JP2001020432A - Electromagnetic shielding type waterproof floor utilizing conductive powder - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electromagnetic shielding type waterproof floor utilizing conductive powder on which an electromagnetic shielding waterproof layer functioning as waterproof capability and electromagnetic shielding capability in combination is fixed. SOLUTION: A waterproof raw material functioning as waterproof capability and fixing capability to concrete in combination is melted, and conductive powder having grain size of 5-30 μm in quantity of one third weight ratio or less of the total amount effective on an electromagnetic shielding is mixed to the molten waterproof raw material. In the electromagnetic shielding type waterproof floor, an electromagnetic shielding waterproof layer 7 functioning as electromagnetic shielding capability and waterproof capability in combination is fixed onto a floor slab 2 made of concrete by using the waterproof raw material into which the conductive powder is mixed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electromagnetic shield type waterproof floor using conductive powder, and more particularly to an electromagnetic shield type waterproof floor using conductive powder suitable for securely fixing a free access floor.

[0002]

2. Description of the Related Art In an office building, a tenant building, and the like, there is an increasing demand for an electromagnetic shield provided in units of floors or rooms for the purpose of preventing electromagnetic interference of electronic devices installed in the building. Electromagnetically shielded floors and rooms are made of a conductive member such as a zinc-plated iron plate or a conductive nonwoven fabric or a composite member thereof (hereinafter, referred to as an electromagnetic shielding material) capable of obtaining a required shielding effect on all wall surfaces including a floor surface and a ceiling surface. ) To form without gaps.

On the other hand, floor slabs of, for example, office buildings are precast concrete plates (hereinafter referred to as PC plates).
If it is formed by bonding such as
Floor slabs are waterproofed for the purpose of preventing water leaking downstairs due to water leakage etc. on the upper floor. In general waterproofing, a waterproof layer such as asphalt is provided on a slab.

Conventionally, an electromagnetic shield for a floor slab provided with a waterproof layer is provided by laying an electromagnetic shield material 9 on the surface of the waterproof layer 6 without gaps, as shown in FIG. Referring to FIG. 3, electromagnetic shielding material 9 is placed on waterproof layer 6.
The construction procedure for providing the above layer will be briefly described. First, a waterproof layer 6 made of asphalt or the like is constructed on the surface of the slab 2 formed by joining the PC plate 1. Asphalt waterproof layer 6
Strongly adheres to the slab 2 with a strong adhesive force. Waterproof layer 6
After the solidification, the electromagnetic shielding material 9 is spread over the waterproof layer 6 without gaps. The electromagnetic shielding material 9 is fixed to the waterproof layer 6 with an adhesive 8 so as not to break the waterproof layer 6.

[0005]

SUMMARY OF THE INVENTION In an office building or the like,
As shown in FIG. 5, a free access floor (hereinafter, referred to as an OA floor) floated away from the floor slab 2 in order to provide a wiring space 10 suitable for storage of wiring of computers and communication devices, storage of connection devices, and the like. There are 11). One example of a method of constructing the OA floor 11 is to support the OA floor 11 distant from the floor slab 2 by the upper end of a column 12 having a lower end fixed on the floor slab 2. In the electromagnetic shield floor and the like shown in FIG. 4 described above, the lower end of the OA floor support 12 is fixed on a layer of the electromagnetic shield material 9 constructed on the surface of the floor slab 2. The OA floor support 12 needs to be fixed to the floor slab 2 or the layer of the electromagnetic shielding material 9 with a strength according to a condition such as not moving even when a predetermined horizontal force M is applied.

However, when the layer of the electromagnetic shielding material 9 is provided on the surface of the waterproof layer 6 on the floor slab 2, the connection between the floor slab 2 and the waterproof layer 6 is strong, There is a problem that it is difficult to secure the fixing strength with the OA floor support 12. As shown in FIG. 5, relatively thin (generally 1
From the viewpoint of protection of the waterproof layer 6, the electromagnetic shield material 9 cannot be fixed to the floor surface with an anchor material such as a nail, but is fixed to the waterproof layer 6 with an adhesive 8 or the like. At this time,
Due to the unevenness of the surface of the waterproof layer 6, that is, unevenness or a step at a joint portion, the entire surface of the electromagnetic shielding material 9 and the waterproof layer 6 cannot be bonded, and strong bonding cannot be expected. This electromagnetic shielding material 9
The OA floor support 12 is fixed thereon with an adhesive 8 or the like, and this portion cannot be fixed by an anchor, so that it is difficult to secure the fixing strength between the floor slab 2 and the OA floor support 12. This is because a thin electromagnetic shielding material 9 is sandwiched between the waterproof layer 6 and the OA floor support 12 although the OA floor support 12 should be bonded directly to the waterproof layer 6. In particular, when the electromagnetic shielding material 9 is a shielding nonwoven fabric, almost no fixing strength can be expected.

Accordingly, an object of the present invention is to provide an electromagnetic shield type waterproof floor using conductive powder to which an electromagnetic shield waterproof layer having both waterproof ability and electromagnetic shield ability is fixed in order to secure the OA floor. To be.

[0008]

Referring to the embodiment shown in FIG. 1, an electromagnetically shielded waterproof floor 4 using conductive powder according to the present invention.
Is an asphalt-based or urethane-based material mixed with a conductive powder having a particle size of 5 to 30 μm in an amount not more than 1/3 weight ratio of the total amount and sufficient for expressing the electromagnetic shielding ability on the top surface of the concrete floor slab 2. An electromagnetic shielding waterproof layer 7 made of a waterproof material is adhered.

[0009] The waterproof material used in the present invention needs to have a waterproof property that does not allow water to permeate and a fixing property that adheres to the concrete floor slab. The waterproofing ability is indispensable for the waterproofing function of the electromagnetically shielded waterproof floor using conductive powder,
The fixing ability is indispensable for securing the fixing of the OA floor. Asphalt-based or urethane-based waterproof material is
It has both the waterproofing ability and the fixing ability.

[0010] The reason why the conductive powder is mixed into the waterproof material is to provide an electromagnetic shielding function. Although the details of the mechanism by which the conductive powder is mixed into the waterproof material to exhibit the electromagnetic shielding ability are not always clear, it is presumed that the waterproof material has a finite impedance due to the mixing. The reason why the particle size of the conductive powder is 30 μm or less is that if the particle size exceeds 30 μm, sufficient electromagnetic shielding ability and mixing uniformity cannot be obtained. The reason why the mixing amount of the conductive powder is set to 1/3 weight ratio or less of the total amount is that when the mixing amount is 1/3 weight ratio or more of the total amount, the workability deteriorates, the cost increases, and the waterproof performance decreases. This is because a problem arises, and the electromagnetic shielding performance reaches a plateau and does not improve much. If the particle size is too small or the amount of the conductive powder mixed is too large, the waterproofing ability of the waterproofing material and the concrete fixing ability are impaired.

Preferred examples of the conductive powder include nickel,
Although it is a powder of copper, aluminum or carbon, the present invention is not limited to these examples.

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The type of waterproof material, the type and particle size of the conductive powder used in the present invention, and the mixing ratio thereof can be determined by experiments.

[Experimental Example] Particle size of 5 to 30 as conductive powder
μm nickel powder is added to molten asphalt waterproofing material in a weight ratio of 1/4 to the total amount (nickel amount / total amount)
And the materials were homogeneously mixed by stirring. This mixing amount can be appropriately selected according to the required electromagnetic shielding performance in the required frequency band.

A 3 mm-thick electromagnetic shielding waterproof layer test piece 7t (see FIG. 3) was prepared from the asphalt-based waterproof material mixed with the nickel powder.

As shown in FIG. 3, a double-layered surrounding wall composed of two metal plates 15 is used to reduce the amount of radio wave attenuation between the inside and outside.
An electromagnetic anechoic chamber 16 of 0 dB or more is created, and the electromagnetic shielding waterproof layer test piece 7t is attached to the test piece mounting window 17 of the dark chamber 16 by the fixing device 14 to conduct an experiment of the electromagnetic shielding effect of the electromagnetic shielding waterproof layer 7. Done. Test radio transmitter 18
A radio wave in the 50 to 3050 MHz band is transmitted toward the test piece 7t of the electromagnetic shielding waterproof layer, transmitted through the test piece 7t into the anechoic chamber 16, and the reception level in the anechoic chamber 16 is measured. Measured at receiver 19. The comparison between the measured reception level of the test radio wave with the electromagnetic shielding waterproof layer test piece 7t removed from the mounting window 17 and the measurement level of the test radio wave with the test piece 7t attached is shown. The electromagnetic shielding effect was measured by calculating the amount of radio wave attenuation of the test piece 7t.

In this experimental example, it was confirmed that a radio wave attenuation of 40 dB or more was obtained in the frequency band of 50 to 3050 MHz. Further, the present inventors have confirmed that there is no problem in the fixing ability of the test piece 7t. That is, the same electromagnetic shielding waterproofing layer as that of the test piece 7t was applied on a concrete flat plate, the support of the OA floor was bonded, and a push-down test was performed. As a result, it was confirmed that the electromagnetic shielding waterproof layer had a sufficient adhesive strength, that is, a fixing ability equivalent to that of a general waterproof layer containing no conductive particles.

Therefore, on the top surface of the concrete floor slab 2 shown in the experimental example, for example, a conductive powder such as a nickel powder having a particle diameter of 5 to 30 μm is added to the asphalt waterproof material at a ratio of 1/3 weight of the total amount. By using the mixed material, the electromagnetic shielding waterproof layer 7 having both waterproof ability and electromagnetic shielding ability can be fixed. Since the electromagnetic shielding waterproof layer 7 is fixed to the floor slab 2, if the support 12 of the OA floor 11 is fixed to the electromagnetic shielding waterproof layer 7, the OA
The floor 11 can be securely fixed.

Thus, an object of the present invention is "an electromagnetically shielded waterproof floor using conductive powder to which an electromagnetically shieldable waterproof layer having both waterproofness and electromagnetic shielding ability is fixed to secure the OA floor". Can be achieved.

[0019]

Referring to FIG. 2, the lower end of the wall shield layer 9w in the surrounding wall 3 surrounding the floor slab 2 and the electromagnetic shielding waterproof layer 7 on the floor slab 2 are electrically connected by the peripheral connection member 5. , The floor slab 2 can be provided with an electromagnetic shield connected to the electromagnetic shield of the peripheral wall 3. The space above the floor slab 2 is a peripheral wall 3 as shown in FIG. 2 and a ceiling (not shown) with an electromagnetic shield connected thereto.
When the space is enclosed by, the space can be electromagnetically shielded. In the figure, reference numeral 13 indicates a wall decorative material.

The present invention also relates to the type of conductive powder to be mixed into the waterproof material to form the electromagnetic shielding waterproof layer 7;
The particle size and the mixing amount can be selected according to the frequency band of the radio wave to be shielded and the required attenuation. The kind of the conductive powder used in combination with various waterproof materials in advance,
For the particle size, and the amount of contamination, if the frequency-radio wave attenuation characteristics of the electromagnetic shield are measured and recorded, within a certain limit, the optimal electromagnetic shield according to the required frequency band and the required attenuation, It can be formed by selecting the type, particle size, and mixing amount of the conductive powder.

[0021]

As described above, the electromagnetically shielded waterproof floor using the conductive powder of the present invention uses the electromagnetically shieldable waterproof layer having both the fixing ability to the concrete floor slab and the electromagnetic shielding ability. Has a remarkable effect.

(A) Since a single-function electromagnetic shield layer is not used, the step of installing such an electromagnetic shield layer is omitted,
It is possible to reduce the cost and shorten the construction period. (B) The OA floor can be securely and stably fixed. (C) When asphalt is used as a waterproofing material, asphalt itself has an electromagnetic shielding ability, so that there are few damages and performance deterioration factors at each stage of construction, and a reliable electromagnetic shielding performance can be secured at the time of completion. Further, even after completion, the surface state of the electromagnetic shield layer can be visually checked. (D) Since the floor finished surface can be used as an electromagnetic shield layer, it is easy to connect to the electromagnetic shield layer on the peripheral wall surrounding the floor. (E) It can be applied to rooftop waterproof floors and other waterproof floors. (F) For the frequency band of the radio wave to be shielded and the required amount of radio wave attenuation, an optimum electromagnetic shield floor can be formed by selecting an appropriate waterproof material and conductive powder.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram of one embodiment of the present invention.

FIG. 2 is an explanatory diagram of a method of connecting an electromagnetic shield type waterproof floor using conductive powder to a surrounding wall.

FIG. 3 is an explanatory diagram of a method of measuring an electromagnetic shielding effect.

FIG. 4 is an explanatory view of a conventional electromagnetic shield type waterproof floor.

FIG. 5 is an explanatory view of a conventional method of installing a free access floor.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Precast concrete slab 2 ... Floor slab 3 ... Perimeter wall 4 ... Electromagnetic shield type waterproof floor 5 ... Peripheral connection member 6 ... Waterproof layer 7 ... Electromagnetic shield waterproof layer 8 ... Adhesive 9 ... Electromagnetic shield material 10 ... For wiring Space 11 OA floor 12 Column 13 Wall decoration material 14 Fixing device 15 Metal plate 16 Anechoic chamber 17 Mounting window 18 Test radio transmitter 19 Test radio receiver

Claims (4)

[Claims] 1. The total amount of 1 to the top of a concrete floor slab
An electromagnetic shielding waterproof layer made of an asphalt-based or urethane-based waterproofing material mixed with a conductive powder having a particle size of 5 to 30 μm in an amount not more than / 3 weight ratio and sufficient for expressing the electromagnetic shielding ability is fixed. Electromagnetic shield type waterproof floor using conductive powder. 2. An electromagnetic shield type waterproof floor according to claim 1, wherein said conductive powder is nickel powder having a particle size of 5 to 30 μm. 3. The waterproof floor according to claim 1, wherein the electromagnetic shielding waterproof layer is made of an asphalt-based waterproof material mixed with nickel powder having a particle diameter of 5 to 30 μm at a ratio of 1/3 by weight of the total amount. Layer with a thickness of 1-4 mm
Electromagnetic shield type waterproof floor using conductive powder that has a radio wave attenuation of 50 to 3050 MHz of 40 dB or more. 4. The waterproof floor according to claim 1, wherein a lower end portion of an electromagnetic shield layer on a peripheral wall surrounding the floor slab is electrically connected to an electromagnetic shield waterproof layer on the floor slab. Electromagnetic shield type waterproof floor using conductive powder provided with a peripheral connection member.