Alkyl nitrite compositions

This invention relates to a method of stabilizing liquid alkyl nitrites by adding ethyl hydroxyethyl cellulose, calcium silicate and mixtures thereof and mixing to produce solid state compositions and to stabilized compositions thereof.

BACKGROUND OF THE INVENTION 
This invention relates to a method of stabilizing liquid alkyl nitrites by 
conversion to a solid state and to stabilized compositions thereof. 
Liquid alkyl nitrite compounds, particularly isobutyl and isoamyl nitrites 
are powerful oxidizers and consequently, dangerous to handle. Shock may 
explode them. Heat may lead to violent decomposition reactions and fire. 
During storage in closed systems, degradation occurs with evolution of gas 
which may lead to detonation. 
In the past, alkyl nitrites in the liquid state have been stabilized 
against degradation with small amounts of alkaline earth metal oxides, 
alkali metal carbonates and phosphates as described in U.S. Pat. No. 
2,927,939 to Yunker et al. 
It has been now discovered that liquid alkyl nitrites can be stabilized by 
converting to a solid state with the aid of ethyl hydroxyethylcellulose, 
calcium silicate and mixtures thereof. These solid state compositions have 
relatively low volatility and are less susceptible to degradation in 
comparison with liquid compositions. Consequently, the solid state 
compositions are safer to handle and to store reducing the risk of 
explosion. 
The stabilized compositions retain their oxidizing properties and can be 
directly incorporated into propellant systems, household products and the 
like. 
SUMMARY OF THE INVENTION 
An object of the invention is to provide a method of stabilizing liquid 
alkyl nitrites selected from the group consisting of isobutyl nitrite and 
isoamyl nitrite by adding ethyl hydroxyethyl cellulose, calcium silicate 
and mixtures thereof to produce a solid state composition 
Another object of the invention is to provide stabilized, solid state alkyl 
nitrite compositions comprising about 70 to 80 percent by weight of alkyl 
nitrite selected from the group consisting of isobutyl nitrite and isoamyl 
nitrite and about 20 to 30 percent by weight of ethyl hydroxyethyl 
cellulose, calcium silicates and mixtures thereof.

DETAILED DESCRIPTION OF THE INVENTION 
In accordance with the invention, liquid alkyl nitrites are converted to a 
solid state with the aid of certain inert materials which are compatible 
with the nitrite and produce no chemical reaction leading to decomposition 
and instability of the compositions. These conditions are satisfied by 
ethyl hydroxyethyl cellulose and calcium silicate both of which are 
chemically inert towards the alkyl nitrites. 
Any ethyl hydroxyethyl cellulose may be used in preparing the solid state 
compositions of the invention. The preferred ethyl hydroxyethyl cellulose 
(EHEC) is one having a viscosity of 125 to 250 centipoises at 25.degree. 
C. The term viscosity means viscosity of 5 percent solution of EHEC in a 
solvent mixture of 80 parts of toluene and 20 parts ethanol. 
The calcium silicates of the invention can be selected from synthetic 
calcium silicates and diatomaceous earth. Particularly preferred is 
hydrous calcium silicate. The solid state compositions can be prepared 
either in gel form or in powder form depending on the applications 
desired. 
The gel type structure is obtained by adding ethyl hydroxyethyl cellulose. 
The amount added will depend somewhat on the viscosity desired. 
Preferably, ethyl hydroxyethyl cellulose is added in the amount of about 
20 to 30 percent by weight to maintain the gel structure of the 
composition during its shelf-life without developing syneresis. The formed 
gel has long shelf-life and displays stability towards temperature 
fluctuations and vibrational influences. 
The powder form is prepared by adding to the liquid nitrite calcium 
silicate in the amount of about 20 to 30 percent by weight. The powders 
which are formed are flowable and easy to handle. For greater economy, 
part of the calcium requirement can be substituted by ethyl hydroxyethyl 
cellulose. The preferred mixtures comprise ethyl hydroxyethyl cellulose 
and calcium silicate in the ratio of about 1:1 to 2:3. 
The following examples are intended to illustrate, but in no manner to 
limit the invention. 
All percentages and parts in the disclosure and claims are based on weight 
unless otherwise indicated. 
EXAMPLE I 
Ninety ml. of isobutyl nitrite was placed in a Hobart mixer, 25g. of ethyl 
hydroxyethyl cellulose was added and the mixture blended at low speed. The 
composition produced was a firm, solid gel. 
The composition was stored at room temperature for two months and examined 
visually. The composition retained its gel structure and no syneresis 
developed. There was no evidence of reaction such as bubble formation or 
discoloration. 
EXAMPLE II 
Twenty five g. of hydrous calcium silicate (Microcel E manufactured by 
Johns-Manville) was added to 90 ml. of isoamyl nitrite in a Hobart mixer. 
The mixture was blended at low speed to produce a powder with flowable 
characteristics. After two months of storage, there was no change in the 
characteristics of the powder. 
EXAMPLE III 
To 90 ml. of isobutyl nitrite was added 20g. of hydrous calcium silicate 
(Microcel E) and 5g. of ethyl hydroxyethyl cellulose. The mixture was 
blended in a Hobart mixer at low speed to produce a flowable powder. The 
powder retained its characteristics upon storage for two months.