Polyester tire cord with excellent dimensional stability and method for manufacturing the same

Patent metadata

Field	Value
Publication number	US-10017883-B2
Application number	US-201515102115-A
Country	US
Kind code	B2
Filing date	Jan 13, 2015
Priority date	Jan 16, 2014
Publication date	Jul 10, 2018
Grant date	Jul 10, 2018

Abstract

A polyester tire cord having improved dimensional stability and methods of manufacturing the polyester tire cord are provided. The method includes forming a discharge yarn, extruded while a polyester containing 85 mol % or more of ethylene terephthalate units is melted and passes through a nozzle; forming an undrawn yarn by spinning the discharged yarn; manufacturing a yarn by multistep drawing the undrawn yarn; plying the yarn by twisting; and dipping the plied yard in a dipping solution, and then drying, drawing, and heat-setting the plied yarn before dipping the plied yarn in resorcinol-formaldehyde latex and again drying an heat-setting the plied yarn. An intermediate elongation of the formed polyester tire cord after vulcanization for 20 minutes at 170° C. is E 2 , an intermediate elongation of the polyester tire cord before vulcanization is E 1 , and a difference between E 2 and E 1 is ΔE. ΔE divided by E 1 is 0.5 or less.

First claim

The invention claimed is:

1. A manufacturing method of a polyester tire cord having dimensional stability, the method comprising the steps of:
forming a discharged yarn extruded while a polyester containing 85 mol % or more of ethylene terephthalate units is melted and passed through a nozzle;
forming an undrawn yarn by spinning the discharged yarn;
manufacturing a yarn by multistep drawing the undrawn yarn by passing the yarn through a plurality of draft rollers so that a total draw ratio is 1.60 or less, wherein at least one draft roller of the plurality of draft rollers has a temperature between 200° C. and 250° C. and the remaining draft rollers of the plurality of draft rollers have temperatures less than 95° C.;
plying the yarn by cable / ply twisting at 300˜500 twist/meter; and
dipping the plied yarn, in a dipping solution of an epoxy and a pexul, and then drying, drawing, and heat-setting the plied yarn, before dipping the plied yarn in resorcinol-formaldehyde latex (RFL) and again drying and heat-setting the plied yarn.

2. The manufacturing method of claim 1 , wherein the yarn prior to plying has an inherent viscosity of 0.90 to 1.00, an intermediate elongation (@4.5 g/d) of 6.5% or less, a shrinkage of 2.0% or less, and a sum of intermediate elongation and dry heat shrinkage ratio (E-S) of not more than 8.0%.

3. The manufacturing method of claim 1 , wherein following the dipping treatments, an intermediate elongation (@2.25 g/d) of the polyester tire cord after vulcanization for 20 minutes at 170° C. is E 2 , an intermediate elongation (@2.25 g/d) of the polyester tire cord before vulcanization is E 1 , and a difference between E 2 and E 1 is ΔE, comprises:
ΔE divided by E 1 is 0.5 or less.

4. The manufacturing method of claim 1 , wherein E 2 and E 1 are each measured at 25° C., 60° C., 90° C., and 120° C.

5. A polyester tire cord produced according to the manufacturing method of claim 1 .

Assignees

• Hyosung Corp

Inventors

• Joo Si-Hwan
• Kim Hong-Un
• Park Jin-Kyeong
• Hwang Su-Yeon
• Kim Cheol

Classifications

• D01F6/62

  from polyesters · CPC title

• D10B2331/06

  polyethers · CPC title

• D02G3/48 Primary

  Tyre cords {(tyre reinforcements B60C9/00; metal cords for reinforcing rubber or plastic articles D07B1/0606)} · CPC title

• D01H13/28

  Heating or cooling arrangements {for yarns (removal of heat from machines D01H1/16)} · CPC title

• D02G3/36

  Cored or coated yarns or threads ({D02G3/34, D02G3/40 take precedence}; elastic yarns or threads D02G3/32) · CPC title