Patent US4021522A successfully refreshed from Google Patents.
US4021522A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of forming collagen dispersions
Assignee: COLLAGEN PRODUCTS PTY Ltd
•
Filing: 1975-06-26
•
Granted: 1977-05-03
•
Expires: 1995-06-26
Abstract
Abstract A method of preparing collagen fibre dispersions comprising treating a collagenous material such as hide corium with a solution containing an alkaline earth metal hydroxide and an alkaline earth hydroxide; coarsely dicing or mincing the collagen, and mechanically dispersing the diced or minced collagen to achieve longitudinal separation of the collagen fibres; the dicing or mincing of the collagen being controlled such that at least 95% by weight of the collagen fibres in the dispersion are retained after neutralization on a 297 micron U.S. standard sieve.
Inventors
- 👤 Leonard Daniel
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 21:50
CPC Classifications
A; A61; A61L; A61L15/00; A61L15/16; A61L15/22; A61L15/32; A61L15/325; A61L15/40; A61L17/00; A61L17/06; A61L17/08; Y; Y10; Y10S; Y10S530/00; Y10S530/827; Y10S530/84; Y10S530/842
Claims Analysis
Total Claims: 21
Claim 1
Independent Claim
161 words
A method of forming a dispersion of collagenous fibres comprising the steps of: (a) treating a collagenous material with an aqueous solution of an alkaline earth metal hydroxide and an alkali metal hydroxide to reduce the cohesion between the collagen fibres, present in the material, the alkali metal hydroxide having a concentration of from 0.25 to 2 molar and the treatment being carried out at a temperature between the freezing point of the mixture and 30° C.; (b) severing the collagenous material into particles; and (c) mechanically dispersing the collagen fibres to free the fibres from one another substantially along their whole length and substantially without further reduction of the fibre length, the size of the particles of step (b) being such that at least 95% by weight of the fibres obtained in step (c) are retained after neutralisation on a 297 micron U.S. standard sieve when a sample of the fibres is placed on the screen and flushed with water.
Claim 2
Independent Claim
161 words
A method of forming a dispersion of collagenous fibres comprising the steps of: (a) treating a collagenous material with an aqueous solution of an alkaline earth metal hydroxide and an alkali metal hydroxide to reduce the cohesion between the collagen fibres, present in the material, the alkali metal hydroxide having a concentration of from 0.25 to 2 molar and the treatment being carried out at a temperature between the freezing point of the mixture and 30° C.; (b) severing the collagenous material into particles; and (c) mechanically dispersing the collagen fibres to free the fibres from one another substantially along their whole length and substantially without further reduction of the fibre length, the size of the particles of step (b) being such that at least 95% by weight of the fibres obtained in step (c) are retained after neutralisation on a 297 micron U.S. standard sieve when a sample of the fibres is placed on the screen and flushed with water.
Claim 3
Dependent Claim
20 words
A method as claimed in claim 1 in which the mechanical dispersion of the collagen fibres is achieved by mashing.
Claim 4
Dependent Claim
23 words
A method as claimed in claim 1 in which the mechanical dispersion of the collagen is achieved by extrusion through a restricted aperture.
Claim 5
Dependent Claim
26 words
A method as claimed in claim 1 in which the alkali metal hydroxide is chosen from the group comprising lithium hydroxide, sodium hydroxide and potassium hydroxide.
Claim 6
Dependent Claim
23 words
A method as claimed in claim 1 in which the alkali metal hydroxide is present in a concentration of 0.4 to 0.9 molar.
Claim 7
Dependent Claim
21 words
A method as claimed in claim 1 in which the collagenous material is severed into discrete particles by mincing or dicing.
Claim 8
Dependent Claim
26 words
A method as claimed in claim 1 in which the alkaline earth metal hydroxide is selected from the group consisting of calcium hydroxide and strontium hydroxide.
Claim 9
Dependent Claim
21 words
A method as claimed in claim 1 in which the collagenous dispersion is at least substantially neutralized after being mechanically dispersed.
Claim 10
Dependent Claim
64 words
A method as claimed in claim 8 in which the neutralisation is effected by a method selected from the group consisting of:- (a) washing with a saturated solution of sodium sulphate. (b) addition of a pulverised solid acid, acid salt or buffer mixture. (c) application of a mist spray of a concentrated liquid acid, (d) application of carbon dioxide under pressure (e) solvent leaching
Claim 11
Dependent Claim
17 words
A method as claimed in claim 9 in which the collagenous dispersion is dried after being neutralised.
Claim 12
Dependent Claim
33 words
A method as claimed in claim 10 in which the dispersion is dried by washing in a solvent selected from the group consisting of acetone, methyl ethyl ketone and alcohol, and air drying.
Claim 13
Dependent Claim
20 words
A method as claimed in claim 10 in which the dispersion is dried by fat liquoring followed by air drying.
Claim 14
Dependent Claim
14 words
A method as claimed in claim 1 which the collagenous material is skin corium.
Claim 15
Independent Claim
156 words
A method of forming a dispersion of collagenous fibers comprising the steps of: (a) treating a collagenous material with an aqueous solution of an alkaline earth metal hydroxide and an alkali metal hydroxide to reduce the cohesion between the collagen fibers, present in the material, the alkali metal hydroxide having a concentration of from 0.25 to 2 molar and the treatment being carried out at a temperature between the freezing point of the mixture and 30° C.; (b) severing the collagenous material into particles; and (c) mechanically dispersing the collagen fibers to free the fibers from one another substantially along their whole length and substantially without further reduction of the fiber length, the size of the particles of steb (b) being such that the fibers obtained in step (c) are substantially retained on a screen having holes in the order of 1 m.m. in diameter if after neutralization and washing they are drained on said screen.
Claim 16
Independent Claim
156 words
A method of forming a dispersion of collagenous fibers comprising the steps of: (a) treating a collagenous material with an aqueous solution of an alkaline earth metal hydroxide and an alkali metal hydroxide to reduce the cohesion between the collagen fibers, present in the material, the alkali metal hydroxide having a concentration of from 0.25 to 2 molar and the treatment being carried out at a temperature between the freezing point of the mixture and 30° C.; (b) severing the collagenous material into particles; and (c) mechanically dispersing the collagen fibers to free the fibers from one another substantially along their whole length and substantially without further reduction of the fiber length, the size of the particles of steb (b) being such that the fibers obtained in step (c) are substantially retained on a screen having holes in the order of 1 m.m. in diameter if after neutralization and washing they are drained on said screen.
Claim 17
Dependent Claim
20 words
A method as claimed in claim 14 in which the mechanical dispersion of the collagen fibers is achieved by mashing.
Claim 18
Dependent Claim
23 words
A method as claimed in claim 14 in which the mechanical dispersion of the collagen is achieved by extrusion through a restricted aperture.
Claim 19
Dependent Claim
26 words
A method as claimed in claim 14 in which the alkali metal hydroxide is chosen from the group comprising lithium hydroxide, sodium hydroxide and potassium hydroxide.
Claim 20
Dependent Claim
23 words
A method as claimed in claim 14 in which the alkali metal hydroxide is present in a concentration of 0.4 to 0.9 molar.
Claim 21
Dependent Claim
12 words
A dispersion of collagen fibers formed by the method of claim 15.
References Cited (Backward Citations)
US3894132A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1980-05-02 | 1980-11-01 | 1981-05-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-05-02 | 1984-11-01 | 1985-05-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-05-02 | 1988-11-01 | 1989-05-03 | $7700.00 | Window Closed / Lapsed |