US4267016A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Polyvinyl alcohol fiber for binding a fibrous sheet and a process for the preparation thereof
Assignee: Kuraray Co Ltd
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Filing: 1979-10-23
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Granted: 1981-05-12
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Expires: 1999-10-23
Abstract
Abstract A water-soluble polyvinyl alcohol fiber is obtained by subjecting to the conventional dry or wet spinning process, a solution prepared by adding to a polyvinyl alcohol aqueous solution, an adduct composed of a polyamide condensation product and 1-halogen-2,3-epoxy propane or ethylene glycol diglycidyl ether in the range from 5 to 50 percent by weight based upon the polyvinyl alcohol-after the solution's pH has been adjusted to 2 to 7. The resulting fiber, which has not been subjected to any heat treatment at a temperature above 120 DEG C. is blended with a fibrous material to make a fibrous sheet such as paper or non-woven fabric. By virtue of a subsequent heat-treatment, said polyvinyl alcohol fiber becomes boiling water-resistant; as a result, the wet strength of the fibrous sheet is significantly increased.
Inventors
- 👤 Masaki Okazaki
- 👤 Akio Mizobe
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 10:57
CPC Classifications
D; D01; D01F; D01F6/00; D01F6/44; D01F6/50; D21; D21H; D21H13/00; D21H13/10; D21H13/12; D21H13/16
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
105 words
A fibrous sheet exhibiting enhanced wet strength comprising a dispersion of paper stock fibers and from 2 to 30 percent by weight of polyvinyl alcohol fibers, said polyvinyl alcohol fiber comprising a water-soluble polyvinyl alcohol fiber containing from 5 to 50 percent by weight of an adduct comprising a polyamide condensation product and a 1-halogen-2,3-epoxy propane or ethylene glycol diglycidyl ether, said fiber, when not having been heat treated at a temperature about 120° C., possesses the latent ability of becoming boiling-water resistant upon being heat treated at a temperature above 120° C., said sheet having been heat treated at a temperature above 120° C.
Claim 2
Dependent Claim
105 words
A fibrous sheet exhibiting enhanced wet strength comprising a dispersion of paper stock fibers and from 2 to 30 percent by weight of polyvinyl alcohol fibers, said polyvinyl alcohol fiber comprising a water-soluble polyvinyl alcohol fiber containing from 5 to 50 percent by weight of an adduct comprising a polyamide condensation product and a 1-halogen-2,3-epoxy propane or ethylene glycol diglycidyl ether, said fiber, when not having been heat treated at a temperature about 120° C., possesses the latent ability of becoming boiling-water resistant upon being heat treated at a temperature above 120° C., said sheet having been heat treated at a temperature above 120° C.
Claim 3
Dependent Claim
25 words
The sheet of claim 1 wherein the adduct is present in an amount of from 20 to 30 by weight of the polyvinyl alcohol fiber.
Claim 4
Dependent Claim
26 words
The sheet of claim 1 wherein the polyvinyl alcohol fiber has a degree of saponification of the polyvinyl alcohol ranges from 80 to 100 mole percent.
Claim 5
Dependent Claim
20 words
The sheet of claim 1 wherein the degree of polymerization of the polyvinyl alcohol fiber ranges from 300 to 3000.
Claim 6
Dependent Claim
21 words
The sheet of claim 1 wherein the polyvinyl alcohol fiber exhibits a dissolving temperature which ranges between 45° and 95° C.
Claim 7
Dependent Claim
144 words
A process for producing fibrous sheet exhibiting enhanced wet strength comprising forming a slurry of paper stock fibers and from 2 to 30 percent by weight of polyvinyl alcohol fibers, forming a sheet from said slurry and drying said sheet at an elevated temperature said polyvinyl alcohol fibers possessing the latent ability of becoming boiling water-resistant upon heat treatment at a temperature above 120° C. and are formed by a process which comprises forming a solution by admixing a 5 to 70 percent by weight aqueous solution of polyvinyl alcohol with from 5 to 50 percent by weight based upon the weight of polyvinyl alcohol of an adduct of a polyamide condensation product and a 1-halogen-2,3-epoxy propane or ethylene glycol diglycidyl ether; adjusting the pH of the solution to from 2 to 7 and forming fibers from said solution by dry or wet spinning.
Claim 8
Dependent Claim
144 words
A process for producing fibrous sheet exhibiting enhanced wet strength comprising forming a slurry of paper stock fibers and from 2 to 30 percent by weight of polyvinyl alcohol fibers, forming a sheet from said slurry and drying said sheet at an elevated temperature said polyvinyl alcohol fibers possessing the latent ability of becoming boiling water-resistant upon heat treatment at a temperature above 120° C. and are formed by a process which comprises forming a solution by admixing a 5 to 70 percent by weight aqueous solution of polyvinyl alcohol with from 5 to 50 percent by weight based upon the weight of polyvinyl alcohol of an adduct of a polyamide condensation product and a 1-halogen-2,3-epoxy propane or ethylene glycol diglycidyl ether; adjusting the pH of the solution to from 2 to 7 and forming fibers from said solution by dry or wet spinning.
Claim 9
Dependent Claim
25 words
A process as defined in claim 6 wherein from 20 to 30 percent by weight of said adduct is admixed with the polyvinyl alcohol solution.
Claim 10
Dependent Claim
19 words
A process as defined in claim 6 wherein the sheet is heat treated at a temperature below 120° C.
Claim 11
Dependent Claim
24 words
A process as defined in claim 6 wherein the sheet is heat treated at a temperature above 120° C. for 1 to 120 seconds.
Claim 12
Dependent Claim
19 words
A process as defined in claim 6 wherein the sheet is heat treated at a temperature above 120° C.
References Cited (Backward Citations)
US3028296A
Cited
US3114670A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1984-05-11 | 1984-11-10 | 1985-05-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-05-11 | 1988-11-10 | 1989-05-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-05-11 | 1992-11-10 | 1993-05-12 | $7700.00 | Window Closed / Lapsed |