JPH05255472A - Expanded insulator - Google Patents

Abstract

PURPOSE:To contribute to settlement of the environmental problem of ozone layer destruction by improving each solubility of a low-boiling foaming agent composed of an HCFC or an HFC and a polyol component, as its result, e.g. reducing the thermal conductivity of a foam and securing the product quality in relation to an expanded insulator and an insulating box body of a refrigerator, a freezer, etc. CONSTITUTION:Addition polymerization between an organic polyisocyanate and ethylene oxide or propylene oxide is carried out in the presence of a diol or a triol as an initiator to synthesize a polyether polyol. A polyol component containing the resultant polyether polyol in an amount of at least 5 to 30wt.%, a foam stabilizer, a catalyst and an HCFC or an HFC having a low boiling point of >=-50 deg.C and <=0 deg.C are mixed and agitated so as to generate foam. Thereby, the objective expanded insulator is obtained. A heat-insulating box body in which the above-mentioned expanded insulator is packed between the inner box and the outer box can be obtained by carrying out the foaming process in the space between both the inner and outer boxes.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a foam insulation material used in refrigerators, freezers and the like and a heat insulation box body filled with the foam insulation material.

[0002]

2. Description of the Related Art In recent years, chlorofluorocarbons (hereinafter referred to as C
Environmental problems such as ozone layer depletion and global warming due to the influence of FC) have been attracting attention, and in manufacturing a rigid urethane foam, which is a typical foam insulation material, C
For the purpose of reducing the amount of FC used, a method of using carbon dioxide gas obtained by the reaction of organic polyisocyanate and water as a part of a foaming agent, or an alternative substance of CFC, which has little influence on ozone destruction 2, Various improvement measures such as foaming with 2-dichloro-1,1,1-trifluoroethane and 1,1-dichloro-1-fluoroethane are being studied.

Conventionally, in the production of foams, foaming with trichlorofluoroethane (hereinafter referred to as CFC11) having a boiling point near room temperature or a floss method using dichlorodifluoromethane (hereinafter referred to as CFC12) which is a low boiling point foaming agent, etc. Has been used. By using a low boiling point compound such as CFC12 as a part of the foaming agent, the foaming raw material liquid is discharged in a cream shape from the nozzle of the foaming machine. Therefore, although the flow of the raw material liquid is small, the shape of the bubbles is close to a sphere, and the internal pressure of the gas trapped in the bubbles is high, so that a foam having excellent low-temperature dimensional stability can be obtained.

For example, JP-A-59-38240 discloses low-boiling point blowing agents such as 1-chloro-2,2,2-trifluoroethane, monobrom monochlorodifluoromethane,
It is characterized by using a mixture of at least one compound of trans-1-chloro-2-fluoroethylene in an amount of 2 to 50% by weight with respect to the total foaming agent to produce a foam insulation material. There is.

[0005]

However, as mentioned in Japanese Patent Application Laid-Open No. 59-38240, the foaming of froth caused by using the low boiling point foaming agent alone or in a large amount exceeding 50% by weight. In the above, there are drawbacks that a large number of froth voids are likely to occur inside the foam, the cells become non-uniform, the closed cell ratio deteriorates, and the thermal conductivity of the foam deteriorates. As a factor of these froth voids and cell communication, there is a limit to the compatibility between the low boiling point blowing agent and the polyetherpolyol generally used as a raw material for a rigid urethane foam, and when the amount exceeds a certain level, It is considered that the low boiling point foaming agent dissolved in the raw material cannot be retained and a bumping phenomenon occurs at the moment of discharge, resulting in poor mixing and coalescence of bubbles.

For this reason, as a means for preventing froth voids and communication of bubbles, as shown in JP-A-59-38240, CFC1, which is a foaming agent having a boiling point near room temperature, is used.
There is a method of auxiliary foaming using carbon dioxide gas generated by mixing with 1 or reaction of water and isocyanate, but from the viewpoint of solving global environmental problems and saving energy,
Low boiling point hydrochlorofluorocarbons (hereinafter referred to as HCFCs) and hydrofluorocarbons (hereinafter referred to as HFCs), which have little effect on ozone layer depletion and global warming, are added to conventional high-pressure blowing agents. The problem was to manufacture a high-performance foam insulation material that can be applied without major changes to the foaming machine equipment and that does not have the problem of froth voids.

In view of the above-mentioned problems, the present invention is an excellent foam insulation material which does not have the problem of froth voids or cell communication even when a foaming agent such as HCFC or HFC having a low boiling point which has little influence on global environmental problems is used. It is intended to provide.

[0008]

In order to solve the above-mentioned problems, the present invention provides a hydroxyl group obtained by addition-polymerizing an organic polyisocyanate and ethylene oxide or propylene oxide by using diol or triol as an initiator. Value 5
At least one component is a polyol component containing at least 5 to 25% of polyether polyol of 0 to 1000 mg KOH / g, a foam stabilizer, a catalyst, and HCFC having a boiling point of -50 ° C or higher and 0 ° C or lower. A foaming agent is obtained by mixing and stirring with a foaming agent.

Further, the present invention provides an organic polyisocyanate and a polyether polyol having a hydroxyl value of 500 to 1000 mgKOH / g, which is obtained by addition-polymerizing ethylene oxide or propylene oxide using diol or triol as an initiator. A foam component containing at least 5 to 30% of a polyol component, a foam stabilizer, a catalyst, and a foaming agent containing HFC having a boiling point of -50 ° C or higher and 0 ° C or lower as at least one component are mixed and stirred to form a foamed heat insulating material. I will get it.

Further, the foamed heat insulating material is foamed and filled in a space portion constituted by an inner box and an outer box to obtain a heat insulating box body.

[0011]

With the above structure, the compatibility of the polyether polyol obtained by addition polymerization of ethylene oxide or propylene oxide with diol or triol as an initiator and the low boiling point blowing agent of HCFC or HFC is extremely high. Since it is good, it is blended with a polyol starting with a diol or a triol even for a general hard polyether foam polyether polyol for which the solubility with a low boiling point foaming agent is remarkably poor. By doing so, the solubility of the entire polyol component with a low boiling point blowing agent composed of HCFC or HFC is improved, a uniform fine bubble structure is generated due to uniform foaming behavior, and excellent foaming without froth voids or bubble communication. It is capable of producing a heat insulating material.

Furthermore, HFC has an ozone depletion coefficient of 0, and not only does it have no effect on ozone depletion alone, but it also causes ozone depletion even in a mixed system with HCFC, which has some effect on ozone depletion. On the other hand, it is possible to produce an effective foam insulation material.

Further, by filling the foamed heat insulating material to form a heat insulating box, it is possible to secure excellent quality as a heat insulating box without problems such as sweating at a void generation portion and deterioration of heat insulating performance. It is a thing.

As the HCFC foaming agent, chlorodifluoromethane (hereinafter referred to as HCFC22), monochloro-1,1,1,2-tetrafluoroethane, 1-chloro-1,1-
Difluoroethane or the like can be used. Further, as the HFC foaming agent, 1,1,1,2-pentafluoroethane (hereinafter referred to as HFC
FC134a), 1,1,1,2,2, -pentafluoroethane, 1,1-difluoroethane and the like can be used.

[0015]

EXAMPLES Hereinafter, the foamed heat insulating material of the present invention will be described with reference to examples.

Polyol A is an aromatic amine-based polyester.
Terpolyol has a hydroxyl value of 460 mgKOH / g, and Polyol B is a polyester having a hydroxyl value of 800 mgKOH / g formed by addition-polymerizing propylene oxide with glycerin as an initiator.
Terpolyol and catalyst are Kaolyzer No. manufactured by Kao Corporation.
1. The foam stabilizer is a silicone surfactant F-335 manufactured by Shin-Etsu Chemical Co., Ltd., and the foaming agents are water, HCFC22 and HFC.
134a, each raw material is mixed in a predetermined mixing number to form a premix component. On the other hand, the isocyanate component is an organic polyisocyanate composed of a crude MDI having an amine equivalent of 135.

The premix component thus prepared and the isocyanate component are mixed in a predetermined mixing number, foamed by a high-pressure foaming machine, and filled inside a box consisting of an inner box and an outer box,
An insulated box was obtained. In order to evaluate the solubility of the foaming agent at this time, the pressure of the tank filled with the premix, the presence or absence of froth voids, the closed cell rate, the thermal conductivity, and the average cell diameter are shown in (Table 1).

At the same time, as a comparative example, a case where a polyol B having a hydroxyl value of 800 mgKOH / g formed by addition polymerization of propylene oxide with glycerin as an initiator was not added (Comparative example A) and a polyol B was used as a polyol. The case of containing 35% of all the components (Comparative Example B) is shown at the same time (Table 1).

[0019]

[Table 1]

As described above, the foamed heat insulating material of the present invention is HCFC which is a low boiling point foaming agent with less problems against ozone destruction.
No. 22 and HFC134a are used, a raw material system that can be stably dissolved in a premix and can be easily foamed even in a conventional high-pressure foaming machine, and a uniform foaming behavior gives a fine and homogeneous cell structure. It was found that an excellent foamed heat insulating material having a high closed cell ratio was obtained. Although the details of this mechanism are unknown, it is possible to use glycerol-initiated polyester
The ether bond in the molecular structure of the polymer is HCFC or HF.
Since it has a strong affinity for C, it exhibits excellent solubility, and it is considered that the solubility of the entire polyol component is improved by using this as a part of the polyol component. As a result, the HCFC or HFC dissolved in the polyol is uniformly foamed, and there is no froth void or bubble breaking phenomenon caused by the bumping of the low boiling point foaming agent, and a foamed heat insulating material having excellent heat insulating properties can be obtained. Is.

As described above, the foamed heat insulating material of the present invention uses low boiling point HCFC or HFC having a small ozone depletion coefficient as a foaming agent, thereby contributing to solving environmental problems such as ozone layer depletion and diole. Alternatively, by using a polyether polyol having a triol as an initiator as a part of the polyol component, it is possible to improve the solubility of the raw material, and the solubility of the conventional foaming agent is remarkably poor. It is possible to select a heat insulating material, which contributes to quality improvement by energy saving due to excellent heat insulating performance.

Furthermore, an HFC having an ozone depletion potential of 0
By using, it is possible to produce an effective foam insulation material against global environmental problems.

The heat-insulating box body filled with the foamed heat-insulating material can ensure excellent quality as a heat-insulating box body without problems such as perspiration at the void generation portion and deterioration of heat insulation performance.

In the comparative example, when the polyether polyol having glycerin as an initiator was not added (Comparative Example A), the low-boiling foaming agent could not be sufficiently dissolved, and the mixed polyol component was used. The pressure increased, and bumping occurred at the time of discharge, resulting in non-uniform mixing, and it was not possible to form a foam due to the generation of froth voids, bubble breakage, and the like.

Further, when 35% of polyetherpolyol having glycerin as an initiator is added to the whole polyol component (Comparative Example B), the low boiling point blowing agent can be sufficiently dissolved. However, due to the compositional characteristics of the polyol component, the closed cell ratio was lowered, and the heat insulating performance was significantly deteriorated.

[0026]

INDUSTRIAL APPLICABILITY As described above, the present invention provides a polymer having a hydroxyl value of 500 to 1000 mgKOH / g, which is obtained by addition-polymerizing an organic polyisocyanate with ethylene oxide or propylene oxide using diol or triol as an initiator. -A polyol component containing at least 5 to 25% of terpolyol, a foam stabilizer, a catalyst, and a blowing agent containing HCFC or HFC having a boiling point of -50 ° C or higher and 0 ° C or lower as at least one component. Since the foam insulation material is generated by stirring, it is possible to improve the compatibility between the low boiling point foaming agent composed of HCFC or HFC and the polyol component, and a uniform fine cell structure is generated by the uniform foaming behavior. It is possible to provide a foamed heat insulating material having excellent physical properties in terms of thermal conductivity. In particular, it is possible to use a general hard polyurethane foam polyether polyol which is effective in reducing the thermal conductivity but has a significantly poor solubility with a low boiling point foaming agent, and the physical properties are remarkably improved. Is something that can be demonstrated.

Furthermore, HFC has an ozone depletion coefficient of 0, and not only does it have no effect on ozone depletion alone, but it also causes ozone depletion in a mixed system with HCFC, which has some effect on ozone depletion. On the other hand, it is possible to produce an effective foam insulation material.

Further, by filling the foamed heat insulating material to form a heat-insulating box, there is no problem of sweating in the void portion or deterioration of heat-insulating performance, and the quality as an excellent heat-insulating box can be secured. This also contributes to the solution of global environmental problems such as ozone layer depletion due to CFC.

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Claims (4)

[Claims] 1. A hydroxyl value of 5 formed by addition-polymerizing an organic polyisocyanate with ethylene oxide or propylene oxide using diol or triol as an initiator.
A polyol component containing at least 5 to 25% of polyether polyol of 0 to 1000 mg KOH / g, a foam stabilizer, a catalyst, and hydrochlorofluorocarbon having a boiling point of -50 ° C to 0 ° C. A foamed heat insulating material produced by foaming by mixing and stirring at least one foaming agent. 2. A hydroxyl value of 5 obtained by addition-polymerizing an organic polyisocyanate with ethylene oxide or propylene oxide using diol or triol as an initiator.
At least a polyol component containing at least 5 to 30% of polyether polyol of 0 to 1000 mg KOH / g, a foam stabilizer, a catalyst, and hydrofluorocarbon having a boiling point of -50 ° C to 0 ° C. A foamed heat insulating material produced by foaming by mixing and stirring a foaming agent as one component. 3. A heat insulation box body comprising an outer box, an inner box, and the foamed heat insulating material according to claim 1, which is foam-filled in a space formed by the outer box and the inner box. 4. A heat insulating box body comprising an outer box, an inner box, and the foamed heat insulating material according to claim 2, wherein a space formed by the outer box and the inner box is foam-filled.