JPH0791817A - Heat insulation box - Google Patents

Abstract

PURPOSE:To eliminate the danger of explosion and/or fire and permit the production of the title box body safely by a method wherein the heat insulation box, utilized for a refrigerator and the like, is constituted of an outer casing, hard urethane foam utilizing hydrocarbon as a foaming agent, and an inner casing, made by forming an antistatic ABS resin composition. CONSTITUTION:A heat insulation box 1 is constituted of an inner casing 2, formed of an antistatic ABS resin composition, an outer casing 3, formed of steel sheets and covering the inner casing 2, and foamed heat insulating material 4, consisting of hard urethane foam and filled into a space between the inner casing 2 and the outer casing 3. Hydrocarbon or pentane or cyclopentane is used for the foaming agent of the foamed heat insulating material 4. According to this method, a problem that the inner casing 2 is charged with static electricity during foaming the hard urethane foam is eliminated while the fear of ignition and/or explosion of the hard urethane foam can be eliminated even when flamable hydrocarbon is employed as the foaming agent. Further, a foaming agent, taking place of chlorofluorocarbon having the problem of destructing the ozone layer of the globe, is permitted to be used safely.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heat insulating box used for refrigerators, frozen prefabs and the like.

[0002]

2. Description of the Related Art In recent years, chlorofluorocarbons (hereinafter C
Environmental problems such as ozone depletion and global warming due to the influence of FC) are drawing attention. From such a viewpoint, reduction of the amount of CFC used as a foaming agent has become an extremely important theme.

Therefore, in a typical urethane foam, which is a heat insulating foam material, a hydrocarbon is used as a foaming agent which does not contain halogen in the molecule, has no ozone layer depletion, and has very little effect on global warming. Proposed to be used.

For example, Japanese Unexamined Patent Publication (Kokai) No. 3-152160 describes a method for producing a polyurethane rigid foamed plastic using a flammable substance such as cyclopentane or cyclohexane, which is a hydrocarbon, as a foaming agent.

[0005]

However, when applying the above hydrocarbon as a foaming agent, there is a problem of flammability of the foaming agent itself. However, there is a risk of explosion or fire caused by the discharge of static electricity charged during foaming as an ignition source, and ensuring safety during the foaming process is a major issue.

In view of the above problems, the present invention is a heat insulating structure which can be produced safely without danger of explosion and fire in the rigid urethane foam foaming process even when a flammable hydrocarbon is applied as a foaming agent. It is intended to provide.

[0007]

In order to solve the above-mentioned problems, the present invention provides an outer box, a rigid urethane foam containing hydrocarbon such as pentane or cyclopentane as a foaming agent, and an antistatic effect. A heat-insulating box is formed with an inner box formed by molding the ABS resin composition.

[0008]

According to the above construction, since the ABS resin composition having the antistatic effect is applied as the inner box, the inner box is not charged with static electricity and the flammable hydrocarbon is applied as the foaming agent. In the case of doing so, there is no discharge that can become an ignition source, and there is no risk of explosion or fire during the rigid urethane foam foaming process, or when taking out the heat-insulating box body after foaming from the jig, and can be safely produced. It is possible to provide a heat insulating box.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIG.

FIG. 1 shows a heat insulating box, which is covered with an inner box 2 formed of an antistatic ABS resin composition and an outer box 3 formed of an iron plate, and a foamed heat insulating material 4 made of hard urethane foam inside.
Are filled and arranged.

The foamed heat insulating material 4 uses cyclopentane, which is a hydrocarbon having no ozone depletion and an extremely small effect on global warming, as a foaming agent.

In order to confirm the effect of this embodiment, changes in the charge amount of the inner box before and after the rigid urethane foam foaming process are shown in (Table 1).

In the examples, GR-500A manufactured by Denka Co., Ltd., which is a type in which a surfactant is kneaded into an ABS resin, was used as the antistatic ABS resin composition.

Further, as a comparative example, the change in the charge amount of the inner box before and after the step of foaming the rigid urethane foam when the inner box molded from the ordinary ABS resin composition was used is also shown (Table 1).

[0015]

[Table 1]

As described above, in the heat insulating box of the present invention, the charge amount of the inner box before and after the step of foaming the rigid urethane foam hardly changed, and it was around 0 Kv. Therefore,
Even when a hydrocarbon having flammability is applied as a foaming agent, there is no discharge of static electricity that can serve as an ignition source, in the rigid urethane foam foaming process, and when taking out the heat-insulated box body after foaming from the jig, etc. There is no risk of explosion or fire, and safe production is possible. However,
In the case of the comparative example, the amount of charge was significantly increased after foaming as compared with that before the foaming process of the rigid urethane foam.
It turns out that it reaches v. Therefore, in the rigid urethane foam foaming process, or when taking out the heat-insulating box body after foaming from the foaming jig, there is a risk of static electricity discharge,
Flammable substances leaking from the insulation box during foaming may catch fire, causing an explosion or fire.

As described above, according to the heat insulating box of the present invention, there is no danger of catching a flammable substance leaking from the heat insulating box during foaming, causing an explosion or a fire, and the safety in manufacturing the heat insulating box is extremely high. growing.

[0018]

INDUSTRIAL APPLICABILITY As described above, the heat-insulating box according to the present invention comprises an outer box, a hard urethane foam containing hydrocarbon such as pentane or cyclopentane as a foaming agent, and an antistatic ABS resin composition. Since it is composed of an inner box that does not have static electricity, the inner box is not charged with static electricity in advance or during foaming of the rigid urethane foam. There is no electric discharge that can cause explosion, and there is no risk of explosion or fire in the rigid urethane foam foaming process, or when taking out the heat-insulated box body after foaming from the jig.
It is possible to provide a heat-insulating box that can be produced safely.

By applying an antistatic agent to the inner box formed of ABS resin, the same effect as in the case of forming the antistatic ABS resin composition can be obtained, and the inner box material is changed. It is not necessary and the effect can be obtained by only partially coating the part where charging is likely to occur, that is, the uneven parts where the inner boxes are likely to contact each other when the inner boxes are stacked. Various uses are possible.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of a heat insulating structure according to an embodiment of the present invention.

[Explanation of symbols]

 1 Insulation box 2 Inner box 4 Foam insulation

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification number Reference number within the agency FI Technical indication location C08L 75:04 (72) Inventor Tomonao Tenra 3-22 Takaidahondori, Higashiosaka-shi, Osaka Matsushita Chiller Co., Ltd.

Claims (2)

[Claims] 1. A heat insulating box body comprising an outer box, a hard urethane foam containing hydrocarbon such as pentane or cyclopentane as a foaming agent, and an inner box formed by molding an antistatic ABS resin composition. 2. An outer box, an inner box made of ABS resin, a hard urethane foam using hydrocarbon such as pentane or cyclopentane as a foaming agent, and an antistatic agent applied to at least a surface in contact with the hard urethane foam. Insulated box made of.