| 摘要 |
In the preparation of spherulitic nitroguanidine of high poured (bulk) and tapped density, nitroguanidine is brought into solution in dipolar aprotic solvents, e.g. DMF, DMSO, NMP or the like, by heating to above the saturation temperature ts and the supersaturated solution is cooled under a controlled temperature gradient ( DEG C/min), with crystal formation being aided by addition of particulate, spherulitic material. To obtain spherical nitroguanidine in high yield in a continuous process with reuse of the mother liquor, regularly spherical control particles having a diameter of from 5 to 500 mu m are added in an amount of from 0.05 to 5.00 % by mass to the solution while heating to above the saturation temperature ts, with the particle size being selected in such a way that, depending on the solution behaviour of the nitroguanidine used and its concentration, spherical control particles continue to be present in the specified amount in the supersaturated solution when the temperature drops below the saturation temperature.
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