WO2021079465A1

WO2021079465A1 - Printing paper

Info

Publication number: WO2021079465A1
Application number: PCT/JP2019/041725
Authority: WO
Inventors: 幸男森村; 亨下島
Original assignee: 株式会社三宅
Priority date: 2019-10-24
Filing date: 2019-10-24
Publication date: 2021-04-29

Abstract

The present invention discloses a printing paper which is easily produced and is able to be detected by a metal detector, while being able to be used as same as the conventional printing papers. A printing paper according to the present invention comprises a metal foil layer and printable layers which are respectively provided on both surfaces of the metal foil layer. With respect to this printing paper, the metal foil layer has a thickness of more than 6 μm but not more than 20 μm, and each printable layer has a thickness of from 40 μm to 55 μm.

Description

Printing paper

The present invention relates to a printing paper, and more particularly to a printing paper suitable for printing confidential information.

Conventionally, for the purpose of preventing counterfeiting and shoplifting, a technique of squeezing or pasting a magnetic wire on paper has been proposed (Patent Documents 1 and 2).

Japanese Unexamined Patent Publication No. 2002-317398 Japanese Unexamined Patent Publication No. 2006-268109

The paper described in Patent Documents 1 and 2 is made of a paper by an apparatus that generates an alternating magnetic field by using a magnetic wire made of a material that causes a phenomenon called a large Barkhausen effect, such as an Fe—Co amorphous material. It is possible to detect the carry-out. Here, the large Barkhausen effect is a phenomenon in which the magnetization direction is reversed due to a change in the external magnetic field.

However, the material that causes the phenomenon called the large Barkhausen effect is expensive, and it is not easy to squeeze or attach wire-like metal to the paper. Therefore, it is not realistic to use it as copy paper or printer paper used in normal business. Further, since the density of the wire in the paper is very low, there is a problem that the detection accuracy decreases as the distance from the coil that generates the magnetic field increases.

In addition, gate-type metal detectors are widely used in sites where it is necessary to monitor the removal of confidential information. Therefore, it is desirable to monitor the take-out of printed matter near the metal detector. However, if a magnetic sensor (EM sensor) that detects an amorphous material is grounded near the metal detector, it is likely to malfunction due to the electromagnetic waves generated by the metal detector. Therefore, it is necessary to reduce the sensitivity of the magnetic sensor for operation, and there is a problem that the detection accuracy is lowered.

The present invention has been made in view of such problems of the prior art, and provides a printing paper that can be used in the same manner as the conventional printing paper and is easy to manufacture and can be detected by a metal detector.

According to one aspect of the present invention, the printing paper has a metal foil layer and printable layers provided on both sides of the metal foil layer, and the thickness of the metal foil layer is thicker than 6 μm and 20 μm or less. There is provided a printing paper characterized in that the thickness of each printable layer is 40 μm or more and 55 μm or less.

According to the present invention, it is possible to provide a printing paper that can be used in the same manner as the conventional printing paper and that is easy to manufacture and can be detected by a metal detector.

Other features and advantages of the present invention will be clarified by the following description with reference to the accompanying drawings. In the attached drawings, the same or similar configurations are designated by the same reference numbers.

The accompanying drawings are included in the specification and are used to form a part thereof, show embodiments of the present invention, and explain the principles of the present invention together with the description thereof.
It is a figure which shows the structural example of the printing paper which concerns on embodiment of this invention. It is a figure which shows the structure of the Example and the comparative example of the printing paper of this invention. It is a figure which shows the evaluation result of the Example and the comparative example of the printing paper of this invention. It is a figure which shows the presentation material used for the evaluation of print quality.

Hereinafter, the present invention will be described in detail with reference to the accompanying drawings based on an exemplary embodiment. The following embodiments do not limit the invention according to the claims. Further, although a plurality of features are described in the embodiment, not all of them are essential to the invention, and the plurality of features may be arbitrarily combined. Further, in the attached drawings, the same or similar configurations are designated by the same reference numbers, and duplicate explanations are omitted.

The printing paper according to the embodiment of the present invention can be used as a substitute for PPC paper or plain paper in printing equipment generally used in offices and homes such as copiers, laser printers, inkjet printers, and plain paper facsimiles. Moreover, it is a printing paper that can be detected by a metal detector.

FIG. 1 is a diagram showing a configuration example of printing paper according to an embodiment, in which a is a plan view and b is a cross-sectional view taken along the line AA of a. The printing paper 100 has a configuration in which printable layers are provided on both sides of the metal foil layer, and specifically, the first printable layer 101 / first adhesive layer 102 / metal foil layer 103 / second. It has a five-layer structure of an adhesive layer 104 / a second printable layer 105.

The first printable layer 101 and the second printable layer 105 may be sheet-like members having the same material and thickness, and may be paper or a medium having the same characteristics as paper in printing (for example, synthetic paper). Further, known additives and coating agents for improving the acceptability of color materials such as inks and toners used for printing and adjusting the whiteness and smoothness may be used.

In the present embodiment, the sheet-like member that can be used as the first printable layer 101 and the second printable layer 105 preferably has a thickness of 55 μm or less, and more preferably 50 μm or less. .. Further, the thickness is preferably 40 μm or more, and more preferably 42 μm or more.

If the thickness exceeds 55 μm, the curl of the printed paper becomes large, which is not preferable. In particular, curling is likely to occur in printing equipment to which high heat is applied in the paper transport path, such as electrophotographic printing equipment, but curling also occurs in inkjet printing equipment.
Further, if the thickness is less than 42 μm, there is no problem in the electrophotographic printing device, but when used in the inkjet printing device, ink bleeding occurs and the print quality deteriorates. Not preferable in terms of points.

A metal foil layer 103 is provided between the first printable layer 101 and the second printable layer 105. The metal foil layer 103 is provided on the entire surface of the printing paper. Any kind of metal foil that can be detected by the metal detector can be used as the metal leaf layer 103. Iron foil, copper foil, aluminum foil and the like can be preferably used in consideration of availability, but aluminum foil is particularly preferable from the viewpoint of lightness, thinness and price.

The thickness of the metal foil layer 103 (that is, the metal foil) is preferably 20 μm or less, more preferably 10 μm or less, and most preferably 8 μm or less. Further, it is preferably thicker than 6 μm. When the thickness is 6 μm or less, the laminating process becomes difficult and the metal foil is liable to be torn. On the other hand, when the metal foil becomes thick, the cost increases, and when the printing paper becomes thick, the number of sheets that can be stored in the tray decreases, and the rigidity increases, which causes an adverse effect. The metal foil is preferably thin if it can be detected by a metal detector.

The printing paper of this embodiment can be easily manufactured by a known wet laminating process. Specifically, an adhesive is applied to the first surface of the roll-shaped metal foil with a coater, bonded to the roll-shaped printable layer member, dried and wound, and the same process is applied to the second surface of the metal foil. After that, it can be manufactured by cutting it into a predetermined size.

Although it is possible to use the adhesive used for laminating as the adhesive used for bonding, a water-soluble or emulsion type adhesive can be preferably used.

The printing paper of the present embodiment may have a thickness similar to that of plain paper or high-quality paper having a ream weight of about 70 to 90 kg used in general printers, copiers, etc., while satisfying the above-mentioned range of thickness of each layer. preferable. Specifically, the total thickness is preferably 88 μm or more and 130 μm or less, and more preferably 110 μm or less. If it exceeds 130 μm, it does not mean that it cannot be used immediately, but if the thickness increases, the number of printing papers that can be stored in the tray decreases, and the rigidity of the printing papers increases, resulting in a difference in usability.

The rigidity (stiffness) of the printing paper is, for example, a value (Nm ・ m) measured by a method compliant with JIS P8125: 2000 or a method compliant with TAPPI UM409, and is preferably 0.8 or less, preferably 0.7. The following is more preferable. Even if the stiffness exceeds 0.8, printing will not be hindered immediately, but it will be clearly harder than general printing paper, so users may feel uncomfortable or mixed with general printing paper. It becomes difficult to use when it is made to use. Further, the stiffness is preferably 0.45 or more.

(Example 1)
An emulsion-type adhesive (MOVIN 987B manufactured by Japan Coating Resin Co., Ltd.) containing acrylic as the main component is applied to an aluminum foil with a thickness of 6.5 μm as a metal foil layer, and the thickness as a printable layer is 44 μm and the basis weight is basis weight. Wet laminating of 37.4 g / m ² paper was performed on both sides of the aluminum foil, and the paper was cut into A4 size to obtain printing paper. The thickness and basis weight are standard values in the standard.
When the thickness and basis weight of the obtained printing paper were actually measured, the thickness was 97 μm and the basis weight was 105.0 g / m ² .

(Example 2)
A printing paper was obtained in the same manner as in Example 1 except that an aluminum foil having a thickness of 20 μm (basis weight 54 g / m ^{2) was used as the metal foil layer.}
When the thickness and basis weight of the obtained printing paper were actually measured, the thickness was 125 μm and the basis weight was 165.5 g / m ² .
(Example 3)
A printing paper was obtained in the same manner as in Example 1 except that a paper having a thickness of 41 μm and a basis weight of 33.5 g / m ^{2 was used as the printable layer.}
When the thickness and basis weight of the obtained printing paper were actually measured, the thickness was 88 μm and the basis weight was 91.4 g / m ² .

(Comparative Example 1)
A printing paper was obtained in the same manner as in Example 1 except that a paper having a thickness of 66 μm and a basis weight of 52.3 g / m ^{2 was used as the printable layer.}
When the thickness and basis weight of the obtained printing paper were actually measured, the thickness was 137 μm and the basis weight was 128.2 g / m ² .
(Comparative Example 2)
A printing paper was obtained in the same manner as in Example 1 except that an aluminum foil having a thickness of 30 μm (basis weight 81 g / m ^{2) was used as the metal foil layer.}
When the thickness and basis weight of the obtained printing paper were actually measured, the thickness was 135 μm and the basis weight was 193 g / m ² .

The printing papers obtained in Examples 1 to 3 and Comparative Examples 1 and 2 were evaluated as follows.
・ Print quality Color presentation documents created with Microsoft PowerPoint 2016 can be printed on electrophotographic printing equipment (Fuji Xerox color multifunction device DocuCentre-IV C2270) and inkjet printing equipment (Epson color inkjet multifunction device). Using the PX-M680F), the presentation material shown in FIG. 3 was color-printed on one side, and the print quality (sharpness) was visually evaluated. For convenience, FIG. 3 shows a grayscale image. In addition, some characters have been changed to protect information.
-Curl amount The curl amount after printing was evaluated for the case of printing on the front side and the case of printing on the back side. The amount of curl after printing was determined to be good when the printed paper was placed on a flat surface and the height of the floating edge at the time when 10 minutes had passed was measured, and the largest value was 1 cm or less.
・ Stiffness (only in Examples 1 and 2 and Comparative Example 2)
The stiffness (Nm ・ m) was measured by a method conforming to JIS P 8125: 2000 or a method conforming to TAPPI UM409. The stiffness of the printing paper in the longitudinal direction and the lateral direction is measured, and the larger value is shown.
-Detectability A gate-type metal detector (HI-PE Plus manufactured by Ceia) was used to evaluate whether or not detection was possible.

The configurations of Examples and Comparative Examples are shown in FIG. 2A, and the evaluation results are shown in FIG. 2B. As shown in FIGS. 2A and 2B, although there was no problem in printing in the comparative example of thick paper, the occurrence of curl was large and it was not suitable for use. It is considered that this is because in the electrophotographic printing, curling is likely to occur due to high heat applied to the printing surface side at the time of fixing, and curling is difficult to return due to the thick paper. Further, in printing by the inkjet method, it is considered that the influence of the expansion of the paper due to the supply of water from the ink only to the printing surface is increased by the thick paper.

Further, in Example 3 in which the paper was thin, it was judged that the electrophotographic printing apparatus using toner could be used without any problem, but in the inkjet printing apparatus, bleeding occurred and the image quality was deteriorated. It is considered that this is because the paper is thin, so that the ink reaches the aluminum foil immediately and easily penetrates in the direction of the paper surface.

Regarding Examples 1 and 2 and Comparative Example 2 in which the same paper was used and the thickness of the aluminum foil was changed, since the paper thickness was appropriate, no significant difference was observed in the evaluation regarding the print quality. However, as the aluminum foil becomes thicker, in addition to the thickness of the printing paper, the stiffness is greatly increased. Therefore, especially in Comparative Example 2, when the aluminum foil is held by hand, the hardness is clearly different from that of general printing paper. feel.

There was no difference in the detectability of the metal detector between the examples and the comparative examples. That is, it is shown that sufficient detectability can be realized even in Examples 1 and 3 in which the thinnest metal foil is used.

As described above, according to the present invention, it is possible to realize a printing paper that is relatively inexpensive, easy to manufacture, and capable of stable detection.

The present invention is not limited to the contents of the above-described embodiment, and various modifications and modifications can be made without departing from the spirit and scope of the invention. Therefore, the following claims are attached to make the scope of the invention public.

Claims

With a metal leaf layer,
A printing paper having printable layers provided on both sides of the metal foil layer.
The thickness of the metal foil layer is thicker than 6 μm and 20 μm or less.
The thickness of each of the printable layers is 40 μm or more and 55 μm or less.
Printing paper that is characterized by that.
The printing paper according to claim 1, wherein the thickness of the printing paper is 88 μm or more and 130 μm or less.
The printing paper according to claim 1 or 2, wherein the thickness of the metal foil layer is 10 μm or less.
The printing paper according to any one of claims 1 to 3, wherein the thickness of each of the printable layers is 42 μm or more and 55 μm or less.
The printing paper according to any one of claims 1 to 4, wherein the stiffness (mN / m) of the printing paper is 0.8 or less.
The printing paper according to any one of claims 1 to 5, wherein the printable layer is paper and the metal foil layer is aluminum foil.