IP Library Granted Patent US 12709677
Granted Patent B2
US 12709677 · App. 18/518,414 · Granted Aug 18, 2026

Method for preparing rubber for elastomer of flexible joint

Inventors: Jianbo Ji (Xi'an, CN); Changqing Ye (Xi'an, CN); Jing Feng (Xi'an, CN); Yanan Hou (Xi'an, CN); Bo Sun (Xi'an, CN); Gui Zhang (Xi'an, CN); Rui Liu (Xi'an, CN)
Assignee: XI'AN SUNWARD AEROMAT CO., LTD.
C08L15/005C08J5/046C08J2315/00C08J2409/02C08J2477/10C08K3/04C08K7/26
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Quick Facts
Patent No.
US 12709677
App. No.
18/518,414
Granted
Aug 18, 2026
Kind
B2
Abstract

A method for preparing a rubber for an elastomer of a flexible joint, includes: weighing hydrogenated nitrile raw rubber, a silica reinforcing agent, aramid fiber pulp, carbon black, liquid nitrile rubber, zinc oxide, stearic acid, an antioxidant, and a peroxide crosslinking agent; plasticating the hydrogenated nitrile raw rubber in a first internal mixer at 125-135° C., collecting a resulting product and cooling, to yield a plasticized rubber; preheating the liquid nitrile rubber; adding the plasticized rubber to a second internal mixer, further adding the aramid fiber pulp, the zinc oxide, the stearic acid, and the antioxidant to the second internal mixer for first mixing; adding the carbon black to the second internal mixer for second mixing; adding the silica reinforcing agent and the preheated liquid nitrile rubber to the second internal mixer for third mixing; and collecting a discharged product when a temperature of the second internal mixer is 140° C.

Claims (12)

1 . A method for preparing a rubber for an elastomer of a flexible joint, the method comprising:

1) weighing 100 parts by weight of hydrogenated nitrile raw rubber, 15-35 parts by weight of a silica reinforcing agent, 10-25 parts by weight of aramid fiber pulp, 30-50 parts by weight of carbon black, 5-15 parts by weight of liquid nitrile rubber, 3-7 parts by weight of zinc oxide, 0.5-3 parts by weight of stearic acid, 0.5-5 parts by weight of an antioxidant, and 2-8 parts by weight of di-tert-butylperoxyisopropyl benzene as a peroxide crosslinking agent;

2) plasticating the hydrogenated nitrile raw rubber in a first internal mixer at 125-135° C., collecting a resulting product and cooling, to yield a plasticized rubber;

3) preheating the liquid nitrile rubber at a temperature of 80-85° C.;

4) adding the plasticized rubber to a second internal mixer, further adding the aramid fiber pulp, the zinc oxide, the stearic acid, and the antioxidant to the second internal mixer for first mixing; adding the carbon black to the second internal mixer for second mixing; adding the silica reinforcing agent and the preheated liquid nitrile rubber to the second internal mixer for third mixing; collecting a discharged product when a temperature of the second internal mixer is 140° C.;

5) adding the discharged product to an open mill, further adding di-tert-butylperoxyisopropyl benzene to the open mill, and passing a resulting mixture through rollers of the open mill for 5-7 times at 45-55° C., to yield a rubber for an elastomer of a flexible joint.

2 . The method of claim 1 , wherein the silica reinforcing agent is gas-phase silicon dioxide.

3 . The method of claim 1 , wherein in 2), the hydrogenated nitrile raw rubber is plasticated in the first internal mixer for 3-4 min.

4 . The method of claim 1 , wherein in 2), after being plasticated, the hydrogenated nitrile raw rubber is cooled in the first internal mixer for 15-20 hours.

5 . The method of claim 1 , wherein in 3), the liquid nitrile rubber is preheated for 3-4 hours.

6 . The method of claim 1 , wherein in 4), the first and second mixing last for 2-3 min, and the third mixing lasts for 3-5 min.

7 . A rubber for an elastomer of a flexible joint, being prepared according to the method of claim 1 .