KR102128419B1 - Security paper containing nitrocellulose and manufacturing method therefo - Google Patents

Abstract

It relates to a security paper using a property that partially increases the light transmittance by a solvent, and a method for manufacturing a security paper and a security paper that can be applied in various ways by using a property that increases the light transmittance only in a part that contacts a specific solvent. It is about. The security paper of the present invention is manufactured by including nitrocellulose, and is characterized by irreversibly increasing light transmittance upon contact with acetone.

Description

SECURITY PAPER CONTAINING NITROCELLULOSE AND MANUFACTURING METHOD THEREFO} SECURITY PAPER CONTAINING NITROCELLULOSE AND MANUFACTURING METHOD THEREFO

The present invention relates to a paper for security using a property that partially increases the light transmittance by a solvent, and relates to a paper for security that can be applied in various ways by using the property that the light transmittance increases only in a part that contacts a specific solvent.

Nitrocellulose is a compound in which hydroxyl groups of cellulose are converted to nitrate esters, also called cotton or cotton, and has various aliases such as flash paper and silk cotton. Depending on the nitrogen content, it can be classified into Gangmyeon, Yakmyeon, and Gummyeon. Nitrocellulose is a material mainly used for the manufacture of dynamite, the production of lead-free chemicals, rocket solid fuels, etc. due to its violent combustion characteristics upon ignition.

Since nitrocellulose has a shape similar to that of cotton fiber, it is conventionally used as a flash paper for magic by mixing it with various components and making it into paper form, cigarette paper for wrapping cigarettes, and bio-related test paper. It is used as a raw material for manufacturing.

Paper is widely used as securities with financial value, such as banknotes, sovereignty, bonds, gift certificates, and lotteries. Watermark the paper itself so that it cannot be easily counterfeit or tampered with paper used for such securities, mix hidden lines in the paper layer, or print special characters such as micro text, intaglio, hidden text, or ultraviolet rays. When irradiated with a wavelength other than visible light such as infrared rays or infrared rays, printing is performed with special ink emitting from visible light, or when copying with printing using an electronic copying device, a special shape in which characters or images such as those copied to the printed pattern after copying appear, or gold foil Metal foils, such as silver foil or silver foil, or foils using a diffractive structure such as holograms or diffraction gratings, which can express stereoscopic images or special decorative images using light interference, are used.

However, these conventional methods have a problem in that the manufacturing process is complicated, a separate device for distinguishing authenticity is required, and the manufacturing cost is greatly increased.

Korea Patent Publication No. 2013-0117975 (2013.10.29 published) Korean Published Patent No. 2011-0042793 (published on April 27, 2011)

An object of the present invention is to provide a security paper and a paper manufacturing method using nitrocellulose having a simple manufacturing process and excellent light transmission characteristics.

The object of the present invention, as a security paper, is made of cotton pulp and nitrocellulose, the nitrocellulose is achieved by a security paper that is 30 to 90% by weight of the total fiber component contained in the paper.

The paper may include a first area and a second area having a higher light transmittance than the first area.

The first region and the second region may have substantially the same thickness, and the first region and the second region may be integrally formed.

The cotton pulp and nitrocellulose may be continuously disposed in the first region and the second region.

The second region is formed by contact of the nitrocellulose and acetone, and in the second region, the nitrocellulose is dried after at least a portion is dissolved by the acetone to become a film film shape in which light transmittance is irreversibly increased. May be

The nitrocellulose may have a nitrogen content of 10.7 to 12.2% by weight.

As another solution for achieving the object of the present invention, a nitrous cellulose is mixed with the beaten cotton pulp to include a resinous paper manufacturing step of preparing a water paper so that the basis weight is 77 to 83 g/m ² , and the cotton The pulp contains linter fibers, and the nitrocellulose is achieved by a method for manufacturing a security paper having a size of 400 mesh to 140 mesh.

It may be further comprising the step of preparing the beaten pulp by beating the cotton pulp to have a concentration in the range of 1.4 to 1.6% and a high degree of solution in the range of 48 to 52°SR.

The linter fibers may have an average length of 4 to 6 mm.

The step of providing the cotton pulp, when the amount of the dried fiber contained in the cotton pulp is 100 parts by weight, the titanium dioxide addition step of adding 4 to 6 parts by weight of titanium dioxide and of the dried fiber contained in the cotton pulp When the amount is 100 parts by weight, it may include a step of adding a strength enhancer to add 0.5 to 0.7 parts by weight of the strength enhancer.

The strength enhancer may include polyamidoamine-epichlorohydrin resin.

The manufacturing step of the water grass paper may include a dehydration process, and may include a silver wire input step of introducing a silver wire during the dehydration process.

After the step of manufacturing the paper sheet, a security pattern printing step of printing a text or pattern on at least one surface of the paper sheet may be further included.

After the step of manufacturing the paper, it may further include the step of irreversiblely increasing the light transmittance of the paper by contacting acetone with at least a portion of the paper.

The paper for security of the present invention can be utilized for discriminating the authenticity of various items, indicating that the product cannot be reused, etc. by using the property of irreversibly increasing light transmittance by contact with acetone, and it is easy to manufacture to provide various types of security products. There is an advantage that can be applied.

1 is a vertical cross-sectional view showing the difference in each step of the security sheet according to an embodiment of the present invention.
2 is a plan view showing a paper for security according to another embodiment of the present invention.
3 is a plan view and a vertical cross-sectional view of a security sheet according to another embodiment of the present invention.

Hereinafter, the present invention will be described in more detail with reference to the drawings.

The accompanying drawings are only examples shown in order to describe the technical spirit of the present invention in more detail, so the spirit of the present invention is not limited to the accompanying drawings. For the same reason, some components in the accompanying drawings are exaggerated, omitted, or schematically illustrated.

The paper for security of the present invention comprises cotton pulp and nitrocellulose. Nitrocellulose contains 30 to 90% by weight of the total fiber component contained in the security paper. Nitrocellulose uses nitrogen having a content of 10.7 to 12.2%, and is often used for paints. Nitrocellulose having a higher nitrogen content is mainly used for gunpowder and is unsuitable for the present invention. In the industrial nitrocellulose, a flake form is mainly used. In the flake form, a large amount of fiber bundles are present, and thus, when used as a paper raw material, an uneven paper is made. Use nitrocellulose smaller than 140 mesh. When the nitrocellulose is larger than 140 mesh, non-uniform paper is made, and when it is smaller than 400 mesh, it does not remain on the paper during the manufacturing process, making the paper of the present invention impossible.

Cotton pulp includes linter fibers, and the average length of linter fibers is 4 to 6 mm. In addition, the security paper may include titanium dioxide as a filler. The security paper formed by mixing cotton pulp and nitrocellulose is opaque, but in a bright environment, a part of light is transmitted and the pattern of the lower surface of the security paper may be faint. Therefore, titanium dioxide may be used as a filler to enhance security, and sufficient opacity can be obtained when using 4 to 6% by weight of the dry paper fiber compared to the paper for the security of the present invention. When titanium dioxide was used more than 6% by weight, there was a problem that the light transmittance after the change by acetone was lowered. As the content of nitrocellulose increases, a problem that the strength of the security paper decreases may occur, and an intelligence enhancer may be included to solve the problem. The strength enhancer is preferably a polyamidoamine-epichlorohydrin (PAE) resin, and when using 0.5 to 0.7% by weight compared to the dry fiber of the paper, it can be used as a security paper at a basis weight of 60g/m ² Tensile strength 3 kg _f /15mm or more can be obtained.

Figure 1 is a vertical cross-sectional view showing the difference between each step before and after the solvent contact of the security sheet 100 according to an embodiment of the present invention, Figure 1 (a) is a sheet of the security sheet 100 of the present invention and acetone It shows the state before contact. 1(b) shows that acetone is brought into contact with the security sheet 100. In the drawing, it is shown that the acetone droplet is dropped and brought into contact through an eyedropper, but any method that can be absorbed by the security paper 100 by contacting acetone is possible. 1(c), after the security sheet 100 is in contact with acetone, acetone is absorbed and the second region 120 in which light transmittance is increased and the first region in which the opaque state is maintained as it is not in contact with acetone ( 110).

When the security paper 100 is in contact with acetone, nitrocellulose among the fibers constituting the paper is melted and a thin film is formed according to the amount, so that the portion is translucently changed. When acetone is dropped on a fiber that is 100% by weight of nitrocellulose, a complete solution is formed and a film is formed when it is dried, but at this time, it is completely dissolved and thus becomes unsuitable as a paper for security. In order to solve this problem, cotton pulp is used in the present invention. This was solved by mixing with.

It was confirmed that the acetone used in the security paper 100 of the present invention reversibly changes only when the purity of acetone is at least 80% or more. When the purity of acetone was lower than 80%, the light transmittance temporarily increased during the wetting phenomenon caused by the acetone solution, but once the solvent evaporated, the light transmittance of the security paper was restored to its original state. However, when the purity of acetone was 80% or more, the light transmittance was irreversibly increased even after all acetone had evaporated.

2 is a plan view showing a paper 100 for security according to another embodiment of the present invention, and shows that a hidden line exists inside or under the paper 100 for security. In FIG. 2(a), the part indicated by the dotted line is a part where the hidden line is present, and is in contact with acetone, and in the state (a), the hidden line is covered by the security sheet 100, so it is not easy to distinguish.( b) When the second area 120 is formed by contacting acetone in an area with a hidden line as in the state, the light transmittance of the security sheet 100 increases, and the hidden line 300, which is not visible in the state (a), In the (b) state, it is exposed in the second region 120. Through this method, it is possible to function as a security paper that can mask authenticity.

3 is a part similar to FIG. 2, but shows an example in which a security pattern or text is used instead of a hidden line. In Figure 3 (a), the security pattern 400 is attached to the bottom of the paper by printing or the like, and when viewed from the top without the security pattern 400, the security pattern 400 is not visible. However, as shown in (b) of FIG. 3, when the acetone is contacted, the light transmittance of the second region 120 in contact with the acetone is irreversibly increased, and the security pattern 400 is also applied to the top of the security sheet. You can check.

As illustrated in FIGS. 1 to 3, the first region 110 and the second region 120 are integrally formed, and are formed by the contact of acetone after formation of the security sheet. Therefore, the first region and the second region have substantially the same thickness. Here, practical means that there is only a difference in the degree of thickness variation that may occur during the paper manufacturing process. In addition, since the first region 110 and the second region 120 are manufactured without a difference in a manufacturing step, there is no distinction, and when the first region 110 comes into contact with acetone, the second region 120 It can change.

The method of manufacturing the paper 100 for security of the present invention is as follows. In the step of preparing the cotton pulp to beat the cotton pulp, the cotton pulp is beaten to a concentration in the range of 1.4 to 1.6% by weight and a high degree of solution in the range of 48 to 52° SR. The main component of cotton pulp is linter fiber, and preferably has an average length of 4 to 6 mm. Linter fiber is a collection of fibers attached to the seeds of cotton. Nitrocellulose uses nitrogen having a content of 10.7 to 12.2%, and is often used for paints. Nitrocellulose having a higher nitrogen content is mainly used for gunpowder and is unsuitable for the present invention. In the industrial nitrocellulose, a flake form is mainly used. In the flake type nitrocellulose, uneven paper is produced when a large amount of agglomerated fibers are used as a paper raw material. This yields nitrocellulose larger than 400 mesh and smaller than 140 mesh. Nitrocellulose, which is smaller than 400 mesh, is not suitable for paper production because it is not left on the paper because all of it goes out with water in the paper production step. Nitrocellulose larger than 140 mesh becomes a non-uniform paper due to agglomeration, making it unsuitable for security.

In the step of preparing the cotton pulp, a filler and an intelligence enhancer may be further added. Titanium dioxide is used as the filler, and when the amount of the dried fiber contained in the cotton pulp is 100 parts by weight, 4 to 6 parts by weight of titanium dioxide is added. The filler serves to increase the opacity of light in the first area where the security paper does not contact acetone, thereby increasing security. The strength enhancer uses polyamidoamine-epichlorohydrin (PAE) resin, and when the amount of the dry fiber contained in the cotton pulp is 100 parts by weight, the strength enhancer is added in an amount of 0.5 to 0.7 parts by weight. The strength enhancer increases the tensile strength of the security paper, so that it can function smoothly as a security paper.

Mixing the beaten cotton pulp and nitrocellulose larger than 400 mesh and smaller than 140 mesh to perform a water grass paper manufacturing step to prepare a water grass paper to have a basis weight of 77 to 83 g/m ² . Water grass paper can be produced using a water grass paper. Nitrocellulose is mixed to contain 30 to 90% by weight of the total fiber component contained in the security paper.

As shown in FIG. 2, the security sheet 100 may include a hidden line. In the city, a hidden line long arranged in one direction of the paper is shown. In addition to this, a number of short length hidden lines may be included, and these hidden lines may be arranged regularly or irregularly. The silver wire may be introduced during the dehydration process included in the manufacturing stage of the waterweed paper. When the hidden line is input in this manner, the thickness of the paper in the position where the hidden line is located in the manufactured security sheet 100 does not differ significantly from other parts. This is a part in which the thickness of the paper in the portion where the hidden line is located is increased by the thickness of the hidden line in the process of attaching the existing hidden line.

After the step of manufacturing the water grass paper, the security pattern 400 may be formed on one surface as shown in FIG. 3. The security pattern 400 may be a text or a pattern. The security pattern 400 may be printed by a laser printer or an inkjet printer, or an individual recognition pattern may be directly written by hand or the like.

Acetone may be brought into contact with at least a portion of the security sheet 100 manufactured as described above to make a product having an increased light transmittance. For example, in the process of forming a hidden line used for banknote paper, etc., when only the portion where the hidden line is present is treated with acetone to increase the transmittance, the process of attaching the hidden line can be replaced more easily than the conventional method of attaching the hidden line. There will be.

The surface pulp having a viscosity of 70 cPs and a high degree of 16° SR was beaten using a beater, and the nitrocellulose having a nitrogen content of 10.7 to 12.2% by weight was removed using a vibrating body to remove portions larger than 400 mesh and smaller than 140 mesh to remove nitrocellulose. Prepare. The weight ratio of cotton pulp and nitrocellulose was 5:5, and a paper having a basis weight of 80±3 g/m ² was prepared using a water paper machine.

It was prepared in the same manner as in Example 1, and the weight ratio of cotton pulp and nitrocellulose was 3:7.

It was prepared in the same manner as in Example 1, the weight ratio of cotton pulp and nitrocellulose was 1:9.

It was prepared in the same manner as in Example 2, and was produced by inserting a silver wire with a width of 2.0 mm printed on a transparent film between papers.

It was prepared in the same manner as in Example 2, and was produced by printing characters or patterns on one side of the produced paper.

Comparison of effects in acetone reaction for each example Cotton pulp
: Nitrocellulose Hidden Line Insertion Effect on acetone reaction Remark Example 1 5:5 - Irreversible partial transparency,
Back Pattern Observation Example 2 3:7 - Irreversible partial transparency,
Back Pattern Observation Example 3 1:9 - Irreversible partial transparency,
Back Pattern Observation Excellent light transmittance Example 4 3:7 Film hidden line Irreversible partial transparency,
Observing the pattern printed on the hidden line Example 5 3:7 Pattern printing Irreversible partial transparency,
Observation of chemical discoloration pigment smear in the hidden area

It was confirmed that the light transmittance increased as the content of nitrocellulose increased, and even in the case of film silver wire or pattern printing, the light transmittance increased after contact with acetone, so that the hidden lines and patterns that were not visible before contact with acetone were used for security paper after contact with acetone. It was confirmed that the light transmittance increased.

The present invention has been described with reference to one embodiment, but this is merely exemplary, and those skilled in the art will understand that various modifications and other equivalent embodiments are possible therefrom. Therefore, the true protection scope of the present invention should be defined only by the appended claims.

Claims (14)

As a security paper,
Made of cotton pulp and nitrocellulose,
The nitrocellulose is 30 to 90% by weight of the total fiber component contained in the paper,
The paper includes a first area and a second area having a higher light transmittance than the first area. delete In claim 1,
The first region and the second region have substantially the same thickness,
The first area and the second area are security paper, characterized in that formed integrally. In claim 1,
The cotton pulp and nitrocellulose is a security paper, characterized in that continuously arranged in the first region and the second region. In paragraph 1
The second region is formed by contact of the nitrocellulose and acetone, and in the second region, the nitrocellulose is dried after at least a portion is dissolved by the acetone to become a film film shape in which light transmittance is irreversibly increased. Security paper, characterized in that. In claim 1,
The nitrocellulose is a paper for security, characterized in that the nitrogen content is 10.7 to 12.2% by weight. A step of preparing a paper grass by mixing nitrocellulose with the beaten cotton pulp so that the basis weight is 77 to 83 g/m ² ; It includes,
The cotton pulp includes linter fibers,
The nitrocellulose is a method for manufacturing a security paper having a size of 400 mesh to 140 mesh. In claim 7,
A method of manufacturing a paper for security, further comprising the step of preparing the consolidated cotton pulp by refining the cotton pulp to a concentration in the range of 1.4 to 1.6% and a high degree of solution in the range of 48 to 52°SR. In claim 7,
The linter fiber is a method for manufacturing a security paper, characterized in that the average length is 4 to 6 mm. In claim 8,
The step of providing the cotton pulp,
A titanium dioxide addition step of adding 4 to 6 parts by weight of titanium dioxide when the amount of dried fibers contained in the cotton pulp is 100 parts by weight; And
When the amount of pre-drying fiber contained in the cotton pulp is 100 parts by weight, the step of adding a strength enhancer to add 0.5 to 0.7 parts by weight of the strength enhancer; Security paper manufacturing method comprising a. In paragraph 10
The intellect enhancer comprises a polyamidoamine-epichlorohydrin resin security paper manufacturing method. In Section 7
The water grass paper manufacturing step,
It includes a dehydration process, a method for manufacturing a paper for security, characterized in that it comprises a hidden line input step of injecting the silver wire during the dehydration process. In claim 7,
After the water grass manufacturing step,
And a security pattern printing step of printing a text or pattern on at least one surface of the water paper. In claim 7,
After the step of manufacturing the paper, further comprising the step of irreversiblely increasing the light transmittance of the paper by contacting acetone with at least a portion of the paper.

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