US4431481A
Expired / Lapsed
US
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Modified cellulosic fibers and method for preparation thereof
Assignee: Kimberly Clark Tissue Co
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Filing: 1982-03-29
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Granted: 1984-02-14
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Expires: 2002-03-29
Abstract
Abstract Cellulosic fibers, characterized by a lack of swellability and incapable of natural fiber-to-fiber bonding, are produced by a process which comprises treating an aqueous slurry of the fibers with a formaldehyde-free polymeric compound, heating the treated fibers to cause the polymeric compound to react with the fibers, and refiberizing to separate individual, treated fibers. The fibers are useful in the preparation of improved cellulosic webs characterized primarily by their increased bulk and improved softness.
Inventors
- 👤 John E. Drach
- 👤 Cleveland O'Neal, Jr.
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 05:00
CPC Classifications
D; D21; D21C; D21C9/00; D21C9/001; D21C9/002; D21C9/005
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
99 words
The method of preparing modified cellulosic fibers which comprises: treating an aqueous slurry of cellulosic fibers with an amic copolymer comprised of (A) a half-acid, half-amide corresponding to the following general formula: ##STR6## wherein R 1 is H and R is a hydrocarbon chain which has radically polymerized with (B) at least one other ethylenically unsaturated monomer, dewatering and drying the treated fibers to cause the copolymer to react with the fiber under conditions wherein the fibers are relatively free from contact with one another, and refiberizing the treated and dried fibers under dry conditions to separate individual fibers.
Claim 2
Independent Claim
99 words
The method of preparing modified cellulosic fibers which comprises: treating an aqueous slurry of cellulosic fibers with an amic copolymer comprised of (A) a half-acid, half-amide corresponding to the following general formula: ##STR6## wherein R 1 is H and R is a hydrocarbon chain which has radically polymerized with (B) at least one other ethylenically unsaturated monomer, dewatering and drying the treated fibers to cause the copolymer to react with the fiber under conditions wherein the fibers are relatively free from contact with one another, and refiberizing the treated and dried fibers under dry conditions to separate individual fibers.
Claim 3
Dependent Claim
16 words
A method in accordance with claim 1, in which the cellulosic fibers are wood pulp fibers.
Claim 4
Dependent Claim
22 words
A method in accordance with claim 1, utilizing a copolymer wherein the half-acid, half-amide corresponding to the general formula is maleamic acid.
Claim 5
Dependent Claim
22 words
A method in accordance with claim 1, utilizing a copolymer wherein the half-acid, half-amide corresponding to the general formula is fumaramic acid.
Claim 6
Dependent Claim
22 words
A method in accordance with claim 1, utilizing a copolymer wherein the half-acid, half-amide corresponding to the general formula is itaconamic acid.
Claim 7
Dependent Claim
30 words
A method in accordance with claim 1, utilizing a copolymer wherein the other ethylenically unsaturated monomer comprises a vinyl ester of an aliphatic acid having one to ten carbon atoms.
Claim 8
Dependent Claim
12 words
The method according to claim 6, wherein said monomer is vinyl acetate.
Claim 9
Dependent Claim
17 words
The method according to claim 7, wherein the copolymer further includes esters of acrylic or methacrylic acids.
Claim 10
Dependent Claim
17 words
A method according to claim 1, wherein the copolymer comprises an ethylenically unsaturated, basic nitrogen containing monomer.
Claim 11
Dependent Claim
20 words
A method according to claim 1, wherein the half-acid, half-amide comprises from 1 to 10% by weight of the copolymer.
Claim 12
Dependent Claim
33 words
A method, as claimed in claim 1, in which the copolymer is added to the fibers in an amount equal to from 3% to 8% of the bone dry weight of the fibers.
Claim 13
Dependent Claim
31 words
A method, as claimed in claim 1, in which the pH of the fiber slurry is maintained at from about 4.0 to about 6.0 during the addition of the polymeric compound.
Claim 14
Dependent Claim
20 words
A method, as claimed in claim 12, in which the pH is maintained by the addition of a mineral acid.
Claim 15
Dependent Claim
20 words
A method, as claimed in claim 1, in which a surface active agent is added to the aqueous fiber slurry.
Claim 16
Dependent Claim
38 words
A method, as claimed in claim 14, in which the surface active agent is added to the fiber slurry in an amount equal to from about 0.1% to about 1.5% of the bone dry weight of the fibers.
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) | 1987-02-13 | 1987-08-15 | 1988-02-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-02-13 | 1991-08-15 | 1992-02-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-02-13 | 1995-08-15 | 1996-02-14 | $7700.00 | Window Closed / Lapsed |