US4293647A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of dissolving collagen-containing tissues
Assignee: Roehm GmbH Darmstadt
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Filing: 1978-02-28
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Granted: 1981-10-06
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Expires: 1998-02-28
Abstract
Abstract What is disclosed is a method for dissolving collagen-containing tissues, such as the wastes arising in leather processing, which comprises enzymatically hydrolyzing said tissues with at least one acid protease at a pH within the acid region.
Inventors
- 👤 Rolf Monsheimer
- 👤 Ernst Pfleiderer
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 17:40
CPC Classifications
A; A23; A23J; A23J3/00; A23J3/30; A23J3/32; A23J3/34; A23J3/341; A23J3/342; C; C02; C02F; C02F3/00; C02F3/34; C02F3/342; C09; C09H; C09H1/00; C09H1/04; Y; Y10; Y10S; Y10S435/00; Y10S435/8215; Y10S435/911; Y10S435/913; Y10S435/918
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
53 words
A method for dissolving collagen-containing tissue to form soluble decomposed products of low viscosity, which method consists essentially of enzymatically hydrolyzing said tissue by treatment with at least one acid protease at a pH within the acid region and in the presence of urea at a concentration between 0.01 mol/liter and 0.3 mol/liter.
Claim 2
Independent Claim
53 words
A method for dissolving collagen-containing tissue to form soluble decomposed products of low viscosity, which method consists essentially of enzymatically hydrolyzing said tissue by treatment with at least one acid protease at a pH within the acid region and in the presence of urea at a concentration between 0.01 mol/liter and 0.3 mol/liter.
Claim 3
Dependent Claim
23 words
A method as in claim 1 wherein said acid protease has an optimum activity in a pH between pH 1.0 and pH 6.0.
Claim 4
Dependent Claim
16 words
A method as in claim 1 wherein said acid protease is derived from an Aspergillus species.
Claim 5
Dependent Claim
20 words
A method as in claim 1 wherein said acid protease is derived from Aspergillus oryzae, Aspergillus saitoi, or Aspergillus parasiticus.
Claim 6
Dependent Claim
17 words
A method as in claim 1 wherein a plurality of different acid proteases are used in combination.
Claim 7
Dependent Claim
17 words
A method as in claim 1 wherein pepsin is used in combination with an acid fungus protease.
Claim 8
Dependent Claim
17 words
A method as in claim 1 wherein pepsin is used in combination with an acid plant protease.
Claim 9
Dependent Claim
20 words
A method as in claim 1 wherein an acid fungus protease is used in combination with an acid fungus protease.
Claim 10
Dependent Claim
28 words
A method as in claim 1 wherein from 100 mU Hb to 4000 mU Hb of enzyme, determined at pH 7.5, are used per gram of dry substrate.
Claim 11
Dependent Claim
21 words
A method as in claim 1 wherein said tissues are reacted with said acid protease for from 1 to 5 hours.
Claim 12
Dependent Claim
18 words
A method as in claim 1 wherein a urea concentration between 0.03 mol/liter and 0.2 mol/liter is present.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1984-10-05 | 1985-04-06 | 1985-10-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-10-05 | 1989-04-06 | 1989-10-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-10-05 | 1993-04-06 | 1993-10-06 | $7700.00 | Window Closed / Lapsed |