| 摘要 |
Novel organosoluble derivatives of chitosan, useful in coating biologically active feedstuff additives intended for ruminants, to provide coatings which are stable at a pH greater than 5 and which release the biologically active substance at a pH below 3.5, consist of a random chain of units represented by the formulae: <IMAGE> in which: R1 represents an alkylcarbonyl radical (2 to 4 carbon atoms), R2 represents an alkyl radical (2 to 21 carbon atoms) or an optionally substituted phenyl radical, and R3 and R4 represent a hydrogen atom or alkylcarbonyl radicals (2 to 4 carbon atoms). |
