Shaped- ammonium nitrate propellant

Claim 1

A SOLID PROPELLANT COMPRISING A SHAPED BODY PORTION, FORMED OF AMMONIUM NITRATE AS THE MAJOR COMPONENT AND AN OXIDIZABLE BINDER THEREFOR, THE SURFACE OF SAID BODY BEING CHARACTERIZED BY THE PRESENCE OF EXPOSED AMMONIUM NITRATE WHICH HAS NOT BEEN COVERED BY SAID BINDER, AN UNDERCOATING ADHERED TO AND ADAPTED TO SEAL THAT PART OF THE SURFACE OF SAID BODY WHERE DIRECT BURNING IS TO BE PREVENTED, WHEREBY CONTACT BETWEEN SAID EXPOSED NITRATE AND ANY MATERIAL POSITIONED ON SAID UNDERCOAT IS BARRED, AND A COMBUSTION RESTRICTOR COATING ADHERED TO SAID UNDERCOATING, WHICH RESTRICTOR IS FORMED FROM A MIXTURE CONSISTING ESSENTIALLY OF AN AROMATIC DIISOCYANATE AND A SATURATED POLYESTER HAVING TERMINAL HYDROXYL GROUPS AND A MOLECULAR WEIGHT BETWEEN ABOUT 600 AND 3000, WHEREIN BETWEEN ABOUT 1 AND 1.5 ISOCYANATE GROUPS ARE PRESENT PER HYDROXYL GROUP, AND A CATALYST FROM THE CLASS CONSISTING OF N-COCOMORPHOLINES, PYRIDINES, QUINOLINES, ISOQUINOLINES, AND ETHOXYLATED AMINES, MANITAINED ON DESIRED PORTION OF SAID BODY FOR THE TIME NEEDED TO FORM A SUBSTANTIALLY SOLID POLYURETHANE RESTRICTOR COATING.