CN106192549A - An anti-theft security paper - Google Patents

Abstract

The present invention relates to an anti-theft security paper, and a method of preparing the same. Specifically, the anti-theft safety paper is implanted with amorphous fibers with a large Barkhausen effect, wherein the diameter of the amorphous fibers is 10-50 microns, preferably 20-30 microns; the length of the amorphous fiber is 2-10mm, or 3-8mm, or 3-5 mm.

Description

An anti-theft security paper

technical field

The present application relates to an anti-theft security paper and a method for preparing the anti-theft security paper.

Background technique

As a resource, information is of special significance to human beings due to its universality, sharing, value-added, processability and multi-utility. According to the definition of the International Organization for Standardization, the meaning of information security mainly refers to the integrity, availability, confidentiality and reliability of information. The fundamental purpose of protecting information security is to protect internal information from internal, external, natural and other threats. Information security is an issue that any country must attach great importance to, and it is a national security strategy that cannot be ignored. Hostile forces or illegal organizations use various means to steal political, military, economic, scientific and technological secret information, and how the government, military and companies can ensure information security has become an urgent problem to be solved. Nowadays, there are many confidential or important paper documents that are not allowed to be taken out of the confidential area without authorization. This requires protection of these confidential papers. It is required that when someone tries to illegally carry the confidential paper out of the confidential area Special detection means can sense and give an alarm.

In the prior art, confidential paper is protected by embedding amorphous strips in the paper. Amorphous strips have a large Barkhausen effect, that is, the domain wall of the material undergoes a jumping irreversible displacement process during the magnetization process, which can be detected by instruments. Put the amorphous strip into the alternating magnetic field. When the magnetic field reaches the switching field of the material, the magnetic domain of the material changes instantaneously, and the instrument can sense a unique electromagnetic signal. In practical applications, the detection equipment is placed at the exit of the confidential area. When someone enters the detection area with paper implanted with amorphous strips, the detection equipment will detect an electromagnetic signal and immediately call the police. Due to the preparation process, it is very difficult to prepare an amorphous strip with a width of less than 1 mm. In order to offset the influence of the demagnetization field, the amorphous strip must maintain a certain length in order to have a large Barkhausen effect. The standard length of the amorphous strip with large Barkhausen effect used in the market is 32 mm, and the shortest can only reach 28 mm. The existing technology is to implant a metal strip with a length of 32 mm and a width of 1 mm into the paper. The amorphous strip is easy to be found and then destroyed, making the alarm function of this anti-theft security paper invalid.

Therefore, a kind of anti-theft security paper with higher anti-theft and anti-vandalism capability is needed.

Contents of the invention

The present invention has prepared amorphous fibers with a diameter of 10-50 microns by using the Taylor spinning method, and found that when the amorphous fibers have a high aspect ratio higher than 100, they can have a large Barkhausen effect. A kind of anti-theft security paper with high anti-theft and anti-destructive ability is obtained by embedding the amorphous fiber with a high aspect ratio into the paper.

Therefore, the present invention includes the following:

Embodiment 1. A kind of anti-theft security paper, implanted in the anti-theft security paper has the large Barkhausen effect amorphous fiber, wherein the diameter of the amorphous fiber is 10-50 microns, preferably 20-30 microns; The length of the amorphous fiber is 2-10mm, or 3-8mm, or 3-5mm.

Embodiment 2. The anti-theft security paper of embodiment 1, wherein the content of the amorphous fiber in the anti-theft security paper is 3-30m/m ² (for example, each A4 paper is 0.2m to 2m), especially preferred The content is 5-15m/m ² (for example, each A4 paper is 0.3m to 1m).

Embodiment 3. The anti-theft security paper of Embodiment 1, wherein the amorphous fibers have a glass coating and are produced by Taylor spinning.

Embodiment 4. The anti-theft security paper according to embodiment 3, wherein the glass coating layer of the glass-coated amorphous fiber has a thickness of 1-15 microns.

Embodiment 5. The anti-theft security paper of any one of the preceding embodiments, wherein the anti-theft security paper is prepared by implanting amorphous fibers directly into the paper.

Embodiment 6. The anti-theft security paper of any one of the preceding embodiments, wherein the amorphous fiber contains:

a) One or more elements in Co, Fe, Mn, Ni;

b) one or more elements of Si, B, C; and

c) Optional rare earth or transition metals.

Embodiment 7. The anti-theft security paper of any one of the preceding embodiments, wherein the amorphous fibers are distributed in the anti-theft security paper in a solid distribution, a localized distribution, or a combination thereof.

Embodiment 8. The anti-theft security paper of any one of the preceding embodiments, wherein the amorphous fibers are arranged in the anti-theft security paper in an ordered arrangement, a random arrangement or a combination thereof.

Embodiment 9. The anti-theft security paper of any one of the preceding embodiments, wherein the amorphous fiber contains:

1-15% by weight Fe;

2-12% by weight Si;

One or more selected from B, Nb, Cu, Mn, Mo, Ni, Cr and Al in a total amount of 2-25% by weight; and

The balance of Co.

Embodiment 10. The anti-theft security paper according to embodiment 1, wherein the content of the amorphous fiber in the anti-theft security paper is 5-15 m/m ² .

Description of drawings

In order to illustrate the technical solutions of the embodiments of the present invention more clearly, the accompanying drawings of the embodiments will be briefly introduced below. Obviously, the accompanying drawings in the following description only relate to some embodiments of the present invention, rather than limiting the present invention .

Figure 1: Schematic diagram of Taylor spinning method (11 feeding zone 12 glass tube 13 master alloy 14 heating zone 15 induction coil 16 cooling zone 17 cooling liquid 18 glass-coated amorphous wire 19 winding roller).

Figure 2: Electron micrograph of glass-coated amorphous fiber.

Figure 3: Large Barkhausen effect curve for amorphous fibers.

Figure 4: Schematic diagram of an anti-theft security paper containing disorderly distributed amorphous fibers.

Figure 5: Schematic diagram of an anti-theft security paper containing orderly distributed amorphous fibers.

Figure 6: Schematic diagram of an anti-theft security paper containing disorderly positioned amorphous fibers.

Figure 7: Schematic diagram of an anti-theft security paper containing orderly positioned and distributed amorphous fibers.

detailed description

In order to make the purpose, technical solutions and advantages of the embodiments of the present invention more clear, the following will clearly and completely describe the technical solutions of the embodiments of the present invention in conjunction with the drawings of the embodiments of the present invention. Apparently, the described embodiments are some, not all, embodiments of the present invention. Based on the described embodiments of the present invention, all other embodiments obtained by persons of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

definition:

In this application, the term "Great Barkhausen effect" refers to a property of amorphous ribbons or fibers in which the material undergoes a jumpy movement or inversion of domain walls during magnetization, which can detected by the instrument. In actual detection, the amorphous strip or fiber is placed in an alternating magnetic field. When the magnetic field reaches the switching field of the material, the magnetic domain of the material changes instantaneously, and the detection instrument can sense a unique electromagnetic signal. In some embodiments, the induced electromagnetic signal is a pulse signal or a higher harmonic. In the present invention, the amorphous fiber has a large Barkhausen effect, as shown in Figure 3, under the excitation of the alternating magnetic field, when a switch magnetic field value is reached, the magnetic induction intensity will jump, thereby inducing an electromagnetic signal, such as: Pulse signals or higher harmonics. When the detection instrument detects the electromagnetic signal generated by the amorphous fiber, it will alarm.

In this application, the term "Taylor spinning method" refers to a method of spinning by the following steps:

1. First provide a master alloy rod with the required composition, and select a matching glass tube. The difference between the melting point of the master alloy and the softening temperature of the glass tube is higher than 50°C and lower than 500°C;

2. Insert the master alloy rod into the bottom of the glass tube;

3. Use a high-frequency induction furnace to melt the bottom of the master alloy rod;

4. Use the molten master alloy to soften the glass tube;

5. Use the drawing method to pull out the wire;

6. The master alloy in molten state is cooled by rapid solidification to form amorphous alloy wire.

The method may further include the following steps:

7. Wind the wire on the take-up roller, keep the coiling speed of the wire at a constant line speed, and the line speed range is 10-100 m/min;

8. By adjusting the feeding speed, temperature and other parameters, the stability of the drawing process can be maintained, and the continuous preparation of silk can be realized.

As shown in Figure 1, Figure 1 describes the specific method for preparing amorphous fibers of the present invention. In Figure 1, the reference signs have the following meanings:

11: Feeding area

12: glass tube

13: master alloy

14: heating zone

15: induction coil

16: Cooling Zone

17: Coolant

18: glass-coated amorphous wire

19: winding roller.

Figure 2 is an example of a glass-coated amorphous fiber prepared by the method described above.

In this application, the term "amorphous fiber" has the meaning generally understood by those skilled in the art. Generally speaking, it refers to an alloy fiber that contains a variety of alloy elements, such as Co, Fe, Mn, Ni, Si, B, C, and transition metal elements.

In a specific embodiment, the present invention provides a kind of anti-theft security paper, implanted in the anti-theft security paper with large Barkhausen effect amorphous fiber, wherein the diameter of the amorphous fiber is 10-50 microns, preferably 20-30 microns; the length of the amorphous fiber is 2-10mm, or 3-8mm, or 3-5mm. The inventors of the present invention have found that the size of the amorphous fiber is low, for example, when the diameter is in the range of 10-50 microns, as long as the aspect ratio of the amorphous fiber is higher than 50, especially when higher than 100, the amorphous fiber still has The Great Barkhausen Effect. Therefore, if the length of the amorphous fiber is too low, it is difficult to detect. In ordinary paper, if the length of the amorphous fiber is too long and the difference between the amorphous fiber and the pulp fiber is too large, it will often have an adverse effect on the papermaking process.

In one embodiment, the content of the amorphous fiber in the anti-theft security paper is 15-30m/m ² , for example, the content of the amorphous fiber in each A4 paper is 1-2 meters. When the content of amorphous fibers is higher than 15 m/m ² (for example, when the content of amorphous fibers in each A4 paper is more than 1 meter), the detection equipment currently on the market can detect with high accuracy. However, if the content is too high, the cost of the anti-theft security paper will be greatly increased, therefore, preferably, the content of amorphous fiber in the anti-theft security paper is less than or equal to 30m/m ² (for example, in each A4 paper The content of amorphous fiber in it is less than 2 meters). In one embodiment, the content of the amorphous fiber in the anti-theft security paper is 3-30m/m ² , which is equivalent to the content of the amorphous fiber in each A4 paper is 0.2m-2m. In the content range below 15m/m ² , although commercially available detection equipment may not be easy to detect, it is still possible to detect by adjusting the parameters of the detection equipment.

In one embodiment, the amorphous fiber has a glass cladding and is produced by Taylor spinning. As defined above, the Taylor spinning method includes the following steps: 1. First provide a master alloy rod with the required composition, and select a matching glass tube, the difference between the melting point of the master alloy and the softening temperature of the glass tube is high at 50°C and lower than 500°C; 2. Insert the master alloy rod into the bottom of the glass tube; 3. Use a high frequency induction furnace to melt the bottom of the master alloy rod; 4. Use the melted master alloy to soften the glass tube; 5. Use drawing 6. The master alloy in the molten state is cooled by rapid solidification to form an amorphous alloy wire. The method can also continue to include the following steps: 7. Winding the wire on the take-up roller, the coiling speed of the wire keeps the line speed constant, and the line speed range is 10-100 m/min; 8. By adjusting the feeding speed , temperature and other parameters to maintain the stability of the drawing process and realize the continuous preparation of silk. The preparation of the amorphous fiber of the present invention by the Taylor spinning method has many advantages. At first, the Taylor spinning method can prepare amorphous fiber filaments with a diameter of 10-50 microns, which usually have a glass coating, according to Depending on the process, the thickness of the glass coating layer of the glass-coated amorphous fiber filament (or corresponding amorphous fiber) is 1-15 microns. The Taylor spinning method can prepare amorphous fiber filaments in a continuous and stable manner, and the prepared amorphous fiber filaments are easy to collect and easy to cut to form amorphous fibers with a desired aspect ratio.

After the amorphous fibers are prepared, the amorphous fibers can be mixed into papermaking raw materials such as pulp during the papermaking process to prepare the anti-theft security paper of the present invention. In this way, an anti-theft security paper with disordered arrangement of amorphous fibers can be prepared.

In some embodiments, the anti-theft security paper of the present invention is prepared by directly embedding amorphous fibers into the paper. In this way, an anti-theft security paper with orderly arranged amorphous fibers can be prepared.

There is no particular limitation on the material of the amorphous fiber, as long as the purpose of the present invention can be achieved. In some embodiments, the amorphous fiber contains:

a) One or more elements in Co, Fe, Mn, Ni;

b) one or more elements of Si, B, C; and

c) Optional rare earth or transition metals.

In the amorphous fiber of this composition, component a) is a component with a ferromagnetic substance, and component b) is a non-metallic alloy element. Component c) is optional, adding different proportions of components may cause the position of the switching field where the material produces the large Barkhausen effect to shift.

In some preferred embodiments, the amorphous fiber contains: 1-15% by weight of Fe; 2-12% by weight of Si; a total of 2-25% by weight of selected from B, Nb, Cu, Mn, Mo, one or more of Ni, Cr, and Al; and Co. In some preferred embodiments, the amorphous fiber contains: 1-15% by weight of Fe; 2-12% by weight of Si; a total of 2-25% by weight of selected from B, Nb, Cu, Mn, Mo, One or more of Ni, Cr and Al; and the balance of Co. Amorphous fibers with such a composition are preferred in the present invention because of their wide range of sources and ease of preparation.

For the anti-theft security paper of the present invention, the distribution range of the amorphous fibers in the paper is not limited, and in a specific embodiment, the amorphous fibers can be distributed in full pattern, positioned or a combination thereof Distributed in said anti-theft security paper. Solid distribution refers to the extent of amorphous fiber distribution throughout the entire paper. Positional distribution means that the range of amorphous fiber distribution is within a certain fixed range of the paper, for example, only at the edge or a corner of the paper.

For the anti-theft security paper of the present invention, there is no specific limitation on the arrangement of the amorphous fibers in the paper. In some embodiments, the amorphous fibers are arranged in the anti-theft security paper in an orderly arrangement, a random arrangement or a combination thereof.

In the present invention, examples of amorphous fibers distributed in paper in disordered full-scale distribution or ordered full-scale distribution or disordered positioning distribution or ordered positioning distribution are shown in Fig. 4 , Fig. 5 , Fig. 6 and Fig. 7 .

Example

The raw materials used in the examples of the present invention are conventional and can be purchased from the market, or can be prepared by conventional methods in a laboratory.

Detection method:

The detection equipment used in the embodiments of the present invention is electromagnetic (EM) label detection equipment, such as: the electromagnetic label detection gate produced by Sensormatic Corporation.

The principle of detection can be described as follows:

The detection equipment contains a signal transmitting device and a signal receiving device. The signal transmitting device generates an excitation magnetic field area by applying an alternating current or an alternating voltage in the induction coil, and the excitation magnetic field is an alternating magnetic field. The signal receiving device is an induction coil. When the amorphous fiber enters the excitation magnetic field region, due to its large Barkhausen effect, its internal magnetic domain structure will change rapidly under the excitation of the alternating magnetic field, and the electromagnetic field induced in the induction coil in the signal receiving device Pulse signals or higher harmonics. When the signal receiving device detects an electromagnetic pulse signal or a high-order harmonic, it indicates that a target detection object appears in the detection area.

Example 1

Preparation of Amorphous Fibers, Taylor Spinning Process

Referring to the accompanying drawing 1, the preparation method of the amorphous fiber of the present invention will be introduced by taking the glass-coated amorphous fiber as an example.

First, a Co-based master alloy rod is provided. The alloy rod has a melting point of 970° C., a diameter of 7 mm, and a composition of Co71.8Fe4.9Nb0.8Si7.5B15. Choose a glass tube with a softening temperature of 780°C, an outer diameter of 12mm, and a wall thickness of 1mm.

Insert the master alloy rod into the bottom of the glass tube;

The master alloy is melted in a high-frequency induction furnace and heated to 1200°C;

Soften the glass tube with molten master alloy;

Pull out the wire by pulling;

Through the cooling water, the master alloy in the molten state will be cooled to form an amorphous alloy;

Wound on the take-up roller, the take-up speed is 30 m/min;

By adjusting the feeding speed, temperature and other parameters, the stability of the drawing process is maintained, and the continuous preparation of silk is realized.

The continuous glass-coated amorphous fiber filament prepared in Example 1 has an inner amorphous core diameter of 15±2 microns and a glass outer layer thickness of 5±1 microns.

The obtained continuous glass-coated amorphous fiber filaments were cut into lengths of 0.5 mm, 1 mm, 2 mm, 5 mm, 10 mm and 15 mm for use.

Example 2

Papers with different contents of amorphous fibers are prepared by directly implanting the amorphous fibers prepared in Example 1 into the paper, wherein the total length distribution of the amorphous fibers in the paper is 0.5m/A4 paper, 0.75m/ A4 paper, 1m/A4 paper, 2m/A4 paper. The prepared paper containing amorphous fibers is tested, and the results are as follows (wherein each result is a statistical result obtained by repeated detection of 1000 sheets of paper, and the detection rate refers to when the paper is put into the detection area of the detection instrument, the detection instrument alarms times):

It can be seen from the above results that the glass-coated amorphous fiber prepared in Example 1 has a large Barkhausen effect. In the case where the length of the amorphous fiber is less than or equal to 1mm, the detection rate of the instrument for this anti-theft security paper is lower than 55%. However, when the length of the amorphous fiber is higher than 2mm, the detection rate of the instrument for the security paper The detection rate is higher than 78%, especially when the total length of the amorphous fiber in A4 paper is more than 1m, the detection rate reaches more than 97%.

The above descriptions are only exemplary implementations of the present invention, and are not intended to limit the protection scope of the present invention, which is determined by the appended claims.

This application claims the priority of Chinese patent application No. 201510156031.0 submitted on April 3, 2015, and the content disclosed in the above Chinese patent application is cited in its entirety as a part of this application.

Claims (10)

1. an anti-theft security paper, implants in this anti-theft security paper and has the non-of large Barkhusen effect Crystalline cellulose, a diameter of 10-50 micron of wherein said amorphous fiber；Described amorphous fiber a length of 2-10mm。

2. the anti-theft security paper of claim 1, wherein said amorphous fiber is in this anti-theft security paper Content is 3-30m/m²。

3. the anti-theft security paper of claim 1, wherein said amorphous fiber has glass fluxing technique layer, is Prepared by Taylor's spin processes.

4. the anti-theft security paper of claim 3, the glass fluxing technique of wherein said glass fluxing technique amorphous fiber The thickness of layer is 1-15 micron.

Anti-theft security paper any one of the most aforementioned claim, wherein said anti-theft security paper passes through will Amorphous fiber is implanted directly into be prepared in the middle of paper.

Anti-theft security paper any one of the most aforementioned claim, wherein amorphous fiber contains:

A) Co, one or more elements in Fe, Mn, Ni；

B) Si, one or more elements in B, C；With

C) optional rare earth or magnesium-yttrium-transition metal.

Anti-theft security paper any one of the most aforementioned claim, wherein said amorphous fiber a diameter of 20-30 micron；The a length of 3-8mm of described amorphous fiber.

Anti-theft security paper any one of the most aforementioned claim, wherein said amorphous fiber a diameter of 20-30 micron；The a length of 3-5mm of described amorphous fiber.

Anti-theft security paper any one of the most aforementioned claim, wherein amorphous fiber contains:

The Fe of 1-15 weight %；

The Si of 2-12 weight %；

Total amount be 2-25 weight % in B, Nb, Cu, Mn, Mo, Ni, Cr and Al One or more；And

The Co of surplus.

10. the anti-theft security paper of claim 1, wherein said amorphous fiber is in this anti-theft security paper Content is 5-15m/m²。