US4405324A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Absorbent cellulosic structures
Assignee: MORCA Inc PO BOX 97 HOPEWELL NJ 08525 A CORP OF
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Filing: 1981-08-24
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Granted: 1983-09-20
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Expires: 2001-08-24
Abstract
Abstract Absorbent, coherent, flexible structures in the form of fibrous webs and porous sponges comprising cellulose derivatives having a DS of between about 0.05 and about 0.35 whereby upon application to the body and wet with aqueous body liquids, the protruding fibers and fibrils or hairs become highly swollen or may dissolve thereby eliminating irritation. The derivative may be such as to impart hemostatic properties and the structure may include uniformly dispersed therein chitin and/or starch derivatives to enhance the hemostatic efficacy. The structures may include water-soluble agents which function as dry binders but when the structure is wet with aqueous body liquids, the agents dissolve and become leached from the structures.
Inventors
- 👤 Mamerto M. Cruz, Jr.
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 11:04
CPC Classifications
A; A61; A61L; A61L15/00; A61L15/16; A61L15/22; A61L15/225; A61L15/28
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
128 words
Absorbent, coherent, flexible cellulosic structures for application to the body comprising water-insoluble cellulose derivatives of the group of cellulose ethers, cellulose mixed ethers and cellulose ether mixed esters prepared from highly fibrillated, chemically purified wood pulp having a CSF not exceeding about 150, the cellulose derivative having a total DS of between about 0.05 to about 0.35, said structures being further characterized in that when applied to the body and wet with aqueous body liquid the protruding fibrils and microfibrils on the surfaces and along the edges of the structures become highly swollen almost instantaneously whereby the structures are non-irritating to the body over the area to which the structure is applied and in having a higher liquid absorbency than a like structure formed from underivatized, unfibrillated cellulose.
Claim 2
Dependent Claim
128 words
Absorbent, coherent, flexible cellulosic structures for application to the body comprising water-insoluble cellulose derivatives of the group of cellulose ethers, cellulose mixed ethers and cellulose ether mixed esters prepared from highly fibrillated, chemically purified wood pulp having a CSF not exceeding about 150, the cellulose derivative having a total DS of between about 0.05 to about 0.35, said structures being further characterized in that when applied to the body and wet with aqueous body liquid the protruding fibrils and microfibrils on the surfaces and along the edges of the structures become highly swollen almost instantaneously whereby the structures are non-irritating to the body over the area to which the structure is applied and in having a higher liquid absorbency than a like structure formed from underivatized, unfibrillated cellulose.
Claim 3
Dependent Claim
20 words
The structure as defined in claim 1 wherein the cellulose derivative has a total DS of between 0.1 and 0.25.
Claim 4
Dependent Claim
21 words
The structure as defined in claim 1 wherein the protruding fibrils and microfibrils upon becoming swollen dissolve in the body liquid.
Claim 5
Dependent Claim
34 words
The structure as defined in claim 1 further characterized by including a water-soluble dry binder whereby upon absorption of body liquid by the structure the dry binder dissolves and is leached from the structure.
Claim 6
Dependent Claim
14 words
The structure as defined in claim 1 in the form of a fibrous sheet.
Claim 7
Dependent Claim
28 words
The structure as defined in claim 1 in the form of a porous sponge containing up to about 25% of derivatized highly fibrillated, chemical purified wood pulp fibers.
Claim 8
Dependent Claim
26 words
The structure as defined in claim 1 being further characterized in absorbing at least 1000% water by weight based upon the dry weight of the structure.
Claim 9
Dependent Claim
27 words
The structure as defined in claim 1 wherein the cellulose derivative is carboxymethyl cellulose prepared from highly fibrillated, chemically purified wood pulp having a CSF about 50.
Claim 10
Dependent Claim
27 words
The structure as defined in claim 1 wherein the cellulose derivative is hydroxypropylmethyl cellulose prepared from highly fibrillated, chemically purified wood pulp having a CSF about 50.
Claim 11
Dependent Claim
29 words
The structure as defined in claim 1 wherein the cellulose derivative is succinylated methyl cellulose or succinylated hydroxypropylmethyl cellulose and the structure being further characterized by exhibiting hemostatic properties.
Claim 12
Dependent Claim
24 words
The structure as defined in claim 1 in the form of a porous sponge and being further characterized by including an alkali soluble polyacrylate.
Claim 13
Dependent Claim
40 words
The structure as defined in claim 1 in the form of a porous sponge and being further characterized by including chitin derivatives of the group chitin ethers, chitin mixed ethers and chitin ether mixed esters and by exhibiting hemostatic properties.
Claim 14
Dependent Claim
44 words
The structure as defined in claim 1 in the form of a sponge wherein the cellulose derivative is succinylated methyl cellulose or succinylated hydroxypropylmethyl cellulose and the structure being further characterized by including succinylated starch or succinylated hydroxypropylmethyl starch and by exhibiting hemostatic properties.
Claim 15
Dependent Claim
24 words
The structure as defined in claim 1 further characterized by including an aqueous isopropanol or aqueous ethanol soluble germicide, moldicide, bacteriocide or pharmaceutical agent.
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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) | 1986-09-19 | 1987-03-21 | 1987-09-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1990-09-19 | 1991-03-21 | 1991-09-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1994-09-19 | 1995-03-21 | 1995-09-20 | $7700.00 | Window Closed / Lapsed |