Celanese Gmbh

Rufus S Jones, Jr

Eui W Choe

Anthony B Conciatori

Marshall Tan

Paul D Taylor

Frank M Berardinelli

A process for the production of high molecular weight oxymethylene copolymer in the presence of impurity is provided. The process provides a high molecular weight oxymethylene copolymer having a predetermined comonomer content. The process comprises the steps of determining the optimal catalyst concentration in a first oxymethylene copolymerization system which contains less than approximately 10 p.p.m. impurity; determining the concentration of impurity containing at least one active proton in a second copolymerization system; adjusting the catalyst concentration in the second copolymerization system so that the total concentration of catalyst and impurity in the second copolymerization system is maintained at the optimal concentration of catalyst in the first copolymerization system; and adjusting the concentration of comonomer in the second copolymerization system so as to maintain the predetermined comonomer content in the oxymethylene copolymer product.

Process for the production of high molecular weight oxymethylene

High performance wholly aromatic polyamide fibers are provided possessing a novel chemical structure. The fibers of the present invention have chain extending bonds from the aromatic nuclei thereof which are coaxial or parallel and oppositely directed, and have a sulfur content of about 0.5 to 10 percent by weight (e.g. 0.5 to 3 percent by weight) as sulfonic acid and/or sulfonate groups attached to the aromatic nuclei. Not only do the fibers exhibit highly satisfactory tenacity (at least 15 grams per denier), elongation (at least 1.5 percent), and initial modulus (at least 400 grams per denier), but they exhibit an increased resistance to burning when compared to conventional unsubstituted aromatic polyamides. The fibers also exhibit particularly good resistance to organic solvents.

High performance wholly aromatic polyamide fibers

An improved process for preparing wholly aromatic polyamide fibers of high performance charcteristics is provided. The process includes the steps of providing a spinning solution of a wholly aromatic polyamide, the polyamide having a sulfur content as sulfonic acid and/or sulfonate groups attached to the aromatic nuclei of at least 0.5 percent by weight based on the weight of the polyamide; spinning the spinning solution of the wholly aromatic polyamide to produce an as-spun fiber having an inherent viscosity of at least 1.0; and heat treating the as-spun fiber under sufficient tension to maintain a constant length or to elongate the fiber up to about 5 percent of the as-spun length while heating within a range of about 150.degree. C. to about 650.degree. C. The resulting fibers have a tenacity of at least 15 grams per denier, an elongation of at least 1.5 percent, and an initial modulus of at least 400 grams per denier.

Process for producing wholly aromatic polyamide fibers of high strength

An improved process is provided for preparing wholly aromatic polyamides from solid monomers; particularly, aromatic diamines and aromatic dicarboxylic acid halides. The solid monomers in particulate form are first mixed in the substantial absence of oxygen and in the absence of a solvent or diluent to prepare a uniform monomer mixture having a desired stoichiometry prior to the initiation of the polymerization reaction. The uniform monomer mixture is thereafter polymerized in the presence of an appropriate solvent as herein defined.

Process for preparing wholly aromatic polyamides by mixing solid

A highly dispersed supported transition metal catalyst is provided having an ability to withstand highly elevated temperatures and caustic solutions. The transition metal is distributed over the surface of a particulate BBB type polymer of unusually high surface area. The supported catalyst may be formed through the formation of a coordination complex between a transition metal salt and benzimidazonitrogen groups present upon the surface of BBB type polymer, and the subsequent reduction of the metal cations of the salt to the metallic form. The resulting supported catalyst may be utilized in a reaction zone provided at a temperature up to about 500.degree.C., and particularly is suited for use in hydrogenation reactions, isomerization reactions, and oxidation reactions or in a fuel cell application wherein oxygen and hydrogen react to generate electrical current.

Transition metal catalyst supported on particulate high surface area BBB

An improved process is provided for the formation of BBB type polymer, i.e. poly(bisbenzimidazobenzophenanthroline) and related nitrogenous polymers, in finely divided form having an unusually high surface area. The condensation reaction of at least one organic tetra-amine and at least one tetracarboxylic acid (which optionally may be in the form of the corresponding half anhydride or dianhydride) is conducted at an elevated temperature with agitation in the presence of a major concentration of a liquid sulfone (e.g. diphenyl sulfone) which is inert under the reaction conditions. The resulting particulate product of BBB type polymer commonly exhibits a surface area of about 100 to 500, or more, square meters per gram, and may be used in the formation of pressure molded articles of high temperature resistance.

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Randolph, NJ, United States of America

Rufus S Jones, Jr