Steel cord for reinforcing rubber article

Patent metadata

Field	Value
Publication number	US-11685191-B2
Application number	US-201917274218-A
Country	US
Kind code	B2
Filing date	Sep 9, 2019
Priority date	Sep 11, 2018
Publication date	Jun 27, 2023
Grant date	Jun 27, 2023

Abstract

Provided is a steel cord for rubber article reinforcement which has excellent corrosion resistance and productivity without deterioration of adhesion with rubber. A steel cord (1) for rubber article reinforcement, in which plural steel filaments (2) are twisted together, includes: a core having at least one core filament (2c); and a sheath having at least one sheath layer formed by twisting at least one sheath filament (2s) around the core. In this steel cord (1), brass plating is performed on the steel filaments (2) and zinc plating is further performed on the outer circumference of the brass plating of the core filament (2c), and the steel filaments (2) have a diameter d of 0.1 mm to 0.6 mm.

First claim

The invention claimed is:

1. A steel cord for rubber article reinforcement formed by twisting plural steel filaments, the steel cord comprising: a core having at least one core filament; and a sheath having at least one sheath layer formed by twisting at least one sheath filament around the core,
wherein
brass plating is performed on the steel filaments, and zinc plating is further performed on the outer circumference of the brass plating of the at least one core filament,
the steel filaments have a diameter d of 0.1 mm to 0.6 mm, and
zinc plating is performed only on the outer circumference of the brass plating of the core filaments or on the outer circumference of the brass plating of the steel filaments other than the outermost-layer sheath filaments.

2. The steel cord for rubber article reinforcement according to claim 1 , wherein the adhesion amount (g/m 2 ) of the brass plating on the at least one core filament is 6d to 10d, and the adhesion amount (g/m 2 ) of the zinc plating is 25d to 95d.

3. The steel cord for rubber article reinforcement according to claim 2 , wherein the steel filaments have a tensile strength Ts (MPa) satisfying a relationship represented by the following formula:
(−2,000× d+ 3,825)≤Ts<(−2,000× d+ 4,525).

4. The steel cord for rubber article reinforcement according to claim 2 , wherein, in an outermost sheath layer constituting the sheath, a gap distance L between the at least one sheath filament is 50 μm or less.

5. The steel cord for rubber article reinforcement according to claim 1 , wherein the steel filaments have a tensile strength Ts (MPa) satisfying a relationship represented by the following formula:
(−2,000× d+ 3,825)≤Ts<(−2,000× d+ 4,525).

6. The steel cord for rubber article reinforcement according to claim 5 , wherein, in an outermost sheath layer constituting the sheath, a gap distance L between the at least one sheath filament is 50 μm or less.

7. The steel cord for rubber article reinforcement according to claim 1 , wherein, in an outermost sheath layer constituting the sheath, a gap distance L between the at least one sheath filament is 50 μm or less.

8. The steel cord for rubber article reinforcement according to claim 1 , wherein the core has at least three core filaments.

9. A steel cord for rubber article reinforcement formed by twisting plural strands,
wherein
the strands each comprise: a core having at least one core filament; and a sheath having at least one sheath layer formed by twisting at least one sheath filament around the core,
brass plating is performed on the steel filaments, and zinc plating is further performed on the outer circumference of the brass plating of the at least one core filament, and
the steel filaments have a diameter d of 0.1 mm to 0.6 mm.

10. The steel cord for rubber article reinforcement according to claim 9 , wherein the adhesion amount (g/m 2 ) of the brass plating on the at least one core filament is 6d to 10d, and the adhesion amount (g/m 2 ) of the zinc plating is 25d to 95d.

11. The steel cord for rubber article reinforcement according to claim 10 , wherein the steel filaments have a tensile strength Ts (MPa) satisfying a relationship represented by the following formula:
(−2,000× d+ 3,825)≤Ts<(−2,000× d+ 4,525).

12. The steel cord for rubber article reinforcement according to claim 10 , wherein, in an outermost sheath layer constituting the sheath, a gap distance L between the at least one sheath filament is 50 μm or less.

13. The steel cord for rubber article reinforcement according to claim 9 , wherein the steel filaments have a tensile strength Ts (MPa) satisfying a relationship represented by the following formula:
(−2,000× d+ 3,825)≤Ts<(−2,000× d+ 4,525).

14. The steel cord for rubber article reinforcement according to claim 13 , wherein, in an outermost sheath layer constituting the sheath, a gap distance L between the at least one sheath filament is 50 μm or less.

15. The steel cord for rubber article reinforcement according to claim 9 , wherein, in an outermost sheath layer constituting the sheath, a gap distance L between the at least one sheath filament is 50 μm or less.

Assignees

• Bridgestone Corp

Inventors

• Ando Nobuhiro

Classifications

• D10B2505/022

  for tyres · CPC title

• D07B2201/2065

  comprising a coating · CPC title

• D07B2201/2066

  characterised by the materials used · CPC title

• D07B2501/2046

  Tyre cords · CPC title

• B60C2009/0014

  Surface treatments of steel cords · CPC title