JPH04224834A - Foamed insulation material - Google Patents

Abstract

PURPOSE:To provide a foamed insulation material to be used in a refrigerator, a freezer or the like by using HCFC141b as a blowing agent without detriment to its foam properties such as density without causing environmental problem such as destruction of the ozone layer. CONSTITUTION:A foamed heat-insulation material prepared by mixing a polyol component containing at least 20% polyetherpolyol with an organic polyisocyanate, a foam stabilizer, a catalyst, a blowing agent comprising HCFC141b, and trimethylolpropane as an initiator under agitation and foaming the mixture.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a foamed heat insulating material used in refrigerators, freezers, etc.

0002

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

[0003] For this reason, in the production of rigid urethane foam, which is a typical foam insulation material, there are methods using carbon dioxide gas obtained by the reaction of organic polyisocyanate and water as part of the blowing agent, and methods using CFC. 1,1, dichloro, 2, which is an alternative substance and has less impact on ozone depletion
2,2, trifluoroethane (hereinafter referred to as HCFC123) and 1,1, dichloro, 1, fluoroethane (
Various improvement efforts are being considered, such as foaming using HCFC141b (hereinafter referred to as HCFC141b).

For example, as announced at the Industrial Pollution Control Association's ``Briefing Session on the Act on the Protection of the Ozone Layer through the Regulation of Specified Substances,'' held on July 15, 1988, HCFC141b was When used as a foaming agent, the initial reactivity (creaming time) is delayed;
It is stated that the fluidity deteriorates and that there are problems with filling properties when considering application to insulating boxes.

[0005] As described above, the current situation is that it is not easy to replace HCFC141b, which has little effect on ozone layer depletion, as a blowing agent for current rigid urethane foams, and there are many problems.

[0006]

[Problems to be Solved by the Invention] In this way, the conventional technology has been proposed in accordance with the Law Concerning the Protection of the Ozone Layer through Regulation of Specified Substances, etc., published by the Industrial Pollution Control Association, held on July 15, 1986. As announced at the ``Briefing session'', when HCFC141b is used in large amounts or alone, the HCFC141b dissolved in the raw material polyol does not vaporize quickly during the foam forming process, resulting in an increase in initial reactivity (creaming). This has disadvantages in that the fluidity deteriorates and the foam density increases due to the slow time (time).

[0007] Therefore, even when HCFC141b is used alone, CFC141b can be used without impairing other physical properties.
The challenge was to obtain a density equivalent to that of 1.

[0008] The present invention solves the conventional problems.
without impairing the foam properties such as the density of the foam insulation material.
The company provides foam insulation materials that solve environmental problems such as ozone layer depletion.

[0009]

[Means for Solving the Problems] In order to solve the above problems, the present invention provides an organic polyisocyanate, a foam stabilizer, a catalyst, a foaming agent consisting of 1,1, dichloro, 1, fluoroethane, and A foamed heat insulating material is obtained by mixing and stirring a polyol component containing 20% or more of a polyether polyol using propane as an initiator.

0010

[Function] With the above structure, the trifunctional trimethyl
The polyether polyol using propane as an initiator is
In addition to having a small affinity with HCFC141b, it quickly starts reacting with the organic isocyanate and rapidly generates reaction heat, so HCFC141b dissolved in the resin starts foaming without any problems and contributes to foam formation. It is.
Therefore, an excellent foamed heat insulating material can be obtained without the disadvantage of increased foam density.

[0011]

[Examples] The foamed heat insulating material of the present invention will be explained below with reference to Examples.

Table (1) shows the raw material formulation.

[0013]

[Table 1]

That is, polyether A is a polyether polyol using trimethylolpropane as an initiator and has a hydroxyl value of 880 mgKOH/g, and polyether B is an aromatic amine-based polyether polyol with a hydroxyl value of 460.
mgKOH/g, foam stabilizer A is F-33 manufactured by Shin-Etsu Chemical Co., Ltd.
5. Catalyst A is Kaolizer No. manufactured by Kao Corporation. 1. The foaming agent is HCFC141b. Each raw material is mixed in a predetermined number of parts to form a premix component.

On the other hand, the isocyanate component is an organic polyisocyanate consisting of crude MDI having an amine equivalent of 135.
It is A.

The premix component and isocyanate component thus prepared were mixed in a predetermined proportion and foamed in a high-pressure foaming machine to obtain a foamed heat insulating material. The reactivity, density, and thermal conductivity at this time are shown in (Table 1).

At the same time, as a comparative example, trimethyl
Foaming without mixing polyether polyol with trimethylolpropane as an initiator (comparative example A) and 10% polyether polyol with trimethylolpropane as an initiator
When mixed and foamed (Comparative Example B) and as a foaming agent,
The case of foaming using CFC-11 (Comparative Example C) is also shown in Table 1.

As described above, in the foamed heat insulating material of the present invention, even if the foaming agent is 100% HCFC141b, the density can be reduced and an excellent foamed heat insulating material can be obtained. This is because polyether polyols using trifunctional trimethylolpropane as an initiator have a small affinity for HCFC141b, and also quickly start reacting with organic isocyanates, rapidly generating heat of reaction. Therefore, the HCFC141b dissolved in the resin starts foaming without any problem and contributes to foam formation.

In Comparative Examples, foaming was performed without mixing polyether polyol using trimethylolpropane as an initiator (Comparative Example A), and when 10% of the polyether polyol was mixed (Comparative Example B), As can be seen from the slow reaction time, HCFC141b
It is not possible to generate enough reaction heat to vaporize the foam, which results in gelation, resulting in a high foam density.

[0020]

Effects of the Invention As described above, the present invention provides a blowing agent consisting of an organic polyisocyanate, a foam stabilizer, a catalyst, 1,1, dichloro, 1, fluoroethane, and a polyester containing trimethylolpropane as an initiator. A polyol component containing 20% or more of terpolyol is mixed and stirred to produce a foamed heat insulating material.

As a result, the polyether polyol using the trifunctional trimethylolpropane as an initiator quickly starts to react with the organic polyisocyanate and rapidly generates reaction heat. Even when used, an excellent foamed heat insulating material can be obtained without impairing the physical properties of the foam, such as increased density.

[0022] Furthermore, it can contribute to solving environmental problems such as ozone layer depletion and global warming caused by the effects of CFCs.

Claims (1)

[Claims] Claim 1: 20% or more of an organic polyisocyanate, a foam stabilizer, a catalyst, a blowing agent consisting of 1,1, dichloro, 1, fluoroethane, and a polyether polyol using trimethylolpropane as an initiator. Foamed insulation material produced by mixing and stirring mixed polyol components.