Method of manufacturing a self-sealing composition

A process of manufacturing a self-sealing elastomer composition that includes a diene elastomer, a hydrocarbon resin with a given softening temperature, and a liquid plasticizing agent, the process comprising, in the listed order, the steps of:

• incorporating the hydrocarbon resin in the diene elastomer by kneading the hydrocarbon resin and the diene elastomer in a mixer up to a hot compounding temperature greater than the softening temperature of the hydrocarbon resin, wherein the hot compounding temperature is greater than 70° C., in order to obtain a masterbatch;
• wherein in the step of incorporating the hydrocarbon resin, the diene elastomer is brought into contact with the hydrocarbon resin in a liquid state, and the hydrocarbon resin is iniected in the liquid state into the mixer;
• incorporating the liquid plasticizing agent in the masterbatch a crosslinking agent for at least 50% by weight of the crosslinking agent, wherein the crosslinking agent is incorporated in the masterbatch by mixing in the mixer or in a different mixer;
• incorporating the liquid plasticizing agent in the masterbatch by kneading the liquid plasticizing agent and the masterbatch in a mixer or in another mixer, in order to obtain the self-sealing composition;
• and forming the self-sealing composition as a semi-finished product capable of being used directly in the assembly of a tire blank, wherein the hydrocarbon resin has a Tg of greater than 25° C., a softening point of greater than 50° C., a number-average molar mass (Mn) of between 400 and 2000 g/mol, a polydispersity index (PI) of less than 3 (PI=Mw/Mn with Mw the weight-average molecular weight).