JP6786880B2 - Composite sheet and camouflage material - Google Patents

Description

The present invention relates to a composite sheet in which a functional imparting layer for imparting various properties to a base material is laminated, and a camouflage material for concealing, for example, an aircraft, a ship, a vehicle, etc. using the composite sheet.

Conventionally, a camouflage material having an anti-visible light, anti-near infrared camouflage effect, anti-far infrared camouflage effect, and excellent anti-radar camouflage effect has been used. As such a camouflage material, a camouflage material in which a metal layer and a camouflage colorant-containing resin layer are laminated in this order on both sides of a base cloth having a conductive resin layer has been proposed (for example, Patent Document 1).

These camouflage materials are used to make it difficult for reconnaissance devices to identify by covering aircraft, ships, vehicles, etc., but the camouflage object may have an engine part that is a heat source, and the camouflage material Is required to have high flame retardancy. As a conventional camouflage material imparted with flame retardancy, a material in which a flame retardant agent is contained in a part of a plurality of thick resin layers on the surface of the camouflage material has been proposed (for example, Patent Documents 2 and 3). ..

On the other hand, with the recent improvement in the performance of reconnaissance devices, even higher camouflage performance, for example, improvement of anti-radar camouflage performance is required. However, in order to improve the camouflage performance, the resin of the conductive resin layer is increased to improve the performance. When attempted, there was a problem that the flame retardancy was lowered. Further, although the flame retardancy is improved by increasing the amount of the flame retardant, there is also a problem that the camouflage material becomes remarkably heavy.

Japanese Unexamined Patent Publication No. 3-28697 Japanese Unexamined Patent Publication No. 5-34093 JP-A-2009-97850

In view of the prior art, the present invention is a composite sheet capable of extremely reducing weight increase without impairing flame retardancy even when anti-visible light, anti-near infrared rays, anti-far infrared rays, and anti-radar camouflage performance are improved. And to provide camouflage material.

The present invention employs the following means in order to solve such a problem. That is, the composite sheet and the camouflage material of the present invention are
(1) A composite sheet comprising one flame-retardant resin layer on each of the front and back surfaces of a base material, and further laminating at least two types selected from a colored layer, a metal layer, and a conductive resin layer . A composite sheet in which the flame-retardant resin layer is adjacent to one side, and a colored layer, a metal layer, or a conductive resin layer is adjacent to the other side opposite to the one side to which the flame-retardant resin layer is adjacent .
(2) Metal layer the decor on the inner side of the outermost layer of the composite sheet (1) Symbol mounting composite sheet.
( 3 ) The composite sheet according to (1) or (2) above, wherein the base material is a fiber sheet.
( 4 ) A camouflage material to which the composite sheet according to any one of (1) to ( 3 ) above is arranged.

According to the present invention, it is possible to provide a composite sheet in which the weight increase is extremely small without impairing the flame retardant performance even when the anti-visible light, anti-near infrared ray, anti-far infrared ray, and anti-radar camouflage performance are improved. .. Therefore, since the camouflage material of the present invention is lightweight, it is excellent in stretchability and workability, and can be suitably used for camouflaging an aircraft, a ship, a vehicle, or the like.

The present invention is dedicated to the above-mentioned problems, that is, a composite sheet capable of extremely reducing the weight increase without impairing the flame retardant performance even when the anti-visible light, anti-near infrared rays, anti-far infrared rays, and anti-radar camouflage performances are improved. In order to maintain high flame retardancy even when the performance of other functional imparting layers is improved by laminating the stacking position of the functional imparting layer to be examined, especially the flame-retardant resin layer at a specific position. It has been clarified that it is possible to suppress an increase in the weight of the flame-retardant resin layer, thereby providing a material having excellent stretchability and workability because it is lightweight as a camouflage material, and has reached the present invention. It is a thing.

The material constituting the base material of the present invention is not particularly limited, but is composed of nylon 6, nylon 6.6, nylon 12, nylon 4.6, a copolymerized polyamide obtained by copolymerizing a nylon 6 component and a nylon 6.6 component, and the like. Polyamide resin, homopolyester such as polyethylene terephthalate and polybutylene terephthalate, and copolymerization of an aliphatic dicarboxylic acid such as isophthalic acid, 5-sodium sulfoisophthalic acid or adipic acid with the acid component constituting the repeating unit of polyester. Examples include polyester resins made of polyester, aramid resins typified by polyparaphenylene terephthalamide, polymetaphenylene isophthalamide, polyvinyl alcohol-based resins, polyphenylene sulfide resins, ultrahigh molecular weight polyethylene resins, vinyl chloride resins, and other synthetic resins. it can. Further, these synthetic resins may contain various additives usually used for improving productivity or characteristics in a manufacturing process or a processing process. For example, a heat stabilizer, an antioxidant, a light stabilizer, a smoothing agent, an antistatic agent, a plasticizer, a flame retardant and the like can be contained.

Fibers and films are obtained using such synthetic resins. The base material of the present invention refers to a sheet made of a fiber sheet or film such as a woven fabric, a knitted fabric, or a non-woven fabric. Among these, a fiber sheet having excellent tensile strength and tear strength is preferable, and a woven fabric is more preferable. ..

The woven fabric used in the present invention can be appropriately selected depending on the required tensile strength and tear strength, such as the type of fiber, the woven structure, and the weaving density. Preferably, for the composite sheet finally obtained a light weight, the basis weight may range of 50 to 300 g / ^{m 2,} more preferably, it is 100 to 200 g / ^{m 2.} As the type of fiber used for the woven fabric, the fiber made of the synthetic resin and the natural fiber such as cotton and hemp can also be used.

The composite sheet of the present invention is formed by selecting and laminating a flame-retardant resin layer and a functionalizing layer such as a colored layer, a metal layer and a conductive resin layer on the base material according to the characteristics required for the composite sheet. Is. The functionalizing layer may include a layer other than the above three types of layers, and can impart other functionality such as water repellency / waterproofing, oil repellency, antibacterial / antibacterial, deodorant, and antifouling. Layers may be included.

Then, at least one flame-retardant resin layer is contained on the front and back surfaces of the base material, and at least two types selected from a colored layer, a metal layer, and a conductive resin layer are laminated, and at least one of the flame-retardant resin layers is formed. The layer needs to be a composite sheet adjacent to the substrate. By arranging the flame-retardant resin layers on both sides of the base material in this way and placing at least one flame-retardant resin layer adjacent to the base material, high flame retardancy can be obtained. When the flame-retardant resin layer is laminated on only one side of the base material, when the composite sheet ignites, the functionalizing layer on the side where the flame-retardant resin layer is not laminated burns, or a large amount of flame-retardant resin is used to suppress combustion. Is used. On the other hand, when the flame-retardant resin layer is arranged on both sides of the base material, but at least one layer is not adjacent to the base material, the metal layer heated by combustion promotes the combustion of the base material or is heated and melted. When a resin such as a layer or a conductive resin layer permeates the base material and the so-called candle burns, the same phenomenon is likely to occur. Therefore, flame-retardant resin layers are laminated on both sides of the base material, and at least one layer is adjacent to the base material.

Examples of the resin forming the flame-retardant resin layer include organic flame-retardant agents such as phosphorus compounds, brominated bisphenols, and halogenated compounds, and inorganic flame-retardant agents such as antimony trioxide and aluminum hydroxide. The fuel component is heat-curable resin such as phenol resin, epoxy resin, melamine resin, urea resin, unsaturated polyester resin, alkyd resin, polyurethane, and heat of polyethylene, polyvinyl chloride, polystyrene, polypropylene, acrylic, polyamide, polyester, etc. Examples thereof include those mixed with a resin such as a plastic resin. The amount of resin used for the flame-retardant resin layer can be appropriately selected depending on the material forming the base material and the configuration of the functionalizing layer other than the flame-retardant resin layer, but from the viewpoint of making the obtained composite sheet lightweight. When the basis weight of the base material is 100, the total weight of the flame-retardant resin layers laminated on both sides of the base material is preferably 20 to 80, more preferably 30 to 50. Further, the basis weight ratio of the flame-retardant resin layers laminated on the front and back surfaces of the base material is preferably 30 to 100 when the layer adjacent to the base material is 100, and more preferably 30 to 100. It is 50 to 90.

The flame-retardant resin layer is applied onto a base sheet or the like by a coating method such as knife coating, knife overroll coating, reverse roll coating, a printing method such as letterpress printing or gravure printing, or a padding method, and dried. Can be formed.

The metal layer constituting the composite sheet of the present invention shields heat radiation emitted from a vehicle or the like, and imparts an excellent far-infrared camouflage effect to the camouflaged sheet to a far-infrared image device such as thermography. It is a thing.

As the metal forming the metal layer, titanium, stainless steel, nickel, chromium, gold, silver, copper, iron, zinc, aluminum and the like, alloys thereof and the like can be adopted. Among them, at least one selected from titanium, stainless steel, aluminum, nickel, and silver is preferably used from the viewpoint of processability and far-infrared camouflage property.

Such a metal layer can be formed by a vacuum deposition method, a sputtering method, an ion plating method, or the like. Among these, the sputtering method is preferably adopted because it is easy to form a thin film.

The thickness of the metal layer is preferably 0.003 to 0.09 μm. That is, when the thickness of the metal layer is 0.003 μm or more, the effect of improving the far-infrared camouflage property can be obtained. On the other hand, when the thickness is 0.09 μm or less, it is possible to prevent the flexibility of the composite sheet from being hindered and to suppress the gloss peculiar to the metal.

At this time, metal layers having different thicknesses may be partially formed. By doing so, the heat radiation of the composite sheet can be distributed in multiple stages, and the far-infrared camouflage effect can be further improved. The term "distributed in multiple stages" as used herein means that a large number of regions having different thermal radiations are distributed on the surface of the composite sheet.

The metal layer may be formed directly on the base material or may be formed on another functionalizing layer. However, in order to obtain the effect of visible light camouflage by the colored layer, it is preferable to form the layer below the colored layer. The flame-retardant resin layer that is not adjacent to the base material may be formed between the metal layer and the colored layer.

In the composite sheet of the present invention, the average thermal emissivity of the surface thereof is preferably controlled in the range of 0.35 to 0.70. When the average heat emissivity is less than 0.35, it tilts to the lower temperature side than the natural environment (background), and when it exceeds 0.70, it tilts to the higher temperature side, so it is difficult to identify the camouflaged object from the surroundings when shooting with an infrared camera. Therefore, the average thermal emissivity of the surface is preferably 0.35 to 0.70.

The colored layer referred to in the present invention improves the camouflage performance of the composite sheet against visible light and near infrared rays by using a colorant. In order to obtain a camouflage effect on a near-infrared camera, it is preferable to use a coloring agent whose near-infrared reflectance as a camouflage sheet is compatible with the environment around the object to be shielded.

Examples of the colorant used for such a coloring layer include pigments and dyes, and among them, inorganic pigments and organic pigments are preferable. Examples of such inorganic pigments include pigments containing titanium oxide, calcium carbonate, red iron oxide and the like as main components, and examples of organic pigments include azo pigments, phthalocyanine pigments, slene pigments and isoindoline pigments. be able to.

Examples of the resin forming such a colored layer include vinyl-based, acrylic-based, urethane-based, polyamide-based, polyester-based, epoxy-based, alkyd-based, polystyrene-based, and fluorine-based resins. Among these, urethane-based resins are preferably used in terms of flexibility and adhesiveness to metal layers.

For such a colored layer, a water-based resin containing a colorant, an organic solvent-based resin or an emulsion is applied onto a base sheet or the like by a coating method, a printing (pigment printing) method, a spraying method, a printing method or the like, and dried. Can be formed.

The thickness of the colored layer alone is preferably 0.5 to 10 μm. By setting the thickness to 0.5 μm or more, it is possible to prevent the color of the base sheet under the colorant-containing resin layer or the layer from being seen through, and to exhibit the color due to coloring. On the other hand, when the thickness is 10 μm or less, it is possible to prevent the flexibility and the storability from being lowered, and also to prevent the far-infrared camouflage effect from being lowered due to the increase in heat radiation emitted from the colorant-containing resin layer.

Further, the colored layer may exhibit a camouflage pattern. By doing so, the visible light camouflage performance and the near infrared camouflage performance can be further enhanced. A camouflage pattern is a pattern with a regular or irregular shape consisting of multiple hues in harmony with the natural environment, that is, trees, grass, soil, and the like. The color forming the camouflage pattern can be obtained by selecting the colorant in the colorant-containing resin. Further, by making the thickness of the colorant-containing resin layer of each color exhibiting the camouflage pattern different, the heat radiation can be distributed in multiple stages.

The colored layer may be formed on either the lower layer or the upper layer of the flame-retardant resin layer. However, in order to obtain the effect of visible light camouflage by the colored layer, it is preferably formed in the outermost layer portion.

Further, if necessary, a near-infrared reflection adjusting agent may be added to the colored layer and / and the flame-retardant resin layer. In terms of reducing the number of steps, it is preferable to add a near-infrared reflection adjusting agent to either the colored layer or the flame-retardant resin layer. By adding the near-infrared reflection adjusting agent, it becomes easy to assimilate the near-infrared reflectance of the surrounding environment, and a high near-infrared camouflage effect can be imparted to the camouflage sheet.

Such a near-infrared reflection adjusting agent refers to a near-infrared reflecting agent or a near-infrared absorbing agent. The near-infrared reflecting agent is not particularly limited, and examples thereof include titanium oxide, aluminum oxide, zinc aluminate, and barium sulfate. The near-infrared absorber is not particularly limited, and examples thereof include carbon black, phthalocyanine compounds, and anthraquinone compounds.

Since the amount of near-infrared reflection varies depending on the thickness of the metal layer or the type of metal, the amount of the near-infrared reflection adjusting agent added to the colored layer or the flame-retardant resin layer depends on the thickness of the metal layer or the type of metal. At the same time, it may be appropriately adjusted so as to be assimilated with the near-infrared reflectance of the surrounding environment.

Further, when the near-infrared reflection adjusting agent is added to the colored layer, it is preferable that the near-infrared reflectance of the composite sheet can be distributed in multiple stages by making the addition amount different for each color.

The composite sheet of the present invention preferably forms a conductive resin layer. Examples of such a conductive resin include a resin containing a conductive material such as an electron conductive filler, and by forming a conductive resin layer, it is possible to obtain an effect of approximating the reflection characteristics with respect to radar waves to the reflection characteristics of the surrounding environment. be able to.

Examples of the electron conductive filler include carbonaceous particles such as carbon black, graphite and carbon nanotubes, metal powders such as carbon fibers, silver and nickel, and conductive metal oxides such as tin oxide, titanium oxide and zinc oxide. A single substance, a core body of insulating particles such as barium sulfate and wet-coated with the conductive metal oxide, a conductive metal carbide, a conductive metal nitride, or a conductive metal boride. Can be mentioned. Further, as the electron conductive filler, one type may be used alone, or a plurality of types may be used in combination.

Examples of the resin forming the conductive resin include vinyl-based, acrylic-based, urethane-based, polyamide-based, polyester-based, epoxy-based, alkyd-based, polystyrene-based, and fluorine-based resins.

The conductive resin layer can be formed by applying a resin liquid mixed with a conductive material to a sheet by a coating method, a dipping method, a printing (pigment printing) method, a spraying method, a printing method, or the like, and drying.

The conductive resin layer may be adjacent to the base material, may be formed between the metal layer and the other functionality-imparting layer, or may be formed between layers of the other functionality-imparting layer or above. However, if it is not adjacent to the base sheet, it must have a thickness and color that does not impair the performance of each functionalizing layer. When the conductive resin layer is also formed on the upper part of the metal layer, it may affect the thermal emissivity of the composite sheet, so it is desirable to take care to control the average thermal emissivity within a desired range. The total thickness of the flame-retardant resin layer formed on one side of the base material and the functionalizing layer including the conductive resin layer is preferably 1 to 20 μm. In order to obtain the effect of improving the performance of each layer, the conductive resin layer is preferably adjacent to the base sheet.

It is preferable that the composite sheet of the present invention satisfies the flame retardancy of the flameproof grades 1 and 2 specified in JIS A 1322 (1966). By satisfying the criteria, even if a flame ignites on the camouflage sheet during use, the flame can be immediately extinguished and the spread of the flame can be prevented.

(1) Flame retardancy of composite sheet Measured according to JIS A 1322-1966.
(Test specimen)
The shape of the test piece was about 30 cm × 20 cm.
Method A was adopted for the pretreatment of the test piece, and the test piece in an air-dried state was dried at 50 ± 2 ° C. for 48 hours, and then left in a desiccator containing silica gel for drying for 24 hours and then heated. The test was conducted.
(Heating test equipment)
The heating test was carried out in a container using a heating test device in accordance with this specification.
As the burner used for the heating test, a Meckel burner having a height of 160 mm and an inner diameter of 20 mm was used, and only gas was sent in without mixing primary air.
As the fuel used for the heating test, liquefied petroleum gas No. 5 specified in JIS K 2240 (2013) was used.
(Heating test)
The burner was placed in a predetermined position of the heating test device, and the length of the flame was adjusted to 65 mm without the support frame attached.
The test piece was attached to the heating test device with no slack and with support scissors in accordance with this regulation.
A sensitive coil was used to ignite the burner, and the fuel cock was closed at the end of heating.
The heating time was 10 seconds.
As a measurement item, for the residual flame, the time during which the test piece raised the flame and continued to burn from the end of heating was measured.
As a measurement item, the residual dust was determined by observing the state of flameless combustion 1 minute after the end of heating.
As a measurement item, the carbonization length was measured by measuring the maximum length of the carbonized portion of the heated surface of the test piece in the longitudinal direction of the support frame.
The number of tests was 3 for each of the front and back surfaces of the composite sheet and the vertical / horizontal, and the maximum value was adopted for each of the above measurement items, and the flame retardancy was classified according to the following criteria.
-Flameproof first grade: The carbonization length was 5 cm or less, there was no residual flame (approximately 1 second or less), and the residual dust did not exist after 1 minute.
-Flameproof second grade: The carbonization length was 10 cm or less, the residual flame was 5 seconds or less, and the residual dust did not exist after 1 minute.
-Flameproof grade 3: The carbonization length was 15 cm or less, the residual flame was 5 seconds or less, and the residual dust did not exist after 1 minute.

(2) Disguise of composite sheet Place a sample with a size of 1 m x 1 m in an environment where vegetation exists around it, and use a radar wave measuring device with a frequency of 9.8 GHz (manufactured by Azilent Technology Co., Ltd.) to disguise it. Confirmed as radar camouflage. In addition, the mixture with the surroundings was visually confirmed as visual camouflage. The case where they were mixed with the surrounding vegetation was marked with ◯, and the case where they were not mixed was marked with x. The test was carried out on each of the front (A) side and the back (B) side of the sample.

[Example 1]
Using polyethylene terephthalate (PET) fibers having a total fineness of 560 dtex and 96 filaments, a plain weave having a weave density of 35 warp / 25 mm and a weft of 35/25 mm was obtained.
The obtained woven fabric was refined by a conventional method and heat-set at 180 ° C. This woven fabric was used as a base sheet.

A flame-retardant resin made of a urethane resin containing 15% by mass of a bromo-based flame-retardant agent is coated on one side (side B) of the base material sheet so as to have a mass of 40 g / m ^2. A layer was formed. Next, a conductive resin is coated on the surface (A surface) opposite to the surface coated with the flame-retardant layer so as to have a mass of 15 g / m ² to form a conductive layer, and the bromo system is further applied thereto. A flame-retardant resin made of a urethane resin containing 15% by mass of a flame-retardant agent was applied by coating so as to have a mass of 20 g / m ² to form a flame-retardant layer. A metal thin film having a thickness of 0.01 μm on one side is laminated on both sides of the sheet to form a metal layer, and a colored layer is further coated on the sheet so that the mass of one side is 10 g / m ^2. Was formed into a camouflaged sheet.

As the metal layers formed on both sides of the base sheet, a metal thin film layer having a thickness of 0.01 μm per one side of the base sheet was formed by sputtering aluminum in an argon atmosphere.

The colored layers formed on both sides of the base material sheet used a colorant-containing resin in which a light green pigment was mixed with an aqueous acrylic resin, but the color was not limited to light green and was dark green as needed. Other pigments such as brown and black can also be used, and they may be formed in a single color or in multiple colors. In the case of forming in multiple colors, in addition to coating by coating, a letterpress printing machine (flexo printing) is used. It can be applied and formed.

[ Reference example 2]
Using the same base material as in Example 1, a flame-retardant layer is adjacent to both sides of the base material, and a conductive layer is formed on one side (A side) of the base material. did.

[Example 3]
Using the same base material as in Example 1, a flame-retardant layer is formed on one side (B side) and a conductive layer on the other side (A side) of the base material by the same method as in Example 1, and both sides thereof. A metal layer was formed on the surface, a conductive layer was formed on the B-side, a flame-retardant layer was formed on the A-side, and colored layers were further formed on both sides to form a camouflaged sheet.

[Example 4]
A camouflaged sheet was used without forming the colored layer on the B surface side of Example 3.

[Comparative Example 1]
The mass of the flame-retardant layer adjacent to the base material of Example 1 was 60 g / m ^2, and the flame-retardant layer was not formed on the conductive layer (the A-plane does not include the flame-retardant layer).

[Comparative Example 2]
The structure was the same as that of Comparative Example 1 except that the mass of the flame-retardant layer was 120 g / m ² .

[Comparative Example 3]
Using the same base material used in Example 1, a conductive layer is formed on one side (A side) and a metal layer on the other side (B side) of the base material by the same method as in Example 1. A metal layer and a flame-retardant layer were formed on the A-side side thereof, a flame-retardant layer was formed on the B-side side, and colored layers were further formed on both sides to form a camouflaged sheet.

[Comparative Example 4]
The flame-retardant layer formed on the B-side side of Comparative Example 3 was removed.

Table 1 shows the performance of each sheet of Examples and Comparative Examples. As shown in Table 1, the examples have the same camouflage properties as the comparative examples, but are excellent in flame retardancy and lightweight.

Claims (4)

A composite sheet comprising one flame-retardant resin layer on the front and back surfaces of the base material and further laminating at least two types selected from a colored layer, a metal layer and a conductive resin layer, wherein the composite sheet is formed on one side of the base material. A composite sheet in which a flame-retardant resin layer is adjacent and a colored layer or a metal layer or a conductive resin layer is adjacent to the other surface opposite to one side to which the flame-retardant resin layer is adjacent . Composite sheet according to claim 1 Symbol placement arranged on the inner layer side of the outermost layer of the composite sheet metal layers. The composite sheet according to claim 1 or 2 , wherein the base material is a fiber sheet. A camouflage material to which the composite sheet according to any one of claims 1 to 3 is arranged.