Chrome-free tanning process of ecological leather

Patent metadata

Field	Value
Publication number	US-2024263257-A1
Application number	US-202218681096-A
Country	US
Kind code	A1
Filing date	May 11, 2022
Priority date	Feb 24, 2022
Publication date	Aug 8, 2024
Grant date	—

Abstract

A chrome-free tanning process of an ecological leather is characterized by a TWS+sodium lignosulfonate+TWLZ ternary tanning process system. The sodium lignosulfonate added can not only have a fixation effect on a TWS tanning agent to make the TWS tanning not undergo detanning at a low pH, but also significantly improve the uniformity of distribution of a TWLZ tanning agent in a hide/skin and promote the formation of a stable cross-linked network structure by the TWLZ tanning agent in a collagen fiber, which effectively overcomes the defects of tanning performance of the existing tanning systems to obtain a leather with uniform and sufficient tanning, a high isoelectric point, a strong electropositivity, excellent absorption for post-tanning chemicals, and a prominent softness, and gives a leather a wide use range and a high quality.

First claim

What is claimed is:

1 . A chrome-free tanning process of an ecological leather, comprising: tanning a pickled hide/skin as a raw material with a TWS tanning agent, adding sodium lignosulfonate to allow a reaction, and tanning a resulting product with a TWLZ tanning agent.

2 . The chrome-free tanning process of the ecological leather according to claim 1 , wherein based on a weight of the limed hide/skin, the TWS tanning agent is added at an amount of 1 wt % to 5 wt %, the sodium lignosulfonate is added at an amount of 1 wt % to 4 wt %, and the TWLZ tanning agent is added at an amount of 2 wt % to 6 wt %.

3 . The chrome-free tanning process of the ecological leather according to claim 1 , wherein the tanning with the TWS tanning agent comprises: allowing a penetration of TWS tanning agent for 2 h to 4 h, adjusting a pH of a resulting system to 7.0 to 8.5, and allowing a binding at 35° C. to 42° C. for 1 h to 3 h.

4 . The chrome-free tanning process of the ecological leather according to claim 1 , wherein the tanning with the TWLZ tanning agent comprises: allowing a penetration of TWLZ tanning agent for 1 h to 4 h at a pH of 3.0 to 4.5, adjusting a pH to 3.5 to 4.5, and allowing a binding at 35° C. to 42° C. for 1 h to 4 h.

5 . The chrome-free tanning process of the ecological leather according to claim 1 , wherein the sodium lignosulfonate is added to allow the reaction at room temperature for 0.5 h to 2 h.

6 . The chrome-free tanning process of the ecological leather according to claim 1 , wherein the pickled hide/skin comprises any one of a pickled sheepskin, a pickled goatskin, and a pickled hide.

7 . The chrome-free tanning process of the ecological leather according to claim 3 , wherein the pH adjustment is conducted with a pH adjusting agent, and the pH adjusting agent comprises any one or more of sodium bicarbonate, sodium carbonate, magnesium oxide, and an automatic pH adjusting agent.

8 . An ecological leather prepared by the chrome-free tanning process according to claim 1 .

9 . The chrome-free tanning process of the ecological leather according to claim 4 , wherein the pH adjustment is conducted with a pH adjusting agent, and the pH adjusting agent comprises any one or more of sodium bicarbonate, sodium carbonate, magnesium oxide, and an automatic pH adjusting agent.

10 . The ecological leather according to claim 8 , wherein in the chrome-free tanning process, based on a weight of the limed hide/skin, the TWS tanning agent is added at an amount of 1 wt % to 5 wt %, the sodium lignosulfonate is added at an amount of 1 wt % to 4 wt %, and the TWLZ tanning agent is added at an amount of 2 wt % to 6 wt %.

11 . The ecological leather according to claim 8 , wherein in the chrome-free tanning process, the tanning with the TWS tanning agent comprises: allowing a penetration of TWS tanning agent for 2 h to 4 h, adjusting a pH of a resulting system to 7.0 to 8.5, and allowing a binding at 35° C. to 42° C. for 1 h to 3 h.

12 . The ecological leather according to claim 8 , wherein in the chrome-free tanning process, the tanning with the TWLZ tanning agent comprises: allowing a penetration of TWLZ tanning agent for 1 h to 4 h at a pH of 3.0 to 4.5, adjusting a pH to 3.5 to 4.5, and allowing a binding at 35° C. to 42° C. for 1 h to 4 h.

13 . The ecological leather according to claim 8 , wherein in the chrome-free tanning process, the sodium lignosulfonate is added to allow the reaction at room temperature for 0.5 h to 2 h.

14 . The ecological leather according to claim 8 , wherein in the chrome-free tanning process, the pickled hide/skin comprises any one of a pickled sheepskin, a pickled goatskin, and a pickled hide.

15 . The ecological leather according to claim 11 , wherein in the chrome-free tanning process, the pH adjustment is conducted with a pH adjusting agent, and the pH adjusting agent comprises any one or more of sodium bicarbonate, sodium carbonate, magnesium oxide, and an automatic pH adjusting agent.

Assignees

• Univ Sichuan

Inventors

• Wang Yanan
• Yu Yue
• Shi Bi
• Zhou Jianfei
• Zeng Yunhang
• Zhang Wenhua

Classifications

• C14C3/28

  Multi-step processes · CPC title

• C14C3/24 Primary

  using lignin derivatives, e.g. sulfate liquor · CPC title

• C14C3/08 Primary

  by organic agents · CPC title

• C14C3/16

  using aliphatic aldehydes · CPC title

• C14C3/04 Primary

  Mineral tanning · CPC title