adhesion to various metals
- excellent corrosion resistance and humidity resistance
- early water resistance
- good pigment compatibility
Properties
solids by weight 50%
viscosity at 25 °C (Brookfield) 100-250 mPa.s
density (as supplied) at 25°C 1.05 kg/m³
pH 7-8
acid value (solids) 15 mg KOH/g
minimum film forming temperature 28 °C
freeze/thaw stable no
Acronal® PRO 763 is an excellent vehicle for general and industrial coatings especially when corrosion protection is required. Acronal® PRO 763 can be used to formulate waterborne direct to metal paints and anticorrosive primers.
Performance
Due to its silane modification Acronal® PRO 763 shows good adhesion to metal and mineral substrates. The silane moities yield to crosslinking already at room temperature, leading to improved properties as compared to merely physical drying dispersions. Acronal® PRO 763 shows excellent anti-corrosive properties both in DTM and primer application. Please notethat this particular dispersion works also as a DTM clearcoat: applied on cold rolled steel it may achieve 500 hours of salt spray resistance at a dry film thickness of approximately 50 µm
Coalescing
To achieve good film formation, itis necessary to have sufficient coalescing solvent present after most of the water has evaporated. Acronal® PRO 763 has been shown to form a good film at room temperature when levels of approx. 6 % coalescing solvent on Acronal® PRO 763 (as supplied) are used. Typical coalescent solvents may be used, in particular butyl diglycol showed good results. For anti-corrosive paint the adhesion and early water resistance may be further improved by the addition of a plasticizer
Foam Control
Typical defoamers for waterborne industrial paint may be used. We found particularly good properties with FoamStar® SI 2210. Typical dosage levels are app. 0.1 % of delivery form on total formulation for pigment grinding and again after let down.
Rheology Control
For the application of Acronal® PRO 763 in anti-corrosive paint especially on uncoated metal it is recommended to use urethane thickeners (HEUR), e.g. Rheovis® PU 1280.
Pigment dispersion
Acronal® PRO 763 is shear stable and can be used as a grind vehicle with the addition of low levels of pigment dispersant. For direct to metal paint Dispex® Ultra PA 4580 was found to show superior performance in DTM as compared to other dispersants.
Flash Rust Inhibition
In order to avoid the formation of flash rust an inhibitor should be used. Acronal® PRO 763 shows good compatibility with most common types on the market, both nitrite and organic.