US4240937A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Alloy fibers of rayon and an alkali metal or ammonium salt of an azeotropic copolymer of polyacrylic acid and methacrylic acid having improved absorbency
Assignee: Akzona Inc
•
Filing: 1978-01-03
•
Granted: 1980-12-23
•
Expires: 1998-01-03
Abstract
Abstract Cardable cellulosic fibers having improved water and fluid absorbency are made by incorporating therein an alkali metal or ammonium salt of a copolymer of acrylic acid and methacrylic acid prepared by a process wherein the two monomers are mixed together in ratios during the polymerization so that the amount of copolymer chains substantially richer in methacrylic acid moieties than the total ratio of acrylic acid and methacrylic acid monomers included in the copolymerization process and the number of copolymer chains considerably lower in degree of polymerization than the copolymer average are minimized.
Inventors
- 👤 Thomas C. Allen
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 23:51
CPC Classifications
D; D01; D01F; D01F2/00; D01F2/06; D01F2/08; A; A61; A61L; A61L15/00; A61L15/16; A61L15/22; A61L15/225
Claims Analysis
Total Claims: 24
Claim 1
Independent Claim
38 words
A highly absorbent cellulosic fiber having incorporated into the cellulosic structure an alkali metal or ammonium salt of an azotropic copolymer of acrylic acid and methacrylic acid in a weight ratio of from about 10:90 to about 90:10.
Claim 2
Dependent Claim
38 words
A highly absorbent cellulosic fiber having incorporated into the cellulosic structure an alkali metal or ammonium salt of an azotropic copolymer of acrylic acid and methacrylic acid in a weight ratio of from about 10:90 to about 90:10.
Claim 3
Dependent Claim
46 words
The fiber of claim 1 wherein the cellulosic fiber is regenerated from a viscose solution and the copolymer is incorporated into the viscose solution in an amount ranging from about 2 to about 30% by weight based on the weight of cellulose in the viscose solution.
Claim 4
Dependent Claim
40 words
An article of manufacture comprising highly absorbent fibers comprising a matrix of regenerated cellulose and an alkali metal or ammonium salt of an azeotropic copolymer of acrylic acid and methacrylic acid ratio of from about 10:90 to about 90:10, respectively.
Claim 5
Dependent Claim
40 words
An article of manufacture comprising highly absorbent fibers comprising a matrix of regenerated cellulose and an alkali metal or ammonium salt of an azeotropic copolymer of acrylic acid and methacrylic acid ratio of from about 10:90 to about 90:10, respectively.
Claim 6
Dependent Claim
45 words
The article of claim 3 wherein the cellulose is regenerated from a viscose solution and the copolymer is incorporated into the regenerated cellulose in an amount ranging from about 2 to about 30% by weight, based on the weight of cellulose in the viscose solution.
Claim 7
Dependent Claim
69 words
A highly absorbent cellulosic fiber regenerated from a viscose solution containing from about 2% to about 30% by weight of an alkali metal salt or ammonium salt of an azeotropic copolymer of acrylic acid and methacrylic acid, based on the weight of cellulose in the viscose solution, the ratio of acrylic acid moieties to methacrylic acid moities in the copolymer being from about 10:90 to about 90:10 by weight.
Claim 8
Dependent Claim
69 words
A highly absorbent cellulosic fiber regenerated from a viscose solution containing from about 2% to about 30% by weight of an alkali metal salt or ammonium salt of an azeotropic copolymer of acrylic acid and methacrylic acid, based on the weight of cellulose in the viscose solution, the ratio of acrylic acid moieties to methacrylic acid moities in the copolymer being from about 10:90 to about 90:10 by weight.
Claim 9
Dependent Claim
12 words
The fiber of claim 5 wherein the weight ratio is about 50:50.
Claim 10
Dependent Claim
8 words
The fiber of claim 5 which is cardable.
Claim 11
Dependent Claim
67 words
An article of manufacture comprising highly absorbent fibers comprising a matrix of regenerated cellulose and an alkali metal salt or ammonium salt of an azeotropic copolymer of acrylic acid and methacrylic acid, said cellulose having been regenerated from a viscose solution containing said salt, the ratio of acrylic acid moities to methacrylic acid moieties in the copolymer in the viscose solution ranging from 10:90 to 90:10, respectively.
Claim 12
Dependent Claim
67 words
An article of manufacture comprising highly absorbent fibers comprising a matrix of regenerated cellulose and an alkali metal salt or ammonium salt of an azeotropic copolymer of acrylic acid and methacrylic acid, said cellulose having been regenerated from a viscose solution containing said salt, the ratio of acrylic acid moities to methacrylic acid moieties in the copolymer in the viscose solution ranging from 10:90 to 90:10, respectively.
Claim 13
Dependent Claim
12 words
The article of claim 8 wherein the weight ratio is about 50:50.
Claim 14
Dependent Claim
11 words
The article of claim 9 in the form of a tampon.
Claim 15
Dependent Claim
121 words
A process for making a cellulosic fiber having improved water and fluid absorbency which comprises spinning a viscose solution containing an alkali metal salt of an ammonium salt of an azeotropic copolymer of acrylic acid and methacrylic acid having a weight ratio of acrylic acid to methacrylic acid from about 90 to 10 mole percent to about 10 to 90 mole percent, and which copolymer has been prepared by a process wherein the addition of each of the two acid monomers is controlled throughout the copolymerization process whereby the ratios of acrylic acid moieties and methacrylic acid moieties in the copolymer chains are substantially the same as the ratios of the total of said acid monomers included in the copolymerization process.
Claim 16
Dependent Claim
121 words
A process for making a cellulosic fiber having improved water and fluid absorbency which comprises spinning a viscose solution containing an alkali metal salt of an ammonium salt of an azeotropic copolymer of acrylic acid and methacrylic acid having a weight ratio of acrylic acid to methacrylic acid from about 90 to 10 mole percent to about 10 to 90 mole percent, and which copolymer has been prepared by a process wherein the addition of each of the two acid monomers is controlled throughout the copolymerization process whereby the ratios of acrylic acid moieties and methacrylic acid moieties in the copolymer chains are substantially the same as the ratios of the total of said acid monomers included in the copolymerization process.
Claim 17
Dependent Claim
51 words
The process of claim 11 wherein the amount of each of said acids at the beginning of the copolymerization and the addition of each of the two acids is controlled during copolymerization whereby the resulting copolymer chains which are substantially richer in methacrylic acid moieties than the copolymerization mixture are minimized.
Claim 18
Dependent Claim
47 words
The process of claim 11 wherein the addition of each of the two acids is controlled throughout the process in ratios whereby the number of copolymer chains which are substantially lower in degree of polymerization than the average degree of polymerization of the copolymer are also minimized.
Claim 19
Dependent Claim
17 words
The process of claim 11, 12 or 13 wherein the resulting copolymer is an approximate 50/50 copolymer.
Claim 20
Dependent Claim
24 words
The process of claim 11 wherein the copolymerizing mixture at the beginning of the copolymerization is richer in acrylic acid than in methacrylic acid.
Claim 21
Dependent Claim
89 words
The process of claim 11 wherein from about 2% to about 40% by weight of the copolymer based on the weight of cellulose in the viscose solution is injected into the viscose solution prior to spinning and the resulting mixture is spun into an acid bath where the cellulose in the resulting filament is regenerated, the resulting fiber is stretched in air from 0% to more than 100%, submerged in a hot aqueous bath, stretched from 0% to 100% in the bath, cut into short fibers, washed and dried.
Claim 22
Dependent Claim
37 words
The process of claim 16 wherein prior to drying, the regenerated fiber is submerged in an aqueous bath containing an alkali metal or ammonium base to convert the included copolymer to an alkali metal or ammonium salt.
Claim 23
Dependent Claim
116 words
A process for making a cardable cellulosic fiber having improved water and fluid absorbency which comprises spinning a viscose solution containing an alkali metal salt or an ammonium salt of an azeotropic copolymer of acrylic acid and methacrylic acid which copolymer contains from 90 to 10 mole percent acrylic acid moieties to 10 to 90 mole percent methacrylic acid moieties and has been prepared by a process wherein the addition of each of the two acids is controlled throughout the copolymerization process whereby the ratios of acrylic acid moieties and methacrylic acid moieties in the copolymer chains are substantially the same as the ratios of the total of said acid monomers included in the copolymerization process.
Claim 24
Dependent Claim
116 words
A process for making a cardable cellulosic fiber having improved water and fluid absorbency which comprises spinning a viscose solution containing an alkali metal salt or an ammonium salt of an azeotropic copolymer of acrylic acid and methacrylic acid which copolymer contains from 90 to 10 mole percent acrylic acid moieties to 10 to 90 mole percent methacrylic acid moieties and has been prepared by a process wherein the addition of each of the two acids is controlled throughout the copolymerization process whereby the ratios of acrylic acid moieties and methacrylic acid moieties in the copolymer chains are substantially the same as the ratios of the total of said acid monomers included in the copolymerization process.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1983-12-23 | 1984-06-23 | 1984-12-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1987-12-23 | 1988-06-23 | 1988-12-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1991-12-23 | 1992-06-23 | 1992-12-23 | $7700.00 | Window Closed / Lapsed |