Leverkusen, Germany -- Tests have shown a PU dispersion can boost the sun protection factor (SPF) of sunscreens, according to Bayer MaterialScience.
The Baycusan C 1000 film-forming polymer, which does not contain any UV-absorbing components, not only increases the SPF, but stabilises emulsions, gives suncare products a good water resistance and feels pleasant on the skin, the company says.
Tests carried out by Bayer have shown that the SPF-boosting effect is not restricted to formulations that include the traditional UVB filters octocrylene and ethylhexyl triazone. The polyurethane dispersion also significantly increases the SPF of sample formulations with a protective effect based on UVA/B filters such as bis-ethylhexyloxyphenol methoxyphenyl triazine (BEMT) and benzophenone-3, the company claims.
"Baycusan C 1000 is the perfect addition as SPF booster, particularly for formulations containing the modern, high-performance filter BEMT," said Dr Sophie Viala, head of technical services for cosmetic raw materials at Bayer MaterialScience.
She added: "Low-cost formulations can be produced with Baycusan C 1000 that feel very pleasant on the skin, meaning they aren't sticky, waxy or greasy."
Tests carried out in accordance with guidelines established by Colipa, the European Cosmetics Association show that a low-viscosity formulation made with the polymer exhibits high water resistance.
Baycusan allows customers to "master the challenge of formulating sunscreen sprays with both high water resistance and high SPF," Viala said. LMH