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US 4,069,215 AGranted
Semipermeable membranes of sulphonated polybenz-1,3-oxazin-2,4-diones
AssigneeBayer Aktiengesellschaft
InventorsKlaus Elfert, Jurgen Hinz, Rudolf Binsack
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Abstract
Semipermeable membranes of sulphonated polybenz-1,3-oxazin-2,4-diones for separating or enriching organic sulphonates by the method of inverse osmosis or ultrafiltration.
Claims3
A semipermeable membrane of a sulphonated polybenze-1,3-oxazin-2,4-dione, said dione having a relative viscosity of from 0.7 to 3.5 measured as a 0.5% by weight solution of dimethyl formamide at 25.degree. C, an acid number of from 1 to 800 and a structure of the formula ##STR7## wherein R is ##STR8## wherein X is a bond, --O--, --S--, --SO.sub.2 --, --C(CH.sub.3).sub.2 -- or --CH.sub.2 --;
- Ar is ##STR9## wherein Y is a bond,
- --O--, --S--, --CH.sub.2 --, --SO.sub.2 --, or --CO--;
- Z is --SO.sub.3 H, a monovalent radical of a sulphonic acid salt of an alkali metal, of an alkaline earth metal or of an organic amine;
- m, n, o, p, q, r and s are the same or different;
- m and n are 0 to 4;
- o, p and q are 0 to 2;
- r and s are 0 to 3 and their sum is greater than 1, and x is 10 to 200.
4 more elements
Dependencies are inferred from the claim text.