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US3867352A Expired / Lapsed US ⏱️ 0.0 years remaining

Isocyanate-modified polymers of aspartic and glutamic acid and method of preparing the same

Assignee: Ajinomoto Co Inc
•
Filing: 1972-12-20
•
Granted: 1975-02-18
•
Expires: 1992-12-20
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Abstract

Abstract Polymers whose backbone includes aspartic or glutamic acid units, peptide-linked by their amino and Alpha -carboxyl groups, improve greatly in wet strength when contacted in a liquid medium with organic isocyanates until a sufficient number of the omega -carboxyl groups in the side chains of the polymer is converted to groups of the formula - CO - NH - C * by reaction with NCO groups of the isocyanate. Compounds having two or more NCO groups may cause cross linking. The high permeability of the glutamic or aspartic acid polymers to moisture, oxygen, carbon dioxide, and solutes in aqueous solutions is not significantly impaired, and may be enhanced by conversion of the omega -carboxyl groups, while wet strength is sharply increased, thereby improving utily of the polymers as dialysis membranes and in like applications.

Inventors

  • 👤 Akira Akamatsu
  • 👤 Akira Okuaki
  • 👤 Shigeo Mori

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-10-23 23:21
CPC Classifications
C; C08; C08G; C08G18/00; C08G18/06; C08G18/70; C08G18/71; A; A61; A61L; A61L15/00; A61L15/16; A61L15/22; A61L15/26; C08G18/28; C08G18/40; C08G18/60; C08G18/603

Claims Analysis

Total Claims: 12
Claim 1
Independent Claim 17 words
A PROCESS OF IMPROVING THE WET STRENGTH OF A SOLID POLYMER HAVING REPEATING UNITS OF THE FORMULA
Claim 2
Dependent Claim 17 words
A PROCESS OF IMPROVING THE WET STRENGTH OF A SOLID POLYMER HAVING REPEATING UNITS OF THE FORMULA
Claim 3
Dependent Claim 30 words
A process as set forth in claim 1, wherein said polymer is formed prior to said contacting by saponifying ester groups in a polymer having repeating units of the formula
Claim 4
Dependent Claim 33 words
A process as set forth in claim 1, wherein said isocyanate is of the formula R1 - NCO, R1 being an organic radical free from constituent elements capable of reacting with said polymer.
Claim 5
Dependent Claim 39 words
A process as set forth in claim 1, wherein said isocyanate is a compound of the formula OCN - R2 - NCO, wherein R2 is a divalent organic radical free from constituent elements capable of reacting with said polymer.
Claim 6
Dependent Claim 18 words
A process as set forth in claim 4, wherein said isocyanate is urethane prepolymer having terminal isocyanato groups.
Claim 7
Dependent Claim 24 words
A process as set forth in claim 1, wherein said liquid medium includes a solvent chemically inert to said polymer and to said isocyanate.
Claim 8
Dependent Claim 39 words
A process as set forth in claim 1, wherein said polymer prior to said contacting is soluble in 5% aqueous sodium bicarbonate solution at 20*C, and is contacted with said isocyanate until substantially insoluble in said sodium bicarbonate solution.
Claim 9
Dependent Claim 33 words
A process as set forth in claim 1, wherein the carbon bound to said at least one NCO group of said organic isocyanate is a member of an aliphatic, cycloaliphatic, or aromatic radical.
Claim 10
Dependent Claim 19 words
A solid polymer, insoluble in 5% aqueous sodium bicarbonate solution at 20*C and havinG repeating units of the formula
Claim 11
Dependent Claim 19 words
A solid polymer, insoluble in 5% aqueous sodium bicarbonate solution at 20*C and havinG repeating units of the formula
Claim 12
Dependent Claim 24 words
A process as set forth in claim 1, wherein said carbon in said isocyanate is a member of an aromatic, aliphatic, or alicyclic group.

References Cited (Backward Citations)

US3371069A Cited
US3634544A Cited
US3585161A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1978-02-17 1978-08-19 1979-02-18 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1982-02-17 1982-08-19 1983-02-18 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1986-02-17 1986-08-19 1987-02-18 $7700.00 Window Closed / Lapsed

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