Special-Primer PP 7550

Solubility
Special-Primer PP 7550 is only soluble in aromatics and chlorinated hydrocarbons. It is possible to blend with other solvents like esters, ketones etc..

Application and Properties
Special-Primer PP 7550 is mainly used to solve adhesion problems with critical substrates like polypropylene. With Special-Primer PP 7550 untreated plastics can be coated with e.g. 2 component polyurethane or epoxy systems. In most cases the adhesion promotion of Special-Primer PP 7550 is superior to Special-Primer PP 5130.

Before usage Special-Primer PP 7550 must be stirred thoroughly. For application SpecialPrimer PP 7550 must be diluted to 2.5% solids (sometimes even lower) with suitable solvents, e.g. aromatic hydrocarbons.

The primer may be applied by spraying, dipping or printing. It is not necessary to clean the substrate before application; only if the extruded polypropylene is dusted after long storage time.

Special-Primer PP 7550 should be applied in a thin and uniform layer. The drying is completely physically. At room temperature recoatability after 2-3 minutes is given. By adding heat the drying time can be further reduced. Further painting, printing or gluing can follow immediately or even months later.

It should be observed that after any longer storage time the substrate treated with Special-Primer PP 7550 may need cleaning before any further coating can be applied.