Amoco Corporation

Standard Oil Company (indiana)

Bp Corporation North America Inc.

The Standard Oil Company

David E James

Imre Puskas

Neal R Nowicki

Edward E Paschke

Melvin L Luetkens, Jr

Gary T Brooks

Bruce I Rosen

Charles W Bauer

David A Peterson

Hobe Schroeder

Lawrence G Packer

Richard N Koeritz

Robert W McCoy

Processes for producing aromatic monomers useful for forming polyesters are disclosed. Cost effective steps employed in the processes permit small amounts of process-related materials typically removed from monomer to remain in an aromatic monomer product. In many cases, the presence of the process-related materials left in the monomer product by the cost effective process steps can enhance the performance of the monomer in certain applications. Aromatic monomer products and polymers produced therefrom having these advantages also are disclosed, as well as products such as pasteurizable bottles made from these polymers

Aromatic acid monomers, polymers, products and processes for their manufacture

Processes for producing aromatic monomers useful for forming polyesters are disclosed. Cost effective steps employed in the processes permit small amounts of process-related materials typically removed from monomer to remain in an aromatic monomer product. In many cases, the presence of the process-related materials left in the monomer product by the cost effective process steps can enhance the performance of the monomer in certain applications. Aromatic monomer products and polymers produced therefrom having these advantages also are disclosed, as well as products such as pasteurizable bottles made from these polymers.

There are provided methods for monitoring the oligomeric content of prepolymers and polymers, which methods employ high-performance liquid chromatographic techniques. Typically, the methods of the present invention may be used to determine the oligomeric content of polyethylene terephthalate polymers and prepolymers.

Monitoring oligomers in a polymer

Aqueous solutions of crude terephthalic acid are purified by hydrogenation in the presence of plural noble metal catalysts in separate layers. Initially, the solution to be purified is passed through a layer of ruthenium-on-carbon catalyst, rhodium-on-carbon catalyst, or platinum-on-carbon catalyst, and thereafter through a layer of palladium-on-carbon catalyst. Optionally, the purified aqueous terephthalic acid solution can be treated further to decrease the 4-carboxybenzaldehyde content thereof by passing it through a layer of rhodium-on-carbon catalyst downstream from the palladium-on-carbon catalyst layer.

Purification of crude terephthalic acid

A process is disclosed for producing cyclized aromatic compounds by the liquid-phase air oxidation of 2-methyl-substituted biphenyls and diphenylmethanes in an acetic acid medium in the presence of a cobalt-manganese-bromine catalyst or a zirconium-cobalt-manganese-bromine catalyst wherein the mole ratio of cobalt-to-manganese is about 1.0:0.1 to about 1.0:10.0 and the ratio of zirconium-to-cobalt is about 0.005:1.0 to about 0.20:1.0, and mole ratio of bromine to total metals of said cobalt-manganese-bromine catalyst or zirconium-cobalt-manganese-bromine catalyst is from about 0.2:1.0 to about 20.0:1.0, which process comprises conducting the reaction in a batch process at a temperature of from 75.degree. C. to about 250.degree. C. at a pressure of from 1 to 100 atmospheres, or continuously in two stages comprising a first-stage reaction at a temperature of about 75.degree. C. to about 200.degree. C. and a second-stage reaction at a temperature of about 150.degree. C. to about 250.degree. C. and recycling the cobalt-manganese catalyst or the zircnium-cobalt-manganese catalyst by oxalate precipitation of the catalyst at temperatures of about 110.degree. C. to about 200.degree. C. prior to the separation of mother liquor and using about 0.25 to about 2.5 moles of oxalic acid per mole of cobalt and manganese or mole of zirconium-cobalt-manganese and continuously recycling the recovered catalyst metals to the oxidation stages. The products of this novel process, anthraquinones and fluorenones, are useful for the manufacture of dyestuffs and pharmaceuticals.

Process for preparation of anthraquinones and fluorenones

A process is disclosed for producing cyclized aromatic compounds by the liquid-phase air oxidation of 2-methyl-substituted biphenyls and diphenylmethanes in an acetic acid medium in the presence of a cobalt-manganese-bromine catalyst or a zirconium-cobalt-manganese-bromine catalyst wherein the mole ratio of cobalt-to-manganese is about 1.0:0.1 to about 1.0:10.0 and the ratio of zirconium-to-cobalt is about 0.005:1.0 to about 0.20:1.0, and mole ratio of bromine to total metals of said cobalt-manganese-bromine catalyst or zirconium-cobalt-manganese-bromine catalyst is from about 0.2:1.0 to about 20.0:1.0, which process comprises conducting the reaction in a batch process at a temperature of from 75.degree. C. to about 250.degree. C. at a pressure of from 1 to 100 atmospheres, or continuously in two stages comprising a first-stage reaction at a temperature of about 75.degree. C. to about 200.degree. C. and a second-stage reaction at a temperature of about 150.degree. C. to about 250.degree. C. and recycling the cobalt-manganese catalyst or the zirconium-cobalt-manganese catalyst by oxalate precipitation of the catalyst at temperatures of about 110.degree. C. to about 200.degree. C. prior to the separation of mother liquor and using about 0.25 to about 2.5 moles of oxalic acid per mole of cobalt and manganese or mole of zirconium-cobalt-manganese and continuously recycling the recovered catalyst metals to the oxidation stages. The products of this novel process, anthraquinones and fluorenones, are useful for the manufacture of dyestuffs and pharmaceuticals.

A process for producing fiber grade terephthalic acid is disclosed. In this process impurities having high molecular weight are eliminated by hydrogenation comprising the following steps: (a) treating an aqueous solution containing at least about 1 percent of said impure terephthalic acid with hydrogen at a temperature in the range of about 300.degree. F. to about 450.degree. F. and at a pressure sufficient to maintain the solution in the liquid phase in the presence of a supported or unsupported metallic Group VIII noble metal catalyst wherein both the metal and support components are insoluble in the solution at the temperature and at a hydrogen partial pressure of from about 30 to about 300 pounds per square inch; (b) separating the treated solution from the catalyst; (c) crystallizing terephthalic acid from the separated solution while retaining impurities and the reduced aromatic compounds dissolved in the resulting mother liquor at a temperature in the range of about 100.degree. F. to about 450.degree. F.; and (d) separating the mother liquor as a liquid phase containing dissolved impurities and reduction products from said crystals while continuing to maintain a temperature in the range of about 100.degree. F. to about 450.degree. F. whereby purified crystals of fiber grade terephthalic acid are recovered. Purified terephthalic acid is useful as a starting material in the manufacture of polyethylene terephthalate which is the principal polymer for polyester fibers, films, and resins for bottles.

Process for removal of high molecular weight impurities in the

A method is disclosed for separating and measuring the fluorescence of 4-carboxy-p-terphenyl in crude terephthalic acid formed by the liquid-phase oxidation of p-xylene in a solvent.

Method for monitoring the fluorescence of 4-carboxy-p-terphenyl in crude

An improved method for producing purified terephthalic acid by catalytic hydrogenation is disclosed. Control of the reduction of colored compounds during the production of purified terephthalic acid is effected by modulating solution hydrogen concentration during hydrogenation.

Purification of terephthalic acid

A process for producing a purified terephthalic acid which comprises reacting in a liquid phase a mixture of hydrogen and crude terephthalic acid, a palladium/rhodium catalyst on a porous carbonaceous support wherein the catalyst compound is prepared by adsorbing palladium on the support from a complex salt formed in the presence of an amine and acetic acid, followed by deposition of rhodium from a solution of sodium hexanitritorhodate.

Process for purification of crude terephthalic acid

A catalyst and process for purifying crude terephthalic acid wherein the catalyst is prepared by contacting a carbonaceous support with an aqueous solution of sodium tetranitropalladate.

Process for preparation of palladium on carbon catalysts used in the

A catalyst and process for purifying crude terephthalic acid wherein the catalyst comprises palladium metal crystallites deposited upon a carbon support wherein the catalyst is prepared by contacting a carbonaceous support with an aqueous solution of a palladium amine complex in the presence of acetic acid.

Palladium on carbon catalyst for purification of crude terephthalic acid

Palladium-rhodium catalyst for purification of crude terephthalic acid

Aqueous solution of weak base (e.g. ammonium hydroxide) incompletely neutralized salt of an inorganic polyacid having three or more replaceable hydrogens also containing 2 to 10 weight percent dissolved alkanol or alkanenitrile buffered to a pH not exceeding 7.5 is a useful mobile phase for liquid chromatographic component separation and content determination of sample containing closely related rather polar compounds by means of a solid phase having a nitrogen-containing exchange base derived from an aminoalkyl-substituted trialkoxysilane. Such mobile phase is superior to prior suggested reverse phase made mobile phases such as 50:50 water and methanol or water and acetonitrile, or acidic aqueous solutions of strong base (e.g. sodium hydroxide) partially neutralized inorganic polyacid having at least three replaceable hydrogens.

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Batavia, IL, United States of America

David E James