JP2009269329A - Foamed plastic base heat insulating material - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide foamed plastic base heat insulating material, which shows performance excellent in heat insulating performance, fire retardant properties and shielding performance against humidity. <P>SOLUTION: In this foamed plastic base heat insulating material, a heat insulating barrier made of heat barring paint is provided on the surface of a plastic base foam. In order to manufacture this foamed plastic base heat insulating material, a foamable resin molding material is discharged on a sheet. Then, the molding material is foamed so as to obtain a plastic base foam with a sheet-like material at least on one side under the condition that the heat insulating barrier has been formed with the heat barring paint in advance on the sheet-like material. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

The present invention relates to a foamed plastic heat insulating material having excellent heat insulating performance and effective for mechanical strength, flame retardancy, and moisture permeability resistance.

Patent Document 1 proposes a heat insulating phenol resin foam laminate in which a face material made of a synthetic fiber nonwoven fabric is bonded to at least one surface of a phenol resin foam without an adhesive layer.

The phenol resin-based heat insulating material has the lowest thermal conductivity among plastic foams, has excellent heat insulating performance, and is excellent in mechanical strength such as compressive strength. The field in which this is actually used is also diverse for housing, vehicles, and industrial applications, and is suitable as a heat insulating material inside and outside the house because of its high heat insulating performance and flame resistance.
Japanese Patent No. 3523196

Although the foam has a low thermal conductivity, it exhibits an excellent effect of heat insulation against heat conduction, but it cannot be said to exhibit a sufficient heat shielding effect against radiant heat transfer by solar rays or infrared heaters.

In addition, although this has a lower moisture permeability coefficient than other foams, it does not have a complete shielding effect against humidity, but slightly absorbs moisture in the air, which lowers the heat insulation performance.

This invention makes it a subject to provide the foamed plastic-type heat insulating material which exhibits the performance excellent in the heat insulation performance, a flame retardance, and the shielding performance with respect to humidity in view of the said situation.

The present invention provides a foamed plastic-based heat insulating material having a heat insulating layer of a heat-shielding paint having a very high heat reflectivity on at least one side. With this heat insulating layer, the shielding effect and moisture can be completely blocked, and high heat insulating performance can be maintained.

The invention according to claim 1 is a foamed plastic-based heat insulating material characterized in that a heat-insulating layer formed of a thermal barrier coating is provided on the surface of a sheet-like material laminated on at least one side of the plastic-based foam. .

The invention according to claim 2 discharges a foamable resin molding material to a sheet-like material and then foams the molding material to obtain a plastic foam having a sheet-like material laminated on at least one side. A method for producing a foamed plastic-based heat insulating material, characterized in that a heat insulating layer is formed with a thermal barrier paint on a sheet.

The invention according to claim 3 is a method for discharging a foamable resin molding material onto a sheet-like material and then foaming the molding material to obtain a plastic foam having a sheet-like material laminated on at least one side. A method for producing a foamed plastic heat insulating material, wherein a heat insulating layer is formed on the surface of the sheet-like material with a thermal barrier paint after foaming.

The invention according to claim 4 is characterized in that the plastic foam is a phenol foam, or the foamed plastic heat insulating material according to claim 1 or the foamed plastic heat insulating material according to claim 2 or 3. Is the method.

The invention according to claim 5 is characterized in that the thermal barrier coating is a coating containing amorphous silica fine particles, or the foamed plastic thermal insulation according to claim 1 or the foamed plastic thermal insulation according to claim 2 or 3. It is a manufacturing method of material.

Examples of the synthetic resin of the plastic foam that is the main component of the foamed plastic heat insulating material according to the present invention include, for example, phenol resins, melamine resins, isocyanurates, urea resins, polyurethanes, thermosetting resins such as thermosetting polyimides, polyethylene, etc. And thermosetting resins such as polypropylene, ethylene / vinyl acetate copolymer, polyvinyl chloride, polystyrene, and acrylic resin. Of these resins, a foam made of a phenol resin having excellent heat insulation performance is preferable. However, other resin foams may be used as appropriate depending on the application.

The thermal barrier coating mainly comprises a thermal barrier and a synthetic resin or water-based emulsion resin as a binder for binding the thermal barrier. Examples of the heat shielding material include titanium dioxide powder, silica powder, aluminum sodium silicate powder, alumina silicate powder, and clay silicate powder. Among them, silica powder, particularly amorphous silica fine particles are preferably used. The synthetic resin as the binder may be, for example, an alkyd resin, amino alkyd resin, acrylic resin, phenol resin, urea resin, melamine resin, epoxy resin, polyurethane, polyvinyl chloride, polyvinyl acetate, and the like. Of these, acrylic resins are preferred. Examples of the aqueous emulsion resin include silicon acrylic emulsion, acrylic emulsion, urethane emulsion, urethane acrylic emulsion, and the like. Of these, silicone acrylic emulsion is preferred.

In the invention of the manufacturing method of claims 2 to 5, a foamable resin molding material is kneaded in advance. Although the kneading method varies depending on the foam resin, an extruder is usually used when the base resin is a thermoplastic resin. However, roll kneading, a mixer, etc. may be used. Specifically, a chemical foaming agent that decomposes and foams when heated and a thermoplastic resin are kneaded, or a physical foaming agent (for example, carbon dioxide or nitrogen) is injected into the thermoplastic resin in an extruder under high pressure. There is a method of kneading the resin. The kneaded material thus obtained is then extruded onto a sheet-like material that retains its shape and fired. When the resin used as the base material is a thermosetting resin, the resin, the foaming agent, and the curing agent are stirred with a mixer. The obtained mixture is then discharged onto a sheet-like material that retains its shape, and foamed and cured.

Examples of the sheet-like material include glass cloth, cold chill, woven or non-woven fabric, and paper. The glass cloth includes a glass mat obtained by weaving as well as a glass fiber woven material. Moreover, the cold chill and the nonwoven fabric are mainly composed of synthetic fibers such as polyester and nylon. The woven fabric may be made of general natural fibers or synthetic fibers. The glass cloth obtained by papermaking may contain a binder for binding short glass fibers. Examples of the binder include thermoplastic resins such as polyvinyl alcohol, saturated polyester, and acrylic resin, and thermosetting resins such as epoxy resin and unsaturated polyester. Examples of the organic fiber constituting the woven fabric and the nonwoven fabric include polyester fiber, cotton, acrylic fiber, nylon fiber, carbon fiber, and aramid fiber.

In the step of forming a heat insulating layer with a thermal barrier coating on the surface of the sheet-like material, the application method of the paint is preferably brush coating, spray coating, roll coater coating, but depending on the type of the sheet-like material, electrostatic coating, Curtain coating, dipping method, etc. are also applicable. Furthermore, as a method for drying / coating after coating, methods such as natural drying and baking can be used, and the method is appropriately selected depending on the properties of the paint.

  100-1000 micrometers is preferable and, as for the thickness of the heat insulation layer formed, 200-600 micrometers is more preferable. If it is less than 100 μm, the heat insulating layer is thin, so that the concealability is inferior and the heat shielding properties tend to be lowered. If it exceeds 600 μm, the concealing property and the heat shielding property are good, but the followability to the base material tends to decrease.

According to the present invention, by forming a heat insulating layer with a heat insulating paint on a sheet-like material on the surface of a plastic foam having high heat insulating properties, high heat insulating performance can be imparted to the foam. In particular, by using a resin foam with excellent heat insulation performance, such as phenol resin foam, and using a paint containing amorphous silica fine particles as the thermal insulation paint, it is a foamed plastic insulation that has outstanding thermal insulation performance. A material can be obtained. Further, since the heat insulating layer is dense and has a high barrier property against water vapor and the like, no condensation occurs inside the foam. Further, the heat insulating layer is difficult to burn, and its performance can be exhibited particularly by being laminated on the phenol foam.

The sheet-like material for forming a heat insulation layer with a thermal barrier paint has excellent shape followability, and can be coated on the surface of a pipe-shaped foam or coated on the surface of an uneven foam. Can be used for industrial purposes.

As described above, according to the present invention, it is possible to provide a foamed plastic heat insulating material that exhibits excellent heat insulating performance, flame retardancy, and shielding performance against humidity.

  Next, in order to specifically explain the present invention, some examples of the present invention and comparative examples for showing comparison with the examples will be given.

Example 1
Create foam:
To 100 parts by mass of a resol type phenolic resin (“PF-330” manufactured by Asahi Organic Materials Co., Ltd.) obtained by reacting phenol and formaldehyde at a molar ratio of 1: 2, castor oil ethylene oxide (22 mol) as a foam stabilizer ) 3 parts by weight of the adduct was added and mixed.

8 parts by mass of 1,1,1,3,3-pentafluorobutane (manufactured by Solvay Co., Ltd., “HFC-365mfc”) adjusted to 0 ° C. as a blowing agent, paratoluene sulfone adjusted to 0 ° C. as a curing agent A foamable phenolic resin molding material was prepared by adding 15 parts by mass of a mixture of acid: xylenesulfonic acid mass ratio = 2: 1.

Subsequently, this molding material is supplied to a mixer, stirred and mixed at a rotational speed of 2,000 rpm, discharged into a formwork laid with a PET non-woven fabric (40 g basis weight), placed in a dryer at 80 ° C., and foamed for 15 minutes. And molded into a 50 mm thick phenolic resin foam.

When the thermal conductivity of the nonwoven fabric-attached foam was measured using a thermal conductivity measuring device (“HC-074 314” manufactured by Eihiro Seiki Co., Ltd.), the initial thermal conductivity was 0.0187 Kw / h.

The phenolic resin foam PET nonwoven fabric was thinly coated with a thermal barrier paint (Aqua Dannets, “Ceramic Cover CC100”) to form the first layer (thickness 0.1 to 0.2 mm). . After drying for about 3 hours, a second layer was formed thereon. Finally, a foamed plastic heat insulating material having a heat insulating layer of 0.5 mm thick thermal barrier paint was prepared.

Performance test The performance test of the following item was done about the obtained foamed plastic-type heat insulating material.

a) Thermal insulation performance The thermal insulation material was cut into 600 mm square, and the obtained test piece was set in the center of the gear oven so that the interior of the oven was completely partitioned into an upper compartment and a lower compartment by the test piece. Three 1 Kw rod-shaped far-infrared heaters were arranged on the inner surface of the top of the oven so that far-infrared rays were uniformly irradiated to the test piece. The distance between the test piece and the heater was set to about 300 mm, and the heater surface was set to 250 ° C. In addition, the side inner surface and the lower inner surface were covered with a heat insulating material so that heat was not transmitted from the frame or the like in the oven. As the heat shielding effect, the ambient temperature of the upper compartment and the lower compartment was measured. As a result, the former ambient temperature was 65 ° C., while the latter temperature was 25 ° C. Moreover, after spraying the surface of the test piece for 30 seconds with a burner from one side, the state of the test piece was confirmed. As a result, only the inside of the heat insulating layer was changed to black, and there was no ignition.

b) Moisture-proof performance room A: In a room of 1000 mm × 1000 mm × 1000 mm capable of temperature adjustment and humidity adjustment, the room temperature was set to 25 ° C. and the relative humidity was set to 50%.

Room B: A room of 1000 mm × 1000 mm × 1000 mm capable of temperature adjustment and humidity adjustment. The room temperature was set to 10 ° C. and the relative humidity was set to 50%.

Room A and room B were partitioned with foamed plastic insulation (35 mm x 1000 mm x 1000 mm).

After leaving in this state for 72 hours, this heat insulating material was taken out and the thermal conductivity was measured. As a result, it was 0.0189 Kw / h, and no difference from the previously obtained initial thermal conductivity was found.

Example 2
In advance, a sheet-shaped PET non-woven fabric was coated with a coating containing amorphous silica fine particles to form a heat insulating layer. This was used as a lower surface material, and the same foamable phenolic resin molding material as in Example 1 was discharged onto this and foamed and cured by heating to produce a foamed plastic heat insulating material.

When the heat insulating performance was evaluated in the same manner as in Example 1, the heat insulating effect was recognized as in Example 1. Moreover, when the ignition test by a burner was done like Example 1, ignition was not recognized.

Comparative Example 1
A foam was obtained by performing the same operation as in Example 2 except that a PET nonwoven fabric to which a coating containing amorphous silica fine particles was not applied was used.

When the heat insulation performance was evaluated in the same manner as in Example 1, the atmosphere temperature in the upper compartment was 60 ° C., and the temperature in the lower compartment was 30 ° C. Moreover, when the ignition test by a burner was done like Example 1, a fire broke out in the PET nonwoven fabric. However, the fire quickly disappeared and the foam was black carbonized. When the moisture-proof performance was measured in the same manner as in Example 1, the thermal conductivity was 0.0195 KW / h, which was higher than the initial thermal conductivity obtained previously.

Claims (5)

A foamed plastic heat insulating material characterized in that a heat insulating layer formed of a thermal barrier coating is provided on the surface of a sheet-like material laminated on at least one surface of a plastic foam. In order to obtain a plastic foam in which a sheet-like material is laminated on at least one surface by discharging a foamable resin molding material onto a sheet-like material and then foaming the molding material, the sheet-like material is previously coated with a heat-shielding paint. A method for producing a foamed plastic heat insulating material, wherein a heat insulating layer is formed. When a foamable resin molding material is discharged onto a sheet-like material, and then the molding material is foamed to obtain a plastic foam in which the sheet-like material is laminated on at least one side, the surface of the sheet-like material after foaming of the molding material A method for producing a foamed plastic heat insulating material, characterized in that a heat insulating layer is formed with a thermal barrier paint. 4. The method for producing a foamed plastic heat insulating material according to claim 1 or claim 3, wherein the plastic foam is a phenolic foam. 4. The method for producing a foamed plastic heat insulating material according to claim 1, or the method for producing a foamed plastic heat insulating material according to claim 2, wherein the thermal barrier paint is a paint containing amorphous silica fine particles.