SILRES® HP 2020
SILRES® HP 2020 is a low-viscous, reactive aminofunctional methyl phenyl silicone resin.
The product is typically used as curing agent/crosslinker for cycloaliphatic epoxy resins in 2-pack high-solids coatings. It significantly improves the weathering resistance of the coating when compared with organic amine curing agents. Such 2-pack epoxypolysiloxane coatings are an isocyanate-free alternative to 2-pack polyurethanes as weathering-resistant topcoats.
SILRES® HP 2020 is used as aminofunctional curing agent for cycloaliphatic epoxy resins in high solids coatings. Epoxypolysiloxane coatings formulated with SILRES® HP 2020 instead of organic curing agents offer a significantly improved weathering resistance.
SILRES® HP 2020 is suitable for the formulation of isocyanate-free topcoats with these properties:
- high initial gloss and good gloss retention
- high long-term weathering resistance
- isocyanate-free ambient temperature crosslinking
- Low VOC coatings, suitable for very high solids coatings
- easy-to-clean/anti-grafitti effect
- corrosion resistance
- Low yellowing
- free of benzylalcohol/alkylphenol
- No intentionally added xylene/ethylbenzene
SILRES® HP 2020 is a reactive aminofunctional silicone resin and cures epoxy resin. It contains primary and secondary amino groups. The amine hydrogen equivalent weight (AHEW) can be calculated by the formlua below using the experimentally determined amine value (available on Certificate of Analysis of the individual batch).
Amine hydrogen equivalent weight (AHEW) [g/mol] = 666,67 / Amine value
Example: Amine value = 2,7 => AHEW = 246,9 g/mol
The epoxy equivalent weight (EEW) of the epoxy resin used allows the correct stoichometric calculation of the amounts to be used. Stoichiometric ratio 1:1 should be the starting point. Over- and undercured coatings are possible and can lead to performance changes of the cured binder.
As an example, the formulation of a weathering-resistant epoxypolysiloxane topcoat might be as follows:
Paint base (Component 1) comprises
- Cycloaliphatic epoxy resin as binder component
- weathering resistant pigments/fillers
optionally additives and solvents
Curing agent (Component 2) comprises
- SILRES® HP 2020
- optionally additives and solvents
Example formulations are available on request.
The two components have to be thouroghly mixed prior to paint application. Pot life is app. 4 h, dry-to-touch time is 4 - 5 h at app. 50 µm dry film thickness (23°C/50% relative humidity).
Ready-to-use coatings can be formulated at very low VOC-values (100 - 250 g/l).
The absence of isocyanates is also a great advantage regarding environmental, health and safety issues.
Due to its excellent weathering resistance, the epoxy amino polysiloxane coating can offer UV-resistance and weather-resistance as a polyurethane top coat combined with the adhesion and barrier properties of an epoxy amine coat within a single coat. They can be an economical alternative by replacing a three coat system (zinc-rich primer, epoxy, polyurethane) by a two coat system (zinc-rich primer, epoxypolysiloxane)
The excellent resistance to solvents adds anti grafitti-properties to epoxypolysiloxanes because of the easy removal of grafittis by solvent washing.
- industrial coatings
- structural steel (infrastructure)
- marine & protective coatings
- pipelines and containers
- automotive coatings (trucks)
- anti-graffiti coatings
- easy-to-clean coatings
SILRES® HP 2020 crosslinks/self-condenses in the presence of moisture. Contact with moisture must be avoided till the final application of the product.
- 25 kg Steel cans
- 200 kg Steel drums
Contact with tin (e.g. with improper metal containers) or moisture will decrease shelf live.
The 'Best use before end' date of each batch is shown on the product label.
Storage beyond the date specified on the label does not necessarily mean that the product is no longer usable. In this case however, the properties required for the intended use must be checked for quality assurance reasons.