The invention relates to a mixture comprising
i) at least one condensation product (A) obtainable by reaction of
a1) at least one aromatic system or heteroaromatic system,
a2) at least one carbonyl compound,
a3) if appropriate at least one sulfonating agent and
a4) if appropriate at least one urea derivative,
where the condensation product (A) has an M
w
value ≧9000 g/mol, and
ii) at least one tanning agent having an M
w
value ≦3000 g/mol.
本发明涉及一种混合物,包括:i)至少一种缩聚产物(A),可通过以下反应得到:a1)至少一种芳香系统或杂环芳香系统,a2)至少一种羰基化合物,a3)如有必要,至少一种磺化剂,a4)如有必要,至少一种
脲衍
生物,其中缩聚产物(A)具有Mw值≧9000 g/mol,以及ii)至少一种鞣剂,其Mw值≦3000 g/mol。