Method of producing a composition based on a polymer crosslinked using a silane, a composition obtained by said method, and a method of producing a cable provided with a sheath of said composition
The present invention concerns a method of producing a composition based on a polymer crosslinked using a silane, the method comprising the following operations: a) mixing: i) a thermoplastic base polymer or a mixture of thermoplastic base polymers containing a flame retarding filler; ii) a carrier polymer for a silane-based crosslinking agent, the carrier polymer being solid and selected from porous sponge type polymers, swellable polymers, and encapsulates, which carrier polymer is soluble or dispersible in the base polymer and does not react with the silane; and iii) a free radical generator; b) heating the mixture; and c) exposing the mixture to a sufficient quantity of water to allow the base polymer to crosslink; and, during the heating operation, the mixture is heated to a temperature to cause the free radical generator to decompose without decomposing the filler, the free radical generator being selected so that its absolute decomposition temperature is less than 165.degree. C., and the crosslinking operation is carried out in an ambient atmosphere.
