§
Luxuse
Patent Intelligence
Sign In
← Back to Patent Explorer
US4715418A Expired / Lapsed US ⏱️ 0.0 years remaining

Pneumatic tires having high uniformity

Assignee: Toyo Tire Corp
•
Filing: 1985-06-17
•
Granted: 1987-12-29
•
Expires: 2005-06-17
📄 Original PDF 🌐 Google Patents 🔄 Sync Now

Abstract

Abstract A process for producing a pneumatic tire having high uniformity with a carcass ply formed of polyester cord, including the steps of: (a) spinning polyester at a tension at the solidifying point of melt polyester between 1.5×10 7 and 7.5×10 7 dyne/cm 2 ; (b) drawing the polyester into a filament at a draw ration of 2.0 to 3.0; (c) twisting a polyester filament at a twist coefficient of from 800 to 2,500; and then (d) heat treating the filament so that the dimension unstabilizing factor is 8.5 or less. The polyester filament is made of polyester having an ethylene terephthalate component of at least 85 mol % and a high degree of polymerization such that the intrinsic viscosity is at least 0.8, and the ratio of the birefringence of the surface portion to that of the central portion in the polyester filament is from 1.03/1 to 1.15/1; the twist coefficient is represented by T×√D (wherein T is the average value of the numbers of turn of the single twist and final twist per 10 cm of cord, and D is the denier of the cord); and the dimension unstabilizing factor is defined as the sum of the elongation (%) at a load of 2.3 g/d and the thermal shrinkage (%) when heated at 150° C. in dry air for 30 minutes.

Inventors

  • 👤 Shoji Miyoshi
  • 👤 Ryuichi Nomura

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-10-23 01:40
CPC Classifications
B; B60; B60C; B60C9/00; B60C9/0042; B60C9/02; B60C9/04; D; D02; D02G; D02G3/00; D02G3/44; D02G3/48; Y; Y10; Y10S; Y10S57/00; Y10S57/902

Claims Analysis

Total Claims: 4
Claim 1
Independent Claim 259 words
A pneumatic tire cord produced according to a method including the following steps: (a) spinning polyester into a filament under tension at the solidifying point of melt polyester between 1.5×10 7 and 7.5×10 7 dyne/cm 2 and at a winding speed of 1,000 to 3,000 m/min.; (b) drawing the polyester into a filament at a draw ratio of 2.0 to 3.0; (c) twisting a plurality of the polyester filaments into a strand and twisting a plurality of said strands into a cord; and (d) heat treating the polyester cord, wherein the filament has an ethylene terephthalate component of at least 85 mol %, a high degree of polymerization such that the intrinsic viscosity is greater than 0.8 and a ratio of the birefringence of the surface portion to that of the central portion from 1.03/1 to 1.15/1, and the cord has a twist coefficient in the range of from 800 to 2,500, and a dimension unstabilizing factor 8.5 or less, wherein the twist coefficient is equal to T×√D, T being the average value between the number of turns of a first twist of the plurality of filaments into the strand and the number of turns of a final twist of the plurality of strands into the cord, each being per 10 cm of cord, and D being the denier of the cord, and wherein the dimension unstabilizing factor is defined as the sum of the elongation (%) at a load of 2.3 g/d and the thermal shrinkage (%) when heated at 150° C. in dry air for 30 minutes.
Claim 2
Dependent Claim 259 words
A pneumatic tire cord produced according to a method including the following steps: (a) spinning polyester into a filament under tension at the solidifying point of melt polyester between 1.5×10 7 and 7.5×10 7 dyne/cm 2 and at a winding speed of 1,000 to 3,000 m/min.; (b) drawing the polyester into a filament at a draw ratio of 2.0 to 3.0; (c) twisting a plurality of the polyester filaments into a strand and twisting a plurality of said strands into a cord; and (d) heat treating the polyester cord, wherein the filament has an ethylene terephthalate component of at least 85 mol %, a high degree of polymerization such that the intrinsic viscosity is greater than 0.8 and a ratio of the birefringence of the surface portion to that of the central portion from 1.03/1 to 1.15/1, and the cord has a twist coefficient in the range of from 800 to 2,500, and a dimension unstabilizing factor 8.5 or less, wherein the twist coefficient is equal to T×√D, T being the average value between the number of turns of a first twist of the plurality of filaments into the strand and the number of turns of a final twist of the plurality of strands into the cord, each being per 10 cm of cord, and D being the denier of the cord, and wherein the dimension unstabilizing factor is defined as the sum of the elongation (%) at a load of 2.3 g/d and the thermal shrinkage (%) when heated at 150° C. in dry air for 30 minutes.
Claim 3
Dependent Claim 15 words
A pneumatic tire cord produced according to claim 1, wherein the polyester is polyethylene terphthalate.
Claim 4
Dependent Claim 22 words
A pneumatic tire cord produced according to claim 2, wherein the twist coefficient is in the range of from 1,300 to 2,300.

References Cited (Backward Citations)

US3216187A Cited
US3665994A Cited
US3413797A Cited
US3838561A Cited
US3690362A Cited
US4043985A Cited
US3854515A Cited
US3929180A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1990-12-28 1991-06-29 1991-12-29 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1994-12-28 1995-06-29 1995-12-29 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1998-12-28 1999-06-29 1999-12-29 $7700.00 Window Closed / Lapsed

Assigned Categories & Tags

No categories assigned to this patent yet.

Assign Category Tag