High-rigidity rubber composition

A method for manufacturing a solid rubber composition comprising the steps of:

• incorporating, in a diene elastomer, during a first step, a reinforcing filler, to make a mixture and kneading the mixture thermomechanically until a maximum temperature of between 110° C. and 190° C. is reached;
• cooling the mixture to a temperature of less than 100° C.;
• then incorporating, during a second step, a crosslinking system, at least one aromatic polyphenol comprising at least one aromatic ring bearing at least two hydroxyl functions in the meta position relative to one another, the two positions ortho to at least one of the hydroxyl functions being unsubstituted, and at least one aldehyde of formula (A)
• in which X comprises N, S or O, and R represents CHO;
• and
• kneading the mixture up to a maximum temperature of less than 110° C.,
• wherein the rubber composition comprises from 30 to 90 phr total reinforcing filler.