Patent US3796540A successfully refreshed from Google Patents.
US3796540A
Expired / Lapsed
US
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Process for whitening durable-press cellulosic fabrics with basic optical brighteners
Assignee: United States Department of Agriculture
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Filing: 1972-03-28
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Granted: 1974-03-12
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Expires: 1992-03-28
Abstract
Abstract Durable-press cellulosic fabrics with increased response to basic optical brighteners have been produced by a novel process wherein ordinary chemical crosslinking formulations are modified by substituting an alpha-hydroxy carboxylic acid for the usual strong inorganic acid to provide a chemically modified cellulose with pendant carboxylic groups. The second phase of the process consists of submitting the chemically modified fabric to a relatively mild treatment with a basic optical brightener.
Inventors
- 👤 R Harper
- 👤 G Gautreaux
- 👤 J Bruno
- 👤 M Donoghue
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 11:42
CPC Classifications
D; D06; D06M; D06M15/00; D06M15/19; D06M15/37; D06M15/39; D06M15/423; D06L; D06L4/00; D06L4/60; D06L4/657; Y; Y10; Y10S; Y10S8/00; Y10S8/916; Y10S8/918
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
12 words
The process of claim 1 wherein the alpha-hydroxy acid is citric acid.
Claim 2
Dependent Claim
12 words
The process of claim 1 wherein the alpha-hydroxy acid is glycolic acid.
Claim 3
Dependent Claim
12 words
The process of claim 1 wherein the alpha-hydroxy acid is lactic acid.
Claim 4
Dependent Claim
12 words
The process of claim 1 wherein the alpha-hydroxy acid is malic acid.
Claim 5
Dependent Claim
12 words
The process of claim 1 wherein the alpha-hydroxy acid is mandelic acid.
Claim 6
Dependent Claim
12 words
The process of claim 1 wherein the alpha-hydroxy acid is mucic acid.
Claim 7
Dependent Claim
12 words
The process of claim 1 wherein the alpha-hydroxy acid is tartaric acid.
Claim 8
Dependent Claim
12 words
The process of claim 1 wherein the alpha-hydroxy acid is tropic acid.
Claim 9
Dependent Claim
14 words
The process of claim 1 wherein the basic optical brightener is Fluorescent Brightener 56.
Claim 10
Dependent Claim
14 words
The process of claim 1 wherein the basic optical brightener is Fluorescent Brightener 101.
Claim 11
Dependent Claim
14 words
The process of claim 1 wherein the basic optical brightener is Fluorescent Brightener 159.
Claim 12
Dependent Claim
15 words
The process of claim 1 wherein the basic optical brightener is a cationic pyrazoline brightener.
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) | 1977-03-11 | 1977-09-10 | 1978-03-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-03-11 | 1981-09-10 | 1982-03-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-03-11 | 1985-09-10 | 1986-03-12 | $7700.00 | Window Closed / Lapsed |