Method of producing high bulk density spheroidal nitroguanidine

Abstract

A process for producing high bulk density spheroidal nitroguanidine by fong a solution of from 2 to 9 weight percent of nitroguanidine, 0.5 to 2.0 weight percent of methylcellulose, and 0.5 to 2.0 weight percent of partially hydrolyzed poly(vinyl alcohol) in water at a temperature of from 50.degree. C. to 100.degree. C., and then cooling the solution at a rate of from I to 20.degree. C./minute until the solution temperature is less than 40.degree. C.

Claims

1. A process for recrystallizing nitroguanidine comprising:

(1) forming an aqueous nitroguanidine solution at a temperature of from about 50.degree. C. to about 100.degree. C. which comprises

(a) from 2 to 9 weight percent of nitroguanidine;

(b) from 0.5 to 2.0 weight percent of methyl cellulose,

(c) from 0.5 to 2.0 weight percent of a polyvinyl alcohol; and with

(d) water being the remainder of the solution;

(2) cooling the aqueous nitroguanidine solution under continuous and vigorous agitation at a cooling rate of from 1.degree. C./minutes to 20.degree. C./minute until the temperature of the solution is below 40.degree. C.; and

(3) isolating the product spheroidal nitroguanidine crystals.

2. The process of claim 1 wherein nitroquandine comprises from 6 to 8 weight percent of the nitroguanidine solution in step (1).

3. The process of claim 1 wherein methyl cellulose comprises from 0.6 to 1.0 weight percent of the nitroguanidine solution in step (1).

4. The process of claim 1 wherein the polyvinyl alcohol comprises from 0.6 to 1.0 weight percent of the nitroguandine solution in step (1).

5. The process of claim 1 wherein the temperature in step (1) is from 50.degree. C. to 100.degree. C.

6. The process of claim 1 wherein the cooling rate in step (2) is from 1.degree. C. to 20.degree. C./min.

7. The process of claim 1 wherein the aqueous nitroguanidine solution is agitated in step (2) by stirring.