| 摘要 |
PURPOSE:To improve comfortableness of a ride, roll resistance and durability of a tire, by constituting micro construction of a carcass with a specific polyester ply cord and a cord layer rubbered by coating rubber of prescribed swelling mesh concentration. CONSTITUTION:Micro construction of polyester cord material, mainly composed of polyethylene terephthalate without lowering extreme limit viscosity IV of polyester, is so adjusted as to provide 160X10<3>-210X10<-3> double refractive index, 45-55% crystalization degree, at least 7.0g/d strength with carboxyl radical within a range of 3-18 equivalent/10<6>g, and a ply cord is formed. This ply cord is rubbered by coating rubber of composition for the swelling mesh concentration within a range of 25X10<-5>-50X10<-5>mol/g rubber. This cord is used for a carcass to constitute a tread part by belt reinforcement, and comfortableness of a ride, roll resistance and durability can be improved. |
