Flexible Urethane Resins and Coating Materials Development.

摘要

Research studies were conducted on polyurethane coating formulations to develop thermally stable,low temperature flexible films that would be non-yellowing when exposed to weathering. A series of different polyols and crosslinking agents were reacted with an aliphatic diisocyanate,cured into films and physical properties determined. Results of this investigation enabled the selection of the most thermally stable polyol components. Diols,triols and tetrols were investigated. They included polyether,polyester and hydrocarbon backbone structures. Polyesters in combination with an isocyanurate crosslinker provided the most thermally stable polyol combination when reacted with 4,4-methylene bis(cyclohexylisocyanate) and cured. In addition to thermal stability and low temperature flexibility,abrasion resistance,energy of rupture,tensile properties at -65F and 70F,solvent resistance and accelerated weathering properties were determined. Non-photochemically reactive solvents were formulated which conform to 'Rule 66'legislation. (Author)