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US 5,668,233 AGranted
Fluorinated ion-exchange polymers and intermediates therefor
AssigneeE. I. Du Pont de Nemours and Company
InventorsAndrew Edward Feiring, Shlomo Rozen
Life of this patent
Estimating the term…
Abstract
Disclosed herein are partially fluorinated (co)polymers containing sulfonic acid or sulfonate salt groups, processes for making those polymers, and intermediates for those (co)polymers. The (co)polymers are useful as ion-exchange resins and (in the sulfonic acid form) acid catalysts.
Claims7
A process to make a partially fluorinated polymer, comprising:
- reacting tetrafluoroethylene, carbon dioxide, and an alkali metal thioalkoxide to obtain the alkali metal salt of a thio-containing partially fluorinated alkali metal carboxylate, and reacting said carboxylate with a dialkyl sulfate to obtain an ester of a thio-containing partially fluorinated carboxylic acid;
- or
- reacting tetrafluoroethylene, an alkali metal thioalkoxide and a dialkyl carbonate to obtain said ester;
- reducing said ester with a suitable reducing agent to the corresponding thio-containing partially fluorinated alcohol;
- reacting said alcohol with a base capable of forming an alkoxide anion from said alcohol, and tetrafluoroethylene, to form a monomer of the formula CF.sub.2 .dbd.CFOCH.sub.2 CF.sub.2 SR.sup.1 ;
- free radically polymerizing said monomer, optionally with tetrafluoroethylene comonomer, to form a thio-containing polymer;
- reacting said thio-containing polymer with a sufficient amount of chlorine at a temperature of about 80.degree. C. to about 140.degree. C. for a period of time sufficient to form a sulfenyl chloride containing polymer;
- and
- reacting said sulfenyl chloride containing polymer with a sufficient amount of chlorine and water, at a temperature of about 80.degree. C. to about 140.degree. C., for a period of time sufficient to form a sulfonyl chloride containing polymer;
- and
- converting said sulfonyl chloride containing polymer to a sulfonic acid, alkali metal sulfonate, or ammonium sulfonate by reaction with water, an alkali metal base or an amine, respectively;
- and wherein R.sup.1 is alkyl containing 1 to 10 carbon atoms.
9 more elements
A process for producing a sulfonyl chloride or sulfonic acid containing polymer, comprising,
- contacting at 80.degree. C. to about 140.degree. C., a sufficient amount of chlorine with a polymer consisting essentially of the repeat units ##STR8## for a period of time sufficient to produce a polymer consisting essentially of the repeat units ##STR9## contacting at 25.degree. C. to about 140.degree. C., a sufficient amount of chlorine and water or an alkali metal hypochlorite with a polymer consisting essentially of repeat units (I) and (IV) for a period of time sufficient to produce a polymer consisting essentially of the repeat units ##STR10## wherein n is an integer of 1 to 10;
- R.sup.1 is an alkyl group containing 1 to 10 carbon atoms;
- and T is SO.sub.2 Cl or SO.sub.3 H;
- and provided that the molar ratio of (I):(III) is 0:100 to about 99:1.
1 more element
Dependencies are inferred from the claim text.