Use of urethane RIM has grown to where more than onethird of cars produced in the United States have RIM front or rear fascias. DABCO catalyst has played an important role in the growth of RIM and will continue to do so in the future because of its unique advantages. Improved flowability, reduction in air entrapment, and proper green strength to allow parts to be demolded with the flash still intact and without part tearing or deformation are all key factors which contribute to efficient processability. DABCO catalyst and tin co-catalyzed RIM parts with DABCO levels as high as 0.5 php (100% active) are being produced today and are successfully coated with commercially available high solids coatings (e.g., Durethane 300) color plus clear, and water based coatings. With PPG's experimental High Solids Durethane Elastomeric Enamel, (higher solids level than Durethane 300) DABCO catalyst can be used in urethane formulations at up to .15 php (100% active) without any adverse effects on the coating. Additional reactive amine catalysts, such as DABCO T, can be added at levels of 0.5 php and greater as a co-catalyst with DABCO catalyst and tin, again without adverse effects on the High Solids coating. RIM parts catalyzed with DABCO catalyst levels greater than 0.15 php were successfully coated in our studies by either subjecting the part to a high temperature water rinse after the normal washing cycle (effective up to 0.3 php DABCO catalyst) or by adding a small amount of add to the primer. For processors who desire DABCO levels up to 1.0 php, RIM parts can be successfully coated with the experimental higher solids coating by the addi tion of an additive to the RIM formulation. The additive was mixed into the reactants which did not interfere with rates of reaction or demold times of the finished part. During the post cure heat cycle the additive reacts with the amine thereby preventing the amine from interfering with the acid catalysis of the paint curing cycle.
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