Decomposition inhibitor for hydrogen- and fluorine-containing ha

Details Decomposition inhibitor for hydrogen- and fluorine-containing ha Decomposition inhibitor for hydrogen- and fluorine-containing ha

1995-06-22

1997-12-09

Ivy, C. Warren

Organic compounds -- part of the class 532-570 series

Organic compounds

Halogen containing

570110, 570111, 570112, 570117, 570121, C07C 1908

Patent

active

056963068

DESCRIPTION:

BRIEF SUMMARY
This application is a 35 USC 371 National Stage filing of PCT/JP93/01639 published as WO94/11329 on May 26,1994.


TECHNICAL FIELD

The present invention relates to a decomposition inhibitor for hydrogen- and fluorine-containing halogenated hydrocarbons and a method of inhibiting decomposition using the same. More particularly, the invention relates to a decomposition inhibitor capable of preventing hydrogen- and fluorine-containing halogenated hydrocarbons which are useful as blowing agents for foamed insulation materials (polyurethane foams) from decomposing during storage as raw materials for foamed insulation materials, during use as blowing agents (in the process of manufacturing foamed insulation materials) or during existence in the bubbles in products (foamed insulation materials) and relates to a method of using the same (for preventing hydrogen- and fluorine-containing halogenated hydrocarbons from decomposing).
In the present specification, "%" and "part(s)" mean "% by weight" and "part(s) by weight", respectively.


BACKGROUND ART

Polyurethane foams, which are produced by using organic polyisocyanates and polyols as principal raw materials, are known as typical foamed insulation materials.
Various blowing agents comprising "halogenated hydrocarbons with all the hydrogen atoms replaced by fluorine and chlorine" (hereinafter referred to as CFCs) have been proposed for use in the production of said polyurethane foams (cf. e.g. Japanese Kokai Tokkyo Koho JP 52-46005) and have been widely used on a large commercial scale.
However, CFCs contained in such blowing agents are known to destroy the ozone layer and therefore restrictions have been imposed on the production and use thereof.
Thus, the advent of novel blowing agents comparable in performance characteristics to CFCs and capable of serving as substitutes therefor has been awaited. For the time being, "hydrogen- and fluorine-containing halogenated hydrocarbons" (hereinafter referred to as HCFCs/HFCs) are regarded as promising since they involve no or little risk of depleting the ozone layer.
Regrettably, however, HCFCs/HFCs are generally lacking in stability as compared with the conventional CFCs. It is known that they are particularly unstable when used in the form of a mixture with an alcoholic hydroxyl-containing compound. In addition, they are readily decomposable in the presence of water an alkali or a metal or under the action of light or heat, for instance. Methods have been proposed for preventing the decomposition of HCFCs/HFCs, for example by adding a nitro-containing hydrocarbon (Japanese Kokai Tokkyo Koho JP 01-128944) or adding a nitro-containing hydrocarbon and an epoxide (Japanese Kokai Tokkyo Koho JP 01-128945).
The methods described in the above-cited patent specifications all aim to prevent the decomposition of such HCFCs/HFCs as mentioned above in an unstable state, for example in the presence of a polyol used as a raw material in the production of polyurethane foams.
However, the known methods described in the above laid-open patent specifications cannot be said to be fully satisfactory in the effect of inhibiting the decomposition of HCFCs/HFCs. This is because HCFCs/HFCs gradually decompose not only during storage thereof but also in the process of polyurethane foam manufacture using HCFCs/HFCs and during a long period of use of polyurethane foam products manufactured by using HCFCs/HFCs (said HCFCs/HFCs thus occurring in the foam (bubbles)). Accordingly, there has been earnestly desired the advent of a novel method of preventing the decomposition of HCFCs/HFCs and thus keeping the HCFCs/HFCs stable under any of the condition mentioned above.


DISCLOSURE OF THE INVENTION

In view of the state of the art as mentioned above, the present inventors made intensive research and found the following: a carboxylic acid having an acid dissociation constant (pKa) of not more than 5 and a tertiary amine having an acid dissociation constant (pKa) of not more than 10; chlorinated hydrocarbons; acid having an acid dissociation constant

REFERENCES:
patent: 4960535 (1990-10-01), Logsdon et al.
The Merck Index, 8th ed. (1968) p. 683.

Affiliated with

Also associated with

Rating

Decomposition inhibitor for hydrogen- and fluorine-containing ha does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Decomposition inhibitor for hydrogen- and fluorine-containing ha, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Decomposition inhibitor for hydrogen- and fluorine-containing ha will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFUS-PAI-O-1609341