JP2012026946A - Oil detection sheet - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an oil detection sheet whose detection object is limited to oil, which is simple and at low cost, avoids an influence of dew condensation and water to detect only the oil, in the that securement of detection performance is easy on manufacture.SOLUTION: The oil detection sheet has a colored color identification film on the rear surface of an optical irregular reflection transparent film, and the optical irregular reflection film sheds water by including water-shedding quality and lipophilic nature in addition to having optical irregular reflection nature by rugged structure, and a color of the color identification film of the ground is recognizable by the fact that only the oil is absorbed by the rugged structure, becomes wet and spreads.

Description

  The present invention relates to an oil detection sheet that repels water and absorbs only oil so that the detection of oil can be visually observed.

    Conventionally, this type of sensor has been reported to measure an electrical change such as an electric resistance or capacitance between two electrodes, a temperature change, and a sensor that visually changes. Patent documents 1 to 6 can be found as examples of the former, and patent document 7 can be found as an example of the latter. In Patent Document 1, when oil enters between conductive particles dispersed between two conductors, the electrical resistance between the conductors is changed to detect the oil. In Patent Document 2 and Patent Document 3, an oil-swellable conductive plastic layer is used, and it is detected that the electrical conductivity is decreased by swelling or dissolving with oil. In Patent Document 4, a polar polymer film is disposed between two conductors, and a decrease in surface electrical resistance due to contact with oil is detected. In Patent Document 5, a change in capacitance between two conductors due to oil is detected. In patent document 6, the change of the heat | fever transfer method by oil is measured using a thermocouple, and oil is detected. In patent document 7, the water and oil which permeated the air permeable film by the air permeable film which allows water and oil to pass through and the white layer which is transparent from white by wetness with water and oil, It is to be visually recognized as a change. In the case of measuring the former electrical change, it is difficult to evaluate the measured data due to the high cost of the measuring device itself, the type, condition, dust mixing, temperature, etc. of water and oil and fat. Not suitable for leak detection.

In the latter example, since a sensor for detection can be easily made, the price can be reduced and it is convenient for detection of simple leaks of water and oil. The thing has the following faults. FIG. 6 shows what is proposed as an example of Patent Document 7.
There is a colored layer 2 on a breathable film 1 through which water or oil passes, and further there is a white layer 3 which is white when dried but becomes transparent when wet with water or oil. Each is arranged in this order. By being transparent by wetting, the color of the colored layer can be visually recognized, so that leakage can be detected, but it must pass through the breathable film 1 and the colored layer 2 until water or oil reaches the white layer. Don't be. Depending on the state of each of the air permeable film 1, the colored layer 2 and the white layer 3 (finished with respect to the permeation of water and oil) and the state of the adhesive connecting them, the water and oil permeability is greatly affected. In addition, since variations as sensors become large, it is inherently difficult to ensure quality in production, and difficult manufacturing management is required. In addition, even when water is condensed on the surface of the white layer 3 without passing through the air permeable film 1 (even when oil is attached), it becomes transparent and the color of the colored layer can be visually recognized. It has the disadvantage that it cannot be judged whether there is leakage or condensation. In addition, there is a drawback that the application is limited to detection of water or oil that has passed through the breathable film 1. Actually, as a request of the user to the present application, there is a desire to detect the presence or absence of mixing of oil with water. Especially when focusing on the detection of such oil, it is important that it does not react with water. In this example, it reacts with both water and oil. It becomes impossible. In addition, since dew condensation occurs in various environments, the oil leak is fatal because it is a false detection.

The problem of the present invention is as described above. In the background, the detection target is limited to oil, and it is simple, inexpensive, and can detect only oil while avoiding the influence of condensation and water. It is an object to provide an oil detection sheet having a structure in which detection performance can be easily secured.

The oil detection sheet of the present invention has a colored color identification film on the back surface of the light irregular reflection transparent film, and the light irregular reflection film is water repellent in addition to having light irregular reflection due to the concavo-convex structure. It is characterized by having lipophilicity.
This will be described below.

The invention described in claim 1 is an oil detection sheet, having a colored color identification film on the back surface of the light diffuse reflective transparent film, and the light diffuse reflective film having light irregular reflectivity due to a concavo-convex structure. In addition to being water-repellent and oleophilic, it repels water, only the oil absorbs with a concavo-convex structure, spreads wet, and makes the color of the color identification film visible by making it transparent from light diffuse reflection It is characterized by that.

According to a second aspect of the present invention, in the oil detection sheet according to the first aspect, the detection liquid penetrates between the color identification film and the light diffuse reflection film so that the detection liquid penetrates the front and back of the oil detection sheet. It is characterized by providing a hole.

According to a third aspect of the present invention, in the oil detection sheet according to the first or second aspect, a cushion for protecting against heavy objects and protrusions is provided on the back surface of the color identification film.

The invention according to claim 4 is a method for regenerating an oil detection sheet, wherein the oil detection sheet according to any one of claims 1 to 3 is washed with a detergent or an organic solvent and dried after use. It is characterized by being removed and reused.

According to a fifth aspect of the present invention, there is provided a vehicle oil leakage detection method, wherein the oil detection sheet according to any one of the first to third aspects is attached to a passage of a vehicle to allow the vehicle to pass through the vehicle. It is characterized by detecting oil leakage.

Water is repelled on the surface of the light-reflective film, and the water does not spread out on the light-reflective film. The structure is satisfied, so that the diffused light reflectivity is suppressed, the light passes through the diffused light reflective film, and the color of the underlying color identification film can be visualized as a wet spread area.
In addition, since the detected oil mainly touches directly from the surface side of a light diffuse reflection film, the variation defect of detection sensitivity like the example of patent document 7 is improved.

It is a figure which shows one embodiment of the oil detection sheet | seat by this invention. It is a figure which shows another embodiment of the oil detection sheet by this invention. It is a figure which shows another embodiment of the oil detection sheet by this invention. It is a figure which shows the example of a detection of the oil leak of the vehicle of the oil detection seat by this invention. It is a figure which shows the example of a detection of the oil leak of the conventional vehicle. It is a figure which shows one embodiment of the conventional oil detection sheet.

The oil detection sheet according to the present invention has a color identification film on the back surface of the light diffuse reflection transparent film, and also has a light diffuse reflectivity so that oil can be detected separately even in a liquid mixture with condensation or water. In addition to having irregular light reflectivity due to the concavo-convex structure, the film is water-repellent and oleophilic, so that water is repelled on the surface of the film, so that water does not wet and spread on the film. It spreads by wetting due to the lipophilicity of the film and fills the concavo-convex structure of the film, so that the diffused light reflection is suppressed, the light is transmitted through the film, and the color of the underlying color identification film can be visualized as a wet spreading area. is there.

As a means for providing a light diffuse reflection transparent film, first, as for light diffuse reflectivity, as is generally known for rubbing glass, etc., a satin pattern, a polished surface polished with a 500 to 2000 rough abrasive sheet, a reflective surface It can be given by unevenness of a hemispherical surface arranged at appropriate intervals so that the surface spreads in a uniform direction. Further, a description that can be referred to in the light irregular reflection processing can be found in Patent Document 8.
As transparent, water-repellent and oleophilic resins, paraffin, polyethylene resin, polypropylene resin, polyester resin, fluororesin, silicon resin and the like are known. It is also effective to apply a water repellent treatment agent to these resins. As the water repellent treatment agent, a polymer containing a perfluoroalkyl group or a commercially available water repellent spray agent containing a fluorine coating agent can be used. is there. Patent Document 9 introduces water repellents, and Patent Document 10 describes paraffin and silicone oil-based water repellents. Patent Document 11 and Patent Document 12 describe a water repellent or water repellent treatment with a long chain fatty acid such as a long chain alkyl group. Therefore, for example, the surface of the transparent fluororesin is made into a satin pattern, the polishing surface is made by polishing the transparent resin, the fluorine coating agent is sprayed, and the spherical body such as silicon resin is attached to the transparent resin or the glass surface It is possible to realize a water repellent and oleophilic light diffuse reflection transparent film of various types. Hereinafter, description will be made using examples.

Japanese Patent Publication No.59-47256 6-9339 JP-A-3-102253 JP-A-6-347456 JP 2000-180289 A JP 2005-114567 A JP-A-10-185742 JP-A-11-192537 JP-A-11-169622 JP2008-69365 Special table 2007-536387 JP-A-2005-320300

FIG. 1 is a view showing an embodiment of an oil detection sheet according to the present invention. In 1-A, for example, a water-repellent / lipophilic light diffusely reflecting transparent film 101 having a surface of a transparent polyester sheet or a surface of which a water-repellent agent made of a fluororesin is further sprayed is used. A color identification film 102 applied to the back surface is shown. The color identification film 102 may be applied by printing with a pigment that can be easily identified, such as red, or application of a paint, or may be attached with a color sheet.
When the pear ground is dry, light is irregularly reflected, and the color of the color identification film 102 is not clearly visible.

In 1-B, the case where the water 103 has adhered to the surface of the 1-A oil detection sheet 100 is shown. Since this surface is water-repellent, the water 103 is repelled and has a round and dispersed shape, so that the color of the color identification film 102 is partially visible (in the form of a dot at the center of the polka dots).

In 1-C, the case where the oil 104 adheres to the surface of the oil detection sheet 100 of 1-A is shown. Since this surface is oleophilic with respect to the oil 104, the oil 104 spreads without being rounded, and the color of the underlying color identification film 102 can be seen over a widened shape. This is because the oil fills the unevenness of the pear ground and suppresses irregular reflection of light. This is the same effect that light appears to pass through when the surface of the ground glass gets wet.

FIG. 2 is a view showing another embodiment of the oil detection sheet according to the present invention, and shows examples of various water-repellent / lipophilic light irregular reflection transparent films. Since 2-A is an example of 1-A, description thereof is omitted. In 2-B, as shown in paragraph 0015, for example, a water-repellent and lipophilic resin spherical body 201 such as a silicone resin is attached to the surface of a transparent resin sheet. In the figure, the resin spherical bodies 201 are arranged uniformly, but this is not always necessary, and a random arrangement may be used. Only the oil is adsorbed and spreads on the surface, suppressing irregular reflection by the resin spherical body 201, and the color of the underlying color identification film 202 can be seen.

In 2-C, the water-repellent and oleophilic transparent resin sheet 203 is provided with a recess 204 for causing irregular reflection of light. The shape of the recess 204 is preferably a hemispherical shape, but is not particularly limited to this. Since the light entering the concave portion 204 is irregularly reflected, the entire sheet looks whitish and the color of the underlying color identification film 202 cannot be seen. When the oil is attached, it spreads over the entire surface of the transparent resin sheet and fills the concave portion 204, so that irregular reflection is suppressed and the color of the underlying color identification film 202 can be seen. In this example, the transparent resin sheet 203 needs to be water repellent and oleophilic.

In 2-D, the transparent resin sheet 203 is provided with a convex portion 205 made of a transparent material in order to cause irregular reflection of light. However, when no oil is adsorbed by the convex portion 205, the light is irregularly reflected and is not substantially transparent. The shape of the convex portion 205 is preferably a hemispherical shape, but this is not particular. Since the light entering the convex portion 205 is irregularly reflected, the entire sheet looks whitish and the color of the underlying color identification film 202 cannot be seen. When the oil is attached, it spreads over the entire surface of the transparent resin sheet and covers the entire transparent resin sheet including the convex portion 205, so that irregular reflection is suppressed and the color of the underlying color identification film 202 can be seen.

In addition, although the hemispherical thing was shown in the figure as an example of a recessed part and a convex part, the semicircle cylinder which cut the cylinder in half may be sufficient.

In the above example, the case where the transparent resin sheet 203 is water-repellent and lipophilic and the case where it is not so are considered. In the case of water repellency and oleophilicity, when the convex portion 205 is also water repellant and oleophilic, the interval between the convex portions 205 is arbitrary.
When the convex part 205 is not water-repellent and lipophilic, the size of the convex part 205 is related to the water-repellent and lipophilic performance. If the size of the convex portion 205 is large, the portion is not water-repellent and oleophilic, so that the influence is exerted and the water-repellent and oleophilic performance as a whole is lowered. In the water-repellent structure called super water-repellent structure, there is a report that this size is about 110 nm. It is a report that researches how much space there is between two water-repellent individuals. According to this report, it is preferable that the size of the convex part 205 when it is not water-repellent and oleophilic is 110 nm or less.

If the transparent resin sheet 203 is not water-repellent and oleophilic, the protrusions 205 need to be water-repellent and oleophilic, and the gap between the protrusions 205 is not water-repellent and oleophilic. Since it is related to water-based and lipophilic performance, it is preferable that the interval between the convex portions 205 is 110 nm or less.

FIG. 3 is a view showing another embodiment of the oil detection sheet according to the present invention. In 3-A, a cushion 301 is attached to the back surface of the oil detection sheet shown in 1-A. This is convenient when it is necessary to protect heavy objects, protrusions, etc., as in the case of use for detecting vehicle oil leaks shown in FIG. In 3-B, a through hole 302 for penetrating the detection liquid penetrating from the front surface to the back surface of the oil detection sheet shown in 1-A is provided. If it does in this way, in the detection stuck on the target surface of leak detection, the oil which came out of the target surface will pass through penetration hole 302, and will be adsorbed by the light irregular reflection transparent film of the surface of an oil detection sheet, and oil Since the leak can be detected, the back side can be detected with the same performance as the direct detection from the front side. The application of 3-A and 3-B is not limited to the 1-A satin of FIG. 1, and can be applied to other examples shown in FIG.

When detecting whether oil is mixed with water, the oil detection sheet as described above can be detected by immersing the oil detection sheet in the liquid and removing it, so that only the oil is adsorbed. It is. In this case, the one of FIGS. 1, 2 and 3A is convenient to use. Moreover, if it sticks on the object site | part which is anxious about an oil leak, a leak can be detected. In this case, the 3-B one is convenient to use.
If an oil detection sheet is made thin and a plurality of sheets are provided as a stack, the sheets can be used while updating each sheet.
In addition, the oil detection sheet on which the oil is adsorbed can be reused as an oil detection sheet again after being washed with a detergent containing a surfactant, a solvent such as alcohol or acetone, and dried. .

FIG. 4 is a view showing an example of detection of oil leakage in a vehicle of the oil detection seat according to the present invention.
An oil detection sheet 401 is attached on the passage 400. When the vehicle passes through the passage 400 and steps on the oil detection sheet 401, if the vehicle leaks, the oil is adsorbed to the oil detection sheet 401, and the leak can be detected.

FIG. 5 is a diagram showing an example of detection of oil leakage in a conventional vehicle. In the middle of the passage 500, a shallow water tank 501 is provided. When the car passes through the water tank 501 and the leaked oil enters the water, the interference color of the oil film stretched on the water is seen, and it can be seen that there is an oil leak. It was troublesome to prepare the water tank 501 and keep the water fresh.

  As described above, the oil detection sheet according to the present invention has a simple and inexpensive configuration, but can detect oil by distinguishing water, and thus has extremely high industrial applicability.

DESCRIPTION OF SYMBOLS 100 Oil detection sheet 101 Light diffuse reflection transparent film 102, 202 Color identification film 103 Water 104 Oil 201 Resin spherical body 203 Transparent resin sheet 204 Concave part 205 Convex part 301 Cushion 302 Through-hole 400, 500 Passage 401 Oil detection sheet 501 Water tank

Claims (5)

A colored color identification film is provided on the back surface of the light irregular reflection transparent film, and the light irregular reflection film has water repellency and oleophilicity in addition to light irregular reflection due to the concavo-convex structure. The oil detection sheet is characterized in that only the oil is absorbed by the concavo-convex structure and spreads by wetting, so that the color of the color identification film can be visually recognized by becoming transparent from light diffuse reflection. 2. The oil detection sheet according to claim 1, further comprising a through hole penetrating between the color identification film and the light diffuse reflection film so that the detection liquid penetrates the front and back of the oil detection sheet. The oil detection sheet according to claim 1, wherein a cushion for protecting against heavy objects and protrusions is provided on the back surface of the color identification film. A method for regenerating an oil detection sheet, comprising washing and drying with a detergent or an organic solvent after use of the oil detection sheet according to any one of claims 1 to 3, removing the oil, and reusing it. A vehicle oil leak detection method comprising: attaching the oil detection sheet according to any one of claims 1 to 3 to a passage of a vehicle, allowing the vehicle to pass therethrough, and detecting the oil leak of the vehicle.

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