Robert L Irwin

US Patent:

51891417, Feb 23, 1993

Filed:

Apr 30, 1991

Appl. No.:

7/693522

Inventors:

Robert S. Irwin - Wilmington DE

Assignee:

E. I. Du Pont de Nemours and Company - Wilmington DE

International Classification:

C08G 6932

US Classification:

528331

Abstract:

High molecular weight aromatic polyamides with pendant carboxyl groups.

US Patent:

55434924, Aug 6, 1996

Filed:

Mar 6, 1995

Appl. No.:

8/399330

Inventors:

Robert S. Irwin - Wilmington DE

Assignee:

E. I. Du Pont de Nemours and Company - Wilmington DE

International Classification:

C08G 6926
C08G 6932

US Classification:

528335

Abstract:

Aramid polymers with small amounts of alkyl- and/or alkoxy-substitution on their aromatic diamine and/or aromatic diacid monomeric units are disclosed. Such aramid polymers show improved properties compared to similar aramids without the substitution. The aramids described herein are useful for films or fibers, for example, as employed in the manufacture of packaging, ropes, filter bags, or composites. The invention also includes a process for making such polymers, involving subjecting fibers or films made from such aramid polymers to heat treatment under tension.

US Patent:

52122573, May 18, 1993

Filed:

Dec 6, 1991

Appl. No.:

7/802910

Inventors:

Robert S. Irwin - Wilmington DE

Assignee:

E. I. Du Pont de Nemours and Company - Wilmington DE

International Classification:

C08L 7710

US Classification:

525432

Abstract:

Aramid block copolymers which contains blocks which are crystalline and blocks that are noncrystalline after drawing and where polymer chains are flexible in solution and in undrawn polymer, but relatively rigid in drawn polymer, are disclosed. The aramids are tough materials with high modulus and tensile strength. Also disclosed is a process for making such block copolymers. The copolymers are useful as fibers and films, for example in ropes and composites.

US Patent:

51732408, Dec 22, 1992

Filed:

Apr 26, 1991

Appl. No.:

7/692162

Inventors:

Robert S. Irwin - Wilmington DE

Assignee:

E. I. Du Pont de Nemours and Company - Wilmington DE

International Classification:

D01F 660

US Classification:

264345

Abstract:

Amorphous fibers or fibrids of poly [4,4'-(2,2'-dicarboxy) biphenyleneterephthalamide] are strengthened and heat stabilized by a relaxed heat-treatment. The fiber or fibrids are heated at temperatures in the range of 310. degree. C. to 365. degree. C. and preferably at temperatures above 325. degree. C. but below decomposition temperatures. The heating is conducted for at least 2 minutes, preferably from 5 to 15 minutes. Increases in tenacity of at least 25%, preferably at least 50% or more are attained. The fiber or fibrids are treated while free of ternsion as they would be in a loose batt, woven or knitted fibric or paper.

US Patent:

52198987, Jun 15, 1993

Filed:

Apr 15, 1992

Appl. No.:

7/868689

Inventors:

Robert S. Irwin - Wilmington DE

Assignee:

E. I. Du Pont de Nemours and Company - Wilmington DE

International Classification:

C08K 534

US Classification:

524104

Abstract:

Anisotropic solutions are prepared from poly[2,2'-bis(trifluoromethyl)benzidine terephthalamide] or poly[2,2'-bis(1,1,2,2-tetrafluoroethoxy)benzidine terephthalamide] in amide solvents containing certain chlorides in specified amount. Crystalline fibers are prepared from the polymers.

US Patent:

52122581, May 18, 1993

Filed:

Oct 29, 1991

Appl. No.:

7/784346

Inventors:

Robert S. Irwin - Wilmington DE

Assignee:

E. I Du Pont de Nemours and Company - Wilmington DE

International Classification:

C08L 7710

US Classification:

525432

Abstract:

Aramid block copolymers which contains blocks whose polymer chains are flexible, and blocks whose polymer chains are flexible in solution and in undrawn polymer, but relatively rigid in drawn polymer, are disclosed. The aramids are tough materials with high modulus and tensile strength. Also disclosed is a process for making such block copolymers. The copolymers are useful as fibers and films, for example in ropes and composites.

US Patent:

42321433, Nov 4, 1980

Filed:

Sep 17, 1979

Appl. No.:

6/076800

Inventors:

Robert S. Irwin - Wilmington DE

Assignee:

E. I. Du Pont de Nemours and Company - Wilmington DE

International Classification:

C08G 6360

US Classification:

528128

Abstract:

An aromatic polyester consisting essentially of p-oxybenzoyl units or the 3-methyl or 3-chloro-derivatives thereof, 4,4'-dioxybenzophenone units or the 3-methyl- or 3-chloro- derivatives thereof, terephthaloyl units and optionally 1,4-dioxyphenylene units.

US Patent:

50268198, Jun 25, 1991

Filed:

Dec 5, 1989

Appl. No.:

7/446339

Inventors:

Robert S. Irwin - Wilmington DE

Assignee:

E. I. Du Pont de Nemours and Company - Wilmington DE

International Classification:

C08G 6932

US Classification:

5283291

Abstract:

The reactivity of aromatic copolyamide fiber and film is enhanced by incorporation of small amounts of 4,4'-diaminodiphenic acid units in the polymer chain.