History of solid propellant development in Japan

Abstract

This paper describes the various types of solid rocket propellants which have been developed in Japan. The propellants developed first in Japan was an extruded doublebase propellant which was applied to the missile F u n y used during World War Il , The production process used was based on the gun propellant technology. The doublebase propellant technology was improved significantly through the mass production requirement using anti-tank rocket projectile soon after World War II . On the other hand, composite propellants were developed after various types of polymers were synthesized. Polyester polymer was the first polymer as a binder used ammonium perchlorate composite propellants. Several types of strand burners were prepared to measure the burning rate characteristics during '60. Small propellant grains were also formulated to evaluate the ballistic properties such as' pressure vs time curve, specific impulse, and ignitability. Using polyurethane polymer and ammonium nitrate, smokeless propellants which burn at low pressure below 1.0 MPa were developed. This technology played an important role because double-base propellants never burned such low pressure region. In '70 the mechanical properties of double-base propellants have been improved by the addition of polymer mixed within nitroglycerine, the so called composite double--base propellants. Furthermore, the technical trends of the propellant ingredients in the past three decades will be presented. Typical examples of energetic polymers are azide polymer characterized with -N I chemical bonds.