JP6308469B2 - Flame retardant laminate - Google Patents

Description

  The present invention relates to a flame retardant laminate, and more particularly, to a flame retardant laminate in which flame retardancy is improved by laminating an infrared reflecting layer.

  As an infrared shielding film, a film in which a specific metal particle-containing layer is laminated on a polymer film is known. The metal particle-containing layer of the infrared shielding film contains at least one kind of metal particle, and the metal particle has 60% by number or more of metal tabular particles, and at least one of the metal particle-containing layers is 800. It has at least two absorption peaks or at least two reflection peaks at ˜2000 nm (Patent Document 1).

  Such an infrared shielding film absorbs or reflects infrared rays well and has a good infrared shielding performance, so that it can be suitably used as a film for vehicles, a laminated structure, a film for building materials, a laminated structure, etc. Has been.

  However, such an infrared shielding film has an unclear relationship between the metal particle-containing layer having at least two absorption peaks or reflection peaks at 800 to 2000 nm and the flame retardancy of the film, and the metal particle-containing layer is a flame-retardant film. It is not elucidated whether it affects sex.

JP2013-205810A

  The present invention was made based on research on infrared reflection and flame retardancy, and provides a flame retardant laminate having improved flame retardancy by laminating a specific infrared reflective layer on a resin substrate. The purpose is to do. And providing the flame retardant laminated body which gave the translucency by selecting the constituent material of an infrared reflective layer, and also improved the flame retardance by laminating | stacking an infrared reflective layer and a clay film layer is also possible. It is aimed.

In order to achieve the above object, the flame retardant laminate according to the present invention has an infrared reflective layer having an average reflectance of infrared rays of 800 to 1300 nm of 20% or more laminated on a resin substrate, and the resin substrate. A clay film layer is provided between the infrared reflection layer and the infrared reflection layer, and the infrared reflection layer is a layer formed of metal nanowires or metal nanotubes .

In the flame retardant laminate of the present invention, it is preferable total light transmittance of the infrared reflective layer is 50% or more.

In the flame-retardant laminate of the present invention, it is desirable that the clay film layer is a film formed by overlapping clay layers formed by electrostatic bonding of dispersed clay particles .

  In the flame-retardant laminate of the present invention, the infrared reflection layer reflects an infrared ray having a wavelength of high infrared energy of 800 to 1300 nm on an average of 20% or more. Thus, the flame retardancy is improved, and as shown in the combustion test data in Table 1 to be described later, the ignition time is extended and the total calorific value and the maximum calorific value are reduced.

In addition, the flame retardant laminate of the present invention is a layer in which the infrared reflective layer is formed of metal nanowires or metal nanotubes, so that the translucency is greatly improved compared to the infrared reflective layer composed of a metal vapor-deposited layer. In addition, the total light transmittance can be increased to 50% or more. Thus, the flame retardant laminated body which has favorable translucency can be obtained by employ | adopting a transparent resin base material as the total light transmittance of an infrared reflective layer is 50% or more.

Further, the flame-retardant laminate of the present invention, since the clay layer is provided between the resin substrate and an infrared reflective layer, as shown in the data of the optical characteristics and burning test in Table 1 below, a good While maintaining the translucency, the flame retardancy is greatly improved, the ignition time is greatly extended, and the total calorific value and the maximum calorific value are remarkably reduced. In addition to the above, the clay film layer has flexibility, gas barrier properties, nonflammability, and the like when the clay layer formed by electrostatic bonding of dispersed clay particles overlaps to form a film.

It is sectional drawing of the flame-retardant laminated body which abbreviate | omitted the clay film layer of this invention. It is sectional drawing of the flame- retardant laminated body of this invention.

  Hereinafter, embodiments of the flame-retardant laminate of the present invention will be described in detail with reference to the drawings.

FIG. 1 is a cross-sectional view showing a flame retardant laminate in which the clay film layer of the present invention is omitted . This flame retardant laminate has a two-layer structure in which an infrared reflecting layer 2 is laminated on a resin substrate 1. It is a laminated body.

The resin substrate 1 is a substrate made of various known synthetic resins. For example, a polycarbonate resin, a polyvinyl chloride resin, a polyolefin resin such as polyethylene or polypropylene, or a polyester resin such as polyethylene terephthalate or polyethylene naphthalate. Resin, polyphenylene sulfide resin, polyether sulfone resin, polyethylene sulfide resin, polyphenylene ether resin, styrene resin, acrylic resin, polyamide resin, polyimide resin, cellulose resin, fluorine resin, etc. Films, sheets, plates, etc. are used. These resin base materials 1 may be colored and opaque, but in order to obtain a flame retardant laminate having good translucency, it is colorless and transparent with a total light transmittance of 80% or more and a haze of 10% or less. It is desirable to selectively use a resin base material.
The resin base material is not limited to a planar shape, and may have various three-dimensional shapes such as a block shape, a column shape, a tubular shape, and an irregular shape.

  The infrared reflective layer 2 laminated on the resin substrate 1 is preferably a layer formed of a metal and / or a metal oxide. Specific examples include a metal vapor deposition film, a metal nanowire, a metal nanotube, metal particles, and a thin layer formed of a metal oxide such as tin-doped indium oxide (ITO) or antimony-doped tin oxide (ATO). And the average reflectance of infrared rays of 800 to 1300 nm is 20% or more by adjusting the kind of metal, metal deposition amount, metal nanowire, metal nanotube, basis weight of metal particles, layer thickness, etc. It was made to become.

The types of metals and metal oxides include metals such as silver, copper, aluminum, titanium, gold, platinum, nickel, zirconium, tin, tin-doped indium oxide (ITO), and antimony-doped oxide from the viewpoint of increasing infrared reflectance. Metal oxides such as tin (ATO), zinc oxide (ZnO), tin oxide (SnO ₂ ), zirconium oxide (ZrO ₂ ), indium oxide (In ₂ O, In ₂ O ₃ ), and the like are preferable. A silver deposited film, silver nanowire, silver nanotube or the like having a high infrared reflectance is preferably employed. Furthermore, metal nanowires, in particular silver nanowires, have very high transparency, conductivity, flexibility and stretchability, have a diameter of 0.3 to 100 nm and a length of 0.1 to 300 μm, preferably a diameter. Those having a length of 1 to 90 nm and a length of 1 to 90 μm are used, and the aspect ratio is about 100 to 3000. Such metal nanowires and metal nanotubes can be deposited and deposited on the surface of the resin substrate 1 in a substantially uniformly dispersed state to form the infrared reflective layer 1.

When the infrared reflective layer 2 is formed of a metal vapor-deposited film, for example, a silver vapor-deposited film, the average reflectance of infrared rays of 800 to 1300 nm is extremely high at 80% or more, and there is an advantage that the flame retardancy of the laminate is greatly improved. . However, since such a silver vapor deposition film has a total light transmittance close to 0%, it is not suitable for obtaining a flame-retardant laminate having translucency, but it does not require translucency. In a place where is required, it is lighter and has better processing and handleability than a metal plate, and is useful.
In addition, when forming the infrared reflective layer 2 which consists of a silver vapor deposition film, the resin base material 1 should just be set to the vapor deposition frame of a vacuum vapor deposition apparatus, and a predetermined amount of silver should be vacuum-deposited on the surface of the resin base material 1. FIG.

  On the other hand, the infrared reflective layer 2 is made of metal nanowires or metal nanotubes (hereinafter collectively referred to as metal nanowires), for example, silver nanowires or silver nanotubes (hereinafter collectively referred to as silver nanowires). And when forming on the surface of the transparent resin base material 1, the average reflectance of the infrared rays of 800-1300nm is 20 by adjusting the thickness of the infrared reflective layer 2, the basis weight of silver nanowires, etc. %, It is possible to obtain a flame-retardant laminate having good flame retardancy and having a total light transmittance of 50% or more and also having good light-transmitting properties.

  As a method of forming the infrared reflective layer 2 with metal nanowires, for example, an aqueous paint prepared by dispersing metal nanowires or the like in a water-soluble solvent such as ethanol or isopropyl alcohol (content of metal nanowires: 0) .2 wt% or less, preferably 0.1 wt% or less) is applied to the surface of the resin substrate 1 with a spray coater or the like and dried to form the infrared reflecting layer 2. In that case, it is preferable to apply a hydrophilic treatment such as corona treatment to the surface of the resin base material 1 in advance to improve the wettability of the surface of the resin base material 1 and improve the coatability of the water-based paint. Moreover, it is still more preferable to combine silver nanowires and binders, such as resin, and to apply a press to a coating film after silver nanowire coating. By combining silver nanowires and a binder such as a resin, the adhesiveness between the binder and the substrate is strengthened, so that there is an effect of preventing peeling of the coating film after coating. Moreover, the coating film is pressed to prevent exfoliation of the metal nanowires and the pressing conditions are not particularly limited. For example, the heating is performed under conditions of a temperature of about 90 ° C. and a pressure of about 40 MPa. It is appropriate to press.

The thickness of the infrared reflecting layer 2 varies depending on the metal material and needs to be a thickness suitable for each material. For example, in the case of silver nanowires, the thickness of the infrared reflection layer 2 is preferably 500 nm or more and less than 900 nm. When the layer thickness is 500 nm or more, the average reflectance of infrared rays of 800 to 1300 nm is 20% or more. Thus, the flame retardancy of the laminate is improved, and if the layer thickness is less than 900 nm, the total light transmittance of the infrared reflecting layer 2 is 50% or more. A flame retardant laminate having good translucency can be obtained. If the layer thickness is less than 500 nm, the average reflectance of infrared rays of 800 to 1300 nm is lowered, and if it is 900 nm or more, the total light transmittance is lowered, both are not preferable. Preferred mass per unit area of the metal nanowires such as to form the infrared reflective layer 2 may vary depending on the thickness as well as the type of metal, in the case of, for example, silver nanowires, etc., is about 75~100g / m ^2.
In addition, what is necessary is just to set it as the thickness of 40 nm or more when forming the infrared reflective layer 2 with a metal vapor deposition film.

  FIG. 2 is a cross-sectional view of a flame retardant laminate according to another embodiment of the present invention. This flame retardant laminate has a clay film layer 3 between a resin substrate 1 and an infrared reflecting layer 2. It is the laminated body of the provided 3 layer structure. Here, the clay film layer is the same as the clay film described in JP-A-2005-313604 and JP-A-2007-63118, and has a layered silicate mineral as a main component and is hydrophilic. Is a clay-like clay film that exhibits plasticity and tackiness when it contains water. In the clay film layer, clay particles dispersed in water are allowed to stand, so that they are electrostatically coupled by the charge of the clay itself to form a clay layer (card house structure). Thereafter, by evaporating the water, the clay layers overlap to form a film having flexibility, gas barrier properties, non-combustibility, and the like.

  The clay film layer 3 is provided between the resin base material 1 and the infrared reflecting layer 2 in order to greatly improve the flame retardancy without greatly reducing the translucency of the flame retardant laminate. Then, clay and a thickening agent such as sodium polyacrylate are sequentially added to water, and after casting the shaken viscous liquid, a clay film obtained by drying is applied to the surface of the resin substrate 1 with an acrylic adhesive. It is glued with etc. The viscous liquid is preferably further improved in dispersibility of clay particles by ultrasonic treatment before casting.

  A preferable thickness of the clay film layer 3 is 10 μm or more. If the thickness of the clay film layer 3 is 100 μm or more, the flame retardancy can be greatly improved without greatly reducing the translucency of the flame retardant laminate, which is extremely effective. When the thickness of the clay film layer 3 is less than 10 μm, the translucency is not substantially lowered, but the flame retardancy is hardly improved.

  In addition, since the resin base material 1 and the infrared reflective layer 2 of a flame-retardant laminated body shown in FIG. 2 are the same as the resin base material 1 and the infrared reflective layer 2 which were mentioned above of the flame-retardant laminated body shown in FIG. The description is omitted.

  Next, more specific examples of the present invention, comparative examples, and reference examples will be described.

[Example 1]
A silver nanowire (blue nano SLV-NW-90L, diameter 90 nm, length 25 μm) in which silver nanowires are dispersed in an ethanol solvent is a transparent plate-like polycarbonate having a thickness of 5 mm. After coating the surface of the resin substrate with a spray coater, drying the coating film to volatilize the solvent, and then hot pressing under conditions of 90 ° C. and 40 MPa, the silver nanowires are dispersed substantially uniformly. A flame retardant laminate was obtained in which an infrared reflective layer having a thickness of 530 nm deposited and deposited on was laminated on the surface of a polycarbonate resin substrate.
While measuring the total light transmittance and haze of the obtained flame-retardant laminate using HAZE METER NDH5000 [manufactured by Nippon Denshoku Industries Co., Ltd.], SHIMAZU UV31-3100 PC [manufactured by Shimadzu Corporation] Then, after measuring the diffuse reflection spectrum of 300-2500 k-, the average value (average reflectance) of the reflectance of 800 to 1300 nm was calculated. The results are shown in Table 1 below.
Moreover, in order to evaluate the flame retardancy of the obtained flame retardant laminate, the ignition time, total calorific value, and maximum calorific value of the flame retardant laminate are determined in accordance with ISO 5660-1 “Cone Calorimeter Method”. It was measured. The results are shown in Table 1 below.

[Example 2]
A transparent plate-like polycarbonate resin substrate with a thickness of 5 mm is cut into a square with a side of 10 cm, and this cut piece is set on a vapor deposition frame of a vacuum vapor deposition apparatus [manufactured by Tokyo Vacuum Co., Ltd.], and Ag is vacuum vapor deposited. Thus, a flame retardant laminate was obtained in which an infrared reflective layer composed of a silver vapor deposition film having a thickness of about 100 nm was laminated on the surface of the polycarbonate resin substrate.
While measuring the total light transmittance, haze, and average reflectance of 800-1300 nm of the obtained flame-retardant laminate in the same manner as in Example 1, the ignition time and the total calorific value of the obtained flame-retardant laminate. The maximum calorific value was measured in the same manner as in Example 1 to evaluate flame retardancy. The results are shown in Table 1 below.

[Example 3]
Clay (Kunimine Kogyo Co., Ltd., Kunipia M spreading direction 100-900 nm, thickness 1 nm) is added to distilled water, shaken, and then sodium polyacrylate [manufactured by Wako Pure Chemical Industries, Ltd.] is added for 1 hour. After shaking, ultrasonic treatment was performed to obtain a viscous liquid. This viscous liquid was cast in a square frame having a side of 15 cm and dried in a gear oven at 30 ° C. for 14 hours to obtain a clay film having a thickness of 45 μm. The clay film is bonded to the surface of a transparent plate-like polycarbonate resin substrate having a thickness of 5 mm with an acrylic adhesive to laminate a clay film layer, and the surface is made of silver nanowires in the same manner as in Example 1. A flame-retardant laminate having a three-layer structure in which an infrared reflective layer having a thickness of 530 nm was laminated was prepared.
The total light transmittance, haze, and average reflectance of 800 to 1300 nm of this flame retardant laminate were measured in the same manner as in Example 1, and the ignition time, total calorific value, and maximum calorific value of this flame retardant laminate were measured. Was measured in the same manner as in Example 1 to evaluate flame retardancy. The results are shown in Table 1 below.

[Comparative example]
For comparison, the total light transmittance was the same as in Example 1 for the transparent plate-like polycarbonate resin substrate (those without an infrared reflective layer laminated) having a thickness of 5 mm used in Examples 1 to 3. In addition to measuring haze and an average reflectance of 800 to 1300 nm, flame retardancy was evaluated by measuring ignition time, total calorific value, and maximum calorific value. The results are shown in Table 1 below.

[Reference example]
For reference, the 45 μm thick clay film obtained in Example 3 was adhered to the surface of a transparent plate-like polycarbonate resin substrate having a thickness of 5 mm with an acrylic adhesive to A laminate having a two-layer structure in which a clay film layer was laminated on the surface was produced.
The total light transmittance, haze, and average reflectance of 800 to 1300 nm of this laminate were measured in the same manner as in Example 1, and the ignition time, total calorific value, and maximum calorific value of this flame retardant laminate were measured in Examples. The flame retardancy was evaluated in the same manner as in 1. The results are shown in Table 1 below.

  In Table 1, PC is a polycarbonate resin base material, AgNW is silver nanowire, Ag is silver, T.I. T represents the total light transmittance, and HAZE represents haze.

From Table 1, the polycarbonate resin base material of the comparative example having no infrared reflective layer has a total light transmittance of 89.1% and a haze of 0.5%, and has excellent transparency, but an infrared ray of 800 to 1300 nm. In the combustion test, the ignition time is as short as 131 seconds, the total heating value is 122.8 MJ / m ² and the maximum heating value is 538.4 kW / m ^2. It turns out that it is inferior in flammability.

  On the other hand, the flame retardant laminates of Examples 1 and 2 in which an infrared reflective layer formed of silver nanowires or a silver deposited film was laminated on the surface of a polycarbonate resin base material had an average infrared reflection of 800 to 1300 nm. Since the rate is 20% or more, it can be seen that the ignition time is extended as compared with the polycarbonate resin substrate of the comparative example, the total calorific value and the maximum calorific value are reduced, and the flame retardancy is improved.

  In particular, the flame retardant laminate of Example 2 in which an infrared reflective layer composed of a silver vapor deposition layer was laminated has a high average reflectance of 81.5% for infrared rays of 800 to 1300 nm, so the ignition time is compared with 403 seconds. The ignition time of the polycarbonate resin base material of the example is extended approximately three times, the total calorific value is also reduced to about 1/2 or less of the polycarbonate resin base material of the comparative example, and the maximum calorific value is also reduced to about 2/3 or less, and flame retardant It can be seen that the performance is greatly improved. However, the flame retardant laminate of Example 2 in which an infrared reflective layer composed of a silver vapor deposition layer is laminated on the surface has a total light transmittance of 0.3% and has substantially no translucency. However, it can be effectively used in places where translucency is not required.

  On the other hand, the flame retardant laminate of Example 1 in which an infrared reflective layer formed of silver nanowires is laminated on the surface does not significantly improve the flame retardancy of the flame retardant laminate of Example 2, Since the infrared reflective layer formed of nanowires has good translucency, the total light transmittance of the flame-retardant laminate is considerably high at 63.3%, and the haze is also considerably low at 18.3%, which is practical. It can be seen that it has a sufficiently satisfactory translucency.

In addition, the flame retardant laminate of Example 3 in which a clay film layer is provided between an infrared reflective layer formed of silver nanowires and a polycarbonate resin base material has good light transmission properties in both the infrared reflective layer and the clay film layer. Therefore, the total light transmittance is 58.8%, which is slightly lower than that of the flame retardant laminate of Example 1 (only the silver nanowire infrared reflective layer laminated without the clay film layer). In addition, since the clay film layer exhibits an excellent flame retarding effect, the ignition time is 309 seconds, which is significantly longer than that of the flame retardant laminate of Example 1, and the total calorific value is also 5.9 MJ. / M ² and the maximum calorific value are surprisingly reduced to 419 kW / m ² , indicating that the flame retardancy is remarkably improved.

Furthermore, when the laminated body of the reference example which laminated | stacked the clay film layer on the surface of a polycarbonate resin base material is shown, since the clay film layer has favorable translucency, the total light transmittance of a laminated body is 73.1%. Although the average reflectance of infrared rays from 800 to 1300 nm is as low as 8.9%, the clay film layer exhibits an excellent flame retardant action, so the ignition time is not likely to be 284 seconds, and the total heat generation It can be seen that the amount is 14.8 MJ / m ² and the maximum calorific value is also reduced to 146.5 kW / m ² , so that flame retardancy is greatly improved.

DESCRIPTION OF SYMBOLS 1 Resin base material 2 Infrared reflective layer 3 Clay film layer

Claims (3)

On the resin base material, an infrared reflective layer having an average reflectance of 800 to 1300 nm of infrared rays of 20% or more is laminated , and a clay film layer is provided between the resin base material and the infrared reflective layer, The flame retardant laminate, wherein the infrared reflective layer is a layer formed of metal nanowires or metal nanotubes . The flame retardant laminate according to claim 1 , wherein the total light transmittance of the infrared reflective layer is 50% or more. The flame retardant according to claim 1 or 2, wherein the clay film layer is a film formed by overlapping clay layers formed by electrostatic bonding of dispersed clay particles. Laminated body.

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