Pneumatic vehicle tire with cap/base tread
The invention relates to a vehicle tire, especially utility vehicle tire, comprising a tread which has a tread cap ( 9 ) and a tread base ( 8 ), both produced from a rubber mixture, and a multilayer ply structure ( 3, 4, 5, 6 ) with at least one undertread strip ( 7, 7′ ) covering the ply edges and separating the same from the tread base, said undertread strip being likewise produced from a rubber mixture. The aim of the invention is to reduce temperature and heat build-up in the area of the ply edges. For this purpose, the tread base ( 8 ) has a heat conductivity that is by at least 20% higher than that of the tread cap ( 9 ) and a heat conductivity that is by at least 10% higher than that of the one or more undertread strips ( 7, 7′ ), and the tread base ( 8 ) contains at least 25 phr of acetylene black.
1 : A pneumatic vehicle tire, in particular a tire for a commercial vehicle, with a tread rubber, which has a tread rubber cap ( 9 ) and a tread rubber base ( 8 ) that are in each case produced from a rubber mixture, and with a multiply breaker belt assembly ( 3 , 4 , 5 , 6 ) with at least one undertread rubber ( 7 , 7 ′) that is likewise produced from a rubber mixture, covering the breaker edges and separating them from the tread rubber base ( 8 ), wherein the tread rubber base ( 8 ) has a thermal conductivity that is at least 20% higher than the tread rubber cap ( 9 ) and a thermal conductivity that is at least 10% higher than the undertread rubber or rubbers ( 7 , 7 ′).
2 : The pneumatic vehicle tire as claimed in claim 1 , wherein the tread rubber base ( 8 ) contains at least 25 parts by weight of acetylene black, referred to 100 parts by weight of rubber in the initial mixture.
3 : The pneumatic vehicle tire as claimed in claim 1 , wherein the tread rubber base ( 8 ) contains between 42 and 60 parts by weight of acetylene black, referred to 100 parts by weight of rubber in the initial mixture.
4 : The pneumatic vehicle tire as claimed in claim 1 , wherein the tread rubber base ( 8 ) has a Shore A hardness that is at most 2 Shore A points lower than the Shore A hardness of the tread rubber cap ( 9 ).
5 : The pneumatic vehicle tire as claimed in claim 1 , wherein the tread rubber base ( 8 ) is produced from a rubber mixture that contains 55 to 100 parts by weight of natural rubber, 0 to 35 parts by weight of butadiene rubber and up to 10 parts by weight of at least one further rubber, in each case based on 100 parts by weight of rubber in the mixture.
6 : The pneumatic vehicle tire as claimed in claim 1 , wherein the tread rubber base ( 8 ) is produced from a rubber mixture that contains sulfur in a proportion that is between 0.5 and 2.5 times the proportion of accelerator.
7 : The pneumatic vehicle tire as claimed in claim 1 , wherein the undertread rubber ( 7 , 7 ′) is produced from a rubber mixture that contains a steel cord bonding system.
8 : The pneumatic vehicle tire as claimed in claim 1 , wherein the tread rubber base ( 8 ) lies completely inside the tire.
9 : The pneumatic vehicle tire as claimed in claim 1 , wherein the tread rubber base ( 8 ) is produced from a rubber mixture that contains between 5 and 20 parts by weight of carbon black of the type N 326 and/or of the type N 339 in addition to acetylene black.