| 摘要 |
The present invention relates to coating composition, which is suitable for preparing light fast coatings and contains a cosolvent-free, aqueous anionic dispersion of polyurethane-ureas, the solids content of which contains the react ion product, present at least partially in salt form, of a) an NCO prepolymer prepared from i) an aliphatic and/or cycloaliphatic diisocyanate, ii) a macrodiol having a number average molecular weight of 500 to 10,000 iii) a 2,2-bis-(hydroxymethyl)alkane monocarboxylic acid and iv) a diol having a molecular weight of 62 to 400, with b) optionally a diamine, c) a monofunctional chain terminating agent, d) water and e) a neutralizing agent, provided that the NCO content of the prepolymer is up to 25% lower than the theoretical value, the entire polyurethane-urea synthesis reaction is performed in the homogeneous phase and no cosolvent having a boiling range of greater than 100.degree.C is used during the preparation of the dispersion of polyurethane-ur eas. The present invention also relates to light fast coatings prepared from these coating compositions and to a process for preparing these coating compositions. Finally, the present invention relates to peelable coatings and to a method for recycling these coatings.
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