JPH0330936A - Insulating wall - Google Patents

Abstract

PURPOSE:To improve qualities by using hard polyurethane foam which is foamed by mean of mixed foaming agent, as a halogenated hydrocarbon foaming agent containing fluorine, composed of HCFC-141b and HCFC-123 at a specific ratio. CONSTITUTION:An insulating wall 1 consists of an inner plate 2 of ABS resin, an outer plate 3 of steel and hard polyurethane foam 4 which is integrally foamed between the inner plate 2 and the outer plate 3. The insulating wall 1 can be safely manufactured without causing cracks or brushing on the inner plate 2 and has excellent foaming properties, while gas of foaming agent is not flammable. As foaming agents, a fluorocarbon foaming agent composed of 70-95mole% HCFC-141b(1,1dichlorol-fluoroethane) and 5-30mole% HCFC-123(1,1 dichloro-2,2-trifluoroethane) is used.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a heat insulating wall for refrigerators, freezers, etc., which uses a foamed heat insulating material such as hard urethane foam.

Conventional technology In recent years, the amount of CFC-based CFCs used as blowing agents has been reduced.
Contributing to the improvement of environmental problems such as ozone destruction and global warming due to the effects of CFC-based fluorocarbons has become an extremely important theme.

For this reason, in the production of rigid urethane foam, which is a typical foam insulation material, the conventional trichlorofluoromethane (hereinafter referred to as cFc-11) is used as a blowing agent.
, 1 dichloro 1-fluoroethane (hereinafter referred to as HCFC-14)
It is necessary to use an alternative blowing agent with an ozone depletion coefficient of 0.02 to 0.1, such as be. HCFC-141 in protecting the global environment
It is essential to use b or HCFC-123,
Efforts have been made to establish these applicable technologies.

As announced at the press conference of the Japan-U.S. Seminar on Thermophysical Properties and Development Trends of Alternative CFC Substances, a lecture hosted by the Japan Refrigeration Association on December 14, 1988, HCFC
-141b is slightly flammable, and in order to ensure the safety of the foam manufacturing process, fire safety seals are required for raw material storage, mixing, transportation, and foaming equipment.
On the other hand, HCFC-123 has an extremely strong chemical attack property on synthetic resins, and the strength of the synthetic resin face material that makes up the heat insulating wall (not shown) is severely degraded. development is essential.

In this way, HCFC-141b and HCFC-123 each have their own inherent drawbacks, and in order to accommodate these, HCFC-141b and 123
Currently, efforts are being made individually to develop manufacturing processes that comply with 141b and materials that comply with HCFC-123.

Problems to be solved by the invention HCFC-141b and HCFC-123 are CFC-11
Compared to HCFC-141b, the ozone depletion power is 1/1 to 1/6 o, and it is essential for environmental protection, but due to its flammability, disaster prevention equipment 4 must be installed and maintained. This also places a heavy burden on safety management, and how to deal with it is an important issue. On the other hand, HCFC-123 has extremely strong chemical attack properties on synthetic resins, and
Developing synthetic resins that meet 3 requirements is difficult and has become a problem. In this way, when applying alternative blowing agents, CF
The challenge was to find a cheap and easy-to-apply measure for safety and quality compared to C-11.

Means for Solving the Problems In order to solve the above problems, the present invention uses HCFC-141b with a mole percentage of 7Q to 95% and HCFC-141b with a mole percentage of 5 to 30% as a fluorine-containing halogenated hydrocarbon blowing agent. 12
A hard urethane foam foamed using a mixed foaming agent constituted by No. 3 is used as an integrally foamed heat insulating material for a heat insulating wall made of a synthetic resin face material.

Effect With the above configuration, the flammability of HCFC-141b is lower than that of H
Mixing CFC-123 eliminates the problem as a blowing agent gas, and the chemical attack property does not pose a major problem because the concentration occupied by HCFC-123 is small, and can be dealt with using existing improved technology. Therefore, as a blowing agent, it can be easily substituted industrially without impairing its characteristic of having a low ozone depletion coefficient, and it is possible to provide a heat insulating wall with excellent quality.

EXAMPLES Hereinafter, the heat insulating wall of the present invention will be explained with reference to Examples and FIG.

Reference numeral 1 denotes a heat insulating wall, which is composed of an inner plate 2 made of ABS resin, an outer plate 3 made of iron plates, and a hard urethane foam 4 integrally foamed between the inner box 2 and the outer box 3. Table 1 shows an example of the raw material formulation for hard urethane foam 4 (/11
, A2).

Polyether/L/A is an aromatic amine polyether with a hydroxyl value of 460 WIgKOH/g, and the foam stabilizer A is F-353 manufactured by Shin-Etsu Chemical. Catalyst A is Kao Raiser 51 manufactured by Kao ■.
1 Blowing agents are pure water, HCFC-141b and HCFC-12
It is 3. Each raw material is mixed in a predetermined number of parts to form a premix component.

The organic polyinsyanate is made of crude MDI having an amine equivalent of 136, and is mixed with premix components at a predetermined ratio, and foamed and filled to obtain a rigid urethane foam 4.

Table 1 also shows the density and thermal conductivity of this hard urethane foam 4, the presence or absence of combustibility of the blowing agent gas, and the appearance of the inner plate 2.

Table 1 At the same time, as a comparative example, the V% of HCFC-123
Table 1 also shows cases where the ratio is less than 5% and cases where the ratio exceeds 30% (Comparative Examples A and B).

As described above, it has been found that the heat insulating wall 1 of the present invention has excellent foam properties without cracking or whitening of the inner plate 2, and is not combustible as a blowing agent gas and can be safely manufactured. . This is because the concentration of HCFC-123 was low, so the chemical attack property as a blowing agent gas was also weakened, and the inner plate 2 did not crack or whiten. Regarding flammability, although the mechanism is unknown, H
Mixing CFC-123 eliminates flammability, making it extremely suitable for disaster prevention.

In addition, as shown in the comparative example, when the morphometric ratio of HCFC-123 is less than 6 cm, combustibility develops as a blowing agent gas, and safety precautions are required in terms of equipment and management.
%, the chemical attack of the blowing agent gas cannot be ignored and whitening of the inner plate 2 occurs, making it difficult to apply.

Effects of the Invention As is clear from the above description, the present invention provides the following effects. That is, the heat insulating wall of the present invention has a hard urethane foam with a Mow% of 70 to s6.
% HCFC-141b and the remaining 6-30% HCFC-
Since foaming is performed using a CFC foaming agent consisting of 123, chemical attack resistance is small even when foamed together with synthetic resin face material, and it can be easily applied without quality problems such as whitening or cracking. Since it is not flammable as a component, there is no need for special firefighting equipment or management during the manufacturing process such as raw material storage, mixing, transportation, foaming, etc., and it can be manufactured safely.

As a result, HCFC, which has a low ozone depletion coefficient and is essential for protecting the global environment, can be easily applied as a foaming gas for foam insulation materials.

[Brief explanation of drawings]

FIG. 1 is an external perspective view of a heat insulating wall according to an embodiment of the present invention, and FIG. 2 is a sectional view of the same heat insulating wall. 1...Insulation wall, 2...Inner plate, 4...
...Hard urethane foam.

Claims (1)

[Claims] As a fluorine-containing halogenated hydrocarbon blowing agent, the mole% is 70
~95% 1,1 dichloro-1-fluoroethane and the remainder 5
A heat insulating wall made by integrally foaming rigid urethane foam using a mixed foaming agent consisting of ~30% of 1,1 dichloro-2,2,2-trifluoroethane with synthetic resin inner panels and other face materials.