JPS6142833Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an improvement in a sheet used as the body of a coal mine blast pipe for introducing fresh air into a coal mine.

In general, for coal mine blast pipes, in order to prevent explosion accidents in coal mines, it is necessary to minimize the generation of static electricity due to the contact dispersion effect and various other phenomena when dust, etc. passes through the blast pipe. .

For this reason, the vinyl processed cloth (generally called vinyl tarpaulin) conventionally used as the main body of coal mine blast pipes is made of polyvinyl chloride resin, which is made by kneading an antistatic agent into the surface of a base cloth that has been previously treated with a cationic antistatic agent. We use a sheet-like material that coats objects, but if this material is mixed with more than a certain amount of antistatic agent, the surface will become sticky and unsuitable for use. There is a limit (up to 3 parts by weight of antistatic agent per 100 parts by weight of polyvinyl chloride resin), and therefore there is a limit to the antistatic effect, and this can be expressed in surface resistivity below 10 ¹⁰ Ω. . In addition, the phenomenon in which the surface becomes sticky is due to the antistatic agent migrating and floating on the surface, and during use as a blower pipe, it may be missing from the surface, or the antistatic effect may gradually decrease due to contamination, etc. There are drawbacks.

On the other hand, safety measures to prevent explosion accidents inside coal mines have been increasingly required to be strengthened in recent years, and coal mine ventilation pipes also need to further enhance their antistatic function.
The characteristics of vinyl tarpaulin used for coal mine blast pipes include a surface resistivity of at least 10 ¹⁰ Ω or less, preferably 10 ⁸ Ω or less, and a charge density of 4 × 10 ^-6 C/m. ² , preferably 3×10 ^-6 C/
The demand is regulated to be less than m ² .

In view of the current situation, the present inventor first created a resin-treated cloth by coating the surface of a base cloth with a thermoplastic synthetic resin composition mixed with an appropriate amount of a specific highly conductive carbon black. This product has a surface specific resistance value of about 10 ⁶ to 10 ⁷ Ω, a charge density of 3 × 10 ^-6 C/m ² or less, and the surface is not sticky like conventional products. Therefore, it was sufficiently excellent as a sheet for coal mine blast pipes in terms of antistatic effect and durability. However, the thermoplastic synthetic resin composition containing specific highly conductive carbon black and other materials is expensive, and the color is completely black, contrary to the yellow color labeling required for use inside coal mines. There were some practical problems.

In order to solve these various problems, the present invention consists of alternating bands of yellow colored layers and highly conductive carbon black layers on the surface of the thermoplastic synthetic resin composition covering the base fabric. The present invention provides a sheet for use in coal mine blast pipes, which exhibits a yellowish appearance as a whole and has a predetermined antistatic performance.

Embodiments of the present invention will be described below with reference to the drawings.

Example 1 1 is 420 denier nylon thread, 20 x 22 threads/
A vinyl tarpaulin T is formed by covering both sides of a base fabric made of a plain-woven fabric having a texture of 100 mm with a coating 2 of a yellow-colored polyvinyl chloride resin composition having the composition shown in Table A below. There is. Highly conductive carbon ink (product name: VSMY Black D...) is applied to the surface 3 of the coating 2 of this vinyl tarpaulin T.
...manufactured by Dainichiseika Co., Ltd.) was applied in strips with a width of 5 mm at intervals of 25 mm, dried and fixed, and a highly conductive carbon black layer C was provided on both sides.

Table A Polyvinyl chloride 100 parts by weight Plasticizer 65 parts by weight Stabilizer 4 parts by weight Filler 20 parts by weight Flame retardant 2 parts by weight Antistatic agent 2 parts by weight Yellow pigment 5 parts by weight The performance of the sheet-like product with the above structure is surface-specific. The resistance value is 10 ⁷ Ω or less, and the charge density is 2.6×
It was 10 ^-6 C/ ^m2 .

In addition, in FIG. 1, the carbon black layer C appears to protrude from the resin layer surface 3 due to the illustration, but in reality, the protrusion of the layer C is almost non-existent, and the surface due to the formation of the layer C is There are almost no unevenness.

Example 2 On the surface 3 of the coating 2 of the polyvinyl chloride resin composition coated on the base fabric 1 in Example 1, 25
A sheet in which a highly conductive carbon black layer with vertical stripes is provided at every mm interval, and a highly conductive carbon black layer with horizontal stripes of 5 mm width and every 25 mm is provided on the back side.

Example 3 On the surface of the coating 2 of the polyvinyl chloride resin composition coated on the base fabric 1 in Example 1, a highly conductive carbon black layer with vertical stripes similar to Example 1 or a highly conductive carbon black layer with a combination of vertical and horizontal stripes was applied. A sheet with a carbon black layer and a highly conductive carbon black layer with a combination of vertical and horizontal stripes on the back side.

Note that the conditions in the above example are as follows.

The base fabric 1 can be made of any suitable synthetic fiber in addition to nylon, and the design of its structure etc. is determined by the physical processing conditions required for the finished product. Further, it is more effective if the fibers constituting the base fabric are made of a material having an antistatic function.

As for the material of the resin coating layer, an appropriate thermoplastic resin may be selected in consideration of the material of the base fabric to be used, but polyvinyl chloride resin is particularly suitable, and antistatic agents should not be mixed in. You don't have to.

In addition to the above-mentioned brands, highly conductive carbon ink that is applied in a band shape to the surface of the resin layer of resin-treated cloth has a surface resistivity value of 10 ³ Ω or less after application and drying.
Any ink-like material may be used as long as it uses a vehicle that has strong adhesion to the material of the resin layer to which it is applied.

Next, in the embodiments of the present invention, the proportion and position of the highly conductive carbon black layer provided in a strip on the resin surface of the resin-treated cloth on the resin layer surface are particularly important. In other words, although the conductive layer of the sheet for coal mine blast pipes according to the present invention is black, it is desirable that the entire blast pipe has an appearance similar to that of yellow, which is a safety color, and also has a predetermined antistatic performance. However, the dissipation of static electricity generated in this kind of sheet material is not only due to the conductivity of the conductive layer, but also the highly conductive carbon black layer, taking into account to the maximum extent the antistatic effect due to corona discharge. As a result of various studies and experiments, the width of the band of the highly conductive carbon black layer is 5 mm and the interval between the bands is 25 mm as shown in the above example. The width of the strip is 1~
A sheet formed with a band width of 10 mm and a band spacing of 25 to 50 mm is effective as a sheet for coal mine blast pipes.

In addition to the above-mentioned examples, in addition to the above-mentioned examples, the following examples are used to form a conductive layer so that the entire air pipe has an appearance similar to that of the safety yellow color and also has a predetermined antistatic property. There is something.

Example 4 A black sheet-like material formed by coating a base fabric with a thermoplastic synthetic resin composition mixed with highly conductive carbon black, was coated with a yellowish thermoplastic synthetic resin paint until the black resin was 5 mm thick. It is applied and dried so that it remains in strips every 25 mm in width.

Example 5 Highly conductive carbon black ink was applied to the resin layer surface of a sheet-like article formed by coating a base fabric with a colorless thermoplastic synthetic resin composition mixed with or without an appropriate amount of an antistatic agent. 5mm and 25mm
It is applied in strips at intervals, and then a yellow-colored thermoplastic synthetic resin paint is applied to the remaining surface and dried.

Note that the following methods are available for producing the sheet-like product of the present invention.

In order to coat the surface of the base fabric with the thermoplastic synthetic resin composition, a sheet-like material having a predetermined thickness is generally produced by any method such as a coating method, a calender roll method, or a lamination method.

Formed by continuously applying highly conductive carbon black ink and/or yellow thermoplastic synthetic resin paint to a predetermined size on the resin layer surface of the sheet by a coating method such as a gravure printing method or a rotary textile printing method. do.

In addition to the above, a widely known coating device such as an extruder may be used.

As mentioned above, the present invention provides a sheet-like article in which one or both sides of a base fabric is coated with a thermoplastic synthetic resin composition, and at least one side of the resin layer surface is coated with a thermoplastic synthetic resin composition.
Coal mine ventilation is arranged so that wide yellowish colored layers and narrow highly conductive carbon black layers appear alternately in a band-like manner, giving an overall yellowish appearance and having a specified antistatic performance. Since it is related to pipe sheets, it eliminates various drawbacks of conventional sheets for coal mine ventilation pipes, expresses a safe color as a whole, exhibits the required antistatic performance, and maintains that performance. This is a highly durable sheet for coal mine air pipes.

[Brief explanation of the drawing]

The drawings show an embodiment of the present invention, and FIG. 1 is a partially enlarged longitudinal sectional view, and FIG. 2 is a partially cutaway perspective view. 1...Base fabric, 2...Yellow colored polyvinyl chloride resin composition coating layer, 3...Resin layer surface, T...Vinyl tarpaulin, C...Highly conductive carbon black layer.

Claims (1)

[Claims for Utility Model Registration] A sheet-like article formed by coating one or both sides of a base fabric with a thermoplastic synthetic resin composition, comprising a wide yellow colored layer and a small cloth on at least one side of the resin layer. 1. A sheet for a coal mine blower pipe, characterized in that the highly conductive carbon black layers are arranged so as to appear alternately, exhibiting a yellowish appearance as a whole, and having a predetermined antistatic property. A sheet for a coal mine blowing pipe according to claim 1, which is a utility model and is coated on one or both sides of a base fabric with a thermoplastic synthetic resin composition containing an appropriate amount of an antistatic agent. The sheet for coal mine blower pipes according to claim 1, which is a registered utility model, wherein one or both sides of the base fabric are coated with a thermoplastic synthetic resin composition that does not contain an antistatic agent. A sheet for a coal mine blowing pipe according to claim 1, 2 or 3, wherein the highly conductive carbon black layer on the surface of the resin layer has a width of 1 to 10 mm and an interval of 25 to 50 mm.