JP2720921B2 - Manufacturing method of heat insulator - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heat insulator used for refrigerators, freezers and the like.

[0002]

2. Description of the Related Art In recent years, attention has been paid to using a heat insulator by reducing the pressure inside as proposed in Japanese Patent Application No. 60-288668 for the purpose of improving the heat insulating performance of a heat insulating box. I have. The configuration of Japanese Patent Application No. 60-288668 will be described below with reference to FIG. 1 is a heat insulator,
Reference numeral 2 denotes a rigid urethane foam panel having an open-cell structure, which is covered with a container 3 made of a metal-plastic laminated film formed by laminating an aluminum-evaporated polyester film and a polyethylene film, and hermetically sealed by reducing the pressure inside.

[0003] In the production of the rigid urethane foam panel 2 having an open-cell structure, a mixed material comprising an organic polyisocyanate, a polyol, a catalyst, a foam stabilizer, a foaming agent, and a cell-communicating agent is mixed with a plastic film having releasability. Is characterized by using a foam obtained by foaming and curing in a jig provided with, and then cutting and removing a skin portion having a low open cell ratio.

[0004]

However, in the above-described structure, a large amount of foam waste is generated due to the necessity of removing the skin part in the production of the rigid urethane foam panel 2, and not only productivity and processing cost but also waste It was also an environmental problem, such as a processing problem.

The present invention provides a method for producing a rigid urethane foam panel having the above-mentioned open-cell structure, in which the open-cell ratio of the skin portion is increased, cutting is not required, and no waste foam is generated.

[0006]

In order to solve the above-mentioned problems, the present invention provides a jig having air permeability, mounting a surface material such as paper or nonwoven fabric having air permeability, and placing organic polyisocyanate, polyol, A rigid urethane foam panel having an open-cell structure obtained by injecting and foaming a mixed raw material comprising a catalyst, a foam stabilizer, a foaming agent, and a cell-communicating agent is used as a core material, and this is a container made of a metal-plastic laminate film. It is manufactured by covering the inside, decompressing the inside and sealing the inside.

[0007]

According to the above-mentioned structure, in the mixed raw material injected into the jig, the bubble film is broken by the bubble communicating agent in the foaming process to be communicated, but the face material in contact with the outer skin portion is made of paper or nonwoven fabric. In addition, since the jig also has air permeability, the internal gas in the foam can be transmitted without great resistance, thereby achieving communication. Therefore, the open cell rate of the skin portion can also be secured to 100%, and this is covered with a container made of a metal-plastic laminated film as a core material,
Even if the inside is reduced in pressure and sealed, there is no closed cell portion, so that the internal pressure does not increase for a long time, and the desired heat insulating performance can be maintained.

As a result, a large amount of foam waste material is not generated, and a heat insulator can be manufactured and provided which has no problem not only in productivity and processing cost but also in environment such as waste treatment.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to FIGS. The same components as those in the related art are denoted by the same reference numerals, and description thereof is omitted.

In the figure, 4 is

[0011]

[Table 1]

This is a rigid urethane foam block which is injected into an open panel jig 5 by a urethane foaming machine using the raw materials and the number of compounding parts shown in FIG.

In the table, the polyol is a polyether polyol having a hydroxyl value of 440 mgKOH / g obtained by subjecting propylene oxide to addition polymerization using an aromatic diamine as an initiator. The foam stabilizer is silicone surfactant F337 manufactured by Shin-Etsu Chemical Co., Ltd., and the foaming agent is Freon R manufactured by Showa Denko KK
It is 11. The catalyst is dimethylethanolamine, and the bubble communication agent is calcium stearate manufactured by NOF Corporation. The organic polyisocyanate is a polyisocyanate having an amine equivalent of 150 obtained by reacting toluylene diisocyanate with trimethylpropane and diethylene glycol.

In foaming the rigid urethane foam block 4, air-permeable paper or non-woven fabric is placed as a face material 6 in an open panel jig 5 and injection is performed. The open panel jig 5 is also made of a ceramic foam or the like. It is made of a material having air permeability.

After that, the rigid urethane foam block 4
Was cut to an arbitrary size to prepare a rigid urethane foam panel 7 using the foam of the central part and the surface part. As a comparative example, bakelite was used as the material of the open panel jig 5, and similarly, air-permeable paper or nonwoven fabric was placed thereon, and injection was performed. It was created. Each open cell rate

[0016]

[Table 2]

[0017] Then, each is heated at 120 ° C. for 2 hours to evaporate the adsorbed moisture and the like, and is enveloped in a container 3 made of a metal-plastic laminated film formed by laminating an aluminum-evaporated polyester film and a polyethylene film. Thus, a heat insulator 8 was obtained. The thermal conductivity of the initial value immediately after sealing of the obtained heat insulator 8 and the thermal conductivity after 30 days are also shown. The thermal conductivity was measured at an average temperature of 24 ° C. using K-MATIC manufactured by Vacuum Riko Co., Ltd.

As is clear from Table 2, injection and foaming are performed by using an open panel jig 5 made of a material having air permeability and a face material 6 made of paper or nonwoven fabric having air permeability. The obtained rigid urethane foam panel 7 has completely open cells with an open cell ratio of 100% even at the surface portion, and the gas diffuses from the closed cells with time to increase the internal pressure, thereby increasing the thermal conductivity. There is no deterioration. On the other hand, bakelite is used as the material of the open panel jig 5,
Similarly, in the case where the injection is carried out by placing air-permeable paper or non-woven fabric, etc., in the rigid urethane foam panel 7 using the foam of the surface part, since the closed cells partially remain, particularly the closed cells are gradually removed. From this, it was found that the gas diffused to increase the internal pressure and deteriorate the thermal conductivity.

In the mixed raw material injected into the jig, the bubble film is destabilized by the bubble communicating agent during the foaming process, and the internal gas whose pressure is increased by the reaction heat acts as a driving force to break the bubble film. Since the face material 6 in contact with the outer surface of the foam is also made of paper or nonwoven fabric, and the jig 5 also has air permeability, as in the present invention, It is considered that communication can be achieved because transmission is possible without large resistance.

The heat insulating performance of the heat insulator 8 obtained by the above manufacturing method does not deteriorate over a long period of time.
It contributes to quality assurance. In addition, since there is no need to remove the skin part in the production of the rigid urethane foam panel 7, a large amount of foam waste is not generated,
It is possible to contribute not only to productivity and processing cost but also to environment such as waste problem.

[0021]

As described above, according to the present invention, a surface material such as paper or nonwoven fabric having air permeability is placed on a jig having air permeability,
Organic polyisocyanate, polyol, catalyst,
A rigid urethane foam having an open-cell structure obtained by injecting and foaming a mixed raw material comprising a foam stabilizer, a foaming agent, and a cell communicating agent is used as a core agent, and the core agent is covered with a container made of a metal-plastic limiting film. Since the heat insulating body is manufactured by depressurizing and sealing the inside, the heat insulating performance of the obtained heat insulating body does not deteriorate for a long time and contributes to quality assurance. In addition, since it is not necessary to remove the skin in the production of rigid urethane foam panels, a large amount of foam waste is not generated, which can contribute not only to productivity and processing costs but also to environmental issues such as waste problems. It is.

[Brief description of the drawings]

FIG. 1 is a perspective view of a rigid urethane foam block according to an embodiment of the present invention.

FIG. 2 is a cross-sectional view of a rigid urethane foam block according to one embodiment of the present invention when it is manufactured.

FIG. 3 is a perspective view of a rigid urethane foam panel according to one embodiment of the present invention.

FIG. 4 is a cross-sectional view of a heat insulator according to one embodiment of the present invention.

FIG. 5 is a cross-sectional view of a conventional heat insulator.

[Explanation of symbols]

 3 container 5 jig 6 face material 7 rigid urethane foam panel 8 heat insulator

Claims (1)

(57) [Claims] 1. An air-permeable jig is provided with a surface material such as a paper or a non-woven fabric having air permeability, and an organic polyisocyanate, a polyol, a catalyst, a foam stabilizer, a foaming agent, and a cell communication agent are placed in the jig. Of a rigid urethane foam panel with an open-cell structure obtained by injecting and foaming a mixed raw material consisting of a core material, covering this with a container made of a metal-plastic laminated film, and depressurizing the inside to produce a closed heat insulator Method.