The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Mar. 27, 1984
Filed:
Mar. 01, 1982
Alain Lauton, Saint-Louis, FR;
Albert Wurmli, Riehen, CH;
Ciba-Geigy Corporation, Ardsley, NY (US);
Abstract
The invention relates to oligomers containing structural units of the formulae ##STR1## wherein X.sub.1 is --CN, --COOR.sub.1, --OOCR.sub.2 or --CONHR.sub.3, Y.sub.1 is --COOH or --COOM.sub.2, Y.sub.2 is --CONH.sub.2, --CH.sub.2 OH, --OCH.sub.3 or --OC.sub.2 H.sub.5, each of Z.sub.1, Z.sub.2 and Z.sub.3 is hydrogen, methyl or ethyl, each of M.sub.1 and M.sub.2 is an amine cation, an ammonium cation or an alkali metal cation, and each of R.sub.1, R.sub.2 and R.sub.3 is C.sub.1 -C.sub.8 alkyl, C.sub.1 -C.sub.8 -hydroxyalkyl or alkoxyalkyl containing altogether at most 8 carbon atoms, fatliquoring the treated leather and drying it, and, if appropriate, additionally dyeing said treated leather before or after it has been fatliquored. These oligomers are suitable for use as tanning agents in a process for retanning chrome-tanned leather. The oligomers are prepared by copolymerizing 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 SO.sub.3 (M).sub.2 or HSO.sub.3 M, and have an average molecular weight of at most 14,000.