JP2000016857A - Fire-resistant electromagnetic wave shield board - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a board with high electromagnetic wave shielding effect, meeting the standard as a fire-resistant construction material by incorporating an aqueous dispersion of disintegrated used magnetic tickets with a fire-resistant matrix material and an electroconductive fiber followed by subjecting the resultant slurry to wet papermaking process or extrusion molding. SOLUTION: This fire-resistant electromagnetic wave shielding board is obtained by incorporating an aqueous dispersion of disintegrated used magnetic tickets with a fire-resistant matrix material and an electroconductive fiber followed by subjecting the resultant slurry to wet papermaking process or extrusion molding; wherein the fire-resistant matrix material to be used is e.g. a mixture of gypsum and water-granulated slag, Portland cement, blast furnace cement, fly ash cement; while the electroconductive fiber to be used is e.g. highly alkali-resistant carbon fiber, metallized synthetic fiber, metallic fiber such as of Cu or Al. The composition of this board is as follows: about 5-20 wt.% of the disintegrated product, about 30-80 wt.% of the fire-resistant matrix material, and about 0.5-5 wt.% of the electroconductive fiber, and pref. furthermore, about 5-60 wt.% of charcoal powder.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fire-resistant electromagnetic wave shield board in which magnetic tickets such as used tickets and entrance tickets are reused.

[0002]

2. Description of the Related Art A method of reusing a magnetic ticket such as a used ticket or an entrance ticket includes the following.
There is known a method in which a magnetic layer is separated from a magnetic ticket and a base material is used as a raw material of toilet paper. For example,
JP-A-5-6526 describes a magnetic recording medium in which the support can be easily recovered and reused because the magnetic layer is easily peeled off by an alkali.

However, in the technique described in the above publication, the ferrite component and the resin component in the magnetic layer are not reused, and are finally disposed of as papermaking sludge. That is,
At present, used magnetic tickets are only reused as paper resources.

[0004] In view of the above prior art, an object of the present invention is to completely reuse a used magnetic ticket.

[0005]

Means for Solving the Problems The inventors of the present invention have made intensive studies on the reuse of used magnetic tickets from the viewpoint of application to building materials. As a result, a specific amount of used magnetic tickets can be replaced with a specific amount of used magnetic tickets. It has been found that the use of the magnetic ticket together with the refractory matrix material and the conductive fiber makes it possible to obtain a refractory electromagnetic wave shielding board which can completely utilize the magnetic ticket and has a high electromagnetic wave shielding effect.

[0006] The present invention has been made based on the above-mentioned findings, and is a disintegration product of used magnetic tickets based on paper.
The above object has been achieved by providing a fire-resistant electromagnetic wave shielding board characterized by containing 30% to 90% by weight of a refractory matrix material and 0.5 to 5% by weight of conductive fibers.

The present invention also relates to a preferred method of manufacturing the above-mentioned fire-resistant electromagnetic wave shielding board, in which the above-mentioned magnetic ticket is disintegrated in water, and the dispersion of the disintegrated product of the above-mentioned magnetic ticket is added to the above-mentioned fire-resistant electromagnetic wave shielding board. It is intended to provide a method for producing a refractory electromagnetic wave shielding board, characterized in that a raw material slurry is obtained by adding a conductive matrix material and the above-mentioned conductive fibers, and the raw material slurry is wet-formed or extruded.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION A fire-resistant electromagnetic wave shield board (hereinafter simply referred to as a shield board) of the present invention comprises a disintegrated product of a used magnetic ticket, a fire-resistant matrix material and conductive fibers. Conventional electromagnetic wave shielding board, gypsum board, calcium silicate board, slag gypsum board,
On the surface of an asbestos slate plate or the like, a metal net or a plate was adhered, or an electromagnetic wave shielding paint was applied.On the other hand, the shield board of the present invention has a conductive fiber in a refractory matrix material. In addition, pulp and magnetic powder derived from used magnetic tickets are dispersed. As described above, the shield board of the present invention is a novel one whose structure and constituent materials are completely different from those of the conventional one.

A used magnetic ticket has a magnetic recording layer provided on a base material made of paper. In the present specification, a magnetic ticket means a sheet-like material on which magnetic information can be recorded and read, and tickets for various transportation means,
This includes not only tickets in a narrow sense, such as admission tickets to various venues such as amusement parks and museums, but also a wide variety of paper-based magnetic recording media.

The base material of the used magnetic ticket is made of paper mainly composed of pulp and generally has a thickness of 0.1 to 1 mm and a basis weight of 30 to 300 g / m ² . The amount of pulp used is about 50 to 100% of the weight of the paper. In addition, limestone powder, talc,
Kaolin or the like is used. On the other hand, the magnetic recording layer of the magnetic ticket is formed by dispersing a ferrite magnetic powder such as permalloy or sendust in a binder made of a polymer material, and its thickness is generally 5 to 50 μm. The particle size of the magnetic powder is generally 0.5 to 10 μm. The amounts of the magnetic powder and the binder in the magnetic recording layer are generally 50 to 90% by weight and 10 to 50% by weight, respectively.

In the shield board of the present invention, a used magnetic ticket is used as a disintegrated material that has been disintegrated by a predetermined method. The disintegration method will be described later. This crushed material
It contains pulp and magnetic powder. Pulp functions as a fiber reinforcement in the shield board of the present invention,
This contributes to increasing the mechanical strength of the shield board.
On the other hand, the magnetic powder contributes to enhancing the electromagnetic wave shielding effect of the shield board by intervening between the conductive fibers described later and expressing conduction between the fibers. As described above, according to the present invention, it is possible to completely and effectively use a used magnetic ticket.

The amount of used magnetic tickets in the shield board of the present invention is 5 to 20% by weight, preferably 5 to 10% by weight, particularly preferably 5 to 6% by weight. If the amount of the magnetic ticket is less than 5% by weight, the fiber reinforcing effect of the pulp decreases, and new pulp raw materials such as waste paper are required. If the amount exceeds 20% by weight, the fire resistance of the shield board is lost. Would.

As the refractory matrix material, those similar to those used for refractory boards for building materials can be used. An example is a mixture of gypsum and granulated slag. The mixing ratio of the gypsum and the granulated slag (the former: the latter) in this mixture is 1: 1 to 1: 5 by weight.
It is preferably 0, especially 1: 1 to 1: 5. Also,
A mixture of the gypsum and the granulated slag further mixed with a hydraulic material such as slaked lime or quick lime can be used as the refractory matrix material. In this case, the amounts of gypsum, granulated slag, and hydraulic material in the mixed material were 2 gypsum each.
４０40%, especially 2-20%, granulated slag 30-80
%, Especially 40 to 60%, and the hydraulic material is preferably 2 to 20%, particularly 5 to 10%.

Further, as a refractory matrix material, Portland cement (JIS R5210), blast furnace cement (JIS R5211), silica cement (JIS R5211)
R5212), fly ash cement (JIS R5
213) can also be used.

In particular, as a refractory matrix material, a mixed material comprising by-product chemical gypsum of flue gas desulfurization gypsum and / or gypsum board waste material (hereinafter collectively referred to as gypsum waste material) and granulated slag discharged from a blast furnace By using, the usage ratio of the recycled material in the raw material of the shield board of the present invention is increased, which further contributes to the reuse of resources. In this case, the waste gypsum is dry-ground or wet-ground with an appropriate amount of water and a surfactant that promotes defibration. In the case of dry pulverization, it is preferable that the gypsum waste material is pulverized by a fred mill or a hammer mill, and then finely pulverized to 80 mesh or less, particularly 100 mesh or less by a Raymond roller mill or the like. On the other hand, in the case of wet pulverization, the surfactant is used in an amount of 0.001 part by weight or more, preferably 0.001 to 0.
The waste gypsum is pulverized and disintegrated by adding 01 parts by weight and further adding a predetermined amount of water. It is preferable to use a surfactant having a polyoxyalkylene group as the surfactant.

The compounding amount of the refractory matrix material in the shield board of the present invention is 30 to 90% by weight,
It is preferably from 80 to 80% by weight, especially from 40 to 60% by weight. If the amount of the refractory matrix material is less than 30% by weight, poor curing will result. If the amount is more than 90% by weight, the amount of used magnetic tickets and conductive fibers will be limited.

The conductive fiber is used for exhibiting an electromagnetic wave shielding effect in the shield board of the present invention. As the conductive fibers, those having high alkali resistance are preferable, and examples thereof include carbon fiber, metal-plated synthetic fibers, and metal fibers such as copper and aluminum. The conductive fiber preferably has a fiber length of 3 to 20 mm, particularly 5 to 10 mm. Fiber length is 3mm
If it is less than the above, there is a possibility that the contact between the fibers per fiber is reduced and the electromagnetic wave shielding effect may be reduced. Therefore, it may be necessary to increase the compounding amount of the conductive fiber. May be entangled and productivity may be reduced. Further, the fiber diameter of the conductive fiber is preferably 0.2 to 5 μm, particularly preferably 0.5 to 2 μm.

The compounding amount of the conductive fiber in the shield board of the present invention is 0.5 to 5% by weight, preferably 0.5 to 2% by weight. 0.5% of conductive fiber
If the amount is less than 10% by weight, the electromagnetic wave shielding effect is reduced, and if it exceeds 10% by weight, the productivity is reduced.

It is preferable to use charcoal powder as a raw material for the shield board of the present invention, in addition to the above-mentioned components, since the electromagnetic wave shielding effect is further improved. This is because, in addition to the ferrite-based magnetic powder derived from the used ticket, by interposing charcoal between the conductive fibers, conduction between the fibers is further developed. As the charcoal powder, one obtained from various woods as a raw material can be used without any particular limitation. In particular, by using as a charcoal powder a material made of waste wood generated due to house demolition, the use ratio of recycled materials in the raw material of the shield board of the present invention is further increased, which further contributes to the reuse of resources. . In addition, the waste wood generated in the demolition of houses was used as a building material, so it was difficult to reuse it as paper resources or charcoal raw materials due to the application of chemicals and the limitation of various tree species. When used as a raw material for boards, there is no such restriction, which leads to effective use of such wood that has been discarded up to now.

It is preferable to use carbonized powder of a used magnetic card instead of or together with the charcoal powder, since the same magnetic shielding effect can be obtained. In this specification, a magnetic card refers to a sheet-shaped magnetic recording medium in which a magnetic recording layer is provided on a substrate made of a carbonizable material, and is generally called a prepaid card, in addition to the above-described magnetic ticket. And a magnetic recording medium in which a magnetic recording layer is provided on a plastic substrate. The significance of recycling the use of the used carbonized powder of the used magnetic card in the present invention is as follows.

That is, in the present invention, as described above, a used magnetic ticket is used as a raw material of the shield board, thereby making it possible to use the magnetic ticket completely and effectively. However, the amount of the magnetic ticket used is 5-20
% Of the used magnetic tickets, it is not easy to recycle all used magnetic tickets generated in Japan, for example, as raw materials for shield boards. On the other hand, by using a magnetic ticket as a raw material of the carbonized powder of the magnetic card, a larger amount of magnetic tickets can be used as a raw material of the shield board,
The amount of recycling increases. Also, the yield of carbonization of the magnetic card is about 30 to 35% by weight, which is almost the same as the yield at the time of normal charcoal production, and since it is already in the form of strips, crushing can be easily performed with a normal crusher. There are advantages. Furthermore, from the viewpoint of global environmental protection, the collection of used paper such as the above magnetic card is being promoted by local governments, etc., but the method of recycling is large-scale facilities that generate electricity using the heat generated by incineration. Although it is a necessary method, according to the present invention, since such a large-scale facility is not required, the collection of the magnetic cards is promoted, which contributes to a reduction in waste disposal costs. The method of carbonizing the used magnetic card is not particularly limited, and the used magnetic card can be carbonized by a simple method such as a baking method or a drum can method.

Each of the charcoal powder and the carbonized powder of the used magnetic card has a particle size of 1 μm to 1 mm, particularly 10 μm.
It is preferably from m to 100 μm. If the particle size is less than 1 μm, the cost for pulverization is high and the curing mechanism of the matrix may be affected. On the other hand, if it exceeds 1 mm, productivity may decrease. The amount of the charcoal powder and the carbonized powder of the used magnetic card are preferably 1 to 60% by weight, particularly 5 to 40% by weight of the weight of the shield board. If the amount exceeds 60% by weight, the product strength may be reduced.

When blending the charcoal powder or the carbonized powder of the used magnetic card, it is preferable to offset the increase in the amount of these components by the decrease in the refractory matrix material. Specifically, the compounding amount of the refractory matrix material is 30
The content is preferably from 80 to 80% by weight, particularly preferably from 40 to 60% by weight. In this case, the amounts of the used magnetic ticket and the conductive fiber are as described above.

In addition to the above components, the shield board of the present invention may contain asbestos or an asbestos substitute in order to increase fire resistance. Glass fiber as an asbestos substitute,
Synthetic fibers, glass wool, wollastonite, mica powder, etc. The amount of these asbestos or asbestos substitutes is 1 to
It is preferably 10% by weight, especially 5 to 8% by weight.
Further, the shield board of the present invention may contain a ferrite-based magnetic powder other than a ferrite-based magnetic powder derived from a used magnetic ticket, and a metal powder such as a copper powder and an aluminum powder, if necessary.

Next, a preferred method of manufacturing the shield board of the present invention will be described with reference to the flowchart shown in FIG.

First, a used magnetic ticket is put into a defibrating tank to obtain a dispersion of the crushed product. As the defibrating tank, a pulper, a beater, a refiner, or the like can be used.
The solid content concentration of this dispersion is adjusted to a value suitable for wet papermaking or extrusion molding described below, and specifically, it is preferably 1 to 5% by weight.

Next, this dispersion is mixed with a conductive fiber and a mixture of gypsum and granulated slag as a refractory matrix material in a mixing tank to obtain a raw material slurry. In addition, the above-mentioned fibrous material or the like is added as needed. The solid content concentration of this raw slurry is 10 to 30% by weight.
It is preferred that

The raw material slurry is formed or formed into a green sheet by a round-mesh or long-mesh wet-type papermaking machine or an extrusion molding machine. The obtained green sheet is cured by steam curing or natural curing to obtain a cured sheet. Excess water from the hardened sheet is removed by a hot-air drying oven, and further cut into predetermined dimensions by a cutting machine to obtain a fire-resistant electromagnetic wave shielding board.

The shield board thus obtained has high fire resistance and electromagnetic wave shielding properties, and has sufficient strength as a building material.

[0030]

The present invention will be described in more detail with reference to the following examples. However, the scope of the present invention is not limited to such an embodiment. In addition, in the following examples, the wet papermaking method was used for manufacturing the shield board, but the shield board can be manufactured similarly by using an extrusion molding method instead. In the following examples, “parts” and “%” indicate parts by weight and% by weight, respectively, unless otherwise specified.

Example 1 A used ticket was put into a defibration tank and crushed to obtain a dispersion of crushed material. This dispersion,
The components shown in Table 1 were mixed in the mixing tank in the amounts shown in the table to obtain a raw material slurry having a solid content of 10%. This raw material slurry is supplied to a round-mesh wet paper machine to obtain a green sheet having a predetermined size.
Cured ~ 48 hours ago. After completion of the pre-curing, the green sheet is carried into a curing room, and the humidity is 95% RH or more, and the temperature is 60 to 70 ° C.
For 15 to 24 hours. The cured sheet is heated at 160 to 190 ° C. in a hot air drying oven at 35 to
It was dried for 60 minutes to obtain a dried plate. Finally, the dried sheet was cut to a fixed size by a cutting machine to obtain a shield board.
The carbon fiber used had a fiber length of 5 mm and a fiber diameter of 1 μm.

Example 2 A shield board was obtained in the same manner as in Example 1 except that the formulations shown in Table 1 were used. The ferrite magnetic powder used in this example had a particle size of 1.6 μm.
m under.

Example 3 A shield board was obtained in the same manner as in Example 1 except that the formulations shown in Table 1 were used. The charcoal powder used in this example had a particle size of 200 μm or less.

[Comparative Examples 1 and 2] A shield board was obtained in the same manner as in Example 1 except that the formulations shown in Table 1 were used.
In this comparative example, unlike the above example, no carbon fiber was blended.

Comparative Example 3 A shield board was obtained in the same manner as in Example 1 except that the formulations shown in Table 1 were used. In this comparative example, the blending amount of the used ticket is 20% or more.

<Evaluation of Performance> Electromagnetic wave shielding characteristics of the shield boards obtained in Examples and Comparative Examples were measured, and a base material test based on JIS A1321 was performed. Table 2 shows the results. In Table 2, the larger the value of the electromagnetic wave shielding property, the greater the shielding effect. The temperature difference in the base material test is 50 ° C or less, so that the criteria for a fire-resistant building material are satisfied. It is.

[0037]

[Table 1]

[0038]

[Table 2]

As is clear from the results shown in Tables 1 and 2, the shield boards of Examples 1 to 3 (products of the present invention) have a high electromagnetic wave shielding effect and satisfy the criteria as a fire-resistant building material. It turns out that it is. On the other hand, although the shield boards of Comparative Examples 1 and 2 satisfy the criteria as a fire-resistant building material, they have no electromagnetic wave shielding effect. The shield board of Comparative Example 3
Although it has an electromagnetic wave shielding effect, it turns out that it is inappropriate as a fire-resistant building material. Although not shown in the table, the shield boards of the examples had sufficient strength as building materials.

[0040]

As described above, according to the present invention,
A refractory electromagnetic wave shielding board in which a used magnetic ticket is completely reused is obtained. This shield board has a high electromagnetic wave shielding effect and satisfies the standard as a fire-resistant building material.

[Brief description of the drawings]

FIG. 1 is a flowchart showing a preferred method for manufacturing a shield board of the present invention.

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Yasumasa Okuda 226-6, Shimokitajima, Chikugo-shi, Fukuoka (72) Inventor Tadashi Sakamoto 1919-4, Amagi, Oji, Aki-shi, Fukuoka (72) Inventor Tetsuo Nakazono Fukuoka 1494-1, Mizoguchi, Chikugo-shi Japan Fire Protection Light Industry Co., Ltd. F-term (reference) 4G012 PA19 PA20 PA27 PA33 PB11

Claims (6)

[Claims] 1. The method according to claim 1, further comprising 5 to 20% by weight of a disintegrated product of a used magnetic ticket based on paper, 30 to 90% by weight of a refractory matrix material and 0.5 to 5% by weight of conductive fibers. Features a fire-resistant electromagnetic wave shield board. 2. The composition contains 5 to 20% by weight of the pulverized product, 30 to 80% by weight of the refractory matrix material and 0.5 to 5% by weight of the conductive fiber, and 5 to 60% by weight of charcoal powder.
The fire-resistant electromagnetic wave shielding board according to claim 1, comprising: 3. The carbonized powder of a used magnetic card, containing 5 to 20% by weight of the crushed material, 30 to 80% by weight of the refractory matrix material and 0.5 to 5% by weight of the conductive fiber. The fire-resistant electromagnetic wave shielding board according to claim 1, which contains about 60% by weight. 4. The fire-resistant electromagnetic wave shielding board according to claim 1, further comprising 1 to 10% by weight of asbestos or an asbestos substitute. 5. The refractory matrix material is made up of Portland cement, blast furnace cement, silica cement, fly ash cement or by-product gypsum and / or gypsum board waste of flue gas desulfurization gypsum and granulated slag discharged from the blast furnace. The fire-resistant electromagnetic wave shielding board according to any one of claims 1 to 4, wherein 6. The method for producing a fire-resistant electromagnetic wave shield board according to claim 1, wherein the magnetic ticket is disintegrated in water, and the dispersion of the disintegrated product of the magnetic ticket obtained by the disintegration is A method for producing a refractory electromagnetic wave shielding board, characterized in that a raw material slurry is obtained by adding a refractory matrix material and the above-mentioned conductive fibers, and the raw material slurry is wet-formed or extruded.