| 摘要 |
The present invention provides a phosphonic acid selected from N-phosphono-methylene-monoaminoalkane-mono- and polyphosphonic acids and N-phosphono-methylene-diaminoalkane polyphosphonic acids having the general formula I wherein n is 1, 2 or 3, R1 is hydrogen, an alkyl radical containing 1 to 11 carbon atoms in the carbon chain or the groupings -OH, (CH2)nPO3H2, -C2H4OH, - (CH2)nCOOH, wherein n is as above, R2 is hydrogen or PO3H2; and R3 and R4 are each hydrogen or CH2PO3H2. |
