Bayer Aktiengesellschaft

Bayer Materialscience Ag

Hanns-Peter Müller

Joachim Petzoldt

Christoph Irle

Holger Mundstock

Meike Niesten

Heino Müller

Jörg Schmitz

Horst Gruttmann

A process for preparing polymers containing polyortho ester groups and optionally NCO groups by reacting A) and B) where A) is a polyortho ester containing at least one isocyanate-reactive group prepared by reacting at least one or more acyclic ortho esters with low molecular weight polyols having a functionality of 4-8 and a number-average molecular weight of 80-500 g/mol and B) is least one polyisocyanate. The polymers obtained from the process can be used to produce coatings, adhesive bonds and/or seals. The coating compositions can include one or more of the above-described polymers, optionally polyisocyanates, catalysts, and optionally auxiliaries and additives and can be used to coat substrates.

Binders containing ortho ester groups

The present invention relates to light fast, aqueous, strippable coating compositions containing A) 40 to 90 wt. %, based on resin solids of A) and B), of aqueous polyurethane-polyureas and B) 10 to 60 wt. %, based on resin solids of A) and B), of polymers prepared from radically polymerizable monomers, wherein the percentages of A) and B) add up to 100, based on the weight of resin solids of A) and B). The present invention relates also to substrates coated with these strippable coating compositions. In addition, the present invention relates to the use of the stripped coatings as recycled material by mechanically comminuting the stripped coatings, optionally after cleaning, and then either pressing them in heatable presses to form sheets, or extruding them in an extruder to form endless thermoplastic threads, and then processing the resulting threads by known granulating methods to form cylindrical, spherical, lenticular or rhombic granules. Finally, the present invention relates to the use of the resulting thermoplastic granules for the production of articles by known processes such as injection molding, blow molding, deep-drawing, slush molding or flat extrusion.

Strippable coating compositions

Growing community of inventors

Odenthal, Germany

Hanns-Peter Müller