Hybrid tire cord and method for manufacturing the same

Patent metadata

Field	Value
Publication number	US-2016376733-A1
Application number	US-201615194741-A
Country	US
Kind code	A1
Filing date	Jun 28, 2016
Priority date	Jun 29, 2015
Publication date	Dec 29, 2016
Grant date	—

Abstract

Disclosed are a hybrid tire cord, which can be easily manufactured and has more uniform physical properties, and improved strength and fatigue resistance, and a method for manufacturing the same. The hybrid tire cord includes a nylon primarily twisted yarn and an aramid primarily twisted yarn, wherein the nylon primarily twisted yarn and the aramid primarily twisted yarn are secondarily twisted together, and after untwisting of the secondary twisting of the hybrid tire cord having a predetermined length, a length of the aramid primarily twisted yarn is 1.005 to 1.025 times a length of the nylon primarily twisted yarn.

First claim

1 . A hybrid tire cord comprising:
a nylon primarily twisted yarn; and an aramid primarily twisted yarn, wherein the nylon primarily twisted yarn and the aramid primarily twisted yarn are secondarily twisted together, and after untwisting of the secondary twisting of the hybrid tire cord having a predetermined length, a length of the aramid primarily twisted yarn is 1.005 to 1.025 times a length of the nylon primarily twisted yarn.

2 . The hybrid tire cord according to claim 1 , wherein the nylon primarily twisted yarn has a first twist direction,
the aramid primarily twisted yarn has a second twist direction, the nylon primarily twisted yarn and the aramid primarily twisted yarn are secondarily twisted together in a third twist direction, the second twist direction is the same as the first twist direction, and the third twist direction is opposite to the first twist direction.

3 . The hybrid tire cord according to claim 1 , wherein the aramid primarily twisted yarn has a lower twist number than a twist number of the nylon primarily twisted yarn.

4 . The hybrid tire cord according to claim 3 , wherein the aramid primarily twisted yarn has a 0.1 to 5% lower twist number than a twist number of the nylon primarily twisted yarn.

5 . The hybrid tire cord according to claim 1 , wherein a weight ratio of the nylon primarily twisted yarn to the aramid primarily twisted yarn is 20:80 to 80:20.

6 . The hybrid tire cord according to claim 1 , further comprising an adhesive agent coated on the nylon primarily twisted yarn and the aramid primarily twisted yarn,
wherein strength at break and elongation at break measured by ASTM D885 are 8.0 to 15.0 g/d and 7 to 15%, respectively, and a strength maintenance percentage after disk fatigue test conducted by JIS-L 1017 of Japanese Standard Association (JSA) is 90% or higher.

7 . The hybrid tire cord according to claim 6 , wherein the hybrid tire cord has 3% LASE, 5% LASE, and 7% LASE measured by ASTM D885, of 0.8 to 2.0 g/d, 1.5 to 4.0 g/d, and 3.0 to 6.0 g/d, respectively.

8 . The hybrid tire cord according to claim 7 , wherein the hybrid tire cord has a shrinkage of 1.5 to 2.5%,
wherein the shrinkage is measured under a primary load of 0.01 g/denier at 180° C. for 2 minutes.

9 . A method of manufacturing a hybrid tire cord comprising:
a first step of primarily twisting an aramid filament yarn in a first direction to form an aramid primarily twisted yarn; a second step of primarily twisting a nylon filament yarn in a second direction to form a nylon primarily twisted yarn, the second step and the first step being conducted simultaneously; and a third step of secondarily twisting the aramid primarily twisted yarn and the nylon primarily twisted yarn in a third direction to form a plied yarn, the third step being conducted continuously with the first and second steps, wherein the first, second and third steps are conducted by one twister, the second direction is the same as the first direction, the third direction is opposite to the first direction, tension applied to the nylon filament yarn in the second step is higher than tension applied to the aramid filament yarn in the first step, and the tension applied to the nylon filament yarn in the second step is higher than the tension applied to the aramid filament yarn in the first step in such an amount that the aramid primarily twisted yarn is 1.005 to 1.025 times longer than the nylon primarily twisted yarn after untwisting of the secondary twist of the hybrid tire cord with a predetermined length.

10 . The method according to claim 9 , further comprising:
dipping the plied yarn in an adhesive agent solution; drying the adhesive agent solution-impregnated plied yarn; and thermally treating the dried plied yarn.

11 . The method according to claim 10 , wherein the dipping, drying and thermal treatment steps are continuously conducted, and
tension applied to the plied yarn in the dipping, drying and thermal treatment steps is 0.4 g/d or less per cord.

Assignees

• Kolon Inc

Inventors

• Jeon Ok Wha
• Lee Min Ho

Classifications

• D01H13/00

  Other common constructional features, details or accessories · CPC title

• D02G3/48 Primary

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

• D02G3/40 Primary

  Yarns in which fibres are united by adhesives; Impregnated yarns or threads · CPC title

• D02G3/045

  all components being made from artificial or synthetic material · CPC title

• D02G3/047

  including aramid fibres · CPC title