New-age Paint Thickening & Rheological Additives: Solvitex &
For Paint Manufacturers worldwide, there has come a radical new development in the legion of Thickening Agents & Colloidal stabilizer for Aqueous Latex Paints. So far most of the companies producing aqueous Paint emulsions, the most preferred thickening agent was Hydroxy ethyl cellulose (HEC). The HEC based thixotropic additives is produced by some of the renowned multi-national companies such as Hercules, Akzo Nobel & Dow.
Here we refer to a Biopolymer based on Polysacchride derived from controlled derivatisation process from plant origin. The product developed by Asian Trade Link Chemicals Division in India has already been a successful venture for replacement of HECs for many paint companies. The Product is known as Solvitex thickening agent & colloidal stabilizer.
The solvitex range of products is offered in wide range of viscosities of aqueous solutions. It comes in Powder form of Offwhite color and the thickening properties are similar to HEC.
But the Advantages of Solviex against HECs are many. The prime factor is the stability & economic pricing. Its been observed that for a Medium viscosity range of products such as Natrosol 250 HBR or Bermcoll 381 the intial drop after settling is by 20% and then the finished paint adheres to be stable for six months.and the viscosity further drops. Solvitex has an initial drop of settling to 10% and the product is stable in physical observation for more than 1year exhibiting the same viscosity.
As known by many Paint technicians, its inevitable that the stability of thickening agent after incorporating in the Paint system, is delicate towards wide temperature changes. Especially applicable for Export shipments when the Paint under goes through various temperature conditions during its transit. A sudden drop & rise in outside temperature can effect the stability. Solvitex has potentially proven to be stable under those conditions.
Amongst HEC, I personally find Cellosize of Dow as the most stable product compared to Bermocoll & Tylose.
Myself as Paint formulator & other colleagues working in different companies had a dilemma existing for selection. For cheaper Paints the Stronger product or High Viscosity grades were used such but there always was a flocculation after some period on shelf storage. For the Expensive ones we had to prefer Medium Viscosities grade to overcome shelf storage time. Most of the companies carry the same practice.
When I came across Solvitex range of Thickeners I was given much competitive prices. Priced at least 10% lower than HEC based Products, but my major concern was to check the colloidal stabilization. The Product was immediately tested and was found to perform excellent.
Apart from that, Solvitex has provided better color acceptance & and coatabilty.
Sooner we came across Solvizen developed by the same company for more economic & cheaper Price. The thickening & stability properties was the same but economically priced.
However, The Water solution clarity of Solvizen was not as clear as of Solvitex or HECs. It was slight turbid. But when incorporated in Paints, we couldn