JP4130116B2 - Antistatic mat - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an antistatic mat that is mainly disposed on a floor and can easily flow static electricity to the ground when a person or object charged with static electricity is placed thereon.
[0002]
[Prior art]
In recent years, environments that dislike static electricity have increased. For example, in a factory that handles electronic components, touching by a worker who is charged with static electricity may damage the electronic component, so that it is necessary to release the static electricity of the charged worker and to improve reliability. Therefore, a film made of a conductive material is often stuck on the floor. However, in such a case, the floor is often made of concrete, the cushioning property is poor, and the fatigue load on the worker is large.
[0003]
Therefore, for example, there is a mat described in Patent Document 1 (Japanese Patent Application Laid-Open No. 9-276205) as an antistatic mat with an emphasis on cushioning properties. This mat is obtained by depositing random loops of monofilaments, and has good cushioning properties, but since the filament length is large, it may not be able to exhibit a sufficient antistatic function. In addition, the filament loop is exposed on the surface that the operator's feet (shoes) step on, making it difficult to walk, and the filament loop that originally stood in the thickness direction has been used for a long time. As a result, there is a problem that the cushioning property deteriorates as a result of falling or sleeping, and there is also a problem that dust tends to collect inside.
[0004]
[Patent Document 1]
Japanese Patent Laid-Open No. 9-276205
[Problems to be solved by the invention]
In view of the above problems, an object of the present invention is to provide an antistatic mat having a good antistatic function and capable of maintaining cushioning properties over a long period of time.
[0006]
[Means for Solving the Problems]
According to invention of Claim 1, it is an antistatic mat,
It is formed by arranging lattice forming members made of a conductive material having elasticity in a lattice shape so as to have many lattice holes of substantially the same shape,
In 20mm square area arbitrarily selected, the ratio of the lattice forming members Ri 15-90% der,
The height of the grid forming member is larger than the thickness, and the upper end of the grid forming member with which the worker's shoes are in contact is tapered.
An antistatic mat is provided.
According to the second aspect of the present invention, there is provided an antistatic mat according to the first aspect, wherein the ratio of the lattice forming member is 40 to 60%.
According to a third aspect of the present invention, there is provided the antistatic mat according to the first aspect, wherein the lower end of the lattice forming member is formed flat.
According to a fourth aspect of the present invention, in the first aspect of the invention, the lattice forming member is inserted into the linear member that is extruded from the extruded type slot at the first speed and from the extruded type slot between the adjacent linear members. An antistatic mat is provided comprising a corrugated member that is extruded at a second speed greater than one and is curved between adjacent linear members.
According to a fifth aspect of the present invention, there is provided an antistatic mat according to the first aspect, wherein a lattice is formed in a honeycomb shape.
According to a sixth aspect of the present invention, there is provided an antistatic mat according to the first aspect, wherein the conductive material has a hardness value of 40 to 70 according to a JIS7215 plastic durometer hardness test method. The
According to a seventh aspect of the present invention, there is provided an antistatic mat according to the first aspect, wherein the leakage resistance of the conductive material is 10 kΩ to 100 MΩ.
[0007]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.
FIG. 1 is a top view of a first embodiment of an antistatic mat 1 according to the present invention, which has a lattice forming member 10 including a linear member 11 and a corrugated member 12, and has two adjacent straight lines. A corrugated member 12 is sandwiched between the members 11, and the linear member 11 and the corrugated member 12 are coupled to each other.
[0008]
And, for example, if one wave-like member 12 has a convex portion in the upper part in the figure as a mountain and a convex part in the lower part in the figure as a valley, two adjacent peaks and the linear member 11 in contact with these peaks A bell-shaped lattice hole 13 (wide in the figure) is formed between them, and a bell-shaped lattice hole (wide in the figure) is formed between two adjacent valleys and the linear member 11 in contact with these valleys. 13 is formed.
[0009]
The antistatic mat 1 has a size of about 90 cm × 60 cm, but includes at least one, preferably two or more lattice holes 13 in an arbitrarily selected 20 mm square region, and forms a lattice. The ratio of the member 10 is 15 to 90%, preferably 40 to 60%. When the ratio of the lattice forming member 10 is 15% or less, the vertical deformation becomes excessive and the shape cannot be maintained, and when it is 90% or more, the amount of static electricity generated becomes large.
[0010]
Here, in an arbitrarily selected 20 mm square area, the antistatic mat is stepped on a person's foot (shoe), and has a size of about 90 cm square, for example. . Therefore, simply defining the ratio of the lattice forming member 10 with respect to the entire area may result in a large lattice hole in which all the feet (shoes) can be entered.
[0011]
FIG. 2 is a cross-sectional view of the corrugated member 12 taken along II-II in FIG. 1, and the upper end thereof is an arc shape as shown in FIG. 2A or as shown in FIG. The shape is trapezoidal and tapered, and the lower end is flattened. Thus, by tapering the upper end, the generation of static electricity is further suppressed, and the static electricity generated by flattening the lower end tends to escape.
[0012]
In both cases (A) and (B), the thickness t1 is set to 0.8 to 2.0 mm, preferably 1.0 to 1.4 mm, more preferably 1.2 mm, and the height h1 is the above. 2 to 20 mm, preferably 5 to 10 mm, more preferably 7 mm.
The radius of the arc at the upper end in the case of (A) is 0.5t to 4t, and the trapezoidal height h 'in the case of (B) is 0.25t to 0.5t.
The number of waves is defined by a length Wf (see FIG. 1) in which five wavy members 12 are in contact with the linear member 11, and Wf = 10 mm to 60 mm, preferably 38 mm.
[0013]
FIG. 3 is a cross-sectional view of the linear member 11 taken along line III-III in FIG. 1, and the thickness t2 is 0.5 to 1.5 mm, preferably 0.8 mm, and the height h2 is a value obtained by removing the upper end portion of the corrugated member 12. Therefore, in the first embodiment, the wavy member 12 is in contact with the operator's foot (shoe).
[0014]
Next, the material of the lattice forming member 10 will be described. The material of the lattice forming member 10 in the first embodiment is obtained by kneading a conductive plasticizer in vinyl chloride. The conductive plasticizer kneaded with vinyl chloride is a so-called surfactant, and kneading the surfactant not only makes the surface of the resin conductive but also prevents charge generation due to surface friction.
[0015]
This surfactant is classified into four types based on ionicity: an anionic active agent, a cationic active agent, an amphoteric active agent, and a nonionic active agent.
Examples of those having good compatibility with vinyl chloride include an anion activator alkyl sulfonate, an cation activator amide type cation, an amphoteric activator alkyl betaine, a nonionic activator fatty acid monoglyceride, and a sorbitan fatty acid ester.
[0016]
About 80 to 180 parts by weight of a conductive plasticizer is added to 100 parts by weight of vinyl chloride, and a small amount of stabilizer is added. As the stabilizer, metal soap (metal salt of higher fatty acid) is used. As the metal, for example, two components of Ba (barium) / Zn (zinc) are used. In this case, Zn soap captures HCl and displaces allyl chloride, Ba soap captures HCl and regenerates the Zn soap by exchanging ligand with ZnCl ₂ and Zn soap by ZnCl ₂ and Ba soap It exhibits a stabilizing effect with excellent reproduction.
[0017]
The material generated as described above has a durometer hardness of 40 to 70, preferably 55, as measured by the “plastic durometer hardness test method” defined in JIS K7215. If the durometer hardness is 40 or less, it is excessively deformed in the vertical direction, and if it is 70 or more, the elasticity of the entire product is lost and the burden on the operator becomes excessive.
[0018]
Further, the conductive plasticizer is kneaded so that the leakage resistance has the following value.
<Material before processing (sheet form)>
Lower limit value = 10 kΩ, upper limit value = 100 MΩ, preferably 500 kΩ
<Processed into the shape of the first embodiment (arranged on the SUS plate)>
Lower limit value = 100 kΩ, upper limit value = 10 MΩ, preferably 10 MΩ
<Processed in the shape of the first embodiment (arranged on other flooring)>
Lower limit value = 100 kΩ, upper limit value = 200 MΩ, preferably 25 MΩ
All are based on the test method of ESD STM7.1.
In addition, there exists a possibility of an electric shock if it is below the lower limit, and static electricity does not escape if it is above the upper limit.
[0019]
Next, a method for manufacturing the antistatic mat 10 of the first embodiment will be described.
The antistatic mat 10 of the first embodiment is manufactured by heating the material produced as described above to a molten state and extruding it from the outlet of the extrusion die 50 as shown in FIG. Since this extrusion molding is described in Japanese Patent Publication No. 6-55403, it will be briefly described.
[0020]
The first slot 51 is for forming the linear member 11, and the second slot 52 is for forming the corrugated member 12. Since the first slot 51 is narrow, the speed of the material coming out of the first slot 51 is low and comes out linearly. On the other hand, since the second slot 52 is wide, the speed of the material coming out of the second slot 52 is fast, and the material coming out of the second slot 52 is bent and corrugated, which is joined to the straight portion. .
[0021]
The performance of the antistatic mat of the first embodiment formed as described above will be described. When the durometer hardness was 55, good cushioning properties were obtained, and the charge potential of the human body measured by the test method of the American ESD Association STM97.2 was 1 V or less.
[0022]
Next, a second embodiment will be described. FIG. 5 is a view of the antistatic mat 1 of the second embodiment as viewed from above, and has a hexagonal honeycomb lattice.
In this case, the thickness t3 of the lattice forming member 20 is 0.8 to 2.0 mm, preferably 1.0 to 1.4 mm, more preferably the same as the thickness t1 of the corrugated portion of the first embodiment. 1.2 mm. Further, when the height h3 is set to the above thickness, it is set to 2 to 20 mm, preferably 5 to 10 mm, and more preferably 7 mm.
[0023]
In the manufacture of the second embodiment, unlike the first embodiment, the half element 21 as shown in FIG. 6 is formed with a mold and sequentially arranged so as to form a hexagonal hole. Then, it is performed by heating or bonding to each other using an adhesive.
Alternatively, as shown in FIG. 7, a hexagonal member 22 is extruded, bundled and heated, or joined together using an adhesive, and then cut to a predetermined height. You can also
Further, the sheet-like conductive material 23 shown in FIG. 8 can be manufactured by making a cut 24 as shown in the figure and then pulling the cut in a direction perpendicular to the cut.
[0024]
As described above, in the first embodiment, the lattice is formed so that the lattice holes are corrugated by the linear member and the corrugated member, and in the second embodiment, the lattice is formed so that the lattice holes are honeycomb-shaped. However, the shape of the lattice or the lattice hole is not limited to these, and may be any other shape. For example, the lattice hole may be square. Is possible.
[0025]
Next, an example of use of the antistatic mat of the present invention produced as described above will be described with reference to FIG.
FIG. 9A shows, for example, a case where the conductive floor 100 is constructed of a tile, a coated floor, or a long sheet metal plate, and is placed on the conductive floor 100. It is only necessary to lay the antistatic mat 1.
(B) shows a case where it is placed on a normal non-conductive floor 100 ′. First, the conductive sheet 110 is placed on the non-conductive floor 100 ′, and the antistatic mat 1 of the present invention is placed thereon. Lay down. The conductive sheet is grounded. The conductive sheet 110 may be made of, for example, a conductive resin or a metal plate such as a stainless plate. Or you may affix a metal foil partially.
(C) is one in which conductive fibers 120 are woven into the antistatic mat 1 and the fibers are grounded.
[0026]
【The invention's effect】
The invention described in each claim is an antistatic mat,
It is formed by arranging lattice forming members made of an electrically conductive material having elasticity in a lattice shape so as to have many lattice holes of substantially the same shape, and the ratio of the lattice forming members is 15 to 15 in an arbitrarily selected 20 mm square region. 90%, the height of the grid forming member is larger than the thickness, and the upper end of the grid forming member that comes into contact with the shoe of the worker is tapered,
It is possible to achieve both good cushioning properties and a good antistatic function.
The ratio of the lattice forming member is preferably 40 to 60% as in the invention of claim 2.
It is preferable that the hardness of the conductive material has a value of 40 to 70 according to the JIS7215 plastic durometer hardness test method as in the invention of claim 6 .
The leakage resistance of the conductive material is preferably 10 kΩ to 100 MΩ as in the invention of claim 7 .
If the lower end portion of the lattice forming member is formed flat as in the invention of claim 3 , static electricity can easily escape.
According to a fourth aspect of the present invention, the lattice forming member has a linear member extruded at a first speed from the extrusion type slot and a first speed higher than the first speed from the extrusion type slot between the adjacent linear members. If it is made of a wave-like member that is extruded at a speed of 2 and bends between adjacent linear members, it can be easily manufactured with an extrusion die.
[Brief description of the drawings]
FIG. 1 is a top view of an antistatic mat according to a first embodiment.
FIG. 2 is a cross-sectional view taken along line II-II in FIG.
3 is a cross-sectional view taken along line III-III in FIG.
FIG. 4 is a view showing a mold for manufacturing the antistatic mat of the first embodiment.
FIG. 5 is a top view of an antistatic mat according to a second embodiment.
FIG. 6 is a diagram showing a halved element in one manufacturing method of the second embodiment.
FIG. 7 is a diagram showing elements having a hexagonal cross section in another manufacturing method according to the second embodiment;
FIG. 8 is a diagram illustrating still another manufacturing method according to the second embodiment.
FIG. 9 is a view showing an example of use of the antistatic mat of the present invention,
(A) shows the case where it puts on the conductive flooring,
(B) shows the case where it puts via a conductive sheet on a normal non-conductive flooring,
(C) shows a case where conductive fibers are woven into the antistatic mat of the present invention and the fibers are grounded.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Antistatic mat 10 ... Lattice formation member 11 ... Linear member 12 ... Wave-like member 13 ... Lattice hole 20 ... Lattice formation member 21 ... Half element 22 ... Hexagonal member 23 ... Conductive material 24 on sheet | seat 50 ... Extrusion Mold 51 ... First slot 52 ... Second slot 100 ... Conductive floor 100 '... Non-conductive floor 110 ... Conductive sheet 120 ... Conductive fiber

Claims (7)

An antistatic mat,
It is formed by arranging lattice forming members made of a conductive material having elasticity in a lattice shape so as to have many lattice holes of substantially the same shape,
In 20mm square area arbitrarily selected, the ratio of the lattice forming member Ri 15-90% der,
The height of the grid forming member is larger than the thickness, and the upper end of the grid forming member with which the shoe of the worker is in contact is tapered,
An antistatic mat characterized by that.   The antistatic mat according to claim 1, wherein a ratio of the lattice forming member is 40 to 60%.   The antistatic mat according to claim 1, wherein the lower end portion of the lattice forming member is formed flat.   The lattice forming member is extruded from the slot of the extrusion mold at a first speed, and the adjacent straight line is extruded between the adjacent linear member at a second speed higher than the first speed from the slot of the extrusion mold. The antistatic mat according to claim 1, comprising an undulating member that bends between the members.   The antistatic mat according to claim 1, wherein a lattice is formed in a honeycomb shape.   2. The antistatic mat according to claim 1, wherein the conductive material has a hardness value of 40 to 70 according to a JIS7215 plastic durometer hardness test method.   The antistatic mat according to claim 1, wherein the leakage resistance of the conductive material is 10 kΩ to 100 MΩ.

Images