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Mineral oils used as defoamers are mostly highly purified paraffin oils or white spirits. They offer the advantage of high stability against environmental influences and do not resinify or become rancid. White spirit is colourless, odourless and free of aromatic compounds. Because of their aliphatic structure, the active ingredients are highly hydrophobic and thus have only limited compatibility with coating systems. This limits the use of mineral oils in many coating systems. Mineral oils are mainly used in architectural coatings with medium to high PVC. In more sensitive applications mineral oils tend to result in flooding or surface defects such as reduced gloss, smearing or fogging which are well known in architectural coatings [9].