New aliphatic curative from Albemarle solves a lot of issues in coatings
by Liz White, editor
Albemarle developed its new aliphatic curing agent Ethacure 90 in response to requests from users for UV-stable one-coat materials, said Dr Sam Lane, business marketing manager.
Over three or four years, “we had a lot of customers asking for aliphatic cures,” Lane said.
Albemarle is the biggest supplier of aromatic curatives, with Ethacure 100, 200 etc — well known curatives that work well and are used globally, Lane said, giving polyurea coatings for China’s high speed rail network as an example.
Although they work well, they are aromatics, and so not very stable to UV light. In time the colour changes, Lane explained.
“What some people will do is, they put the normal polyurea/polyurethane layer on and then come back and put an aliphatic coat on to give the required UV resistance,” the Albemarle expert said, speaking 11 Oct, in an interview during the 2010 conference of the Center for the Polyurethanes Industry, held in conjunction with the UTECH North America 2010 exhibition in Houston, Texas.
“That’s the get-around to give a colour-stable layer,” Lane continued.
This top layer is often a thin — 3-5 mil (0.09 mm) — layer on top of the base coat which can be perhaps 80 mil thick, he added. “If you get any kind of abrasion or wear the aliphatic layer can be scraped away and then the colour stability problem arises again,” Lane…