Patent US3811832A successfully refreshed from Google Patents.
US3811832A
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Tanning improvements
Assignee: National Research Development Corp UK
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Filing: 1971-04-08
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Granted: 1974-05-21
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Expires: 1991-04-08
Abstract
Abstract A process for tanning hides or skins comprises first treating the hides or skins with a basic salt of a multivalent metal; and then treating the hides or skins with a reaction medium containing a water-soluble salt of a dibasic organic acid, the water-soluble salt being one that forms an alkaline solution in water, and being present in an amount sufficient to maintain an alkaline pH in the reaction medium.
Inventors
- 👤 P Briggs
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 08:04
CPC Classifications
C; C14; C14C; C14C3/00; C14C3/02; C14C3/28
Claims Analysis
Total Claims: 28
Claim 1
Independent Claim
36 words
A process according to claim 1, in which the hide or skin is neutralized after treatment with the basic salt of a multivalent metal and prior to treatment with the salt of a dibasic organic acid.
Claim 2
Dependent Claim
18 words
A process according to claim 1, in which the multivalent metal has a valence of three or more.
Claim 3
Dependent Claim
23 words
A process according to claim 3, in which the multivalent metal is selected from the group consisting of chromium, aluminum, zirconium and cerium.
Claim 4
Dependent Claim
20 words
A process according to claim 1, in which the basic salt of a multivalent metal is a mineral acid salt.
Claim 5
Dependent Claim
36 words
A process according to claim 1, in which the quantity of basic salt used is sufficient to give from 1.5 to 3.0 percent by weight calculated as metal oxide based on the weight of the leather.
Claim 6
Dependent Claim
32 words
A process according to claim 1, in which the dibasic organic acid is a dicarboxylic acid in which the carboxyl groups are separated by a chain having 7 or more carbon atoms.
Claim 7
Dependent Claim
31 words
A process according to claim 7, in which the dibasic organic acid is one in which the carboxyl groups are separated by a chain containing from 7 to 36 carbon atoms.
Claim 8
Dependent Claim
17 words
A process according to claim 8, in which the dibasic organic acid is a saturated dicarboxylic acid.
Claim 9
Dependent Claim
34 words
A process according to claim 9, in which the dibasic organic acid is selected from the group consisting of azelaic acid, sebacic acid, a straight chain C-12 or C-19 dicarboxylic acid, and di-oleic acid.
Claim 10
Dependent Claim
17 words
A process according to claim 7, in which the dibasic organic acid is an unsaturated dicarboxylic acid.
Claim 11
Dependent Claim
16 words
A process according to claim 11, in which the unsaturated dibasic organic acid is di-linoleic acid.
Claim 12
Dependent Claim
32 words
A process according to claim 1, in which the salt of the dibasic organic acid is selected from the group consisting of alkali metal salts, ammonium salts and salts of organic bases.
Claim 13
Dependent Claim
27 words
A process according to claim 1, in which the quantity of dibasic organic acid salt used is from 2 to 10 percent by weight of the leather.
Claim 14
Dependent Claim
23 words
A process according to claim 1, in which the further treatment with a salt of a multivalent metal is with a basic salt.
Claim 15
Dependent Claim
25 words
A process according to claim 15, in which the further treatment with a basic salt is with the same basic salt as that initially used.
Claim 16
Dependent Claim
23 words
A process according to claim 1, in which the further treatment with a salt of a multivalent metal is with a normal salt.
Claim 17
Dependent Claim
23 words
A process according to claim 17, in which the normal salt is selected from the group consisting of copper, zinc and nickel salts.
Claim 18
Dependent Claim
24 words
A process according to claim 1, in which the hide or skin is immersed in aqueous solutions of each of the reagents in turn.
Claim 19
Dependent Claim
17 words
A process according to claim 1, that is carried out at a temperature of up to 50*C.
Claim 20
Dependent Claim
23 words
A process according to claim 1, in which the hide or skin is washed with water after treatment with each of the reagents.
Claim 21
Dependent Claim
114 words
A hydrophobic leather tanned with a basic tanning salt of a multivalent metal compound and containing chemically bonded residues of a dibasic organic acid, said leather being produced by (a) treating a hide or skin with a basic tanning salt of a multivalent metal, (b) then chemically reacting the hide or skin with an aqueous medium containing a water-soluble salt of a dibasic organic acid, the water soluble salt being one that forms an alkaline solution in water, and present in an amount sufficient to maintain an alkaline pH in the medium, and (c) after treatment with the dibasic organic salt, further treating the hide or skin with a salt of a multivalent metal.
Claim 22
Dependent Claim
32 words
A leather according to claim 22, in which the dibasic organic acid is an dicarboxylic acid in which the carboxyl groups are separated by a chain having 7 or more carbon atoms.
Claim 23
Dependent Claim
28 words
A leather according to claim 22, in which the multivalent metal of the basic tanning salt is selected from the group consisting of chromium, aluminum, zirconium and cerium.
Claim 24
Dependent Claim
21 words
A leather according to claim 22, in which the basic tanning salt of a multivalent metal is a mineral acid salt.
Claim 25
Dependent Claim
31 words
A leather according to claim 23, in which the dibasic organic acid is one in which the carboxyl groups are separated by a chain containing from 7 to 36 carbon atoms.
Claim 26
Dependent Claim
17 words
A leather according to claim 26, in which the dibasic organic acid is a saturated dicarboxylic acid.
Claim 27
Dependent Claim
34 words
A leather according to claim 27, in which the dibasic organic acid is selected from the group consisting of azelaic acid, sebacic acid, a straight chain C-12 or C-19 dicarboxylic acid, and di-oleic acid.
Claim 28
Dependent Claim
15 words
A leather according to claim 26, in which the dibasic organic acid is di-linoleic acid.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-05-20 | 1977-11-19 | 1978-05-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-05-20 | 1981-11-19 | 1982-05-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-05-20 | 1985-11-19 | 1986-05-21 | $7700.00 | Window Closed / Lapsed |