JPH0222272Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a light-permeable heat insulating board that allows a good amount of light to enter and has a good heat insulating effect.

2. Description of the Related Art Conventionally, light-permeable heat insulating boards are known in which a reinforcing layer such as a resin film is provided on the surface of a thermoplastic resin foam sheet. However, these have poor sunlight transmittance, poor weather resistance, and are expensive.

As a result of intensive research to improve these drawbacks, the inventor of the present invention has found that by enlarging the bubbles in a thermoplastic resin foam sheet, it improves lighting performance and reduces costs, and also uses a specific acrylic film as an adhesive layer. We have discovered a light-permeable heat insulating board that has improved weather resistance by laminating layers with .

In other words, the gist of the present invention is that the average bubble diameter in the thickness direction
0.5mm or more, total thickness 2mm to 50mm, foaming ratio 3
Through an adhesive layer excluding acrylic and epoxy adhesives on at least one side of a thermoplastic resin foam sheet of 50 times to 50 times, it has a light transmittance of 75% or more, and a transmittance of 10 at wavelengths of 330 millimicrons or less. % or less of an acrylic resin film layer.

The thermoplastic resin foam sheet used in the present invention includes foam sheets made of polystyrene resin, acrylic resin, polycarbonate resin, polyolefin resin, vinyl chloride resin, etc. Of these, polystyrene resins and polyethylene resins are preferred. These resins can be easily produced by an extrusion foaming method using an extruder. That is, a foamed sheet having a predetermined thickness is obtained from a circular die, and a flat fused laminate can be obtained by touching the inner surface of a cylindrical foam extruded from a circular die. This fused laminate has high-density foam layers on both surfaces and in the middle, so it is strong, and since both surfaces are well balanced, it is stable and preferable as a flat plate, but it is slightly inferior in lighting performance. Foam sheets can also be manufactured by slicing thick slabs of foam to a predetermined thickness. In this case, the bubbles are cut in the middle, and the lighting is very good.

Thermoplastic resin foam sheets are mainly selected from the viewpoints of heat insulation and lighting. From the point of view of insulation, the smaller the bubble diameter and the larger the overall thickness, the better.
The average bubble diameter in the thickness direction is 0.5, as the lighting performance will be poor.
mm or more, with a total thickness of 2 mm to 50 mm. In particular, when the bubble diameter is 1.0 mm or more, the lighting performance is good. however,
Practically speaking, a suitable upper limit for the bubble diameter is approximately 10 mm. Regarding the foaming ratio, the higher the foaming ratio, the better the lighting performance.
Since the strength is not suitable for practical use, 3 times to 50 times is selected. In applications where particularly high strength is required, a material with a strength as low as about 5 times is used. Various extrusion foaming methods have been developed to increase the size of bubbles in order to improve lighting. For example, in the case of polystyrene resin, when sodium chloride is used as a nucleating agent, the cell diameter is 2.
It is possible to produce a foam sheet with suitable light-permeability of mm to 5 mm. Polyolefin resins can be produced by reducing the amount of a nucleating agent such as talc, adding stearyl monoglyceride, and performing extrusion foaming.

The acrylic resin film layer used in the present invention has a light transmittance of 75% or more and a transmittance of 10% or less at wavelengths of 330 millimicrons or less. The thickness of this film layer is typically 10 microns to 1000 microns. Here, the light transmittance is measured according to JISK6717, and the ultraviolet transmittance is measured according to JISK6714 as the thickness of each film. As the acrylic resin, resins such as polymethyl methacrylate resin and copolymers of methyl methacrylate and methacrylic acid or other polymerizable monomers are suitable. Acrylic resin film has good light transmittance and is itself weather resistant, so it will not discolor or crack after many years of use, but it does not sufficiently block the transmission of ultraviolet rays with a wavelength of 330 millimicrons or less. I don't get it. The transmitted ultraviolet rays cause the thermoplastic resin foam sheet, which has a heat insulating effect, to discolor and deteriorate, resulting in cracks and loss of strength for practical use. Therefore, the wavelength of the present invention
A transmittance of 10% or less for 330 mm or less can be achieved by further mixing an ultraviolet absorber with the acrylic resin. Examples of such ultraviolet absorbers include benzophenone series such as 2-hydroxy-4-methoxybenzophenone and 2,2'-dihydroxy-4,4'-dimethoxybenzophenone, benzotriazole series, phenyl salicylate series, triazine series, and nickel. 1% to 3% of salt and nickel complex salts are mixed (Rubber Digest Co., Ltd., "Rubber/Plastic Compounding Chemicals", 115-122)
(see page).

Then, the thermoplastic resin foam sheet and the acrylic resin film layer are integrated using an adhesive layer excluding acrylic and epoxy adhesives,
As this adhesive layer, a hot melt type, solvent type, or emulsion type adhesive layer containing an ethylene/vinyl acetate copolymer resin as a main component is preferably used, and other urethane resin adhesives may also be used.

Next, the lighting insulation board of the present invention will be explained with reference to the drawings.

1 is a polystyrene resin foam sheet, 2 and 2' are urethane resin adhesive layers, and 3 and 3' are polymethyl methacrylate resin films having a thickness of 75 μm and having a transmittance of 8% for wavelengths of 330 millimicrons or less. The polystyrene resin foam sheet is an extruded foam sheet that is extruded from a circular die using an extruder, and has a thickness of 3 mm, an average cell diameter in the thickness direction of 0.5 mm, a number of cells in the thickness direction of 6, and a foaming ratio of 10 times. In this case, the adhesive 2, 2' is applied to the resin film 3,
After coating and drying, the foamed sheet 1 was bonded and integrated with both sides of the foamed sheet 1 by heat press to produce a light-permeable heat insulating board with a light transmittance of 46%.

This material showed only a 4% decrease in light transmittance after 300 hours of irradiation with a sunshine weatherometer. A film using a regular acrylic resin film showed a decrease in light transmittance of about 10% under similar conditions.

The present invention is constructed as described above, with an average cell diameter in the thickness direction of 0.5 mm or more, an overall thickness of 2 mm to 50 mm,
Because it uses a thermoplastic resin foam sheet with a foaming ratio of 3 to 50 times, it has excellent lighting and heat insulation properties.The surface of this thermoplastic resin foam sheet is transparent and has a wavelength of 330 millimicrons. It is protected by an integrated acrylic resin film layer with a UV transmittance of 10% or less, resulting in improved strength and further improved weather resistance. Also,
In the present invention, the average cell diameter of the thermoplastic resin foam sheet is set to 0.5 mm or more to increase the size of the cells, improve lighting, and make the sheet an inexpensive material, making the overall price economical.

Therefore, the daylight insulation board of the present invention can be practically installed on windows, shoji screens, daylight openings, etc. in place of conventional window glasses and paper shoji screens with poor insulation properties in energy-saving houses or houses in cold regions. It is.

[Brief explanation of the drawing]

FIG. 1 is a partially cutaway sectional view of an example of the light-transmitting heat insulating board of the present invention. 1...Thermoplastic resin foam sheet, 2, 2'...
Adhesive layer, 3, 3'...acrylic resin film layer.

Claims (1)

[Scope of utility model registration request] Average bubble diameter in thickness direction 0.5mm or more, total thickness 2mm
A thermoplastic resin foam sheet with a diameter of 50 mm to 50 mm and a foaming ratio of 3 to 50 times has a light transmittance of 75% or more and a wavelength of 330 through an adhesive layer excluding acrylic and epoxy adhesives on at least one side. A daylight insulation board made of an integral acrylic resin film layer with a millimicron diameter and a transmittance of 10% or less.