CAR PNEUMATIC TIRE FOR WINTER SEASON

摘要

In these pneumatic tyres which are constructed as radial tyres, the part of the contact strip zone located above the belt is of two- layered construction. An upper layer having the tread is provided above a base layer. In order to exclude damage due to elevated temperature effects and thus obtain high speed resistance and also to avoid formation of fractures in the profile base, a synthetic rubber with a dynamic E module of approximately 6 to 15 N/mm<2> and a dynamic loss module of approximately 1.5 to 4.0 N/mm<2> is used for the base layer facing the belt. The base layer designed in this way should receive a hardness which is greater than that of the upper layer, that is to say be harder by approximately 10 to 15 Shore Grade A. In particular, the grip in wet conditions of the base layer should be greater than the grip in wet conditions of the upper layer. The differences should be approximately 4 to 7%. The dividing face between the upper layer and the base layer can also be arranged above the profile base.