Composite layer for reinforcement of objects such as tires or belts

Abstract

The present invention pertains to a fibrous cord comprising yarns twisted together wherein the cord has a twist multiplier of from 5.0 to 12.0, and comprises a blend of aromatic polyamide or aromatic copolyamide yarns and polyester yarns. The invention further pertains to a composite layer comprising an elastomer and a fabric wherein the fabric comprises from about 25 to 60 weight percent of the total composite layer, and comprises a plurality of inventive cords.

1 . A fibrous cord, comprising a blend of yarns twisted together wherein the cord
 (i) has a twist multiplier of from 5.0 to 12.0, and   (ii) comprises a blend of polyester yarn with either aromatic polyamide or aromatic copolyamide yarns.   
     
     
         2 . The cord of  claim 1 , wherein the polyamide or copolyamide yarns are pre-twisted to a twist multiplier of at least 3.5 before cord assembly and have a linear density of at least 400 dtex. 
     
     
         3 . The cord of  claim 1 , wherein the polyester yarns are pretwisted to have a twist multiplier of at least 3.5 and have a linear density of at least 444 dtex. 
     
     
         4 . The cord of  claim 1 , wherein the aromatic polyamide is para-aramid. 
     
     
         5 . The cord of  claim 1 , wherein the polyester is polyethyleneterephthalate, polybuthyleneterephtalate, polyethylenenaphtalene or poly(trimethylene terephthalate). 
     
     
         6 . A composite layer, comprising an elastomer and a fabric wherein the fabric
 (i) comprises from about 25 to 60 weight percent of the weight of elastomer plus fabric, and   (ii) comprises a plurality of cords of  claim 1 .   
     
     
         7 . The composite layer of  claim 6 , wherein the elastomer is nitrile butadiene rubber (hydrogenated and nonhydrogenated), ethylene-propylene-diene monomer rubber, ethylene propylene diamine monomer, chlorosulfonyl-polyethylene, ethylene oxide, chloromethyl oxirane, hexafluoropropylene vinylidene fluoride, natural rubber, styrene-butadiene rubber or mixtures thereof. 
     
     
         8 . The composite layer of  claim 7 , wherein the ethylene-propylene-diene monomer is 5-ethylidene-2-norbornene (5-ethylidenebicyclo[2.2.1]hept-2-ene), dicyclopentadiene(bicyclo[2.2.1]hepta-2,5-diene), or 1,4-hexadiene. 
     
     
         9 . A composite layer of  claim 6  for use in tires or belts. 
     
     
         10 . A method for producing a composite layer of  claim 6 , the method comprising at least the steps of preparing a fabric with a plurality of cords having a twist multiplier of from 5.0 to 12, wherein the cords are formed by blending aromatic polyamide or aromatic copolyamide yarns and polyester yarns. 
     
     
         11 . The method of  claim 10 , wherein the polyamide or copolyamide yarns are pre-twisted to have a twist multiplier of at least 3.5 and have a linear density of at least 400 dtex. 
     
     
         12 . The method of  claim 10 , wherein the polyester yarns are pre-twisted to have a twist multiplier of at least 3.51 and have a liner density of at least 444 dtex. 
     
     
         13 . A fibrous cord comprising a blend of yarns twisted together, wherein the cord
 (i) has a twist multiplier of from 5.0 to 12.0, and   (ii) comprises a blend of aromatic polyamide and aliphatic polyamide yarns.   
     
     
         14 . A fibrous cord, comprising a blend of yarns twisted together wherein the cord
 (i) has a twist multiplier of from 5.0 to 12.0, and   (ii) comprises a blend of m-aramid and p-aramid yarns with either aromatic polyamide or aromatic copolyamide yarns or a blend of m-aramid plus p-aramid plus polyester yarns with either aromatic polyamide or aromatic copolyamide yarns.   
     
     
         15 . The cord of  claim 1 , wherein the cord or the p-aramid component is staple, stretch broken or texturized.