Trying to thicken formulations with low surfactant levels using traditional ingredients can be challenging, the company explained.
“In some formulations there is not enough surfactant to reach the critical micelle concentration, which is needed in order to get a good thickening effect,” explained Duane Krzysik, Lubrizol’s manager of hair care and cleansing applications and Kevin Yoder, global strategic marketing manager for the same division.
According to Lubrizol, formulators often try to lower the levels of surfactants in body washes and shampoos in order to save costs, and until now, thickening such products and improving their flow properties has been challenging.
Using traditional non-ionic thickeners for these low surfactant products does not always have positive results, according to Krzysik and Yoder, who explained that it can often lead to undesirable jelly-like flow properties.
In addition, low surfactant products that use non-ionic thickeners can be less stable over wide temperature ranges, they said.
In addition, a new generation of mild sulfate-free cleansers is appearing on the market.
“While surfactant levels in these products may not be as low as in the economy formulas, they can still be difficult to thicken,” Krzysik and Yoder added.
A further application for the ingredient could be body washes with a high oil load, where it can help in stabilizing the high degree of oil in an oil and water emulsion, Yoder added.
Hyper-HASE solution
Novethix L-10 is a hydrophobically modified alkali-swellable polymer (a hyper HASE solution) and has been designed to help concentrate the surfactants so they can be structured more easily, and the formulation thickened.
Hydrophobically modifying the polymer involves adding a long chain hydrocarbon which helps it associate with the surfactant and aid the thickening, Krzysik explained.
The alkali-swellable aspect means that in slightly alkaline environments the polymer unravels, exposing the hydrophobe chains.
Ease of formulation
Novethix L-10 can be formulated with anionic, nonionic and zwitterionic surfactants, as well as being easier to formulate than many of the more traditional non-ionic thickeners.
According to the company, the ingredient can be cold processed without the need for long mixing times.