities, lotteries, and confidential documents.

To date, elements such as silver (hidden pictures), fluorescent color yarns, and security threads have been used for security paper.

For security purposes, U. S. Patent No. 5,123, 999 adds a dye that dissolves in organic solvents in the manufacture of paper, and contains a high viscosity containing 2,3,4-trihydroxyacetophenone (2,3,4-trihydroxyacetophenone) and carboxymethylcellulose. A method of producing paper by coating with a coating solution is disclosed. Paper produced by this method is discolored in yellow by reaction with an ink eraser, an alkaline solution, sodium sulfite and sodium bisulfite.

French patent publication A-2365656 discloses a process for producing paper which reacts with an acidic indicator by adding phthaleins or sulfophthaleins.

French patent publication E-2399503 discloses a process for making paper by adding oxypyrenetricarboxylic acid. Paper produced by this method discolors in fluorescent yellow in response to an ink eraser.

Accordingly, it is an object of the present invention to provide a method for producing a security paper which is prevented from forgery and tampering and is easy to identify the authenticity.

In accordance with the above object, in the present invention, a wetland is prepared by adding at least one dye which is water insoluble and dissolved in an organic solvent to a stock, and then first drying it, and then including at least one coloring agent reacting with a bleach or an alkali component. It provides a method for producing a security paper comprising the step of surface treatment with a surface treatment solution and then dried.

Hereinafter, the method of the present invention will be described in detail.

First, at least one dye is dissolved in organic solvents such as alcohol, acetone, isopropyl alcohol, and xylene, which is water-insoluble, and then added to paper (a paper-making raw material in which pulp, filler, and various chemicals are mixed to produce paper). (Formed paper and wet before drying) is prepared and then dried first. As the dye, copper phthalocyanine-based, azo-based, anthraquinone-based dyes having a particle size of 0.5 to 5 μm may be used, and representative commercially available products include Savinyl Blue GNJ PA ^R , Savinyl Fire Red 3GLS NEW PA ^R , Foron Blue ^R , Nitro Fast Blue 2B PASTE ^R (Clariant, France) and the like, but is not limited thereto. The dye may be used in an amount of 0.005 to 0.1% by weight based on the pulp dry weight. In particular, when two kinds of dyes are selected and used by color, each of the dyes may be used at random, preferably 1: 1 to 1: 0.02 weight ratio. Representative examples of the organic solvent include alcohol, acetone, isopropyl alcohol, xylene, benzene and the like having a purity of 80% or more.

Subsequently, the wetland is surface treated with a surface treatment solution containing at least one color developing agent reacting with a bleach or an alkali component and then dried to prepare a security paper. Examples of the coloring agent that reacts with the bleach include benzotriazole, guanidine hydrochloride, and the like. Typical representative products on the market include Piosafe ^R (Vining, USA), Oxocheck ^R , and chlorostein ( Chlorostain ^R , Bayer, Germany), Vulkazit D ^R , Bayer, Germany). In addition, examples of the coloring agent that reacts with the alkali component include tannic acid, gallic acid, and Na-3-oxypyrene trisulfonic acid (Pyranin ^R , Bayer, Germany). The coloring agent may be used in an amount of 0.01 to 5% by weight based on the surface treatment solution. Examples of the surface treatment solution used with the coloring agent include 2 to 5% polyvinyl alcohol, 2 to 30% oxide starch or 2 to 20% amphoteric starch solution. Representative examples of the bleach to which the dyes react include sodium hypochlorite, calcium hypochlorite, and the like. Examples of the alkaline component include potassium hydroxide and sodium hydroxide.

Paper produced according to the method of the present invention contains dyes and coloring agents as anti-counterfeiting and tamper-resistant elements, making it difficult to forge and tamper with paper and to easily identify the authenticity of its contents. That is, the paper produced according to the method of the present invention is in contact with the organic solvents such as alcohol, acetone, isopropyl alcohol, xylene, etc., the dyes present on the surface and the inside of the paper is dissolved to give a color. In this case, the color may be in the form of spots, or may be in the form of a halo in which only the edges of the portions in contact with the organic solvent are colored. In addition, the paper produced according to the method of the present invention will be colored in various colors depending on the type of the color development drug when contacted with alkali or bleach.

Thus, when modulators use an ink eraser containing an organic solvent or bleach for the purpose of tampering with the ink printed or written on paper made in accordance with the method of the present invention, the organic solvent or bleaching agent Existing dyes or coloring agents will change color due to color development, making it easy to determine whether or not the modulation.

In addition, when the counterfeiters circulate the printed matter printed on the paper produced according to the method of the present invention, the forged printed matter can be easily judged by authenticity by contacting with an organic solvent or bleach.

Hereinafter, the present invention will be described in more detail with reference to the following examples. However, the following examples are only for illustrating the present invention, and the scope of the present invention is not limited thereto.

Example 1

Savinyl Blue GNJ PA ^R , Savinyl Fire Red 3GLS NEW PA ^R and Foron Blue ^R (Clariant, France) are mixed at a ratio of 7: 2.5: 0.5 and then used as paper stocks (each high altitude 30 ° SR NBKP) To the pulp fibers obtained by mixing 20% by weight of bleached kraft pulp) and 80% by weight of LBKP (softwood bleached kraft pulp), 0.1% by weight of epoxy resin, 0.15% by weight of AKD, 1.0% by weight of starch and 20% by weight of solid starch were added. To a papermaking raw material having a concentration of 0.5% by weight) was added in an amount of 0.08% by weight based on the dry weight of the pulp to form a wetland and dried first. The dried paper was then surface treated with a solution in which Piosafe ^™ (Vining, USA) was added in an amount of 0.3% by weight to a surface treatment solution (10% aqueous starch oxide solution), and then dried to prepare a paper.

As a result of dropping alcohol, acetone and isopropyl alcohol on the prepared paper, blue and red spots appeared as dye mixing ratios. Also, when xylene and benzene were dropped on the paper, blue spots did not appear, and only red spots developed. The interface of the spots was colored blue-blue. Also, when the bleach 5% sodium hypochlorite solution was dropped on the paper, this area turned dark brown.

Example 2

Nitro Fast Blue 2B PASTE ^R , Savinyl Fire Red 3GLS NEW PA ^R and Foron Blue ^R (Clariant, France) were mixed at a ratio of 7: 2.5: 0.5 and then placed on pulp dry weight on paper stock as used in Example 1 It was added in an amount of 0.01% by weight relative to the wetland to form and dried first. Subsequently, paper was prepared by surface treatment using a solution in which Oxocheck ^R was added in an amount of 0.3% by weight to the surface treatment solution as used in Example 1, followed by drying.

As a result of dropping alcohol, acetone, isopropyl alcohol, xylene, and benzene on the prepared paper, the result was similar to that of Example 1, and blue spots appeared darker blue and there were more spots. In addition, 5% sodium hypochlorite solution was dropped on the paper, and the area was dark yellow.

Example 3

Savinyl Blue GNJ PA ^R and Savinyl Fire Red 3GLS NEW PA ^R (Clariant, France) were mixed in a ratio of 7: 3 and then in a paper stock as used in Example 1 in an amount of 0.08% by weight relative to the pulp dry weight. The wetland was added to form a first dry. Subsequently, paper was prepared by surface treatment using a solution added to Chlorostain ^R (Bayer, Germany) in an amount of 1.0% by weight to the surface treatment solution as used in Example 1 and then dried.

As a result of dropping alcohol, acetone, isopropyl alcohol, xylene, and benzene on the prepared paper, spots similar to those of Example 1 were observed, and the edges of the contact areas with organic solvents were It was lighter blue-red. As a result of dropping 5% sodium hypochlorite solution on the paper, it was initially discolored to yellow and discolored to light green.

Example 4

Savinyl Blue GNJ PA ^R and Savinyl Fire Red 3GLS NEW PA ^R (Clariant, France) were mixed in a ratio of 7: 3 and then in a paper stock as used in Example 1 in an amount of 0.01% by weight relative to the pulp dry weight. The wetland was added to form a first dry. Subsequently, paper was prepared by surface treatment using a solution in which an aqueous solution of Vulkazit D ^R (Bayer, Germany) was added in an amount of 1.5% by weight to the surface treatment solution as used in Example 1, followed by drying.

As a result of dropping alcohol, acetone, isopropyl alcohol, xylene and benzene on the prepared paper, spots similar to those of Example 3 appeared, and the number of spots was more. In addition, a 5% sodium hypochlorite solution was added to the paper and the area turned dark brown.

Example 5

Savinyl Blue GNJ PA ^R and Savinyl Fire Red 3GLS NEW PA ^R (Clariant, France) were mixed at a ratio of 7: 3 and then in a paper stock as used in Example 1 in an amount of 0.01% by weight relative to the pulp dry weight. It was added to form a wetland and then dried first. Subsequently, paper was prepared by surface treatment using a solution in which tannic acid powder was added in an amount of 1.0% by weight to the surface treatment solution as used in Example 1, followed by drying.

As a result of dropping alcohol, acetone, isopropyl alcohol, xylene, and benzene on the prepared paper, spots of the same form as in Example 4 appeared. In addition, a 2% potassium hydroxide solution, an alkaline solution, was added to the paper and the area turned brown.

Example 6

Savinyl Blue GNJ PA ^R and Savinyl Fire Red 3GLS NEW PA ^R (Clariant, France) were mixed in a ratio of 7: 3 and then in a paper stock as used in Example 1 in an amount of 0.01% by weight relative to the pulp dry weight. The wetland was added to form a first dry. Subsequently, paper was prepared by surface treatment using a solution in which gallic acid powder was added in an amount of 1.0% by weight to the surface treatment solution as used in Example 1, followed by drying.

The results of dropping alcohol, acetone, isopropyl alcohol, xylene and benzene on the prepared paper and dropping 2% potassium hydroxide solution were the same as in Example 5.

Paper produced according to the method of the present invention prevents forgery and tampering of security papers, such as securities and secret documents, and facilitates forgery and tampering.

Claims (7)

1) At least one dye which is water insoluble and dissolved in an organic solvent is added to the stock to prepare a wetland, followed by first drying and then surface treatment with a surface treatment solution containing a bleach or a coloring agent reacting with an alkali component, followed by drying. Method of manufacturing a security paper comprising a. The method of claim 1, The dye is a copper phthalocyanine-based, azo-based or anthraquinone-based dye having a particle size of 0.5 to 5㎛. The method of claim 1, The dye is used in an amount of 0.005 to 0.1% by weight based on the pulp dry weight. The method of claim 1, Wherein said surface treatment solution is 2-5% polyvinyl alcohol, 2-30% starch oxide or 2-20% amphoteric starch solution. The method of claim 1, The coloring agent reacting with the bleach is benzotriazole or guanidine hydrochloride. The method of claim 1, The coloring agent that reacts with the alkali is tannic acid, gallic acid or Na-3-pyrene trisulfonic acid. The method of claim 1, Using the coloring agent in an amount of 0.01 to 5% by weight relative to the surface treatment solution.