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US 6,548,622 B1Granted
Manufacture of polysulfones
AssigneeE. I. Du Pont de Nemours and Company
InventorMarc Bruce Goldfinger
Life of this patent
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Abstract
Polysulfones are manufactured by reacting a sulfuric acid or sulfur trioxide with a bireactive aromatic compound, using as a “promoter” a carboxylic acid anhydride. The product polymers are useful as molding resins.
Claims8
A process for the production of polysulfones, comprising, contacting an aromatic compound which is bireactive selected from the group consisting of naphthalene, methylnaphthalene, methoxynaphthalene, benzyl ether, stilbene, diphenyl carbonate, benzyl phenyl ether, biphenyl,
- wherein R1 is —O— or alkylidene, and R3 is hydrocarbylene, substituted hydrocarbylene or hydrocarbylidene,
- a carboxylic acid anhydride;
- and at least one sulfonyl containing species selected from the group consisting of surfuric acid, sulfur trioxide and a mixture of surfuric acid, and sulfur trioxide, wherein the molar ratio of the aromatic compound to the total sulfonyl containing species is 1:1, and wherein the reaction temperature range is 0° C. to 300° C.
Dependencies are inferred from the claim text.