Cords made of cellulosic multifilament yarns having an increased linear density of individual filaments

Abstract

A cord, in particular for reinforcing tyres, containing a cellulosic multifilament yarn is disclosed, where the cellulosic multifilament yarn has a strength of at least 35 cN/tex and the individual filaments of the multifilament yarn have a linear density of at least 2.3 dtex. In use, such cords exhibit a significantly improved fatigue behaviour—i.e., a significantly higher fatigue resistance—than standard cords with an individual-filament linear density between 1 and 2 dtex.

1 . A cord containing a cellulosic multifilament yarn, wherein the cellulosic multifilament yarn has a strength of at least 35 cN/tex and individual filaments of the multifilament yarn have a linear density of at least 2.3 dtex. 
     
     
         2 . The cord according to  claim 1 , wherein the individual filaments of the cellulosic multifilament yarn have a linear density of at least 2.7 dtex. 
     
     
         3 . The cord according to  claim 1 , wherein the cellulosic multifilament yarn has a strength of at least 40 cN/tex. 
     
     
         4 . The cord according to  claim 1 , wherein a cord construction with a twist factor of T f =185 in the disc fatigue test with compression/elongation settings of −20/+2% and 855,000 cycles—performed and evaluated in accordance with ASTM D 6588—exhibits a higher fatigue resistance by a factor of at least 1.1 than with the same twist factor and an individual-filament linear density of ≦2.0 dtex. 
     
     
         5 . The cord according to  claim 1 , wherein the cellulosic multifilament yarn is obtained by a regeneration process. 
     
     
         6 . The cord according to  claim 5 , wherein the cellulosic multifilament yarn is a rayon yarn. 
     
     
         7 . The cord according to  claim 1 , wherein the cellulosic multifilament yarn is obtained by a direct solvent process. 
     
     
         8 . The cord according to  claim 7 , wherein the cellulosic multifilament yarn is obtained by a direct solvent process in a tertiary amine oxide or in ionic liquids.