Propallent compsns. cased in epoxy- or polyester insulating layer - with polyurethane adhesion- and anti-diffusion interlayer

Propellant compsn. with insulation of elasticized plastic, are composed of (a) a composite propellant, (b) an insulating layer based on epoxy- or polyester resin with an elongation at break of >=40% and (c) between the components (a) and (b), a thin adhesion-promoting and diffusion-limiting layer of polyurethane is not >500 mu m thick. Compsn. gives prods. less prone to mechanical damage during storage and transport; prevents gap formation between charge and insulation, which upsets burning characteristics; reduces cracking of the charge or the insulation during tempt. changes of -40 to + 60 degrees C; prevents diffusion of components such as nitroglycerine from the charge into the insulation, and/or of materials from the insulation, such as plasticizers, into the charge, which may affect the burning properties in the border region; prevents premature damage to the insulation by the effect of heat and/or too strong burning during firing of the charge. A preferred embodiment is a slow burning charge with a total burning time of 10-1000, esp. 100-400 sec. Pref. the polyurethane interlayer between the charge and insulation is 10-50 mu m thick. The insulator layer is pref. of a filled plastic compsn. contg. 10-80%, esp. 30-50% of a filler such as a metal borate, zinc sulphice or barium sulphate.