| 摘要 |
<p>Process for retanning leather with acrylic-based oligomers Known oligomers containing structural units of the formulae < IMG > and optionally < IMG > and -SO3M1, wherein X1 is -CN, -COOR1, -OOCR2 or -CONHR3, Y1 is -COOH or -COOM2, Y2 is -CONH2, -CH2OH, -OCH3 or -OC2H5, each of Z1, Z2 and Z3 is hydrogen, methyl or ethyl, each of M1 and M2 is an amine cation, an ammonium cation or an alkali metal cation, and each of R1, R2 and R3 is C1-C8alkyl, C1-C8-hydroxyalkyl or alkoxyalkyl containing altogether at most 8 carbon atoms, are suitable for use as tanning agents in a process for retanning chrome-tanned leather. The oligomers are prepared by copolymerising comonomers of the acrylic acid series corresponding to the structural units of the indicated formulae, in the presence of sulfite or hydrogen sulfites of the formulae SO3(M1)2 or HSO3M1 and have an average molecular weight of at most 14,000.</p> |
