Patent attributes
The invention is a runflat insert comprising an outer contacting portion for contacting the interior surface of the tire during deflated operation; a reinforced annular band disposed radially inward of the outer contacting portion comprising an elastomeric shear layer, a membrane adhered to the radially inward extent of the elastomeric shear layer and a second membrane adhered to the radially outward extent of the elastomeric shear layer; a sidewall portion extending radially inward from the contacting portion for connecting the annular band to a base member fitted around the wheel rim for securing the insert to the rim; and a carcass layer adhered to the annular band and extending radially inward from the annular band and anchored in the base member. The elastomeric shear comprises a dienic composition that includes a metal salt of an unsaturated carboxylic acid and a peroxide curative agent.