JPH10226996A - Forgery-proof paper - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain forgery-proof paper whose thickness is intermittently thinned in the flow direction to form window-opening 1 where threads 4 are exposed, with, during the process of papermaking, the areas where the threads are exposed not smearing the cylinder dryer, canvas, touch roll, etc., in the driving zone of the papermaking machine. SOLUTION: The tread has a laminar structure wherein one layer thereof is a substantially light-nontransmittable layer (b), the thread surface (exposed area) is made of a layer (c) which does not melt or soften at the temperature of the drying zone of the papermaking machine, the back face of the thread (at the back of the exposed surface or where it comes in contact with the forgery-proof paper) is made of a heat-sensitive adhesive layer (d) which appears to be different in color from the surface, and the thread surface is exposed at the window opening. As the surface and the back of the thread are easily distinguished from each other, the surface and the back of the thread can be quickly detected during the papermaking process, and in case the back face of the thread is exposed, the thread can be instantly inverted to restore the normal position for insertion.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a so-called "windowed threaded paper" type forgery prevention paper in which threads are intermittently exposed on the surface of the paper.

[0002]

2. Description of the Related Art Threaded paper in which a thread is inserted into a paper layer
Anti-counterfeit papers, which are referred to as, are well known. As a typical example of the thread, there is a thread as described later in detail. Paper that incorporates these requires extremely advanced technology for production, so it is very effective in preventing forgery,
As is well known, it is often used for banknotes and the like in various countries.

[0003] There are two main types of threaded paper. One is a type in which a thread is inserted into a sheet and is not exposed on the surface of the sheet, and the other is a type called "window-opening threaded paper" in which a part of the thread is exposed on the surface of the sheet.

In the former method of producing paper, a nozzle is inserted into a flow of stock in a sliced portion of a fourdrinier paper machine, and a thread is fed out while flowing water through the nozzle to form a paper formed on the paper net. A method of milling a filamentous material in the animal
No. 1-130309), a method of installing a thread-like material insertion device into the material flowing out of the flow box of a fourdrinier paper machine, and forming a thread while keeping the material in a non-contact state with the material by air flow (particularly, (Kaihei 2-169790) Using a round paper machine having two or more tanks, feeding the filamentous material between the paper layers using a feeding pipe having irregularities on the inner wall by laminating two or more layers, A method of forming a thread between paper layers (Japanese Patent Publication No. 5-400)
No. 80) has been proposed.

As a method of manufacturing the latter "paper with a window opening thread", a belt mechanism having a groove through which a thread is passed at the tip of a convex portion of a guide having an uneven portion is buried in a stock suspension on a wire. Manufacturing method (Japanese Patent Publication No. 5-85680)
Or, use a net processed into an uneven shape for the upper net of a circular net paper machine,
A method in which a thread is inserted into a window opening portion by inserting a thread while making contact with an uneven portion on the surface of a net (US Patent No. 4462).
No. 866) or a method in which a compressed air nozzle is incorporated in a rotary drum on a wire of a fourdrinier paper machine, and a slurry on a thread-like material previously inserted into a paper web is intermittently blown off with compressed air to expose the thread-like material. (JP-A-6-272200) and the like have been proposed.

[0006] "Paper with window opening thread" using a thread as a thread is characterized in that the thread is exposed at a window opening formed intermittently in the direction of paper flow. Therefore, in the case of paper manufactured using a thread whose surface is not coated with an adhesive, rubbing the exposed part of the thread with a nail or the like may cause the thread to be easily peeled off, or the thread to rise during printing, which is fatal. Disadvantages. For this reason, a window-threaded paper is made using a thread coated with a heat-sensitive adhesive on both front and back sides, and the heat-sensitive adhesive applied to the thread when the paper is dried in the drying zone of the paper machine is removed. By melting or softening, measures have been taken to increase the peel strength by securely bonding the cellulose fibers and the threads that constitute the paper to each other. The reason why the heat-sensitive adhesive is applied to both sides of the thread is to ensure that a good adhesive force can be obtained regardless of which side of the thread is inserted into the paper.

[0007]

However, when a heat-sensitive adhesive is applied to both sides of the thread, the surface of the thread exposed at the window opening of the paper may become a cylinder dryer, a canvas, a touch roll, etc. in the middle of the drying zone of the paper machine. Inevitably, the heat-sensitive adhesive is melted or softened by heat, causing a problem of contaminating the surface of a cylinder dryer or the like. Also, by contact with a cylinder dryer or the like, the smoothness of the heat-sensitive adhesive applied to the thread surface exposed at the window opening is lost, and in a thread having a metal deposition layer as described later, This causes a problem that the glitter is remarkably reduced. Also, when the thread with the metal deposition layer is exposed at the window opening,
The heat-sensitive adhesive applied on the metal-deposited layer is partially removed, causing a problem that the metal-deposited layer is easily corroded.

In order to manufacture a thread coated with a heat-sensitive adhesive on both sides, a method of slitting a film as a raw material coated with a heat-sensitive adhesive on both sides with a microslitter is employed. When a machine is used, it is difficult to apply a heat-sensitive adhesive to both surfaces of the film. That is, the heat-sensitive adhesive applied first on one side of the film melts and adheres to the touch roll when the heat-sensitive adhesive is applied on the other side for the second time. Therefore, it is necessary to select a type of heat-sensitive adhesive having a different melting temperature, or a troublesome measure such as using a floating drying method is required.

The present inventors have conducted intensive studies in order to solve the above-mentioned problems. First, a thread having a heat-sensitive adhesive applied to only one side is manufactured, and a thread having no heat-sensitive adhesive applied is manufactured. The thread surface (the thread surface) is exposed at the window opening of the paper, and the heat-sensitive adhesive is applied to the thread surface (the thread back surface)
Tried to insert a thread when making paper so that the paper touched the paper. However, in this method, since there is no difference in appearance between the front and back surfaces of the thread, it is very difficult to visually determine whether or not the front and back surfaces have been correctly inserted when the thread is inserted during papermaking. A method in which the obtained paper is sampled by a take-up unit of a paper machine, a peeling force between the sled exposed at a window opening of the paper and the paper is measured, and it is determined whether or not the sled is inserted normally. However, in such a determination method, when a thread insertion error is determined, a considerable length of paper is produced, and the yield is greatly reduced. Such a decrease in yield is a very serious problem when paper is formed with many sheets inserted.

Therefore, the present invention can easily and quickly identify the front and back surfaces of a thread coated with a heat-sensitive adhesive on only one side. It is an object of the present invention to provide a forgery prevention sheet into which a thread capable of judging this immediately and returning to a correct insertion state is incorporated.

[0011]

Means for Solving the Problems The present inventors have further studied a thread coated with a heat-sensitive adhesive only on the back surface, and as a result, it is possible to solve the above-mentioned problems by making the colors of the front and back surfaces of the thread different. And completed the present invention.

That is, the present invention relates to a forgery prevention paper in which a thread is exposed at a window opening formed by reducing the thickness intermittently in the flow direction of the paper, wherein the thread has (a) a laminated structure, (b) one layer of the laminated structure is a substantially light-impermeable layer, (c) the thread surface is a layer that does not melt or soften at the temperature of the drying zone of the paper machine,
(d) The back surface of the thread is made of a heat-sensitive adhesive layer that looks different from the surface, and (e) the surface of the thread is exposed at the window opening.

In the anti-counterfeit paper of the present invention, the surface of the thread exposed at the window opening is made of a layer that does not melt or soften in the drying zone of the paper machine, and is not coated with a heat-sensitive adhesive. There is no danger of contaminating the surfaces of these devices even if they come into contact with dryers, canvases, touch rolls and the like.

Further, since the back surface of the thread is formed of a heat-sensitive adhesive layer that looks different from the front surface, the heat-sensitive adhesive melts or softens at the temperature of the drying zone of the paper machine, and firmly adheres to the paper. , Even if the front and back are inserted reversely when inserting the thread during papermaking,
This abnormality can be immediately identified by color, and the thread can be quickly inverted to return to the normal insertion state.

[0015]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows an example of a gift certificate using a forgery prevention paper made of a two-layered laminated paper, and FIG. This will be described with reference to FIG. The anti-counterfeit paper shown
The outermost paper layer 2 is composed of two layers, ie, the outermost paper layer 2 and the paper layer 3 other than the outermost layer. The outermost paper layer 2 intermittently extends in the vertical direction of the paper (the flow direction of the paper layer during papermaking). An opening 1 is provided. A thread 4 is inserted between the outermost paper layer 2 and the paper layer 3 in contact therewith, and the thread 4 is
It is exposed at the part. If necessary, window opening 1
A forgery made of characters or images may be applied to the inside, and the forgery prevention ability can be further enhanced by applying both threads for texting and characters or images.

Next, in order to understand the characteristics of the thread used in the present invention in which only one surface is coated with the heat-sensitive adhesive and the method of inserting the thread, a method of manufacturing forgery prevention paper will be described with reference to specific examples. First, softwood bleached kraft pulp (NBK
P), hardwood bleached kraft pulp (LBKP), softwood bleached sulphite pulp (NBSP) and other wood pulp and hemp,
Non-wood pulp made from cotton and straw is appropriately mixed and beaten, and filler, dry paper strength agent, wet paper strength agent, sizing agent, fixing agent, retention improver, drainage improver, An antifoaming agent, a dye, a coloring pigment, a fluorescent agent and the like are appropriately added, and usually 400 to 250 ml of freeness. S. F. Prepare a stock adjusted to.

When producing anti-counterfeit paper by laminating two or more layers, a multi-tank-type round paper machine conventionally used generally for producing laminated paper can be used. FIG.
Fig. 2 shows an example of a two-tub-type mesh paper machine for producing a laminated paper comprising two paper layers 2 and 3 (Fig. 2), and a paper layer 3 other than the outermost layer without the window opening 1 is shown. (First tank before the last tank) 11 and second tank (final tank) 12 for forming the outermost paper layer 2 having the window opening 1
And

The upper net 12 of the circular cylinder cylinder 12a of the tank 12
As shown in FIG. 4, a mold 13 corresponding to the window opening 1 made of metal, resin, paper, or the like is attached to b with a thin metal wire, soldered, or attached with an adhesive. The shape of the mold 13 corresponding to the window opening is rectangular in the illustrated example, but may be any other shape such as a square, a circle, an ellipse, and the like.

When the mold 13 as shown in FIG. 4 is attached to the upper net 12b of the circular cylinder of the tank 12 for forming the outermost paper layer 2, the flow direction of the paper layer indicated by the arrow W (the vertical direction of the paper) In the direction X) corresponding to the window opening 1
And a non-window-opening portion 5 located between the window-opening portions
It is desirable that the mold 13 be intermittently mounted at an interval such that the ratio to the length Y corresponding to (FIG. 1) is 3: 1 to 1: 2. When the ratio of the window opening portion 1 is in this range, not only the effect of preventing wrinkles from occurring when the paper is continuously wound into a roll is ensured, but also the design of the paper surface is favorable.

An upper net without any work is attached to the net cylinder 11a of the tank 11 of the net paper machine shown in FIG. The paper layer 3 made by the mesh cylinder 11a equipped with an upper net without any work is transferred to the blanket 14, and the mold 13 of the tank 12 is formed.
The outermost paper layer 2 made by the cylinder 12a is stacked on the cylinder 12a, and the paper having two paper layers is formed. The insertion of the thread 4 is performed at a position indicated by an arrow V immediately before the paper layer 3 and the paper layer 2 are overlapped. As a method of feeding the thread 4, a method of feeding the thread using a feeding pipe provided with irregularities on the inner wall, as proposed by the same applicant as the present application in the above-mentioned Japanese Patent Publication No. Hei 5-40080, or A mesh machined into an uneven shape as in the method proposed in U.S. Pat. No. 4,462,866 is used as the upper mesh of a round paper machine, and a thread is inserted into the window opening by inserting a thread into contact with the uneven portion on the mesh surface. Can be adopted. Although the mold 13 attached to the mesh cylinder 12a is illustrated in some places in FIG. 3 and simplified, it is actually intermittently attached to the entire circumference of the mesh cylinder 12a.

The forgery prevention paper having the structure shown in FIGS. 1 and 2 can be manufactured by the above-described two-layer assembling method. That is, in the outermost paper layer 2 formed by the mesh cylinder 12a to which the mold 13 is attached, the window opening 1 in which the stock is not placed is formed in a portion corresponding to the mold 13. By inserting the thread 4 between the paper layers 2 and 3 so as to enter into the window opening 1, the thread 4 is exposed in the window opening 1, and between the paper layers 2 and 3 in the non-window opening 5. The thread is buried at the point.

The anti-counterfeit paper of the present invention can be produced using a fourdrinier paper machine as shown in FIG. Wear. That is, in order to form the window opening 1 in which the paper layer is partially thinned and insert the thread 4 with respect to the wet paper 21 on the papermaking net 20 of the fourdrinier paper machine moving in the direction of the arrow W. A plurality of molds 2 having a shape corresponding to the window opening 1
3 is attached to the papermaking net 20
The wet paper is brought into contact with the upper wet paper 21 and rotated while pressing the wet paper. The dandy roll 22 is driven to rotate in the direction of the arrow by a suitable driving device. When the surface of the wet paper web 21 on the papermaking net is pressed by the dandy roll 22, the fibers of the wet paper web are pushed away at the portion corresponding to the mold 23, and as a result, the window opening 1 of a thin paper layer is formed. At this time, the thread 4 is supplied to the center of the mold 23 and inserted into the wet paper 21.
Is exposed at the window opening 1. The adjacent mold 23
The fiber also moves between the mold and the mold 23, and the moved fiber covers the surface of the thread 4, thereby forming the non-window-opening portion 5 (FIG. 1). Instead of attaching the mold 23 to the upper net of the dandy roll 22, a projection having a shape corresponding to the window opening 1 may be formed on the upper net itself by a molding method or the like.

The anti-counterfeit paper of the present invention can also be manufactured by various methods other than those described above. For example, as proposed in Japanese Patent Publication No. 5-85680 introduced in the prior art as a method of manufacturing “paper with window opening thread”, a groove is provided at the tip of a convex portion of a guide having an uneven portion, and a thread is passed through this groove. In this state, the guide is embedded in the stock suspension on the wire of the fourdrinier paper machine, and when the moisture of the stock suspension is dehydrated downward from the wire and the paper layer is almost formed, the guide is raised. To form a window opening in which the thread is exposed at the portion in contact with the tip of the convex portion of the guide, as disclosed in JP-A-6-272200. A rotating drum with a built-in compressed air nozzle is installed on the wire, and the compressed air nozzle in the rotating drum intermittently blows compressed air from the compressed air nozzle into the wet paper web on which the thread is inserted. A method of intermittently forming a window opening where a thread is exposed by blowing off the slurry of the above-described method. As proposed in US Pat. No. 4,462,866, a net having a part of the surface processed into an uneven shape is a circular net. Used as the upper net of the paper machine, when the net is rotated in the tank containing the stock suspension, the thread is brought into contact with the uneven part on the net surface, and the thread is brought into contact with the convex part on the net surface. For example, a method of exposing the thread that has been exposed to the window opening can be adopted.

In producing the anti-counterfeit paper of the present invention, it is possible to apply starch, polyvinyl alcohol, various surface sizes and the like to the paper surface during the paper making process using a size press device or the like. Further, if necessary, a machine calendering treatment or a super calendering treatment may be performed to improve the surface smoothness as appropriate.

The thread 4 used in the anti-counterfeit paper of the present invention uses various films such as cellophane, a polypropylene film, a polyester film, a nylon film, a polyvinyl alcohol film, a polyvinyl chloride film, a polycarbonate film, and a thin paper as a raw material. After applying various processes to the front and back surfaces to provide a heat-sensitive adhesive coating layer, a metal deposition layer, various resin coating layers, a magnetic paint coating layer, a pattern and a fine character printing layer, and the like, a micro slitter is used. It is usually obtained by slitting to a narrow width of 0.3 to several mm. A variety of films and thin papers as raw materials can be usually used in a thickness of 10 to 50 g / m ² .
The thread thus obtained has a laminated structure. In particular, the thread used in the present invention comprises a layer whose surface (exposed surface exposed at the window opening) does not melt or soften at the temperature of the drying zone of the paper machine. It is necessary that the back surface of the thread (the surface that is in contact with the paper on the back side of the exposed surface) is made of a heat-sensitive adhesive coating layer. By inserting a thread having such a laminated structure in the papermaking process while controlling the surface so as to be exposed at the window opening of the paper,
The heat-sensitive adhesive layer on the back side of the thread is melted or softened by the heat of the drying zone of the paper machine, so that the thread is securely bonded to the cellulose fibers constituting the paper and the thread portion exposed at the window opening is reliably prevented from peeling off. While being able to
Even if the thread surface exposed at the window opening is in contact with a cylinder dryer, canvas, touch roll, etc. in the drying zone of the paper machine, it does not melt or soften due to heat because it is not coated with a heat-sensitive adhesive, There is no risk of contaminating the cylinder dryer and the like. Layers that do not melt or soften at the temperature of the drying zone on the thread surface are typically 90
It is necessary to have a property not to be tacky at a temperature of a drying zone of from 110 ° C. to 110 ° C., for example, the surface of the various films used as a raw material as described above may be exposed as it is, A resin coating layer may be provided on the surface of the raw film.

The heat-sensitive adhesive layer on the back surface of the thread is made of an ionomer resin, polyester resin, polyvinyl acetate resin, polyvinyl chloride resin, polyacrylate resin, ethylene-vinyl acetate copolymer resin or the like. It can be formed by applying a known heat-sensitive adhesive to a water-based or solvent-based paint and applying it to the back surface of various films as a raw material using a conventional coating machine such as an air knife coater or a gravure coater. The coating amount is usually 0.5 to 10 g / m ²
And

In the present invention, it is necessary that the heat-sensitive adhesive layer on the back surface of the thread has a different color from the front surface of the thread. Can be reliably and promptly determined whether or not is correctly inserted so as to be exposed. Identification of whether the front and back of the sled is inserted correctly can be made by detecting the color of the sled exposed surface immediately after the sled is inserted in the middle of papermaking and immediately after being exposed to the window opening. Paper generation can be minimized. The determination of the thread color can be automatically performed by visual observation, imaging using a CCD, or the like. When the color is automatically detected, an alarm can be issued at the same time.

If the back surface of the thread is exposed as a result of the color determination, it is necessary to immediately reverse the thread insertion state so that the thread surface is exposed. As a method of inverting the thread insertion state, a manual method in which a thread is cut at a thread insertion point, and then the thread is inverted and inserted again, or a method in which a thread insertion device is provided with a thread inversion function and mechanically performed is considered. Can be
In the case of mechanically inverting the thread, the thread can be automatically inverted by linking it with the result of the determination of the thread color in the window opening.

In order to make the back surface of the thread different in color from the front surface, a method of making the color of each film of the raw material used for manufacturing the thread itself different from the front surface by making the color visible from the back surface, A method of applying a heat-sensitive adhesive to which a coloring agent such as a pigment or a pigment is added, a method of changing the hue of a surface in contact with a layer that is substantially impermeable to light, and brushing a heat-sensitive adhesive coating layer to make it white. Various methods such as a method can be adopted.

As the coloring agent to be added to the heat-sensitive adhesive, not only a coloring agent that is colored in the visible light wavelength region but also a colorant that is colorless or pale in visible light and that develops color when irradiated with ultraviolet light or infrared light. Can be used. The color of the colorant may be not only chromatic but also achromatic. In the present invention, a dye that develops color upon irradiation with ultraviolet light can be preferably used as a colorant. From the viewpoint of a counterfeit prevention effect, a dye that is colorless upon irradiation with white light and that develops color upon irradiation with ultraviolet light can be particularly preferably used.

The thread used in the present invention requires that one layer of the laminated structure is a substantially light-impermeable layer. A substantially light impermeable layer does not transmit light,
A layer that transmits only very little is meant. By providing such a layer, mixing of colors due to light transmitted from both sides of the thread can be prevented, and the difference in color between the front and back surfaces of the thread can be reliably determined. As a substantial light opaque layer, a layer obtained by vacuum-depositing a metal such as aluminum, tin, cobalt, and nickel on various films or thin paper used as a raw material, a magnetic powder such as iron oxide, and a binder as main components. A layer coated with a magnetic paint to be applied, a layer coated with a paint mainly containing a dark colorant and a binder such as carbon black can be used,
An opaque film or the like in which a colorant or a filler is mixed in various films used as a raw material itself can be used as a substantial light impermeable layer.

Next, an example of manufacturing a thread used in the present invention will be described. The coating amount and the coating thickness in these production examples all mean values after drying.

Production Example of Silver Thread (See FIG. 6) After 400 to 500 angstroms of metallic aluminum is vapor-deposited on one surface of a polyester film a having a thickness of 12 μm to form an aluminum vapor-deposited layer b, two liquids are further formed thereon. A curable acrylic resin is applied using a gravure coater of about 2 μm to form an acrylic resin coated layer c. On the other surface of the polyester film a, a heat-sensitive adhesive is applied to a thickness of about 5 μm to form a heat-sensitive adhesive coating layer d. A coloring agent composed of a pigment or a dye is added to the heat-sensitive adhesive. However, it is preferable to use a dye that requires a small amount of addition and has a small decrease in adhesive strength. The thread is then continuously slit into small widths using a microslitter to produce threads and wound onto bobbins. In the thread having this configuration, the acrylic resin coating layer c becomes a thread surface that does not melt or soften at the temperature of the drying zone of the paper machine, the heat-sensitive adhesive coating layer d becomes the thread back surface, and the aluminum vapor deposition layer b is substantially formed. Since it becomes a light-impermeable layer, the aluminum deposited layer b looks silver through the acrylic resin coating layer c when viewed from the thread front side, and the coloring agent added to the heat-sensitive adhesive coating layer d when viewed from the thread back side Looks like the color.

Manufacturing Example of Gold Thread (See FIG. 7) In FIG. 6, a yellow dye is added to the two-component curable acrylic resin coating layer c, and the heat-sensitive adhesive coating layer d is colored. No agent is added. In this configuration, when viewed from the thread front side, the aluminum deposited layer b looks golden through the acrylic resin coating layer c colored yellow, and when viewed from the thread back side, the aluminum deposited layer b passes through the heat-sensitive adhesive coating layer d. Appears silver. When a blue or red dye is added to the acrylic resin coating layer c, the aluminum deposition layer b looks blue or red silver through the acrylic resin coating layer c, respectively.

Manufacturing Example of Thread with Gold Stripe Pattern (See FIG. 8) In FIG. 7, an acrylic resin coating layer c to which a yellow dye is added is coated in a stripe pattern on an aluminum vapor-deposited layer b to form an acrylic resin. In the portion where the resin-based coating layer c is applied, the aluminum-deposited layer b looks golden, and in the portion where the acrylic resin-coated layer c is not applied, the aluminum-deposited layer b looks silver as it is. It can be seen as a golden stripe pattern inside.

At this time, in order to protect the aluminum deposited layer b, a transparent resin protective layer (not shown) is coated on the entire surface of the aluminum deposited layer in advance, and then the dye-added acrylic resin coated layer c is striped. Coating, or
As shown in FIG. 8, a dye-added acrylic resin coating layer c is applied in a stripe shape on the aluminum vapor-deposited layer b, and then a transparent resin protective layer (not shown) is applied over the entire surface. Is preferred. When a blue or red dye is added to the acrylic resin coating layer c, it looks like a blue silver or red silver stripe pattern in silver. Also, when the acrylic resin coating layer to which the yellow dye is added is applied in a dot shape, it looks as a gold dot pattern in silver.

Example of Producing Hologram Thread (See FIG. 9) A transparent thermoplastic resin is coated on one side of a polyester film a having a thickness of 12 μm by about 2 μm to form a thermoplastic resin coating layer e. Then, the hologram pattern f is thermally embossed. Next, metal aluminum is further deposited on the hologram pattern f by 400 to 500 angstroms to form an aluminum deposited layer b, and a thermosensitive adhesive colored with a fluorescent dye is applied on the aluminum deposited layer b to form a heat sensitive adhesive. The agent coating layer d is formed. In this configuration, the polyester film a surface becomes a thread surface that does not melt or soften at the temperature of the drying zone of the paper machine, and when viewed from the thread surface side, the hologram pattern f can be visually recognized through the polyester film a. Layer d) is a surface that develops color when irradiated with ultraviolet light.

In this structure, the thermoplastic resin coating layer e
When a yellow, blue or red dye is added to the hologram pattern, the gold, blue silver or red silver hologram pattern f can be seen through the polyester film a when viewed from the thread surface side.

Example of manufacturing magnetic thread (see FIG. 10) A polyester film a having a thickness of 12 μm
A magnetic coating mainly composed of a liquid-curable polyester resin and iron oxide powder is applied using a gravure coater of about 10 μm to form a magnetic coating applied surface g. On the other surface of the polyester film a, a heat-sensitive adhesive containing a coloring agent is applied to a thickness of about 5 μm to form a heat-sensitive adhesive coating layer d. In this configuration, the magnetic paint coating layer g becomes a thread surface that does not melt or soften at the temperature of the drying zone of the paper machine, and at the same time, becomes a substantially light impermeable layer, and when viewed from the thread surface side, the magnetic paint coating layer g g looks like the color of the iron oxide powder, and when viewed from the back side of the thread, looks like the color of the coloring agent added to the heat-sensitive adhesive coating layer d. Magnetic information can be recorded on the thread having the magnetic coating layer g.

Manufacturing Example of Thread with Micro-Characters (See FIG. 11) After printing a micro-character as a back character using black ink on one side of a polyester film a having a thickness of 12 μm, a metal is printed on the printing h. Aluminum is vacuum deposited to form an aluminum deposited layer b. Next, a heat-sensitive adhesive colored with a fluorescent dye is further applied on the aluminum deposition layer b to form a heat-sensitive adhesive coating layer d. In this configuration, the surface of the polyester film a becomes a thread surface that does not melt or soften at the temperature of the drying zone of the paper machine, and the aluminum vapor-deposited layer b becomes a substantially light-impermeable layer, and is enlarged with a loupe or the like from the thread surface side. Observation, a print h of fine black regular characters can be seen in the silver background of the aluminum vapor-deposited layer b through the polyester film a, and the back surface of the thread (the heat-sensitive adhesive coated layer d surface) is colored by irradiation with ultraviolet rays. Surface. The minute characters may be formed by punching instead of printing.

Since the conventional thread has no distinction between front and back,
Which side of the thread is exposed at the window opening of the paper was half established, so when printing small characters, both "normal characters" and "reverse characters" must be printed. And the reading of characters was uncomfortable. On the other hand, since the front and back sides are distinguished in the above-described thread, it is only necessary to print only the “regular characters” that can be read from the front side of the thread.

Example of manufacturing an iris thread (FIGS. 12 and 13)
As shown in FIG. 12, a polyester film a having a thickness of 12 μm was coated on one surface of a polyester film a with a thickness of 50 μm using a vacuum evaporation machine.
An aluminum vapor deposition layer b2 of about Å is formed. Next, a transparent deposited layer of silicon dioxide having a thickness of 0.1 to 1 .mu.m is formed thereon as a light interference layer i, and an aluminum deposited layer b1 having a thickness of about 500 .ANG. Is further formed thereon. Aluminum deposition layer b1
A heat-sensitive adhesive coating layer d colored with a fluorescent dye is formed thereon, and formed into threads with a microslitter.

When viewed from the side of the polyester film a, the hue of the thread having this configuration changes according to the viewing angle. The reason why the hue changes is the same as the reason why the hue of the soap bubble changes, and is due to the light interference effect. That is, in the above-described thread configuration, the aluminum deposited layer b2 having a thickness of about 50 angstroms acts as a light semi-transmissive layer, and the aluminum deposited layer b1 having a thickness of about 500 angstroms acts as a light reflecting layer (light impermeable layer). . Light incident from the polyethylene film a side is transmitted through the semi-transmissive layer b.
2 is partially reflected, partially transmitted through the semi-transmissive layer b2, refracted and transmitted through the interference layer i, and reflected by the reflective layer b1. At this time, the light reflected by the semi-transmissive layer b2 and the light reflected by the reflective layer b1 interfere with each other to produce an interference color. When the incident light is white light or illumination light, since the refractive index in the interference layer is different depending on the light of various colors having different wavelengths, an interference color corresponding to the thickness of the interference layer is developed, and the hue varies depending on the viewing angle. Will change. With anti-counterfeit paper that exposes a thread with such a configuration to the window opening of the paper, the hue of the thread changes when the viewing angle is changed, and even when color copying is performed, the exposed part of the thread is copied to black. It is extremely excellent in anti-counterfeiting effect.

In order to manufacture an iris-colored thread that can obtain the above-described light interference effect, the stacking order may be reversed from that of FIG. That is, as shown in FIG.
The order of lamination of aluminum deposited layer (semi-transmissive layer) b2 / interference layer i / aluminum deposited layer (reflective layer) b1 / polyester film a / heat-sensitive adhesive coating layer d can also be used. In this case, if necessary, a protective layer j made of a transparent resin having excellent heat resistance may be provided on the semi-transmissive layer b2.

In the above-described example, the light reflection layer b1 and the semi-transmission layer b2 are made of aluminum vapor-deposited layers.
It may be a deposited layer of a metal such as silver. The interference layer i can be a transparent deposited layer made of titanium oxide, magnesium fluoride, aluminum oxide, or the like, in addition to the deposited layer of silicon dioxide, and furthermore, a transparent resin is applied to form an interference layer. It can also be a layer.

Example of manufacturing an iris thread whose color changes within a small area (see FIGS. 14 and 15) In the iris thread due to the light interference effect described above, the thickness of the interference layer i is reduced within the small area. Usually 0.1 ~
By making various changes in the range of 1 μm, it is possible to produce an iris thread in which the color appears to change in a very small area. That is, the thread laminated structure shown in FIG. 14 is exactly the same as that of FIG. 12 except that the thickness of the interference layer i in FIG. 12 is variously changed within a small area. Further, FIG. 15 is similar to FIG. 1 except that the thickness of the interference layer i in FIG.
This is a laminated structure completely similar to that of No. 3. Interference layer i in this case
Can be formed as a transparent resin coating layer, for example, using a gravure coating machine. That is, by changing the engraving depth of the gravure roll variously in a minute area, the thickness of the transparent resin coating layer can be variously changed in the minute area.

Example of manufacturing an iris-colored thread excellent in pearl feeling (see FIG. 16) In an iris-colored thread due to the light interference effect as shown in FIG. By forming a laminated structure in which transparent resins different from each other are laminated in multiple layers, the transparent resin multilayer laminated body itself can exhibit an iris color excellent in pearly feeling. A multilayer laminate of transparent resins having different refractive indices can be manufactured by melting various transparent resins having different refractive indices, alternately extruding these molten resins in a multilayer manner, and then stretching to form a film. FIG. 16 shows a configuration example of a thread using a transparent resin multilayer laminate as a light interference layer, and an aluminum vapor-deposited layer b (light-impermeable layer) on one surface of the multilayer laminate.
, And a heat-sensitive adhesive coating layer d is further provided thereon, and this is used as a thread by a microslitter.

[0048]

【Example】

Manufacture of thread After 400 Å of metal aluminum was formed on one side of a polyester film having a thickness of 12 μm to form an aluminum vapor-deposited layer, a polyester-based heat-sensitive adhesive (trade name “Byron”, manufactured by Toyobo Co., Ltd.) was further formed thereon. ) Was coated with 5 g / m ² (dry basis) of a coating in which a thiophene-based fluorescent dye was added in an amount of 0.5% by weight to form a heat-sensitive adhesive coating layer. Next, the thread was slit to a width of 1.5 mm using a microslitter to produce a thread. In the thread having such a configuration, the polyester film surface serves as the thread surface, and the heat-sensitive adhesive coating layer serves as the thread back surface, and develops a bluish-white color by ultraviolet irradiation.

Preparation of paper stock NBKP (20 parts by weight) and LBKP (80 parts by weight) were subjected to a freeness of 350 ml C.I. S. F. 10 parts by weight of clay, 0.3 parts by weight of a paper strength agent (trade name "Polystron 191", manufactured by Arakawa Chemical Industry Co., Ltd.), a sizing agent (trade name "Size Pine E", Arakawa 1.0 part by weight (manufactured by Chemical Industry Co., Ltd.) and an appropriate amount of a sulfuric acid band were added to prepare a stock.

Manufacture of Paper Netting The short net 1 is attached to the upper net 12b (width 1300 mm) of the net cylinder 12a of the net making machine as shown in FIGS.
A number of molds 13 each made of a resin plate having a thickness of 0 mm, a long side of 25 mm, and a thickness of 0.3 mm were continuously attached at intervals of 5 mm (Y) in the flow direction W of the paper layer using an adhesive. Six rows were attached at equal intervals in the width direction of the upper net 12b.

Paper Making The upper net without any work is attached to the net cylinder 11a in the first tank of the two tank type net paper machine as shown in FIG.
An upper net 12b to which the above-mentioned mold 13 was attached was attached to the second net cylinder 12a. The paper layer 2 of the second layer (outermost layer) formed in the second tank is overlapped with the paper layer 2 of the second layer formed in the first layer formed in the first tank.
A two-layer laminated paper was produced at m / min. At this time, the first layer (50 g / m ² in terms of dry weight) and the second layer (5
0 g / m ² ).
The mold 13 was inserted at a position corresponding to the center of the mold 13 using the method proposed in No. -40080. A black light (not shown) was installed at the position of the coach roll 15, and the wet paper was irradiated with ultraviolet rays. If the thread exposed to the window opening of the paper appears to be colored blue-white by irradiation of ultraviolet light, it means that the heat-sensitive adhesive coating layer on the back of the thread is exposed,
An operation of cutting the thread inserted at the thread insertion position V, reversing the front and back surfaces of the thread, and then inserting the thread again was performed. By performing this operation until the thread does not develop color by the irradiation of ultraviolet rays, a normal thread insertion state can be obtained. Subsequently, the wet paper was dehydrated according to a conventional method, and then dried with a cylinder drier to produce a forgery prevention paper of the present invention comprising a two-layer laminated paper. The length X of the window opening 1 in the paper flow direction is 10
mm, the length Y of the non-window opening 5 was 5 mm, the thread 4 was exposed inside the window opening 1, and the thread 4 was buried between the paper layers in the non-window opening 5. .

[0052]

According to the forgery prevention paper of the present invention as described above, the following remarkable effects can be obtained. 1) The thread surface is not coated with a heat-sensitive adhesive and does not melt or soften at the temperature of the drying zone of the paper machine, so that the thread surface is exposed at the window opening of the forgery prevention paper during papermaking. By controlling thread insertion, drying zone cylinder dryer, canvas,
These devices will not be contaminated even if they come into contact with a touch roll or the like.

2) Since the surface of the thread exposed at the window opening of the forgery prevention paper is not melted or softened by the heat of the drying zone of the paper machine, even in the case of a glittering thread using a metal deposition layer, the thread surface is not Since there is no roughening, the glitter does not decrease.

3) Apply heat-sensitive adhesive to one side (back side) of thread
Since only the thread is coated, the cost can be reduced as compared with the conventional thread coated on both sides. Also, when manufacturing such a thread, when applying the heat-sensitive adhesive on both sides, a special device using a floating drying method is required, whereas the heat-sensitive adhesive is applied on only one side. The production of the thread has the advantage that a normal coating machine can be used.

4) Since it is possible to easily identify the front and back surfaces of the thread, it is possible to quickly detect whether or not the thread is correctly inserted during papermaking. As a result, the thread insertion state can be determined immediately when the exposed portion of the thread is formed in the middle of papermaking, and if incorrect, the thread insertion state can be quickly reversed and returned to the normal state. Therefore, it is possible to significantly increase the production yield of the forgery prevention paper in which the thread is correctly inserted.

5) When the heat-sensitive adhesive layer is colored using a dye or the like which develops a color when irradiated with ultraviolet rays, not only can the front and back surfaces of the thread be reliably identified, but also the anti-counterfeit ability can be further enhanced. .

6) The thread is distinguished between the front and back sides, and the thread is inserted so that the thread surface is always exposed at the window opening. Therefore, when printing a minute character on the thread, only the "regular character" is used. Since it is sufficient to make the characters visible, it is possible to easily read the small characters without a sense of incongruity.

The anti-counterfeit paper obtained according to the present invention utilizing the above characteristics can be suitably used for bills, checks, stock certificates, bonds, gift certificates, cards, confidential documents, passports, identification cards and the like.

[Brief description of the drawings]

FIG. 1 is a top view of an example of a gift certificate using the forgery prevention paper of the present invention.

FIG. 2 is an enlarged sectional view of a window opening portion of FIG.

FIG. 3 is an explanatory view showing an example of a two-tank-type round-mesh paper machine that can be preferably used for producing the anti-counterfeit paper of the present invention.

FIG. 4 is a partial explanatory view showing a state in which a mold for forming a window opening is attached to the upper net of the net cylinder used in the net paper machine shown in FIG. 3;

FIG. 5 is an explanatory view showing another example of a papermaking apparatus that can be preferably used for producing the forgery prevention paper of the present invention.

FIG. 6 is a cross-sectional view illustrating an example of a stacked structure of silver threads.

FIG. 7 is a cross-sectional view illustrating an example of a stacked structure of a gold thread.

FIG. 8 is a cross-sectional view showing an example of a stacked structure of a thread having a golden stripe pattern.

FIG. 9 is a cross-sectional view illustrating an example of a laminated structure of a hologram thread.

FIG. 10 is a sectional view showing an example of a laminated structure of a magnetic thread.

FIG. 11 is a cross-sectional view illustrating an example of a laminated structure of a thread with minute characters.

FIG. 12 is a sectional view showing an example of a laminated structure of an iris thread.

FIG. 13 is a cross-sectional view showing another example of the laminated structure of the iris thread.

FIG. 14 is a cross-sectional view illustrating an example of a laminated structure of iris threads whose color changes within a small area.

FIG. 15 is a cross-sectional view showing another example of a laminated structure of an iris thread whose color changes within a minute area.

FIG. 16 is a cross-sectional view showing an example of a laminated structure of an iris thread having an excellent pearly feeling.

[Explanation of symbols]

 1: windowed part 2: outermost paper layer 3: paper layer in contact with the outermost layer 4: thread 5: non-windowed part a: polyester film b: metal deposition layer c: thermosetting resin coating layer d: heat sensitive Adhesive coating layer e: thermoplastic resin coating layer f: hologram pattern g: magnetic paint coating layer h: letter printing i: light interference layer

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁶ Identification code FI D21H 27/34 D21H 1/08 Z

Claims (17)

[Claims] 1. An anti-counterfeit paper in which a thread is exposed at a window opening formed by intermittently reducing the thickness in the flow direction of the paper, wherein the thread has (a) a laminated structure,
(b) one layer of the laminate structure is a substantially light-impermeable layer, (c) the thread surface is a layer that does not melt or soften at the temperature of the drying zone of the paper machine, and (d) the thread back surface (E) consisting of a heat-sensitive adhesive layer that looks different from the surface
Anti-counterfeit paper, wherein a thread surface is exposed at the window opening. 2. The forgery prevention paper according to claim 1, wherein a coloring agent is added to the heat-sensitive adhesive layer. 3. The anti-counterfeit paper according to claim 2, wherein the colorant is a dye which develops a color when irradiated with ultraviolet rays. 4. The anti-counterfeit paper according to claim 2, wherein the colorant is a dye that is colorless when irradiated with white light and is colored when irradiated with ultraviolet light. 5. The forgery according to claim 1, wherein said thread surface layer is a magnetic paint coating layer containing magnetic powder, and said magnetic paint coating layer constitutes a light impermeable layer. Prevention paper. 6. The anti-counterfeit paper according to claim 1, wherein a process is performed on the thread surface so that minute characters of regular characters can be seen. 7. The anti-counterfeit paper according to claim 1, wherein the laminated structure of the threads is laminated in the order of a thermosetting resin layer / a metal deposition layer / a polyester film layer / a heat-sensitive adhesive layer. . 8. The anti-counterfeit paper according to claim 7, wherein a dye is added to the thermosetting resin layer. 9. The forgery prevention according to claim 7, wherein a dye is added to the thermosetting resin layer, and the thermosetting resin layer is coated in a stripe shape or a dot shape. Paper. 10. The laminated structure of the thread is laminated in the following order: a polyester film layer / a thermoplastic resin layer having a hologram pattern embossed on one surface / a metal deposition layer provided on the hologram pattern / a heat-sensitive adhesive layer. 2. The forgery prevention paper according to claim 1, wherein: 11. The forgery prevention paper according to claim 10, wherein a dye is added to said thermoplastic resin layer. 12. A laminated structure of the thread, wherein a light transmissive layer composed of a polyester film layer / a metal vapor deposited layer / a light interference layer composed of a transparent layer / a light reflective layer composed of a metal vapor deposited layer / a heat-sensitive adhesive layer. The forgery prevention paper according to claim 1, wherein the paper is laminated in the following order. 13. The light emitting device according to claim 13, wherein the layered structure of the thread is a semi-transmissive light layer formed of a metal deposition layer / a light interference layer formed of a transparent layer.
2. The forgery prevention paper according to claim 1, wherein a light reflection layer composed of a metal deposition layer, a polyester film layer, and a heat-sensitive adhesive layer are laminated in this order. 14. A laminated structure of the thread, wherein a light transmissive layer composed of a polyester film layer / a metal vapor deposited layer / a light interference layer composed of a transparent layer / a light reflective layer composed of a metal vapor deposited layer / a heat-sensitive adhesive layer The forgery prevention paper according to claim 1, wherein the interference layer is laminated in the following order, and the thickness of the interference layer is changed within a minute area. 15. The light emitting device according to claim 15, wherein the layered structure of the thread is a semi-transmissive light layer formed of a metal deposition layer / a light interference layer formed of a transparent layer.
2. The light reflecting layer comprising a metal deposition layer / polyester film layer / thermosensitive adhesive layer, which are laminated in this order, wherein the thickness of the interference layer is changed within a small area. Anti-counterfeit paper. 16. The laminated structure of the threads is laminated in the order of a light interference layer composed of a multilayer laminate of various transparent resins having different refractive indexes / a light reflection layer composed of a metal vapor deposition layer / a heat-sensitive adhesive layer. 2. The forgery prevention paper according to claim 1, wherein: 17. The ratio of the length (X) of the window portion in the paper flow direction to the length (Y) of the non-window portion located between the window portions is 3: The forgery prevention paper according to any one of claims 1 to 11, wherein the paper is set to a ratio of 1 to 1: 2.