YISTAB"UV-1 is liquid formamidine ultraviolet absorber. The effective UV absorptivity is in the region 240-350nm. The biggest absorption peak is 308nm. It can almost entirely absorb the ultraviolet radiation in the regin 300-330nm. The polyurethane is easy to degrade due to the radiation of this wave range. So it has excellent light stability for the polyurethane products like flexible foam,rigid foam,elastomer, artificial leather, adhesive and coating etc. It prevents the aging and improves the color stability to prolong the service life of the products.