PHENODUR® PR 612/80B

Phenodur PR 612 is less reactive than the Phenodur grades PR 217, PR 285, PR 401, PR 515, VPR 1775 and VPR 1776. Phenodur PR 612 is lower viscous compared to the Phenodur grades PR 217, PR 285, PR 373, PR 722 and PR 723.

Phenodur PR 612 is preferably used as curing resin in combination with high molecular weight epoxide resins to formulate interior can coating systems. Phenodur PR 612 is additionally used in electro-insulation varnishes and magnetic wire enamels.

Heat-curable phenolic/epoxide resin combinations, high-adhesion, chemically resistant protective coatings for apparatus, vessels and pipelines. Phenodur PR 612 also for wire insulation varnishes.

Can coating

After being stoved, cominbations of 30 - 45 % Phenodur PR 612 and 70 - 55 % Beckopox EP 307 or EP 309 (based on solids in each case) yield highly flexible films with good adhesion and chemical resistance for the interior coating of cans, tubes and other packaging containers used in the food and luxury commodity industries. The additon of acid catalysts, e. g. up to 6 % Additol XK 406 (based on solid resin) increases the reactivity of the lacquers and the adhesion (especially on aluminum) of the stoved films, as well as their hardness and resistance to sulfur compounds. The gold coloring can be intensified by adding 5 - 10 % Phenodur PR 308 (based on solids content).

Chemically resistant protective coatings

Phenodur PR 612 can be used as sole binder for relatively brittle, highly resistant pigmented stoving enamels on rigid substrates, e. g. for chemically resistant interior linings for vessels, apparatus and pipelines. Polyvinyl butyral grades in additions of only 5 - 25 %, improve the film flexibility without impairing the resistance of the protective coatings to chemicals. In the case of multiple-coat paint applications as required for protective coatings of this type, the first coats are not fully cured initially, but only cured completely together with the last coat.

Wire coatings, electroinsulation varnishes

Phenodur PR 612 can be used as binder in such coatings, specially in combinations with (poly) vinyl formal resins. The mixing ratio between Phenodur PR 612 and the (poly) vinyl formal resin is approx. 40 : 60, the "solvent" mixture contains phenol/cresol and alcohol. Such lacquers can be used as wire coating systems and applied by a multi layer process and cured between 300 and 350 °C.

Glycol ether, ester, diacetone alcohol and ketones are suitable solvents/diluents for Phenodur PR 612. This resin can be pigmented with inert pigments and fillers like titanium dioxide, iron oxide red talk and spars. Pigmented systems are preferably used in acid and alkaline resistant systems.

Stoving conditions

Depending on the form of use and required coating thickness, the stoving conditions are between 30 and 10 minutes at 180 - 220 °C. The upper temperature limit where overstoving begins to occur and flexibility accordingly starts to decline is 220 °C For thin films such as can coatings, conditions of 10 - 15 min/190 - 200 °C are adequate, or 90 s/265 °C (shock-drying). Good resistance to chemicals is obtained as from 190 °C.

Catalysis

The additon of acidic catalysts increases the reactivity and the film hardness. At the same time, this catalysis improves the adhesion on aluminum and tinplate.

At temperatures up to 25 °C storage stability packed in original containers amounts to at least 730 days.