| 摘要 |
PURPOSE:To improve a rate of modulus heat shrinkage, heat resistance, fatigue resistance, etc. of a tire, by processing polyester raw string of specific work loss, dry heat shrinkage rate, limiting viscosity and carboxy content with the prescribed twist coefficient, obtaining a cord of prescribed physical properties and using said cord for a carcass of the tire. CONSTITUTION:Polyester raw string of distortion factor 0.5in/min, ten inches long with 1,000deniers at stress circulation between 0.6-0.5g/d, work loss 0.005- 0.037pound/inch cycle at 150 deg.C, dry heat shrinkage rate not more than 0.8% for 3min at 150 deg.C, limiting viscosity 0.8-1.0 in a solvent orthochlorphenol at 25 deg.C and carboxy content not more than 15 equivalent/10<6>g, is adhesively heat treated with vertical twist of the twist coefficient 0.10-0.50 as shown by the prescribed formula, and a cord of intermediate elongation 2.0-5.0% at strength of 5.5- 7.1g/d, 2.25g/d, dry heat free shrinkage rate 2.0-5.0% is adjusted and used for a carcass. In this way, modulus heat shrinkage rate, fatigue resistance, etc. can be improved. |
