E.i. Dupont De Nemours and Company

Rajiv Dhawan

Joachim C Ritter

Ekaterini Korovessi

David J Rodini

Steven R Allen

Roger Keith Siemionko

Frederick K Mallon

Annalisa Hargis

New triaminophenol compositions and related compounds are disclosed, as are processes for their preparation and for the preparation of novel salts and diacid complexes from such compounds. Polymers prepared from these compositions can be made into high strength fiber, film, and tape and are useful in applications such as protective apparel, aircraft, automotive components, personal electronics, and sports equipment.

2,4,5-triaminophenols and related compounds

A process is provided to produce 2,3,5,6-tetraaminotoluene. Highly pure salts of 2,3,5,6-tetraaminotoluene are produced via reduction of 2,6-diamino-3,5-dinitrotoluene. The 2,3,5,6-tetraaminotoluene salt is precipitated as a clean (&#x3e;99% purity) product. The salt is a precursor for monomers to make a polybenzimidazole for high performance fibers.

Process for the preparation of monomers for polybenzimidazole materials

Highly pure 2,3,5,6-tetraaminotoluene species are produced by chemically reducing undesirable oxidation byproducts. The 2,3,5,6-tetraaminotoluene species are then used in the manufacture of superior high-performance polybenzimidazole polymers.

Process for the preparation of highly pure monomers for polybenzimidazole materials

An integrated process is provided for preparing 2,3,5,6-tetraminotoluene and salts thereof starting with nitration of 2,6-dihalotoluene. The process design eliminates costly intermediate drying and recrystallization steps. Handling of solid materials with possible skin sensitizing properties and toxicity is avoided, thereby eliminating human and environmental exposure.

Integrated process for the preparation of polybenzimidazole precursors

Processes are provided for preparing complexes of 2,3,5,6-tetraaminotoluene with an aromatic diacid where the aromatic diacid is insoluble in water under ambient conditions. An integrated process design starting with nitration of 2,6-dihalotoluene eliminates costly intermediate drying and recrystallization steps. Handling of solid materials with possible skin sensitizing properties and toxicity is avoided, thereby eliminating human and environmental exposure.

An integrated process is provided for preparing complexes of 2,3,5,6-tetraminotoluene with an aromatic diacid starting with nitration of 2,6-dihalotoluene. The process design eliminates costly intermediate drying and recrystallization steps. Handling of solid materials with possible skin sensitizing properties and toxicity is avoided, thereby eliminating human and environmental exposure.

Complexes of 2,3,5,6-tetraaminotoluene with an aromatic diacid are prepared by reaction with a divalent salt of the aromatic diacid while maintaining the pH of the reaction solution between 3 and 10. The resulting complexes are suitable for making high molecular weight polybenzimidazole polymers for high-performance fibers.

An improved process is provided for the preparation of 2,6-diamino-3,5-dinitrotoluene by amination of 2,6-dichloro-3,5-dinitrotoluene. The presence of water unexpectedly results in a highly pure product, free of glycol ether impurities. This product can be used to make highly pure 2,3,5,6-tetraaminotoluene, which in turn can be used to make high molecular weight polybenzimidazoles for high strength fibers.

Process for the synthesis of 2,6-diamino-3,5-dinitrotoluene

An integrated process is provided for preparing 1,2,4,5-tetraminobenzene and salts thereof, starting in certain embodiments with nitration of 1,3-dihalobenzene. The process design eliminates costly intermediate drying and recrystallization steps. Handling of solid materials with possible skin sensitizing properties and toxicity is avoided, thereby eliminating human and environmental exposure.

Integrated process for the preparation of tetraaminobenzene

A process is provided for preparing complexes of 1,2,4,5-tetraminobenzene with an aromatic diacid. The process design eliminates costly intermediate drying and recrystallization steps. Handling of solid materials with possible skin sensitizing properties and toxicity is avoided, thereby eliminating human and environmental exposure.

Growing community of inventors

Wilmington, DE, United States of America

Rajiv Dhawan