POLA KASEI uses new technology to improve UV protection while avoiding squeaky feeling

 POLA CHEMICAL INDUSTRIES has succeeded in developing a technology that improves the UV protection effect of sunscreen products while ensuring comfort during use. This technology was realized by making good use of components obtained by decomposing air pollutants in the air.

The film of sunscreen products applied to the skin rubs off when it comes into contact with clothes or is washed off by sweat, making it impossible to obtain the expected effects. It is

In the research so far, the method of hardening the membrane has mainly been used, but with this method, it was difficult to achieve both comfort and comfort because the hardness of the membrane leads to a squeaky feeling.

Therefore, this time, we aimed to establish a new technology that can achieve both "comfort of the film" and "UV protection function". We focused on the "thickness of the film," applying the law of light, which states that if the thickness doubles, the light attenuation rate will increase tenfold. We proceeded with research based on the idea that if the film can be made thicker during use, even if some of the film is removed, the UV cut function can be compensated to some extent.

From previous research, we have found that the thickness of the film increases when certain types of powder agglomerate, and our proprietary UV-cut powder (a type of silylated silica) reacts with ions in the solution. It was clarified that the film containing this powder actually "increases in thickness when it encounters ions". Therefore, we decided to make good use of the fact that acetate ions are generated by our own technology that decomposes acetaldehyde, an air pollutant gas. As a result of the research, we succeeded in constructing a sunscreen technology that increases the thickness of the film with acetate ions and maintains the UV cut effect.

In the experiment, a sunscreen formulation containing UV-blocking powder (a type of silylated silica, a proprietary product developed by the company) that agglomerates upon encountering ions was evenly applied to the substrate, and an aqueous solution (0.5% Acetic acid solution) was sprayed in the form of a mist, and the thickness before and after that and the UV cut effect were measured.

As a result, it was found that spraying water alone did not thicken the film, but spraying an aqueous solution containing acetate ions made the film slightly thicker. Furthermore, it was confirmed that the UV cut effect did not change with water, but increased by about 30% with an aqueous solution containing acetate ions.

From the above, it was confirmed that the newly developed sunscreen formulation has a thicker film due to acetate ions and has a higher UV cut effect. According to the company, when acetaldehyde is decomposed on the skin and acetate ions are generated, "a similar reaction is expected to occur."