JP6193098B2 - Antistatic sheet for sheet shutter - Google Patents

Description

  The present invention relates to an antistatic sheet for a sheet shutter used for a sheet shutter installed at an entrance or other opening of a building such as a factory or a warehouse.

  In general, factories and warehouses that frequently open and close doorways are provided with sheet shutters that are lighter and can be opened and closed at a relatively higher speed than iron shutters.

  Such seat shutters can be used for various purposes such as maintaining indoor temperature by air conditioning, preventing leakage of manufacturing gas into the environment, preventing noise, and preventing entry of insects and dust from outside the building. It is used.

  In many cases, the sheet base material used for the sheet shutter is usually formed of a composite material in which a plastic film such as vinyl chloride is superimposed on a fiber base material so as to reduce the weight by increasing the strength as much as possible.

  However, the sheet shutter made of such a composite material is a sheet shutter that is formed by friction between the overlapping sheets when the sheet is wound around the take-up drum or when the sheet is unwound or when the sheet is in sliding contact with the guide rail. There is a problem that static electricity tends to accumulate on the whole.

By the way, if static electricity is accumulated in the sheet for the sheet shutter and is charged to a considerable extent, spark discharge is likely to occur, and if there is flammable gas in the surrounding area, there is a possibility of ignition or explosion.
Therefore, in order to ensure safety when using the shutter in an atmosphere where a flammable gas exists, antistatic property is required to discharge static electricity generated in the sheet for the sheet shutter promptly at all times.

  As shown in FIGS. 5 and 6, as a known means for providing the sheet shutter sheet 20 with an antistatic function, for example, a conductive material (carbon black, metal powder, etc.) is dispersed in the entire synthetic resin sheet. The sheet is made conductive by being held, or by attaching a conductive material made of a fibrous metal such as copper or aluminum, or a wire mesh (mesh) 21 or a thin film metal to the sheet material. It is known (Patent Document 1).

  In addition, it has excellent wear resistance due to friction between sheets or friction with guide rails without impairing necessary functions such as flexibility of the sheet shutter, and excellent peeling resistance of the conductive layer on the sheet surface. Known as an antistatic sheet for sheet shutters is one in which the wire diameter and mesh of the wire mesh are adjusted when the wire mesh is superimposed on the thermoplastic resin layer forming the surface of the sheet-like substrate. (Patent Document 2).

JP 2007-113298 A JP 2012-255281 A

However, the antistatic sheet of the conventional sheet shutter described above has a conductive material such as a wire mesh 21 attached to the surface of the sheet-like base material, so that it is used for a long time in a state where the sheet is frequently wound or unwound. Then, the state where the metal meshes on the surface rub against each other cannot be avoided.
Therefore, the metal mesh 22 is rubbed, or the metal mesh and the sheet base material are rubbed and the metal powder 22 adheres, or the metal mesh 21 or a part of the sheet-like base material is discolored black. In some cases, the part of the metal mesh that has been rubbed easily becomes a part 21a peeled off from the resin layer of the base material, or a part of the metal mesh that has been frayed is broken to cause a break 21b. Such conductive materials deteriorated and were easily damaged.

  Accordingly, the present invention solves the above-mentioned problems, and the antistatic sheet of the sheet shutter is soiled without being discolored due to deterioration of the sheet surface even when used for a long period of time with a high frequency of winding or rewinding. It is difficult, and the wire mesh is not peeled off from the sheet, it does not break due to scuffing, it has sufficient use durability, and it is also an object to make an antistatic sheet that also has the original antistatic property Yes.

  In order to solve the above problems, in the present invention, a drum around which an antistatic sheet is wound is provided around the opening of a building, and the antistatic sheet is electrically grounded to the drum. In the antistatic sheet of the sheet shutter that winds or unwinds and opens and closes the opening, the antistatic sheet is integrated by overlapping one surface of a metal mesh on a sheet base material, and is formed on the other surface of the metal mesh. An antistatic sheet for sheet shutters is provided, in which a resin layer is provided in an integrated manner and a large number of through-holes penetrating both the front and back surfaces are dispersed throughout the resin layer.

  The antistatic sheet for sheet shutter according to the present invention configured as described above is formed when the sheet is wound up in a roll shape when the sheet shutter is opened or closed, or is unwound and unwound by a resin layer provided on a metal mesh. In addition, the surfaces of the overlapping sheets are in frictional contact with each other, and the metal meshes are not in direct contact with each other through the resin layer, so that no metal powder is generated due to the friction between the metals. Accordingly, the sheet surface is free from black stains due to contact between metals, and the wire mesh is prevented from being worn or worn, thereby improving the durability of the antistatic sheet.

  In addition, the large number of through holes formed on the entire surface of the resin layer makes it easier for static electricity that tends to accumulate on the sheet surface because a part of the wire mesh is exposed to the through holes, or to the wire mesh in the sheet, or If the thickness is conductive enough to release static electricity, and part of the wire mesh is exposed in the through hole, parts of the wire mesh come into contact with each other due to elastic deformation of the resin layer on the surface of the stacked sheets. In some cases, static electricity is electrically grounded by being guided from a resin or wire mesh to a conductive guide rail or drum. As a result, an antistatic sheet for sheet shutters having sufficient antistatic properties, antifouling properties and durability for use is obtained.

The resin layer is preferably a resin layer having a thickness of 1 to 7 μm so that the conductivity and antifouling property for antistatic properties are sufficiently and with good durability.
Moreover, in order to make it easy for the static electricity that tends to accumulate on the sheet surface to be efficiently released to the wire mesh in the sheet, the through hole is preferably a through hole formed in the mesh of the wire mesh.

  In order for such an antistatic sheet to sufficiently perform its function, the sheet shutter includes an electrically grounded conductive guide rail, and the surface of the antistatic sheet or a wire mesh is provided on the conductive guide rail. It is preferable to take up or pay out while sliding.

  The present invention relates to an antistatic sheet for a sheet shutter, in which one surface of a wire mesh is integrated with a sheet base material, and a resin layer is integrally provided on the other surface of the metal mesh, and the entire resin layer is front and back. Since a large number of through-holes that penetrate both sides are provided, both the antifouling property of the resin layer and the antistatic property of the wire mesh are combined, and even when used for a long period of time with a high frequency of winding or rewinding There is an advantage that the surface of the metal is not discolored, the wire net is not peeled off from the sheet, or is hardly worn and broken, has sufficient durability for use, and has excellent antistatic properties.

The perspective view which cuts out the antistatic sheet of 1st Embodiment and shows a multilayer structure Sectional drawing of the antistatic sheet of 1st Embodiment Sectional drawing of the antistatic sheet which shows 2nd Embodiment The front view which shows the sheet shutter which uses 1st Embodiment Perspective view of conventional antistatic sheet Sectional view of a conventional antistatic sheet

Embodiments of the present invention will be described below with reference to the accompanying drawings.
As shown in FIGS. 1 to 4, the first and second embodiments are such that the antistatic sheet 1 is electrically grounded in a housing 2 fixed around the opening of a building. Charging used in a sheet shutter that is wound around a drum 3 and rotated or wound around the drum 3 by a motor 4 or the like to wind or feed out the antistatic sheet 1 in a grounded state so that the opening can be opened and closed. This is the preventive sheet 1.

The sheet shutter shown in FIG. 4 has an electrical conduction path from the antistatic sheet 1 to the ground (ground G), and the path is formed by winding the side edges and front and back surfaces of the antistatic sheet 1. The conductive winding drum 3 leads to the ground G from the rotating shaft of the winding drum 3 through the supporting column, the guide rail 6, the housing 2, and other metal parts. The side edge portions of the antistatic sheet 1 and both end surfaces of the cut sheet are also electrically connected to the guide rail 6 that is in contact therewith.
Although not shown in the figure, it may be directly grounded via an electric cord separately provided from the rotating shaft of the winding drum 3 or the guide rail 6 as necessary.
Moreover, the code | symbol 1a in FIG. 4 shows the joint of an antistatic sheet | seat, and is a part normally reinforced with crosspiece members, such as a metal plate.

As shown in FIGS. 1, 2, and 4, the antistatic sheet 1 of the first embodiment has a thermoplastic resin layer 8 stacked on one side or both sides of a sheet-like fiber material 7, and these are bonded or thermally welded. One side of the metal mesh 5 is overlapped on one side or both sides of the integrated sheet base material 9 and integrated by thermal welding, and the resin layer 10 is overcoated on the other side of the metal net 5 to a predetermined thickness. The resin layer 10 is formed with a large number of mesh-like through holes 11 penetrating both front and back surfaces.
As shown in FIG. 3, as a second embodiment, a wire mesh 5 ′ of the same material is separately prepared on the lower surface of the sheet base material 9 of the antistatic sheet 1 of the first embodiment described above, One side is overlapped with the thermoplastic resin layer 8 and integrated by thermal welding, and the other side (the lower surface in the figure) of the wire mesh 5 ′ is overlapped to provide the resin layer 10 ′ by coating a predetermined number of times. May be provided with a large number of through-holes 11 'penetrating both front and back surfaces. If it does in this way, the antistatic sheet excellent in the antistatic function and use durability on both surfaces can be obtained.

  The sheet base material 9 used for the antistatic sheet for sheet shutter of the present invention has a thermoplastic resin layer such as polyvinyl chloride resin or polyolefin resin on one side or both sides of a sheet-like fiber material 7 made of glass fiber or polyester fiber. One integrated by overlapping, heat welding, or an adhesive can be used.

  In addition to the above, the sheet base material 9 can be configured by appropriately combining lighter materials and materials having excellent tensile strength in accordance with the purpose and size of use of the sheet shutter. Usually, it is preferable to adopt a thermoplastic resin having flexibility and to heat-weld it by superimposing a wire mesh, and it is preferable that the integration is reliable. As the above-mentioned thermoplastic resin layer, a vinyl chloride resin is adopted. Favorable results have been obtained.

  It is not necessary to use the metal wire of the material for the sheet base material which is overlapped and integrated with the above-mentioned sheet base material. However, in consideration of durability, stainless steel wire or copper wire can be used. Such a conductive metal wire is preferably used, and a well-known conductive wire mesh can be adopted by selectively adopting the thickness and mesh size according to the use environment and purpose of the sheet shutter. . In addition, a well-known wire mesh weave can be employed, and examples thereof include plain weave, twill weave, and turtle weave.

  As described in Patent Document 2, the wire mesh wire diameter (D) is D: 0.03 to 0.57 mm, and the mesh value (M) is M: 0.25 to 325. You can also. Thus, when the wire diameter and mesh value of the conductive metal wire of the wire mesh are set, the wire mesh sufficiently exhibits the required wear resistance and peeling resistance, and also the flexibility necessary for winding and unwinding the sheet shutter. Easy to obtain.

  Resin layers that are provided integrally on such a wire mesh include, for example, vinyl resins such as polyvinyl chloride, polyolefin resins such as polyethylene and polypropylene, polyamide (nylon) resins, urethane resins, acrylic resins, etc. Is mentioned.

  These resin layers can be provided at a required thickness of, for example, about 1 to 7 μm by coating a resin dissolved in a volatile solvent a predetermined number of times. It is also possible to provide a sheet-like resin layer formed thereon and laminate it on a metal mesh by heat welding or the like to be integrated. For the above-described coating, a known coating method such as spray coating can be employed.

  In this way, a large number of through-holes that penetrate both the front and back surfaces are formed in the entire resin layer that is provided integrally with the metal mesh. The through-hole may be a continuous or open-type pore in which the formed pores are formed by continuous foaming in the foamed resin layer, but the non-foamed resin layer is perforated by post-processing. It may be mechanically formed by a method such as piercing a large number of needles, or the resin layer may be foamed while being applied by dissolving the resin in a volatile solvent, or not so as to cover the mesh of the wire mesh. By forming a foamed resin film and applying such that a part of the thin resin film is broken, the through holes may be formed in the mesh of the metal mesh.

  The foamed resin having the above-mentioned continuous ventilation holes can be obtained by a known foamed resin manufacturing method. For example, a foaming method using a chemical reaction (chemical reaction gas utilization method), a foaming method using a solvent having a low boiling point (low-boiling solvent utilization method) ), A foaming method in which air is mixed (mechanical mixing method), and a foaming method (solvent removal method) in which voids are formed in the process of removing the contained solvent.

  The hole diameter of the through hole is not particularly limited. For example, when a wire net having a mesh of about 1 × 1 mm is employed, if a through hole having a hole diameter of about 50 to 1000 μm is formed, excellent conductivity can be obtained. It has been found.

  The antistatic sheet 1 is used by joining a plurality of strip-shaped antistatic sheets 1 cut with a required width of the sheet shutter so as to be electrically connected to each other at the joint 1a, but the joining method is particularly limited. Alternatively, well-known joining means such as welding or other adhesion means or sewing, and further snap engagement or engagement using metal fittings may be employed.

  When performing the above-mentioned sewing, if the main sewing or chain stitching is performed with a sewing machine using a conductive thread such as a metal thread, the front and back surfaces of the joining sheet are short-circuited by the sewing line in which the upper thread and the lower thread are intertwined. Thus, the conductivity on both sides is improved.

  Further, at the time of joining, a crosspiece made of a conductive material such as a metal plate (steel plate or the like) is integrally fixed along the joint 1a, and the joining sheet is reinforced to obtain a required strength. In addition, both ends of the crosspiece may be brought into sliding contact with the conductive guide rail 6 (see FIG. 4).

As for the surface resistance of the antistatic sheet 1 obtained in this way, the leakage resistance (ground resistance) when used for a sheet shutter is 1.0 × 10 ⁶ Ω or less, and the surface resistivity of the sheet material is 1.0 ×. If it is set to be 10 ¹⁰ Ω or less, an antistatic sheet shutter having excellent explosion-proof performance due to its conductivity can be obtained.

  A sheet base material made of stainless steel and laminated with a polyvinyl chloride resin layer on one side of a sheet-like fiber material made of plain woven glass fibers and integrated by heat welding is made of stainless steel with a wire diameter of 0.114 mm, 26 mesh (1 One side (bottom surface) of a metal mesh of (25.4 / 26) -0.114 = 0.86 mm) was overlapped and integrated by heat welding.

  On the surface of the wire mesh integrated with the obtained sheet base material, a liquid solution of polyvinyl chloride resin diluted with acetone (acetone: polyvinyl chloride resin = 1: 1 (mass ratio)) is repeatedly applied by spray coating a predetermined number of times. The film thicknesses (μm) shown in Table 1 were provided. In the obtained resin layer, a rectangular or indeterminate through-hole penetrating both the front and back surfaces is formed in the entire resin layer. For example, those having a hole diameter of about 0.1 to 1 mm are arranged in a mesh shape Was recognized.

[Measurement of surface resistance]
Three anti-static sheets having a square shape (20 cm × 15 cm) obtained as described above, at a total of seven locations, that is, the four corners and the center and the middle of the two opposing long sides. The surface resistance (MΩ) was measured at an applied voltage of 50 V or 100 V, and the average value of the measured values obtained is shown in Table 1 for each resin layer thickness.
The surface resistance was measured in accordance with the measurement method in Appendix E.9 (Measurement of Resistance) in [Electrostatic Safety Guidelines 2007 (Independent Administrative Institution, Occupational Safety and Health Research Institute, issued on June 1, 2007)].

  As is clear from the results in Table 1, the antistatic sheet having a low surface resistance (MΩ) of 0 to 0.003 MΩ (those marked with * in the table) The resin layer had a thickness of 1 to 7 μm in a state where a large number of through holes penetrating both surfaces were formed.

[Real machine durability test]
An antistatic sheet (Example) obtained as described above and an antistatic sheet (Comparative Example) prepared in exactly the same manner as in the Examples except that no resin layer was formed on the surface in this Example. A stainless steel 26 mesh and a wire mesh with a wire diameter of 0.114 mm were used on one side of the sheet, and each was attached to an electric test shutter (opening was 1 m wide and 4 m high) shown in FIG.
Then, using these electric shutters, an actual machine durability test was repeated in which the operation of winding the sheet onto a drum and then rewinding it was continuously repeated. The evaluation is that the shutter is fully opened from the fully closed state to the fully closed state again, and is repeated up to 300,000 cycles (times) until blackening (dirt) or a hole (damaged part) occurs. The number of repetitions was examined, and the results are shown in Table 2.

As is clear from the results in Table 2, in the example, the number of times the shutter was opened and closed until the occurrence of darkening (dirt) was 85000, but in the comparative example, it was 38000, and the example was 2 of the comparative example. The durability more than doubled was recognized.
In the comparative example, holes or tears occurred in the wire mesh provided on the surface of the sheet base material after opening and closing 54,000 times, but in the examples, holes and tears occurred even after passing the test limit number of 300,000 times. Without it, excellent durability was recognized.

DESCRIPTION OF SYMBOLS 1 Antistatic sheet | seat 1a Seam 2 Housing 3 Winding drum 4 Motor 5, 5 'Wire net 6 Guide rail 7 Sheet-like fiber material 8 Thermoplastic resin layer 9 Sheet base material 10, 10' Resin layer 11, 11 'Through-hole

Claims (4)

A sheet shutter provided with a drum around which an antistatic sheet is wound is provided around the opening of a building, and the antistatic sheet is wound or fed around the drum while being electrically grounded to open and close the opening. In the antistatic sheet,
This antistatic sheet is formed by integrating one surface of a metal mesh on a sheet base material, and integrally providing a resin layer on the other surface of the metal mesh. An antistatic sheet for sheet shutter, characterized in that a through hole is provided.   The antistatic sheet for a sheet shutter according to claim 1, wherein the resin layer is a resin layer having a thickness of 1 to 7 μm.   The sheet shutter antistatic sheet according to claim 1 or 2, wherein the through hole is a through hole formed in a mesh of a wire mesh.   The sheet shutter includes a conductive guide rail that is electrically grounded, and is wound or delivered while the surface of the antistatic sheet or the wire mesh is in sliding contact with the conductive guide rail. The antistatic sheet for sheet shutters according to any one of 3 above.

Images