New building blocks for rigid polyurethane pipe coatings
Proceedings Publication Date
Solvent-free two component polyurethane (2-K-PUR) systems have been approved since many years as suitable protective coatings systems. This product class comprises polyols in combination with polyisocyanates (PIC) and pre-polymers (Prep). Because of their special properties two component polyurethanes are favored where high performance and durability have to be accomplished under harsh conditions within pipeline and tank constructions (e.g. field application, high service temperatures, high salt load, wet soil conditions etc.). Based on exchange of experience with experts of the pipeline industry, raw material property profile was modified in order to fulfill the requirements. Reactivity characteristic of the rigid 2-K-PUR system was balanced to reach the end-hardness within hours. This was considered appropriate to apply liquid 2-K-PUR coatings in the field (faster backfilling / handling of the pipe) and as well the fast processing required for OEM in factories. Selected pre-tests of the coatings in the laboratory showed very good results. The design of the tests was engineered to correspond to the typical ambient conditions of the Middle East region. Two field trials were carried out as part of the evaluation process; after 15 month in wet soil conditions (subkha) the coating was in excellent condition. New raw material products for rigid 2-K-PUR external coatings are presented.