Process for coating pyrotechnic materials

• US 4,179,327 A
• Filed: 07/13/1978
• Issued: 12/18/1979
• Est. Priority Date: 07/13/1978
• Status: Expired due to Term

• Current Assignee: Allied Chemical Corporation (Honeywell International Inc.)
• Original Assignee: Allied Chemical Corporation (Honeywell International Inc.)
• Inventors: Seldner, Alvin A.
• Primary Examiner(s): Powell, William A.
• Application Number:
  US05/924,262
• Time in Patent Office: 523 Days
• Field of Search: 427/307, 427/309, 427/212, 427/215, 149/2, 149/3, 102/99, 102/104, 156/625, 156/626, 156/667, 156/668, 252/79.1
• US Class Current: 216/101
• CPC Class Codes: C06B 21/0083 Treatment of solid structures, e.g. for coating or impregnating with a modifier compositions therefor C06B23/00

Abstract

A method for preparing the surface of pyrotechnic propellant compositions for coating by emersing said compositions in an aqueous/alcohol solution.

Claims

1. A method of treating the surface of a pyrotechnic propellant material prior to application of a coating on said material which comprises etching the surface of the material with a solution comprised of about 1 to 10 vol. % water and 99 to 90 vol. % of a C₁ to C₄ aliphatic alcohol for an effective amount of time.

2. The method of claim 1 wherein the C₁ to C₄ alcohol is selected from the group consisting of methanol, ethanol, and isopropanol.

3. The method of claim 2 wherein the solution consists of about 2 to 4 vol. % water and 98 to 96 vol. % alcohol.

4. The method of claim 3 wherein the pyrotechnic propellant is in pellet form.

5. The method of claim 1 wherein the pyrotechnic material is comprised of an inorganic oxidizer, an oxygen-containing polymeric compound, and a coolant.

6. The method of claim 5 wherein the inorganic oxidizer is sodium chlorate, the oxygen-containing polymeric compound is a polyacetal resin, and the coolant is calcium hydroxide.

7. The method of claim 1 wherein the pyrotechnic material is comprised of an alkali or alkaline earth metal azide and a metal oxide.

8. The method of claim 7 wherein the alkali-metal azide is sodium azide and the metal oxide is iron oxide.