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US4022631A
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Process for producing regenerated cellulosic articles
Assignee: Rayonier Inc
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Filing: 1975-05-19
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Granted: 1977-05-10
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Expires: 1995-05-19
Abstract
Abstract Cellulosic articles are regenerated from a cellulosic solution formed by the addition of cellulosic material to dimethyl sulfoxide and formaldehyde or paraformaldehyde by contacting the cellulosic solution with an aqueous solution having a pH greater than seven of a water soluble nucleophilic compound selected from the group consisting of ammonia, ammonium salts, saturated amines and salts of sulfur compounds in which the sulfur has a valence of less than six.
Inventors
- 👤 Albin F. Turbak
- 👤 Richard B. Hammer
- 👤 Norman A. Portnoy
- 👤 Richard E. Davies
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 11:58
CPC Classifications
C; C08; C08B; C08B16/00
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
99 words
A process for producing a regenerated cellulosic article from a cellulosic solution formed by the addition of cellulosic material to dimethyl sulfoxide and an aldehyde selected from the group consisting of formaldehyde and a paraformaldehyde comprising contacting said cellulosic solution with a regeneration medium comprising an aqueous solution having a pH greater than 7 of from 0.25% to the maximum solubility of the compound in water of a water soluble nucleophilic compound selected from the group consisting of ammonia, ammonium salts, saturated amines and salts of sulfur compounds in which the sulfur has a valence of less than 6.
Claim 2
Dependent Claim
99 words
A process for producing a regenerated cellulosic article from a cellulosic solution formed by the addition of cellulosic material to dimethyl sulfoxide and an aldehyde selected from the group consisting of formaldehyde and a paraformaldehyde comprising contacting said cellulosic solution with a regeneration medium comprising an aqueous solution having a pH greater than 7 of from 0.25% to the maximum solubility of the compound in water of a water soluble nucleophilic compound selected from the group consisting of ammonia, ammonium salts, saturated amines and salts of sulfur compounds in which the sulfur has a valence of less than 6.
Claim 3
Dependent Claim
14 words
The process of claim 1 in which the nucleophilic compound is a nitrogenous compound.
Claim 4
Dependent Claim
17 words
The process of claim 1 in which the nucleophilic compound is a salt of a sulfur compound.
Claim 5
Dependent Claim
12 words
The process of claim 2 in which the nucleophilic compound is ammonia.
Claim 6
Dependent Claim
14 words
The process of claim 2 in which the nucleophilic compound is an ammonium salt.
Claim 7
Dependent Claim
14 words
The process of claim 2 in which the nucleophilic compound is a saturated amine.
Claim 8
Dependent Claim
19 words
The process of claim 3 in which the salt is selected from the group consisting of sulfides and thiosulfates.
Claim 9
Dependent Claim
12 words
The process of claim 7 in which the salt is sodium sulfide.
Claim 10
Dependent Claim
12 words
The process of claim 7 in which the salt is sodium thiosulfate.
Claim 11
Dependent Claim
34 words
The process of claim 1 in which the ratio by weight of the aldehyde to the cellulose in said cellulosic solution is at least 0.8 parts of the aldehyde to 1 part of cellulose.
Claim 12
Dependent Claim
11 words
The process of claim 1 in which the aldehyde is paraformaldehyde.
Claim 13
Dependent Claim
12 words
The process of claim 1 in which the cellulosic solution is anhydrous.
Claim 14
Dependent Claim
28 words
The process of claim 1 in which the cellulosic solution is heated to a temperature of from 60°-189° C in order to promote solution of the cellulosic material.
Claim 15
Dependent Claim
23 words
The process of claim 1 in which the cellulosic article is a fiber and the cellulosic solution is spun into the regeneration medium.
References Cited (Backward Citations)
US3236669A
Cited
US3706526A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1980-05-09 | 1980-11-08 | 1981-05-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-05-09 | 1984-11-08 | 1985-05-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-05-09 | 1988-11-08 | 1989-05-10 | $7700.00 | Window Closed / Lapsed |