JPH0248940A - Camouflaging material for infrared ray - Google Patents

Abstract

PURPOSE:To achieve camouflaging effect, which makes the shape recognition on far infrared picture difficult, by a constitution wherein the heat emissivities of films, which are adjacent to each other, are set to be within the specified range. CONSTITUTION:A random pattern is produced by combining sheet pieces, which are respectively made of composite sheets B-E having far infrared heat emissivities in the range of 0.5-0.9, by laminating thin metal layer 3 onto one side of a film 4 and the difference between far infrared heat emissivities of which adjacent to each other is 0.4 or less. Concretely, the sheet piece B having the heat emissivity of 0.5, the sheet piece C having that of 0.6, the sheet piece D having that of 0.7 and the sheet piece E having that of 0.8 are arranged in the order named so as to be adjacent to each other in order to produce an optically camouflaging pattern. By covering a heat radiating body with said sheet-like camouflaging material, the infrared picture of the body makes no contrast, resulting in making the shape recognition of the matter to be detected very difficult.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to a camouflage material that is difficult to recognize by far-infrared images and is also difficult to detect by instruments using infrared detectors.

(Prior Art) Japanese Patent Application Laid-Open No. 59-190842 proposes a film structure in which a film made of polyethylene or polypropylene and a metal film are attached as a defense material against infrared rays.

(Problems to be Solved by the Invention) However, although such conventional disguise materials exhibit the property of reducing heat radiation, this alone does not eliminate shape recognition.

In view of such prior art, the present invention clearly achieves a camouflage effect whose shape is difficult to recognize on far-infrared images by configuring a combination of films so that the thermal emissivity of adjacent films is within a specific range. It was possible to do so.

(Means for Solving the Problems) In order to achieve the above object, the present invention employs the following configuration. That is, (1) A random pattern is formed by combining sheet pieces made of a composite sheet having a thin metal layer laminated on at least one side of the film and having a far-infrared thermal emissivity in the range of 0.5 to 0.9. , and the adjacent sheet pieces have a difference in far-infrared thermal emissivity of 0.4 or less.

(2) The far-infrared camouflage material according to claim 1, wherein the camouflage pattern is composed of a sheet in which a difference in far-infrared thermal emissivity varies proportionally with distance.

(3) The far-infrared camouflage material according to claim (1), wherein the film is composed of a plurality of film laminates.

(4) The film is composed of at least two selected from polypropylene, polyethylene, polystyrene, polymethylpentene, vinyl acetate resin, vinyl chloride resin, acrylic resin, urethane resin, and copolymers thereof. The far-infrared camouflage material according to claim (1).

(5) The far-infrared camouflage material according to claim 1, wherein the metal foil layer is formed by any one of a plating method, a vapor deposition method, and a sputtering method.

(6) The far-infrared camouflage material according to claim (1), wherein the metal is aluminum.

(7) A thin metal layer is laminated on the surface of the fabric, a film is laminated on the surface, and the far infrared thermal emissivity is 0.5 to 0.
A far infrared ray, characterized in that a random pattern is formed by combining sheet pieces made of composite sheets in the range of 9, and the difference in far infrared thermal emissivity between adjacent sheet pieces is 0.4 or less. For camouflage material.

(8) The far-infrared camouflage material according to claim 7, wherein the fabric has at least a flattened surface.

Thermal emissivity in the present invention refers to the ()andsAER0 emissivity meter (manufactured by [)evices 3ervicens)
This is the thermal emissivity measured by attaching or coating a sample film on aluminum foil (thermal emissivity: 0.03).

Alternatively, it is also possible to apply the film to an infrared spectrophotometer and express the absorption area in the region of 750 to 1200 C. For those with a value of 5 to 0.6, this value is 0.
25-0.401, thermal emissivity 0.6-0.7, this value is 0.10-0.25, thermal emissivity 0.7-0.8
Those with this value of 0.10 or less are respectively expressed.

The far-infrared camouflage material referred to in the present invention is one that produces a camouflage effect in the far-infrared wavelength range, and has good camouflage properties in the visible and photographic ultraviolet and near-infrared wavelength ranges as well as the above-mentioned camouflage. It is difficult to recognize the shape in detection or instrument detection, and the key point lies in the fact that an optical camouflage pattern is formed by combining adjacent sheet pieces with similar thermal emissivity.

By forming a pattern by placing sheets with similar thermal emissivity adjacent to each other, an excellent blurring effect was induced, which closely resembled the temperature distribution of the surrounding background, making it possible to achieve a naturally harmonious camouflage. .

This phenomenon is greatly facilitated by changing the difference in thermal emissivity of adjacent sheets in proportion to the distance. Of course,
Since some changes are normal in nature, the blurring effect can be achieved if they are arranged approximately proportionally. In short, an artificial arrangement may actually make it easier to recognize.

Specifically, a sheet piece with a thermal emissivity of 0.5 is followed by a sheet piece with a thermal emissivity of 0.6, then a sheet piece with a thermal emissivity of 0.7, and then a sheet piece with a thermal emissivity of 0.8. By basically arranging them in this order, an optical camouflage pattern is formed. The area of the sheet piece can be varied accordingly to eliminate an artificial feel.

At this time, the detection status with far infrared rays is that the 0.5 part is black.
It is detected as a dim light that gradually changes in brightness as you move away from it. This blurring effect is achieved by combining sheets in which the difference in thermal emissivity between adjacent sheets is 0.4 or less, preferably 0.2 or less, particularly preferably 0.1.

This is achieved by configuring such a combination of sheets with gradually changing thermal emissivity.

If a heat sink is covered with a sheet-like camouflage material with such a configuration, the true shape of the detected object (heat sink) cannot be grasped, and the obtained infrared image has no contrast and is very blurry. This makes it extremely difficult to recognize the shape of the object to be detected.

The thin metal layer of the present invention is selected from metals having a thermal emissivity of 0.1 or less, preferably 0.05 or less.

Examples of such metals include gold, silver, copper, aluminum, nickel, chromium, iron, zinc, lead, and alloys thereof.

Among these metals, aluminum and nickel are selected in terms of price and performance.

Such a thin metal layer is laminated in the form of a foil on a film or fiber fabric, and a foil created by a rolling method may be attached to the film with an adhesive, but it is also possible to use a plating method or vapor deposition (vacuum vapor deposition). It can be coated on a film in a thin layer by a known film forming method such as a method or a sputtering method. When coating a fiber fabric by the above-mentioned method, it is preferable to flatten and smooth the fibers in at least the surface layer of the fabric by applying a thermal calender or a hot press from the viewpoint of thermal radiation properties.

Among these, a metal thin layer formed by sputtering is preferred from the viewpoint of film tension, and this film is unique in that it contains a metal oxide.

The thickness of the metal thin layer has a slight effect on the thermal emissivity, and thicker is better than thinner, but it does not need to be transparent, and is usually less than 100 μm, preferably 300 μm to 50 μm.
In particular, a film with a thickness of about 1 to 20 μm is selected. Such a thin metal layer may be bonded to either side of the fabric or film, but is preferably bonded to the film side in view of the uniformity of the film. Ordinary adhesives can be used for joining, but
Preferably acrylic adhesive or polyurethane adhesive,
A rubber adhesive or the like can be used.

The material constituting the film layer of the present invention is selected from polypropylene, polyethylene, polystyrene, polymethylpentene, vinyl acetate resin, vinyl chloride resin, acrylic resin, urethane resin, and copolymers thereof. can be given.

Examples of copolymers include ethylene/vinyl acetate and vinyl chloride/acrylic nail polish copolymers.

The film made of these resins may be any film-like material such as a stretched film, an unstretched film, and a coating film.

Such films are not limited in thickness, but typically have a thickness of 10
A thickness range of ~250μ is selected to set the thermal emissivity. Thermal emissivity is determined by the type of material, but even for the same material, as the thickness increases, the thermal emissivity tends to increase. Also, the more transparent the material, the lower the thermal radiation.

Such a film can be colored with a pigment having a hue similar to that found in nature or a pigment having near-infrared reflectance to impart a visible camouflage pattern.

Such films can be prepared in advance with various types of laminated metal layers, which are then cut and collected to form a camouflage pattern. However, another method is to form a camouflage pattern with various films or to laminate the films. You can also create a camouflage pattern with your body and attach a thin layer of metal to it. Furthermore, there are also methods such as attaching such a film sheet to a fabric, or separately laminating a thin metal layer on the fabric, and then laminating a film thereon or coating the film with a resin forming the film. Of course, these methods can be combined to form a camouflage pattern, and each sheet piece can also be colored in a visible camouflage color or pattern as appropriate.

The fabrics of the present invention include fabrics made of ordinary natural fibers and synthetic fibers, as well as aramid fibers having high strength and high elasticity, and polypropylene, polyethylene, and polyvinyl stretched to a high stretching ratio (e.g., 8 to 12 times or more). Examples include fabrics made of IIi fibers made of alcohol, polyacrylonitrile, and the like.

The disguise material made of the composite sheet of the present invention may be obtained by laminating a plurality of layers of the composite sheet. It may be laminated on both sides of the fabric or film.

The heat radiating body covered by the present invention may be formed by suitable heat radiating means, for example, by cutting the camouflage material into a suitable shape to form a blinder function, a canopy, a roof, or a leaf-shaped cut.

(Example) Example 1 Polyester fiber M woven fabric (100M m) was fabricated using a urethane adhesive and a 12μ aluminum strip (thermal emissivity = 0.
03> were laminated.

This laminated fabric was coated with a methyl ethyl ketone solution of vinyl chloride/methyl acrylate copolymer containing a forest-like green pigment to a thickness of 10 μ(A) and 20 μ(A).
B), 30μ (C), and 40μ ([)) were respectively formed to obtain four types of composite sheets having the cross-sectional structures shown in FIG.

Separately, the same laminated fabric as above was coated with a urethane resin containing the same pigment to obtain a composite sheet (E) having a coating having a thickness of 40 μm.

Separately, the same laminated fabric as above was coated with a vinyl chloride resin containing the same pigment to obtain a composite sheet (F) having a coating having a thickness of 100 μm.

The thermal emissivity of such a sheet is measured using a D and S AERO thermal emissivity meter.
When measured with A (manufactured by S company), A=0.4, B=0.5,
C=0.6, D=0.7, E-0.8, F=0.9.

This sheet was cut into sheet pieces each having a leaf-shaped cut, and these pieces were bonded onto a mesh net sheet (85 mm square) in a camouflage pattern as shown in FIGS. 2 to 6.

In this example, sheet pieces were cut into pieces and fitted one by one to form a camouflage material.

In order to test these far-infrared camouflage materials, we placed a 1600cc light van in a forest with a forest in the background.
The engine was left idling.

This car was observed from a distance of 150 m using an infrared imaging device (Infraeye 560, manufactured by Fujitsu) with a detection wavelength of 8 to 14 μm.

First, an infrared image with only a forest background, then an image with only cars,
Finally, we compared three images of the car covered with camouflage material. The results are shown in Table 1.

The method of comparison is to take an infrared image as a black and white photo, set the brightness of only the light van in the photo to 100, and set the brightness of the forest background to O.
The brightness of the camouflage material cover photograph was determined as follows. The lower the luminance value, the harder it is to identify.

As a precaution, in Figure 6, the composite sheet (E)
on top of the composite sheet (D), on top of it (C), then on (B)
) was laminated and adhered to form a disguise material. That is, a composite sheet was made in which another sheet piece was laminated and pasted on top of two composite sheets, but the effect was the same as that of the above-mentioned fitted sheet.

(Effects of the Invention) The present invention can provide a disguise material that is difficult to recognize using far-infrared images and is also difficult to be detected by instruments using infrared detectors.

[Brief explanation of the drawing]

FIG. 1 shows the cross-sectional structure of one example of the composite sheet of the present invention. Figures 2 to 6 illustrate examples of the disguise material of the present invention. In the diagram 1: Fiber fabric 2: Adhesive layer 3: Metal thin layer 4: Film layer A-F: Composite sheets with different thermal emissivities Patent applicant: Director of the Gigajutsu Research Headquarters, Defense Agency Toshi Co., Ltd.

Claims (8)

[Claims] (1) A random pattern is formed by combining sheet pieces made of a composite sheet with a thin metal layer laminated on at least one side of the film and having a far-infrared thermal emissivity in the range of 0.5 to 0.9, and A far-infrared camouflage material characterized in that adjacent sheet pieces have a difference in far-infrared thermal emissivity of 0.4 or less. (2) The far-infrared camouflage material according to claim 1, wherein the camouflage pattern is composed of a sheet in which a difference in far-infrared thermal emissivity varies proportionally with distance. (3) The far-infrared camouflage material according to claim (1), wherein the film is composed of a plurality of film laminates. (4) The film is composed of at least two selected from polypropylene, polyethylene, polystyrene, polymethylpentene, vinyl acetate resin, vinyl chloride resin, acrylic resin, urethane resin, and copolymers thereof. The far-infrared camouflage material according to claim (1). (5) Claim (5) wherein the metal foil layer is formed by any one of a plating method, a vapor deposition method, and a sputtering method.
1) Disguising material for far infrared rays as described. (6) The far-infrared camouflage material according to claim (1), wherein the metal is aluminum. (7) A random pattern is created by combining sheet pieces made of a composite sheet with a far-infrared thermal emissivity in the range of 0.5 to 0.9, which has a thin metal layer laminated on the surface of the fabric and a film laminated on the surface. A far-infrared camouflage material, characterized in that the adjacent sheet pieces have a difference in far-infrared thermal emissivity of 0.4 or less. (8) The far-infrared camouflage material according to claim (7), wherein the fabric has at least a flattened surface.