Method of manufacturing a self-sealing composition

摘要

A self-sealing elastomer composition that includes a diene elastomer, a hydrocarbon resin with a given softening temperature, and a liquid plasticizing agent, is manufactured according to a process that includes successive stages. In one stage, the hydrocarbon resin is incorporated in the diene elastomer by kneading the resin and the elastomer in a mixer at or up to a temperature referred to as “hot compounding” temperature, which is greater than the softening temperature of the resin, in order to obtain a masterbatch. In another stage, the liquid plasticizing agent is incorporated in the masterbatch by kneading the agent and the masterbatch in the same mixer or in another mixer, in order to obtain the self-sealing composition. The self-sealing composition then is formed dimensionally.

主权项

1. 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).