Cosolvent-free aqueous, anionic polyurethane dispersions and their use as peelable coatings

US5965195A · kind A · utility

Assignee

• BAYER HEALTHCARE LLC · DE

Inventors

• Hanns P. Muller · Leverkusen, DE
• Horst Gruttmann · Leverkusen, DE
• Holger Casselmann · Odenthal, DE
• Heino Muller · Leverkusen, DE
• Joachim Petzoldt · Monheim, DE
• Manfred Bock · Leverkusen, DE

Key dates

• Filing date: Dec 11, 1997
• Grant date: Oct 12, 1999
• Expiry date: Dec 11, 2017

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C09J175/12
• WIPO field: Macromolecular chemistry, polymers
• WIPO sector: Chemistry

Abstract

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 reaction product, present at least partially in salt form, of PA1 a) an NCO prepolymer prepared from PA2 i) an aliphatic and/or cycloaliphatic diisocyanate, PA2 ii) a macrodiol having a number average molecular weight of 500 to 10,000 PA2 iii) a 2,2-bis-(hydroxymethyl)alkane monocarboxylic acid and PA2 iv) a diol having a molecular weight of 62 to 400, with PA1 b) optionally a diamine, PA1 c) a monofunctional chain terminating agent, PA1 d) water and PA1 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-ureas. The present invention also relates to light fast coatings prepared from these coating compositions and to a process for preparing these coating compositions. Final…