JPH04143586A - Adiabatic body - Google Patents

Abstract

PURPOSE:To develop very prominent adiabatic performance and improve productivity by a method wherein foamed resin body, obtained through mixed foaming employing organic polyisocyanate, benzyl ether type liquid phenol resin composition, catalyst, foam stabilizer, foam communicating agent and the foaming agent of perfluoroalkane and provided with continuous foam structure is employed. CONSTITUTION:A core material or hard urethane foam 4 is provided with continuous foam structure obtained by mixing the materials of organic polyisocyanate, benzyl ether type liquid phenol resin composition, catalyst, foam stabilizer and the foaming agent of perfluoroalkane and foaming them. In this case, a fluorine series surface active agent is preferably utilized as the foam stabilizer. Further, the individual body or the mixture of perfluorohexane or perfluoropenthane is preferably used for the foaming agent or the perfluoroalkane. The hard urethane foam 4, obtained in such a manner, is covered by a bag type vessel 5, consisting of a metal-plastic laminate film made by laminating constitution while the inside of the vessel 5 is evacuated and sealed whereby an adiabatic body 6 can be obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a heat insulator used in refrigerators, frozen prefabricated products, and the like.

BACKGROUND OF THE INVENTION FIG. 3 shows a conventional heat insulator. The configuration of the conventional example will be explained below with reference to FIG.

In recent years, attention has been paid to the use of heat insulators with reduced pressure inside to improve the heat insulation performance of heat insulating boxes. Powder such as perlite, honeycomb, foam, etc. are used as the core material of this heat insulating body.

For example, as shown in Japanese Unexamined Patent Publication No. 57-133870, a proposal has been made to use a hard urethane foam having open cells as the core material. This Japanese Patent Publication No. 57-133870
To explain the publication with reference to FIG. 3, in the figure, reference numeral 1 is a heat insulating structure, in which a hard urethane foam 2 having open cells is covered with a container 3 made of an airtight thin film, and the inside thereof is covered with a 0.0.
The pressure is reduced to 0011IIIHq and the container is sealed. Hard urethane foam 2 has a closed cell ratio of approximately 80 to 90%.
It is characterized by the fact that commercially available materials are vacuum degassed under high temperature and high humidity to break the cell membrane and obtain open cells.

Problems to be Solved by the Invention However, in the conventional heat insulating structure 1 as described above, since the rigid urethane foam 2 manufactured by a general foaming method using a general-purpose resin raw material is used as a base material, a foam skeleton is formed. The amount of heat conducted through the solid is large, and unless the amount of heat conducted through the gas is made sufficiently small, a practically sufficient heat insulating performance cannot be obtained.

That is, in the conventional example, the bubble skeleton diameter is approximately 3 oo~
1ooOμm, the contribution of gas heat conduction will not become sufficiently small unless the pressure is reduced to O,oQ 1 m Hg.
Excellent heat insulation performance could not be obtained. However, from the point of view of production efficiency, the inside of the heat insulating structure 1 having a bubble skeleton diameter of about 300 to 1ooOμI is 0.0016 Hg.
However, exhaust conductance is extremely small and exhaust time is extremely long, which in turn poses a major problem in mass production.

Furthermore, in the 0.001 wnHQO high vacuum range, it is susceptible to gas release from the material, and in the case of organic foams that tend to contain unreacted monomer components of low molecular weight, it is necessary to lengthen the evacuation time, which should be resolved. There was an issue.

In order to solve the above-mentioned problems, the present invention provides a heat insulator that shortens exhaust time and is excellent in mass production by obtaining a hard urethane foam that exhibits excellent heat insulation performance even in a vacuum range that is easy to handle industrially. The purpose is to

Means to Solve the Problems In order to solve the above problems, the present invention provides a mixture using an organic polyisocyanate, a benzyl ether type liquid phenolic resin composition, a catalyst, a foam stabilizer, and a blowing agent tosite perfluoroalkane. The resin foam with an open cell structure obtained by foaming is used as the core material of the vacuum insulation material.

In addition to the silicone surfactant, a fluorine surfactant is preferably used as the foam stabilizer. Further, as the perfluoroalkane which is a blowing agent, perfluorohexane or perfluoropentane is preferably used alone or as a mixture.

Effect With the above structure, the core material is covered with a container made of metal or plastic laminate film and the inside is depressurized, because the cell membrane of the core material breaks during the foaming process, and the open cell ratio becomes substantially 100%, and the cell skeleton becomes fine. ,0.1~0.01
Excellent heat insulation performance can be obtained even at a pressure that is industrially easy to handle, such as HrB Hg, and mass production efficiency can be greatly improved by shortening the evacuation time.

Example The following is an example of the heat insulating body of the present invention shown in FIG.

This will be explained based on FIG.

In the figure, 4 is a hard urethane foam manufactured using a urethane high-pressure foaming machine using the raw materials and blended parts shown in the table below, aged at room temperature, and then cut into predetermined sizes. .

In the table, polyol A has a hydroxyl value of 480119K.
OH/f Benzyl ether type liquid phenolic resin composition polyol B is an aromatic amine polyol with a hydroxyl value of 460 WKOH/l. Foam stabilizer A is Tegostarb 8404, manufactured by Goldschmidt Co., Ltd., which is a silicone surfactant, and foam stabilizer B is FC-1yoc, manufactured by Tennuri M Co., Ltd., which is a fluorosurfactant. The blowing agent A is perfluorohexane, the blowing agent B is perfluoropentane, and the blowing agent C is a mixture of perfluorohexane and perfluoropentane in the same molar ratio.

The main blowing agent is trichloromonofluoromethane. Catalyst A is MDABCO-TM manufactured by Sankyo Protaric Co., Ltd.
R, catalyst B is dimethylethanolamine.

The bubble communication agent is Nippon Oil & Fats Co., Ltd.'s Calcium Stearate. Organic polyisocyanate A was a polyinocyanate with a weight of 150 m/amine obtained by reacting toluylene diisocyanate, trimethylpropane, and diethylene glycol, and foaming was performed using various combinations of these raw materials.

Comparative examples are shown in the table. These hard urethane foam 4
The table shows the reactivity such as density, open cell ratio, average cell skeleton diameter, creaming time during foaming, and gelling time.

(Left below) After that, heat treatment is carried out at 120°C for about 2 hours to evaporate adsorbed water and unreacted slag, and a bag made of a metal-plastic laminate film with a laminate structure of aluminum vapor-deposited polyester film and polyethylene film. The inside is covered with a container 5 having a shape of 0.01 irrm Hf,
The pressure was reduced to 0.1 mm Hl and sealed to obtain a heat insulator 6. The exhaust time at this time was 5 minutes,
The time was 1 minute and 30 seconds. The thermal conductivity of the obtained heat insulating body 6 is shown in the bottom row of the back. Thermal conductivity is provided by Shinku Riko Co., Ltd. K-Ma
Measurements were made using tic at an average temperature of 24°C.

As is clear from the table, the heat insulator 6 of the present invention has a fine cell skeleton and is easy to handle industrially.
It was found that excellent heat insulation performance was exhibited even at a pressure of H2.

That is, the perfluoroalkane used as a blowing agent has extremely weak chemical polarity and low compatibility with other raw material components. For this reason, foaming begins in an emulsified state, resulting in a large number of boiling nuclei and a fine bubble skeleton, but a detailed explanation of this process has not been obtained. Similarly,
Since the Fuson thread surfactant also has a molecular structure similar to that of a foaming agent, it is thought to be related to compatibility and contribute to foaming stability during foaming.

Also, benzyl ether type liquid phenolic resin composition B
In foaming behavior, the time from creaming time to gelling time is short, and due to the rapid foaming rise, the bubble skeleton is formed while maintaining its fineness from the initial stage of foaming, and the foam has a fine bubble skeleton. It is considered that it was obtained.

By using the hard urethane foam 4 having a fine cell skeleton as the core material of the heat insulating body 6, the gas heat conduction in the heat insulating body 6 can be carried out at a higher pressure than when the cell skeleton is larger. However, it can be reduced to the same level, and exhibits excellent heat insulation performance at o, 1 to 0.01 mmH7, which is easy to handle industrially. As a result, since the evacuation time is short, mass production is easy, and pressure can be obtained with a simple evacuation device, which greatly contributes to productivity.

Note that if the bubble skeleton is made finer, the exhaust resistance increases and the exhaust time required to reduce the pressure to a predetermined pressure of 1 becomes longer, but there is no effect in the 0.01 mmHf range. Therefore, even when miniaturized, insulation performance is fully demonstrated.
, olmmHf, there is no problem with productivity.

Effects of the Invention As is clear from the above description, the present invention provides the following effects. That is, the vacuum heat insulating body of the present invention has extremely excellent heat insulation performance even when the degree of vacuum is 0.1 to 0.01 H2. As a result, mass production can be carried out in a short time and with simple exhaust equipment, which has the advantage of contributing to a significant improvement in productivity.

[Brief explanation of drawings]

FIG. 1 is an external perspective view of a rigid urethane foam according to an embodiment of the present invention, FIG. 2 is a sectional view of the same heat insulating body, and FIG. 3 is a sectional view of a conventional heat insulating structure. 4... Hard urethane foam, 5... Thickness u,
6...Insulator. Figure Figure 4 '-Jj Fee Creta Frame 7-

Claims (5)

[Claims] (1) Foaming of an open-cell structure obtained by mixing and foaming an organic polyisocyanate, a benzyl ether type liquid phenolic resin composition, a catalyst, a foam stabilizer, a cell communication agent, and a perfluoroalkane as a foaming agent The resin body is covered with a container made of metal or plastic laminate film,
An insulator whose interior is sealed by reducing pressure. (2) The heat insulator according to claim 1, wherein perfluorohexane is used as the perfluoroalkane blowing agent. (3) The heat insulator according to claim 1, wherein perfluoropentane is used as the perfluoroalkane blowing agent. (4) The heat insulator according to claim 1, wherein the blowing agent perfluoroalkane is a mixture of perfluorohexane and perfluoropentane. (5) The heat insulator according to claim 1, wherein a fluorine-based surfactant is used as a foam stabilizer.