JP2009024361A - Fire prevention floor of gas station - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve the problem that gasoline etc. may conventionally take fire due to an electric shock etc., caused by static electricity generated because the human body becomes charged in a gas station etc. <P>SOLUTION: When a paint for neutralizing static charges is used for the coating of a floor of a self-service gas station etc., a flashing accident caused by an electrostatic shock is prevented. This coating is also effective, for example, for a floor of a factory which deals with a flammable material product. The coating makes the static charges neutralized by mixing discontinuous fibers of carbon fibers into the paint. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

Gas stations are rapidly becoming self-service to reduce labor costs.
According to the report by the Technical Center for Hazardous Material Accident Prevention, there were 27 cases of fires in the self-service stand for 5 years from 1998 to 2015. Of these, 15 cases (55.6%) were due to insufficient charge removal from the human body. On the other hand, there were 558 fires at the self-service stand (all refueling stations), and 13 cases (2.2%) were caused by insufficient charge removal from the human body. The number of gas stations at the end of March 2007 was 45790.

    Many drivers are unfamiliar with gasoline refueling work and often operate the refueling machine with static electricity of 3 kV or more on the human body. Therefore, spark discharge may occur when a human body touches the metal part of the fueling machine. When the lid of a gasoline tank is opened, a mist of gasoline rising from the tank may ignite and a fire may occur.

There are the following problems in removing the electrification of the human body from the self-service stand.
(1) Static charge during refueling activities, when standing up from the seat of a car, has caused peeling of clothes and sheets, but it is not felt by the human body.
(2) Normally, when the human body is charged with 3 kV or more, there is an energy that causes a fire by causing a discharge between the conductor and igniting a combustible vapor of a low flash point dangerous material such as gasoline.
(3) Customers who use self-service stands do not have knowledge about the dangers and safe handling of dangerous goods such as gasoline. Sometimes you don't touch the ground button.

    From the above, new measures are needed to eliminate static electricity even if the customer refuels without removing the human body charge in advance or without knowing the static elimination method.

To prevent static electricity, use a grounding method. There are methods such as increasing humidity and neutralizing static electricity.

    1. The method based on earth requires conducting wires to make the ground resistance less than 100 ohms for electrical conductivity, but it is the case of conductors that can surely release the charge, and the sole is made of synthetic resin. If it is a product, it becomes an insulator and there is a limit to static electricity removal.

    2. Static elimination due to humidity. It is necessary to increase and maintain the relative humidity to 65% or more by watering or a humidifier. However, since the gas station is open to the outside air, it is difficult to maintain humidity.

    3. Static elimination with a self-discharge type static eliminator using carbon fiber ionizes air and neutralizes the charge of the charged substance, and can effectively remove static electricity in a limited place.

    An object of the present invention is to automatically remove static electricity from a human body when a customer of a self-service stand approaches a fixed refueling facility.

    A concrete floor is coated by uniformly mixing and dispersing 2 to 10% (owf) of short fibers having a fiber length of 3 mm to 12 mm with a weather resistant and oil resistant water-based paint. Around the periphery, 2-10% (owf) of short fibers of carbon fiber having a fiber length of 3 mm to 12 mm are coated on the nonwoven fabric, and an aluminum foil is pasted on the back surface.

    When a customer or a gas station worker performs a refueling operation, he / she walks on the carbon fiber short fiber coating or coating table, and the human body charge is automatically neutralized.

      The neutralization phenomenon is that when a fibrous conductive material comes into contact with a charged substance, the tip of the conductive substance becomes an antenna, and ions + or-opposite to the charged body gather and combine with the ions of the charged body to eliminate the charge. . This phenomenon occurs only in the fibrous conductive material, and it is economical to use a fiber length of 3 mm to 12 mm. Examples of fibrous conductive materials include stainless steel fibers, metal plating alloys, and carbon fibers, but carbon fibers are the best in terms of price and durability. Table 1 shows the charge removal performance.

"Test conditions"
Thickness 0.1 t. c A polyester film with a width of 100 cm is moved at 50 m / min charged to (+ .-) 2 to 10 kv. Distance between electrode and film 1mm Room temperature 19.4 ° C, Humidity 31%, Matsuda et al. From "Carbon Fiber"

    The function of carbon fiber is to automatically collect ions (electrons) in the atmosphere. If there is a positively charged human body, negative ions are collected in the carbon fiber, and the positive ions in the human body and the negative ion are neutralized in the carbon fiber to remove the human body charge.

The characteristics of carbon fiber are as follows.
1. Since electricity is neutralized by neutralization of ions (electrons), even an insulator can remove static electricity without being grounded.
2. No special equipment or installation work is required.
3. It can be molded at a lower cost than other methods.
4). Maintains functional effects over a long period of time without maintenance.
5). Because no sparks are generated, flammable vapors and gases are not ignited.
6). There is no toxicity.

      By painting the parts where humans move around the gas station equipment by the method according to the present invention, the charged human static electricity is automatically removed and the risk of fire is eliminated. It is recommended to repaint once every two years to confirm the effect.

        Hereinafter, the present invention will be described in detail by way of examples. Carbon fibers produced from acrylic nitrile polymer fibers under standard conditions are cut to a fiber length of 3 mm. The sizing agent added at the time of carbon fiber manufacture adheres to this, and even if it cuts to 3 mm, it does not separate easily into every fiber. 800 ° C in a heating furnace to sublimate and remove the sizing agent. After heat treatment for 15 minutes, it was naturally cooled and stirred in water. The fibers were well separated when the stirrer was treated at 2000 R / M for 10 minutes. The specified paint (weather resistance, oil resistance) was added thereto, and the mixture was further stirred for 10 minutes. The finished carbon fiber mixed paint was applied to a predetermined area around the gas station facility within 5 hours.

Prepare the following groundwork for the area to be painted around the gas station.
1. Substrate adjustment Remove dirt on the ground with a waste cloth or brush.
2. Undercoat Apply an elastic sealer with a roller brush.
The coating amount is 0.1 kg / _m ² and the drying time is 2 hours.

        After applying the paint of the present invention, after curing for 24 hours or more, 2-10% (owf) of short fibers having a carbon fiber length of 3 mm to 12 mm are uniformly dispersed on the non-woven fabric around the floor where the work is applied. Then, the tape for construction of the floor which laminated the aluminum foil and the adhesive on the back and laminated was stuck. After that, gasoline refueling work was performed, and when the refueling worker stopped the car next to the stand equipment and got off, the human body charge was measured to be 3.9 kv. When the same person entered the painting place of the present invention and measured the human body charge after 1 minute, it was 2.1 kv. There was a static elimination effect. The workers' clothes were polyester / rayon blends, and the shoes were wearing sports shoes with rubber bottoms.

        Carbon fibers produced under standard conditions were cut from acrylic nitrile polymer fibers into a fiber length of 12 mm and heat-treated at 800 ° C. for 15 minutes in a heating furnace. Water was added thereto, and the mixture was stirred with a stirrer at 2000 R / M × 10 minutes.

        A primer was coated with a spray on a mortar-finished cement board having a length of 300 mm, a width of 300 mm, and a thickness of 50 mm, and dried for 4 hours. It was overcoated and dried for 4 hours. As a top coat, synthetic resin emulsion paint (JIS k5663) first type (outdoor weather resistance) is mixed with 7% owf of the above-mentioned carbon fiber agitated, and 1000R / M × 5 minutes. The stirred paint was brush painted.

        Samples were made after drying for 24 hours. When the surface was observed with a magnifier of 5 times, it was confirmed that carbon fibers were dispersed.

        Shimadzu's electrostatic high voltage generator (handcraft generator) generated 10000v of static electricity to cause a spark discharge, and a crack was observed. Here, when the carbon fiber coating sample plate was brought closer, the spark discharge disappeared even in a non-contact manner with an interval of 20 to 50 mm. It disappears completely on contact. This was due to the electrostatic neutralization phenomenon caused by the short fibers of carbon fibers, and the same effect as in Example 1. The amount of static electricity was attenuated from 10000v to 1000v.

A person standing on a fire prevention floor using the carbon fiber according to the present invention Fire prevention floor slab test apparatus using carbon fiber according to the present invention Experiment drawing of fire prevention floor slab using carbon fiber according to the present invention

1. Human
2. Human body charge measuring instrument
3. Painted surface mixed with short carbon fibers
4). Primer undercoat
5). Concrete floor
6). Electrostatic high voltage generator (hand-craft generator)
7). Discharge ball
8). Experimental bench
9. Concrete sample stand

Claims (3)

    In facilities that use flammable chemicals such as gas stations, when processing floors of such facilities, paint that uniformly distributes 2 to 10% (owf) of short fibers with a carbon fiber length of 3 to 12 mm on the concrete floor Floor construction method characterized by painting with     Attached around the floor where the floor is constructed, and coated with 2 to 10% (owf) of short fibers having a carbon fiber length of 3 mm to 12 mm uniformly coated on the nonwoven fabric, and an aluminum foil on the back surface. 2. The floor construction tape according to claim 1, wherein the adhesive is laminated and laminated.     PAN-based or pitch-based carbon fiber short fibers are heated in a heating furnace at 500 to 1000 ° C. for 5 to 15 minutes to sublimate the sizing agent (chemical formula, structural formula, unpublished) attached to the surface at the time of carbon fiber production, The method for producing a paint according to claim 1, wherein the paint is easily dispersed in the paint or coating agent.

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