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US4634470A Expired / Lapsed US ⏱️ 0.0 years remaining

Cellulose dope, process for preparation and method for application thereof

Assignee: Asahi Kasei Corp
•
Filing: 1984-11-28
•
Granted: 1987-01-06
•
Expires: 2004-11-28
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Abstract

Abstract Described is a cellulose dope which is an aqueous alkali solution containing substantially at least 3% by weight of cellulose having a degree of polymerization of at least 100, wherein in the 13 C-NMR spectrum of the cellulose, the C 4 -position carbon peak is found at a magnetic field higher by at least 7 ppm than the magnetic field of the C 4 -position carbon peak of solid cellulose attributed to the strong intramolecular hydrogen bond. This dope is prepared by maintaining a mixture comprising 100 weight parts of cellulose, which may have any crystal form, and 10 to 1000 weight parts of a hydrogen bond-cleaving solution at 100° C. to 350° C. under a pressure of 10 to 250 atmospheres, promptly exposing the mixture to the ambient atmosphere, mixing the resulting cellulose with an aqueous alkali solution maintained at a temperature not higher than 50° C., and then stirring the mixture at a temperature not higher than 10° C. to dissolve the cellulose in the aqueous alkali solution. The dope may be used for the manufacture of a shaped article or for coating.

Inventors

  • 👤 Kenji Kamide
  • 👤 Kunihiko Okajima

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-07 14:58
CPC Classifications
C; C08; C08L; C08L1/00; C08L1/02; C08B; C08B1/00; C08B16/00

Claims Analysis

Total Claims: 8
Claim 1
Independent Claim 75 words
A cellulose dope suitable for shaping which comprises an aqueous alkali solution containing substantially at least 3% by weight of cellulose having a polymerization degree of at least 100, wherein in the 13 C-NMR spectrum of said cellulose, the C 4 carbon peak is found at a magnetic field higher by at least 7 ppm than the magnetic field of the C 4 carbon peak of solid cellulose attributed to the strong intramolecular hydrogen bond.
Claim 2
Dependent Claim 75 words
A cellulose dope suitable for shaping which comprises an aqueous alkali solution containing substantially at least 3% by weight of cellulose having a polymerization degree of at least 100, wherein in the 13 C-NMR spectrum of said cellulose, the C 4 carbon peak is found at a magnetic field higher by at least 7 ppm than the magnetic field of the C 4 carbon peak of solid cellulose attributed to the strong intramolecular hydrogen bond.
Claim 3
Dependent Claim 114 words
A process for the preparation of the cellulose dope set forth in claim 1, which comprises the steps of: maintaining a mixture comprising 100 parts by weight of cellulose, which may have any of crystal form, and 10 to 1000 parts by weight of a hydrogen bond-cleaving solution at a temperature of 100° C. to 350° C. under a pressure of 10 to 250 atmospheres, promptly discharging the mixture in the open air, and then, mixing the resulting cellulose with an aqueous alkali solution maintained at a temperature not higher than 50° C. and stirring the mixture at a temperature not higher than 10° C. to dissolve the cellulose in the aqueous alkali solution.
Claim 4
Dependent Claim 78 words
A process for the preparation of cellulose dope set forth in claim 1, which comprises the step of: mixing cellulose having a crystal form of cellulose I with a solvent capable of dissolving cellulose, solidifying the mixture either by removing a part of the volatilizable solvent component or introducing the mixture into an organic solvent, regenerating the solidified cellulose, and, then, dissolving the regeneraged cellulose in an aqueous alkali solution at a temperature not higher than 10° C.
Claim 5
Dependent Claim 46 words
A cellulose shaped article having a well-developed intramolecular hydrogen bond which is prepared by introducing a cellulose dope as set forth in claim 1 into a coagulating bath and then into a neutralizing bath by using an extruder, and then drawing and winding the coagulated cellulose.
Claim 6
Dependent Claim 22 words
A cellulose dope suitable for shaping as recited in claim 1 wherein said cellulose is completely molecularly dispersed in said cellulose dope.
Claim 7
Dependent Claim 26 words
A process as defined in cliam 3 wherein said regenerated cellulose is dissolved in an aqueous alkali solution at a temperature not higher than 7° C.
Claim 8
Dependent Claim 26 words
A process as defined in cliam 3 wherein said regenerated cellulose is dissolved in an aqueous alkali solution at a temperature not higher than 7° C.

References Cited (Backward Citations)

US2978446A Cited
US3388119A Cited
US3758458A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1990-01-05 1990-07-07 1991-01-06 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1994-01-05 1994-07-07 1995-01-06 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1998-01-05 1998-07-07 1999-01-06 $7700.00 Window Closed / Lapsed

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