UV protection in thin layer PU coating
UV protection in thin layer PU coating
(OP)
Hi,
I need to coat a solvent borne 2K polyurethane coating onto a flexible plastic (PET) surface. The coating thickness can't be more than 10-12 micron in order to stay flexible.
The coating will have some light stabilisers (HALS) to protect the coating itself but I also have to add protection for the plastic substrate. I am trying to find out what will work better for a thin coating like this. The solution can be UV absorbers like Tinuvin (BP, BTZ) or it can be an inorganic blocker, like titanium dioxide or zinc oxide. Or perhaps something else I don't know about.
My priorities are:
1/ maximum possible protection of the substrate within a 12 micron coating thickness
2/ minimum degradation of the coating (flexibility, elongation, adhesion) over 1 years of continuous outdoor use in a south florida environment
3/ minimum increase of coating viscosity
The coating is not pigmented. Clarity or gloss is not an issue and it can become translucent but should not become pigmented. Carbon black is therefore not an option.
I can't add anything to the plastic substrate, as this is not produced by us.
Any advice will be much appreciated !
I need to coat a solvent borne 2K polyurethane coating onto a flexible plastic (PET) surface. The coating thickness can't be more than 10-12 micron in order to stay flexible.
The coating will have some light stabilisers (HALS) to protect the coating itself but I also have to add protection for the plastic substrate. I am trying to find out what will work better for a thin coating like this. The solution can be UV absorbers like Tinuvin (BP, BTZ) or it can be an inorganic blocker, like titanium dioxide or zinc oxide. Or perhaps something else I don't know about.
My priorities are:
1/ maximum possible protection of the substrate within a 12 micron coating thickness
2/ minimum degradation of the coating (flexibility, elongation, adhesion) over 1 years of continuous outdoor use in a south florida environment
3/ minimum increase of coating viscosity
The coating is not pigmented. Clarity or gloss is not an issue and it can become translucent but should not become pigmented. Carbon black is therefore not an option.
I can't add anything to the plastic substrate, as this is not produced by us.
Any advice will be much appreciated !





RE: UV protection in thin layer PU coating
RE: UV protection in thin layer PU coating
I am hoping that someone has an unbiased opinion about what will work better for a thin coating.
I will eventually do a xenon test to evaluate the protection but they take time and cost money so I would like to take the right direction in first attempt.
RE: UV protection in thin layer PU coating
http://americas.kynar.com/export/sites/kynar-ameri...
TTFN

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