JP2783379B2 - Insulation structure - 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 insulating structure used for a refrigerator, a freezing prefab, and the like.

[0002]

2. Description of the Related Art In recent years, chlorofluorocarbon (hereinafter referred to as C)
Attention has been paid to environmental problems such as ozone layer depletion and global warming caused by the influence of the FC. From such a viewpoint, reduction of the amount of CFC used as a foaming agent has become a very important theme.

For this reason, it has been proposed to use a hydrocarbon containing no halogen in the molecule as a foaming agent for a rigid urethane foam which is a typical foamed heat insulating material. For example, in JP-A-3-152160,
A method for producing a rigid polyurethane foamed plastic using cyclopentane or cyclohexane as a foaming agent is described. And, in the detailed description of the invention, flame retardants are mentioned as additives, but halogen-substituted phosphates and inorganic flame retardants are described as candidates.

[0004]

There is a problem of flammability in applying the above-mentioned hydrocarbon as a foaming agent, and it is difficult to use a foam insulation material containing a flammable gas in a heat insulating wall. However, there is the danger of fire spreading during a fire, which is a major issue.

[0005] However, when using the foamed heat insulating material containing a flame retardant as described above, when a metal pipe for circulating the refrigerant is used in a heat insulating structure filled with the foamed heat insulating material such as a refrigerator. However, there is a problem of metal corrosion and application is difficult. In addition, there is also a problem of toxicity such as migration through a face material when preserving food for a long time.
The present invention has been made in view of the above-described problems, and even if hydrocarbon is used as a foaming agent, the spread of fire in a fire is not dangerous at least at the same burning rate as that of the conventional CFC11 foaming, and the metal pipe is corroded. It is an object of the present invention to provide a heat insulating structure which does not cause a problem in safety even if the refrigerant leaks or the food is stored for a long time.

[0006]

In order to solve the above-mentioned problems, the present invention comprises a blowing agent containing a hydrocarbon such as pentane or cyclopentane, and comprising an organic polyisocyanate,
Polyol, catalyst, foam stabilizer, and molecular weight of the raw material mixture foamed to foam insulation obtained to the additive and the organic phosphorus compound of non-halogen containing having an OH group as a functional group at 150 or higher, the metallic pipe The heat insulating structure is formed by injection molding into the space provided.

[0007]

According to the above construction, although the foamed heat insulating material filled in the heat insulating structure contains a combustible gas, the combustibility of the resin portion is suppressed by the effect of the organic phosphorus compound, and the combustion is at least equivalent to the conventional CFC11 foaming. The speed is increased, and there is no danger of the spread of fire in the event of a fire. This contributes to solving global environmental problems such as ozone depletion and can be used safely.

In addition, since the organic phosphorus compound does not contain halogen, even if the insulated structure is incinerated at the time of disposal, there is no problem with respect to the environment without releasing halogen which causes acid rain into the atmosphere. Can be expected. In addition, since an organic phosphorus compound having a molecular weight of 150 or more and having an OH group as a functional group is applied as an organic phosphorus compound, it reacts with the organic polyisocyanate as a raw material to polymerize, and as a result, phosphorus is ionized and liberated, thereby corroding the metal pipe. There is no possibility to make it happen. In particular, in the case of a metal pipe that circulates a refrigerant, such as a refrigerator, moisture that has entered from the outside may be condensed on the metal pipe and corroded easily due to the low surface temperature. Can be suppressed, and the reliability can be improved in long-term use of the product. Simultaneously, by polymerizing, it is possible to provide a heat-insulating structure which does not transfer plastics to face materials, does not become contaminated even if food is stored for a long time, and has no problem in product safety.

[0009]

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

Reference numeral 1 denotes a heat insulating structure, which is covered with a face material 2 made of plastics such as ABS and an iron plate 3, and is filled with a foamed heat insulating material 4 made of hard urethane foam. Reference numeral 5 denotes a copper pipe for circulating a refrigerant, which is buried by a foamed heat insulating material 4.

An example of the raw material formulation of the foam insulation 4 is shown in Table 1.

[0012]

[Table 1]

Polyether A is an aromatic amine polyether polyol having a hydroxyl value of 460 mg KOH / g, foam stabilizer A is F335 manufactured by Shin-Etsu Chemical Co., Ltd., catalyst A is Kaolyzer No. 1 manufactured by Kao Corporation, and foaming agent A is Cyclopentane and blowing agent B are pure water. Further, using di-butyl oxymethyl e Suhoneto or Ranaru organophosphorus compound as a additive A. On the other hand, the isocyanate component is an organic polyisocyanate composed of crude MDI having an amine equivalent of 135. The premix component and the isocyanate component prepared in this manner are mixed in a predetermined blending number by a high-pressure foaming machine, and a face material 2 in which a copper pipe 5 is previously disposed.
Into the iron plate 3 to obtain the heat insulating structure 1. The burning degree of the obtained foamed heat insulating material 4 is also shown in Table 1 as the characteristic value of the burning time in the flammability test item in JIS-A9514.

Further, the results of analysis of the corrosion degree of the copper pipe when the heat insulating structure 1 was operated at 40 ° C. and 95% RH for 3 months and the transfer of phosphorus to the face material 2 were also analyzed (Table 1).
It was shown to.

[0015] When not using the additive B as a comparative example at the same time, and as a additive B halogen-containing Tris -
(2-chloroethyl) when added phosphate, furthermore illustrated in the case of using the CFC11 as a foaming agent C is also (Table 1).

[0016] Thus dibutyl hydroperoxide oxymethyl phosphorylase molecular weight are organic phosphorus compounds in non-halogen containing having an OH group as a functional group 224 as an additive Honeto
In the case of using CFC11, even if cyclopentane, which is a flammable hydrocarbon, is used as the blowing agent, the combustibility of the resin part of the foamed heat insulating material 4 is suppressed. It was average. As a result,
There is no danger of the spread of fire in the event of a fire, which contributes to solving global environmental problems such as ozone depletion, and the product can be used safely. And di-butyl oxymethyl e Suhoneto is larger molecular weight and 224, to have an OH group as a functional group, the result of polymerization by reacting with an organic polyisocyanate in the raw material, phosphorus is possible to corrode the metal pipe by free ionization There was no. In particular, there was no problem even in the case where the moisture invading from the outside under the humid condition was condensed on the copper pipe 5 and easily corroded.
In other words, it has been found that ionization of phosphorus can be suppressed by polymerizing, and reliability can be improved in long-term use of the product.

Furthermore, it was found that the transfer of phosphorus from the plastics to the face material 2 was not detected, and that it was possible to provide a heat insulating structure having no contamination and no problem in product safety even when food was stored for a long period of time.

On the other hand, when no additive is used as a comparative example, there is a phenomenon that the burning rate becomes higher than that when CFC11 is used, which is difficult to apply.
Further, when halogen-containing tris- (2-chloroethyl) phosphate is added as an additive, it is similarly difficult to apply the copper pipe 5 due to a large corrosion and a problem that phosphorus transfer to the face material 2 is detected.

[0019]

As described above, the present invention comprises a hydrocarbon such as pentane or cyclopentane as a foaming agent, an organic polyisocyanate, a polyol, a catalyst, a foam stabilizer, and a OH as a functional group having a molecular weight of 150 or more. the foam insulation obtained by raw materials and additives of organic phosphorus compounds in non-halogen containing having a base mixture foamed to, and forms a heat-insulating structure by casting in a space which is disposed a metallic pipe Therefore, although the foamed heat insulating material contains a flammable gas, at least the conventional CF
The burning rate is the same as that of C11 foaming, and there is no danger of the spread of fire in the event of a fire. This contributes to solving global environmental problems such as ozone destruction and can be used safely.

Further, since the organic phosphorus compound does not contain halogen, even if the heat-insulating structure is incinerated at the time of disposal, there is no problem with respect to the environment without releasing halogen which causes acid rain into the atmosphere. Can be expected. In addition, since an organic phosphorus compound having a molecular weight of 150 or more and having an OH group as a functional group is applied as an organic phosphorus compound, it reacts with an organic polyisocyanate as a raw material to be polymerized, so that a metal pipe is placed in a foamed heat insulating material. Even in the case of disposing, there is no possibility that phosphorus is ionized and released to corrode the metal pipe, and reliability can be improved in long-term use of the product. In addition, there is no transfer of plastics to the face material, and even if the food is stored for a long period of time, there is no contamination and a heat insulating structure having no problem in product safety can be provided.

[Brief description of the drawings]

FIG. 1 is a perspective view of a heat insulating structure according to an embodiment of the present invention, with a part cut away.

FIG. 2 is a sectional view of a heat insulating structure according to one embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Insulation structure 4 Foam insulation material 5 Metal pipe

──────────────────────────────────────────────────続 き Continuation of the front page (51) Int.Cl. ⁶ Identification code FI F25D 23/08 F25D 23/08 A // (C08G 18/48 101: 00) C08L 75:04 (72) Inventor Tomohisa Amara Matsushita Refrigerating Machine Co., Ltd., 3-22 Takaidahondori, Higashiosaka City, Osaka Prefecture (56) References JP-A-63-312828 (JP, A) JP-A-3-505599 (JP, A) JP-A-60-123539 (JP, A) (58) Field surveyed (Int. Cl. ⁶ , DB name) C08J 9/00-9/42

Claims (1)

(57) [Claims] 1. A foaming agent containing a hydrocarbon such as pentane and cyclopentane as an organic polyisocyanate, a polyol, a catalyst, a foam stabilizer and a molecular weight of 150.
Heat insulating structure formed by casting a raw material mixed foaming to foam insulation obtained to the additive and the organic phosphorus compound of non-halogen containing having an OH group as a functional group, in a space which is disposed a metallic pipe above body.