Gas generating composition for inflator containing melamine cyanurate

Abstract

To provide a gas generating composition for air bag which is low in toxicity, large in burning rate, and low in combustion temperature. Gas generating compositions comprising (a) melamine cyanurate or a mixture of melamine cyanurate and nitrogen-containing organic compound and (b) oxygen-containing oxidant, and gas generating compositions comprising (c) binder and (d) additive are provided.

Description

TECHNICAL FIELD TO WHICH THE INVENTION BELONGS [0001] The present invention relates to a gas generating composition which is suitable for air bag restraining system in automobiles and the like, its molded article and an air bag inflator using the same. PRIOR ART [0002] Conventionally, compositions using sodium azide have been often used as a gas generating agent for an air bag which serves as an occupant protecting apparatus in an automobile. However, as the toxicity to human body [LD50(oral-tat)=27 mg / kg] and danger in handling of sodium azide is becoming problems, gas generating compositions containing various kinds of nitrogen-containing organic compounds have been developed as so-called non-azide based gas generating compositions which are safer alternatives. [0003] U.S. Pat. No. 4,909,549 discloses a composition comprising a hydrogen-containing tetrazole, a triazole compound and an oxygen-containing oxidant. U.S. Pat. No. 4,370,181 discloses a gas generating composition compris...

AI Technical Summary

Benefits of technology

[0013] Since the gas generating composition and its molded article according to the present invention are low in toxicity and less dangerous, so that they are safe in handling, and have a large burning rate, a low combustion temperature and small amounts of generated carbon monoxide and nitrogen oxide at the time of combustion.PREFERRED EMBODIMENT OF THE INVENTION

[0014] Melamine cyanurate or a mixture of melamine cyanurate and nitrogen-containing organic compound of Component (a) used in the present invention is low in toxicity, and is preferably combined with Component (b) because low combustion temperature and large burning rate can be obtained.

[0015] Melamine cyanurate is desirable because it has such low toxicity of LD50 (oral-rat)=2020 mg / kg and excellent thermal stability, and is safe in handling and inexpensive.

[0019] The basic copper nitrate has excellent thermal stability because phase transition does not occur in the use temperature range and it has a high melting point. In addition, since it acts to lower the combustion temperature of gas generating agent, an amount of generated nitrogen oxide can also be reduced.

Problems solved by technology

However, as the toxicity to human body [LD50(oral-tat)=27 mg / kg] and danger in handling of sodium azide is becoming problems, gas generating compositions containing various kinds of nitrogen-containing organic compounds have been developed as so-called non-azide based gas generating compositions which are safer alternatives.

The above non-azide based gas generating compositions, however, have problems in respect of combustion temperature, burning rate, phase transition, amounts of generated carbon monoxide and nitrogen oxide, gas output, safety in handling and the like.

The gas generating composition disclosed in U.S. Pat. No. 4,369,079 has a high combustion temperature, and hence require a large amount of coolant in practical use.

As to the gas generating agent in JP-A No. 10-72273, a molded article of a gas generating composition is broken due to a form change caused by phase transition of ammonium nitrate in the use temperature range, so that stable combustion cannot be obtained.

In the patents of non-azide based gas generating agents other than JP-A No. 2001-220282, tetrazoles, nitroguanidine, TAGN and the like are used as a fuel for gas generating agent, but they are dangerous substances and has to be handled with special attention.