Leather or leather article and method for producing same, hexavalent chromium treatment agent, method for treating hexavalent chromium in crude leather or crude leather article

Patent metadata

Field	Value
Publication number	US-10358686-B2
Application number	US-201515501487-A
Country	US
Kind code	B2
Filing date	Jul 29, 2015
Priority date	Aug 4, 2014
Publication date	Jul 23, 2019
Grant date	Jul 23, 2019

Abstract

An object of the invention is to provide a heat-resistant hexavalent chromium removal agent, which is capable of remaining in a leather or leather article for a long period of time and stably detoxifying hexavalent chromium over the long term even when a leather or leather article contains hexavalent chromium, and a leather or leather article, in which the hexavalent chromium content is less than 3 ppm. The leather or leather article of the present invention contains at least: an organic compound (A) having a structure shown in chemical formula (1) and hydroxyphenyl but not aldehyde and carboxyl, which organic compound has a property to reduce hexavalent chromium to trivalent chromium; and trivalent chromium, and the hexavalent chromium content determined in accordance with ISO 17075: 2008-02 is less than 3 ppm.

First claim

The invention claimed is:

1. A leather or leather article, containing at least:
an organic compound (A) having a structure shown in chemical formula (1) below and hydroxyphenyl, wherein said organic compound (A) does not have reactive functional groups of an aldehyde and carboxyl, the organic compound acting to reduce hexavalent chromium to trivalent chromium; and
trivalent chromium, wherein the hexavalent chromium content is less than 3 ppm:

(where R 1 , R 2 , R 3 , R 4 and R 5 are each independently a substituent composed of at least one selected from C, H and O, and R 1 or R 2 may be combined with R 3 , R 4 , or R 5 to form a ring),
wherein the organic compound (A) contains:
(i) gallic acid ester; and
(ii) at least one compound selected from tannic acid and a derivative thereof.

2. The leather or leather article according to claim 1 , wherein the total chromium content obtained by X-ray fluorometry is not less than 5000 ppm.

3. The leather or leather article according to claim 1 , wherein the organic compound (A) includes a compound having a structure shown in chemical formula (1) and dihydroxyphenyl or trihydroxyphenyl, wherein said compound does not have reactive functional groups of an aldehyde and carboxyl, the compound acting to reduce hexavalent chromium to trivalent chromium.

4. The leather or leather article according to claim 3 , wherein the organic compound (A) includes a compound having a structure shown in chemical formula (1) and 1,2,3-trihydroxyphenyl, wherein said compound does not have reactive functional groups of an aldehyde and carboxyl, the compound acting to reduce hexavalent chromium to trivalent chromium.

5. The leather or leather article according to claim 1 , wherein the compound (ii) is tannic acid.

6. A leather or leather article, containing at least:
an organic compound (A) having a structure shown in chemical formula (1) below and hydroxyphenyl, wherein said organic compound (A) does not have reactive functional groups of an aldehyde and carboxyl, the organic compound acting to reduce hexavalent chromium to trivalent chromium;
an organic compound (B) having a structure shown in chemical formula (1) wherein said organic compound (B) does not have a hydroxyphenyl, aldehyde, and carboxyl, the compound (B) acting to reduce hexavalent chromium to trivalent chromium; and
trivalent chromium, wherein the hexavalent chromium content is less than 3 ppm:

(where R1, R2, R3, R4 and R5 are each independently a substituent composed of at least one selected from C, H and O, and R1 or R2 may be combined with R3, R4, or R5 to form a ring).

7. The leather or leather article according to claim 6 , wherein the organic compound (B) is at least one compound selected from the group consisting of ascorbic acid, a derivative of ascorbic acid, erythorbic acid, and a derivative of erythorbic acid.

8. A hexavalent chromium treatment agent, containing at least:
an organic compound (A) having a structure shown in chemical formula (1) and hydroxyphenyl, wherein said organic compound (A) does not have reactive functional groups of an aldehyde and carboxyl, the organic compound acting to reduce hexavalent chromium to trivalent chromium; and
an organic compound (B) having a structure shown in chemical formula (1) wherein said organic compound (B) does not have a hydroxyphenyl, aldehyde, and carboxyl, the organic compound acting to reduce hexavalent chromium to trivalent chromium:

(where R1, R2, R3, R4 and R5 are each independently a substituent composed of at least one selected from C, H and O, and R1 or R2 may be combined with R3, R4, or R5 to form a ring).

9. The hexavalent chromium treatment agent according to claim 8 , wherein the organic compound (B) is at least one compound selected from the group consisting of ascorbic acid, a derivative of ascorbic acid, erythorbic acid, and a derivative of erythorbic acid.

10. The hexavalent chromium treatment agent according to claim 8 , wherein the organic compounds (A) and (B) are contained at a weight percent ratio of 50-90:10-50 (provided that the sum of A and B equals to 100% by weight).

11. The hexavalent chromium treatment agent according to claim 8 , which is an aqueous solution containing a solvent consisting of water.

12. The hexavalent chromium treatment agent according to claim 8 , which further contains C1-C3 alcohol.

13. The hexavalent chromium treatment agent according to claim 12 , which further contains water.

14. The hexavalent chromium treatment agent according to claim 8 , which further contains water and C1-C3 alcohol, wherein the water and alcohol are contained at a weight percent ratio of 20-80:20-80 (provided that the sum of both equals to 100% by mass), and wherein the organic compounds (A) and (B) are dissolved in the water and alcohol.

15. The hexavalent chromium treatment agent according to claim 8 , which further contains at least one solvent selected from hexane and heptane.

16. The hexavalent chromium treatment agent according to claim 15 , which further contains C1-C3 alcohol.

17. The hexavalent chromium treatment agent according to claim 8 , which further contains C1-C3 alcohol, and hexane and/or heptane, wherein the alcohol and hexane and/or heptane are contained at a weight percent ratio of 20-80:20-80 (provided that the sum of both equals to 100% by mass), and wherein the organic compounds (A) and (B) are dissolved in the alcohol and hexane and/or heptane.

18. The hexavalent chromium treatment agent according to claim 11 , which is capable of permeating a leather or leather article.

19. The hexavalent chromium treatment agent according to claim 11 , wherein kinetic viscosity at 25° C. is from 0.001 (cSt) to less than 5 (cSt).

20. The hexavalent chromium treatment agent according to claim 8 , wherein the organic compound (A) includes a compound having a structure shown in chemical formula (1) and dihydroxyphenyl or trihydroxyphenyl, wherein said compound does not have reactive functional groups of an aldehyde and carboxyl, the compound acting to reduce hexavalent chromium to trivalent chromium.

21. The hexavalent chromium treatment agent according to claim 20 , wherein the organic compound (A) includes a compound having a structure shown in chemical formula (1) and 1,2,3-trihydroxyphenyl, wherein said compound does not have reactive functional groups of an aldehyde and carboxyl, the compound acting to reduce hexavalent chromium to trivalent chromium.

22. The hexavalent chromium treatment agent according to claim 21 , wherein the organic compound (A) contains:
(i) gallic acid ester; and
(ii) at least one compound selected from tannic acid and a derivative thereof.

23. The hexavalent chromium treatment agent according to claim 22 , wherein the compound (ii) is tannic acid.

24. The hexavalent chromium treatment agent according to claim 22 , wherein the compound (i), the compound (ii) and the organic compound (B) are contained at a weight percent ratio of 1-20:30-89:10-50 (provided that the sum of (i), (ii), and (B) equals to 100% by weight).

25. The hexavalent chromium treatment a

Assignees

• Citizen Watch Co Ltd

Inventors

• Akao Yuji

Classifications

• A62D2101/43

  containing heavy metals, in the bonded or free state · CPC title

• C14C11/00 Primary

  Surface finishing of leather · CPC title

• C14C3/06 Primary

  using chromium compounds · CPC title

• C07D307/33

  in position 2, the oxygen atom being in its keto or unsubstituted enol form · CPC title

• C14C9/04

  Fixing tanning agents in the leather · CPC title