JP4339752B2 - Snow sliding sheet - Google Patents

Description

  The present invention relates to a snow sliding sheet that is used on a roof in a snowfall area to prevent a large amount of snow from accumulating.

  In snowy countries, snow removal is often performed after snowfall using snow shoveling tools and machinery, but due to the weight of snow on the roof, houses, temporary construction materials, simple warehouses, garages, The damage caused by the collapse of agricultural houses, etc. is significant. In order to prevent such damage, various attempts have been made to remove snow during snowfall.

For example, a method of installing a bag body on the roof, introducing gas into the bag body, repeatedly expanding and contracting and pushing up the snow accumulated on the bag body and sliding it down (Patent Document 1), a sheet of belt conveyor structure on the roof A method of installing and dropping a shape (Patent Document 2), a method of providing a heating means on the roof and dropping it while melting snow (Patent Document 3), a method of using a coating material such as fluororesin (Patent Document 4), etc. Can be mentioned.
However, in a simple warehouse, garage, agricultural house, etc., which has a roof that does not require a strong structure, it is difficult to provide the snow removal equipment as described above, and it is expensive and simple and inexpensive. Has not yet been found.

JP-A-10-140879 (page 2) JP-A-10-140877 (2 pages) Japanese Utility Model Publication No. 6-24114 (2 pages) JP-A-4-85369 (page 2)

  The present invention has been made paying attention to the above problems, and is a lightweight, high-strength sheet that can be easily covered with a covering and can easily remove snow. For the purpose of provision.

  The gist of the present invention is a snow sliding sheet characterized by laminating an infrared absorbing layer on the surface of a woven cloth cloth woven with a stretched yarn made of thermoplastic resin, and laminating an infrared reflecting layer on the back surface thereof. , Exist.

  The snow sliding sheet of the present invention has an infrared absorbing layer on the surface of a woven cloth formed by weaving a stretched yarn made of thermoplastic resin, and an infrared reflecting layer is laminated on the back surface thereof, so that the wavelength from the sun rays to the infrared region is increased. Is absorbed by the infrared absorbing layer, and the light having the wavelength in the infrared region transmitted from the infrared absorbing layer is reflected by the infrared reflecting layer provided on the back surface of the woven cloth cloth and absorbed again by the infrared absorbing layer. By improving the absorption efficiency in the infrared absorption layer and increasing the amount of heat conversion, it is possible to remove and remove the snow accumulation on the surface of the snow sliding sheet while melting at an early stage. It is highly powerful and inexpensive, and is suitable for use as a snow sliding sheet by covering the roofs of houses, temporary construction materials for construction work, simple warehouses, garages, agricultural houses and the like.

Hereinafter, the present invention will be described in detail.
In the present invention, examples of the thermoplastic resin used for the drawn yarn made of thermoplastic resin include polyolefin, polyvinyl chloride, polystyrene, polyester, polyamide, and polyvinyl alcohol. Examples of the polyolefin include high density polyethylene, linear low density polyethylene, branched low density polyethylene, ethylene-vinyl acetate copolymer, ethylene-acrylic acid ester copolymer, and polypropylene. Among these, high-density polyethylene and polypropylene that are easy to form a drawn yarn and have excellent mechanical properties are preferable.

  As the form of the drawn yarn, any of monofilament, multifilament, flat yarn, split yarn and the like can be used. Of these, flat yarns that are flexible, have excellent moldability, and are easy to form a smooth cloth are preferred. The fineness of the drawn yarn is in the range of 50 to 3000 dtex (hereinafter referred to as dt), preferably in the range of 100 to 2000 dt.

  A woven fabric is formed by weaving the drawn yarn as a warp and weft. The driving density of the woven fabric is in the range of 8 to 25 pieces / inch, and preferably in the range of 10 to 20 pieces / inch. Moreover, the fabric weight of a woven fabric is the range of 30-600 g / m2, Preferably it is the range of 50-400 g / m2.

  In the present invention, a laminate layer of a thermoplastic resin (hereinafter referred to as infrared absorption) containing an infrared absorbent having a maximum absorption in the wavelength region of 800 to 1400 nm on the surface of a woven cloth formed by weaving a stretched yarn made of thermoplastic resin. A thermoplastic resin laminate layer (hereinafter abbreviated as an infrared reflective layer) containing an infrared reflective agent that reflects light in the wavelength region of 800 to 1400 nm on the back surface. Lamination is performed to form a laminated sheet. As the laminating method, a known extrusion laminating method, dry laminating method, thermocompression laminating method or the like can be adopted, but the extrusion laminating method is preferable in terms of moldability. The thermoplastic resin used in the laminate layer is a low density polyethylene, a linear low density polyethylene, an ethylene-vinyl acetate copolymer, an ethylene-acrylic acid ester copolymer, a polypropylene, etc., which is usually used for laminating methods. it can.

The thickness of the laminate layer is 50 μm or more, preferably in the range of 50 to 400 μm, and more preferably in the range of 80 to 300 μm.
When the thickness of the laminate layer is less than 50 μm, the unevenness of the stretched yarn forming the woven cloth cloth appears on the surface of the obtained laminated sheet, which is inferior in smoothness, and is not preferable because the slipperiness of falling snow is insufficient. If it exceeds 400 μm, the weight increases, the specific gravity is light, and the advantage of being light is lost.

  In the present invention, first, an infrared absorption layer is laminated on the surface of the woven cloth, and light having a wavelength in the infrared region from sunlight is absorbed by the infrared absorption layer and converted into heat, whereby snow accumulation on the surface of the snow sliding sheet is obtained. It is characterized in that it is removed by removing it while melting it at an early stage.

  As an infrared absorber to be blended in the infrared absorption layer, an inorganic infrared absorber, an organic infrared absorber, or the like having maximum absorption in a wavelength region of 800 to 1400 nm can be used. Examples of inorganic infrared absorbers include composite hydroxides such as lithium aluminum composite hydroxide, hydroxyaluminum hydroxycarbonate and hydrotalcite compounds, tin oxide, magnesium oxide, calcium oxide, aluminum oxide, silicon oxide, and oxidation. Metal oxides such as zinc, iron oxide, antimony oxide, lead oxide, hydroxides such as lithium hydroxide, magnesium hydroxide, calcium hydroxide, aluminum hydroxide, magnesium carbonate, calcium carbonate, potassium sulfate, magnesium sulfate, Sulfates such as calcium sulfate, zinc sulfate, aluminum sulfate, phosphates such as lithium phosphate, sodium phosphate, potassium phosphate, calcium phosphate, zirconium phosphate, magnesium oxalate, calcium oxalate, aluminum oxalate, titanium oxalate, etc. Acid salts Examples include aluminates such as sodium aluminate, potassium aluminate and calcium aluminate, aluminosilicates such as sodium aluminosilicate, potassium aluminosilicate and calcium aluminosilicate, and clay minerals such as kaolin, clay and talc. It is done. The inorganic infrared absorber is desirably in the form of fine particles, preferably having an average particle size in the range of 0.005 to 10 μm, particularly preferably having an average particle size in the range of 0.01 to 2.0 μm. belongs to. As a compounding quantity of these inorganic type infrared absorbers, it is the range of 0.01 to 5 weight%, Preferably it is the range of 0.1 to 5 weight%.

  On the other hand, examples of organic infrared absorbers include polymethine, phthalocyanine and naphthalocyanine cyanine, metal complex, aminium, iminium, perylene, quaterrylene, imonium, diimonium, and anthraquinone. And quinone-based compounds such as naphthoquinone-based compounds, dithiol metal complex-based compounds, indolephenol-based compounds, azo-based compounds, and triallylmethane-based compounds. The compounding amount of these organic infrared absorbers is in the range of 0.01% to 5% by weight, preferably in the range of 0.01 to 1% by weight.

In addition, an infrared reflection layer that reflects light in the wavelength region of 800 to 1400 nm is laminated on the back surface of the woven fabric, and the transmitted light that passes through the infrared absorption layer from sunlight is reflected by the infrared reflection layer. Again, it is also characterized in that it absorbs light having a wavelength in the infrared region, converts it into heat, and drops and removes the snow on the surface of the snow sliding sheet while melting it at an early stage.
The infrared reflective layer in the present invention is desirable as the reflectance with respect to light in the wavelength region of 800 to 1400 nm is higher, and is desirably 40% or more, preferably 60% or more. The infrared reflective layer has a transmittance for near infrared rays in the wavelength region of 800 to 1400 nm of 30% or less, preferably 20% or less. The reflectance, transmittance, and absorptance mean numerical values measured for the entire layer, and these measurements can be made using, for example, an automatic recording spectrophotometer “U-4000” manufactured by Hitachi. The reflectance can be measured, for example, under the condition of 5 ° regular reflection.

As the infrared reflecting layer, a layer formed of a resin composition containing an infrared reflecting agent having characteristics of efficiently reflecting near infrared rays and efficiently emitting far infrared rays is preferable. The resin component used for the infrared reflecting layer is the thermoplastic resin used for the laminate layer described above.
As the infrared reflecting agent, both inorganic pigments and organic pigments can be used.
Examples of the inorganic pigment include one or more selected from iron oxide pigments, titanium oxide pigments, complex oxide pigments, titanium oxide-coated mica pigments, iron oxide-coated mica pigments, scaly aluminum pigments, zinc oxide, and the like. It can be used.
Organic pigments include copper phthalocyanine pigment, dissimilar metal (nickel, cobalt, iron, etc.) phthalocyanine pigment, metal-free phthalocyanine pigment, chlorinated phthalocyanine pigment, chlorine / brominated phthalocyanine pigment, brominated phthalocyanine pigment, anthraquinone pigment, quinacridone Pigment, diketopyrrolopyrrole pigment, perylene pigment, monoazo pigment, disazo pigment, condensed azo pigment, metal complex pigment, quinophthalone pigment, indanthrene blue pigment, dioxazine violet pigment, anthraquinone pigment Metal complex pigments, benzimidazolone pigments, and the like can be used. In addition to these, pigments with little infrared absorption can be used. Among these, titanium oxide is particularly preferable from the viewpoint of reflection performance and cost.

  The content of the pigment of the infrared reflecting agent in the infrared reflecting layer is preferably 5 to 80% by weight, more preferably 10 to 80% by weight, and still more preferably 40 to 80% by weight. The average particle diameter of the infrared reflecting pigment in the infrared reflecting layer is in the range of 0.01 to 100 μm, and preferably in the range of 0.1 to 25 μm. In particular, when titanium oxide is used, the particle diameter is preferably in the range of 0.05 to 1 μm from the viewpoint of reflection performance. When titanium oxide is used in the infrared reflecting layer, a higher reflectance can be obtained by further mixing a scaly aluminum pigment, a mica pigment or the like. The reflective layer is not limited to a single layer, and may be two or more layers.

  If necessary, an extender pigment having infrared reflectivity such as silica, magnesium silicate and calcium carbonate may be added to the infrared reflection layer to adjust the gloss. The content of the extender pigment is not limited, but it is preferably 25% by weight or less of each layer.

  Further, the infrared reflection layer may be formed by applying a resin composition formed as a paint as a coating film by applying, spraying, or the like, or by laminating a film formed by various forming means. In the case of forming as a paint, in order to facilitate the coating operation, it may be diluted with an appropriate solvent, for example, an organic solvent, water, a mixture of water and an organic solvent, or made into a liquid, or may be in a powder form. Good. Moreover, you may add a dispersing agent and a dispersing aid to a solvent as needed.

Furthermore, the infrared reflective layer may be a laminate of a metal layer formed on a film formed by various forming means.
As the metal material constituting the metal layer, metals such as Au, Ag, Cu, and Al, alloys thereof, or a wide optical band gap such as Sb-doped SnO2 or Sn-doped In2O3 (ITO) and a high degree of freedom. A semiconductor thin film having an electron density is exemplified. Among these, one or more metals selected from Au, Ag, and Cu, or alloys thereof are preferable, and Ag that hardly absorbs visible light is particularly preferable. In addition, you may use 2 or more types of metal substances together as needed. As a method for forming such a metal layer, a vapor deposition method is preferable, and a vacuum evaporation method, a sputtering method, or a plasma CVD method is particularly preferable. The thickness of the metal layer is in the range of 5 to 1000 nm.

  Furthermore, it is desirable that a higher fatty acid amide is added to the laminate layer in order to impart lubricity to the sheet surface. Specific examples of the higher fatty acid amide include any of saturated fatty acid amides such as stearic acid amide, palmitic acid amide, and behenic acid amide, and unsaturated fatty acid amides such as oleic acid amide and erucic acid amide. Also, it is desirable to use a higher fatty acid amide in combination with a polyhydric alcohol ester of a fatty acid, metal soaps, wax, etc., because the lubricity can be maintained for a long time.

  The blending ratio of the higher fatty acid amide is in the range of 500 to 5000 ppm, preferably in the range of 1000 to 3000 ppm with respect to the laminate layer. If the amount of the higher fatty acid amide exceeds 5000 ppm, the slipperiness becomes excessive and handling of the sheet becomes difficult, and if it is less than 500 ppm, the slipperiness becomes insufficient, which is not desirable.

  The thermoplastic resin used in the present invention includes an antioxidant, an ultraviolet absorber, a light stabilizer, a lubricant, an antistatic agent, a pigment, a flame retardant, an inorganic filler, a nucleus within the scope of the present invention. You may mix | blend normally used additives, such as an agent.

Example 1:
High density polyethylene (MFR = 0.7 g / 10 min, density = 0.957 g / cm ³ , Tm = 129 ° C.) was used to extrude into a film using an inflation method, and cooled to form a film. This film was stretched by a hot plate contact stretching method at a stretching ratio of 9 to form a flat yarn having a fineness of 1700 dt.
This flat yarn was used as the warp and the weaving density was 16 × 16 / inch as the warp and a plain woven fabric was obtained.

On the surface of the woven fabric, low density polyethylene (MFR = 8.0 g / 10 min, density = 0.918 g / cm ³ ), 2% by weight of hydroxyaluminum hydroxycarbonate (trade name: MIZUKALAC) as an infrared absorber and Elca A 200 μm thick infrared absorption layer laminate was formed by extrusion lamination using a composition containing 1500 ppm of acid amide. Further, an extrusion laminating method using a resin composition in which 5% by weight of a titanium oxide pigment is blended with low density polyethylene (MFR = 8.0 g / 10 min, density = 0.918 g / cm ³ ) is used on the back surface of the woven fabric. As a result, a laminated body laminated through a laminate layer of an infrared reflective layer having a thickness of 200 μm was obtained. The basis weight of this laminate was 585 g / m ² .

The snow sliding sheet thus obtained was subjected to a snow sliding performance test as follows. That is, the snow sliding sheet was cut into a size of 50 cm × 500 cm and stuck outdoors at an inclination angle of 15 °. From the evening to the night, it was confirmed that an ice film was formed on the sheet surface by radiation cooling, and the amount of snowfall until the next morning was 15 cm. One hour after sunrise (6:30), melted water started to flow on the sheet, and after 2 hours, snow completely slid. This is presumed to be because the infrared absorbent blended in the sheet absorbed the wavelength in the infrared region of sunlight and converted it into heat.
The indicated temperature of the thermocouple attached to the sheet surface was as shown in Table 1.

Comparative Example 1:
In Example 1, it carried out similarly except not mix | blending an infrared reflector with a back surface.
As a result, melted water flowed out 2 hours after sunrise, and snow completely slid after 3 hours.
The indicated temperature of the thermocouple attached to the sheet surface was as shown in Table 1.

Comparative Example 2:
In Example 1, it carried out similarly except not having mix | blended the infrared absorber and the infrared reflective agent with the front and back, respectively. As a result, it was in a state of snow accumulation even after 3 hours, and snow melting on the sheet could not be confirmed.
The indicated temperature of the thermocouple attached to the sheet surface was as shown in Table 1.

Table 1

Claims (3)

  A snowslide sheet comprising an infrared absorbing layer laminated on the surface of a woven cloth made of woven thermoplastic resin drawn yarn, and an infrared reflecting layer laminated on the back surface thereof.   The snow sliding sheet according to claim 1, wherein the infrared absorbing layer is a laminate layer of a thermoplastic resin containing an infrared absorber having a maximum absorption in a wavelength region of 800 to 1400 nm.   2. The snow sliding sheet according to claim 1, wherein the infrared reflection layer is a laminate layer of a thermoplastic resin containing a pigment of an infrared reflection agent that reflects light in a wavelength region of 800 to 1400 nm.