WO2022225282A1 - Recording medium for preventing leakage of hard copy - Google Patents

Abstract

The present invention relates to a recording medium for preventing leakage of hard copy, the recording medium including a substrate and a detection layer including microwires that are dispersedly incorporated inside the substrate and satisfy the conditions of: (1) 0.5 cm ≤ length ≤ 1.0 cm; (2) 200 < length/diameter of cross-section < 2000; and (3) 0.3 cm^-1 < curvature (K) < 3.0 cm^-1, wherein 30 to 300 microwires per 100㎠ of the recording medium are included, and the detection layer satisfies (4) the condition of a distance between most adjacently located microwires < 3.0 cm if necessary.

Description

Recording media to prevent leakage of printouts

The present invention relates to a recording medium for preventing leakage of printed matter.

As the need to control the export of printed documents as well as control of storage media increases, there is an attempt to prevent the export of secure documents by including a detection material in the recording medium. One method is to install a detection gate at the entrance, detect when a security document containing a detection material passes through the detection gate, and provide an alarm signal to prevent export. A magnetic material is used as the detection material, and an electromagnetic (EM) type security gate that detects the magnetic material is installed at the entrance.

The strip-type security paper is basically capable of identifying the detection material with the naked eye because of the size of the strip itself (generally about 20㎛ thick, 0.65~1.0mm wide, 3~5cm long). Accordingly, Korean Patent Laid-Open Publication No. 2008-0107977 proposes to introduce a shielding layer in order to prevent the detection material from being identified with the naked eye. However, in order to manufacture the security paper in which the shielding layer is introduced, a shielding layer introduction process such as coating, printing, and lamination must be added, which complicates the manufacturing process and increases the manufacturing cost.

In the case of strip-type security paper, several strips (usually two or so are inserted since the detection material is expensive) are inserted into one A4 sheet. However, in the EM security gate, it is known that a difference in sensing power occurs depending on the direction of the security paper. That is, the detection power is highest when the longitudinal direction of the detection material is perpendicular to the gate passage direction, and the detection force is very low when the detection material is horizontal to the passage direction. This phenomenon may be reversed depending on the setting of the gate. For this reason, with two or three strips inserted in any direction, it is impossible to guarantee more than a certain level of sensing power in all directions.

In addition, in the case of the strip-type security paper, the number of strips is small and the size is large, so it can be easily removed, and when the detection material is removed after printing, the function as the security paper is lost. An improved version of this is the microwire type security paper. Generally, microwires with a diameter of about 15 to 20 μm and a length of 5 to 10 mm are inserted into A4 size paper up to about 1,000. As such, hundreds of microwires are dispersed on a single A4 sheet, so it is not easy to remove.

For the production of microwire type security paper, a papermaking machine of a paper company, that is, a paper production facility used in the production of general copy paper is used. At this time, on production facilities, the microwire tends to be oriented in the MD direction (machine direction, usually in the vertical direction of A4 paper, 297 mm) rather than in the CD direction (cross-machine direction, generally A4 paper horizontal direction, 210 mm) (MD /CD=9/1 to 7/3). Therefore, in a directional EM security gate, high for all directions In order to maintain the level of sensing power, it should be produced based on the number of microwires in the CD direction of the security paper. However, in this case, a larger amount of microwires than necessary are inserted in the MD direction (vertical direction) of the security paper, which increases the manufacturing cost of the product, so it is necessary to improve it.

One object of the present invention is to overcome the technical limitations of the prior art, and to provide a recording medium for preventing output leakage having excellent detection and detection power in an electromagnetic type security gate using a microwire type detection material.

Another object of the present invention is to provide a recording medium for preventing output from leaking, which is excellent in detection sensing power in an electromagnetic type security gate and also in a recognition rate in a security printer.

The present inventors have found that when using a microwire-type detection material instead of a strip-type detection material used in the prior art, when used in a curved shape, that is, in an arc shape, the detection detection power in the electromagnetic type security gate, as well as the recognition rate in the security printer, are also It was found to be excellent, and the present invention was completed. Accordingly, the means for solving the problems of the present invention are as follows:

1. A detection layer comprising a substrate and microwires dispersed and incorporated in the substrate, satisfying the conditions of (1) to (3) below

(1) 0.5cm ≤ the length of the microwire ≤ 1.0cm,

(2) 200 < length of microwire/diameter of cross-section of microwire < 2000, and

(3) 0.3 cm ^-1 < Curvature (K) of microwire < 3.0 cm ^-1

As a recording medium for preventing output leakage comprising a,

A recording medium for preventing the leakage of output that contains 30 to 300 microwires per 100 cm 2 of the recording medium.

2. The recording medium for preventing output from leaking in 1 above, wherein 70% or more of the microwires included in the detection layer satisfy the conditions (1) to (3).

3. The recording medium for preventing the leakage of the output of 1 or 2 above, wherein the detection layer satisfies the condition of (4):

(4) The distance between the microwires present in the closest position < 3.0cm.

4. The recording medium for preventing output from leaking in 1 above, wherein the microwire includes a metal core and an insulating layer coated on the metal core.

5. The recording medium for preventing leakage of the output according to 4 above, wherein the insulating layer is made of glass and has a thickness of 0.5 to 3.0 μm.

6. The recording medium for preventing leakage of the output of 4 above, wherein the metal core includes Co, Fe, Cr, Si and B.

7. The recording medium for preventing the leakage of the output of 1 above, further comprising a layer of a substrate in which microwires are not incorporated on one or both sides of the detection layer.

8. The recording medium for preventing the output of the above 7 in the form of four or more laminated papers in which two or more two-ply papers are provided with a substrate layer in which microwires are not mixed on one side of the detection layer, and are laminated with an adhesive layer interposed therebetween.

9. The recording medium for preventing the output of the above 8, wherein the adhesive layer is laminated so as to be in contact with the surface of the detection layer of the two-ply paper.

10. The recording medium for preventing output from leaking according to 1 or 2 above, wherein the detection layer includes a microwire having a curvature angle of 0.3 to 1.5 radians.

According to the present invention, it comprises a substrate and a detection layer including microwires dispersed and mixed in the substrate and satisfying the conditions of (1) to (3) described above, and 30 to 300 per 100 cm of recording medium. Provided are a recording medium for preventing leakage of output including microwires and a method for manufacturing the same.

In the recording medium for preventing output leakage according to the present invention, a microwire type detection material having a curved shape (arc shape) is used, so that excellent detection and detection power can be secured in an electromagnetic type security gate.

In addition, in the present invention, by making the microwires that satisfy the above-mentioned conditions (1) to (3) less than a certain distance, it is possible to secure excellent detection and detection power in the electromagnetic type security gate as well as excellent recognition rate in the security printer, Compared with the conventional security paper, the ability to prevent ejection of printed documents is further improved.

1A and 1B show a method of calculating the curvature (K) of a microwire.

2 is a graph showing the detection sensing power according to the curvature (K) of the microwire in the electromagnetic type security gate.

3A and 3B are views showing a plane in the direction of the paper during a detection test of a recording medium for preventing leakage of an A4 size printout in an electromagnetic (EM) type security gate for one person.

The present invention relates to a recording medium for preventing output leakage, wherein the recording medium for preventing output leakage includes a substrate and microwires dispersed and mixed in the interior of the substrate, satisfying the following conditions (1) to (3) a detection layer,

(1) 0.5cm ≤ the length of the microwire ≤ 1.0cm,

(2) 200 < length of microwire/diameter of cross-section of microwire < 2000, and

(3) 0.3 cm ^-1 < Curvature (K) of microwire < 3.0 cm ^-1 ,

30 to 300 microwires per 100 cm 2 of the recording medium.

In the present invention, the 'recording medium for preventing leakage of printed matter' means 'electronic sensitive security paper' among the types of security paper. Security paper is largely divided into 'electronic sensitive security paper', 'copy-obstructed security paper' and 'counterfeit prevention security paper'. 'Electronic sensitive security paper' is a printing paper designed to generate an alarm when an electronic sensitive gate (EM gate) installed at the doorway detects when the printout is leaked. It is a printing paper designed so that anyone can easily distinguish the original from the copy by creating a different image. 'Anti-counterfeiting security paper' does not show a special condition on the surface, but is designed to distinguish the genuine product through a special lamp or phenomenon.

The printout leakage prevention system is essentially composed of a security paper and a security gate, and optionally a security printer is further provided. A security printer is a printer that recognizes and prints only security paper, but does not print plain paper. If an organization or organization that wants to prevent printouts uses only secure paper as print paper, even if someone tries to secretly take out confidential documents using a general printer, it is detected at the security gate and can prevent leakage of important documents. However, these security gates are useless when a person who wants to take out confidential documents secretly brings in plain paper and prints it out on a regular printer before taking it out. Therefore, it is desirable to configure a printout prevention system in connection with a security printer in order to completely prevent printouts from leaking. Therefore, according to the output prevention system, it may be more preferable that the recording medium for preventing the output leakage has a high recognition rate in the security printer as well as the detection detection power in the security gate.

When the length of the detection material is the same, an increase in the cross-sectional area increases the electromotive force (e ≒NBAf), that is, the size of the harmonic component. A larger /A4) may be advantageous. In the recording medium for preventing printouts according to the present invention, it is preferable that the number of microwires per 100 cm 2 of the recording medium is 30 to 300 when a plurality of microwires are introduced into one sheet of A4 size paper in any direction. If the number of microwires per 100cm2 is less than 30, the detection power is low, and if it is greater than 300, the detection power is high, but the amount of microwires used is large, resulting in a cost increase, and it is not preferable because the white sensitivity is lowered by affecting the basic color of the paper. .

In the recording medium for preventing output leakage according to the present invention, the detection layer includes a microwire satisfying the characteristics of (1) to (3) as a detection material, thereby exhibiting a level of sensing power required for an electromagnetic type security gate. can Hereinafter, the conditions of the above (1) to (4) will be described in detail.

(1) Length of microwire

In the recording medium for preventing output leakage according to the present invention, the detection layer includes microwires having a length of 0.5 cm or more and 1.0 cm or less. If the length of the microwire is less than 0.5 cm, the anti-magnetic effect is increased, and the recognition rate in the security printer is also lowered. If the length of the microwire exceeds 1.0 cm, When the security recording medium is manufactured, the dispersibility of the microwires is deteriorated and agglomeration occurs, which is undesirable because the yield is lowered and the price of the security recording medium is increased.

(2) Ratio of the length of the microwire/diameter of the cross-section of the microwire

In the recording medium for preventing output leakage according to the present invention, the detection layer includes microwires satisfying 200 < microwire length/cross-sectional diameter < 2000. If the microwire satisfies these conditions, an excellent sensing effect can be obtained in the EM security gate. When the value of the length of the microwire / the cross-sectional diameter of the wire is less than 200, the anti-magnetic field effect is large and the sensing power is weakened. Since it is difficult to stably maintain the magnetism of the recording medium, it is difficult to secure quality as a detection/identification sensor.

When the value of the length of the microwire/diameter of the cross-section of the wire is less than 200, the anti-magnetic field effect is increased, and the thickness (total diameter) of the microwire is large compared to the total thickness of the recording medium, so that the microwire is exposed on the surface of the recording medium. As this increases, the smoothness is adversely affected. In addition, there is a possibility that the skin puncture problem due to the protrusion of the microwire may occur. In order to completely block the protrusion of microwires from the surface of the recording medium, it can be produced in the form of overlapping paper. Considering this, it is preferable that the ratio of the thickness is less than 0.4. On the other hand, it is difficult to uniformly manufacture microwires having a ratio of less than 0.1 in view of current manufacturing technology, and the magnetic properties required for the detection material tend to decrease rapidly, which is not preferable. Therefore, the ratio between the thickness of the microwire (total diameter) and the thickness of the recording medium is preferably 0.1 to 0.4.

(3) Curvature and angle of curvature of microwire

In the recording medium for preventing output leakage according to the present invention, the detection layer includes microwires satisfying the condition of 0.3 cm ^-1 < curvature (K) of microwire < 3.0 cm ^-1 .

The magnetic properties of the magnetic material detection material largely depend on its composition, but even if the composition is the same, it may vary depending on the shape of the magnetic material. In particular, the demagnetizing effect is very sensitive to the shape of the magnetic material. When a thin and long magnetic material is placed in a magnetic field in the longitudinal direction, the demagnetizing effect is very small, but when the short side is placed in the magnetic field, the demagnetizing effect is very large. This means that when a magnetic field is applied to a magnetic material from the outside, the actual magnetic field felt by the magnetic material may vary greatly depending on the shape and direction of the magnetic material. For this reason, in the EM-type security gate, the detection power varies greatly depending on the longitudinal direction of the detection material.

The recording medium for preventing the leakage of printed matter is produced using a paper machine of a paper company. Basically, in the paper produced by the paper machine, additional materials such as cellulose or elongated materials tend to be oriented in the MD direction (vertical direction). Therefore, the security paper must be produced based on the number of microwires in the CD direction (horizontal direction) to secure excellent sensing power. However, since this will cause a large amount of microwires to be inserted in the MD direction than necessary, it is a factor that significantly increases the unit cost of the product. In the present invention, microwires arranged at an angle of less than 45 degrees with a straight line parallel to the vertical direction of the recording medium are referred to as microwires in the MD direction, and microwires arranged at an angle of 45 degrees or more are referred to as microwires in the CD direction. .

If the MD/CD ratio of the detection material can be improved during the production of a recording medium using a paper machine, the problem of detection detection power deviation according to the directionality of the detection material can be solved, but the MD/CD ratio cannot be improved without supplementing the process equipment. difficult. Accordingly, in the present invention, a security recording medium is manufactured using an existing paper machine, but the direction problem in the EM type security gate is solved by using a curved shape, that is, an arc shape, of a microwire, which is a detection material.

[Equation 1]

As shown in FIG. 1A and Equation 1, the curvature K in the circle can be calculated from the length of the radius. In FIG. 1A, if P and P' are both ends of the microwire, Δs corresponds to the length of the microwire, and Δθ corresponds to the angle of curvature (radians). 1B shows an example of measuring a diameter to calculate a curvature of a microwire of a recording medium.

In the present invention, by including a microwire in a curved form in the detection layer, specifically, a microwire satisfying the condition of 0.3 cm ^-1 < microwire curvature (K) < 3.0 cm ^-1 , the directionality in the security gate of the EM method to minimize the deviation in sensing power. If the curvature of the microwire is less than 0.3 cm ^-1 , the curvature effect is small, so the directionality problem in the security gate is hardly improved ^. It does not perform its role as a detection material properly, which seems to be due to the sudden increase in the anti-magnetic field effect.

In the recording medium for preventing output leakage according to the present invention, the detection layer may include a microwire having a curvature angle of 0.3 to 1.5 radians. In Equation 1, the curvature angle (Δθ) is a value calculated as curvature x wire length, and represents the difference in angle between both ends of the bent microwire. If the curvature angle of the microwire is less than 0.3 radian, the curvature effect is small, so the directionality problem in the security gate is hardly improved. The magnetic field effect may be increased and the function as a detection material may be deteriorated.

In the present invention, in order to be well detected by an electromagnetic (EM) type security gate and to be properly recognized by a security printer, the recording medium for preventing output leakage includes at least some microwires satisfying the conditions of (1) to (3) described above. , Preferably it is good to contain 70% or more. Although 100% of the microwire may satisfy all of the conditions of (1) to (3) described above, in this case, the manufacturing cost may be excessively increased, and the microwire that does not satisfy all of these conditions in the microwire manufacturing process may be included. In addition, when 70% or more of the microwires included as the detection material satisfy the above conditions, the security gate can detect within an error range. Accordingly, within 30% of the total microwires included in the recording medium for preventing output leakage according to the present invention, microwires that do not satisfy one or more of the conditions (1) to (3) may be included.

In the present invention, as the microwire, any one manufactured by any method can be used as long as the conditions of (1) to (3) are satisfied. Examples thereof include, but are not limited to, in-rotating-water quenching method, cold drawn method, melt extraction method, quenching-and-drawing method, Taylor-Ulitovsky method, Adar-Bolotinsky method, and the like.

(4) distance between microwires

The distance between the microwires closest to each other in the microwires included in the detection layer in the recording medium for preventing output leakage according to one embodiment of the present invention may be less than 3.0 cm. This is because, if the distance between the microwires is greater than 3.0 cm, the identification recognition rate in the security printer tends to decrease. Therefore, when a security printer is provided in the output leakage prevention system, it may be desirable to further satisfy the condition of (4) above in order to secure an identification recognition rate in the security printer.

Although the magnetic property of a detection material is an important factor in the detection of a security gate, the presence or absence of a specific recognizable metal is an important factor in the recognition rate in a security printer. Although a recognition method using magnetism can be introduced to security printers, in this case, the cost increases and the equipment configuration becomes complicated.

In the present invention, the microwire may include a metal core and an insulating layer coated on the metal core. The metal core may include Co, Fe, Cr, Si, and B, and the insulating layer may be made of glass, and the thickness thereof may be 0.5 to 3 μm. In the present invention, since the metal core constituting the microwire contains Co, Fe, Cr, Si and B, it is possible to secure the detection power in the security gate and the recognition rate in the security printer to a required level.

In the present invention, the microwire The cross-sectional diameter means the diameter of the magnetically meaningful metal core, and the thickness of the microwire means the total diameter including the metal core and the insulating layer.

The recording medium for preventing output leakage according to the present invention may further include a substrate layer in which microwires are not incorporated on one or both sides of the detection layer. In addition, the recording medium for preventing output leakage according to the present invention may be in the form of a four-ply or more laminated paper in which two or more two-ply papers having a layer of a substrate not mixed with microwires on one side of the detection layer are stacked with an adhesive layer therebetween. . In this case, the adhesive layer may be configured to be in contact with the surface of the detection layer of the two-ply paper.

The basis weight of the recording medium for preventing output leakage according to the present invention is a final product (a single-ply paper consisting only of a substrate and a detection layer in which microwires are mixed in the substrate, and a layer of the substrate in which microwires are not mixed on one side of the detection layer is provided 30 to 100 g / m 2 based on double-layered paper, multi-ply paper with four or more layers stacked with two or more of the two-ply paper, or three-ply paper with a substrate layer in which microwires are not mixed on both sides of the detection layer) to be. Since the recording medium for preventing output leakage according to the present invention basically corresponds to copy/printing paper for a printer, it is preferable to have a basis weight similar to that of existing commercial copy/printing paper. If the basis weight is lower than 30 g/m2, it is difficult to manufacture paper with microwires mixed in, and it is too thin to use. can

The recording medium for preventing output leakage according to the present invention is manufactured by using a paper machine of a paper company equipped with a Jangmang paper machine, a Hwanmang paper machine and a combination paper machine, for example, by the method described in Korean Patent Application Laid-Open No. 2017-0053027. can When using a combination paper machine, 2-ply, 3-ply, 4-ply, etc. can be manufactured at a time, and at this time, at least one layer (ply) becomes a detection layer including microwires as a detection material. In addition, the final recording medium may be manufactured using a laminating machine using the paper manufactured in the paper machine as a base stock (substrate). A laminating machine is a facility that coats one side of a base base paper with an adhesive and laminates the other base base paper to make a final product. The two base base papers may be the same kind of base paper or different kinds of base paper. That is, when there are two base base papers, they may be one in which microwires are mixed or not, one-ply paper or two-ply paper or more, respectively. For example, one base stock paper is a two-ply paper composed of a layer of a substrate in which microwires are incorporated (that is, a detection layer) and a substrate in which microwires are not incorporated, and the other base stock paper is a substrate in which microwires are not incorporated. In the case of one-ply paper made of , the final product may be three-ply paper.

Since the recording medium for preventing output leakage according to the present invention basically corresponds to copying/printing paper for printers, the material of the substrate may be white paper which occupies most of the copy paper regardless of whether microwires are mixed , but it may be thin paper, but the The composition may be similar to that of white paper.

The layered shape of the final product does not affect the detection power at the security gate of the recording medium for preventing printouts or the recognition rate in the security printer. However, the recording medium for preventing output leakage is three or more layers, at least one of the inner layers is a detection layer in which microwires are mixed in the substrate, and the outermost both sides of the recording medium are composed of a layer of the substrate in which microwires are not mixed. It may be advantageous in that it does not cause problems such as skin puncture due to microwire protrusion.

Example

Hereinafter, the present invention will be described in more detail through examples. However, these examples are merely illustrative of the present invention, and are not intended to limit the scope of the present invention to the scope of the present invention.

Examples 1 to 13

Micro having a cross-sectional diameter of 5 to 25 μm, a metal core in the form of an amorphous alloy containing Fe, Co, Cr, B and Si, and an insulating layer made of glass (silicon dioxide) and having a thickness of 0.5 to 3 μm Wires were prepared by the modified/modified Taylor-Ulitowski method, and microwires in which conditions (1) to (3) had the values shown in Table 1 were prepared.

The prepared microwires are mixed with the slurry pulp, and papermaking is performed by a known method (for example, the method described in Korean Patent Application Laid-Open No. 2017-0053027) using a paper machine equipped with a long mesh paper machine, a Hwan mesh machine and a combination paper machine to make final basis weight. The recording media of Examples 1 to 13 were prepared in which the content was 80 g/m 2 and condition (4) had the values shown in Table 1 below.

Comparative Examples 1 to 15

Recording media of Comparative Examples 1 to 15 were prepared in the same manner as in Example 1, except that conditions (1) to (4) had the values shown in Table 1 below.

Description of conditions (1) to (4)

(1) Length of microwire (Δs)

(2) Length of microwire/diameter of cross section of microwire

(3) Curvature of microwire (K)

(4) The distance between the microwires in the closest position (based on A4)

Angle of curvature (radians, Δθ) = K x Δs; Curvature K = Δθ/Δs = Δθ/RΔθ = 1/R

Examples 14 to 16 and Comparative Examples 15 to 17

The conditions shown in Table 2 below were satisfied using the microwires (microwire A) used in Examples 1, 2, and 5 to 7 and the microwires (microwire B) used in Comparative Examples 1, 5, 9, 12 and 13. A recording medium was prepared.

Experimental example

Examples 1 to 16 and Comparative Examples 1 to 17 were evaluated for the following items, and the results are shown in Table 3.

1. Security gate detection detection power

Sensitivity when a recording medium was passed through two electromagnetic gates (mono type EVOLVE EM system manufactured by Checkpoint Corporation, dual type EM system manufactured by SSL T) was measured, and the detection sensitivity was indicated by a 5-point method. The higher the number, the higher the sensitivity, and X is not recognized by the gate. In Table 3, in the paper flat display, uppercase letters mean the vertical direction of the paper (297mm for A4 paper), and lowercase letters mean the horizontal direction of the paper (210mm for A4 paper). 3 is a view showing the plane of the paper direction during the detection test of a recording medium for preventing leakage of A4 size output in an electromagnetic (EM) type single-person security gate (Zx plane: when passing an A4 paper vertically in the chest; Zy plane: when passing an A4 sheet vertically by the side).

2. Secure printer identification awareness

When the recording medium was printed on a security printer (CLP-755N_M-fine laser printer manufactured by Korate), it was recognized as security paper and the actual printing progress was checked, and the identification and recognition power was displayed in a 5-point method (the larger the number, the higher the recognition power). indicates that).

3. White sensitivity

A portion of the paper was measured using an eXact meter from X-rite, USA. The larger the measured value, the more it appears white when observed with the naked eye.

According to Table 3, it was confirmed that the recording medium for preventing output leakage of Examples 1 to 13, in which the values of conditions (1) to (3) satisfies the range of the present invention, have excellent sensing power in the electromagnetic type security gate. Examples 1 to 12 satisfy condition (4) the distance between the microwires present in the closest position < 3.0 cm, and thus the identification recognition power in the security printer is also excellent. Comparative Examples 1 to 14 are recording medium 100 cm2 When any one or more of the conditions (1) to (3) of 30 to 300 per microwire is out of the scope of the present invention, the detection detection power at the security gate is insufficient, or the white sensitivity is low as less than 110 for printing paper It was confirmed that it was not suitable for use as a recording medium for preventing the leakage of printouts as well as (copy paper).

Comparative Example 4 used a 1.5 cm long microwire, that is, condition (1) was outside the upper limit of the present invention, and the retention rate was poor for reasons such as poor dispersibility when manufacturing a security recording medium, and removal in the selection process. This lowered to less than 60% (the retention rate when the length of the microwire is 1.0 cm or less is 80 to 95%), and the unit price rose more than the lengthened amount. In terms of physical properties, the detection power of the dual-type EM gate is good, but the detection power of the Zx plane was low in the mono-type security gate. (2.143), as a result, it seems that the anti-magnetic field effect is increased (in all of Examples 1 to 12, the curvature angle is less than 1.5 (0.31 to 1.48)).

In the case of Comparative Examples 1, 5, and 9, condition (1) is outside the lower limit of the present invention, and when the length of the microwire is less than 0.5 cm, even if condition (2) is satisfied (Comparative Example 1) Sensing power at the security gate You can see this very low. Although the aspect ratio of the microwire is important, it seems that the EM method has an excellent effect when it is basically more than the minimum length.

In the case of Comparative Example 3, the condition (3) exceeded the upper limit of the present invention (curvature 3.45 cm ^-1 ), regardless of the curvature effect of the microwire, the function as a detection material fell, and the detection power was rapidly lowered. It was analyzed that the effect of the anti-magnetic field effect was also present with a curvature angle of 2 or more.

Comparative Examples 8, 10, 12, 13 and 14 are cases in which condition (3) is outside the lower limit of the present invention (Comparative Examples 12 to 14 use a straight wire), and the curvature effect is small or absent in the security gate. It was confirmed that the directionality problem was not improved.

In Comparative Examples 2 and 7, the number of microwires per 100 cm 2 was less than 30, and the number of microwires was insufficient and thus hardly detected in the EM gate. In addition, if the distance between the microwires that are closest to the detection layer (condition (4)) exceeds 3.0 cm, the distance between the microwires is too long so that the identification sensor of the security printer cannot recognize it in a short time. The probability was lowered and there were cases where it was not recognized as a security paper.

In Comparative Examples 6 and 11, the number of wires per 100 cm2 was 300 or more, and the detection power in the security gate or the recognition power in the security printer were excellent, but the white sensitivity was less than 110, and more than necessary microwires were used, resulting in an increase in unit cost did.

On the other hand, Examples 14 to 16 are recording media containing 70% or more of microwires satisfying the conditions of (1) to (3), and both the detection power in the EM method security gate and the recognition power in the security printer are excellent. Confirmed. On the other hand, Comparative Examples 15 to 17 are recording media containing more than 30% of microwires that do not satisfy any one or more of (1) to (3), and it was confirmed that the sensing power of the EM gate was insufficient.

As described above, in the recording medium for preventing output leakage according to the present invention, the problem of directionality in the electromagnetic type security gate is improved by using a large number of curved, that is, arc-shaped detection microwires, and as a result, the Sensitivity has been improved.

Claims (10)

1. A detection layer comprising a substrate, and microwires dispersed and mixed in the substrate and satisfying the conditions of (1) to (3) below

   (1) 0.5cm ≤ the length of the microwire ≤ 1.0cm,

   (2) 200 < length of microwire/diameter of cross-section of microwire < 2000, and

   (3) 0.3 cm ^-1 < Curvature (K) of microwire < 3.0 cm ^-1

   As a recording medium for preventing output leakage comprising a,

   A recording medium for preventing the leakage of output that contains 30 to 300 microwires per 100 cm 2 of the recording medium.
2. The recording medium for preventing output leakage according to claim 1, wherein 70% or more of the microwires included in the detection layer satisfy the conditions (1) to (3).
3. The recording medium for preventing output leakage according to claim 1 or 2, wherein the detection layer satisfies the following condition (4):

   (4) The distance between the microwires present in the closest position < 3.0cm.
4. The recording medium of claim 1, wherein the microwire includes a metal core and an insulating layer coated on the metal core.
5. The recording medium of claim 4 , wherein the insulating layer is made of glass and has a thickness of 0.5 to 3 μm.
6. 5. The recording medium of claim 4, wherein the metal core includes Co, Fe, Cr, Si and B.
7. The recording medium for preventing output leakage according to claim 1, further comprising a layer of a substrate in which microwires are not incorporated on one or both surfaces of the detection layer.
8. The recording medium for preventing output leakage according to claim 7, wherein two or more two-ply papers having a substrate layer in which microwires are not mixed are provided on one surface of the detection layer and in the form of four or more laminated papers stacked with an adhesive layer therebetween.
9. The recording medium of claim 8 , wherein the adhesive layer is laminated so as to be in contact with the surface of the detection layer of the two-ply paper.
10. The recording medium of claim 1 or 2, wherein the detection layer includes microwires having a curvature angle of 0.3 to 1.5 radians.

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