JPH0362815A - Foamed insulation material - Google Patents

Abstract

PURPOSE:To obtain a foamed insulation material which is used in freezers and refrigerators without damage on the foam properties of increased density, by agitating a mixture comprising an organic polyisocyanate, a foaming agent, a catalyst, a specific foaming agent and a specific polyol component. CONSTITUTION:A foaming agent comprising an organic polyisocyanate, a foam stabilizer, a catalyst, and dichlorotrifluoroethane is mixed under stirring with the polyol component comprising more than 20% of polyether-polyol prepared by using trimethylolpropane as an initiating agent to effect foaming whereby the subject insulating material is obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a foamed heat insulating material used in refrigerators, freezers, etc.

Prior art In recent years, chlorofluorocarbons (hereinafter referred to as CFCs)
Environmental problems such as ozone layer depletion and global warming due to the effects of environmental pollution are attracting attention. From this point of view, reducing the amount of CFC used as a blowing agent has become an extremely important theme.

For this reason, in the production of rigid urethane foam, which is a typical foam insulation material, there are methods that use carbon dioxide gas obtained by the reaction of organic polyisocyanate and water as part of the blowing agent, or alternative materials for CFC. Foaming with dichlorotrifluoroethane (hereinafter referred to as HCFC123) and dichlorofluoroethane (hereinafter referred to as HCFC-141b), which have little impact on ozone depletion, etc.
Various improvement efforts are being considered.

For example, as an example of foaming rigid urethane foam using HCFC-123, JP-A No. 6218418 describes trichlorofluoroethane (hereinafter referred to as CFC-11).
and HCFC-123 in a weight mixing ratio of 97:3 to so:40.

Problems to be Solved by the Invention However, as mentioned in JP-A-62-18418, when HCFC123 is used in large amounts or alone, the density of the hard urethane foam increases, which is the problem 3. have. This means that the molecular weight of HCFC-123 is C
It may be larger than FC-11, but more than that, H
Due to CFC-123's high affinity with resin and strong solubility, the HCFC-123 dissolved in the raw material polyol during the foam formation process does not vaporize quickly and has a high density. It is considered to be a thing. Therefore, even when HCFC-123 is used alone,
The challenge was to obtain a density equivalent to that of CFC-11 without impairing other physical properties.

In view of the above problems, the present invention provides a foam insulation material that solves environmental problems such as ozone layer depletion without impairing the foam properties such as density of the foam insulation material.

Means for Solving the Problems In order to solve the above problems, the present invention uses a blowing agent consisting of an organic polyisocyanate, a foam stabilizer, a catalyst, and dichlorotrifluoroethane, and a polyether polyol having dolimethylolpropane as an initiator. A foamed heat insulating material is obtained by mixing and stirring a polyol component in which at least 20 tI) of polyol is mixed.

Effect With the above configuration, the polyether polyol using trifunctional trimethylopropane as an initiator can be used as an HCFC-1
HCFC-123 has a small affinity with HCFC-123 and quickly starts to react with the organic incanate, rapidly generating reaction heat, so HCFC-123 dissolved in the resin starts foaming without any problems and contributes to foam formation. . Therefore, an excellent foamed heat insulating material can be obtained without the disadvantage of increased foam density.

Example Hereinafter, the foamed heat insulating material of the present invention will be explained with reference to Examples.

Table 1 shows the raw material formulation of one example.

Polyether A is a polyether polyol using trimethylolpropane as an initiator and has a hydroxyl value of 880 KOH.
/y, polyether B is an aromatic amine-based polyether polyol with a hydroxyl value of 460 KOH/3, foam stabilizer A is F-335 manufactured by Shin-Etsu Chemical @), and catalyst A is Kaolizer Todoroki 1 manufactured by Kao Corporation. , the blowing agent is 6...HCFC-123. Each raw material is mixed in a predetermined number of parts to form a premix component.

On the other hand, the isocyanate component is organic polyisocyanate A consisting of crude MDI having an amine equivalent of 136.

The thus prepared premix component and isocyanate component were mixed in a predetermined number of parts and foamed using a high-pressure foaming machine to obtain a foamed heat insulating material. The reactivity and density at this time,
The thermal conductivity is shown in Table 1.

At the same time, as a comparative example, foaming was performed without mixing polyether polyol using trimethylolpropane as an initiator (Comparative Example A), and foaming was performed by mixing 10% of polyether polyol using trimethylolpropane as an initiator. (Comparative Example B) and as a blowing agent, CFC-11
Table 1 also shows the case of foaming using (Comparative Example C).

In this way, the foamed heat insulating material of the present invention uses HCF as a foaming agent.
Even if C-123 is greater than 100, an excellent foamed heat insulating material can be obtained with a lower density.

This is because polyether polyols using trifunctional trimethylolpropane as an initiator have a small affinity with HCFC-123, and also quickly start reacting with organic isocyanates, rapidly generating heat of reaction. Therefore, HCFC-123 dissolved in the resin starts foaming without any problem and contributes to foam formation.

In addition, in the comparative examples, foaming was performed without mixing polyether polyol with trimethylolpropane as an initiator (comparative example A), and when 10q6 was mixed (comparative example B).
), as can be seen from the slow creaming time, it is not possible to generate enough reaction heat to vaporize HCFC-123 in the early stage of the reaction, resulting in gelation. , the foam density becomes higher.

Effects of the Invention As described above, the present invention provides a blowing agent consisting of an organic polyisocyanate, a foam stabilizer, a catalyst, dichlorotrifluoroethane,
And, since the polyol component is mixed and stirred with 20% or more of polyether polyol with trimethylolpropane as an initiator, it is produced as a foamed insulation material, so polyether with trimethylolpropane as an initiator is produced. Since the polyol quickly starts to react with the organic polyisocyanate and rapidly generates reaction heat, HCF
Even when 100% C-123 is used, an excellent foamed heat insulating material can be obtained without impairing the physical properties of the foam such as increased density.

As a result, it is possible to contribute to solving environmental problems such as ozone layer depletion and global warming due to the influence of CFCs.

Claims (1)

[Claims] Foamed insulation produced by mixing and stirring a foaming agent consisting of an organic polyisocyanate, a foam stabilizer, a catalyst, and dichlorotrifluoroethane, and a polyol component that is a mixture of 20% or more of polyether polyol using trimethylolpropane as an initiator. Material.