As is known to all, when plastic products are exposed to outdoor sunlight, the strong UV light will produce different degrees of damage to the polymer materials. From the internal structure of the material, the main reason of light aging is that there are unstable structures in the polymer material which are easy to form excited states, such as unsaturated double bond, branch chain, carbonyl group and terminated hydroxyl group. When the absorbed photon energy is higher than polymer’s bond energy, these functional groups will be excited to generate free radicals and hydroperoxides. Macroscopically, the product will appear discoloration, surface crack and poor mechanical properties of the material.
The sensitive bands of different types of materials to UV light are as follows:
The sensitive wavelength of most plastic is mainly concentrated in the UVB band. However, with the destruction of the environment, ultraviolet light in nature gradually becomes stronger. End users are becoming more and more stringent on the quality and service life of plastic products. Plastic products with full band UV protection have become a new development hotspot and research direction for plastic manufacturers at home and abroad!
UVA and UVB band UV can be added to the material such as benzotriazole, benzophenone UV absorber to protect, then how to protect UVC band (180-280nm)?
Our novel hindered benzoate uv absorber for UVC band uv absorption enhancement was developed,which can implement and solve such problems.
ØMechanism and characteristics of OMNISTAB UV6198:
It can be clearly seen from above that the main absorption wavelength of UV6198 is 204-260nm. Therefore, the uv absorption below 280nm can be well supplemented, resulting in excellent synergistic effect when used with uv absorbers such as benzopenone.
The conjugated structure of UV6198 molecule is formed by the double construction of hydroxyl group, benzene ring and ester group. After being irradiated by ultraviolet light, the hydrogen ions of phenolic hydroxyl group in the molecule leave, and the molecule rises from the ground state to the excited state and absorbs ultraviolet light. The excited state formed after the resonance of UV6198 falls back to the ground state due to instability, thus releasing the energy in the form of heat.
It is worth mentioning that UV6198 is divided into hindered phenolic structure in the middle, so it also has the additional effect of antioxidant. Through the mechanism of free radical capture, it has antioxidant activity in the process of thermal processing and cooling and heating, which can effectively protect the polymer.In addition, the long ester branch chain in molecular structure ensures its high compatibility in polymer materials.
ØApplications of OMNISTAB UV6198
üUsed in PVC sheets and PVC tiles with high weatherability requirements.
The PH of UV6198 is about 6.5, so it will not react with acid in an acidic flame retardant system. However, traditional HALS such as LS770 and LS944 will neutralize with acids in acidic systems and reduce their activity, so UV6198 shows better performance in these formulations.
üUsed in Air conditioning shell and Automotive exteriors.
Its molecules have long alkyl chains, which ensure that UV6198 has good compatibility with polyolefin and polyester materials, and this characteristic makes it low mobility, which is hard to produce spray phenomenon.Therefore, the “Additive package” of UV6198 has excellent effect on the maintenance of surface color and improvement of gloss of plastic products.
üApplied to polyolefin plastics.PE/PP (film, wire, injection molding and rolling products).
The combination with Phenolic & Phosphite antioxidant and HALS will produce excellent outdoor weather resistance.
üIt can also be used in TPO, PET, PBT, PC and soft PVC materials.
Series of mature “Additive package” of UV6198 has been constantly developed, such as the combination with OMNISTAB UV531, OMNISTAB UV3853, OMNISTAB LS3346 and other OMNISTAB additives. For more information about the use of UV absorbers, light stabilizers and antioxidants, please consult the relevant business staff of Deltachem Co., Ltd or visit our official website “www.deltachem.net” for enquiries. Deltachem Co., Ltd is looking forward to your inquiry!
