JP3140438B1 - Thermal insulation panel and manufacturing method thereof - Google Patents

Abstract

Abstract: PROBLEM TO BE SOLVED: To produce a heat insulation panel having a polyurethane foam layer 1 as a heat insulation layer, and to influence the environment and resources /
While suppressing the consumption of energy as much as possible, the heat insulating property of the polyurethane foam layer 1 is minimized from decreasing over time. SOLUTION: A polyurethane foam layer 1 is formed from a polyurethane foam of carbon dioxide gas foaming, and the entire periphery of the polyurethane foam layer 1 is air-tightly covered with a coating 3 capable of preventing carbon dioxide gas from permeating to form a heat insulating panel. Form.
It is more preferable that the cover 3 is formed of the laminate film 5 in which the inner surface 6 is formed of a film material 4 having good adhesion to polyurethane. In order to form the polyurethane foam layer 1 in the cover 3, it is more preferable to seal the opening of the cover 3 before the polyurethane foam is cured.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a heat insulating panel having a polyurethane foam layer as a heat insulating layer and a method for producing the same.

[0002]

2. Description of the Related Art Some of the above-mentioned conventional heat insulating panels are mainly used for heat insulation of tanks for low-temperature liquefied gas transport ships and tanks for storing low-temperature liquefied gas on land. In these tanks, various types of heat insulating materials and heat insulating methods are used to suppress evaporation of the liquefied gas due to intrusion of heat from the outside, and a type using a polyurethane foam layer as a heat insulating layer is typical. is there. Foaming agents for forming the polyurethane foam layer include mainly CFC-based H
CFC-141b is mainly used.

[0003]

The above-mentioned conventional foaming agent, HCFC-141b, is considered to be a cause of destruction of the ozone layer as a global environmental problem, and will not be used in a few years. For this reason, various alternative foaming agents have been studied, and CFC-based HFC-245fa and HFC-365mfc which do not cause the destruction of the ozone layer, hydrocarbon-based blowing agents, water, and the like are listed as candidates. But,
The HFC-245fa and the HFC-365mfc
Is not a cause of the destruction of the ozone layer, but is subject to regulation as a global warming gas. Incidentally, the H
FC-245fa and HFC-365mfc have an ozone depletion potential of 0, but a warming potential of 820 and 8 respectively.
40. In addition, since the hydrocarbon-based blowing agent generates a flammable gas, there is a restriction that the manufacturing facility must have explosion-proof specifications, and there is a possibility that danger may be involved when manufacturing a polyurethane foam. is there. Further, both of them require factory equipment for supply, and have a problem that resource and energy consumption cannot be ignored.

[0004]

[Means for Solving the Problems]

[Structure] A characteristic structure of the invention according to claim 1 is a heat insulating panel including a polyurethane foam layer as a heat insulating layer, wherein the polyurethane foam layer is formed from a polyurethane foam of carbon dioxide gas foaming, and the permeation of the carbon dioxide gas is performed. And the entire periphery of the polyurethane foam layer is air-tightly covered with a laminate film having a glass fiber layer formed on the inner surface.

[0005] A feature of the invention according to claim 2 is that the outside of the laminate film is covered with a panel exterior material separate from the laminate film.

According to a third aspect of the present invention, there is provided a method of manufacturing a heat insulating panel having a polyurethane foam layer as a heat insulating layer, wherein the polyurethane foam layer is formed from a polyurethane foam of carbon dioxide gas foam, After performing corona discharge machining on the inner surface of the laminate film capable of preventing gas permeation and chemically activating the inner surface of the laminate film, the laminate film is heat-sealed to hermetically seal the entire periphery of the polyurethane foam layer. To cover.

[Action and Effect] According to the invention of claim 1, the polyurethane foam layer is formed from a carbon dioxide gas foamed polyurethane foam,
Since the carbon dioxide gas can be prevented from permeating, and the entire periphery of the polyurethane foam layer is airtightly covered with a laminate film having a glass fiber layer formed on the inner surface, self-adhesion to the inner surface of the laminate film is prevented. Surely
As well as to prevent the thermal insulation properties from deteriorating over time.
it can. In other words, a polyurethane foam foamed with carbon dioxide gas is originally a foam gas that easily escapes, and the heat insulating property tends to decrease over time. , The carbon dioxide gas is not released to the outside. Therefore, even if the carbon dioxide gas leaks out of the polyurethane foam layer, the leaked gas is confined in the space in the laminate film, and the leaked carbon dioxide gas in the leakage space in the laminate film , The leakage of carbon dioxide gas from the polyurethane foam layer can be suppressed. Besides, the glass fiber layer
Is also effective in maintaining the strength of the laminate film.
The glass fiber layer exposed on the inner surface is polyurethane
It also makes the self-adhesion good. Therefore, the glass
Polyurethane foam layer is formed by the presence of fiber layer
Inner surface of the laminated film made of polyurethane
Self-adhesion to the panel and insulation of the insulation panel
The deterioration of the characteristics can be prevented. From this point, the inside of the coating
Measures to increase the partial pressure of carbon dioxide gas in the space
If by Flip, dioxide from the Poriu urethane foam layer
Leakage of carbon gas can be suppressed more reliably.

According to the second aspect of the present invention, in addition to the effect of the first aspect of the invention, the outside of the laminate film can be covered with a panel exterior material separate from the laminate film. because there, insulation construction site
Insulation panels conforming to the requirements can be easily manufactured. That is, the polyurethane foam layer is formed by foaming polyurethane in a laminate film that can be accommodated in the panel exterior material and that can easily form a polyurethane foam layer . Put in
Thus, it becomes possible to form a heat insulating panel. Therefore,
Urethane foam layer can maintain good heat insulation properties
Because it can be formed into a shape,
Satisfactorily can be maintained. In addition, the panel exterior
Material and the polyurethane foam sealed in the coating
If a heat insulating material such as powder is sealed between the layers,
It is effective. Here, the panel exterior material is a heat insulating
Forming the outer surface of the panel and retaining the outer shape of the insulation panel
Surface shape that plays a role in protecting the thermal insulation layer from damage
It refers to the raw material.

According to the third aspect of the present invention, the polyurethane foam layer is formed from a polyurethane foam of carbon dioxide gas foaming, and a corona discharge machining is performed on an inner surface of the laminate film capable of preventing the transmission of the carbon dioxide gas. ,
Wherein after chemically activated inner surface of the laminate film, since the laminated film is thermally welded to cover airtightly entire circumference of the polyurethane foam layer, laminate off
Polyethylene on the inner surface of the film for corona discharge machining
More chemical activation allows urethane and polyethylene
Can further improve the adhesiveness of the
It is possible to manufacture a heat insulating panel in which prevention is ensured.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a heat insulating panel and a method for manufacturing the same according to the present invention will be described below with reference to the drawings. FIG. 1 is a perspective view showing an example of a heat insulating panel according to the present invention, FIG. 2 is a sectional view thereof, FIG. 3 is an enlarged sectional view of a main part thereof, and FIGS. It is explanatory drawing of the manufacturing process of the container which consists of a coating.

As shown in FIG. 1, a heat insulating panel 10 is formed by covering a heat insulating layer with a laminate film 5 to form a flat heat insulator 11 and forming one side of the laminate film 5 on one side. Are sealed by heat fusion. The laminate film 5 is an example of the cover 3 that hermetically covers the heat insulating layer. The laminate film 5 adjusts the outer shape of the heat insulating panel 10 and also functions as a panel exterior material 8 that protects the heat insulating layer. Specifically, as shown in a cross section in FIG. 2, the entire periphery of the polyurethane foam layer 1 forming the heat insulating layer is air-tightly covered with the laminate film 5 as the cover 3 to form a heat insulator 11. The inner surface 6 of the laminate film 5 is adhered to the surface 1a of the polyurethane foam layer 1. For example, as shown in FIG. 3 in an enlarged manner, the laminated film 5 is formed of an outer coating 5 a, an aluminum deposition film 5 b, a gas permeation preventing film 5 c, and a heat as a film material 4 for forming the inner surface 6 of the coating 3. It can be composed of the fusion film 5d.

The polyurethane foam layer 1 is foamed with carbon dioxide gas, and polyurethane is foamed inside a bag formed of the laminate film 5 to form a polyurethane foam. It is self-adhered to the inner surface 6 of the film 5.
In the laminated film 5 shown in FIG. 3, the outer coating 5a is formed of, for example, a polyester film on which the aluminum vapor-deposited film 5b is formed, and the gas permeation preventing film 5c is formed of a polyethylene-polyvinyl alcohol copolymer. The heat sealing film 5d is formed of a polyethylene film 9, and the gas permeation preventing film 5c and the heat sealing film 5d are sequentially arranged inside the outer coating 5a and adhered to each other. If formed, the outer coating 5a protects the inside, the heat-sealing film 5d maintains the self-adhesion of the polyurethane foam layer 1 satisfactorily, and the gas permeation preventing film 5c forms a heat insulating panel 10 for heat insulation. The deterioration of the characteristics is prevented. The polyethylene film 9 as the heat-sealing film 5d is also a film material 4 having good adhesiveness to the polyurethane, and the coating material 3 as a film material 4 capable of maintaining good self-adhesion of the polyurethane foam layer 1. Even if the carbon dioxide gas leaking from the polyurethane foam layer 1 through the film made of the polyethylene-polyvinyl alcohol copolymer forming the inner surface 6 of the This prevents the permeated carbon dioxide gas from permeating to the outer coating 5a side, thereby preventing the carbon dioxide gas from being diffused and released from the heat insulator 11. This heat insulator 11 is used as the heat insulation panel 10.

An example of a process for manufacturing the above-described heat insulating panel 10 will be described. [1] As shown in FIG. 4, the inner surface 6 is formed of a film material 4 made of a polyethylene film 9 having good adhesion to polyurethane. One end of the cylindrical laminated film 5 (see FIG. 1A) is heat-fused to form a bag-shaped or box-shaped container 2 (see FIG. 2B). [2] Then, as shown in FIG. 5, water is added to one of two polyurethane foaming liquid solutions, which are water-foamable, in the container 2, and both are poured together (see FIG. 5A). The one polyurethane stock solution does not react with water and reacts with the other polyurethane stock solution to produce polyurethane, and the other polyurethane stock solution reacts with water to produce carbon dioxide gas. It is. Therefore, when the two polyurethane undiluted solutions are injected into the container 2, the polyurethane reacts to generate polyurethane and contains bubbles formed by the carbon dioxide gas. [3] Here, the air in the container 2 is eliminated (see FIG. 2B), and the opening 2a of the container 2 is sealed by heat sealing to seal the polyurethane foam in the container 2. (See FIG. 3C). [4] When the hermetically sealed polyurethane foam is cured in the container 2, the hermetically sealed polyurethane foam hardens with time to become the polyurethane foam layer 1 and form the heat insulator 11.

If the inner surface 6 of the laminate film 5 is subjected to corona discharge machining in advance, the inner surface 6 of the polyethylene film 9 can be chemically activated. 1
When forming the above, the surface 1a of the polyurethane foam layer 1 can be favorably self-adhered to the inner surface 6 of the container 2.

[Other Embodiments] Embodiments of the present invention other than those described in the above embodiment will be described below.

<1> In the above-described embodiment, an example in which the panel exterior material 8 is constituted by the cover 3 has been described. However, as conceptually shown in FIG. Panel exterior material 8 forming the outer skin of heat insulation panel 10
May cover the outside of the cover 3. For example, as shown in FIG. 7, the polyurethane foam layer 1 covered with the cover 3 is used as a heat insulating layer inside a panel exterior material 8 that prepares the outer shape of the heat insulating panel 10 and protects the heat insulating layer. The heat insulating panel 10 may be formed by being inserted in a state where the powder heat insulating material 12 is interposed therebetween. That is, the container 2 formed by the cover 3 is formed smaller than the panel exterior material 8, and the polyurethane foam layer 1 is generated in the container 2 to form the heat insulator 11 covered by the cover 3. After the formation, the heat insulator 11 is inserted into the panel exterior material 8, and the heat insulator 11 and the panel exterior material 8 are inserted.
Another heat insulating material may be filled in between. Note that the outer surface of the cover 3 may be bonded to the inner surface of the one panel exterior material 8 in the thickness direction of the heat insulating panel 10, or the one cover 3 in the thickness direction may be attached to the panel exterior material. It may be 8 as well.

<2> In the above-described embodiment, an example in which the panel exterior material 8 is constituted by the cover 3 has been described. However, the panel exterior material 8 separate from the cover 3 is provided in advance by the cover 3, a container 2 in which the cover 3 and the panel exterior material 8 are integrated is formed, and the polyurethane foam layer 1 is formed in the container 2 to form the cover 3 and Thermal insulation 1 covered with panel exterior material 8
1 may be formed as a heat insulating panel 10.

<3> In the above embodiment, an example in which the inner surface 6 of the cover 3 made of the laminate film 5 is adhered to the surface 1a of the polyurethane foam layer 1 has been described. The cover 3 may be merely adhered to the surface 1a. For example, as described in the above <1>, the heat insulating material 11 is covered with the panel exterior material 8 from outside the cover 3, and the heat insulating material 12 is press-fitted between the panel exterior material 8 and the heat insulator 11. Then, the coating 3 may be brought into close contact with the surface 1 a of the polyurethane foam layer 1. When the coating 3 is brought into close contact with the surface 1a of the polyurethane foam layer 1 as described above, the carbon dioxide gas diffused and leaking from the inside of the polyurethane foam layer 1 is introduced into the openings of the bubbles exposed on the surface 1a. Because of the confinement, the partial pressure of the carbon dioxide gas sharply rises in the opening, thereby preventing the carbon dioxide gas from diffusing and leaking from the inside.
Incidentally, instead of forming the inner surface 6 of the cover 3 from a material to which polyurethane easily adheres, an adhesive capable of easily adhering the polyurethane may be arranged on the inner surface 6.

<4> In the above embodiment, the laminate film 5 is used as the outer coating 5 a, the aluminum deposition film 5 b, the gas permeation prevention film 5 c, and the film material 4 forming the inner surface 6 of the coating 3. An example in which the heat sealing film 5d and the inner surface 6 of the laminate film 5 are used has been described.
May be formed by the glass fiber layer 7. For example, the glass fiber layer 7 formed by impregnating a glass fiber with a heat-fusible polymer such as polyethylene may be used as the heat sealing film 5d. The glass fiber layer 7 formed in this way is effective for maintaining the strength of the coating 3, and the glass fiber exposed on the inner surface also improves the self-adhesion of polyurethane. Therefore, if such a glass fiber layer 7 is disposed on the inner surface 6 and corona discharge machining is performed on the inner surface 6 as described in the above embodiment, the glass fibers are further exposed on the inner surface 6. The self-adhesion of the polyurethane can be further enhanced.

<5> In the above-described embodiment, the inner surface 6 is formed of the film material 4 made of the polyethylene film 9 as the cover 3, and one end side as a peripheral portion of the cylindrical laminated film 5 is formed. Is sealed by heat sealing to form a container 2, the polyurethane foam layer 1 is formed in the container 2, and the opening 2a at the other end is sealed by heat sealing. The sealing of the opening 2a is not limited to the thermal fusion, but may be sealed by other means. For example, an adhesive or a pressure-sensitive adhesive may be applied to and adhered to the inner surface of the film material 4, or a solvent capable of dissolving the inner surface of the film material 4 may be applied to the inner surface and brought into close contact with each other to be welded. Good. Further, a sealing means such as a tape-shaped or film-shaped adhesive sheet or an adhesive sheet capable of sealing the peripheral portion or the opening 2a with another material is formed, and the peripheral portion or the opening is formed by the sealing means. The opening 2a may be sealed.

<6> In the above embodiment, an example was described in which the laminated film 5 was used as the covering 3. However, the covering 3 may be air-tight.
As shown in FIG. 8, the cover 3 may be formed of another material. That is, the container 2 may be formed in a box body with a lid that can be opened and closed, the urethane foam stock solution may be injected through the opening 2a, the lid may be closed and sealed, and the heat insulating panel 10 may be formed. . This box is covered with the cover 3
When the polyurethane foam is cured, the heat insulating panel 1 having a well-shaped shape can be used.
0 can be formed. Therefore, the cover 3 may be a metal can or a metal container which can block the permeation of carbon dioxide gas and can form an airtight container 2 and which can hermetically seal the opening. It may be a plastic can or a plastic container, or may be a metal can with an inner surface covered with plastic and the opening can be hermetically sealed. In addition, it is preferable that the inner surface 6 of the cover 3 is made of a material to which polyurethane is easily adhered, and it is more preferable that the inner surface 6 is made of a material to which the polyurethane is easily self-adhered.

<7> In the above embodiment, as an example of the laminated film 5, the outer film 5a is formed of a polyester film having an aluminum vapor-deposited film 5b formed inside, and the gas permeation preventing film 5c is formed of polyethylene-polyvinyl alcohol. The heat-sealing film 5d is formed of a polymer, the heat-sealing film 5d is formed of a polyethylene film 9, and the gas permeation preventing film 5c and the heat-sealing film 5d are sequentially arranged inside the outer film 5a and adhered to each other. Although the formed one has been described, the materials of the outer coating 5a, the gas permeation preventing film 5c, and the heat fusion film 5d are arbitrary. Incidentally, when the gas permeation preventing film 5c is formed of the polyethylene-polyvinyl alcohol copolymer, if the polyethylene-polyvinyl alcohol copolymer absorbs moisture, the gas permeation preventing ability is reduced. 5b is disposed outside the polyethylene-polyvinyl alcohol copolymer as a water vapor permeation blocking film,
This also functions as a heat ray reflective film. here,
If the outer coating 5a can be provided with a function of preventing water vapor permeation, or if the gas permeation preventing film 5c does not decrease in gas permeation function even by moisture absorption, the aluminum vapor-deposited film 5b is omitted. There may be. For example, when the heat insulator 11 in which the polyurethane foam layer 1 is air-tightly covered with the coating 3 is covered with the panel exterior material 8 and the panel exterior material 8 is provided with a means for reflecting radiant heat, This is because there is a case where it is not necessary to provide the same means in the cover 3. For example, as described with reference to FIG. 7 in <1> above, when the space between the heat insulator 11 and the panel outer material 8 is filled with another heat insulator 12, the panel outer material 8 and the heat What is necessary is just to interpose a heat ray reflector instead of the aluminum vapor-deposited film 5b between the body 3 and the cover 3.

<8> In the above embodiment, as an example of a manufacturing process, referring to FIG. 4, one end of a cylindrical laminated film 5 is heat-sealed to form a container 2. Water is added to one of two water-foamable polyurethane stock solutions, and both are injected together to form a polyurethane foam, and after the air in the vessel 2 is eliminated, the container 2 An example in which the opening 2a is heat-sealed and sealed, the polyurethane foam is sealed in the container 2, and then the polyurethane foam is cured to form the polyurethane foam layer 1 has been described. Container 2
After the polyurethane is foamed and cured in the inside to form a polyurethane foam layer 1 and the air in the container 2 is eliminated, the opening 2a of the container 2 is sealed by heat fusion. Good. Even in such a process, the polyurethane foam layer 1 is self-adhered to at least the inner surface 6 other than the opening 2a. Therefore, the inner surface 6 of the opening 2a that slightly remains may be bonded to the surface 1a of the polyurethane foam layer 1 using an adhesive or the like. It is preferable that this bonding be performed as soon as possible immediately after the formation of the polyurethane foam layer 1.

<9> Instead of the above <8>, after injecting the water-foamable polyurethane stock solution and water into the container 2, the opening 2a of the container 2 is immediately sealed by heat fusion. Then, the polyurethane may be foamed and cured in the sealed container 2 to form the polyurethane foam layer 1 in the container 2. In this case, the foaming is continued even after the opening 2a is sealed, and the surface of the polyurethane foam is brought into close contact with the inner surface 6 of the container 2 by the internal pressure of the bubbles of the polyurethane foam. If the inner surface 6 of the polyurethane foam layer 1 is formed of a material having good self-adhesiveness, the surface 1a of the polyurethane foam layer 1 to be formed is securely adhered to the inner surface 6 of the cover 3, and the inner surface 6 is formed of polyurethane. Even when a material that is difficult to adhere to itself is used, the inner surface 6 of the cover 3 is in close contact with the surface 1 a of the polyurethane foam layer 1, so that the carbon dioxide gas diffuses and leaks from inside the polyurethane foam layer 1. Can be prevented.

<10> In the above embodiment, a polyurethane foam consisting of two water-foamable liquids is injected into the container 2 to form a polyurethane foam, and after the air in the container 2 is eliminated, the container 2 Although it has been described that the opening 2a of the second container 2 is sealed by heat-sealing, if air does not remain in the container 2 or remains only to the extent that it does not need to be removed, the above <9> As described above, after injecting the undiluted polyurethane solution into the container 2, the opening 2a of the container 2 may be sealed without removing the air in the container 2. The shape of the container 2 may be a bag-shaped cover 3 or a box-shaped cover 3, and the shape is arbitrary. Further, the container 2 may form the panel exterior material 8 or may be an outer skin for forming the heat insulator 11. Therefore,
The thickness of the coating 3 is arbitrary, and may be sufficient to provide shape retention.

<11> In the above embodiment, the example in which the urethane foam is formed in the cover 3 has been described. However, after the urethane foam is formed in another container, the urethane foam is formed in the cover 3. It may be enclosed in a box. Also in this case, it is preferable that the coating 3 is bonded to the surface 1a of the polyurethane foam layer 1, and it is preferable that the bonding be performed as soon as possible.

[0027]

[Examples] With respect to an example of the heat insulating panel described in the above embodiment, a change with time of heat insulating characteristics was examined. A laminated film was used as a container in the examples, that is, as a coating. The configuration of the laminated film used is as follows.

[0028]

[Table 1]

In the embodiment, two laminated films are used, the surfaces on the heat-sealing film side are overlapped, and heat-sealed along both sides in the width direction and one side in the length direction to form a bag. A container was formed. About 60 g of a water-foamed polyurethane stock solution was poured into this container, and foamed in the container. Immediately after the completion of the foaming, the opening of the container was heat-sealed so that no gap was formed between the container and the polyurethane foam, sealed and cured to form a heat insulator. That is, the polyurethane foam was also self-adhered to the sealed opening. The dimensions of the formed foam were about 230 mm in length and width and 25 mm in thickness. As a comparative example, a heat insulator made of a bare urethane foam, in which the same water-foamed urethane stock solution was foamed and cured in a mold having a length and width of about 200 mm and a depth of 25 mm, was prepared.

The change with time of the thermal conductivity of both was measured according to JIS A
1412 (1994). The measurement of the thermal conductivity was performed at a measurement temperature of 23 ° C. The measured thermal conductivity was as shown in Table 2.

[0031]

[Table 2]

As is clear from Table 2, the thermal conductivity in the comparative example increased by about 5% in one week, increased by about 9% in 2 weeks, increased by about 24% in 5 weeks, and increased in about 7 weeks. 30%
Although it shows a tendency to increase and gradually saturate, it increases by about 35% by 9 weeks. On the other hand, the thermal conductivity of the heat insulator according to the present invention was 9 days after the heat insulator was formed.
Stable without change over the week. In the heat insulator according to the present invention, the increase in the thermal conductivity is at most 0.8%.
It was only.

From the above results, if the coating is adhered to the polyurethane foam made of water-foamed urethane and the coating is provided with a carbon dioxide gas permeation inhibiting ability, the heat insulating property can be maintained stably for a long period of time. I can do it.

[Brief description of the drawings]

FIG. 1 is a perspective view showing an example of a heat insulating panel according to the present invention.

FIG. 2 is a longitudinal sectional view of the heat insulating panel shown in FIG.

FIG. 3 is a partially enlarged view of FIG. 2;

FIG. 4 is a perspective view illustrating a manufacturing process of the heat insulating panel according to the present invention.

FIG. 5 is a perspective view illustrating a manufacturing process of the heat insulating panel according to the present invention.

FIG. 6 is a perspective view showing another example of the heat insulating panel according to the present invention.

FIG. 7 is a sectional view of the heat insulating panel shown in FIG. 6;

FIG. 8 is a perspective view illustrating another example of the manufacturing process of the heat insulating panel according to the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Polyurethane foam layer 1a Surface of polyurethane foam layer 2 Container 2a Container opening 3 Coating material 4 Membrane material 5 Laminate film 6 Inner surface 7 Glass fiber layer 8 Panel exterior material 9 Polyethylene film

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) F16L 59/02

Claims (3)

(57) [Claims] 1. A heat insulating panel comprising a polyurethane foam layer as a heat insulating layer, wherein the polyurethane foam layer is formed from a polyurethane foam of carbon dioxide gas foam, and is capable of preventing the transmission of the carbon dioxide gas, and has an inner surface. A heat insulating panel, wherein the entire periphery of the polyurethane foam layer is airtightly covered with a laminate film having a glass fiber layer formed thereon. 2. The heat insulating panel according to claim 1, wherein the outside of the laminate film is covered with a panel exterior material separate from the laminate film. 3. A method for manufacturing a heat insulating panel comprising a polyurethane foam layer as a heat insulating layer, wherein the polyurethane foam layer is formed from a polyurethane foam of carbon dioxide gas foam, and the laminate is capable of preventing the transmission of the carbon dioxide gas. A method of manufacturing a heat insulating panel, wherein a corona discharge machining is performed on an inner surface of a film to chemically activate the inner surface of the laminate film, and then the laminate film is thermally welded to hermetically cover the entire periphery of the polyurethane foam layer.